bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolism of amino acids in cats with severe cobalamin deficiency
Authors: Ruaux Craig G. , Steiner Jörg M. , Williams David A. 
Published: December 2005

AbstractObjective—To validate an automated chemiluminescent immunoassay for measuring serum cobalamin concentration in cats, to establish and validate gas chromatography-mass spectrometry techniques for use in quantification of methylmalonic acid, homocysteine, cysteine, cystathionine, and methionine in sera from cats, and to investigate serum concentrations of methylmalonic acid, methionine, homocysteine, cystathionine, and cysteine as indicators of biochemical abnormalities accompanying severe cobalamin (vitamin B12) deficiency in cats.Sample Population—Serum samples of 40 cats with severe cobalamin deficiency (serum cobalamin concentration < 100 ng/L) and 24 control cats with serum cobalamin concentration within the reference range.Procedure—Serum concentrations of cobalamin were measured, using a commercial automated chemiluminescent immunoassay. Serum concentrations of methylmalonic acid, methionine, homocysteine, cystathionine, and cysteine were measured, using gas chromatography-mass spectrometry, selected ion monitoring, stable-isotope dilution assays.Results—Cats with cobalamin deficiency had significant increases in mean serum concentrations of methylmalonic acid (9,607 nmol/L), compared with healthy cats (448 nmol/L). Affected cats also had substantial disturbances in amino acid metabolism, compared with healthy cats, with significantly increased serum concentrations of methionine (133.8 vs 101.1 µmol/L) and significantly decreased serum concentrations of cystathionine (449.6 vs 573.2 nmol/L) and cysteine (142.3 vs 163.9 µmol/L). There was not a significant difference in serum concentrations of homocysteine between the 2 groups.Conclusions and Clinical Relevance—Cats with gastrointestinal tract disease may have abnormalities in amino acid metabolism consistent with cobalamin deficiency. Parenteral administration of cobalamin may be necessary to correct these biochemical abnormalities. (Am J Vet Res2001;62:1852–1858)
Effects of exercise on biomechanical properties of the superficial digital flexor tendon in foals
Authors: Cherdchutham Worakij , Meershoek Liduin S. , van Weeren Paul R. , Barneveld Albert 
Published: December 2005

AbstractObjective—To determine the effects of exercise on biomechanical properties of the superficial digital flexor tendon (SDFT) in foals.Animals—43 Dutch Warmblood foals.Procedure—From 1 week until 5 months of age, 14 foals were housed in stalls and not exercised, 14 foals were housed in stalls and exercised daily, and 15 foals were maintained at pasture. Eight foals in each group were euthanatized at 5 months, and remaining foals were housed together in a stall and paddock until euthanatized at 11 months. After euthanasia, SDFT were isolated and fit in a material testing system. Mean cross-sectional area (CSA) was measured and traction forces recorded. Normalized force at rupture (forcerup), normalized force at 4% strain, strain at rupture, stress at 4% strain (stress4%strain), and stress at rupture were compared among and within groups.Results—At 5 months, mean CSA and normalized forcerup were significantly greater and stress4%strainsignificantly less in the pastured group, compared with the other groups. At 11 months, CSA and normalized forcerupwere not significantly different among groups, because forcerupincreased significantly from 5 to 11 months in the nonexercised group and decreased significantly in the pastured group.Conclusions and Clinical Relevance—Exercise significantly affected the biomechanical properties of the SDFT in foals. Evenly distributed moderate- and low-intensity exercise at a young age may be more effective for development of strong, flexible tendons in horses than single episodes of high-intensity exercise superimposed on stall rest. This effect may impact later susceptibility to SDFT injury. (Am J Vet Res2001;62:1859–1864)
Anticoagulant effects of repeated subcutaneous injections of high doses of unfractionated heparin in healthy dogs
Authors: Mischke Reinhard H. , Schüttert Christina , Grebe Susanne I. 
Published: December 2005

