bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linear, logarithmic, and polynomial models of M-mode echocardiographic measurements in dogs
Authors: Gonçalves Ana C. , Orton E. Christopher , Boon June A. , Salman M. D. 
Published: January 2006

AbstractObjective—To determine whether logarithmic and polynomial models are superior to simple linear models for predicting reference values for M-mode echocardiographic variables in dogs with a wide range of body weights.Animals—69 apparently healthy adult male and female dogs of various breeds, ages (range, 1 to 12 years; median, 3.5 years), and body weights (range, 3.9 to 97.7 kg; median, 25.4 kg).Procedure—Echocardiographic M-mode measurements of the interventricular septum, left ventricular dimension (LVD), left ventricular wall, aorta, and left atrium were obtained. Simple linear, second-order polynomial, third-order polynomial, and logarithmic regression models were determined by use of the least-squares method to describe the relationship between M-mode measurements and body weight. Differences in adjustedR2values of logarithmic and polynomial models were tested for significance of contribution, compared with the simple linear model.Results—Significant differences in adjustedR2 were found when comparing simple linear with logarithmic or polynomial models for LVD-diastole, LVD-systole, aorta, and left atrium. Differences in adjusted R2 between second-order polynomial, third-order polynomial, and logarithmic models were not significant for any M-mode measurement.Conclusions and Clinical Relevance—In this study, logarithmic or second-order polynomial models predicted reference values of M-mode measurements for size of the cardiac chambers better than simple linear models for dogs with a wide range of body weights. Logarithmic and polynomial models were not superior to simple linear models for M-mode measurements of cardiac wall thickness. (Am J Vet Res2002;63:994–999)
Biocompatibility of three-dimensional chondrocyte grafts in large tibial defects of rabbits
Authors: Cook James L. , Williams Ned , Kreeger John M. , Peacock John T. , Tomlinson James L. 
Published: January 2006

AbstractObjective—To evaluate biocompatibility and effects of implantation of 3-dimensional chondrocyte-agarose autografts in tibial defects in rabbits and to compare in vitro and in vivo chondrocyte-agarose constructs with respect to cell viability, differentiation, and matrix production.Animals—24 adult New Zealand White rabbits.Procedure—Three-dimensional constructs with (grafted group) or without (control group) autogenous chondrocytes were implanted into tibial defects of rabbits and cultured in vitro. During an 8-week period, defects were evaluated radiographically, grossly, histologically, biochemically, and immunohistochemically. In vitro constructs were evaluated histologically, biochemically, and immunohistochemically.Results—Tibial defects had significantly higher radiographic densitometry values at 4 and 6 weeks after implantation in grafted group rabbits, compared with control group rabbits. Number of observed centers of endochondral ossification was significantly greater in defects of grafted group rabbits, compared with control group rabbits. On day 14, glycosaminoglycan concentration was significantly higher in tibial defects of grafted group rabbits, compared to defects of control group rabbits or in vitro constructs. At weeks 2, 4, and 8, glycosaminoglycan concentrations were significantly lower in the in vitro control constructs, compared with other groups. Collagen type I was present in bone and bony callous in defects of grafted and control group rabbits. Collagen type II was identified in cartilaginous tissues of grafted and control group rabbits. Collagen type X was associated with hypertrophic chondrocytes. Only type II collagen was found in the in vitro chondrocyte constructs.Conclusion and Clinical Relevance—Chondrocyte-agarose grafts are biocompatible in large tibial defects and appear to provide a cell source for augmenting endochondral ossification. (Am J Vet Res2003;64:12–20)
Effects of acetylcysteine and migration of resident eosinophils in an in vitro model of mucosal injury and restitution in equine right dorsal colon
Authors: Rötting Anna K. , Freeman David E. , Eurell Jo Ann C. , Constable Peter D. , Wallig Matthew 
Published: January 2006

