BACKGROUND: Poly-lactic glycolic acid (PLGA) is a promising cell scaffold material. However, its hydrophilicity and cellular affinity is poor, so it is necessary to modify its performance.OBJECTIVE: To explore the hydrophilic ability of the modified PLGA scaffold compounded with type Ⅰ collagen, and the cellular biocompatibility with chondrocyte of rabbit ear.METHODS: PLGA scaffold was modified with Poly-L-Lysine and compounded with type I collagen. The gross structure of scaffold was observed by inverted microscopy. The modified PLGNtype-Ⅰ collagen scaffold (experimental) and PLGA scaffold (control) were immerged in distilled water for 0.5, 1, 2, 4, 8, 12 and 24 hours. Chondrocytes were cultured by enzyme digestion method, and the second passage cells were seeded on surfaces of two scaffolds. Cell morphology was observed by phase contrast microscopy; cell attachment rate 24 hours after seeding was calculated, and the cell proliferation was determined by MTT assay at 1, 2, 4 and 6 days.RESULTS AND CONCLUSION: Modified composite scaffold exhibited high porosity and increased surface roughness compared with control group. Water uptake of two scaffolds displayed statistically significance at the same time point (P < 0.01), indicating the modification improved the hydrophilicity. The attachment rate of chondrocytes was 0.908 0+0.019 2 in modified compound scaffolds and 0.733 2±0.047 5 in control scaffold after 24 hours (P < 0.05), indicating the improved cellular affinity following modification. After 1, 2, 4 and 6 days, the absorbance between two groups was significantly different (P < 0.05), indicating the modified scaffold improved cell proliferation.

Aim To investigate whether the polypeptide from Chlamys farreri(PCF)protected HaCaT cells from UVB-induced apoptosis through Fas-caspase-3 and ROS-cytochrome C.Methods Experiment designs were divided into five groups:control group,UVB model group,UVB+5.69 mmol?L-1PCF group,UVB+2.84 mmol?L-1 PCF group,UVB+1.42 mmol?L-1 PCF group.SiRNA for Fas inhibited Fas expression of UVB-induced HaCaT cells.Using agarose gel electrophoresis,the effects of Fas siRNA and ROS scavenger NAC on UVB-induced apoptosis of HaCaT cells were investigated.Expression levels of cytochrome C andcaspase-3 after inhibitory Fas were determined by Western blot analysis.Intracellular ROS was detected by means of an oxidation-sensitive fluorescent probe(DCFH-DA).Results SiRNA for Fas had inhibitory effects on UVB-induced apoptosis of HaCaT cells and caspase-3 expression.NAC had inhibitory effects on UVB-induced apoptosis of HaCaT cells.PCF inhibited UVB-induced generation of ROS and cytochrome C release dose-dependently.Conclusions PCF protected HaCaT cells from UVB-induced apoptosis.Its inhibitory effect on apoptosis could be attributed to inhibition of Fas-caspase-3 and ROS-cytochrome C pathways.

Objective To raise the vigilance for pregnancy complicated with acute abdominal diseases and to reduce the maternal mortality rate. Methods A retrospective study was done. Results (1) The maternal mortality of pregnancy complicated with acute abdominal diseases was 1 31/10 5 in the period of 1989～1993, which was significantly higher than that in the period of 1994～1998 (0 71/10 5). (2) The main cause of maternal deaths was misdiagnosis and the rate of misdiagnosis was 72 7%.(3) Among the acute abdominal diseases, pregnancy complicated with pancreatitis ranked the first that accounted for 54 6%. Conclusions For the purpose of reducing the mortality rate of pregnancy complicated with acute abdominal diseases, the correct diagnosis and proper treatment especially for those with acute pancreatitis are important.

A typical smooth-form lipopolysaccharide (LPS) isolated from Salmonella abortus equi was fractionated into a S (smooth)-and a R (rough)-fraction and their serological and biological properties were investigated. It was shown that S- fraction expressed an O-antigenicity while R-fraction predominately a Rb-antigenicity. The R-fraction was endowed with higher bioactivities than the S-fraction in lethal toxicity, local Shwartzman reaction and pyrogenicity. Both S-and R-fractions were active in inducing mitogenicity to murine spleen cells. A reconstituted LPS preparation with fractionated S-fraction and a trace amount of R-fraction (1% of the original preparation) exhibited a same extent of lethal toxicity as that of the original one. Antr-Ra and -Rb antiserum with a liter of 1?4096 showed a .highly effective protection against the lethal challenge of LPS, indicating that the R-fraction in the natural LPS preparations plays a critical role to the lethality of LPS.

Superoxide anion releasing from activated murine macrophages stimulated with recombinant human interferon-? (IFN-?), tumour necrosis factor-? (TNF-?) and bacterial lipopolysaccharidc were studied. The results showed that both of the cytokines enhanced superoxide anion release in a dose and time - dependent manner, but lipopolysaccharide had no such an effect as compared with IFN-? and TNF-?. It was also shown that O2- generation from macrophages was highly enhanced after primed with IFN-? or TNF-? for 24 hours. It was concluded from these data that cytokines released from macrophages and lymphocytes during inflammatory reactions could promote O2- generation which may play a crucial role in destruction or kill of intracellular pathogenic bacteria, and tumour cells.

