Resultado da pesquisa (2)
Termo utilizado na pesquisa Bothrops alternatus
#1 - Hemostatic evaluation of rabbits envenomed with Bothrops alternatus treated with anti-bothropic serum, desmopressin and tranexamin acid
Abstract in English:
In Brazil, snakes from the Bothrops genus are responsible for thousands of accidents, and their venoms are mainly composed of proteolytic enzymes. Although the antibothropic serum produced by the Brazilian Institutes is remarkably efficient, more studies are necessary, especially in veterinary medicine. The venom contain enzymes and non-enzymatic proteins that interfere with hemostasis leading to hemorrhage or even thrombosis. Possible treatment associations with known bothropic antivenom were the reason for the development of the present study. The aim of this study was to evaluate hemostasis alterations caused by Bothrops alternatus venom in rabbits followed by treatments with anti-bothropic serum, tranexamic acid and desmopressin. Twenty New Zealand rabbits were distributed into five groups (n=4) that were experimentally envenomed with 150mcg/kg of B. alternatus venom via intramuscular injection and treated as follow: Group 1 (G1) was the positive control and received venom and PBS/BSA; Group 2 (G2) was treated with tranexamic acid; Group 3 (G3) with desmopressin; Group 4 (G4) with tranexamic acid and anti-bothropic serum; and Group 5 (G5) with anti-bothropic serum and desmopressin. Blood samples were collected before venom administration, and one, four, eight and 12 hours after, for Partial activated partial thromboplastin time, Prothrombin Time, Thrombin Time and fibrinogen evaluation. Thrombin generation (TG) test was carried out with a pool of samples from final times (8 and 12h). At the end of 12h, all animals were euthanized and necropsy was conducted. Samples from muscle tissue, heart, lungs and kidney were analyzed. Classic coagulation tests showed no significant differences amongst groups and times. However, TG indicated that the venom causes a hypocoagulability state, which was not reversed by proposed treatments. Histology showed muscle inflammation, hemorrhage and necrosis, as well as hemorrhage in other tissues with no differences amongst groups. B. alternatus envenomation causes hypocoagulability detected by TG assay, but not through classical coagulation tests. The use of tranexamic acid and desmopressin for hemostasis stabilization after inoculation of the venom did not show advantage in coagulation restoration.
Abstract in Portuguese:
No Brasil, as serpentes do gênero Bothrops são responsáveis por milhares de acidentes, e seus venenos são compostos principalmente de enzimas proteolíticas. Embora o soro antiofídico produzido pelos institutos brasileiros seja notavelmente eficiente, mais estudos são necessários, especialmente na medicina veterinária. O veneno contem enzimas e proteínas não-enzimáticas que interferem com a hemostasia levando a hemorragias ou trombose. A associação de outros tratamentos ao soro antibotrópico foi a razão para o desenvolvimento do presente estudo. O objetivo deste estudo foi avaliar as alterações da hemostasia causadas pelo veneno de Bothrops alternatus em coelhos, após tratamento com soro antibotrópico, ácido tranexâmico e desmopressina. Vinte coelhos da Nova Zelândia foram distribuídos em cinco grupos (n = 4) que foram submetidos a experimentos com 150mcg/kg de veneno de B. alternatus por injeção intramuscular. O Grupo 1 (G1) foi o controle positivo e recebeu veneno e PBS / BSA, enquanto o Grupo 2 (G2) foi tratado com ácido tranexâmico, o Grupo 3 (G3) com desmopressina, o Grupo 4 (G4) com ácido tranexâmico e soro antibotrópico, e o Grupo 5 (G5) com soro antibotrópico e desmopressina. As amostras de sangue foram coletadas antes da administração do veneno, e uma, quatro, oito e 12 horas após os tratamentos para realização de tempo de tromboplastina parcial ativada parcial (TTPa), tempo de protrombina (TP), tempo de trombina (TT) e mensuração de fibrinogênio. Para o ensaio de geração de trombina (TG) foi realizado com um pool de amostras nos tempos finais (8 e 12h). Ao final das 12h, todos os animais foram sacrificados e a necropsia foi realizada. Amostras de tecido muscular, coração, pulmões e rins foram analisadas. Os testes TTPa, TP, TT e fibrinogênio não mostraram diferenças significativas entre os grupos e os tempos. No entanto, o TG indicou que o veneno causa um estado de hipocoagulabilidade, que não foi revertido pelos tratamentos propostos. Na histologia, foram observadas inflamação muscular, hemorragia e necrose, além de hemorragia em outros tecidos, sem diferenças entre os grupos. O envenenamento por B. alternatus causa hipocoagulabilidade detectada mais precocemente pelo teste de geração de trombina. O uso de ácido tranexâmico e desmopressina para estabilização da hemostasia após a inoculação do veneno não mostrou vantagem na restauração da coagulação.