AbstractObjectives—To evaluate the in vitro protective effects of acetylcysteine and response of resident mucosal eosinophils in oxidant-induced injury to tissues of right dorsal colon of horses.Animals—9 adult horses.Procedure—Gastrointestinal mucosa was damaged in vitro with 3mM hypochlorous acid (HOCl), with and without prior exposure to 6mM acetylcysteine. Control tissues were not exposed to HOCl or acetylcysteine. Control and damaged tissues were incubated in Krebs-Ringer-bicarbonate solution and tissue resistance measured during 240 minutes. Tissue permeability to radiolabeled mannitol was also used to assess mucosal barrier integrity. Tissues were examined by light microscopy before and after HOCl exposure and during and after incubation.Results—Exposure to HOCl caused tissue damage and decreased tissue resistance. Restitution did occur during the incubation period. Eosinophils were located near the muscularis mucosae in freshly harvested tissues and migrated towards the luminal surface in response to HOCl-induced injury. Compared with tissues treated with HOCl without acetylcysteine, pretreatment with acetylcysteine prevented HOCl-induced tissue damage, changes in resistance, and histologically detectable eosinophil migration. The permeability to mannitol increased to the same extent in tissues treated with HOCl alone or with acetylcysteine and HOCl.Conclusions and Clinical Relevance—Eosinophils migrated toward the mucosal surface in equine colon in response to oxidant-induced damage in vitro. This novel finding could be relevant to inflammation in equine colon and a pathophysiologic feature of many colonic diseases. Acetylcysteine protected the mucosa against oxidant-induced injury and may be useful as a treatment option for various gastrointestinal tract disorders in horses. (Am J Vet Res2003;64:1205–1212)
Determination of reference range values indicative of glucose metabolism and insulin resistance by use of glucose clamp techniques in horses and ponies
Authors: Rijnen Kim E. P. M. , van der Kolk Johannes H. 
Published: January 2006

Abstract

Objectives—To acquire reference range values
indicative of glucose metabolism by use of the hyperglycemic
clamp technique in healthy horses and evaluate
the usefulness of the euglycemic hyperinsulinemic
clamp technique in healthy horses and ponies.

Animals—5 Dutch Warmblood horses and 4 Shetland
ponies.

Procedure—The hyperglycemic clamp technique was
used for quantification of the sensitivity of beta cells
to exogenous glucose infusion in horses. The euglycemic
hyperinsulinemic clamp technique was used
to determine the sensitivity and responsiveness of
tissues to exogenous insulin in horses and ponies.

Results—During the hyperglycemic clamp technique,
the mean amount of glucose metabolized (M) in horses
was 0.011 ± 0.0045 mmol/kg·min–1 (95% confidence
interval [CI], 0.0018 to 0.020 mmol/kg·min–1;
range, 0.000035 to 0.021 mmol/kg·min–1) and the
mean M value-to-plasma insulin concentration (I) ratio
(ie, mmol of glucose/kg·min–1 per pmol of insulin/L X
100) was 0.017 ± 0.016 (95% CI, –0.014 to 0.049;
range, 0.000025 to 0.055). During the euglycemic
hyperinsulinemic clamp technique, the mean M value
was 0.014 ± 0.0055 mmol/kg·min–1 (95% CI, 0.0026 to
0.025 mmol/kg·min–1; range, 0.0042 to 0.023
mmol/kg·min–1) in horses and 0.0073 ± 0.0020
mmol/kg·min–1 (95% CI, 0.0034 to 0.011
mmol/kg·min–1; range, 0.0049 to 0.011 mmol/kg·min–1)
in ponies. The M value was significantly lower in
ponies than in horses, whereas the M:I ratios were
not significantly different between horses and ponies.

Conclusion and Clinical Relevance—Glucose clamp
techniques offer good methods to investigate glucose
metabolism in horses and ponies. A higher degree of
insulin resistance was found in ponies, compared with
Dutch Warmblood horses. (Am J Vet Res 2003;64: 1260–1264)
Effect of first-pass hepatic metabolism on the disposition of levamisole after intravenous administration in rabbits
Authors: Villanueva Irma , Diez M. José , García Juan J. , Fernández M. Nélida , Sahagún Ana M. , Sierra Ana , Sierra Matilde 
Published: January 2006

AbstractObjective—To evaluate the contribution of first-pass hepatic metabolism of levamisole on levamisole disposition in rabbits.Animals—30 male New Zealand White rabbits.Procedures—Rabbits were randomly placed into 2 groups. Rabbits in the first group received levamisole via the marginal ear vein at the following 3 doses: 12.5, 16, and 20 mg/kg (5 rabbits for each dose). Rabbits of the second group received levamisole via the jejunal vein at the same doses (5 rabbits each). During the following 240-minute period, plasma samples were obtained and quantified for levamisole concentrations by reversed-phase high-performance liquid chromatography.Results—No significant differences were found between pharmacokinetic parameters calculated by compartmental or noncompartmental analysis. Mean hepatic extraction ratio ranged from –0.044 to 0.017 and from 0.020 to 0.081 when area under the plasma concentration-time curve values were obtained after compartmental or noncompartmental analysis, respectively. After compartmental analysis, plasma concentration decreased bi-exponentially. Mean pharmacokinetic parameter values were as follows for each dose (12.5, 16, and 20 mg/kg, respectively): after levamisole administration via the marginal ear vein, volume of distribution at steady state (Vss) = 4.26, 4.33, and 3.20 L/kg; total body clearance (Cl) = 49.04, 43.77, and 39.26 mL/kg·min; and half-life associated with β-phase (t1/2β) = 77.93, 85.39, and 69.79 minutes. After levamisole administration via the jejunal vein, Vss= 4.38, 2.85, and 2.97 L/kg; Cl = 48.14, 42.40, and 39.69 mL/kg·min; and t1/2b= 101.9, 76.71, and 76.13 minutes.Conclusions—Levamisole has a low degree of hepatic extraction in rabbits. (Am J Vet Res2003;64: 1283–1287)
Comparison of the effect of propofol and sevoflurane on the urethral pressure profile in healthy female dogs
Authors: Byron Julie K. , March Philip A. , DiBartola Stephen P. , Chew Dennis J. , Muir III William W. 
Published: January 2006

