bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of changes in power setting of an ultrasonic aspirator on amount of damage to the cerebral cortex of healthy dogs
Authors: Bagley Rodney S. , Harrington Michael L. , Gay John M. , Silver Gena M.
Published: December 2005

Objective—To determine the minimal ultrasonic aspirator
pressure necessary to damage the cerebral cortex
of healthy dogs.

Animals—9 mixed-breed dogs.

Procedure—The study comprised 2 parts. In part A,
6 dogs were euthanatized immediately prior to the
experiment. In part B, 3 dogs were anesthetized for
recording of physiologic variables. In both parts,
craniectomy and durotomy were performed to bilaterally
expose the lateral aspect of the cerebral cortex.
An ultrasonic aspirator was placed in contact with various
areas of the cerebral cortex, and aspirator power
was altered (10, 20, 30, and 40%). Duration of contact
at each power was 5 and 10 seconds.
Subsequently, gross morphologic and histologic damage
was assessed in the cortex.

Results—Gross observations for all dogs were similar.
At 10% power, visible or histologic damage was
not evident in the cortex. At 20% power, the cortex
was slightly indented from contact with the hand
piece; however, cortical disruption was not evident.
Cortical disruption was initially detectable at 30%
power in some dogs and was consistently evident at
40% power in both sets of dogs.

Conclusions and Clinical Relevance—Ultrasonic
aspirator power of < 20% created minimal acute morphologic
damage to the cortex. Power settings
between 20 and 30% may superficially damage the
cerebral cortex in healthy dogs, whereas 40% power
consistently damages the cerebral cortex. Knowledge
of the degree of damage to cerebral cortex caused by
various amounts of power for ultrasonic aspirators
will allow surgeons to avoid damaging normal brain
tissues during surgery. (Am J Vet Res 2001;62:
248–251)
Comparative responses of bronchial rings to mediators of airway hyperreactivity in healthy horses and those affected with summer pastureassociated obstructive pulmonary disease
Authors: Venugopal Changaram S. , Moore Rustin M. , Holmes Earnestine P. , Koch Catherine E. , Seahorn Thomas L. , Beadle Ralph E.
Published: December 2005

Objective—To compare responses of bronchial rings obtained from healthy horses and horses affected with summer pasture-associated obstructive pulmonary disease (SPAOPD) to selected mediators of airway hyperreactivity in vitro.

Sample Population—Bronchial rings from 6 healthy horses and 6 horses affected with SPAOPD.

Procedure—Bronchial rings obtained from each group of horses were mounted in organ baths and attached to force transducers interfaced with a polygraph. After applying 2g of tension, each ring was allowed to equilibrate for 45 minutes in Tyrode's solution at 37 C. Cumulative concentration-response relationships to graded concentrations of selected mediators (10–8to 10–4M) were determined and analyzed for significance at each concentration.

Results—Acetylcholine, histamine, 5-hydroxytryptamine, and leukotriene D4induced concentrationdependent contractile responses in bronchial rings. Prostaglandin F2αinduced weak and inconsistent contractile responses. The other 2 agents, norepinephrine and substance P, did not induce concentrationdependent responses. Considering the overall groupdrug effect, acetylcholine, histamine, 5-hydroxytryptamine, and leukotriene D4were effective in inducing consistent concentration-dependent contractile responses in both groups. Only 5-hydroxytryptamine and histamine induced significant responses in contractility between groups. The response of bronchial rings from horses with SPAOPD to 5-hydroxytryptamine was significantly greater than those from control horses, whereas the response to histamine was significantly lower. Significant responses were evident at concentrations ranging from 10–6to 10–4Mfor both drugs.

Conclusions and Clinical Relevance—Because the airways of horses with SPAOPD had increased responsiveness to 5-hydroxytryptamine in vitro, treatment modalities using 5-hydroxytryptamine antagonists should be investigated to address this phenomenon. (Am J Vet Res2001;62:259–263).
Use of long-term vaccination with a killed vaccine to prevent fecal shedding of Mycobacterium avium subsp paratuberculosis in dairy herds
Authors: Kalis Cees H. J. , Hesselink Jan Willem , Barkema Herman W. , Collins Michael T.
Published: December 2005

Objectives—To determine whether vaccination with a killed vaccine prevents fecal shedding ofMycobacterium aviumsubspparatuberculosis, to compare effectiveness of a culture and cull program in vaccinated and nonvaccinated herds, and to compare paratuberculosis-related preventive management in vaccinated and nonvaccinated herds.

Sample Population—58 commercial Dutch dairy herds.

Design—Cross-sectional study (study A) in vaccinated (n = 25) and nonvaccinated (29) herds of dairy cows. Longitudinal study (study B) in vaccinated (n = 2) and nonvaccinated (2) herds of dairy cows.

Procedure—In study A, fecal samples were obtained from adult cows in herds with and without a history of vaccination with a killed vaccine. Management measures were evaluated. In study B, fecal samples were obtained 4 times at 6-month intervals from cows older than 6 months. Cows that had positive test results were removed from the herd directly after the outcome of the culture.

Results—In study A, differences were not detected among the 25 herds that were vaccinated; culture results were positive forM aviumsubspparatuberculosisin 4.4% of herds. In 29 herds that had not been vaccinated, culture results were positive in 6.7%. In study B, the percentage of positive results on culture decreased from 10.9% and 5.7% to 3.5% and 0%, respectively in the 2 vaccinated herds. In the 2 nonvaccinated herds, percentages decreased from 6.1% and 16.5% to 0% and 2.3%, respectively. Management practices were different between herds that were vaccinated and herds that were not; owners of herds that were not vaccinated followed more preventive management procedures and practiced less feeding of raw milk to calves.

