bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of pilocarpine-induced aqueous humor flare, hypotony, and miosis by topical administration of anti-inflammatory and anesthetic drugs to dogs
Authors: Krohne Sheryl Greve , Gionfriddo Juliet , Morrison Elizabeth A. 
Published: January 2024

Abstract

Objective
To investigate the mechanism by which pilocarpine causes increased aqueous humor (AH) flare, hypotony, and miosis in dogs.

Animals
6 dogs with normal eyes.

Procedure
Both eyes of each dog were treated topically with a 2% solution of pilocarpine, and 1 eye of each dog was additionally treated with commercially available ophthamic solutions. Breakdown of the blood-aqueous barrier (BAB) was quantitated in each eye, using laser flaremetry to measure AH flare. Intraocular pressure and pupil size were also measured.

Results
Pilocarpine caused increased flare from BAB breakdown that was inhibited by the drugs tested. Inhibition (most to least) of BAB breakdown was flurbiprofen more than diclofenac, proparacaine, or suprofen, which were more than 0.125 or 1.0% prednisolone. Inhibition appeared dose-dependent and caused consensual inhibition in the contralateral eye. Intraocular pressure was decreased only in proparacaine-treated eyes and increased in eyes treated with nonsteroidal anti-inflammatory drugs (NSAID). Flurbiprofen and proparacaine were the most effective at blocking miosis.

Conclusions
Pilocarpine produced a predictable, reproducible BAB breakdown in dogs. Miosis and increased AH flare were inhibited equally by proparacaine or NSAID, suggesting that these signs were caused by neuropeptide release into the AH from antidromic stimulation, which subsequently triggers prostaglandin production. Hypotony was inhibited only by anti-inflammatory drugs.

Clinical Relevance
Proparacaine in combination with pilocarpine would be the best choice for treating dogs with acute glaucoma. Topical administration of NSAID should not be used to treat dogs with acute glaucoma, because they increase intraocular pressure and negate the effects of pilocarpine. (Am J Vet Res 1998;59:482–488)
Vascular and transsynovial forces of the isolated stationary equine joint
Authors: Bertone Alicia L. , Hardy Joanne , Simmons Emily J. , Muir William W. 
Published: January 2024

Abstract

Objective
To provide quantitative assessment of forces affecting filtration of synovial fluid in response to incremental changes in arterial and venous hemodynamics.

Animals
7 clinically normal adult horses.

Procedure
Using a stationary, isolated metacarpophalangeal joint preparation, blood flow (Qacir), tissue perfusion, arterial pressure (Pacir), venous pressure (Pvcir), transsynovial fluid flow, total vascular resistance, vascular compliance, and tissue compliance were evaluated before and after arterial and venous pressure manipulations. At isogravimetric conditions, pre- and postcapillary resistance and ratios, osmotic reflection coefficient (σd), capillary pressure, net filtration pressure, and transitional microvascular pressure were determined.

Results
Synovial tissue blood flow was similar before, immediately after, and 3.5 hours after joint isolation. The σd for the joint was low, owing to the high oncotic pressure of synovial fluid at filtration-independent states. Transsynovial flow occurred in preference to lymph flow because of the high permeability of synovial tissue (low σd). Synovial fluid production and transfluid flow (synovium weight gain) increased at Pacir > 200 mm of Hg, indicating a threshold phenomenon for synovial filtration. Net filtration pressure > 6 mm of Hg is needed to effect an increase in synovial fluid flow, and pressure of approximately 11 mm of Hg is necessary to increase lymphatic flow. Vascular compliance in the joint was low, but increased markedly with Pvcir. Vascular and tissue compliance increased with increased Pacir. Vascular compliance changes caused by increased arterial pressure were minimal, compared with those caused by increased venous pressure owing to the greater elastance of arteries and the larger muscular arterial wall.

Conclusion
This isolated joint preparation permitted evaluation of codependent hemodynamic, microvascular, and transsynovial flow responses to hemodynamic manipulations. Synovial tissue permeability was markedly affected by increased vascular forces altering filtration pressures toward synovial fluid production. (Am J Vet Res 1998;59:495–503)
Effect of bilateral blockade of the pharyngeal branch of the vagus nerve on soft palate function in horses
Authors: Holcombe Susan J. , Derksen Frederik J. , Stick John A. , Robinson N. Edward 
Published: January 2024

Abstract

Objective
To determine the effect of bilateral blockade of the pharyngeal branch of the vagus nerve on soft palate function in horses.

Animals
5 Standardbreds.

