bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of craniofacial growth in leptin deficient (ob/ob) mice
Authors: Yagasaki Y. , Yamaguchi T. , Watahiki J. , Konishi M. , Katoh H. , Maki K. 
Published: December 2004

Structured AbstractAuthors – Yagasaki Y, Yamaguchi T, Watahiki J, Konishi M, Katoh H, Maki K.Objectives – To elucidate the role of leptin on maxillo‐facial morphological growth using hereditary obesity model ob/ob mice, and to examine the presence of the leptin receptor gene expression in the mouse condylar head cartilage.Design – Leptin was intraperitoneally administered once a day in 10 C57BL/6J (lean) and 10 C57BL/6J‐ob (ob/ob) mice (leptin administration group), and phosphate‐buffered saline (PBS) in 10 lean and 10 ob/ob mice (PBS administration group), between the fifth and 11th week after birth. The amount of fat, the body amount without fat, the rate of body fat, and the width of the condylar cervical area were measured during the11th week, and roentgenographic cephalometric analysis was performed at the fifth, eighth, and 11th week. Furthermore, the condylar head cartilage in C57BL/6J mice was stereoscopically excised to extract total RNA, and RT‐PCR method was performed regarding the leptin receptor gene.Results – The body fat amount in ob/ob mice with leptin production insufficiency was greater than that in lean mice, and significant differences were noted in every measurement item regarding maxillo‐facial morphology. Recovery of bone length was noted in ob/ob mice by administering leptin. Furthermore, the expression of the leptin receptor gene in the condylar head cartilage was confirmed.Conclusion – Exogenous leptin administration leads to significant increases in craniofacial dimensions; and leptin receptors are expressed in mandibular condylar cartilage. These results indicate an important role for leptin in craniofacial growth and morphology. We speculate that leptin's direct peripheral effect on bone and cartilage is closely involved in this role.
Using Self‐Reported Data to Predict Expenditures for the Health Care of Older People
Authors: Pacala James T. , Boult Chad , Urdangarin Cristina , McCaffrey David 
Published: December 2004

OBJECTIVES: To create and test a method for using self‐reported data to predict future expenditures for the health care of older people.DESIGN: A two‐stage regression model of the relationship between self‐reported data and Medicare expenditures during the following year was constructed from a randomly selected (derivation) half of a cohort of fee‐for‐service Medicare beneficiaries. For the other (validation) half of the cohort, two sets of predictions of 12‐month Medicare expenditures were generated, one using the new two‐stage model and the other using the principal inpatient diagnostic cost group (PIP‐DCG) method now used to risk‐adjust capitation payments to Medicare + Choice health plans. Both sets of predictions were compared with Medicare's actual 12‐month expenditures for the validation cohort.SETTING: Ramsey County, Minnesota.PARTICIPANTS: Community‐dwelling Medicare beneficiaries aged 70 and older (N = 13,682) who responded to a mailed survey.MEASUREMENTS: Predicted‐to‐observed ratio (PTOR) of Medicare expenditures.RESULTS: For the validation cohort, Medicare's actual 12‐month expenditures totaled $26.5 million. The two‐stage model predicted Medicare expenditures of $26.4 million (PTOR = 1.00); the PIP‐DCG method predicted $31.2 million (PTOR = 1.18). Within subpopulations of healthy and ill beneficiaries, the two‐stage model's predictions remained considerably more accurate than the PIP‐DCG predictions.CONCLUSION: Self‐reported data may predict future Medicare expenditures more accurately than administrative data about beneficiaries' demographic characteristics, and previous hospitalizations.
Functional Outcomes of Excessive Daytime Sleepiness in Older Adults
Authors: Gooneratne Nalaka S. , Weaver Terri E. , Cater Jacqueline R. , Pack Frances M. , Arner Heidi M. , Greenberg Andra S. , Pack Allan I. 
Published: December 2004

