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Objectives: The Brazilian Ministry of Health reports about 20,000 accidents per year caused by venomous snakes, mainly by the genus Bothrops (90.5%). Despite this high frequency, few studies have reported the clinical aspects of venomous snakebites in children in Brazil. This study evaluated the clinical aspects and outcome of bites caused by Bothrops spp snakes in children less than 14 years old. Case Series: From January 1984 to March 1999, 73 children (ages 1 y-14 y, median 9 y) were admitted after being bitten by Bothrops spp. The severity of envenoming was classified according to the recommendations of the Brazilian Ministry of Health. Upon hospital admission, 26.0% patients were classified as mild envenoming, 50.7% as moderate envenoming and 20.6% as severe envenoming. Two patients (2.7%) showed no signs of envenoming (dry bites). Most of the patients presented local manifestations, mainly indurated edema (95.9%), pain (94.5%), ecchymosis (74.0%) and local bleeding (21.9%). Systemic bleeding was observed in 9 patients, mainly gingival (9.6%). Before antivenom (AV) administration, blood coagulation disorders were observed in 62.5% (incoagulable blood in 39.3%) of the 56 children that received AV only in our hospital (mild accidents, median = 4 vials; moderate accidents, median = 7 vials; severe accidents, median = 10 vials; 1 vial = 10 mL of [Fab'.sub.2]). AV early reaction was observed in 44.6% of the cases (15/30 patients not pretreated and in 10/26 patients pretreated with hydrocortisone and histamine antagonists H1 and H2), most of which were considered mild. Only one patient presented an acute severe early reaction. More than 76% of these 56 children received AV less than 6 h after the bite. The main clinical complications observed were local infections (15.1%) (including cellulitis, 9.6%, and abscesses, 5.5%), compartment syndrome (4.1%), gangrene (1.4%) and acute renal failure (1.4%). There were no significant differences with regard to severity of envenoming and the frequency of blood coagulation disorders among the three categories of envenoming (p = 0.75), or in the frequency of early AV reactions between the groups that were and were not pretreated (p = 0.55). The frequency of local infections was significantly greater in severe cases (p = 0.001, RR = 6.53, OR = 11.38). Patients admitted more than 6 h after the bite had a higher risk of developing severe envenomation (p = 0.04, RR = 1.65, OR = 4.75). No deaths were observed. Conclusion: The prognosis can be very good as long as the children receive prompt medical care, including adequate AV prescription, fluid replacement to avoid renal ischemia, and correct treatment of the main complications., Bucaretchi F, Herrera SRF, Hyslop S, Baracat ECE, Vieira RJ. Deptos de Pediatria, Clinica Medica e Farmacologia, Centro de Controle de Intoxicacoes, Faculdade de Ciencias Medicas, Hospital de Clinicas, Universidade [...]

A phosphodiesterase was purified from the venom of the snake Bothrops alternatusby a combination of gel filtration and ion exchange chromatographies. In SDS-PAGE, the enzyme gave a single band with a molecular mass of 105 kDa, which was unaltered in the presence of β-mercaptoethanol, indicating that the protein contained no subunits. A single protein band was also observed in native PAGE. There were no contaminating 59-nucleotidase, alkaline phosphatase and protease activities. The enzyme was recognized by commercial bothropic antiserum and gave a single band in immunoblotting. The enzyme had a pH optimum in the range of 7.5–9.5 and the optimum temperature was 60°C, with activity being rapidly lost within 1 min at ≥70°C. The Kmof the enzyme was 2.69 mM. PDE activity was potentiated by cobalt and, to a lesser extent, by calcium, whereas copper, manganese, zinc, EDTA, and β-mercaptoethanol were inhibitory. These properties show that this enzyme is very similar to that isolated from other snake venoms.

A crotoxin homolog was purified from the Crotalus durissus collilineatusvenom using molecular exclusion and reverse-phase HPLC. This crotoxin contained one PLA2(Cdcolli III F6) and four crotapotin isoforms, whereas crotoxin from Crotalus durissus terrificusvenom had three PLA2isoforms and two crotapotin isoforms. SDS-PAGE showed that the C. d. collilineatusPLA2and crotapotin had relative molecular mass of 15 and 9 kDa, respectively. Neither the PLA2(Cdcolli III F6) nor the crotapotins (Cdcolli III F3 and F4) had any neurotoxicity in mouse phrenic nerve-diaphragm preparations when tested alone. However, when PLA2and crotapotin were coincubated before testing, the neurotoxicity was restored to a level similar to test in the venom in native crotoxin. The two crotapotins (Cdcolli III F3 and F4) differed in their ability to inhibit PLA2activity, perhaps because of variations in their affinities for this enzyme. Cdcolli III F6 showed allosteric enzymatic behavior, with maximal activity at pH 8.3 and 36°C. Full PLA2activity required the presence of a low Ca2+concentration and was inhibited by Cu2+and Zn2+and by Cu2+and Mg2+in the presence and absence of Ca2+, respectively. These results indicate that crotoxin from C. d. collineatusvenom is very similar enzymatically to crotoxin from C. d. terrificus.