Objective To probe into the significance and role of double testing of blood for virus markers.Methods The data on the results of routine blood testing at some blood centers in China from July to December,1999 were gathered and analysed.The blood donors with inconsistent results during the double testing were followed up and their blood samples were collected at least half a year later.Nucleic acid amplification testing(NAT) was performed on the samples.Results Only 0.63% of the donors showed inconsistent results during the double testing.Most of the positive results were false positive.Conclusion The double testing currently implemented does not help significantly improve the quality of the blood supply.It is important to enhance blood safety further by improvement of quality of the reagents and introduction of NAT.

OBJECTIVEThis study aims to construct a three-dimensional finite element model of a maxillary anterior teeth retraction force system in light wire technique and to investigate the difference of hydrostatic pressure and initial displacement of upper anterior teeth under different torque values of tip back bend.

METHODSA geometric three-dimensional model of the maxillary bone, including all the upper teeth, was achieved via CT scan. To construct the force model system, lingual brackets and wire were constructed by using the Solidworks. Brackets software, and wire were assembled to the teeth. ANASYS was used to calculate the hydrostatic pressure and the initial displacement of maxillary anterior teeth under different tip-back bend moments of 15, 30, 45, 60, and 75 Nmm when the class II elastic force was 0.556 N.

RESULTSHydrostatic pressure was concentrated in the root apices and cervical margin of upper anterior teeth. Distal tipping and relative intrusive displacement were observed. The hydrostatic pressure and initial displacement of upper canine were greater than in the central and lateral incisors. This hydrostatic pressure and initial intrusive displacement increased with an increase in tip-back bend moment.

CONCLUSIONLingual retraction force system of maxillary anterior teeth in light wire technique can be applied safely and controllably. The type and quantity of teeth movement can be controlled by the alteration of tip-back bend moment.

Objective To study the effects of CBL teaching mode on treatment plan making process among orthodontic postgraduates. Methods Totally 42 junior and senior orthodontic post-graduates were randomly divided into 2 groups (21 per group)named as experimental group and test group. Each group was further divided in to 3 teams involved in CBL and traditional teaching. Six cases of the same type malocclusion were selected each time;after 4 teaching cycle,test scores of two groups were analyzed with SPSS 19.0. Results were shown as mean ± standard deviation and t test andχ2 test were applied to evaluate the rationality and accuracy of treatment plan made by students. Survey questionnaire were issued to teachers and students after class and the assessment results of CBL teaching mode were summed up. Results Test scores were (88.61±8.34)in experimental group and (76.13±8.59)in control group with significant differences (t=3.16,P=0.01). Pass rate of two groups were 96.12%and 87.51%with significant differences (χ2=4.76,P=0.02). During the first teaching program, accurate rates of experimental group and control group were respectively 31.00% and 36.70% and ra-tionality were 33.31%and 33.30%. During the second teaching program,accurate rates of experimen-tal group and control group were 68.80%and 45.70%and rationality were 62.72%and 43.37%. During the third teaching program,accurate rates of experimental group and control group were 89.70% and 51.20%,and rationality were 95.00% and 66.70%. During the fourth program,accurate rates of ex-perimental group and control group were respectively 97.80% and 55.30% and rationality were 98.30% and 75.60%. Conclusions CBL teaching mode is helpful to improve the students' ability of analyzing clinical cases and making more accurate and rational treatment plan,however the increasing teaching cost and the course load are also involved.

Objective To assess the prevalence of c-Kit and FLT3 gene mutations in core binding factor related acute myeloid leukemia (CBF-AML) and analyze the karyotype characteristics of the CBF-AML patients. Methods Mutations of c-Kit, FLT3-ITD and FLT3-TKD were detected by genomic DNA PCR and sequencing, and the karyotype changes were analyzed in 48 newly diagnosed CBF-AML patients. Results c-Kit aberrations were detected in 13(27.1 %) out of 48 patients, including 5 cases with exon 8 mutation and 8 cases with exon 17 mutation. c-Kit was more prominent in t(8;21) AML patients than in inv(16) AML patients [(33.3 %(9/27) vs 19.0 %(4/21), P<0.05]. Only 1 case (2.1 %) had FLT3-ITD mutation (FLT3-ITD+) and 3 cases (6.3 %) had FLT3-TKD mutation (FLT3-TKD +). Prevalence of RUNX1-RUNX1T1 with additional chromosome abnormality was as high as 25.9 %(7/27), in which sex chromosome elimination was the most common one, while prevalence of CBFβ-MYH11 with additional chromosome abnormality was low. Conclusion c-Kit gene mutations and RUNX1-RUNX1T1 additional chromosome abnormalities are common in patients with CBF-AML and would be helpful for individualized treatment studies.