OBJECTIVES: To describe the effect of self‐reported excessive daytime sleepiness (EDS) on functional outcomes.DESIGN: Case‐control study designed to examine differences in functional status between cases (with daytime sleepiness) and controls (no daytime sleepiness) with regard to demographic factors, general health, sleep history, and medications.SETTING: Retirement communities in southeastern Pennsylvania, Delaware, and New Jersey.PARTICIPANTS: Seventy‐six nondepressed, nondemented adults, aged 65 and older, were cases (had daytime sleepiness) and 38 were controls (had no daytime sleepiness).MEASUREMENTS: Standardized questionnaires to assess disease‐specific functional status (Functional Outcomes of Sleepiness Questionnaire (FOSQ) and Epworth Sleepiness Scale (ESS)), depression (Geriatric Depression Scale‐Short Form and the Center for Epidemiologic Studies‐Depression Scale), dementia (Short Blessed Test), demographic factors, current medical history, and sleep complaints.RESULTS: There was a significant difference in functional status between sleepy cases and nonsleepy controls. Sleepiness had a moderate to large negative effect (effect size range from 0.59 to 0.83, P < .005) on the following functional domains of the FOSQ: social outcome, general productivity, vigilance, activity level, and global assessment of functional status. Correlation between ESS and FOSQ subscales were −0.31 to −0.67, P < .05. Examination of cases with daytime sleepiness revealed increased functional impairment in individuals with more than three medical conditions or those taking more than four medications (P < .001 and P = .03, respectively).CONCLUSION: Daytime sleepiness is associated with functional impairments in a broad range of activities. The decrease in daily functioning noted in the sleepy subjects has implications for deconditioning and related comorbidity. These findings suggest that exploration of daytime sleepiness should be part of the ongoing assessment of the elderly, particularly those with multiple medical conditions.
Gastrointestinal Disease Control After Histamine2‐Receptor Antagonist Dose Modification for Renal Impairment in Frail Chronically Ill Elderly Patients
Authors: Lackner Thomas E. , Heard Tom , Glunz Samantha , Gann Nicole , Babington Maude , Malone Daniel C. 
Published: December 2004

OBJECTIVES: To determine whether histamine2‐receptor antagonist (H2RA) dose modified for renal impairment affects gastrointestinal (GI) disease control.DESIGN: Concurrent medical record review.SETTING: One hundred forty‐six nursing facilities throughout the United States.PARTICIPANTS: Three hundred thirty‐six patients aged 65 and older receiving H2RAs for GI disorders.INTERVENTION: H2RA dose modified for renal impairment or no dose change.MEASUREMENTS: Disease control (no H2RA dose increase for 6 months or longer, additional GI medication, hospitalizations, emergency room visits, and unscheduled physician visits for GI symptoms) was evaluated using chart review at 3, 6, 9, and 12 months in nursing home patients aged 65 and older with H2RA dose modified for decreased creatinine clearance (ClCr) according to manufacturer.RESULTS: Three hundred thirty‐six patients, mean age ± standard deviation 85.9 ± 7.9, with mean ClCr of 33.6 ± 10.4 mL/min, were recommended to receive lower H2RA doses based upon estimated renal function. Patients were analyzed in two groups: H2RA dose reduced (Group 1) and dose reduction not adopted or implemented (Group 2). There was no difference in baseline characteristics (age, weight, ClCr, or starting H2RA dose and indication) between the two groups. One hundred ninety‐eight patients in Group 1 were taking 195.5 ± 71.0 mg per day of nizatidine or equivalent, compared with 183.7 ± 66.6 mg for 138 patients in Group 2. For patients with 90 days of follow‐up, the mean H2RA dose in Group 1 was 100.2 ± 44.3 mg, compared with 187.8 ± 69.9 for Group 2 (P < .0001) The mean decrease in daily dose for Groups 1 and 2 after 365 days were 98.9 ± 72.9 mg and 22.2 ± 68.2 mg, respectively (P < .0001). Except for more physician visits in Group 2, disease control was similar for all groups. Major and minor GI bleeding events were similar across both groups and over time. The 12‐month mortality rate was 12.1% and 21.7% for Groups 1 and 2, respectively. This difference was statistically significant (P = .02).CONCLUSION: The findings suggest that the dose of H2RAs may be decreased based upon renal function in frail elderly patients without compromising GI disease control.
Direct measurement of hepatic tissue hypoxia by using a novel tcpO2/pCO2 monitoring system in comparison with near‐infrared spectroscopy
Authors: Yang Wenxuan , Hafez Tariq , Thompson Cecil S. , Mikhailidis Dimitri P. , Davidson Brain R. , Winslet Marc C. , Seifalian Alexander M. 
Published: December 2004