Conclusions and Clinical Relevance—Vaccination of calves with a killed vaccine does not prevent transmission ofM aviumsubspparatuberculosis; therefore, hygienic practices remain essential in herd management. (Am J Vet Res2001;62:270–274)
Kinetics of mRNA expression of alkaline phosphatase isoenzymes in hepatic tissues from glucocorticoid-treated dogs
Authors: Wiedmeyer Charles E. , Solter Philip F. , Hoffmann Walter E.
Published: December 2005

Objective—To clone segments of the canine liver alkaline phosphatase (LALP) and corticosteroidinduced alkaline phosphatase (CIALP) genes and use those clones to determine the tissue source of CIALP, the kinetics of LALP and CIALP mRNA expression for glucocorticoid-treated dogs, and the correlation between LALP and CIALP transcript concentrations and isoenzyme activities.

Sample Population—Tissues obtained from 7 dogs treated with prednisone (1 mg/kg, SC, q 24 h) for up to 32 days and 1 untreated (control) dog.

Procedure—Gene segments of LALP and CIALP were obtained by reverse transcription-polymerase chain reaction (RT-PCR) assay. The tissue source of CIALP and IALP mRNA was determined by northern blot analysis of tissues from 1 of the glucocorticoidtreated dogs. Hepatic tissues and serum samples were obtained from the 6 remaining glucocorticoidtreated dogs on days 0, 2, 5, 10, and 32 of prednisone treatment, and relative expression of LALP and CIALP mRNA was correlated with LALP and CIALP activity.

Results—A 2,246-base pair (bp) segment of canine LALP and a 1,338-bp segment of CIALP were cloned. Northern blot analysis revealed CIALP mRNA expression in hepatic tissues only after glucocorticoid treatment. Kinetics of LALP and CIALP mRNA expression in the liver of glucocorticoid-treated dogs paralleled liver and serum activities of LALP and CIALP.

Conclusions and Clinical Relevance—The liver is the most likely source for CIALP in dogs. Analysis of kinetics of serum and hepatic LALP and CIALP mRNA suggests that after glucocorticoid treatment, both are regulated by modification of mRNA transcript concentrations, possibly through differing mechanisms. (Am J Vet Res2002;63:1089–1095)
Effectiveness of glyceryl trinitrate for enhancing digital submural perfusion in horses
Authors: Hoff Tracy K. , Hood David M. , Wagner Ilka P.
Published: December 2005

Objective—To evaluate the clinical efficacy of topically administered glyceryl trinitrate (GTN) for inducing digital submural vasodilation in clinically normal horses.

Animals—7 adult horses without foot abnormalities.

Procedures—A concurrent-control crossover design was used to determine whether topical application of GTN ointment for prevention or treatment of laminitis would result in a detectable increase in digital perfusion. Heat-acclimated horses instumented for detection of wall surface temperature (HWST), mean systemic pressure, and heart rate were used. Horses were exposed to cold to induce digital vasoconstriction and treated with GTN in an attempt to induce digital vasodilation.

Results—Application of GTN failed to induce an increase in digital submural perfusion but did induce a mild decrease in mean systemic pressure.

Conclusionss and Clinical Relevance—Topical application of 60 mg of GTN as a 2% ointment on the skin over the major vasculature in the region of the proximal interphalangeal joint (pastern) of horses was not effective in significantly increasing digital perfusion. A decrease in mean systemic pressure following treatment was observed, implying that the drug was absorbed. Use of GTN may result in a decrease in digital submural perfusion secondary to induction of peripheral constriction or a decrease in digital perfusion pressure. (Am J Vet Res2002;63:648–652)
Examination of nasopharyngeal and tracheal somatosensory evoked potential recordings in dogs
Authors: Mikó László , Székely György M. , Dobai József G. , Mikó Irén , Csécsei György I.
Published: December 2005

Objective—To investigate the value of nasopharyngeal and tracheal recordings of somatosensory evoked potentials (SSEP) in anesthetized dogs.

Animals—10 healthy mixed-breed dogs (5 males and 5 females).

Procedure—Square-ware electrical stimuli (50 microseconds duration, 4Hz) were delivered through bipolar surface electrodes to the median nerve of the right forelimb with 7 to 12 mA constant current. The SSEP were recorded with soft electrodes placed on the epipharynx and dorsal wall of the trachea, respectively. Traditional scalp and neck recordings of SSEP were also performed, using SC-inserted needle electrodes. The potentials recorded dorsally and ventrally from the neuraxis were compared to assess the application of these signals for intraoperative neurophysiologic monitoring.

Results—Electrical stimulation of the median nerve resulted in multiphasic potentials recorded from all 4 recording sites. Latency and phase shifts were observed between the far-field potentials placed ventrally and dorsally from the neuraxis.

Conclusions and Clinical Relevance—Potentials recorded with nasopharyngeal and tracheal electrodes are regarded suitable for intraoperative neurophysiologic monitoring in anesthized dogs. (Am J Vet Res2002; 63:669–672)
Effects of formaldehyde fixation on equine platelets using flow cytometric methods to evaluate markers of platelet activation
Authors: Kingston Janene K. , Bayly Warwick M. , Sellon Debra C. , Meyers Kenneth M. , Wardrop K. Jane
Published: December 2005

Objective—To investigate the effects of formaldehyde fixation on equine platelets using flow cytometric methods to evaluate markers of platelet activation.

Sample Population—Blood samples from 6 Thoroughbreds.

Procedure—The degree of fluorescence associated with binding of fluorescein isothiocyanate (FITC)-conjugated anti-human fibrinogen antibody and FITCannexin V in unactivated and adenosine diphosphate (ADP)-, platelet activating factor (PAF)-, and A23187- activated platelet samples in unfixed and 0.5, 1.0, and 2.0% formaldehyde-fixed samples was assessed by use of flow cytometry.

