Nondestructive Assessment of Glycosaminoglycans in Engineered Cartilages Using Hexabrix-Enhanced Micro-Computed Tomography

It is very useful to evaluate the content and 3D distribution of extracellular matrix non-destructively in tissue engineering. This study evaluated the feasibility of using micro-computed tomography (µCT) with Hexabrix to measure quantitatively sulfated glycosaminoglycans (GAGs) of engineered cartilage. Rabbit chondrocytes at passage 2 were used to produce artificial cartilages in polyglycolic acid scaffolds in vitro. Engineered cartilages were incubated with Hexabrix 320 for 20 min and analyzed via µCT scanning. The number of voxels in the 2D and 3D scanning images were counted to estimate the amount of sulfated GAGs. The optimal threshold value for quantification was determined by regression analysis. The 2D µCT images of an engineered cartilage showed positive correlation with the histological image of Safranin-O staining. Quantitative data obtained with the 3D µCT images of 14 engineered cartilages showed strong correlation with sulfated GAGs contents obtained by biochemical analysis (R² = 0.883, p < 0.001). Repeated exposure of engineered cartilages to Hexabrix 320 and µCT scanning did not significantly affect cell viability, total DNA content, or the total content of sulfated GAGs. We conclude that µCT imaging using Hexabrix 320 provides high spatial resolution and sensitivity to assess the content and 3D distribution of sulfated GAGs in engineered cartilages. It is expected to be a valuable tool to evaluate the quality of engineered cartilage for commercial development in the future.

Expression of estrogen receptor alpha in the testis of infertile men with spermatogenic arrest / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the association of spermatogenic arrest with the expression of estrogen receptor alpha (ERalpha) in human testes.</p><p><b>METHODS</b>We examined the testicular biopsy specimens of 120 infertile men by HE staining, detected the expression of ERalpha in the specimens of those with spermatogenic arrest by the two-step immunohistochemical method, and compared the results with those of 10 healthy men.</p><p><b>RESULTS</b>Of the 120 specimens from the infertile men, 31 (25.8%) met the diagnostic criteria of spermatogenic arrest. In the testis tissue of normal men, ERalpha expressed in Sertoli, myoid and Leydig cells, but not in spermatogenic cells, while in the testis tissues of those with spermatogenic arrest, ERalpha expressed lowly in Sertoli, myoid and Leydig cells, with statistically significant differences in immunostaining intensity between the two groups (P < 0.05).</p><p><b>CONCLUSION</b>Androgen receptor (AR) and ERalpha may play a coordinating role in facilitating spermatogenesis. Spermatogenic arrest may be related to a complex series of disorders in cell signal transduction involving AR, ERalpha and HSP90.</p>