Scielo RSS <![CDATA[Journal of Venomous Animals and Toxins]]> vol. 5 num. 2 lang. en <![CDATA[SciELO Logo]]> <![CDATA[<B>CEVAP’S NEW POST-GRADUATION TEACHING CONCEPTS IN TOXINOLOGY</B>]]> <![CDATA[<B>THE IMPROVEMENT AND STANDARDIZATION OF ANTIVENOM PRODUCTION IN DEVELOPING COUNTRIES</B>: <B>COMPARING ANTIVENOM QUALITY, THERAPEUTICAL EFFICIENCY, AND COST</B>]]> The first antivenom was prepared by Calmette in 1894. More than a century later, it is still the only specific treatment for envenoming. The methods currently used by almost all antivenom producers worldwide to isolate and concentrate antivenom antibodies and their enzymatically derived fragments are improvements of those originally developed by Pope in 1938. Several new alternatives have been proposed to produce F(ab')2 or Fab antivenoms to improve their purity, neutralizing potency, and safety and to overcome the problems encountered in the production protocols based on ammonium sulfate precipitation of equine immunoglobulin. These include complete or partial modifications in the antivenom production regarding animal producers (ovine, laying hens...), immunization protocols, crude serum preparation and/or purification procedures concerning antibody extraction (PEG, caprylic acid, ion-exchange chromatography or immunoaffinity chromatography), and cleavage conditions (pepsin, papain...). In Tunisia, antivenom has been produced since the 1950's. Constant improvements and standardization of all the steps involved in antivenom production, purification, and quality control have resulted in a pure, safe, and efficient F(ab')2 product with no side effects when used intravenously, and with a high seroneutralization yield, as a result of the high toxin specific F(ab')2 concentration. The real impact of the new or modified procedures is a substantial increase in the cost of an antivenom dose. The quality is similar to that of the old procedure when its production was accurately standardized, optimized, correctly conducted and controlled. In addition, severe side effects have been reported after application of either equine F(ab')2 or ovine Fab antivenoms purified by the new methods (i.e. ion-exchange chromatography and immunoaffinity chromatography). Consequently, the introduction of these methods in developing countries still needs justification. <![CDATA[<B>EVALUATION OF THE INTRADERMAL SENSITIVITY TEST IN PATIENTS SUBMITTED TO HETEROLOGOUS SEROTHERAPY</B>]]> This review deals with heterologous sera produced and used in Brazil. The authors studied 64 patients. Of these, 35 had been attacked by domestic and wild animals and received antirabies serum; 20 had been bitten by venomous animals (snakes and scorpions) and were treated with specific antivenoms; and 9 had traumas and received antitetanic serum All these patients were submitted to the intradermal sensitivity test before, and 30 days after reveiving heterologous serotherapy. The following results obtained by the authors agree with those in literature: - The intradermal test using undiluted heterologous serum produced a more acute reaction than that using heterologous serum diluted 1:10; - The larger the volume of serum, the larger was the wheal directly after inoculation; - The antigenic concentration influenced the final local reaction; - The reading 30 minutes after inoculation was always higher than that 15 min after; - No systemic reaction was observed during the tests; - The use of promethazine as a prophylactic medication did not protect against the early reactions; - Tests performed 30 days after serotherapy showed a higher reactivity, probably due to sensitization; - The intradermal sensitivity test did not allow the authors to predict early reactions. After these observations, the authors do not recommend the intradermal sensitivity test for patients submitted to heterologous serotherapy. They, however, strongly recommend a careful observation during the infusion and clinical follow up in the first 24 hours. <![CDATA[<B>THE USE OF SEROTHERAPHY TO REVERSE ECG and CARDIAC ENZYME CHANGES CAUSED BY SCORPION <I>Mesobuthus tamulus concanesis</I>, Pocock ENVENOMING</B>]]> Acute myocardiopathy in experimental dogs and rabbits was induced by subcutaneous (SQ) injection of 3.5 mg/kg of scorpion venom from Mesobuthus tamulus concanesis, Pocock. An increase in circulating lactic dehydrogenase (LDH), serum glutamic oxalacetic transaminase (SGOT), creatine kinase-MB isoenzyme (CK-MB), serum glutamine pyrovate transaminase (SGPT) and alpha hydroxy butyrate dehydrogenase (HBDH) enzyme levels was observed in dogs 60 min after venom injection, and a further rise was observed 120 min after venom injection. The administration of the species-specific scorpion antivenom (SAV) at different time intervals after venom injection resulted in reversal of electrocardiographic changes and a reduction in cardiac enzyme levels. The administration of SAV to scorpion envenomed alloxan-pretreated animals did not cause clinical or biochemical improvement. On the other hand, administering insulin to envenomed only animals or envenomed alloxan-pretreated animals resulted in a biochemical and clinical improvement, as well as in a reduction of the cardiac enzyme levels. Insulin administration in scorpion envenoming syndrome is essentially a metabolic support to control the adverse effects