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PubmedSumm119900 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: 2005 after a detailed polyphasic study and reclassification on the genus thermoactinomyces
. at present
the genus laceyella has four recognized species namely ; laceyella putida
, l. sacchari , type species of the genus laceyella
, laceyella sediminis
and laceyella tengchongensis
.
cells are aerobic , non - acid - fast , produce endospores and chemo - organotrophic .
l. sacchari strain gs 1 - 1 , was isolated from hot spring of chumathang , leh , ladakh , india , ( n 32 58 e78 15 ) , at the height of 4600 m above sea level .
genomic dna was extracted from 36 h old culture using zr fungal / bacterial dna miniprep as per manufacturer 's instructions .
the genome of l. sacchari strain gs 1 - 1 was sequenced using the illumina - hiseq 1000 paired - end technology that produced a total of 40,874,820 paired - end reads ( paired distance ( insert size ) ~ 330 bp ) of 101 bp .
clc bio workbench v6.0.2 ( clc bio , denmark ) was employed for preprocessing the data so as to trim and remove low quality sequences .
a total of 40,668,128 high quality , vector filtered reads ( ~ 1194 times coverage ) were used for assembly with clc bio workbench ( at word size of 45 and bubble size of 98 ) .
the final assembly contains 42 contigs of total size 3,324,316 bp with n50 contig length of 249,341 bp ; the largest contig assembled measures 698,403 bp .
this draft genome comprising 3,324,316 bp was annotated with the help of rast ( rapid annotation using subsystem technology ) system server .
a total of 3429 predicted coding regions ( cdss ) , 6 rrnas and 69 trnas were predicted .
rast indicates that strain geobacillus thermodenitrificans strain ng80 - 2 ( score 502 ) , geobacillus kaustophilus strain hta426 ( score 471 ) and geobacillus sp .
strain g11mc16 ( score 436 ) are the closest neighbors of the strain gs 1 - 1 .
the strain gs 1 - 1 contains the genes for glycolysis and gluconeogenesis , tca cycle and pentose phosphate pathway .
genes of alkaline phosphatase ( ec 3.1.3.1 ) , ferroxidase ( ec 1.16.3.1 ) , manganese superoxide dismutase ( ec 1.15.1.1 ) , shikimate kinase i ( ec 2.7.1.7.1 ) , chorismate synthase ( ec 4.2.3.5 ) , alcohol dehydrogenase ( 1.1.1.1 ) and superoxide dismutase [ fe ] ( ec 1.15.1.1 ) and pathogenicity islands are also present in the genome annotation of strain gs 1 - 1 .
we have mapped all predicted 3429 cdss to kegg pathways with the help of kass server .
the genome has all the essential pathways for dna , rna metabolism , iron , sulfur and phosphorus acquisition and metabolism pathways ( fig .
the l. sacchari strain gs 1 - 1 whole genome shot gun ( wgs ) project has been deposited at ddbj / embl / genbank under the project accession aszu00000000 of the project ( 01 ) that has the accession numbers aszu00000000 and consists of sequences aszu01000001aszu01000042 .
the authors declare that there is no conflict of interest on any work published in this paper .
Output:
| we report the 3.3-mb draft genome of laceyella sacchari strain gs 1 - 1 , isolated from hot spring water sample , chumathang , leh , india . draft genome of strain gs 1 - 1 consists of 3 , 324 , 316 bp with a g + c content of 48.8% and 3429 predicted protein coding genes and 75 rnas .
geobacillus thermodenitrificans strain ng80 - 2 , geobacillus kaustophilus strain hta426 and geobacillus sp .
strain g11mc16 are the closest neighbors of the strain gs 1 - 1 . |
PubmedSumm119901 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: the basic fasting protocol is to transfer the fish , at their normal density , to a clean tank , then withhold food
. for longer - term fasting that requires more rigorous conditions ( e.g. , for blood glucose studies ) , see additional considerations in the discussion .
for a 100 ml volume , dissolve the following in distilled water : 725 mg nacl ( 124.1 mm ) 38 mg kcl ( 5.1 mm ) 41 mg na2hpo4 ( 2.9 mm ) 24 mg mgso47h2o ( 1.9 mm ) 16 mg cacl22h2o ( 1.4 mm ) 100 mg nahco3 ( 11.9 mm ) 4 g polyvinylpyrrolidone ( pvp ) ( 4% ) 1,000 usp units heparin filter , sterilize and store at 4c .
cover the microscope base with plastic wrap for protection in case of spills . put a paper towel on top of the plastic wrap .
this will eliminate or minimize further focal adjustment once the fish is on the surgical table .
cover the microscope base with plastic wrap for protection in case of spills . put a paper towel on top of the plastic wrap .
pre - adjust focus by viewing the surgical table and focusing on the sponge .
weigh the fish . fill a 500 ml beaker about 1/3 full with fish facility water .
wick excess water away from the net and fish by briefly dabbing the net on paper towels .
wick excess water away from the net and fish by briefly dabbing the net on paper towels .
, we recommend a 35 g beveled steel needle and a 10 l nanofil microsyringe .
it is important to remove any bubbles from the syringe and tubing . after filling the syringe and tubing ,
mount the syringe on the pump , and program the injection volume for the first fish .
prepare the surgical table . cut a soft sponge ( such as # l800-d , jaece industries ) so that it is approximately 20 mm in height . on the flat face ,
set the petri dish with sponge into a suitably - sized pipette tip box lid .
the lid needs to be large enough to hold water to help maintain sponge temperature , but it should be shallow enough to not get in the way .
we use a lid from a p200 tip box that is 11.4 cm l x 7.7 cm w x 1.5 cm d. these three items assembled together ( sponge in petri dish in box lid ) constitute the surgical table . cut a soft sponge ( such as # l800-d , jaece industries ) so that it is approximately 20 mm in height . on the flat face , make a cut that is 10 - 15 mm deep .
set the petri dish with sponge into a suitably - sized pipette tip box lid .
the lid needs to be large enough to hold water to help maintain sponge temperature , but it should be shallow enough to not get in the way .
we use a lid from a p200 tip box that is 11.4 cm l x 7.7 cm w x 1.5 cm d. prepare the anesthetic .
tip : using typical ice cube trays , it will take 3 trays to anesthetize 10 - 12 fish .
put the surgical table into a larger container such as a 2.4 liter rubbermaid food storage container .
pour some facility water ( warm ) into the outer container and the surgical table .
put the surgical table into a larger container such as a 2.4 liter rubbermaid food storage container .
pour some facility water ( warm ) into the outer container and the surgical table .
important : do n't go below 17c for this step . use a net to transfer the fish to the outer container . slowly add ice chips to the container to bring the temperature down to 12c , over the course of several minutes .
monitor fish behavior : at 17c or slightly lower , the fish typically will spread its pectoral fins horizontally , gasp , and have rapid operculum movements . as the temperature drops , the fish will swim more slowly and finally stop swimming . as the surgical plane of anesthesia
is approached , gasping will stop and operculum movements will slow . the fish is ready for injection when it does not react to being handled . for most fish ,
as the required temperature is reached ( ~12c or colder ) , press on the sponge to saturate it . keep your fingers in the cold water sufficiently so that they will not warm up the fish and bring it out of anesthesia during handling . with cold fingers
, gently transfer the fish to the trough of the sponge . position the fish with the abdomen up and the gills in the trough . quickly transfer the surgical table to the microscope stage .
working quickly , carefully insert the needle into the midline between the pelvic fins . the needle should point cranially and be inserted closer to the pelvic girdle than to the anus
. you should be able to feel when the needle is deep to the body wall . inject the appropriate volume and withdraw the needle .
after injection , immediately transfer the fish back to its warm - water ( ~28.5c ) tank for recovery by releasing the fish from the sponge over the tank water .
tip : if the fish does not begin swimming immediately , help it to recover by gently swirling water towards the gills .
occasionally a scale may be attached and should be removed prior to the next injection . for subsequent injections , use warm facility water to bring the anesthetic chamber water temperature back up to 17c before introducing the next fish .
the basic fasting protocol is to transfer the fish , at their normal density , to a clean tank , then withhold food
. for longer - term fasting that requires more rigorous conditions ( e.g. , for blood glucose studies ) , see additional considerations in the discussion .
for a 100 ml volume , dissolve the following in distilled water : 725 mg nacl ( 124.1 mm ) 38 mg kcl ( 5.1 mm ) 41 mg na2hpo4 ( 2.9 mm ) 24 mg mgso47h2o ( 1.9 mm ) 16 mg cacl22h2o ( 1.4 mm ) 100 mg nahco3 ( 11.9 mm ) 4 g polyvinylpyrrolidone ( pvp ) ( 4% ) 1,000 usp units heparin filter , sterilize and store at 4c .
cover the microscope base with plastic wrap for protection in case of spills . put a paper towel on top of the plastic wrap .
this will eliminate or minimize further focal adjustment once the fish is on the surgical table .
cover the microscope base with plastic wrap for protection in case of spills . put a paper towel on top of the plastic wrap .
pre - adjust focus by viewing the surgical table and focusing on the sponge .
weigh the fish . fill a 500 ml beaker about 1/3 full with fish facility water .
wick excess water away from the net and fish by briefly dabbing the net on paper towels .
wick excess water away from the net and fish by briefly dabbing the net on paper towels .
, we recommend a 35 g beveled steel needle and a 10 l nanofil microsyringe .
it is important to remove any bubbles from the syringe and tubing . after filling the syringe and tubing ,
mount the syringe on the pump , and program the injection volume for the first fish .
prepare the surgical table . cut a soft sponge ( such as # l800-d , jaece industries ) so that it is approximately 20 mm in height . on the flat face ,
set the petri dish with sponge into a suitably - sized pipette tip box lid .
the lid needs to be large enough to hold water to help maintain sponge temperature , but it should be shallow enough to not get in the way .
we use a lid from a p200 tip box that is 11.4 cm l x 7.7 cm w x 1.5 cm d. these three items assembled together ( sponge in petri dish in box lid ) constitute the surgical table . cut a soft sponge ( such as # l800-d , jaece industries ) so that it is approximately 20 mm in height . on the flat face , make a cut that is 10 - 15 mm deep .
set the petri dish with sponge into a suitably - sized pipette tip box lid .
the lid needs to be large enough to hold water to help maintain sponge temperature , but it should be shallow enough to not get in the way .
we use a lid from a p200 tip box that is 11.4 cm l x 7.7 cm w x 1.5 cm d. prepare the anesthetic .
tip : using typical ice cube trays , it will take 3 trays to anesthetize 10 - 12 fish .
put the surgical table into a larger container such as a 2.4 liter rubbermaid food storage container .
pour some facility water ( warm ) into the outer container and the surgical table .
put the surgical table into a larger container such as a 2.4 liter rubbermaid food storage container .
pour some facility water ( warm ) into the outer container and the surgical table .
important : do n't go below 17c for this step . use a net to transfer the fish to the outer container . slowly add ice chips to the container to bring the temperature down to 12c , over the course of several minutes .
monitor fish behavior : at 17c or slightly lower , the fish typically will spread its pectoral fins horizontally , gasp , and have rapid operculum movements . as the temperature drops , the fish will swim more slowly and finally stop swimming . as the surgical plane of anesthesia
is approached , gasping will stop and operculum movements will slow . the fish is ready for injection when it does not react to being handled . for most fish ,
. as the required temperature is reached ( ~12c or colder ) , press on the sponge to saturate it .
keep your fingers in the cold water sufficiently so that they will not warm up the fish and bring it out of anesthesia during handling . with cold fingers , gently transfer the fish to the trough of the sponge . position the fish with the abdomen up and the gills in the trough . quickly transfer the surgical table to the microscope stage . working quickly ,
carefully insert the needle into the midline between the pelvic fins . the needle should point cranially and be inserted closer to the pelvic girdle than to the anus
. you should be able to feel when the needle is deep to the body wall .
after injection , immediately transfer the fish back to its warm - water ( ~28.5c ) tank for recovery by releasing the fish from the sponge over the tank water .
tip : if the fish does not begin swimming immediately , help it to recover by gently swirling water towards the gills .
occasionally a scale may be attached and should be removed prior to the next injection . for subsequent injections , use warm facility water to bring the anesthetic chamber water temperature back up to 17c before introducing the next fish .
intraperitoneal injection involves five steps : fasting , weighing , anesthetizing , injection , and recovery . for each step there
this practice is taken from the fish veterinary literature ( e.g. , brown 1993 ) .
longer - term fasting : we have found that a 72-hour fast is required to decrease blood glucose to a baseline level prior to injection ( eames et al . , 2010 ) .
we have also found that for glucose studies there are several procedures that are required to ensure that the fish are fasted properly .
tanks should be offline , clearly labeled as ' fasting ' , and in a location where enthusiastic fish care personnel will not feed them .
evaluate the external environment of the tank and take steps to prevent the fish from being stressed from disturbances , as stress is known to raise blood glucose ( chavin and young , 1970 ; groff et al .
for example , we had a fasting experiment in which a radio was operated daily on the bench that was holding the fish tanks .
we found that blood glucose was unusually high and concluded that the fish were stressed by the vibrations .
fish should be kept at a density that conforms with good fish husbandry practices . for recommendations ,
we have had good results fasting our fish at a density of 10 - 12 fish in a 9 liter tank ( with 3 layers of marbles taking up some of that volume ) .
separating the sexes may cause stress , so we recommend maintaining a mixed - sex population during the fast .
this means that eggs can be laid , and the eggs need to be sequestered so that they will not be eaten .
a simple way to sequester eggs is to cover the tank bottom with 2 - 3 layers of marbles .
water quality needs to be maintained by removing eggs and waste and by replacing about 10 - 15% of the tank water , daily . for removing eggs and waste , siphoning works well . weighing : when weighing fish that are not anesthetized , care should be taken to minimize water transfer from the net into the beaker , to ensure accurate weighing .
if the net ( with fish ) is blotted on paper towels , the majority of the excess water can be removed , and the weight can be accurately measured .
it may be easier to anesthetize the fish prior to weighing , but we have not tested the possible effects of anesthetizing a fish twice in one day .
we have tested our technique by weighing the fish first with the netting / blotting method and then re - weighing the fish after it has been anesthetized , and gently blotted dry .
we found no significant difference in weight between the methods ( p = 0.7927 , t - test ) .
additionally , we tested whether this netting / blotting method affected blood glucose , in comparison with simply transferring the fish to the beaker as soon as it is netted ( no blotting ) .
we found no significant difference in blood glucose level between the two transfer methods ( p = 0.2241 , t - test ) .
here we have demonstrated cold water anesthesia as an alternative , because many anesthetics ( including tricaine / ms-222 ( brown , 1993 ) ) , raise blood glucose . in previous studies
, we have determined that cold water does not raise blood glucose in zebrafish ( eames et al .
, 2010 ) . for cold water anesthesia , the temperature should be decreased slowly .
the rate of decrease seems to depend on the size of the fish , with smaller fish going under faster than larger fish . following injection
, you may observe that the fish is recovering too slowly from the anesthetic ( see below ) .
this can result when either the starting temperature is too low , or when the temperature is decreased too rapidly .
the starting temperature is too low if the fish bends laterally upon entering the water .
it will rotate its pectoral fins to a horizontal position , gasp , and have rapid operculum movements .
, movements will decrease and the fish will lose equilibrium . a surgical plane of anesthesia
is reached when the fish can be handled without reacting . to maintain the fish under surgical anesthesia , your fingers must be cold , so keep them in the water prior to handling the fish .
the sponge must also be kept cold at the same temperature as the water used for anesthetizing the fish .
it is important to saturate the sponge with water that is sufficiently cold to maintain anesthesia once the fish is placed onto it .
injection : prior to undertaking injections , you may want to dissect at least one fish to get a sense of body wall thickness .
this can help you to judge how far the needle needs to insert to enter the abdominal cavity .
additionally , as you insert the needle , you can feel the body wall " give " when the needle enters the abdominal cavity . during the injection ,
make sure the sponge is saturated with the correct temperature cold water to prevent the fish from reviving during injection .
a well - saturated and soft sponge is important for minimizing damage to the scales and mucus covering of the skin .
finally , once the fish is anesthetized , work quickly to minimize the time that the fish is under .
recovery : the fish should recover from the anesthesia virtually upon entering the warm tank water . if the fish does not begin swimming immediately , gently swirl the water towards its gills to speed recovery . if recovery is slow , then the fish went under too quickly and you should adjust the anesthesia procedure appropriately .
Output:
| a convenient method for chemically treating zebrafish is to introduce the reagent into the tank water , where it will be taken up by the fish .
however , this method makes it difficult to know how much reagent is absorbed or taken up per fish .
some experimental questions , particularly those related to metabolic studies , may be better addressed by delivering a defined quantity to each fish , based on weight . here
we present a method for intraperitoneal ( ip ) injection into adult zebrafish .
injection is into the abdominal cavity , posterior to the pelvic girdle .
this procedure is adapted from veterinary methods used for larger fish .
it is safe , as we have observed zero mortality .
additionally , we have seen bleeding at the injection site in only 5 out of 127 injections , and in each of those cases the bleeding was brief , lasting several seconds , and the quantity of blood lost was small .
success with this procedure requires gentle handling of the fish through several steps including fasting , weighing , anesthetizing , injection , and recovery .
precautions are required to minimize stress throughout the procedure .
our precautions include using a small injection volume and a 35 g needle .
we use cortland salt solution as the vehicle , which is osmotically balanced for freshwater fish .
aeration of the gills is maintained during the injection procedure by first bringing the fish into a surgical plane of anesthesia , which allows slow operculum movements , and second , by holding the fish in a trough within a water - saturated sponge during the injection itself .
we demonstrate the utility of ip injection by injecting glucose and monitoring the rise in blood glucose level and its subsequent return to normal . as stress
is known to increase blood glucose in teleost fish , we compare blood glucose levels in vehicle - injected and non - injected adults and show that the procedure does not cause a significant rise in blood glucose . |
PubmedSumm119902 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: neuropathic pain , defined as pain arising as a direct consequence of a lesion or a disease affecting the somatosensory system,1 is a disorder that can considerably affect quality of life for patients .
even though up to 5% of the general population could be involved , treatment of neuropathic pain continues to be challenging due to the inadequate effectiveness of systemic therapies and their frequent central side effects.2 in the wide area of peripheral neuropathic pain , the identification of specific neuropathic pain syndromes that affect only a circumscribed area of the body may drive a clinical decision to use targeted localized treatment(s ) .
characterized by consistent and circumscribed area(s ) of maximum pain associated with negative or positive sensory signs3 as localized neuropathic pain ( lnp ) . according to the relevant guidelines,46 5% lidocaine medicated plaster
could be considered as a first - line treatment option for lnp due to its good efficacy and safety profile , especially in elderly patients where comorbidities are quite often present and polypharmacy is poorly tolerated . up to 83% of patients with post - herpetic neuralgia ( phn ) complain of an lnp syndrome,3 for which 5% lidocaine medicated plaster showed better effectiveness versus placebo7,8 and substantially better pain relief than pregabalin,9,10 with fewer systemic side effects even in long - term treatment.1113 several different mechanisms sustain phn,14 including peripheral inflammation , nerve damage and denervation , and peripheral and central sensitization .
lidocaine acts by blocking abnormally functioning ( sensitized ) nav 1.7 and nav 1.8 sodium channels in dermal nociceptors,15 thereby reducing ectopic discharges , which raise the peripheral ectopic discharge threshold.15 topical 5% lidocaine plaster does not affect a - beta fibers , so does not cause any paresthesia and/or numbness.16 finally , a passive protective action of the plaster itself has been reported.810 in a cohort of patients with lnp due to nerve trauma,17 5% lidocaine medicated plaster showed optimal efficacy in reducing pain and the size of the painful area . to our knowledge , no other structured trial has investigated this possible new endpoint in phn patients . in our first eight phn patients treated with versatis 5% plaster ( grunenthal , germany ) ( the drug was approved in italy in may 2013 ) , we investigated whether it could be helpful both in reducing pain and allodinic ( static and/or dynamic ) areas .
allodynia is a phenomenon in which normally nonpainful stimuli are perceived as painful , and can be a clinical sign of peripheral and central sensitization .
the two components can be differentiated using different types of stimuli , ie , peripheral sensitization can be evoked by static mechanical stimulation ( static mechanical allodynia ) whereas allodynia to dynamic mechanical stimulation is the result of central sensitization .
while the static component is only found in the injured area , the dynamic component also extends into the halo of undamaged tissue surrounding the injury.18
consistent with the literature and following approval in italy , 5% lidocaine medicated plaster was used in a group of phn patients with untreated lnp , lnp that was inadequately controlled , or side effects from systemic drugs .
following our hospital administrative rules , all patients signed an informed consent allowing anonymous use of their clinical data for research purposes . in accordance with our clinical practice
, the patients were screened at the first visit and then followed up after 15 , 30 , and 90 days .
patients could telephone and ask for another consultation if they experienced side effects or inadequate analgesia . at all visits
, we recorded : daily pain intensity ( mean , least , and worst , using the numeric rating scale ) ; paresthesia and dynamic allodynia ( scale 0 [ none ] to 5 [ worst imaginable ] ) ; and static allodynia with the von frey hair test ( caliber from 0 [ worst allodynia ] to 18 [ normal sensation ] of von frey monofilaments perceived as painful
we used a well established von frey hair set ( touch test sensory evaluators ; north coast medical , inc .
morgan hill , ca , usa ) , with a 5.07 caliper corresponding to 10 g applied for 1.5 seconds , which delivers a clear mechanical suprathreshold nonpainful stimulus .
the area of statical tactile allodynic area was measured in cm . during their first visit
, patients were instructed regarding how to apply the 5% lidocaine medicated plaster to the most painful areas of intact skin ; they were allowed to use a maximum of three plasters for 12 hours a day .
depending on the clinical results seen during follow - up , we reduced their systemic analgesic medication if good pain relief ( of at least 30% ) was achieved .
eight patients with phn lnp ( five men and three women ) were observed from may to september 2013 .
their mean age was 77.757.10 ( range 6989 ) years and mean body mass index ( bmi ) was 28.15.5 kg / m .
the acute episode of herpes zoster had occurred at a mean of 3.73.6 years earlier .
the rash affected the trunk in all cases , except for one patient whose left hand was affected .
all patients were on polypharmacy , taking a mean of 42 nonanalgesic drugs for comorbid conditions .
all patients reported having tried at least one systemic drug for pain relief ( antidepressant , anticonvulsant , and/or opioids ) with inadequate pain control ( five patients ) or good pain control but severe side effects ( three patients ) .
one patient reported an accidental fall with a rib fracture due to dizziness on anticonvulsant treatment .
the patients reported good pain relief ( 45.00%19.75% ) as early as 2 weeks after the start of topical therapy , with further improvement as treatment continued ( 52.00%23.87% by month 1 and 60.00%18.70% by month 3 ) , and reduction / cessation of systemic treatment in six patients ( table 1 ) .
paresthesia and dynamic allodynia decreased significantly at 3 months from 2.881.64 to 1.201.10 and from 3.750.71 to 1.801.64 , respectively .
we observed a similarly consistent reduction in static allodynia from 8.633.58 to 14.000.82 over 3 months .
the allodynic ( static or dynamic ) area was measured in five of eight patients with thoracic phn ( figure 1a ) .
the area became progressively smaller from a baseline measurement of 236.38140.34 cm to 128.8095.7 cm after one month ( 46% reduction , p=0.129 ) and to 81.3859.19 cm after 3 months ( 66% reduction , p=0.02 ) . with the reduction in size of the area
a more pronounced reduction was observed in the height ( 50% ) than in the length ( 33% ) of the affected area ( figure 1b ) .
neuropathic pain continues to be a challenging clinical problem.2 people with neuropathic pain are often elderly and may have several comorbidities and a high risk of drug drug interactions , which presents a serious limitation to therapy.19 to achieve good pain relief , it is often necessary to give a combination of two or more drugs,20 which increases the risk of drug drug interactions and side effects .
the mainstay of treatment for neuropathic pain is still adequate personalized therapy based on an understanding of the pain pathophysiology and the patient s clinical features.21 the majority of patients evaluated in our case series complained of the limited effectiveness of pain treatments and/or side effects from systemic treatment for phn , and had had their pain for several months or years . when patient refers a lnp , correctly diagnosed according to validated diagnostic algorithm,22
more recent guidelines4,5 suggest topical products as the first - line therapeutic option since they are better tolerated , have no or few systemic effects and drug drug interactions , and have better patient compliance.9,10,23,24 our case series reflects all these common clinical aspects .
the main mechanism of the therapeutic action of lidocaine is blockade of voltage - gated sodium channels.15,25 however , topical lidocaine may have other peripheral actions through a desensitizing effect of trpa1 channels , contributing to its nonanesthetic analgesic
effects.26 thus , the reduction in peripheral sensitization could be attributed to both blockade of pathological sodium channel expression and desensitization of trpa1 channels .
a characteristic feature of phn is the presence of an area of primary hyperalgesia ( static mechanical and thermal allodynia within the damaged area ) and secondary hyperalgesia ( dynamic mechanical allodynia that surrounds the first area).27 the static mechanical allodynia is mainly mediated by sensitized peripheral nociceptors , while the dynamic component is probably a consequence of altered processing of large diameter primary afferent inputs in the central nervous system .
these alterations are at least partially maintained by the barrage of nociceptor activity from both normal and abnormal inputs.27 the importance of ongoing activity to maintain the secondary hyperalgesia has not been completely elucidated , even though in patients with neuropathic pain , secondary hyperalgesia and allodynia have been seen to be critically dependent on continuous afferent input.18 hence , 5% lidocaine medicated plaster could act by adding blockade of pathological sodium and trpv1 channels to the reduction of mechanical noxious / non - noxious inputs via the protective action of the plaster .
this reduction of peripheral inputs could contribute to reducing both primary and secondary sensitization , and consequently the size of the painful area,28,29 as also suggested by a healthy volunteer study.30 in our study , the mean size of the painful area was 236.38140.34 cm , which is in agreement with data in the literature.31 regarding the reduction of the static allodynic area , we noticed that there is a much greater reduction of the height ( number of metameres involved ) rather than of the length ( area of the same nerve involved ) of the painful area . in phn ,
the secondary hyperalgesic area is mainly distributed above and below the primary painful area in the dermatome where an overlapping of innervation is anatomically present .
it could be arguable that if neural plasticity can be induced by treatment , it may be more evident in peripheral areas of secondary hyperalgesia.18 hence this treatment could have another important clinical effect : the reduction of the allodynic area , as also suggested in a study about lnp with recent onset.17 in fact , a more than 50% reduction in the size of the painful area was recorded , even though the patients had been complaining of phn for several months or years .
due to the small number of patients , it was not possible to evaluate if the reduction in size of the painful area was related to the time of onset of phn or to the more pronounced reduction of static rather than dynamic allodynia .
nevertheless , our case series highlights a possible role of chronic topical treatment not only in treating lnp but also in reducing the size of the painful area .
these data have to be confirmed by appropriately designed controlled trials investigating this endpoint as well as the mechanisms for the activity of 5% lidocaine medicated plaster , ie , whether it acts more on primary rather than secondary hyperalgesia , and whether the time of onset of phn / lnp could be a predictive factor of efficacy .
Output:
| post - herpetic neuralgia ( phn ) is neuropathic pain persisting after an acute episode of herpes zoster , and is associated with severe pain and sensory abnormalities that adversely affect the patient s quality of life and increase health care costs .
up to 83% of patients with phn describe localized neuropathic pain , defined as a type of neuropathic pain characterized by consistent and circumscribed area(s ) of maximum pain .
topical treatments have been suggested as a first - line treatment for localized neuropathic pain .
use of 5% lidocaine medicated plaster could reduce abnormal nervous peripheral discharge and via the plaster could have a protective function in the affected area .
it has been suggested that use of this plaster could reduce pain as well as the size of the painful area . to evaluate this possible outcome
, we retrospectively reviewed eight patients with phn , treated using 5% lidocaine medicated plaster . during a follow - up period of 3 months , we observed good pain relief , which was associated with a 46% reduction in size of the painful area after one month ( from 236.38140.34 cm2 to 128.8095.7 cm2 ) and a 66% reduction after 3 months ( 81.3859.19 cm2 ) .
our study cohort was composed mainly of elderly patients taking multiple drugs to treat comorbidities , who have a high risk of drug drug interactions .
such patients benefit greatly from topical treatment of phn .
our observations confirm the effectiveness of lidocaine plasters in the treatment of phn , indicating that 5% lidocaine medicated plaster could reduce the size of the painful area .
this last observation has to be confirmed and the mechanisms clarified in appropriate larger randomized controlled trials . |
PubmedSumm119903 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: nephrotic syndrome ( ns ) in children is usually idiopathic , but may also be triggered by immunological stimuli like vaccination , infection , insect sting , or pollen hypersensitivity .
humoral and cellular immune function studies suggest that abnormal immune response is the probable cause in this clinical entity .
bee sting has been implicated in the development of ns , but occurrence in children has rarely been reported in literature .
these patients need a shorter course of steroids , but show excellent response and have a low risk of relapse .
a 2-year - old boy was hospitalized with generalized edema and decreased urine output of 4-day duration .
facial swelling developed initially and then the edema extended to the legs , eventually affecting the entire body .
there was a history of a bee sting on the dorsal aspect of his right hand 7 days earlier , which had resulted in severe pain , redness , and local swelling for about 48 hours .
he had no history of atopy or similar episodes in the past . on physical examination , he was afebrile , had facial edema , pitting pedal edema with abdominal distension .
his blood pressure was normal ( 90/60 mm hg ) , and a bee sting mark was visualized over the dorsum of the right hand [ figure 1 ] .
laboratory investigations revealed hemoglobin of 13.7 g / dl , white blood cell count of 25 400/ mm , 35% neutrophils , 58% lymphocytes , 5% eosinophils , 2% monocytes , and platelet count of 331 000/mm .
his erythrocyte sedimentation rate was 69 mm / hr and peripheral smear showed normocytic normochromic red blood cells with leukocytosis and adequate platelets .
he had decreased serum proteins ( total protein 3.9 g / dl , and albumin 1.5 g / dl ) ; elevated serum cholesterol ( 382 mg / dl ) ; and normal renal parameters ( blood urea 34 mg/ dl and creatinine and 0.37 mg/ dl ) .
urine analysis revealed 3 + proteinuria with a 24-hour urinary protein excretion of 0.9 g. complement c3 level was 1.16 g / dl ( 0.90 - 1.80 g / dl ) ; immunoglobulins profile showed iga - 0.32 g / dl ( 0.14 - 1.59 g / dl ) , igm - 0.9 g/ dl ( 0.43 - 2.07 g / dl ) , igg - 2.92 g / dl ( 3.45 - 12.36 g / dl ) , and ige - 245 iu / l ( < 230
chest x - ray was normal and the ultrasound revealed free fluid in the abdomen .
bee sting over the dorsum of the right hand on admission , he was managed symptomatically with diuretics and with salt and fluid restriction . after the laboratory results , he was started on oral prednisolone ( 2 mg / kg / day ) .
the boy progressively improved and diuresis set in on the fifth day ; edema regressed by the seventh day ; and urine became albumin - free by the 10 day of admission .
corticosteroids were then changed to alternate - day regimen and tapered gradually after 8 weeks and withdrawn . during the regular 1-year follow - up after the end of treatment , the boy remained well without any recurrence .
ns in childhood , can be triggered by immunological stimuli including infection , vaccination , insect bites , pollen and drug - induced hypersensitivity .
bee stings are usually followed by minor local allergic reactions and rarely anaphylactic or delayed hypersensitivity reactions .
other reported systemic complications following multiple bee stings include acute renal failure ( arf ) , myocarditis , myocardial infarction , centrilobular necrosis of liver , acute encephalopathy , guillain - barre syndrome , vasculitis , disseminated intravascular coagulation , and thrombocytopenia .
though causal relationship and association between bee stings and development of ns has long been described , no report has demonstrated the presence of bee venom antigens in the glomeruli .
ns can develop even after a single bee sting , like in our case which occurred within 7 days .
the cause - and - effect relationship between the bee sting and renal disease is speculative , made on the basis of a temporal association .
it is postulated that components of the bee venom mediate immunological disturbances , with involvement of t - lymphocytes and their cytokine secretion , influencing the permeability of the glomerular basal membrane with consequent development of proteinuria .
pathologic findings of ns following a bee sting are diverse , which include minimal change lesions , mesangial proliferative glomerulonephritis , membranous glomerulonephritis , and glomerulosclerosis .
arf following multiple bee stings is attributed to acute tubular necrosis due to hypotension or pigment nephropathy resulting from rhabdomyolysis , intravascular hemolysis , and acute interstitial nephritis .
most reported cases had a favorable clinical course with corticosteroid treatment . in our case ,
steroids shortened the duration of disease , and no relapse or chronic renal disease is so far reported .
cytotoxic agents may also induce remission in the occasional steroid - resistant cases . in conclusion , though rare , children with insect stings , particularly bee stings , must be closely followed up for multiple problems , especially immune - mediated complications such as ns .
Output:
| the occurrence of nephrotic syndrome following a bee sting is rarely reported in the literature .
hypersensitivity is believed to be the precipitating factor for the renal disease .
we report a two - year - old boy , who developed generalized edema and decreased urine output , seven days after a bee sting . physical examination and laboratory findings were consistent with nephrotic syndrome ; and corticosteroid treatment induced prompt remission with resolution of clinical symptoms and normalization of laboratory findings . there was no relapse of the disease during a one - year follow up . |
PubmedSumm119904 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: emergency department ( ed ) use is common for both children and adults not only in a country without universal health insurance like the united states but also in countries like france where virtually all residents have health insurance . in 2006
the annual rate of ed visits for parisian children less than 2 years old ranged , according to district , from 46.9 to 91.3 per 100 children .
many of these visits are not for true emergencies but for what ed physicians , insurers , policy makers , and researchers consider as inappropriate or
nonurgent , that is , minor complaints that could have been dealt with in primary care offices on either that or the following day .
durand and colleagues found that , in studies in a variety of countries around the world , the estimates of nonurgent visits by adults and children ranged from 4.8% to 90% , with a median of 32% .
one reason for the variation was the inconsistency in defining nonurgent , as pointed out also by mistry and colleagues for pediatric ed visits .
recent figures on pediatric nonurgent visits include 58% in the united states , 57.1% in italy , and 39.9% in belgium .
in many cases , parents do not even try to contact a primary care physician [ 79 ] .
furthermore , they go to eds even though they often have long waits ; their children are likely to undergo more testing and treatment than by their own doctors ; the ed physicians do not know their medical histories and usually do not provide follow - up ; and in many cases the costs to them will be higher
. many researchers have , therefore , tried to understand why parents decide to bring their children to eds .
they hope to find out how to reduce unnecessary ed visits and thereby how to improve continuity of care ; to lessen overcrowding in eds , distraction from true emergencies , and diversion of ambulances to less crowded but more distant eds [ 11 , 12 ] ; and to decrease health care expenses [ 6 , 11 , 13 , 14 ] .
reasons given by parents for their decisions to go to pediatric eds ( peds ) , even without referral by their children 's primary care physicians , include that they seek a quick and convenient solution to a health issue [ 1 , 8 , 10 , 1518 ] ; that they view the ped as the best place to go because of its better physicians and/or medical equipment [ 1 , 5 , 7 , 8 , 10 , 17 , 19 ] ; that they are dissatisfied with their primary care physician 's office or the physician 's diagnosis and/or treatment [ 8 , 15 , 20 ] ; that they are very worried about their child 's health [ 8 , 15 , 17 , 21 ] ; that they are in financial straits [ 17 , 20 ] ; that they have a habit of going to the ed [ 1 , 7 , 8 ] ; and that they have no access to other care [ 1 , 17 , 19 ] .
the methodologies of the above - mentioned studies were not based on a broad theory of human motivation and may , as a result , have neglected important motives . in this study , therefore , we examined parental motives by applying michael apter 's metamotivational theory ( mtt ) [ 23 , 24 ] , which encompasses and systematizes the great diversity of human motives . by including all theoretically possible categories of motives in the questionnaire , we could ensure that it was psychologically complete , that is , that no possible parental motive was missed .
objectives of the study were ( a ) to inventory the motives for going to peds ; ( b ) to order these motives , or categories of motives , as a function of their importance ; and ( c ) to find out how demographic characteristics were associated with these motives .
the study was approved by the ethics committee of the children 's hospital of toulouse .
the participants were parents attending the ped of the children 's hospital , a tertiary - level pediatric hospital in toulouse , france .
the research assistant invited the parents of every child to participate , informed them about the survey , and obtained oral consent from those who agreed to participate .
the first questionnaire contained 69 items referring to motives for going to a ped ( table 1 ) .
forty - eight items were created by the members of the research team , inspired by mmt ( see table 5 ) , by the medical literature ( cited above ) , and by their personal experience as physicians .
items were purposely and systematically created to correspond to all of mmt 's categories of motives .
this questionnaire was then presented to a focus group of parents that reformulated items judged as ambiguous and suggested additional items based on their personal experiences as parents .
the new questionnaire was presented to another focus group , and the process was repeated until saturation occurred .
the common wording of all items in the questionnaireone of the reasons i came to the ped today with my childwas chosen to acknowledge that several motives could be operating at the same time .
the second questionnaire asked about demographics , about previous ed use , and about prior doctor visits during this illness .
participants responded individually in the waiting room , before their children were seen . if both parents were present , only one filled out the questionnaires but that one could confer with the other .
the research assistant was , in most cases , not present during the process in order not to influence them .
they indicated how much they agreed with each statement on the first questionnaire by putting a mark on the 10-point response scale under each one .
the treating physician subsequently indicated the severity of each child 's illness on a scale of 1 ( not severe ) , 2 ( mildly severe ) , or 3 ( severe)and whether the child was hospitalized .
the character of this study was both exploratory and confirmatory . through exploratory factor analyses using two - thirds of the sample ,
exploratory factor analysis is a statistical technique that is used to reduce a number of variables into a smaller set of unobserved factors .
the variables within each factor are empirically highly correlated with each other but not with the other variables .
if the correlation between items and any factor was lower than 0.30 and their means were very low , the items were removed from the analysis .
confirmatory factor analysis is a statistical technique used to test whether a set of factors that has been obtained through exploratory factor analysis of data from one sample fits the data observed in another sample . as the exploratory factor analysis has to be conducted on all the useable items , the confirmatory analysis
should only be done on a representative and more manageable subset of items , namely , on the three items with the highest
loadings ( the highest correlations with the factor ) within each of the factors found in the exploratory analysis .
therefore , the exploratory factor analysis requires a larger sample size than the confirmatory analysis , calculated in this case to be 2 to 1 .
the sample size of 500 was determined in accordance with the technical requirements of factor analysis for a maximum expected number of factors of 10 .
our choice of 10 was based on our analysis of the previous studies of reasons to go to the ed .
table 1 shows the mean ratings ( on a scale of 1 to 10 ) of each item in the exploratory factor analysis using the first subsample ( n = 332 ) .
thirteen of the 69 items did not load on any factor ( correlation between item and any factor < .30 ) , and their means were very low .
six interpretable and independent factors emerged , namely , ( 1 ) being considered by others as responsible parents ( which explained 13% of the variance ) ; ( 2 ) empathic concern for child 's suffering ( 8% of the variance ) ; ( 3 ) seeking quick diagnosis , treatment , and reassurance ( 12% ) ; ( 4 ) dissatisfaction with previous consultation ( 7% ) ; ( 5 ) ped as the best place ( 7% ) ; ( 6 ) and external factors ( 5% ) , such as the family physician 's absence , the impossibility of borrowing money , and a recommendation from the service that provides urgent home visits .
the results of the confirmatory factor analysis , conducted on the three items with the highest loadings on each of the six factors using the second subsample ( n = 168 ) , are shown in table 3 .
the mean scores for each factor in the final model on a 10-point scale range from 1.79 ( dissatisfaction with previous consultation ) to 6.82 ( seeking quick diagnosis , treatment , and reassurance )
.
table 4 shows correlations between demographic characteristics , severity indices ( as subsequently judged by physicians ) , and motives . seeking quick diagnosis ,
treatment , and reassurance was significantly more strongly endorsed by parents of one child than by parents of more than one .
considering the ped as the best place to go was given a higher rating by younger fathers than by older ones .
empathic concern for the child 's suffering was given a higher rating by parents with only one child .
being considered by others as responsible parents was a stronger motive for parents of boys than of girls , for younger mothers , for less educated parents , and for parents who were more likely to go to eds without first consulting their regular physician , and a stronger motive in cases judged by the treating physician to be of lesser severity .
finally , external factors were more strongly endorsed as motives by parents of older children who had siblings and in cases in which symptoms had more recently appeared .
the aim of our study was to make an inventory of the motives of parents in bringing their children to peds using a broad theoretical framework .
we found that , as in other studies [ 8 , 15 , 17 , 21 ] , parents endorsed a wide variety of motives .
finding factors meant the guarantee that parents ' responses were meaningful , that is , that their responses were sufficiently coherent such that statistical analysis could reveal a clear structure to them .
the emergence of a clear factorial structure also enabled measurement of the strength of each motive .
telic in mmt ) seemed to be highly goal - oriented , going to a ped to obtain care they saw as important .
this is consistent with findings in other countries [ 8 , 15 , 17 , 26 ] .
