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Summary

A selected group of pharmaceutical compounds were evaluated for the ability to inhibit the biochemical activity of fibrinoligase (coagulation factor XIIIa*) in pooled equine plasma. Criteria for the pharmaceuticals selected were based on the mechanism of the transglutamination biochemical reaction mediated by coagulation factor XIIa*. These criteria were complemented by recognition of the molecular configuration and chemical composition of amino acid residue side chains involved in the process of covalent fibrin monomer polymerization (cross-linking, transglutamination) mediated by this enzyme. Each pharmaceutical was evaluated individually and in combination with other potential coagulation factor XIIIa* inhibitors in an effort to detect additive and synergistic phenomenon. In this context, pharmaceuticals with a carbonylamide (eg, cefuroxime, Girard's reagent-P, prolinamide) were applied in concert with compounds with a terminal amine (eg, d-arginine, l-lysine) functional group. In concept, this method theoretically served to competitively simulate glutamine and lysine amino acid residues within strands of fibrin monomer substrate involved in phase I (carbonylamide) and phase II (terminal amine) of the transglutamination reaction (covalent fibrin monomer cross-linking). Halogen-dinitro and ethylene compounds were also evaluated because of their reported ability to inactivate enzyme systems dependent on an intact sulfhydryl group located at their biochemically active site (eg, cystine amino acid residue). This group of pharmaceutical compounds failed to inhibit the biochemical activity mediated by coagulation factor XIIIa* in equine plasma.

Free access
in American Journal of Veterinary Research

Summary

Several pharmaceutical compounds were evaluated for their ability to selectively inhibit activated coagulation factor-XIII-like enzyme activity (eg, Xllla*) in pooled equine plasma. Presence of coagulation factor-XIIIa*-like enzyme activity in plasma was established by assay procedures involving incorporation of the fluorescent amine compound, monodansylcadaverine, into purified casein, which served as a protein substrate.

Pharmaceuticals inhibitory to coagulation factor-XIIIa*-like enzyme activity were recognized by plasma gel formation of high spectrophotometric transmittance (transparency), solubility of transparent fibrin gels in concentrated urea solution, in conjunction with simultaneous depletion of native fibrinogen fractions, and production of fibrin monomer. Compounds acting primarily as anticoagulants were recognized by lack of plasma gel formation, but retaining high spectrophotometric transmittance and no detectable depletion of native fibrinogen fractions. Compounds failing to inhibit either thrombin-mediated fibrinogen-fibrin transformation (ie, coagulation) or coagulation factor-XIIIa*-like enzyme activity were recognized by opaque plasma gels caused by fibrin polymerization, low spectrophotometric transmittance values, and coinciding with depletion of native fibrinogen fractions.

Pharmaceuticals capable of exerting selective inhibition of coagulation factor-XIIIa*-like enzyme activity were further classified as competitive inhibitors of phase 1 (carbamide) or phase 2 (terminal amine) of the transglutamination process.

Free access
in American Journal of Veterinary Research

SUMMARY

Two human variable-number tandem repeat probes, pYNH24 and pYNA23, were examined for their possible ability to detect polymorphisms in the porcine genome. Useful DNA polymorphisms were detected in the porcine species, using both probes. In addition, results of Southern blot analysis of these markers in family studies indicated that the genome fragments obey mendelian laws of inheritance.

Free access
in American Journal of Veterinary Research

Summary

A murine IgM monoclonal antibody, which recognizes dog erythrocyte antigen (dea) 1.1, has been produced. The antibody correctly identified canine rbc possessing dea 1.1 in a panel of rbc typed by an independent laboratory. Reactivity of the monoclonal antibody was compared with canine anti-dea 1.1 antiserum with 163 rbc samples from 145 dogs. Results of agglutination tests with the 2 reagents were in agreement for all samples. A card agglutination test that uses the monoclonal antibody with blood is described. A monoclonal antibody-based test should facilitate blood typing for dea 1.1 in clinical practice.

Free access
in Journal of the American Veterinary Medical Association

Summary

Eighteen 9- to 10-week old Beagles were fed casein-based diets (4,710 kcal of metabolizable energy /kg of body weight) containing either 12, 80, or 160 mg of iron/kg of diet. Growth and feed consumption were monitored throughout the 47-day study. Hematocrit (Hct), hemoglobin (Hb) concentration, mean corpuscular volume (mcv), mean corpuscular hemoglobin (mch), mean corpuscular hemoglobin concentration (mchc), rbc numbers, erythrocyte protoporphyrin (ep) concentration, serum iron concentration, serum total iron-binding capacity (tibc), and serum ferritin concentration were determined weekly. Growth rate and feed efficiency were not significantly influenced by dietary iron content. At 14 days, Hb concentration, Hct, mcv, mch, rbc numbers, and serum iron concentration were significantly (P < 0.05) lower in dogs fed the 12 mg/kg diet, and remained significantly low for the remainder of the study. Erythrocyte protoporphyrin concentration increased significantly (P < 0.05) by 14 days in dogs fed the basal diet, and remained significantly high relative to that in dogs of the other dietary groups for the remainder of the study. Serum ferritin concentration decreased in dogs of the group fed the basal diet, with a significant (P < 0.05) difference beyond day 42. Differences in Hct, mch, mcv, or hemoglobin, serum iron, serum ferritin, or ep concentration were not found between groups fed 80 and 160 mg of iron/kg of diet. Liver nonheme iron content was significantly (P < 0.05) affected by dietary iron content.

