Objective To investigate the efficacy and mechanism of tibial transverse bone transfer in the treatment of lower limb ulcer wounds in diabetic rabbits.Methods Animal models of diabetic foot lower extremity ischemia we...Objective To investigate the efficacy and mechanism of tibial transverse bone transfer in the treatment of lower limb ulcer wounds in diabetic rabbits.Methods Animal models of diabetic foot lower extremity ischemia were made,and grouped Animal models of diabetic foot lower extremity ischemia were made,and grouped control studies were designed to evaluate the time of wound healing and the expression level of vascular endothelial growth factor(VEGF),platelet derived growth factor(PDGF),and epidermal cell growth factor(EGF)in the wound during the same period of time.Results In animal experiments,transverse tibial bone transfer can shorten the healing time of diabetic ulcer and increase the expression of wound growth factor(VEGF,PDGF,EGF).Conclusion In animal experiments,diabetes can inhibit the expression of growth factors(VEGF,PDGF,EGF)in ulcer wounds,and tibial transverse bone transfer can promote wound healing.The mechanism may be related to the increased expression of VEGF,PDGF and EGF in the wound surface.展开更多
Human temporal bone specimens are used in experiments to measure the sound transfer function of the middle ear.This standard method for the development of middle ear implants requires temporal bones that possess appro...Human temporal bone specimens are used in experiments to measure the sound transfer function of the middle ear.This standard method for the development of middle ear implants requires temporal bones that possess appropriate mechanical properties and structural stability and are free from pathological conditions.A laser Doppler vibrometer is commonly employed to measure the vibration of the stapes footplate.These experiments are typically conducted in the middle ear by leaving the inner ear intact,exposing the stapes footplate through the tympanic cavity,and directing the laser beam onto the footplate.However,previous studies have shown that the influence of inner ear impedance on the middle ear transfer function cannot be ignored,and any surgical manipulation may cause a change in inner ear pressure,resulting in instability in the middle ear transfer function.Therefore,this study aims to eliminate the influence of the inner ear and to establish a new experimental method in human temporal bone specimens that is more suitable for the study of sound conduction in middle ear implants.As a result,a range for middle ear transfer function was developed,which serves as a reference for assessing the conformity of temporal bone specimens to experimental standards,and the stability of this range was demonstrated under experimental conditions.展开更多
We have shown previously that high-efficient gene transfer can be attained in primary hematopoietic cells using liposome-mediated gene transfer strategy. In order to examine the stability of gene expression mediated b...We have shown previously that high-efficient gene transfer can be attained in primary hematopoietic cells using liposome-mediated gene transfer strategy. In order to examine the stability of gene expression mediated by this gene transduction protocol, we observed the expression of marker gene in vivo by using bone marrow transplantation (BMT) to engraft lethally irradiated mouse with the genetically modified hematopoietic cells. The results showed that the mouse transplanted with appropriated number of transduced cells remained alive andhealthy. The PCR analysis and G418 selection of the spleen colonies and bone marrow cells isolated from lethally irradiated animals 15 days and 30 days after injection of genetically modified bone marrow cells showed that the progeny cells of the transduced hematopoietic stem cells still contained and expressed the transduced genes, suggesting that the hematopoietic system is at least partially re-constructed by the stem cells with marker gene and that the stable expression of foreign genes in vivo can be attained by using this easy and harmless transduction protocol. These findings provide experimental basis for clinician to further investigate the biology of marrow reconstruction and the mechanism of leukemia relapse after BMT.展开更多
Objective To develop retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2 in mesenchymal stem cells.Methods Mesenchymal stem cells from New Zealand white rabbits were transduced with retroviral pLEGFP-B...Objective To develop retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2 in mesenchymal stem cells.Methods Mesenchymal stem cells from New Zealand white rabbits were transduced with retroviral pLEGFP-BMP_2 vector by the optimized retroviral transduction protocol.Fluorescent microscopy's examination was to evaluate the results of the transduction,flow cytometer's analysis was to evaluate the transduction efficiency and the Fluorescence-activated cell sorting method was to sort the transduced cells.Bioactivity test from C_2C_12K_4 cells was to show the expression and bio-activity of the fusion gene.Results Fluorescent microscopy showed the success of the transduction.By flow cytometer's analysis,the mean efficiency of the transduction with EGFP was(42.8±6.1)% SD.Transduced cells were sorted efficiently by the fluorescence-activated cell sorting method and after sorting,almost of those showed the expression of BMP_2.Fluorescently and strongly bioactivity test for C_2C_12K_4 cells demonstrated that fluorescent materials were located the surface of cells and the activity of luciferase increased compared with the control.Analysis of long-term expression showed there was no difference between 2 week-time point and 3 month-time point of culture post-sorting.Conclusion Mesenchymal stem cells can be transduced efficiently by retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2,the highly pure transduced cells are obtained by the fluorescence-activated cell sorting technique,the expressed chimeric protein embraced the double bioactivity of EGFP and BMP_2,and moreover,the expression had not attenuated over time.展开更多
文摘Objective To investigate the efficacy and mechanism of tibial transverse bone transfer in the treatment of lower limb ulcer wounds in diabetic rabbits.Methods Animal models of diabetic foot lower extremity ischemia were made,and grouped Animal models of diabetic foot lower extremity ischemia were made,and grouped control studies were designed to evaluate the time of wound healing and the expression level of vascular endothelial growth factor(VEGF),platelet derived growth factor(PDGF),and epidermal cell growth factor(EGF)in the wound during the same period of time.Results In animal experiments,transverse tibial bone transfer can shorten the healing time of diabetic ulcer and increase the expression of wound growth factor(VEGF,PDGF,EGF).Conclusion In animal experiments,diabetes can inhibit the expression of growth factors(VEGF,PDGF,EGF)in ulcer wounds,and tibial transverse bone transfer can promote wound healing.The mechanism may be related to the increased expression of VEGF,PDGF and EGF in the wound surface.
