bluuebunny/crossref_metadata_2025 huggingface dataset:
Neutron Probe Calibration in a Vertically Stratified Vadose Zone
Authors: Yao T. , Wierenga P. J. , Graham A. R. , Neuman S. P.
Published: July 2010

A procedure is described for neutron probe calibration in deep multilayer vadose zones. Calibration equations relating neutron count ratios (CR) to soil water content were developed for the upper 2.5 m of layered soil profiles using soil texture, water content, and neutron probe data. These equations were extended down to a depth of 10 m by relying on neutron probe data to delineate soil texture zones at depth. Data from two constant‐flux field infiltration experiments were used to verify the calibration procedure. The water balance for each of nine soil profiles within the infiltrated area was computed using up to four separate calibration equations for each soil profile. The use of two or more texture‐based calibration equations greatly improved the agreement between water applied at the surface and water measured within each of the nine layered profiles. Best results were obtained using four such equations, three corresponding to distinct soil horizons and one to interfaces between them (soil texture boundaries). The calibration procedure proposed here is applicable to deep soil profiles when soil texture and bulk density data are only available for the upper soil profile.
Using Soil Freezing Characteristics to Model Multi‐Season Soil Water Dynamics
Authors: Flerchinger G. N. , Seyfried M. S. , Hardegree S. P.
Published: July 2010

The soil moisture characteristic (SMC) is a fundamental soil property for simulating soil water dynamics but is difficult and time‐consuming to measure. When the soil is frozen, the soil water potential and liquid water content are strongly dependent on temperature. The relation between soil freezing temperatures and liquid water content, termed the soil freezing characteristic (SFC), is related to the SMC. With the widespread use of time‐domain reflectometry (TDR) to measure liquid water in frozen soil, simultaneous measurement of soil temperature and liquid water content under frozen conditions enables in situ estimation of the SMC curve through its similarity to the SFC. We investigated the applicability of deducing the SMC curve from in situ measurements of the SFC for simulation of both frozen and unfrozen soil water dynamics. Results suggest that SMC parameters deduced from the SFC may be used for model simulations without a significant loss of accuracy, as compared with model simulations based on pressure plate analyses.
Growth inhibition of Microcystis aeruginosa by white-rot fungus Lopharia spadicea
Authors: Wang Q. , Su M. , Zhu W. , Li X. , Jia Y. , Guo P. , Chen Z. , Jiang W. , Tian X.
Published: July 2010

Harmful cyanobacterial blooms cause water deterioration and threaten human health. It is necessary to remove harmful cyanobacteria with useful methods. A bio-treatment may be one of the best ways to do this. A strain of specific white-rot fungus, Lopharia spadicea, with algicidal ability was isolated. Its algicidal ability on algae under various conditions was determined using three main influence factors: initial chlorophyll-a content, initial pH, and algal cell mixture. The  result showed that the chlorophyll-a content of Microcystis aeruginosa FACHB-912, Oocystis borgei FACHB-1108, and Microcystis flos-aquae FACHB-1028 decreased from 798 ± 13, 756 ± 40, and 773 ± 24 μg/L to 0 within 39 h. L. spadicea could also remove more than 95% chlorophyll-a when initial chlorophyll-a content increased from 397 ± 13 to 2,132 ± 4 μg/L. Moreover, the strain has great removal ability under a broad initial pH range of 5.5 to 9.5. The chlorophyll-a content of the three algal strain mixtures decreased from about 672 ± 23 μg/L to 0 within 45 h. After superoxide dismutase (SOD) and malondialdehyde (MAD) were assessed in a co-culture of L. spadicea, it was observed that an increase in MAD content was correlated with the decrease in chlorophyll-a content of M. aeruginosa FACHB-912. This result suggested that the algae was not only greatly inhibited but also severely damaged by the fungus.
An advanced oxidation process using ionized gas for wastewater treatment
Authors: Lee Eun Ju , Chung Paul Gene , Kwak Dong Heui , Kim Lee Hyung , Kim Min Jeong
Published: July 2010

This study on removing non-degradable materials in wastewater focused primarily on advanced oxidation methods such as ozone, ozone/UV and ozone/H2O2. Wastewater treatment using an ionized gas from plasma has been actively progressing. The ionized gas involves reactive species such as O2+, O2− cluster, O radical and OH radical. Since the ionized gas method has such outstanding characteristics as relatively simple structures, non-calorification, non-toxicity and low electricity consumption, it evidently of interest as a new process. A series of experiments were conducted to demonstrate the feasibility of ionized gas as a useful element for the diminution of nondegradable organic matters. On the other hand, a large amount of organic matters were changed to hydrophilic and the compounds containing aromatic functional group gradually decreased. The results implied that the ionized gas has been able to degrade the non-biodegradable organic matters. Therefore, the oxidation process by using an ionized gas process could be considered as an effective alternative unit in water and wastewater treatment plants.
The effect of iron and aluminium for phosphorus removal on anaerobic digestion and organic sulfur generation
Authors: Novak John T. , Park Chang Min
Published: July 2010