AbstractObjective—To compare the effects of propofol and sevoflurane on the urethral pressure profile in female dogs.Animals—10 healthy female dogs.Procedure—Urethral pressure profilometry was performed in awake dogs, during anesthesia with sevoflurane at 1.5, 2.0, and 3.0% end-tidal concentration, and during infusion of propofol at rates of 0.4, 0.8, and 1.2 mg/kg/min. A consistent plane of anesthesia was maintained for each anesthetic protocol. Maximum urethral pressure, maximum urethral closure pressure, functional profile length, and functional area were measured.Results—Mean maximum urethral closure pressure of awake dogs was not significantly different than that of dogs anesthetized with propofol at all infusion rates or with sevoflurane at 1.5 and 2.0% end-tidal concentration. Functional area in awake dogs was significantly higher than in anesthetized dogs. Functional area of dogs during anesthesia with sevoflurane at 3.0% end-tidal concentration was significantly lower than functional area for other anesthetic protocols. Individual differences in the magnitude of effects of propofol and sevoflurane on urethral pressures were observed.Conclusions and Clinical Relevance—Sevoflurane is an alternative to propofol for anesthesia in female dogs undergoing urethral pressure profilometry. Use of these anesthetics at appropriate administration rates should reliably distinguish normal from abnormal maximum urethral closure pressures and functional areas. Titration of anesthetic depth is a critical component of urodynamic testing. (Am J Vet Res2003;64:1288–1292)
Evaluation of T lymphocytes in captive African lions (Panthera leo) infected with feline immunodeficiency virus
Authors: Bull Marta E. , Kennedy-Stoskopf Suzanne , Levine Jay F. , Loomis Michael , Gebhard Douglas G. , Tompkins Wayne A.F. 
Published: January 2006

AbstractObjective—To determine whether FIV infection in captive African lions is associated with changes in immune cell variables similar to those detected in domestic cats infected with FIV.Animals—5 captive African lions naturally infected with FIV (FIV+) and 5 lions not infected with FIV (FIV–).Procedure—Peripheral blood samples were collected from FIV+lions during annual examinations conducted during a 7-year period and at a single time point from the FIV–lions. From results of CBC and flow cytometry, lymphocyte subsets were characterized and compared.Results—Flow cytometric analysis revealed that the percentage and absolute number of CD4+and CD8+T cells were significantly lower in FIV+ lions, compared with these values in FIV– lions. In FIV+lions, severe depletion in the absolute number of CD4+and CD8+T cells was detected, although this did not correlate with clinical signs. Muscle wasting was the most consistent clinical sign of infection.Conclusions and Clinical Relevance—Results suggest that FIV+African lions develop lymphocyte deficiencies, including significant decreases in the absolute number of CD4+and CD8+T cells; these findings of immune dysfunction are similar to those defined for FIV+domestic cats. It is important to monitor the number of CD4+T cells in infected animals as a measure of disease progression. (Am J Vet Res2003; 64:1293–1300)
Effects of iron modulation on growth and viability of Rhodococcus equi and expression of virulence-associated protein A
Authors: Jordan Misty C. , Harrington Jessica R. , Cohen Noah D. , Tsolis Renee M. , Dangott Lawrence J. , Weinberg Eugene D. , Martens Ronald J. 
Published: January 2006

