Objective:To observe the color change of tooth i nduced by hydrogen peroxide gel. Method:12 extracted teeth were randomly assigned to two groups (n=6) and treated with 350 g/L and 75 g/L hy drogen peroxide gel respectively. One of the 6 samples in each group was used as the control. The bleaching gel was placed onto the enamel surface of the sample s. In 350 g/L gel group digital photographs were taken just before,10 and 30 min after the process, in 75 g/L gel group digital photographs were taken before an d 1.5?N(N=0,1,2,3,4,5,6,7) hours after the process respectively. All photograph s were taken at the same illuminating conditions and photographic parameters wer e analyzed with Photoshop7.0 software. Results:10.5 h after trea tment in the 75 g/L gel group L *, a * and b * values on the teeth surface were in creased(+) or decreased(-) by +4.5,-1.4 and -0.5,those on the inner sections 2.7 ,-1.0 and -0.8,respectively. 30 min after treatment in the 350 g/L gel group L *, a * and b * values on the teeth surfaces were increased(+) or decreased (-) by +1.9,-0.6 and 0,those on the inner sections +0.4,-0.4 and -0.6,respectively. Conclusion:Effective bleaching effect may be obtained in 10~30 min b y 75 g/L or 350 g/L hydrogen peroxide gel on teeth surface and in inner dentin. 75 g/L hydrogen peroxide bleaching gel may produce more reliable and save effect than 350 g/L.

[Objective]To discuss surgical approaches,results and complications of ossification of posterior longitudinal ligament(OPLL)of cervical spine.[Method]The clinic data of 48 patients from 2000 with cervical OPLL were reviewed and analyzed.Eighteen of them were decompressed from an anterior approach and 30 from a posterior approach.The improvement rate according to JOA scoring system were evaluated,some relevant imaging examination data including X-rays,CT and MRI were also measured,which were taken preand post-operatively.Surgical complications were also recorded.[Result]Of 48 patients,23 had cervical stenosis,the mean occupancy rate was 41.4%,and 19 had the abnormal signal in spinal cord.The mean postoperative improvement rate was 68.3% in patients treated by anterior decompression and 51.3% in those treated by posterior decompression.There were 2 patients with dural tear,5 with segmental nerve root palsy and 2 with hematoma after operation.[Conclusion]Suitable operation methods should be chosen according to the location,extent and occupancy ratio of OPLL,which is important for avoiding complications and improving surgical results.

Objective To observe the impacts of valsartan combined with amlodipine or hydrochlorothiazide regimen on blood pressure variability (BPV) in elderly hypertensive patients.Methods Eighty elderly patients with hypertension were randomized into valsartan and amlodipine (the amlodipine group, n=38) or valsartan and hydrochlorothiazide (the hydro-chlorothiazide group,n=37) group.The 24-hour dynamic blood pressure was monitored at baseline, 6-week and 12-week after treatment for the blood pressure and blood pressure variability. The control rate of blood pressure was calculated at 6-week after treatment, and side effects were observed during the treatment.Results Values of 24 h systolic blood pressure (SBP), daytime SBP, nighttime SBP, morning SBP and 24 h systolic blood pressure variability (SBPV) were significantly low-er at 6-week and 12-week than those of baseline in both two groups(P<0.05). There was an interaction between the group-ing factors and time on 24 h SBP, daytime SBP, nighttime SBP, 24 h SBPV and daytime SBPV (P<0.05). At the 6 and 12-week treatment, 24 h SBP, daytime SBP, nighttime SBP and daytime SBPV were significantly lower in amlodipine group than those in hydrochlorothiazide group (P<0.05). At 12-week treatment, 24 h SBPV was significantly lower in amlodipine group than tjat in hydrochlorothiazide group (P<0.01). There were no significant differences in control rate of blood pressure and side effects between two groups. Conclusion Valsartan in combination with amlodipine or hydrochlorothiazide can both ef-fectively control BPV in elderly hypertensive patients, and valsartan conbined with amlodipine has better effects on lowering blood pressure and BPV.

[Objective] To discuss the prognostic factors for cervical OPLL treated by anterior decompression.[Method]A total of 48 patients with cervical OPLL,who underwent anterior decompression,were followed up for 1～4 years,with an average of 2.1 years.The patients were classified into a good-prognosis group and a poor-prognosis group according to the JOA neruologic scoring system.Age,sex,JOA score,duration of symptoms,diabetes mellitus,Pavolv ratio,occupying rate,type of ossification,CT double-layer sign,hyperintense areas,level of segments,and treatment of ossification were testified using multiple logistic regression analysis.[Result]Treatment of ossification was the only statistically significant factor predicting clinical results in this study.[Conclusion]It is the most important to resect the ossification and decompress the spinal cord thoroughly in the process of antarior decompression for cervical OPLL.

