Analysis of G-banding in tumor cell lines derived from human neural stem cells

BACKGROUND： The application of neural stem cell （NSC） is restricted because of its tumorigenesis, and the possible pathogenesis needs investigation. OBJEETIVE： To compare the differences of chromosomal G-banding between human NSCs （hNSCs） derived tumor cell line and hNSCs derived normal cell lines. DESIGN： A randomized controlled observation SETTING ： Building of Anatomy, Peking University Health Science Center MATERIALS ①The hNSC lines and hNSC-derived tumor cell lines were provided by the Research Center of Stem Cells, Peking University; DMEM/F12 （1：1） medium, N2 additive, B27 additive epidermal growth factor （EGF） and basic fibroblast growth factor （bFGF） were produced by GIBCO BRL Company （USA）; fetal bovine serum by HYCLONE Company （USA）. METHODS： The experiments were carried out in the Department of Genetics, Peking University Health Science Center from February 2003 to July 2004. Human fetal striatal NSCs were inoculated hypodermically on the right scapular of nude mice; Normal human fetal striatal NSCs were cultured to 5-8 passages as controls. Karyotyping was performed on the 5^th passage of hNSC-derived tumor cells at 6 weeks after hNSC transplantation into nude mice （T1） and tumor cells at 15 weeks after transplantation （T2）. Metaphase chromosomes were examined with microscope, G-banding cytogenetic analysis and karyotyping were performed according to the Cytoscan Karyotyping FISH and CGH software system （United biotechnology USA Corporation）. MAIN OUTCOME MEASURES： G-banded analytical results of human fetal striatal nerve stem cells derived tumor cell lines （T1 and T2） of metaphase chromosomes were observed. RESULTS： ① Chromosome analysis of hNSC-derived tumor cell lines 1 （T1）： Twenty-five well-spread metaphases were randomly selected for analysis. The karyotypes were 64, XX （8, 32%）; 65, XX （1, 4%）; 67, XX （5, 20%）; 68, XX （11, 44%）. The modal number of chromosomes in this cell lines was 68, which were all hypotriploid. The analysis of 8 G-banded karyotypes showed that about （70.2±3.4）% of the chromosomes lost normal figures in each karyotype, and the chromosomes with structural rearrangements, including deletion and translocation, were observed, most of which changed in a random way.② Chromosome analysis of hNSC-derived tumor cell lines 2（T2）： Twenty-five well-spread metaphases were randomly selected for analysis. The karyotypes were 64, XX （2, 8%）; 65, XX （1, 4%）; 66, XX （2, 8%）; 67, XX （5, 20%）; 68, XX （9, 36%）; 69, XX （6, 24%）. The modal number of chromosomes in this cell lines was 68, which were hypotriploid and triploid. The analysis of 8 G-banded karyotypes indicated that about （75.1±4.5）% of the chromosomes were abnormal in each karyotype. Chromosomes with structure alterations were observed, including deletion, translocation and dicentric. ③ Chromosome analysis of human fetal striatal NSC-derived normal cell lines： Twenty-five well-spread metaphases were analyzed randomly and the karyotypes were all 46, XX. Eight randomly selected G-banded karyotypes were analyzed and found no chromosome aberrations, and hNSC cells were all normal diploid. CONCLUSION： Chromosomal abnormalities are preferentially involved in numerical and structural rearrangements in the hNSC-derived tumor cell lines that derived from the same hNSC cell line, which suggest us to disclose intrinsic mechanisms of tumorigenesis of NSCs.

Prevalence and influence factors of self-medication in Chinese middle-aged and elderly people: evidence from 2011, 2013 and 2015 CHARLS panel data

Self-medication is an increasingly frequent phenomenon worldwide and has an important influence on health.In this study,we analyzed the self-medication prevalence rate in Chinese middle-aged and elderly people,and explored the influence factors.The data from China Health and Retirement Longitudinal Study(CHARLS)in 2011,2013 and 2015 were used.Self-medication prevalence was calculated as the number of whole people divided by the number of people taking self-medication.The influence factors of self-medication were analyzed by panel data random effect model.We excluded observations with missing values in our analysis,leaving 16 962,17 876 and 19 572 observations in 2011,2013 and 2015,respectively.The average 3-year self-medication prevalence was 45.52%.Moreover,11.70%of respondents practiced self-medication with prescription medicine in 2011,2013 and 2015.Respondents living in non-rural areas(P=0.009)and western region(P=0.000)took more self-medication.Self-medication was a common phenomenon among middle-aged and elderly population in China.The government should strengthen the guidance for the middle-aged and elderly people who took more self-medication,such as those living in urban and western region.

Maternal periconceptional consumption of pickled vegetables and risk of neural tube defects in offspring

Background Maternal exposure to nitrate, nitrite, and N-nitroso compounds from drinking water or diet has been associated with an increased risk of neural tube defects （NTDs） in some studies. Pickled vegetables contain relatively large amounts of nitrite and N-nitroso compounds. We examined the association between maternal periconceptional consumption of pickled vegetables and NTDs in Shanxi Province of northern China. Methods Data were derived from a population based case-control study of major external birth defects in four counties of $hanxi Province. Participants included 519 NTDs cases identified between 2003 and 2007 and 694 healthy controls. Exposure information was collected within 1 week after delivery. Multivariable non-conditioanal Logistic regression model was used to estimate the adjusted odds ratio （OR） controlling for potential confounding variables.

Distribution and equity trends for general practitioners in China from 2012 to 2015

Objective:This study aimed to identify the distribution and equity trends for general practi-tioners(GPs)in China from 2012 to 2015 and to provide evidence to guide the discipline’s develop-ment of general practice and for policy-making.Methods:On the basis of data from the National Health Statistics yearbooks,the distribution and equity trends for GPs from 2012 to 2015 were analyzed with the Lorenz curve and Gini coef-ficient as indictors of health equity.Results:From 2012 to 2015 the number of GPs increased at rates ranging from 9.3%to 32.5%,while the number of registered GPs increased at rates ranging from 32.6%to 37.2%.In 2015 the average number of GPs was 1.38 per 10,000 people(among the 31 provinces the highest rate was 3.90 per 10,000 people in Zhejiang and the lowest rate was 0.50 per 10,000 people in Xizang)and 1.98 per 100 km2(among 31 provinces the highest rate was 89.23 per 100 km2 in Shanghai and the lowest rate was 0.01 per 100 km^(2) in Xizang).From 2012 to 2015 the Gini coefficients weighted by population were 0.31,0.29,0.26,and 0.25 respectively,while the Gini coefficients weighted by geographical area were 0.74,0.72,0.72,and 0.72 respectively.Conclusion:The number of GPs increased rapidly in China;however,the proportion of regis-tered GPs was unsatisfactory,and there were inequities among the different provinces.The govern-ment should launch integrated strategies to encourage GP trainees to become registered GPs and optimize the distribution and equity of GPs.