BACKGROUND: The vibration of high speed handpiece during tooth preparation may have adverse effect on the continuous force of the bonding interfaces among the cement, dentin, and post core. OBJECTIVE: To find the effect of different types of cements on the coronal microleakage of fiber post under different tooth preparation timings, and to provide evidence for the clinical operation. METHODS: The extracted mandibular premolars were divided into 3 groups, and they were cemented by Rely X luting, Panavia F and Paracora 5 mL, respectively. Each group was averagely divided into 3 subgroups: A, B, C groups which were prepared 15 minutes, 45 minutes, and 90 minutes after the cements mixed. All roots were then dyed and transparented. The teeth were observed under stereoscopic microscope and the dyeing scores were also recorded. RESULTS AND CONCLUSION: Rely X luting caused the highest coronal microleakage of fiber post, followed by Panavia F, while Paracore 5 mL, brought about the lowest under the same tooth preparation timing. Different tooth preparation timing caused no significant effect on the coronal microleakage of fiber post when the cement had been completely set.

Objective To evaluate the analytical performance of Mindray BS‐820 automatic biochemical analysis system used in primary hospitals in Guangzhou area for verifying whether its performance meeting the clinical requirements .Methods Accord‐ing to the EP5‐A2 ,EP6‐A ,EP7‐A2 and EP‐17A files recommended by CLSI and the Pharmaceutical Industry Standard of the Peo‐ple′s Republic of China YY/T0654‐2008 ,the precision ,linear rang ,anti‐interference capability ,sensitivity and carry‐over rate of the Mindray BS‐820 automatic biochemical analysis system were evaluated by adopting 16 routine biochemical items .Results The pre‐cision results of all 16 analyzing items conducted by the Mindray BS‐820 automatic chemical analysis system conformed to the re‐quirements .The results of 15 items showed good linear relation during the testing range (r≥0 .997 9) .In 16 biochemical items ,the anti‐interference capability of TBIL ,TP ,TC ,TG ,LDL ,HDL ,UREA and Ca to bilirubin ,triglyceride and hemoglobin conformed to or were higher than the anti‐interference capability declared by manufacturer ,but among other 8 items ,the anti‐interference capabil‐ity of 3 items was lower than that declared by manufacturer .The limit of blank(LOB) of all 16 analyzing items was less than LOB in the kit instruction .The carry‐over rate of Glu was 0 .02% ,less than 0 .50% .Conclusion This instrument has good precision , sensitivity and low carry‐over rate(0 .02% ) ,the linear range is ideal ,r≥0 .997 9 ,the anti‐interference capability basically satisfies the clinical needs .Therefore this instrument is suitable for the use in the middle‐small scale laboratory department .

Objective To investigate the effect of cyclosporine on matrix metalloproteinase-3 (MMP-3)’ s genetic expression on bladder cancer in rats induced with BBN and its clinical significance.Methods Twenty SD rats were divide into experimental group or control group randomly.Ten samples of SD rats bladder cancer induced with BBN and cyclosporine simultaneously and 10 samples of SD rats bladder cancer induced with BBN only as control were used to observe the effect of cyclosporine on MMP-3’ s genetic expression.Real time RT-PCR and immunohistochemistry stain were used to analyze MMP-3 mRNA and protein levels of bladder cancer in rats respectively.Results The MMP-3 mRNA median expression were 7.6 (4.2-9.1) in experimental group and 4.7 (2.8-7.7) in control group.The MMP-3 protein expression were 1 case with (-),4 cases (+),5 cases (++) in experimental group and 3 cases (-),4 cases (+),3 cases (++) in control group.The differences of MMP-3 mRNA and protein levels of bladder cancer between experimental group and control group were both significant (P ＜ 0.05).Conclusion Cyclosporine may stimulate the growth and development of bladder cancer through changing expression of some genes like MMP-3,and MMP-3 maybe become one of the targets of chemoprevention for post-transplantation bladder cancer.