The addition of iron or aluminium into activated sludge basins for phosphorus removal is likely to impact both the efficiency of the anaerobic digestion process and the generation of odor-causing compounds following digestion and dewatering. In this study, the impact of iron and aluminium addition on digestion and odor-causing compounds was investigated by using batch digestion of combined primary and waste activated sludge. It was found that aluminium addition resulted in a decrease in volatile solids destruction by anaerobic digestion of approximately 2%. Of the 7 sludges tested, 5 showed a small increase in volatile solids destruction after iron addition. With regard to the generation of organic sulfur odors from the dewatered sludge cakes, both iron and aluminium reduced odor-causing gases except for one sludge that had already received iron for phosphorus control in the full-scale process. It appears that iron and aluminium addition will benefit odor control.
Lipophilicity and antifungal activity of some 2-substituted benzimidazole derivatives
Authors: Podunavac-Kuzmanovic Sanja , Cvetkovic Dragoljub
Published: July 2010

In the present paper, the antifungal activity of some 2-methyl and 2- aminobenzimidazole derivatives was evaluated against yeast Saccharomyces cerevisiae. The tested compounds displayed in vitro antifungal activity and minimum inhibitory concentration (MIC) was determined for all compounds. The partition coefficients of the studied compounds were measured by the shake flask method (logP) and by theoretical calculation (ClogP). The logP values were compared and the relationships between the logP values and antifungal activities were investigated. The mathematical models have been developed as a calibration models for predicting the antifungal activity of this class of compounds. The quality of models was validated by leave one out (LOO) technique as well as by the calculation of statistical parameters for the established models. The results of the present study may be useful for the designing of new more potent benzimidazole derivatives against yeast Saccharomyces cerevisiae.
New method for synthesis of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropylthiocarbamates by oxidation of ammonium salt of xhantogenic acid
Authors: Milisavljevic Smiljka , Marinkovic Aleksandar , Milosavljevic Milutin
Published: July 2010

A synthesis of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates by oxidation of ammonium salt of ethyl and isopropylxanthogenic acid in a presence of sodium hypochlorite and hydrogen peroxide were performed. Ammonium salt of ethyl and isopropylxanthogenic acid was obtained by the reaction of alkylammonium sulfate and sodium ethyl and isopropyl xanthate. Studies on a dependence of N-ethyl-O-isopropylthiocarbamate yield and purity with respect to reaction parameters (reaction time, molar ratio of oxidant and ethylamonium salt of isopropylxanthogenic acid) were performed. Optimal reaction conditions for synthesis of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates were established. Synthesized compounds have been fully characterized by FTIR, 1H NMR and MS data, while purity has been determined by GC method. A plausible pathway for the N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates synthesis, in the presence of the oxidative agents sodium hypochlorite and hydrogen peroxide, was proposed. The presented synthetic methods has been developed at laboratory and applied at semi-industrial level. The developed optimal method provides a powerful and versatile method for the preparation of N-alkyl and N,N-dialkyl-O-ethyl and O-isopropyl thiocarbamates. This new optimized method offer several benefits, namely, simple operation, mild reaction conditions, bypass of hazardous organic solvents, moderately toxic and inexpensive reagents, and also short reaction times and high product yields.
Molecular weight dependent antistaphylococcal activities of oligomers/polymers synthesized from 3-aminopyridine
Authors: Akgul Cahit , Yildirim Mehmet
Published: July 2010

The main aim of this study was to investigate the relationship between molecular weight and the antistaphylococcal activity of oligomers/polymers synthesized from 3-aminopyridine. Different oligomers/polymers were synthesized from 3-aminopyridine by changing the oxidative polycondensation reaction conditions. They were characterized by size exclusion chromatography and their antibacterial activities were compared by employing standardized susceptibility assays. The obtained experimental results demonstrated that 3-aminopyridine had no antistaphylococcal activity. However, as a result of polymerization, strong antistaphylococcal activity was obtained. Oligomers/polymers synthesized from 3-aminopyridine had varying degrees of antistaphylococcal activity and the maximum activity was obtained from relatively very short oligomers. It was therefore concluded that polymerization of 3-aminopyridine is required for antistaphylococcal activity and strength of this activity depends on the molecular weights of the synthesized molecules.
Cognitive dimensions of creativity: What makes the difference between creative and non-creative university students?
Authors: de Fátima Morais Maria , Almeida Leandro , Azevedo Maria , Nęcka Edward
Published: July 2010

Cognitive dimensions of creativity: What makes the difference between creative and non-creative university students?

This paper analyses the contribution of specific cognitive functions on creative performance. The main question was which cognitive variables differentiate extreme levels of creative performance and therefore can characterize highly creative college students. A sample of Portuguese university students of Fine Arts and Literature (n=166) took part in this study. A battery of verbal and figural cognitive tasks, as well as two kinds of creative tasks (text and poster production) have been considered. Results showed that there were mostly the same cognitive dimensions (figurative reasoning, divergent thinking, insight problem solving, and problem-finding), which differentiate extreme levels of creative performance in both text and poster productions. These results are discussed considering the relevance of the cognitive approach to explain creativity. Some practical ideas, possible to put into the educational context, are also discussed.
Situational Determinants of Envy and Schadenfreude
Authors: Piskorz Joanna , Piskorz Zbigniew
Published: July 2010

