Acellular human glans extracellular matrix as a scaffold for tissue engineering: in vitro cell support and biocompatibility

ABSTRACT Objectives: Diseases of the genitourinary tract can lead to significant damage. Current reconstructive techniques are limited by tissue availability and compatibility. This study aims to assess if the decellularized human glans can be used as a biomaterial for penile reconstruction. Materials and Methods: Samples of the glans matrices were descellularized. We evaluate the presence of collagen type I and III, and elastic fibers. Biocompatibility assays were performed to assess the cytotoxic and non-cytotoxic interactions between the acellular matrix and 3T3 cells. The matrices were seeded with mesenchymal stem cells and were assessed for viability and integration of these cells. Biomechanical tests in native tissue, descellularized matrix and seeded matrix were performed to characterize their biomechanical properties. Results: The tissue architecture of the decellularized matrix of human glans was preserved as well as the maintenance of the biomechanical and biological properties. The analyzes of glans seeded with mesenchymal stem cells revealed the integration of these cells to the matrices, and its viability during two weeks "in vitro". Conclusion: The decellularization process did not alter the biological and biomechanical characteristics of the human glans. When these matrices were seeded they were able to maintain the cells integrity and vitality

Differentiation of Leydig Cells in the Mongolian Gerbil

Information on postnatal Leydig cell (LC) differentiation in the Mongolian gerbil has been unavailable. Therefore, current investigation was designed to examine LC lineage differentiation in this rodent, from birth to adulthood. Gerbil testes at I day, 1-7 weeks (w), 2 and 3 months of age were conventionally processed by light and transmission electron microscopy. Immunocytochemistry for specific markers of steroidogenic enzymes, namely 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and 11 beta-hydroxysteroid steroid dehydrogenase 1 (11 beta-HSD1) and also for androgen receptor (AR) was performed. The establishment of adult Leydig cell populations (ALC) during testis maturation in the gerbil follows the pattern previously described in other mammalian species, with the four progressive stages of differentiation. The LC progenitors were identified at second w by 3 beta-HSD expression; the first newly formed ALC were recognized at fourth w whereas immature ALC appeared at fifth w. The latter were recognized by abundance of cytoplasmic lipid, in addition to expression of 11 beta-HSD1 and intense nuclear AR immunoreaction. Mature ALC in gerbil exhibited irregular eccentric nuclei and a cytoplasmic canaliculus in the perinuclear area. Only one third of mature ALC in adult gerbils showed a high expression of 11 beta-HSD1 and AR expression was highly variable among them. In conclusion, the process of differentiation of ALC population in gerbil follows the pattern previously established for other rodents. However, the resulting mature ALC are strikingly different due their singular asymmetric morphology and presence of a cytoplasmic canaliculus and as well as their functional heterogeneity. Microsc. Res. Tech. 73:119-127, 2010. (C) 2009 Wiley-Liss, Inc.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Initial invasive or conservative strategy for stable coronary disease

BACKGROUND Among patients with stable coronary disease and moderate or severe ischemia, whether clinical outcomes are better in those who receive an invasive intervention plus medical therapy than in those who receive medical therapy alone is uncertain. METHODS We randomly assigned 5179 patients with moderate or severe ischemia to an initial invasive strategy (angiography and revascularization when feasible) and medical therapy or to an initial conservative strategy of medical therapy alone and angiography if medical therapy failed. The primary outcome was a composite of death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest. A key secondary outcome was death from cardiovascular causes or myocardial infarction. RESULTS Over a median of 3.2 years, 318 primary outcome events occurred in the invasive-strategy group and 352 occurred in the conservative-strategy group. At 6 months, the cumulative event rate was 5.3% in the invasive-strategy group and 3.4% in the conservative-strategy group (difference, 1.9 percentage points; 95% confidence interval [CI], 0.8 to 3.0); at 5 years, the cumulative event rate was 16.4% and 18.2%, respectively (difference, 121.8 percentage points; 95% CI, 124.7 to 1.0). Results were similar with respect to the key secondary outcome. The incidence of the primary outcome was sensitive to the definition of myocardial infarction; a secondary analysis yielded more procedural myocardial infarctions of uncertain clinical importance. There were 145 deaths in the invasive-strategy group and 144 deaths in the conservative-strategy group (hazard ratio, 1.05; 95% CI, 0.83 to 1.32). CONCLUSIONS Among patients with stable coronary disease and moderate or severe ischemia, we did not find evidence that an initial invasive strategy, as compared with an initial conservative strategy, reduced the risk of ischemic cardiovascular events or death from any cause over a median of 3.2 years. The trial findings were sensitive to the definition of myocardial infarction that was used