Presence of chromatoid bodies in the Rhodnius genus detected by cytochemical analysis.

In addition to the epidemiological importance regarding the transmission of Chagas disease, triatomines are also important biological models for cellular studies, because they have holocentric chromosomes, post-reductional meiosis for sex chromosomes, and nucleolar persistence. Although the nucleolus is present during spermiogenesis, it was suggested that it is inactivated and all transcriptional activity necessary for cell differentiation is supported by the chromatoid body (CB). Thus, considering the importance of CB to triatomine spermatogenesis, this paper aims to analyze the presence of this organelle in the Rhodnius genus. The testicles of five adult R. neglectus and R. prolixus males were analyzed after semi-fine sections were performed, and the material was subjected to silver ion impregnation. The CB organelle was found in the spermatid of both species. Most CB studies focused on the Triatoma genus. This study described the existence of CB in Rhodnius, confirming thus the importance of this cytoplasmic organelle to spermiogenesis of these insect vectors of Chagas disease.

Entoepidemiology of Chagas disease in northwest São Paulo and cytogenetic analysis of its main vector, Triatoma sordida (Hemiptera: Triatominae).

One century after the discovery of Chagas disease, it is still considered as a major health problem, causing more deaths in the Americas than any other parasitic disease. The northwest region of São Paulo, a macro-region that includes cities with a high-quality of life, has particularly high rates of Chagas disease. Therefore, this study aimed to assess the number of patients with Chagas disease, and to identify the triatomine fauna in the northwest region of São Paulo State, and to cytogenetically analyze Triatoma sordida mutants, thus providing new knowledge to control these species and avoid possible infections by Chagas disease. A total of 700 Chagas patients of both genders and variable age, who were born in and residents of the northwest region of the State of São Paulo were recruited for this study. Regarding the entoepidemiological fauna, both T. sordida and Rhodnius neglectus were captured from 2004 to 2011 in the northwest region of the São Paulo; however, T. sordida was the predominant species. Some of these collected triatomines were infected by Trypanosoma cruzi in several developmental stages. Furthermore, the lactoacetic orcein method was used for cytogenetic analysis. Several abnormalities were observed during meiosis of the T. sordida mutants, including condensed chromosomes with no chiasma, chromatin bridges between the autosomes, and some non-pairing homologous chromosomes. Thus, our study suggests that Chagas disease is currently not under control in Brazil. Furthermore, we suggest that cryptic speciation may be occurring in populations of T. sordida of Brazil. Further studies are necessary to understand the mechanisms behind these phenomena.

Hemorragia digestiva e ingestao de drogas. / Digestive hemorrhage and drug ingestion

Os autores estudaram 278 pacientes, entre 635 com hemorragia digestiva, examinados endoscopicamente na vigencia da hemorragia no periodo de maio de 1972 a setembro de 1981. So foram incluidos aqueles com lesoes gastricas e duodenais, sendo tambem excluidas as neoplasias destes orgaos. O grupos total foi dividido em Grupo 1 com historia de ingestao de drogas nas ultimas 24 e 48 horas anteriores ao acidente hemorragico e Grupo II, sem esta historia.Foi verificado que 37,7% dos pacientes com hemorragia digestiva pertenciam ao Grupo I que neste mesmo grupo a principal causa da hemorragia foi a ulcera gastrica (49%). Os autores concluem tambem que as drogas consideradas ulcerogenicas lesam preferentemente o estomago, sendo a diferenca entre as lesoes deste orgao e do duodeno, estatisticamente significante (p 0,05).As drogas que mais comumente estiveram envolvidas com a hemorragia digestiva foram o acido acetil salicilico e seus derivados.Julgam que medidas acauteladoras devem ser tomadas em relacao ao uso das drogas consideradas ulcerogenicas