Navegando por Palavras-chave "Mitotic index"

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    Cytotoxicity and genotoxicity of low doses of mercury chloride and methylmercury chloride on human lymphocytes in vitro
    (Associação Brasileira de Divulgação Científica, 2005-06-01) Silva-Pereira, Liz Carmem; Cardoso, Plinio Cerqueira dos Santos; Leite, Daniel Silva; Bahia, Marcelo de Oliveira; Bastos, Wanderley Rodrigues; Smith, Marilia de Arruda Cardoso [UNIFESP]; Burbano, Rommel Rodríguez [UNIFESP]; Faculdade de Itaituba Departamento de Pós-Graduação; Universidade Federal do Pará Centro de Ciências Biológicas Departamento de Biologia; Universidade Federal do Pará Centro de Ciências Biológicas Departamento de Patologia; Universidade de São Paulo (USP); Fundação Universidade Federal de Rondônia Departamento de Medicina Laboratório de Biogeoquímica Ambiental; Universidade Federal de São Paulo (UNIFESP)
    Mercury is a xenobiotic metal that is a highly deleterious environmental pollutant. The biotransformation of mercury chloride (HgCl2) into methylmercury chloride (CH3HgCl) in aquatic environments is well-known and humans are exposed by consumption of contaminated fish, shellfish and algae. The objective of the present study was to determine the changes induced in vitro by two mercury compounds (HgCl2 and CH3HgCl) in cultured human lymphocytes. Short-term human leukocyte cultures from 10 healthy donors (5 females and 5 males) were set-up by adding drops of whole blood in complete medium. Cultures were separately and simultaneously treated with low doses (0.1 to 1000 µg/l) of HgCl2 and CH3HgCl and incubated at 37ºC for 48 h. Genotoxicity was assessed by chromosome aberrations and polyploid cells. Mitotic index was used as a measure of cytotoxicity. A significant increase (P < 0.05) in the relative frequency of chromosome aberrations was observed for all concentrations of CH3HgCl when compared to control, whether alone or in an evident sinergistic combination with HgCl2. The frequency of polyploid cells was also significantly increased (P < 0.05) when compared to control after exposure to all concentrations of CH3HgCl alone or in combination with HgCl2. CH3HgCl significantly decreased (P < 0.05) the mitotic index at 100 and 1000 µg/l alone, and at 1, 10, 100, and 1000 µg/l when combined with HgCl2, showing a synergistic cytotoxic effect. Our data showed that low concentrations of CH3HgCl might be cytotoxic/genotoxic. Such effects may indicate early cellular changes with possible biological consequences and should be considered in the preliminary evaluation of the risks of populations exposed in vivo to low doses of mercury.
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    Lymphocyte proliferation stimulated by activated human macrophages treated with Canova
    (Elsevier B.V., 2009-01-01) Burbano, Rommel Rodriguez; Leal, Mariana Ferreira [UNIFESP]; Costa, Joana Borges da; Bahia, Marcelo de Oliveira; Lima de Lima, Patricia Danielle; Khayat, Andre Salim; Seligman, Igor Chamon; Assumpcao, Paulo Plmentel de; Buchi, Dorly de Freitas; Cardoso Smith, Marilia de Arruda [UNIFESP]; Fed Univ Para; Universidade Federal de São Paulo (UNIFESP); Univ Fed Parana
    Introduction: Canova (CA) is a homeopathic medication with immunomodulatory properties, recommended for patients with a depressed immune system. CA has been reported to increase in leukocyte numbers, cellular differentiation and reduction in tumor size.Aim and method. Since CA may stimulate lymphocyte differentiation, proliferation, and/or survival, the aim of the present study was to compare the mitotic index (MI) of phytohemagglutinin-stimulated human lymphocytes cultured in a medium supplemented with human macrophages activated by CA, with lymphocytes cultured in a medium without CA-treated macrophages.Results: in this study, the MI of lymphocyte cultured received the medium containing CA-stimulated macrophages showed a higher proliferation index (p < 0.01) than the lymphocytes cultured in a medium without CA-treated macrophages. Our results suggest that CA treatment, in addition to activating macrophages, indirectly induces lymphocyte proliferation and has potential as a new adjuvant therapeutic approach. Homeopathy (2009) 98, 45-48.