AbstractObjective—To evaluate SC administration of unfractionated heparin (UFH) in accordance with a dosing regimen for high-dose treatment in dogs.Animals—10 healthy adult Beagles.Procedures—Two groups of dogs (5 dogs/group) were given 6 injections of heparin (500 units of UFH/kg of body weight, SC) at intervals of 8 (experiment 1) and 12 (experiment 2) hours. Blood samples were collected before and 4 hours after heparin injections to determine amidolytic heparin activity, activated partial thromboplastin time (APTT), thrombin time, antithrombin activity, platelet count, and Hct.Results—For experiments 1 and 2, mean ± SD heparin activities before (experiment 1, 1.32 ± 0.20 U/ml; experiment 2, 0.69 ± 0.174 U/ml) and 4 hours after the last heparin injection (experiment 1, 1.71 ± 0.30 U/ml; experiment 2, 1.10 ± 0.30 U/ml) were higher than values calculated for the regimen used in experiment 1. Results of the investigated thrombin time test system with low thrombin activity were frequently beyond the measurement range, even with UFH activities ≥ 0.6 U/ml. Moreover, a severe decrease of antithrombin activity became evident during both experiments (eg, in experiment 2 from 95.6 ± 4.8 to 59.2 ± 6.6%). In each treatment group, 2 dogs developed hematomas.Conclusions and Clinical Relevance—Calculations of the course of heparin activity after a single injection do not result in a reliable dosing regimen for highdose heparin treatment in dogs. High-dose treatment must be monitored for each dog. Thrombin time measured with low thrombin activity is unsuitable for this purpose. (Am J Vet Res2001;62:1887–1891)
Effects of oral administration of phenylbutazone to horses on in vitro articular cartilage metabolism
Authors: Beluche Lisa A. , Bertone Alicia L. , Anderson David E. , Rohde Carsten 
Published: December 2005

AbstractObjective—To evaluate the effects of orally administered phenylbutazone on proteoglycan synthesis and chondrocyte inhibition by IL-1β in articular cartilage explants of horses.Animals—11 healthy 1- to 2-year-old horses.Procedure—Horses were randomly assigned to the control (n = 5) or treated group (4.4 mg of phenylbutazone/ kg of body weight, PO, q 12 h; n = 6). Articular cartilage specimens were collected before treatment was initiated (day 0), after 14 days of treatment, and 2 weeks after cessation of treatment (day 30). Proteoglycan synthesis and stromelysin concentration in cartilage extracts were assessed after 72 hours of culture in medium alone or with recombinant human interleukin-1β (IL-1β; 0.1 ng/ml).Results—On day 0, proteoglycan synthesis was significantly less in cartilage explants cultured in IL-1β, compared with medium alone. Mean proteoglycan synthesis in explants collected on days 14 and 30 was significantly less in treated horses, compared with controls. However, incubation of explants from treated horses with IL-1β did not result in a further decrease in proteoglycan synthesis. Significant differences in stromelysin concentration were not detected between or within groups.Conclusions and Clinical Relevance—Oral administration of phenylbutazone for 14 days significantly decreased proteoglycan synthesis in articular culture explants from healthy horses to a degree similar to that induced by in vitro exposure to IL-1β. Phenylbutazone should be used judiciously in athletic horses with osteoarthritis, because chronic administration may suppress proteoglycan synthesis and potentiate cartilage damage. (Am J Vet Res2001; 62:1916–1921)
Effects of acetylpromazine or morphine on urine production in halothane-anesthetized dogs
Authors: Robertson Sheilah A. , Hauptman Joseph G. , Nachreiner Ray F. , Richter Marlee A. 
Published: December 2005

AbstractObjective—To assess the influence of preanesthetic administration of acetylpromazine or morphine and fluids on urine production, arginine vasopressin (AVP; previously known as antidiuretic hormone) concentrations, mean arterial blood pressure (MAP), plasma osmolality (Osm), PCV, and concentration of total solids (TS) during anesthesia and surgery in dogs.Animals—19 adult dogs.Procedure—Concentration of AVP, indirect MAP, Osm, PCV, and concentration of TS were measured at 5 time points (before administration of acetylpromazine or morphine, after administration of those drugs, after induction of anesthesia, 1 hour after the start of surgery, and 2 hours after the start of surgery). Urine output and end-tidal halothane concentrations were measured 1 and 2 hours after the start of surgery. All dogs were administered lactated Ringer's solution (20 ml/kg of body weight/h, IV) during surgery.Results—Compared with values for acetylpromazine, preoperative administration of morphine resulted in significantly lower urine output during the surgical period. Groups did not differ significantly for AVP concentration, Osm, MAP, and end-tidal halothane concentration; however, PCV and concentration of TS decreased over time in both groups and were lower in dogs given acetylpromazine.Conclusions and Clinical Relevance—Preanesthetic administration of morphine resulted in significantly lower urine output, compared with values after administration of acetylpromazine, which cannot be explained by differences in AVP concentration or MAP. When urine output is used as a guide for determining rate for IV administration of fluids in the perioperative period, the type of preanesthetic agent used must be considered.(Am J Vet Res2001;62:1922–1927)
In vitro responses of equine colonic arterial and venous rings to adenosine triphosphate
Authors: Tetens Joanne , Venugopal Changaram S. , Holmes Earnestine P. , Koch Catherine E. , Hosgood Giselle , Moore Rustin M. 
Published: December 2005

