Navegando por Palavras-chave "mosquito"

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    Cell death and regeneration in the midgut of the mosquito, Culex quinquefasciatus
    (Elsevier B.V., 2007-12-01) Okuda, Kendi; Almeida, Fabio de; Mortara, Renato A.; Krieger, Henrique; Marinotti, Osvaldo; Bijovsky, A. Tania; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Univ Calif Irvine
    Haematophagy, the utilization of blood as food, has evolved independently among insects such as mosquitoes, bedbugs, fleas, and others. Accordingly, several distinct biological adaptations have occurred in order to facilitate the finding, ingestion and digestion of blood from vertebrate sources. Although blood meals are essential for survival and reproduction of these insects, mechanical and chemical stresses are caused by the ingestion of a sizable meal (frequently twice or more times the weight of the insect) containing large amounts of cytotoxic molecules such as haem. Here we present data showing that the stresses caused by a blood meal induce cell death in the midgut epithelium of Culex quinquefasciatus mosquitoes. the process involves apoptosis, ejection of dead cells to the midgut lumen and differentiation of basal regenerative cells to replace the lost digestive cells. the basal cell differentiation in blood-fed mosquito midguts represents an additional mechanism by which insects cope with the stresses caused by blood meals. C quinquefasciatus adult females are unable to replace lost cells following a third or fourth blood meal, which may have a significant impact on mosquito longevity, reproduction and vectorial capacity. (c) 2007 Elsevier B.V. All rights reserved.
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    Effect of the antimicrobial peptide gomesin against different life stages of Plasmodium spp.
    (Elsevier B.V., 2007-08-01) Moreira, Cristina K.; Rodrigues, Flavia G.; Ghosh, Anil; Varotti, Fernando de P.; Miranda, Antonio; Daffre, Sirlei; Jacobs-Lorena, Marcelo; Moreira, Luciano A.; Fundacao Oswaldo Cruz; Johns Hopkins Bloomberg Sch Publ Hlth; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)
    While seeking strategies for interfering with Plasmodium development in vertebrate/invertebrate hosts, we tested the activity of gomesin, an antimicrobial peptide isolated from the hemocytes of the spider Acanthoscurria gomesiana. Gomesin was tested against asexual, sexual and pre-sporogonic forms of Plasmodium falciparum and Plasmodium berghei parasites. the peptide inhibited the in vitro growth of intraerythrocytic forms of P. falciparum. When gomesin was added to in vitro, culture of P. berghei mature gametocytes, it significantly inhibited the exflagellation of male gametes and the formation of ookinetes. in vivo, the peptide reduced the number of oocysts of both Plasmodium species in Anopheles stephensi mosquitoes, and did not appear to affect the mosquitoes. These properties make gomesin an excellent candidate as a transmission blocking agent for the genetic engineering of mosquitoes. (c) 2007 Elsevier Inc. All rights reserved.
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    Estudo molecular e funcional de um inibidor de cisteínoproteases identificado no genoma do mosquito aedes aegypti
    (Universidade Federal de São Paulo (UNIFESP), 2013-11-27) Oliveira, Felipe Araujo de Alcantara [UNIFESP]; Tanaka, Aparecida Sadae Tanaka [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Objetivo: Caracterizar um inibidor de protease da família das cistatinas no mosquito Aedes aegypti, abordando parâmetros bioquímicos e verificar seus possível papel na infecção do mosquito com vírus da DENV. Métodos: A proteína foi expressa em E. colí para a produção de anticorpos, afim de confirmar a presença da proteína nativa, e para a realização de testes enzirnáticos. Reações de cadeia da polimerase quantitativos (qPCRs) foram realizadas afim de verificar quais tecidos o transcrito está expresso e sua modulação com a infecção por DENV. Resultados: A proteína pertence à família das estefinas (125B) e inibe diversas cisteinopeptases como as cathepsias humanas B, L1, L2, S e a papaína. O anticorpo produzido apresentou afinidade por uma proteína de tamanho similar ao esperado. A cistatina se encontrada majoritariamente no intestino e a quantidade de transcritos apresenta redução durante a infecção.