Objective To discuss the clinical significance of the diffuse calcified distribution in diagnosis of benign and malignant breast lesions .Methods 379 patients with different benign and malignant breast lesions confirmed by surgery underwent digital X‐ray mammography .The morphology ,distribution ,number ,diameter ,concentration and density of calcification in lesions ,the maximum range of the calcified area and other accompanied manifestations in benign and malignant breast lesions were analyzed .Results As for the morphology of calcification ,tiny polymorphic calcification was found in 58 .5% of malignant lesions ,meanwhile ,dot‐like one was found in 49 .3% of benign lesions .Fine linear calcification or branched linear one occurred in malignant lesions ,however ,round one occurred in benign lesions .As for the calcification distribution ,regional distribution was found in 43 .9% of malignant lesions , meanwhile the clustered distribution was found in 58 .4% of benign lesions .And all lobar or segmental distribution was seen in malig‐nant lesions .As for the calcification diameter ,the calcification with the diameter less than 0 .5 mm occurred in 71 .6% of malignant lesions ,however ,that with diameter more than 1 .0 cm occurred in 69 .3% of benign lesions .As for the concentration of calcification , lesions with calcification more than 25 were 71 .8% of malignant ones ,whereas those with calcification of 15-25 were 58 .4% of be‐nign ones .As for calcified density ,uneven calcification occurred in 94 .2% of malignant lesions ;however the even one occurred in 63 .4% of benign lesions .The maximum diameter of calcification ranged from 40 mm to 80 mm was found in 59 .0% of malignant lesions , whereas that ranged from 0 mm to 40 mm was in 77 .2% of benign lesions .Conclusion Statistical differences have been found in the morphology ,distribution ,diameter ,concentration ,density and maximum diameter of calcification between the breast benign and ma‐lignant lesions .

Objective To research the serum urea nitrogen (BUN),creatinine (Cr),urinary inhibition C (CysC) and retinol binding protein (RBP) four biochemical indicators of joint detection on the early diagnostic value of lupus nephritis (LN).Methods According to the American Rheumatology Association (ACR) 2012 revision of the diagnostic criteria,collected 177 LN patients with kidney disease from January 2011 to April 2016 in Shaanxi Provincial People's Hospital,at the same time,choose 167 cases of healthy physical examination as normal control group.With Hitachi 7170A a fully automated analy zer on two groups of serum BUN,Cr,CysC and concentration of RBP for testing,the data obtained by SPSS17.0 statistical software for statistical analysis.Results LN patient group compared with healthy controls,the serum BUN (6.67 ± 1.43 mmol/L vs 6.57±1.16 mmol/L),Cr (96.9±10.1 μmol/L vs 92.6±13.2 μmol/L),CysC (1.7±0.5 mg/L vs 0.75±0.15 mg/L),RBP (180.5±8.28 mg/L vs 42.6±9.6 mg/L) concentrations were higher,and serum CysC,RBP higher level com pared with healthy control group difference was statistically significant (t=8.145,21.594,all P＜0.05).Single parameter detected abnormal rate in terms of LN patients serum BUN,Cr,CysC and RBP abnormal rates were 28.3％,29.4％,68.4 ％,65.0 ％,four indicators combined detection of abnormal rate was 85.3 ％,significantly higher than the single parameter test (x2 =35.973～168.742,all P＜0.01).Conclusion Conbined detection of BUN,Cr,CysC and RBP four early diagnosis of renal damage in patients with lupus nephritis had important clinical value.

Objective To identity the risk factors for supine hypotension syndrome (SHS) after spinal anesthesia in parturients.Methods A total of 204 parturients,scheduled for elective cesarean section,were divided into either control group or SHS group depending on whether or not SHS (systolic blood pressure [SBP] in the upper extremity decreased by ＞ 30 mmHg or decreased to ＜ 80 mmHg) developed after spinal anesthesia.The baseline patient characteristics such as age,body height and weight,gestational weeks and biparietal diameter were recorded.Supine stress test (SST) was performed.Heart rate,blood pressure in upper and lower extremities,perfusion index,pleth variability index and intravesical pressure were recorded when patients were in supine position and in left lateral position before spinal anesthesia.The risk factors of which P values were less than 0.05 would enter the multi-factor logistic regression analysis to stratify the risk factors for SHS.Results Among the 204 patients,99 cases developed SHS after spinal anesthesia,and the incidence was 48.5％.Logistic regression analysis showed that maternal body weight,biparietal diameter,the difference in SBP between upper and lower extremities in supine position,the difference in SBP in upper extremities caused by changing position and positive SST were risk factors for SHS after spinal anesthesia (P＜0.05 or 0.01).Conclusion Maternal body weight,biparietal diameter,the difference in SBP between the upper and lower extremities in supine position,the difference in SBP in upper extremities caused by changing position and positive SST are risk factors for SHS after spinal anesthesia in parturients.

