Abstract in English:In Venezuela, the restricted manner of works on scorpion envenoming has contributed little to the real magnitude and knowledge of this subject in our country. The lack of basic scorpiofauna knowledge, distribution, clinical manifestations, and especially of specific treatments justify multidisciplinary studies. The purpose of these studies is to obtain information that allows the elaboration of a preventive plan. This paper demonstrates the magnitude of scorpion envenomings in Venezuela.
Abstract in English:Scorpion envenoming is a public health concern in northeastern Venezuela. Specimens of the genus Tityus are responsible for most of these. In experimental animals, Tityus venom produces histopathological changes in the skeletal muscle and pancreas, but its toxicity to the reproductive system has not been studied. The aim of this work is to describe the histopathological changes in testis and epididymis of albino mice induced by the administration of Tityus n. sp. venom. Sub-lethal doses of venom (3.75 mg/g mouse) were administered intramuscularly (IM) daily for 4 days. On the fifth day, the animals were sacrificed and the testes and epididymes were quickly removed and processed for light microscopy. The venom induced alterations in spermatogenesis. Sertoli cell vacuolation, immature germ cell shedding, spermatocyte arrest, and low sperm volume were observed in seminiferous tubules. Leydig cells were hardly affected. Vascular dilation and congestion were detected in the interstitial tissue. Immature germ cells were found in epididymal tubule lumina, but no abnormalities were observed in epididymal epithelial cells. These results show that Tityus n. sp. venom causes changes in mouse seminiferous epithelium, probably due to indirect action through the Sertoli cell.
Abstract in English:The objective of this study was to evaluate the efficacy of fibrin adhesive made up of snake venom and bubaline fibrinogen by rat colon anastomosis. Eighty rats were randomly assigned into 2 experimental groups: GI control (anastomosis with extramucous interrupted suture) and GII (repair suture + fibrin glue). The animals were studied at the following 4 times: T0 – preoperative, T1 – 7th day postoperative, T2 – 14th day postoperative, and T3 – 21 st day postoperative. The macroscopic characteristics of the intestinal segment open and closed anastomosis and the bursting strength of the anastomosed segments were observed at each of the above times. The results showed that the anastomosed segments coapted and there was no difference in the bursting strength values between the 2 groups. There was a decrease in the bursting strength values up until the 7 th day postoperative in both groups with its progressive increase at the other times. Although important experimental studies using large animals are needed for a better evaluation of tissue repair processes, this adhesive may become a valuable tool for use in anastomosis.
Abstract in English:Blood samples of 50 healthy specimens from each of the following species: Bothrops alternatus, Bothrops jararacussu, Bothrops moojeni, and Bothrops neuwiedi diporus all kept in captivity were taken to determine the hematocrit (PCV) value, red blood cell count (RBC), total leukocyte (WBC) and differential leukocyte count, thrombocyte count, mean corpuscular volume (MCV), hemoglobin concentration (HbC), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). These hematological parameters were compared to those obtained from other Bothrops species. PCV values, RBC, hemoglobin, WBC count, and differential leukocyte count are within the range of values reported for other Bothrops species, while the thrombocyte count was significantly lower. All the hematological parameters obtained from the four studied Bothrops species were higher than those described for B. ammodytoides.
Abstract in English:Propolis has been the subject of several recent studies, with the aim of elucidating its biological and pharmacological properties. Propolis has a well-known antimicrobial activity as well as antioxidant, antitumoral, antiinflammatory, and regenerative properties, but literature about its effects on the immune response is scarce. The goal of this work was to evaluate the propolis effect on macrophage activation by oxygen (H2O2) and nitrogen (NO) metabolite determination. Propolis was produced by africanized honeybees and hydroalcoholic solutions were prepared at different concentrations. Peritoneal macrophages were obtained from male BALB/c mice and culture cells were stimulated in vitro with propolis or interferon-gamma (IFN-gamma). In the in vivo assay, the animals were sacrificed after propolis treatment and cells were stimulated with IFN-gamma. We also investigated the co-stimulant action of propolis associated with IFN-gamma on macrophages. The results show that propolis induces a discreet elevation in H2O2 release and a mild inhibition of NO generation, depending on concentration. Propolis had no co-stimulant activity, diminishing IFN-gamma action on H2O2 and NO production. Data suggest that propolis acts on host non-specific immunity by macrophage activation.
Abstract in English:Fibrin glue has been used on its own or in conjunction with suturing materials to promote hemostasis, reduce adherence, strengthen the wound site, and improve healing. Snake venom derived fibrin glue was evaluated as an alternative to conventional uterine suturing after ovine caesarean surgery. Twenty-eight pregnant ewes of known mating date were used. The animals submitted to conventional caesarean sections showed a better wound healing process. As expected, all the operated animals had retained placenta, compromising coaptation of wound edges. This had a strong influence in the results observed with the animals in which fibrin glue was used. The animals were divided into four groups GI, GII, GIII, and GIV and sacrificed, respectively, 3, 7, 15, and 30 days after surgery for macro and microscopic examination of the uterus. From each group, six animals underwent surgery using fibrin glue and four animals were submitted to comparative conventional hysterorrhaphy using catgut.
Abstract in English:It has been previously shown that the crude venom of Tityus serrulatus can cause convulsions. This study was designed to investigate the neurotoxic effects of B, C, G, and K fractions isolated from this venom. Intravenous injection of these fractions in mice (0.6 - 6.0 mg/kg body weight) showed that the C fraction is a potent convulsant and G fraction decreased the threshold for tonic hand limb extension elicited by transauricular electroshock. Unilateral injection of B, C, and K fractions, but not G fraction, into the hippocampus of rats (0.6 - 6.0 µg) caused electroencephalographic alterations consisting of spikes and epileptic discharges that began in the hippocampus and evolved to the cortex. The following motor signs were observed: movements of facial muscles, wet dog shake, immobility, myoclonus, wild-running with clonus, and in some cases, loss of postural control. Intrahippocampal injection of B, C, and K fraction, but not G fraction, caused neuronal loss at the injection site as well as in other hippocampal areas. The effect of these fractions on epileptiform activity and on neuronal loss was dose-dependent. The severity of the epileptiform activity in the ipsilateral hippocampus correlated with the severity of the neuronal loss. The electrographic, behavioral, and histological changes induced by B, C, and K fractions were similar to those obtained with other drugs that are commonly used to induce convulsion. The convulsant effects of the crude venom may be caused by the fractions studied in this work.
Abstract in English:In Costa Rica, approximately 700 snakebite cases occur each year, 5 to 10 of which result in death. At the Hospital Nacional de Niños (HNN), 6 to 10 cases are reported annually, more than half of these cases and nearly all deaths are result from Bothrops asper snakebite. This venomous snake, popularly known as the "terciopelo", most often attacks the lower or upper limbs and characteristically produces local tissue damage, which can be severe. The following is a report of the first case of a non-fatal and unusual facial bite caused by Bothrops asper in our country.
Abstract in English:The photodynamic action of UV sensitized methylene blue (MB) was studied on the venom of Thailand cobra Naja siamensis. The reaction mixture comprising phosphate buffer (B), methylene blue (S), and venom protein (P) was exposed to UVR (ultra violet radiation) for 2 hours at 37°C. Stable excited species (S’) were generated by photodynamic action. These in B environment produced reduced substates SH2 and photooxidised products PO in the presence of atmospheric oxygen. Increased absorbance (OD) of the reaction mixture after UVR with a corresponding loss of protein was suggested to be due to the formation of photooxidised venom products. The detoxification profile of venom protein using visible radiation in the presence of MB and oxygen appeared similar to the profile using UVR.