Procedure
Peak tracheal inspiratory and expiratory pressures and airflow were measured while horses exercised at the speeds corresponding to 75 and 100% of the speed that resulted in maximal heart rate, with and without pharyngeal branch of the vagus nerve blockade. Respiratory frequency-to-stride frequency coupling ratio was measured by correlating foot fall measurements with respiratory frequency. The pharyngeal branch of the vagus nerve was blocked bilaterally as the nerve coursed through the auditory tube diverticulum (guttural pouch) across the longus capitus muscle.

Results
Persistent, reversible dorsal displacement of the soft palate (DDSP) occurred in all horses after nerve blockade, and lasted from 1 to 3 hours; normal nasopharyngeal function returned within 3 hours. Compared with control values, peak expiratory tracheal pressure increased (P = 0.001), expiratory impedance increased (P = 0.007), and minute ventilation decreased (P = 0.04). Respiratory frequency-to-stride frequency coupling ratio decreased (P = 0.009) so that horses took 1 breath/stride without the nerve block and, approximately, 1 breath/2 strides with the block.

Conclusion
DDSP creates flow-limiting expiratory obstruction and may be caused by neuromuscular dysfunction involving the pharyngeal branch of the vagus nerve. It may alter performance by causing expiratory obstruction and by altering breathing strategy in horses.

Clinical Relevance
A repeatable, reversible model of DDSP exists that allows further study of the disease. Dysfunction of the neuromuscular group, pharyngeal branch of the vagus nerve and palatinus and palatopharyngeus muscles, may be implicated in the pathogenesis of clinical DDSP. (Am J Vet Res 1998;59:504–508)
Supplemental dietary biotin for prevention of lesions associated with aseptic subclinical laminitis (pododermatitis aseptica diffusa) in primiparous cows
Authors: Midla Lowell T. , Hoblet Kent H. , Weiss William P. , Moeschberger Melvin L. 
Published: January 2024

Abstract

Objective
To evaluate, in primiparous cows, the effect of dietary biotin supplementation on severity of lesions of aseptic subclinical laminitis.

Animals
100 primiparous cows in a 800-cow commercial dairy herd.

Procedure
Cows were assigned after calving to a biotin-supplemented (20 mg/head/d) or control group on an alternating basis. Digits 3 and 4 of the left forelimb and right hind limb were examined at a mean of 25, 108, and 293 days after parturition. Toe length, hoof angle, and heel depth were measured, and hooves were examined for solear hemorrhage, yellow solear discoloration, separation of the white line, and heel erosion. Serum and milk biotin concentrations were also measured.

Results
Serum biotin concentrations were significantly higher for supplemented than for control cows. During the second examination, prevalence of separation of the white line of digits 3 and 4 of the hind limb and digit 4 of the forelimb was lower for supplemented than for control cows. Mean decrease in heel depth between the first and third examinations was approximately twice as great for digit 4 of the forelimb and 4 times as great for digit 3 of the forelimb in supplemented, versus control, cows. Other differences were not found.

Conclusions and Clinical Relevance
Results suggest that supplemental dietary biotin may have a beneficial effect on hoof health in intensively managed primiparous dairy cows. (Am J Vet Res 1998;59:733-738)
Comparison of amikacin dosing regimens in neutropenic guinea pigs with Escherichia coli infection
Authors: McClure J. T. , Rosin Eberhard 
Published: January 2024

Abstract

Objective
To derive pharmacokinetic data for 3 amikacin dosing regimens in guinea pigs and to determine whether the antibacterial activity of 15 mg/kg of body weight given twice daily is equivalent to administering the drug more frequently.

Animals
10 guinea pigs in pharmacokinetic trials, and 10 guinea pigs in pretreatment, control, and amikacin treatment groups.

Procedure
Amikacin pharmacokinetic data were determined in guinea pigs after single IM administration of 3.75, 7.5, and 15 mg/kg. Guinea pigs had been made neutropenic by treatment with cyclophosphamide. All guinea pigs were inoculated with 2.8 × 108 colony-forming units (CFU) of Escherichia coli in the thigh muscle, then were allotted to 5 groups: pretreatment (euthanatized 4 hours after inoculation), control, and 3 amikacin treatment groups (3.75 mg/kg, q 3 h; 7.5 mg/kg, q 6 h; and 15 mg/kg, q 12 h). Amikacin administration was begun 4 hours after E coli inoculation and was continued for 72 hours. Numbers of E coli CFU in infected thigh muscle were determined for each guinea pig.