] described guardians as worried that symptoms represented serious illness and that it was important to seek medical attention . similarly , durand and colleagues , in their study of french adult patients , characterized them as rational consumers ( in contrast to the abusive and irresponsible consumers portrayed by the ed health professionals they interviewed ) .
these parents are unlikely , therefore , to agree with the charge that large numbers of visits to peds are unwarranted .
the second most highly rated factor was ped as the best place to go ( which would be called a conformist motive by mtt ) .
their respect for the ped may have been stimulated by television shows and by reports in the media about the technology and specialization available in hospitals ( as well as , in the united states , by advertising ) .
they may not have appreciated that technology and specialized care are not always beneficial to patients .
empathic concern for child 's suffering received a lower overall rating . those parents who strongly endorsed these motives ( labeled as sympathy in mtt ) were no longer able to put up with their children 's suffering .
they tended to be parents of a single child and , therefore , likely to be less experienced in coping with sick children .
it is striking , however , that distress at their child 's current suffering was much less important than the goal - oriented aim of obtaining the most effective treatment .
the other three factors were rated quite low overall but were endorsed by some parents . being considered by others as responsible parents was rated highly by parents who seemed to be concerned about their own image as parents ( labeled as
these parents tended to be younger ( especially the mothers ) and less educated than other parents and to go to eds for themselves more frequently .
their child 's condition was not likely to be judged as bad by the ed physician .
physicians and health services experts , especially in the us , often cite structural factors as important determinants of excessive ed utilization [ 6 , 11 , 13 , 15 , 2730 ] .
those few parents who endorsed these motives strongly indicated thereby that going to peds was not a truly personal decision .
they followed the instruction of the urgent care service or could not go to another medical facility owing to the absence of a physician or to lack of money .
their child 's illness tended to be more acute ; that is , the child was more likely than others to have experienced pain and/or fever for less than 12 hours .
the lowest average rating was for dissatisfaction with previous consultation ( a negativist motive in the terminology of mmt ) .
only a few parents were very unhappy with the care provided by their family physicians , in accordance with findings in other countries [ 8 , 31 ] .
it was conducted in a single site in france , and the motives of the 35% of parents who declined to participate are unknown .
the study 's results must , therefore , be generalized with caution to other populations of children and parents and to other sites . furthermore , even if the questionnaire is based on a broad theory of motivation , it has not been validated and should , therefore , be used prospectively again to confirm these results . nonetheless , our findings can help to illuminate the current debate about the overuse of eds .
access to care is a key issue for parents , as well as for adult patients , and , therefore , is a focus of reform efforts .
the 2011 national health interview survey in the united states found that , among adults who went to eds and were not admitted to the hospital ( 68.9% of those visiting the ed ) , 78.9% had had at least one access issue for going to the ed ( defined as indicating not having another place to go , doctor 's office or clinic being not open , ed being the closest provider ' , and/or clinic being not open ) .
it seems possible to reduce ed visits , therefore , by improving access to other sources of care ( as in the state of north carolina ) . without this , as the medicaid experience in the state of oregon showed , expanding insurance will not reduce ed use ; it will increase it . accordingly , many reformers have proposed encouraging pediatric practices to expand the availability of urgent visits [ 10 , 30 ] ; france has tried to set up primary care units at or near eds ; and italy is requiring its primary care offices to be open 24 hours a day 7 days a week .
wang and colleagues tested in the united states a pilot ped diversion program for children with medicaid using extended office hours , multiple access locations , and care coordination that reduced ed visits by 8 visits per 1000 members per month ( compared with the control group ) . because their diversion program was so expensive , however , the overall cost of care was not reduced .
our study demonstrates the limits or barriers , from the parents ' perspective , to the success of such efforts .
we found that parents generally bring their children to peds with serious , goal - oriented motives .
similarly , in the united states , the 2011 national health interview survey found that 65.0% of adults not admitted to the hospital cited at least one acuity issue ( defined as indicating only hospital could help , advised by health provider to go to ed , and/or problem too serious for doctor 's office or clinic ) ; kubicek and colleagues found that 63% of parents bringing their children for reasons assessed as nonurgent perceived the visit as very or
extremely urgent ; and kalidindi and colleagues found that parents assessed 94% of their visits as urgent , even though 27% of these urgent visits were assessed as nonurgent by the physicians .
thus , even if access issues were greatly reduced in the us and other countries , the acuity issues would persist . because there is no consensus between the population and physicians about what is urgent and what is not
, staff members in the eds tend to define many visits as nonurgent , to label them as inappropriate , and to feel frustrated [ 17 , 31 ]
. in general eds in the united states , the presenting complaints of adult patients judged subsequently as primary care treatable do not in fact differ from those judged as needing ed care . furthermore , as cresson
] states , to speak of false urgency ' in situations where there is urgency for the patient and not for the doctors is to act as if the latter were the only ones capable of defining urgency . if overworked ed physicians , as well as researchers and policy makers , focus on ultimate diagnoses and wasted resources , they forget that the parents do not have the medical knowledge to make these diagnoses , do not know what the final diagnoses will be , and do not know how the illnesses are going to evolve . as adams concludes , trying to discern low - acuity conditions and putting up barriers to receiving care or denying payment after receiving care will work no better in future generations than in the past [ 38 , p. 1174
one logical solution would be to educate parents better [ 5 , 10 , 17 ] and specifically those parents whose own characteristics for example , in a us study , single parents , those who were themselves brought to eds as children , and those with medicaid make them more likely to use the ed .
these efforts could involve targeted messaging to high utilizers or more formal instruction , but so far success has been limited . in one study ,
130 families were randomly assigned to receive , or not , an educational intervention in the ped that involved reviewing with a research assistant a booklet about how to manage minor illnesses and watching a 10-minute video . at 6 months
there was no difference between groups in ped utilization , and most visits were still for minor illnesses .
similarly , a 90-minute , interactive educational activity at primary care offices increased 32 parents ' knowledge of fever , colds , and minor trauma and increased their after - hours telephone use ; but it did not decrease their ed use .
education may , of course , have greater effects on other groups of parents than those studied and if done more intensively and repeatedly .
yet our findings point to one possible reason for the limited impact of greater knowledge : the importance for many parents of emotional motives of anxiety about and empathetic concern for the child ( as would be expected of parents ) as well as , for some , of a desire to be seen as a caring parent .
the setting able immediately to soothe their anxiety and distress is the hospital and its emergency department .
it is not surprising , therefore , that the rate of ed visits has been increasing even in countries , like france , that have extended basic insurance to all residents .
when parents in france , as elsewhere , think their children are suffering and might be seriously ill , they are goal - oriented and , often , frightened . they bring their children to the places that are immediately available and that , they think , are most capable of helping their children , to the peds .
thus , as hendry , beattie , and heaney in the united kingdom concluded , perhaps it is the service design , rather than patient behavior , that is inappropriate
the solution is not only to provide anxious parents with expanded daytime sick visits , 24-hour telephone access , and even night - time home visits , as is currently possible in many places .
the solution may also be to expand the peds , that is , to provide urgent visit capacity for minor illnesses and injuries , at lower cost than truly urgent visits , in the places of reassurance and security , the peds themselves .
Output:
| parents frequently bring their children to general or pediatric emergency departments ( eds ) , even though many of these visits are judged by others to be nonurgent and inappropriate .
this study examined the motives behind parents ' decisions to take their children to a pediatric emergency department ( ped ) . at a ped in toulouse , france ,
497 parents rated their level of agreement with each of 69 possible motives representing all categories of human motivation for coming to the ped that day .
exploratory and confirmatory factor analyses found evidence for six separable motives , called ( in order of importance ) ( a ) seeking quick diagnosis , treatment , and reassurance ; ( b ) ped as the best place to go ; ( c ) empathic concern for child 's suffering ; ( d ) being considered by others as responsible parents ; ( e ) external factors ; and ( f ) dissatisfaction with previous consultation . conclusions .
parents ' motives in bringing their children to the ped are primarily serious and goal - oriented .
they are also often emotion based , as would be expected in parents of ill children
. the parents would be unlikely to agree that these visits were inappropriate . |
PubmedSumm119905 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: south carolina , like many other cities and states that have historically had few latinos , has experienced recent surges in immigration and now has small informal enclaves and social structures .
many latinos in these new communities may lack documentation for us residency . consequently , our sampling design took into account the fact that many probability - based sampling designs ( e.g. , random - digit dialing telephone survey , mail survey from a published list of addresses ) would not adequately access this hard - to - reach population . adult ( 18 years of age ) latinos attending 2 clinics in the greater charleston , south carolina , area that serve a primarily latino population were approached for participation in a face - to - face , structured , confidential interview in which no names were recorded .
eligible persons included both those seeking care as well as those accompanying patients since the goal was to collect data from latino adults regarding health behavior that was not necessarily linked to a current illness .
persons in the waiting rooms of the clinic were approached by an interviewer , who was introduced to the prospective respondent by clinic personnel .
if persons did not consider themselves to be latino , they were not included in the study .
previously used and validated surveys designed for use with latino populations were accessed from the scientific literature and were consulted for question wording relevant to the present study 's aims . an instrument was created in english , pretested initially in english for flow and comprehension , and following modifications was then translated into spanish . once in spanish
the first pretest was with medical center personnel who were fluent with spanish and dealt with latino populations .
following modifications from the first pretest , the second pretest was conducted with latino persons seen at a clinic different from the ones used in the study to provide pretest experience with the instrument with a similar population .
after the second pretest , the instrument was translated back into english so that the wording of the questions could be checked for consistency in both english and spanish .
two trained bilingual interviewers administered the survey in a structured format in the participant 's preferred language ( spanish or english ) and reinforced to the potential respondents the anonymous nature of the survey .
first , questions were included that assessed acquiring antimicrobial drugs without a prescription while outside the united states and corresponding self - medication .
these questions were asked to get an idea of health behavior in their home culture and society .
in addition , we asked whether the respondents believed that antimicrobial drugs should be available in the united states without a prescription .
second , questions were included that provided an assessment of the importation of nonprescription antimicrobial drugs into the united states and the context and circumstances related to this behavior .
third , a set of questions was included that assessed acquisition of nonprescribed antimicrobial drugs within the united states .
we were specifically interested in the scope of acquisition of nonprescribed antimicrobial drugs from bodegas , pharmacias , or other stores since this behavior had been suggested in a study in new york city ( 17 ) . for both importing nonprescribed antimicrobial drugs and acquiring them within the united states ,
a series of questions was asked , based on the pretest information , to gain an understanding of why the respondents would engage in these practices .
initially , descriptive statistics were computed to gain an understanding of the extent of the acquisition and importation of nonprescribed antimicrobial drugs .
we also computed chi - square values to examine bivariate relationships between importation of nonprescribed antimicrobial drugs and acquisition of nonprescribed antimicrobial drugs in the united states by health beliefs and behavior in the home country , access to care in the united states , and demographic characteristics .
finally , a stepwise logistic regression model was computed on the dependent variable of acquisition of nonprescribed antimicrobial drugs with the same set of variables ( acquired antimicrobial drugs without a prescription outside the united states , believe antimicrobial drugs should be available in the united states without a prescription , health insurance , age , sex , education , time in united states , country of birth , health status ) to determine the best predictors of this behavior . because no one born in the united states had acquired nonprescribed antimicrobial drugs in the united states , the category variable of country of birth was not used as a predictor of acquiring nonprescribed antimicrobial drugs . instead , country of birth was coded for inclusion in the regression as 1 ) born in mexico or 2 ) born elsewhere .
previously used and validated surveys designed for use with latino populations were accessed from the scientific literature and were consulted for question wording relevant to the present study 's aims . an instrument was created in english , pretested initially in english for flow and comprehension , and following modifications was then translated into spanish . once in spanish
the first pretest was with medical center personnel who were fluent with spanish and dealt with latino populations .
following modifications from the first pretest , the second pretest was conducted with latino persons seen at a clinic different from the ones used in the study to provide pretest experience with the instrument with a similar population .
after the second pretest , the instrument was translated back into english so that the wording of the questions could be checked for consistency in both english and spanish .
two trained bilingual interviewers administered the survey in a structured format in the participant 's preferred language ( spanish or english ) and reinforced to the potential respondents the anonymous nature of the survey .
first , questions were included that assessed acquiring antimicrobial drugs without a prescription while outside the united states and corresponding self - medication .
these questions were asked to get an idea of health behavior in their home culture and society .
in addition , we asked whether the respondents believed that antimicrobial drugs should be available in the united states without a prescription .
second , questions were included that provided an assessment of the importation of nonprescription antimicrobial drugs into the united states and the context and circumstances related to this behavior .
third , a set of questions was included that assessed acquisition of nonprescribed antimicrobial drugs within the united states .
we were specifically interested in the scope of acquisition of nonprescribed antimicrobial drugs from bodegas , pharmacias , or other stores since this behavior had been suggested in a study in new york city ( 17 ) . for both importing nonprescribed antimicrobial drugs and acquiring them within the united states ,
a series of questions was asked , based on the pretest information , to gain an understanding of why the respondents would engage in these practices .
initially , descriptive statistics were computed to gain an understanding of the extent of the acquisition and importation of nonprescribed antimicrobial drugs .
we also computed chi - square values to examine bivariate relationships between importation of nonprescribed antimicrobial drugs and acquisition of nonprescribed antimicrobial drugs in the united states by health beliefs and behavior in the home country , access to care in the united states , and demographic characteristics .
finally , a stepwise logistic regression model was computed on the dependent variable of acquisition of nonprescribed antimicrobial drugs with the same set of variables ( acquired antimicrobial drugs without a prescription outside the united states , believe antimicrobial drugs should be available in the united states without a prescription , health insurance , age , sex , education , time in united states , country of birth , health status ) to determine the best predictors of this behavior . because no one born in the united states had acquired nonprescribed antimicrobial drugs in the united states , the category variable of country of birth was not used as a predictor of acquiring nonprescribed antimicrobial drugs . instead , country of birth was coded for inclusion in the regression as 1 ) born in mexico or 2 ) born elsewhere .
four persons who were initially approached indicated that they did not consider themselves to be latino . of the remaining 273 , 54 refused or provided incomplete information , leaving a sample of 219 .
a large proportion of the sample ( 30.6% ) believed that antimicrobial drugs should be available in the united states without a prescription .
the behavior of acquiring antimicrobial drugs without a prescription while outside of the united states was quite common , with 45.2% indicating that they had done this .
a substantial number of persons had transported nonprescribed antimicrobial drugs into the united states ( 16.4% ) .
the primary illnesses for which they bought the antimicrobial drugs were primarily for what we believe to have been viral respiratory infections . among respondents who reported bringing back antimicrobial drugs that they purchased without seeing a doctor first
, the reported conditions they were trying to treat included cough ( 88.9% ) , ear infections ( 88.9% ) , sore throat ( 69.4% ) , and colds ( 58.3% ) .
when asked whether , on their next trip outside the united states , they would purchase antimicrobial drugs without seeing a doctor first and bring them back into the country , 23.7% of the sample reported " likely " or " very likely . " among persons who transported nonprescribed antimicrobial drugs into the united states , the primary reason reported for doing so was because they had a mistrust of medicines in the united states and were more comfortable with medicines from the home country ( 30.6% ) ; other reasons included the following : to pay less for medicines bought in the home country than they would for those bought in the united states ( 19.4% ) , to avoid going to the doctor while in the united states ( 16.7% ) , to avoid the language barrier to care in the united states ( 13.9% ) , to prepare for future illness ( 13.9% ) , and to treat someone else 's medical problem ( 5.6% ) . acquiring antimicrobial drugs not prescribed for the respondent within the united states was also a common behavior ( 19.2% ) . among those who acquired antimicrobial drugs in the united states without a prescription , 92.9% reported that they had acquired them without prescription at stores in the united states .
as with transportation of nonprescribed antimicrobial drugs into the united states , the primary illnesses for which they acquired the drugs without a prescription were what we believe to have been viral respiratory infections . among respondents who reported acquiring antimicrobial drugs without a prescription , they reported attempting to treat " gripe " ( flu ) ( 97.6% ) , ear infections ( 97.6% ) , cough ( 83.3% ) , and sore throat ( 80.9% ) . additionally , 97.6% reported acquiring antimicrobial drugs to treat diarrhea . among persons who had acquired antimicrobial drugs in the united states without a prescription ,
64.3% suggested that doing so was preferable to going to the doctor , while 26.2% reported that it was cheaper than paying for the doctor visit in addition to paying for the prescription .
only 7.1% of this group reported acquiring antimicrobial drugs in this way because of language barriers .
tables 2 and table 3 show the relationship between home country behaviors , health beliefs , access to care variables , and demographic characteristics to importing nonprescribed antimicrobial drugs and acquiring nonprescribed antimicrobial drugs in the united states .
persons who acquired nonprescribed antimicrobial drugs in the united states had beliefs and practices consistent with limited regulations on antimicrobial drugs .
the best predictors of acquiring antimicrobial drugs in the united states without a prescription are shown in table 4 .
the strongest predictors were health beliefs and practices consistent with limited regulations on antimicrobial drugs .
this study confirms the existence of a large reservoir of nonprescription antimicrobial drugs in the united states that are used for likely inappropriate self - medication in the latino community . besides being imported , many of these nonprescription drugs
are acquired from small stores , showing an organized system of nonprescription antimicrobial drug distribution within the latino community in the united states the cultural beliefs and practice of obtaining antimicrobial drugs without prescriptions , particularly for what are likely viral respiratory infections , is reflected in the antimicrobial drug use patterns of the latino community in this united states .
health beliefs and practices that were instilled in their countries of origin appear to be maintained even after living in the united states , as the relatively high frequency of acquisition of nonprescription antimicrobial drugs in the united states demonstrates . as previous research
has shown , persons born in the united states are less likely to acquire antimicrobial drugs without a prescription within the united states ( 16 ) . in fact , none of the latino respondents born in the united states had acquired antimicrobial drugs without a prescription in the united states .
thus , a special emphasis with patient education should be made to target this population to instill health beliefs that are more consistent with those proposed by the us medical and public health communities .
an additional issue that may play a role in the ability to encourage appropriate use of antimicrobial drugs in this community are problems associated with access to health care .
although health insurance was not a distinguishing variable , common reasons given by the respondents for both importation and acquisition of nonprescribed antimicrobial drugs in the united states revolved around the economics of doctor visits and costs of medication in the united states . a lack of health insurance may encourage latinos to self - medicate with antimicrobial drugs .
first , the sample was recruited from a single mid - sized community , thereby limiting the generalizability of the results . however
, many areas in the united states have seen recent large increases in the latino population .
these new communities may reflect different practices than communities that have had generations of latino immigrants ( e.g. , miami , new york , san antonio ) . a second limitation concerns the location of data collection . by focusing on persons who sought treatment at a health clinic ,
latinos who may not access care in the formal health care system would not be represented in this study .
a direction for future research would be to investigate these issues about antimicrobial drug use in a broader community sampling frame .
third , the results are based on self - reports of behavior , some of which may be somewhat threatening to relate to an interviewer .
thus , the reports of antimicrobial drug importation and acquisition of nonprescribed antimicrobial drugs may be an underreport of actual behavior .
several strategies were used to try and obtain valid reports , including multiple pretests and having the clinic staff introduce the interviewers to the potential participants .
following the pretests , the interview was modified to contain several instances of descriptions of antimicrobial drugs and names that would be recognizable to the latino community . moreover ,
each time a respondent reported acquiring antimicrobial drugs , the respondent was asked by the interviewer to name the drug to make sure that the respondent had actually acquired antimicrobial drugs .
if in fact the results represent underreporting , the findings are even more dramatic because nearly 20% acknowledged getting antimicrobial drugs without a prescription in the united states .
however , because this study is one of the first to document the problem and the first , to our knowledge , to specifically focus on both importation and us acquisition of nonprescribed antimicrobial drugs , government agencies have not yet responded to this problem .
the south carolina department of health and environmental control has a judicious antibiotic use initiative ( south carolina careful antibiotic use , http://www.scdhec.gov/health/disease/sccause ) .
their initiatives are similar to many other initiatives that focus on both physician and patient education , but thus far have not focused on latinos and nonprescription antimicrobial drug importation and local acquisition . a substantial number of persons within the us latino community self - medicate with antimicrobial drugs obtained without a prescription both inside and outside the united states , which adds to the reservoir of these drugs in the united states
. the public health system and clinicians should be aware of the different health belief systems and practices in ethnic minority communities .
patient education materials should communicate in a culturally competent way the dangers of self - medication and antimicrobial misuse to both recent immigrants and others in the latino community .
us health policies also may need to be revised , with consideration given to tightening regulations to reduce the presence of nonprescribed antimicrobial drugs and to increasing access to care for many latinos .
Output:
| we investigated in a sample of latinos the practices of antimicrobial drug importation and use of nonprescribed antimicrobial drugs . in interviews conducted with 219 adults , we assessed health beliefs and past and present behaviors consistent with acquiring antimicrobial drugs without a prescription in the united states .
many ( 30.6% ) believed that antimicrobial drugs should be available in the united states without a prescription . furthermore , 16.4% had transported nonprescribed antimicrobial drugs into the united states , and 19.2% had acquired antimicrobial agents in the united states without a prescription .
a stepwise logistic regression analysis showed that the best predictors of having acquired nonprescribed antimicrobial drugs in the united states were beliefs and behavior consistent with limited regulations on such drugs .
many persons within the latino community self - medicate with antimicrobial drugs obtained without a prescription both inside and outside the united states , which adds to the reservoir of antimicrobial drugs in the united states . |
PubmedSumm119906 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: the author receives funding from the swedish research council , the ragnar sderbergs stiftelse , the novonordisk foundation and lund university .
the author is also part of the following strategic research consortia in diabetes : the linnaeus lund university diabetes center ( ludc ) funded by the swedish research council and the excellence of diabetes research in sweden ( exodiab ) supported by the swedish government .
the author was responsible for the conception , design and drafting of the manuscript and approved the final version for publication .
this article is distributed under the terms of the creative commons attribution noncommercial license which permits any noncommercial use , distribution , and reproduction in any medium , provided the original author(s ) and the source are credited .
Output:
| common genetic variations in the gene encoding transcription factor 7-like 2 ( tcf7l2 ) reveal the strongest association with type 2-diabetes known to date . these lead to impaired insulin production and output , but the mechanisms of disease
remain incompletely known . in this issue of diabetologia ,
two publications provide new insights into tcf7l2-dependent diabetes . |
PubmedSumm119907 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: acquired retinal astrocytoma is a benign glial intraretinal tumor.1 it is considered the retinal equivalent of low - grade brain astrocytomas . despite its benign cytology , it can show progressive growth and behave as a locally aggressive malignant tumor .
the clinical course can be complicated with exudative retinal detachment , vitreous hemorrhage , neovascular glaucoma and a blind , painful eye , ultimately leading to enucleation.23 ] the management of acquired astrocytoma remains controversial .
external beam radiotherapy,2 laser photocoagulation,4 cryotherapy , plaque radiotherapy and pars plana vitrectomy and endoresection5 were previously proposed as the treatment options to avoid enucleation.3 however , these treatments have been ineffective in many patients.234 over time , some studies revealed success with verteporfin photodynamic therapy ( pdt ) in the treatment of acquired retinal astrocytomas.678 in this case report , we present a patient with symptomatic , presumed acquired retinal astrocytoma - without evidence of tuberous sclerosis - that showed dramatic regression after a single session of pdt .
a 42-year - old female noted decreased visual acuity in her right eye for 1 month .
the visual acuity was counting fingers at one meter in the right eye and 20/20 in the left eye .
, there was a juxtapapillary , amelanotic , yellow - white lesion with circinate exudation , exudative inferior hemiretinal ( including fovea ) detachment and overlying marginal retinal hemorrhages [ figure 1a ] .
the lesion was 3.6 mm in thickness and had a basal diameter of 3 mm .
optical coherence tomography ( oct ) imaging through the fovea demonstrated a serous retinal detachment [ figure 1b ] .
oct through the lesion showed preservation of the linear configuration of the retinal pigment epithelial layer with deep optical shadowing , suggesting a tumor of retinal and not choroidal origin [ figure 1c ] .
fluorescein angiography revealed early hypofluorescence with scarce intrinsic vascularity [ figure 1d ] and diffuse late - phase hyperfluorescence with subretinal fluorescein leakage [ figure 1e ] .
ultrasonography disclosed a solid , pedunculated lesion inferior to the optic disc with medium internal reflectivity and inferior exudative retinal detachment [ figure 1f ] .
there was no systemic evidence of tuberous sclerosis or neurofibromatosis . before photodynamic therapy : ( a ) color fundus photograph shows a juxtapapillary , yellow - white retinal lesion with circinate exudation and exudative retinal detachment .
( b ) optical coherence tomography ( oct ) through the fovea demonstrates serous foveal detachment .
( c ) oct through lesion shows preservation of the linear configuration of the retinal pigment epithelial layer with deep optical shadowing , suggesting a tumor of retinal origin .
( e ) diffuse late - phase hyperfluorescence with subretinal fluorescein leakage and note the lack of typical small , well - defined fine blood vessels over the tumor in the early vascular filling phases .
( f ) ultrasonography reveals a non - calcified , pedunculated retinal mass with acoustic solidity and inferior retinal detachment patient was diagnosed with presumed acquired retinal astrocytoma . with informed consent from the patient ,
the tumor was treated with a single session of pdt using standard treatment parameters ( 50 j / cm light dose , 600 mw / cm power and 83 s duration ) .
an intravenous injection of 6 mg / m body surface area verteporfin over 10 min was performed then laser with emission wavelength of 689 nm was delivered to the entire tumor in one spot ( 5400 microns ) , avoiding the optic disc as much as possible . following pdt ,
the visual acuity decreased to hand motion due to dense vitreous hemorrhage that developed during the 1 week after treatment [ figure 2a ] .
thereafter , the visual acuity gradually improved to 20/40 with complete regression of the tumor into a fibrotic scar - like tissue at 6 months , 20/25 with complete resolution of lipid exudation and exudative retinal detachment at 14 months and 20/20 at 2 years [ figure 3 ] . at 51 months
follow - up , visual acuity remained stable with complete tumor atrophy and no recurrence .
regression of tumor after photodynamic therapy at : ( a ) 1 week , ( b ) 1 months , ( c ) 2 months and ( d ) 3 months 2 years after photodynamic therapy : ( a ) marked regression of the tumor .
( b ) optical coherence tomography ( oct)(fovea ) shows disappearance of the serous retinal detachment .
( c ) oct ( lesion ) precisely demonstrates the intraretinal location of the tumor with overlying epiretinal membrane .
( e ) late phase angiography showing hyperfluorescence with staining of the residual , intraretinal fibrotic tissue
benign retinal astrocytic lesions include reactive retinal gliosis , astrocytic hamartoma and acquired astrocytoma.17 retinal gliosis usually occurs after trauma , inflammation , or infection .
astrocytic hamartoma is typically stable , diagnosed in early childhood and is often associated with tuberous sclerosis or neurofibromatosis.1 in contrast , acquired astrocytoma is a sporadic tumor that occurs in relatively older individuals , is not associated with tuberous sclerosis and is often symptomatic and progressive.13 thus , any delay in the diagnosis and treatment may result in poor visual outcomes and increased ocular morbidity .
the diagnosis of acquired retinal astrocytoma depends on the clinical finding and imaging results.1 it appears as a yellow - white nodular lesion within the sensory retina .
fluorescein angiography typically shows small , well - defined fine blood vessels in the tumor in the early vascular filling phases and rather intense , diffuse late staining .
oct can be used to document the intraretinal location of the tumor and its highly reflective features .
fine needle aspiration may be required in establishing the correct diagnosis in atypical cases.7 the differential diagnosis of acquired retinal astrocytoma includes choroidal melanoma , solitary idiopathic choroiditis , retinoblastoma and retinal hemangioblastoma.1 the tumor reported in the current case was located in the sensory retina .
the confirmation of the retinal location with oct ( especially images from follow - up such as figure 2c ) aided in differentiate it from a tumor of choroidal origin . furthermore , the color of the tumor was yellow - white and it was hypofluorescent without any evidence of small , well - defined capillaries in the early phase of angiography .
in contrast , retinal hemangioblastoma is typically a reddish - pink tumor of the fundus and shows rapid hyperfluorescence in the arterial phase of the fluorescein angiography .
finally , retinoblastoma of comparable size to our case does not usually cause such lipid exudation and exudative retinal detachment .
the pedunculated architecture with acoustic solidity and lack of calcification in b - scan ultrasonography also favors the diagnosis of presumed acquired astrocytoma . despite its atypical features in fluorescein angiography and lack of histopathologic confirmation
, our case presumably represents an example for an acquired retinal astrocytoma.138 we believe that the presence of lipid exudation and exudative retinal detachment is consistent with the aggressive behaviour.8 pdt has been used for treatment of various intraocular tumors , including choroidal hemangioma,9 osteoma,10 melanoma,11 exudative changes over nevus / combined hamartoma,1213 retinal capillary hemangioma14 and retinal vasoproliferative tumors.15 due to the poor response of acquired astrocytoma to laser photocoagulation and radiotherapy , recent studies have focused on pdt to avoid enucleation in the management of this lesion.678 in 2006 , mennel et al.6 reported the first successful treatment with pdt of a symptomatic retinal astrocytic hamartoma associated with tuberous sclerosis .
they demonstrated complete resolution of subretinal fluid , disappearance of tumor vessels and improved vision after one session ( 166 s ) of pdt . in 2008 , shields et al.7 described the use of pdt for a pigmented variant of acquired astrocytoma in an 18-year - old female with no history of tuberous sclerosis .
they showed minimal involution of the tumor , but complete resolution of macular exudation , edema and subretinal fluid with improvement of visual acuity following one session of pdt with standard parameters .
eskelin et al.8 reported similar outcome in two cases with symptomatic , locally aggressive astrocytomas .
they used pdt successfully as a secondary treatment ( after failure with prior laser photocoagulation ) for a juxtapapillary astrocytoma in a 34-year - old male with tuberous sclerosis and as a primary treatment for a macular astrocytoma in a 68-year - old man without tuberous sclerosis .
following one session of pdt with standard parameters , they observed regression of tumors and complete resolution of exudative retinal detachment in both patients . in our case , a pronounced effect on the symptomatic , juxtapapillary , presumed acquired retinal astrocytoma was obtained with a single session of pdt .
the vitreous hemorrhage after pdt presumably occurred due to the rupture of superficial vessels over the tumor .
our paper demonstrates dramatic regression of a symptomatic , juxtapapillary , presumed acquired retinal astrocytoma with complete resolution of exudative retinal detachment and lipid exudation after one session of pdt .
thus , pdt can be considered as a first - line treatment in cases with acquired retinal astrocytoma .
Output:
| photodynamic therapy ( pdt ) has been used for treatment of various intraocular tumors including choroidal hemangioma , vasoproliferative tumor , amelanotic choroidal melanoma and choroidal neovascular membrane due to choroidal osteoma .
this case report documents the effect of pdt for a presumed acquired retinal astrocytoma .
a 42-year - old female with a juxtapapillary acquired astrocytoma was treated with a single session of pdt using standard parameters .
the tumor showed dramatic regression over 6 months into a fibrotic scar .
it remained regressed and stable with 20/20 vision after 51 months of follow - up .
we believe that pdt can be used as a primary treatment for acquired retinal astrocytoma . |
PubmedSumm119908 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: hemangioblastoma ( hb ) of the central nervous system is a benign neoplasm of the central nervous system that usually involves the brain and spinal cord .
it may occur sporadically or in association with von hippel - lindau ( vhl ) disease ( 1 - 5 ) . in sporadic , non - vhl cases ,
the tumors are usually solitary , and local recurrences are seen occasionally after surgery ( 1 , 2 , 5 ) .
in contrast , hbs associated with vhl disease are usually multiple and continue to arise over the course of a patient 's life , which necessitates lifelong surveillance ( 2 - 5 , 7 ) .
disseminated hb is an extremely unusual type of recurrence , and it has recently been called hemangioblastomatosis ( 10 - 16 ) .
we report a case of hemangioblastomatosis in a patient without vhl and discuss the biological and clinical features associated with this disease .
in 1996 , a 41-yr - old man underwent surgical excision of a solitary cerebellar mass with the pathological diagnosis of hb ( fig .
he had no family history or clinical stigmata to suggest the presence of vhl disease .
gross total removal of the tumor was possible , and no evidence of residual or recurrent disease was observed on magnetic resonance imaging ( mri ) performed 1 yr after the surgery ( fig .
ten years after the surgery , he returned to the hospital complaining of low back pain and hypesthesia in his right posterior thigh .
mri of the brain showed multiple mass lesions in the suprasellar area and in the anterior aspect of the upper spinal cord accompanied by diffuse leptomeningeal enhancement ( fig .
whole - spine mri revealed numerous tiny enhancing nodules suggestive of leptomeningeal metastasis along the spinal cord and cauda equina ( fig .
genomic dna was isolated from peripheral blood leukocytes using a wizard genomic dna purification kit according to the manufacturer 's instructions ( promega , madison , wi , u.s.a . ) .
the three exons of the vhl gene as well as their flanking introns were amplified and sequenced by an abi 3730 sequencer ( ame bioscience , toroed , norway ) .
the patient underwent surgical resection of the cauda equina lesion and subtotal removal of the tumor .
histopathological examination confirmed the diagnosis of hb , and the microscopic findings were identical to those of the cerebellar hb operated on 10 yr earlier ( fig . 2c ) .
he subsequently received fractionated radiotherapy ( a total dose of 3,600 cgy ) for a residual lesion in the cauda equina .
brain mri scans obtained 6 months after the diagnosis of recurrence revealed interval growth of the suprasellar lesion , and gamma knife radiosurgery was performed .
although the treated lesions showed no further growth , his condition gradually deteriorated with general weakness , anorexia , and frequent vomiting .
the patient died of septic shock and respiratory failure at 1 yr after the diagnosis of disseminated recurrence .
hbs account for 1 to 2% of primary intracranial tumors and 5 to 15% of posterior fossa tumors in adults ( 2 - 5 , 7 , 8) .
approximately 62% of hbs arise sporadically , and 38% occur in association with vhl disease ( 6 ) .
the average age at presentation of sporadic cerebellar hbs is approximately 35 yr , and these tumors are more common in men .
hb is thought to be a benign tumor curable by microsurgery ; however , several previous studies have reported that the recurrence rate after surgical excision is 15 - 27% ( 9 ) .
vhl disease is an autosomal - dominant neoplasia syndrome caused by a germline mutation or deletion on the short arm of chromosome 3 .
patients with vhl tend to present with neurological symptoms and signs at a younger age than those with sporadic disease .
the syndrome is characterized by the development of multiple visceral and central nervous system ( cns ) lesions .
tumors of the cns include hbs , which affect 48 - 80% of patients with predisposing sites in the cerebellum ( 44 - 73% ) , brainstem ( 10 - 25% ) , spinal cord ( 13 - 50% ) , and retina ( 25 - 60% ) , as well as endolymphatic sac tumors , which affect 10 - 15% of patients ( 17 - 19 ) .
the visceral lesions include renal cell carcinoma , renal cyst , pheochromocytoma , pancreatic cyst , and pancreatic neuroendocrine tumor .
only 12 cases of disseminated hb have been reported previously ( 10 - 16 ) .
mohan et al . ( 11 ) first reported two cases of disseminated hb that developed several years after complete excision .
bakshi et al . ( 10 ) reported a case of diffuse spinal leptomeningeal enhancement on mri associated with multiple hbs and termed this condition hemangioblastomatosis .
all 12 previously reported cases of disseminated hb arose in patients who had solid cerebellar hb as a primary lesion , and 9 of the patients had no association with vhl disease ( 10 - 16 ) .
all of the patients underwent surgical treatment of the primary lesion , and hemangiomatosis developed after variable intervals ranging from 6 months to 22 yr . in reported cases ,
biopsy specimens from the primary and secondary lesions were similar in histopathology to that in our case .
tumor infiltration to leptomeninges was identified in five cases by mri demonstrating diffuse leptomeningeal enhancement on the surface of the brainstem and spinal cord ( 10 , 12 , 14 - 16 ) .
the outcomes after recurrence were very poor , and most patients died within 3 yr .
the most common cause of death was respiratory failure due to pontomedullary or cervical cord compression .
the currently available treatment did not have a significant effect on the progression of the disease .
eight patients with disseminated hb received from 13 to 56 gy of irradiation to the posterior fossa or spinal cord ; however , long - term tumor control was not achieved ( 11 - 16 ) .
advanced radiation techniques , such as radiosurgery , may be more effective than conventional fractionated radiotherapy , but it is difficult to perform high - dose radiation therapy or radiosurgery for numerous lesions scattered throughout the entire neuraxis . the use of interferon- , thalidomide or a vascular endothelial growth factor receptor antagonist to inhibit angiogenesis ( 20 , 21 ) did not result in remarkable tumor response . though vhl gene mutation was not detected in our case , the vhl gene may be mutated in sporadic cases of hb of the cns ( 7 ) . in a molecular genetic analysis of four cases of hemangioblastomatosis without vhl , weil et al .
( 14 ) found no evidence of germline alterations in the vhl gene , but the somatic deletion of one copy of the vhl gene .
these findings implicate a monoclonal origin of multiple , separate deposits of tumors in patients with sporadic hb .
the results of comparative genomic hybridization studies suggest that other genes , in addition to the vhl gene , may be involved in the dissemination of hbs ( 15 ) .
because no case of de novo development of disseminated hb without previous surgery has been reported , it is strongly suggested that the spillage and spread of tumor cells through the csf space may be an origin of hemangioblastomatosis in patients with a genetic predisposition to the condition .
all previously reported cases showed multiple mass lesions exclusively in the infratentorial area and spinal cord except only one case ( 13 ) .
paucity of supratentorial lesions may reflect csf flow and effect of gravity supporting the hypothesis of tumor spread through csf pathway .
preventive measures to reduce tumor cell spillage should be considered during operation , and further study to determine the biological risk factors of disseminated recurrence is needed .