Results—In samples incubated with FITC-anti-human fibrinogen antibody prior to fixation, addition of 2.0% formaldehyde resulted in a 30% increase in total fluorescence in ADP- and PAF-activated samples and a 60% increase in A23187-activated samples. Fixation for 24 hours prior to addition of antibody resulted in reduced fluorescence of samples containing antihuman fibrinogen antibody for all 3 concentrations of formaldehyde in PAF-activated samples. The addition of all 3 concentrations of formaldehyde after incubation with FITC-annexin V resulted in significant increases in fluorescence in unactivated and activated platelet samples. As length of fixation time increased, there was a gradual increase in fluorescence that was significant at 24 hours.

Conclusion and Clinical Relevance—Because fixation with 2.0% formaldehyde results in significant changes in fluorescence in activated platelet samples containing anti-fibrinogen antibody, lower concentrations of formaldehyde should be used to fix equine platelet samples. Formaldehyde-fixed platelet samples should be analyzed within 12 hours of fixation to avoid artifactual increases in fluorescence. Fixation of samples containing FITC-annexin V should be avoided because of significant increases in fluorescence that may interfere with interpretation of results. (Am J Vet Res2002;63:840–844)
Expression of bone morphogenetic protein-6 and -2 and a bone morphogenetic protein antagonist in horses with naturally acquired osteochondrosis
Authors: Semevolos Stacy A. , Nixon Alan J. , Strassheim M. Lisa
Published: December 2005

Objective—To determine the mRNA expression of bone morphogenetic protein (BMP)-6 and -2 and a BMP antagonist (Noggin) in horses with osteochondrosis.

Sample Population—Samples of articular cartilage from affected stifle or shoulder joints of 10 immature horses with naturally acquired osteochondrosis and corresponding joints of 9 clinically normal horses of similar age; additionally, samples of distal femoral growth plate cartilage and distal femoral articular cartilage were obtained from a normal equine fetus.

Procedure—Cartilage specimens were snap-frozen in liquid nitrogen, and total RNA was isolated. Adjacent specimens were fixed in 4% paraformaldehyde for histologic examination. Expression of BMP-6, BMP-2, and Noggin mRNA was evaluated by real-time quantitative polymerase chain reaction (PCR) assays. Spatial tissue mRNA expression of BMP-6 was determined by in situ hybridization.

Results—Nucleotide sequences were obtained for portions of the BMP-6 propeptide and mature peptide region, as well as the signal and mature peptide region of Noggin. Expression of BMP-6, BMP-2, and Noggin mRNA was found to be similar in cartilage from normal and osteochondrosis-affected horses. Spatial expression of BMP-6 correlated with the middle and deep layers of articular cartilage; no differences were observed in overall expression between cartilage specimens from the 2 groups of horses. No expression of BMP-6 was found in the superficial layer, subchondral bone, or osteochondrosis-affected cleft fibrous tissue.

Conclusions and Clinical Relevance—Although these signaling peptides may play important roles in cartilage differentiation, results did not provide evidence to suggest that they are involved in the disease process of osteochondrosis. (Am J Vet Res2004;65:110–115)
Characterization of gelatinases in bronchoalveolar lavage fluid and gelatinases produced by alveolar macrophages isolated from healthy calves
Authors: Lakritz Jeffrey , Marsh Antoinette E. , Cockrell Mary , Smith Michael F. , Tyler Jeff W.
Published: December 2005

Objective—To characterize gelatinases in bronchoalveolar lavage fluid (BALF) and gelatinases produced by alveolar macrophages of healthy calves.

Sample Population—Samples of BALF and alveolar macrophages obtained from 20 healthy 2-month-old calves.

Procedure—BALF was examined by use of gelatin zymography and immunoblotting to detect gelatinases and tissue inhibitor of metalloproteinase (TIMP)-1 and -2. Cultured alveolar macrophages were stimulated with lipopolysaccharide (LPS), and conditioned medium was subjected to zymography. Alveolar macrophage RNA was used for reverse transcriptasepolymerase chain reaction assay of matrix metalloproteinases (MMPs), cyclooxygenase-2, and inducible nitric oxide synthase.

Results—Gelatinolytic activity in BALF was evident at 92 kd (14/20 calves; latent MMP-9) and 72 kd (18/20; latent MMP-2). Gelatinolytic activity was evident at 82 kd (10/20 calves; active MMP-9) and 62 kd (17/20; active MMP-2). Gelatinases were inhibited by metal chelators but not serine protease inhibitors. Immunoblotting of BALF protein and conditioned medium confirmed the MMP-2 and -9 proteins. Endogenous inhibitors (ie, TIMPs) were detected in BALF from all calves (TIMP-1) or BALF from only 4 calves (TIMP-2). Cultured alveolar macrophages expressed detectable amounts of MMP-9 mRNA but not MMP-2 mRNA.

Conclusions and Clinical Relevance—Healthy calves have detectable amounts of the gelatinases MMP-2 and -9 in BALF. Endogenous inhibitors of MMPs were detected in BALF (ie, TIMP-1, all calves; TIMP-2, 4 calves). Lipopolysaccharide-stimulated alveolar macrophages express MMP-9 but not MMP-2 mRNA. The role of proteases in the pathogenesis of lung injury associated with pneumonia has yet to be determined. (Am J Vet Res2004;65:163–172)
Effects of insulin-like growth factor-II on the mitogenic and metabolic activities of equine articular cartilage with and without interleukin 1-β
Authors: Davenport-Goodall Celia L. M. , Boston Raymond C. , Richardson Dean W.
Published: December 2005

Objective—To investigate the effects of insulin-like growth factor-II (IGF-II) on DNA and glycosaminoglycan (GAG) synthesis and the expression of matrix-related genes in equine articular cartilage explants and chondrocytes, respectively, with and without interleukin 1-β (IL1-β).

