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Summary

The biocompatibility and osteoconductive properties of biocompatible osteoconductive polymer (bop), a synthetic implant, were evaluated. Bilateral oval cortical defects (1 × 2 cm) were made in the lateral subtrochanteric area of the proximal portion of the femur in 16 dogs that later were treated with bop fiber (n = 16) or autogenous cancellous bone (n = 11), or were not treated (n = 5). The bop block was attached extraperiosteally to the proximal portion of the humerus in 6 dogs. Radiographic assessment of surgery sites was performed at 4-week intervals, and histologic evaluation was performed at 4, 8, 16, and 24 weeks after surgery. Radiographic signs of bone healing were not observed in defects treated with bop fiber. Defects treated with cancellous bone or not treated had radiographic signs of progressive bone ingrowth. Radiographic evidence of periosteal new bone formation near control and bop-treated defects was observed 4 weeks after surgery; increased periosteal reaction was associated with bop fiber. This new bone had resorbed by week 24, except bone adjacent to bop fiber, where continued periosteal reaction was apparent. Histologic evidence of bone formation was observed extending to, but not incorporating, bop fibers. The bop fibers became surrounded by a fibrous capsule, and fibrovascular connective tissue infiltrated between and into bop fibers, but minimal bone formation incorporated the bop material during the follow-up period. During that time, active periosteal new bone formation was evident adjacent to the bop fibers. Defects treated with cancellous bone or not treated healed by ingrowth of cancellous bone during the first 12 weeks after surgery and by reformation of the lateral cortical wall by week 24. The bop blocks became surrounded by a fibrous capsule, but connective tissue or bone ingrowth into bop blocks was not observed. Results indicate that bop is not osteoconductive within a 6-month time frame when used in subtrochanteric femoral defects or when placed extraperiosteally on the proximal portion of the humerus of clinically normal dogs.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether cardiovascular dysfunction is evident in horses with leukoencephalomalacia experimentally induced by administration of fumonisin B1.

Animals—11 healthy horses of various breeds (body weight, 252 to 367 kg).

Procedure—Horses were randomly assigned to 3 groups and administered fumonisin B1 daily. Horses received IV injections of 0 (control horses; n = 4), 0.01 (3), or 0.20 mg (4) of fumonisin B1/kg for 7 to 28 days. Horses were examined daily for evidence of neurologic disease. When neurologic signs consistent with leukoencephalomalacia were evident, horses were anesthetized, and catheters were inserted for evaluation of the cardiovascular system. After recovery from anesthesia, hemodynamic measurements were obtained.

Results—Fumonisin-treated horses with clinical signs of neurologic disease had evidence of cardiovascular dysfunction manifested as decreases in heart rate, cardiac output, right ventricular contractility (assessed by measuring the maximal rate of change of right ventricular pressure), coccygeal artery pulse pressure, and pH and base excess in venous blood as well as increases in systemic vascular resistance, compared with values for control horses. Fumonisin-treated horses with and without clinical signs of neurologic disease also had higher serum and right ventricular sphinganine and sphingosine concentrations than control horses.

Conclusions and Clinical Relevance—An association was detected among fumonisin-induced neurologic disease, increased serum and myocardial sphinganine and sphingosine concentrations, and decreased cardiovascular function in horses. Fumonisin-induced decreases in cardiovascular function may contribute to the pathophysiologic development of leukoencephalomalacia in horses. (Am J Vet Res 2002;63:538–545).

Full access
in American Journal of Veterinary Research

Abstract

Recent state and federal legislative actions and current recommendations from the World Health Organization seem to suggest that, when it comes to antimicrobial stewardship, use of antimicrobials for prevention, control, or treatment of disease can be ranked in order of appropriateness, which in turn has led, in some instances, to attempts to limit or specifically oppose the routine use of medically important antimicrobials for prevention of disease. In contrast, the AVMA Committee on Antimicrobials believes that attempts to evaluate the degree of antimicrobial stewardship on the basis of therapeutic intent are misguided and that use of antimicrobials for prevention, control, or treatment of disease may comply with the principles of antimicrobial stewardship. It is important that veterinarians and animal caretakers are clear about the reason they may be administering antimicrobials to animals in their care. Concise definitions of prevention, control, and treatment of individuals and populations are necessary to avoid confusion and to help veterinarians clearly communicate their intentions when prescribing or recommending antimicrobial use.

Full access
in Journal of the American Veterinary Medical Association