Navegando por Palavras-chave "Epidermis"
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- ItemSomente MetadadadosCutaneous changes in rats induced by chronic skin exposure to ultraviolet radiation and organophosphate pesticide(Acta Cirurgica Brasileira, 2014-01-01) Fernandes, Tania Rita Moreno de Oliveira [UNIFESP]; Santos, Itamar [UNIFESP]; Korinsfky, Juliana Pedrosa; Silva, Benedyto Savio de Lima e [UNIFESP]; Carvalho, Luis Otavio; Plapler, Helio [UNIFESP]; Fed Univ Sao Francisco Valley UNIVASF; Fundacao Univ Fed Vale Sao Francisco; Oswaldo Cruz Inst Fdn FioCruz; Universidade Federal de São Paulo (UNIFESP)PURPOSE: To study the possible potentiation of the carcinogenic effects of ultraviolet radiation associated with an organophosphate pesticide.METHODS: Forty Wistar rats were assigned into four groups (n=10 each) randomized according to the procedures: group A received only UVR-B radiation; group B, UVR-B for eight weeks followed by a seven week period of pesticide exposure; group C, UVR-B + pesticide concomitantly: group D, only pesticide application. At the end of the fifth, tenth and fifteenth weeks the animals were photographed. Skin biopsy and histopathological study with Hematoxylin-Eosin were done on the fifteenth week. Statistical analysis with Fisher's and Sign (unilateral) tests, 5% value for significance.RESULTS: Macroscopic lesions in the group A evolved from the erythema to erythema + desquamation. The groups B and C, with the association of two carcinogens, and group D presented evolution to keratosis, with higher incidence in group D. The histology showed a significant increase in the severity of injuries when the UVR-B and the pesticide were applied simultaneously, leading to cellular atypia.CONCLUSIONS: Concurrent association of UVR-B to organophosphate pesticide produced more severe lesions microscopically, although this has not been so apparent macroscopically. In daily practice the clinical evaluation should be complemented with laboratory evaluation.
- ItemAcesso aberto (Open Access)Diferenciação de células-tronco mesenquimais do cordão umbilical em queratinócitos: estudo da biologia da epiderme e perspectivas para a compreensão do desenvolvimento de doenças(Universidade Federal de São Paulo (UNIFESP), 2017-01-31) Santos, Jeniffer Farias dos [UNIFESP]; Araujo, Mariana da Silva [UNIFESP]; http://lattes.cnpq.br/0506590353074487; http://lattes.cnpq.br/7619659858372916; Universidade Federal de São Paulo (UNIFESP)The skin is the cover of the body and isolates the organic components of the external environment. The human skin is composed by three layers: epidermis, dermis and subcutaneous tissue. The epidermal cells, the keratinocytes, are constantly renewed. Different approaches have been proposed for studying the events involved in the differentiation of keratinocytes. In this context, stem cells appear as an interesting strategy, allowing therapeutic applications and to study biological processes. An important source of stem cells is the human umbilical cord, which collection involves a safe and simple procedure. Considering that epidermal stem cells isolation is very complex and often gives low yields, we are interested in evaluating the differentiation potential of mesenchymal stem cells (MSC) from umbilical cord into keratinocytes, and to study some molecular events involved in this process, such as the expression of epidermal cell markers (p63, involucrin, cytokeratins 5, 10 and 14), and the activity of different proteases such as kallikrein 5 (hK5), 6 (hK6) and 7 (hK7). After MSC isolation, their characterization was performed considering the adherence to the culture plate, the fibroblastoid shape, and the ability to undergo to adipogenic, chondrogenic and osteogenic differentiation in vitro, as well as the expression of specific surface markers such as CD44, CD29, CD90, CD105, CD73, CD34 and CD31. The ability of MSC to differentiate into keratinocytes was confirmed by cytokeratin 5 and 14 expression at 1st day of cultivation, p63 at the 7th, involucrin from the day 7, and activity of tissue kallikrein hK5, hK6 and hK7 from the day 14. These data suggest that MSC differentiated into keratinocytes similarly to that occurs in vivo; Therefore the model established here consists of a suitable approach for the study of biological processes involving the human epidermis. Furthermore, the low immunogenicity and immunomodulatory capacity of the MSC make them excellent candidates for regenerative medicine and tissue engineering for skin traumas and diseases.
- ItemAcesso aberto (Open Access)Induction of neoplastic cells in rat skin(Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia, 2014-02-01) Korinfsky, Juliana Pedrosa; Plapler, Helio [UNIFESP]; Moreno, Tania Rita; Santos, Itamar; Maria, Celeste; Universidade Federal de São Paulo (UNIFESP); UNIVASF Department of Medicine; Oswaldo Cruz FoundationPURPOSE:To investigate the induction of neoplastic lesions under the action of ultraviolet B radiation (UVR-B) and dimethyl benzanthracene (DMBA).METHODS:Forty Wistar rats were assigned to four groups (ten animals each), according to the procedure: group A received UVR-B irradiation, group B received topic DMBA, group C, UVR-B+DMBA and group D as control, observed for ten weeks. In the tenth week they went through a skin biopsy and histopathological study. The average thickness of the epidermis was calculated and evaluated statistically.RESULTS:Macroscopic lesions in group B were more of inflammatory kind compared to group A. Group C presented more injuries with neoplastic features than the others (p<0.01). Histologically there was a significant increase in thickness of the epidermis of all groups compared to control, however the greatest thickness measures occurred in Group C (p<0.01).CONCLUSIONS:The population exposed to ultraviolet B radiation is subject to suffer skin lesions that can develop into cancer. The association with hydrocarbons as the dimethyl benzanthracene increases the possibility of malignancy. May not be clinically evident determine when a solar keratosis ends and when a CEC begins. For this reason, histological study associated with health education prompting the early and irreversible injury prevention is necessary.