Sample Population—Articular cartilage from 12 adult horses.

Procedure—Articular cartilage was incubated in standard media with and without equine IL1-β (10 ng/mL) containing various concentrations of IGF-II for 72 hours. Synthesis of DNA and GAG was determined by incorporation of thymidine labeled with radioactive hydrogen (3H) and sulfate labeled with radioactive sulfur (35S), respectively. Total GAG content of the explants and spent media was determined by use of the 1,9-dimethylmethylene blue assay. Northern blots of RNA from cultured equine articular cartilage chondrocytes were hybridized with cDNA of major matrix molecules.

Results—Insulin-like growth factor-II stimulated DNA and GAG synthesis at concentrations of 25 and 50 ng/mL, respectively. In cartilage explants conditioned with IL1-β, IGF-II stimulated DNA and GAG synthesis at concentrations of 500 and 50 ng/mL, respectively. Insulin-like growth factor-II had no effect on total GAG content as determined by the 1,9-dimethylmethylene blue assay. No specific effects on steady-state levels of messenger RNAs were observed.

Conclusions and Clinical Relevance—Insulin-like growth factor-II stimulated DNA and GAG synthesis in equine adult cartilage and may have potential application in vivo. (Am J Vet Res2004;65:238–244)
Assessment of leukotriene B4 production in leukocytes from horses with recurrent airway obstruction
Authors: Lindberg Åsa , Robinson N. Edward , Näsman-Glaser Barbro , Jensen-Waern Marianne , Lindgren Jan Åke
Published: December 2005

Objective—To determine the ex vivo leukotriene (LT)
biosynthesis in peripheral blood neutrophils (PBNs)
and inflammatory cells in bronchoalveolar lavage fluid
(BALF) obtained from horses affected with recurrent
airway obstruction (RAO).

Animals—6 RAO-affected and 6 control horses.

Procedure—Before and 6, 24, and 48 hours after
stabling, disease severity was determined subjectively
by clinical and mucus scores and measurement of
the maximal change in pleural pressure (ΔPplmax);
PBNs were isolated and BALF samples were examined
cytologically. The PBN and BALF cells were activated
with a calcium ionophore in the presence of
arachidonic acid, and production of LTC4 and LTB4
was measured per 106 cells.

Results—Clinical and mucus scores and ΔPplmax
increased during stabling in RAO-affected horses, but
not in control horses. In neutrophils and BALF cells
from both groups, production of LTB4 exceeded that
of LTC4. At all times, LTB4 production by PBNs was
less in RAO-affected horses than it was in control
horses. Before stabling, LTB4 production by cells in
BALF was low in RAO-affected horses, but increased
considerably after 6 hours of stabling. This increase
coincided with the migration of neutrophils into the
airways. In control horses, production of LTB4 did not
change during stabling.

Conclusions and Clinical Relevance—Results suggested
increased production of LTB4 in airways of
RAO-affected horses, compared with control horses,
that may contribute to the infiltration of neutrophils
into the lungs and the sustained inflammation associated
with RAO. ( Am J Vet Res 2004;65:289–295)
Alterations in thyroid hormone concentrations in healthy sled dogs before and after athletic conditioning
Authors: Evason Michelle D. , Carr Anthony P. , Taylor Susan M. , Waldner Cheryl L.
Published: December 2005

Objective—To determine effects of athletic conditioning on thyroid hormone concentrations in a population of healthy sled dogs.

Animals—19 healthy adult sled dogs.

Procedure—Serum concentrations of thyroxine (T4), triiodothyronine (T3), thyroid-stimulating hormone (TSH), free T4(fT4), free T3(fT3), and autoantibodies directed against T3, T4, and thyroglobulin were measured in sled dogs that were not in training (ie, nonracing season) and again after dogs had been training at maximum athletic potential for 4 months.

Results—Analysis revealed significant decreases in T4and fT4concentrations and a significant increase in TSH concentration for dogs in the peak training state, compared with concentrations for dogs in the untrained state. Serum concentrations of T4and fT4were less than established reference ranges during the peak training state for 11 of 19 and 8 of 19 dogs, respectively; fT4concentration was greater than the established reference range in 9 of 19 dogs in the untrained state.

Conclusions and Clinical Relevance—Decreased total T4and fT4concentrations and increased serum concentrations of TSH were consistently measured during the peak training state in healthy sled dogs, compared with concentrations determined during the untrained state. Although thyroid hormone concentrations remained within the established reference ranges in many of the dogs, values that were outside the reference range in some dogs could potentially lead to an incorrect assessment of thyroid status. Endurance training has a profound impact on the thyroid hormone concentrations of competitive sled dogs. (Am J Vet Res2004;65:333–337)
Effects of xylazine on canine coronary artery vascular rings
Authors: Teng Bunyen , Muir III William W.
Published: December 2005

Objective—To determine the effects of xylazine on canine coronary artery smooth muscle tone.

Sample Population—Hearts of 26 healthy dogs.

Procedure—Dogs were anesthetized with pentobarbital, and vascular rings of various diameters were prepared from the epicardial coronary arteries. Vascular rings were placed in tissue baths to which xylazine was added (cumulative concentrations ranging from 10–10to 10–4M), and changes in vascular ring tension were continuously recorded. Effects of the nitric oxide inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 5mM), the α1-adrenoceptor antagonist prazosin (10mM), and the α2-adrenoceptor antagonist atipamezole (10mM) on xylazine-induced changes in vascular ring tension were determined. Results were expressed as percentage of maximal contraction for each vascular ring preparation.

