Venom phospholipases of Russell's vipers from Myanmar and eastern India--cloning, characterization and phylogeographic analysis.

Venoms of Russell's vipers (genus Daboia) are known for their deadly coagulopathic and other effects. We herein studied various isoforms of venom phospholipases A(2) (PLAs) from two Daboia species at their geographic boundary. From Myanmar Daboia siamensis venom (designated as DsM), four PLAs (designated DsM-aI, aI', aII' and bI') were purified, and the cDNAs encoding two acidic (DsM-aI and aII) and two basic PLAs (DsM-bI and S1) were also cloned from its venom-glands.

Biochemical and biological properties of the venom from Russell's viper (Daboia russelli siamensis) of varying ages.

Russell's viper (Daboia russelli siamensis) venoms of four different lengths (21-25 cm, 40-60 cm, 81-90 cm and 101-110 cm) were studied by SDS-PAGE electrophoresis and immunoblotting. Studies on biological and biochemical properties of the venom were also carried out. The venom of young snakes (21-60 cm) had a high lethal potency and possessed powerful coagulant and defibrinogenating activities compared to adults (101-110 cm).

Local compression pads as a first-aid measure for victims of bites by Russell's viper (Daboia russelii siamensis) in Myanmar.

A prospective study of the efficacy of applying local pressure by compression pads in retarding spread of venom was carried out on 15 cases of bite by Russell's viper (Daboia russelii siamensis) in Myanmar. A firm rubber pad was applied with cotton bandaging over the site of bite and the limb was immobilized with a splint. Serial monitoring of venom levels by enzyme immunoassay (EIA) was carried out at 15 min intervals for 1h (2h in one case) while the pad was in place and at 15 and 30 min after its removal.

King cobra (Ophiophagus hannah) bites in Myanmar: venom antigen levels and development of venom antibodies.

Venom, venom IgG and IgM antibody and total serum IgG levels following king cobra bites in two reptile handlers were measured by enzyme immunoassay. The patient in case 1 received antivenom while the patient in case 2 did not. Case 1 made a complete recovery following the bite and produced a high titre short-lived antibody.

Humoral response following Russell's viper (Daboia russelli siamensis) bites in Myanmar.

A prospective study of the development, intensity and protective ability of the antibody response to Russell's viper bite and its relation to the severity of envenoming was carried out in 15 patients 3 to 116 weeks after the bites using enzyme immunoassay. Retrospective screening in 123 cases revealed antibody in 112/123 (91%) which could be detected from 1 week to 15 years after the bite. A slow peaking (30 weeks) and waning of antibody response was observed in the majority of cases.

The efficacy of compression immobilization technique in retarding spread of radio-labeled Russell's viper venom in rhesus monkeys and 'mock venom' NaI131 in human volunteers.

The efficacy of the modified compression immobilization technique in retarding spread of radio-labeled Russell's viper venom in 3 rhesus monkeys (Macaca mulata) and "mock venom" NaI131 in 14 human volunteers was studied. 0.1 microgram of Russell's viper venom having 10 microCi radioactivity in 0.

Renal ischaemia, transient glomerular leak and acute renal tubular damage in patients envenomed by Russell's vipers (Daboia russelii siamensis) in Myanmar.

Fifty-two patients who had been bitten by Russell's vipers in Myanmar developed acute renal failure (serum creatinine exceeding 1.3 mg/dL). Thirty-four of them (65%) became oliguric, but the other 18 (35%) maintained a urine output of more than 400 mL/24 h.

Heparin therapy in Russell's viper bite victims with disseminated intravascular coagulation: a controlled trial.

A controlled clinical trial of low dose heparin was carried out in confirmed cases of Russell's viper bite. Twenty patients with systemic envenoming were included in the study. They were randomized to receive low dose heparin in an initial dose of 50 units/kg body weight intravenously immediately after antivenom followed by a continuous infusion of 10 unit 3 kg/hour in isotonic saline for 24 hours, or antivenom alone.

Bites by Russell's vipers (Daboia russelii siamensis) in Myanmar: effect of the snake's length and recent feeding on venom antigenaemia and severity of envenoming.

