Enxerto autólogo de células-tronco derivadas do tecido adiposo: uma nova visão de sua aplicação no tratamento de queimados e na cirurgia plástica reparadora / Adipose tissue-derived stem cell autologous grafts: a new approach to application in the treatment of burn victims and reconstructive plastic surgery

No Brasil, 1 milhão de acidentes com queimaduras acontecem por ano e as infecções são responsáveis por 75% dos óbitos nestes pacientes, além de deixar lesões que ocasionam deformidades nas áreas atingidas. Sendo assim, o objetivo deste trabalho é fornecer uma visão atual sobre células-tronco mesenquimais (MSCs), com ênfase nas células-tronco derivadas do tecido adiposo (ADSCs), associadas a gel de plasma, gel de fibrina e membranas (scaffold). O uso de géis e membranas tendem a auxiliar o crescimento celular visando sua possível aplicação na Cirurgia Plástica Reparadora para o tratamento pacientes queimados ou que necessitam de enxerto de pele. O presente trabalho abordou de forma exploratória e narrativa o tema células-tronco mesenquimais, células-tronco mesenquimais derivadas do tecido adiposo, gel de fibrina, gel de plasma e scaffold. O tipo de pesquisa empregada foi conduzido com coleta de informações utilizando-se a Biblioteca Virtual em Saúde (BVS) e PubMed. O número absoluto de artigos publicados relacionados ao tratamento de queimaduras é considerável. Até o momento, a quantidade de pesquisas relacionadas à terapia com células-tronco derivadas do tecido adiposo, gel de fibrina, gel de plasma e scaffold para o tratamento de queimaduras apresenta-se escassa. O autoenxerto de ADSCs associado a biocurativos torna-se uma perspectiva promissora na Cirurgia Plástica Reparadora para o tratamento e recuperação de pacientes que sofreram queimaduras ou outros acidentes que necessitam de enxerto de pele. Estes recursos podem reduzir a dor e prover a dessecação da lesão, promovendo neovascularização e a reepitelização da ferida.

In Brazil, 1 million burn accidents occur annually, and subsequent wound infections account for 75% cases of deaths among these patients, in addition to inducing deformities in the affected areas. Therefore, the aim of this study was to discuss the current status of mesenchymal stem cells, with an emphasis on adipose-derived stem cells (ADSCs), in combination with plasma gel, glue fibrin, and membranes (scaffold). The use of gels and membranes supports cell growth, and aims at potential application in reconstructive plastic surgery for the treatment of burn patients or individuals requiring skin grafts. This study explores and discusses the role of mesenchymal stem cells, adipose-derived mesenchymal stem cells, glue fibrin, plasma gel, and the scaffold. This research collected information from the Virtual Health Library (VHL) and PubMed. A considerable number of articles have been published on burn treatment. However, there is little research on burn treatment with ADSCs, glue fibrin, plasma gel, and scaffold. An ADSC autograft combined with a biological dressing is promising in reconstructive plastic surgery for the treatment and recovery of burn patients or individuals with other injuries that require skin grafts. These features can reduce pain and aid in drying of the lesion, thus promoting neovascularization and wound reepithelialization.

Altered ß-catenin expression in oral mucosal dysplasia: a comparative study

Objective The current study aimed to investigate the β-catenin expression in oral leukoplakia (OL) with different degrees of epithelial dysplasia and normal oral mucosa.Material and Methods Formalin-fixed, paraffin-embedded tissue samples of 39 OL (mild dysplasia n=19, moderate dysplasia n=13, and severe dysplasia n=7), and 10 normal oral mucosa (control group) were submitted to immunohistochemical reactions to anti-β-catenin primary antibody. A qualitative β-catenin analysis was performed based on the percentage of positive cells. The cellular location and the epithelial layer were also considered. The Chi-square test and the Fisher’s exact test were used to verify possible differences in the β-catenin expression among the OL groups. A p-value of <0.05 was considered statistically significant.Results Membranous expression of β-catenin in parabasal and basal layers was gradually lost in the higher degrees of epithelial dysplasia. In normal oral mucosa, β-catenin was detected only in the cytoplasmic membrane. However, a significant increase in cytoplasmic β-catenin could be observed between mild and moderate dysplasia (Fisher Exact test - p<0.001) and between mild and severe dysplasia (p<0.001).Conclusions The β-catenin cytoplasmic expression observed in this study may represent the initial stage of modifications in the E-cadherin-catenin complex, along with morphological cellular changes.