Situational Determinants of Envy and Schadenfreude

In this article the results of research on situational determinants of envy and schadenfreude are presented. Based on a literature review conducted, five hypotheses were devised concerning various situational factors influencing the intensity of envy and schadenfreude. The questionnaire used in the research was devised on the basis of interactional psychology and measured envy and schadenfreude. Situational dimensions concerned in the research were type of relation (close vs. distant/strange person) and the level of justice vs. injustice of the situation. 248 people participated in the research. Devised hypotheses were confirmed. Empirical results point out that along with expectations, the strongest envy is experienced in situations with subjectively perceived elements of injustice and towards distant acquaintances and strangers. The strongest schadenfreude was experienced by participants finding the situation of a stranger justifiable. It also occurred that women react with stronger envy in situations of the unjust success of a stranger whereas men, regardless of the situation, experience stronger schadenfreude in situations of the failure of a close as well as an unknown person.
Effectiveness of school-based smoking prevention programmes
Authors: Koprivnikar Helena
Published: July 2010

Učinkovitost Programov Preprečevanja Kajenja V Šolah

S kajenjem začnejo odrasli redni kadilci skorajda vedno v obdobju adolescence. Pomembno je torej, da se usmerjamo v preprečevanje kajenja med otroki in mladostniki. Programi preprečevanja kajenja v šolah so eden od učinkovitih pristopov za doseganje tovrstnih ciljev. Veliko število raziskav potrjuje, da so programi preprečevanja kajenja med mladostniki v šolskem okolju zmerno in kratkoročno učinkoviti. O dolgoročnih učinkih teh programov je zaenkrat na voljo premalo podatkov, kljub temu pa obstajajo dokazi, da lahko intenzivnejši in obsezKnejši programi učinkujejo vse do konca najstniških let.

V Sloveniji velika večina slovenskih osnovnih šol izvaja različne tovrstne programe in dejavnosti. Napogosteje izvajajo program "Spodbujajmo nekajenje". Programi se večinoma izvajajo na prostovoljni ravni, kar ne zagotavlja dolgoročnega izvajanja programov in vrednotenja njihove učinkovitosti. Za enotno in sistematično izvajanje, razvoj in vrednotenje tovrstnih programov in vsebin je potrebno poskrbeti tudi v Sloveniji.
The vision of health centers in Slovenia
Authors: Klančar Darinka , Švab Igor , Kersnik Janko
Published: July 2010

Vizija Prihodnosti Zdravstvenih Domov V Sloveniji

Članek predstavlja teoretična izhodišča za posodobitev zdravstvenih domov v Sloveniji. Novi zdravstveni dom naj bi ohranil svoje poslanstvo in osnovna izhodišča, nadgradili pa bi ga z novimi vsebinami, ki jih prinaša moderna druzKba.

Zdravstveni dom naj bi postal sodobni integrirani socialnomedicinski center, v skladu z novimi usmeritvami center za promocijo zdravja s poudarkom na preventivi skrbi za zdravje.
Concurrent or sequential development of medial meniscal and subchondral cystic lesions within the medial femorotibial joint in horses (1996–2006)
Authors: HENDRIX S. M. , BAXTER G. M. , Mc ILWRAITH C. W. , HENDRICKSON D. A. , GOODRICH L. R. , FRISBIE D. D. , TROTTER G. W.
Published: July 2010

Reasons for performing study:Medial meniscal injuries and subchondral cystic lesions (SCL) are known to occur independently within the medial femorotibial (MFT) joint in horses. However, there are no reports of a potential clinical relationship between these 2 types of lesions.

Objectives:To: 1) document the concurrent presence or sequential development of medial meniscal and SCL of the medial femoral condyle within the MFT joint; and 2) determine the prognosis with both types of lesions.

Methods:Retrospective case series of horses with both a medial meniscal and SCL of the medial femoral condyle identified concurrently or sequentially by radiography, arthroscopy orpost mortemexamination. Case records and radiographs were reviewed, and a telephone survey of referring veterinarians, owners and trainers was conducted.

Results:Twenty‐one horses (9.1% of all horses undergoing MFT joint arthroscopy) were identified to have both a medial meniscal injury and SCL of the medial femoral condyle. Thirteen horses had both abnormalities identified concurrently, 6 developed a meniscal lesion subsequent to SCL debridement, and 2 developed a SCL subsequent to a medial meniscal injury. Only 4/19 horses were classified as successful and returned to their intended use. The severity of the meniscal injury was significantly associated with the severity of lameness but not with outcome.

Conclusions:A low percentage of horses may develop both a meniscal injury and SCL of the medial femoral condyle within the MFT joint and have a poor prognosis.

Potential relevance:Trauma to the MFT joint may lead to both meniscal and subchondral bone damage of the medial femoral condyle that may be recognised concurrently or sequentially.
Monitoring bacterial contamination in equine platelet concentrates obtained by the tube method in a clean laboratory environment under three different technical conditions
Authors: ÁLVAREZ M. E. , GIRALDO C. E. , CARMONA J. U.
Published: July 2010

Reasons for performing study:There is a growing interest in the use of autologous platelet concentrates (PCs) as treatment for chronic musculoskeletal diseases in horses. However, there is no information on the risk of bacterial contamination during their preparation.

Objectives:To: 1) assess the risk of bacterial contamination in equine PCs obtained by the tube method under 3 technical conditions: a) in a laminar flow cabinet, in a clean laboratory environment both with (b) and without (c) Bunsen burner; 2) identify the critical points of the process of PCs preparation with risk of bacterial contamination; and 3) identify the potential bacterial contaminants in the process and their antibiotic susceptibility.

