The transplantation of polylactic glycolic acid conduits combining bone marrow mesenchymal stem cells and extracellular matrix gel for the repair of sciatic nerve injury is effective in some respects, but few data com...The transplantation of polylactic glycolic acid conduits combining bone marrow mesenchymal stem cells and extracellular matrix gel for the repair of sciatic nerve injury is effective in some respects, but few data comparing the biomechanical factors related to the sciatic nerve are available. In the present study, rabbit models of 10-mm sciatic nerve defects were prepared. The rabbit models were repaired with autologous nerve, a polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells, or a polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel. After 24 weeks, mechanical testing was performed to determine the stress relaxation and creep parameters. Following sciatic nerve injury, the magnitudes of the stress decrease and strain increase at 7,200 seconds were largest in the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel group, followed by the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells group, and then the autologous nerve group. Hematoxylin-eosin staining demonstrated that compared with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells group and the autologous nerve group, a more complete sciatic nerve regeneration was found, including good myelination, regularly arranged nerve fibers, and a completely degraded and resorbed conduit, in the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel group. These results indicate that bridging 10-mm conduit ＋ bone marrow mesenchymal stem sciatic nerve defects with a polylactic glycolic acid cells ＋ extracellular matrix gel construct increases the stress relaxation under a constant strain, reducing anastomotic tension. Large elongations under a constant physiological load can limit the anastomotic opening and shift, which is beneficial for the regeneration and functional reconstruction of sciatic nerve. Better regeneration was found with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel grafts than with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells grafts and the autologous nerve grafts.展开更多
Binary and ternary terbium complexes were synthesized: Tb(N PA) 3·4H 2O and Tb(N PA) 3(phen·2H 2O (N HPA = N phenyl 2 aminobenzoic acid and phen = 1,10 phenanthroline). These complexes were introd...Binary and ternary terbium complexes were synthesized: Tb(N PA) 3·4H 2O and Tb(N PA) 3(phen·2H 2O (N HPA = N phenyl 2 aminobenzoic acid and phen = 1,10 phenanthroline). These complexes were introduced into inorganic polymeric porous silica matrix by the sol gel method. The luminescence behavior of the complexes in silica gels was compared with the corresponding solid state complexes by means of emission, excitation spectra and luminescence lifetimes. The result indicates that the terbium ions show fewer emission lines and lower emission intensities in the silica gel than those in pure terbium complexes. The lifetimes of terbium ions in silica gel doped with terbium complexes become longer than those of terbium complexes.展开更多
The electrodes of a cochlear implant are located far from the surviving neurons of the spiral ganglion, which results in decreased precision of neural activation compared to the normal ear. If the neurons could be ind...The electrodes of a cochlear implant are located far from the surviving neurons of the spiral ganglion, which results in decreased precision of neural activation compared to the normal ear. If the neurons could be induced to extend neurites toward the implant, it might be possible to stimulate more discrete subpopulations of neurons, and to increase the resolution of the device. However, a major barrier to neurite growth toward a cochlear implant is the fluid filling the scala tympani, which separates the neurons from the electrodes. The goal of this study was to evaluate the growth of cochlear neurites in three-dimensional extracellular matrix molecule gels, and to increase biocompatibility by using fibroblasts stably transfected to produce neurotrophin-3 and brain-derived neurotrophic factor. Spiral ganglion explants from neonatal rats were evaluated in cultures. They were exposed to soluble neurotrophins, cells transfected to secrete neurotrophins, and/or collagen gels. We found that cochlear neurites grew readily on collagen surfaces and in three-dimensional collagen gels. Co-culture with cells producing neurotrophin-3 resulted in increased numbers of neurites, and neurites that were longer than when explants were cultured with control fibroblasts stably transfected with green fluorescent protein. Brain-derived neurotrophic factor-producing cells resulted in a more dramatic increase in the number of neurites, but there was no significant effect on neurite length. It is suggested that extracellular matrix molecule gels and cells transfected to produce neurotrophins offer an opportunity to attract spiral ganglion neurites toward a cochlear implant.展开更多
Objective： Nuclear matrix protein is tissue, cell-type specific, and tumor-relative. It plays an important role in the regulation of intranuclear processes. Some researches also showed that a c-erbB-2 promoter-specif...Objective： Nuclear matrix protein is tissue, cell-type specific, and tumor-relative. It plays an important role in the regulation of intranuclear processes. Some researches also showed that a c-erbB-2 promoter-specific DNA-binding nuclear matrix protein is present only in malignant human breast tissues and induces mitogenesis and cell surface expression of the c-erbB-2 protein in resting NIH/3T3 cells. But it is not clear that how it in colon adenocarcinomas. Methods： Two-dimensional gel electrophoretic method was used for NMP identification and immunohistochemistry was used for c-erbB-2 detection in 12 cases of colon adenocarcinomas and matched adjacent normal colon tissues. Results： 5 different nuclear matrix proteins （named C1-C5） were identified in 12 colon adenocarcinoma specimens, but not in the matched adjacent normal colon tissues; 3 nuclear matrix proteins （named N1-N3） were identified in all 12 matched adjacent normal colon tissues, but not in colon adenocarcinoma specimens. A nuclear matrix protein （named N4） was detected in all of 9 moderated-well differentiated adenocarcinomas and all 12 matched adjacent normal colon tissues, but not in 3 poor-differentiated adenocarcinomas. All of the 10 colon adenocarcinomas which had the nuclear matrix protein C4 were c-erbB-2 expression positive. Conclusion： The data suggest that there are specific nuclear matrix proteins in colon adenocarcinomas and its subtypes, which maybe valuable to serve as markers of colon adenocarcinomas in future. Nuclear matrix protein C4 probably is a c-erbB-2 promotor-specific nuclear matrix protein in colon adenocarcinomas, and may induce the expression of c-erbB-2.展开更多
基金supported by the Science and Technology Development Program of Jilin Province in China,No.20110492
文摘The transplantation of polylactic glycolic acid conduits combining bone marrow mesenchymal stem cells and extracellular matrix gel for the repair of sciatic nerve injury is effective in some respects, but few data comparing the biomechanical factors related to the sciatic nerve are available. In the present study, rabbit models of 10-mm sciatic nerve defects were prepared. The rabbit models were repaired with autologous nerve, a polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells, or a polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel. After 24 weeks, mechanical testing was performed to determine the stress relaxation and creep parameters. Following sciatic nerve injury, the magnitudes of the stress decrease and strain increase at 7,200 seconds were largest in the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel group, followed by the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells group, and then the autologous nerve group. Hematoxylin-eosin staining demonstrated that compared with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells group and the autologous nerve group, a more complete sciatic nerve regeneration was found, including good myelination, regularly arranged nerve fibers, and a completely degraded and resorbed conduit, in the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel group. These results indicate that bridging 10-mm conduit ＋ bone marrow mesenchymal stem sciatic nerve defects with a polylactic glycolic acid cells ＋ extracellular matrix gel construct increases the stress relaxation under a constant strain, reducing anastomotic tension. Large elongations under a constant physiological load can limit the anastomotic opening and shift, which is beneficial for the regeneration and functional reconstruction of sciatic nerve. Better regeneration was found with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel grafts than with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells grafts and the autologous nerve grafts.
