Objective: We established a transplantation tumor model of human osteosarcoma in chick embryo, studied its morphological and biological characteristics, and observed its dynamic process of angiogenesis induction so th...Objective: We established a transplantation tumor model of human osteosarcoma in chick embryo, studied its morphological and biological characteristics, and observed its dynamic process of angiogenesis induction so that a simple and practical model can be provided for studying osteosarcoma. Methods: Human osteosarcoma cells at different concentrations were inoculated in chorioallantoic membrane (CAM) of chick embryos at different embryonic ages to observe the factors affecting the survival of the transplanted osteosarcoma in chick embryo, growth characteristics of the transplantation tumor, and the morphological characteristics and biological characteristics of the transplantation tumor. Results: The transplantation tumor model of human osteosarcoma in chick embryo was successfully established. It was found that the transplantation tumor was easy to grow and it showed strong angiogenesis-inducing effects. Under the light microscope, the transplantation tumor showed a similar tissue structure to human osteosarcoma. Conclusion: It is feasible to establish a transplantation tumor model of human osteosarcoma in chick embryo. The model can be easily duplicated with a simple operation, which provides a useful animal model for studying osteosarcoma.展开更多
AIM： To correlate the significance of liver biochemical tests in diagnosing post orthotopic liver transplantation （OLT） biliary complications and to study their profile before and after endoscopic therapy.METHODS：...AIM： To correlate the significance of liver biochemical tests in diagnosing post orthotopic liver transplantation （OLT） biliary complications and to study their profile before and after endoscopic therapy.METHODS： Patients who developed biliary complications were analysed in detail for the clinical information, laboratory tests, treatment offered, response to it, follow up and outcomes. The profile of liver enzymes was determined. The safety, efficacy and outcomes of endoscopic retrograde cholangiography （ERC） were also analysed. RESULTS： 40 patients required ERC for 70 biliary complications. GGT was found to be 〉 3 times （388.1 ± 70.9 U/mL vs 168.5 4± 34.2 U/L, P = 0.007） and SAP 〉 2 times （345.1 ± 59.1 U/L vs 152.7 ± 21.4 U/L, P = 0.003） the immediate post OLT values. Most frequent complication was isolated anastomotic res in 28 （40%）. Sustained success was achieved in 26 （81%） patients. CONCLUSION： Biliary complications still remain an important problem post OLT. SAP and GGT can be used as early, non-invasive markers for diagnosis and also to assess the adequacy of therapy. Endoscopic management is usually effective in treating the majority of these biliary complications.展开更多
Objective To investigate the feasibility of tendon engineering in vitro using tenocyws and polyglycolic acids （ PGA ）. Methods Tenocytes were isolated by tissue explant method and expanded in vitro. Cells of the sec...Objective To investigate the feasibility of tendon engineering in vitro using tenocyws and polyglycolic acids （ PGA ）. Methods Tenocytes were isolated by tissue explant method and expanded in vitro. Cells of the second passage were collected and seeded onto PGA scaffolds made from PGA unwoven fibers at the density of 20 × 10^6 cells/ml. At 1 week postseeding ,the constructs were divided into three groups as follows： cell-scaffold constructs under constant tension generated by a U-shaped spring as the experimental group （ n = 5 ）, cell-scaffold constructs under no tension as control group 1 （ n = 4 ）, cell-free scaffolds under constant tension as control group 2 （n =3）. Samples were harvested at 2, 4 and 6 weeks for histological and immunohistochemical （ IHC ） examinations. Transmission electron microscopy （TEM） and mechanical test were performed to evaluate the constructs of 6 weeks. Results At 2 weeks, the constructs were mainly composed of undegraded PGA fibers. Gross and histological examination revealed no difference between the groups. At 4 weeks, neo-tendon was visible through gross observation in experimental group and control group 1. Histology and immunohistochemistry revealed the formation of collagen fibers. While in control group 2, PGA fibers were mostly degraded. At 6 weeks, the constructs were much thinner in experimental group than those in control group 1 （ 1.44 ± 0.13mm vs 2.55 ± 0. 18mm in diameter ）. TEM showed periodical strata of collagen fibers in the constructs from experimental group and control group 1. However, histology in experimental group revealed longitudinal alignment of collagen fibers, which more resembled natural tendon than neotendon formed in control group 1. Besides, the maximum load to failure（ Newton/mm^2 ） was greater in experimental group than that in control group 1 （1. 107 ±0. 327 vs 0. 294 ± 0. 138, P 〈0.05）. Conclusion It＇ s possible to engineer tendon substitutes in vitro. Cyclic strain generated by a bioreactor may be the optimal mechanical stimulation and is currently under investigation.展开更多
