PURPOSE:To establish methods for cryopreservation of human retinal pigment epithelial cells (RPEs)and cell culture from thawing of frozen cells. METHODS:Primary cultured RPEs or its first or second passages,added with 10 dimetbylsulfoxide,were kept in --20℃ for 1 to 2 hours,and then further froze to -40~C over night before being placed in liquid nitrogen. The frozen cells were thawed in 60℃ within 2 minutes. Trypan blue staining and immunocytochemical staining with anti-human keratin were performed for cell viability and differentiation. The growth curve was also determined by calculating the total number of cells/well/day. RESULTS:The viable rate from frozen RPEs was 90%. No differences were observed for growth activity between cultures from frozen cells and controls. The cells were positive with anti-human keratin staining. The logarithmic growth phase was during I to 4 days and the doubling time yeas 1.55 days. CONCLUSION: Cryopreservation of RPEs in liquid nitrogen can maintain biological activities of cells with normal growth and features after thaw- ing. This will provide cell lines for in vitro experiments and possibly for cell banks for RPE transplantation for some fundus diseases. （Chin J Ocul Fundus Dis,1997,13:157-159）
【Abstract】Objective To investigate the injury of calcium on the liver. Methods By using collagenase-containing solution to perfuse the rat livers, the rat liver suspension with different viability was prepared, preserved hypothermically, and the cytosolic calcium comcentration was detected with Fura2/AM. Results ① The concentration of cytosolic calcium after 2-hour storage: Experiment group 1(viability 5%) (1055.0±30.79) nmol/L, experiment group 2(viability 10%) (853.0±20.42) nmol/L, experiment group 3(viability 30%) (616.0±13.20) nmol/L, experiment group 4(viability 50%) (562.0 ±26.06) nmol/L, experiment group 5(viability 70%-80%) (318.0±13.01) nmol/L, experiment group 6(viability 90%) (114.6±6.11) nmol/L. ②The concentration of cytosolic calcium after 24hour storage: Experiment group A(viability 10%) (1704.0±70.11) nmol/L, experiment group B(viability 50%) (1125.0±23.22) nmol/L. The results showed that the lower was the viability, the higher was the cytosolic calcium concentration.With the same viability the cytosolic calcium concentration elevated more than two times higher than the original concentration with the time lengthened. Conclusion Calcium overload is one of the main factors which attribute to the ischemiareperfusion injury of the hepatocytes.
OBJECTIVE: To investigate the repairing effect of transplantation of allogeneic fetal bone in combination with a covering cryopreserved periosteal allograft to bone defect. METHODS: Twenty Long-eared white male rabbits were chosen as experimental model of bilateral 12 mm combined bony and periosteal radial defect. Cryopreserved allograft periosteum with allogeneic fetal bone were implanted in the left defect as experimental side and fetal bone was simply transplanted in the right defect as control side. Bone repair process in the two groups were compared by macroscopy, microscopy, roentgenograms and the contents of calcium and phosphate in the defect area at 2, 4, 8 and 12 weeks after transplantation. RESULTS: There was significant statistic difference in the contents of calcium and phosphate between the experimental and control sides at 4, 8 and 12 weeks after transplantation (P lt; 0.05). With time passing by, the contents of calcium and phosphate have the increasing trends. In the experimental group, lamella bone was seen and medullary canal recanalized at 8 weeks postoperatively. The histological section showed the bone lacuna and lamella bone were formed. CONCLUSION: It suggests that allogeneic fetal bone in combination with a covering cryopreserved periosteal allograft can promote bone repair, and allogeneic fetal bone is excellent bone substitute.
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 study the preventive measure of the subambient temperature burn by analysing the pathogenesis feature. Methods The cl inical data were analysed from 351 cases of subambient temperature burn between February 2004 and February 2009, including age, sex, burn season, burn factors, burn position, burn area, burn degree, treatment way, and wound heal ing. Results Subambient temperature burn occurred in every age stage. The susceptible age stages included infant, children, and the elderly. Female patients were more than male patients. The common burn reasons werehot-water bottle burn, honey warm keeper burn, and heating device burn. The peak season was winter. Lower l imb was the most common site of the subambient temperature burn. The deep II degree to III degree were the most common level, and the burn area was always small, often 1% of total body surface area. Most of patients were treated with changing dressings at cl inic and few patients needed hospital ization. Though the surface of wound could heal finally, and the wound healed well with no obvious scar in patients who received operation. Conclusion Subambient temperature burn is the frequently encountered disease in winter. Use of the warming articles should be cautious, at the same time safety awareness should be strengthened so as to decrease the incidence rate of subambient temperature burn and the injury degree.
In order to repair cartilage defect in joint with transplantation of cryopreserved homologous embryonic periosteum, 30 rabbits were used and divided into two groups. A 4 mm x 7 mm whole thickness cartilage defect was made in the patellar groove of femur of each rabbit. The homologous embryonic rabbit skull periosteum (ERSP), preserved in two-step freezing schedule, was transplanted onto the cartilage defect of joints of one group and autogenous periosteal graft was done in the joint defect of the other group. The knees were not immobilized, following operation and 16 weeks later, the newly formed tissue in the defects were assessed by gross observation, histochemical examination and biochemical analysis. The results showed that new hyaline-like cartilage was formed in the cryopreserved ERSP grafted knee, and had no significant difference from that of the knee receiving autogenous periosteal graft, but had significant difference from that of the fresh ERSP grafted knee and the non-grafted knee. Furthermore, the new hyaline-like cartilage had the biochemical characteristics of a fibrous cartilage. The conclusion was that this method might be feasible to repair articular cartilage defects.