Objective To test the toxicity of genetically engineered strain R32 released to the environment.Methods Acute,chronic and cumulative toxicity test on mice,micronucleus assay of mice bone marrow cell and mice sperm malformation test were conducted to assess the toxicity of strain R32.Results R32 did not cause acute,chronic,cumulative and genetical toxic effect on mice before it absorbed heavy metal chromium.Although the mice bone marrow micronucleus frequency increased and some cumulative toxic effect emerged after R32 absorbed chromium,it did not cause acute and chronic toxicity effect on mice and mice sperm malformation rate did not increase neither.Furthermore,whether R32 absorbed heavy metal chromium or not,the effect of its secretion was not significant in all experiments compared with the control.Conclusion R32 can not cause toxic effect on mice before it absorbed chromium.Whether R32 absorbed chromium or not,the effect of its secretion was not significant in all toxicological experiments conducted in the present paper.Large content of R32 may cause some cumulative toxic effect in mice after it absorbed chromium.

Objective To observe the intervention effect of Ginkgo biloba extract EGb761 on tert-butyl hydroperoxide ( t-BHP)-induced injury in human umbilical cord-derived mesenchymal stem cells ( hUC-MSCs) . Methods Proliferation of hUC-MSCs after primary culture was detected by methyl thiazolyl tetrazolium (MTT) assay, and then the optimal concentrations of t-BHP and EGb761 for oxidative stress injured MSC model were screened. Cell apoptosis was assessed by flow cytometry after Annexin V-fluorescein isothiocyanatel propidium iodide ( Annexin V-FITC/PI) staining. Content of malondialdehyde ( MDA) and superoxide dismutase (SOD) activity in hUC-MSCs were evaluated, and the expression levels of p53 and p21Cip1/Waf1 were analyzed by real-time fluorescence PCR. Results Pretreatment with 10~200 mg/L of EGb761 for 3 hours reduced the sensitivity of hUC-MSCs to t-BHP ( 100 μmol/L) induced proliferation inhibition, while EGb761 over 100 mg/L had no significant effect on enhancing the protection of hUC-MSCs . EGb761 at 100 mg/L prohibited hUC-MSCs apoptosis and MDA accumulation in hUC-MSCs induced by 100μmol/L of t-BHP acting for 6 hours, maintained the enzymatic activity of SOD, and decreased the expression of p53 and p21Cip1/Waf1 in hUC-MSCs with t-BHP-induced injury. Conclusion EGb761 is capable of protecting hUC-MSCs against oxidative stress injury, and its mechanism is probably related with the modulation of p53/p21 signal pathway.

AIM:To investigate the effect of Haikun Shenxi Capsule(fucoidan)on disorder of lipid metabolism on the patients with chronic kidney disease(CKD).METHODS:98 patients with CKD 3、4 stage were divided into 2 groups at random:control group were given routine therapy and therapy group were given routine therapy plus Haikun Shenxi Capsule.The changes of the levels of TCH,TG,HDL-Ch,LDL-Ch,VLDL-Ch,ApoA-1,ApoB in 2 groups were observed.RESULTS:The level of TCH,TG decreased significantly(P 0.05).CONCLUSION:Haikun Shenxi Capsule has a positive effect on disorder of lipid metabolism on the patients with CKD.

Human rhinoviruses (HRVs) are the causative pathogens in more than half of viral upper respiratory tract infections. Currently, no antiviral agents that are active against HRVs are available for clinical use. Because only higher primates are susceptible to HRVs, the screening of new drug is most commonly based on the cell line model. In this study, isolated rabbit airway smooth muscles (ASM) tissue model has been established, and the airway responsiveness with different treatment has been examined. Relative to control tissues, the maximal constrictor (Tmax) response to ACh increased significantly 150% in ASM inoculated with HRV, and relaxation to isoproterenol has been attenuated to 63%. And the abnormal responsiveness can be inhibited in presence of pretreatment with several new compounds which have been exhibited effective anti-HRV activity on cell lines. The results demonstrate that the established ASM model will be applied to screening the anti-HRVs drugs.

Objective To observe osteocyte survival and osteogenesis after nonvascularized free bone graft transplantation for canine mandible mass defect restoration. Methods An experimental canine premolar was extracted. 1 month later, the length of 3.0 cm edentulous mandible was cut off, as the same length as that nonvascularized and soft-free tissue complete ilium block was cut off and fixed into mandible defect in 40, 120 min. The survival osteocyte and osteogenesis of the nonvascularized graft were detected 4 and 8 weeks after transplantation. Results The continuity of canine mandible segmental defect of 3.0 cm length was repaired by free nonvascularized free bone graft, live osteocytes and osteogenesis were observed in non-vascularized free bone graft at off-body 40 min group in 4-8 weeks. But the nonvascularized free bone graft off-body 120 min was a dead bone, no survival osteocytes were observed, some osteoclasts were seen in the bone graft. Conclusion The length of 3.0 cm canine mandible defect can be restored by non-vascularized free bone graft; the osteocyte survival and osteogenesis are related to their off-body time before they are fixed into recipient.