Free access
in Journal of the American Veterinary Medical Association

SUMMARY

Surface structures of Bacteroides nodosus were examined by electron microscopy. Collodion film and chrome shadowing were used for maximizing the visualization of B nodosus pili and ring structures. The existence of B nodosus pili in foot rot lesions was confirmed. Contrary to previous reports, it was found that B nodosus pili production can be retained through serial broth transfer under certain conditions. Capsule production by B nodosus was irregular in that it could be either lacking or variable in thickness. A bacteriophage capable of infecting B nodosus also was detected.

Free access
in American Journal of Veterinary Research

SUMMARY

Microcytosis is a common laboratory finding in dogs with congenital portosystemic shunt (pss), although its pathogenesis is not yet understood. Because the most common cause of microcytosis in dogs is absolute or relative iron deficiency, iron status was evaluated in 12 young dogs with pss. Complete blood counting was done before surgical correction in all dogs, and in 5 dogs after surgery, by use of an automated hematology analyzer. Serum iron concentration and total iron-binding capacity (tibc) were determined coulometrically, and percentage of transferrin saturation was calculated. Erythrocyte protoporphyrin content was quantified by use of front-face fluorometry. Serum ferritin concentration was measured by use of elisa. Serum ceruloplasmin content was determined colorimetrically (with p-phenylene-diamine dihydrochloride as substrate) as an indirect indicator of subclinical inflammation, which may result in impaired iron utilization. Special stains were applied to liver (10 dogs; Gomori's) and bone marrow aspiration biopsy (7 dogs; Prussian blue) specimens for qualitative assessment of tissue iron content. Nonpaired Student's t-tests were used to compare serum iron concentration, tibc, percentage of transferrin saturation, and erythrocyte protoporphyrin, ferritin, and ceruloplasmin concentrations in dogs with pss with those in clinically normal dogs. All dogs had microcytosis before surgery; microcytosis resolved in 3 dogs after surgical correction. Serum iron concentration and tibc were significantly lower in pss-affected dogs than in clinically normal dogs. Erythrocyte protoporphyrin, ferritin, and ceruloplasmin concentrations in pss-affected dogs were not significantly different from those in healthy dogs. Excess iron was not detected consistently in liver or bone marrow samples. These results suggest that relative iron deficiency, perhaps associated with altered iron transport and not absolute iron deficiency, is related to microcytosis in dogs with pss.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To provide an updated evaluation of the efficacy and safety of sometribove zinc suspension (rbST-Zn), a form of recombinant bovine somatotropin, in lactating dairy cows.

Design—Meta-analysis.

Sample—26 studies published in peer-reviewed journals or reviewed by a regulatory agency.

Procedures—To be included, a study had to involve the use of the rbST-Zn formulation available to US producers in accordance with the label instructions for treatment initiation (57 to 70 days postpartum), dose (500 mg, q 14 d), and route (SC).

Results—For cows treated with rbST-Zn, mean milk, 3.5% fat-corrected milk, fat, and protein yields were increased by 4.00, 4.04, 0.144, and 0.137 kg/d (8.8, 8.89, 0.32, and 0.30 lb/d), respectively; however, the concentration of milk components did not change. Pregnancy proportion for the first 2 breeding cycles was increased by 5.4%, and pregnancy proportion for the duration of the trial was reduced by 5.5% for rbST-Zn–treated cows, compared with proportions for untreated cows. Mean body condition score (1 to 5 scale) was reduced by 0.06 points during the period of rbST-Zn use for treated cows. Administration of rbST-Zn had no effect on milk somatic cell count, the number of days to pregnancy, or inseminations per pregnancy; rates of fetal loss, twins, cystic ovaries, clinical lameness, lameness lesions, or traumatic lesions of the integumentary system; and odds of clinical mastitis or culling.

Conclusions and Clinical Relevance—Results indicated that rbST-Zn administration to dairy cows effectively increases milk production with no adverse effects on cow health and well-being.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the effectiveness of an oral rabies vaccination (ORV) project conducted from 1998 through 2007 in Anne Arundel County, Md, for the control of rabies in terrestrial animals.

Design—Retrospective analysis of surveillance data (1997 through 2007).

Animals—Free-ranging raccoons (Procyon lotor) and other terrestrial mammals.

Procedures—Vaccinia-rabies glycoprotein recombinant virus oral rabies vaccine–bait units were distributed annually by aircraft and ground teams targeting free-ranging raccoons. Approximately 2 to 4 weeks following the vaccine-bait placement, raccoons were live trapped, sedated, processed, and then released. Serologic samples were tested for the presence of rabies virus–neutralizing antibodies (RVNAs). Bait acceptance was estimated by analysis of tetracycline biomarking of sampled teeth. Rabies incidence was determined by the passive identification of rabid terrestrial animals.

Results—The incidence of rabies in terrestrial animals decreased 92% between 1997 (the year prior to the start of the ORV project) and 2007. The mean RVNA prevalence across all years was 33% among trapped raccoons in areas baited with a fish meal polymer bait type, whereas the mean bait acceptance was 30%. Adult raccoons had a seropositivity rate twice that of juvenile raccoons, whereas the bait acceptance rate between adults and juveniles did not differ significantly. For areas baited with a coated sachet bait, adults and juveniles had the same seroprevalence. Juveniles had better seroprevalence when the annual campaign started in September and October, compared with August.

Conclusions and Clinical Relevance—The ORV project contributed to a significant decrease in annual incidence of terrestrial animal rabies in Anne Arundel County, Md, during the 10-year project period. For fish meal polymer baits, juvenile raccoons accessed bait at the same rate as adult raccoons but had a significantly lower prevalence of RVNAs. For coated sachet baits, seroprevalence was the same in both age groups. The time of year the bait distribution occurred and the bait type used may be partial explanations for the difference in RVNA seroprevalence between adults and juvenile raccoons.

Full access
in Journal of the American Veterinary Medical Association