bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of intraosseous blood for repeated hematologic and biochemical analyses in healthy pigs
Authors: Greco Suellen C. , Talcott Michael R , LaRegina Marie C , Eisenbeis Paul E. 
Published: December 2005

AbstractObjective—To evaluate the clinical and histologic effects of repeated intraosseous (IO) needle placement in domestic pigs and determine whether blood and serum obtained intraosseously could be used for CBC and biochemical analyses.Animals—5 healthy 10-week-old pigs.Procedure—An IO needle was placed in the proximomedial region of the tibia of anesthetized pigs every other week for 2 months, and IO blood was obtained for CBC and serum biochemical analyses. Results were compared with those obtained for blood collected at the same time from the auricular vein. Two weeks after the final samples were obtained, pigs were euthanatized and tibias were processed for histologic examination.Results—Clinical abnormalities, including lameness, were not detected following IO needle placement. Histologic examination revealed only mild multifocal periosteal fibrosis and slight thickening of the periosteum without evidence of osteomyelitis. Chloride, creatinine, glucose, total protein, sodium, and BUN concentrations, alanine transaminase and gamma glutamyl transpeptidase activities, RBC count, mean corpuscular volume, and Hct did not significantly differ between IO and venous samples. However, aspartate transaminase activity, potassium, hemoglobin, and mean corpuscular hemoglobin concentrations, mean corpuscular hemoglobin, and platelet and WBC counts were significantly different.Conclusion and Clinical Relevance—Repeated placement of IO needles may be a safe and clinically useful method to obtain serial blood samples from domestic pigs, particularly when other vascular sites are not accessible. Intraosseous blood can be used for many of the tests comprising CBC and serum biochemical analyses. (Am J Vet Res2001;62:43–47)
Usefulness of dobutamine stress tests for detection of cardiac abnormalities in dogs with experimentally induced early left ventricular dysfunction
Authors: Mc Entee Kathleen , Clercx Cécile , Soyeur Daniel , Amory Hélène , Michaux Charles , Flandre Thierry , Jonville Eva , Pynnaert Catherine , Miserque Nathalie , Henroteaux Marc 
Published: December 2005

AbstractObjective—To determine whether dobutamine stress tests (DST) can be used to detect cardiac dysfunction in dogs with early left ventricular dysfunction (ELVD) induced by rapid right ventricular pacing (RRVP).Animals—7 adult male Beagles.Procedure—A pacemaker was surgically implanted in each dog at the level of the right ventricular apex. Electrocardiography, Doppler sphygmomanometry, and Doppler echocardiography were performed before and during a DST prior to activation of the pacemaker and every 3 to 4 days during the period of RRVP. Dobutamine stress tests were performed by infusing dobutamine at incremental dosages ranging from 12.5 to 42.5 µg/kg of body weight/min.Results—Clinical signs of congestive heart failure were not observed during the pacing period. However, all dogs developed ELVD associated with significant changes in values for most Doppler echocardiographic variables obtained prior to DST. Adverse cardiac effects were not detected during DST. Most Doppler echocardiographic indices of cardiac function were significantly altered in response to dobutamine infusion during the pacing period, compared with prepacing values. However, a dobutamine-induced 2-fold increase in cardiac output was maintained.Conclusions and Clinical Relevance—Dobutamine stress tests can be safely performed in dogs with experimentally induced ELVD. Dobutamine stress tests may be a sensitive, noninvasive diagnostic method, complementary to standard clinical examinations, for detection of early cardiac dysfunction in dogs asymptomatic for dilated cardiomyopathy. (Am J Vet Res2001;62:448–455)
Cardiovascular effects of romifidine in dogs
Authors: Pypendop Bruno H. , Verstegen John P. 
Published: December 2005