In order to verify the origin relations of Zhouhou Emergency and modern clinical medicine in emergency treatments,we choose Zhouhou Emergency as study object,and try to verify four treatments including artificial respiration,urethral catheterization,surgical infection and hemostasis. Through tracing back to the initiation and developing history of modern medical technique,it fixes its position in modern emergency treatments,and affirms the important roll of Chinese ancient books in promoting the techniques of modern emergency science.

Objective:To study the vertical and horizontal proportions in facial area and the difference between Han and Kazak normal adults in Xinjiang area.Methods:According to certain standards,the adult Han and Kazak college students in Urumqi were randomly selected.Frontal photographs were taken for the subjects in accordance with the same standards.The data were imported into computer, and 20 standard anthropometric marks were determined,then 1 5 measurements were performed by photoshop soft ware,1 9 proportion i-tems of the mesurements was established.Independent sample t-test was applied for statistic analysis by SPSS1 9.0.Results:The face of the males was shorter and wider than that of the females.The males have smaller fissure width and bigger alar width than the females. However,the Han subjects have smaller fissure width and mouth width,bigger alar width and intercanthal width than the Kazak.Con-clusion:This study suggests that facial proportions were significantly different between the two nationalities and between sexes in Xin-jiang.

Objective In order to analyze of poisoning causes,a new method was established utilizing hydrophilic liquid chromatography-tandem triple quadrupole mass spectrometer (HILIC-MS/MS) coupled with dispersive solid phase extraction for rapid qualitative and quantitative analysis of tetrodotoxin in nassarius and shellfish.Methods Sample (1.0 g) was extracted with 0.1％ acetic acid in boiling water bath,purified by dispersive solid phase extraction with 50 mg hydrophilic-lipophilic balance (HLB),5 mg graphitized carbon black (GCB) and protein precipitation with acetonitrile,and then filtered through a polytetrafluoroethylene (PTFE) membrane.The analytes were separated on a HILIC column,and detected in selected reaction monitoring (SRM) mode via positive electrospray ionization.The matrix matching and external standard method was used for quantification.Results Tetrodotoxin showed good linearity in the concentration range between 2.0 and 40.0 ng/ml,the correlation coefficient was higher than 0.999.The detection limit of tetrodotoxin in seafood was 10.0 pg/kg.The rates of recovery varied between 74.2％ and 87.9％ with relative standard deviations from 2.3％ to 9.1％ at spiked concentrations of 25,100 and 200 pg/kg.The proposed method was applied in the detection of tetrodotoxin in shellfish and nassarius from coastal cities of Zhejiang Province.Conclusion The method was accurate,fast,easy to operate,which could meet the requirements of public health emergency testing or routine testing.

Objective To investigate the value of dynamic contrast-enhanced magnetic resonance imaging ( DCE-MRI) in differentiating serological negative early stage rheumatoid arthritis (RA) from osteoarthritis (OA)in hand. Methods Plain MRI, enhanced MRI of whole hand and DCE-MRI of single slice were performed in 53 patients suspected of RA or OA and 18 healthy volunteers. Twenty-three of them were diagnosed as RA,including 18 cases of serological negative RA and 18 of them were diagnosed as OA after 3 to 6 months follow-up. The contrast rate,slope, thickening of synovial membrane were measured on DCE-MRI in three groups and the MRI findings were also were detected in both RA and OA groups. The contrast rate and slope of synovial membrane were compared among three groups using rank sum test. The thickening of synovial membrane were compared among three groups using variance analysis. MRI signs of RA and OA group were evaluated with rank sum test Results The dynamic contrast rate of synovial membrane in RA group,OA group and control group was(100.78±61.96)%,(40.44±15.43)% and (23.56±9.14)%,respectively.Individually,RA group to OA group,u=3.101,P=0.002;RA group to control group,u=4.669,P=0.000;OA group to control group,u=3.482,P=0.000.The slope of contrast curve of synodal membrane of RA group,OA group and control group was 72.50°±13.34°,45.39°±9.94°,14.56°±5.75°,respectively.Individually,RA group to OA group,u=8.002,P=0.000;RA group to control group,u=17.102,P=0.000;OA group to control group,u=9.100,P=0.000.The synovial membrane thickening of RA group,OA group and control group was(3.3±0.5),(2.8±0.7)and (1.4±0.6)mm,respectively.Individually,RA group to OA group,q=2.622,P=0.011;RA group to control group,q=9.583,P=0.000;OA group to control group,q=6.961,P=0.000.Conclusion The quantitative index of DCE-MRI,including contrast rate and synovial membrane thickening may provide useful information for differentiating OA from semlogical negative early stage RA.The contrast rate and thickening of synovial membrane in RA group are higher than those in OA group.Many signs of MRI Can help differentiate OA from RA.