文摘Human temporal bone specimens are used in experiments to measure the sound transfer function of the middle ear.This standard method for the development of middle ear implants requires temporal bones that possess appropriate mechanical properties and structural stability and are free from pathological conditions.A laser Doppler vibrometer is commonly employed to measure the vibration of the stapes footplate.These experiments are typically conducted in the middle ear by leaving the inner ear intact,exposing the stapes footplate through the tympanic cavity,and directing the laser beam onto the footplate.However,previous studies have shown that the influence of inner ear impedance on the middle ear transfer function cannot be ignored,and any surgical manipulation may cause a change in inner ear pressure,resulting in instability in the middle ear transfer function.Therefore,this study aims to eliminate the influence of the inner ear and to establish a new experimental method in human temporal bone specimens that is more suitable for the study of sound conduction in middle ear implants.As a result,a range for middle ear transfer function was developed,which serves as a reference for assessing the conformity of temporal bone specimens to experimental standards,and the stability of this range was demonstrated under experimental conditions.
文摘We have shown previously that high-efficient gene transfer can be attained in primary hematopoietic cells using liposome-mediated gene transfer strategy. In order to examine the stability of gene expression mediated by this gene transduction protocol, we observed the expression of marker gene in vivo by using bone marrow transplantation (BMT) to engraft lethally irradiated mouse with the genetically modified hematopoietic cells. The results showed that the mouse transplanted with appropriated number of transduced cells remained alive andhealthy. The PCR analysis and G418 selection of the spleen colonies and bone marrow cells isolated from lethally irradiated animals 15 days and 30 days after injection of genetically modified bone marrow cells showed that the progeny cells of the transduced hematopoietic stem cells still contained and expressed the transduced genes, suggesting that the hematopoietic system is at least partially re-constructed by the stem cells with marker gene and that the stable expression of foreign genes in vivo can be attained by using this easy and harmless transduction protocol. These findings provide experimental basis for clinician to further investigate the biology of marrow reconstruction and the mechanism of leukemia relapse after BMT.
基金This work was supported by the National Natural Science Foundation of China(No.30400163).
文摘Objective To develop retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2 in mesenchymal stem cells.Methods Mesenchymal stem cells from New Zealand white rabbits were transduced with retroviral pLEGFP-BMP_2 vector by the optimized retroviral transduction protocol.Fluorescent microscopy's examination was to evaluate the results of the transduction,flow cytometer's analysis was to evaluate the transduction efficiency and the Fluorescence-activated cell sorting method was to sort the transduced cells.Bioactivity test from C_2C_12K_4 cells was to show the expression and bio-activity of the fusion gene.Results Fluorescent microscopy showed the success of the transduction.By flow cytometer's analysis,the mean efficiency of the transduction with EGFP was(42.8±6.1)% SD.Transduced cells were sorted efficiently by the fluorescence-activated cell sorting method and after sorting,almost of those showed the expression of BMP_2.Fluorescently and strongly bioactivity test for C_2C_12K_4 cells demonstrated that fluorescent materials were located the surface of cells and the activity of luciferase increased compared with the control.Analysis of long-term expression showed there was no difference between 2 week-time point and 3 month-time point of culture post-sorting.Conclusion Mesenchymal stem cells can be transduced efficiently by retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP_2,the highly pure transduced cells are obtained by the fluorescence-activated cell sorting technique,the expressed chimeric protein embraced the double bioactivity of EGFP and BMP_2,and moreover,the expression had not attenuated over time.
