Management of Snakebite and Research Management of Snakebite ...

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(LD 50IV .), coagulant (10MCD), haemorrhagic (3MHD), necrotic (3MND), defibrinogenating (5MDD) and capillary permeability increasing (100MCPID) activities by the antivenoms using WHO recommended standard test of neutralizing activity (Theakston and Reid, 1983). Briefly, a fixed amount of venom is mixed with a variable dilution of antivenom, incubated at 37 0 C for 30 min. and injected into laboratory animals. The end point is taken as the minimum amount of antivenom required to neutralize 50% of the biological effects of venom. For determination of neutralization of lethal activity ED 50 (median effective dose) is used. It is the minimal amount of antivenom that will save 50% of the test animals. SDS-PAGE electrophoresis, immunoblotting and immunostaining of the venom with the antivenoms were carried out according to the methods already described (Lamelii, 1970, Towbin et al., 1979). RESULTS Results of neutralization of the different biological properties of the venom by the antivenoms are shown in Table 1. Table 1. Amount of antivenom required for neutralizing different biological properties of the Russell’s viper venom Method/antivenom 5LD 50iv 233.7 µg/ml 3MHD 2.53 mg/ml 3 MND 2.39 mg/ml 10MCD 50.25 µg/ml 5MDD 120 µg/ml 100 MCPID 1.48 µg/ml Control 5* 1.25* 2.5* 0.0781* 2.5* 5* Pot/grd schedule A 10 2.5 2.5 0.0781 2.5 1.25 Pot/grd schedule B 10 5 2.0 0.1562 5 5 Pot/house schedule A 5 1.25 5 0.3125 5 2.5 Pot/huse schedule B 5 1.25 2.5 0.0781 5 10 * = µl Control = the same batch of antivenom stored at 40C. Pot/grd = antivenom of pot/ground. Pot/huse= antivenom of pot/house. Schedule A= daily watering of the sand. Schedule B= every third day watering of the sand Potency Assay of the Liquid Russell’s Viper Antivenom Stored at Different Environment LD50 iv= lethality, MDD = minimum defibrinogenating dose, MCD = minimum coagulant dose, MHD = minimum haemorrhagic dose, MND = minimum necrotic dose, MCPID = minimum capillary permeability increasing dose. In pot/ground method, the neutralizing efficacy of the antivenom with daily watering (Schedule A) was comparable to the control (except in neutralization of lethal and haemorrhagic) and has a better performance than the antivenom with every third day watering (Schedule B). In pot/house method, the neutralizing efficacy of the antivenom with daily watering (Schedule A) was inferior to that of the antivenom with every third day watering (Schedule B). 83
Management of Snakebite and Research 84 A better preservation of antivenom efficacy was observed in pot/ground with daily watering than pot/house with daily watering. Immunoblotting of the venom with the antivenoms showed there were no quantitative differences in recognizing bands by the antivenoms (Figure 3). Figure 3. Picture of immunoblot of the Russell’s viper venom with the antivenoms under studied TGO=antivenom of pot/ground, TDG=antivenom of pot/ house, A= daily watering of the sand, B=every 3 rd day watering of the sand, Control= antivenom stored at +4°C. The relationship between the temperature of the sand inside the pot and shade/ room temperature is shown in Table 2. Daily watering of the sand keeps the sand temperature 1-2 0 C cooler than every third day watering and could maintain temperature of the sand at 30-32 0 C (8-10 0 C lower) when the shade/room temperature reaches 40 0 C during the hot summer months. Table 2. Relationship between temperature of the sand inside the pot and shade/ room temperature in the two study sites Season Study site Month Winter Taungoo Taungdwingyi Summer Taungoo Taungdwingyi Dec-Feb Jan-Feb Mar-Jun Mar-May Shade/room temp. o C min-max 23-32 21-32 29-40 23-40 Sand temp. inside the pot o C min-max 19-26 17-23 28-32 18-30 Temp. differences o C min-max 4-6 4-9 1-8 5-10
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World Health Organization Regional
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ii WHO Library Cataloguing in Publi
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iv 10. Recent Advances in the Exper
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The seminar, convened at the Depart
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Early use of antivenom by health wo
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� Raising awareness of endotrache
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