Canine trypanosomiasis: etiology of infection and implications for public health

Canine trypanosomiasis, caused by protozoans of the genus Trypanosoma, is divided into two primary types: the American form (Chagas disease), due to Trypanosoma cruzi infection, and the African form (sleeping sickness or surra), provoked by Trypanosoma evansi. This disease was originally enzootic and affected only wild animals, including mammals and birds, which served as reservoirs. Later, it spread to domestic animals such as horses, cattle and dogs. The disease became a zoonosis when contact between rural inhabitants and natural Trypanosoma foci occurred, due to ecological imbalances and increasing migration. Dogs are significantly involved in this context, because they are the main domestic animals and participate in the transmission and maintenance cycles of these parasites. This article reports etiological, epidemiological and public health aspects of canine trypanosomiasis, and the most important peculiarities of this zoonosis in dogs.

Treatment with Azadirachta indica in diabetic pregnant rats: Negative effects on maternal outcome

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Active surveillance of canine visceral leishmaniasis and american trypanossomiasis in rural dogs from non endemic area

A leishmaniose visceral canina (LVC) e a tripanossomíase americana são importantes zoonoses para a saúde pública que encontram no cão o principal reservatório doméstico para o homem. O trabalho procurou estimar a prevalência de anticorpos circulantes anti-Trypanosoma cruzi e anti-Leishmania spp., em amostras de cães provenientes da zona rural do município de Botucatu, SP. Durante a campanha de vacinação antirrábica canina da zona rural do município, foram coletadas 689 amostras de soro e processadas pela técnica de imunofluorescência indireta. Os testes sorológicos revelaram a ausência de anticorpos anti-Leishmania spp. e, na pesquisa dos anticorpos anti-T. cruzi, foram detectados 3 (0,4%) cães.

A Generalized Log-Normal Model for Grouped Survival Data

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Immunodominant Antigens of Leishmania chagasi Associated with Protection against Human Visceral Leishmaniasis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Chromosomal location of heterochromatin and 45S rDNA sites in four South American triatomines (Heteroptera: Reduviidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Phylogenetic approach to the study of Triatomines (Triatominae, Heteroptera)

Os triatomíneos são insetos pertencentes à ordem Hemiptera, subordem Heteroptera, família Reduviidae e subfamília Triatominae. Todos os membros desta subfamília são hematófagos. Os triatomíneos surgiram a partir de reduvídeos predadores e provavelmente têm origem polifilética. A combinação dos fatores anatômicos, fisiológicos e etológicos presentes no grupo, bem como os caracteres plésio e apomórficos que diferenciam as cinco tribos e os quatorze gêneros de triatomíneos reforçam a hipótese polifilética. As tribos Rhodniini, Cavernicolini, Bolboderini, Linshcosteini e Alberproseniini constituem grupos monofiléticos, per si, enquanto a tribo Triatomini é considerada polifilética. O Novo Mundo é claramente o centro de diversidade dos triatomíneos e possivelmente é a região de sua origem. Entre as aproximadamente 129 espécies desses insetos, 105 ocorrem somente nas Américas. Atualmente, os triatomíneos são considerados um grupo polifilético, definido com base em seus caracteres apomórficos convergentes relacionados à hematofagia. Acredita-se que este hábito alimentar tenha surgido várias vezes nos Reduviidae durante sua evolução. O presente trabalho faz uma revisão sobre a filogenia destes vetores da Doença de Chagas, aborda tópicos como a origem da hematofagia nos triatomíneos e ancestralidade proposta para o grupo.

