Study on genetic structure differences and adjustment strategies in different areas of China / 中华流行病学杂志

Objective: To describe the genetic structure of populations in different areas of China, and explore the effects of different strategies to control the confounding factors of the genetic structure in cohort studies. Methods: By using the genome-wide association study (GWAS) on data of 4 500 samples from 10 areas of the China Kadoorie Biobank (CKB), we performed principal components analysis to extract the first and second principal components of the samples for the component two-dimensional diagram generation, and then compared them with the source of sample area to analyze the characteristics of genetic structure of the samples from different areas of China. Based on the CKB cohort data, a simulation data set with cluster sample characteristics such as genetic structure differences and extensive kinship was generated; and the effects of different analysis strategies including traditional analysis scheme and mixed linear model on the inflation factor (λ) were evaluated. Results: There were significant genetic structure differences in different areas of China. Distribution of the principal components of the population genetic structure was basically consistent with the geographical distribution of the project area. The first principal component corresponds to the latitude of different areas, and the second principal component corresponds to the longitude of different areas. The generated simulation data showed high false positive rate (λ=1.16), even if the principal components of the genetic structure was adjusted or the area specific subgroup analysis was performed, λ could not be effectively controlled (λ>1.05); while, by using a mixed linear model adjusting for the kinship matrix, λ was effectively controlled regardless of whether the genetic structure principal component was further adjusted (λ=0.99). Conclusions: There were large differences in genetic structure among populations in different areas of China. In molecular epidemiology studies, bias caused by population genetic structure needs to be carefully treated. For large cohort data with complex genetic structure and extensive kinship, it is necessary to use a mixed linear model for association analysis.

Epidemiology related to soil-borne nematode disease in Danzhou city, Hainan province / 中华流行病学杂志

Objective: To understand the prevalence, trend and related factors on soil-borne nematode in Danzhou city to provide information for prevention and control of the disease. Methods: According to the guidelines set by the National National soil-borne nematode technical solutions, one village was randomly chosen from every township as the monitoring location, in the east, west, south and north parts of Danzhou city. A total of 200 residents aged 3 years and over were randomly selected in each monitoring site, with modified Kato thick smear and Cellophane tape anal swab used for microscopy. Results: In this survey, we retrospectively analyzed the rates on soil borne nematode infection in five monitoring locations of Danzhou city and the results showed that the overall positive rates of infection was 19.5% (195/1 000). Comparing with the previous surveys, rates on soil-borne parasites infection were decreasing. The main types of soil-borne nematode infection appeared as roundworm, whipworm, hookworm and pinworm in Danzhou city, with rate of hookworm-egg infection ranking the highest (42.5%, 85/200) in Dacheng. The infection rate was seen significantly higher in females than males. People aged over 60 and between 3-10, had a higher rates of infection. Rate on multiple infections reached 16.9%, including 5 triple infection cases. Conclusion: Rates of infection on soil-borne nematodes in Danzhou city showed a decreasing trend from 2013 to 2016 with hookworm and whipworm as the major ones.

Association between fatty liver and type 2 diabetes in the baseline population of Jinchang Cohort / 中华流行病学杂志

Objective: To explore the association between fatty liver and type 2 diabetes mellitus (T2DM) in the baseline-population of Jinchang cohort study. Methods: Data from all the participants involved in the baseline-population of Jinchang cohort study was used, to compare the risks of T2DM in fatty liver and non fatty liver groups and to explore the interaction between family history or fatty liver of diabetes and the prevalence of T2DM. Results: Among all the 46 861 participants, 10 574 were diagnosed as having fatty liver (22.56%), with the standardized rate as 20.66%. Another 3 818 participants were diagnosed as having T2DM (8.15%) with standardized rate as 6.90%. The prevalence of T2DM increased in parallel with the increase of age (trend χ(2)=2 833.671, trend P<0.001). The prevalence of T2DM in the fatty liver group was significantly higher than that in the non-fatty liver group, both in men or women and in the overall population. Compared with the group of non-fatty liver, the risks of T2DM in fatty liver group were seen 1.78 times higher in males, 2.33 times in women and 2.10 times in the overall population, after adjustment for factors as age, levels of education, smoking, drinking, physical exercise, BMI, family history of diabetes and some metabolic indicators (pressure, TC, TG, uric acid, ALT, AST, gamma-glutamyl transferase). Date from the interaction model showed that fatty liver and family history of diabetes present a positive additive interaction on T2DM (RERI=1.18, 95%CI: 0.59-1.78; AP=0.24, 95%CI: 0.14-0.34; S=1.43, 95%CI: 1.21-1.69). Conclusions: Fatty liver could significantly increase the risk of T2DM and a positive additive interaction was also observed between fatty liver and family history of diabetes on T2DM. It was important to strengthen the prevention program on T2DM, in order to effectively control the development of fatty liver.

