Objective To estimate the relationship of genetic polymorphisms of glutathione s-transferase M1, T1 (GSTM1 and GSTT1) and the susceptibility to childhood acute leukemia. Methods Meta-analysis was employed to estimate the relationship of genetic polymorphisms of GSTM1, GSTT1 and childhood acute leukemia based on relevant epidemiological papers published at home and abroad. Random effect model and fixed effect model analysis were used to calculate the incorporated odds ratio (ORc) based on homogeneity test. Results The ORc and 95% confidence interval for childhood acute leukemia associated with GSTM1 null and GSTT1 null was 1.31(95%CI: 1.01～1.71), 0.98(95%CI: 0.82～1.17) respectively. Conclusion GSTM1 null may be an important host risk factor for childhood acute leukemia, whereas GSTT1 null does not show a significant relationship with the risk to childhood acute leukemia.

Objective To know the effect ofof the particulates sampled from the air of the railway transport station of hazard chemicals on rat typeⅡpneumocytes and the antagonism of antioxidants. Methods The rat typeⅡpneumocytes cultured by routine method were pre-treated with antioxidants N-acetylcysteine (NAC), Vitamin C and Vitamin E, then were exposed to the abstract of particulates. The damages of rat typeⅡpneumocytes and DNA cross-links were detected with MTT assay and ethidium bromide fluorescence assay. Results The abstract of particulates caused obvious damages and DNA cross-links in the rat typeⅡpneumocytes and the significant dose-effect relationship was seen. NAC, Vitamin C and Vitamin E reduced significantly the damages and DNA cross-links. Conclusion Abstract of the particulates sampled from the air of the railway transport station of hazard chemicals may induce the damages and DNA cross-links in rat typeⅡpneumocytes and these adverse effects can be antagonized by antioxidants such as NAC, Vitamin C and Vitamin E.

Objective To investigate the micronucleus frequency in mice peripheral blood reticulocytes induced by air particulate pollutants in a railway transport station of chemical dangerous goods (RTSCDG) Methods Male BALB/C mice were selected and randomly divided into exposure groups and control groups One time exposure experiment was carried out among mice exposed to acetone extracts of air particulate pollutants at doses of 20,40,80,160 mg/kg by intraperitoneal injection Multiple time exposure experiment was carried out among mice exposed to acetone extacts of air particulate pollutants at dose of 10 mg/kg by consecutive intraperitoneal injection one time per day for 5 days The peripheral blood was sampled from mice tails and the micronucleus frequencies in reticulocytes were observed at 24, 48 and 72 h after the exposure Results The frequencies of micronuclei in peripheral blood reticulocytes revealed good time response relationship and reached the highest levels at 48 h after exposure,at the same time the frequencies of micronuclei in dose groups of 20,40,80,160 mg/kg were all higher than those in control group The multiple frequencies exposure experiment with lower dose showed that the frequencies of micronuclei in peripheral blood reticulocytes in exposure group always revealed significantly higher levels compared with those in control group during the 24th~72th hour after the exposure ( P

Objective To examine the possible role of hepatocyte growth factor (HGF) in transdifferentiation induced by TGF ? 1 in cultured human renal tubular epithelial cell lines(HKC). Methods The HKC cells were divided into negative control, positive control, HGF group, HGF inhibition group, HGF delayed administration group. Then the expression of E cadherin and alpha smooth muscle actin(? SMA)of HKC cells were assessed by indirect immunofluorescence ,the expression of ? SMA mRNA of HKC cells were assessed by reverse transcriptase ploymerase chain reaction(RT PCR). Results HKC cells treated with TGF ? 1 present a clear fibroblast like morphology, loss of epithelial marker E cadehrin and de novo expression of ? SMA. Simultaneous incubation of HGF or delayed administration of HGF abrogated the ? SMA expression and E cadherin depression triggered by TGF ? 1 in HKC cells in a dose dependent manner. HGF also blocked morphologic transformation of tubular epithelial cells. Conclusion TGF ? 1 is a key mediator that regulates the transdifferentiation of tubular epithelial cells into ? SMA (+) myofibroblast, HGF can inhibit transdifferentiation of HKC cells induced by TGF ? 1 , Delayed administration of HGF effectively suppresses, and partially reverses myofibroblastic transition of tubular epithelial cells

Objective To investigate the association of ILK expression in human renal interstitium and the pathological injury of renal interstitium in the patients with chronic nephropathy.Methods The expressions of ILK,TGF?1,E-cadherin and fibronectin(FN) in renal tissue were investigated with immunohistochemistry and computer image analysis system in 49 patients with chronic kidney disease.According to the score of the renal interstitial pathologic injury,49 patients were divided into four groups: 4 in no injury group(the normal control group),17 in slight injury group,16 in mild injury group,12 in severe injury group.Results ILK was hardly detected in normal control group,and ILK was observed in tubulointerstitial area in 3 injury groups.The expression of ILK was prominent in tubular epithelial cells,next in the damaged tubulointerstitial area.A significant positive correlation was found between the expression of ILK in renal interstitial tissue and the degree of renal tubulointerstitial pathological injury(r=0.736),as well as that of TGF?1(P

