CESAR ISAAC
Projetos de Pesquisa
Unidades Organizacionais
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
2 resultados
Resultados de Busca
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- Estabelecimento de protocolo para armazenamento de pele autógena refrigerada(2017) CONCEIÇÃO, RENATA OLIVEIRA DA; PAGGIARO, ANDRÉ OLIVEIRA; POLO, EUGÊNIO FERRAMUNDO; MARTINES, KARINA; ISAAC, CESAR; CARVALHO, VIVIANE FERNANDES DE; GOMEZ, DAVID DE SOUZA; GEMPERLI, ROLFABSTRACT Introduction: Autologous skin grafts are used for treatment of burn patients. These grafts can be stored and preserved, as long as the storage process is performed with strict quality control to reduce the risk of infection. Methods: A retrospective cohort study was conducted in the Burn Unit of the Hospital das Clínicas de São Paulo from February 2015 to July 2016. During this period, a protocol was established to store refrigerated skin, with control of collection, preservation, and packaging, and recording of all processes. To ensure quality, graft biopsies were collected for preand poststorage microbiology testing and a cross-sectional study for contamination was performed. Results: Critical deficiencies included inadequate packaging, lack of processing records, lack of biopsies for microbiology testing, and failure to discard specimens. Most of the samples were contaminated before and after storage (84.2%). Only two samples were sterile before storage but became contaminated after storage, with growth of Gram-positive skin bacteria. Conclusion: A promising method for the storage of refrigerated skin was established, but requires minor adjustments in quality control.
- Oxysterols in adipose tissue-derived mesenchymal stem cell proliferation and death(2017) SILVA, Suelen Feitoza; LEVY, Debora; RUIZ, Jorge Luis Maria; MELO, Thatiana Correa de; ISAAC, Cesar; FIDELIS, Maira Luisa; RODRIGUES, Alessandro; BYDLOWSKI, Sergio PauloMesenchymal stem cells (MSCs) are multipotent cells characterized by self-renewal and cellular differentiation capabilities. Oxysterols comprise a very heterogeneous group derived from cholesterol through enzymatic and non-enzymatic oxidation. Potent effects in cell death processes, including cytoxicity and apoptosis induction, were described in several cell lines. Very little is known about the effects of oxysterols in MSCs. 7-ketocholesterol (7-KC), one of the most important oxysterols, was shown to be cytotoxic to human adipose tissue-derived MSCs. Here, we describe the short-term (24 h) cytotoxic effects of cholestan-3 alpha-5 beta-6 alpha-triol, 3,5 cholestan-7-one, (3 alpha-5 beta-6 alpha)- cholestane-3,6-diol, 7-oxocholest-5-en-3 beta-ylacetate, and 5 beta-6 beta epoxy-cholesterol, on MSCs derived from human adipose tissue. MSCs were isolated from adipose tissue obtained from three young, healthy women. Oxysterols, with the exception of 3,5 cholestan-7-one and 7-oxocholest-5-en-3 beta-yl acetate, led to a complex mode of cell death that include apoptosis, necrosis and autophagy, depending on the type of oxysterol and concentration, being cholestan-3 alpha-5 beta-6 alpha-triol the most effective. Inhibition of proliferation was also promoted by these oxysterols, but no changes in cell cycle were observed.