AIM To examine the antitumor activity of clostridium difficile toxin A. METHODS Highly purified toxin A from clostridium difficile was obtained by bovine thyroglobulin affinity chromatography followed by ion exchange chromatography steps on Q sepharose. The antitumor activity of toxin A of clostridium difficile on TPC 1 cell line was studied with Vero cell line as the normal cell line. The estimating ways used in this study were trypan blue exclusion test, MTT calorimetric assay, membrane damage test using 3H Uridine and observation by optical, fluorescence microscopes. RESULTS Exposed to toxin A, the cell growth inhibition, apoptosis index, non adherent cells and membrane damage in TPC 1 cell line were much more great than that in vero cell line, and the effect was dependent upon the concentration and treating time. CONCLUSION The antitumor activity of toxin A on TPC 1 cells was much higher than that on vero cell line. The data are of potential importance for the development of toxin A and the exploration of antitumor drugs.

Objective To describe the status of sleeping time among Chinese population.Method The data of 2002 China National Nutrition and Health Survey was used for the analysis.197 954 subjects aged 6 years and above were involved.Results The average daily sleeping time of the domestic Chinese was 8.3 hrs.In groups of 6～12 yrs,13～17 yrs,18～44 yrs,45～59 yrs,60 yrs and above,the daily sleeping time were 9.1 hrs,8.5 hrs,8.2 hrs,7.9 hrs and 7.8 hrs,and the rate of insufficient sleeping was 69.0%,58.5%,4.1%,9.2% and 17.1%,respectively.The rate of excessive sleeping in groups of 18～44 yrs,45～59 yrs and 60 yrs and above were 27.1%,20.2%,24.3%,respectively.Conclusion The status of insufficient and excessive sleeping existed in Chinese at the same time,and further research should be developed on the association between sleeping time and health.

An α-amylase inhibitor (α-AI) was isolated from white kidney beans (Phaseolus vulgaris. L) by ethanol fractional precipitation, ion exchange chromatography and gel filtration column chromatography. It was a homogeneity glycoprotein demonstrated by SDS-PAGE and gel filtration on CL-6B. The glycoprotein contained 88.2% protein and was rich in aspartic acid, glutamic acid, leucine, threonine and serine. The carbohydrate moiety was consisted of Man, Glc, Gal and Xyl in a mole ratio of 2.42∶1.50∶1.52∶1.00. The glycan and the core protein backbone was connected by O-linkage as determined by β-elimination reaction. The continuous oral administration of the α-AI (150 mg·kg-1·d-1 ) for 7 days can lower fasting blood glucose and 300 mg·kg-1 ·d-1 α-AI for 7 days can improve the sugar tolerance on alloxan-dependent diabetic model rats. The result showed the α-AI obtained from white kidney beans had good hypoglycemic effect on alloxan induced diabetic rats and may have high potential pharmaceutical value as a regulative digestive-starch degradation in patients suffering from diabetes.

Objective To investigate the correlation between methylation status and death-associated protein kinase 1 (DAPK1) in SiHa and Hela cell line of cervical carcinoma and intervention of DNA methyltransferase inhibitor 5-azacytidine on the expression of DAPK1 and the proliferation of the cells. Methods DAPK1 methylation status was analyzed using methylation-specific PCR methods. The expression of mRNA and protein of DAPK1 were analyzed by RT-PCR and SABC methods after the treatment with 5-azacytidine. MTT assay was used to observe the changes of proliferation activity of the cells after 5-azacytidine treatment. Results DAPK1 genes were methylated and did not express in SiHa cells in the cervical carcinoma. Its expression could be restored by 5-azacytidine. MTT assay showed 5-azacytidine could weaken the proliferation of cancerous cells. Conclusion DAPK1 methylation plays an important role in the carcinogenesis of cervical cells and can reexpress after the treatment with 5-azacytidine which also restored its inhibitory function on carcinoma.

Aim To investigate the effects of Guaveno-ic acid (GA)on proliferation,insulin synthesis and secretion in INS-1 cells and their possible mechanism. Methods INS-1 βcells were cultured in vitro.Control group,medium group,model group,drug groups and positive group were set.INS-1 cells were treated with GA (0.3,1 ,3,1 0,30 nmol·L -1 )for 48 h.The cell proliferation was tested by MTT assay.Acid-alco-hol was used to extract the insulin in the cells and the amount of insulin synthesis of INS-1 cells was tested by RIA.5.6,1 6.7 mmol·L -1 glucose was used to chal-lenge INS-1 cells for 1 h to the insulin secretion model (BIS and GSIS)was tested,and the insulin secretion of INS-1 cells was tested via RIA.The mRNA expres-sion of insulin gene,PDX-1 and MafA was tested by q-PCR.Results Compared with medium group,GA could promote the proliferation of INS-1 cells signifi-cantly (P <0.01 )and promote the synthesis of insulin in INS-1 cells significantly (P <0.01 ).GA(0.3 ~30 nmol· L -1 )could promote the BIS,GSIS of INS-1 cells significantly (P <0.05 or P <0.01 ).GA (3,30 nmol·L -1 )could up-regulate the mRNA expression of insulin gene,PDX-1 ,MafA in INS-1 cells signifi-cantly (P <0.01 ).Conclusions GA could signifi-cantly improve the proliferation of INS-1 cells and pro-mote the insulin synthesis and secretion of INS-1 cells, which may be associated with up-regulation of insulin gene,PDX-1 ,MafA mRNA expression.