AbstractObjective—To determine the importance of iron for in vitro growth ofRhodococcus equi, define potential iron sources in the environment and mechanisms by whichR equimay obtain iron from the environment, and assess expression and immunogenicity of iron-regulated proteins.Sample Population—10 virulent and 11 avirulent strains ofR equi.Procedure—In vitro growth rates and protein patterns ofR equipropagated in media with normal, excess, or limited amounts of available iron were compared. Immunoblot analyses that used serum from foals naturally infected withR equiand monoclonal antibody against virulence-associated protein (Vap)A were conducted to determine immunogenicity and identity of expressed proteins.Results—Excess iron did not alter growth of anyR equistrains, whereas growth of all strains was significantly decreased in response to limited amounts of available iron. VirulentR equiwere able to use iron from ferrated deferoxamine, bovine transferrin, and bovine lactoferrin. Only virulentR equiexpressed an iron-regulated, immunogenic, surface-associated protein identified as VapA.Conclusions and Clinical Relevance—Iron is required for the growth and survival ofR equi. Sources of iron forR equi, and mechanisms by whichR equiacquire iron in vivo, may represent important virulence factors and novel targets for the development of therapeutic and immunoprophylactic strategies to controlR equiinfection in foals. Expression of VapA is substantially upregulated when there is a limited amount of available iron. (Am J Vet Res2003;64:1337–1346)
Evaluation of gradual occlusion of the caudal vena cava in clinically normal dogs
Authors: Peacock John T. , Fossum Theresa W. , Bahr Anne M. , Miller Matthew W. , Edwards John F. 
Published: January 2006

AbstractObjective—To devise a technique for gradual occlusion of the caudal vena cava in dogs and determine effects of complete occlusion of the caudal vena cava.Animals—8 mixed-breed hounds that weighed between 25 and 30 kg.Procedure—Baseline evaluation of dogs included serum biochemical analyses and determination of glomerular filtration rate (GFR) with dynamic renal scintigraphy and plasma clearance analysis. An occluder was placed around the vena cava in the region cranial to the renal veins. The occluder was attached to a vascular access port. The vena cava was gradually occluded over 2 weeks. The GFR was measured every 2 weeks after surgery, and venograms were performed every 3 weeks after surgery. Blood samples were collected every 48 hours for the first week and then weekly thereafter to measure BUN and creatinine concentrations and activities of alanine transaminase, alkaline phosphatase, and creatinine kinase. Dogs were euthanatized 6 weeks after surgery, and tissues were submitted for histologic examination. The GFR and biochemical data were compared with baseline values.Results—Gradual occlusion of the caudal vena cava was easily and consistently performed with this method, and adverse clinical signs were not detected. Formation of collateral vessels allowed overall GFR to remain constant despite a decrease in function of the left kidney. Measured biochemical values did not deviate from reference ranges.Conclusions and Clinical Relevance—Gradual occlusion of the caudal vena cava may allow removal of adrenal gland tumors with vascular invasion that would otherwise be difficult or impossible to resect. (Am J Vet Res2003;64:1347–1353)
Assessment of the reliability of a technique to measure postural sway in horses
Authors: Clayton Hilary M. , Bialski David E. , Lanovaz Joel L. , Mullineaux David R. 
Published: January 2006

Abstract

Objective—To assess the reliability of the center-ofpressure
(COP) values obtained from a force platform
for analysis of postural sway in horses.

Animals—Six 2-year-old horses that were free from
lameness and neurologic disease.

Procedure—Horses stood stationary with all 4
hooves on a force platform; COP data were collected
at 1,000 Hz and 3-dimensional kinematics collected at
60 Hz for 10 seconds. Five trials were recorded at
each of 3 time periods (15-minute intervals) or at 1
time period on 3 separate days. Mean values for each
set of 5 trials and actual, normalized, and relative COP
variables were calculated. The reliability was quantified
by use of agreement boundary.

Results—The COP results within and across days
were similar and provided small agreement boundary
limits (eg, across days, in order of least relative reliability:
area, ± 62 mm2; mediolateral range, ± 8 mm;
radius, ± 2 mm; craniocaudal range, ± 4 mm; and
velocity, ± 3 mm/s). Head height possessed the greatest
relative intraday reliability (12%) but a high agreement
boundary limit (± 0.15 m).

Conclusions and Clinical Relevance—The use of a
force platform to analyze postural sway in a group of
young healthy horses was found to produce reliable
results and may provide a simple and sensitive measure
for assessing balance deficiencies in horses.
Agreement boundaries provide 95% confidence intervals
for use as limits of error and variability in measurements
that, if exceeded, may signify meaningful
effects. (Am J Vet Res 2003;64:1354–1359)
Evaluation of activated neutrophils in the blood of horses with colic
Authors: Weiss Douglas J. , Evanson Oral A. 
Published: January 2006