To explore the changes of biomechanical properties of cortical allograft in different mechanical environments. Methods: Cortical allograft was transplanted to each side of the midshaft diaphyseal ulna of each one of 4...To explore the changes of biomechanical properties of cortical allograft in different mechanical environments. Methods: Cortical allograft was transplanted to each side of the midshaft diaphyseal ulna of each one of 40 rabbits. The left transplanted allograft underwent normal physiological load, while the right one underwent lower load. After animals were killed,specimens were taken for examination of bone mineral density, bone porosity and maximal three-point-bend breaking load. Results: The union strength of allograft-host bone junction was increased constantly; meanwhile, the internal creeping substitution led to an initial greater weakening of the cortical allograft itself and a later recovery of its strength. In comparison, the union strength of the normally loaded graft-host bone construct was significantly higher than that of the lower loaded side at the 8th and 16th week after transplantation. At the 16th week, there was greater bone strength in normally loaded graft than that in lower loaded graft. Conclusions: The internal repair can lead to initial greater weakening of cortical allograft and later gradual recovery of its strength. The effect of physiological load can accelerate the improvement of the biomechanical properties of allograft.展开更多
Objective: To test the suture strength on the tendon or ligament end and evaluate the stitch in the reconstruction of cruciate ligament and its clinical application. Methods: Twenty-four specimens of patellar tendon w...Objective: To test the suture strength on the tendon or ligament end and evaluate the stitch in the reconstruction of cruciate ligament and its clinical application. Methods: Twenty-four specimens of patellar tendon with free ends were divided into 3 groups: Group I (3 Krackow stitches), Group II (2 Krackow stitches) and Group III (2 Krackow stitches with the first stitch passing through the tendon tissue as a modified Krackow stitch). These 3 groups were further divided into 6 subgroups according to different suture materials, No 1 Ethilon or stainless steel wire (φ= 0.4 mm). Tensile test was undertaken to find out the least stitches with efficient suture pattern. Results: Two Krackow locking stitches had stronger strength than 0.4 mm-diameter stainless steel wire. The fixation strength of 2 stitches with No 1 Ethilon was more than 80 N, superior to the failure strength of the material itself. The same strength was maintained if the first stitch was across the tendon tissue transversely. There was no statistically significant difference in the suture strength between 2 and 3 Krackow locking stitches. Conclusions: The suture strength is greater than the failure strength of the suture material. Less suture exposure can be achieved when the first stitch is across the tendon tissue while maintaining a comparable strength to other sutures. To attain higher suture strength, stronger materials or multiple strands rather than more stitches are preferred. Therefore, a rapid early rehabilitation of range of motion (ROM) is possible and reliable in practice.展开更多
文摘Objective: We established a transplantation tumor model of human osteosarcoma in chick embryo, studied its morphological and biological characteristics, and observed its dynamic process of angiogenesis induction so that a simple and practical model can be provided for studying osteosarcoma. Methods: Human osteosarcoma cells at different concentrations were inoculated in chorioallantoic membrane (CAM) of chick embryos at different embryonic ages to observe the factors affecting the survival of the transplanted osteosarcoma in chick embryo, growth characteristics of the transplantation tumor, and the morphological characteristics and biological characteristics of the transplantation tumor. Results: The transplantation tumor model of human osteosarcoma in chick embryo was successfully established. It was found that the transplantation tumor was easy to grow and it showed strong angiogenesis-inducing effects. Under the light microscope, the transplantation tumor showed a similar tissue structure to human osteosarcoma. Conclusion: It is feasible to establish a transplantation tumor model of human osteosarcoma in chick embryo. The model can be easily duplicated with a simple operation, which provides a useful animal model for studying osteosarcoma.
文摘AIM： To correlate the significance of liver biochemical tests in diagnosing post orthotopic liver transplantation （OLT） biliary complications and to study their profile before and after endoscopic therapy.METHODS： Patients who developed biliary complications were analysed in detail for the clinical information, laboratory tests, treatment offered, response to it, follow up and outcomes. The profile of liver enzymes was determined. The safety, efficacy and outcomes of endoscopic retrograde cholangiography （ERC） were also analysed. RESULTS： 40 patients required ERC for 70 biliary complications. GGT was found to be 〉 3 times （388.1 ± 70.9 U/mL vs 168.5 4± 34.2 U/L, P = 0.007） and SAP 〉 2 times （345.1 ± 59.1 U/L vs 152.7 ± 21.4 U/L, P = 0.003） the immediate post OLT values. Most frequent complication was isolated anastomotic res in 28 （40%）. Sustained success was achieved in 26 （81%） patients. CONCLUSION： Biliary complications still remain an important problem post OLT. SAP and GGT can be used as early, non-invasive markers for diagnosis and also to assess the adequacy of therapy. Endoscopic management is usually effective in treating the majority of these biliary complications.