Immunohistochemical expression of p63, epidermal growth factor receptor (EGFR) and notch-1 in radicular cysts, dentigerous cysts and keratocystic odontogenic tumors

The aim of this study was to assess the immunohistochemical expression of p63 protein, epidermal growth factor receptor (EGFR) and Notch-1 in the epithelial lining of radicular cysts (RC), dentigerous cysts (DC) and keratocystic odontogenic tumors (KOT). For this study, 35 RC, 22 DC and 17 KOT were used. The clinical and epidemiological data were collected from the patient charts filed in the Oral Pathology Laboratory, University of Ribeirão Preto, Brazil. Immunohistochemical reactions against the p63, EGFR and Notch-1 were performed in 3-µm-thick histological sections. The slides were evaluated according to the following criteria: negative: <5% of positive cells, low expression: 5-50% of positive cells, and high expression: >50% of positive cells. Moreover, the intensity of EGFR and Notch-1 expressions was also evaluated. Fisher's exact test and Spearman's correlation coefficients were used for statistical analysis, considering a significance level of 5%. Almost all cases demonstrated p63, EGFR and Notch-1 expressions. The p63 expression was significantly higher in KOT (p<0.001). Positive correlation between these immunomarkers was observed. These findings suggest the participation of p63, EGFR and Notch-1 in the development, maintenance and integrity of cystic odontogenic epithelial lining, favoring lesion persistence. The high expression of p63 in KOT suggests that it may be related to their more aggressive biological behavior and marked tendency to recurrence.

O objetivo deste estudo foi avaliar a expressão imunoistoquímica da proteína p63, receptor do fator de crescimento epidérmico (EGFR) e Notch-1 no revestimento epitelial de cistos radiculares (CR), cistos dentígeros (CD) e tumores odontogênicos queratocísticos (TOQ). Para este estudo, 35 CR, 22 CD e 17 TOQ foram utilizados. Os dados clínicos e epidemiológicos foram coletados das fichas dos pacientes arquivadas no Laboratório de Patologia Oral, Universidade de Ribeirão Preto, Brasil. Reações imunoistoquímicas contra p63, EGFR e Notch-1 foram realizadas em cortes histológicos de 3 µm. As lâminas foram avaliadas de acordo com os seguintes critérios: negativo <5% das células positivas, baixa expressão - 5%-50% das células positivas e alta expressão >50% das células positivas. Além disso, a intensidade de expressão de EGFR e Notch-1 foi também avaliada. Teste exato de Fisher e coeficiente de correlação de Spearman foram usados para análise estatística, considerando um nível de significância de 5%. Quase todos os casos demonstraram expressão de p63, EGFR e Notch-1. A expressão de p63 foi significativamente maior nos TOQ (p<0.001). Correlação positiva entre os imunomarcadores foi observada. Esses achados sugerem a participação de p63, EGFR e Notch-1 no desenvolvimento, manutenção e integridade do revestimento epitelial cístico, favorecendo a persistência das lesões. A alta expressão de p63 no TOQ sugere que ela pode estar relacionada ao comportamento biológico mais agressivo e marcada tendência a recorrência.

Transmission electron microscopy for characterization of acrosomal damage after Percoll gradient centrifugation of cryopreserved bovine spermatozoa

The objective of this study was to characterize acrosomal ultrastructure following discontinuous Percoll gradient centrifugation of cryopreserved bovine sperm. Semen was collected from six bulls of different breeds and three ejaculates per bull were evaluated. Frozen semen samples were thawed and the acrosomal region of sperm cells was evaluated by transmission electron microscopy (TEM) before (n = 18) and after (n = 18) Percoll centrifugation. The evaluation of 20 sperm heads from each of the 36 samples analyzed ensured that a large number of cells were investigated. The data were subjected to analysis of variance at a level of significance of 5%. Percoll centrifugation reduced the percentage of sperm exhibiting normal acrosomes (from 61.77 to 30.24%), reduced the percentage of sperm presenting atypical acrosome reactions (from 28.38 to 4.84%) and increased the percentage of sperm exhibiting damage in the acrosome (from 6.14 to 64.26%). The percentage of sperm with typical acrosome reactions was not significantly different before (3.70%) and after (0.67%) centrifugation. TEM distinguished four different types of acrosomal status and enabled ultrastructural characterization of acrosomal injuries. The percentage of sperm exhibiting normal acrosomes decreased and damage in the acrosome was the most frequent acrosomal injury with the Percoll gradient centrifugation protocol utilized.