Objective To investigate the effect of cyclosporine on signal transducer and activator of transcription 1 (STAT1) genetic expression on bladder cancer in rats induced by BBN and its clinical significance.Methods Twenty SD rats were divide into experimental group or control group randomly.Ten samples of SD rats bladder cancer induced with BBN and cyclosporine simultaneously as experimental group,and 10 samples of SD rats bladder cancer induced with BBN only as control.Real time RT-PCR and immunohistochemistry stain were used to detect STAT1 mRNA and protein level expressions of bladder cancer in rats respectively.Results The STAT1 mRNA median expression fold was 4.5 (2.1-6.6) in experimental group and 5.6 (3.4-8.5) in control group.The STAT1 protein expression were 5 cases with (-),3 cases (+),2 cases (++) in experimental group and 0 case (-),5 cascs (+),5 cases (++) in control group.The expression of STAT1 mRNA and protein level of bladder cancer between experimental group and control group were both significant different (P ＜ 0.05).Conclusions Cyclosporine may stimulate the growth and development of bladder cancer through changing expression of some genes like STATI,and STAT1 maybe become one of the targets of chemoprevention for post-transplantation bladder cancer.

ObjectiveTo investigate DNA loads and risk factors of BK virus infection in renal transplant recipients.MethodsWe developed a real-time PCR assay to quantitate BK virus loads in 80 patients receiving renal transplantation in our center,and correlation between the BK virus load and clinical course was analyzed.BK virus loads were measured in urine and plasma. Epidemiological features and risk factors of BK virus infection were analyzed.ResultsThe positive rate of BKV viruria and viremia in 80 renal recipients was 37.5％ (30/80) and 8.75％ (7/80),respectively.BKV loads were higher in renal allograft recipients whose age was more than 50 years old.BKV loads were observed in urine and plasma (compared with group whose age was less than 50 years,P=0.017 and 0.05,respectively).BKV DNA copies were higher in group Tac than that in group CSA (P＜0.05),and the peak of BKV load in serum appeared at14th and10th month after transplantation,respectively,but the peak in urine was ahead of that in serum,appeared at 2nd and 8th month,respectively.ConclusionSerial measurement of BKV viral loads by quantitative PCR is a useful tool in monitoring the course of BK virus infection.The ages of recipients (＞50 years) and using Tac + MPA can reactivate BK virus and then result in BKVAN in renal transplant recipients. Intensive BKV monitoring is necessary for these recipients.

To investigate the clinical features and principles of diagnosis and treatment of early postoperative inflammatory ileus (EPII). The clinical data of 69 patients with EPII treated in this hospital were retrospectively reviewed. EPII mostly occurred in 3-11d after abdominal surgery, and the average time was 5d. Sixty two cases were cured in a mean period of (22±13)d through combination therapy including gastroenteral decompression, somatostatin, dexamethasone and total parenteral nutrition (TPN). Seven cases were cured by operation. EPII is a special type of early intestinal obstruction which often occurs in two weeks after abdominal operation. Its typical symptoms are abdominal distension; conservative therapy is effective for most cases and reoperation is usually contradicted.

Objective To investigate the effects of cyclosporine on cell proliferation, apoptosis and angiogenesis of bladder cancer in rats induced with BBN.Methods Ten samples of SD rats bladder cancer induced with BBN and cyclosporine simultaneously and 10 samples of SD rats bladder cancer induced with BBN only as control were used to observe the effects of cyclosporine on cell proliferation, apoptosis and angiogenesis of bladder cancer in rats.Immunohistochemistry stain with PCNA, TUNEL and immunohistochemistry stain with CD31 were used to analyze cell proliferation,apoptosis and angiogenesis of bladder cancer in rats respectively. Results The differences of proliferation index (35.3±8.6)% and (28. 7±8.0)% respectively (P＜0.05), apoptotic index (2. 5±0.8)% and (4.3±1.3)% respectively (P＜0.05) and microvessel density 32.5±8.2 and 26.3±8.1 respectively (P＜0.05) between experimental group and control group were all significant.Conclusions Cyclosporine may stimulate the growth and development of bladder cancer through mechanisms of cell proliferation, apoptosis and angiogenesis.

