Leishmania spp.: isolamento de parasitos pela inoculação de macerados de biopsias de pacientes em camundongos deficientes em interferon gama

Isolation of Leishmania parasite and species identification are important for confirmation and to help define the epidemiology of the leishmaniasis. Mice are often used to isolate pathogens, but the most common mouse strains are resistant to infection with parasites from the Leishmania (Viannia) subgenus. In this study we tested the inoculation of interferon gamma knockout (IFNγ KO) mice with biopsy macerates from Leishmania-infected patients to increase the possibility of isolating parasites. Biopsies from twenty five patients with clinical signs of leishmaniasis were taken and tested for the presence of parasites. Immunohistochemical assay (IHC) and conventional histopathology detected the parasite in 88% and 83% of the patients, respectively. Leishmania sp. were isolated in biopsy macerates from 52% of the patients by culture in Grace's insect medium, but 13% of isolates were lost due to contamination. Inoculation of macerates in IFNγ KO mice provides isolation of parasites in 31.8% of the biopsies. Most isolates belong to L. (Viannia) subgenus, as confirmed by PCR, except one that belongs to L. (Leishmania) subgenus. Our preliminary results support the use of IFNγ KO mice to improve the possibility to isolate New World Leishmania species.O isolamento e a identificação da espécie de parasito do gênero Leishmania são importantes para a confirmação e auxiliam na epidemiologia da leishmaniose. Os camundongos são freqüentemente utilizados para isolar patógenos, porém, as linhagens mais comuns de camundongos são resistentes à infecção por parasitos do subgênero Leishmania (Viannia). Neste estudo, avaliamos a inoculação de macerados de biópsias de pacientes infectados em camundongos deficientes do gene do interferon gama (IFNγ KO) como um método para aumentar a possibilidade de isolar Leishmania spp. Biópsias de 25 pacientes infectados com Leishmania sp. foram avaliadas para a presença de parasitos pelos métodos de imunohistoquímica (IHC) e histopatologia convencional. Os parasitos foram observados, respectivamente, em 88% e 83% das biópsias. Leishmania sp. foi isolada de macerados de biópsia de 52% dos pacientes infectados, quando cultivados em meio Grace, porém, 13% destes isolados foram perdidos devido a contaminações. Inoculação dos macerados em camundongos IFNγ KO proporcionou o isolamento de parasitos oriundos de 31,8% dos pacientes. A maioria dos isolados pertence ao subgênero L. (Viannia), exceto um que pertence ao subgênero L. (Leishmania), como confirmado pela reação da polimerase em cadeia. Nossos resultados preliminares sugerem que o uso de camundongos IFNγ KO pode ser útil para aumentar a possibilidade de isolamento de leishmânias encontradas nas Américas

S-nitrosoglutathione (gsno) Is Cytotoxic To Intracellular Amastigotes And Promotes Healing Of Topically Treated Leishmania Major Or Leishmania Braziliensis Skin Lesions-authors' Response.

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Trypanosoma cruzi: parasite shed vesicles increase heart parasitism and generate an intense inflammatory response

Trypanosoma cruzi trypomastigotes continuously shed into the medium plasma membrane fragments sealed as vesicles enriched in glycoproteins of the gp85 and trans-sialidase (TS) superfamily and alpha-galactosyl-containing glycoconjugates. Injection of a vesicle fraction into BALB/c mice prior to T. cruzi infection led to 40% of deaths on the 16th day post-infection and 100% on day 20th whereas 20% of untreated animals survived for more than 30 clays. The vesicle-treated animals developed severe heart pathology, with intense inflammatory reaction and higher number of amastigote nests. Analysis of the inflammatory infiltrates 15 days after infection showed predominance of TCD4(+) lymphocytes and macrophages, but not of TCD8(+) cells, as well as a decrease of areas labeled with anti-iNOS antibodies as compared to the control. Higher levels of IL-4 and IL-10 mRNAs were found in the hearts and higher IL-10 and lower NO levels in splenocytes of vesicles pretreated animals. Treatment of mice with neutralizing anti-IL-10 or anti-IL-4 antibodies precluded the effects of pre-inoculation of membrane vesicles on infection. These results indicate that T. cruzi shed membrane components increase tissue parasitism and inflammation by stimulation of IL-4 and IL-10 synthesis and thus may play a central role in the pathogenesis of Chagas` disease acute phase. (c) 2008 Elsevier Masson SAS. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundagdo de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)[2004/03303-5]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNP

Leishmania spp.: isolamento de parasitos pela inoculação de macerados de biopsias de pacientes em camundongos deficientes em interferon gama