Methods:Bacteriological samples were taken from: the skin (shaved or unshaved) of the venipuncture site in 15 horses, both before and after being disinfected; hands and throat of the operator; caps of the tubes where the blood was processed; environment where the equine blood samples were collected; laboratory environment; laminar flow cabinet; bacteriological stove; and PCs obtained under 3 technical conditions.

Results:Bacteria were isolated from nonaseptically prepared equine skin, hands and throat of the operator, and the place where the blood samples were taken. Bacteria were not isolated from tube caps, laboratory environment, laminar flow cabinet or PCs. The isolated bacteria were normal biota from equine skin, human skin and throat, and environmental contaminants. Of the isolated bacteria, 23% were resistant to penicillin, 19% to ampicillin, 2.12% to ceftiofur, 3.2% to sulphamethoxazole/trimethoprim and 1.1% to enrofloxacin. Resistance to amikacin and gentamicin was not seen.

Conclusions and potential relevance:Uncontaminated PCs can be obtained by the tube method in a clean laboratory environment without the need for either a laminar flow cabinet or a Bunsen burner. It is mandatory to perform the procedure following strict aseptic technique.
Use of ultrasound to evaluate outcome following colic surgery for equine large colon volvulus
Authors: SHEATS M. K. , COOK V. L. , JONES S. L. , BLIKSLAGER A. T. , PEASE A. P.
Published: July 2010

Reasons for performing study:The post operative response of the large colon wall after a surgically corrected large colon volvulus (LCV) has not been investigated.

Objectives:To use transabdominal ultrasound to monitor the post operative change in large colon wall thickness following surgical correction of LCV.

Hypothesis:A prolonged period to colon wall involution is correlated with an increased rate of post operative morbidity and mortality.

Methods:A prospective clinical study including horses that presented to the North Carolina State University Veterinary Teaching Hospital for colic between September 2006 and March, 2008, had surgically diagnosed and corrected LCV (at least 360°) without resection and recovered from anaesthesia. Ultrasound of the ventral large colon was performed at the time of anaesthetic recovery and every 6–8 h until the colon wall returned to normal thickness (≤5 mm). Outcome was evaluated using a one‐way ANOVA to compare average time to colon wall involution between: 1) survivors and nonsurvivors; and 2) horses that developed multiple organ dysfunction syndrome (MODS) during the post operative period and those that recovered without evidence of MODS.

Results:Sixteen horses that recovered without evidence of MODS had a significantly shorter period to colon wall involution (≤5 mm) compared to those diagnosed with MODS (mean ± s.e. 19.6 h ± 2.5 and 39.7 h ± 6.7 respectively, P = 0.006). There was no significant difference in mean period to colon wall involution between survivors and nonsurvivors (26.2 ± 4.9 and 33.2 ± 7.8 h, respectively).

Conclusions:A shorter time to colon wall involution was associated with decreased post operative morbidity in horses presented for surgical correction of large colon volvulus without resection.

Potential relevance:Ultrasonographic monitoring of colon wall involution after surgical correction of LCV may aid in identifying those cases at risk of MODS. Further investigation of colon wall involution time using a larger number of horses is warranted.
Are horses that undergo an exploratory laparotomy for correction of a right dorsal displacement of the large colon predisposed to post operative colic, compared to other forms of large colon displacement?
Authors: SMITH L. J. , MAIR T. S.
Published: July 2010

Reason for performing study:It is a clinical impression that horses diagnosed with a right dorsal displacement (RDD) of the large colon, are more likely to suffer from recurrent episodes of colic post operatively, compared to other forms of nonstrangulating large colon displacement.

Objectives:To investigate whether the type of nonstrangulating large colon displacement identified at exploratory laparotomy would influence long‐term outcome.

Hypothesis:Horses identified with a RDD of the large colon at exploratory laparotomy would be more likely to experience recurrent episodes of post operative colic than other types of displacement.

Materials and methods:Medical records for horses undergoing an exploratory laparotomy, from 2000–2008, for a nonstrangulating large colon displacement were reviewed. Data retrieved included: subject details, previous medical history, details of current episodes of colic, results of preoperative examination, surgical findings and procedures, post operative management and complications. Follow‐up information was obtained by reference to computerised clinical records and by telephone questionnaire administered to the horse's owner or carer, and included details of any colic episodes exhibited by the horse after discharge and whether a repeat celiotomy had been required to resolve the colic episodes.

Results:There were 165 surgeries identified, in 154 horses. It was found that those horses with RDD were significantly more likely to experience recurrent episodes of colic requiring veterinary intervention post operatively compared to other types of displacement.

Clinical relevance:Long‐term prognosis and likelihood of post operative complications is an important consideration for both owners and veterinarians.
Endoparasite control management on horse farms – lessons from worm prevalence and questionnaire data
Authors: FRITZEN B. , ROHN K. , SCHNIEDER T. , VON SAMSON‐HIMMELSTJERNA G.
Published: July 2010

Reasons for performing study:Increasing prevalence of anthelmintic resistance in equine nematodes calls for a reexamination of current parasite control programmes to identify factors influencing control efficacy and development of resistance.

Objectives:To investigate if associations occur between prevalence of parasitic nematodes and management practices.

Methods:German horse farms (n = 76) were investigated in 2003 and 2004. Information on farm and pasture management with respect to endoparasite control measures obtained using a questionnaire survey. Faecal examinations were performed in parallel.

