Objective To compare the effect and coverage of bacteriostasis of chitosan and sodium hyaluronate. Methods Each of the five bacteria, Proteus mirabilis, Escherichia coli, Candida albicans, Pseudomonas aeruginosa, Staphylococcus aureus, was cultivated for 33 tubes of broth culture. Leaving three tubes each group as control group, ploidy diluted concentration of high relative molecular weight chitosan, low relative molecular weight chitosan and sodium hyaluronate were added respectively in the broth culture. All the tubes were cultivated for 18 hours at 37 ℃ with homeothermia. Then the growth of bacteria was observed. ResultsThe minimal inhibitory concentrations (MIC) of high relative molecular weight chitosan were : Proteus mirabilis 0.031%, Escherichia coli 0.063%, Candida albicans 0.063%, Pseudomonas aerugionosa 0.063%, Staphylococcus aureus 0.063%; and the MIC of low relative molecular weight chitosan were: Proteus mirabilis 0.125%, Escherichia coli 0.025%, Candida albicans 0.25%, Pseudomonas aeruginosa 0.25%, Staphylococcus aureus 0.125%; bacteria grew well in each tube of sodium hyaluronate group and control group. Conclusion The above results show that sodium hyaluronate has no bacteriostasis, while chitosan has bacteriostasison broad spectrum and high relative molecular weight chitosan has ber effect.
Purpose To investigate the effects of intervention with Tanakan on anterior ocular segment in diabetic retinopathy (DR) after retinal photocoagulation． Methods Prospective random controlled study was performed on 72 patients (72 eyes) with ultrasound biomicroscopy (UBM),by obtaining and quantitatively analyzing the changes of anterior ocular segment including anterior chamber, anterior chamber angle, ciliary body and choroids before and the 3rd day and the 7th day after retinal photocoagulation. Results Three days after photocoagulation, significant elev ated IOP and narrowed chamber angle were observed in control group and 4 eyes (1 1.11%) in Tanakan group (Plt;0.01)． Choroidal detachment in 32 eyes (88.89%) in control group and in 2 eyes (5.56%) in Tanakan group and the severity of ciliochoroidal detachment in tanakan group was significantly lower than that in control group． Conclusion Tanakan is effective to prevent the complications of anterior segment, such as ciliochoroidal detachment, elevation of IOP, narrowing of chamber angle occurring early after retinal photocoagulation and reduce the severity of ciliochoroidal detachment． (Chin J Ocul Fundus Dis, 2001,17:187-189)
Objective To discuss the role of heparan sulfate (HS) in bone formation and bone remodeling and summarize the research progress in the osteogenic mechanism of HS. Methods The domestic and abroad related literature about HS acting on osteoblast cell line in vitro, HS and HS composite scaffold materials acting on the ani-mal bone defect models, and the effect of HS proteoglycans on bone development were summarized and analyzed. Results Many growth factors involved in fracture healing especially heparin-binding growth factors, such as fibroblast growth factors, bone morphogenetic protein, and transforming growth factor β, are connected noncovalently with long HS chains. HS proteoglycans protect these proteins from protease degradation and are directly involved in the regulation of growth factors signaling and bone cell function. HS can promote the differentiation of stem cells into osteoblasts and enhance the differentiation of osteoblasts. In bone matrix, HS plays a significant role in promoting the formation, maintaining the stability, and accelerating the mineralization. Conclusion The osteogenesis of HS is pronounced. HS is likely to become the clinical treatment measures of fracture nonunion or delayed union, and is expected to provide more choices for bone tissue engineering with identification of its long-term safety.