Isolation of Leishmania parasite and species identification are important for confirmation and to help define the epidemiology of the leishmaniasis. Mice are often used to isolate pathogens, but the most common mouse strains are resistant to infection with parasites from the Leishmania (Viannia) subgenus. In this study we tested the inoculation of interferon gamma knockout (IFNγ KO) mice with biopsy macerates from Leishmania-infected patients to increase the possibility of isolating parasites. Biopsies from twenty five patients with clinical signs of leishmaniasis were taken and tested for the presence of parasites. Immunohistochemical assay (IHC) and conventional histopathology detected the parasite in 88% and 83% of the patients, respectively. Leishmania sp. were isolated in biopsy macerates from 52% of the patients by culture in Grace's insect medium, but 13% of isolates were lost due to contamination. Inoculation of macerates in IFNγ KO mice provides isolation of parasites in 31.8% of the biopsies. Most isolates belong to L. (Viannia) subgenus, as confirmed by PCR, except one that belongs to L. (Leishmania) subgenus. Our preliminary results support the use of IFNγ KO mice to improve the possibility to isolate New World Leishmania species.O isolamento e a identificação da espécie de parasito do gênero Leishmania são importantes para a confirmação e auxiliam na epidemiologia da leishmaniose. Os camundongos são freqüentemente utilizados para isolar patógenos, porém, as linhagens mais comuns de camundongos são resistentes à infecção por parasitos do subgênero Leishmania (Viannia). Neste estudo, avaliamos a inoculação de macerados de biópsias de pacientes infectados em camundongos deficientes do gene do interferon gama (IFNγ KO) como um método para aumentar a possibilidade de isolar Leishmania spp. Biópsias de 25 pacientes infectados com Leishmania sp. foram avaliadas para a presença de parasitos pelos métodos de imunohistoquímica (IHC) e histopatologia convencional. Os parasitos foram observados, respectivamente, em 88% e 83% das biópsias. Leishmania sp. foi isolada de macerados de biópsia de 52% dos pacientes infectados, quando cultivados em meio Grace, porém, 13% destes isolados foram perdidos devido a contaminações. Inoculação dos macerados em camundongos IFNγ KO proporcionou o isolamento de parasitos oriundos de 31,8% dos pacientes. A maioria dos isolados pertence ao subgênero L. (Viannia), exceto um que pertence ao subgênero L. (Leishmania), como confirmado pela reação da polimerase em cadeia. Nossos resultados preliminares sugerem que o uso de camundongos IFNγ KO pode ser útil para aumentar a possibilidade de isolamento de leishmânias encontradas nas Américas.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)UFG - FunapeFAPEGSECTEC/GO - CNP

Interleukin-12 stimulation of lymphoproliferative responses in Trypanosoma cruzi infection

The cytokine interleukin-12 (IL-12) is essential for resistance to Trypanosoma cruzi infection because it stimulates the synthesis of interferon-γ (IFN-γ), a major activator of the parasiticidal effect of macrophages. A less studied property of IL-12 is its ability to amplify the proliferation of T or natural killer (NK) lymphocytes. We investigated the role of endogenously produced IL-12 in the maintenance of parasite antigen (T-Ag)-specific lymphoproliferative responses during the acute phase of T. cruzi infection. We also studied whether treatment with recombinant IL-12 (rIL-12) would stimulate T-Ag-specific or concanavalin A (Con A)-stimulated lymphoproliferation and abrogate the suppression that is characteristic of the acute phase of infection. Production of IL-12 by spleen-cell cultures during T. cruzi infection increased in the first days of infection (days 3–5) and decreased as infection progressed beyond day 7. The growth-promoting activity of endogenous IL-12 on T-Ag-specific proliferation was observed on day 5 of infection. Treatment of cultures with rIL-12 promoted a significant increase in Con A-stimulated proliferation by spleen cells from normal or infected mice. Enhanced T-Ag-specific proliferation by rIL-12 was seen in spleen cell cultures from infected mice providing that nitric oxide production was inhibited by treatment with the competitive inhibitor N(G)-monomethyl-l-arginine (NMMA). Enhancement of proliferation promoted by IL-12 occurred in the presence of neutralizing anti-interleukin-2 (IL-2) antibody, suggesting that this activity of IL-12 was partly independent of endogenous IL-2. Thymidine incorporation levels achieved with rIL-12 treatment of the cultures were ≈ 50% of those stimulated by rIL-2 in the same cultures

Implementation of integration strategies between primary care units and a regional general hospital in Brazil to update and connect health care professionals: a quasi-experimental study protocol

International audienceBackground: Better communication among field health care teams and points of care, together with investments focused on improving teamwork, individual management, and clinical skills, are strategies for achieving better outcomes in patient-oriented care. This research aims to implement and evaluate interventions focused on improving communication and knowledge among health teams based on points of care in a regional public health outreach network, assessing the following hypotheses: 1) A better-working communication process between hospitals and primary health care providers can improve the sharing of information on patients as well as patients' outcomes. 2) A skill-upgrading education tool offered to health providers at their work sites can improve patients' care and outcomes