Expression of B7-1 costimulatory molecules in patients with multibacillary leprosy and reactional states.

BACKGROUND: The expression of B7 as a costimulatory molecule on the surface of antigen-presenting cells such as macrophages and on dendritic cells characterizes the efficiency of the cell-mediated immune response. AIMS: Our purpose was to evaluate B7-1 expression in peripheral blood mononuclear cells (PBMCs) immediately after cell isolation ('spontaneous' B7 expression), and in inflammatory cells from cutaneous lesions of patients with multibacillary leprosy (MB-L) without and during the reactional states of erythema nodosum leprosum (ENL) or reversal reaction (RR). METHODS: Peripheral blood samples and skin biopsies of eight patients without (MB-L) and with reactional episodes (ENL and RR) were studied using antibodies against B7-1, CD1b, DR and CD14 in flow-cytometry and immunohistochemistry experiments. RESULTS: The flow-cytometry studies (mean +/- SD% of fluorescent cells) revealed significant B7-1 expression on PBMCs isolated from patients with ENL (8.0 +/- 0.6%) and RR (15.0 +/- 1.4%) compared with that observed for patients with MB-L (0.4 +/- 0.2%). Similar results were observed for cutaneous lesions of these patients by immunohistochemical assays. One patient studied before and during ENL revealed weak B7 expression before the reactional episode (0.3% of cells) compared with the marked level of B7-expressing cells detected during ENL (8.5% fluorescent cells). Interestingly, an even higher B7 expression (15% of cells) was observed in patients with RR. CONCLUSIONS: Our results strongly suggest that B7 expression precedes reactional episodes in MB-L, which could be related to the acquisition of effective immunity to Mycobacterium leprae during reactional episodes in leprosy. We propose B7 expression as a marker of CMI response in reactional episodes in leprosy.

[The enteroparasitic contamination of commercial vegetables in the cities of Niterói and Rio de Janeiro, Brazil]. / Contaminação por enteroparasitas em hortaliças comercializadas nas cidades de Niterói e Rio de Janeiro, Brasil.

The aim of this study was to evaluate the parasitological contamination of vegetables to be consumed raw and commercialized in Niterói and Rio de Janeiro cities. We studied 128 samples of vegetables--lettuce (Lactuca sativa) and watercress (Nasturtium officinale)--from supermarkets, greengrocer shops and self-service restaurants. Only 6.2% of the samples were positive for parasitic structures with morphological aspects similar to those of animal parasites. We detected acarids, acarid eggs, insects, nematode larvae and ciliated protozoa in most of the samples (96.1%), including those from restaurants. This high percentage suggests a risk of human infection since parasite structures capable of infecting man may exist in association with these agents.

Paleoparasitology: perspectives with new techniques.

Paleoparasitology is the study of parasites found in archaeological material. The development of this field of research began with histological identification of helminth eggs in mummy tissues, analysis of coprolites, and recently through molecular biology. An approach to the history of paleoparasitology is reviewed in this paper, with special reference to the studies of ancient DNA identified in archaeological material.

Experimental paleoparasitology: identification of Trypanosoma cruzi DNA in desiccated mouse tissue.

The polymerase chain reaction (PCR) has been used for clinical diagnosis of infectious disease and to research ancient animal and microbiological DNA from a wide range of tissues. PCR was used to study the possibility of Trypanosoma cruzi kinetoplast DNA (kDNA) extraction from experimentally desiccated mouse tissue (heart, skeletal muscle, liver, spleen, and pancreas). The results obtained suggest the application of this technique to T. cruzi detection in archaeological material.

Correlation between tissue damage and malondialdehydemia in mice infected with Trypanosoma cruzi.

Evolution of the acute phase of experimental Chagas' disease was correlated with tissue damage and plasma levels of malondialdehyde. Heart lesions were quantified by the Tissue Damage Unit (TDU) and malondialdehydemia (MDA) by the colorimetric determination of malondialdehyde. The binary correlations were: C(X,Y) = 0.965 (P less than 0.001); C(Y,Z) = 0.784 (P less than 0.01); and C(X,Z) = 0.824 (P less than 0.01), where X = days of infection, Y = TDU means and Z = MDA means. These results show a positive correlation between the duration of the acute phase of experimental Chagas' disease and TDU, and between the duration and MDA. The methods for measuring tissue damage and MDA are shown to be simple and adequate for monitoring tissue aggression in the protozoosis studied.

Malondialdehydemia and parasitemia during acute phase of experimental Chagas' disease in mice.

Parasitemia and malondialdehydemia were compared during the acute phase of the infection caused by the CL and Y strains of T. cruzi. Parasitemia was measured by counting blood trypomastigote forms, and malondialdehydemia by a colorimetric method. The duration of the acute phase of Chagas' disease was correlated with malondialdehydemia in both CL and Y strains. The correlations between parasitemia and duration of the acute phase, as well as between parasitemia and malondialdehydemia, were significant only in the group infected with the CL strain. These data suggest that malondialdehydemia may be an adequate parameter for evaluating and monitoring the acute phase in experimental Chagas' disease.

Correlation between tissue damage and malondialdehydemia in mice infected with Trypanosoma cruzi

Evolution of the acute phase of experimetnal Chagas' disease was correlated with tissue damage and plasma levels of malondialdehyde. heart lesions were quantified by the Tissue Damage Unit (TDU) and malondialdehydemia (MDA) by the colorimetric determination of malondialdehyde. the binary correlations were: C(X,Y) =0.965 (P < 0.001); C(y,Z) =0.784 (P < 0.01); and C(X,Z) =0.824 (P < 0.01), where X = days of infection, Y = TDU means and Z = MDA means. These results show a positive correlation between the duration of the acute phase of experimental Cchagas' disease and TDU, and between the durtion and MDA. The methods for measuring tissue damage and MDA are shown to be simple and adequate for monitoring tissue aggression in the protozoosis studied

Malondialdehydemia and parasitemia during acute phase of experimental Chagas' disease in mice

Parasitemia and malondialdehydemia were compared during the acute phase of the infection caused by the CL and Y strains of T. cruzi. Parasitemia was measured by counting blood trypamastigote forms, and malondialdehydemia by a colorimetric method. The duration of the acute phase of Chagas' disease was correlated with malondialdehydemia in both CL and y strains. The correlations between parasitemia and duration of the acute phase, as well as between parasitemia and malondialdehydemia, were significant only in the group infected with the CL strain. These data suggest that malondialdehydemia may be an adequate parameter for evaluating and monitoring the acute phase in experimental Chagas' disease