ABSTRACT
Fibrin glue has been researched as an alternative method for tissue synthesis and is known for its capability to promote hemostasis at the application site, good approximation of wound edges and fast healing. The current study consisted in the application of fibrin glue derived from snake venom as treatment for experimental corneal ulcers. Twenty-one dogs had their corneas experimentally prepared through lamellar keratectomy (of standardized diameter and depth). Animals were divided into seven groups of three animals each. Six experimental groups were periodically evaluated and collection was carried out on the 1st, 3rd, 7th, 15th, 30th and 60th post-operative days, whereas one control group was evaluated throughout the experiment. Analyses consisted in the clinical evolution and in the histopathological study of all operated on eyes. Results indicated that fibrin glue was efficient in repairing keratectomy wounds in dogs and contributed to an earlier healing phenomenon, avoiding edema formation and keeping corneal clearness. The use of fibrin glue derived from snake venom showed to be easy to apply, feasible with animal models and of low cost, avoiding the lesion progress and allowing fast and appropriate corneal healing.
Subject(s)
Animals , Dogs , Fibrin Tissue Adhesive/therapeutic use , Corneal Ulcer , Snake Venoms/therapeutic useABSTRACT
The objective of this study was to evaluate the effects of the thrombin-like fraction of Crotalus durissus terrificus venom, Reptilase©, and bovine thrombin of fibrinogen polls on bovine, equine, ovine, bubaline and human cryoprecipitates. The authors also made a comparative study between animal and human cryoprecipitates to see if there was any possibility of future use in medicine. Fibrinogen levels in cryoprecipitate were studied using 48 blood samples obtained as follows: 12 samples from humans, 9 from bovine, 10 from equine, 10 from ovine and 7 from bubaline. The results obtained showed average levels of 375.50 mg per cent for humans, 218.33 mg per cent for bovine, 240.80 mg per cent for equine, 267.70 mg per cent for ovine and 664.00 mg per cent for bubaline. Upon the formation of pools of human and animals fibrinogens, the following results were obtained: 435 mg per cent for humans, 444 mg per cent for bovine, 337 mg per cent por equine, 390 mg per cent for ovine and 530 mg per cent for bubaline. Statistical analysis (using the analysis of variance for entirely randomized experiment for the calculation of F statistics) demonstrated that the bubaline fibrinogen level was higher than that of human, and both were higher than those of ovine, equine, and bovine. Clotting times were determined using different dilutions of bovine thrombin, thrombin-like fraction of Crotalus durissus terrificus venom, and Reptilase©. Comparing these clotting times, results for human and bovine were found to be very similar, whereas using equine, ovine and bubaline the results above a dilution of 1:3 were markedly different. The results obtained permitted the following conclusions to be drawn show that: 1) bovine thrombin presented better interactivity with fibrinogen extracted both from human and bovine cryoprecipitates; 2) there was similar behavior when bovine thrombin was substituted for Reptilase© and for the thrombin-like fraction of Crotalus durissus terrificus venom; 3) cryoprecipitate from bovine can, in special circumstances, substitute human cryoprecipitate in medical practice; 4) human and bovine cryoprecipitates can be used with both Reptilase© and Crotalus durissus terrificus fractions using a dilution up to 1:5; 5) the use of bovine cryoprecipitate can be recomended using either bovine thrombin, Reptilase©, or thrombin-like fraction of Crotalus durissus terrificus venom.