Abstract: Background/Aims: Hepatic hypoxia occurs during liver surgery and transplantation and it may also appear within liver tumours, correlating with prognosis and efficacy of the treatment. The present study measured liver tissue hypoxia by directly using near‐infrared spectroscopy (NIRS) and a novel tcpO2/pCO2 monitoring system. Methods: Graded hypoxia was achieved in a rabbit model by a stepwise reduction of the fraction of inspired oxygen (FiO2) from 0.3 to 0.0. Animals were allowed to recover from hypoxia at FiO2 of 3.0 indicated by normalised arterial blood gas values. Hepatic tissue oxyhaemoglobin (HbO2), deoxyhaemoglobin (Hb), cytochrome oxidase (Cyt Ox), oxygen partial pressure (pO2) and carbon dioxide partial pressure (pCO2) were measured continuously with the help of NIRS and a Clark‐type surface tcpO2/pCO2 monitoring system, throughout the period of hypoxaemia.Results: There was an immediate reduction in hepatic HbO2 with hypoxia and a simultaneous increase in hepatic Hb. Similarly, hepatic tissue pO2 decreased significantly but tissue pCO2 remained unchanged until the FiO2 was below 0.1. Hepatic HbO2 showed a positive correlation with tissue pO2 (r = 0.53, P < 0.001). Hepatic Hb showed a negative correlation with tissue pO2 (r = 0.47, P < 0.001). Hepatic Cyt Ox decreased significantly with an FiO2 of 0.1 or less and showed a positive correlation with hepatic tissue pO2 (r = 0.64, P < 0.001). A significant correlation was found between hepatic tissue pO2 and arterial blood pO2 (r = 0.44, P < 0.001). Arterial blood pCO2 also correlated with hepatic tissue pCO2 (r = 0.53, P < 0.001) measured by the tcpO2/pCO2 monitoring system.Conclusion: The data from the present study suggest that, like NIRS, the tcpO2/pCO2 monitoring system can be reliably used for the direct monitoring of hepatic tissue oxygenation in vivo.
An endoscopic approach to biliary complications following orthotopic liver transplantation
Authors: Thuluvath Paul J. , Atassi Tamer , Lee John 
Published: December 2004

Abstract: Biliary complications following orthotopic liver transplantation (OLT) may be associated with significant morbidity and mortality. In this report, we reviewed our endoscopic experience of managing post OLT biliary complications in 79 patients over a 12‐year period.Methods: OLT (n = 423) recipients between 10/86 and 12/98 were obtained from the transplant registry at the Johns Hopkins Hospital. OLT recipient who underwent at least one endoscopic retrograde cholangiography (ERC) were identified through a radiology database. Indications, findings and interventions performed were noted for each ERC report. Outpatient and inpatients medical records were reviewed for outcome and complications.Results: Seventy‐nine (79/423, 18.7%) patients had at least one ERC for suspected biliary complication. Sixty‐four (15.1%) patients had at least one or more biliary complications. The mean follow‐up for patients with abnormal ERC was 33.9 months. Nineteen patients had bile leaks; 10 of these patients had leak at the exit site of the T‐tube and five patients had at the anastomosis. Biliary stenting with or without endoscopic sphincterotomy led to resolution of bile leak in 16 patients. Three patients failed endoscopic therapy: one underwent surgery and two had percutaneous drainage. Twenty‐five patients presented with biliary strictures. Nineteen strictures were at the anastomotic or just proximal to the anastomosis, one at the hilum (ischemic in nature) and three were at the distal, recipient common bile duct; one had strictures at the anastomosis as well as the distal recipient bile duct and another had diffuse intrahepatic strictures. Seventeen patients in the stricture group improved with endoscopic intervention. One patient was re‐transplanted (diffuse intrahepatic strictures), but no patient underwent percutaneous drainage.Conclusions: ERC is safe and effective in the diagnosis and management of biliary complications following liver transplantation with choledochocholedochal anastomosis and obviates the need for surgical or percutaneous transhepatic approaches in majority of cases.
Triiodothyronine and interleukin‐6 (IL‐6) induce expression of HGF in an immortalized rat hepatic stellate cell line
Authors: Kariv R. , Enden A. , Zvibel Isab , Rosner G. , Brill S. , Shafritz D. A. , Halpern Z. , Oren R. 
Published: December 2004

