GUILHERME GARCIA BARROS
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/26 - Laboratório de Pesquisa em Cirurgia Experimental, Hospital das Clínicas, Faculdade de Medicina
LIM/26 - Laboratório de Pesquisa em Cirurgia Experimental, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
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- Is maintenance of the ileocecal valve important to the intestinal adaptation mechanisms in a weaning rat model of short bowel?(2018) BARROS, Guilherme Garcia; TANNURI, Ana Cristina Aoun; ROTONDO, Italo Gerardo; VAISBERG, Vitor Van; SARMENTO, Leandro Silveira; NETO, Cicero Mendes; SERAFINI, Suellen; GONCALVES, Josiane de Oliveira; COELHO, Maria Cecilia Mendonca; TANNURI, UenisPurpose To evaluate the role of maintenance of the ileocecal valve (ICV) in intestinal adaptation mechanisms, in a weaning rat experimental model of short bowel. Methods Forty animals were operated on to produce short bowel syndrome. They were divided into five groups: maintenance (MV) or resection of ICV (RV), kill after 4 days (MV4 and RV4) or 21 days (MV21 and RV21), and a control group (21-day-old rats). Body weights, small bowel and colon lengths and diameters, villus heights, crypt depths, lamina propria and muscle layer thickness, as well as the apoptosis index of villi and crypts and expression of pro-and anti-apoptotic genes, were studied. Results Preservation of the ICV promoted increased weight gain (p = 0.0001) and intestinal villus height after 21 days; crypt depth was higher in comparison to controls. It was verified a higher expression of Ki-67 in bowel villi and crypts (p = 0.018 and p = 0.015, respectively) in RV4 group and a higher expression in bowel villi of MV4 group animals (p = 0.03). The maintenance of ICV promoted late increased expression of the anti-apoptotic gene Bcl-XL in the colon (p = 0.043, p = 0.002, p = 0.01). Conclusion The maintenance of the ICV led to positive changes in this model.
- Are there differences in the growth adaptation processes of growing and mature organism models of short bowel syndrome?(2018) TANNURI, Ana Cristina Aoun; ROTONDO, Italo Geraldo; BARROS, Guilherme Garcia; VAISBERG, Victor Van; MENDES-NETO, Cicero; PAES, Vitor Ribeiro; COELHO, Maria Cecilia Mendonca; GONCALVES, Josiane; SERAFINI, Suellen; TANNURI, UenisOBJECTIVES: The purpose of this study was to present an experimental model of short bowel syndrome (SBS) in weaning rats and to compare the adaptative mechanisms of the remaining bowel in weaning rats and adult animals by means of morphometric, histologic and molecular methods. METHODS: Twenty-four weaning rats were divided into 3 groups of 8 animals, one control group and two short bowel groups (euthanasia after 4 and 21 days), and were compared with similar adult groups. Morphometric evaluations of the animals and histopathological and molecular studies of the remaining bowel were performed. RESULTS: The weight of young rats increased after enterectomy, whereas that of adult rats decreased after enterectomy (p < 0.0001). The ratio of intestinal length/body weight was significantly higher in weaning rats than in adults (p < 0.002), showing that intestinal growth was more intense in weaning rats. Intestinal resection promoted increased thickness of the small bowel lamina propria (p=0.001) and reduced thickness of the colon lamina propria (p=0.04) in weaning rats relative to those in adults. In addition, intestinal resection promoted increased expression of the Bcl-xl gene (antiapoptotic) in adult animals compared with that in weaning rats (p=0.001). CONCLUSION: Morphometric, histological and molecular differences were shown in the adaptation processes of growing and mature organisms.
conferenceObject DEEP DORSAL VEIN BED PLICATION FOR VENTRAL PENILE CURVATURE(2023) ZANDONA, Pedro Caetano Edler; BARROS, Guilherme Garcia; COIMBRA, Igor Valente; GOES, Plinio Moreira De; PATO, Eduardo Zinoni Silva; NAHAS, William Carlos; NASCIMENTO, Bruno Chiesa Gouveia; HALLAK, Jorge- Directional Topography Influences Adipose Mesenchymal Stromal Cell Plasticity: Prospects for Tissue Engineering and Fibrosis(2019) LIGUORI, Gabriel Romero; ZHOU, Qihui; LIGUORI, Tacia Tavares Aquinas; BARROS, Guilherme Garcia; KUHN, Philipp Till; MOREIRA, Luiz Felipe Pinho; RIJN, Patrick van; HARMSEN, Martin C.Introduction. Progenitor cells cultured on biomaterials with optimal physical-topographical properties respond with alignment and differentiation. Stromal cells from connective tissue can adversely differentiate to profibrotic myofibroblasts or favorably to smooth muscle cells (SMC). We hypothesized that myogenic differentiation of adipose tissue-derived stromal cells (ASC) depends on gradient directional topographic features. Methods. Polydimethylsiloxane (PDMS) samples with nanometer and micrometer directional topography gradients (wavelength49-3, 425nm) were fabricated. ASC were cultured on patterned PDMS and stimulated with TGF-1 to induce myogenic differentiation. Cellular alignment and adhesion were assessed by immunofluorescence microscopy after 24h. After seven days, myogenic differentiation was examined by immunofluorescence microscopy, gene expression, and immunoblotting. Results. Cell alignment occurred on topographies larger than w=1758nm/a=630nm. The number and total area of focal adhesions per cell were reduced on topographies from w=562nm/a=96nm to w=3919nm/a=1430nm. Focal adhesion alignment was increased on topographies larger than w=731nm/a=146nm. Less myogenic differentiation of ASC occurred on topographies smaller than w=784nm/a=209nm. Conclusion. ASC adherence, alignment, and differentiation are directed by topographical cues. Our evidence highlights a minimal topographic environment required to facilitate the development of aligned and differentiated cell layers from ASC. These data suggest that nanotopography may be a novel tool for inhibiting fibrosis.