AIM: To determine whether the elevated vascular endothelial growth factor (VEGF) expression produced by the transfected vascular endothelial cells (VECs) could stimulate angiogenesis of the graft islets and exert its ...AIM: To determine whether the elevated vascular endothelial growth factor (VEGF) expression produced by the transfected vascular endothelial cells (VECs) could stimulate angiogenesis of the graft islets and exert its effect on the graft function. METHODS: Thirty diabetic recipient rats were divided into three groups (n = 10 per group). In the control group,300 IEQ islets were transplanted in each rat under the capsule of the right kidney,which were considered as marginal grafts. In the VEC group,VEC together with the islets were transplanted in each rat. In the VEGF group,VEC transfected by pIRES2-EGFP/ VEGF165 plasmid and the islets were transplanted in each rat. Blood glucose and insulin levels were evaluated every other day after operation. Intravenous glucose tolerance test (IVGTT) was performed 10 d after the transplantation. Hematoxylin and eosin (HE) staining was used to evaluate the histological features of the graft islets. Immunohistochemical staining was used to detect insulin-6,VEGF and CD34 (MVD) expression in the graft islets. RESULTS: Blood glucose and insulin levels in the VEGF group restored to normal 3 d after transplantation. In contrast,diabetic rats receiving the same islets with or without normal VECs displayed moderate hyperglycemia and insulin,without a significant difference between these two groups. IVGTT showed that both the amplitude of blood glucose induction and the kinetics of blood glucose in the VEGF group restored to normal after transplantation. H&E and immunohistochemical staining showed the presence of a large amount of graft islets under the capsule of the kidney,which were positively stained with insulin-6 and VEGF antibodies in the VEGF group. In the cell masses,CD34-stained VECs were observed. The similar masses were also seen in the other two groups,but with a fewer positive cells stained with insulin-6 and CD34 antibodies. No VEGF-positive cells appeared in these groups. Microvessel density (MVD) was significantly higher in the VEGF group compared to the other two groups. CONCLUSION: Elevated VEGF production by trans-fected vascular endothelial cells in the site of islet transplantation stimulates angiogenesis of the islet grafts. The accelerated islet revascularization in early stage could improve the outcome of islet transplantation,and enhance the graft survival.展开更多
Background: Over the past years, scientists have been working on the mechanisms of the scarless healing. The remarkable phenotypic differences between fetal and adult healing may lead us to find out their characterist...Background: Over the past years, scientists have been working on the mechanisms of the scarless healing. The remarkable phenotypic differences between fetal and adult healing may lead us to find out their characteristics in genetics, which represent potentially important mechanisms to explain the differences in the quality of wound repair observed in fetus versus adult tissues. Methods: Middle laparotomy and hysterotomy were performed on pregnant rabbits on 20-day gestation to expose the fetal back, and longitudinal incision which penetrated full skin was made on the back of fetus. The trauma fetus skin was harvested at 12 h post-operation (FT), the fetus control (FC) and trauma adult skin (AT) were taken at the same time. dscDNA was synthesized from total RNA of skin samples with SMART technology. An improved suppression subtractive hybridization (SSH) method was applied to analyze the samples. Having taken one of the three samples as Tester respectively, the other two together as Drivers, one forward and two reverse hybridization products were gotten. Having amplified by selective PCR, the products were inserted into vector, and then transferred into E.coli HB101. The colonies were screened by electrophoresis, reverse Northern afterwards, and the positive clones were sequenced. BLAST in NCBI was performed to compare and analyze the positive clones (expressed sequence Tag, ESTs). Results: Totally 298 clones were gotten and 61 positive clones were obtained after screening. The 61 selected positive clones were sequenced and 54 sequences were goten. Conclusion: Instead of traditional SSH, an improved SSH with 2 Drivers was applied in the experiment. The improved program is reasonable and correct in both theory and practice.展开更多
Objective To study the cell growth factor secretion and vascular regeneration in acute in-farcted myocardium after autologous skeletal muscle satellite cell implantation. Methods Autologous skeletal muscle satellite c...Objective To study the cell growth factor secretion and vascular regeneration in acute in-farcted myocardium after autologous skeletal muscle satellite cell implantation. Methods Autologous skeletal muscle satellite cells from adult mongrel canine were implanted into the acute myocardial infarct site via the ligated left anterior descending (LAD) artery. Specimens were harvested at 2, 4 , 8 weeks after implantation for the expression of insulin-like growth factor-1 (IGF-1), basic fibroblast growth factor ( bFGF) and the vascular density. Results The expression of IGF-1, bFGF and the vascular density in skeletal muscle satellite cell implant group were higher than that in the control group. Conclusion The skeletal muscle satellite cells, after being implanted into the acute myocardial infarction, not only showed myocardial regeneration, but also showed the ability to secrete the cell factors, hence representing a positive effect on the regeneration of the infarcted myocardium.展开更多
