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Treatment of envenomation after Echis ocellatus bites in burkina faso
164
Report
and Abstracts
true onset of membrane hydlin disease. The lesions were the same in PC and 1dPC but were more frequent in NPC. We conclude that the fibrin deposition, particularly in one PC, and the great number of NL suggest that PE after GESS has ARDS physiopathology or partial ARDS. Nevertheless, myocardial signs described elsewhere for GESS led us to think that the physiopathology is mixed. Rapid reversal qfhrown snake (Pseudonaja sp.) venom-;t~&ced neuroroxicity hy a Fah-hasrd antivenom. R. G. A. Jones and D. C. Smith (Therapeutic Antibodies Ltd, The Medical College of St Bartholomew’s Hospital, Charterhouse Square, London ECI M 6BQ, U.K.). Brown snakes (Pseudonaja sp.) are among the most deadly found in Australia, the venom containing both presynaptic and postsynapiic neurotoxins. The presynaptic component, textilotoxin, is thought to be the most potent and complex toxin isolated from a snake venom, while the predominant postsynaptic neurotoxin, pseudonajatoxin-a, binds irreversibly to acetylcholine receptors and is unusually large for a venom component of this type (12,280 mol. wt). A murine hemidiaphragm preparation has been used to show, for the first time. the rapid ( < I hr) in vi/r0 reversal of the neurotoxicity produced by brown snake venom. Presynaptic and postsynaptic components were distinguished by increasing the temperature and frequency of nerve stimulation, and it was concluded that venom toxicity was predominantly of a postsynaptic nature, and was devoid of any myotoxic activity. Treatmen of’envmomation ajier Echis ocellatus hires in Burkina Faso. J. Kabort’ and P. Revault” (‘C. H. N. Ouedraogo, Service de Mtdecine Interne, B.P. 7022, Ouagadougou 03, Burkina Faso; and ‘ORSTOM, B.P. 182, Ouagadougou 0 I. Burkina Faso). In the region of Ouagadougou in 1992, snakebites represented up to 14% of the hospitalizations in the rural health care units. Each year, 75% of the patients hospiealized for snakebites are bitten by Echis ocellams. Fewer than one patient in ten bitten by Echis sp. does not develop an envenomation. Without serotherapy and an efficient treatment, the mortality of the patients hospitalized for Echb sp. bites can exceed 10%. It is necessary to differentiate the traditional healing care, even if at times this is effective on the local symptomatology, from a patient’s family care, which mostly proves to be dangerous. Treatment in the rural health care units is not adequate. The transfer of patients is often delayed, especially in cases showing signs of serious complications. The intensity of the local oedema does not appear as a good clinical indicator for the prognosis. However, the presence of spontaneous bleeding (gingival bleeding associated with complications) seems to represent a good indicator. The diluted serum Ipser Afrique” anti-Bitis-&his-BajaDendroaspis (in 5% glucose solution), precociously injected, seems to be associated with the removal of the haemorrhagic symptomatology, whereas no early allergic reactions were recorded amongst the 25 patients treated in 1992. Selective proteolysis of platelet q/I, integrin (GPlallla) by jarorhugin, a hnemorrhagic metrllloproteinase .from Bothrops jararaca venom. A. S. Kamiguti, C. R. M. Hay and M. Zuzel (Department of Haematology, Royal Liverpool University Hospital, Liverpool L3 5QA, U.K.). The types of systemic bleeding observed in Borhrops envenoming suggest altered platelet function. We have found that jararhagin, the main haemorrhagic metalloproteinase from B. jararaca venom, selectively inhibits platelet aggregation by collagen. Preincubation studies showed that this inhibition was not due to collagen degradation, suggesting an alteration of collagen receptor(s) on the platelet surface (gpIa/IIa, gpIV or gpIIb/ IIIa). Although jararhagin completely abolished collagen-induced aggregation, the response to collagen was apparently fully restored when platelet gpIIb/IIIa was activated by a low concentration of ADP (0.2 M). GpIIb/IIIa was therefore intact and this was confirmed by preserved platelet aggregation response to an antigpIIb mAb, PL2-49. The aggregation response to OKM.5 (mAb to platelet collagen receptor, gpIV) was also preserved. However, flow cytometry using an anti-gpIa mAB (anti-a* chain of a$, integrin) showed reduced cell fluorescence after treatment with jararhagin of platelets in both plasma and washed cell suspensions. Immunoprecipitation of glycoproteins from lysates of ‘251-labelled platelets with specific mAbs showed reduction of gpIa/IIa complex only. Thus, our data demonstrate a highly selective proteolysis of platelet gpIa/ IIa by jararhagin. Since congenital deficiency of platelet glycoprotein Ia leads to a significant haemostatic defect, and since jararhagin is not inhibited in plasma, it is likely that jararhagin plays an important role in the aetiology of the systemic bleeding in Bothrops envenoming. Prepararion and use of different immunogens .for production of’ antiscorpionic immune sera. R. Kharrat,’ I. Zenouaki,’ Z. Ben Lasfar,’ K. Miled,’ H. Karoui’ and M. El Ayeb’ (‘Laboratoire des Venins et Toxines, and 2Service des Unit& Animal&es, Institut Pasteur de Tunis, B.P. 74, 1002 Tunis-Belvidkre, Tunisia). In Tunisia, scorpion envenomation represents a real health problem. Presently, equine immune sera are the only accepted immune therapeutic possibility. Different immunogen preparations from venoms of dangerous species Androctonus awtralis (Aah) and Buthus occitunus (Bot) are conceived and realized. Sephadex G-50 purified fractions, either native or chemically modified by polymerization with glutaraldehyde or by reduction and
