197 research outputs found
Neutrophils activate macrophages for intracellular killing of Leishmania major through recruitment of TLR4 by neutrophil elastase
No full textWe investigated the role of neutrophil elastase (NE) in interactions between murine inflammatory neutrophils and macrophages infected with the parasite Leishmania major. A blocker peptide specific for NE prevented the neutrophils from inducing microbicidal activity in macrophages. Inflammatory neutrophils from mutant pallid mice were defective in the spontaneous release of NE, failed to induce microbicidal activity in wild-type macrophages, and failed to reduce parasite loads upon transfer in vivo. Conversely, purified NE activated macrophages and induced microbicidal activity dependent on secretion of TNF-alpha. Induction of macrophage microbicidal activity by either neutrophils or purified NE required TLR4 expression by macrophages. Injection of purified NE shortly after infection in vivo reduced the burden of L. major in draining lymph nodes of TLR4-sufficient, but not TLR4-deficient mice. These results indicate that NE plays a previously unrecognized protective role in host responses to L. major infection
Susceptible hosts: a resort for parasites right in the eye of the immune response
No full textTrypanosomatid protozoan parasites express an aggressive strategy of parasitism by infecting host macrophages and inducing extensive T-lymphocyte activation. One goal of such strategy is to drive the immune response of genetically susceptible hosts to a state of unresponsiveness regarding parasite killing. Unresponsiveness is achieved through different mechanisms, depending on the parasite species. In this brief review, recent findings on the molecular and cellular bases of the parasites' exploitation of host immune responses are discussed
A NEW SUBSPECIES OF PROECHIMYS-IHERINGI THOMAS (RODENTIA, ECHIMYIDAE) FROM THE STATE OF RIO-DE-JANEIRO, BRAZIL
No full textDescribed a new subspecies of Proechimys iheringi based on specimens collected in the coastal sand plains of the state of Rio de janeiro, southeastern Brazil. This new subspecies can be distinguished by a combination of traits that include an absence of cinnamon ground color in the subapical zone of setiform hairs tail longer than head and body with a whitish brush in the tip, bullae large and well inflated, and by the structure of the septum of the incisive foramen, where the vomer is visible ventrally between the premaxillae and maxillae.58318119
Evasion of immune responses by Trypanosoma cruzi, the etiological agent of Chagas disease
No full textInfection with the protozoan parasite Trypanosoma cruzi leads to Chagas disease, which affects millions of people in Latin America. Infection with T. cruzi cannot be eliminated by the immune system. A better understanding of immune evasion mechanisms is required in order to develop more effective vaccines. During the acute phase, parasites replicate extensively and release immunomodulatory molecules that delay parasite-specific responses mediated by T cells. This immune evasion allows the parasite to spread in the host. In the chronic phase, parasite evasion relies on its replication strategy of hijacking the TGF-β signaling pathway involved in inflammation and tissue regeneration. In this article, the mechanisms of immune evasion described for T. cruzi are reviewed
PROECHIMYS ALBISPINUS MINOR, A NEW SUBSPECIES FROM THE STATE OF BAHIA, NORTHEASTERN BRAZIL (RODENTIA, ECHIMYIDAE)
No full textDescribed a new subspecies, Proechimys albispinus minor, based on specimens from the highlands locality of Morro do Chapeu in the state of Bahia, in northeastern Brazil. The new subspecies can be distinguished by a smaller body and cranial size, finer pelage, absence of an ochraceous subapical zone in the aristiform hairs in the middorsal region, and ochraceous-orange subapical region in the setiform hairs in the middorsal region and outer thighs.60423724
Apoptosis in parasites and parasite-induced apoptosis in the host immune system: a new approach to parasitic diseases
No full textApoptosis, a form of programmed cell death (PCD), has been described as essential for normal organogenesis and tissue development, as well as for the proper function of cell-renewal systems in adult organisms. Apoptosis is also pivotal in the pathogenesis of several different diseases. In this paper we discuss, from two different points of view, the role of apoptosis in parasitic diseases. The description of apoptotic death in three different species of heteroxenic trypanosomatids is reviewed, and considerations on the phylogenesis of apoptosis and on the eventual role of PCD on their mechanism of pathogenesis are made. From a different perspective, an increasing body of evidence is making clear that regulation of host cell apoptosis is an important factor on the definition of a host-pathogen interaction. As an example, the molecular mechanisms by which Trypanosoma cruzi is able to induce apoptosis in immunocompetent cells, in a murine model of Chagas' disease, and the consequences of this phenomenon on the outcome of the experimental disease are discussed
Cyclosporin A-treated guinea pig responder cells secrete a genetically restricted factor that suppresses the mixed leukocyte reaction.
No full textO SEMINÁRIO DA CONCEIÇÃO: UM PROJETO DE EDUCAÇÃO
No full textDOI: 10.18312/cadernounivag.v0i4.288Este artigo esquadrinha a atuação do primeiro bispo de Mato Grosso, D. José Antônio dosReis, à frente do Seminário Episcopal da Conceição, no correr da segunda metade do séculoXIX demonstrando a importância do projeto de educação religiosa para formação de uma elitelocal responsável pelo destino político, social e econômico da Província de Mato Grosso. OSeminário se incumbia da educação sacerdotal, formação semelhante àquela que os outrosseminários espalhados pelo Brasil o faziam:- impregnar o clero imbuído dos preceitos de umaeducação liberal e burguesa, sempre fiel, no entanto, aos princípios da Santa Sé.Palavras-chave: Seminário piscopal; Educação; Sociedade
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