Objective:To study the effect of nerve growth f actor (NGF) and Schwann cells on axon regeneration of the inferior alveolar nerv e following mandibular lengthening with distraction osteogenesis. Methods:Unilateral man...Objective:To study the effect of nerve growth f actor (NGF) and Schwann cells on axon regeneration of the inferior alveolar nerv e following mandibular lengthening with distraction osteogenesis. Methods:Unilateral mandibular osteodistraction was performed i n 9 healthy adult male goats with a distraction rate of 1 mm/d. Every 3 goats we re killed on days 7, 14 and 28 after mandibular lengthening, respectively. The i nferior alveolar nerves in the distraction callus were harvested and processed f or ultrastructural and NGF immunohistochemical study. The inferior alveolar nerv es from the contralateral side were used as controls. Results:On day 7 after distraction, axon degeneration and Schw ann cell proliferation were observed, and very strong staining of NGF in the dis tracted nerve was detected. On day 14 after distraction, axon regeneration and r emyelination were easily observed, and NGF expression started to decline. On day 28 after distraction, the gray scale of NGF immunoreactivity recovered to the n ormal value and the Schwann cells almost recovered to their normal state. Conclusions:Gradual mandibular osteodistraction can result in mild or moderate axon degeneration of the inferior alveolar nerve. Nerve trauma may stimulate the proliferation of Schwann cells and promote the synthesis and s ecretion of NGF in the Schwann cells. Schwann cells and NGF might play important roles in axon regeneration of the injured inferior alveolar nerve following man dibular lengthening.展开更多
Objective： To explore the feasibility of using regenerated silk fibroin membrane to construct artificial skin substitutes for wound healing, it is necessary to evaluate its cytocompatibility. Methods： The effects of...Objective： To explore the feasibility of using regenerated silk fibroin membrane to construct artificial skin substitutes for wound healing, it is necessary to evaluate its cytocompatibility. Methods： The effects of regenerated silk fibroin film on cytotoxicity, adhesion, cell cycle, and apoptosis of L929 cells, growth and vascular endothelial growth factor （VEGF） expression of ECV304 cells, and VEGF, angiopoietin-1 （Ang-1）, platelet-derived growth factor （PDGF） and fibroblast growth factor 2 （FGF2） expression of WI-38 cells were assessed by 3-（4,5）-dimethylthiahiazo （-z-yl）-3,5-di-phenytetrazoliumromide （MTT） assay, viable cell counting, flow cytometry （FCM）, and enzyme-linked immunosorbant assay （ELISA）. Results： We showed that the regenerated silk fibroin film was not cytotoxic to L929 cells and had no adverse influence on their adhesion, cell cycle or apoptosis; it had no adverse influence on the growth and VEGF secretion of ECV304 cells and no effect on the secretion of VEGF, Ang-1, PDGF and FGF2 by WI-38 cells. Conclusion： The regenerated silk fibroin film should be an excellent biomaterial with good cytocompatibility, providing a framework for reparation after trauma in clinical applications.展开更多
基金Supported by National Natural Science Foundation of China, No. 30672094
文摘AIM: To determine whether the elevated vascular endothelial growth factor (VEGF) expression produced by the transfected vascular endothelial cells (VECs) could stimulate angiogenesis of the graft islets and exert its effect on the graft function. METHODS: Thirty diabetic recipient rats were divided into three groups (n = 10 per group). In the control group,300 IEQ islets were transplanted in each rat under the capsule of the right kidney,which were considered as marginal grafts. In the VEC group,VEC together with the islets were transplanted in each rat. In the VEGF group,VEC transfected by pIRES2-EGFP/ VEGF165 plasmid and the islets were transplanted in each rat. Blood glucose and insulin levels were evaluated every other day after operation. Intravenous glucose tolerance test (IVGTT) was performed 10 d after the transplantation. Hematoxylin and eosin (HE) staining was used to evaluate the histological features of the graft islets. Immunohistochemical staining was used to detect insulin-6,VEGF and CD34 (MVD) expression in the graft islets. RESULTS: Blood glucose and insulin levels in the VEGF group restored to normal 3 d after transplantation. In contrast,diabetic rats receiving the same islets with or without normal VECs displayed moderate hyperglycemia and insulin,without a significant difference between these two groups. IVGTT showed that both the amplitude of blood glucose induction and the kinetics of blood glucose in the VEGF group restored to normal after transplantation. H&E and immunohistochemical staining showed the presence of a large amount of graft islets under the capsule of the kidney,which were positively stained with insulin-6 and VEGF antibodies in the VEGF group. In the cell masses,CD34-stained VECs were observed. The similar masses were also seen in the other two groups,but with a fewer positive cells stained with insulin-6 and CD34 antibodies. No VEGF-positive cells appeared in these groups. Microvessel density (MVD) was significantly higher in the VEGF group compared to the other two groups. CONCLUSION: Elevated VEGF production by trans-fected vascular endothelial cells in the site of islet transplantation stimulates angiogenesis of the islet grafts. The accelerated islet revascularization in early stage could improve the outcome of islet transplantation,and enhance the graft survival.