AbstractObjective—To characterize the cardiovascular effects of romifidine at doses ranging from 5 to 100 µg/kg of body weight, IV.Animals—25 clinically normal male Beagles.Procedure—Romifidine was administered IV at a dose of 5, 10, 25, 50, or 100 µg/kg (n = 5/group). Heart rate, arterial pressure, central venous pressure, mean pulmonary arterial pressure, pulmonary capillary wedge pressure, body temperature, cardiac output, and PCV were measured immediately prior to and at selected times after romifidine administration. Cardiac index, stroke index, rate-pressure product, systemic and pulmonary vascular resistance indices, and left and right ventricular stroke work indices were calculated. Degree of sedation was assessed by an observer who was blinded to the dose administered.Results—Romifidine induced a decrease in heart rate, pulmonary arterial pressure, rate-pressure product, cardiac index, and right ventricular stroke work index and an increase in central venous pressure, pulmonary capillary wedge pressure, and systemic vascular resistance index. In dogs given romifidine at a dose of 25, 50, or 100 µg/kg, an initial increase followed by a prolonged decrease in arterial pressure was observed. Arterial pressure immediately decreased in dogs given romifidine at a dose of 5 or 10 µg/kg.Conclusion and Clinical Relevance—Results suggest that IV administration of romifidine induces dose-dependent cardiovascular changes in dogs. However, the 2 lowest doses (5 and 10 µg/kg) induced less cardiovascular depression, and doses ≥ 25 µg/kg induced similar cardiovascular changes, suggesting that there may be a ceiling on the cardiovascular effects of romifidine. (Am J Vet Res2001; 62:490–495)
Effect of centrally administered opioid receptor agonists on CSF and plasma oxytocin concentrations in dogs
Authors: Brown Dorothy C. , Perkowski Sandra Z. , Shofer Frances , Amico Janet A. 
Published: December 2005

Abstract

Objective—To measure oxytocin concentrations in
blood and CSF following central administration of opioid
agonists in dogs.

Animals—5 male dogs.

Procedure—In a crossover design, CSF and blood
were collected immediately before and 15 and 30
minutes after cisternal administration of D-Ala2,
MePhe4, Gly-ol-enkephalin (DAMGO, a µ-receptor
agonist); D-Pen, pCl-Phe4, D-Pen5-enkephalin (a δ-receptor agonist); U50488H (a κ-receptor agonist);
morphine; and saline (0.9% NaCl) solution.

Results—Plasma oxytocin concentration was significantly
increased 15 minutes after administration of
DAMGO and 30 minutes after administration of
U50488H, compared with concentrations obtained
after administration of saline solution. Concentration
of oxytocin in CSF was significantly decreased 30
minutes after administration of U50488H, compared
with concentration after administration of saline solution.

Conclusion and Clinical Relevance—Results suggest
that in male dogs, activation of centrally located
µ and κ receptors elicits an overall excitatory effect on
neurons that regulate peripheral release of oxytocin,
whereas activation of centrally located κ receptors
elicits an overall inhibitory effect on neurons that regulate
central release. These results are in contrast to
those reported for other species, in which opioids
have a pronounced inhibitory effect on release of oxytocin
from the neurohypophysis. (Am J Vet Res 2001;
62:496–499)
Infusion of a combination of propofol and medetomidine for long-term anesthesia in ponies
Authors: Bettschart-Wolfensberger Regula , Freeman Sarah L. , Jäggin-Schmucker Nicola , Clarke Kathleen W. 
Published: December 2005

AbstractObjective—To determine the minimal infusion rate of propofol in combination with medetomidine for longterm anesthesia in ponies and the effects of atipamezole on recovery.Animals—12 ponies.Procedure—Ponies were sedated with medetomidine (7 µg/kg of body weight, IV). Ten minutes later, anesthesia was induced with propofol (2 mg/kg, IV). Anesthesia was maintained for 4 hours, using an infusion of medetomidine (3.5 µg/kg per hour, IV) and propofol at a rate sufficient to prevent ponies from moving after electrical stimulation. Arterial blood pressures and blood gas analysis, heart rates, and respiratory rates were monitored. For recovery, 6 ponies were given atipamezole (60 µg/kg, IV). Induction and recovery were scored.Results—Minimal propofol infusion rates ranged from 0.06 to 0.1 mg/kg per min. Mean arterial blood pressure was stable (range, 74 to 86 mm Hg), and heart rate (34 to 51 beats/min) had minimal variations. Variable breathing patterns were observed. Mean Pao2(range, 116 to 146 mm Hg) and mean Paco2(range, 48 to 51 mm Hg) did not change significantly with time, but hypoxemia was evident in some ponies (minimal Pao2, 47 mm Hg). Recovery was fast and uneventful with and without atipamezole (completed in 20.2 and 20.9 minutes, respectively).Conclusion and Clinical Relevance—Infusion of a combination of medetomidine and propofol was suitable for prolonged anesthesia in ponies. Recovery was rapid and uneventful. A combination of propofol and medetomidine may prove suitable for long-term anesthesia in horses. Monitoring of blood gases is essential because of potential hypoxemia. (Am J Vet Res2001;62:500–507)
Generation of reactive oxygen species by equine spermatozoa
Authors: Ball Barry A. , Vo Anthony T. , Baumber Julie 
Published: December 2005