AbstractObjective—To evaluate the in vitro effects of adenosine tryphosphate (ATP) on vasomotor tone of equine colonic vasculature.Sample Population—Arteries and veins from the left ventral colon of 14 mixed-breed horses euthanatized for reasons unrelated to cardiovascular or gastrointestinal tract disease.Procedures—Endothelium-intact and -denuded arterial and venous rings were precontracted with 10–7and 1.8 × 10–8Mendothelin-1, respectively. In 1 trial, endothelium-intact rings were also incubated with 10–4MNω-nitro-L-arginine methyl ester (L-NAME) to inhibit nitric oxide (NO) production. Adenosine triphosphate (10–8to 10–3M) was added in a noncumulative manner, and relaxation percentage versus time curves were generated. Areas under the curves (ie, percentage of relaxation time) were calculated.Results—Relaxation response of arterial and venous rings to ATP was dose-dependent. Percentage of relaxation time in response to 10–4and 10–3MATP was significantly greater, compared with that for rings not treated with ATP. Removal of endothelium attenuated but did not eliminate the relaxation response. Addition of L-NAME did not attenuate the relaxation response in arteries. At higher concentrations, the vascular response to ATP was biphasic.Conclusions and Clinical Relevance—ATP applied to equine colonic arterial and venous rings with and without intact endothelium induced a biphasic response characterized by transient contraction followed by slow, substantial, and sustained relaxation. This ATP-induced response is possibly mediated by a mechanism other than NO. Adenosine triphosphate may be a useful treatment to modulate colonic vasomotor tone in horses with strangulating volvulus of the ascending colon. (Am J Vet Res2001;62:1928–1933)
Effects of topical administration of 0.005% latanoprost solution on eyes of clinically normal horses
Authors: Willis A. Michelle , Diehl Kathryn A. , Hoshaw-Woodard Stacy , Kobayashi Ichirio , Vitucci Michael P. , Schmall L. Michael 
Published: December 2005

AbstractObjective—To determine the effect of 0.005% latanoprost solution on intraocular pressure (IOP) of eyes of clinically normal horses and establish the frequency of adverse effects of drug administration.Animals—20 adult clinically normal horses.Procedure—IOP was recorded (7, 9, and 11 AM; 3, 5, and 7 PM) on days 1 and 2 (baseline), days 3 to 7 (treatment), and days 8 to 9 (follow-up). Latanoprost was administered to 1 randomly assigned eye of each horse every 24 hours during the treatment period, following the 7 AM IOP recording. Pupil size and the presence or absence of conjunctival hyperemia, epiphora, blepharospasm, blepharedema, and aqueous flare were recorded prior to IOP measurement.Results—IOP was reduced from baseline by a mean value of 1.03 mm Hg (5%) in males and 3.01 mm Hg (17%) in females during the treatment period. Miosis developed in all treated eyes and was moderate to marked in 77% of horses, with the peak effect observed 4 to 8 hours after drug administration. Conjunctival hyperemia, epiphora, blepharospasm, and blepharedema were present in 100, 57, 42, and 12% of treated eyes, respectively, 2 to 24 hours following drug administration. Aqueous flare was not observed at any time point.Conclusions and Clinical Relevance—Although IOP was reduced with every 24-hour dosing of latanoprost, the frequency of prostaglandin-induced adverse events was high. Because recurrent uveitis appears to be a risk factor for glaucoma in horses, topical administration of latanoprost may potentiate prostaglandin-mediated inflammatory disease in affected horses. (Am J Vet Res2001;62:1945–1951)
Methodology and validity of assessing kinematics of the thoracolumbar vertebral column in horses on the basis of skin-fixated markers
Authors: Faber Marjan , Schamhardt Henk , Weeren René van , Barneveld Ab 
Published: December 2005

Abstract

Objective—To determine the validity of using skin-fixated
markers to assess kinematics of the thoracolumbar
vertebral column in horses.

Animals—5 Dutch Warmblood horses without abnormalities
of the vertebral column.

