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1.
Br J Dermatol ; 150(3): 570-4, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15030344

RESUMO

BACKGROUND: Nerve damage is a common and disabling feature of leprosy, with unclear aetiology. It has been reported that the peroxidizing agents of myelin lipids-nitric oxide (NO) and peroxynitrite-are produced in leprosy skin lesions. OBJECTIVES: To investigate the localization of nitrotyrosine (NT)-a local end-product of peroxynitrite-in leprosy lesions where dermal nerves are affected by a granulomatous reaction. METHODS: We investigated by immunohistochemistry and immunoelectron microscopy the localization of the inducible NO synthase (iNOS) and NT in biopsies exhibiting dermal nerves from patients with untreated leprosy. RESULTS: There were abundant NT-positive and iNOS-positive macrophages in the borderline leprosy granulomas infiltrating peripheral nerves identified by light microscopy, S-100 and neurofilament immunostaining. Immunoelectron microscopy showed NT reactivity in neurofilament aggregates and in the cell wall of Mycobacterium leprae. CONCLUSIONS: Our results suggest that NO and peroxynitrite could be involved in the nerve damage following borderline leprosy.


Assuntos
Hanseníase/metabolismo , Dermatopatias Bacterianas/metabolismo , Pele/inervação , Tirosina/análogos & derivados , Tirosina/análise , Granuloma/enzimologia , Granuloma/metabolismo , Granuloma/patologia , Humanos , Imuno-Histoquímica/métodos , Hanseníase/enzimologia , Hanseníase/patologia , Macrófagos/metabolismo , Microscopia Imunoeletrônica/métodos , Mycobacterium leprae/metabolismo , Óxido Nítrico Sintase/análise , Nervos Periféricos/metabolismo , Nervos Periféricos/patologia , Proteínas S100 , Pele/metabolismo , Pele/patologia , Dermatopatias Bacterianas/enzimologia , Dermatopatias Bacterianas/patologia
2.
Br J Dermatol ; 145(5): 809-15, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11736907

RESUMO

BACKGROUND: In the response to T-helper cell (Th1)-type cytokines and interactions with pathogens, high levels of nitric oxide (NO) are produced by activated macrophages expressing the inducible NO synthase (iNOS). The role and importance of reactive nitrogen intermediates (RNIs) such as NO and peroxynitrite in the host response to diseases caused by intracellular pathogens such as Mycobacterium leprae and M. tuberculosis is unclear. OBJECTIVES: The aim of this study was to investigate the presence of local production of NO and peroxynitrite in borderline leprosy by using antibodies against iNOS and the product of peroxynitrite, nitrotyrosine (NT). METHODS: We detected the presence of iNOS and NT in skin biopsies from borderline leprosy patients, with and without reversal reaction (RR), by immunohistochemistry (n = 26). RESULTS: In general, the granulomas from borderline leprosy lesions with and without RR showed high and specific expression of iNOS and NT. Moreover, strong immunoreactivity to iNOS and NT was observed in granulomas surrounding and infiltrating dermal nerves. The expression of iNOS and NT was also strong in keratinocytes, fibroblasts and endothelial cells in close relation to the granulomatous reaction. In contrast, normal human skin showed no expression of iNOS and NT in these cells. CONCLUSIONS: We conclude that iNOS and NT are expressed in granulomas from borderline leprosy patients with and without RR and propose that RNIs might be involved in the nerve damage following RR in leprosy.


Assuntos
Hanseníase Dimorfa/metabolismo , Óxido Nítrico Sintase/metabolismo , Tirosina/análogos & derivados , Tirosina/metabolismo , Biópsia , Humanos , Técnicas Imunoenzimáticas , Hanseníase Dimorfa/enzimologia , Hanseníase Dimorfa/patologia , Hanseníase Tuberculoide/enzimologia , Hanseníase Tuberculoide/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo II , Ácido Peroxinitroso/biossíntese , Pele/enzimologia , Pele/metabolismo
5.
Lancet ; 344(8916): 165-6, 1994 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-7912768

RESUMO

Between 1988 and 1992 three cross-sectional surveys for antibodies to HIV were done in 644 Ethiopian patients with histologically proven leprosy. Whereas the frequency of HIV-1 infection gradually increased from 3.2% to 6.5%, the clinical presentation, number of new patients, and frequency of relapse did not differ between HIV negative and positive patients. Thus HIV appears unlikely to have a significant impact on the incidence of leprosy in sub-Sahelian populations.


Assuntos
Infecções por HIV/epidemiologia , HIV-1 , Hanseníase/epidemiologia , Adulto , Estudos Transversais , Etiópia/epidemiologia , Feminino , Infecções por HIV/complicações , Humanos , Hanseníase/complicações , Masculino , Morbidade
6.
Lepr Rev ; 64(2): 104-9, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8341112

RESUMO

A total of 220 untreated leprosy patients who underwent parallel skin and nerve biopsies are included in this study, which is intended to evaluate the extent of previously reported differences in bacillary load between skin and nerve lesions in leprosy and to describe the response of peripheral blood lymphocytes to Mycobacterium leprae antigens in such patients. In 161 patients out of the 220, the skin and nerve biopsies were diagnostic for leprosy. When patients were grouped according their skin and nerve lesions, the 3 groups observed were (1) paucibacillary skin and nerve lesions; (2) multibacillary skin and nerve lesions, and (3) paucibacillary skin and multibacillary nerve lesions. There was no observation of a group of patients with multibacillary skin and paucibacillary nerve lesions. In all patients with multibacillary nerve lesions, regardless of the type of skin lesions, a low response of peripheral blood lymphocytes to M. leprae was consistently noted. These results suggest that the bacillary load in the nerve is certainly one of the factors determining the immunological spectrum observed in leprosy.


Assuntos
Hanseníase/microbiologia , Mycobacterium leprae/isolamento & purificação , Nervos Periféricos/microbiologia , Humanos , Hanseníase/patologia , Nervos Periféricos/patologia , Pele/microbiologia , Pele/patologia
8.
Int J Lepr Other Mycobact Dis ; 58(3): 560-5, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2401839

RESUMO

A technique for immunoelectronmicroscopy has been used to investigate major histocompatibility class II expression in leprosy nerves. In normal nerves, endothelial cells and occasional endoneural cells (not Schwann cells) were constitutively class II positive. In both paucibacillary and multibacillary leprosy nerve biopsies, infiltrating leukocytes were positive but class II-positive Schwann cells were not seen. These observations indicate that Schwann cells may not be involved in presenting Mycobacterium leprae antigens to T cells in leprosy. This conflicts with evidence from in vitro studies, but may be explained by the fact that in vivo Schwann cells are surrounded by basement membranes and are closely associated with axons.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Antígenos de Histocompatibilidade Classe II/análise , Hanseníase/imunologia , Nervos Periféricos/imunologia , Endotélio/imunologia , Fibroblastos/imunologia , Humanos , Imuno-Histoquímica , Linfócitos/imunologia , Macrófagos/imunologia , Microscopia Eletrônica
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