AbstractObjective—To characterize generation of reactive oxygen species (ROS) by equine spermatozoa.Sample Population—Multiple semen samples collected from 9 stallions.Procedure—Equine spermatozoa were separated from seminal plasma on a discontinuous polyvinylpyrrolidone (PVP)-coated silica gradient and resuspended in a modified Tyrode albumin-lactate-pyruvate medium. Amount of hydrogen peroxide (H2O2) generated was assayed by use of a 1-step fluorometric assay, using 10-acetyl-3,7-dihydroxyphenoxazine as a probe for detection of H2O2in a microplate assay format. Concentration of H2O2was determined by use of a fluorescence microplate reader.Results—Amount of H2O2generated increased significantly with time and spermatozoa concentration for live and flash-frozen spermatozoa, and amount of H2O2generated was significantly greater for flash-frozen than for live spermatozoa. Addition of the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) significantly increased generation of H2O2by live and flash-frozen spermatozoa. Addition of a calcium ionophore also significantly increased the amount of H2O2generated by live spermatozoa but did not have an effect on amount of H2O2generated by flash-frozen spermatozoa. Abnormal equine spermatozoa generated significantly greater amounts of H2O2than did normal spermatozoa.Conclusion and Clinical Relevance—Equine spermatozoa generate ROS in vitro, possibly via a NADPH-oxidase reaction. Spermatozoa damaged during flash-freezing or morphologically abnormal spermatozoa generated significantly greater amounts of ROS than did live or morphologically normal spermatozoa. Damaged and abnormal spermatozoa generate greater amounts of ROS that may contribute to reduced fertility or problems related to semen preservation. (Am J Vet Res2001;62:508–515)
Clinical signs, evaluation of bronchoalveolar lavage fluid, and assessment of pulmonary function in horses with inflammatory respiratory disease
Authors: Couëtil Laurent L. , Rosenthal Frank S. , DeNicola Dennis B. , Chilcoat Clayton D. 
Published: December 2005

AbstractObjective—To evaluate the association among clinical signs, results of cytologic evaluation of bronchoalveolar lavage (BAL) fluid, and measures of pulmonary function in horses with inflammatory respiratory disease.Animals—9 healthy horses, 5 horses with inflammatory airway disease (IAD), and 9 horses with chronic obstructive pulmonary disease (COPD).Procedure—Clinical examination, lung function tests, and BAL were performed on each horse.Results—Standard lung mechanics of horses with exacerbated COPD differed significantly from those of healthy horses; however, there were few differences among horses with IAD, horses with COPD during remission, and healthy horses. Most variables for forced expiration (FE) in horses with COPD or IAD differed significantly from those for healthy horses. Results of clinical examination had low to moderate sensitivity and predictive values for a diagnosis of COPD (range, 67 to 80%). Results of FE tests had high sensitivity, specificity, and predictive values for a diagnosis of COPD (79 to 100%), and results of standard lung mechanics tests had low sensitivity and predictive values (22 to 69%). Percentage of neutrophils in BAL fluid was highly sensitive (100%) but moderately specific (64%) for a diagnosis of COPD.Conclusion and Clinical Relevance—Clinical examination is moderately accurate for establishing a diagnosis of COPD. Forced expiration tests can specifically detect early signs of airway obstruction in horses with COPD and IAD that may otherwise be inapparent. Cytologic evaluation of BAL fluid allows early detection of inflammatory respiratory disease, but it is not specific for COPD. (Am J Vet Res2001;62: 538–546)
Effects of sodium citrate, low molecular weight heparin, and prostaglandin E1 on aggregation, fibrinogen binding, and enumeration of equine platelets
Authors: Kingston Janene K. , Bayly Warwick M. , Sellon Debra C. , Meyers Kenneth M. , Wardrop K. Jane 
Published: December 2005