#2 - Aspectos clínico-patológicos e laboratoriais do envenenamento experimental por Bothrops alternatus em bovinos, p.303-313
Abstract in English:
ABSTRACT.- Caldas S.A., Tokarnia C.H., França T.N., Brito M.F., Graça F.A.S., Coelho C.D. & Peixoto P.V. 2008. [Clinic and pathological and laboratory aspects of experimental poisoning by Bothrops alternatus venom in cattle.] Aspectos clínico-patológicos e laboratoriais do envenenamento experimental por Bothrops alternatus em bovinos. Pesquisa Veterinária Brasileira 28(6):303-312. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: saulo-andrade@bol.com.br
The aim of this study was to determine the clinical-pathological alterations and laboratory findings in cattle inoculated with Bothrops alternatus venom, with the intention of providing information for the establishment of diagnosis and differential diagnosis procedures, as well as to elucidate some obscurities observed in the pertinent literature. The lyophilized venom was diluted in 1 ml of physiologic solution. It was administered to 5 bovines by the subcutaneous route at doses of 0.0625, 0.125 and 0.25mg/kg body weight, and to 2 bovines by the intramuscular route at doses of 0.25 e 0.45mg/kg. Six bovines died and the only animal that survived, who had subcutaneously received the venom at a dose of 0.0625mg/kg, recovered. The first clinical signs were observed from 25min to 5h30min after the inoculation. The clinical evolution time varied from 7 hours 18 minutes to 92 hours. Regardless of the dose, the clinical picture was characterized by swelling (hemorrhage/hematoma) at the site of inoculation, increase in bleeding time and capillary refill time, paleness of mucous membranes and apathy. The laboratory exams revealed progressive normocytic normochromic anemia, thrombocytopenia, reduction in fibrinogen and total plasma proteins, decreased hematocrit and hemoglobin, and slight increase in creatine kinase and lactate dehydrogenase. When subjected to necropsy, the animals that received the venom through the subcutaneous route showed large hematomas and hemorrhagic areas in the subcutaneous tissue, extending from the site of inoculation. The animals in which inoculation was performed intramuscularly exhibited, in addition, intramuscular hemorrhage. The left endocardium showed extensive hemorrhagic lesions, and petechiae were found on the serosae of rumen, omasum, abomasum and gall bladder. The colon, rectum and perirenal areas were surrounded by clotted blood in three animals. Besides hemorrhage, the histological examination revealed hemorrhage and coagulative muscle necrosis in the vicinities of the inoculation site in the animals that received the venom by the intramuscular route. These lesions were mild in the muscles close to the site of inoculation in the animals inoculated by the subcutaneous route. The swelling on the site of inoculation and its surroundings was a consequence of blood accumulation and not merely edema. Myoglobinuria and gross or microscopic lesions were not observed in the kidneys. This study indicates that B. alternatus can lead adult bovines to death if they release all their venom during a bite. Conversely, since venomous ophidians can control the amount of poison they inoculate and they probably do not identify bovines as potential preys, it is likely that the number of accidents involving this species is small, which is in agreement with the findings of the majority of the centers for anatomical-pathological diagnosis in Brazil.
Abstract in Portuguese:
ABSTRACT.- Caldas S.A., Tokarnia C.H., França T.N., Brito M.F., Graça F.A.S., Coelho C.D. & Peixoto P.V. 2008. [Clinic and pathological and laboratory aspects of experimental poisoning by Bothrops alternatus venom in cattle.] Aspectos clínico-patológicos e laboratoriais do envenenamento experimental por Bothrops alternatus em bovinos. Pesquisa Veterinária Brasileira 28(6):303-312. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: saulo-andrade@bol.com.br
The aim of this study was to determine the clinical-pathological alterations and laboratory findings in cattle inoculated with Bothrops alternatus venom, with the intention of providing information for the establishment of diagnosis and differential diagnosis procedures, as well as to elucidate some obscurities observed in the pertinent literature. The lyophilized venom was diluted in 1 ml of physiologic solution. It was administered to 5 bovines by the subcutaneous route at doses of 0.0625, 0.125 and 0.25mg/kg body weight, and to 2 bovines by the intramuscular route at doses of 0.25 e 0.45mg/kg. Six bovines died and the only animal that survived, who had subcutaneously received the venom at a dose of 0.0625mg/kg, recovered. The first clinical signs were observed from 25min to 5h30min after the inoculation. The clinical evolution time varied from 7 hours 18 minutes to 92 hours. Regardless of the dose, the clinical picture was characterized by swelling (hemorrhage/hematoma) at the site of inoculation, increase in bleeding time and capillary refill time, paleness of mucous membranes and apathy. The laboratory exams revealed progressive normocytic normochromic anemia, thrombocytopenia, reduction in fibrinogen and total plasma proteins, decreased hematocrit and hemoglobin, and slight increase in creatine kinase and lactate dehydrogenase. When subjected to necropsy, the animals that received the venom through the subcutaneous route showed large hematomas and hemorrhagic areas in the subcutaneous tissue, extending from the site of inoculation. The animals in which inoculation was performed intramuscularly exhibited, in addition, intramuscular hemorrhage. The left endocardium showed extensive hemorrhagic lesions, and petechiae were found on the serosae of rumen, omasum, abomasum and gall bladder. The colon, rectum and perirenal areas were surrounded by clotted blood in three animals. Besides hemorrhage, the histological examination revealed hemorrhage and coagulative muscle necrosis in the vicinities of the inoculation site in the animals that received the venom by the intramuscular route. These lesions were mild in the muscles close to the site of inoculation in the animals inoculated by the subcutaneous route. The swelling on the site of inoculation and its surroundings was a consequence of blood accumulation and not merely edema. Myoglobinuria and gross or microscopic lesions were not observed in the kidneys. This study indicates that B. alternatus can lead adult bovines to death if they release all their venom during a bite. Conversely, since venomous ophidians can control the amount of poison they inoculate and they probably do not identify bovines as potential preys, it is likely that the number of accidents involving this species is small, which is in agreement with the findings of the majority of the centers for anatomical-pathological diagnosis in Brazil.