Output:
| we report a very rare case of hemangioblastomatosis that developed after surgical removal of a solitary cerebellar hemangioblastoma ( hb ) . a 51-yr - old man presented with back pain 10 yr after undergoing surgery for cerebellar hb .
magnetic resonance imaging showed numerous mass lesions along the entire neuraxis accompanied by prominent leptomeningeal enhancement .
genomic dna analysis showed no mutation in the von hippel - lindau ( vhl ) genes . a surgical specimen obtained from a lesion in the cauda equina showed pathological findings identical to those of the cerebellar hb that had been resected 10 yr earlier .
external beam radiation therapy and radiosurgery were subsequently performed ; however , the patient succumbed one year after receiving the diagnosis of hemangioblastomatosis .
the reduction of tumor cell spillage during surgery and regular long - term follow - up are recommended for patients with hbs . |
PubmedSumm119909 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: in the recent years , the identification of genes involved in the modulation of inflammatory and apoptotic processes and the improved understanding of mechanisms linked to the aberrant activation of the inflammasome , amultiprotein intracytoplasmatic scaffold complex synthesizing the biologically active interleukin- ( il-1 ) , the prototypic master cytokine affecting nearly all cell types , have allowed the delineation of a new group of diseases called monogenic autoinflammatory syndromes ( maiss ) . from the etiopathogenetic point of view , in spite of the heterogeneity of genes responsible for the various maiss ( table 1 ) , the inflammasome represents an ideal point of convergence of most of these diseases , that is , the cell structure crucial to the regulation of innate immunity : its proper assembly allows for regular activation of caspase-1 and physiological production of proinflammatory cytokines , in primis il-1 , necessary to respond to a heap of different danger signals , as bacterial peptidoglycans , genotoxic stress , and crystals . in the pathogenesis of many maiss , the erroneous assembly of the inflammasome leads to an exaggerated conversion of pro - il-1 to its active form and subsequent disproportionate overwhelming inflammatory response .
autoimmune , was intended to highlight the spontaneous nature of the inflammatory attacks , which occur in the absence of any pathogenetic role of autoantibodies or autoreactive t lymphocytes .
therefore , the contribution of as - yet unidentified environmental factors as potential triggers of abnormal inflammatory processes might be likely [ 3 , 4 ] . clinically speaking ,
a few characteristics common to all maiss have been identified , such as the recurrent nature of inflammatory episodes , presence of fever , and frequent involvement of the skin , serous membranes , eyes , joints , lymph nodes , gastrointestinal tract , and nervous system .
each of these syndromes may manifest itself with more or less severe inflammatory signs and symptoms of varying frequency and duration , associated , from the laboratory point of view , with increased phlogistic parameters [ 5 , 6 ] ( table 2 ) . to date ,
there are twelve known maiss : familial mediterranean fever ( fmf ) ; tumor necrosis factor receptor - associated periodic syndrome ( traps ) ; cryopyrin - associated periodic syndrome ( caps ) , a group which includes familial cold urticaria syndrome ( fcas ) , muckle - wells syndrome ( mws ) , and chronic infantile neurological cutaneous articular ( cinca ) syndrome ; mevalonate kinase deficiency ( mkd ) ; nlrp12-associated autoinflammatory disorder ( nlrp12ad ) ; granulomatous maiss which include blau syndrome ( bs ) and early - onset sarcoidosis ( eos ) ; and , finally , the hereditary pyogenic disorders including papa ( pyogenic arthritis , pyoderma gangrenosum , and acne ) syndrome , majeed syndrome ( ms ) , and deficiency of the il-1 receptor antagonist ( dira ) .
maiss are generally characterized by early onset ( in the first year of life or early childhood ) , but , in more than a few cases , in particular for fmf and traps , adult onset has also been described [ 7 , 8 ] . in such cases ,
the utilization of a highly sensitive and specific score can be useful in guiding diagnosis [ 911 ] .
type aa amyloidosis is the most serious complication of most maiss , due to excessive production of serum amyloid - a ( saa ) , synthesized in the liver following stimulation by certain proinflammatory cytokines , such as il-1 , and also il-6 and tumor necrosis factor- ( tnf- ) . due to persistent activation of the chronic inflammatory process , whether clinically manifested orsubclinically , excess saa is deposited in the form of fibrils in various organs , particularly the kidneys , with the consequent progressive development of severe proteinuria , leading to nephrotic syndrome and kidney failure .
other areas that may be involved include the autonomous nervous system ( with orthostatic hypotension , impotence , and altered intestinal motility ) , liver and spleen ( with hepatosplenomegaly ) , muscles , heart ( with contractility and circulation abnormalities ) , and gastrointestinal tube ( with diarrhea and malabsorption ) .
therefore , close monitoring of serum saa levels even during healthy periods is necessary to prevent or promptly treat a secondary amyloidosis or to verify the efficacy of treatment . from a therapeutic point of view
, colchicine has been proven to be the treatment of choice for patients with fmf , while nonsteroidal anti - inflammatory drugs ( nsaids ) and corticosteroids are utilized above all to treat symptoms in most of the other maiss , with varying results .
the introduction of biological agents , such as anti - tnf ( etanercept , infliximab , and adalimumab ) and anti - il-1 ( anakinra , canakinumab , and rilonacept ) , has nonetheless opened up new interesting possibilities for the management of these heterogeneous disorders .
the purpose of this paper is to describe the main genetic , clinical , and therapeutic aspects of maiss , focusing on their current classification and general details , shown in tables 1 and 2 , with the ultimate goal of increasing awareness of these conditions among various specialties of internal medicine .
familial mediterranean fever ( omim 249100 ) is transmitted by autosomal recessive inheritance and , in its most frequent and classic phenotype , is characterized by recurrent acute fever episodes , polyserositis , arthritis , and erysipelas - like erythema : it is due to the presence of mutations ( among the 200 identified to date ) in the mefv ( from mediterranean fever ) gene which encodes the protein pyrin , also known by its european name marenostrin [ 16 , 17 ] ( table 1 ) .
this protein is made up of 781 amino acids and is expressed mainly in neutrophil and eosinophil granulocytes , monocytes / macrophages , and fibroblasts of the skin , peritoneum , and synovia .
pyrin mutations cause altered inflammasome function , which leads to increased synthesis of proinflammatory cytokines ( mainly il-1 ) , activation of transcription factor nf-b , and altered inhibition of apoptosis , all demonstrated in subjects with fmf [ 1720 ] . in the past
, fmf was believed to pertain almost exclusively to populations living near the mediterranean basin , but today it is widely held that other populations can also be affected .
still , the most affected populations continue to be armenians , turks , arabs , and non - ashkenazi jews with a rate of occurrence that oscillates between 1 : 400 and 1 : 1.000 in turkey and that is around 1 : 1000 in israel and 1 : 500 in armenia .
onset of fmf usually occurs in the first two decades of life , with a relatively small number of adult - onset cases [ 7 , 8 ] . from the clinical point of view
, three different fmf phenotypes have been identified : phenotype 1 is characterized by recurrent inflammatory episodes lasting 1272 hours , sometimes triggered by stress , physical exercise , or infections and preceded by nonspecific symptoms like lack of appetite , malaise , and irritability . during these episodes , fever and abdominal pain
abdominal pain due to sterile peritonitis may sometimes last a few days after the fever has ceased .
about half of patients present thoracic pain with acute pleuritis , almost always monolateral , and/or pericarditis [ 15 , 24 ] .
inflammation of the tunica vaginalis of the testis may also occur , leading to recurrent episodes of acute orchiepididymitis in these subjects .
skin manifestations , also of brief duration ( usually 1248 hours ) and generally associated with fever , are characterized by the periodic appearance of erysipelas - like lesions , approximately 10 cm in diameter , usually localized on the surface of the legs between the hip and knee and/or on the tops of the feet .
muscular - skeletal involvement is frequent , often in the form of arthralgia and myalgia , which may be prolonged and crippling , significantly reducing patients ' quality of life [ 27 , 28 ] .
about 30% of fmf patients have also arthritis , especially affecting the large joints , which may last for several days after fever has resolved : arthritis is only rarely erosive and is generally mono- or oligoarticular .
possible , but rare , is aseptic meningitis , accompanied by headache and possibly by electroencephalographic alterations and convulsions .
in addition , fmf has also been associated with other rheumatological diseases , such as spondyloarthritis , rheumatoid arthritis , systemic lupus erythematosus , vasculitis of small and medium vessels ( like henoch - schenlein purpura , polyarteritis nodosa , and behet 's disease ) , and vasculitis of large vessels ( like takayasu 's arteritis ) .
acute episodes are associated with increased laboratory phlogosis indicators , particularly erythrosedimentation rate ( esr ) , c - reactive protein ( crp ) , saa , and fibrinogen ; other laboratory findings may include neutrophil leukocytosis , thrombocytosis , anemia , and , less frequently , an increase in immunoglobulins , particularly classes a and d .
the increase in saa during fmf attacks , which is also possible during asymptomatic periods , is a clue to the progression towards amyloidosis : saa measurement is thus a useful parameter for highlighting a state of subclinical inflammation and revealing a potential secondary systemic amyloidosis [ 6 , 12 , 35 ] .
phenotype 2 refers to fmf patients with proteinuria or kidney failure resulting from amyloidosis , in whom the inflammatory attacks typical of fmf occur only afterwards .
this phenotype also includes subjects belonging to the families of fmf patients who evolve towards systemic amyloidosis as the sole manifestation of the disease [ 3638 ] .
phenotype 3 includes subjects carrying one of two mutations ( homozygous or heterozygous ) of the mefv gene without presenting with any of the known clinical manifestations .
diagnosis of fmf is primarily clinical and based on the use of the tel - hashomer diagnostic criteria , divided into major and minor signs , as shown in table 2 : the presence of two major criteria , or one major and two minor criteria , allows for a definitive fmf diagnosis , while the presence of a single major criterion and one minor one may point towards a probable diagnosis , which can be confirmed thereafter by the presence of mutations in the mefv gene .
the most common of the mefv gene mutations is m694v ( in exon 10 ) , which , in homozygous cases , is correlated with an earlier disease onset and , more frequent , joint involvement , and occurrence of amyloidosis [ 41 , 42 ] . from a therapeutic point of view , colchicine is now recognized as the drug of choice in the treatment of fmf , as it is effective in almost 95% and completely prevents the acute episodes in 60% of the patients .
in addition , colchicine has also been proven to be effective in preventing secondary complications of amyloidosis [ 13 , 14 , 4348 ] . unlike the case of gout , colchicine is not effective in aborting an established acute episode and should be used for prophylaxis only .
initial dose is usually 11.2 mg daily , to increase every 1 - 2 months ( depending on the frequency of the acute attacks ) until an effective response is obtained , up to a maximal dose of 2.02.4 mg per day , if tolerated .
optimal dosage should be determined on case - by - case basis to achieve maximal efficacy with minimal side effects . in children with fmf , 0.02 - 0.03 mg / kg / day of colchicine
should be given , up to a maximum daily dosage of 1.82.0 mg / day .
since colchicine treatment is often complicated by frequent gastrointestinal side effects , some experts recommend lactose - free diet in order to improve colchicine tolerance .
colchicine therapy for fmf during pregnancy has not been reported to harm either the mother or her fetus .
contraindications to colchicine will include hypersensitivity to any component of its formulation and severe renal or hepatic impairments , requiring a cautious use in the elderly with renal , liver , or biliary disease
. nsaids and corticosteroids , sometimes at high doses , rarely achieve satisfying clinical results to control the disease [ 14 , 51 , 52 ] .
valid therapeutic alternatives in patients who fail to respond to colchicine include il-1 inhibitors ( anakinra , canakinumab , and rilonacept ) and anti - tnf- agents ( adalimumab , etanercept , and infliximab ) .
traps ( omim 142680 ) is an autosomal dominant disease caused by prevalently missense mutations in the tnfrsf1a gene , made up of 10 exons encoding for the p55 1a receptor of tnf ( tnfr1a ) : the vast majority of mutations are found on exons 2 , 3 , 4 , and 6 [ 16 , 55 , 56 ] , and they can be distinguished as high- or low - penetrance ones .
the former are located in cysteine - rich n - terminal domains , fundamental for the assembly of the receptor 's three - dimensional structure [ 57 , 58 ] , and they are characterized by early disease onset and more severe clinical manifestations ; the low - penetrance mutations , such as r92q and p46l , tend to be associated with onset of disease in adulthood and less pronounced or atypical clinical characteristics [ 5965 ] . although the biological alteration involves the tnf receptor , the pathogenesis of traps also seems to be associated with a dysregulation in the secretion of il-1 and il-6 , as well as oxidative damage correlated with the mitochondrial production of free radicals [ 61 , 66 , 67 ] . clinically speaking ( table 2 ) ,
patients complain of inflammatory attacks of extremely variable duration and intensity ( from 1 - 2 days to 3 - 4 weeks ) , characterized by fever episodes accompanied more or less constantly by sterile peritonitis with abdominal pain , diarrhea or constipation , nausea , and vomiting [ 55 , 68 , 69 ] . mono- or bilateral periorbital edema is a very characteristic and almost pathognomonic sign of the disease , often associated with conjunctivitis and periorbital pain .
also very frequent are arthralgias , muscle cramps , and/or centrifugally spreading migratory myalgias and chronic fasciitis .
muscular symptoms may include edema and swelling of the muscular group involved , usually localized , while skin symptoms mostly include a serpiginous rash consisting of migratory and painful patches , histologically characterized by the presence of perivascular lymphocytic and monocytic infiltrates [ 70 , 71 ] .
serous membrane inflammation is also common , usually in the form of polyserositis [ 6265 , 7274 ] .
pericardial or myocardial involvement has also been reported as the only clinical manifestation of traps [ 911 , 62 , 64 , 71 , 73 , 7577 ] . during acute episodes , and
sometimes also in asymptomatic periods , there is a marked increase in phlogosis indicators ( esr , crp , and saa ) , as well as neutrophil leukocytes , aptoglobin , fibrinogen , and platelets [ 5 , 6 ] . in up to 25% of patients carrying mutations involving cysteine residues and in about 2% of those carrying low - penetrance mutations ,
therefore , proteinuria and saa serum levels must be constantly monitored to avoid overlooking an occult subclinical amyloidosis and its progression towards end - stage kidney damage , which is the most dreaded complication of the disease [ 56 , 59 ] .
diagnosis requires the identification of a mutation in the tnfrsf1a : thus , for patients with clinical symptoms that lead to the suspicion of traps , genetic tests are indispensible . from a therapeutic point of view
, high doses of nsaids and corticosteroids may prove useful during acute phases , though they do not reduce the frequency of attacks and furthermore do not prevent amyloidosis .
in addition , when administered for long periods of time , high - dose corticosteroids can cause serious systemic side effects .
colchicine and immunomodulating or immunosuppressant agents have also been proven to have very little efficacy in traps [ 14 , 55 , 68 , 72 , 78 ] . due to the genetic defect at the origin of the pathology , it was clear that the use of anti - tnf agents could have an important effect in these patients .
in fact , etanercept has been proven to be useful in reducing the intensity and duration of acute attacks , although in some cases it gradually loses efficacy [ 7881 ] .
infliximab and adalimumab , by contrast , for reasons only partially understood , may , paradoxically , evoke typical acute inflammatory attacks of the disease [ 81 , 82 ] .
treatment with anti - il-1 agents , on the other hand , has been proven to be particularly efficacious in preventing attacks and inducing a rapid and long - lasting remission of the disease , as well as in the prevention and even regression of amyloidosis [ 77 , 80 , 83 , 84 ] . recently
, the il-6 receptor antagonist tocilizumab has been used in etanercept- and anakinra - resistant patients with good results , suggesting a possible role of il-6 in the pathogenesis of traps .
cryopyrin - associated periodic syndromes are a group of autoinflammatory diseases transmitted by autosomal dominant inheritance caused by mutations in the nlrp3 gene ( also called cias1 or pypaf ) encoding for cryopyrin , a crucial inflammasome protein that directly activates il-1. to date , more than 90 nlrp3 gene mutations have been identified , most of them in exon 3 .
these mutations induce an imbalance in il-1 production , leading to fever attacks associated with other multiple inflammatory symptoms ( table 1 ) [ 16 , 86 , 87 ] .
the least severe is familial cold autoinflammatory syndrome ( fcas ) ( omim 120100 ) .
muckle - wells syndrome ( mws ) ( omim 191900 ) is the clinical phenotype of medium severity .
finally , chronic infantile neurological cutaneous articular ( cinca ) syndrome ( omim 607115 ) , also known as nomid ( neonatal - onset multisystem inflammatory disease ) , presents a decidedly more severe overall clinical picture [ 86 , 87 ] .
while fcas and mws may be family associated , cinca syndrome due to the seriousness of the clinical phenotype is usually associated only with sporadic mutations [ 78 , 88 ] .
fcas generally appears during the first few months of life and is characterized by brief recurrent inflammatory episodes , usually triggered by generalized exposition to low temperatures or sudden changes in temperature .
recently , the possible emergence of a fcas - like phenotype in adult patients or carriers of low - penetrance mutations has been described .
symptoms include fever , urticaria - like rash that responds poorly to antihistamines , conjunctivitis , headache , arthralgia and/or arthritis , and fatigue .
generally , inflammatory attacks in fcas decrease spontaneously , and an increase in acute - phase phlogistic indicators is usually seen during acute episodes .
progress to amyloidosis is rather rare in patients with fcas , in contrast with other caps [ 12 , 89 ] .
mws is characterized by a variable clinical progression , with an episodic - recurrent or chronic pattern , and early childhood onset , usually in the first months of life .
in addition to the symptoms typical of fcas , patients often also manifest episcleritis , neurosensorial deafness , and secondary amyloidosis in up to 25% of cases [ 91 , 92 ] . finally , cinca syndrome , the most severe of the caps , appears in the first weeks of life , being characterized by widespread nonpruritic urticaria - like skin rash [ 9396 ] .
in addition to the manifestations seen in fcas and mws , cinca syndrome may also manifest with uveitis , papilledema , optic nerve atrophy leading to blindness , cerebral atrophy , mental retardation , increased intracranial pressure , ventriculomegaly , chronic aseptic meningitis , and , finally , a characteristic deforming osteoarthropathy of the large joints and hypertrophy of growth plates .
many patients present a typical facies characterized by prominent frontal eminences , saddle nose , and hypoplasia of facial bones .
also in cinca syndrome , there is a risk of amyloidosis with frequent progressive kidney involvement .
in addition , from the laboratory point of view , all caps are characterized by persistent elevated neutrophil leukocytosis , increased acute - phase proteins , and chronic anemia [ 5 , 6 ] .
on the basis of etiopathogenetic mechanisms rooted in overproduction of il-1 , caps have been treated with anti - il-1 agents : anakinra was the first drug utilized in these patients , with exciting results from the neurological point of view as well [ 97 , 98 ] .
the safety and tolerability of rilonacept have been demonstrated in a group of pediatric and adult caps patients , while canakinumab has been shown to be safe and effective both in controlling clinical / laboratory indicators of disease activity and in controlling amyloidosis - related complications [ 14 , 99101 ] .
also known as hyperimmunoglobulinemia d syndrome , mkd ( omim 260920 ) is an autosomal recessive disease caused by mutations in the mvk gene ( table 1 ) , encoding for the enzyme mevalonate kinase , involved in the atp - dependent phosphorylation of mevalonic acid into 5-phosphomevalonate .
the most frequently found mutations are v377i , i268 t , h20p / n , and p167l , at least one of which is found in 71.5% of patients : they are responsible for reduced mevalonate kinase activity , which leads to overproduction of proinflammatory isoprenoids , reduced synthesis of cholesterol , and accumulation of mevalonic acid in plasma and urine .
the disease onset usually occurs during early childhood , generally within the first year of life , or in any case within the first 5 years .
the emergence of symptoms after 5 years of age automatically excludes a diagnosis of mkd .
acute episodes generally occur every 46 weeks and last about 37 days on average , with asymptomatic periods between attacks .
the main clinical manifestations are recurrent fever ( above 38.5c ) , headache , mouth ulcers , abdominal pain , vomiting , and/or diarrhea ( table 2 ) .
more than 60% of patients may present with joint involvement in the form of arthralgia and/or arthritis , especially affecting large joints . during acute episodes , a nonspecific maculopapular rash may appear , while urticaria , erythema nodosum , and purpura are less frequently reported .
attacks are generally more frequent during childhood and adolescence , but the disease may persist into adulthood in more than half of patients .
amyloidosis may be present in a smaller number of patients in comparison with other maiss , estimated at around 3% of cases .
the possibility of macrophage activation syndrome during the course of an inflammatory attack has been observed in a patient with mkd .
a closely related disease is mevalonic aciduria ( omim 610.377 ) , which is due to a near - total inactivity of the enzyme mevalonate kinase : in this condition , recurrent fever episodes appear in association with serious systemic signs , such as delayed growth , cranial - facial dysmorphism , microcephalia , cerebellar atrophy , ataxia , psychomotor retardation , retinal dystrophy , and cataracts . in terms of laboratory findings
, mkd is invariably marked by leukocytosis and elevated phlogosis indicators during fever attacks , while many patients show increased serum igd concentration ( with levels above 100 iu / ml ) and , less frequently , serum iga between fever attacks .
urinary concentration of mevalonic acid may be increased during acute febrile flares and may thus sometimes be useful to the diagnosis [ 5 , 6 ] .
however , genetic testing to evaluate the mvk gene remains essential for a definite confirmation of mkd . in terms of therapy
, nsaids and corticosteroids may bring about partial relief of symptoms [ 109 , 110 ] .
statins , in particular , simvastatin , seem efficacious in reducing the duration of acute episodes .
the rationale behind their utilization is based on an attempt to reduce production of mevalonic acid by blocking the enzyme 3-hydroxy-3-methylglutaryl - coenzyme a reductase . in resistant cases ,
treatment with anti - il-1 [ 110 , 112 ] and anti - tnf [ 110 , 113 ] drugs has been proven to reduce both the frequency and the intensity of inflammatory attacks .
this is an autosomal dominant disease caused by mutations in the nlrp12 gene encoding for the protein nlrp12 ( or monarch-1 ) , which plays a crucial role in immune system mechanisms against pathogenic agents ( table 1 ) . as in the case of caps
, it can be induced by generalized exposure to cold and is characterized by recurrent fever episodes lasting for 510 days accompanied by skin rash , headache , lymphadenopathy , mouth ulcers , and abdominal pain .
treatment choice depends on the seriousness of the overall clinical picture and is based on the use of antihistamines , nsaids , and corticosteroids in less serious cases or the administration of anakinra in more serious ones [ 14 , 114 , 115 ] .
however , loss of efficacy of anakinra has been described in a few patients [ 14 , 116 ] , raising the possibility of using anti - tnf- and anti - il-6 agents .
granulomatous autoinflammatory diseases include blau syndrome ( bs , omim 186580 ) and early - onset sarcoidosis ( eos , omim 609464 ) ; both are caused by mutations in the nod2/card15 gene , with subsequent dysregulation of the inflammatory response and formation of noncaseous granulomas ( table 1 ) .
blau syndrome is an autosomal dominant granulomatous inflammatory disease caused by mutations in the region encoding for the nucleotide - binding domain region of the nod2/card15 gene ( table 1 ) [ 118 , 119 ] : the protein nod2 is mainly expressed in monocytes and plays a crucial role in the clearance of bacteria , particularly , mycobacterium tuberculosis , as it is capable of interacting with peptidoglycan and activating the nf-b signal route .
the most frequently observed mutations are missense substitutions involving arginine residue at position 334 within the nod2/card15 gene ( r334w or r334q ) [ 121 , 122 ] .
the onset is generally in childhood , around the age of 5 , and the disease affects joints , skin , and eyes : the most common manifestation is a symmetrical polyarthritis of hands , feet , wrists , elbows , and ankles , which can also lead to joint ankylosis [ 123 , 124 ] .
skin lesions may be in the form of dark red macular - papular - nodular rash or lichenoid - like lesions , which are generally symmetrical and appear on the trunk and/or limbs .
under histological examination , the skin lesions present noncaseous granulomas with gigantic multinuclear cells [ 123 , 124 ] .
eye involvement is the most serious complication of bs and is manifested in the form of recurrent bilateral anterior uveitis or bilateral granulomatous panuveitis , associated with eye pain , photophobia , and blurred vision .
ocular inflammation often leads to chorioretinitis , keratopathy , cataracts , glaucoma , or retinal detachment and may also involve other ocular structures such as conjunctiva , tear ducts , retina , and optic nerve .
additionally , bs has been described in association with persistent or intermittent fevers , granulomatous arteritis , cranial neuropathies , and hearing loss [ 123 , 124 ] .
the familial form of bs can be differentiated from eos , a multiorgan sporadic disease characterized by onset in the first 4 years of life , joint , skin , eye , lymph node involvement , and recurrent fevers , with possible abdominal or central nervous system involvement . from the histological point of view , the presence of noncaseous epithelioid granulomas is observed in the involved tissues .
pulmonary parenchyma , involved in more than 90% of patients with adult sarcoidosis , is usually spared in eos [ 125127 ] . in spite of the notable clinical similarities ,
later , genetic analyses demonstrated that many patients with eos also presented with mutations in the nod2/card15 gene .
for this reason , some authors have proposed that bs and eos are , respectively , familial and sporadic forms of the same disease .
sporadic bs in that they are carriers of mutations in the nod2/card15 gene and limiting diagnosis of eos to those pediatric patients with sarcoidosis but no mutations .
high doses of corticosteroids may be utilized with variable success [ 130 , 131 ] .
the use of anti - tnf- and anti - il-1 biological agents also seems encouraging [ 132134 ] .
the hereditary pyogenic disorders include papa ( pyogenic arthritis , pyoderma gangrenosum , and acne ) syndrome , majeed syndrome ( ms ) , and deficiency of the il-1 receptor antagonist ( dira ) : all of these disorders are characterized by the presence of sterile abscesses that mainly affect the skin , joints , and bones .
papa syndrome ( omim 604416 ) is an autosomal dominant disease caused by mutations in the pstpip1 gene encoding for cd2-binding protein-1 ( cd2bp1 ) , involved in the proper assembly of the cytoskeleton , which normally inhibits pyrin - mediated inflammatory signals and the activation of caspase-1 [ 135138 ] .
it appears in early childhood and is characterized by joint involvement , manifested with severe self - limiting pyogenic arthritis . in terms of skin involvement ,
the appearance of pyoderma gangrenosum and nodular - cystic acne is described in early childhood .
arthritic episodes usually respond readily to treatment with corticosteroids , while pyoderma gangrenosum is treated with topical immunosuppressant drugs [ 14 , 134 ] . in a few reports ,
patients with papa syndrome responded wonderfully to treatment with anti - tnf- and anti - il-1 agents [ 139141 ] .
majeed syndrome ( omim 609628 ) is a very rare autosomal recessive disease described for the first and only time in 1989 in two brothers and a cousin with childhood - onset recurrent chronic multifocal osteomyelitis and congenital dyserythropoietic anemia ; neutrophilic dermatosis was also reported in the two brothers .
the disease is caused by homozygous mutations in the lpin2 gene ( table 1 ) encoding for lipin 2 , the role of which has not yet been clarified .
clinically , this syndrome is characterized by recurrent fever attacks associated with multifocal sterile osteomyelitis , dyserythropoietic anemia , and chronic diffuse neutrophilic dermatosis with onset in early childhood .
its treatment is empirically based on the use of nsaids and corticosteroids , although excellent results have recently been described with administration of anakinra and canakinumab [ 144 , 145 ] .
dira ( omim 612852 ) is an autosomal recessive disease caused by missense mutations in the il1rn gene encoding for the il-1 receptor antagonist 1 ; there is a lack of endogenous self - regulation of il-1 activity , with consequent excessive proinflammatory action of il-1 itself ( table 1 ) .
disease onset is in the first weeks of life , and , in the initial phases , it may mimic neonatal sepsis , with multifocal osteomyelitis , periostitis , pustular skin lesions of various sizes , skin , ungueal alterations , hepatosplenomegaly , and the risk of multiorgan failure .
radiological findings may include signs of osteolytic lesions , bone sclerosis , enlargement of the epiphysis of the long bones , and periosteal reaction [ 147 , 148 ] .
due to the absence of endogenous il-1 receptor antagonist , treatment is based on the use of anakinra , bringing about an excellent clinical improvement in a few days or weeks .
thus , in conclusion , the elucidation of the molecular basis of maiss has helped us recognize the consequences of excessive il-1 signaling , proinflammatory isoprenoid production , or aberrant nk-b activation ( figure 1 ) .
future studies will hopefully also evaluate the clinical benefit of different highly selective biologicals for each of the maiss : the availability of these new therapeutic options for patients who have previously failed to respond to conventional treatments ( nsaids , corticosteroids , colchicines , or immunomodulating agents ) and the promise of patient - centered treatment strategies are doubtlessly the start of a new era in the management of these rare complex disorders .
Output:
| monogenic autoinflammatory syndromes ( maiss ) are caused by innate immune system dysregulation leading to aberrant inflammasome activation and episodes of fever and involvement of skin , serous membranes , eyes , joints , gastrointestinal tract , and nervous system , predominantly with a childhood onset .
to date , there are twelve known maiss : familial mediterranean fever , tumor necrosis factor receptor - associated periodic syndrome , familial cold urticaria syndrome , muckle - wells syndrome , cinca syndrome , mevalonate kinase deficiency , nlrp12-associated autoinflammatory disorder , blau syndrome , early - onset sarcoidosis , papa syndrome , majeed syndrome , and deficiency of the interleukin-1 receptor antagonist .
each of these conditions may manifest itself with more or less severe inflammatory symptoms of variable duration and frequency , associated with findings of increased inflammatory parameters in laboratory investigation .
the purpose of this paper is to describe the main genetic , clinical , and therapeutic aspects of maiss and their most recent classification with the ultimate goal of increasing awareness of autoinflammation among various internal medicine specialists . |
PubmedSumm119910 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: brain tumors located in the suprasellar region are frequently found in childhood , and
include craniopharyngioma , germinoma , optic nerve glioma and histiocytosis ( 1 ) . following the extension of the tumor or intervening
procedures , such as surgery , chemotherapy and radiation , considerable damage to the
hypothalamic pituitary axis is almost inevitable .
accordingly , most children with
suprasellar tumors suffer from endocrinological sequelae , even after the original lesion has
been cured ( 2 ) .
in addition , these children have been
shown to have a high risk of developing morbid obesity , which has recently been referred to
as hypothalamic obesity ( 3,4,5,6 ) . in this report
, we studied the prevalence of obesity among children with
suprasellar tumors who had been treated at our institute .
additionally , we evaluated
metabolic aberrations in these patients , and tried to correlate them with clinical features
and endocrinological alterations of the patients .
patients with remitted suprasellar tumors , who had been diagnosed and treated at our
institute and had attended our endocrinological unit more than once from april 2005 to april
2006 , were enrolled in this study . those with rathke s cleft cyst or hypophysitis were
excluded .
in addition , a 28-yr - old male with craniopharyngioma , who had been subjected to
long - term bed rest because of a serious neurological sequela , was also excluded . as depicted
in table 1table 1 profiles of 23 patients with remitted suprasellar tumors ,
a total of 23 patients ( 10 males and 13 females ) met the enrollment criteria ,
including 10 patients with craniopharyngioma ( 43% ) , 7 patients with germinoma ( 30% ) , 4 with
optic nerve glioma ( 17% ) , and single cases of infundibuloma and langerhans cell
histiocytosis .
the current ages of the patients were distributed from 3 to 22 yr old , the
median of which was 14 yr old .
all craniopharyngioma patients had near - total or total tumor
removal for the first line treatment , followed by additional radiotherapy or chemotherapy in
cases of incomplete resection or tumor recurrence .
some cases were forced to undergo
repetitive operations . in patients with germinoma and optic nerve glioma , radiotherapy and
chemotherapy were the mainstay of the treatment , following biopsy or partial resection .
one
case of germinoma with syncytiotrophoblastic giant cells underwent autologous peripheral
stem cell transplantation . with each patient ,
a retrospective review regarding the contents of therapies and the
extent of endocrinological dysfunction was carried out .
for the assessment of metabolic
alteration , the degree of overweight ( % -overweight ) was determined and body fat mass was
estimated for each patient .
the percent overweight was expressed as the quotient of the
excess weight to the ideal weight . in female patients
less than 15 yr of age and males less
than 18 , ideal weight was based on the auxological data from normal japanese children ( 7 ) . for the remaining patients , the weight compatible with
a body mass index of 22
body fat mass was measured by whole - body
bioelectrical impedance analysis ( tbf-310 , tanita corp .
in addition , blood
pressure , total cholesterol level , triglyceride ( tg ) level and the homeostatic model
assessment of insulin resistance ( homa - r : fasting iri ( u / ml ) fasting glucose ( mg / dl)/405 )
was determined .
the diagnosis of gh deficiency followed the consensus guideline of the growth hormone
research society ( 8) as well as the national
guidelines for the diagnosis of gh deficiency . in brief , the gh responses to exogenous gh
secretagogues less than 3 ng / ml indicated severe gh deficiency ( sghd ) whereas gh responses
between 36 ng / ml were considered to be moderate gh deficiency ( mghd ) .
obesity was defined according to the criteria made by national experts ( 9 ) as follows : more than 20% overweight and/or % -body fat
exceeding 25% in males , 30% in females younger than 11 yr , and 35% in females older than 11
yr .
hyperlipemia was defined as either an elevated fasting total cholesterol level above 220
mg / dl or fasting tg level above 140 mg / dl ( 10 ) .
presence of insulin resistance was suggested when homa - r exceeded 2.5 , according to the
guidelines from the japan diabetes society ( 11 ) .
statistical analysis was performed using ystat2000.xls . for the comparison among groups
according to tumor pathology , the yates -test and non - parametric statistical
methods ( kruskal wallis - h - test ) were applied because of the relatively small samples and
skewed distribution of the data . for the comparison between groups with or without gh
administration , the yates -test or fisher s test was applied as necessary .
table 2table 2 endocrinological status of 23 patients shows the endocrinological status of the patients at the time of study .
all
patients with craniopharyngioma suffered from panhypopituitarism with diabetes insipidus
except case 1 , in whom the tumor was identified by chance through evaluation for head
injury .
all patients with germinoma also had more than one defect of the pituitary
hormones .
on the other hand , none of the patients with optic nerve glioma showed adrenal
insufficiency or diabetes insipidus , but they had been treated for precocious puberty .
the
condition of so - called growth without gh , normal or accelerated linear growth despite gh
deficiency , was observed in 6 patients . of these
, 3 patients had chosen to take gh
supplementation , expecting the effect to improve their metabolic aspects . in table
3table 3 metabolic status of 23 patients , the results of investigation for the metabolic aspects of the patients are
summarized .
obesity , judged from either the % -overweight or % -body fat , was found in 12
out of 23 patients ( 7 males , 5 females ) .
fasting blood samples in the morning could be obtained in all but one
patient . in those samples ,
an elevated total cholesterol level ( > 220 mg / dl ) was
identified in 4 patients .
elevated tg ( > 140 mg / dl ) was found in 6 patients , including 2
patients ( cases 5 & 13 ) who exhibited strikingly elevated postprandial tg levels of
more than 1,200 mg / dl .
in addition , another patient ( case 16 ) also had postprandial
hypertriglyceridemia , as much as 1,029 mg / dl , despite a normal fasting tg level .
homa - r exceeding 2.5 was found in 7 patients ( 3
males , 4 females ) including one ( case 9 ) whose fasting glucose was 101 mg / dl . collectively , out of 23 patients , 16 patients had at least one metabolic aberration , such
as obesity , hyperlipemia and insulin resistance , which accounted for two thirds of all the
patients .
of these , obesity was most frequently found , and 9 out of 12 obese patients had
either accompanying hyperlipemia or insulin resistance . the relationship between obesity ,
hyperlipemia and insulin resistance
is summarized in table 4table 4 summary of the relationship between obesity , hyperlipemia and insulin
resistance ( n=22 ) , with categorization according to the tumor pathology . among the 3 major groups of tumor pathology ( craniopharyngioma , germinoma and optic nerve
glioma ) ,
the incidence of obesity was not significantly different : 60% craniopharyngioma ,
43% germinoma and 75% in optic nerve glioma ( p=0.90 ) .
in addition , the % -overweight in
each group did not differ significantly ( p=0.66 ) .
hyperlipemia was most frequently
observed in germinoma ( 71% ) , followed by craniopharyngioma ( 30% ) , and optic nerve glioma
( 0% ) .
this order was reversed in insulin resistance : optic nerve glioma 75% ,
craniopharyngioma 30% and germinoma 14% .
these differences showed no statistical
significance ( p=0.22 and p=0.38 , respectively ) . among the gh deficient patients , 11 patients were on gh replacement therapy ,
whereas 11
patients were not at the time of evaluation . in each group ,
likewise , the incidences of hyperlipemia and insulin
resistance were not significantly different ( 3/11 vs. 6/11 , p=0.39 ; 4/11 vs. 2/11 , p=0.64 ,
respectively ) .
these results did not change fundamentally , when 2 patients with previous
gh usage were added to the gh treatment group . the dose of supplemented hydrocortisone ( mg / m / day ) did not correlate with the
degree of overweight , as shown in the fig .
1 the relationship between supplemented hydrocortisone doses ( mg / m / day )
and the degree of overweight ( % ) in patients with acth deficiency .. the relationship between supplemented hydrocortisone doses ( mg / m / day )
and the degree of overweight ( % ) in patients with acth deficiency .
all 6 patients with growth without gh had at least one metabolic aberration : obesity in
4 , hyperlipemia in 5 and insulin resistance in 3 .
conversely , all 3 patients with combined
obesity , hyperlipemia and insulin resistance had accompanying growth without gh .
table 2table 2 endocrinological status of 23 patients shows the endocrinological status of the patients at the time of study .
all
patients with craniopharyngioma suffered from panhypopituitarism with diabetes insipidus
except case 1 , in whom the tumor was identified by chance through evaluation for head
injury .
all patients with germinoma also had more than one defect of the pituitary
hormones .
on the other hand , none of the patients with optic nerve glioma showed adrenal
insufficiency or diabetes insipidus , but they had been treated for precocious puberty .
the
condition of so - called growth without gh , normal or accelerated linear growth despite gh
deficiency , was observed in 6 patients . of these
, 3 patients had chosen to take gh
supplementation , expecting the effect to improve their metabolic aspects .
in table 3table 3 metabolic status of 23 patients , the results of investigation for the metabolic aspects of the patients are
summarized .
obesity , judged from either the % -overweight or % -body fat , was found in 12
out of 23 patients ( 7 males , 5 females ) .
no patients were hypertensive at the time of
investigation . fasting blood samples in the morning
an elevated total cholesterol level ( > 220 mg / dl ) was
identified in 4 patients .
elevated tg ( > 140 mg / dl ) was found in 6 patients , including 2
patients ( cases 5 & 13 ) who exhibited strikingly elevated postprandial tg levels of
more than 1,200 mg / dl .
in addition , another patient ( case 16 ) also had postprandial
hypertriglyceridemia , as much as 1,029 mg / dl , despite a normal fasting tg level .
homa - r exceeding 2.5 was found in 7 patients ( 3
males , 4 females ) including one ( case 9 ) whose fasting glucose was 101 mg / dl . collectively , out of 23 patients , 16 patients had at least one metabolic aberration , such
as obesity , hyperlipemia and insulin resistance , which accounted for two thirds of all the
patients .
of these , obesity was most frequently found , and 9 out of 12 obese patients had
either accompanying hyperlipemia or insulin resistance .
the relationship between obesity ,
hyperlipemia and insulin resistance is summarized in table 4table 4 summary of the relationship between obesity , hyperlipemia and insulin
resistance ( n=22 ) , with categorization according to the tumor pathology .
among the 3 major groups of tumor pathology ( craniopharyngioma , germinoma and optic nerve
glioma ) , the incidence of obesity was not significantly different : 60% craniopharyngioma ,
43% germinoma and 75% in optic nerve glioma ( p=0.90 ) .
in addition , the % -overweight in
each group did not differ significantly ( p=0.66 ) .
hyperlipemia was most frequently
observed in germinoma ( 71% ) , followed by craniopharyngioma ( 30% ) , and optic nerve glioma
( 0% ) .
this order was reversed in insulin resistance : optic nerve glioma 75% ,
craniopharyngioma 30% and germinoma 14% .
these differences showed no statistical
significance ( p=0.22 and p=0.38 , respectively ) . among the gh deficient patients , 11 patients were on gh replacement therapy ,
whereas 11
patients were not at the time of evaluation . in each group ,
likewise , the incidences of hyperlipemia and insulin
resistance were not significantly different ( 3/11 vs. 6/11 , p=0.39 ; 4/11 vs. 2/11 , p=0.64 ,
respectively ) .
these results did not change fundamentally , when 2 patients with previous
gh usage were added to the gh treatment group .
the dose of supplemented hydrocortisone ( mg / m / day ) did not correlate with the
degree of overweight , as shown in the fig .
