Antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, on Leishmania (Leishmania) amazonensis

BACKGROUND Leishmaniasis, a neglected disease caused by the parasite Leishmania, is treated with drugs associated with high toxicity and limited efficacy, in addition to constant reports of the emergence of resistant parasites. In this context, snake serums emerge as good candidates since they are natural sources with the potential to yield novel drugs. OBJECTIVES We aimed to show the antileishmanial effects of γCdcPLI, a phospholipase A2 inhibitor from Crotalus durissus collilineatus snake serum, against Leishmania (Leishmania) amazonensis. METHODS Promastigotes forms were exposed to γCdcPLI, and we assessed the parasite viability and cell cycle, as well as invasion and proliferation assays. FINDINGS Despite the low cytotoxicity effect on macrophages, our data indicate that γCdcPLI has a direct effect on parasites promoting an arrest in the G1 phase and reduction in the G2/M phase at the highest dose tested. Moreover, this PLA2 inhibitor reduced the parasite infectivity when promastigotes were pre-treated. Also, we demonstrated that the γCdcPLI treatment modulated the host cell environment impairing early and late steps of the parasitism. MAIN CONCLUSIONS γCdcPLI is an interesting tool for the discovery of new essential targets on the parasite, as well as an alternative compound to improve the effectiveness of the leishmaniasis treatment.

Evaluation of pathogen P21 protein as a potential modulator of the protective immunity induced by Trypanosoma cruzi attenuated parasites

BACKGROUND TcP21 is a ubiquitous secreted protein of Trypanosoma cruzi and its recombinant form (rP21) promotes parasite cell invasion and acts as a phagocytosis inducer by activating actin polymerisation in the host cell. OBJECTIVE Our goal was to evaluate if the additional supplementation of rP21 during a prime/boost/challenge scheme with T. cruzi TCC attenuated parasites could modify the well-known protective behavior conferred by these parasites. METHODS The humoral immune response was evaluated through the assessment of total anti-T. cruzi antibodies as well as IgG subtypes. IFN-γ, TNF-α and IL-10 were measured in supernatants of splenic cells stimulated with total parasite homogenate or rP21. FINDINGS Our results demonstrated that, when comparing TCC+rP21 vs. TCC vaccinated animals, the levels of IFN-γ were significantly higher in the former group, while the levels of IL-10 and TNF-α were significantly lower. Further, the measurement of parasite load after lethal challenge showed an exacerbated infection and parasite load in heart and skeletal muscle after pre-treatment with rP21, suggesting the important role of this protein during parasite natural invasion process. MAIN CONCLUSION Our results demonstrated that rP21 may have adjuvant capacity able to modify the cytokine immune profile elicited by attenuated parasites.

Detection of Cryptosporidium - specific coproantigen in human immunodeficiency virus/acquired immunodeficiency syndrome patients by using a commercially available immunoenzymatic assay

The aim of this study was to verify the occurrence of Cryptosporidium infection in 52 human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients (group 1) and 38 clinically healthy individuals (group 2) by using enzyme immunoassay (EIA). All fecal samples collected were submitted to the Baermann, Lutz, and Ritchie methods, the Safranin/Methylene Blue, and Weber's chromotrope modified Trichrome staining techniques, and EIA. In group 1, parasitological staining techniques and EIA were both positive for Cryptosporidium sp. infection in 3/52 (5.8 percent) samples and both negative in 45/52 (86.5 percent) samples, while 4/52 (7.7 percent) samples were positive in EIA and negative in parasitological staining techniques. Concerning group 2, all samples were negative by EIA and microscopy for Cryptosporidium infection. In conclusion, EIA may be an alternative method for detecting Cryptosporidium-specific coproantigen in HIV/AIDS patients.

Intestinal parasites and commensals among individuals from a landless camping in the rural area of Uberlândia, Minas Gerais, Brazil

We evaluated the occurrence of intestinal parasites and commensals among children and adults from a landless camping in the rural area of Uberlândia, State of Minas Gerais, Brazil, from October to November 2001. Stool samples from 78 individuals were examined by both the Baermann-Moraes and Lutz methods. Fifty-one (65.4 percent; CI 54.8 - 76.0) individuals were found to be infected, 23 (45.1 percent) children and 28 (54.9 percent) adults, of whom 34 (66.7 percent) were mono-infected, 9 (17.6 percent) bi-infected, and 8 (15.7 percent) poly-infected. In conclusion, the high prevalence of intestinal parasites and commensals suggests that parasitological exams should be periodically carried out in addition to the sanitation education and health special care in this population

Aspectos eletroencefalográficos na disfunçäo cerebral mínima / Electroencephalographic aspects of minimal brain dysfunction

Os AA analisaram 50 casos de pacientes portadores de disfunçäo cerebral mínima e concluíram que o eletroencefalograma pode ser normal ou exteriorizar (1) atividade lenta posterior; (2) assimetria e assincronia da atividade; (3) descargas na faixa "theta" com ondas de morfologia espiculada e distribuiçäo difusa; (4) ondas de morfologia espiculada no lobo temporal; (5) complexo ponta-onda difuso

Disfunçäo cerebral mínima / Minimal brain dysfunction

Nossa casuística consiste de cinqüenta casos de disfunçäo cerebral mínima retirados de maneira näo selecionada, entre aqueles que foram avaliados e acompanhados por nós, durante o período de maio de 1975 a maio de 1983. Verificamos predominância do sexo masculino sobre o feminino em torno de 3:1, e maior freqüência de pacientes de cor branca. O desenvolvimento da sintomatologia pode ocorrer em qualquer faixa etária, sendo mais freqüente na idade pré-escolar entre seis e oito anos. As manifestaçöes clínicas predominantes foram a hiperatividade, alteraçöes do sono e dificuldade de aprendizagem

Vascularizaçäo da medula espinhal do gambá / Vascular supply of the opossum's spinal cord

A medula espinhal do gambá (Didelphis marsupialis aurita) apresenta na face ventral três e na face dorsal duas artérias e no mínimo três veias com disposiçäo crânio-caudal. Os vasos radiculares anastomosam-se com os vasos espinhais dorsais e ventrais. As veias dos segmentos cervicais dirigem-se para os seios venosos da dura-máter. Os vasos centrais (sulco-comissurais) penetram na mudula espinhal pela fissura mediana ventral e, ao nível da comissura branca ventral, curvam-se, em geral alternadamente, em direçäo à cabeça da coluna cinzenta ventral. Outros vasos penetram pelas faces ventral, lateral e dorsal da medula espinhal. Cada artéria intramedular tem a seu lado uma veia, formando pares vasculares que näo se anastomosam entre si. Os capilares formados do encontro das arteríolas com as vênulas dos pares vasculares terminais adquirem o formato de alças