Results—Xylazine induced vasoconstriction of small (< 500-µm-diameter) and medium (500- to 1,000-µmdiameter) vascular rings but not of large (> 1,000-µmdiameter) rings. For large vascular rings, L-NAME, atipamezole, and prazosin did not significantly affect the contractile response to xylazine. For small vascular rings, the contractile response following addition of xylazine to rings treated with L-NAME was not significantly different from the contractile response following addition of xylazine to control rings, except at a xylazine concentration of 10–6M. Xylazine-induced vasoconstriction of small vascular rings was blocked by atipamezole, but the addition of prazosin had no effect on xylazine-induced vasoconstriction.

Conclusions and Clinical Relevance—Results suggest that xylazine increases smooth muscle tone of small canine coronary arteriesand that this effect is predominantly mediated by stimulation of α2adrenoceptors.(Am J Vet Res2004;65:431–435)
Sequential measurements of the tibial plateau angle in large-breed, growing dogs
Authors: Odders Jacob W. , Jessen Carl R. , Lipowitz Alan J.
Published: December 2005

Objectives—To determine the earliest age that canine tibial plateau angles (TPAs) can be reliably measured and determine whether TPAs change during long bone growth.

Animals—10 Labrador Retrievers and 20 Labrador Retriever-hound crossbreeds.

Procedure—Stifle joints were radiographed every 2 months from 8 weeks of age to radiographic closure of the tibial physes. Four examiners radiographically evaluated TPA, physeal closure status (ie, complete or incomplete) of the proximal and distal tibial physis, and whether anatomic TPA measurement landmarks were sufficiently visible (LSV) or insufficiently visible (LIV) for accurate measuring. Linear regression analysis was performed to detect change in TPAs over time. Mean ages with 95% confidence intervals (CIs) were determined for dogs with radiographs classified as LIV and LSV.

Results—TPAs did not change from 90 days of age to physeal closure. Mean age for dogs with radiographs classified as LIV was 70.2 days (95% CI, 68.12 to 72.28 days), with no dog with LIV radiographs over 81 days of age. Mean age for dogs with radiographs classified as LSV was 85.5 days (CI, 76.73 to 94.27 days).

Conclusions and Clinical Relevance—TPAs in Labrador Retrievers and Labrador Retriever-hound crossbreeds can be measured accurately after 90 days of age, and earlier attempts to measure result in falsely low TPA measurements. Measuring TPAs in growing dogs may allow earlier detection of premature physeal closures. As more is learned about the role of the TPA in cranial cruciate ligament injury, early treatment may be possible for growing dogs with cruciate ligament injuries and excessive tibial slope. (Am J Vet Res2004;65:513–518)
Comparison of surgical techniques for synovectomy in New Zealand White rabbits with induced inflammatory arthritis
Authors: Davis Kechia M. , King Dana S. , Philips Lynette , Lu Yan , Edwards Ryland B. , Kalscheur Vicki , Markel Mark D.
Published: December 2005

Objective—To compare effects of synovectomy performed by use of monopolar radiofrequency energy (MRFE) versus mechanical debridement in rabbits with induced inflammatory arthritis.

Animals—25 mature female New Zealand White rabbits.

Procedure—Inflammatory arthritis was induced in both femoropatellar joints of each rabbit. Joints then were treated by mechanical debridement or MRFE treatment or served as sham-operated controls. Rabbits were euthanatized 2 weeks or 3 months after surgery. Biopsy specimens of synovium were analyzed by use of light microscopy.

Results—At 2 weeks after surgery, samples from MRFE-treated joints had fewer plasma cells and more heterophils than the other 2 groups and more lymphocytes than sham-operated controls, whereas samples from mechanically debrided joints had greater numbers of lymphocytes and heterophils than sham-operated controls. At 3 months after surgery, samples from MRFE-treated joints had fewer plasma cells than sham-operated controls, more heterophils than mechanically debrided and sham-operated controls, and more macrophages than mechanically debrided joints. There was no difference in synovial ablation, synovial proliferation, or fibrosis among the 3 groups at 2 weeks or 3 months after surgery.

Conclusions and Clinical Relevance—Analysis of results of this study documented a similar degree of synovial ablation when comparing use of MRFE to mechanical debridement. In rabbits with this method of induced inflammatory arthritis, there were no detectable benefits of MRFE or mechanical debridement on the synovium, compared with results for sham-operated control joints, at 2 weeks and 3 months after surgery for most of the synovial variables evaluated. (Am J Vet Res2004;65:573–577)
Evaluation of serum values of pancreatic enzymes after endoscopic retrograde pancreatography in dogs
Authors: Spillmann Thomas , Happonen Irmeli , Sankari Satu , Wittker Andrea , Kähkönen Tuomo , Westermarck Elias
Published: December 2005

Objective—To assess the safety of endoscopic retrograde
pancreatography (ERP) in dogs by performing
repeated clinical examinations and laboratory analyses
of serum amylase, lipase, canine trypsin-like
immunoreactivity (cTLI), and canine pancreatic elastase
1 (cE1) after the procedure.

Animals—7 healthy Beagles.

Procedure—Clinical examinations were performed
and blood samples obtained for serum enzyme determinations
before and at intervals (10 minutes; 2, 4,
and 6 hours; and 1, 2, and 3 days) after ERP.