Objective To explore the effects of drugs on functions of mitochondria in retinal nerve cells, and to lay a foundation of the investigation of drug protection for retinal nerve cells. Methods Cultivation of the retinal nerve cells of 8 eyes of neonatal calves was performed. The changes of fluorescent density of the mitochondria of cultured cells labeled by dye rhodamine 123 (Rh123) before and after the activation of the medicines, including ferulic acid (FA), arginine, glycine,taurine, vitamine E and brain derived neurotrophic factor( BDNF) respectively, were detected by laser-scanning confocal microscopy. Results FA with the concentration of 500 μg/ml led the diphasic variation of the fluorescent intensity of mitochondria. After scanning for 60.772 seconds when treated with FA firstly, the fluorescent intensity decreased rapidly (from 45.425±4.153 to 22.135±5.293); while after 112.774 seconds when treated secondly, the in tensity increased obviously (from 19.655±4.383 to 28.247±4.764), and after 168.773 seconds when treated thirdly the intensity still increased. After scanning for 56.457 seconds when treated with vitamin E (12.5 mg/ml), the fluorescent in tensity increased obviously (from 88.255±5.039 to 111.273±4.529), which suggested that vitamin E with the concentration of 12.5 mg/ml strengthen the fluorescent intensity. After scanning for 58.147 and 134.148 seconds when treated with BDNF(50 ng/ml) respectively, the fluorescent intensity increased obviously (from 69.115±5.038 to 77.225±5.131) which suggested that BDNF with the concent ration of 50 ng/ml led the increase of the fluorescent intensity. Glycine (2.5 mg/ml) and arginine(30 mg/ml) didn’t affect the fluorescent intensity of mitochondria, and taurine (6.25 mg/ml) caused the appreciable decrease of the fluorescent intensity . Conclusion FA, BDNF and vitamin E may promote the metabolism of retinal nerve cells via the path of mitochondria, while amino acids may adjust the activation of retinal nerve cells through other ways. (Chin J Ocul Fundus Dis，2004，20：229-232)
Objective To examine the influence of retinal pigment epithelium(RPE) cells on antigen-specific activatedlymphocytes in vitro,and to explore the role of RPE cells in the immune privilege of the eye. Methods Co-culture systems of RPE cells with antigen-specific T lymphocyte lines and resting T lymphocytes were established in vitro．Induction of apoptosis was detected by genomic DNA electrophoresis,DNA in situ end-labelling and flow cytometry. Results RPE cells induced apoptosis in antigen-specific activated T lymphocytes. 24 hours after culture,the signs of apoptosis appeared in lymphocytes co-incubated with RPE cells．As time of co-culture went on,the number of apoptosic cells increased．Quantitative analysis of apoptosic cells showed that apoptosic cells accounted for 5.95% after 24 hours, 9.38% after 48 hours,and 17.95% after 72 hours．In contrast,RPE cells induced few apoptosis in resting T lymphocytes. Conclusions These results suggest that RPE cells possess the ability to induce the apoptosis of invading lymphocytes. This phenomenon serves as a restrain mechanism of immune response and may be of vital importance in the maintenance of immune privilege in posterior segment of eye and in the protection of eye from the damage of immunogenic inflammation. (Chin J Ocul Fundus Dis, 1999, 15: 241-244)
Objective To observe the changes in the peripheral blood T lymphocyte subsets and the histomorphology of the transplanted tissues in the rabbits in the early stage after transplantation of the tissue engineered boneconstituted by the biologically-derived scaffold and to confirm the feasibility of the biologicallyderived materials as a scaffold in the bone tissue engineering. Methods Forty-eight healthy New Zealand rabbits (weight, 2.0-2.5 kg) with a 1-cm defect were equally and randomly divided into 4 groups: Groups A-D. The partial demineralized freeze-dried bone (PDFDB), the tissue engineered bone constructed by the osteoblasts derived from the lactant rabbit periosteum as a seeding cell, the xenogeneic cancellous bone undergoing the antigen self-digestion, partial demineralization and freeze-driedprocess as a scaffold, and the fresh xenogeneic allografting bone were respectively transplanted into the segmental defects of the rabbit radii in Groups A-D.To examine the effects of the 4 different materials, the flow cytometry was used to observe the changes in the T lymphocyte subsets in the rabbit peripheral blood at 1, 2, and 4 weeks after the operations and to examine the osteogenesis achieved by the 4 materials, the histological observations were also performed at 2, 4, 8, and 12 weeks after the operations. Results Two weeks after the tissue engineered bone transplantation in Group B, the osteoblasts and chondroblasts were found in the apertures of the scaffold, the new bone formation could be observed, the osteoclasts could be seen in the peripheral zone, and some of the netlike frameworks were destroyed and absorbed. Four weeks after the operation, the histological observation revealed that the osteocartilagionous callus turned into a woven bone. The peripheral blood T lymphocyte subsets of CD4+ and CD8+ were significantly greater in number 1-2 weeks after the operations and in Groups A and B than before the operations and in the other groups (.Plt;0.05)；4 weeks after the operations the T lymphocyte subset of CD4+ was only slightly greater in number than before the operations, but with no statistically significant difference (Pgt;0.05). In Group C, the increase of the T lymphocyte subsets of CD4+ and CD8+ was not significant after the operation (Pgt;0.05). The T lymphocyte subsets of CD4+ and CD8+ were significantly greater in number 1, 2 and 4 weeks after the operations and in Group D than before the operation and in the other groups (Plt;0.05). Conclusion The tissue engineered bone constructed by the partial demineralized freezedried bone as a scaffold does not cause a serious immunologic rejection in the early stage after the transplantation and does not affect its good ability to repair the bone defect. The biologicallyderived bone canbe used as a scaffold in the bone tissue engineering.