Objective To evaluate the role of silent information regulator 1 (SIRT1) in ischemic preconditioning (IPC)-induced alleviation of myocardial ischemia-reperfusion (I/R) injury in rats.Methods Forty-eight male Sprague-Dawley rats,aged 12 weeks,weighing 200-250 g,were randomly divided into 4 groups (n =12 each):sham operation group (S group),I/R group,IPC group and IPC + SIRT1 inhibitor ex527 group (IPC + ex527 group).Myocardial I/R was induced by 30 min occlusion of left anterior descending branch of coronary artery followed by 120 min reperfusion.IPC was induced by 3 episodes of 5 min occlusion of left anterior descending branch at 5 min intervals before myocardial ischemia.SIRT1 inhibitor ex527 1 μg/kg was injected intravenously 15 min before myocardial ischemia and at 1 min before reperfusion.Blood samples were collected before myocardial ischemia and at 120 min of reperfusion for measurement of serum TNF-α and IL-6 concentrations by ELISA.The rats were then sacrificed and myocardial specimens were obtained for determination of myocardial lactic dehydrogenase (LDH) and creatine kinase MB (CK-MB) activities,SIRT1 expression and acetylation of NF-κB p65.Results Compared with S group,the serum TNF-α and IL-6 concentrations at 120 min of reperfusion,and myocardial LDH and CK-MB activities and acetylation of NF-κB p65 were significantly increased,and SIRT1 expression was down-regulated in I/R and IPC + ex527 groups (P ＜ 0.05).Compared with I/R group,the serum TNF-α and IL6 concentrations at 120 min of reperfusion,and myocardial LDH and CK-MB activities and acetylation of NF-κB p65 were significantly decreased,SIRT1 expression was up-upregulated in group IPC (P ＜ 0.05),and no significant change was found in the parameters mentioned above in group IPC + ex527 (P ＞ 0.05).Compared with IPC group,the serum TNF-α and IL-6 concentrations at 120 min of reperfusion,and myocardial LDH and CK-MB activities and acetylation of NF-κB p65 were significantly increased,and SIRT1 expression was down-regulated in group IPC + ex527 (P ＜ 0.05).Conclusion SIRT1 is involved in IPC-induced alleviation of myocardial I/R injury in rats.

Objective To investigate the effects of hydrogen gas on the myocardial injury in rats with endotoxemia.Methods Forty-eight healthy male Sprague-Dawley rats,weighing 200-220 g,were randomly divided into 4 groups (n =12 each ):control group (group C ),hydrogen gas control group (group HC ),endotoxemia group (group E) and hydrogen gas + endotoxemia group (group LH).Endotoxemia was induced by intraperitoneal lipopolysaccharide (LPS) 20 mg/kg in groups E and LH,while the equal volume of normal saline was given in groups C and HC.After LPS administration,the rats were exposed to the air containing 2％ hydrogen gas for 6 h in groups HC and LH,and the rats were exposed to the air for 6 h in groups C and E.Blood samples were taken from the abdominal aorta after 6 h inhalation of hydrogen gas to determine the serum level of cTnI.The hearts were then removed to determine the content of TNF-α and IL-6 and expression of phosphorylated nuclear factor κB ( NF-κB) inhibitory protein (p-IκB-α) and p38 mitogen-activated protein kinase (p-p38MAPK) in the myocardial tissues.Results Compared with group C,no significant change was found in the levels of cTnI,TNF-α and IL-6 and expression of p-IκB-α and p-p38MAPK in group HC ( P ＞ 0.05),and the levels of cTnI,TNF-α and IL-6 were significantly increased and the expression of p-IκB-α and p-p38MAPK was up-regulated in groups E and LH ( P ＜ 0.05).Compared with group E,the levels of cTnI,TNF-α and IL-6 were significantly decreased and the expression of p-IκB-α and p-p38MAPK was down-regulated in group LH ( P ＜ 0.05).Conclusion Hydrogen gas can reduce the myocardial injury in rats with endotoxemia,and inhibition of the p38MAPK and NF-κB pro-inflammatory pathway and reduction of the inflammatory response of myocardial tissues are involved in the mechanism.