FERNANDA GUEDES LUIZ

(Fonte: Lattes)
Índice h a partir de 2011
1
Projetos de Pesquisa
Unidades Organizacionais
LIM/56 - Laboratório de Investigação em Dermatologia e Imunodeficiências, Hospital das Clínicas, Faculdade de Medicina

Resultados de Busca

Agora exibindo 1 - 3 de 3
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    Confocal Microscopy Image Analysis of Pancreatic beta-Cells K-ATP Channel Proteins in Congenital Hyperinsulinism (CHI)
    (2012) LOVISOLO, S. M.; GARIPPO, A. L.; GUEDES, F.; ZERBINI, M. C.
    Background: CHI is a life-threatening disorder of glucose metabolism of neonates characterized by serum insulin levels unresponsive to blood glucose concentrations. Pancreatic ß-cells regulates insulin secretion through ATP sensitive potassium channels (KATP channel) formed by sulfonylurea receptor 1 (SUR1) and potassium inward rectifying 6.2 (Kir 6.2) proteins. The ß-cell K ATP channel dependent CHI is classically associated with loss-of-function mutations of these subunits genes. In a previous study [1], no mutations in the Kir6.2 gene and in the 33-37 exons hot spot region of the SUR1 gene were identified in these patients. The aim of this study is to investigate if these subunits were present in the ß-cells of CHI patients. Design: Pancreatic surgical paraffin tissue from 7 neonates (3F/4M, 4-13 mo) with CHI and 8 autopsy pancreatic control tissue (5F/3M, 4-11 mo) were included in the study. Confocal microscopy double-staining immunofluorescence (insulin/SUR1 and insulin/Kir6.2) was performed in order to detect each protein specifically in the ß-cells All sections were analyzed under a Zeiss 510 Meta confocal laser scanning microscope (63x). At least 10 different endocrine islets were captured to evaluate the expression of either Kir6.2 or SUR1 (green-488nm) and insulin (red-633nm). Co-expression of insulin/SUR1 and insulin/Kir6.2 was analysed visually (green x red→yellow) and through correlation Pearson’s coefficient(PC) that estimates the goodness of rate association of the two fluorochromes. PC was compared among cases and controls using a nonparametric method (Mann-Whitney). Results: Visual observation clearly revealed the presence of Kir6.2 and SUR1 in a granular cytoplasmic pattern in the ß-cells of cases and controls. Nevertheless, overlap of insulin/Kir6.2 and insulin/SUR1 seemed to be more constant and uniform in controls than in CHI cases, confirmed by the analysis through PC showing a statistically significant decrease in Kir6.2 (P= 0.0084) and SUR1 (P= 0.041) in the ß-cells of CHI patients. Conclusions: This is the first demonstration of K ATP channels subunits Kir6.2 and SUR1 in the pancreatic ß-cells of CHI patients using an in situ method. Our results show that both subunits were present in the ß-cells, but are under-expressed in CHI patients compared to controls, adding a new information to this rare condition with a complex pathogenesis.
  • conferenceObject
    Confocal Microscopy Image Analysis of Pancreatic beta-Cells K-ATP Channel Proteins in Congenital Hyperinsulinism (CHI)
    (2012) LOVISOLO, S. M.; GARIPPO, A. L.; GUEDES, F.; ZERBINI, M. C.
    Background: CHI is a life-threatening disorder of glucose metabolism of neonates characterized by serum insulin levels unresponsive to blood glucose concentrations. Pancreatic ß-cells regulates insulin secretion through ATP sensitive potassium channels (K ATP channel) formed by sulfonylurea receptor 1 (SUR1) and potassium inward rectifying 6.2 (Kir 6.2) proteins. The ß-cell K ATP channel dependent CHI is classically associated with loss-of-function mutations of these subunits genes. In a previous study [1], no mutations in the Kir6.2 gene and in the 33-37 exons hot spot region of the SUR1 gene were identified in these patients. The aim of this study is to investigate if these subunits were present in the ß-cells of CHI patients. Design: Pancreatic surgical paraffin tissue from 7 neonates (3F/4M, 4-13 mo) with CHI and 8 autopsy pancreatic control tissue (5F/3M, 4-11 mo) were included in the study. Confocal microscopy double-staining immuno fluorescence (insulin/SUR1 and insulin/Kir6.2) was performed in order to detect each protein specifically in the ß-cells. All sections were analyzed under a Zeiss 510 Meta confocal laser scanning microscope (63x). At least 10 different endocrine islets were captured to evaluate the expression of either Kir6.2 or SUR1 (green-488nm) and insulin (red-633nm). Co-expression of insulin/SUR1 and insulin/Kir6.2 was analysed visually (green x red→yellow) and through correlation Pearson’s coefficient(PC) that estimates the goodness of rate association of the two fluorochromes. PC was compared among cases and controls using a nonparametric method (Mann-Whitney). Results: Visual observation clearly revealed the presence of Kir6.2 and SUR1 in a granular cytoplasmic pattern in the ß-cells of cases and controls. Nevertheless, overlap of insulin/Kir6.2 and insulin/SUR1 seemed to be more constant and uniformin controls than in CHI cases, confirmed by the analysis through PC showing a statistically significant decrease in Kir6.2 ( P = 0.0084) and SUR1 ( P = 0.041) in the ß-cells of CHI patients. Conclusions: This is the first demonstration of K ATP channels subunits Kir6.2 and SUR1 in the pancreatic ß-cells of CHI patients using an in situ method. Our results show that both subunits were present in the ß-cells, but are under-expressed in CHI patients compared to controls, adding a new information to this rare condition with a complex pathogenesis.
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    Analysis of the Expression of Toll-like Receptors 2 and 4 in Keratinocytes of Patients with Extensive Dermatophytosis due Trichophyton rubrum
    (2012) CRIADO, P. R.; OLIVEIRA, C. B.; VASCONCELLOS, C.; VALENTE, N. Y. S.; SOTTO, M. N.; LUIZ, F. Guedes; BELDA JUNIOR, W.
    Rationale There are few studies to concern the role of innate immune response in dermatophytosis, so we conducted an investigation to define the involvement of TLRs in the course of tinea corporis by T. rubrum. Methods We allocated 14 patients without primary or secondary immunosuppression with extensive dermatophytosis, defined as the ringworm on at least 3 body segments of the same patient. In each patient the skin were biopsied from the active edge of the tinea and normal skin distant at least 4 cm of the lesion. Other skin fragments (control skin) were obtained from cosmetic surgery and without tinea. We use immunohistochemical staining with antibodies for antigens TLR 2 and 4. Images were analyzed in Image Pro Plus program. Results The Wilcoxon Signed Ranks Test showed: (i) regarding the expression of TLR2 of patients with tinea, found on the skin surface, average percentage of the marked area of 24.36 (1-76) in skin with tinea and 39.77 (9-84) in normal skin, p 0.043; (ii) analysis of TLR4 expression in the epidermis of patients with tinea met index higher optical density in normal skin than in skin with tinea, average 111.21 (99.44 to 134.34) and 104.50 (97.76 to 113.82), respectively, p 0.028. Conclusions We found a lower expression of TLR2 and 4 in the skin with tinea compared to healthy skin of the same patients with extensive dermatophytosis, as well as a tendency toward higher expression of TLR2 in the healthy peripheral skin, which could explain the spread in extension, in these cases of tinea.