1 the relationship between supplemented hydrocortisone doses ( mg / m / day )
and the degree of overweight ( % ) in patients with acth deficiency
.. the relationship between supplemented hydrocortisone doses ( mg / m / day )
and the degree of overweight ( % ) in patients with acth deficiency .
all 6 patients with growth without gh had at least one metabolic aberration : obesity in
4 , hyperlipemia in 5 and insulin resistance in 3 .
conversely , all 3 patients with combined
obesity , hyperlipemia and insulin resistance had accompanying growth without gh .
hypothalamic obesity refers to intractable weight gain following hypothalamic damage , which
has been described in both children and adults ( 3,4,5,6 ) .
this complication has been most
frequently observed after treatment for craniopharyngioma , accounting for 50 to 70% of
children with craniopharyngioma ( 4 , 6 ) .
dietary modification tends to fail , leaving these
patients at high risk of developing morbid obesity .
because obesity is a primary risk factor
for morbidity in the general population , hypothalamic obesity may be a serious complication
both in physical fitness and in psychological aspects .
excessive hunger due to a disturbed satiety center was once postulated ( 12 , 13 ) .
however ,
it was demonstrated that the energy intake in children with hypothalamic obesity is not
always increased ( 14 ) .
insulin hypersecretion from
pancreatic beta cells resulting from diminished vagal tone due to a damaged ventromedical
hypothalamus is a promising hypothesis ( 15 , 16 ) .
in addition , increased 11-beta - hydroxysteroid
dehydrogenase activity was demonstrated in hypothalamic obesity patients ( 17 ) , which may play an additional role in its
pathogenesis . in assessing obesity ,
three
patients ( case 8 , 14 , 19 ) showed adequate weight despite their increased % -body fat ,
highlighting the importance of measuring the fat mass in addition to anthropometric data .
it
may be more appropriate to evaluate the visceral fat mass directly by ct scan .
the incidence of obesity was as high as 52% , a figure that is in accordance with previous
reports ( 4 , 6 ) .
the identified risk factors for developing hypothalamic obesity include the presence of any
endocrinopathy , tumor infiltration into the hypothalamus , irradiation to the hypothalamus
greater than 51 gy , and a younger age at diagnosis ( 4 ,
18 ) . in our series ,
most of the craniopharyngiomas
extended to the hypothalamus , making post - surgical panhypopituitarism inevitable .
on the
other hand , many patients with germinoma or optic nerve glioma received high - dose
irradiation , which caused multiple pituitary hormone deficiency .
these factors may have
contributed to the high incidence of obesity in our series . of note ,
obese patients with
optic nerve glioma lacked diabetes insipidus , suggesting that the presence of diabetes
insipidus is not always necessary for the development of hypothalamic obesity .
gh supplementation , either previous or current , did not decrease the incidence of obesity .
this finding is in accordance with the report from the kigs database in which gh treatment
for 3 yr did not influence the body mass index of craniopharyngioma patients ( 19 ) .
the hydrocortisone dosage , given to patients with
acth deficiency , was merely physiological , and it showed no relationship with obesity .
these
findings imply that endocrinological management ( gh supplementation or hydrocortisone
reduction ) is not capable of ameliorating obesity .
about one third of the patients were estimated to have insulin resistance by homa - r .
visceral fat accumulation ( 6 ) and an elevated leptin
level ( 20 , 21 )
have been demonstrated in hypothalamic obesity , which elucidates the high prevalence of
insulin resistance in our series .
as mentioned above , insulin hypersecretion resulting from
hypothalamic damage was thought to be the main cause of hypothalamic obesity ( 16 ) .
however , it has not been clarified whether insulin
hypersecretion precedes and causes visceral fat accumulation or whether hypothalamic damage
directly increases the visceral fat mass . in any case , insulin secretion must be enhanced to
compensate for insulin resistance , which would further increases the visceral fat
accumulation .
therefore , once this cycle is established , progressive deterioration in
metabolism may be inevitable .
the effectiveness of somatostatin - analogue , which inhibits
insulin secretion , has been reported in the reduction of body weight in hypothalamic obesity
children ( 16 ) .
considering the prevalence of insulin
resistance , this agent seems promising in our series , especially those with high iri
levels .
hyperlipemia , either hypercholesterolemia or hypertriglyceridemia , was found in 9 patients
out of 21 tested . in particular , inordinately elevated postprandial tg was found in 3
patients .
the contribution of a genetic factor may be minimal in them , because preoperative
examinations showed normal tg levels , and neither of their parents had elevated tg levels .
reported that 6 craniopharyngioma patients had higher tg levels than the control obese group
( 6 ) . in their report
our finding underlines the importance of evaluating the lipid
metabolism in hypothalamic obesity , in particular a high tg level .
gh deficiency must be responsible , because untreated children ,
adolescents and adults with gh deficiency have been found to have elevated tg levels ( 22 ) .
however , gh deficiency alone seems insufficient to
elucidate the extremely elevated postprandial tg values .
effort should be focused on
delineating tg metabolism in hypothalamic obesity , unraveling the mechanism and establishing
a pertinent treatment . in our series , hyperlipemia was frequently found in germinoma
patients , while the incidence of insulin resistance was high in optic nerve glioma .
we could
not explain this difference , and it may be due to the small sample size .
another notable issue we found was that patients with growth without gh tended to have
profound metabolic alteration .
this condition has been encountered mainly in children
following surgery for suprasellar tumors ( 23 , 24 ) .
in addition , insulin hypersecretion has been
considered to be a major cause of growth without gh ( 24 ) .
thus , both hypothalamic obesity and growth without gh arise following the
hypothalamic damage , and both conditions are closely related to insulin metabolism .
we
showed that the patients with growth without gh had increased incidences of obesity ( 67% ) ,
hyperlipemia ( 83% ) and insulin resistance ( 50% ) , compared to the whole study group , and
patients presenting with growth without gh may be regarded as at particularly increased risk
for metabolic aberration .
it has been demonstrated that hyperinsulinemia is not always
present in growth without gh patients ( 6 ) , which was
also true in our series .
this finding indicates that some additional factor(s ) other than
insulin hypersecretion must be involved in the development of growth without gh .
this
unknown factor(s ) may provide the reason for the high prevalence of metabolic aberration in
growth without gh .
half of the patients with suprasellar tumors manifested obesity after the completion of
therapy , irrespective of its pathohistology and gh treatment .
a high incidence of insulin
resistance and/or hyperlipemia , including inordinately elevated postprandial tg , was also
found . in growth without gh cases ,
Output:
| weight gain is a common sequela of suprasellar tumors , referred to as hypothalamic
obesity .
we undertook an evaluation of obesity and metabolic aberrations among patients
treated at our institute . during the 12 mo from apr .
2005 , 23 patients ( 10 males and 13
females ) with remitted suprasellar tumors attended our clinic : 10 patients with
craniopharyngioma , 7 with germinoma , 4 with optic nerve glioma and others .
of these , 12
patients ( 52% ) were found to have obesity on the basis of percent overweight and/or
percent body fat .
elevated cholesterol and/or triglyceride ( tg ) was found in 9 patients
( 39% ) , and insulin resistance was suspected in 7 patients ( 30% ) .
three patients exhibited
strikingly elevated postprandial tg levels .
all 6 patients with the growth without gh
phenomenon had at least one metabolic aberration . in conclusion ,
the prevalence of
hypothalamic obesity was nearly half in our series , and hyperlipemia and insulin
resistance were also frequently found . the increased risk for metabolic aberration in
growth without gh patients was suggested . |
PubmedSumm119911 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: mechanical valve thrombosis ( mvt ) may cause valve dysfunction , and its onset may be acute or gradual , according to the nature of thrombi ( rapid or slow growth ) and involvement of hinge point ( abrupt or insidious ) .
edmunds defined mechanical valve thrombosis as a complication attributable to any type of thrombus , without evidence of infection , attached around a mechanical valve , deranging hemodynamics , or interfering with valvular function ( 1 ) .
the risk of valve thrombosis is highest in the tricuspid position , with reported rates as high as 20% ( 2 ) , while the incidence of left side valve thrombosis varies from 4% to 8.6% within 5 yr of initial valve replacement ( 3 , 4 ) .
eleven - year probability of prosthetic valve thrombosis has been reported to be 0.01% to 0.02% in the mitral or aortic position ( 5 ) , and tilting disc valves are most commonly reported in association with this complication ( 6 ) .
detection of valve thrombosis may be easy or difficult , and if valve thrombosis is suspected , transthoracic echocardiographic evaluation can be used to confirm the diagnosis ( 7 ) .
transesophageal echocardiographic examination is often necessary in the mitral position because of the thrombi involvement along the left atrial side of the sewing ring ( 8) .
several factors such as inadequate anticoagulation , drug interaction , pannus overgrowth , and pregnancy have been suggested to promote valve thrombosis ( 9 ) .
this analysis was undertaken to evaluate the risk factors and outcome of mechanical valve thrombosis in patients who had undergone valve replacement .
between january 1981 and march 2006 , 2,908 mechanical valve replacements were performed in 2,298 patients . among these
hospital records were reviewed retrospectively , including ; preoperative clinical findings , initial valve procedures and etiologies , any type of event during follow - up or anticoagulation , diagnostic methods and characteristics of valve thrombosis , perioperative management , and outcomes .
several factors were evaluated to identify risk factors of mvt development ; including sex , valve location , and number of valves replaced .
twenty patients presented with mvt , 6 ( 30% ) men and 14 ( 70% ) women .
valve replacement involved a single valve in 13 patients ( 65% ) , and double valve replacement was done in 7 patients ( 35% ) ( table 1 ) .
one patient had a history of cerebral embolism and another patient had a history of unilateral lower extremity edema . left atrial appendage resection was performed in 4 ( 20% ) , and the cox - maze procedure in 4 ( 20% ) .
the mean postoperative left ventricular ejection fraction was 579.3% , and the mean initial hospital stay was 16.96.7 days .
anticoagulation ( heparin and warfarin ) was started 24 to 48 hr after all valvular procedures .
patients were discharged with an international normalized ratio ( inr ) level of 2.0 to 2.5 for mitral and aortic valve replacement cases and of 2.5 to 3.0 for tricuspid valve replacement cases .
the mean age at mvt diagnosis was 42.014.0 ( 27 - 66 ) yr . the distribution of mvts according to the site of valve implantation was as follows : 14 ( 70% ) mitral , 3 ( 15% ) tricuspid , 2 ( 10% ) aortic , and 1 ( 5% ) tricuspid / aortic . among double - valve prosthesis recipients ( 7 ) , mvts were in a mitral prosthesis in 3 , an aortic prosthesis in 3 , and in a tricuspid prosthesis in 2
the mean time from first valve replacement to prosthetic valve thrombosis was 121.875.4 ( 0.9 - 284.7 , median 96.0)months .
the mean time between the diagnosis ofmvt and surgical treatment was 22.342.5 days ( range,0 - 180 days ) .
symptoms at presentation were dyspnea in 12 ( 60% ) patients , cardiogenic shock in 1 ( 5% ) patient , and miscellaneous symptoms ( myalgia , cough , or fever ) in 2 ( 10% ) patients ( table 2 ) . in five patients ,
the majority of patients ( 11 , 55% ) with mvt were of nyha functional class iii or iv at the time of diagnosis .
the mean duration between symptom onset and surgical treatment was 87.8121.7 days ( range , 0 - 365 days ) .
thromboembolism ( stroke , limb or organ ischemia ) occurred between initial valve replacement and valve thrombosis in 2 ( 10% ) patients .
mvt was diagnosed by transthoracic echocardiography ( tte ) in 13 ( 65% ) patients , and by transesophageal echocardiography ( tee ) in 7 ( 35% ) patients .
inr profiles when thrombosis was diagnosed were 1.660.64 ( 1.02 - 2.68 ) for left - sided valves and 1.420.53 ( 1.07 - 2.03 ) for tricuspid valves .
mvt occurred during pregnancy in 7 ( 35% ) patients , and of these , two patients had a history of denying warfarin for fear of possible embryopathy .
one patient experienced thrombosis at full term and underwent valve replacement , 2 days later she had a normal full term baby without any adverse event .
poor compliance with anticoagulant treatment leading to a lower inr than recommended was responsible for mvt in another 5 ( 25% ) patients . adding two patients with pregnancy , poor warfarin compliance was responsible for 7 patients ( 35% ) .
these patients skipped warfarin for no distinct reason , and their compliances with treatment and medication were poor . in 2 ( 10% )
patients mvt was thought to be related to a drug interaction , i.e. , one received medication for a common cold 1 week before thrombosis detection and the other patient had consumed nutritional supplements with or without medication .
one patient with a bjork - shiley convexo - concave tilting disc valve did not take any warfarin probably due to poor compliance .
he did not take medications for 285 months , and we could not follow him up .
he presented at out clinic due to cold sweating and dyspnea 3 weeks before a diagnosis of mvt .
pannus formation was present with thrombus at the time of operation in 45% ( 9/20 ) of the patients .
two ( 10% ) of the 20 received streptokinase - based thrombolytic therapy , but it was not successful .
one patient had acute mitral valve thrombosis , and due to hemodynamic instability , the patient received thrombolysis .
both were treated by surgical intervention and have been in good physical condition until now .
all patients underwent surgery under redomedian sternotomy , consisting of mitral valve replacement in 14 patients ( 70.0% ) , tricuspid valve replacement in 3 patients ( 15.0% ) , aortic valve replacement in 2 ( 10% ) , and tricuspid/ aortic valve replacement in one ( 5% ) .
thrombi were found around valve hinge points and sewing rings , and all valves concerned were replaced other than thrombectomy .
only one patient received a tissue valve ; she was 65 yr at the time of diagnosis , and she was non - compliant to warfarin with a frequent bleeding history .
the aortic cross clamping time averaged 104.942.8 min ( range , 52 - 191 min ) , and the cardiopulmonary bypass time was 164.662.7 min ( range , 79 - 286 min ) . emergent or urgent operation was done in 8 cases ( 40% ) due to heart failure and hemodynamic compromise .
early complications were atrial fibrillation ( 3 ) , bleeding ( 1 ) , vocal cord paralysis ( 1 ) , cerebral infarction ( 1 ) , atrioventricular conduction block ( 1 ) , and pneumonia ( 1 ) .
oral anticoagulation after surgical treatment consisted of warfarin alone in 16 ( 16/19 , 83% ) patients and a combination of warfarin and plavix in 3 ( 3/19 , 17% ) patients .
the mean hospital stay was 18.518.0 ( range , 8 - 89 ) days , and the mean intensive care unit stay was 3.32.4 days ( range , 1 - 9 ) days .
no late mortality or mvt recurrence occurred over 63.349.9 ( 0.5 - 165.1 ) months of mean follow - up .
our data show that mvt is a very rare complication after valve replacement and that its clinical manifestations are various .
the time between initial valve replacement and diagnosis of mvt was 121.875.4 months , and the median was 96.0 months . in most cases , thrombosis occurred insidiously ; only one patient presented with acute valve thrombosis one month after valve replacement .
( 10 ) reported 39 cases of prosthetic valve thrombosis with a 39.0 42.0-month mean interval of occurrence from initial operation and an in - hospital mortality of 41% .
the difference between our series and durrleman 's data might be due to different patient populations .
some patients might have been lost , and possible unknown sudden death can not be ruled out .
clinical course might depend on the type of replaced valves ; patients with bileaflet mechanical valves might have had stable hemodynamics due to a well - functioning single leaflet or have had unstable vital signs due to bileaflet involvement .
the fact is that the clinical manifestations of mvt are various . during follow - up , we usually suspect valve thrombosis in cases with valve click loss , skipped warfarin , newly appeared symptoms , and so on . in the present study ,
tte detected valve thrombosis in 75% of our series , and we found incidental valve thrombosis using this modality in five patients during routine echocardiographic follow - ups . in those cases , none had symptoms , and we could not follow with urgent operations .
detection of valve thrombosis may be difficult , and some series have reported that as many as 50% of cases are diagnosed postmortem ( 4 ) . in a recent study ,
the delay between first onset of symptoms and hospitalization was found ( from 1 to 45 days ) ( 11 ) .
previous studies have shown that a delay in diagnosis and a long duration of symptoms result in a higher mortality ( 12 ) .
however , physical examination is an inadequate diagnostic tool and strong clinical suspicion is the most important to detect these complications .
any new or worsening symptoms in a patient with mechanical valve warrant a thorough investigation to exclude valve thrombosis . in the present series ,
mvt was diagnosed by tte in 13 ( 65% ) patients and by transesophageal echocardiography in 7 ( 35% ) patients . during follow - up , we suggest a periodical echocardiographic examination . early detection and diagnosis may often be limited by a progressive or insidious course . the difference of valve thrombosis incidence and the pattern of onset between tilting disc and bileaflet valve is still uncertain .
another remarkable point of the present study is that pregnancy and inadequate anticoagulation influenced the occurrence of this complication .
buttard and colleagues ( 11 ) found inadequate anticoagulation at the time of diagnosis in 45% of their patients : 27% for medical reasons
( surgical intervention , neurologic events , or pregnancy ) and 17% because of poor drug compliance . a definite relationship has already been established between inadequate anticoagulation and valve thrombosis ( 11 - 14 ) .
anticoagulation during pregnancy is a difficult problem to solve , as pregnancy induces various biophysiologic changes and a hypercoagulable status .
the risk of warfarinization during pregnancy is teratogenicity , particularly between the 6th and 12th weeks of gestation ( 15 , 16 ) .
therefore , it is obvious and mandatory to use anticoagulation extremely carefully to prevent valve thrombosis or thromboembolism .
our data also demonstrate difficulties in maintaining adequate anticoagulation during pregnancy ; however , no safe and reliable protocol for anticoagulation therapy during pregnancy has been established ( 17 ) .
pannus formation , defined as excessive fibrosis around a prosthetic valve , may occur in 25% of patients as early as the first postoperative month ( 11 ) .
it plays an important role in the mechanism of obstruction and could be the sole cause of mechanical valve thrombosis occurrence ( 9 ) . in the present series , the precise role of pannus in the pathogenesis of valve thrombosis remains unknown .
however , whether it caused valve thrombosis or not was still uncertain , so we did not include it as a cause of valve thrombosis .
recently , roudaut et al . ( 18 ) conducted a retrospective study of 110 patients treated with fibrinolytic therapy and concluded that this treatment should be reserved for selected patients ( those with tricuspid thrombosis , critically ill patients , and patients with contraindications to surgical intervention ) .
thrombolysis appears to be useful as a medical bridge to operation and as a major curative modality when a patient 's medical condition or hemodynamics is poor . in the present series
the present study shows that pregnancy and inadequate anticoagulation probably influenced the occurrence of this rare complication .
however , our knowledge of mvt is still inadequate , and more efficient ways of eradicating this complication should be suggested .
Output:
| in the present study , the authors investigated the management of mechanical valve thrombosis ( mvt ) . from january 1981 through march 2006 , 2,908 mechanical valve replacements were performed in 2,298 patients at our institution . twenty ( 0.87% ) patients presented with mvt , 14 ( 70.0% ) were women , and the mean age of the patients was 42.014.0 ( 27 - 66 ) yr .
thrombosis involved mitral in 14 ( 70.0% ) , aortic in 2 ( 10.0% ) , tricuspid / aortic in 1 ( 5% ) , and tricuspid in 3 ( 15% ) .
the interval from first operation to valve thrombosis was 121.875.4 ( 0.9 - 284.7 ) months .
the most frequent clinical presentation was heart failure ( 13/20 , 65% ) , and predisposing causes of mvt were : poor compliance with warfarin ( 7 ) , pregnancy ( 5 ) , drug interaction ( 2 ) , and unknown ( 6 ) .
all 20 patients underwent valve replacement : mitral ( 14 , 70.0% ) , tricuspid ( 3 , 15.0% ) , aortic ( 2 , 10% ) and tricuspid / aortic ( 1 , 5% ) .
one early death occurred due to left ventricular failure , but no late mortality occurred during 63.349.9 ( 0.5 - 165.1 ) months of follow - up .
mvt was treated successfully , and pregnancy and inadequate anticoagulation were found to influence the occurrence of this rare complication . |
PubmedSumm119912 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: squamous cell carcinoma ( scc ) of the thyroid is an extremely rare disease accounting for less than 1% of all thyroid tumors . in the world health organization classification
, squamous cell carcinoma thyroid is defined as scc of the thyroid should be composed entirely of tumor cells with squamous differentiation . , , it is thought to arise from undifferentiated follicular cells , metaplastic follicular epithelium or remnant tissue of the thyroglossal duct .
primary scc of the thyroid affects older patients ( fifth to sixth decade of life ) with rapidly increasing thyroid mass with or without cervical lymphadenopathy .
other symptoms include dysphagia , dyspnea and hoarseness of voice due to infiltration of adjacent structures . at the time of diagnosis
, these tumors are usually locally advanced with invasion into trachea , esophagus or major vessels .
although the outcome is dismal , aggressive surgery along with adjuvant radiotherapy are recommended in the management of this rare and aggressive cancer for optimum outcome .
here , we are reporting such a rare case of scc of thyroid who has been treated with palliative radiotherapy .
a 70-year - old male patient noticed a rapidly increasing painless mass at the anterior aspect of the left side of neck for 1 month . it was also associated with dysphagia and stridor for 2 weeks .
he was a heavy smoker who used to smoke 1 pack of cigarettes / day .
there was no history of any previous radiation exposure in the neck . on physical examination ,
an 11 cm 7 cm firm lobulated mass was found in the left side of the anterior aspect of the neck .
contrast enhanced computed tomography scan showed evidence of well - defined large , lobulated heterogeneously enhancing solid cystic lesion measuring 11 cm 8.6 cm 7.4 cm in relation to the left lobe of thyroid gland .
the lesion showed multiple thin intervening septae along with few specks of calcification within it .
posteriorly lesion was extending up to the vertebral column and inferiorly retrosternally up to the brachiocephalic trunk .
mass effect of the lesion was seen in the form of compression and displacement of the trachea toward right and there was also compression and displacement of the left subclavian and carotid vessels , left internal jugular vein and left sternocleidomastoid [ figure 1 ] .
on positron emission tomography scan , a large multi lobulated heterogeneously enhancing solid - cystic mass ( 7.8 cm 7.7 cm 5.8 cm ) was seen in the left side of the neck arising from the left lobe of the thyroid gland with intense fluorodeoxyglucose ( fdg ) avidity ( standardized uptake value max 17.7 ) in the solid component and along the peripheral margin of the cystic component .
the mass was extending into the anterior mediastinum until the level of d4 vertebra and posteriorly until the prevertebral fascia .
it was seen to displace the trachea to the right and compressing it [ figure 2 ] .
contrast enhanced computed tomography scan showed evidence of well - defined large , lobulated heterogeneously enhancing solid cystic lesion measuring 11 cm 8.6 cm 7.4 cm in relation to the left lobe of thyroid gland .
the lesion showed multiple thin intervening septae along with few specks of calcification within it .
mass effect of the lesion was seen in the form of compression and displacement of the trachea toward right and there was also compression and displacement of the left subclavian and carotid vessels , left internal jugular vein and left sternocleidomastoid positron emission tomography scan revealed a large multi lobulated heterogeneously enhancing solid - cystic mass ( 7.8 cm 7.7 cm 5.8 cm ) was seen in the left side of the neck arising from the left lobe of the thyroid gland with intense fluorodeoxyglucose avidity ( standardized uptake value max 17.7 ) in the solid component and along the peripheral margin of the cystic component fine - needle aspiration cytology ( fnac ) revealed scattered malignant epithelial cells which showed moderate pleomorphism , high nuclear cytoplasmic ratio , hyperchromatic nuclei and mild to moderate cytoplasm .
aggressive treatment in the form of radical surgery was not possible in this particular patient because of its unresectability due to encasement of major vessels .
hence , we delivered palliative radiotherapy 30 gy in 10 fractions over 2 week 's period . though there was not much regression of the disease , but
his pain and shortness of breath was improved reasonably and patient is leading a good quality - of - life for last 1 year .
( a ) fine needle aspiration cytology smear shows scattered and cluster of tumor cells with moderately pleomorphic , hyperchromatic nuclei and inconspicuous nucleoli , moderate to abundant cytoplasm .
( b ) photomicrograph showing fiber cell with elongated cytoplasm and hyperchromatic nucleus , characteristic of squamous cell carcinoma
most of the cases were reported in elderly patients with the presence of local invasion at the time of presentation .
the overall prognosis of the tumor is poor with a survival rate of less than a year after the diagnosis .
, , the etiology of this condition is not clear , but hypothesis include the metaplasia theory
( squamous cells originating from remnant ultimobranchial duct or thyroglossal duct ) as a result of metaplasia of papillary or follicular cells of the thyroid or from the embryonic remnants with metaplasia of follicular epithelium ( thyroglobulin positive variety ) ( follicular variable )
. it may also arise as de novo appearance from the follicular cells without metaplasia ( thyroglobulin negative variety ) , which has a worse prognosis . , , fnac confirms the diagnosis of scc , but it is mandatory to exclude scc that has spread from adjacent upper aero digestive tract sites , as well as metastasis from distant sites , such as the lung , kidney or gastrointestinal tract .
the evaluation therefore usually involves a combination of endoscopy and radiographic examination by computed tomography to rule out the neighboring or metastatic carcinoma .
, in our patient , we could not perform biopsy because there was encasement of major vessels and the diagnosis was confirmed by fnac only .
we have excluded the possibility of the tumor arising from an adjacent structure such as the esophagus or representing a metastasis from a primary growth elsewhere , by different investigative procedures . in several reports based on small series of patients with scc of the thyroid ,
the recommended treatment was an early diagnosis and combining the best available therapeutic modalities with extensive surgery .
, however , the success rate of radical surgery was compromised by the invasive nature of the tumor and a poor definition of surgical treatment .
described optimal surgical therapy as hemithyroidectomy or total thyroidectomy , depending upon the multifocality , followed by radiotherapy .
the addition of post - operative radiotherapy could lead to improved loco - regional control . until date
simpson and carruthers noted no benefit in two patients treated with adriamycin nor in another treated with 5-fluorouracil and mitomycin , while shimaoka and tsukada failed to achieve a response in three patients treated with nitrogen mustard , vincristine and ab-132 , respectively .
cisplatin has been shown to have benefited patients suffering from other squamous cell cancers of the head and neck but , to date , no information is available on its use in scc of thyroid .
even after optimum treatment , this aggressive malignancy has very dire prognosis with dismal outcome . in this kind of deadly disease , where survival is not expected to be more than 1 year , quality - of - life is very important . in this particular situation , though we were not able to deliver optimum treatment to the patient , but we could achieve effective palliation with radiotherapy alone and gift patient a good quality - of - life .
Output:
| primary squamous cell carcinoma of the thyroid is an extremely rare neoplasm with aggressive behavior . until date , only around 60 cases have been reported in the literature .
primary treatment of the patient is radical surgery . with optimum treatment survival
is not more than 6 months in this aggressive malignancy .
however in our patient surgery it was not possible because of unresectability of the mass due to encroachment of major vessels .
hence , we have delivered radiotherapy alone , with which effective palliation could be achieved and patient is leading a good quality - of - life for last 1 year . |
PubmedSumm119913 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: although levodopa ( ld ) still remains the gold standard for symptomatic efficacy in reducing the motor symptoms of parkinson s disease ( pd),1 its long - term use is associated with the development of potentially disabling motor complications , including response oscillations as well as drug - induced dyskinesias ( ld - induced dyskinesias ) , affecting approximately 30% of patients after only 2 years of ld exposure.2 the precise underlying pathophysiology of ld - induced motor complications is still incompletely understood ; however , it is believed that pulsatile dopamine - receptor stimulation , leading to neuroplastic changes in the basal ganglia circuitry , plays a pivotal role.1,35 dopamine agonists ( das ) act directly on striatal dopamine receptors , with preferential effects on the d2 over d1 subfamily , and generally have considerably longer half - lives than ld ( table 1).6 while the first agents of this class were ergolinic compounds with affinities to multiple non - da - receptor types , the newer agents are nonergolinic and seem to lack the risk for cardiovalvular fibrosis , recently reported for ergolinic agonists,7 which have since been withdrawn from many markets . in clinical trials involving patients with early pd , initial monotherapy with das
was consistently associated with a significantly reduced risk of motor complications compared with ld , over double - blind follow - up periods of up to 5 years ( table 2),810 such that das are currently recommended as first - line therapies particularly for patients with younger age at onset.11,12 in addition , das are established first - line therapies to reduce motor fluctuations in ld - treated patients.11,12 both types of clinical benefit from das are likely to be related to their longer half - life , resulting in more continuous striatal da - receptor stimulation .
continuous 24-hour delivery with once - daily dosing has become possible with a transdermal formulation of the short half - life agonist rotigotine and , recently , novel extended - release ( er ) formulations have been developed for the nonergolinic oral compounds ropinirole and pramipexole .
the latter principle is likely to increase convenience and possibly adherence , particularly for patients with early disease that can be managed with monotherapy .
the aminobenzothiazole compound is highly selective for the d2 receptor family and , intragroup , has preferential affinity for the d3 receptor subtype.13 the agent lacks affinity for dopamine receptors d1 and d5 and displays only little affinity for d2 and d4 receptor subtypes.14 pramipexole er was designed as a prolonged - release tablet with pramipexole dihydrochloride monohydrate dispersed homogeneously throughout the matrix .
the active substance is released proportional to the square - root of time15 by two different mechanisms : diffusion and erosion,15 reaching its maximum plasma concentration ( cmax ) approximately 6 hours after oral administration ( immediate release [ ir ] : cmax 13 hours ) . in other respects
the pharmacokinetic profile mostly coincides with the well - known ir formulation . following oral administration
, the agent shows a bioavailability of > 90%.15 in fact , pharmacokinetic studies observed an increase in cmax with concomitant intake of a high - fat meal ( 24% after a single dose administration and about 20% after multiple dose administrations ) , but there was no significant change in overall area under the curve ( auc024 hours).15,16 protein binding is < 20% and the agent is metabolized only to a small extent and predominantly eliminated by renal excretion ( ~90% ) . with a renal clearance of approximately 400 ml/ min ,
the elimination half - life ( t ) varies from 8 hours in the young to 12 hours in the elderly .
pramipexole er is available in five dosage strengths ( 0.26 [ 0.375 ] mg , 0.52 [ 0.75 ] mg , 1.05 [ 1.5 ] mg , 2.1 mg , and 3.15 [ 4.5 ] mg [ all doses are expressed in terms of pramipexole base ; corresponding dose strengths of pramipexole salt are given in brackets ] ) and is approved for use in early pd as well as adjunct therapy in advanced pd with motor complications .
two large randomized double - blind placebo - controlled phase iii trials were conducted to evaluate the clinical efficacy of pramipexole er in early pd patients.17,18 these are summarized as follows .
two hundred and fifty - nine patients with early pd at hoehn and yahr stage 1 to 3 , diagnosed within the preceding 5 years , were randomized ( 2:2:1 ) to receive pramipexole er ( 0.263.15 [ 0.3754.5 ] mg qd ) , pramipexole ir ( 0.0881.1 [ 0.1251.5 ] mg tid ) , or placebo . following a 7-week - flexible up - titration phase , drug doses were maintained for an additional 26 weeks , during which , to maximize patient retention in the trial , open - label ld rescue medication was permitted for subjects experiencing insufficient control of parkinsonism .
post - ld - rescue data were censored for the primary analysis . at 18 weeks an interim analysis on a subset of 253 patients
was planned to evaluate superiority of efficacy of pramipexole er to placebo on the unified parkinson s disease rating scale ( updrs ) ii + iii ( primary endpoint).18 at 33 weeks , the study aimed to demonstrate noninferiority of pramipexole er to pramipexole ir in the combined score on updrs ii + iii ( primary endpoint).17 noninferiority was predefined as a treatment - group difference for which the lower bound of the 95% confidence interval ( ci ) did not exceed 3 points .
this margin had been chosen conservatively to be well outside the minimally clinically relevant difference on the updrs , which has been suggested to be 7 points for parts ii and iii combined.19 at 18 weeks , the adjusted mean change in updrs ii + iii combined scores , censoring post - ld - rescue data , was 7.4 ( 1.1 ) in the pramipexole er group , compared with 2.7 ( 1.3 ) in the placebo group ( p = 0.0010 vs placebo ) and 7.5 ( 1.1 ) in the pramipexole ir group ( p = 0.0006 vs placebo).18 including data from subjects receiving ld rescue medication , the adjusted mean change was 5.1 ( 1.3 ) for placebo , 8.1 ( 1.1 ) for pramipexole er ( p = 0.0282 vs placebo ) , and 8.4 ( 1.1 ) for pramipexole ir ( p = 0.0153 vs placebo).18 hence , using either approach , a statistically significant difference between pramipexole groups and placebo could be demonstrated from week 4 onward ( er p = 0.0111 , ir p = 0.0042 vs placebo at week 4 by either approach).18 at 33 weeks , updrs ii + iii change censoring post - ld - rescue data was 8.2 for er and 8.7 for ir .
the resultant treatment difference was 0.5 ( 95% ci : 2.3 to + 1.3 ) , thereby establishing noninferiority of the er formulation .
including ld - rescue data , the adjusted mean decrease was 8.5 versus 9.4 , revealing a difference of 0.9 ( 95% ci : 2.7 , + 0.9 ) , which is still well within the predefined margin.17 as already demonstrated at 18 weeks , the 33-week analysis confirmed the superiority of pramipexole er over placebo ( adjusted mean change in updrs ii + iii score : 8.2 er vs 1.2 placebo [ p < 0.0001]).17 consistent with the symptomatic efficacy of pramipexole , fewer patients on active treatment required ld - rescue medication ( 7.0% er , 4.3% ir , 21.4% placebo).17 superiority of both pramipexole formulations could also be shown for secondary outcome measures , including global impression of improvement responder rates ( 41.4% er , 45.1% ir vs 20.6% placebo [ p = 0.0003 and p < 0.0001 ] ) , patient global impression of improvement responder rates ( 34.4% er , 32.4% ir vs 16.5% placebo [ p = 0.0008 and p = 0.0020 ] ) , and updrs ii + iii responder rates ( 66.7% er , 63.8% ir vs 35.0% placebo [ p < 0.0001]).17 a summary of the primary and key secondary endpoints at week 33 is given in table 3 .
rascol et al conducted a randomized , double - blind , double - dummy , parallel - group study to assess efficacy , safety , and tolerability of an overnight switch from pramipexole ir to er in early pd patients.20 after a 24-week open - label run - in on pramipexole ir tid , 156 patients were switched overnight either to er or to ir at an unchanged daily dosage ( randomized 2:1 ) .
subjects were allowed a one - step dose adjustment as required for efficacy and/or tolerability 4 and 5 weeks after switching .
the primary efficacy endpoint was defined as the proportion of patients successfully switched ( with or without any dosage adjustment ) at the end of week 9 , determined as no worsening from baseline updrs ii + iii score > 15% and no withdrawal due to drug - related adverse events ( aes ) .
noninferiority was predefined as a 95% ci with a lower bound not exceeding 15% . at week 9 , 84.5% of patients in the er versus 94.2% in the ir group were considered successfully switched ( table 4 ) .
the absolute difference between groups was 9.76% ( 95% ci : 18.81% , + 1.66% ) , hence noninferiority of pramipexole er was not formally demonstrated . however , after 9 weeks , 80.6% of er and 84.6% of ir recipients were successfully switched without requiring any dose adjustments . in the er group , 16.5%
had increased and 2.9% had decreased their dosage , while corresponding percentages in the ir group were 13.5% versus 1.9% ( table 5 ) .
the between - group difference for increased versus unchanged / decreased dosage was not significant ( p = 0.6190 ) .
the mean pramipexole dosage at 9 weeks was 2.75 ( 0.95 ) mg / day ( + 0.12 mg / day from baseline ) in the er , compared with 2.83 ( 0.86 ) mg / day ( + 0.09 mg / day from baseline ) in the ir group .
pooled safety data of the clinical trials in early and advanced pd , comprising information from 803 pd patients exposed to clinically effective doses of pramipexole er , show a slightly higher rate of aes for both pramipexole ir and er compared with placebo .
however , no significant difference in ae profiles has been found between the two pramipexole formulations .
a summary of the most common side effects is given in table 6.15 safety evaluation of the 33-week trial in early pd17 also identified somnolence , gastrointestinal complaints , and dizziness as the most frequent aes . in this study , a small numerical increase in epworth sleepiness scale score was observed in both pramipexole groups but mean values remained below the cut - off for excessive daytime sleepiness ( 10 ) .
impulse control disorders were also slightly more common in both active treatment groups ( four patients in the er , three in the ir , and one in the placebo group ) . taken as a whole , pramipexole er showed the same safety and tolerability profile as pramipexole ir .
poor compliance has been identified as a major issue in several disease areas2124 including pd.25,26 the irregular intake of prescribed medication affects health care on many levels , including poor symptom control and reduced quality of life,27 distortion of treatment effectiveness28 as well as increased health care expenditure.29,30 the reasons for noncompliance are manifold and include fear of side effects , complex drug regimens incompatible with everyday life , and dementia . in one study ,
poorer compliance was identified to be more likely among younger patients and those with complex drug regimens , depression , and lower quality of life.26 grosset et al demonstrated an inverse correlation of compliance and drug doses per day in pd patients31 and showed that low therapy adherence was significantly associated with poor motor scores ( updrs ) , more days absent from work , and worse mobility ( pdq39).31 in this study , all measures of therapy adherence ( total number of days adherent , timing adherence , and total therapy adherence ) were significantly higher for once - daily medications , including das taken once versus three times daily.31 therefore , the availability of once - daily formulations of das with established efficacy in pd represents an advantage even if there is no added benefit of enhanced clinical efficacy or safety .
in addition , from the patient perspective there is the obvious advantage in terms of convenience and ease of use , particularly in early disease where monotherapy with a single dose per day is possible . due to blinding purposes ,
the possible beneficial effects of a once - daily formulation on convenience and adherence have not been possible to assess in the phase iii trials.17,18,20,32 er formulations of a long - acting da such as pramipexole may also contribute to improved symptom control during the night , although this has not been formally studied to date and is more relevant to advanced rather than early pd . furthermore , there is a possibility that the pharmacokinetic profile of a slow - release formulation may reduce the risk of peripheral dopaminergic side effects such as nausea and vomiting as well as central adverse reactions , including somnolence and daytime sleepiness , by avoiding rapid plasma level increases and high peak concentrations as compared with their ir counterparts .
this has , however , not been demonstrated in the pivotal clinical trials with pramipexole er .
pramipexole is widely established as a symptomatic treatment in early as well as advanced pd .
the development of an er formulation , with stable pramipexole plasma concentration over 24 hours , now offers a bioequivalent once - daily alternative .
double - blind randomized controlled trials in early as well as advanced pd have established the noninferiority of pramipexole er compared with ir as well as the superiority of both formulations over placebo . the overnight switch from the standard to the once - daily formulation
was shown to be successful in > 80% of patients without requiring any dose adjustments .
potential benefits of prolonged - release once - daily da formulations include improved compliance and a potential for better symptomatic control over the day as well as during the night .
however , the latter , along with reduced risk of dopaminergic side effects , has not been formally demonstrated in the pivotal trial program . from a patient perspective
there is little doubt that once - daily drugs offer major advantages in terms of convenience , especially for initial monotherapy in early pd .