Results:Horses (n = 2000) were examined by faecal nematode egg counts, grouped into foals, yearlings and mature individuals for statistical analyses. Farms were categorised into 3 types, riding, stud farms and small holdings. Count regression models were used to analyse strongyle faecal egg count data. Following dichotomisation of faecal egg count (FEC) data, prevalence of strongyle andParascaris equoruminfections were assessed by logistic regression models as a function from various management factors. Yearlings on stud farms showed a 2‐fold higher risk of being positive for strongyle FEC, higher (i.e. ≥3 per year) anthelmintic drug treatment frequencies were associated with reduced strongyle infection rates only in mature individuals but not in foals or yearlings, foals on farms fertilising pastures with horse manure had a significantly higher risk of beingP. equorumFEC positive and yearlings on stud farms were more often showing incomplete FECR following anthelmintic treatment compared to yearlings on other farm types. The mean yearly treatment frequencies per age group were: foals 4.52, yearlings 3.26 and mature horses 2.72 times, respectively.

Conclusion and potential relevance:To delay the development of anthelmintic, resistance management should include additional nonchemotherapeutic parasite control strategies, FEC‐monitoring, controlled quarantine treatment of new arrivals and control of efficacy by the faecal egg count reduction test on a regular basis.
Birth of live triplets in a mare
Authors: HODDER A. D. J. , COYNE C. P. , MADIGAN J. E
Published: July 2010

An 11‐year‐old American Buckskin mare gave birth to live triplets unattended at approximately 300 days gestation. All foals were small and dysmature, requiring intensive care. The smallest foal died 4 days after admission, the second was subjected to euthanasia 24 days after admission due to poor healing of a third metatarsal fracture. The remaining foal survived to discharge and was considered small but otherwise normal at age one year.
A study of the thickness of cheek teeth subocclusal secondary dentine in horses of different ages
Authors: WHITE C. , DIXON P. M.
Published: July 2010

Reasons for performing study:There is limited knowledge on the thickness of subocclusal secondary dentine in equine cheek teeth (CT).

Hypotheses:Subocclusal secondary dentine is of consistent thickness above different pulp horns in individual horses and its thickness increases with age.

Methods:408 permanent CT were extractedpost mortemfrom 17 horses aged 4–30 years, with no history of dental disease. The CT were sectioned longitudinally in the medio‐lateral (bucco‐palatal/lingual) plane through each pulp horn, and the thickness of the secondary dentine overlying each pulp horn was measured directly.

Results:The subocclusal thickness of secondary dentine above the pulp horns of CT varied from a mean thickness (above all pulp horns) of 12.8 mm (range 5–33 mm) in a 4‐year‐old to 7.5 mm (range 2–24 mm) in a 16‐year‐old horse. There was wide variation in the depth of subocclusal secondary dentine above different pulp horns, even within the same CT. In contrast to expectations, occlusal secondary dentine thickness did not increase with age. There were no significant differences in occlusal secondary dentine thickness between rostral and caudal, or medial and lateral aspects of the CT, or between contralateral CT. Mandibular CT had significantly thicker subocclusal secondary dentine than maxillary CT. Pink coloured secondary dentine was sometimes found 1–3 mm occlusal to the pulp horn in sectioned CT and this was likely caused by artefactual blood staining from the underlying pulp during sectioning.

Conclusions:The thickness of subocclusal secondary dentine varies greatly between individual pulp horns, teeth and individual horses and can be as low as 2 mm over individual pulp horns.

Potential relevance:Due to the great variation in the thickness of subocclusal secondary dentine between horses, and even between pulp horns in individual CT, there is a risk of exposure or thermal damage to pulp and thus of apical infection, even with modest therapeutic reductions of CT occlusal overgrowths. In the light of these findings, great care should be taken when reducing equine CT overgrowths and larger dental overgrowths should be reduced in stages.
Clinical update on the use of mesenchymal stem cells in equine orthopaedics
Authors: FRISBIE D. D. , SMITH R. K. W.
Published: July 2010

Stem cells have received much attention in recent times because of their potential to improve healing of othropaedic problems. This manuscript presents the genesis, issues and current state of stem cell treatment in equine medicine. Current literature supports the use of mesenchymal stem cells (MSCs) for treatment of orthopaedic problems.
Measurement of C‐peptide concentrations and responses to somatostatin, glucose infusion, and insulin resistance in horses
Authors: TÓTH F. , FRANK N. , MARTIN‐JIMÉNEZ T. , ELLIOTT S. B. , GEOR R. J. , BOSTON R. C.
Published: July 2010

Reasons for performing study: Hyperinsulinaemia is detected in horses with insulin resistance (IR) and has previously been attributed to increased pancreatic insulin secretion. Connecting peptide (C‐peptide) can be measured to assess pancreatic function because it is secreted in equimolar amounts with insulin and does not undergo hepatic clearance.

Hypothesis: A human double antibody radioimmunoassay (RIA) detects C‐peptide in equine serum and concentrations would reflect responses to different stimuli and conditions.

Methods: A validation procedure was performed to assess the RIA. Six mature mares were selected and somatostatin administered i.v. as a primed continuous rate infusion, followed by 50 nmol human C‐peptide i.v. Insulin and C‐peptide concentrations were measured in horses (n = 6) undergoing an insulin‐modified frequently sampled i.v. glucose tolerance test, and in horses with insulin resistance (n = 10) or normal insulin sensitivity (n = 20).

