Biological characterization of Trypanosoma cruzi epimastigotes derived from trypomastigotes isolated from Brazilian chagasic patients.

Chagas disease (CD), caused by Trypanosoma cruzi, occurs in several countries in Latin America and non-endemic countries. Heterogeneity among T. cruzi population has been the Achilles' heel to find a better treatment for CD. In this study, we characterized the biochemical parameters and mitochondrial bioenergetics of epimastigotes differentiated from eight T. cruzi isolates (I1-I8) obtained from Brazilian CD patients. Molecular analysis of parasites DTUs grouped all of them as TcII. The profile of the growth curves in axenic cultures was distinct among them, except for I1 and I3 and I2 and I4. Doubling times, growth rates, cell body length, and resistance to benznidazole were also significantly different among them. All the isolates were more glucose-dependent than other T. cruzi strains adapted to grow in axenic culture. Mitochondrial bioenergetics analysis showed that each isolate behaved differently regarding oxygen consumption rates in non-permeabilized and in digitonin-permeabilized cells in the presence of a complex II-linked substrate. When complex IV-linked respiratory chain substrate was used to provide electrons to the mitochondrial respiratory chain (MRC), similarity among the isolates was higher. Our findings show that TcII epimastigotes derived from patients' trypomastigotes displayed their own characteristics in vitro, highlighting the intra-TcII diversity, especially regarding the functionality of mitochondrial respiratory complexes II and IV. Understanding T. cruzi intraspecific biological features help us to move a step further on our comprehension regarding parasite's survival and adaptability offering clues to improve the development of new therapies for CD.

Estudo da anomalia de Pelger-Huët em núcleo familiar: [carta ao editor] / Pelger-Huët anomaly study in a family: [letter to the editor]

The Pelger-Huët anomaly is a dominant autosomal disease, characterized by the incomplete segmentation of the granulocytes nucleus without lost of the cellular function. The heterozygotes form of this anomaly is assintomatic and it did not possess physic meant, while the homozygote form is rare and can be lethal, being therefore, important differentiates of other infectious alterations. The pseudo-anomaly can occasionally be observed in cases of granulocitic leukemia, mieloproliferatives Diseases, some infections and after exposition the determined drugs. We evaluate eleven members of a familiar nucleus and, after the blood cells analysis, six of then had presented neutrophils and eosinophils with nuclei characteristic of the heterozygotes form of the Pelger-Huët anomaly. The recognition of this leukocyte anomaly, mainly in patients without infection and presenting great number of not segmented neutrophils, can prevent wrong interpretations of the blood cells count and unnecessary clinical and therapeutically behaviors.

Tromboembolismo venoso e terapia de reposiçäo hormonal da menopausa: uma análise clínico-epidemiológica / Venous thromboembolism and hormonal replacement therapy in menopause: a clinical-epidemiological analysis

A terapia de reposiçäo hormonal da menopausa (TRHM) tem sido empregada de forma crescente, visando benefícios a curto, médio e longo prazo. A ocorrência de potenciais riscos, incluindo câncer de mama, câncer endometrial e fenômenos tromboembólicos, está em constante avaliaçäo. A associaçäo entre a TRHM e risco de tromboembolismo venoso (TEV) tem sido alvo de muitas controvérsias. Vários estudos observacionais têm mostrado que mulheres usando TRHM possuem maior risco de TEV, principalmente no primeiro ano de reposiçäo. Limitações metodológicas, controle inadequado de fatores de confundimento e outros vieses podem superestimar esse risco. A maioria dos estudos epidemiológicos disponíveis säo de caso-controle e poucos ensaios clínicos bem desenhados foram realizados para analisar essa possível associaçäo. As publicações existentes na Medline sobre o assunto, nos últimos 10 anos, foram levantadas, utilizando-se como palavras-chave para a busca: terapia de reposiçäo hormonal, menopausa, tromboembolismo venoso, estrogênios e hemostasia. Publicações mais antigas de maior relevância foram também incluídas. Neste texto, faz-se uma análise da plausibilidade biológica e da consistência clínica-epidemiológica dessa associaçäo. Concluiu-se que as mulheres usuárias da TRHM têm risco relativo de tromboembolismo venoso entre 2,1 e 3,5. O risco absoluto tem a dimensäo de 14 a 32 eventos por 100.000 mulheres/ano.