Output:
| the aim of this article is to provide a short review of the most relevant pharmacological and clinical data on pramipexole extended release ( er ) as well as to address the clinical utility and potential advantages of a once - daily formulation especially in the treatment of early parkinson s disease ( pd ) .
pramipexole is widely established as a symptomatic treatment in early as well as advanced pd .
the development of an er formulation , with stable pramipexole plasma concentration over 24 hours , now offers a bioequivalent once - daily alternative .
double - blind randomized controlled trials in early and advanced pd , have established noninferiority of pramipexole er compared with immediate release as well as superiority of both formulations over placebo . the overnight switch from the standard to the once - daily formulation
was shown to be successful in > 80% of patients without requiring any dose adjustments .
potential benefits of the prolonged - release design , which have not yet been formally demonstrated in the pivotal trial program , include improved compliance and a potential for better symptomatic control , particularly in patients with early disease that can be managed with monotherapy . |
PubmedSumm119914 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: glutaric aciduria type i is caused by deficiency of the enzyme glutaryl coa - dehydrogenase ( gcdh ) in the metabolic pathway of lysine , hydroxylysine , and tryptophan , leading to an accumulation of glutaric acid ( ga ) and its derivative 3-hydroxy glutaric acid ( 3ohga ) ( funk et al . 2005 ; harting et al .
2-hydoxyglutaric ( 2ohga ) acidurias are characterized by the presence of elevated concentrations of either l-2ohga or its enantiomer d-2ohga and of -ketoglutarate ( kg ) in body fluids ( read et al .
2007 ) . whereas l-2ohga aciduria is caused by mutations of the fad - dependent l-2ohga dehydrogenase ( rzem et al . 2004 ) , the underlying metabolic defects of d-2ohga aciduria are due to mutations of the enzyme d-2-hydroxyglutarate dehydrogenase ( struys et al . 2005 ) .
we have recently identified the sodium - dependent dicarboxylate transporter 3 ( nadc3 ) and the organic anion transporter 1 ( oat1 ) to be responsible for the uptake of ga and its derivatives from the blood into renal proximal tubular cells ( hagos et al .
whereas oat1 is involved in the efflux of various neurotransmitter metabolites from the cerebrospinal fluid to the blood across the choroid plexus ( alebouyeh et al .
2006 ) and possibly the choroid plexus ( pajor et al . 2001 ) . besides nadc3 ,
another electrogenic sodium - dependent di- or tricarboxylate transporter , hnact , has been identified in the brain .
nact is preferentially located in neurons , especially in the hippocampus , cerebellum , cerebral cortex and olfactory bulb ( inoue et al .
since neuropathological findings observed in patients suffering from glutaric aciduria type 1 as well as from d- and l-2ohga aciduria occur in neurons , we investigated the impact of ga derivatives on hnact expressed in xenopus laevis oocytes .
in vitro transcription of hnact- and hnadc3-crna capped crna from the human nact ( genbank accession no .
plasmids were linearized with not i and in vitro crna transcription was performed using the t7 mmessage mmaschine kit ( ambion , austin , tx , usa ) according to the manufactor s instructions .
the resulting crna was suspended in purified , rnase - free water to a final concentration of 1 g/l .
solutions a standard oocyte ringer solution ( ori ) was used for oocyte preparation , storage , and for the uptake as well as for the electrophysiologic measurements .
ori contained ( in mm ) : 110 nacl , 3 kcl , 2 cacl2 , 5 hepes / tris , adjusted to ph 7.5 .
citrate , succinate , glutarate ( ga ) , its derivatives , 3-hydroxyglutarate ( 3ohga ) , d- ( d-2ohga ) , and l-2-hydroxyglutarate ( l-2ohga ) , and glutamate were added to ori in the concentrations indicated in the figure legends and ph was adjusted to 7.5 .
all chemicals , including those for ori , for oocyte preparation and storage , as well as for the uptake and electrophysiologic experiments were purchased from sigma - aldrich ( taufkirchen , germany ) .
3ohga was obtained from c. mhlhausen ( uke , hamburg , germany ) . oocyte preparation and storage stage v and vi oocytes from xenopus laevis ( nasco , fort atkinson , wi , usa ) were separated by an overnight treatment with collagenase ( typ cls ii ; biochrom , berlin , germany ) , subsequent washings in calcium - free ori and maintained at 1618c in ori containing a calcium concentration of 2 mm .
one day after removal from the frog , oocytes were injected with 23 nl crna coding either for hnact or hnadc3 , or an equivalent amount of water ( mocks ) and maintained at 1618c in ori supplemented with 50 m gentamycin and 2.5 mm sodium pyruvate .
after 34 days of incubation with daily medium changes , oocytes were used for tracer uptake studies .
transport experiments uptake of [ c]citrate ( ccitric acid ; ge health care , freiburg , germany ) or [ c]glutarate ( cglutaric acid ; mp biomedicals , heidelberg , germany ) in hnact- or of [ c]succinate ( csuccinic acid ; perkin elmer , rodgau , germany ) in hnadc3-expressing oocytes was assayed at room temperature .
inhibition of citrate uptake was determined by simultaneous application of 12 m c - citrate and ori containing 1 mm of ga , 3ohga , d- or l-2ohga , respectively , for 30 min .
c - glutarate was used at a concentration of 20 m . inhibition of succinate uptake was determined by simultaneous application of 18 m c - succinate plus 40 m sodium succinate and ori containing 1 mm glutamate .
after incubation in the respective solutions , radioactivity was aspirated and the oocytes were washed twice in ice - cold ori .
oocytes were dissolved by gently shaking for 2 h in 100 l 1 n naoh , neutralized with 100 l 1 n hcl , and their c - contents were determined by liquid scintillation counting ( tricarb 2900tr ; perkin elmer ) .
inhibition experiments were performed at least in duplicate with 810 oocytes for each experimental condition .
electrophysiologic analysis these studies were carried out 34 days after crna injection at room temperature .
oocytes were placed into a 0.5-ml chamber on the stage of a microscope and impaled under direct view with borosilicate glass microelectrodes filled with 3 m kcl ( biomedical instruments , zllnitz , germany ) .
current - voltage ( i - v ) recordings were performed using a two - electrode voltage clamp device ( oc725a ; warner , hambden , ct , usa ) in the voltage clamp mode .
substrate - associated currents were obtained by subtraction of the currents in the presence from those in the absence of the substrate of interest .
paired student s t test was used to show statistically significant difference of citrate uptake in the absence and presence of the ga derivatives or of succinate uptake in the absence and presence of glutamate .
michaelis - menten constants ( km ) for 3ohga , d- and l-2ohga were determined by sigmaplot software ( systat software , point richmond , ca , usa ) using the michaelis - menten equation i = imax [ s]/(km + [ s ] ) , where i is the current , imax is the maximum current observed at saturating substrate concentrations , km is the substrate concentration at half - maximal current , and s is the substrate concentration .
in hnact - expressing oocytes ( 5 oocytes from 4 donors ) , application of 1 mm citrate led to potential - dependent inward currents showing larger current amplitudes at 90 mv than at more depolarizing potentials ( fig .
the inward currents were abolished upon substitution of all sodium by n - methyl - d - glucamine ( data not shown ) .
in contrast to citrate , the ga derivatives 3ohga , d-2ohga , l-2ohga , and ga itself , did not evoke any potential - dependent inward currents .
the individual currents induced by these compounds were similar in hnact - expressing oocytes ( fig .
did not change this result ( data not shown ) , indicating that ga and ga derivatives are either not transported by hnact or transport is electroneutral . to discriminate between these possibilities , the uptake of [ c]citrate was compared to the uptake of [ c]glutarate within 30 min in the same batch of hnact - expressing oocytes ( fig .
1c ) . whereas citrate uptake increased by a factor of 3.76 0.63 ( three independent experiments ) as compared to mocks , the uptake of ga in hnact - expressing oocytes and in mocks was virtually identical .
current - voltage ( i - v ) relations of substrate - associated currents in hnact - expressing oocytes are shown in ( a ) , ( c ) and mocks ( b ) .
oocytes were superfused first with ori and subsequently with ori to which 1 mm of the respective ga derivative was added .
subtraction of the currents obtained in the presence from those in the absence of the respective substrate revealed the substrate - associated currents , i .
oocytes were first tested for the current induced by the prototypical substrate , citrate , to test for successful expression and only oocytes showing citrate - associated currents > 20 na at 90 mv were used in this study . afterwards ,
3ohga , d- , l-2ohga , kg , and ga were applied at random order .
a , b means sem of 5 oocytes from 4 donors and of 3 oocytes from 3 donors , respectively .
c comparison of the uptake of labeled citrate and glutarate in the same batch of oocytes . whereas the hnact - expressing oocytes ( 3 independent experiments with 10 oocytes for each experimental condition ) took up citrate ( 12 m ) ,
current - voltage ( i - v ) relations of substrate - associated currents in hnact - expressing oocytes are shown in ( a ) , ( c ) and mocks ( b ) .
oocytes were superfused first with ori and subsequently with ori to which 1 mm of the respective ga derivative was added .
subtraction of the currents obtained in the presence from those in the absence of the respective substrate revealed the substrate - associated currents , i .
oocytes were first tested for the current induced by the prototypical substrate , citrate , to test for successful expression and only oocytes showing citrate - associated currents > 20 na at 90 mv were used in this study . afterwards ,
3ohga , d- , l-2ohga , kg , and ga were applied at random order .
a , b means sem of 5 oocytes from 4 donors and of 3 oocytes from 3 donors , respectively .
c comparison of the uptake of labeled citrate and glutarate in the same batch of oocytes . whereas the hnact - expressing oocytes ( 3 independent experiments with 10 oocytes for each experimental condition ) took up citrate ( 12 m ) ,
no uptake of glutarate ( 20 m ) was observed . in hnadc3-expressing oocytes ( 4 oocytes from four donors ) , succinate ( 1 mm ) evoked substrate - dependent inward currents at all potentials tested ( fig . 2a , closed circles ) .
subsequent application of glutamate ( 1 mm ) did not give rise to such currents ( fig . 2a , open circles ) .
neither succinate- nor glutamate - associated currents were observed in mocks ( data not shown ) .
in addition , succinate uptake was only marginally inhibited by 1 mm glutamate during an incubation time of 15 min ( fig .
2effect of succinate and glutamate on hnadc3 . a current - voltage ( i - v ) relations as a function of membrane potential ( vc ) in hnadc3-expressing oocytes were obtained by substraction of the currents in the presence of 1 mm succinate in ori ( ) or of 1 mm glutamate ( ) in ori from those measured in ori alone .
data present mean values sem of 4 oocytes from 4 donors . b succinate uptake in the absence and presence of 1 mm glutamate in hnadc3-expressing oocytes ( black columns ) and mocks ( grey columns ) as obtained in two independent experiments with 810 oocytes for each experimental condition .
effect of succinate and glutamate on hnadc3 . a current - voltage ( i - v ) relations as a function of membrane potential ( vc ) in hnadc3-expressing oocytes were obtained by substraction of the currents in the presence of 1 mm succinate in ori ( ) or of 1 mm glutamate ( ) in ori from those measured in ori alone .
b succinate uptake in the absence and presence of 1 mm glutamate in hnadc3-expressing oocytes ( black columns ) and mocks ( grey columns ) as obtained in two independent experiments with 810 oocytes for each experimental condition . uptake of succinate in the absence and presence of glutamate was not significantly different . at 60 mv ,
hnadc3 mediates translocation of 3ohga , d- , and l-2ohga with low affinity ( hagos et al .
these kinetic measurements were now extended to a broader potential range ( 90 to 0 mv ) , because , in the disease , astrocytes might have lower membrane potentials and the transporter may change its affinity to the ga derivatives . at all potentials
tested , the km for 3ohga was larger than the km for d- and l-2ohga . whereas the km values for d- and l-2ohga were similar and decreased with depolarizing membrane potential , the km for 3ohga increased at depolarization ( fig .
the largest current amplitudes were observed for d-2ohga ( 3 oocytes from 3 donors ) ; the amplitudes measured for 3ohga ( 7 oocytes from 3 donors ) and l-2ohga ( 6 oocytes from 5 donors ) were similar in magnitude at all potentials tested ( fig .
3michaelis - menten constants ( km ( mm ) ) ( a ) and maximal substrate - inducible currents ( imax ( na ) ) ( b ) of the ga derivatives as a function of membrane potential ( vc ) .
hnadc3-expressing oocytes were subsequently superfused with increasing substrate concentrations of 3ohga : 0.1 , 0.2 , 0.5 , 1 , 2 , and 5 mm ; d- and l-2ohga : 0.01 , 0.05 , 0.1 , 0.5 , and 1 mm in ori at ph 7.5 .
data were obtained at the end of a 10-s perfusion with the respective solution at the indicated vc and were calculated from 7 oocytes of 3 donors for 3ohga , for d-2ohga from 3 oocytes from 3 donors , and for l-2ohga from 5 oocytes from 4 donors .
michaelis - menten constants ( km ( mm ) ) ( a ) and maximal substrate - inducible currents ( imax ( na ) ) ( b ) of the ga derivatives as a function of membrane potential ( vc ) .
hnadc3-expressing oocytes were subsequently superfused with increasing substrate concentrations of 3ohga : 0.1 , 0.2 , 0.5 , 1 , 2 , and 5 mm ; d- and l-2ohga : 0.01 , 0.05 , 0.1 , 0.5 , and 1 mm in ori at ph 7.5 .
data were obtained at the end of a 10-s perfusion with the respective solution at the indicated vc and were calculated from 7 oocytes of 3 donors for 3ohga , for d-2ohga from 3 oocytes from 3 donors , and for l-2ohga from 5 oocytes from 4 donors .
to date , the brain is the only mammalian tissue from which nact has been cloned ( inoue et al .
subsequent studies have shown that its expression is restricted to neurons ( wada et al .
therefore , we reasoned that hnact might be able to accept ga derivatives which were suggested to induce the neuronal damage observed in patients suffering from glutaric aciduria type 1 and d , l - hydroxyglutaric aciduria .
however , these compounds neither induced substrate - associated currents nor did they inhibit the uptake of citrate , the prototypical substrate of hnact , in hnact - expressing oocytes .
in addition , we found no interaction of hnact with kg , a compound recently described to be taken up by neurons ( shank and bennett 1993 ) .
consequently , uptake of the ga derivatives into neurons by nact is not the cause of the observed neurodegeneration . particularly for glutaric aciduria type 1
, it is suggested that glutaryl - coa , ga , and 3ohga accumulating in the synaptic cleft is involved in the pathogenesis of the disease ( klker et al .
because these compounds do not readily cross the blood - brain barrier , they accumulate within the brain ( klker et al .
2004 ; wajner et al . 2004 ; gerstner et al . 2005 ; sauer et al . 2006 ) , where they may inhibit the delivery of neurometabolic precursors .
due to the absence of pyruvate carboxylase ( cesar and hamprecht 1995 ; hassel 2001 ) , neurons lack the capacity to perform de novo synthesis of tricarboxylic cycle constitutents ( tca ) and therefore depend on extracellular sources of tca intermediates to replenish intracellular pools of neurotransmitters , such as glutamate and -aminoisobutyrate ( gaba ) .
astrocytes , which in contrast to neurons , express pyruvate carboxylase ( shank et al . 1985 ) , play a major role in feeding tca constituents to the neurons . since nact is localized in neurons , we assumed that nact is responsible not only for the uptake of citrate but also for the uptake of other tri- and dicarboxylic acid derivatives into neurons .
this , however , was not the case : ga and kg were not accepted by nact .
the synaptic action of glutamate is terminated by its uptake into astrocytes and or into presynaptic neurons .
uptake of glutamate into astrocytes occurs by distinct excitatory amino acid transporters ( eaats ) and possibly by low affinity sodium - dependent transport systems ( danboldt 2001 ; holten et al .
one such candidate transporter may be nadc3 , recently localized to astrocytes ( yodoya et al .
however , glutamate neither induced inward currents nor inhibited succinate uptake in hnadc3-expressing oocytes , and 1 mm glutamate reduced succinate uptake only by 19.9 8.5 % ( n.s . ) . therefore , hnadc3 can be excluded as a transporter facilitating glutamate uptake into astrocytes as opposed to recent speculation ( frizzo et al .
2008 ) . at 60 mv , hnadc3 carries kg and ga with high and the other ga derivatives with moderate affinity ( hagos et al . 2008 ) .
in the present study , we found that the affinities for d- and l-2ohga increased whereas that of 3ohga decreased at depolarized potentials . besides km
the different ga derivatives also differ in their imax being largest for d-2ohga , indicating that d-2ohga can be taken up into astrocytes at high rates and may interfere with the uptake of kg which is needed by astrocytes for the synthesis of glutamine ( peng et al .
although our findings did not elucidate the mechanisms by which the ga derivatives induce the neuronal damage observed in the affected patients , we can definitely exclude nact as a transporter facilitating the uptake of d- and l-2ohga as well as 3ohga into neurons .
the impaired uptake of kg due to the efficient interactions of d- and l-2ohga with nadc3 could interfere with the astrocytes ability to produce tca derivatives and to feed neurons with these compounds needed for synthesis of neurotransmitters . as , during brain development , energy requirements are increasing ( harting et al . 2009 ) , the metabolic support of astrocytes may be limited due to accumulating ga derivatives in the synaptic cleft .
this in turn may induce the observed neuronal damage due to shortage of fuels when the brain is in a most vulnerable phase as recently discussed by strauss et al .
Output:
| concentrations of glutarate ( ga ) and its derivatives such as 3-hydroxyglutarate ( 3ohga ) , d- ( d-2ohga ) and l-2-hydroxyglutarate ( l-2ohga ) are increased in plasma , cerebrospinal fluid ( csf ) and urine of patients suffering from different forms of organic acidurias .
it has been proposed that these derivatives cause neuronal damage in these patients , leading to dystonic and dyskinetic movement disorders .
we have recently shown that these compounds are eliminated by the kidneys via the human organic anion transporters , oat1 and oat4 , and the sodium - dependent dicarboxylate transporter 3 , nadc3 . in neurons ,
where most of the damage occurs , a sodium - dependent citrate transporter , nact , has been identified .
therefore , we investigated the impact of ga derivatives on hnact by two - electrode voltage clamp and tracer uptake studies .
none of these compounds induced substrate - associated currents in hnact - expressing xenopus laevis oocytes nor did ga derivatives inhibit the uptake of citrate , the prototypical substrate of hnact .
in contrast , d- and l-2ohga , but not 3ohga , showed affinities to nadc3 , indicating that d- and l-2ohga impair the uptake of dicarboxylates into astrocytes thereby possibly interfering with their feeding of tricarboxylic acid cycle intermediates to neurons . |
PubmedSumm119915 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: fibromyalgia is a chronic pain syndrome of unknown origin , estimated to affect 25% in all populations studied ( raspe , 1992 ; wolfe et al . , 1995 ;
fibromyalgia is characterized by widespread pain , fatigue , poor sleep , and dyscognition ( wolfe et al . , 2010 ) and is often also associated with mood disorders such as depressive episodes and anxiety .
although the underlying pathophysiology is not entirely understood , fibromyalgia has been associated with augmented central nervous system ( cns ) processing of nociceptive stimuli using both quantitative sensory testing ( qst ) and functional neuroimaging .
( gracely et al . , 2002 ; desmeules et al . , 2003 ; petzke et al . , 2003 ; smith et al . ,
context the notion of dysfunctional endogenous pain inhibition has been proposed to play a pivotal role in the genesis of chronic widespread pain .
this is supported by studies demonstrating impaired or absent conditioned pain modulation ( cpm ) in these patients ( lautenbacher and rollman , 1997 ; vierck et al . , 2001 ; julien et al . , 2005 ; chalaye et al . ,
functional ( gracely et al . , 2002 ; giesecke et al . , 2004 ; jensen et al . ,
2012 ) and structural ( kuchinad et al . , 2007 ; schmidt - wilcke et al . , 2007 ;
2013 ) brain imaging studies have shed some light on possible central mechanisms that might play a role in the genesis of chronic pain in fibromyalgia .
one such approach is the investigation of fluctuations in blood oxygenation level dependent ( bold ) signals at rest , termed resting state functional connectivity ( rs - fc ) .
only recently have changes in rs - fc been demonstrated in fibromyalgia , such as a hyper - connectivity between the default mode network ( dmn ) , a constellation of brain regions involved in self - referential thought , and the insular cortex ( ic ) , a brain region known to play a pivotal role in pain perception ( napadow et al . , 2010 ) .
interestingly this hyper - connectivity may be a marker for chronic pain intensity as two independent trials have shown that decreases in connectivity between the dmn and ic following treatment were associated with reductions in clinical pain ( napadow et al . , 2012 ; harris et al . , 2013 ) .
treatment of fibromyalgia in terms of a clinically relevant reduction in widespread pain is often challenging and both pharmacological and non - pharmacological approaches ( bernardy et al . , 2013 ) .
food and drug administration for the treatment of pain in fibromyalgia : pregabalin , a compound that binds to the 2 subunit of a voltage dependent presynaptic calcium channel , and two selective serotonin ( 5-ht ) and norepinephrine ( ne ) reuptake inhibitors , milnacipran ( mln ) and duloxetine ( goldenberg et al . , 2010 ; schmidt - wilcke and clauw , 2010 ; schmidt - wilcke and clauw , 2011 ) .
other drugs , such as tricyclic compounds ( tca , e.g. amitryptiline ) , viewed as non - selective 5-ht and ne reuptake inhibitors , have also repeatedly been shown to be efficacious in the treatment of fibromyalgia and are frequently used in pharmacological treatment regimens .
the way 5-ht and ne reuptake inhibitors act to reduce pain is still a matter of debate as spinal , subcortical , and cortical mechanisms have all been proposed .
however the overall effect of any of these individual treatments has been modest ( huser et al . , 2013 ) .
moreover a key limitation in the treatment of fibromyalgia , and chronic pain in general , is that there are no reliable tools to guide treatment assignment for individual patients . as such
recently our group has shown that chemical and functional imaging in fibromyalgia can be used to predict treatment response to pregabalin in fibromyalgia ( harris et al . , 2013 ) .
here we sought to identify rs - fc patterns that might predict treatment response in fibromyalgia to the selective 5-ht and ne reuptake inhibitor mln .
since preclinical studies have indicated that dual reuptake inhibitors are thought to have a favorable effect on endogenous pain inhibition which is believed to be dysfunctional in fibromyalgia ( lautenbacher and rollman , 1997 ; julien et al . , 2005 )
, we specifically focused on rs - fc to brain regions involved in antinociception and pain modulation such as : the periaqueductal gray ( pag ) , the rostral part of the anterior cingulate cortex ( acc ) , the dorsolateral prefrontal cortex ( dlpfc ) and the amygdala .
inclusion criteria were : ( 1 ) meeting 1990 american college of rheumatology criteria for fm with chronic widespread pain for at least 6 months ; ( 2 ) 1870 years of age ; ( 3 ) non - lactating and non - pregnant ; ( 4 ) right handed ; ( 5 ) score between 40 and 90 mm ( inclusive ) on a 100 mm pain visual analogue scale ( vas ) ; ( 6 ) willing to withdraw from cns - active therapies marketed as antidepressants ( monoamine oxidase inhibitors , tricyclics , tetracyclics , selective serotonin reuptake inhibitors , norepinephrine reuptake inhibitors , and snris ) ; ( 7 ) willing to withdraw from stimulant medications such as those used to treat attention deficit disorder and attention deficit hyperactivity disorder ( e.g. mixed amphetamine salts , methylphenidate , dextroamphetamine ) or fatigue associated sleep apnea or shift work ( e.g. modafinil ) ; ( 8) willing to withdraw from anorectic agents such as diethylpropion , sibutramine , and phentermine ; and ( 9 ) if currently taking pregabalin and/or gabapentin , to remain on a stable dosage throughout the duration of the study .
major exclusion criteria were : ( 1 ) significant risk of suicide ; ( 2 ) medical conditions including cardiac diseases , glaucoma , autoimmune disease , systemic infections ( e.g. human immunodeficiency virus , hepatitis ) , active cancer , pulmonary disease or dysfunction , unstable endocrine disease ( must be stable at least 3 months prior to study enrollment ) , unstable diabetes , unstable thyroid disease ; ( 3 ) pregnant or lactating ; ( 4 ) any other severe , acute , or chronic medical or psychiatric conditions that could increase risk or interfere with trial results ; ( 5 ) body mass index greater than 36 ; ( 6 ) treatment with any experimental agent , including mln , within 30 days before screening ; and ( 7 ) contraindications with mri procedures .
all study participants gave written informed consent . the study protocol and informed consent documents were approved by the university of michigan institutional review board ( ann arbor , michigan ) and forest laboratories ( new york , ny ) .
all imaging data were stored , validated , analyzed , and assessed for quality at the university of michigan independent of forest personnel .
patient demographics , medications , and identification of inclusion for analysis are listed in table 1 .
all patients were randomized in a double - blind , two - period crossover study of mln versus placebo ( fig .
potential participants underwent an initial visit , prior to the first neuroimaging session , wherein they were evaluated for study criteria .
after meeting inclusion / exclusion criteria , consenting patients were randomized to either mln first or placebo first for period 1 , and which followed 14 week washout period to withdraw from all excluded medications that could interfere with efficacy and neuroimaging measures .
this washout period included a 1-week single - blind placebo run - in period to reduce the possibility of placebo effects during the first double - blind treatment period .
following the placebo run - in period , all participants underwent their first neuroimaging scan ( pretreatment for period 1 ) which involved functional connectivity magnetic resonance imaging ( fcmri ) . following this initial scan ,
subjects randomized to receive mln in the first period , underwent dose escalation of mln up to 200 mg / day over the course of 2 weeks , with a maintained fixed dose for 4 weeks , at which time an identical post - treatment fcmri session was conducted .
those subjects randomized to placebo for period 1 took matching placebo pills over the course of 6 weeks before undergoing an identical post - treatment fcmri session .
all participants then entered a 1 week taper and 2 weeks of a placebo washout , during which time a placebo sugar pill was consumed daily .
once the washout period was completed , all patients crossed over to the other study drug for period 2 ( i.e. those who had mln for period 1 received placebo for period 2 and vice versa . ) .
placebo data included in all analyses came from either period 1 or period 2 ( depending on treatment order ) , and were included for all subjects regardless of treatment order .
all subjects were informed that they would be dosed with mln or placebo at various times throughout the study , but were not told when they were transferred from one treatment to the other .
we assessed treatment response for both clinical pain as well as evoked experimental pain in all participants prior to and following each study period .
clinical pain was assessed with the short form of the brief pain inventory ( bpi ) which captures both pain severity ( bpi sev ) and interference due to pain ( bpi int ) ( cleeland and ryan , 1994 ) measured over the course of the previous week .
changes in these components ( post minus pre ) were used as measures of treatment response for clinical pain .
changes in pain both following mln and placebo were assessed in spss , version 20 , by performing paired t - tests .
further , we specifically investigated whether changes following mln treatment differed significantly from changes following placebo treatment by performing paired samples t - tests of the change scores for all behavioral measures , also in spss , version 20
. when assessing for responders compared to non - responders to a treatment period , we defined a patient to be a responder if she had 30% improvement for a behavioral measure after a treatment period .
patients with < 30% improvement after a treatment period were categorized as non - responders . evoked experimental pain data was also collected in and outside the mri scanner before and after each treatment period .
pressure - pain was administered to the left thumbnail with three distinct conditions using the multi - modal automated sensory testing ( mast ) system ( harte et al . , 2013 ) :
1 ) an equal pressure condition of 1.5 kg / cm , 2 ) the amount of pressure required to elicit pain50 on the 0100 nrs , and 3 ) a faint touch rest condition .
both behavioral and bold fmri response data will be analyzed and reported in a subsequent manuscript . in this investigation
we were primarily interested in identifying baseline neuroimaging parameters that could predict changes in clinical and evoked pain specifically following treatment with mln . resting state fmri data
were acquired using a t2 * -weighted spiral sequence ( tr = 2.0 s , te = 30 ms , fa = 90 , matrix size 64 64 with 43 slices , fov = 20 cm and 3.12 3.12 3 mm voxels ) , using a 3 tesla general electric , signa scanner 9.0 , vh3 with 16 rod birdcage transmit receive radio frequency coil . during the 6 min resting state fmri acquisition period ( 180 scans ) ,
subjects were asked to remain awake with their eyes open and to stare at a motionless cross presented on the screen .
minimal cognitive tasks such as staring at a cross are thought not to disrupt resting state networks ( greicius et al . , 2003 ) .
the first 6 images of the resting state scan were discarded from the data set and not analyzed in order to avoid equilibration effects . a t-1 weighted structural gradient echo data set ( tr 1400 ms , te 1.8 ms , flip angle 15 , fov 256 256 , yielding 124 sagittal slices with a defined voxel size of 1 1 1.2 mm ) was also acquired for each subject .
data were pre - processed and analyzed using fsl ( http://www.fmrib.ox.ac.uk/fsl ) and statistical parametric mapping software packages ( spm , version 8 , functional imaging laboratories , london , uk ) , as well as the functional connectivity toolbox conn ( cognitive and affective neuroscience laboratory , massachusetts institute of technology , cambridge , usa ) running under matlab 7.5b ( mathworks , sherborn , ma , usa ) . upon collection of the functional data , cardiorespiratory artifacts were corrected for using the retroicor ( hu et al .
pre - processing steps included motion correction ( realignment to the first image of the time series ) , normalization to the standard spm epi template ( generating 2 2 2 mm resolution images ) and smoothing ( convolution with an 8 mm fwhm gaussian kernel ) .
subject head motion was assessed by evaluating three translations and three rotations for each scan .
translational thresholds were set to 2 mm , while rotational thresholds were limited to 1. a subject was to be excluded from the analysis if head motion exceeded either of the thresholds in one of the six dimensions .
as snris are thought to augment antinociceptive mechanisms , we were particularly interested in rs - fc to brain regions known to be involved in the descending antinociceptive / pain modulatory system .
the following regions were chosen based on the current literature suggesting involvement in antinociception / pain modulation ( bingel , 2010 ) : three seeds covering the rostral acc , the ventral ( vacc ) , pre - genual ( pgacc ) and subgenual ( sgacc ) regions , and bilateral seeds in : the dorsolateral prefrontal cortex ( dlpfc ) , the amygdala , and the periaqueductal gray ( pag ) ; seed regions were created using the spm extension tool marsbar .
all seed regions were created as spheres . for further information including size and location ,
, seed regions ' time - series were extracted ; white matter , cerebrospinal fluid , and realignment parameters were entered into the analysis as covariates of no interest . a band - pass filter ( frequency window : 0.010.1 hz )
first level analyses were performed correlating seed region signal with voxel signal throughout the whole brain , thereby creating seed region to voxel connectivity maps ( one map per seed per individual ) . for group analyses we focused on pre- mln rs - fc as a predictor of subsequent change in pain resulting from the drug .
our primary approach was to enter pre - treatment connectivity maps in a multiple regression analysis with changes in pain ( post - mln minus pre - mln ) in spm .
results were deemed significant using a family wise error ( fwe ) cluster corrected threshold of p < 0.05 . within a priori brain regions ,
including : the ic , posterior cingulate cortex ( pcc ) , precuneus , inferior parietal lobule ( ipl ) , and dlpfc , a small volume correction using a sphere with a radius of 5 mm was performed , and results were deemed significant at a ( fwe ) cluster level corrected threshold of p < 0.05 .
these regions had been selected as a priori regions because we were specifically interested in rs - fc changes to regions known to be involved in pain processing , which allowed for small volume correction analysis based on previously published results .
significant results were then extracted and entered into spss , version 20 , to assess for outliers . to determine if these results were specific to mln , identical analyses were performed for the placebo period , using the significant regions identified as predicting response to mln . in order to rule out chance differences by treatment period at baseline , we compared the mln and placebo correlations for the two cross - over periods separately ( i.e. those that had mln first and those that had placebo first ) .
correlations were performed in spss , version 20 , and results were found to be significant at p < 0.05 .
finally , we sought to incorporate multiple functional connectivity measures in a regression analysis to explore for collinearity amongst our rs - fc outcomes and to further improve prediction of treatment response , while simultaneously controlling for pre - treatment pain levels ( harris et al . ,
a multiple linear regression model was created with pre - treatment pain measures and rs - fc correlation values serving as independent variables and post - treatment pain as the dependent variable .
a model was first constructed with each rs - fc measure individually and then in combination ( when multiple rs - fc values predicted the same pain outcome ) by way of forward selection .
eight were excluded from the analysis for the following reasons : six withdrew prior to completing all neuroimaging sessions ( two prematurely stopped taking mln , two had side effects from the drug that prevented participation in the trial , and two terminated due to personal reasons ) , and two additional participants were excluded because they did not reach the pre - specified dose of mln before imaging .
the drop - out rate due to adverse events of the medication was 9% ( 2 of 23 participants ) .
thus fifteen subjects ( mean age : 40.7 10.2 ) were included in the present analysis .
multiple dimensions of clinical pain were found to show significant decreases and trends towards decreased pain after treatment with mln but not placebo ( bpi sev change ; mln : mean = 0.88 1.8 , p = 0.076 ; pbo : mean = 0.17 2.3 , p = 0.78 ; bpi int change ; mln : mean = 1.1 1.7 , p = 0.03 ; pbo : mean = 0.56 2.1 , p = 0.31 ) . when comparing the effects of treatment periods to each other , no significant differences between mln and placebo treatment were observed ( bpi sev : p = 0.39 , bpi int : p = 0.50 ) . according to our a priori definition of responders : 5 of 15 patients ( 33% ) were responders to mln and 3 of 15 patients ( 20% ) were responders to placebo treatment for bpi sev , whereas 7 of 15 patients ( 47% ) were responders to mln treatment and 4 of 15 patients ( 27% ) were responders to placebo for bpi int scores ( table 2 ) .
we found strong associations between baseline rs - fc values ( i.e. rs - fc correlation values between our pre - specified antinociceptive brain regions and other brain regions involved in pain processing / modulation ) and changes in clinical and experimental pain measures after treatment periods ( table 3 ) .
a significant association was found between rs - fc of the right pag seed and the right mid - ic , and subsequent reduction in clinical pain severity ( bpi sev ; mln : r = 0.885 , p < 0.001 ; placebo : r = 0.216 , p = 0.440 ; table 3 and fig .
less rs - fc activity was associated with greater reductions in clinical pain following mln treatment but not placebo .
we also observed a significant association between connectivity of the right dlpfc and the left ipl , and changes in bpi sev during mln but not placebo ( mln : r = 0.873 , p < 0.001 ; placebo : r = 0.030 , p = 0.917 ; table 3 and fig .
3b ) . with respect to the limbic system , connectivity between the left amygdala and the precuneus / posterior cingulate cortex ( pcc ) was found to have a negative correlation with change in bpi sev in response to mln but not placebo ( mln : r = 0.916 , p < 0.001 ; placebo : r = 0.389 , p = 0.152 ; table 3 and fig .
low levels of connectivity between the pgacc and the right posterior ic were found to be associated with a greater reduction in clinical pain interference ( bpi int ) following mln but not placebo ( mln : r = 0.900 , p < 0.001 ; placebo : r = 0.082 , p = 0.771 ; table 3 and fig .
4a ) . for placebo , lower levels of connectivity between the pgacc and the left dlpfc
were associated with greater pain reduction , i.e. patients with less connectivity of these two structures at baseline would showed a greater response in clinical pain interference ( bpi int ) during placebo treatment ( placebo : r = 0.869 , p < 0.001 , mln : r = 0.050 , p = 0.859 ; table 3 , fig . 5 ) .
when assessing each treatment period separately , it was found that order of treatment ( mln or placebo administered in the first period ) did not impact the results .
two linear regression models predicting changes in bpi sev during the mln period were constructed .
the first model for this measure included pre - mln bpi sev values ( adjusted r square = 0.34 , p = 0.014 ) , right pag to right mid - ic connectivity ( adjusted r square = 0.50 , p < 0.001 ) , and right dlpfc to left ipl connectivity ( adjusted r square = 0.10 , p = 0.001 ) as independent predictors and explained 94% of the variance of post - mln pain severity .
a second model explained 95% of the variance of post - mln bpi sev scores which included pre - mln bpi sev values ( adjusted r square = 0.34 , p = 0.014 ) , right pag to right mid - ic connectivity ( adjusted r square = 0.51 , p < 0.001 ) , and left amygdala to right pcc / precuneus ( adjusted r square = 0.10 , p < 0.001 ) as independent predictors ( table 4 ) .
independent predictors including pre - mln bpi int scores ( adjusted r square = 0.58 , p = 0.001 ) and pre - mln connectivity between the pgacc and right posterior ic ( adjusted r square = 0.32 , p < 0.001 ) explained 90% of the variance of post - mln pain interference ( table 4 ) .
we investigated rs - fc of cortical and subcortical structures involved in pain modulation to determine parameters that would predict treatment response to treatment with mln in patients with fibromyalgia .
importantly , we find that acc ic as well as pag ic connectivity at baseline were predictive of treatment response : patients that displayed lower pgacc ic connectivity or pag ic connectivity , respectively , showed greater reductions in clinical pain following mln treatment .
other rs - fc measures were also predictive of clinical response to mln treatment , such as dlpfc ipl and amygdala precuneus / pcc connectivity , while less pgacc dlpfc connectivity was predictive of placebo response .
we hypothesize that a subgroup of fibromyalgia patients with poor connectivity between pro- and antinociceptive brain regions , profits from snri treatment , and this pattern reflects a dysfunctional endogenous antinociceptive system or can be viewed as a biomarker thereof .
a dysfunctional endogenous antinociceptive system has been suggested to be a contributor to the genesis of pain in fm ( lautenbacher and rollman , 1997 ; vierck et al .
there is indeed evidence that cns levels of the two key neurotransmitters within the antinociceptive system , 5-ht and ne , are lowered in fm as indicated by decreased levels of the corresponding metabolites in the cerebrospinal fluid ( russell et al . , 1992 ;
snris are thought to support the antinociceptive system by increasing synaptic 5-ht and ne levels that in turn reduce the nociceptive input to the brain .
snris are well characterized with respect to their molecular mechanisms , targeting presynaptic transporter proteins ( e.g. sert ) , thereby raising synaptic 5-ht and ne levels . however , since 5-ht and ne can bind to different receptor subtypes with different effects and concentrations at different cns sites , the overall effect of 5-ht and ne reuptake inhibition is highly complex . in the context of pain and pain modulation however predominantly spinal mechanisms
are discussed to account for the analgesic effects ( yoshimura and furue , 2006 ; burnham and dickenson , 2013 ) . for 5-ht
this is via binding to 5-ht1a , 5-ht1b and 5-ht1d receptors that lead to pre- and post - synaptic hyperpolarization of pain transmitting neurons .
furthermore 5-ht increases inhibitory transmitter release ( e.g. gaba ) from interneurons via 5-ht3 and possibly 5-ht2 .
ne , on the other hand is thought to act via presynaptic 1 receptors leading to a suppression of glutamate release from both a and c afferent fibers , as well as via 2 receptors increasing inhibitory transmitter release from interneurons . importantly these mechanisms seem to play a beneficial role in a variety of chronic pain conditions , such as diabetic neuropathy ( boyle et al . , 2012 ) , osteoarthritis ( chappell et al . , 2009 ) as well as fibromyalgia ( goldenberg et al . , 2010 ; huser et al
, 2012b ) and are not thought to be specific to one particular pain condition .
interestingly for fibromyalgia a recently published study investigating spinal effects of mln via the assessment of the nociceptive flexion reflex ( r iii ) , came to the conclusion that mln must also have supraspinal effects , based on the observation that there was a dose dependent analgesic effect in the absence of an mln associated modulation of the nociceptive flexion reflex ( matthey et al . , 2013 ) .
the only study to date that we are aware of to directly test whether diminished descending analgesic activity is predictive of treatment response with these classes of drugs is a study by yarnitsky and colleagues showing that those neuropathic pain patients with impaired descending activity at baseline on qst were more likely to respond to duloxetine ( yarnitsky et al . , 2012 ) .
our choice of seed regions for the rs - fc connectivity analyses was based on the current literature highlighting the role of some key structures in pain inhibition and pain modulation , i.e. the pag , the rostral acc , the dlpfc and the amygdala ( petrovic et al .