Chromatoid body: Remnants of nucleolar proteins during spermatogenesis in triatomine (Heteroptera, Triatominae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Differential distribution of some extracellular matrix fibers in an experimentally denervated rat megaileum

Absence of enteric neurons is associated with thickening of the intestinal muscularis externa in Chagas' disease. The thickening is due to hyperplasia and hypertrophy of the smooth muscle cells and increased extracellular matrix components. The influence of the nervous system on the structure of the smooth muscle cells and its associated matrix has been poorly investigated. An experimental model of denervation of the ileum in rats was performed by application of the surfactant agent benzalkonium chloride that selectively destroys the myenteric plexus. Three months later, ileal tissue samples were obtained and studied by histochemistry and transmission electron microsocopy. Sham operated rats were used as controls. The diameter of collagen fibrils was evaluated in electron micrographs. The histopathological analysis showed thickening of the muscular layer. The thin and weakly arranged collagen and reticulin fibers surrounding the smooth muscle cells, observed in control cases by Picrosirius polarization (PSP) stain method, corresponded to a population of loosely packed thin collagen fibrils of uniform diameters (mean = 29.16 nm) at the ultrastructural level. In contrast, the thick and strongly birefringent fibers around the muscle cells, observed in the treated group, stained by PSP, corresponded to densely packed thicker fibrils with large variation in diameter (mean = 39.41 nm). Comparison of the data demonstrated statistically significant difference between the groups suggesting that the replacement of loosely arranged reticulin fibers by fibrous tissue (with typical collagen fiber), may alter the biomechanical function resulting in impairment of muscular contraction. (c) 2007 Elsevier Ltd. All rights reserved.

Spermatogenesis and nucleolar activity in Triatoma klugi (Triatomine, Heteroptera)

Triatoma klugi is a Chagas disease vector in the Rio Grande do Sul State. Triatominae chromosomes are holocentric and sex chromosomes segregation is post-reductional. In this paper we describe the karyotype of male T. klugi and a meiotic analysis including the nucleolar behavior during spermatogenesis. Testis cells were analyzed after lacto-acetic orcein and silver nitrate staining. Two autosomes and the heterochromosomes presented nucleolar activity (Ag-NORs) during diplotene-diakinesis. The analysis of metaphase I and II revealed a karyotype with 2n = 20+XY. In metaphase I a prominent nucleolar mass was observed in the cell periphery and small silver grains were detected in metaphase II. During anaphase, the chromosomes segregated in parallel and a typical holocentric late migration behavior was observed. The restoration of the nucleolus was an important feature in this phase. During telophase nucleolar masses persisted and in early spermiogenesis the spermatids presented a small peripheral mass until elongation. The present study is a contribution to the study of chromatin behavior and nucleolar persistence in meiosis.

kDNA gene signatures of Trypanosoma cruzi in blood and oesophageal mucosa from chronic chagasic patients

Trypanosoma cruzi presents a high degree of intraspecific variability, with possible implications for the pathogenesis of Chagas disease. The aim of this study was to evaluate T cruzi kDNA minicircle gene signatures using the low-stringency single-specific-primer PCR technique in both peripheral blood and oesophageal. mucosa from chronic chagasic patients, with or without megaesophagus, atone or in combination with cardiopathy and megacolon. It was not possible to identify a uniform pattern of shared bands between blood and oesophageal mucosa samples from individuals with the same clinical. form or mixed forms, suggesting multiple T. cruzi infections with differential tissue tropism. Thus, the results indicate that there is an intense intraspecific variability in the hypervariable regions of T cruzi kDNA, which has so far made it impossible to correlate the genetic profile of this structure with the clinical manifestations of Chagas disease. (C) 2008 Royal. Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. AIL rights reserved.

Cytochemical characterization of Triatoma infestans and Panstrongylus megistus salivary gland cells (Hemiptera, Reduviidae, Triatominae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Expression of Ki-67 Antigen and Caspase-3 Protein in Benign Lesions and Esophageal Carcinoma

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

On the search for potential anti-Trypanosoma cruzi drugs: Synthesis and biological evaluation of 2-hydroxy-3-methylamino and 1,2,3-triazolic naphthoquinoidal compounds obtained by click chemistry reactions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

In vitro activity of compounds isolated from Piper crassinervium against Trypanosoma cruzi

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)