Procedure—Kinematics of T6, T10, T13, T17, L1, L3,
L5, S3, and both tuber coxae were determined by use
of bone-fixated and skin-fixated markers. Threedimensional
coordinate data were collected while
horses were walking and trotting on a treadmill.
Angular motion patterns were calculated and compared
on the basis of 2-dimensional analysis of data
from skin-fixated markers and 3-dimensional analysis
of data from bone-fixated markers.

Results—Flexion-extension of thoracolumbar vertebrae
and axial rotation of the sacrum were satisfactorily
determined at both the walk and trot, using skinfixated
markers. Data from skin-fixated markers were
accurate for determining lateral bending at the walk in
the midthoracic and lower lumbar portion of the vertebral
column only. However, at the trot, data from
skin-fixated markers were valid for determining lateral
bending for all thoracolumbar vertebrae.

Conclusions and Clinical Relevance—Caution
should be taken when interpreting data obtained by
use of skin-fixated markers on lateral bending
motions during the walk in horses. For determination
of other rotations at the walk and all rotations at the
trot, use of skin-fixated markers allows valid calculations
of kinematics of the vertebral column.
Understanding to what extent movements of skin-fixated
markers reflect true vertebral motion is a compulsory
step in developing noninvasive methods for
diagnosing abnormalities of the vertebral column and
related musculature in horses. (Am J Vet Res
2001;62:301–306)
Comparative efficacy of tricaine methanesulfonate and clove oil for use as anesthetics in red pacu (Piaractus brachypomus)
Authors: Sladky Kurt K. , Swanson Clifford R. , Stoskopf Michael K. , Loomis Michael R. , Lewbart Gregory A. 
Published: December 2005

Abstract

Objective—To compare the anesthetic efficacy and
physiologic changes associated with exposure to tricaine
methanesulfonate and clove oil (100%
eugenol).

Animals—15 adult cultured red pacu (Piaractus
brachypomus).

Procedure—Fish were exposed to each of 6 anesthetic
concentrations in a within-subjects complete
crossover design. Stages of anesthesia and recovery
were measured, and physiologic data were collected
before and during anesthesia.

Results—Interval to induction was more rapid and
recovery more prolonged in fish exposed to eugenol,
compared with those exposed to tricaine methanesulfonate.
The margin of safety for eugenol was narrow,
because at the highest concentration, most fish
required resuscitation. Mixed venous-arterial PO2 consistently
decreased with anesthesia, while PCO2 consistently
increased with anesthesia in all fish regardless
of anesthetic agent. The increase in PCO2 was
accompanied by a decrease in pH, presumably secondary
to respiratory acidosis. Anesthesia was associated
with increased blood glucose, potassium, and
sodium concentrations as well as Hct and hemoglobin.
Fish anesthetized with eugenol were more likely
to react to a hypodermic needle puncture than fish
anesthetized with tricaine methanesulfonate.

Conclusions and Clinical Relevance—Anesthesia
induced with tricaine methanesulfonate or eugenol
contributes to hypoxemia, hypercapnia, respiratory
acidosis, and hyperglycemia in red pacu. Similar to tricaine
methanesulfonate, eugenol appears to be an
effective immobilization compound, but eugenol is
characterized by more rapid induction, prolonged
recovery, and a narrow margin of safety. Care must
be taken when using high concentrations of eugenol
for induction, because ventilatory failure may occur
rapidly. In addition, analgesic properties of eugenol
are unknown. (Am J Vet Res 2001;62:337–342)
Role of excessive maternal iron in the pathogenesis of congenital leukoencephalomalacia in captive black rhinoceroses (Diceros bicornis)
Authors: Paglia Donald E. , Kenny David E. , Dierenfeld Ellen S. , Tsu I-Hsien 
Published: December 2005