Objective To investigate the effects of 5-Aza-2'-deoxycytidine (5-Aza-dc),a methylation inhibitor,on the proliferation of androgen-sensitive prostate cancer line (LNCaP),and on its regulation of methylation on glutathione s transferaseP1 (GSTP1) and retinoic acid receptorβ2 (RARβ2) gene.Methods LNCaP cells were treated with 5-Aza-dc in different concentration,CCK8 method was used to detect the growth of LNCaP cells.The methylation of GSTP1 and RARβ2 gene in LNCaP cell was detected by nested methylation specific polymerase chain reaction (nMSP).Results The proliferation of LNCaP cells was inhibited after exposed to 5-Aza-dc.The methylation of GSTP1 and RARβ2 gene was changed from hypermethylation to demethylation by the 5-Aza-dc.These effects were dose-and time-dependent within certain concentration of 5-Aza-dc,but LNCaP cells grew better after 72 h than within 48 h when exposed to 5 Aza dc below 1.0 μmol/L.Also the methylation of GSTP1 and RARβ2 gene changed from hypermethylation to demethylation by the 5-Aza-dc was not different when exposed to 5-Aza-dc below 1.0 μmol/L within 72 h and 48 h.Conclusions 5-Aza-dc may effectively inhibit the growth of LNCaP cells and reverse the DNA methylation damage in some tumor suppressor genes,but the continuity and stability of low dose 5-Aza-dc is changeable.The study will provide a research basis for clinical treatment.

Objective To study the correlation between serum level of antiendothelial cells auto-antibodies (AECA) and anticardiolipin antibodies (ACA) and the roles in the pathogenesis of Behcet′s disease (BD). Methods Thirty two BD patients were randomly selected from our outpatients and inpatients. Thirty-three healthy controls were studied in parallel. AECA/ACA were examined by indirect immunoflourescence technique and enzyme linked immunosorbent assay (ELISA) respectively, IgG-AECA and IgM-AECA antibodies were detected, too. Results The positivity rates of AECA, IgG-AECA and IgM-AECA in BD patients were 81.3%, 71.9% and 53.1%, respectively. Increased serum AECA levels were observed in all BD patients compared with those of normal controls. There was some significant positive correlation in the positivity rate of AECA between erythema nodosum, nodular vasculitis and rapid erythrocyte sedimentation rate. The positivity rate of ACA was 53.1%, A significant difference in the positivity rate of ACA compared with those of normal controls. Neither of these two kinds antibodies was significantly correlated with oral ulcers, clinical manifestations of skin and external genital organ, anemia or erythrocyte sedimentation rate. Conclusion The detection of AECA level is useful to identify cutaneous vasculitis and the activity of disease in BD, but the value of ACA in the diagnosis of the condition of BD needs further study. [

Objective To explore the therapeutic effects an d the appropriate treating time of the artificial liver support system through obs ervation and analysis of the changes of the liver function indexes before and af ter the treatment of the artificial liver support system. Methods The changes of BIL-T, BIL-D, ALT, AST, ALP, TBA, ALB, GLB, A/G of the liver fu nction indexes in a total of 38 cases with serious hepatitis treated by artifici al liver support system were observed. Besides, the dynamic changes of the BIL- T, ALT of one case of middle stage and late stage serious type hepatitis respect ively before and after the artificial liver treatment several times were observe d. Results The BIL-T, BIL-D, ALT, AST, ALP of the liver func tion indexes after the artificial liver support system treatment showed remarkab le decline, significant differences existed before and after the treatment (P

Objective To describe a new technique with mini-open reconstruction of lateral ligaments of ankle with partial tendon of its peroneus brevis and evaluate its effect in treatment of chronic lateral ankle instability. Methods A total of 11 cases of chronic lateral ankle instability;at mean age of 27.6 years(16-42 years),were treated with mini-open reconstruction of the lateral ligaments of the ankle with partial tendon of its peroneus brevis.The mean delay between the initial episode of ankle sprain and the surgery was 10.3 months(4-32 months).Postoperatively,all cases were examined with MRI,stress X-rays and comparative stability of bilateral ankle inspection at clinical follow-up.The function of the ankle were evaluated bv American Orthopaedic Foot & Ankle Society (AOFAS)score and ankle-hind foot scale. Results The average duration of follow-up was 17.5 months(12-37 months).The mean AOFAS ankle-hindfoot score was 88.3 points(72-96 points)at the time of the latest follow-up,including excellent result in 6 cases(55%),good in 4(36%)and fair in 1(9%).MRI results showed that the ruptured lateral collateral ligaments of the ankle were repaired and remodeled very well in all patients.There was no recurrence of the ankle instability or other complications. Conclusion Mini-open reconstruction of the lateral ligaments of ankle with partial tendon of its peroneus brevis is safe and effective for treatment of chronic lateral ankle instability.