, 2002 ; wager et al . , 2004 ; bingel et al . , 2007 ) .
our strongest findings , which are also well in line with our a priori hypotheses is , that acc
ic connectivity and pag ic connectivity were predictive of treatment response . within the endogenous antinociceptive system the pag plays a central role coordinating via the rostroventromedial medulla ( rvm ) ( moreau and fields , 1986 ; heinricher et al . ,
2009 ) activity in the descending 5-ht and ne pathways that project to the spinal cord to decrease nociceptive routing from the periphery .
the pag itself receives input from both spinal nociceptive neurons a variety of cortical structures .
it has been hypothesized that there are two cortical systems that mediate cortical top down modulation ; one pathway involves descending input from the rostral acc ( to the prefrontal cortex and then to the pag ) ; a second pathway arrives at the pag from the ic via the amygdala ( schweinhardt and bushnell , 2010 ) . that said , it needs to be acknowledged that most evidence stems from animal research ( fields , 2004 ) and that the precise mapping of these pathways in humans is currently unknown .
however , the notion of the rostral acc pag connectivity ( hardy and leichnetz , 1981 ) , interacting in this regard , has recently been supported by both functional ( petrovic et al . , 2002 ; bingel , 2010 ; kong et al . , 2010 ) and structural ( stein et al . , 2012 ) imaging studies .
the interaction of the rostral acc and ic in antinociception and pain modulation on the other hand remains to be further elucidated .
both structures are part of a cortical opioidergic network ( petrovic et al . , 2002 )
, as such the rostral acc might exert direct antinociceptive activity on the ic cortex , or both structures modulate the pag either interactively or independently , and rs - fc reflects coordinated activity of the two systems .
when looking at resting state networks the bilateral ic together with the dorsal acc , mcc and supplementary motor area make up the so called salience network and connectivity within this network influences perceptual decisions on pain .
the vacc , pgacc and sgacc as such are not part of the salience network , but rather belong to the executive control network ( vacc ) and the dmn ( pgacc and sgacc ) ( beckmann et al . ,
as such one would not expect highly correlated bold activity between the rostral acc and ic even in healthy subjects ; intriguingly a negative correlation in resting state activity between these two regions is predictive of mln response . in a recently performed study we found an increased rostral acc ic rs - fc in young patients with temporomandibular disorder that we interpreted as an early compensatory mechanism in a group of young patients developing a chronic pain condition ( ichesco et al . , 2012 ) .
effort , it is tempting to hypothesize that a break down in this mechanism is then associated with further pain chronification , based on an increasingly dysfunctional antinociceptive system .
the other rs - fc patterns that predicted response to mln treatment were the right dlpfc and the left ipl as well as amygdala and the posterior cingulate cortex .
the ipl as well as the posterior cingulate cortex are both part of the dmn .
the role of the dmn in chronic pain is beginning to be investigated , as in our previous work in fibromyalgia suggesting that ic connectivity to the dmn is associated with increased pain ( napadow et al . , 2010 ) .
interestingly in this present work , we show that lowered dmn connectivity to antinociceptive regions , such as the dlpfc , are predictive of response to mln .
other dmn regions such as the pcc have also been highlighted as being involved in pain in other functional and structural imaging studies ( erpelding et al . ,
another interesting finding of our study is that pgacc left dlpfc connectivity predicted response to placebo treatment .
fibromyalgia patients with a lower pgacc left dlpfc connectivity showed greater pain reductions while undergoing placebo treatment .
the placebo effect in fibromyalgia patients has recently been investigated in meta - analyses based on randomized , placebo - controlled trials . in these studies , 1830% of patients
have been shown to be placebo responders ; as such the magnitude of placebo responders in drug trials of fibromyalgia is similar to that seen in other chronic pain conditions ( huser et al . , 2011
the neural mechanisms underlying the clinical observation that cognitive factors such as beliefs and expectations can modulate pain perception have been investigated using various brain imaging methods ( petrovic et al . , 2002 ; bingel , 2010 ) , mostly using short term interventions .
the role of the dlpfc cortex in placebo research has been underlined by both fmri studies ( wager et al . , 2004 ;
wager et al . , 2011 ) as well as transcranial magnetic stimulation ( tms ) studies describing a significant impairment of placebo analgesia associated with tms induced functional lesions of the left dlpfc ( krummenacher et al . , 2010 ) .
as such the dlpfc is viewed as key region for initiating placebo related changes in pain perception , the implementation of which then requires the interaction of other cortical and subcortical brain regions , such as the rostral acc and the pag . while increases in the rostral acc activity and acc pag connectivity during placebo analgesia are most likely to be mediated by opioidergic transmission ( petrovic et al . , 2002 )
dlpfc playing a key role in placebo analgesia , they also extend it to a clinical setting , where baseline rs - fc predicts placebo effects visible 6 weeks after treatment initiation .
despite the significant progress that has been made in understanding the pathophysiology of fibromyalgia , these advances have not yet been translated into pharmacological treatment .
it is generally thought that the underlying pathophysiology of fibromyalgia is heterogeneous leading to a similar phenotype of chronic widespread pain , with only a subgroup of patients with diminished synaptic 5-ht and ne levels responding to drugs that augment this activity . despite our small sample size
the rates of both drug and placebo responders are well in line with larger , randomized studies .
consistent with this idea , the effect of any one of the united states food and drug administration 's approved drugs examined in isolation is modest with a 30% improvement in pain occurring in only 3040% of patients ( huser et al . , 2012b ) , which is also the case in other chronic pain states ; nsaids and opioids for example have modest efficacy in conditions such as osteoarthritis or chronic low back pain ( clauw , 2010 ) .
this stresses the need to develop tools that predict treatment response , in order to then design individually tailored therapies ( woolf , 2010 ) . only very recently have studies indicated that brain imaging might be suited to perform such predictions ( harris et al . , 2013 ;
resting state fmri might be a particularly interesting tool , as it is easy and safe to perform with only little demands on patients ' cognition and cooperation .
first of all our study is based on a rather small study sample , i.e. our findings might not be representative of the larger fibromyalgia population and may only apply to a subgroup of fibromyalgia patients .
also while our drop - out rates , as well as treatment response to mln and placebo , were comparable to those seen in larger randomized , placebo - controlled trials , our results need to be reproduced in a larger study sample .
as rs - fc analyses allow no assumptions on causality , or on the directedness of influence , it is conceivable that connectivity between two regions could be driven by a third region , not identified in the analysis .
furthermore there is no necessity for a direct causal relationship between brain connectivity patterns identified in this study and clinical response .
dual reuptake inhibitors are likely to act first and foremost on the spinal level ( in the context of pain inhibition ) , and the connectivity measures of forebrain structures might thus relate only indirectly to the site of action . in this scenario connectivity measures would need to be viewed as surrogate markers , however this would not detract from their potential clinical usefulness . finally , there are four snris used in clinical practice , including venlafaxine , desvenlafaxine , duloxetine and mln .
mln blocks 5-ht and ne reuptake to an equal extent whereas greater selectivity at 5-ht sites has been described for venlafaxine and duloxetine . in this regard
it is uncertain whether our results can be generalized to other snris or even tcas . besides confirmation by studies with larger sample sizes further research
is needed to extent our findings to other snri and non - selective reuptake inhibitors ( e.g. tcas . ) .
overall we were able to show that rs - fc patterns of brain structures involved in antinociception and pain modulation might be useful parameters for the prediction of treatment response to the snri mln in fibromyalgia patients .
as in clinical practice only a subset of patients respond to pharmacological treatment , such approaches might turn out useful tools to identify subgroups of patients likely to respond to one or the other approach moving towards an individualized medicine .
Output:
| fibromyalgia is a chronic pain syndrome characterized by widespread pain , fatigue , and memory and mood disturbances . despite advances in our understanding of the underlying pathophysiology
, treatment is often challenging .
new research indicates that changes in functional connectivity between brain regions , as can be measured by magnetic resonance imaging ( fcmri ) of the resting state , may underlie the pathogenesis of this and other chronic pain states . as such , this parameter may be able to be used to monitor changes in brain function associated with pharmacological treatment , and might also be able to predict treatment response.we performed a resting state fcmri trial using a randomized , placebo - controlled , cross - over design to investigate mechanisms of action of milnacipran ( mln ) , a selective serotonin and norepinephrine reuptake inhibitor ( snri ) , in fibromyalgia patients .
our aim was to identify functional connectivity patterns at baseline that would differentially predict treatment response to mln as compared to placebo . since preclinical studies of mln suggest that this medication works by augmenting antinociceptive processes , we specifically investigated brain regions known to be involved in pain inhibition.15 fibromyalgia patients completed the study , consisting of 6 weeks of drug and placebo intake ( order counterbalanced ) with an interspersed 2 week wash out period . as a main finding
we report that reductions in clinical pain scores during mln were associated with decreased functional connectivity between pro - nociceptive regions and antinociceptive pain regions at baseline , specifically between the rostral part of the anterior cingulate cortex ( acc ) and the insular cortex ( ic ) , as well as between the periaqueductal gray ( pag ) and the ic : patients with lower preexisting functional connectivity had the greatest reduction in clinical pain .
this pattern was not observed for the placebo period .
however a more robust placebo response was associated with lower baseline functional connectivity between the acc and the dorsolateral prefrontal cortex.this study indicates that acc ic connectivity might play a role in the mechanism of action of mln , and perhaps more importantly fcmri might be a useful tool to predict pharmacological treatment response . |
PubmedSumm119916 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: several malignant tumours can metastasize to the colon , including those of the stomach , breast , ovary , cervix , kidney , lung , prostate and skin .
clinical symptoms and signs may suggest the diagnosis , but one third of such patients are asymptomatic and the diagnosis may be an incidental finding at autopsy .
therapeutic options include resection with intent to cure ( primary and secondary tumours resection ) , palliative interventions ( colonic resection or colostomy ) , or non - surgical treatment .
if all metastases can be resected , the prognosis is reportedly the same as that of the primary tumour .
two years previously , a 49-year - old male caucasian patient , a chronic smoker , was diagnosed with small cell carcinoma of the lung . a ct scan of the thorax revealed mediastinal lymphadenopathy , and ct scans of the abdomen , pelvis and brain were essentially normal .
the patient received chemotherapy for 3 months , with a partial response in the thoracic changes on ct , followed by three months of radiotherapy , including prophylactic radiotherapy to the brain .
one year later there was no residual tumour on a ct scan of the thorax or at bronchoscopy .
follow - up by the chest department a further year later showed significant progression of the lung cancer , with lung and lymphatic metastases on a follow - up chest ct scan ( the abdomen was not scanned ) .
further chemotherapy was given but the patient 's health deteriorated ; he received several blood transfusions for normochromic normocyctic anaemia .
six months later he attended the emergency department with anorexia , asthenia and generalized abdominal pain for 3 days , with obstipation for 8 days , without nausea or vomiting .
he looked pale and was tender in the right lower abdomen with rebound tenderness over mcburney 's point ( blumberg 's sign ) ; he had normal bowel sounds .
abdominal ultrasound ( us ) revealed an area of liquid in the right lower quadrant containing an elongated structure suggestive of acute appendicitis . through a mcburney incision surgical exploration revealed a mass in the right colon .
a midline incision was then made , and two tumours were identified : the one in the right colon was mobile , and a second one in the sigmoid colon was fixed to the sacrum and deemed irresectable . a right hemicolectomy with an ileocolic side - to - side stapled anastomosis was performed together with a sigmoid loop colostomy .
the appendix was normal macroscopically and also on histology of the resected bowel which confirmed that the right colonic tumour was a secondary from small cell carcinoma of the lung ( immunohistochemistry showed immunoreactivity of tumour cells for cytokeratin cam 5,2 dot - like , for chromogranin , for synaptofisin and cd56 ) with secondary cancer confirmed by intense and diffuse immunoreactivity for thyroid transcription factor-1 ( ttf-1 ) consistent with metastatic lung cancer .
he was discharged on the 11th post - operative day , and died 12 weeks after surgery .
colonic metastases are rare , and usually secondary to malignant tumours of the stomach , breast , ovary , cervix , kidney , lung , prostate , or skin .
the few published reports suggest that colon metastases from lung cancer tend to be from giant cell carcinoma and squamous cell carcinoma .
although a third of such colonic metastases are asymptomatic or found only at autopsy , more often they present clinically .
ochsner and debakey found gastrointestinal involvement in 4.3% of 3047 autopsies . usually colonic metastases are diagnosed later than the primary tumour ; however there are cases of synchronous or prior diagnosis .
exuberant symptoms are rare , but there can be signs and symptoms of bowel obstruction , lower gastrointestinal haemorrhage ( macroscopic or occult ) , intestinal perforation , gastrointestinal fistula , anaemia , and weight loss .
transfusion - dependent anaemia has been described in the literature , and normochromic / normocytic anaemia is frequent in chronic oncologic diseases . with the current availability of positron emission tomography ( pet scanning ) , colonic metastases
may be diagnosed more frequently than previously , even in patients without mediastinal lymph node involvement .
pet scans may come to have a major role in the evaluation of lung cancer .
a pathological diagnosis is crucial . in our case confirmation that the right colonic lesion was metastatic from the lung cancer came from the intense diffuse immunoreactivity for ttf-1 , which is not expressed by primary colonic cancer , and there was immunoreactivity of tumour cells for cytokeratin cam 5,2 dot - like , for chromogranin , for synaptofisin and cd56 .
the prognosis of lung cancer with intestinal metastases is poor , with a mean survival of 4 to 8 weeks and a maximum of 16 weeks , as we found in our patient ( who survived 12 weeks post - operatively ) .
if resection of the colonic metastases is possible , the prognosis is that of the primary tumour .
cases complicated by bowel obstruction , haemorrhage or intestinal perforation managed by emergency laparotomy with resection of metastases have a reported mean survival of 6 months , with a maximum of 13 months .
chemotherapy in patients with both primary and secondary non - resectable lesions may prolong survival ( 23 weeks has been reported ) but chemotherapy can induce intestinal perforation in patients with known intestinal metastases .
therapy must be individualized , and there are three surgical options : resection with curative intent ( of both primary and secondary lesions ) , palliative therapy ( colon resection or colostomy ) , or no intervention at all . in selected cases ,
given the poor general health of our patient and the non - resectability of both the primary and secondary lesions , the management decisions appear to have been appropriate .
metastatic lesions of the colon are rare , and may raise difficult problems of management .
survival reports and treatment options vary . the dilemma as to which lesion to treat first ( primary or secondary ) needs to be considered case - by - case . gastrointestinal metastatic disease should be considered in the differential diagnosis of patients with lung cancer presenting with an acute abdomen .
aggressive surgical management provides the best chance of palliation , can decrease the duration of hospitalization , and improves quality of life .
resecting both the secondary colonic and lung primary tumours may increase survival , as can chemotherapy though treatment must be individualised .
written informed consent was obtained from the patient for publication of this case report.a copy of the written consent is available for review by the editor - in - chief of this journal on request .
ceca data collection , manuscript writing , manuscript review , lsr data collection , cmca manuscript review
Output:
| introductioncolonic metastases are rare , and usually secondary from malignant tumours of the stomach , breast , ovarian , cervix , kidney , lung , prostate , or skin . around one third
are asymptomatic or found only at autopsy.case reporta middle - aged male smoker , who had a small cell carcinoma of the lung diagnosed two years previously and treated with radiotherapy and chemotherapy , was admitted to the emergency room with intense abdominal pain and constipation . with the suspicion of an acute appendicitis
he was submitted to surgery . at laparotomy
he was found to have a normal appendix but two hard colonic lesions : a mobile one in the right colon and the other fixing the sigmoid colon to the sacrum .
a right hemicolectomy and a sigmoid loop colostomy were performed .
pathology showed those lesions to be colonic metastases from small cell carcinoma of the lung.discussioncolonic secondaries are most frequently diagnosed in patients who have had a known primary tumour , and may present with bowel obstruction , lower gastrointestinal haemorrhage , gastrointestinal fistula , or intestinal perforation .
presentation with acute abdomen is rare , and survival is usually limited.conclusioncolonic metastatic disease should be considered in any patient presenting with an acute abdomen and past history of lung malignancy . |
PubmedSumm119917 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: the use of dental implants has revolutionized prosthodontics and the fixed treatment options that can be offered to patients .
high survival rates and long - term predictability for clinically loaded endosseous implants have been consistently reported resulting in one of the most successful treatment modalities in dentistry [ 14 ] . however , despite the early characterization of factors related to implant fixture success , it is noticeable that the understanding of prosthetic - related failures has been less explored .
typically , an implant - supported rehabilitation is comprised by an endosseous implant that connects to a transmucosal abutment ( 2-piece ) , which receives the single or multiple unit prosthetic restoration .
the location of this connection can be either submerged or at bone crest level or nonsubmerged .
regardless of location and type of connection ( internal or external ) , it is important that the best implant - abutment interface fit is achieved in order to favor the stress distribution between connecting components and biological response , hindering microorganism colonization at this interface [ 68 ] .
the most commonly used internal or external connections involve the use of a screw to clamp implant fixture and abutment .
the stability of this connection is secured through a clamping force which is challenged by unclamping forces derived from occlusal function . according to bolted joint mechanics , to achieve and maintain the stability of the screw - type connection ,
it is important that the gap size is minimum , which will decrease the likelihood of screw loosening .
it has been demonstrated that when gaps were minimized , the chances of screw loosening also decreased [ 911 ] , thus showing the positive relationship between gap size and screw loosening .
clinically , the absence of a gap - free implant - abutment interface can induce biological and mechanical complications , jeopardizing the implant long - term success .
an intense host immunological response ( acute inflammatory process ) has been found at or near to gaps around implant - abutment interface , leading to a potential bone loss [ 1214 ] .
the bacterially contaminated interface may elicit and maintain an inflammatory process ( peri - implantitis ) [ 15 , 16 ] .
such bacterial colonization may initiate during the surgical placement of the implant , the reopening , and installation of an intermediary or through the misfit of the prosthetic connection [ 7 , 12 , 13 , 17 ] .
thus , as the interface gap allows fluid and bacterial microleakage [ 6 , 1820 ] , the implant well may serve as a bacterial reservoir that allows microorganisms to seep in and out , perpetuating a peri - implantitis disease .
however , implant design junctions have changed over time , providing a more predictability of bone stability as displayed by one - piece implant and by switching platform concept [ 2125 ] .
these positive reports may intensify the clinical negative impact provided by marginal misfit , when the implant - abutment interface is located at or below the alveolar crest . from a mechanical perspective
it has been identified in a systematic review that the most common technical complication of a single - unit implant - supported reconstruction is abutment or occlusal screw loosening , with a cumulative incidence of 12.7% after 5 years of followup .
one potential reason for this type of failure could be an ill - fitted implant - abutment interface destabilizing the implant - abutment connection [ 2832 ] . despite the outstanding success rates of modern implantology ,
one crucial factor is the maintenance of bone level on the long term , which can be negatively affected by mechanical and biological complications .
since the establishment of peri - implant bone level after the healing period is somewhat predictable , its stability over time can be affected by inherent issues in the implant - abutment connection [ 33 , 34 ] from a mechanical [ 911 , 29 , 31 , 32 ] and biological perspective [ 12 , 17 , 3540 ] .
studies have most commonly investigated the sealing capability to bacterial [ 7 , 8 , 14 , 41 ] or color marker migration towards or from the implant well .
direct observations of the implant - abutment interface have also been performed by x - ray , scanning electron microscopy ( sem ) [ 43 , 44 ] , and optical microscopy .
another possibility is the cross - sectional analysis and evaluation of the misfit made as a function of implant radius , which allows a more comprehensive observation of the adaptation along the implant - abutment interface .
however , the evaluation of implant - abutment sealing capability followed by sem direct observation has not been addressed to date .
this study sought to compare the sealing capability and marginal fit of two external hexagon implant systems by spectrophotometric quantification of microleakage at several incubation times followed by sem observation of the implant - abutment interface .
two external hexagon implant systems ( 4.1 mm diameter ) were used for this study ( n = 10 per system : tryon - sin , sistema de implantes nacional , so paulo , sp , brazil and osseotite - biomet 3i , palm beach , fla , usa ) . the implants and their proprietary abutments were first subjected to the sealing capability testing and then to direct sem observation of the interface .
in order to quantify the amount of the color marker ( 1% acid - red in propylene glycol hydrosoluble pigment ) ( caries detector , kuraray medical incorporation , okayama , japan ) dissolved in the distilled water , a calibration curve was determined through linear regression ( best line fit ) using a fraction of a color marker volume in water .
seven color marker increments of 0.1 l ( to 0.7 l ) were added using an automated pipette ( eppendorf research pro , westbury , usa ) to 1.3 ml of distilled water placed in 2.5 ml vials .
the absorbance of these color marker increments dissolved in water ( figure 1 ) was quantified with a spectrophotometer calibrated to a wavelength of 560 nm ( fluostar optima
the maximum amount of 0.7 l was determined from a pilot study which indicated that this volume was enough to fill the implant well and remained free of contact with the torqued abutment screw most apical portion .
samples from each increment ( n = 5 per increment ) were analyzed in the spectrophotometer calibrated to a wavelength of 560 nm to acquire the absorbance values , which were used to compose the absorbance curve . the starting point to formulate the absorbance curve was pure distilled water without color marker . in the most apical portion of the implant
well 0.7 l amount of color marker was dispensed by means of an automated pipette .
subsequently , the implants were held by a vise connected to a bench in a vertical position where the abutments were assembled onto the implants and torqued to 20 ncm ( as per manufacturers recommendations ) using a hand torque wrench ( tmec , sin sistema de implantes , so paulo , brazil ) .
the connected implants were placed into 2.5 ml vials ( eppendorf research pro , westbury , usa ) filled with 1.3 ml of distilled water assuring that the implant - abutment interface remained immersed , but not the interface between abutment and screw .
the capped vials containing the implants and water were then kept at room temperature . using an automated pipette ,
samples of 100 l ( n = 3 for each implant ) were acquired at 1 , 3 , 6 , 24 , 48 , 72 , 96 , and 144 hrs incubation time at room temperature .
each sample was transferred from the respective vial to a microplate ( costar 96 , costar
the arithmetic average of the three absorbance values was determined and used for statistical analyses .
two - way anova at 95% level of significance and tukey 's test for multiple comparisons were utilized .
specimens were subjected to marginal fit evaluation in the sem ( model 3500s , hitachi ltd . ,
osaka , japan ) at a 15 kv acceleration voltage and 750x magnification .
the calibration curve generated by the 0.1 l increments of the color marker ( up to 0.7 l ) dissolved in water was linear presenting a r of 0.9974 ( figure 2 ) .
the color marker release quantification showed no statistical difference ( p > .05 ) between groups .
however , both groups increased the amount of color marker release as a function of incubation time ( figure 3 ) .
the highest amount of color marker release was observed at 144 hours relative to all previous incubation times ( p < .000001 ) for both groups .
although our results showed the presence of gaps during the sem marginal observation of the interface , caution must be taken when only this technique is considered as a method to evaluate the fit of the joint , since variations in gap sizes have been shown to occur along the implant radius in cross - sectional observations of this interface .
in addition , whereas knowledge of the interface size can allow the understanding of the potential of the bacterial colonization , it is limited in providing more insight into the possibility of fluid passage through the implant - abutment interface .
when compared to the results of sealing capability testing of internal connecting systems , the present data shows leakage also occurring in the investigated external connection systems .
the external hexagon connection was chosen for its long history of use and the plethora of data concerning its application [ 30 , 47 ] . although efforts to reduce leakage by the use of polymeric components in the interface have hindered but not eliminated bacterial colonization , only a screw less interference - fit implant - abutment connection has shown to restrain bacterial passage along its interface .
besides the alteration in connection designs , positive outcomes in bone level maintenance , when compared with matching implant - abutment dimensions , have been noticed in clinical prospective studies by two distinct approaches .
the first involves the positioning of the implant - abutment interface inward and away from the outer edge of the implant ( platform switching concept ) [ 21 , 22 , 24 , 25 , 49 ] and the second comprises the absence of the connection by the use of one - piece implants .
the results for the first may be mainly attributed to distance increase between abutment interface and bone level , perhaps decreasing the bone response and consequently the bone loss . for one - piece implants ,
however , the application of the platform switching concept seems to be limited to larger - diameter implants ( 5.0 or 6.0 mm ) of the prosthetic platform diameter .
considering that a relationship between extension of bone loss and the magnitude of the inflammatory process has been suggested , likely associated with the presence of microorganism in the implant - abutment interface [ 15 , 16 ] , there seems to be a direct relationship between peri - implant disease and interface gap [ 7 , 15 ] .
therefore , alterations in connection designs have always gained attention in implant - supported prosthodontics where considerable effort has been devoted to improve the stability and minimize the implant - abutment interface gap [ 7 , 35 , 39 , 46 , 51 ] .
imperfections related to machining of implants components , excessive torque during abutment placement ( which may allow the distortion of its parts ) , and in addition the misfit between implant - abutment are factors that have been related to interface gap origin . therefore , new studies involving the sealing capability of different connection systems combined with fatigue testing to evaluate the effect of misfit on systems mechanical performance may bring insight for the development of new connection designs .
evaluation of the sealing capability of two different systems showed the passage of fluids in both groups , and both groups presented implant - abutment gaps in the sem micrographs .
Output:
| to evaluate the sealing capability of external hexagon implant systems and assess the marginal fit , two groups ( n = 10 each ) were employed : sin ( sistema de implantes nacional , brazil ) and osseotite , ( biomet 3i , usa ) .
sealing capability was determined by placing 0.7 l of 1% acid - red solution in the implant wells before the torque of their respective abutments .
specimens were then placed into 2.5 ml vials filled with 1.3 ml of distilled water with the implant - abutment interface submerged .
three samples of 100 l
water were collected at previously determinate times .
the absorbance was measured with a spectrophotometer , and the data were analyzed by two - way anova ( p < .05 ) and tukey 's test .
marginal fit was determined using sem .
leakage was observed for both groups at all times and was significantly higher at 144 hrs .
sem analysis depicted gaps in the implant - abutment interface of both groups .
gaps in the implant - abutment interface were observed along with leakage increased at the 144 hrs evaluation period . |
PubmedSumm119918 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: postmenopausal osteoporosis is a systemic skeletal condition that affects many millions of women around the world .
the national institutes of health consensus conference defined osteoporosis as a disease of increased skeletal fragility accompanied by microarchitectural deterioration and low bone mineral density ( a t score for bone mineral density below 2.5 ) . osteoporosis prevention and treatment have relied on hormonal treatments such as estrogens and selective estrogen - receptor modulators , and on anticatabolic drugs and bone resorption inhibitors including bisphosphonates .
. these compounds are potent suppressor of osteoclast activity , improve trabecular and cortical architecture , and increase bone mineral density thereby reducing the risk of fracture in women osteoporosis .
since 2003 , numerous reports proposed an association between bisphosphonate use and osteonecrosis of the jaw bone as a long - term side effect of this class of agents . according to the american association of oral and maxillofacial surgeons ' position paper , patients may be considered to have bisphosphonates - related osteonecrosis of the jaw ( bronj ) if all of the following three characteristics are present : ( 1 ) current or previous treatment with a bisphosphonate , ( 2 ) exposed , necrotic bone in the maxillofacial region that has persisted for more than eight weeks , and ( 3 ) no history of radiation therapy to the jaws .
although bronj is a dose - related side effect and it is more common in cancer patients , a recent paper showed that the frequency of osteoporosis patients on oral bps affected by bronj was higher than previously reported ( n = 470 , 7.8% ) . the purpose of this longitudinal study is to present data from 76 female patients treated with bisphosphonates for postmenopausal osteoporosis and referred to the unit of oral diagnosis and day surgery of the university of milano for diagnosis and treatment .
starting in 2005 , all female osteoporotic patients treated with bps were referred to the unit of oral diagnosis and day surgery for evaluation and management . before the visit and treatment ,
this study was approved by the director of the clinic in accordance with the declaration of helsinki .
each tooth was probed at four sites ( three buccally and one lingually ) using a north carolina probe to measure probing pocket depth and recession .
periodontitis was based on measures of the presence and extent of cal in at least 20% of the sites probed , cal > 4 mm .
relevant clinical data regarding bps treatment , comorbidities , oral findings , dental treatment plan , and past and present dental therapies , were assessed .
patients were followed up every three months for routine clinical examination , oral hygiene instructions and debridement ; restorative care , periodontal and dentoalveolar procedures were provided when needed according to the american association of oral and maxillofacial surgeons guidelines .
individuals were included in the stage i group if they had asymptomatic exposed bone without any evidence of infection .
finally , patients were included in the stage iii group if they had exposed necrotic bone with evidence of infection , pain , and one or more of the following : pathologic fracture , extraoral fistula , or osteolysis extending to the inferior border of the mandible or sinus floor .
the management of bronj aimed to reduce lesion size , soft and hard tissue inflammation and to alleviate pain .
nonsurgical treatment included wide spectrum antibiotics , antifungal agents , and mouthwashes with an antimicrobial solution .
surgical treatment included debridement without mucosal elevation and removal of loose segments of bony sequestra .
we described the distribution of participants ' characteristics , including demographics , smoking status , medical history , and the prevalence and clinical features of bronj .
we performed a logistic regression analysis to estimate odds ratios ( ors ) and 95% ci for exposures of interest such as diabetes , hypertension , dental or periodontal abscess , multiple dental decays , periodontitis , dental extraction , and the presence of onj .
a total of 76 caucasian women were included in this analysis . at the time of enrollment , patients ranged in age from 51 to 91 years , with a median age of 69 years ( interquartile range 6274 ) ( table 1 ) .
in addition , 34.2% suffered from hypertension , 21.1% had cardiovascular disease , 5.3% of patients reported having diabetes , 5.3% were in treatment with an immunosuppressant agent , and 3.9% previously underwent chemo- and radiotherapy .
multiple dental decays and periodontitis were present in 61.8% and 77.6% of the individuals , respectively .
61.8% of patients were receiving alendronate , 21.1% clodronate , 3.9% ibandronate , or 13.2% risedronate .
patients had received bps consecutively for a mean duration of time of 191 weeks ( 95% ci , 150.9230.7 ) . of these 76 patients , seven ( 9.2% ) had active onj at first visit and were being treated in our clinics ( table 1 ) .
three patients were classified as being stage i , and four individuals were stage ii . among these , the majority ( 85.7% ) was in the mandible while 14.3% had onj in the maxilla .
the triggering events for onj were identified as previous dentoalveolar surgery ( n = 2 ) , local trauma from dentures ( n
all bronj patients received wide spectrum antibiotic therapy , and four patients underwent surgical debridement .
closure of the exposure and complete remission was obtained in 4 cases out of 7 . at present none of the non - onj patients submitted to invasive dental treatments developed onj signs and/or symptoms .
individuals with dental or periodontal abscess were significantly more likely to develop onj ( table 2 ) .
women with a positive history for diabetes had a significant increase in the odds of having onj ( or : 3.7 , 95% ci 0.340.9 ) .
patients who underwent dental extraction while receiving bps therapy were three times more likely to develop onj ( or : 2.9 , 95% ci 0.515.9 ) .
no significant associations were observed for the following variables : age , smoking status , type of bps used , hypertension , cardiovascular disease , immunosuppressant , previous radio- and chemotherapy , and multiple dental decays .
bisphosphonates are the most widely prescribed drugs for the treatment of osteoporosis , with more than 190 million prescriptions dispensed worldwide .
the results of our analysis showed that the incidence of onj attributable to the use of bisphosphonates was 9% .
our findings are in agreement with those of otto et al . , who conducted a large multicenter trial on the relationship between onj and the use of bps and showed that 7.8% of cases
( n = 470 ) were associated with oral bps therapy due to osteoporosis .
the risk increased also for patients who underwent dental - alveolar procedures and for those women who had periodontal disease and dental or periodontal abscess .
our results are also consistent with those from a paper by the m. d. anderson cancer center group , which reported that patients who had a dental or periodontal abscess and were taking bisphosphonates , were at a seven - fold increased risk for developing bronj .
individuals who had dental extractions were three times more likely to be diagnosed with bronj .
. showed that cancer patients with a positive history of dental extractions were associated with a significant increase in the odds of detecting onj ( or : 13.2 ; 95% ci 3.747.3 ; p < .0001 ) .
however , our odds ratios are lower than those reported by hoff and colleagues .
it may be suggested that cancer patients have a slower healing process than cancer - free but osteoporotic patients ; both radiation therapy and chemotherapy can affect the ability of cells to reproduce , which slows the healing process in the mouth .
in addition , chemotherapy may reduce the number of white blood cells and weaken the immune system , making it easier for the patient to develop an infection .
though small numbers limited our ability to fully evaluate the risk factors for onj , no associations were observed for tobacco use , presence of multiple decays , previous radiotherapy and/or chemotherapy , or concomitant use of immunosuppressant medications .
another limitation to note for this study is that our study population was hospital based .
therefore , our results may not be generalizable to the population at large . in order to overcome these sample - size issues ,
our findings indicate that patients with osteoporosis receiving bps may develop osteonecrosis of the mandible , especially in the presence of an active infectious process in the mouth such as periodontal disease or suppuration .
in addition , management of this condition requires the use of prolonged medical treatment and may require oral surgical procedures . as such , there is an urgent need to fill a knowledge gap in better characterizing this condition , identifying the main cause , and determining individual susceptibility for the intervention and prevention of bronj . to follow up on our findings ,
additional large clinical trials that aim to find how to overcome bisphosphonate - associated onj and to predict who may benefit from bisphosphonate treatment without accompanying risk of onj are warranted . in the meantime
, patients receiving bisphosphonates therapy should be followed carefully to avoid the occurrence of extended osteonecrotic lesions .
Output:
| the aim of this longitudinal study is to present data from 76 female patients treated with bisphosphonates ( bps ) for postmenopausal osteoporosis and referred to the unit of oral diagnosis and day surgery of the university of milano for diagnosis and treatment .
all patients received a thorough oral examination .
the diagnosis of osteonecrosis of the jaw bone ( onj ) was made from radiographic and clinical findings .
9% of individuals had bronj at first visit .
patients with dental or periodontal abscess were significantly more likely to develop bronj ( or : 2.9 , 95% ci 0.515.9 ) .
patients with osteoporosis receiving bps may develop bronj , especially in the presence of an active infectious process in the mouth .
clinicians should carefully follow up on individuals receiving bisphosphonates therapy to avoid the occurrence of osteonecrotic lesions . |
PubmedSumm119919 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: eukaryotic cells depend on vesicle - mediated endocytosis and secretion to interact and communicate with their environment .
such membrane - based cellular processes are dynamic as well as closely interconnected and thus require complex cellular logistics .
small vesicles , for example , cycle between the endoplasmic reticulum ( er ) , golgi and larger spherical compartments termed endosomes .
these endosomes are actively transported along polarized microtubules by the action of kinesin and dynein motor proteins to cover long distances .
kinesins mainly transport their cargo to the plus ends of microtubules whereas dynein mediates transport in the opposite direction . in simple eukaryotes such as
membrane trafficking is necessary to support fast expansion of growth cones at the hyphal tip . at the apex ,
a particular active zone of secretion is visible as spitzenkrper , which is proposed to act as a vesicle supply center .
adjacent to this structure the polarisome assembles actin cables and , most likely , anchors microtubules to the membrane thereby directing the cytoskeleton - dependent membrane traffic toward the tip .
they also deliver biosynthetic enzymes such as chitin and glucan synthases to sustain the formation of cell walls as well as hydrolytic enzymes for nutrient acquisition and cell wall remodelling .
in addition , pathogenic fungi secrete a battery of effector proteins to interact with their animal or plant host .
trafficking in the reverse direction by endocytosis is required for the uptake of membranes and membrane - associated proteins such as trans - membrane receptors .
protein cargo can be either recycled to the plasma membrane or directed to the vacuole for degradation . in fungi ,
the basidiomycete ustilago maydis has been established as a fungal model system that is particularly well - suited to study the mechanism and biological function of microtubule - dependent membrane dynamics .
important for infection is a developmental switch from saprophytic yeast cells , which proliferate by budding ( fig .
the key transcriptional regulator that triggers filamentous growth is the heterodimeric transcription factor bw / be . to constitute an active heterodimer subunits
thus , in wild type cells plasmogamy of the mates is a prerequisite for generating the active transcription factor .
however , monokaryotic lab strains have been established that express an active bw / be heterodimer under control of regulated promoters ( induced by either arabinose or nitrate ) . in these haploid strains hyphal growth , which closely resembles that of wild type filaments , can be elicited synchronously and reproducibly by switching the carbon or nitrogen source of the medium ( fig .
( a ) yeast and ( b ) filamentous form of strain ab33rab5ag expressing an active bw2/be1 variant under the control of a nitrogen - source regulated promoter and the green fluorescent protein ( gfp ) fused to the n - terminus of rab5a ( filamentous growth was induced by changing the nitrogen source of the medium ; size bars , 10 m ) .
rab5ag - positive endosomes ( arrowheads in the inverted image detecting gfp fluorescence ) shuttle bi - directionally along microtubules ( kymograph in the lower panel ) . in the kymograph time
thus , motion of rab5ag is visible as defined tracks ( note the highly processive movement and the reversal of shuttling at the poles ) .