Report
and Abstracts
true onset of membrane hydlin disease. The lesions were the same in PC and 1dPC but were more frequent in NPC. We conclude that the fibrin deposition, particularly in one PC, and the great number of NL suggest that PE after GESS has ARDS physiopathology or partial ARDS. Nevertheless, myocardial signs described elsewhere for GESS led us to think that the physiopathology is mixed. Rapid reversal qfhrown snake (Pseudonaja sp.) venom-;t~&ced neuroroxicity hy a Fah-hasrd antivenom. R. G. A. Jones and D. C. Smith (Therapeutic Antibodies Ltd, The Medical College of St Bartholomew’s Hospital, Charterhouse Square, London ECI M 6BQ, U.K.). Brown snakes (Pseudonaja sp.) are among the most deadly found in Australia, the venom containing both presynaptic and postsynapiic neurotoxins. The presynaptic component, textilotoxin, is thought to be the most potent and complex toxin isolated from a snake venom, while the predominant postsynaptic neurotoxin, pseudonajatoxin-a, binds irreversibly to acetylcholine receptors and is unusually large for a venom component of this type (12,280 mol. wt). A murine hemidiaphragm preparation has been used to show, for the first time. the rapid ( < I hr) in vi/r0 reversal of the neurotoxicity produced by brown snake venom. Presynaptic and postsynaptic components were distinguished by increasing the temperature and frequency of nerve stimulation, and it was concluded that venom toxicity was predominantly of a postsynaptic nature, and was devoid of any myotoxic activity. Treatmen of’envmomation ajier Echis ocellatus hires in Burkina Faso. J. Kabort’ and P. Revault” (‘C. H. N. Ouedraogo, Service de Mtdecine Interne, B.P. 7022, Ouagadougou 03, Burkina Faso; and ‘ORSTOM, B.P. 182, Ouagadougou 0 I. Burkina Faso). In the region of Ouagadougou in 1992, snakebites represented up to 14% of the hospitalizations in the rural health care units. Each year, 75% of the patients hospiealized for snakebites are bitten by Echis ocellams. Fewer than one patient in ten bitten by Echis sp. does not develop an envenomation. Without serotherapy and an efficient treatment, the mortality of the patients hospitalized for Echb sp. bites can exceed 10%. It is necessary to differentiate the traditional healing care, even if at times this is effective on the local symptomatology, from a patient’s family care, which mostly proves to be dangerous. Treatment in the rural health care units is not adequate. The transfer of patients is often delayed, especially in cases showing signs of serious complications. The intensity of the local oedema does not appear as a good clinical indicator for the prognosis. However, the presence of spontaneous bleeding (gingival bleeding associated with complications) seems to represent a good indicator. The diluted serum Ipser Afrique” anti-Bitis-&his-BajaDendroaspis (in 5% glucose solution), precociously injected, seems to be associated with the removal of the haemorrhagic symptomatology, whereas no early allergic reactions were recorded amongst the 25 patients treated in 1992. Selective proteolysis of platelet q/I, integrin (GPlallla) by jarorhugin, a hnemorrhagic metrllloproteinase .from Bothrops jararaca venom. A. S. Kamiguti, C. R. M. Hay and M. Zuzel (Department of Haematology, Royal Liverpool University Hospital, Liverpool L3 5QA, U.K.). The types of systemic bleeding observed in Borhrops envenoming suggest altered platelet function. We have found that jararhagin, the main haemorrhagic metalloproteinase from B. jararaca venom, selectively inhibits platelet aggregation by collagen. Preincubation studies showed that this inhibition was not due to collagen degradation, suggesting an alteration of collagen receptor(s) on the platelet surface (gpIa/IIa, gpIV or gpIIb/ IIIa). Although jararhagin completely abolished collagen-induced aggregation, the response to collagen was apparently fully restored when platelet gpIIb/IIIa was activated by a low concentration of ADP (0.2 M). GpIIb/IIIa was therefore intact and this was confirmed by preserved platelet aggregation response to an antigpIIb mAb, PL2-49. The aggregation response to OKM.5 (mAb to platelet collagen receptor, gpIV) was also preserved. However, flow cytometry using an anti-gpIa mAB (anti-a* chain of a$, integrin) showed reduced cell fluorescence after treatment with jararhagin of platelets in both plasma and washed cell suspensions. Immunoprecipitation of glycoproteins from lysates of ‘251-labelled platelets with specific mAbs showed reduction of gpIa/IIa complex only. Thus, our data demonstrate a highly selective proteolysis of platelet gpIa/ IIa by jararhagin. Since congenital deficiency of platelet glycoprotein Ia leads to a significant haemostatic defect, and since jararhagin is not inhibited in plasma, it is likely that jararhagin plays an important role in the aetiology of the systemic bleeding in Bothrops envenoming. Prepararion and use of different immunogens .for production of’ antiscorpionic immune sera. R. Kharrat,’ I. Zenouaki,’ Z. Ben Lasfar,’ K. Miled,’ H. Karoui’ and M. El Ayeb’ (‘Laboratoire des Venins et Toxines, and 2Service des Unit& Animal&es, Institut Pasteur de Tunis, B.P. 74, 1002 Tunis-Belvidkre, Tunisia). In Tunisia, scorpion envenomation represents a real health problem. Presently, equine immune sera are the only accepted immune therapeutic possibility. Different immunogen preparations from venoms of dangerous species Androctonus awtralis (Aah) and Buthus occitunus (Bot) are conceived and realized. Sephadex G-50 purified fractions, either native or chemically modified by polymerization with glutaraldehyde or by reduction and