Browsing by Autor "Jean-Loup Lemesre"

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    Additional data on Trypanosoma cruzi isozymic strains encountered in Bolivian domestic transmission cycles
    (Oxford University Press, 1986) Michel Tibayrenc; Ary A. Hoffmann; Olivier Poch; Lourdes Echalar; François Le Pont; Jean-Loup Lemesre; P. Desjeux; Francisco J. Ayala
    We have collected in Bolivia 212 stocks of Trypanosoma cruzi from domestic transmission cycles and have assayed for nine enzyme systems (11 gene loci). Only a few different isozyme profiles exist, without recombination between them, a situation also encountered in previous Bolivian samples. The 212 stocks, combined with 207 stocks previously studied, have been analysed to uncover any spatial patterns. The frequency of heterozygous strains (2 and 2a) decreases westwards and with increasing altitude. Given that longitude and altitude are correlated with each other, it is not possible to decide which of these two geographic variables is the relevant one, or if both are. These associations might be due to climatic factors. Studies by other authors have shown, however, that heterozygous strains are rare or absent in the Amazon Basin, which is at low altitude.
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    Depressão humoral específica em pacientes crônicos infectados pelo Trypanosoma cruzi
    (University of São Paulo, 1984) Simone Frédérique Brénière; Olivier Poch; Hugo Selaes; Michel Tibayrenc; Jean-Loup Lemesre; G Antezana; P. Desjeux
    Realizamos um estudo comparativo entre o xenodiagnóstico e os testes sorológicos para a doença de Chagas. Cento e cincoenta pacientes de algumas áreas endêmicas foram estudados. Quatro deles pareceram revelar um estado particular com um xenodiagnóstico positivo e uma sorologia negativa, esta realizada com quatro diferentes técnicas clássicas (teste de immunofluorescência, ELISA: Enzyme Linked Immunosorbent Assay, teste de fixação do complemento e teste de immuno-eletroforese). O soro de um dos pacientes que apresentou depressão humoral específica mostra elevada quantidade de antígenos circulantes comprovada pela técnica da immuno-eletroforese. Os Autores sugerem o uso de um teste sorológico para detectar a presença de antígenos circulantes de T. cruzi, além da utilização de testes sorológicos clássicos. Isto permitiria o diagnóstico da doença de Chagas em pacientes com uma baixa (ou mesmo inexistente) produção de anticorpos específicos.
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    Identification of a major 72 kilodalton surface antigen in twelve isolates of Leishmania braziliensis braziliensis
    (Elsevier BV, 1987) Dominique Legrand; P. Desjeux; François Le Pont; Simone Frédérique Brénière; Jean-Loup Lemesre; F Santoro; A Capron
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    Specific and Sensitive Immunological Diagnosis of Chagas' Disease by Competitive Antibody Enzyme Immunoassay Using a Trypanosoma cruzi-Specific Monoclonal Antibody
    (American Society of Tropical Medicine and Hygiene, 1986) Jean-Loup Lemesre; D. Afchain; Oscar Orozco; M. Loyens; Simone Frédérique Brénière; P. Desjeux; Y Carlier; Ubaldo O. Martín; J. A. Nogueira-Queiroz; D. Le Ray
    Coexistence of Chagas' disease with leishmaniasis and T. rangeli infection in endemic areas and cross-reactivity between corresponding etiological agents can confuse the immunodiagnosis of Chagas' disease. A discriminative serological test could therefore represent a major advance in specific immunodiagnosis. A competitive antibody enzyme immunoassay against a component 5-enriched preparation, using a T. cruzi species-specific monoclonal antibody has allowed development of a specific serodiagnosis of Chagas' disease with high sensitivity (96.6% in undetermined and chronic phases of infection). This test can differentiate Chagas' disease from other cross-reacting parasitic diseases in areas where concomitant infections are unknown or suspected.
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    Specific immunodiagnosis of Chagas disease: immunodiffusion test using a specific serum anti-Trypanosoma cruzi component 5.
    (National Institutes of Health, 1987) Simone Frédérique Brénière; Yves Carlier; Roxana Carrasco; S Molinedo; Jean-Loup Lemesre; P. Desjeux; D. Afchain
    A micro double diffusion test (MD), allowing the identification of precipitation brand 5 by identity reaction, using a rabbit specific anti-component 5 serum, was evaluated for the immunological diagnosis of Chagas' disease. The previous studies on the Trypanosoma cruzi specificity of component 5[g] were completed, showing it to be absent in Leishmania brazilienis, but present in different strains of T. cruzi. 200 sera from Bolivian patients were studied. (88 with a positive xenodiagnosis, 45 with mucocutaneous leishmaniasis but without Chagas' disease, and 67 controls). Band 5 was found in 74 (84.1%) of the sera with positive xenodiagnosis but was never found either in the leishmaniasis or in the control groups. MD, allowing an easy detection of T. cruzi specific band 5, cheap and simple to perform, can be recommended in association with other serological tests, when highly specific immunodiagnosis of Chagas' disease is required.