( c ) model depicting the motor - dependent mechanism ( three motor system ) of endosome transport ( endosomes carry the small g protein rab5a and the snare yup1 ; symbols are explained in the inlay ) . in u. maydis ,
microtubule - dependent transport of endosomes is important for various steps of the life cycle : triggering cell separation during budding , receptor recycling during pheromone signaling and maintenance of polarity during filamentous growth . here , we review recent advances on the detailed transport mechanism as well as on the biological function of endosomes in signaling , endocytosis and mrna transport . for further information on microtubule transport and u. maydis biology
as mentioned above , the processes involving membrane trafficking are tightly interwoven and highly complex .
a common concept in investigating endosomal compartments is the identification of characteristic marker proteins that differentiate endosomes . at present ,
two different classes of endosomes are known in u. maydis : mcs1- and rab5a - positive endosomes .
mcs1 , the fungal class 17 myosin , consists of two domains : an n - terminal myosin motor domain and a c - terminal chitin synthase domain . transport of mcs1-positive endosomes does not depend on the myosin motor domain of mcs1 and is mediated by other actin- and microtubule - dependent motors .
the integral motor domain of mcs1 is thought to tether the membrane units to the hyphal tip .
membrane - based mcs1 trafficking is needed for its secretion by exocytosis , a process apparently required for cell wall remodelling and virulence .
rab5a is a small g protein belonging to the family of rab proteins , which serve as specific markers of distinct classes of endosomes . in u. maydis ,
rab5a - positive endosomes were suggested to be early endosomes because they can also be stained with the styryl dye fm464 , which has been used to study the endocytic pathway .
however , fm464 is not specific for endocytosis because it also stains secretory vesicles of the fungal spitzenkrper as well as secretory vesicles downstream of the trans - golgi network in plant cells .
moreover , it has not so far been reported that rab5a - positive endosomes maturate into late endosomes in u. maydis , and there is a second rab5 protein , rab5b , encoded in the genome .
therefore , we use the more generic term rab5a - positive endosomes throughout this review . an important component of rab5a - positive endosomes is the t - snare - like protein yup1 ( related to vam7p from s. cerevisiae ) that has been proposed to function in fusing endocytic vesicles with endosomes .
its precise role is yet unclear but loss of yup1 results in altered cell morphology and reduced endocytic recycling of the pheromone receptor pra1 ( see below ) .
moreover , yup1 is important for endosome movement , because their motility is drastically impaired in temperature - sensitive yup1 mutants under restrictive conditions . in the last decade ,
endosomal transport in u. maydis has been studied in great detail , both in the yeast form and in filaments .
rab5a - positive endosomes shuttle along microtubules throughout the cell moving in a highly processive fashion . at the poles they change direction without extensive pause ( fig .
each cell contains two to four microtubule bundles that consist of single microtubules oriented in an antiparallel fashion .
near the poles of filaments ( i.e. , about 10 m from both ends ) microtubules are not arranged in antiparallel bundles but form single unidirectional extensions with plus ends facing to the poles ( fig .
- end directed movement of endosomes along antiparallel bundled as well as single microtubules is mediated by kin3 ( fig .
1c ) , a kinesin-3 type motor that is related to unc104 and kif1a from nematodes and mammals , respectively .
the motor contains a c - terminal pleckstrin homology ( ph ) domain for interaction with phosphatidylinositol lipid containing membranes .
the ph domain is essential for unc104-dependent transport in neurons of c. elegans and kin3-driven movements of endosomes in filaments of u. maydis .
each endosome contains about three to six kin3 and these are responsible for the highly processive bidirectional movement along the antipolar bundles in filaments ( fig .
minus - end directed transport of endosomes is mediated by the dynein motor dyn1/2 ( fig .
this becomes important at the poles of filaments because in the unidirectional region of the microtubule cytoskeleton , minus end - directed transport is the only option for endosomes to return to the antiparallel array .
this can nicely be seen in temperature - sensitive mutants of dyn2 where rab5a - positive endosomes accumulate at the poles under restrictive conditions .
dyn1/2 can also move in the minus - end direction independently of rab5a - positive endosomes .
if such a minus - end directed dyn1/2 motor meets an oncoming endosome , dyn1/2 is able to reverse the direction of the moving endosome toward the minus end .
this process has been proposed to protect endosomes from falling off the track . how are motors recycled once they reach the ends of microtubules ? kin3 associates with rab5a - positive endosomes in both directions of transport .
this holds true , even at the poles , where unidirectional microtubules and no longer antiparallel bundles are present . in this area
dyn1/2 mediates minus - end directed transport of endosomes . here , kin3 is a cargo and no specific recycling system for kin3 is needed .
in contrast , dynein is actively transported back to the plus - ends of microtubules by conventional kinesin .
therefore endosomes accumulate at the poles in the absence of conventional kinesin because dynein required for minus - end directed transport is missing at the poles . in summary , a tripartite motor system consisting of kin3 , dynein and conventional kinesin manages the complex logistics of long - distance transport of endosomes along a highly organized array of microtubules ( fig .
interestingly , rab5a - positive endosomes exhibit rather diverse functions throughout the life cycle of u. maydis . in yeast cells they play an important role in septum formation and cell separation .
2a ) reminiscent of the mutants don1 and don3 that were originally identified owing to their striking colony morphology .
the explanation for this mutant phenotype is the failure to form a secondary septum , which is essential for cell separation after cytokinesis ( fig .
don1 encodes a guanine nucleotide exchange factor ( gef ) specific for the small gtp binding protein cdc42 and don3 is a ste20-like protein kinase acting parallel to this signaling module .
don1 carries a c - terminal fyve domain that is specific for the recognition of phosphatidylinositol-3-phosphate lipids and thus targets don1 to rab5a - positive endosomes
. kin3-mediated transport of these don1-loaded endosomes is critical for cell separation in order to synchronize cdc42-triggered secondary septum formation with the accumulation of vesicles involved in lysis of the fragmentation zone ( fig . 2c and d ) .
( a ) colony and ( b ) yeast cell morphology of strain ab33kin3 in comparison to the progenitor strain ( size bar , 10 m ) .
( c , d ) model depicting the function of rab5a - positive endosomes in the delivery of don1 to the site of septation , a process essential for formation of the secondary septum . the red rectangle shown in the middle panel of c is enlarged in d. during mating rab5a - positive endosomes are involved in endocytic recycling of the pheromone receptor pra1 .
pra1 accumulates in endocytic vesicles inside the cell in temperature - sensitive yup1 mutants under restrictive conditions and thus is missing at the plasma membrane of conjugation tubes .
this correlates with a reduced recognition of compatible mating partners and results in a fusion defect of conjugation tubes .
thus , endocytic recycling of pra1 mediated by rab5a - positive endosomes appears to be important for polarized accumulation of the receptor at the growth cones of mating hyphae that orient their growth toward pheromone sources . during filamentous growth microtubule - dependent motor function
is important for maintaining unidirectional growth of the tip cell and the concomitant formation of retraction septa at the distal end of the hyphae .
3a ) and predominantly bipolar filaments lacking retraction septa , indicating that unipolar growth is disturbed ( fig . 3b and c ) .
similar observations were made in the absence of functional dynein and conventional kinesin or in filaments treated with the microtubule inhibitor benomyl .
( a ) colony and ( b , c ) cell morphology of kin3 filaments .
the edges of colonies growing under filament - inducing conditions are shown in ( a ) .
monokaryotic filament carrying wild type allele of kin3 ( b ) is compared with the bipolarly growing filament of kin3 ( c ) strain grown under filament - inducing conditions ( size bars , 10 m ) .
( d , e ) model depicting the function of rab5a - positive endosomes during transport of mrnps .
red rectangle shown at the growth cone is enlarged in e ( symbols are explained in the inlay ) .
it is noteworthy that loss of rna - binding protein rrm4 causes a similar growth defect : mutant filaments grow mainly bipolar and fail to insert retraction septa .
this rrm - type ( rna recognition motif ) rna - binding protein constitutes an integral part of a transport machinery mediating microtubule - dependent long - distance transport of mrnas .
rrm4 binds to distinct sets of target mrnas encoding cytotopically related proteins including polarity factors such as rho3 and ribosomal proteins such as ubi1 , a natural fusion protein of ubiquitin , and rpl40 of the large ribosomal subunit .
rrm4-mediated mrna transport is believed to promote subcellular accumulation of rho3 at the retraction septum by local translation ( fig .
co - transport is observed throughout the whole filament and co - localization with these endosomes does not depend on the presence of kin3 .
in the absence of rrm4 , endosomal movement is not drastically impaired suggesting that rab5a - positive endosomes shuttle independently of rrm4 and its mrna cargo .
nevertheless , loss of rrm4 causes defects in filamentous growth resembling mutants with defects in microtubule function .
thus , mrna transport appears to be an important function of trafficking rab5a - positive endosomes , particularly during filamentous growth ( fig .
this novel function of endosomes has broad implications for mrna transport in general . in u. maydis
we could demonstrate unambiguously that microtubule - dependent mrna transport is mainly endosome dependent ( fig .
it has been observed before that mrna transport can be tightly linked to membrane trafficking . in s.
cerevisiae actin - dependent transport of mrnas can be achieved by hitchhiking on the er . during development of d. melanogaster , the endosomal marker rab11 as well as components of escrt - ii ( endosomal sorting complex required for transport ) are important for correct subcellular localization of mrnas encoding morphogens .
therefore , it is speculated that endosomes might be directly involved in short range mrna transport .
research in recent years has revealed that endosome action is a lot more complex than previously anticipated .
this is well supported by recent findings on the variety of endosomal functions in the fungal model system u. maydis : along with their function in endocytosis , rab5a - positive endosomes are important for cell separation , pheromone signaling and mrna transport .
the connection to mrna transport , in particular , adds a novel aspect to the growing list of endosomal functions . thus substantiating current views that these endomembrane compartments function as multipurpose platforms
if , for example , mrnas encoding proteins involved in endocytosis are themselves transported by endosomes , alterations of endosome function might disturb endocytosis not only directly but also indirectly via mrna transport . in the future ,
joint efforts of scientists focusing on mrna and membrane trafficking are needed to explain both the mechanistic and functional aspects of this complex and interlaced molecular sorting machinery .
Output:
| long - distance trafficking of membranous structures along the cytoskeleton is crucial for secretion and endocytosis in eukaryotes .
molecular motors are transporting both secretory and endocytic vesicles along polarized microtubules . here
, we review the transport mechanism and biological function of a distinct subset of large vesicles marked by the g - protein rab5a in the model microorganism ustilago maydis . these rab5a - positive endosomes shuttle bi - directionally along microtubules mediated by the unc104/kif1a - related motor kin3 and dynein dyn1/2 .
rab5a - positive endosomes exhibit diverse functions during the life cycle of u. maydis .
in haploid budding cells they are involved in cytokinesis and pheromone signaling . during filamentous growth endosomes
are used for long - distance transport of mrna , a prerequisite to maintain polarity most likely via local translation of specific proteins at both the apical and distal ends of filaments .
endosomal co - transport of mrna constitutes a novel function of these membrane compartments supporting the view that endosomes function as multipurpose platforms . |
PubmedSumm119920 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: fiber post systems are routinely used in restorative dentistry . in the absence of solid consensus
as regards the selection criteria of the post system , clinicians often succumb to marketing tactics as opposed to clinical evidence .
this study attempts to bridge this gap by using finite element analysis model to analyze the effect of oblique loading forces and their stress concentration in the entire assembly when incorporated into the tooth structure .
the likelihood of survival of a pulpless tooth is directly related to the quantity and quality of the remaining dental tissue . a post is commonly placed in an attempt to strengthen the tooth .
however , in vitro and in vivo studies have demonstrated that a post does not reinforce endodontically treated teeth , despite improving retention when less than 3 to 4 mm of vertical height or around 25 to 50% of clinical crown is remaining .
recent developments in esthetic dentistry have supported the use of a fiber post to restore endodontically treated teeth .
the need for light translucent composite resins and ceramics to mimic natural tooth requires the use of translucent posts to replace metal posts in the esthetic zone of the oral cavity .
the presence of a metal post can cause shadowing of the soft tissues adjacent to the root surface ; this adversely affects the esthetic results required of bonded resin and ceramic restorations in the anterior region .
when a fiber - reinforced post is bonded within the root canal , it dissipates functional and parafunctional forces , reducing the stress on the root .
acute consequences of such forces in the assembly are not anticipated , but there will be a gradual build - up of destructive stresses that finally cause the failure of the assembly . when a catastrophic force is placed on the crown of the tooth ,
the crown will fracture instead of the post , transmitting the energy of force down the root and creating a vertical root fracture .
consequently , a post system should be able to dissipate the function of energy and even overcome moderate trauma .
fiber - reinforced posts have demonstrated the ability to fracture at the coronal portion of a tooth restoration with the presence of catastrophic forces without root fracture , permitting scope of retreatment of the remaining root structure .
thus , the structural integrity and clinical longevity of post- and core - restored teeth are therefore strongly dependent on the state of stress created in their different regions due to occlusal loads .
in addition to the magnitude and direction of such loads , the stress state at a given point within a restored tooth is also influenced by factors like the design and material of the post and the quantity and quality of the remaining root tissue .
as the extensive loss of root dentin increases the risk of radicular fracture , appropriate mechanical behavior of the post is considered , in this case , to be fundamental to the success of rehabilitating restored teeth .
earlier , various methods have been used to study stress concentration in the tooth structures namely , photo - elastic studies ( photomechanical investigations ) , strain gauge studies , etc . finite element analysis ( fea )
is one of the more commonly used techniques for stress analysis.[36 ] this basic concept of this technique is the visualization of actual structure as an assembly of a finite number of elements .
three post systems from different manufacturers were used in maxillary central incisors ( virtual model ) and were subjected to forces so as to elicit data regarding their tensile strength .
varied biomechanical behavior under different stresses is expected as the post systems used are significantly dissimilar in their design , taper , and modulus of elasticity .
a maxillary central incisor was created virtually using computer - aided designing ( cad ) in a 2-dimensional model [ figure 1a , mesial view ] .
this design has all parts of an endodontically treated tooth , i.e. , enamel , dentin , cementum , alveolar bone , gutta - percha , fiber - post , luting cement , and full coverage crown .
material properties like young 's modulus and poisson 's ratio were provided to the design .
the design had only one variation which was shape of three brands , group - a ( dt light post , rdt , bisco , france ) , group - b ( luscent anchor , dentatus , usa ) , and group - c ( relyx , 3 m espe , germany ) according to their taper ( due to design patent ) and modulus of elasticity .
dt light post is double tapered ; luscent anchor in comparison has parallel shape with taper in last 1.8 mm of the apical end and in contrast relyx has uni - taper ( 8% ) in middle third of the post shape [ tables 1 and 2 ] .
( a ) shows the virtual model , ( b ) shows meshed assembly , ( c ) shows comparative results with lowest value of force generated , ( d ) shows parallelism of glass fibers in relyx post modulus of elasticity of the post systems used for study elastic properties of the materials involved in the fem calculation virtual model was rendered to meshing [ figure 1b ] , which represents division of the virtual model into smaller elements constrained by four nodes and they show dimensional changes as individual units ; the entire design assembly was subjected to finite element analysis software ( ansys ) for oblique loading forces ( 25 n , 80 n , and 125 n ) at 60 degrees to the lingual surface of the incisor .
a maxillary central incisor was created virtually using computer - aided designing ( cad ) in a 2-dimensional model [ figure 1a , mesial view ] .
this design has all parts of an endodontically treated tooth , i.e. , enamel , dentin , cementum , alveolar bone , gutta - percha , fiber - post , luting cement , and full coverage crown .
material properties like young 's modulus and poisson 's ratio were provided to the design .
the design had only one variation which was shape of three brands , group - a ( dt light post , rdt , bisco , france ) , group - b ( luscent anchor , dentatus , usa ) , and group - c ( relyx , 3 m espe , germany ) according to their taper ( due to design patent ) and modulus of elasticity .
dt light post is double tapered ; luscent anchor in comparison has parallel shape with taper in last 1.8 mm of the apical end and in contrast relyx has uni - taper ( 8% ) in middle third of the post shape [ tables 1 and 2 ] .
( a ) shows the virtual model , ( b ) shows meshed assembly , ( c ) shows comparative results with lowest value of force generated , ( d ) shows parallelism of glass fibers in relyx post modulus of elasticity of the post systems used for study elastic properties of the materials involved in the fem calculation
virtual model was rendered to meshing [ figure 1b ] , which represents division of the virtual model into smaller elements constrained by four nodes and they show dimensional changes as individual units ; the entire design assembly was subjected to finite element analysis software ( ansys ) for oblique loading forces ( 25 n , 80 n , and 125 n ) at 60 degrees to the lingual surface of the incisor .
when all three groups were subjected to analysis , group c showed maximum stress distribution in the entire structure and least forces generated ( stress concentration ) at apical third of the tooth model , which was significantly different from other two groups .
the results [ figure 1c ] in each model were presented in terms of the von misses stress values which decides the likelihood of failure of structure and material analyzed .
when oblique forces were applied to the structure , the design showed movement in the direction of force applied , i.e. , buccal flexion transferring compression at the interface of crown - core - dentin ( coronal ) near the cej ( cemento - enamel - junction ) .
similar change of shades of colors occurred at gutta - percha - post - dentin ( radicular ) interface confirming stress concentrations at this junction that can act as potential site of bond failure . colored bar at the bottom of the analysis showed maximum force ( red ) and minimum force ( blue ) generated when the analysis was conducted in ansys software .
minimal changes in colors were observed in apical third of the tooth structure that signifies complete dissipation of occlusal load and predicting potential absence of vertical fractures that were a result of using metal post in in vivo and in vitro experiments conducted in the past .
the structure of the tooth which remains after endodontic treatment is usually undermined by previous episodes of caries , fracture , and tooth preparation .
it is established that many detrimental effects produced during rehabilitative procedures are due to lack of understanding biomechanical principles underlying the treatment .
the purpose of using products that have mechanical properties closer to dentin and enamel has always been to obtain best resistance and retention of the restoration done during application of dislodging or occluding forces , thus protecting the remaining tooth structure .
when occlusal forces act on tooth surface , they divide into two components ( vectors ) .
such forces create stresses as dentin is a dynamic structure and such stress escapes into dentin in the form of crack propagation , ultimately resulting in crazing .
fiber post systems are a popular choice of modern dentists for replacing and restoring missing tooth structure in grossly mutilated teeth .
this vogue of fiber post is due to their ease of handling , manipulation , and impeccable esthetic value , especially for anterior teeth .
fea is a mathematical analysis of designs which can demonstrate the amount of stress generated on application of forces and site of fracture and application of this technology in dentistry is very important which can reduce operator 's bias during sample preparation for in vitro studies .
all variables were eliminated due to cad and only the product desired for study acted as a variable . for conducting fem study ,
poisson 's ratio and young 's modulus of elasticity of all components were taken from previous studies.[916 ] variety of products in the same genre always adds to dilemma of choosing rightly .
anterior teeth subjected to oblique forces angulated at 60 degrees form the long axis on the lingual surface as mandibular incisors contact the maxillary teeth at this angulation .
three different amounts of forces were chosen to observe behavior of post system from mild forces ( 25 n ) for biting to heavy bruxism forces ( 125 n ) and a near mean average of the forces ( 80 n ) .
relyx , when subjected to forces within the parameters of the study , resulted in least amount of forces ( stress concentration ) that reached the gutta - percha - cement - post interface [ figure 1c ] at the apical third of endodontically treated tooth .
this result can be attributed to the parallel fibers present in the post and unique modulus of elasticity , which provided better resistance to applied forces [ figure 1d ] .
for superior mechanical properties , the glass fibers have parallel orientation and are distributed equally over the surface area .
additionally , during the manufacturing process , the glass fibers are pretensioned for enhanced post stability .
therefore , during the clinical application , relyx fiber posts have to be cut with a diamond disc ( according to manufacturer 's specifications provided in product brochure ) . in a restored tooth , when the loading angle is kept fixed , increasing the load was found to increase the von misses stress . applying this data to a real model
, one can suggest that the loading at which the tooth is being subjected may not create immediate failure in the tooth , but may create cracks in the tooth assembly which may , over a duration of time , cause catastrophic failure .
a virtual model can not completely mimic an in vivo model that is subjected to all types of occlusal forces .
a 2-d model can never represent an actual 3-dimensional tooth structure . also , the accuracy of the entire analysis depends on software , model created , and elemental values given to the study .
incorrect values as inputs and inaccurate design can lead to varying results which are vulnerable to wrong results . an accurate estimation of results can be obtained which can increase anticipation for a better clinical performance , when mechanical testing for failure will be conducted , and improves their predictability .
data available in the literature indicating better performance with fiber post are probably the result of the use of adhesive cementation . because the longevity of bonding procedures involving radicular dentin are uncertain , a long - term clinical follow - up is necessary to confirm the effectiveness of glass fiber posts as a restorative solution for endodontically treated teeth .
disclaimer : as the author of the abovementioned article , affirm that i neither have financial affiliation ( e.g. , employment , direct payment , stock holdings , retainers , consultant - ships , patent licensing arrangements , or honoraria ) or involvement with any commercial organization with direct financial interest in the subject or materials discussed in this manuscript , nor have any such arrangements existed in the past three years .
within the confined limitations of fea , in the given framework , fiber post relyx ( 3 m ) is the best choice among other competitive products available , resulting in longevity of the restoration that is the final goal of the grossly decayed teeth .
it is conclusive from the results of the study that fiber post system with components of higher modulus will enable better stress distribution .
additional observations suggest that when oblique load ( tensile ) is applied on a tooth restored with fiber post , there is high stress concentration at gutta - percha - cement - post interface . also , the stress concentration was present in the immediate vicinity of apical end of the post and was found to be inversely proportional to the young 's modulus value of the post system used .
mechanical testing of these products with larger sample sizes are required to support the result of studies conducted using fea .
Output:
| aims and objectives : to study the stress concentrations in endodontically treated maxillary central incisor teeth restored with 3 different fiber post systems subjected to various oblique occlusal loads.materials and methods : fem analysis was used to analyze stress concentrations generated in maxillary anterior teeth .
computer aided designing was used to create a 2-d model of an upper central incisor .
post systems analyzed were the dt light post ( rdt , bisco ) , luscent anchor ( dentatus ) & relyx ( 3m - espe ) .
the entire design assembly was subjected to analysis by ansys for oblique loading forces of 25n , 80n & 125 nresults : the resultant data showed that the relyx generated the least amount of stress concentration.conclusions:minimal stress buildups contribute to the longevity of the restorations .
thus relyx by virtue of judicious stress distribution is the better option for restoration of grossly decayed teeth . |
PubmedSumm119921 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: in most of the peer review publications in the late 17 century , authorship of papers generally used to be autonomous and was attributed to the sponsors ( 1 ) .
however , now the readers wish to know who paid for research and who did the work .
problems with authorship persist everywhere despite the international committee of medical journal editors ( icmje ) criteria ( 2 ) . authorship is considered as currency in the field of biomedical sciences and most of the researchers open their first publication account either during their undergraduate or during postgraduate studies and then continue to add further when they acquire faculty positions ( 2 ) .
someone with impressive research publications curriculum vitae ( cv ) has much better chances of selection and it also helps in further academic promotions .
strong publication record also leads to further publications , providing great career opportunities ; they are preferred to be considered for tenure status appointments , grants and funding .
in addition they also earn respect and admiration in the community of research scientists ( 3 ) .
publish or perish has been very popular in the west now for many years . in the developing third world countries , recognition and credit for published research work for academic appointments in medical institutions started only about two decades ago with the result that now faculty members are under compulsion to write and publish , hence at times the quality of their research is not very good .
there is also a temptation to get gift authorship and this menace has been spreading everywhere .
it is generally felt that manuscripts having too many authors certainly include a few whose names have been added without any intellectual contribution and they are the recipients of gift authorship . in order to overcome this problem , renie proposed contributor - ship system many years ago ( 4 ) . listing contributor - ship
european medical writers association ( emwa ) guidelines state that medical writes and statistician do not qualify for authorship but their role should be acknowledged ( 5 ) .
issues related to authorship consist of almost 25% of the cases discussed at cope meetings ( 6 ) and this issue is discussed at almost every peer review congress and medical editors conferences held in different parts of the world .
just like everywhere else , in pakistan too , medical editors have been faced with this issue of authorship and many times even the details of contribution which is now demanded by some journals , do not enable those listed in the bylines as authors but the editors can not do much in this regard .
the objective of this study was to assess the knowledge and ascertain views of researchers on icmje criteria for authorship , their current practice of choosing authors of scientific papers , views on gift authorship and experience of authorship problems .
it was a cross sectional survey of 218 faculty members ( 180 males and 38 females ) of various medical universities ( dow university of health sciences - karachi , baqai medical university karachi , liaquat university of medical sciences - hyderabad , avicenna medical college lahore , king edward medical university
the main outcome measures were awareness and use of icmje criteria for authorship , awareness as to which contributions to research merit authorship , perceptions about gift authorship .
the participants were also asked about the problems they faced in deciding authorship and what strategies they wish should be adopted to eliminate gift authorship .
majority of the respondents 105 ( 48.2% ) out of 218 faculty members who participated in the study were senior registrars and again one hundred twenty eight ( 58.7% ) were from surgery and allied disciplines because the principal investigator was himself a surgeon .
ninety six ( 44.0% ) had between one to five publications while 60 ( 27.5% ) had six to ten published papers to their credit ( table 1 ) .
demographic profile of the respondents ( n = 218 ) one hundred eleven participants ( 50.9% ) said they were aware about the existence of guidelines on criteria for authorship however only twenty two ( 19.8% ) could name this document , only four ( 1.8% ) could correctly state the criteria for authorship suggested by the icmje ( table 2 ) .
knowledge of icmje criteria of authorship ( n = 218 ) responding as to what they thought of the icmje authorship criteria , 201 ( 92.7% ) agreed with the first criteria as regards substantial contribution to conception and design , acquisition of data and its analysis , interpretation while 186 ( 85.3% ) also agreed with drafting the article and revising it critically and an almost similar number 179 ( 82.1% ) agreed with the final approval of the version to be published .
however , only 120 ( 55.0% ) said that all the above three criteria must be met to be eligible for authorship ( table 3 ) .
views of the participants as regards contributions which merit authorship for scientific publications are given in table 4 .
attitude about the icmje criteria of authorship(n = 218 ) faculty view of criteria which alone contribution merits author of scientific publication ( n = 218 ) only 34 ( 19.7% ) of the respondents felt that authorship should be based on contributions while 98 ( 45.0% ) felt it is decided by the main author who also decide the order of authorship ( table 5 ) .
ninety three ( 42.7% ) stated that they were not included as authors in the study though they deserved to be while sixty three said that they were included as authors though they did not merit .
strangely 42 ( 19.3% ) said that they were not aware when they were listed as authors ; 52 two said they had been assigned inappropriate co - authorship and the same number had perception of incorrect placing in authorship order ( table 6 ) .
faculty current trend of co -authorship and order of authorship ( n = 218 ) faculty perception of any problems with authorship ( n = 218 )
fifty percent of respondents in our study had knowledge about the existence of some guidelines regarding criteria for authorship but only19.8% could name it whereas only four out of 218 ( 1.8% ) could state the icmje authorship criteria which is a very dismal picture .
hence those participants , who claimed that they were aware of it but had forgotten , could have easily picked it up from there . since they could
( 7 ) . in their study fifty out of sixty respondents supported the criteria for authorship though only a few knew about it or used it and only five people could specify all the three criteria and out of them only one knew that all the three criteria s have to be met as against 55% in our study who felt that all three criteria s must be met for authorship .
they also reported that gift authorship was quite common which was promoted by pressure to publish , to motivate research team and maintain working relationship .
they were of the view that a signed statement which could justify authorship besides contributions by each author could help tackle the issue of gift authorship .
their conclusions were that there is a gap between the editor s criteria for authorship and researchers practice .
they believe that the future criteria for authorship should be agreed by researchers and it should not be imposed by the editors . in a french study pignatell et al . who interviewed 39 investigators who submitted 48 proposals during 1994 - 96 , half of the respondents said that they were aware of the authorship criteria and also knew about icmje but
most of them disagreed with the obligation to meet all the three criteria justifying co - authorship because they found it too rigid and inapplicable which is similar to the findings in our study .
again 59% in the french study had been recipients of gift authorship and they felt that there was a need to have french guidelines for authorship .
french researchers had serious reservations regarding third criteria i.e. approval of the final version to be published .
few people question ghost or gift authorship and most of them consider it normal which is a serious problem requiring in - depth debate and discussions .
they also suggested that guidelines on authorship should be prepared by professionals , by learned societies , representatives of biomedical journals besides public research institutes and national organizations ( 8) . in a survey from india among teaching faculty ( 9 ) , 39% of respondents out of 77 reported conflict on authorship issues like pressure for gift authorship , academic competition , personality differences and intellectual passion besides ownership of data .
they also suggested training in ethical concerns in research at undergraduate level . though most authors do understand the authorship issues but as stated by dr .
it is not sufficiently considered that men require more often to be reminded than to be informed . in a debate on authorship issues in bmj
, scot tim remarked that the present authorship system should continue its slow evolution since it reflects the real power relations in science ( 10 ) but richard smith , editor bmj reported that authorship is influenced by power and departmental politics ( 11 ) .
currie opined that authors saw fraud , misconduct and unfairness to more junior staff and the culprits are most often the senior researchers .
those applying for specialists registrars should be asked to choose two of their best publications for inclusion in cv and they should be prepared to discuss one of the two publications they have submitted in the previous year . for consultants merit awards and cme points should be related more to quality and relevance than to number of publications ( 11 ) .
tramara bates and colleagues in their study reported that as per authors published contributions , number of honorary authors was highest in annals of internal medicine 21.5% followed by bmj 9.5% and jama 0.5% .
the number of articles with honorary authors was 60% in annals , 215 in mbj and 4% in jama ( 12 ) .
out of 6,686 researches only 68% fulfilled the icmje criteria as per author s contributions lists of radiology articles published during 1998 - 2000 ( 13 ) .
these criteria of fulfillment decreased as the number of authors increased , 2,316 researchers ( 35% ) contributed to one or two categories .
this study further showed that a total of 2,172 ( 32.5% ) out of 6,686 authors appearing in the bylines did not fulfill the icmje criteria for authorship ( 13 ) . in our study over 80% of the respondents opined that designing the study and collection of data were important followed by conceiving the research idea besides literature search and review as regards eligibility for authorship .
goodman reported that one third of 84 authors did not meet authorship criteria in an analysis of twelve articles ( 14 ) while shapiro after survey of 184 articles with multiple authors from ten medical journals reported that 268 ( 26% ) of 1014 authors had insufficient contributions to research to meet authorship criteria ( 15 ) .
ana marusic and colleagues did a single blind randomized trial of1462 authors of 232 manuscripts from a general medical journal who answered one of the three different contribution disclosure forms .
they asked the respondents to decide in their own words their contribution to the submitted manuscripts .
they found that the structure of the contribution disclosure form significantly influenced the number of contributions reported by the authors and their compliance with icmje criteria .
they have concluded that editors of journals should not take the existing contribution disclosure and the authorship forms on their face value ( 16 ) .
more than half of the major papers published in american journal of roentgenology ( ajr ) had five or more co - authors ( 17 ) .
the incidence of undeserved co - authors increased from 9% on papers with three authors to 30% in papers with more than six authors which mean that more authors a manuscript has , more are the chances of gift authorship .
gift authorship was primarily attributed to those who had some control over the first author because of fear or obligation .
moreover a temporary staff member they found was more likely to gift the authorship than a permanent faculty ( 17 ) .
conception and design , analysis and interpretation and drafting of articles were recognized as the most important of the icmje criteria ( 18 ) .
final approval and critical revision should be taught as important authorship criteria to the future scientists ( 18 ) .
vesnailakovac and colleagues in their study which included 919 authors of 201 articles submitted to a general medical journal found that more than two third of the corresponding authors ( 67.9% ) differed in at least one contribution choice between the two disclosure statements made about their own contributions ( 19 ) .
some others studies report that giving medical students clear guidelines and exposing them to high ethical standards should be a long term solution to the problem of authorship abuses in the field of medical research ( 20 ) .
a recent study from iran reported that 89% of published bio - medical articles in iran have at least one honorary author .
more than 50% of article authors did not meet the authorship criteria according to icmje .
about 20% authors confessed they had colleagues omitted from the authors list of the final manuscript .
the author of this iranian study concluded that regardless of authorship criteria recommended by icmje and followed by many journals , still there are cases when authorship criteria is not followed ( 21 ) .
it all shows that we have not yet found an answer which is acceptable to the editors , authors as well as researches as regards authorship and this debate still continues and perhaps will continue for some more time .
various suggestions are being put forward to redefine the criteria for authorship but the final word has not yet been spoken .
it is also evident from the fact that authorship is an important topic which comes under discussion at various forums .
icmje , other bodies of science editors as well as representatives from research institutions and researchers need to come up with authorship guidelines which are acceptable to most of the stakeholders . finding a hundred percent consensus is neither possible nor it should be aimed at since some people will continue to have their own view point on this issue .
majority of our participants in the study was junior faculty members i.e. registrars or assistant professors who had just begun their academic career and an overwhelming majority one hundred eighty out of two hundred eighteen participants were male .
most of this junior faculty had either not written any or just one to five papers .
hence they were either not aware about the existence of any guidelines or familiar with icmje .
this was also the main reason that over 98% of them could not correctly state the icmje criteria of authorship .
yet another limitation was that in a self - administered questionnaire based survey , participants tend to provide information which may not be 100% correct .
medical students should be exposed to the art of medical writing from the beginning and those institutions which have not yet included the subject of medical writing and research methodology it in their curriculum must be advised to do so .
similarly regular workshops particularly for junior faculty members , postgraduates on medical writing , guidance on how to plan , conduct study , highlighting the existing guidelines on authorship by various bodies including icmje will help them expose to the scientific publishing world thus improving the quality of their studies as well .
majority of our participants in the study was junior faculty members i.e. registrars or assistant professors who had just begun their academic career and an overwhelming majority one hundred eighty out of two hundred eighteen participants were male .
most of this junior faculty had either not written any or just one to five papers .
hence they were either not aware about the existence of any guidelines or familiar with icmje .
this was also the main reason that over 98% of them could not correctly state the icmje criteria of authorship .
yet another limitation was that in a self - administered questionnaire based survey , participants tend to provide information which may not be 100% correct .
medical students should be exposed to the art of medical writing from the beginning and those institutions which have not yet included the subject of medical writing and research methodology it in their curriculum must be advised to do so .
similarly regular workshops particularly for junior faculty members , postgraduates on medical writing , guidance on how to plan , conduct study , highlighting the existing guidelines on authorship by various bodies including icmje will help them expose to the scientific publishing world thus improving the quality of their studies as well .
a vast majority of young faculty members are not aware of the existence of authorship criteria by icmje and gift authorship is quite common in pakistan .
ethical issues ( including plagiarism , informed consent , misconduct , data fabrication and/or falsification , double publication and/or submission , redundancy , etc ) have been completely observed by the authors .
Output:
| abstractbackgroundthe objective of this study was to assess the knowledge and views of faculty members on criteria for authorship by international committee of medical journal editors ( icmje ) , their current practice of choosing the authors , views on gift authorship and problems they had faced concerning authorship.methodsit was a cross sectional survey from january 2011 to july 2011 among faculty members of various private and public sector medical institutions of pakistan through a self - administered questionnaire .
main outcome measures included awareness and use of icmje criteria , which contribution to research merit authorship and their perceptions about gift authorship.resultstwo hundred eighteen faculty members ( 180 males , 38 females ) participated in the study .
one hundred twenty eight ( 58.7% ) were from surgery and allied disciplines .
ninety six percent had published between one to five papers while 60(27.5% ) had six to ten papers to their credit .
one hundred eleven ( 50.9% ) claimed they were aware about the authorship criteria , only twenty two ( 19.8% ) could name this document .
only four ( 1.8% ) could correctly state this . only one hundred twenty ( 55.0% ) said that all three criteria s must be met to be eligible for authorship .
ninety three ( 42.7% ) said that they were not included as authors though they deserved it while sixty three said they did not merit but were still included .
forty two ( 19.3% ) said that they were not aware when they were listed as authors.conclusiona vast majority of young faculty members are not aware of the existence of authorship criteria and gift authorship is quite common . |
PubmedSumm119922 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input:
the reveal registry is a longitudinal registry involving 54 pulmonary hypertension centers in the united states ( e - appendix 1 ) .
diagnosis was defined as the date of diagnostic right - sided heart catheterization ( rhc ) occurring at or before the date of enrollment .
patients with new diagnoses were defined as those whose diagnostic rhc occurred within 90 days of enrollment .
all consecutive patients who , in the opinion of the enrolling investigator , had a clinical diagnosis of pah who group 1 and met the following inclusion criteria were eligible for enrollment : ( 1 ) mean pulmonary artery pressure of > 25 mm hg at rest or 30 mm hg with exercise , ( 2 ) mean pulmonary capillary wedge pressure or left ventricular end diastolic pressure of 18 mm hg , ( 3 ) pvr of 240 dynes / s / cm ( divide by 80 for wood units [ wu ] ) , and ( 4 ) 3 months of age . the data in the reveal registry was collected prospectively , but the analyses for this study were performed retrospectively .
the database of 3,515 patients was locked on february 4 , 2013 , for the current analyses .
we developed an algorithm ( fig 1 ) to exclude patients with exercise - induced pah , in accordance with the dana point classification criteria , and those with pulmonary capillary wedge pressure > 15 mm hg , who have been shown to differ in many respects from those meeting the traditional hemodynamic definition of pah , and included only patients with ctd - apah .
we also excluded those with evidence of significant interstitial lung disease ( ild ) , defined as those with evidence of severe fibrosis on high - resolution ct scan of the chest or
we divided the patients with ctd - apah into those with ssc - apah ( ssc group ) and those with non - ssc - ctd - apah ( non - ssc group ) .
strobe diagram of the registry to evaluate early and long - term pah management ( reveal ) registry patients used in this analysis .
we included only patients with ctd - apah who met the strict criteria of world health organization group 1 pulmonary arterial hypertension .
ctd - apah = pulmonary arterial hypertension associated with connective tissue disease ; hrct = high - resolution ct scan of the chest ; ild = interstitial lung disease ; non - ssc - ctd = connective tissue disease other than systemic sclerosis ; pcwp = pulmonary capillary wedge pressure ; ssc = systemic sclerosis ; tlc = total lung capacity .
baseline characteristics at the time of enrollment were compared between the ssc and non - ssc groups , using the student t or wilcoxon test to compare continuous variables and the or fisher exact test to compare categorical variables . because bnp levels were highly skewed , the variables were log transformed for comparison as continuous variables
. cumulative probabilities of survival at 3 years were calculated using the kaplan - meier estimator for both the previously and newly diagnosed populations , and differences between the ssc and non - ssc groups were compared using the log - rank test .
cox regression models identified significant predictors of mortality in the ssc and non - ssc populations .
all variables identified previously as candidate predictors of mortality in the overall reveal registry population were evaluated in univariate and multivariate models .
stepwise selection was used to determine the final model , retaining only variables with p < .05 .
sas , version 9.1 ( sas institute inc ) statistical software was used for all analyses .
the reveal registry is a longitudinal registry involving 54 pulmonary hypertension centers in the united states ( e - appendix 1 ) .
diagnosis was defined as the date of diagnostic right - sided heart catheterization ( rhc ) occurring at or before the date of enrollment .
patients with new diagnoses were defined as those whose diagnostic rhc occurred within 90 days of enrollment .
all consecutive patients who , in the opinion of the enrolling investigator , had a clinical diagnosis of pah who group 1 and met the following inclusion criteria were eligible for enrollment : ( 1 ) mean pulmonary artery pressure of > 25 mm hg at rest or 30 mm hg with exercise , ( 2 ) mean pulmonary capillary wedge pressure or left ventricular end diastolic pressure of 18 mm hg , ( 3 ) pvr of 240 dynes / s / cm ( divide by 80 for wood units [ wu ] ) , and ( 4 ) 3 months of age .
the data in the reveal registry was collected prospectively , but the analyses for this study were performed retrospectively .
the database of 3,515 patients was locked on february 4 , 2013 , for the current analyses .
we developed an algorithm ( fig 1 ) to exclude patients with exercise - induced pah , in accordance with the dana point classification criteria , and those with pulmonary capillary wedge pressure > 15 mm hg , who have been shown to differ in many respects from those meeting the traditional hemodynamic definition of pah , and included only patients with ctd - apah .
we also excluded those with evidence of significant interstitial lung disease ( ild ) , defined as those with evidence of severe fibrosis on high - resolution ct scan of the chest or
we divided the patients with ctd - apah into those with ssc - apah ( ssc group ) and those with non - ssc - ctd - apah ( non - ssc group ) .
strobe diagram of the registry to evaluate early and long - term pah management ( reveal ) registry patients used in this analysis .
we included only patients with ctd - apah who met the strict criteria of world health organization group 1 pulmonary arterial hypertension . ctd - apah = pulmonary arterial hypertension associated with connective tissue disease ; hrct = high - resolution ct scan of the chest ; ild = interstitial lung disease ; non - ssc - ctd = connective tissue disease other than systemic sclerosis ; pcwp = pulmonary capillary wedge pressure ; ssc = systemic sclerosis ; tlc = total lung capacity .
baseline characteristics at the time of enrollment were compared between the ssc and non - ssc groups , using the student t or wilcoxon test to compare continuous variables and the or fisher exact test to compare categorical variables . because bnp levels were highly skewed , the variables were log transformed for comparison as continuous variables .
cumulative probabilities of survival at 3 years were calculated using the kaplan - meier estimator for both the previously and newly diagnosed populations , and differences between the ssc and non - ssc groups were compared using the log - rank test .
cox regression models identified significant predictors of mortality in the ssc and non - ssc populations .
all variables identified previously as candidate predictors of mortality in the overall reveal registry population were evaluated in univariate and multivariate models .
stepwise selection was used to determine the final model , retaining only variables with p < .05 .
sas , version 9.1 ( sas institute inc ) statistical software was used for all analyses .
of 3,515 patients enrolled in the reveal registry , 815 were identified as having ctd - apah ( fig 1 ) . of these ,
804 ( 500 ssc and 304 non - ssc ) who did not have significant ild were selected for these analyses .
the majority of patients in the non - ssc group had systemic lupus erythematosus - apah or mixed ctd - apah ( table 1 ) .
patients with ssc were older and had a shorter time between diagnostic rhc and enrollment into the database than did the patients with non - ssc - ctd - apah ( table 2 ) .
patients with ssc - apah had more severe disease overall , with a higher nyha fc , shorter 6mwd , higher borg dyspnea index , lower dlco , and higher bnp level .
patients with ssc - apah were also more likely to have renal insufficiency and pericardial effusions than patients with non - ssc - ctd - apah .
although there was a strong trend toward higher mrap in the ssc group , there were no significant differences in hemodynamics or pah - specific therapies at the time of enrollment in the ssc vs non - ssc groups .
apah = associated with pulmonary arterial hypertension ; ctd = connective tissue disease ; non - ssc - ctd = connective tissue disease other than systemic sclerosis ; ssc = systemic sclerosis .
characteristics , hemodynamics , and cardiac and pulmonary function at enrollment p value calculation uses test for categorical data or fisher exact test for categorical data with small cell counts ( 5% ) , and student t test for continuous data .