Results—Repeated clinical examinations revealed no
signs of ERP-induced complications in the 7 dogs.
Results of repeated laboratory tests indicated a transient
increase in serum values of amylase, lipase, and
cTLI but not cE1. Mean ± SD lipase activity increased
from 120.7 ± 116.4 U/L to 423.4 ± 243.1 U/L at 4
hours after ERP. Median serum cTLI concentration
increased from 16.2 µg/L (range, 7.7 to 26.5 µg/L) to
34.9 µg/L (range, 16.6 to 68.3 µg/L) 10 minutes after
ERP. Enzyme values returned to baseline levels at the
latest on day 2 in 6 of 7 dogs. Highest values for
serum amylase, lipase, and cTLI and their delayed
return to baseline values were detected in 1 dog with
contrast filling of the pancreatic parenchyma.

Conclusions and Clinical Relevance—Results indicated
that ERP appears to be a safe imaging technique
of pancreatic ducts in healthy dogs, although it
induced a transient increase in serum values of pancreatic
enzymes. In dogs, repeated clinical examinations
and serum enzyme determinations can be used
to monitor ERP-induced complications such as acute
pancreatitis. ( Am J Vet Res 2004;65:616–619)
Effect of thalidomide on growth and metastasis of canine osteosarcoma cells after xenotransplantation in athymic mice
Authors: Farese James P. , Fox Leslie E. , Detrisac Carol J. , Van Gilder James M. , Roberts Sara L. , Baldwin Jamie M
Published: December 2005

Objective—To determine whether thalidomide inhibits the growth of primary and pulmonary metastatic canine osteosarcoma in mice after xenotransplantation.

Animals—Athymic nude mice.

Procedure—Canine osteosarcoma cells were injected SC in 50 mice. Mice were randomly placed into the following groups: control group (n = 13; DMSO [drug vehicle] alone [0.1 mL/d, IP]); low-dose group (12; thalidomide [100 mg/kg, IP]), mid-dose group (13; thalidomide [200 mg/kg, IP]); and high-dose group (12; thalidomide [400 mg/kg, IP]). Starting on day 8, treatments were administered daily and tumor measurements were performed for 20 days. On day 28, mice were euthanatized and primary tumors were weighed. Lungs were examined histologically to determine the number of mice with metastasis and tumor emboli. Mean area of the pulmonary micrometastatic foci was determined for mice from each group.

Results—Primary tumor size and weight were not significantly different among groups. The number of mice in the mid-dose (200 mg/kg) and high-dose (400 mg/kg) groups with micrometastasis was significantly less than the number of control group mice; however, the number of mice with tumor emboli was not affected by thalidomide treatment. Size of micrometastasis lesions was not affected by thalidomide treatment.

Conclusions and Clinical Relevance—Mean area of micrometastases was not affected by treatment; however, growth of micrometastases had not yet reached an angiogenesis-dependent size. Although thalidomide did not affect growth of primary tumors in mice after xenotransplantation of canine osteosarcoma cells, our findings indicate that thalidomide may interfere with the ability of embolic tumor cells to complete the metastatic process within the lungs. (Am J Vet Res2004;65:659–664)
Evaluation of a sensor-based system of motion analysis for detection and quantification of forelimb and hind limb lameness in horses
Authors: Keegan Kevin G. , Yonezawa Yoshiharu , Pai P. Frank , Wilson David A. , Kramer Joanne
Published: December 2005

Objective—To compare a sensor-based accelerometer-gyroscopic (A-G) system with a video-based motion analysis system (VMAS) technique for detection and quantification of lameness in horses.

Animals—8 adult horses.

Procedure—2 horses were evaluated once, 2 had navicular disease and were evaluated before and after nerve blocks, and 4 had 2 levels of shoe-induced lameness, alternatively, in each of 4 limbs. Horses were instrumented with an accelerometer transducer on the head and pelvis, a gyroscopic transducer on the right forelimb and hind feet, and a receiver-transmitter. Signals from the A-G system were collected simultaneously with those from the VMAS for collection of head, pelvis, and right feet positions with horses trotting on a treadmill. Lameness was detected with an algorithm that quantified lameness as asymmetry of head and pelvic movements. Comparisons between the A-G and VMAS systems were made by use of correlation and agreement (κ value) analyses.

Results—Correlation between the A-G and VMAS systems for quantification of lameness was linear and high (r2= 0.9544 and 0.8235 for forelimb and hind limb, respectively). Quantification of hind limb lameness with the A-G system was higher than measured via VMAS. Agreement between the 2 methods for detection of lameness was excellent (κ = 0.76) for the forelimb and good (κ = 0.56) for the hind limb.

Conclusions and Clinical Relevance—The A-G system detected and quantified forelimb and hind limb lameness in horses trotting on the treadmill. Because the data are collected wirelessly, this system might be used to objectively evaluate lameness in the field. (Am J Vet Res2004;65:665–670)
Evaluation of experimental transmission of Candidatus Mycoplasma haemominutum and Mycoplasma haemofelis by Ctenocephalides felis to cats
Authors: Woods James E. , Brewer Melissa M. , Hawley Jennifer R. , Wisnewski Nancy , Lappin Michael R.
Published: December 2005

Objective—To determine whetherCtenocephalides feliscan transmitMycoplasma haemofelis(Mhf) andCandidatusMycoplasma haemominutum (Mhm) through hematophagous activity between cats.

Animals—11 cats.

Procedure—2 cats were carriers of either Mhf or Mhm. Nine cats had negative results via polymerase chain reaction (PCR) assay for Mhf and Mhm DNA; 3 of those cats were infected from the chronic carriers via IV inoculation of blood. At the time of maximum organism count for each of theMycoplasmaspp, 1 chamber containing 100C feliswas bandaged to the amplifier cats. Five days later, fleas, feces, larvae, or eggs from each chamber were analyzed forMycoplasmaspp DNA. Viable fleas from the chambers were allocated into new chambers (3 Mhm and 6 Mhf) and attached to naïve cats for 5 days. Cats were monitored daily for clinical signs and weekly via CBC and PCR assay for infection with Mhf or Mhm for a minimum of 8 weeks.

