<abstract>Aim: To study the expression and regulation of Smadl, Smad2 and Smad4 proteins (intracellular signaling molecules of transforming growth factor-β family) in rat testis during postnatal development. Me...<abstract>Aim: To study the expression and regulation of Smadl, Smad2 and Smad4 proteins (intracellular signaling molecules of transforming growth factor-β family) in rat testis during postnatal development. Methods: The whole testes were collected from SD rats aged 3, 7, 14, 28 and 90 (adult) days. The cellular localization and developmental changes were examined by immunohistochemistry ABC method with the glucose oxidase-DAB-nickel enhancement technique. Quantitative analysis of the immunostaining was made by the image analysis system. The Smads proteins coexistence in the adult rat testis was tested by the double immune staining for CD14-Smad4 and Smad2-Smad4. The protein expression of Smad during rat testicular development was examined by means of Western blots. Results: Smadl, Smad2 and Smad4 were present throughout testicular development. The immunostaining of Smadl and Smad2 were present in spermatogenic cells. A positive immunoreactivity was located at the cytoplasm, but the nucleus was negative. Smadl was immunolocalized at the d14, d28 and adult testes, while Smad2, at the d7, d14, d28 and adult testis. There was positive irnmunoreaction in the Sertoli cells and Leydig cells as well. The immunolocalization of Smad4 was exclusively at the cytoplasm of Leydig cells and the nuclei were negative throughout the testicular development. No expression was detected in the germ cells. The results of image and statistical analysis showed that generally the expression of Smadl, Smad2 and Smad4 in the testis tended to increase gradually with the growth of the rat. Conclusion: The present data provide direct evidences for the molecular mechanism of TGF-βaction in rat testes during postnatal development and spermatogenesis.展开更多
Objective To find out a proper way to detect green fluorescent protein (GFP). Methods Kidneys, livers and femurs from GFP transgenic mice and C57BL/6J wild type mice were employed for in vivo study. The samples were d...Objective To find out a proper way to detect green fluorescent protein (GFP). Methods Kidneys, livers and femurs from GFP transgenic mice and C57BL/6J wild type mice were employed for in vivo study. The samples were dehydrated with alcohol and acetone individually before embedding, then frozen, paraffin and resin sections were made for the detection of GFP. C3 P12 cells which derived from calvaria bone cells of GFP transgenic mouse were used for the detection of GFP in vitro. Cells were exposed to alcohol, acetone and PBS after paraformaldehyde fixation. Laser scanning microscopy was employed for GFP detection. Results In frozen sections, both kidney and liver samples which exposed to 4% buffered paraformaldehyde fixation had strong GFP signals, while GFP signal disappeared completely in fresh frozen sections without fixation. Much stronger GFP intensity was found in acetone treated samples than in alcohol treated paraffin sections, but without apparent difference in GFP intensity in acetone and alcohol treated resin samples. Acetone and alcohol made no difference in fixed C3 cells in different time courses. Conclusion Acetone treated paraffin sections are preferable for GFP detection.展开更多
The aim of this study was to assess the stress patterns on the peri-implant zone and residual alveolar ridge in different overdenture attachment system designs by the photoelasticity method. Four attachments systems w...The aim of this study was to assess the stress patterns on the peri-implant zone and residual alveolar ridge in different overdenture attachment system designs by the photoelasticity method. Four attachments systems were tested: O-ring, ERA, Bar-clip, and Bar-clip/O-ring association. The prostheses were loaded with 100 N in five pre-determined points and the photoelastic model was evaluated by a circular polariscope. The anterior load, O-ring, and ERA showed better stress distribution in relation to the bars systems, which presented stress levels surrounding implants. The molar load, Bar-clip/O-ring association, presented the biggest stress concentration on the peri-implant region in relation to the others. When the second molar was loaded, there was a concentration of stress in the alveolar ridge in all situations analyzed. Within the limitation of this “in vitro” study, it could be concluded that there were biomechanical differences among the attachments systems analyzed, principally between isolated and the bars systems. The O-ring showed better stress distribution and the Bar-clip/O-ring showed higher stress concentration.展开更多
文摘<abstract>Aim: To study the expression and regulation of Smadl, Smad2 and Smad4 proteins (intracellular signaling molecules of transforming growth factor-β family) in rat testis during postnatal development. Methods: The whole testes were collected from SD rats aged 3, 7, 14, 28 and 90 (adult) days. The cellular localization and developmental changes were examined by immunohistochemistry ABC method with the glucose oxidase-DAB-nickel enhancement technique. Quantitative analysis of the immunostaining was made by the image analysis system. The Smads proteins coexistence in the adult rat testis was tested by the double immune staining for CD14-Smad4 and Smad2-Smad4. The protein expression of Smad during rat testicular development was examined by means of Western blots. Results: Smadl, Smad2 and Smad4 were present throughout testicular development. The immunostaining of Smadl and Smad2 were present in spermatogenic cells. A positive immunoreactivity was located at the cytoplasm, but the nucleus was negative. Smadl was immunolocalized at the d14, d28 and adult testes, while Smad2, at the d7, d14, d28 and adult testis. There was positive irnmunoreaction in the Sertoli cells and Leydig cells as well. The immunolocalization of Smad4 was exclusively at the cytoplasm of Leydig cells and the nuclei were negative throughout the testicular development. No expression was detected in the germ cells. The results of image and statistical analysis showed that generally the expression of Smadl, Smad2 and Smad4 in the testis tended to increase gradually with the growth of the rat. Conclusion: The present data provide direct evidences for the molecular mechanism of TGF-βaction in rat testes during postnatal development and spermatogenesis.
文摘Objective To find out a proper way to detect green fluorescent protein (GFP). Methods Kidneys, livers and femurs from GFP transgenic mice and C57BL/6J wild type mice were employed for in vivo study. The samples were dehydrated with alcohol and acetone individually before embedding, then frozen, paraffin and resin sections were made for the detection of GFP. C3 P12 cells which derived from calvaria bone cells of GFP transgenic mouse were used for the detection of GFP in vitro. Cells were exposed to alcohol, acetone and PBS after paraformaldehyde fixation. Laser scanning microscopy was employed for GFP detection. Results In frozen sections, both kidney and liver samples which exposed to 4% buffered paraformaldehyde fixation had strong GFP signals, while GFP signal disappeared completely in fresh frozen sections without fixation. Much stronger GFP intensity was found in acetone treated samples than in alcohol treated paraffin sections, but without apparent difference in GFP intensity in acetone and alcohol treated resin samples. Acetone and alcohol made no difference in fixed C3 cells in different time courses. Conclusion Acetone treated paraffin sections are preferable for GFP detection.
文摘The aim of this study was to assess the stress patterns on the peri-implant zone and residual alveolar ridge in different overdenture attachment system designs by the photoelasticity method. Four attachments systems were tested: O-ring, ERA, Bar-clip, and Bar-clip/O-ring association. The prostheses were loaded with 100 N in five pre-determined points and the photoelastic model was evaluated by a circular polariscope. The anterior load, O-ring, and ERA showed better stress distribution in relation to the bars systems, which presented stress levels surrounding implants. The molar load, Bar-clip/O-ring association, presented the biggest stress concentration on the peri-implant region in relation to the others. When the second molar was loaded, there was a concentration of stress in the alveolar ridge in all situations analyzed. Within the limitation of this “in vitro” study, it could be concluded that there were biomechanical differences among the attachments systems analyzed, principally between isolated and the bars systems. The O-ring showed better stress distribution and the Bar-clip/O-ring showed higher stress concentration.