Objective: To design the “one-year physical activity questionnaire” used in 2002 China National Nutrition and Health Survey. Methods: The intensity of each activity in the questionnaire was assessed from literature review and experts consultation. The energy intake was calculated from food frequency questionnaire for validation of the physical activity questionnaire. Results: The average daily energy expenditure per capita estimated from the questionnaire was 11.6MJ (male 11.9MJ, female 11.2MJ). The average physical activity level (PAL) was 1.95 (male 1.88, female 2.02). There was significant correlation between energy expenditure and energy intake (r = 0.13, P

Objective: To describe the physical activity level and its influencing factors of Chinese professionals, to provide basis for developing intervention strategies. Method: The information on physical activity was collected by one year physical activity questionnaire in "2002 China National Nutrition and Health Survey", and 29 783 professionals aged 18-59 years old(male 15 911, female 13 872)were involved. Metabolic equivalent (MET) was adopted to estimate the intensity level of physical activities. Physical activity level (PAL) was calculated to classify sufficient (PAL≥1.7) or insufficient (PAL

Objective: To analyze the drinking practice of people in China. Method: The data of 2002 China National Nutrition and Health Survey was used for this study. 159 117 subjects aged 15 years and over were involved. The information on drinking practice was collected using interview-administrated questionnaire. Results: The overall current drinking rate of people in China was 21.0%, 39.6% for male and 4.5% for female, respectively. The current drinking rates in urban and rural areas were 20.9% and 21.0%, respectively. The 45 to 59 years age group reached the highest. The rate of onset age of drinking younger than 18 years old was 8.8% in current drinkers. 39.9% male and 29.5% female current drinkers drank at least once a day. Distilled spirits was the first choice for 50.3% current drinkers. 58.2% male drinkers and 77.3% female drinkers consumed 100-150g and 50-100g distilled spirits, respectively. Conclusion: Alcohol drinking has become a public health problem in China, it is necessary to carry out further surveys to reveal the influencing factors.

Objective To investigate the breakfast behaviors and nutritional quality among primary and secondary students,and to provide scientific evidence for developing intervention strategies.Method Random three-stage clustering sampling method was employed in the study.A questionnaire survey was conducted among 9194 primary and secondary students aged 6-17y,from seven cities in China.Results The rates of primary and secondary students having breakfast everyday were 97.0%,92.4%,and 93.4%,Most of the students had their breakfast within 30 min after getting up,the rates being 75.4%,74.7%,and 68.6% respectively.Mothers primarily cook breakfast for the students,the rates being 53.1%,49.9%,and 49.7% respectively.In most cases,they had breakfast at home,the rates being 71.8%,67.0%,and 63.8% respectively.The rates of students having poor quality breakfast were above 80%.Conclusion Primary and secondary students are one of the focal target people for preventing unhealthy dietary behaviors due to shortcomings of eating breakfast.It is necessary to improve the nutritional quality of breakfast for better health of students.

Objective To explore the association of C20orf54 gene rs3746804 position single nucleotide polymorphism and susceptibility to esophageal squamous cell carcinoma (ESCC).Methods Purification of genomic DNA from whole blood was used the Maxwell(R) 16 System.rs3746804 in C20ort54 was detected by direct sequencing in 434 ESCC patients from Changzhi (Shanxi province) and Linzhou (Henan province) and 554 healthy controls from Changzhi,Linzhou and including immigrators from Linzhou to Changzhi.Results For rs3746804,the genotypic frequencies of CT(37.5％ vs 51.0％,37.5％ vs 52.0％),CC (44.2％ vs 34.8％,44.2％ vs 33.0％) in Changzhi ESCC patients showed significant differences with healthy Changzhi controls and the healthy immigrator controls (all P ＜ 0.05),and the frequencies of TT(18.3％ vs 4.1％) and CC (44.2％ vs 54.6％) in Changzhi ESCC patients showed significant differences with Linzhou ESCC patients (all P ＜0.05).The genotypic frequencies of TT (4.1％ vs 15.0％),CT (41.2％ vs 52.0％) and CC(54.6％ vs 33.0％) showed significant differences between Linzhou ESCC patients and the healthy immigrator controls (all P ＜ 0.05),and the frequencies of TT (4.1％ vs 14.1％) and CC (54.6％ vs 34.8％) showed significant differences between Linzhou ESCC patients and Changzhi healthy controls (all P ＜ 0.01).Meanwhile,there were significant differences between ESCC patients (including Changzhi and Linzhou ESCC patients) and healthy controls (including the healthy Changzhi,Linzhou and immigrator controls) in genotypic frequencies of CT(39.2％ vs 48.7％) and CC (48.8％ vs 38.2％) (all P ＜ 0.01).CT and CT + TT genotype could decrease the risk of ESCC compared with the CC genotype (OR =0.630,95％ CI0.481-0.826 ; OR =0.654,95％ CI 0.507-0.844).Conclusion There is a closed relationship between SNP rs3746804 in C20orf54 and susceptibility to ESCC.