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 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 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 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 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.

Child ; Exostoses, Multiple Hereditary ; genetics ; Female ; Humans ; Mutation ; N-Acetylglucosaminyltransferases ; genetics ; Pedigree

Objective To explore the expression of PRR11(Proline-rich protein 11) in human osteosarcoma and investigate the effect of PRR11 on the proliferation of human osteosarcoma cells.Methods Immunohistochemical staining was applied to detect the PRR11 expression in 75 cases of osteosarcoma and corresponding normal tissues.Western blotting was used to examine PRR11 protein expression levels in osteosarcoma cell lines.We used siRNA to knock down the expression of PRR11 and tested the effects of PRR11 down-regulation on the proliferation in SaOS2 cells.Results PRR11 was overexpressed in osteosarcoma specimens compared to their paired normal tissues,the over expression rate of PRR11 in osteosarcoma and corresponding paracancerous tissues were 76％(57/75) and 9.33％(7/75) with statistical difference(P<0.05).The high expression of PRR11 was correlated with tumor pathological grade and lymphatic metastasis(P<0.05).PRR11 was expressed in 4 osteosarcoma cell lines which were SaOS2,143B,U2OS and MG63 respectively,the expression was highest in SaOS2 cells.Silencing PRR11 inhibited cell growth as compared with control cells(P<0.05).Conclusion PRR11 is overexpression in human osteosarcoma and promotes its progression by enhancing proliferation.The increased expression of PRR11 in osteosarcoma is a new target for treatment and early diagnosis of human osteosarcoma patients.

Objective To compare the dosimetric parameters between the use of Tandem and Ring (TR;Nucletron#090.617) or Tandem and Ovoid (TO;Nucletron#189.730) applicators during three-dimensional (3D) high-dose rate (HDR) brachytherapy (BT) for cervical cancer.Methods The records of 40 cervical cancer (ⅡB-ⅣA) patients treated with 3D-image-guided HDR-BT were reviewed.Of these 40 patients, 20 were treated with the TO applicator, and 20 with the TR applicator.The D100% and V150% of the clinical target volume (CTV) and the D2 cc of organs at risk (OAR)(the rectum, bladder, and small intestine) during 3D-HDR-BT using TO and TR were compared using the independent sample t-test.ResultsOverall metrics:CTV volume:66.04±13.86 cm3(TR) vs.65.67±15.08 cm3(TO)(P=0.052);CTV D100:3.71±0.34 Gy (TR) vs.3.37±0.49 Gy (TO)(P=0.016);CTV V150%:0.54±0.02(TR) vs.0.56±0.04(TO)(P=0.034);rectum D2 cc:3.38±0.30 Gy (TR) vs.2.95±0.80 Gy (TO)P=0.037);bladder D2 cc:4.33±0.39 Gy (TR) vs.2.93±1.27 Gy (TO)(P=0.00);and small ntestine D2 cc:3.04±1.02 Gy (TR) vs.3.41±0.57 Gy (TO)(P=0.171).Conclusions TR has better CTV coverage than TO during 3D HDR brachytherapy for cervical cancer.In addition, D2 cc of the rectum and bladder were both igher with TR than with TO, though there is no significant dosimetric difference in the small intestine between the two applicators.Therefore, tumor location, extent of invasion, and vaginal conditions should be considered when selecting the suitable pplicator for the treatment of cervical cancer.

Evidence-based medicine(EBM) emphasizes that the clinical practice should be based on the combination of the best available clinical evidence,medical experiences and patient desire to cope with the demand of medical decision-making.Guidelines for good clinical(research) practice,conduct of more trials as multicentre trials,and the cochran collaboration may all help apply the best research evidence to clinical practice.China is challenged by variety of health problems.The implementation of EBM will improve the decision-making and health care services and protect the doctors and patients rights.