Results: A human RIA was validated for use with equine sera. Endogenous C‐peptide secretion was suppressed by somatostatin and median (range) clearance rate was 0.83 (0.15–1.61) ml/min/kg bwt. Mean ± s.d. C‐peptide‐to‐insulin ratio significantly (P = 0.004) decreased during the glucose tolerance test from 3.60 ± 1.95 prior to infusion to 1.03 ± 0.18 during the first 20 min following dextrose administration. Median C‐peptide and insulin concentrations were 1.5‐ and 9.5‐fold higher, respectively in horses with IR, compared with healthy horses.

Conclusions: Endogenous C‐peptide secretion decreases in response to somatostatin and increases after dextrose infusion. Results suggest that relative insulin clearance decreases as pancreatic secretion increases in response to dextrose infusion. Hyperinsulinaemia in insulin resistant horses may be associated with both increased insulin secretion and decreased insulin clearance.

Potential relevance: Both C‐peptide and insulin concentrations should be measured to assess pancreatic secretion and insulin clearance in horses.
Pediatric neurosurgery during Operation Enduring Freedom
Authors: Klimo Paul , Ragel Brian T. , Scott William H. , McCafferty Randall
Published: July 2010

Object

Operation Enduring Freedom (OEF) is the current US military conflict against terrorist elements in Afghanistan. Deepening US involvement in this conflict and increasing coalition casualties prompted the establishment of continuous neurosurgical assets at Craig Joint Theater Hospital (CJTH) at Bagram Airfield, Afghanistan, in September 2007. As part of the military's medical mission, children with battlefield-related injuries and, on a selective case-by-case basis, non–war-related pathological conditions are treated at CJTH.

Methods

A prospectively maintained record was created in which all rotating neurosurgeons at CJTH recorded their personal procedures. From this record, the authors were able to extract all cases involving patients 18 years of age or younger. Variables recorded included: age, sex, and category of patient (for example, local national, enemy combatant), date, indication and description of the neurosurgical procedure, mechanism of injury, and in-hospital morbidity and mortality data.

Results

From September 2007 to October 2009, 296 neurosurgical procedures were performed at CJTH. Fifty-seven (19%) were performed in 43 pediatric patients (16 girls and 27 boys) with an average age of 7.5 years (range 11 days–18 years). Thirty-one of the 57 procedures (54%) were for battlefield-related trauma and 26 for humanitarian reasons (46%). The vast majority of cases were cranial (49/57, 86%) compared with spinal (7/54, 13%), with one peripheral nerve case. Craniotomies or craniectomies for penetrating brain injuries were the most common procedures. There were 5 complications (11.6%) and 4 in-hospital deaths (9.3%).

Conclusions

As in previous military conflicts, children are the unfortunate victims of the current Afghanistan campaign. Extremely limited pediatric neurosurgical service and care is rendered under challenging conditions and Air Force neurosurgeons provide valuable, life-saving pediatric treatment for both war-related injuries and humanitarian needs. As the conflict in Afghanistan continues, military neurosurgeons will continue to care for injured children to the best of their abilities.
Deep brain stimulation between 1947 and 1987: the untold story
Authors: Hariz Marwan I. , Blomstedt Patric , Zrinzo Ludvic
Published: July 2010

Deep brain stimulation (DBS) is the most rapidly expanding field in neurosurgery. Movement disorders are well-established indications for DBS, and a number of other neurological and psychiatric indications are currently being investigated.

Numerous contemporary opinions, reviews, and viewpoints on DBS fail to provide a comprehensive account of how this method came into being. Misconceptions in the narrative history of DBS conveyed by the wealth of literature published over the last 2 decades can be summarized as follows: Deep brain stimulation was invented in 1987. The utility of high-frequency stimulation was also discovered in 1987. Lesional surgery preceded DBS. Deep brain stimulation was first used in the treatment of movement disorders and was subsequently used in the treatment of psychiatric and behavioral disorders. Reports of nonmotor effects of subthalamic nucleus DBS prompted its use in psychiatric illness. Early surgical interventions for psychiatric illness failed to adopt a multidisciplinary approach; neurosurgeons often worked “in isolation” from other medical specialists. The involvement of neuro-ethicists and multidisciplinary teams are novel standards introduced in the modern practice of DBS for mental illness that are essential in avoiding the unethical behavior of bygone eras.

In this paper, the authors examined each of these messages in the light of literature published since 1947 and formed the following conclusions. Chronic stimulation of subcortical structures was first used in the early 1950s, very soon after the introduction of human stereotaxy. Studies and debate on the stimulation frequency most likely to achieve desirable results and avoid side effects date back to the early days of DBS; several authors advocated the use of “high” frequency, although the exact frequency was not always specified. Ablative surgery and electrical stimulation developed in parallel, practically since the introduction of human stereotactic surgery. The first applications of both ablative surgery and chronic subcortical stimulation were in psychiatry, not in movement disorders. The renaissance of DBS in surgical treatment of psychiatric illness in 1999 had little to do with nonmotor effects of subthalamic nucleus DBS but involved high-frequency stimulation of the very same brain targets previously used in ablative surgery. Pioneers in functional neurosurgery mostly worked in multidisciplinary groups, including when treating psychiatric illness; those “acting in isolation” were not neurosurgeons. Ethical concerns have indeed been addressed in the past, by neurosurgeons and others. Some of the questionable behavior in surgery for psychiatric illness, including the bygone era of DBS, was at the hands of nonneurosurgeons. These practices have been deemed as “dubious and precarious by yesterday's standards.”
Placement of occipital condyle screws for occipitocervical fixation in a pediatric patient with occipitocervical instability after decompression for Chiari malformation
Authors: Bekelis Kimon , Duhaime Ann-Christine , Missios Symeon , Belden Clifford , Simmons Nathan
Published: July 2010

In cadaveric studies and recently in one adult patient the occipital condyle has been studied as an option to allow bone purchase by fixation devices. In the current case the authors describe the use of occipital condyle screws in a child undergoing occipitocervical fixation. To the best of the authors' knowledge this case is the first reported instance of this technique in a pediatric patient.