AbstractObjective—To investigate the effects of sodium citrate, low molecular weight heparin (LMWH), and prostaglandin E1(PGE1) on aggregation, fibrinogen binding, and enumeration of equine platelets. Sample Population—Blood samples obtained from 4 Thoroughbreds.Sample Population—Blood samples obtained from 4 Thoroughbreds.Procedure—Blood was collected into syringes in the ratio of 9 parts blood:1 part anticoagulant. Anticoagulants used were sodium citrate, LMWH, sodium citrate and LMWH, or 300 nMPGE1/ml of anticoagulant. Platelet aggregation in response to ADP, collagen, and PGE1was assessed, using optical aggregometry. Platelet activation was evaluated, using flow cytometry, to detect binding of fluorescein- conjugated anti-human fibrinogen antibody. Plasma concentration of ionized calcium was measured, using an ion-selective electrode.Results—Number of platelets (mean ± SEM) in samples containing LMWH (109.5 ± 11.3 × 103cells/µl) was significantly less than the number in samples containing sodium citrate (187.3 ± 30.3 × 103cells/µl). Increasing concentrations of sodium citrate resulted in reductions in platelet aggregation and plasma concentration of ionized calcium. Addition of PGE1prior to addition of an agonist inhibited platelet aggregation in a concentration-dependent manner, whereas addition of PGE14 minutes after addition of ADP resulted in partial reversal of aggregation and fibrinogen binding.Conclusion and Clinical Relevance—A high concentration of sodium citrate in blood samples decreases plasma concentration of ionized calcium, resulting in reduced platelet aggregation and fibrinogen binding. Platelets tend to clump in samples collected into LMWH, precluding its use as an anticoagulant. Platelet aggregation and fibrinogen binding can be reversed by PGE1, which may result in underestimation of platelet activation. (Am J Vet Res2001; 62:547–554)
Evaluation of a nonradioactive colorimetric assay for analysis of lymphocyte proliferation in healthy cats
Authors: Saker Korinn E. , Kalnitsky Joan , Gogal Robert M. , Ward Daniel L. 
Published: December 2005

Abstract

Objective—To compare results of a nonradioactive
colorimetric microplate assay with results of a traditional
radioactive proliferation assay for determination
of its use as a reliable and accurate alternative
method for determination of proliferative activity of
feline lymphocytes.

Sample Population—Blood samples from 10 clinically
normal domestic shorthair cats.

Procedure—Double-density gradient separation was
used to isolate mononuclear cells. Isolated cells were
stimulated with various concentrations of concanavalin
A (Con-A) and cultured for 72 hours.
Lymphocyte proliferation was measured by radioactive
([3H]thymidine) and nonradioactive (colorimetric)
techniques. Immunophenotypic analysis with felinespecific
CD4+ and CD8+ monoclonal antibody was performed,
using flow cytometry.

Results—Mononuclear cells were successfully isolated
(97 to 99% purity and viability) from blood samples.
A similar dose-dependent proliferative response
to Con-A stimulation was measured with [3H]thymidine
incorporation and the colorimetric assay. For
both techniques, concentrations of 0.1 and 1.0 µg of
Con-A/ml were submitogenic, and 100 µg/ml was
toxic to cultured cells. For both techniques, maximal
proliferation was observed with 5 µg of Con-A/ml.

Conclusion and Clinical Relevance—These results
indicate that the nonradioactive colorimetric technique
is a reliable and accurate method for measuring
proliferative activity of feline lymphocytes. Clinically,
this assay can be used as part of a screening process
to determine immunocompetence of at-risk cats and
to evaluate treatments for cats with immune-mediated
or T-cell-dependent diseases. (Am J Vet Res 2001;
62:567–571)
Comparison of fermentation of selected fructooligosaccharides and other fiber substrates by canine colonic microflora
Authors: Vickers Robert J. , Sunvold Gregory D. , Kelley Russell L. , Reinhart Gregory A. 
Published: December 2005

