No abstract

Leprosy and human immunodeficiency virus-1 (HIV-1) are examples of human infections where interactions between the pathogen and the host cellular immunity determine the clinical manifestations of disease. Hence, a significant immunopathological interaction between HIV-1 and leprosy might be expected. In the present study we explored several aspects of cellular immunity in patients co-infected with HIV-1 and Mycobacterium leprae. Twenty-eight individuals were studied, comprising four groups: healthy controls, HIV-1 and M. leprae co-infection, HIV-1 mono-infection, and M. leprae mono-infection. Subjects in the mono-infection and co-infection groups were matched as far as possible for bacillary load and HIV disease status, as appropriate. Peripheral blood mononuclear cells (PBMC) were analysed using six-and seven-colour flow cytometry to evaluate T-cell subpopulations and their activation status, dendritic cell (DC) distribution phenotypes and expression of IL-4 by T cells. The co-infected group exhibited lower CD4 : CD8 ratios, higher levels of CD8 + T-cell activation, increased Vd1 : Vd2 T cell ratios and decreased percentages of plasmacytoid DC, compared with HIV-1 mono-infected subjects. Across infected groups, IL-4 production by CD4 + T lymphocytes was positively correlated with the percentage of effector memory CD4 + T cells, suggesting antigenically driven differentiation of this population of T cells in both HIV-1 and M. leprae infections. Co-infection with M. leprae may exacerbate the immunopathology of HIV-1 disease. A T helper 2 (Th2) bias in the CD4 + T-cell response was evident in both HIV-1 infection and leprosy, but no additive effect was apparent in co-infected patients.

Because of its distinctive clinical features and histopathological characteristics, zosteriform connective tissue nevus is considered a separate entity from other connective tissue nevi. Only two cases have previously been reported in the worldwide dermatological literature. Here we report a zosteriform connective tissue nevus in a 3-year-old boy with similar clinical presentation.

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Relatamos um caso de actinomicose cutânea primária do pé simulando neoplasia de partes moles, com revisão da literatura sobre sua incidência, aspectos clínicos, patológicos e de imagem. Utilizamos radiografias simples, ressonância magnética e estudo anatomopatológico. A importância do estudo se deve à raridade da enfermidade, localização atípica e, particularmente, ao diagnóstico diferencial com neoplasia de partes moles.

In this report, we present and discuss the signal intensity of brain metastases from colon cancer on both T1- and T2-weighted images. In five of 6 cases, metastases were seen as markedly hypointense areas on T2-weighted images. This finding should alert one to the possibility of a primary cancer of the colon. Some haemorrhagic metastases from other malignancies also showed marked hypointensity. They usually exhibited hyperintensity on T1-weighted images. A case of colon metastasis was also haemorrhagic, and in this case a hyperintense area was observed on T1-weighted images. The marked hypointense area corresponded to peripheral necrosis and probably some viable tumour. Aetiologically, such hypointensity was not induced by severe fibrosis, calcification or excessive iron deposition.