Objective To study the Mandarin long-term average speech spectrum (LTASS),the effects of gender,language and region material on LTASS were explored.This research would provide reference for clinical and academic use of Mandarin LTASS.Methods One hundred and sixty subjects from eight major dialectic regions of China,aging 16~30 (average 22.3±3.3),were asked to read two materials (storybook,newspaper)in Manda-rin at a steady speed and conversational level inside a standard soundproof booth.Ten males and ten females were in each dialectic region.A microphone (B&K 4192)was used to monitor each subject's speech which was analyzed with a real-time spectrum analyzer to obtain the long-term spectrum (B&K PULSE 3560C).Results Different Man-darin LTASS spectra were obtained based on gender,material and regions.The spectra were tested with profile a-nalysis.Language material had no significant effects on the Mandarin LTASS (F =2.52,P =0.11 ).There was, however,significant gender difference (F =116.39,P =0.00).Males had spoken with intensity levels higher than females at 100 Hz to 200 Hz.There was also a dialectic difference in the Mandarin LTASS (F =1.29,P =0.02). Speakers from Guangdong had the lowest intensity levels compared to those from other regions.Conclusion Genders and regions are factors that need to be considered when LTASS is used for clinical purpose and academic study.

In this paper,the educational mode of master of public health (MPH) in America and China were reviewed through literatures searching and internet searching and the difference between America and China were compared from the sources of students,students' characters,educational objective,specialties and curricula,methods of teaching and management.There is still a certain gap in education of MPH in China.The educational mode needs optimizing with changing enrollment methods,definitude training objectives,perfect curriculum setting,increased opportunities for practice and strict quality control,so that the educational mode of MPH will be perfected in China.

Objective To assess the dignosis value of CT three-dimensional reconstruction with Fisher discriminant model in small solitary pulmonary nodules before operation.Methods CT data of 40 cases with SPN were retrospectively analyzed and divided into into malignant pulmonary nodules (25 cases),squamous cell carcinoma (4 cases),adenocarcinoma (13 cases),lung cancer (4 ca-ses),small cell lung cancer (2 cases),large cell carcinoma (1 case),metastases tumor (1 case),benign nodules (1 5 cases,6 cases of tuberculosis,2 cases of hamartoma,and 7 cases of non-specific inflammatory nodules)by pathology and follow-up results.The CT features of pulmonary nodules were evaluated through multi-planar reformation (MPR),curved-planar reformation (CPR),volume rendering (VR),maximum intensity proj ection (MIP)and other three-dimensional reconstruction.The three-dimensional data were divided into benign and malignant groups.In each of the two groups,the significant signs of morphological signs of discrimination indicators were adminstrated Fisher discriminant,and the probalitiy of false positives were estimated using cross-validation method. Results The positive features of pulmonary nodules in there-dismensional images were much more than in two-dimensional images. Fisher discriminant formula of solitary pulmonary nodules in three-dimensional images was Z=1.143X1 + 0.454X2+1.606X3-0.262X4+0.04X5+0.483X6+1.611X7-2.164.Discriminant boundary value Zc was-0.516.When Zcgreater than -0.516,nodules were proneed to considere as malignant nodules.In 25 cases of malignant nodules,4 cases mistook for benign.When Zc less than -0.516,nodules were proneed to considere as benign nod-ules.In 1 5 benign nodules,2 cases mistook for malignant.The total misdiagnosis and accuracy rate were 15 % and 85% respec-tively.Conclusion CT three-dimensional reconstruction combined with Fisher discriminant model have a high clinical value in dif-fereiating diagonsis of pulmonary nodules were proneed to considere as malignant nodules.In 25 cases of malignant nodules,4 cases mistook for benign.When Zc less than -0.516,nodules were proneed to considere as benign nodules. In 15 benign nodules,2 cases mistook for malignant.The total misdiagnosis and accuracy rate were 15 % and 85% respec-tively.Conclusion CT three-dimensional reconstruction combined with Fisher discriminant model have a high clinical value in differeiating diagonsis of pulmonary nodules.

Abstract In recent years, mental health problems of children and adolescents are increasingly recognised as one of the most significant public health concerns. The article briefly describes the contemporary characteristics of mental health problems in children and adolescents, and proposes the implementation of school mental health social service system, including the establishment of comprehensive school mental health social service policies, the improvement of the school mental health social service model, the construction of regional school mental health service centers, and the strengthening of school mental health service practices in order to address youth mental health needs.

Objective To assess the reliability and validity of the Chinese version on Alcohol Use Disorders Identification Test (AUDIT) among medical students in China and to provide correct way of application on the recommended scales.Methods An E-questionnaire was developed and sent to medical students in five different colleges.Students were all active volunteers to accept the testings.Cronbach's α and split-half reliability were calculated to evaluate the reliability of AUDIT while content,contract,discriminant and convergent validity were performed to measure the validity of the scales.Results The overall Cronbach's α of AUDIT was 0.782 and the split-half reliability was 0.711.Data showed that the domain Cronbach's α and split-half reliability were 0.796 and 0.794 for hazardous alcohol use,0.561 and 0.623 for dependence symptoms,and 0.647 and 0.640 for harmful alcohol use.Results also showed that the content validity index on the levels of items I-CVI)were from 0.83 to 1.00,the content validity index of scale level (S-CVI/UA) was 0.90,content validity index of average scale level (S-CVI/Ave) was 0.99 and the content validity ratios (CVR) were from 0.80 to 1.00.The simplified version of AUDIT supported a presupposed three-factor structure which could explain 61.175％ of the total variance revealed through exploratory factor analysis.AUDIT semed to have good convergent and discriminant validity,with the success rate of calibration experiment as 100％.Conclusion AUDIT showed good reliability and validity among medical students in China thus worth for promotion on its use.