Results—Uptake of Mhf and Mhm DNA into fleas, feces, and, potentially, eggs and larvae was detected. Of the naïve cats fed on by Mhf-infected fleas, 1 cat transiently yielded positive PCR assay results for Mhf on 1 sampling date without clinical or hematologic changes consistent with Mhf infection.

Conclusions and Clinical Relevance—Results suggest that hematophagous transfer of Mhm and Mhf into fleas occurred and thatC felisis a possible vector for Mhf via hematophagous activity. (Am J Vet Res2005;66:1008–1012)
Characterization of an A-kinase anchor protein in equine spermatozoa and examination of the effect of semen cooling and cryopreservation on the binding of that protein to the regulatory subunit of protein kinase-A
Authors: Turner Regina M. O. , Casas-Dolz Raul , Schlingmann Karen L. , Hameed Saima
Published: December 2005

Objective—To determine whether a homologue of A-kinase anchor protein 4 (AKAP4) is present and functional as an AKAP in equine spermatozoa and examine the effect of semen cooling and cryopreservation on binding of equine AKAP4 to the regulatory (RII) subunit of protein kinase-A (PK-A).

Sample Population—Ejaculated semen collected from 2 fertile stallions, 3 bulls, and 3 humans.

Procedure—Identification of an equine homologue of AKAP4 was investigated via DNA sequencing. Protein was extracted from the spermatozoa of each species for immunoblot analysis to identify AKAP4 and its precursor protein, pro-AKAP4; immunofluorescence microscopy was used to localize those proteins in spermatozoa. Ligand overlay assays were used to determine whether the identified proteins bound to the RII subunit of PK-A and whether cooling or cryopreservation of spermatozoa affected that binding.

Results—The partial genomic sequence ofAKAP4was identified in equine spermatozoa, and immunoblot analysis confirmed that AKAP4 and pro-AKAP4 are present in equine spermatozoa. Via immunofluorescence microscopy, these proteins were localized to the spermatozoal principal piece. Results of ligand overlay assays indicated that equine AKAP4 and pro-AKAP4 bind to the RII subunit of PKA and are AKAPs; AKAP4-RII binding was not affected by cooling or cryopreservation of spermatozoa.

Conclusions and Clinical Relevance—Results suggest that equine AKAP4 anchors PK-A to the spermatozoal flagellum (where the kinase is likely to be required for the regulation of spermatozoal motility), but decreases in spermatozoal motility in cooled or cryopreserved semen are not associated with decreased binding of AKAP4 and PK-A. (Am J Vet Res2005;66:1056–1064)
In vitro evaluation of the contractile response to endothelin-1 of the circular and longitudinal myometrial layers of the uterine horn of nongravid mares
Authors: Walesby Honor A. , Venugopal Changaram S. , Hosgood Giselle , Eades Susan C. , Moore Rustin M.
Published: December 2005

Objective—To characterize the in vitro response of circular and longitudinal myometrial layers of the uterine horn (CMLH and LMLH, respectively) of horses to endothelin (ET)-1 by use of specific ETA(BQ-123) and ETB(IRL-1038) receptor antagonists.

Sample Population—Uteruses from 10 nongravid mares in anestrus.

Procedure—Muscle strips from the CMLH and LMLH were suspended in tissue baths and connected to force-displacement transducers interfaced with a polygraph. Strips were incubated for 45-minute intervals with no antagonist (control specimens), and 3 concentrations (10–9, 10–7, and 10–5M) of BQ-123, IRL- 1038, or BQ-123 and IRL-1038 before concentrationresponse curves to ET-1 were generated. Contractile response to cumulative concentrations of ET-1 (10–9to 10–6M) was quantified by measuring change in the area under the curve (AUC) for the 3-minute period after each ET-1 dose.

Results—ET-1 caused concentration-dependent contraction of the CMLH and LMLH specimens. Application of BQ-123 decreased AUC values for both layers. Application of IRL-1038 increased the AUC value for LMLH specimens but did not affect the CMLH value. The combination of BQ-123 and IRL-1038 decreased the AUC value for LMLH tissue and increased that for CMLH tissue.

Conclusions and Clinical Relevance—ET-1 causes contraction of the CMLH and LMLH in nongravid horses. In both layers, ETAreceptors mediate contraction but the role of ETBreceptors remains unclear. In the LMLH, ETAreceptors have a dominant role; the presence of another receptor or receptor subtype within this layer is suggested. These findings support a physiologic role for ET-1 in uterine contractility. (Am J Vet Res2005;66:1094–1100)
Temporal folate status during lactation in mares and growth in foals
Authors: Ordakowski-Burk Amy L. , Kronfeld David S. , Williams Carey A. , Gay Louisa S. , Sklan David J.
Published: December 2005

Objective—To identify changes in folate status of mares and foals during lactation and growth, respectively.

Animals—20 Thoroughbred mares and foals.

Procedures—Pregnant mares, and following foaling the same mares with their foals, were maintained on mixed grass-legume pasture and fed either a traditional dietary supplement rich in sugar and starch (SS) or a dietary supplement high in fat and fiber (FF). Blood samples were collected monthly from mares and foals up to 6 months after foaling. Total folate concentration in feed and forage was determined. Analyses of plasma folate, RBC folate, plasma homocysteine (HCY), and milk folate concentrations were performed.

