Management of venomous snakebites in dogs and cats in Brazil

Snake envenoming is a major problem both to veterinary and human medicine in tropical countries due to high incidence, severity, and sequelae. In Brazil, most envenomings involving animals are caused by Bothrops and Crotalus snakes; these are the highest risk to animals. This study reports on Bothrops and Crotalus envenomings in dogs, the man species responsible for epidemiology, pathogenesis, venom action, clinical signs, sequelae and complications, clinical pathology, necropsy findings, diagnosis, and treatment. Veterinarians must be capable of identifying the snake not only by observing its characteristics but also symptom evolution.

The impact of multimedia on teaching tropical medicine

This study evaluated the impact of multimedia in the information transfer of subjects specific to Tropical Diseases - Tetanus and Snake Envenoming. we evaluated the autonomous learning process of 76 fourth-year medical students at Botucatu School of Medicine of UNESP, using printed matter, video, and CD-ROM. The students were submitted to a specific test, which was repeated approximately one week later. They were divided into groups and received a kit containing a textbook, a video, and a CD-ROM. These materials were used for out-of-class study. Before the second test, the students gave a seminar, where they discussed and resolved their doubts with their professor. The results of the first test showed averages between 4.27±1.41 and 6,41±1.61. The second test, given after the seminar, presented averages that increased to 8.41±0.76 and 9.52±0.42, significance alfa = 5 per cent. At the end of the course, the students answered a questionnarie, which evaluated the material quality and acquired knowledge. The students concluded that multimedia was a more efficient and quick means for knowledge building than traditional teaching materials. They said that the active participation and interactivity with the CD-ROM were the major differences. The authors continue to study the associated use of printed matter, video, and CD-ROM as a faster alternative to the traditional method of information transfer, which may be of help in the knowledge building process in medical education.

Evaluation of the impact of printed matter, video, and multimedia on the learning/teaching process in tropical diseases

This study evaluated the impact of printed matter, video, and multimedia on the learning/teaching process in Tropical Diseases. Eighty-four of 90 fourth-year medical students at Botucatu School of Medicine of UNESP were evaluated. The students received a kit containing a textbook, a video, and a CD-ROM on the Clinical Study of Tetanus to prepare a seminar on the subject. They were then asked to complete a questionnaire, which led to the following conclusions: 67.86 per cent read the textbook, 91.66 per cent watched the video, and 77.38 per cent explored the CD-ROM. These results were obtained observing the total number of students using each different media. When asked which of these media contributed most, the CD-ROM came out on top. The authors stress that this learning teaching process motivated the students by opening possibilities for new teaching alternatives in medicine.

Use of an ELISA assay to evaluate venom, antivenom, IgG and IgM human antibody levels in serum and cerebrospinal fluid from patients bitten by Crotalus durissus terrificus in Brazil

A sandwich-type ELISA technique for specific and sensitive detection of Crotalus durissus terrificus venom antigens, horse-antivenom, human IgG and IgM antibodies was set up. Sixteen patients, 13 males and 3 females aged between 13 to 63 years (mean 33 ñ 15) bitten by Crotalus durissus terrificus snakes were studied. Of the 15 patiens, 6 had previously received anti-Crotalus venom and no seric venom was detected. For the other 9 patients studied, the venom levels ranged from 2 to 108mg/ml according to the severity of each case. Seric antivenom was detected up to 44 days after the bite. IgM human antibody levels against Crotalus venom were higher between 3 and 18 days after specific treatment. IgG human antibody levels against Crotalus venom were detected between 30 and 90 days after envenoming. Venom and antivenom levels in cerebrospinal fluid were not observed 24 h after the bite. This suggests that neither the venom nor the antivenom is capable of crossing the blood-brain barrier. In addition, when either venom or the antivenom is presented to the immune system cells an immune response is prepared.

Antitumor effect of snake venoms

The search for biological antitumor agents has been pursued for over half a century. Snake venom has been shown to possess a wide spectrum of biological activities. The objectives of the present review are to evaluate the existing controversies on this subject published in a number of papers and to propose probable explanations for the phenomena observed. We reported our results obtained in a study, in which we evaluated the action of the venoms of Crotalus durissus terrificus and Bothrops jararaca on Ehrlich ascites tumor cells. We noticed an important antitumor effect, mainly with Bothrops jararaca venom, as well as an increase in the functional activity of macrophages. We also observed an increase in the number of mononuclear and polymorphonuclear cells with Bothrops jararaca venom. Considering these findings, we postulate that both Bothrops jararaca and Crotalus durissus terrificus venoms can act directly on tumor cells. In addition, we propose an indirect mechanism, based on the stimulation of the inflammatory response, to inhibit tumor growth and to promote its rejection.

Acute-phase reactions, including cytokines, in patients bitten by Bothrops and Crotalus snakes in Brazil

Thirty-one patients bitten by venomous snakes in Botucatu area (State of Säo Paulo - Brazil), sixteen by Bothrops spp. and fifteen by Crotalus durissus terrificus, were studied. The group comprised twenty-nine males and two females, ranging from fourteen to sixty-three years of age (mean 33 ñ 15.Leukocytosis with neutrophilia and lymphopenia, increase of mucoproteins and C reactive protein, decrease of total serum protein and albumin, were observed on the first day after the accident. In addition, increased serum levels of the cytokines IL-6 and IL-8, but not of IL-1 beta and TNF-alpha, were observed. The alterations were generally more intense in patients bitten by Crotalus durissus terrificus than by Bothrops spp. It is concluded that these snakebite envenomations closely resemble an acute trauma, inducing a typical acute-phase response.

Human envenomations due to snakebites in Marilia, State of Säo Paulo, Brazil. A retrospective epidemiological study

Eighty-four patients bitten by venomous snakes were studied retrospectively at the School of Medicine of Marília from January 1990 to August 1994. The majority of these patients were rural workers, 65 (77.38 per cent] males and 19 (22.62 per cent) females, aged eight to seventy-five. Forty-three (51.19 per cent) patients were diagnosed as having been bitten by snakes of the genus Bothrops and 41 (48.81 per cent) by Crotalus. Fifty-eight patients (69.04 per cent ) were bitten in the legs and 26 (30.96 per cent ) in the arms. January, March, April and November were the months of higher incidence of bothropic envenomations, while crotalic envenomations were not recorded only in August and September. This study showed that the prevalence of crotalic envenomations in Marília was higher than that of any other regions in Brazil. Further prospective epidemiological studies are needed for a better understanding of these findings.