Abstract: Background/Aims: Despite its being considered a primary mitogen for hepatocytes, triiodothyronine (T3) has no effect on the proliferation of hepatocytes in vitro, and in our studies, induces significant in vivo hepatocyte proliferation only during liver injury. We hypothesized that T3 may affect hepatocytes proliferation indirectly, by inducing other cells in the liver to secrete hepatic mitogens.Methods: In vivo studies: Lipopolysaccharide, T3 and a combination of the two were injected into rats, and hepatocyte proliferation was determined by PCNA staining and mitotic index. In vitro studies: a rat hepatic stellate cell line (HSC‐6T) was cultured with T3, IL‐6 and a combination of the two, and we assessed the effect of these cytokine/hormone combinations on the cell proliferation and on secretion of IL‐6 and HGF, measured by ELISA. Expression of thyroid hormone receptors was assessed by RT‐PCR.Results: In vivo: T3, together with lipopolysaccharide, enhances PCNA staining and the mitotic index of hepatocytes in the treated rats. In vitro: the hepatic stellate cell line expresses thyroid hormone receptor α1, but not β1. Proliferation of stellate cells is not affected by T3, with or without IL‐6. T3 has no effect on secreted levels of IL‐6 in the stellate cell line. Hepatic stellate cells cultured with T3 and IL‐6 show significantly increased amounts of secreted HGF after 48 h in culture.Conclusion: T3 may induce hepatocyte proliferation in vivo during injury by turning on expression of HGF in stellate cells and acting together with IL‐6.
Hepatic stimulator substance administration ameliorates liver regeneration in an animal model of fulminant hepatic failure and encephalopathy
Authors: Margeli Alexandra P. , Papadimitriou Lila , Ninos Sotirios , Manolis Evangelos , Mykoniatis Michael G. , Theocharis Stamatios E. 
Published: December 2004

Abstract: Aims/Background: Hepatic stimulator substance (HSS) is a liver‐specific growth factor implicated in hepatocellular proliferation and hepatoprotection in models of acute liver injury. In the present study, we examined the effect of exogenous HSS administration on liver proliferating capacity and survival outcome in an experimental animal model of fulminant hepatic failure (FHF) and encephalopathy, induced by repeated injections of thioacetamide (TAA) in rats.Methods: Fulminant hepatic failure was induced in adult male Wistar rats by three consecutive intraperitoneal injections of TAA (400 mg/kg of body weight), at 24 h time intervals. The animals received intraperitoneally either a saline solution or HSS (50 mg protein/kg of body weight), 2 h after the second and third TAA injections. The animals were killed at 6, 12 and 18 h post the last injection of TAA.Results: Levels of liver enzymes and urea in serum, blood ammonia values, liver histology, stage of hepatic encephalopathy and survival were statistically significantly improved in TAA‐intoxicated and HSS‐treated rats compared to TAA‐intoxicated and saline‐treated ones. Furthermore, HSS ameliorated liver regenerative indices – DNA biosynthesis, thymidine kinase activity and hepatocyte mitotic activity – in a statistically significant manner.Conclusions: Our data suggest the beneficial effect of HSS administration in this animal model of FHF and encephalopathy, supporting evidence for a possible use of HSS as supportive therapy, by increasing hepatocellular proliferation, in management of FHF.
Morphological and life history responses to predators in larvae of seven anurans
Authors: Lardner Björn 
Published: December 2004

Amphibian larvae often face two major sources of mortality: pond desiccation and predation. Tadpoles of seven anuran species with different preferences for type of breeding habitat, on a hydroperiod scale, were tested for responses to the presence of predators by raising them experimentally in the presence and absence of a separately caged invertebrate predator that was fed on conspecific tadpoles.  The species typically breeding in temporary or semi‐permanent ponds (Rana temporaria, Rana arvalis, Rana dalmatina and
Hyla arborea) – where invertebrate predator populations are
predicted to vary considerably spatiotemporally – all showed marked
induced increases in tail fin depth in response to predator presence.
These species also tended to respond by reduced growth rates.
The representative of the most ephemeral habitats, Bufo calamita,
did not respond in any of these traits. Its congeneric, Bufo bufo,
a toxic inhabitant of permanent ponds and lakes, tended to respond to
predator presence by reducing its growth rate, though not by a tail depth
increase. I argue that the rather poor swimming performance in Bufo
tadpoles may opt for defences other than locomotor ability.
The palatable, permanent pond species Pelobates fuscus did not alter either its growth rate or tail morphology. Possible explanations for this result are discussed.
Effects of fish chemical cues on the interactions between tadpoles and crayfish
Authors: Nyström Per , Åbjörnsson Kajsa 
Published: December 2004