An improved enzyme immunoassay technique (EIA) was used in the diagnosis of 311 suspected Russell's viper bite cases in Myanmar [Burma], 181 of whom (58%) had systemic envenoming. Russell's viper venom was detected in the sera of 175 (56.3%), cobra or green pit viper venoms in 4 (1.

Bites by the king cobra (Ophiophagus hannah) in Myanmar: successful treatment of severe neurotoxic envenoming.

Three patients bitten by the world's largest species of venomous snake, the king cobra (Ophiophagus hannah), were observed in Myanmar (Burma). All three were involved in the famous snake dance in Yangon (Rangoon) Zoological Gardens. One patient showed no signs of envenoming despite a sustained bite, another developed only signs of local envenoming, but in a third there was severe neurotoxic envenoming requiring mechanical ventilation for 64 1/2 hours, episodes of hypotension and massive swelling of the bitten limb.

Heparin therapy in Russell's viper bite victims with impending dic (a controlled trial).

A controlled clinical trial of low-dose heparin was carried out in confirmed cases of Russell's viper bite. Twenty-eight patients with coagulable blood and serum FDP levels (more than 80 micrograms/ml) were included in the study. They were randomised to receive low-dose heparin in an initial dose of 50 units/kg body weight intravenously immediately after antivenom followed by a continuous infusion of 10 units/kg/hr in isotonic saline for 24 hours, or antivenom alone.

Contribution of focal haemorrhage and microvascular fibrin deposition to fatal envenoming by Russell's viper (Vipera russelli siamensis) in Burma.

In Burma, clinicopathological studies were carried out in three young farmers who died 15, 52 and 36 h after being bitten by Russell's vipers. Clinical features included local swelling, spontaneous systemic bleeding, defibrination, shock, cardiac arrhythmia, hypoglycaemia, coma and oliguria. On admission to hospital, 15, 48 and 21 h after the bites, serum venom antigen concentrations ranged from 50 to 130 ng/ml.

Acute and chronic pituitary failure resembling Sheehan's syndrome following bites by Russell's viper in Burma.

Pituitary function was investigated in 9 patients in shock after Russell's viper bites and in 24 individuals who had been severely envenomed 2 weeks to 24 years previously. 3 out of 9 patients had hypoglycaemia and inappropriately low serum cortisol, plasma growth hormone, and plasma prolactin concentrations. 4 who died had pituitary haemorrhage and 1 had adrenal haemorrhage as well.

The efficacy of tourniquets as a first-aid measure for Russell's viper bites in Burma.

The efficacy of the tourniquets commonly used by Russell's viper bite victims in retarding venom movement from the bite was studied in 37 cases by measuring venom antigen levels by enzyme-linked immunosorbent assay in venous samples taken proximal and distal to the tourniquets and also before and after release of tourniquets. In most cases, the tourniquet did not prevent proximal spread of venom. In 8/37 cases, however, venom antigen assays suggested but did not prove that venom absorption was being delayed by the tourniquet.

Amount of venom injected by Russell's viper (Vipera russelli).

The total yield of venom (desiccated) in 25 adult V. russelli (mean length 111 +/- 1.8 cm (S.

Bites by Russell's viper (Vipera russelli siamensis) in Burma: haemostatic, vascular, and renal disturbances and response to treatment.

Of 123 patients with proved Russell's viper bite, 28% showed no evidence of envenoming, 28% had local swelling alone, but 44% had systemic envenoming manifested by incoagulable blood (100% of those admitted before treatment), thrombocytopenia (26%), spontaneous systemic bleeding (20%), hypotension (35%), evidence of increased capillary permeability (24%), and oliguria (44%). Patients with systemic envenoming usually had more local swelling than those without, but 5 had no local signs. Snake length correlated with the amount of local swelling, but snakes causing systemic envenoming were no longer than those causing local or no envenoming.

Russell's viper venom levels in serum of snake bite victims in Burma.

Serum levels of venom antigen were measured using enzyme-linked immunosorbent assay (ELISA) in 38 Russel's viper bite victims before and after administration of 40 ml of monovalent liquid antivenom. Initial serum levels ranged from one with less than 10.0 ng to 290 ng/ml and in one case a level of 75 ng/ml was detected 27 hours after the bite.