triggered by catecholamines and other counter-regulatory hormones. <![CDATA[<B>NOVEL SNAKE VENOM PROTEINS CYTOLYTIC TO CANCER CELLS <I>IN VITRO</I> AND <I>IN VIVO</I> SYSTEMS</B>]]> Cancer cell inhibitors, named Atroporin and Kaotree, having molecular weights of 35 kDa and 6 kDa have been isolated from the venoms of Crotalus atrox and Naja naja kaouthia, respectively, by fractionation on high pressure liquid chromatography. The purified Atroporin and Kaotree showed killing effects on various types of human (breast, colon, liver, ovary, etc.) and animal cancer cells in concentrations as low as 0.5µg/ml, and having no effect on normal mouse kidney, liver, spleen, and erythrocytes up to 5.0µg/ml. Both Atroporin and Kaotree prevent the formation of ascitic tumors caused by myeloma cells in Balb/C mice. In addition, both Atroporin and Kaotree showed regression of ascitic tumors formed by myeloma cells. Atroporin and Kaotree complement each other, as in combination they showed elevated anti-cancer activity in vitro and in vivo systems. However, Atroporin and Kaotree are immunologically distinct proteins showing no cross reactivity. Atroporin and Kaotree, individually or in combination, have the potential for cancer biotherapy. <![CDATA[<B>PURIFICATION AND CHARACTERIZATION OF TOXINS FROM WHEAT ISOLATES OF <I>Drechslera tritici-repentis, Bipolaris bicolor, </I>AND<I> Bipolaris sorokiniana</B></I>]]> Low molecular weight metabolites produced by Bipolaris bicolor, Bipolaris sorokiniana, and Drechslera tritici-repentis are considered to be toxins that facilitate disease in wheat cultivars. Several such toxins were isolated from these fungi. Electrophoresis demonstrated bands of proteins that reduced shoot inhibition in susceptible plants but not in resistant plants. Chlorophyll content was reduced during the first 10 hours of light in the susceptible plants and after 18 hours in the resistant plants. The enzyme beta-1,3-glucanase increased in the resistant plants after treatment with toxins, but in the susceptible plants this enzyme decreased compared to the control. This suggests that the toxin was a protein and the susceptible plants needed other mechanisms for induced resistance. <![CDATA[<B>INSULIN ADMINISTRATION IN SEVERE SCORPION ENVENOMING</B>]]> The efficacy of insulin-glucose infusion in reversing myocardial damage, haemodynamic changes, peripheral circulatory failure, and pulmonary oedema was evaluated in 25 victims of venomous scorpion stings from the Rayalaseema region in the south of India. Myocardial damage with peripheral circulatory failure was seen in all scorpion sting victims. Ten of these victims also had pulmonary oedema. All the patients received continuous infusion of regular crystalline insulin at the rate of 0.3 U/g of glucose and glucose at the rate of 0.1 g/kg/h with supplementary potassium as needed, inotropic agents, oxygen, as well as maintenance of fluid, electrolytes and acid-base balance. Insulin-glucose infusion was associated with reversal of cardiovascular and haemodynamic changes, and pulmonary oedema in 24 of the 25 victims. One severely envenomed victim admitted 72 hours after the sting died. The scorpion envenoming syndrome with myocardial damage, cardiovascular disturbances, peripheral circulatory failure, pulmonary oedema, and many other clinical manifestations may cause multi-system organ failure (MSOF). It is characterised by a massive release of catecholamines, angiotensin II, glucagon, cortisol, and inhibition of insulin secretion. Under these altered conditions in the hormonal milieu, scorpion envenoming essentially results in a syndrome of fuel-energy deficits and an inability to use the existing metabolic substrates by vital organs, causing MSOF and death. Administration of insulin-glucose infusion to scorpion sting victims appears to be the physiological basis for the control of the metabolic response when that has become a determinant to survival. <![CDATA[<B>A HOLDING DEVICE FOR LIVE SPIDERS</B>]]> This paper describes a new restraining device for live spiders. This device is recommended for reducing or eliminating contact between the handler and potentially dangerous spiders, as well as to avoid serious injury to the specimens. <![CDATA[<B>THE ISOLATION AND CHARACTERIZATION OF THREE BASIC PROTEINASES IN THE VENOM OF <I>Bothrops moojeni</B></I>]]> This paper describes a new restraining device for live spiders. This device is recommended for reducing or eliminating contact between the handler and potentially dangerous spiders, as well as to avoid serious injury to the specimens. <![CDATA[<B>THE ISOLATION AND STRUCTURAL AND FUNCTIONAL CHARACTERIZATION OF SERINE PROTEINASES IN THE VENOM OF <I>Bothrops jararaca</B></I>]]> This paper describes a new restraining device for live spiders. This device is recommended for reducing or eliminating contact between the handler and potentially dangerous spiders, as well as to avoid serious injury to the specimens. <![CDATA[<B>THE USE OF FIBRIN ADHESIVE DERIVED FROM SNAKE VENOM AND THE EVALUATION OF SKIN GRAFTING USING SKIN FROM THE PATIENT’S NASOLABIAL FOLD</B>]]> This paper describes a new restraining device for live spiders. This device is recommended for reducing or eliminating contact between the handler and potentially dangerous spiders, as well as to avoid serious injury to the specimens.