We studied the effects of predatory crayfish (Pacifastacus
leniusculus), the non‐lethal effects of fish chemical cues
(Oncorhynchus mykiss), and the combined effects of crayfish and
fish chemical cues on the performance of tadpoles of two co‐existing
anuran species, Rana temporaria and Bufo bufo, in
experimental pools. We also examined grazing effects on periphyton, the
main food source for the tadpoles. Crayfish significantly reduced tadpole
survival, particularly by feeding on Bufo. Rana benefited
from reduced numbers of competitors, resulting from crayfish predation,
by increased growth rate, whereas the growth rate of Bufo was
unaffected by crayfish. The proportion of Rana in refuges (in
relation to the number of survivors at the end of the experiment) was
unaffected by crayfish, whereas proportionally more Bufo stayed in
refuges in the presence of crayfish, relative to controls. Fish cues had
no effect on tadpole survival of either species. During the entire larval
period, Rana responded to fish cues by increasing the use of
refuges relative to controls, whereas Bufo did not show any
significant behavioural response to fish cues. In accordance with these
observations, the proportion of Rana in refuges at the end of the
experiment was high in the presence of fish cues, whereas the use of
refuges by Bufo was not affected by fish cues. Predatory crayfish
and fish chemical cues had additive effects on tadpole survival, growth
and refuge use.
Tadpoles in all treatments reduced periphyton biomass. Both crayfish and
fish cues had positive indirect effects on periphyton biomass. The
positive indirect effect of fish cues on periphyton was likely an effect
of reduced grazing from Rana. Thus lethal, as well as non‐lethal, predator effects on prey populations can influence lower trophic levels.
Variation in the outcome of competition between two aphid species on pecan: plants matter more than predators
Authors: Petersen Mette K. , Hunter Martha S. 
Published: December 2004

The relative importance of resource‐mediated competition versus apparent competition was studied in two native aphids, Monellia caryella, and Melanocallis caryaefoliae, on pecan, Carya illinoensis. We compared reproduction and body size of the two aphid species when they were caged on pecan leaves as single or mixed species, and when green lacewing larvae (Chrysoperla comanche or Chyrsopa nigricornis) were present or absent. The experiment was repeated two times on mature compound leaves in the field in the autumn of 1997 and summer of 1998 and once in a greenhouse, on young seedlings with simple leaves.
Our results suggest that interspecific competition was variable and asymmetric; in both the Summer 98 experiment and the greenhouse experiment, reproduction of M. caryaefoliae was significantly reduced in the mixed species treatments relative to the single species treatment, while M. caryella reproduction was significantly reduced only in the Summer 98 experiment. No evidence of an effect of competition on reproduction was found in the Autumn 97 experiment. M. caryella body size was reduced in one of the mixed species treatments in the Autumn 97 experiment. Body size of both aphid species was reduced in the mixed species treatments of the greenhouse experiment.
The introduction of green lacewing larvae reduced the reproduction of aphids in two of the three experiments in comparison to controls. However, a significant interaction between aphid and predator treatment (M. caryella in the greenhouse experiment) was found in only one experiment. Variation in the outcome of competition was more likely to be due to aspects of plant quality, including leaf age and previous aphid feeding.
Suitability of stressed and vigorous plants to various insect herbivores
Authors: Inbar Moshe , Doostdar Hamed , Mayer Richard T. 
Published: December 2004

We conducted a controlled experiment to test the plant vigor and the plant stress hypotheses. The two hypotheses associate plant physiological conditions to insect feeding mode and performance. We exposed tomato, Lycopersicon esculentum, to different types of growing conditions: optimal (vigorous plants), resource based stress (water and/or nutrient deficit), and physical stress (punched hole in terminal leaflets). Plant performance, foliar nutritional value for insects and chemical defenses were analyzed after 14 d. These plants were offered to insects belonging to distinct feeding guilds: the silverleaf whitefly, Bemisia argentifolii, a phloem feeder; the leafminer, Liriomyza trifolii; and the corn earworm, Heliothis zea, a leaf chewing caterpillar.

The experimental conditions generated a gradient of plant growth in the following order: optimal (vigorous)>control=hole punched>no fertilizer>no water>no water and no fertilizer. The last two treatments resulted in plants with poor nutritional value (based on %water, C/N, %N) and higher levels of defensive compounds (i.e., peroxidase and total phenolics) compared with control and the vigorous plants. Hole‐punching neither affected plant growth nor any of the phytochemicals measured. In a choice experiment adult whitefly ovipositioning was not affected by either vigor or punching but was reduced on the other plants (P<0.01). Leafminer feeding and oviposition and corn earworm larval growth rates were higher on the vigorous plants and lower on the punched, no fertilizer, no water, and no water and no fertilizer host plants (P<0.01).  Regardless of insect species or bioassay method, the results in the tomato system support the plant vigor hypothesis that predicts positive association between insect performance and plant growth. The results contradict the plant stress hypothesis that rank stressed plants as better hosts for insects. The mechanisms involved are a combination of poor nutritional value and chemical defenses. We demonstrate a negative association between plant growth and chemical defense. However, induced response triggered by hole‐punching was not cost effective to the plants.