This girl had a history of posterior fossa decompression for Chiari malformation Type I when she was 22 months of age. When she was 6 years old she presented with neck pain on flexion and extension of her head. Magnetic resonance imaging in flexion and extension revealed occipitocervical instability. She underwent an occiput to C-2 posterior arthrodesis with bilateral screw placement in the occipital condyles, C-2 lamina, and C-1 lateral masses. Postoperatively, she was neurologically intact. Computed tomography demonstrated a stable construct, and her cervical pain had resolved on follow-up.
Cerebellar stimulation in the management of medically intractable epilepsy: a systematic and critical review
Authors: Fountas Kostas N. , Kapsalaki Eftychia , Hadjigeorgiou Georgios
Published: July 2010

Object

The wide application of deep brain stimulation in the management of movement as well as other degenerative neurological and psychiatric disorders has renewed the interest in using deep brain stimulation in the management of medically intractable epilepsy. Various stimulation targets have been used with significantly varying results in aborting seizure activity. Electrical cerebellar stimulation (CS) has been used for more than 50 years in the management of epilepsy, with conflicting results. In the current study, the authors review the pertinent literature to outline the role of CS in the management of medically refractory epilepsy.

Methods

The PubMed medical database was systematically searched for the following terms: “cerebellar,” “epilepsy,” “stimulation,” and “treatment,” and all their combinations. Case reports were excluded from this study.

Results

The pertinent articles were categorized into 2 large groups: animal experimental and human clinical studies. Particular emphasis on the following aspects was given when reviewing the human clinical studies: their methodological characteristics, the number of participants, their seizure types, the implantation technique and its associated complications, the exact stimulation target, the stimulation technique, the seizure outcome, and the patients' psychological and social poststimulation status. Three clinical double-blind studies were found, with similar implantation surgical technique, stimulation target, and stimulation parameters, but quite contradictory results. Two of these studies failed to demonstrate any significant seizure reduction, whereas the third one showed a significant poststimulation decrease in seizure frequency. All possible factors responsible for these differences in the findings are analyzed in the present study.

Conclusions

Cerebellar stimulation seems to remain a stimulation target worth exploring for defining its potential in the treatment of medically intractable epilepsy, although the data from the double-blind clinical studies that were performed failed to establish a clear benefit in regard to seizure frequency. A large-scale, double-blind clinical study is required for accurately defining the efficacy of CS in epilepsy treatment.
Deep brain stimulation of the posteromedial hypothalamus: indications, long-term results, and neurophysiological considerations
Authors: Franzini Angelo , Messina Giuseppe , Cordella Roberto , Marras Carlo , Broggi Giovanni
Published: July 2010

Object

The aim of this study was to review the indications for and results of deep brain stimulation (DBS) of the posterior hypothalamus (pHyp) in the treatment of drug-refractory and severe painful syndromes of the face, disruptive and aggressive behavior associated with epilepsy, and below-average intelligence. The preoperative clinical picture, functional imaging studies, and overall clinical results in the literature are discussed.

Methods

All patients underwent stereotactic implantation of deep-brain electrodes within the pHyp. Data from several authors have been collected and reported for each clinical entity, as have clinical results, adverse events, and neurophysiological characteristics of the pHyp.

Results

The percentage of patients with chronic cluster headache who responded to DBS was 50% in the overall reported series. The response rate was 100% for short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing and for chronic paroxysmal hemicrania, although only 2 patients and 1 patient, respectively, have been described as having these conditions.

None of the 4 patients suffering from refractory neuropathic trigeminal pain benefited from the procedure (0% response rate), whereas all 5 patients (100%) affected with refractory trigeminal neuralgia (TN) due to multiple sclerosis (MS) and undergoing pHyp DBS experienced a significant decrease in pain attacks within the first branch of cranial nerve V. Six (75%) of 8 patients presenting with aggressive behavior and mental retardation benefited from pHyp stimulation; 6 patients were part of the authors' series and 2 were reported in the literature.

Conclusions

In carefully selected patients, DBS of the pHyp can be considered an effective procedure for the treatment of refractory trigeminal autonomic cephalalgias, aggressive behavior, and MS-related TN in the first trigeminal branch. Only larger and prospective studies along with multidisciplinary approaches (including, by necessity, neuroimaging studies) can lead us to better patient selection that would reduce the rate of nonresponders.
Endoscopic repair of a rare basioccipital meningocele associated with recurrent meningitis
Authors: Ko Andrew L. , Gabikian Patrik , Perkins Jonathan A. , Gruber David P. , Avellino Anthony M.
Published: July 2010

Anatomical variants of the basiocciput are uncommon and usually clinically benign. While the majority remain undetected, these anomalies rarely manifest as CSF rhinorrhea or recurrent meningitis associated with meningocele. Compromise of the leptomeninges provides an avenue of ingress for pathological organisms and can lead to recurrent meningitis, necessitating operative repair of the defect to prevent infection. A review of the literature reveals only 3 cases in which a congenital basioccipital defect has been associated with a meningocele requiring surgical repair.

