Search Results

You are looking at 1 - 10 of 15 items for

  • Author or Editor: Andrew J. Mackin x
  • Refine by Access: Content accessible to me x
Clear All Modify Search
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

SUMMARY

Effects of a single iv administered therapeutic dose of vincristine sulfate on platelet numbers and function were evaluated in 16 clinically normal dogs over the 2 weeks after drug administration. Results were statistically compared with those of a previous control study in which the same 16 dogs were administered saline solution (iv), instead of vincristine. Of the 16 dogs, 8 were orally administered daily immunosuppressive doses of prednisone concurrently throughout the saline-control and vincristine study periods. Platelet numbers and mean platelet volume were measured, using an automated hematology analyzer. Platelet function was evaluated by turbidimetric measurement of platelet aggregation in response to collagen, platelet-activating factor, and adenosine diphosphate (adp), and by clot retraction (diluted whole-blood method) and buccal mucosa bleeding time.

Vincristine had a significant (P < 0.05) effect on circulating platelet numbers. Vincristine induced a transient mild decrease in platelet numbers, followed by a moderate increase in numbers, with peak platelet count observed 8 days after drug administration. Mean platelet volume was not significantly affected by administration of vincristine.

Vincristine had no significant effects on platelet aggregation in response to collagen, low or high doses of platelet-activating factor, and a high dose of adp. The maximal degree of platelet aggregation attained in response to a low dose of adp was not significantly affected by prior administration of vincristine. The maximal rate of platelet aggregation induced by a low dose of adp after vincristine administration, however, was significantly (P < 0.05) lower than the rate of aggregation induced by a similar dose of adp in the previous control study. Vincristine had no significant effects on clot retraction and bleeding time. Prednisone did not significantly affect platelet numbers and function, and did not modify vincristine's effects on the same variables.

Free access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To evaluate coagulation factors in units of leukoreduced (LR) and nonleukoreduced (non-LR) canine fresh-frozen plasma (cFFP).

ANIMALS

8 healthy research dogs.

PROCEDURES

In a crossover study, dogs were randomly assigned to 1 of 2 groups from which blood was collected and either did or did not undergo leukoreduction. After a recovery period of ≥ 28 days, the dogs were switched between protocols. After each collection, blood samples were centrifuged, and cFFP was stored frozen for later comparative analysis of coagulation factors, antithrombin, and protein C activities (reported as comparative percentages of the corresponding activities determined in a canine pooled plasma standard); prothrombin and activated partial thromboplastin times; and fibrinogen concentration.

RESULTS

There were no significant differences detected between results for LR cFFP, compared with those for non-LR cFFP.

CONCLUSIONS AND CLINICAL RELEVANCE

Although there was variation among residual activities of coagulation factors in LR and non-LR cFFP, the variations and differences were considered unlikely to impact the efficacy of LR cFFP transfused for coagulation factor replacement in dogs. However, owing to the small sample size and high variability of results in the present study, additional research with a larger sample size is required for definitive conclusions on the effects of leukoreduction on coagulation factors in cFFP and to develop treatment guidelines for LR cFFP use in dogs with congenital and acquired coagulopathies.

Full access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association