Results
Difference in survival between control and the amikacin-treated groups was significant. The E coli infection concentration (log10 CFU) increased significantly in the control, compared with the pretreatment, group. Infection concentration decreased significantly in all treatment groups, compared with the pretreatment group. There was no significant difference in bacterial killing among the 3 treatment groups.

Conclusion
Amikacin had a significant effect on survival of neutropenic guinea pigs with E coli infection. Antibacterial activity did not differ among 3 doses of amikacin administered at different intervals.

Clinical Relevance
Aminoglycoside dosing regimen with high peak concentration and long drug-free interval is as efficacious as divided dose regimens. (Am J Vet Res 1998;59:750-755)
Effect of finasteride on serum concentrations of dihydrotestosterone and testosterone in three clinically normal sexually intact adult male dogs
Authors: Kamolpatana Kaitkanoke , Johnston Shirley D. , Hardy Sharon K. , Castner Susan 
Published: January 2024

Abstract

Objective
To determine the effect of finasteride at dosages of 0.10, 0.25, and 0.50 mg/kg of body weight, PO, q 24 h, on serum concentrations of dihydrotestosterone (DHT) and testosterone (T) in clinically normal sexually intact adult male dogs.

Animals
3 intact adult male dogs less than 5 years old.

Procedure
Concentrations of DHT and T were measured by radioimmunoassay of serum from dogs randomly assigned to 1 of 3 treatment groups (0.10, 0.25, or 0.50 mg of finasteride/kg, PO, q 24 h, for 7 days) in a Latin square design with repeated measures. Blood was obtained before and on days 1, 2, 4, and 7 of treatment; 3 blood samples were obtained at 20 minute intervals to detect pulsatile secretion of DHT and T. Dogs were untreated at least 2 weeks between treatments.

Results
Finasteride at all doses was associated with a mean decrease in concentration of DHT of 55% (range, 155 ± 32.3 pg/ml to 70 ± 15 pg/ml), but had no effect on concentration of T (before treatment, 2.6 ± 0.38 ng/ml; after treatment, 2.2 ± 0.63 ng/ml).

Conclusions
Finasteride at these doses significantly decreased serum concentration of DHT in sexually intact adult male dogs. Concentrations of DHT and T before and 7 days after treatment did not differ by dosage of finasteride administered.

Clinical Relevance
Finasteride (5 mg; 1 tablet) may be a drug of choice for treatment of benign prostatic hypertrophy in 10- to 50-kg dogs. (Am J Vet Res 1998;59:762-764)
Morphologic changes and xanthine oxidase activity in the equine jejunum during low flow ischemia and reperfusion
Authors: Vatistas Nicholas J. , Snyder Jack R. , Nieto Jorge , Hildebrand Susan V. , Woliner Michael J. , Harmon Faye A. , Barry Sean J. , Drake Christiana 
Published: January 2024

Abstract

Objective
To determine whether xanthine oxidase and dehydrogenase activities are altered during low flow ischemia and reperfusion of the small intestine of horses.

Animals
5 clinically normal horses without histories of abdominal problems.

Procedure
With the horse under general anesthesia, a laparotomy was performed and blood flow to a segment of the distal jejunum was reduced to 20% of baseline for 120 minutes and was then reperfused for 120 minutes. Biopsy specimens were obtained before, during, and after ischemia for determination of xanthine oxidase and dehydrogenase activities, and for histologic and morphometric analyses.

Results
Percentage of xanthine oxidase activity (as a percentage of xanthine oxidase and dehydrogenase activity) was not altered during ischemia and reperfusion. An inflammatory response developed and progressed during ischemia and reperfusion. Mucosal lesions increased in severity after ischemia and reperfusion. Mucosal surface area and volume decreased during ischemia and continued to decrease during reperfusion. Submucosal volume increased slightly during ischemia, and continued to increase during reperfusion.

Conclusions and Clinical Relevance
Evidence for conversion of xanthine dehydrogenase to xanthine oxidase during ischemia was not found. Factors other than production of reactive oxygen metabolites may be responsible for progressive epithelial loss, decrease in mucosal surface area and volume, and increase in submucosal volume observed in this study. Other methods of determining xanthine oxidase activity that detect the enzyme in sloughed epithelial cells should be used to better define the importance of this pathway in jejunal reperfusion injury in horses. (Am J Vet Res 1998;59:772-776)
Effect of tumor necrosis factor antibody given to horses during early experimentally induced endotoxemia
Authors: Barton Michelle H. , Bruce Elizabeth H. , Moore James N. , Norton Natalie , Anders Brendan , Morris Debra D. 
Published: January 2024

Abstract

Objective
To test efficacy of murine monoclonal, rabbit polyclonal recombinant equine or human tumor necrosis factor-α (rETNF or rHTNF, respectively) antibodies to inhibit native equine tumor necrosis factor (TNF) activity.