文摘Objective To investigate the feasibility of tendon engineering in vitro using tenocyws and polyglycolic acids （ PGA ）. Methods Tenocytes were isolated by tissue explant method and expanded in vitro. Cells of the second passage were collected and seeded onto PGA scaffolds made from PGA unwoven fibers at the density of 20 × 10^6 cells/ml. At 1 week postseeding ,the constructs were divided into three groups as follows： cell-scaffold constructs under constant tension generated by a U-shaped spring as the experimental group （ n = 5 ）, cell-scaffold constructs under no tension as control group 1 （ n = 4 ）, cell-free scaffolds under constant tension as control group 2 （n =3）. Samples were harvested at 2, 4 and 6 weeks for histological and immunohistochemical （ IHC ） examinations. Transmission electron microscopy （TEM） and mechanical test were performed to evaluate the constructs of 6 weeks. Results At 2 weeks, the constructs were mainly composed of undegraded PGA fibers. Gross and histological examination revealed no difference between the groups. At 4 weeks, neo-tendon was visible through gross observation in experimental group and control group 1. Histology and immunohistochemistry revealed the formation of collagen fibers. While in control group 2, PGA fibers were mostly degraded. At 6 weeks, the constructs were much thinner in experimental group than those in control group 1 （ 1.44 ± 0.13mm vs 2.55 ± 0. 18mm in diameter ）. TEM showed periodical strata of collagen fibers in the constructs from experimental group and control group 1. However, histology in experimental group revealed longitudinal alignment of collagen fibers, which more resembled natural tendon than neotendon formed in control group 1. Besides, the maximum load to failure（ Newton/mm^2 ） was greater in experimental group than that in control group 1 （1. 107 ±0. 327 vs 0. 294 ± 0. 138, P 〈0.05）. Conclusion It＇ s possible to engineer tendon substitutes in vitro. Cyclic strain generated by a bioreactor may be the optimal mechanical stimulation and is currently under investigation.
文摘To explore the changes of biomechanical properties of cortical allograft in different mechanical environments. Methods: Cortical allograft was transplanted to each side of the midshaft diaphyseal ulna of each one of 40 rabbits. The left transplanted allograft underwent normal physiological load, while the right one underwent lower load. After animals were killed,specimens were taken for examination of bone mineral density, bone porosity and maximal three-point-bend breaking load. Results: The union strength of allograft-host bone junction was increased constantly; meanwhile, the internal creeping substitution led to an initial greater weakening of the cortical allograft itself and a later recovery of its strength. In comparison, the union strength of the normally loaded graft-host bone construct was significantly higher than that of the lower loaded side at the 8th and 16th week after transplantation. At the 16th week, there was greater bone strength in normally loaded graft than that in lower loaded graft. Conclusions: The internal repair can lead to initial greater weakening of cortical allograft and later gradual recovery of its strength. The effect of physiological load can accelerate the improvement of the biomechanical properties of allograft.
文摘Objective: To test the suture strength on the tendon or ligament end and evaluate the stitch in the reconstruction of cruciate ligament and its clinical application. Methods: Twenty-four specimens of patellar tendon with free ends were divided into 3 groups: Group I (3 Krackow stitches), Group II (2 Krackow stitches) and Group III (2 Krackow stitches with the first stitch passing through the tendon tissue as a modified Krackow stitch). These 3 groups were further divided into 6 subgroups according to different suture materials, No 1 Ethilon or stainless steel wire (φ= 0.4 mm). Tensile test was undertaken to find out the least stitches with efficient suture pattern. Results: Two Krackow locking stitches had stronger strength than 0.4 mm-diameter stainless steel wire. The fixation strength of 2 stitches with No 1 Ethilon was more than 80 N, superior to the failure strength of the material itself. The same strength was maintained if the first stitch was across the tendon tissue transversely. There was no statistically significant difference in the suture strength between 2 and 3 Krackow locking stitches. Conclusions: The suture strength is greater than the failure strength of the suture material. Less suture exposure can be achieved when the first stitch is across the tendon tissue while maintaining a comparable strength to other sutures. To attain higher suture strength, stronger materials or multiple strands rather than more stitches are preferred. Therefore, a rapid early rehabilitation of range of motion (ROM) is possible and reliable in practice.