文摘Background: Over the past years, scientists have been working on the mechanisms of the scarless healing. The remarkable phenotypic differences between fetal and adult healing may lead us to find out their characteristics in genetics, which represent potentially important mechanisms to explain the differences in the quality of wound repair observed in fetus versus adult tissues. Methods: Middle laparotomy and hysterotomy were performed on pregnant rabbits on 20-day gestation to expose the fetal back, and longitudinal incision which penetrated full skin was made on the back of fetus. The trauma fetus skin was harvested at 12 h post-operation (FT), the fetus control (FC) and trauma adult skin (AT) were taken at the same time. dscDNA was synthesized from total RNA of skin samples with SMART technology. An improved suppression subtractive hybridization (SSH) method was applied to analyze the samples. Having taken one of the three samples as Tester respectively, the other two together as Drivers, one forward and two reverse hybridization products were gotten. Having amplified by selective PCR, the products were inserted into vector, and then transferred into E.coli HB101. The colonies were screened by electrophoresis, reverse Northern afterwards, and the positive clones were sequenced. BLAST in NCBI was performed to compare and analyze the positive clones (expressed sequence Tag, ESTs). Results: Totally 298 clones were gotten and 61 positive clones were obtained after screening. The 61 selected positive clones were sequenced and 54 sequences were goten. Conclusion: Instead of traditional SSH, an improved SSH with 2 Drivers was applied in the experiment. The improved program is reasonable and correct in both theory and practice.
基金Supported by grants from the Nature Science Foundation of China(39770735)
文摘Objective To study the cell growth factor secretion and vascular regeneration in acute in-farcted myocardium after autologous skeletal muscle satellite cell implantation. Methods Autologous skeletal muscle satellite cells from adult mongrel canine were implanted into the acute myocardial infarct site via the ligated left anterior descending (LAD) artery. Specimens were harvested at 2, 4 , 8 weeks after implantation for the expression of insulin-like growth factor-1 (IGF-1), basic fibroblast growth factor ( bFGF) and the vascular density. Results The expression of IGF-1, bFGF and the vascular density in skeletal muscle satellite cell implant group were higher than that in the control group. Conclusion The skeletal muscle satellite cells, after being implanted into the acute myocardial infarction, not only showed myocardial regeneration, but also showed the ability to secrete the cell factors, hence representing a positive effect on the regeneration of the infarcted myocardium.
基金ThisstudywassupportedbytheNationalNaturalScienceFoundationofChina (No .3 9970 797)
文摘Objective:To study the effect of nerve growth f actor (NGF) and Schwann cells on axon regeneration of the inferior alveolar nerv e following mandibular lengthening with distraction osteogenesis. Methods:Unilateral mandibular osteodistraction was performed i n 9 healthy adult male goats with a distraction rate of 1 mm/d. Every 3 goats we re killed on days 7, 14 and 28 after mandibular lengthening, respectively. The i nferior alveolar nerves in the distraction callus were harvested and processed f or ultrastructural and NGF immunohistochemical study. The inferior alveolar nerv es from the contralateral side were used as controls. Results:On day 7 after distraction, axon degeneration and Schw ann cell proliferation were observed, and very strong staining of NGF in the dis tracted nerve was detected. On day 14 after distraction, axon regeneration and r emyelination were easily observed, and NGF expression started to decline. On day 28 after distraction, the gray scale of NGF immunoreactivity recovered to the n ormal value and the Schwann cells almost recovered to their normal state. Conclusions:Gradual mandibular osteodistraction can result in mild or moderate axon degeneration of the inferior alveolar nerve. Nerve trauma may stimulate the proliferation of Schwann cells and promote the synthesis and s ecretion of NGF in the Schwann cells. Schwann cells and NGF might play important roles in axon regeneration of the injured inferior alveolar nerve following man dibular lengthening.
基金supported by the National Basic Research Program (973) of China (No.2005CB623906)the Medical Development Foundation of Soochow University (No.EE134702),China
文摘Objective： To explore the feasibility of using regenerated silk fibroin membrane to construct artificial skin substitutes for wound healing, it is necessary to evaluate its cytocompatibility. Methods： The effects of regenerated silk fibroin film on cytotoxicity, adhesion, cell cycle, and apoptosis of L929 cells, growth and vascular endothelial growth factor （VEGF） expression of ECV304 cells, and VEGF, angiopoietin-1 （Ang-1）, platelet-derived growth factor （PDGF） and fibroblast growth factor 2 （FGF2） expression of WI-38 cells were assessed by 3-（4,5）-dimethylthiahiazo （-z-yl）-3,5-di-phenytetrazoliumromide （MTT） assay, viable cell counting, flow cytometry （FCM）, and enzyme-linked immunosorbant assay （ELISA）. Results： We showed that the regenerated silk fibroin film was not cytotoxic to L929 cells and had no adverse influence on their adhesion, cell cycle or apoptosis; it had no adverse influence on the growth and VEGF secretion of ECV304 cells and no effect on the secretion of VEGF, Ang-1, PDGF and FGF2 by WI-38 cells. Conclusion： The regenerated silk fibroin film should be an excellent biomaterial with good cytocompatibility, providing a framework for reparation after trauma in clinical applications.