Primary PNET of kidney: report of two cases and review of literature.

PNET of the kidney is a rare tumor with only a few published reports. In view of poorer prognosis and different therapeutic approach, renal PNET should therefore be differentiated from other primary renal neoplasma such as Wilms tumor, renal neuroblastoma and malignant rhabdoid tumor which on histology resemble renal PNET. Two cases of renal PNET have been described in this report. Cut surface of the tumor in both cases was greyish white lobulated, with multiple tiny cystic areas. Histologically, tumor consisted of loosely cohesive sheets of small to medium sized monomorphic cells with round nuclei and little cytoplasm. Tumor cells showed diffuse strong membrane positivity for MIC2 and focal weak to moderate positivity for NSE and vimentin. Renal PNET should therefore be included in differential diagnosis of rapidly enlarging renal lumps presenting with local infiltration and aggressive behaviour, particularly in children and young adults. Diffuse strong membrane positivity for MIC2 in PNET is helpful in differentiating it from other primary renal neoplasms.

Immunohistochemical alterations of dystrophin in congenital muscular dystrophy

Foi estudada a distribuiçäo da distrofina na membrana plasmática das fibras musculares em 22 crianças com distrofia muscular congênita, através de técnicas de imuno-histoquímica. A distrofina foi identificada nas biópsias musculares processadas a fresco, por técnicas de imunofluorescência utilizando anticorpos policlonais. Todos os casos tinham interrupçöes da imunofluorescência na membrana plasmática. Em 17 elas eram grandes, em 12 eram pequenas e em 7 eram de ambos os tipos. Fibras com interrupçöes pequenas e constantes, como um rosário, foram vistas em 15 casos. Essas anormalidades estavam presentes em todas as fibras em 5 casos, eeram freqüentes em 8, ocasionais em 5 e raras em 4. Cinco casos mostraram fibras sem distrofina. Esses dados sugerem que a expressäo da distrofina é anormal nesse grupo de crianças. Essas anormalidades podem também ser encontradas em casos precoces de distrofia muscular de Becker e distrofia autossômica recessiva da infância. Portanto, isoladamente a imuno-histoquímica näo permite a diferenciaçäo

Surface Properties of Cell Membrane in Early Stage of Transformed Cell -I. Early Detection of Transformed Cell by Concanavalin A; II. Properties of Plasma Membrane of Transformed Rat Liver Cell Induced by 3'-Me DAB

The present study was designed in order to investigate the lectin induced cytoagglutination properties of normal and transformed cells and surface alterations in the early stage of the transformed cells by characterizing the structural changes on the hepatoma surface membrane. Rat and rabbit erythrocytes and Sarcoma 180 ascites tumor cells were used for the lectin-induced cytoagglutination. Plotting % agglutination versus concanavalin A(Con A) concentration, sigmoid curves appeared in all cases. alpha-methyl-D-mannopyranoside(alphaMM) inhibited Con A induced cytoagglutination and the degrees of inhibition depended on the cell types and species. When rats were fed a diet containing 0.06% 3'-methyl-4dimethylaminoazobenzene(3'-Me DAB) for 12 weeks, almost all of the rats had solid liver tumors. Polyacrylamide gel electrophoresis of surface membrane proteins of these rat livers and of transplanted tumor cells showed three distinct protein bands, of which two were absent in normal rat livers. The molecular weights of these proteins were 73,000, 66,000, and 57,000 daltons. Antiserum against primary hepatocarcinoma surface proteins precipitated with three membrane proteins obtained from primary hepatocarcinoma cells as well as transplanted hepatocarcinoma cells, suggesting the presence of specific tumor antigens in these cells.