AbstractObjective—To compare fermentation characteristics of fructooligosaccharides (FOS) and other fiber substrates that are commonly found in canine diets.Sample Population—Fecal samples from 3 adult dogs.Procedure—The ability of fiber substrates to be used in microbial fermentation reactions was assessed by use of an in vitro fermentation system. Dogs were fed a commercially available food, and feces were collected for use as the microbial inoculum. Substrates used were beet pulp, cellulose, soy fiber, mannanoligosaccharides (MOS), FOS, and 4 inulin products (inulin 1, 2, 3, and 4). Each substrate was incubated anaerobically with fecal inoculum and growth media for 6, 12, and 24 hours, and production of short-chain fatty acids (SCFA) was measured.Results—Total production of SCFA was higher for fermentation of the 4 inulin products and FOS, whereas fermentation of beet pulp, MOS, and soy fiber resulted in moderate concentrations of SCFA. Fermentation of cellulose produced the lowest concentrations of total SCFA without detection of butyrate or lactate. Butyrate production was greatest for fermentation of the 4 inulin products and FOS. Total lactate production was greatest for FOS and inulin 4. As expected, production of SCFA increased for all substrates as fermentation time increased.Conclusion and Clinical Relevance—Canine fecal microflora ferment FOS-containing substrates in a similar manner, with little fermentation of cellulosebased carbohydrates. Furthermore, results of an in vitro fermentation system indicate that fiber type affects the metabolic activity of microorganisms, thus influencing the amount and nature of the end products of fermentation. (Am J Vet Res2001;62: 609–615)
Impact of doramectin treatment at the time of feedlot entry on the productivity of yearling steers with natural nematode infections
Authors: MacGregor D. Scott , Yoder Darwin R. , Rew Robert S. 
Published: December 2005

Abstract

Objective—To measure the reduction in fecal nematode
egg counts and productivity impact of treatment
of yearling steers with doramectin at entry into the
feedlot, compared with control steers treated only
with fenthion.

Animals—6,096 crossbred yearling steers with a
mean (± SD) body weight of 377.0 (± 37) kg.

Procedure—Steers were implanted with zeranol and
alternately separated to fill each of 24 pens. Groups of
steers within 12 matched pairs of pens were randomly
allocated to treatment with doramectin or no treatment
with doramectin for internal nematodes. Fecal
samples were collected from approximately every
twentieth steer from each pen at day 0 and at reimplant
(approx day 60). Each steer was weighed on day
0 and at reimplant and then mean body weights of
steers per pen were determined at 120 to140 days
after trial initiation.

Results—Treatment steers had a significantly lower
fecal egg count at reimplant than control steers.
Treatment steers had a significantly greater mean
daily gain during the study, significantly greater feed
consumption, significantly lower feed-to-gain ratio,
and significantly better quality carcass grades at
slaughter.

Conclusion and Clinical Relevance—Under the
conditions of our trial, there was a significant fecal
egg count reduction response to doramectin treatment,
which resulted in significantly improved productivity.
Results of economic analysis of return on
investment indicated that even with low egg counts
in heavy body weight cattle, nematode egg count
reduction with doramectin significantly improved
returns. (Am J Vet Res 2001;62:622–624)
Assessment of a point-of-care instrument for identification of primary hemostatic disorders in dogs
Authors: Callan Mary Beth , Giger Urs 
Published: December 2005

AbstractObjective—To assess a point-of-care instrument for identification of primary hemostatic disorders in dogs.Animals—29 healthy dogs and 23 nonanemic dogs with primary hemostatic disorders (thrombocytopenia, n = 6; thrombopathia, 6; von Willebrand disease [vWD], 11).Procedure—Citrated blood was obtained and closure times (CT) were determined by measuring the time required for occlusion of an aperture by a platelet plug within the point-of-care instrument. Reference ranges for CT were established, and CT were determined for dogs with primary hemostatic disorders.Results—CT measured with adenosine diphosphate as the platelet agonist (ADP-CT) ranged from 52 to 86 seconds for healthy dogs (mean ± 2 SD, 67 ± 7.8 seconds; median, 65 seconds), and CT measured with epinephrine as the agonist (EPI-CT), from 97 to 225 seconds (151 ± 38 seconds; 148 seconds). In thrombocytopenic dogs, ADP- and EPI-CT were prolonged (> 165 and > 264 seconds, respectively). Five of 6 dogs with thrombopathia had prolonged ADP-CT, whereas EPI-CT was prolonged in all 6 dogs. In all dogs with vWD, ADP-CT was prolonged; EPI-CT was prolonged in 10 of these dogs. Sensitivity and specificity for ADP-CT were 95.7 and 100%, respectively, and positive and negative predictive values, 100 and 96.7%, respectively, whereas for EPI-CT, these values were 95.7 and 82.8%, respectively, and 81.5 and 96%, respectively.Conclusions and Clinical Relevance—The point-ofcare instrument allowed quick assessment of primary hemostasis in nonanemic dogs. Use of this instrument may be helpful for making decisions regarding management of dogs with primary hemostatic disorders. (Am J Vet Res2001;62:652–658)