文摘Binary and ternary terbium complexes were synthesized: Tb(N PA) 3·4H 2O and Tb(N PA) 3(phen·2H 2O (N HPA = N phenyl 2 aminobenzoic acid and phen = 1,10 phenanthroline). These complexes were introduced into inorganic polymeric porous silica matrix by the sol gel method. The luminescence behavior of the complexes in silica gels was compared with the corresponding solid state complexes by means of emission, excitation spectra and luminescence lifetimes. The result indicates that the terbium ions show fewer emission lines and lower emission intensities in the silica gel than those in pure terbium complexes. The lifetimes of terbium ions in silica gel doped with terbium complexes become longer than those of terbium complexes.
基金supported by grants from the Research Service of the United States Veterans Administration (to Allen Frederic Ryan and Stephen Fausti)the National Institute of Health/National Institute on Deafness and Other Communication Disorders (to Allen Frederic Ryan)+2 种基金the National Institute of Health Summer Research Program (to Joanna Xie)the Deafness Research Foundation (to Lina Mullen)the National Organization for Hearing Research (to Lina Mullen)
文摘The electrodes of a cochlear implant are located far from the surviving neurons of the spiral ganglion, which results in decreased precision of neural activation compared to the normal ear. If the neurons could be induced to extend neurites toward the implant, it might be possible to stimulate more discrete subpopulations of neurons, and to increase the resolution of the device. However, a major barrier to neurite growth toward a cochlear implant is the fluid filling the scala tympani, which separates the neurons from the electrodes. The goal of this study was to evaluate the growth of cochlear neurites in three-dimensional extracellular matrix molecule gels, and to increase biocompatibility by using fibroblasts stably transfected to produce neurotrophin-3 and brain-derived neurotrophic factor. Spiral ganglion explants from neonatal rats were evaluated in cultures. They were exposed to soluble neurotrophins, cells transfected to secrete neurotrophins, and/or collagen gels. We found that cochlear neurites grew readily on collagen surfaces and in three-dimensional collagen gels. Co-culture with cells producing neurotrophin-3 resulted in increased numbers of neurites, and neurites that were longer than when explants were cultured with control fibroblasts stably transfected with green fluorescent protein. Brain-derived neurotrophic factor-producing cells resulted in a more dramatic increase in the number of neurites, but there was no significant effect on neurite length. It is suggested that extracellular matrix molecule gels and cells transfected to produce neurotrophins offer an opportunity to attract spiral ganglion neurites toward a cochlear implant.
文摘Objective： Nuclear matrix protein is tissue, cell-type specific, and tumor-relative. It plays an important role in the regulation of intranuclear processes. Some researches also showed that a c-erbB-2 promoter-specific DNA-binding nuclear matrix protein is present only in malignant human breast tissues and induces mitogenesis and cell surface expression of the c-erbB-2 protein in resting NIH/3T3 cells. But it is not clear that how it in colon adenocarcinomas. Methods： Two-dimensional gel electrophoretic method was used for NMP identification and immunohistochemistry was used for c-erbB-2 detection in 12 cases of colon adenocarcinomas and matched adjacent normal colon tissues. Results： 5 different nuclear matrix proteins （named C1-C5） were identified in 12 colon adenocarcinoma specimens, but not in the matched adjacent normal colon tissues; 3 nuclear matrix proteins （named N1-N3） were identified in all 12 matched adjacent normal colon tissues, but not in colon adenocarcinoma specimens. A nuclear matrix protein （named N4） was detected in all of 9 moderated-well differentiated adenocarcinomas and all 12 matched adjacent normal colon tissues, but not in 3 poor-differentiated adenocarcinomas. All of the 10 colon adenocarcinomas which had the nuclear matrix protein C4 were c-erbB-2 expression positive. Conclusion： The data suggest that there are specific nuclear matrix proteins in colon adenocarcinomas and its subtypes, which maybe valuable to serve as markers of colon adenocarcinomas in future. Nuclear matrix protein C4 probably is a c-erbB-2 promotor-specific nuclear matrix protein in colon adenocarcinomas, and may induce the expression of c-erbB-2.