Animals
8 and 18 healthy adult horses for parts 1 and 2 of the study, respectively.

Procedures
In part 1, supernates from endotoxin-activated peritoneal macrophages were incubated with various dilutions of each rETNF antibody and subsequently tested for TNF activity. Serum was also obtained from a horse 1 hour after infusion with 20 ng of endotoxin/kg of body weight and was incubated with various dilutions of rabbit polyclonal rHTNF antibody. In part 2, 20 ng of endotoxin/kg was infused in horses during a 30-minute period. Fifteen minutes after the endotoxin infusion was initiated, 1 of 3 preparations was infused: 0.1 mg of rabbit polyclonal rHTNF antibody/kg, 0.1 mg of human IgG/kg, or 500 ml of 5% dextrose. Clinical and hematologic data were collected for 24 hours.

Results
Compared with the monoclonal antibody, the rabbit polyclonal rETNF antibody was more effective in inhibiting TNF activity. The 50% effective doses of the murine monoclonal rETNF, rabbit polyclonal rETNF, and rabbit rHTNF antibodies were 1.8, 0.8, and 0.6 μg of antibody/ml, respectively. In part 2, endotoxin infusion resulted in significant alternations in all variables; however, differences among treatment groups were not significant.

Conclusions and Clinical Relevance
Although murine monoclonal and rabbit polyclonal rETNF or rHTNF antibodies are capable of inhibiting native equine TNF activity in vitro, when given after initiation of endotoxemia, administration of 0.1 mg of rabbit polyclonal rHTNF/kg does not alter the response to infusion of endotoxin. (Am J Vet Res 1998;59:792-797)
Hyperglobulinemia and lymphocyte subset changes in naturally infected, inapparent carriers of equine infectious anemia virus
Authors: Russell Karen E. , Walker Kathy M. , Miller Richard T. , Sellon Debra C. 
Published: January 2024

Abstract

Objective
To determine blood protein concentration, immunoglobulin concentration, and lymphocyte profiles in equine infectious anemia virus (EIAV) seropositive, naturally infected horses without clinical signs of disease.

Animals
26 clinically normal seropositive horses, 6 febrile ponies with experimentally induced EIA, and 52 clinically normal seronegative horses and ponies.

Procedure
Serum and EDTA-anticoagulated blood were obtained from all horses and ponies, and total serum protein and albumin concentrations, immunoglobulin concentrations, and blood lymphocyte subset counts were determined.

Results
Compared with seronegative horses, EIAV seropositive inapparent carrier horses had no significant difference in serum reverse transcriptase activity, PCV, or platelet count. Inapparent carrier horses had increased plasma total solids and serum globulin concentrations and decreased serum albumin concentration and albumin-to-globulin ratio. Total serum immunoglobulin and serum IgM concentrations were increased. In-apparent carrier horses had significantly decreased percentages of CD5+ and CD4+ blood lymphocytes.

Conclusions
Serum protein and lymphocyte subset changes in EIAV-infected inapparent carrier horses are consistent with immune activation or chronic inflammation, both of which may, in part, be the result of virus-induced polyclonal B-cell activation.

Clinical Relevance
EIAV seropositive horses have immune-related abnormalities consistent with ongoing viral activity regardless of the duration they have been infected, even when the usual signs of disease (anemia, fever, weight loss) are not apparent. (Am J Vet Res 1998;59:1009–1015)
Pulmonary function in horses with recurrent airway obstruction after aerosol and parenteral administration of beclomethasone dipropionate and dexamethasone, respectively
Authors: Rush Bonnie R. , Raub Elizabeth S. , Rhoads William S. , Flaminio M. Julia B. F. , Matson Charles J. , Hakala Joyce E. , Gillespie Jerry R. 
Published: January 2024

Abstract

Objective
To determine changes in clinical signs of disease and response to pulmonary function testing in horses with recurrent airway obstruction (heaves) after aerosol and parenteral administration of beclomethasone dipropionate and dexamethasone, respectively.

Animals
6 horses with inducible and reversible heaves.

Procedure
Episodes of heaves were induced by exposure (challenge) to moldy hay and straw for 7 days. Horses were assigned to treatment groups (aerosolized beclomethasone dipropionate, parenterally administered dexamethasone, aerosolized propellant [control]), and respiratory frequency and subjective assessment of respiratory effort were determined twice daily. Maximal change in pleural pressure (ΔPplmax), pulmonary resistance (RL), and dynamic compliance (Cdyn) was determined on days 0, 7, 10, 14, and 21.