AbstractObjective—To evaluate the activation status of neutrophils in blood samples obtained from horses with naturally occurring colic associated with strangulating obstruction, nonstrangulating obstruction, or inflammatory bowel disease.Animals—30 horses with naturally occurring colic and 30 healthy control horses.Procedure—Activation status of neutrophils was determined by assessing the number of neutrophils that could pass through filters with 5-µm pores, cellsurface CD11-CD18 expression, and alterations in size and granularity of neutrophils.Results—Horses with impaction or gas colic did not have evidence of activated neutrophils. Horses with inflammatory bowel disease consistently had evidence of activated neutrophils, including decreased leukocyte deformability, increased CD11-CD18 expression, increased neutrophil size, and decreased neutrophil granularity. Horses with strangulating colic had variable results. Of horses with strangulating colic, 7 of 14 had marked changes in filtration pressures, 5 of 14 had increased CD11-CD18 expression, 6 of 14 had changes in neutrophil size, and 5 of 14 had changes in neutrophil granularity. Among horses with strangulating colic, changes in deformability, size, and granularity of neutrophils correlated with an adverse outcome.Conclusions and Clinical Relevance—Activated neutrophils were detected in all horses with inflammatory bowel disease and a few horses with strangulating colic. Correlation of activated neutrophils with horses that had strangulating colic that died or were euthanatized indicates that activated neutrophils are a negative prognostic indicator. Additional studies are needed to determine whether activated neutrophils contribute directly to the adverse outcome in horses with strangulating colic. (Am J Vet Res2003;64:1364–1368)
Effect of darglitazone on glucose clearance and lipid metabolism in obese cats
Authors: Hoenig Margarethe , Ferguson Duncan C. 
Published: January 2006

AbstractObjective—To examine the effect of darglitazone, a compound of the thiazolidinedione class, on glucose clearance and lipid metabolism in obese cats.Animals—18 obese and 4 lean adult neutered female cats.Procedure—IV glucose tolerance tests with measurements of glucose, insulin, and nonesterified fatty acid (NEFA) concentrations were performed before and 42 days after daily administration of darglitazone (9 obese cats) or placebo (9 obese and 4 lean cats). Additionally, cholesterol, triglyceride, leptin, and glycosylated hemoglobin concentrations were measured.Results—Darglitazone-treated cats had significantly lower cholesterol, triglyceride, and leptin concentrations, compared with placebo-treated obese cats. A significant decrease in the area under the curve for NEFAs, glucose, and insulin during an IV glucose tolerance test was seen in darglitazone-treated cats. The drug was well tolerated.Conclusions and Clinical Relevance—The response of obese cats to darglitazone was similar to the response to thiazolidinediones in obese humans and rodents Darglitazone was effective in improving insulin sensitivity and glucose and lipid metabolism in obese cats. (Am J Vet Res2003;64:1409–1413)
Use of the impulse oscillometry system for testing pulmonary function during methacholine bronchoprovocation in horses
Authors: Erck Emmanuelle van , Votion Dominique M. , Kirschvink Nathalie , Art Tatiana , Lekeux Pierre 
Published: January 2006

AbstractObjective—To compare sensitivity of the impulse oscillometry system (IOS) with that of the conventional reference technique (CRT; ie, esophageal balloon method) for pulmonary function testing in horses.Animals—10 horses (4 healthy; 6 with recurrent airway obstruction [heaves] in remission).Procedure—Healthy horses (group-A horses) and heaves-affected horses (group-B horses) were housed in a controlled environment. At each step of a methacholine bronchoprovocation test, threshold concentration (TC2SD; results in a 2-fold increase in SD of a value) and sensitivity index (SI) were determined for respiratory tract system resistance (Rrs) and respiratory tract system reactance (Xrs) at 5 to 20 Hz by use of IOS and for total pulmonary resistance (RL) and dynamic lung compliance (Cdyn), by use of CRT.Results—Bronchoconstriction resulted in an increase in Rrsat 5 Hz (R5Hz) and a decrease in Xrsat all frequencies. Most sensitive parameters were Xrsat 5 Hz (X5Hz), R5Hz, and R5Hz:R10Hzratio; RLand the provocation concentration of methacholine resulting in a 35% decrease in dynamic compliance (PC35Cdyn) were significantly less sensitive than these IOS parameters. The TC2SDfor Xrsat 5 and 10 Hz was significantly lower in group-B horses, compared with group-A horses. The lowest TC2SDwas obtained for X5Hzin group-B horses and R5Hzin group-A horses.Conclusions and Clinical Relevance—In contrast to CRT parameters, IOS parameters were significantly more sensitive for testing pulmonary function. The IOS provides a practical and noninvasive pulmonary function test that may be useful in assessing subclinical changes in horses. (Am J Vet Res2003;64:1414–1420)