Dopa-stained melanocytes in the macular lesions of early leprosy
The mechanism of association of hypopigmentation and sensorial loss in a leprosy macular lesions has not been clarified yet. The biopsy of a macular lesion on the medial face of the right forearm of a fourteen-year old male leprosy patient was submitted to DOPA-staining for melanocytes, which is sp...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Instituto Lauro de Souza Lima
1996-11-01
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| Series: | Hansenologia Internationalis |
| Online Access: | https://periodicos.saude.sp.gov.br/hansenologia/article/view/36475 |
| _version_ | 1827583294009507840 |
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| author | Sérgio Luiz Gomes Antunes Samantha Lee Salgueiro Alves Suzana Corte-Real Maria Nazaré Meireles José Augusto da Costa Nery Euzenir Nunes Sarno |
| author_facet | Sérgio Luiz Gomes Antunes Samantha Lee Salgueiro Alves Suzana Corte-Real Maria Nazaré Meireles José Augusto da Costa Nery Euzenir Nunes Sarno |
| author_sort | Sérgio Luiz Gomes Antunes |
| collection | DOAJ |
| description |
The mechanism of association of hypopigmentation and sensorial loss in a leprosy macular lesions has not been clarified yet. The biopsy of a macular lesion on the medial face of the right forearm of a fourteen-year old male leprosy patient was submitted to DOPA-staining for
melanocytes, which is specific for the melanocytic tyrosinase enzyme and it is a proper method for identifying and counting these cells in the skin. A contralateral specimen of the same patient went through the same procedure as a control experiment. The specimen from the macular lesion
showed a higher number of DOPA-stained melanocytes than the control fragment. Dermal melanocytes were present in high amounts in the abnormal specimen. Increased expression of tyrosinase by melanocytes in the macular lesions may reflect a positive feed-back stimulus
represented by the lack of substrate tyrosine, which may in turn be utilized by the mycobacterial agent. Ultrastructural study of the normal and pathological specimens showed no significant differences in the morphological appearance of melanocytes and their melanosomes. These results suggest that the utilization of phenolic compound by the Mycobacterium leprae may be involved in the mechanism of hypopigmentation. A higher number of cases will be necessary to confirm this hypothesis.
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| first_indexed | 2024-03-08T23:04:44Z |
| format | Article |
| id | doaj.art-b4cff86febd04088a16c6eba081ddcdb |
| institution | Directory Open Access Journal |
| issn | 1982-5161 |
| language | English |
| last_indexed | 2024-03-08T23:04:44Z |
| publishDate | 1996-11-01 |
| publisher | Instituto Lauro de Souza Lima |
| record_format | Article |
| series | Hansenologia Internationalis |
| spelling | doaj.art-b4cff86febd04088a16c6eba081ddcdb2023-12-15T14:15:41ZengInstituto Lauro de Souza LimaHansenologia Internationalis1982-51611996-11-0121210.47878/hi.1996.v21.36475Dopa-stained melanocytes in the macular lesions of early leprosySérgio Luiz Gomes Antunes0Samantha Lee Salgueiro Alves1Suzana Corte-Real2Maria Nazaré Meireles3José Augusto da Costa Nery4Euzenir Nunes Sarno5Leprosy Laboratory - Oswaldo Cruz Institute - Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brasil.Leprosy Laboratory - Oswaldo Cruz Institute - Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brasil.Department of Ultrastructure and Cellullar Biology, Oswaldo Cruz InstituteDepartment of Ultrastructure and Cellullar Biology, Oswaldo Cruz InstituteLeprosy Laboratory - Oswaldo Cruz Institute - Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brasil.Leprosy Laboratory - Oswaldo Cruz Institute - Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brasil. The mechanism of association of hypopigmentation and sensorial loss in a leprosy macular lesions has not been clarified yet. The biopsy of a macular lesion on the medial face of the right forearm of a fourteen-year old male leprosy patient was submitted to DOPA-staining for melanocytes, which is specific for the melanocytic tyrosinase enzyme and it is a proper method for identifying and counting these cells in the skin. A contralateral specimen of the same patient went through the same procedure as a control experiment. The specimen from the macular lesion showed a higher number of DOPA-stained melanocytes than the control fragment. Dermal melanocytes were present in high amounts in the abnormal specimen. Increased expression of tyrosinase by melanocytes in the macular lesions may reflect a positive feed-back stimulus represented by the lack of substrate tyrosine, which may in turn be utilized by the mycobacterial agent. Ultrastructural study of the normal and pathological specimens showed no significant differences in the morphological appearance of melanocytes and their melanosomes. These results suggest that the utilization of phenolic compound by the Mycobacterium leprae may be involved in the mechanism of hypopigmentation. A higher number of cases will be necessary to confirm this hypothesis. https://periodicos.saude.sp.gov.br/hansenologia/article/view/36475 |
| spellingShingle | Sérgio Luiz Gomes Antunes Samantha Lee Salgueiro Alves Suzana Corte-Real Maria Nazaré Meireles José Augusto da Costa Nery Euzenir Nunes Sarno Dopa-stained melanocytes in the macular lesions of early leprosy Hansenologia Internationalis |
| title | Dopa-stained melanocytes in the macular lesions of early leprosy |
| title_full | Dopa-stained melanocytes in the macular lesions of early leprosy |
| title_fullStr | Dopa-stained melanocytes in the macular lesions of early leprosy |
| title_full_unstemmed | Dopa-stained melanocytes in the macular lesions of early leprosy |
| title_short | Dopa-stained melanocytes in the macular lesions of early leprosy |
| title_sort | dopa stained melanocytes in the macular lesions of early leprosy |
| url | https://periodicos.saude.sp.gov.br/hansenologia/article/view/36475 |
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