Results
The RL and ΔPplmax were increased, and Cdyn was decreased in all horses in response to natural challenge. Beclomethasone reduced RL on day 10, reduced ΔPplmax on days 14 and 21 and increased Cdyn on day 14. Dexamethasone reduced RL and ΔPplmax on days 10, 14, and 21 and increased Cdyn on days 10 and 14. Respiratory effort (subjective assessment) improved after 2 and 3 days of beclomethasone and dexamethasone administration but rebounded to pretreatment values 1 and 3 days after discontinuation of drugs.

Conclusions
Pulmonary function testing responses and clinical signs of airway obstruction were improved by administration of beclomethasone. The magnitude of response to aerosolized beclomethasone generally was less marked than the response to parenterally administered dexamethasone. Higher or more frequent dosing of aerosolized beclomethasone may be necessary to achieve the anti-inflammatory response to parenterally administered dexamethasone. (Am J Vet Res 1998;59:1039–1043)
Determination of age in dogs and cats by use of changes in lens reflections and transparency
Authors: Tobias Gerald , Tobias Todd A. , Abood Sarah K. , Hamor Ralph E. , Ballam Joan M. 
Published: January 2024

Abstract

Objective
To develop and test a noninvasive technique for determining age in dogs and cats on the basis of changes in lens reflections and transparency.

Animals
85 dogs representing 5 breeds and 73 domestic shorthair cats.

Procedure
While examining dilated eyes in a darkened room, using a penlight, 2 experienced examiners who were blinded to actual age of animals individually measured the diameter of reflections from the anterior (La) and posterior (Lb) surfaces of the lens and scored lens transparency (Ltr) from 1 (clear) to 5 (severe opacity). Models were developed to predict age on the basis of these measurements.

Results
Aging models developed for dogs and cats were as follows: Agedogs = 2.197 − 0.070 × (La) + 1.361 × (Lb) + 1.193 × (Ltr) and Agecats = 1.988 + 1.024 × (La) + 2.220 × (Lb) + 1.019 × (Ltr), where age was expressed in years, and La and Lb were in millimeters. All variables, except La in dogs, contributed significantly to accuracy of the models. Correlation between predicted and actual ages, as measured by Pearson's product-moment correlation coefficient, was significant in both species (P < 0.0001). Significant differences were not found between examiners or between the first and second evaluations by the same examiner.

Conclusions and Clinical Relevance
A noninvasive technique based on evaluation of lens reflections and transparency can provide clinically useful predictions of age in mature dogs and cats. This technique could be an important tool for veterinarians or humane shelters in determining differential diagnoses and assessing longevity and adoptability of mature animals of unknown age. (Am J Vet Res 1998;59:945–950)
Further validation of antibody-capture and antigen-capture enzyme-linked immunosorbent assays for determining exposure of cattle to bovine coronavirus
Authors: Smith David R. , Nielsen Paul R. , Gadfield Kathy L. , Saif Linda J. 
Published: January 2024

Abstract

Objective
To further validate an antibody-capture ELISA for measuring bovine coronavirus (BCV) exposure (antibody seroresponse) in cattle and to explain the apparent loss of sensitivity of a BCV antigen-capture ELISA when testing feces from adult versus neonatal cattle.

Animals
98 adult cows from herds with and without winter dysentery; 10 gnotobiotic or colostrum-deprived calves.

Procedures
Results of an antibody-capture ELISA for BCV and a plaque reduction virus neutralization assay performed on paired serum samples from 24 cattle were compared with each other and with results of immunoelectron microscopy (IEM) of feces for BCV. For samples from 98 cattle, results of antibody-capture ELISA were compared with results of IEM. Calves were inoculated with feces ELISA-positive or IEM-positive for BCV and monitored for BCV infection. An ELISA was developed to detect BCV antigen-antibody complexes in feces and results were compared with results of an antigen-capture ELISA and IEM.

Results
Antibody-capture ELISA results correlated with neutralization assay results, but agreed more closely with results of IEM. Calves became infected with BCV following inoculation with either ELISA-positive or ELISA-negative but IEM-positive feces. Results of the antigen-antibody ELISA correlated with results of IEM and the antigen-capture ELISA.

Clinical Implications
In adult cattle, testing of paired serum samples by use of an antibody-capture ELISA may be a better indicator of recent BCV exposure than results of virus neutralization tests. Antigen-antibody binding in feces may interfere with results of antigen-capture ELISA for BCV. (Am J Vet Res 1998;59:956–960)