AbstractObjective—To investigate the possibility that excessive maternal iron (overload) may contribute to development of congenital leukoencephalomalacia in captive black rhinoceroses.Sample Population—Tissue specimens and serum samples from 18 rhinoceroses in 2 kindreds harboring 4 (possibly 5) affected female calves.Procedure—Fresh and archival sera and necropsy tissue specimens were evaluated to determine the nature and extent of iron overload in captive and wild black rhinoceroses as well as other rhinoceros species.Results—Quantitative serum and tissue assays of iron and iron analytes, corroborated by histopathologic findings, indicated that these kindreds carried the greatest body burdens of iron yet found among captive black rhinoceroses. Fourteen of 18 rhinoceroses had the highest serum ferritin concentrations measured among 64 black rhinoceroses in captivity in the United States. Dams of affected calves had serum ferritin concentrations 2 orders of magnitude higher than clinically normal humans, equids, or free-ranging rhinoceroses. A neonatal serum sample from 1 affected female calf had a high ferritin concentration (approx 100-fold increase), but a male sibling of another affected female did not, suggesting a possible sex disparity in fetal response to maternal iron overload. Morphologic hallmarks of hemochromatosis were prominent in dams and grandams of affected calves.Conclusions and Clinical Relevance—Excessive maternal iron may affect female fetuses more than males, possibly inducing leukoencephalomalacia by catalyzing production of highly toxic hydroxyl free radicals during crucial periods of in utero development. Reduction of maternal iron overload may decrease the probability of developing leukoencephalomalacia and some other disorders commonly affecting rhinoceroses in captivity. (Am J Vet Res2001;62:343–349)
Spectral analysis of circadian rhythms in heart rate variability of dogs
Authors: Matsunaga Toshiyuki , Harada Takuma , Mitsui Takeshi , Inokuma Masanori , Hashimoto Masatoshi , Miyauchi Makoto , Murano Hiroyuki , Shibutani Yasunori 
Published: December 2005

Abstract

Objective—To determine characteristics of power
spectral analysis of heart rate variability (HRV) during
a 24-hour period in dogs and to evaluate the effects of
vagal and sympathetic tone on HRV.
Animals—16 healthy adult Beagles.

Procedure—Power spectral analysis of HRV was conducted,
using 24-hour ambulatory ECG recordings.
Circadian rhythms were evaluated in terms of
absolute units of low-frequency (LF) and high-frequency
(HF) powers, their ratio (LF:HF), and their
adjusted (normalized) units (LF[norm] and HF[norm]).
Three or 4 dogs were used for simultaneous measurement
of heart rate and respiratory waveform as
well as to evaluate treatment (propranolol, atropine,
or both) administered to cause blockade of the autonomic
nervous system.

Results—Values for LF and HF powers, LF:HF,
LF(norm), and HF(norm) had obvious rhythmicity in
clinically normal dogs. The HF power of HRV in dogs
was extremely high, compared with that of other
species, and HF peaks corresponded to peaks
obtained from respiratory waveforms. Blockade of
the autonomic nervous system documented that
HRV in dogs was mostly attributable to vagal activity.

Conclusion and Clinical Relevance—We determined
characteristics of power spectral analysis of
HRV in dogs, including circadian rhythm of the autonomic
nervous system. Power spectral analysis of
HRV may provide a useful noninvasive technique for
assessing the effect of drugs on activity of the autonomic
nervous system in dogs. ( Am J Vet Res
2001;62:37–42)
Antioxidant prevention of Heinz body formation and oxidative injury in cats
Authors: Hill Ana S. , O'Neill Sharron , Rogers Quinton R. , Christopher Mary M. 
Published: December 2005

AbstractObjective—To determine the effectiveness of 3 antioxidants in preventing Heinz body anemia in cats.Design—Prospective study.Animals—44 specific-pathogen-free healthy cats.Procedure—Cats were housed individually, divided randomly into 4 groups, and given the following orally every 12 hours: empty gelcaps (control cats), Nacetylcysteine (NAC, 100 mg/kg of body weight), vitamin E (d,l-α-tocopherol; 400 IU), or ascorbate (250 mg). After 2 weeks, Heinz bodies were induced by dietary onion powder (OP; 1% or 3% of dry matter) or propylene glycol (PG, 8% wt/vol in drinking water) for an additional 3 weeks. Intake of treated water or food was recorded daily. Body weight, PCV, Heinz body and reticulocyte percentages, reduced glutathione concentration, and total antioxidant status were measured twice weekly in all cats.Results—Heinz body percentage and degree of anemia did not differ significantly among cats receiving antioxidants and control cats except in cats that ingested water containing PG, in which antioxidant supplementation was associated with a decrease in water intake. Of cats that were fed a diet that contained OP, cats that received NAC had significantly higher reduced glutathione concentrations, compared with other cats in the experiment. Total antioxidant status did not consistently correlate with antioxidant supplementation or type of oxidant administered (ie, OP or PG).Conclusions and Clinical Relevance—Although the effect of antioxidant supplementation on Heinz body anemia in cats was minimal, antioxidants may have subclinical biochemical effects such as GSH sparing that may be important against milder forms of oxidative stress. (Am J Vet Res2001;62:370–374)