Results—Mare plasma folate concentrations declined moderately during 6 months of lactation. Mare RBC folate concentrations initially increased after foaling up to 3 months but declined toward the end of the study. Plasma HCY concentration was higher for mares fed the SS supplement, compared with mares fed the FF supplement from foaling to 6 months of lactation. Milk folate concentrations decreased during the first 3 months and then increased. Foal plasma folate initially declined but then increased. Stable concentrations of RBC folate were observed in foals. Plasma HCY concentrations in foals were unaffected by growth during the last 5 months. References range values for plasma folate, RBC folate, milk folate, and plasma HCY concentrations in healthy lactational mares and young growing foals were determined.

Conclusions and Clinical Relevance—Folate status was not impaired in lactating mares and growing foals under the conditions in our study. It appears that folate supplementation is not necessary. (Am J Vet Res2005;66:1214–1221)
Comparison of results for intradermal testing between clinically normal horses and horses affected with recurrent airway obstruction
Authors: Wong David M. , Buechner-Maxwell Virginia A. , Manning Thomas O. , Ward Daniel L.
Published: December 2005

Objective—To evaluate differences in response to ID injection of histamine, phytohemagglutinin (PHA), andAspergillusorganisms between clinically normal horses and horses with recurrent airway obstruction (RAO).

Animals—5 healthy adult horses and 5 adult horses with RAO.

Procedure—Intradermal testing (IDT) was performed on the neck with 2 positive control substances (histamine and PHA) and a mixture comprising 5Aspergillusspecies. Four concentrations of each test substance plus a negative control substance were used. Equal volumes (0.1 mL) of each test substance were prepared to yield 15 syringes ([4 concentrations of each test substance plus 1 negative control substance] times 3 test substances) for each side of each horse (ie, 30 syringes/horse). Intradermal injections were administered; diameter of wheals was recorded 0.5, 4, and 24 hours after injection.

Results—Hypersensitive responses to ID injection of histamine were detected 0.5 hours after injection, and a delay in wheal formation after ID injection ofAspergillusmixture 24 hours after injection was detected in RAO-affected horses but was not observed in clinically normal horses. No differences were detected between the 2 groups after ID injection of PHA.

Conclusions and Clinical Relevance—RAO-affected horses are hypersensitive to histamine, suggesting that RAO is associated with a heightened vascular response to histamine. Higher concentrations ofAspergillusmixture may be needed to detect horses that are sensitive to this group of antigens. Wheal reactions toAspergillusmay be a delayed response, suggesting that IDT results should be evaluated 0.5, 4, and 24 hours after ID injection. (Am J Vet Res2005;66:1348–1355)
Comparison of various canine blood-typing methods
Authors: Giger Urs , Stieger Knut , Palos Hanna
Published: December 2005

Objective—To compare canine blood-typing results determined by use of the card (CARD), gel (GEL), Michigan State University (MSU), and tube (TUBE) tests.

Sample Population—Blood samples from 23 healthy dogs.

Procedures—Blood samples anticoagulated with EDTA were screened by use of each blood-typing method according to manufacturers' protocols.

Results—Strong RBC agglutination reactions were observed with dog erythrocyte antigen (DEA) 1.1 reagents of the CARD and GEL tests as well as MSU test (only after adding Coombs' reagent) in 9 blood samples. By use of the CARD test, RBCs from 4 additional dogs agglutinated weakly; on the basis of MSU test results, these 4 dogs were classified as DEA 1.2 positive. All blood samples agglutinated with the B antigen reagent of the TUBE test. All but 2 blood samples had strong positive reactions with the DEA 4 reagent of the MSU test. All but 3 blood samples reacted with the E antigen reagent of the TUBE test. Three blood samples agglutinated with the DEA 3 reagent of the MSU test and A antigen reagent of the TUBE test. Five blood samples had strong agglutination reactions with the DEA 5 reagent of the MSU test.

Conclusions and Clinical Relevance—Use of the CARD test allows for rapid identification of DEA 1.1 but may produce weak reactions with blood from DEA 1.2-positive dogs. The GEL test is a reliable and rapid clinical laboratory method for identification of DEA 1.1. The MSU test requires Coombs' reagent for identification of DEA 1.1 and 1.2. (Am J Vet Res2005;66:1386–1392)
Quantitation of house dust mite allergens (Der f 1 and group 2) on the skin and hair of dogs
Authors: Randall Amy J. , Hillier Andrew , Cole Lynette K. , Kwochka Kenneth W. , Needham Glen , Wassom Donald L.
Published: December 2005

Objective—To determine the concentration of house
dust mite (HDM) allergens, Der f 1 and group 2, on
the skin and hair of dogs and whether associations
exist between the presence of Der f 1 and group 2
allergens on the skin and hair of dogs and household
and dog characteristics.

Animals—63 pet dogs from 50 homes.

Procedure—Dogs were weighed and body surface
area in square meters was determined. Skin and hair
samples were obtained by vacuuming dogs.
Collected dust was analyzed by use of standard
ELISA techniques.

Results—HDM allergen was detected in 21 of 59
skin and hair samples. Presence of group 2 allergen
on skin and hair of dogs was significantly associated
with long hair, compared with short or medium length
hair. Median house dust sample concentrations of
Der f 1 and group 2 allergens were high in homes
with dogs that had skin and hair samples that were
positive for Der f 1 and group 2 allergens. Dogs with
skin and hair samples that were positive for Der f 1
and group 2 allergens resided in homes with a high
number of house dust samples that were positive for
Der f 1, group 2, or both allergens and in homes with
a mean house dust sample allergen concentration of
≥ 2 µg/g of dust.

Conclusions and Clinical Relevance—Associations
exist between environmental HDM allergen concentrations
and HDM allergens on the skin and hair samples
of dogs. Environmental allergen load is a major
factor in accumulation of allergens on the skin and
hair of dogs. (Am J Vet Res 2005;66:143–149)