0.05).ConclusionThe neoadjuvant radiochemotherapy can improve the sphincter-saving rate,probably can improve the resection rate and reduce the recurrence rate for the middle-lower rectal carcinoma.

Human ScFv against botulinum neurotoxin serotype A(BoNTa) was modified by fusing human IgG1 Fc to C terminal of ScFv. ScFv-Fc fusion protein was expressed at high level over 30% of total host cell proteins in E.coli. Recombinant protein existed in inclusion body form. Renatured ScFv-Fc was purified to 90%~95% by Protein G Sepharose column. In vitro ScFv-Fc could bind specific to toxiod BoNTa in ELISA. Recombinant ScFv-Fc had similar relative affinity to parent ScFv and had improved stability.

Objective To investigate whether porcine endothelial cells transfected with SP1 de-coy ODNs could resist complement-mediated cytotoxicity during the model of SV-40-PED with human serum in vitro. Methods Immortalized porcine aortic endothelial cells of the line PED were divided in-to three groups. The transfected group was SV-40-PED with SP1 decoy ODNs. The mismatched group was SV-40-PED with scrambled SP1 decoy ODNs. The negative group was cells with oligo-fectamine only. The expression of α1,3-GT mRNA and αGal was detected after 26 h by using fluores-cence microscope, Western blot, RT-PCR and lactate dehydrogenase (LDH) activity assay. Results Fluorescence microscopy observed the decreased fluorescence of αGal after SP1 decoy ODNs transfec-tion. Dotted fluorescent decrease could be observed on some membrane while the mismatched group and negative group with bright green fluorescence. Western blot showed that the average absorbance of the PED cells transfected with decoy ODNs was decreased to 52.6% of the negative group (P<0.05). The expression of α1,3-GT mRNA in the PED cells transfected with decoy ODNs was 0.42±0.20 (isoform 1) and 0.27±0.12 (isoform 2) respectively, significantly lower than in the negative group (isoform 1, 0.72±0.17; isoform 2, 0.50±0.19; both P<0.05). The expression of α1, 3-G Tin the mismatch group was not different from that in the negative group (P>0.05). 20% normal hu-man serum (NHS) and 40 % NHS had cytotoxic effect on both mismatch and negative groups, but de-coy ODNs could confer SV-40-PED protection from the cytolysis effect (P<0.05), which made a re-markable reduction of complement-mediated cytotoxicity towards SV-40--PED. Conclusions SP1 decoy ODNs could confer porcine endothelial cells protection from complement-mediated cytotoxicity effect in vitro.

This study evaluated, over a 4-month study period, the amount of apical root resorption occurring in maxillary central incisors following their retraction when employing either micro-implant or J-hook headgear anchorage. The prospective randomised clinical trial was conducted in Orthodontic Clinic, College of Stomatology, China from 2008-2009. Subjects are patients requiring fixed appliances on waiting list (n=20). In female Han Chinese patients aged from 16-26 years, standardized periapical radiographs from 10 randomly assigned patients with maxillary protrusions comprising the micro-implant group, and from 10 similar patients comprising the J-hook headgear group, were assessed for maxillary central incisor apical root resorption. Measurements before and after orthodontic therapy were also obtained from lateral cephalometric radiographs to calculate incisor horizontal retraction and vertical intrusion distances. Estimated retraction force vectors were calculated in horizontal and vertical directions for both treatment groups. Data analysis employed t-tests and the Pearson correlation test, with α=0.05 for statistical significance. The results showed that when compared with the J-hook group, significantly more apical root resorption shortening of the maxillary central incisors was observed in the micro-implant group (1.27 mm difference, 95% CI=0.70-1.84, P<0.001), which was associated with a significantly larger retraction distance (P=0.004) and a smaller vertical force component (P<0.0001). We are led to conclude that continuous activation of the nickel-titanium coil springs used in the micro-implant group resulted in significantly more apical root resorption shortening and maxillary central incisor retraction than when intermittent J-hook retraction was employed. The employment of continuous duration orthodontic forces presents a risk for increased apical root resorption that requires careful radiographic monitoring.

Effects of Cr 6+ concentration and culture time on four heavy metal removing strains,stability of these four strains removing Cr 6+,configuration changes inside or outside their cells,effects of Cr 6+ on soluble reductive sugar inside their cells,and effect of several factors on these strains had been studied,and the Cr 6+ resistance mechanisms of these strains have been discussed elementarily. The results showed that the Lethality of these strains caused by Cr 6+ was similar with one another, namely, increasing at first, then decreasing, and finally increasing again as culture time passed. Acclimatization of Candida sp. was better than Sporobolomycetaceae sp.,and the Cr 6+ resistance of Sporobolomycetaceae sp. 7-3 was the best of the four. The research also demonstrated that the metabolic activity of these strains had been influenced by Cr 6+ in a certain extent. Scanning electron microscopy,transmission electron microscopy,and atomic force microscopy observations approved that removal of Cr 6+ by Candida sp. was depended on both surface adsorption and intracellular accumulation. Effects of Cr 6+ concentration, pH, culture time, nitrogen source, carbon source and adsorption time on these strains are not the same.