6mwd = 6-min walk distance ; bnp = brain natriuretic peptide ; bpm = beats per min ; ccb = calcium channel blocker ; dlco = diffusion capacity of the lung for carbon monoxide ; era = endothelin receptor agonist ; fc = functional class ; fco = fick cardiac output ; mpap = mean pulmonary arterial pressure ; mrap = mean right atrial pressure ; nyha = new york heart association ; pah = pulmonary arterial hypertension ; pcwp = pulmonary capillary wedge pressure ; pde-5 = phosphodiesterase type-5 ; pvr = pulmonary vascular resistance ; rhc = right - sided heart catheterization . see table 1 legend for expansion of other abbreviations .
cardiac output = fco , or , if fco is missing , then cardiac output = thermodilution cardiac output .
pvr ( wood units ) = ( mean pulmonary arterial pressure at rest pcwp at rest)/cardiac output , where cardiac output = fco , or , if fco is missing , then cardiac output = thermodilution cardiac output . predicted value based on hankinson et al computation .
three - year survival in the ssc group was worse than in the non - ssc group in both the previously and newly diagnosed populations ( 61.4% 2.7% vs 80.9% 2.7% and 51.2% 4.0% vs 76.4% 4.6% , respectively ; p <
three - year survival curves in patients with ssc and non - ssc - ctd - apah .
a , three - year survival from enrollment in the newly diagnosed ssc group was 51.2% 4.0% compared with 76.4% 4.6% in the non - ssc - ctd group ( p < .001 ) .
b , three - year survival from enrollment in the previously diagnosed ssc group was 61.4% 2.7% compared with 80.9% 2.7% in the non - ssc - ctd group ( p < .001 ) .
figure 3 shows the univariate analyses of previously identified predictors of mortality from the overall reveal registry cohort in the ssc and non - ssc groups .
the following variables were predictive of mortality in both groups : age > 60 years , nyha fc iii or iv status , 6mwd < 165 m , and bnp > 180 pg / ml .
unique predictors of mortality in the ssc group , but not the non - ssc group , included male sex , systolic bp ( sbp ) 110 mm hg , pericardial effusion , dlco 32% predicted , mrap > 20 mm hg within 1 year , pvr > 32 wu , and newly diagnosed status .
bnp levels < 50 pg / ml were protective in patients with ssc ( hazard ratio [ hr ] = 0.34 ; 95% ci , 0.16 - 0.72 ; p = .005 ) but not in the non - ssc group ( hr = 0.68 ; 95% ci , 0.36 - 1.29 ; p = .24 ) .
figure 3 also shows the univariate analyses of additional variables that are relevant to the ctd - apah population .
mild to moderate ild was the only feature that increased mortality in patients with non - ssc - ctd - apah but not in patients with ssc - apah ( hr = 2.19 ; 95% ci , 1.14 - 4.23 ; p = .02 vs hr = 0.84 ; 95% ci , 0.55 - 1.30 ; p = .44 ) . when compared with ipah , mrap >
20 mm hg within 1 year , pvr > 32 wu , and newly diagnosed status remained unique predictors of death in the ssc - apah group .
predictors of mortality for patients with ssc - apah and non - ssc - ctd - apah using univariate cox regression analyses .
unique predictors of mortality in the ssc group , but not the non - ssc group , included male sex , sbp 110 mm hg , pericardial effusion , dlco 32% predicted , mrap > 20 mm hg within 1 y , pvr > 32 wu , and newly diagnosed status .
bnp levels < 50 pg / ml were protective in patients with ssc , but not in the non - ssc group .
mild to moderate ild was the only feature that increased mortality in the non - ssc group but not in patients with ssc .
6mwd = 6-min walk distance ; bnp = brain natriuretic peptide ; dlco = diffusion capacity of the lung for carbon monoxide ; fc = functional class ; gfr = glomerular filtration rate ; hr = hazard ratio ; mrap = mean right atrial pressure ; nyha = new york heart association ; pvr = pulmonary vascular resistance ; sbp = systolic bp ; who = world health organization ; wu = wood units .
, the following variables remained predictive of mortality in both the ssc and non - ssc groups : nyha fc iii or iv status and bnp > 180 pg / ml ( table 3 ) .
unique predictors of mortality in the ssc group included men > 60 years , sbp 110 mm hg , 6mwd < 165 m , mrap > 20 mm hg within 1 year , and pvr > 32 wu . 6mwd 440
m was protective in the non - ssc group , but not in the ssc group , whereas bnp < 50 pg / ml was protective in the ssc group , but not in the non - ssc group .
of 3,515 patients enrolled in the reveal registry , 815 were identified as having ctd - apah ( fig 1 ) . of these ,
804 ( 500 ssc and 304 non - ssc ) who did not have significant ild were selected for these analyses .
the majority of patients in the non - ssc group had systemic lupus erythematosus - apah or mixed ctd - apah ( table 1 ) .
patients with ssc were older and had a shorter time between diagnostic rhc and enrollment into the database than did the patients with non - ssc - ctd - apah ( table 2 ) .
patients with ssc - apah had more severe disease overall , with a higher nyha fc , shorter 6mwd , higher borg dyspnea index , lower dlco , and higher bnp level .
patients with ssc - apah were also more likely to have renal insufficiency and pericardial effusions than patients with non - ssc - ctd - apah .
although there was a strong trend toward higher mrap in the ssc group , there were no significant differences in hemodynamics or pah - specific therapies at the time of enrollment in the ssc vs non - ssc groups .
apah = associated with pulmonary arterial hypertension ; ctd = connective tissue disease ; non - ssc - ctd = connective tissue disease other than systemic sclerosis ; ssc = systemic sclerosis .
characteristics , hemodynamics , and cardiac and pulmonary function at enrollment p value calculation uses test for categorical data or fisher exact test for categorical data with small cell counts ( 5% ) , and student t test for continuous data .
6mwd = 6-min walk distance ; bnp = brain natriuretic peptide ; bpm = beats per min ; ccb = calcium channel blocker ; dlco = diffusion capacity of the lung for carbon monoxide ; era = endothelin receptor agonist ; fc = functional class ; fco = fick cardiac output ; mpap = mean pulmonary arterial pressure ; mrap = mean right atrial pressure ; nyha = new york heart association ; pah = pulmonary arterial hypertension ; pcwp = pulmonary capillary wedge pressure ; pde-5 = phosphodiesterase type-5 ; pvr = pulmonary vascular resistance ; rhc = right - sided heart catheterization . see table 1 legend for expansion of other abbreviations .
cardiac output = fco , or , if fco is missing , then cardiac output = thermodilution cardiac output .
pvr ( wood units ) = ( mean pulmonary arterial pressure at rest pcwp at rest)/cardiac output , where cardiac output = fco , or , if fco is missing , then cardiac output = thermodilution cardiac output . predicted value based on hankinson et al computation .
three - year survival in the ssc group was worse than in the non - ssc group in both the previously and newly diagnosed populations ( 61.4% 2.7% vs 80.9% 2.7% and 51.2% 4.0% vs 76.4% 4.6% , respectively ; p < .001 ) ( fig 2 ) .
three - year survival curves in patients with ssc and non - ssc - ctd - apah .
a , three - year survival from enrollment in the newly diagnosed ssc group was 51.2% 4.0% compared with 76.4% 4.6% in the non - ssc - ctd group ( p < .001 ) .
b , three - year survival from enrollment in the previously diagnosed ssc group was 61.4% 2.7% compared with 80.9% 2.7% in the non - ssc - ctd group ( p < .001 ) . see figure 1 legend for expansion of abbreviations .
figure 3 shows the univariate analyses of previously identified predictors of mortality from the overall reveal registry cohort in the ssc and non - ssc groups .
the following variables were predictive of mortality in both groups : age > 60 years , nyha fc iii or iv status , 6mwd < 165 m , and bnp > 180 pg / ml .
unique predictors of mortality in the ssc group , but not the non - ssc group , included male sex , systolic bp ( sbp ) 110 mm hg , pericardial effusion , dlco 32% predicted , mrap > 20 mm hg within 1 year , pvr > 32 wu , and newly diagnosed status .
bnp levels < 50 pg / ml were protective in patients with ssc ( hazard ratio [ hr ] = 0.34 ; 95% ci , 0.16 - 0.72 ; p = .005 ) but not in the non - ssc group ( hr = 0.68 ; 95% ci , 0.36 - 1.29 ; p = .24 ) .
figure 3 also shows the univariate analyses of additional variables that are relevant to the ctd - apah population .
mild to moderate ild was the only feature that increased mortality in patients with non - ssc - ctd - apah but not in patients with ssc - apah ( hr = 2.19 ; 95% ci , 1.14 - 4.23 ; p = .02 vs hr = 0.84 ; 95% ci , 0.55 - 1.30 ; p = .44 ) .
when compared with ipah , mrap > 20 mm hg within 1 year , pvr > 32 wu , and newly diagnosed status remained unique predictors of death in the ssc - apah group .
predictors of mortality for patients with ssc - apah and non - ssc - ctd - apah using univariate cox regression analyses .
unique predictors of mortality in the ssc group , but not the non - ssc group , included male sex , sbp 110 mm hg , pericardial effusion , dlco 32% predicted , mrap > 20 mm hg within 1 y , pvr > 32 wu , and newly diagnosed status .
bnp levels < 50 pg / ml were protective in patients with ssc , but not in the non - ssc group .
mild to moderate ild was the only feature that increased mortality in the non - ssc group but not in patients with ssc .
6mwd = 6-min walk distance ; bnp = brain natriuretic peptide ; dlco = diffusion capacity of the lung for carbon monoxide ; fc = functional class ; gfr = glomerular filtration rate ; hr = hazard ratio ; mrap = mean right atrial pressure ; nyha = new york heart association ; pvr = pulmonary vascular resistance ; sbp = systolic bp ; who = world health organization ; wu = wood units .
, the following variables remained predictive of mortality in both the ssc and non - ssc groups : nyha fc iii or iv status and bnp > 180 pg / ml ( table 3 ) .
unique predictors of mortality in the ssc group included men > 60 years , sbp 110 mm hg , 6mwd < 165 m , mrap > 20 mm hg within 1 year , and pvr > 32 wu . 6mwd 440
m was protective in the non - ssc group , but not in the ssc group , whereas bnp < 50 pg / ml was protective in the ssc group , but not in the non - ssc group .
our study provides further evidence that patients with ssc - apah experience higher mortality rates than do patients with other ctd - apah in both incident and prevalent populations .
our results validate the usefulness of the risk score calculator in patients with ctd - apah , including in patients with ssc - apah .
we identified several baseline risk factors that were significantly associated with mortality in the ssc - apah population in comparison with the non - ssc - ctd - apah population , including being an elderly man , having a low sbp , having poor exercise capacity , and having severe hemodynamic indices including elevated mrap and pvr . identifying patients with ssc - apah with high mortality risk based on
the presence of these unique predictors of mortality will enable physicians to monitor these patients more closely and escalate therapy when indicated .
three - year survival in the newly diagnosed ssc - apah population was 51% , which is similar to survival rates found in other cohorts assessed in the modern treatment era .
other studies have found better survival rates ( 75%-81% ) in patients with ssc - apah ; these rates are similar to the survival rate of 77% that we and others observed in patients with non - ssc - ctd - apah .
this survival discrepancy could be related to early detection algorithms that have been implemented in these ssc - apah cohorts , with the goal to initiate pah - specific therapy when the disease is less severe .
survival in patients with non - ssc - ctd - apah appears to be more similar to those with ipah than to those with ssc - apah , despite similar baseline hemodynamics and pah - specific therapies .
whether initiating aggressive pah treatment in patients with ssc - apah with a particular high mortality risk may improve outcomes remains an important question to be answered .
overall , predictors identified in the multivariate model in ssc - apah were very similar to the core predictors for pah as a whole , including all subtypes .
our results concur with those of other studies on patients with ssc - apah in that male sex , older age , and fc iii and iv status were significant predictors of death .
our results confirmed those of a single - center study that identified high pvr as a strong predictor of mortality . unlike these other studies
, we did not find that low dlco or glomerular filtration rate were predictive of mortality in the ssc - apah group in multivariate analyses , although they were significant in univariate analyses .
lefvre et al identified additional poor prognostic factors in patients with ssc with pulmonary hypertension in a meta - analysis including patients with who groups ii and iii pulmonary hypertension : pericardial effusion , low 6mwd , high mean pulmonary arterial pressure , poor cardiac index , and elevated mrap were poor prognostic factors .
although pericardial effusion lost its significance in our multivariate analysis of patients with ssc - apah , poor exercise capacity and elevated mrap remained significant predictors of death .
m was protective only in the non - ssc - ctd - apah group in multivariate analyses .
a potential explanation for these discrepancies is that patients with ssc can suffer from the presence of contractures and tendon friction rubs that can significantly limit mobility ( particularly those with diffuse skin disease ) in addition to other factors that limit exercise capacity ( such as anemia and joint or muscle inflammation ) in patients with other ctds .
however , including all variables in the multivariate model without stepwise selection , 6mwd < 165 m was a significant predictor of death in the non - ssc group ( hr = 2.03 ; 95% ci , 1.01 - 4.12 ; p = .05 ) , and 6mwd 440 m showed a trend toward a protective effect in the ssc group ( hr = 0.62 ; 95% ci , 0.33 - 1.15 ; p = .13 ) .
in addition , when we evaluated the effect of 6mwd on mortality risk in the various cutaneous subgroups of ssc , an increase in distance of 100 m was significantly protective in all three groups ( p <
.001 ) : diffuse hr = 0.53 ( 95% ci , 0.38 - 0.75 ) ; limited 0.59 ( 95% ci , 0.51 - 0.68 ) ; unclassified 0.54 ( 95% ci , 0.40 - 0.71 ) . in our study , bnp > 180 pg / ml increased the risk of death in both the ssc and non - ssc - apah groups by more than twofold , as has also been shown in patients with ipah .
we and others have shown that patients with ssc - apah have markedly elevated bnp and n - terminal - pro - bnp ( nt - pro - bnp ) levels compared with patients with ipah and patients with non - ssc - ctd - apah .
williams et al found in a uk ssc - apah cohort that for every order of magnitude increase in baseline nt - pro - bnp level there was a fourfold increased risk of death ( p = .002 ) .
in addition , several studies have found that nt - pro - bnp is useful in the screening and early detection of pah in patients with ssc , and this biomarker has been integrated into novel screening algorithms . to our knowledge
, our study is the first to show that bnp is an independent predictor of mortality in patients with ctd - apah and ssc - apah , in particular .
unfortunately nt - pro - bnp levels were not available in 89% of our ctd - apah cohort , and , therefore , they could not be included in the regression models .
to our knowledge , this is the first study to identify low baseline sbp 110 mm hg as an independent predictor of death in patients with ssc - apah .
other studies have shown that low sbp , both at peak exercise and upon admission to the hospital for right - sided heart failure , is an independent risk factor for death in pah .
a potential pathophysiologic explanation for this finding is that the presence of high right ventricular pressure results in a more pronounced effect of low sbp on coronary perfusion .
in addition , low sbp may be a sign of low cardiac output , reduced stroke volume , and neurohormonal activation . unless complicated by renal disease , patients with ssc have relatively low baseline bp , and the mean sbp was 119 19 mm hg in the patients with ssc - apah in our study . given that bp can be monitored easily , identification of low baseline sbp as a risk factor in ssc - apah is an important finding .
we did not find that mild to moderate ild was predictive of death in patients with ssc - apah .
although a significant predictor in the non - ssc - apah group in univariate analysis , it was no longer significant in multivariate analysis .
we attempted to exclude patients with substantial ild as defined previously but did not have precise measurements regarding the degree of fibrosis on imaging .
the ssc - apah and non - ssc - ctd - apah cohorts are smaller than the overall cohort .
thus , differences in significant multivariable predictors may be caused by loss of power as opposed to true differences in predictors for different subtypes .
the majority of reveal registry patients , particularly patients who had previous diagnoses , were receiving phosphodiesterase-5 inhibitors , endothelin receptor antagonists , prostacyclins , or a combination .
although 86% of the patients with ctd - apah were enrolled at sites that routinely involve a rheumatologist in the diagnosis and care of these patients , misclassification of some patients may have occurred .
finally , the analysis only assessed variables available in the reveal registry database . there may be additional factors particular to patients with ctd - apah , such as autoantibody status , that could impact the results .
in conclusion , patients with ssc - apah have higher mortality rates than patients with non - ssc - ctd - apah .
our results validate the usefulness of the pah risk score in patients with ssc - apah .
we have identified unique predictors of mortality in patients with ssc - apah , including being an older man , having a low baseline sbp , having poor exercise capacity , and having an elevated mrap and pvr ; these can be used to identify high - risk patients who may benefit from closer monitoring and more aggressive treatment .
Output:
| background : patients with pulmonary arterial hypertension ( pah ) associated with systemic sclerosis ( ssc - apah ) experience higher mortality rates than patients with idiopathic disease and those with other connective tissue diseases ( ctd - apah ) .
we sought to identify unique predictors of mortality associated with ssc - apah in the ctd - apah population.methods:the registry to evaluate early and long - term pah management ( reveal registry ) is a multicenter , prospective us - based registry of patients with previously and newly diagnosed ( enrollment within 90 days of diagnostic right - sided heart catheterization ) pah .
cox regression models evaluated all previously identified candidate predictors of mortality in the overall reveal registry population to identify significant predictors of mortality in the ssc - apah ( n = 500 ) vs non - ssc - ctd - apah ( n = 304 ) populations.results:three-year survival rates in the previously diagnosed and newly diagnosed ssc - apah group were 61.4% 2.7% and 51.2% 4.0% , respectively , compared with 80.9% 2.7% and 76.4% 4.6% , respectively , in the non - ssc - ctd - apah group ( p < .001 ) . in multivariate analyses , men aged > 60 years
, systolic bp ( sbp ) 110 mm hg , 6-min walk distance ( 6mwd ) < 165 m , mean right atrial pressure ( mrap ) > 20 mm hg within 1 year , and pulmonary vascular resistance ( pvr ) > 32 wood units remained unique predictors of mortality in the ssc - apah group ; 6mwd 440
m was protective in the non - ssc - ctd - apah group , but not the ssc - apah group.conclusions:patients with ssc - apah have higher mortality rates than patients with non - ssc - ctd - apah . identifying patients with ssc - apah who are at a particularly high risk of death , including elderly men and patients with low baseline sbp or 6mwd , or markedly elevated mrap or pvr , will enable physicians to identify patients who may benefit from closer monitoring and more aggressive treatment.trial registry : clinicaltrials.gov ; no .
: nct00370214 ; url : www.clinicaltrials.gov |
PubmedSumm119923 | ***TASK***
the task is to summarize an input biomedical literature in six sentences
***INPUT***
the input is a biomedical literature
***OUTPUT***
the output is the summary of an input biomedical literature in six sentences
***DOCUMENTATION***
***EXAMPLES***
Input: cerebral palsy is a nonprogressive central nervous system disorder that results in physical impairments and functional limitations that change as the children grow older . among a large number of instruments [ 24 ] , for measuring the physical ability of children with cp , the gross motor function classification system ( gmfcs ) introduced by palisano et al . in 1997 has been widely applied in clinical and research settings .
the gmfcs is a five - level classification system that identifies abilities and functional limitations , based on the need of assistive devices of the cerebral palsy child , during self - initiated movements , such as walking and sitting .
the system application is quick and easy and it gives a brief description of which level the child resembles based on his / her current gross motor function .
the reliability and validity of the gmfcs in differentiating cerebral palsy children with different functional levels have been reported .
similarly , the stability of the system over time proved to be very consistent , suggesting that the gmfcs could be used routinely in clinical practice to follow children with cerebral palsy .
however , due to the heterogeneous nature of cerebral palsy , some overlap between levels i and ii has been observed and , indeed , anticipated by the authors [ 2 , 5 , 7 ] .
gmfcs level i is associated with children with persistent neuromotor abnormalities not as severe as children from level ii .
overlap between levels occurred more often when deciding if a child has limitations walking outdoors , going up stairs , jumping , or running .
many studies aimed to determine which outcome tools could assist clinicians and researchers to improve the classification levels i and ii of the gmfcs [ 1 , 4 , 8 ] .
correct classification at clinical settings has been corroborated by tests such as the gmfm-66 , gait velocity , and the weefim mobility [ 8 , 9 ] .
child with cerebral palsy often develops changes in muscle length over time , more common at the hip and knee flexors and at the ankle dorsiflexors [ 10 , 11 ] .
kilgour and colleagues ( 2005 ) using passive range of motion tests reported that diplegic children levels i and ii of the gmfcs had minimal loss of hip extension compared to a matched control group . since the gmfcs classification is based on functional activities , it would be more interesting to obtain measurements during dynamic activities .
in addition , it is expected that muscle shortness is more advanced in diplegic children level ii than level i of the gmfcs
. therefore , range of motion comparison between levels i and ii is also relevant .
these muscles changes might affect the range and amplitude of the lower limb during dynamic activities such as gait .
however , to date , none of the studies tried to discriminate gmfcs levels i and ii according to the angular displacement of the pelvis , hip , knee , and ankle / foot complex during gait .
instrumented gait analysis is a complex procedure and a highly costly diagnostic tool ; however , the kinematic data obtained provides quantitative information on gait abnormalities that can not be detected during visual observation .
raising the knowledge of the gait biomechanical differences between child with cerebral palsy level i and ii of the gmfcs can improve observational gait analysis skills and , at the same time , improve classification accuracy and more coherent physical therapy approaches based on the functional status of children with cerebral palsy .
therefore , the research questions for this study were : ( 1 ) are there differences in the kinematics gait profiles of the pelvis and lower limb joints during gait between diplegic cerebral palsy children classified as gmfcs levels i and ii ? ( 2 ) if differences in the kinematics were found , which ones would be the most discriminatory between these groups ?
a cross - sectional observational study was conducted with diplegic cerebral palsy children classified by a trained physical therapist , as gmfcs levels i and ii .
the intra - rater reliability of the physical therapist in assessing the gmfcs levels was excellent ( icc = 0.941 ) .
all children were community ambulates from outpatient clinics and , together with their parents or guardians , were invited to participate in the study .
the temporal and spatial gait parameters and kinematics of the pelvis , hip , knee , and ankle / foot joints were collected on one day in a laboratory .
the present study received approval from the ethics committee of the universidade federal de minas gerais , process number etic 088/04 .
prior to participation , all procedures were explained to the child and his / her parent or guardian and an informed written consent was obtained .
twenty - two ( 22 ) diplegic cerebral palsy children were included in the study , 15 male and 7 females between the ages of 7 and 12 , who could ambulate independently without assistive devices for a minimum of 6 meters without resting .
patients were excluded if they had other neurological diseases , botulin injections , or history of orthopedic surgery in the past six months .
characteristics of the participants , such as age ( years ) , height ( m ) , and body mass index ( bmi , kg / m ) , were obtained in order to describe the anthropometrics of the groups .
three - dimensional kinematics of the right lower limb ( hip , knee , and ankle / foot joints ) and pelvis during the stance phase of the gait cycle were obtained with a six camera motion analysis system ( motion capture unit - qualisys medical ab 411 12 , gothenburg , sweden ) .
the children walked barefoot over a 6-meter walkway , for an average of 9 ( sd = 3.1 ) trials at their natural speed .
reflective markers and clusters of tracking markers were used to determine coordinate systems and motions of the pelvis , thigh , shank , and ankle / foot segments according to recommendations for minimizing soft tissue artifacts . a footswitch synchronized to the motion system
was fixed under the children 's foot to determine contact to and loss of contact from the walking surface , and consequently , delimiting stance and swing phases during gait cycle .
the resulting data were processed through the visual 3d motion analysis software ( c - motion , inc , rockville , maryland ) where the rigid segments corresponding to the pelvis , shank , thigh , and ankle / foot segments were first created .
the position of the reflective anatomical markers were used for attributing coordinate systems for each segment and were located at left and right iliac crest , left and right greater trochanter , medial and lateral epicondyle of the femur , medial and lateral malleoli , 1st and 5th head of the metatarsus , and calcaneal tuberosity .
one rigid cluster with 4 noncollinear markers was placed at the base of the sacrum and two nonrigid clusters with 3 noncollinear markers were placed at the medial side of the thigh and shank .
data were smoothed using a zero - lag fourth - order butterworth low pass filter with a cut - off frequency of 6 hz .
three - dimensional angular motion was calculated using the cardan sequence , defined as the orientation coordinate system of one segment in relation to the orientation of the coordinate system of the adjacent segment .
the hip , knee , and ankle / foot joint angles were obtained using as reference the pelvis , thigh , and the shank segments , respectively . the sign convention used in defining the clinical rotation angles
were as follows : ( 1 ) flexion of the hip and knee , anterior tilt of the pelvis , and ankle dorsiflexion , all of which occur about the lateral - medial or x - axis and were positive angles ; ( 2 ) adduction of the hip and knee , pelvic obliquity ( meaning the height of the iliac crest of the stance foot higher in relation to the height of the iliac crest of the opposite foot ) and internal rotation of the ankle / foot complex , all of which occur about the anterior - posterior or y - axis and were considered positive angles ; ( 3 ) internal rotation of the pelvis , hip and knee joints and adduction of the ankle / foot complex occurs about the distal - proximal or z - axis and all were positive angles . gait velocity ( m / s ) , stride length ( m ) , and cycle time ( s ) for the entire gait cycle , and swing and stance time ( s ) , were also obtained .
baseline characteristics of participants are presented as values , means , and standard deviations ( sd ) .
the mean difference between the groups with a 95% ci of the subject 's characteristics and temporal and spatial gait parameters were also obtained . a principal component analysis ( pca )
was applied to the stance phase of the gait waveforms to reduce the data and explore the profiles characterizing typical functions between levels i and ii of the gmfcs [ 15 , 16 ] . in pca ,
this technique determines a linear combination of the original variables that are used to summarize a new set of variables called principal components , which are uncorrelated and ordered so that the first component retains most of the variation present in the original data .
therefore , each principal component represents a specific feature of the waveform data . the criteria to choose the number of principal components was 90% of the total sample variance .
for each pc extracted , a score is calculated for each subject that aids in describing the meaning of the variation component according to the characteristics of each group .
the higher the score , the more correlated the subject 's waveform is with a specific pc .
to interpret the components , two waveforms were created based on the mean waveform one standard deviation of the pc scores times the loading vector for each pc .
the principal component scores were analyzed using student 's t - test with bonferroni correction for difference between groups .
the pcs retained after the discriminant analysis were described according to the discriminant function coefficient to determine its relative importance in separating the groups .
group gmfcs level i had 11 children with an average age of 9.1 years ( sd : 2.3 ) , average height of 1.3 m ( sd : 0.1 ) and bmi of 16.7 kg / m ( sd : 0.2 ) .
group level ii , also with 11 children , had average age of 9.8 years ( sd : 2.1 ) , height of 1.3 m ( sd : 0.1 ) , and bmi of 17.2 kg / m ( sd : 3.8 , table 1 ) . table 2 describes the temporal and spatial parameters between groups with the 95% confidence interval showing no significant difference between groups .
principal component analyses were carried out for three - dimensional angular displacement of the pelvis , hip , knee , and ankle / foot complex .
the pc scores generated for each subject in each component were tested for differences between groups .
the results showed that only the scores from the first component ( pc1 ) of the pelvis and hip joint in the frontal plane were statistically different between the groups ( table 3 , p < .05 ) .
no difference was found in the curve profiles of the knee joint and ankle / foot complex . at the pelvis ,
figure 1(a ) shows the angular displacement of the pelvis during the stance phase ( normalized to 100% ) between level i and ii groups of the gmfcs .
the coefficient of pc1 has all positive values ( figure 1(b ) ) ; therefore , it captures the magnitude of the pelvic obliquity angle in the frontal plane during the stance .
figure 1(c ) shows the mean waveform and the high and low curves created based on the mean waveform one standard deviation of the pc1 score times the loading vector for each pc1 .
the results confirm that , on average , diplegic pc children level ii , during the stance phase of the gait , walked with reduced pelvic obliquity in comparison with children from group level i. the average range of pelvic obliquity during the stance phase of the gait cycle for group level i was 6.2 and for level ii was 3.3.
figure 1(d ) shows the average angular displacement of the hip joint in the frontal plane between groups during the stance phase of the gait cycle . at the hip joint , two pcs were extracted with pc1 explaining 86.1% and pc2 8.5% , a total of 94.6% of variance explained .
pc1 , with all positive values , measured the magnitude of the adduction angle of the hip ( figure 1(e ) ) .
the mean waveform and the high and low waveforms are shown on figure 1(f ) and confirm that children in gmfcs level ii presented reduced hip adduction during the stance phase when compared to cerebral palsy children in level i. the average range of hip adduction / abduction during the stance phase of the gait cycle for group level i was 11.3 and for level ii was 8.9. a stepwise discriminant analysis was conducted with the pc1s of the pelvis and hip in the frontal plane .
wilk 's lambda score was significant ( = .217 , ( 2 , n = 22 ) = 29.002 , p = .000 ) and showed that both pelvic obliquity and hip abduction angle are stronger discriminant variables , with 95.5% cross - validation .
the magnitude of the coefficients of the pcs in the standardized canonical discriminant function showed that pelvic obliquity has higher impact on separating the groups ( 0.711 ) followed by hip abduction angle ( 0.654 ) during the stance phase of gait .
to our knowledge , this is the first study that compared the angular displacement of the pelvis and lower limb joints , between diplegic cerebral palsy children classified according to the gmfcs as levels i and ii .
the results demonstrated that children with diplegia level ii of the gmfcs significantly reduce the amplitude of pelvic obliquity and hip adduction angles during the stance phase of the gait cycle .
gait velocity , stride length , stance / swing and cycle time were similar in outcome for both groups .
children classified as gmfcs level i of ages between 7 and 12 years , are expected to walk independently inside and outside their homes , to go up and down stairs , and to run and jump .
however , their gait velocity , balance , and motor coordination may be reduced compared to a paired child with normal development .
difference between children of gmfcs levels i and ii included limitations in walking outdoors and in the community , on uneven surfaces , and in crowded places .
children of level ii may hold onto a rail to climb stairs , may require wheeled mobility when traveling long distances , and their ability to perform gross motor skills such as running and jumping are minimal compared to children in level i .
studies showing disagreement between levels i and ii have been reported , suggesting difficulty in classifying if a child has functional limitation or can perform gross motor skills [ 5 , 7 ] . during normal gait strike , the hemipelvis of the stance limb is aligned with the contralateral hemipelvis . at the beginning of loading response and mid - stance , the contralateral hemipelvis drops in the frontal plane , and the stance hemipelvis is higher around 4 to 7 .
the effect of pelvic drop is to adjust the length of the support lower limb , helped by some degree of knee flexion , avoiding excessive lower vertical displacement of the center of mass .
the hip abduction / adduction displacement at this moment is dependent on the pelvis movement over the femur . while hemipelvis elevation favors adduction of the stance limb , hemipelvis drop favors , on the contralateral side , hip abduction movement .
besides saving body energy by preventing greater inferior displacement of the center of mass , hip adduction of the stance limb , also shifts the body center of mass towards the center of rotation of the hip being loaded .
the result would be a decrease in the external adductor moment of force , favoring the mechanical advantage of the hip abductor muscles during stance .
the summation of these actions prevents excessive pelvic drop and the trendelenburg gait . as well , when the support limb begins terminal stance and preswing phases , the opposite will occur .
the pelvis will begin to drop , favoring hip abduction which is important to assist the release of the foot from the ground , permitting the body to swing forward [ 22 , 24 ] .
therefore , pelvic obliquity and hip adduction are two mechanisms that work synchronously to maintain stability and forward movement of the body . in diplegic children with cerebral palsy ,
reduced pelvic obliquity could be a result of abductor muscles weakness bilaterally and adductor muscles spasticity .
another explanation could be that , by reducing pelvic elevation on the supported limb in the stance phase of the cycle , children with cerebral palsy are probably trying to decrease leg length to facilitate the next initial contact of the same foot .
however , this strategy would increase inferior displacement of the center of mass cycle , resulting in a less efficient gait [ 25 , 27 ] . at the hip joint ,
reduced hip adduction in the stance phase increases the internal abductor moment of the support limb . since children with cerebral palsy normally show weakness of the hip abductor muscles , the gait pattern would be unstable , forcing them to increase base of support or to spend less time in the unipodal phase [ 14 , 22 ] .
the decreased hip adduction could also be a response to alterations in pelvic obliquity , once the loaded hemipelvis is lower than normal , challenging the hip mechanics to generate hip adduction .
the combination of reduced pelvic obliquity and hip adduction during the stance phase of the gait cycle , reinforce the evidence that children with cerebral palsy gmfcs level ii are more unstable during gait compared to children in level i. in threatening situations , such as walking on uneven or inclined surfaces , the greater instability of children in gmfcs level ii could justify their need for assistive devices .
it also justifies their use a rail to walk up and down stairs , since reduced pelvic obliquity would decrease hip abduction that could also affect hip flexion . although the kinematic analysis was not a tool used to assist the development of gmfcs classification system , the findings of the present study support the differences between levels i and ii of the gmfcs , recently revised by the authors .
the discriminant model revealed that pelvic obliquity has a higher impact in discriminating children gmfcs level i from those of level ii .
clinically , this result shows that pelvic obliquity in the frontal plane explains better the mechanical difference between children in level i and ii .
the importance of pelvic obliquity during gait was introduced in 1953 by saunders and coworkers as one of the most important gait marker that minimizes the vertical displacement of the center of mass . in 2001
, della croce and coworkers confirmed that pelvic obliquity and single support knee flexion are the second most important gait determinants in reducing center of mass dislocation and consequently improving gait efficiency .
the present study demonstrated that gait velocity was similar between cp children in level i and ii .
in a multicentre study conducted with 562 children with cerebral palsy , classified in levels i to iii of the gmfcs , determined that gait velocity is a discriminant factor between levels i and ii . similar results were reported by oeffinger et al . .
in addition , damiano and abel reported that the temporal and spatial parameters were important indicators of the severity level of the cerebral palsy children .
the classification in levels i and ii , proposed by palisano et al . , was based primarily in the limitation of the child to execute movements that involved velocity and stability , such as walking , jumping , and going up and down stairs .
therefore , we would expect a significant difference between levels i and ii in the gait spatial and temporal markers .
it is likely that the different instruments used to capture temporal and spatial gait markers and the fact that our sample was composed only of diplegic cerebral palsy children probably justify the different results found in the present study .
gait alterations in children with cerebral palsy may also occur in other planes of motion .
rodda and graham proposed a classification system for diplegic children based on the kinematic and kinetic analyses focused in the sagittal plane .
however , the authors agreed that important alterations may also occur in the frontal and transverse planes .
for example , excessive internal pelvic rotation during initial contact contributes to a higher range of hip abduction motion observed during gait strike . on the other hand ,
increased pelvic obliquity may be secondary to a decrease in the hip and knee sagittal motions .
the lack of significant findings in the sagittal plane could be related to the nature of the movement . as in the sagittal plane ,
the range of motion is greater compared to the other planes , the variability is normally smaller when compared to movements with smaller range of motions [ 33 , 34 ] .
one option would be to increase the sample size , in an attempt to identify the subtle variances that could occur in the sagittal plane .
nevertheless , in the present study , even with a relatively small sample size the results could discriminate the groups , showing that , in fact , a difference between levels i and ii , although subtle , could be detected with the multivariate analysis technique applied .
the present study offers new information on angular displacement in all three planes of gait stance of children with cerebral palsy classified as gmfcs levels i and ii . clinical observation of reduced pelvic obliquity and hip adduction during gait is a difficult task .
the literature on observational gait analysis has shown that training and experience are important for a more consistent observation of the pelvic and hip movements during gait . therefore , the kinematic idiosyncrasy of each gmfcs level could be added as one important clinical parameter to help the classification process of mild - to - moderate children with diplegia .
in addition , prior knowledge of the biomechanical differences between gmfcs levels i and ii may guide further physical therapy strategies , focused on regaining pelvic obliquity and hip adduction range of motion of the support limb . such strategies may promote gait stability of cerebral palsy children level ii , with less energy expenditure and free from assistive devices .
Output:
| objective . to determine
if gait waveform could discriminate children with diplegic cerebral palsy of the gmfcs levels i and ii .
patients .
twenty - two children with diplegia , 11 classified as level i and 11 as level ii of the gmfcs , aged 7 to 12 years .
methods .
gait kinematics included angular displacement of the pelvis and lower limb joints during the stance phase .
principal components ( pcs ) analyses followed by discriminant analysis were conducted .
results .
pc1s of the pelvis and hip in the frontal plane differ significantly between groups and captured 80.5% and 86.1% of the variance , respectively .
pc1s captured the magnitude of the pelvic obliquity and hip adduction angle during the stance phase .
children gmfcs level ii walked with reduced pelvic obliquity and hip adduction angles , and these variables could discriminate the groups with a cross - validation of 95.5% .
conclusion .
reduced pelvic obliquity and hip adduction were observed between children gmfcs level ii compared to level i. these results could help the classification process of mild - to - moderate children with diplegia .
in addition , it highlights the importance of rehabilitation programs designed to improve pelvic and hip mobility in the frontal plane of diplegic cerebral palsy children level ii of the gmfcs . |