OBJECTIVE: To investigate availability of deep freeze stored allogenic tendon with sheath grafting in repairing the tendon and sheath defect in the II area of flexor digitorum tendon. METHODS: Sixty chickens with tendon and sheath defect were divided into 2 groups randomly, group A was treated with allogenic grafting and group B was treated with autogenic grafting, these two groups were divided into two subgroups respectively, they were, group A1 allogenic tendon with whole sheath grafting, group A2 allogenic tendon with partial sheath grafting, group B1 autogenic tendon with whole sheath grafting and group B2 autogenic tendon with whole sheath grafting. All the allogenic grafts were treated by deep freeze. Histomorphological study, histoimmunological study and slipping function of the grafts were measured after operation. RESULTS: In group A1 and B1, the local reaction was sever, the nutrition of tendon graft was barricaded by the whole sheath resulting in adhesion, degeneration and necrosis. In group A2 and B2, the tendon graft healed well and little adhesion existed between tendon and sheath. The results showed that there were significant differences between tendon grafting with whole sheath and tendon grafting with partial sheath. CONCLUSION: Deep freeze store can reduce the immunogenicity of allogenic tendon with sheath. Allogenic tendon with partial sheath grafting can be used as a new biological material for repairing the tendon and sheath defect.
Abstract In order to supply allografts for reconstruction of finger, repair of tendon or tendon sheath, the hands from fresh cadavers of healthy young persons who died from accident were amputated at the wristlevel. After disinfected, packed and labelled, the hands were stored into a deep freezer at -30℃ as bank storage. Before grafting, the skin and subcutaneoustissue were stripped from the frozen finger. Then it was immersed in an antibiotic fluid for 1 hour. The results showed that the immunological antigenicity of allograft was decreased by the freezing method. Bony union between the impacted host bone and the allogeneic phalangeal bone was seen on X-ray films. Bone absorption and joint degeneration were found at the area where no impaction between bones. The healing between tendons from host and that from the allografts was b. It was concluded that establishing a cadaveric hand bank in hospital was as important as establishing a bone bank for the supply of bone, joint, tendon, tendon sheath and finger composite tissue, for allogeneic grafts.
Objective To evaluate which is better method zymogen or low temperature frozen in removing vascular endothelial cell so as to lay a foundation for creating a kind of brace which is not to be rejected and the same as own blood vessel. Methods Fresh and not damaged umbilical blood vessel was collected from natural labour women, human umbilical blood vessel was remove carefully from normal foetus, then was put into disinfectant at 37℃ for 24 hours. They were divided into 3 groups:normal group(NG),zymogen group(ZG) and low temperature frozen group(LG). ZG: 0.1% collagenⅡ enzyme was addedin umbilical blood vessel and closed the both sides and the vascular endothelialcell was removed in 37℃ water. LG:Umbilical blood vessel was put into liquidnitrogen for 24 hours after frozened step by step, and then it was put into 37℃ water for 30-60 s and the vascular endothelial cells were washed away by normal saline. NG:Umbilical blood vessel was kept into 4℃ Kerb’s liquid. The bacteria were culturedin each group. The samples were stained by HE,elastic fiber and collagen fiberwere observed by light and scanning electron microscope. The difference of compliance was compared. Human leukocyte antigen ABC(HLA-ABC) and HLA-DR were observed by immunohistochemical method and the expression of antigen of umbilical blood vessel was analysed. Results In LG, umbilical vascular endothelial cells were removed completely; artery showed vertical smooth muscle and vein showed elastic membrane. InZG, umbilical vascular endothelial cells were removed completely after 20 minutes;artery showed vertical smooth muscle cells and vein showed lower endothelial layer. The vascular compliance in LG was higher than that in NG, and the latter was also higher than that in ZG,but showing no significant differences (Pgt;0.05). The compliance of umbilical vein was 2-3 times as much asthat of umbilical artery.The expression of HLA-ABC and HLA-DR in LG andZG were lower than that in NG, showing significant differences (Plt;0.01). Conclusion Low temperature frozen methodand zymogen method(0.1% collagen Ⅱ enzyme for 20 min) can remove vascular endothelial cells of human umbilical blood vessel completely.Low temperature frozenmethod was better than zymogen method.
Objective To observe the enzymic histochemical and ultrastructral changes of cryopreserved human retina. Methods To compare the activity of lactate dehydrogenase (LDH), succinate dehydrogenase (SDH) and ATPase in cryopreserved retina with those in fresh retina and to observe the histological and ultrastructural changes of cryopreserved retina. Results There was no statistical difference between the activity of LDH,SDH and ATPase in fresh and in cryopreserved retina. Histologically, in the cryopreserved retina, fluid in neural fiber and outer plexiform layers, as well as in cone and rod layer, was sligthly more than normal. The ultrastructure is normal except that the mitochondria was swollen in different degree. Conclusion Cryopreservation may be an effective method for keeping the retinal cells alive for a long period and might free the transplantation from dependance on aviability of fresh dornor tissue. (Chin J Ocul Fundus Dis,2000,16:139-212)
Objective To observe the configuration and viability of full thickness human fetal retina after short-, mid- and long-term preservation. Methods Twenty-two full thickness human fetal retinae of gestational age of 12-24 weeks were coated by glutin and cut into 88 pieces, and then preserved in Ames' solution, DX solution, -80℃ refrigerator or under cryopreservation condition. The cell viability of retinal neuroepithelial layer was determined by trypan blue staining, retinal configuration was determined by light microscope and electromicroscope. Results The viability of neuroepithelial layer was (94.79plusmn;2.85) % in fresh fetal retina, gt;80% in Ames' solution within 4 hours, and gt;77% in DX solution within 2 days. There was no significant difference between those solution-preservations and the fresh fetal. In -80℃ refrigerator, the viability was (65.83plusmn;5.06)% after 7 days, and then dropped to (57.54plusmn;16.18)% at the end of the first month. Under the cryopreservation condition, the viability was (69.46plusmn;9.31)% at the end of first month. Light and transmission electron microscopy had not deteced any abnormals in the full thickness human fetal retina preserved in Ames' solution within 2 hours, but showed clear retinal layers with bigger intercellular space after preserved in DX solution for 2 days, in -80℃ refrigerator for 7 days and under cryopreservation condition for 1 month. Conclusion Ames' solution and DX solution can preserve good viability and configuration of full thickness human fetal retina in a certain time period.
Microfluidic chips can be used to realize continuous cryoprotectants (CPA) loading/unloading for oocytes, reducing osmotic damage and chemical toxicity of CPA. In this study, five different Y-shape microfluidic chips were fabricated to realize the continuous CPA loading/unloading. The effects of flow rate, entrance angle, aspect ratio and turning radius of microchannels on the mixing efficiency of microfluidic chips were analyzed quantitatively. The experimental results showed that with the decrease of flow rates, the increase of aspect ratios and the decrease of turning raradius of microchannel, the mixing length decreased and the mixing velocity was promoted, while the entrance angle had little effect on the mixing efficiency. However, the operating conditions and structural parameters of the chips in practical application should be determined based on an overall consideration of CPA loading/unloading time and machining accuracy. These results would provide a reference to the application of microfluidic chip in CPA mixing.