NIVALDO ALONSO
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Cirurgia, Faculdade de Medicina - Docente
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
3 resultados
Resultados de Busca
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- Prefabricated Bone Flap: An Experimental Study Comparing Deep-Frozen and Lyophilized-Demineralized Allogenic Bones and Tissue Expression of Transforming Growth Factor beta(2013) RODRIGUES, Leandro; REIS, Luciene Machado dos; DENADAI, Rafael; RAPOSO-AMARAL, Cassio Eduardo; ALONSO, Nivaldo; FERREIRA, Marcus Castro; JORGETTI, VandaBackground: Extensive bone defects are still a challenge for reconstructive surgery. Allogenic bones can be an alternative with no donor area morbidity and unlimited amount of tissue. Better results can be achieved after allogenic bone preparation and adding a vascular supply, which can be done along with flap prefabrication. The purpose of this study was to evaluate demineralized/lyophilized and deep-frozen allogenic bones used for flap prefabrication and the tissue expression of transforming growth factor beta (TGF-beta) in these bone fragments. Methods: Fifty-six Wistar rat bone diaphyses were prepared and distributed in 4 groups: demineralized/lyophilized (experimental group 1 and control group 2) and deep freezing (experimental group 3 and control group 4). Two bone segments (one of each group) were implanted in rats to prefabricate flaps using superficial epigastric vessels (experimental groups) or only transferred as grafts (control groups). These fragments remained in their respective inguinal regions until the death that occurred at 2, 4, and 6 weeks after the operation. Semiquantitative histologic (tetracycline marking, cortical resorption, number of giant cells, and vascularization) and histomorphometrical quantitative (osteoid thickness, cortical thickness, and fibrosis thickness) analyses were performed. Transforming growth factor beta immunohistochemistry staining was also performed. Results: Group 1 fragments presented an osteoid matrix on their external surface in all periods. Cartilage formation and mineralization areas were also noticed. These findings were not observed in group 3 fragments. Group 1 had more mineralization and double tetracycline marks, which were almost not seen in group 3. Cortical resorption and the number of giant cells were greater in group 3 in all periods. Vascularization and fibrosis thickness were similar in both experimental groups. Group 1 had more intense TGF-beta staining within 2 weeks of study. Nevertheless, from 4 weeks onward, group 3 presented statistically significant stronger staining. Conclusions: Although there are some differences between the preparation methods of allogenic bone, it is possible to prefabricate flaps with demineralized/lyophilized and deep-frozen bones.
- Three-Dimensional Upper Lip and Nostril Sill Changes After Cleft Alveolus Reconstruction Using Autologous Bone Grafting Versus Recombinant Human Bone Morphogenetic Protein-2(2016) RAPOSO-AMARAL, Cassio Eduardo; DENADAI, Rafael; ALONSO, NivaldoCleft alveolus in patients with unilateral complete cleft lip and palate has been alternatively reconstructed with recombinant human bone morphogenetic protein (rhBMP)-2. However, its effects on upper lip and nostril sill anatomy are not known. Thus, the objective of this investigation was to assess and compare upper lip and nostril sill changes after cleft alveolus reconstruction with autologous bone from the iliac crest region and rhBMP-2. Patients were randomly allocated into 2 groups. In group 1, autologous bone from the iliac crest region was used to fill the cleft alveolus (n = 4), and in group 2, rhBMP-2 was used to fill the cleft alveolus (n = 8). Preoperatively and at one after the surgery, computerized tomography (CT) was performed. Reformatted CT imaging was used to perform cephalometric linear measurements of the upper lip and nostril sill regions. Inter-and intragroup data of the pre and postoperative reformatted CT measurements of the upper lip and nostril sill regions did not show differences (P>0.05) in cutaneous upper lip height and projection, nostril sill elevation, and subnasale projection. There were no significant upper lip and nostril sill anatomical changes after cleft alveolus reconstruction using autologous bone grafting and rhBMP-2.
- Human Bone Morphogenetic Protein-2 Use for Maxillary Reconstruction in Cleft Lip and Palate Patients(2012) CANAN JR., Lady Wilson; FREITAS, Renato da Silva; ALONSO, Nivaldo; TANIKAWA, Daniela Yukie Sakai; ROCHA, Diogenes Laercio; COELHO, Julio Cezar UiliBackground: The conventional methods of maxillary alveolar reconstruction in patient with cleft are the periosteoplasty and autologous bone grafting. As an important alternative of bone substitution, there is the recombinant human bone morphogenetic protein-2 (rhBMP-2). This study compares the rhBMP-2 with periosteoplasty and autologous bone grafting. Methods: Patients with cleft and alveolar defect were divided into 3 groups of 6 patients who underwent to autologous iliac crest bone grafting, resorbable collagen sponge with rhBMP2, and periosteoplasty, respectively. The analysis was performed through computed tomographic scan preoperatively and at months 3, 6, and 12 postoperatively. The variables analyzed were the alveolar defect volume, formed bone volume, bone formation rate, maxillary height repair rate, and the formed bone density mean. Results: The formed bone volume was similar comparing the bone graft and BMP groups at 1-year postoperative analysis (P = 0.58). Both of them had the formed bone volume significantly larger than the periosteoplasty group at 3 and 6 months postoperatively. In this last group, the 1-year follow-up was canceled because the bone formation was insufficient. The bone formation rate, the maxillary height repair rate, and the mean of density of the formed bone were similar in the bone graft and BMP groups at 1-year follow-up with P values of 0.93, 0.90, and 0.81, respectively. Conclusions: The amount of formed bone in the periosteoplasty group was insufficient. There was no difference among the bone graft and rhBMP-2 therapy considering the parameters analyzed.