The authors present a case of recurrent meningitis in an infant with a congenital basioccipital meningocele treated with a minimally invasive endoscopic technique. At the 2-year follow-up the repair remained successful, with no evidence of recurrence of the meningocele or CSF infection. The literature regarding the etiology and treatment of these lesions was reviewed, with an emphasis on the safety and efficacy of the endoscopic approach. Note that recurrent meningitis in the setting of a skull base defect may indicate the presence of other congenital anomalies that will necessitate multidisciplinary care for a patient's long-term well-being.
Ependymoma of the spinal cord in children and adolescents: a retrospective series from the HIT database
Authors: Benesch Martin , Weber-Mzell Daniela , Gerber Nicolas U. , von Hoff Katja , Deinlein Frank , Krauss Jürgen , Warmuth-Metz Monika , Kortmann Rolf-Dieter , Pietsch Torsten , Driever Pablo Hernáiz , Quehenberger Franz , Urban Christian , Rutkowski Stefan
Published: July 2010

Object

Reports on spinal cord ependymoma in children are rare. The aim of this study was to evaluate the clinical spectrum, treatment, and outcome of children with primary ependymoma of the spinal cord who were registered in the database of the pediatric German brain tumor studies Hirntumor (HIT) '91 and HIT 2000.

Methods

Between 1991 and 2007, 29 patients (12 male and 17 female, median age at diagnosis 13.6 years) with primary spinal cord ependymoma (myxopapillary ependymoma WHO Grade I, II, and III tumors in 6, 17, and 6 patients, respectively) were identified. Four patients had neurofibromatosis Type 2.

Results

With a median follow-up of 4.2 years (range 0.48–15 years), 28 patients (96.6%) were alive. Seven patients (24.1%) developed progressive disease or relapse, 2 after gross-total resection (GTR) and 5 after incomplete resection or biopsy. One patient with anaplastic ependymoma (WHO Grade III) died 65 months after diagnosis of disease progression. Primary adjuvant treatment (radiotherapy, chemotherapy, or both) was used in 8 (50%) of 16 patients following GTR and in 9 (82%) of 11 patients who underwent less than a GTR. Three additional patients were treated adjuvantly following progression. Estimated progression-free survival and overall survival rates at 5 years were 72.3% (95% CI 50%–86%) and 100%, respectively. Progression-free survival at 5 years is 84.4% (95% CI 50%–96%) for patients following GTR compared with 57.1% (95% CI 25%–69%) for patients who achieved a less than GTR (p = 0.088, log-rank test). A high relapse incidence (4 of 6) was observed among patients with myxopapillary ependymoma.

Conclusions

Gross-total resection is the mainstay of treatment for patients with primary spinal cord ependymoma and may be achieved in about 50% of the patients using modern surgical techniques. Primary adjuvant treatment was commonly used in children with spinal cord ependymoma irrespective of the extent of resection or tumor grade. The impact of adjuvant treatment on progression-free and overall survival has to be investigated in a prospective trial.
Sixteen-year single-surgeon experience with coil embolization for ruptured intracranial aneurysms: recurrence rates and incidence of late rebleeding
Authors: Plowman R. Scooter , Clarke Alison , Clarke Mike , Byrne James V.
Published: July 2010

Object

Over a 16-year period, 570 patients presenting with acute aneurysmal subarachnoid hemorrhage were successfully treated using endosaccular coil embolization within 30 days of hemorrhage by a single surgeon. Patients were followed to assess the stability of aneurysm occlusion and its longer-term efficacy in protecting against rebleeding.

Methods

Patients were followed for 6 to 191 months (mean 73.7 months, median 67 months) by clinical review, angiography performed at 6 and 24 months posttreatment, and questionnaires sent via the postal service every 5 years. Late rebleeding was defined as > 30 days after treatment.

Results

Stable angiographic occlusion was evident in 74.5% of small, 72.2% of large, and 60% of giant aneurysms. Recurrent filling was found in 119 (26.3%) of 452 aneurysms. Rebleeding was diagnosed in 9 patients (6 treated aneurysms) and occurred between 2 and 114 months posttreatment. It was due to aneurysm recurrence in 6 patients, rupture of a coincidental untreated aneurysm in 2 patients, and rupture of a de novo aneurysm in 1 patient. Rebleeding occurred in 3 (2.5%) of 119 unstable aneurysms and in 3 (0.9%) of 333 stable aneurysms, as seen on initial follow-up angiography studies. Annual rebleeding rates ranged from 0.2% to 0.6% for all causes and from 0.2% to 0.4% for rebleeding of treated aneurysms. No rebleeding was recorded after the first decade, with 138 patients having more than 10 years of follow-up.

Conclusions

Periodic follow-up with angiographic studies after coil embolization is recommended to identify aneurysm recurrence and patients at a high risk of late rebleeding in the medium term. More frequent follow-up is recommended for patients harboring coincidental unruptured aneurysms.