Falciparum malaria in naturally infected human patients: X . Ultrastructural pathological alterations of renal glomeruli

The ultrastructural pathological alteration of the renal glomeruli is described in nine patients with acute Plasmodium falciparum infection. Glomeruli were large and hypercellular with various types of blood cells in their capillary lumena. These were occasionally occluded with enlarged endothelial cells. Epithelial cells, or podocytes, were hypertrophied with extensively diffused fool processes fusion and numerous villous transformation, or appeared aedematous filling the urinary space. The glomeruli basement membrane was irregular in thickness or focally missing. Mesangial cells were undergoing proliferation and contained electron-dense deposits. Subendothelial "hump"-like deposits, similar to those previously described in immune complex nephritis, were detected in most cases; but the largest amount was found in three youngest patients in whom parasitaemia levels were the highest. This study showed that the kidney may become the target damage mediated by immuno-pathologic mechanism, and the developed lesions may correspond, for certain extent, to membranoproliferative glomerulonephritis with abnormal deposits, during the acute infection with falciparum malaria. The amount and density of the immune complex deposit could be correlated with the degree of parasitaemia and, in return, with the degree of glomerular immunopathological alterations

Human cutaneous leishmaniasis: ultrastructural interactions between the inflammatory cells and leishman bodies in the skin lesions

The ultrastructural interactions between the inflammatory infiltrate and Leishman bodies (LBs) were described in skin lesions from 16 patients with acute cutaneous leishmaniasis. In early stages of the inflammation, the cellular infiltrate consisted of both undifferentiated and differentiated (activated) monocytes (M), macrophages (Mc), multinucleated giant cells (MNGC), plasma cells (PC), lymphocytes (Ly), and fibroblasts (F). In late stages, the infiltrate was in the form of tuberculous granulomas consisted mainly of type I secretory, and type II vesicular epithelioid cells (ECs), in addition to remnant of some inflammatory cells seen in the early stages. The two types of ECs were found only in six patients. The activated M, Mc and MNGC were often parasitized by LBs. The parasites were enclosed within the host cell digestive vacuoles (DVs), or phagolysosomes, together with skin melanosomes which are known to have lysosomal effect. In the DVs, LBs either survived or were killed and expelled from the host cell cytoplasm. This study showed, for the first time, that the melanosomes were apparently involved in killing of the LBs possibly by increasing the fatal effects of the DVs hydrolytic enzymes. Plasma cells were packed with large « Russell's bodies » indicating a high cellular immunoglobulin activity. The large, granular lymphocytes were in close contact to the activated M, possibly to promote delivery of activation signals. The type I secretory ECs contained mucin-like granules with electrondense cores. In late stages of inflammation, the type II vesicular ECs contained lysosomal granules, and were found together with the type I ECs in broken-down tuberculous granulomas. The type I secretory ECs were previously thought to produce a mediator, or « granuloma factor » which recruits undifferentiated mononuclear cells to perpetuate the granulomatous process; while the type II vesicular ECs were thought to appear where the granulomatous process in brought to an end, preceeding the healing by fibrosis

Caracterização dos tipos celulares presentes na hemolinfa de larvas e ninfas de Rhipicephalus sanguineus (Latreille) (Ixodoidea, Ixodidae) em diferentes estados nutricionais Characterization of the celular types present in the Haemolymph of larvae and nimphs of Rhipicephalus sanguineus (Latreille) (Ixodoidea, Ixodidae) in different nutritional stages

<abstract language="eng">With the purpose of characterize morphologically the hemocytes of larvae and nymphs of Rhipicephalus sanguineus on different nutritional phases, it was obtained samples of haemolymph were obtained by sectioning the forelegs and collecting the drop there formed. After dried, the samples were fixed by methanol and stained by Giemsa. Microscopical observation resulted in the characterization of five basic cellular types: prohemocytes, plasmatocytes, granulocytes, spherulocytes and oenocytoids. Moreover, undefined cell types, whose morphological patterns didn't have correlation with the characteristics cited for hemocytes, were found in low frequency. The change in the relative composition of the haemolimph was characterized by decrease of the number of granulocytes and greater variabilily of the cell types present in the hemolymph as the tick evolved. This fact may be linked to the alterations that these cells suffer along the development of the tick