Objective To investigate the influence of lipid metabolic markers on hip osteoarthritis (OA) and the correlation with the pain of hip.Methods In this retrospectively cross sectional analysis,393 subjects fufilling the inclusive criteria were continuously included from June 2013 to September 2014.The presentation of hip X-ray of subjects were classified into OA group and non-OA group in terms of Kellgren-Lawrence grading scale,the subjects with Kellgren-Lawrence (K-L)≥2 was classified into OA group.The average of age in total was (62±9) years.There were 183 males and 210 females,the number of patients with OA was 182.There were 210 patients with hypertension and 118 patients with diabetes while the number of smoking patients was 74.The demographic information,risk factors,blood pressure,blood glucose,lipid metabolic markers were analyzed.Differences in proportions were compared using the Chi-square test.Difterences in continuous variables were tested for statistical significance using t test analysis.VAS score was used to evaluate the severity of hip pain.Independent risk factors were confirmed by using multiple logistic regression analysis.The correlation between the risk factors and severity of hip pain was analyzed by Spearman correlation analysis.Results Statistically significance existed in age (t=-4.849),sex (x2=8.946),BMI (t=-4.794),hypertension (x2=4.751),smoking (x2=7.062),metabolic syndrome (x2=34.406),apolipoprotein A1 (t=2.352),apolipoprotein B (t=-6.870),high density lipoprotein cholesterol (t=2.519),triglyceride (t=-4.652) and ApoB/ApoA1 ratio (t=-4.901) between OA group and non OA group.Age [OR =1.060(1.033,1.086)],metabolic syndrome [OR=3.682(2.284,5.938)] and ApoB/ApoA1 ratio [OR=5.743(2.393,13.785)] were the independent risk factors.The ApoB/ApoA1 ratio had positive correlation with the severity of hip pain(r=0.379).Conclusion ApoB/ApoA1 ratio is the independent risk factor of hip osteoarthritis,and has positive correlation with the severity of hip pain.The ApoB/ApoA1 ratio should be monitored in hip osteoarthritis patients in clinical work,to get the relief of pain and improve hip osteoarthritis.

Objective To look for and confirm the downstream regulated gene of microRNA (miRNA)-148a in pancreatic cancer cell line.Methods The target gene regulated by miRNA-148a was predicted through bio-informatics analysis.The plasmid containing desired gene and with luciferase 3'-untranslated region (3'-UTR) reporter was constructed.Pancreatic cancer cells BXPC-3 were transfected with analogs and inhibitors of miRNA-148a by liposomes.The activity of luciferase was measured to determine whether miRNA-148a directly connected with desired gene.The expression level of miRNA-148a was changed in BXPC-3 cells,and the changes of target gene v-verb-b2 erythroblastic leukemia viral oncogene homolog 3 (awian) (ErbB3) expression were detected by Western blot at protein level.The data were analyzed by one way ANOVA.Results There was a conservative binding site of ErbB3 with miRNA-148a detected by bio-informatics analysis,miRNA-148a directly combined with ErbB3 and the activity of luciferase decreased to (25.00+47.00) ％ of the negative control (F=4.66,P＜ 0.01).After miRNA-148a overexpression,the gray value of ErbB3 expression in BXPC-3 cells decreased to (26.16±4.69)％ of control group (F=6.563,P＜0.05).Conclusion miRNA-148a directly targeted and regulated the expression of ErbB3 in pancreatic cancer cell line BXPC-3.

Teaching and research section of orthodontics of the Affiliated Hospital of Stomatology of Chongqing Medical University took the lead in carrying out ‘ three early education' Students of stomatology in Chongqing Medical University established ‘ social practice volunteer team' and conducted ‘ three early education' in orthodontic clinic during winter,summer holiday and weekend.This let students of low grades contact with society,clinical practice and scientific research at early stage thus to comprehensively improve their overall quality.Questionnaire for student volunteers of the Affiliated Hospital of Stomatology of Chongqing Medical University showed that ‘ three early education' can effectively improve medical students' comprehensive quality.In the early stages of learning for students of stomatology,we cultivated students' occupation spirit,innovation consciousness,scientific literacy,clinical thinking and teamwork ability by strengthening training of students' social practice ability,communication ability,organization and coordination ability,professional interests,professional senses of belonging,team spirit and moral emotion.We achieved certain results and our experiences are worth extending.