Objective To investigate the signal transducer and activator of transcription 1(STAT1) and matrix metalloproteinase 3(MMP3)′s genetic expressions and their clinical significance on urothelial carcinoma after renal transplantation. Methods Fifty-one patients with urothelial carcinoma were recruited in this study. Sixteen of them who had renal transplant were in the experimental group and 35 of them without renal transplant were in the control group. All the cases had been proved postoperatively having transitional cell carcinoma by histopathological study. The human genome oligo arrays were used to analyze the gene expression spectrum of urothelial carcinoma after transplantation, aiming the STAT1 and MMP3's expression. Real time RT-PCR and immunohistochemical staining were used to compare the differences in the 2 groups. Results The experimental group showed that there were 35 genes up-regulated compared with the control group. Of them, 23had known gene function or partly known, and 12 had unknown gene function. There were 76 genes down-regulated. Of them, 46 had known gene function or partly known, and 30 had unknown gene function. After pathway analysis of the differentially expressed genes, there were 23 groups of pathways which had significant differences (P＜0.05), referring to the aspects of immunosuppressive and tumor growth. The levels of STAT1 and MMP3 expressions had significant differences between the 2groups(P＜0.05)as well. Conclusions The differential expression of urothelial tumor genes is obvious between patient who has had renal transplant and who has not. There are many aspects that are related to the tumor's growth like signaling pathways regulating proliferation, apoptosis of tumor cells, tumor angiogenesis and the tumor metastasis potential. STAT1 and MMP3 maybe become the targets of chemoprevention for post-transplantation urothelial carcinoma.

BACKGROUND:Under different induction conditions,bone marrow mesenchymal stem cells can differentiate into the mesodermal tissues such as osteoblasts,chondroblasts,muscle cells,adipocytes and so on.OBJECTIVE:To verify the effect on repairing the rabbit articular cartilage injury using bone marrow mesenchymal stern cells (MSCs)induced by tissue engineering method.DESIGN,TIME AND SETTING:Randomized controlled animal experiment was performed in the Clinical Center Laboratory of Shenyang Medical College between May 2005 and December 2007.MATERIALS:Twenty health New Zealand rabbits,irrespective of genders,aged 2-3 months,were used.METHODS:①Rabbit bone marrow MSCs were cultured in vitro,experiment group was cultured for one week withdexamethasone,basic fibroblast growth factor and vitamin C,then for additional 3 weeks with transforming growth factor-β instead of basic fibroblast growth factor;calls without inductors served as controls;②Twenty rabbits were used to establish knee articular cartilage defect models,which were then divided into three groups at random. Experiment group (n=5) was transplanted with the induced bone marrow MSCs;control group with the non-induced cells;blank control group with saline. At 2,4,6,8 weeks postoperation,two rabbits in the experiment group were killed,while one animal in control group and blank control group was killed for the index determination.MAIN OUTCOME MEASURES:①Cell morphology. ②Alkaline phosphatase activities.③General observation. ④X-ray observation.⑤Histological observation.RESULTS:①The morphology of the induced bone marrow MSCs was changed,from long fusiform to polygon,which was similar to cartilage calls-like morphology.②After the bone marrow MSCs were induced for 4 weeks,the alkaline phosphatase activities were obviously enhanced(P＜0.05).③Eight weeks after transplantation,the specimens in the experiment group exhibited smooth surface and unclear outlines with surrounding cartilage;X-ray results showed joint space broadened,subchondral bone sack was improved;histological slices observation revealed similarity with normal chondrocytes.CONCLUSION:Autologous MSCs transplantation can repair articular cartilage injury.

Objective To investigate the influence of experimental scotoma on multifocal visual evoked potential (mf-VEP). Methods The mf-VEP of 10 healthy individuals (20 eyes) was measured with VERIS Science 4.0. Every eye was measured for 3 times. The right eye was measured with full field stimulation and upper hemi-field or lower hemi-field masked. The left eye was measured with full field stimulation and central three-rings area or lower nasal field masked. The first slice responses of the second order in different field were analyzed and compared by VERIS software. Results The mf-VEP in masked area was undetectable or obviously decreased in all subjects. In most unmasked field, the amplitudes of mf-VEP were not changed, except that in some place decreased slightly with statistically significant difference in comparison to the full field stimulation mode. Conclusion mf-VEP is influenced with experimental scotoma. The mf-VEP changes are consistent with the visual field masked.