Automatic detection of liver tumor motion by fluoroscopy images

Background: A method to track liver tumor motion signals from fluoroscopic images without any implanted gold fiducial markers was proposed in this study to overcome the adverse effects on precise tumor irradiation caused by respiratory movement

Materials and Methods: The method was based on the following idea: [i] Before treatment, a series of fluoroscopic images corresponding to different breathing phases and tumor positions were acquired after patient set-up; [iii] The wavelet transform method and Canny edge detection algorithm were used to detect motion trajectory of the diaphragm; [iv] The motion curves of center of lipiodol in the images were obtained by mathematical morphology and median filtering algorithm. The method was evaluated using by five sequences of fluoroscopic images from TACE patients who received transcatheter arterial chemoembolization therapy

Results: The position of liver tumor was significantly affected by respiratory motion; the motion trajectories of the diaphragm and lipiodolagreed well with the manually marked locations in amplitude and period; the motion trajectories of the diaphragm and lipiodol almost had similar period and amplitude in one treatment fraction. The respiratory period and amplitude of the same patient in different fractions had no significant differences; however, the difference was obvious for different patients. The proposed lipiodol detection methods can effectively reflect the relevant rules of tumor location caused by respiratory movement

Conclusion: Direct tracking of liver tumor motion in fluoroscopic images is feasible. The automatic detection method can reflect the characteristics of respiratory and tumor motions, which can save much time and significantly improve measurement precision compared with manual measurement

biological effects induced by high-charged and energy particles and its application in cancer therapy

The radiobiological effects of high atomic number and energy [HZE particles] ion beams are of interest for radioprotection in space and tumor radiotherapy. Space radiation mainly consists of heavy charged particles from protons to iron ions, which is distinct from common terrestrial forms of radiation. HZE particles pose a significant cancer risk to astronauts on prolonged space missions. With high delivered energies and intense ionization, HZE particles can damage not only the biological systems but also the shielding materials. HZE particles are more effective than low-LET radiation like gamma- or X-rays to induce genetic mutation and cancer. On Earth, similar ions are being used for targeted cancer therapy due to the advantage of the inverse dose profile, with delivering higher doses to the tumor while keeping lower doses to the surrounding tissues. In this review, we focus on the recent insights into the biological effects caused by HZE particles and the corresponding mechanism. We also discuss the current application of HZE particle in cancer therapy. Understanding the mechanisms underlying the repair of DNA damage induced by HZE particles contribute to accurately estimate the risks to human health associated with HZE particle exposure and to improve the effectiveness of tumor radiotherapy

Ultrasonography of immature teratomas: 11 case reports

Ovarian immature teratoma is a very rare type of tumor associated with a high relapse rate and mortality. Correspondingly, early diagnosis is important for effective treatment. The goal of this study was to retrospectively analyze the ultrasound characteristics of 11 cases of immature teratomas. Between January 2002 and December 2010, 11 patients were diagnosed with pathologically confirmed immature teratomas. Patients enrolled in this study underwent a transabdominal ultrasound examination prior to surgery. Tumor size, shape, internal echo, calcification, cystic degeneration, and blood flow for each immature teratoma were analyzed. Levels of alpha fetal protein [alphaFP] were also evaluated. The average tumor size was 8 cm [range, 4-13]. Echo patterns obtained included mixed echo [n = 7], solid echo [n = 2], and cystic echo [n = 2]. Coarse calcifications were detected in five cases, while blood flow signal was detected in one case, and ascites were detected in three cases. Only one case had elevated levels of alphaFP. Ultrasound imaging of immature teratomas detected large tumors that were predominantly involved mixed-echo masses, cystic degeneration, and coarse calcification on the cavity wall. In some cases, blood flow signal was detected in the mass and ascites were present in the abdominal cavity

Report on childhood obesity in China (8): effects and sustainability of physical activity intervention on body composition of Chinese youth / 生物医学与环境科学（英文）

<p><b>OBJECTIVES</b>To determine whether a large-scale physical activity intervention could affect body composition in primary school students in Beijing, China.</p><p><b>METHODS</b>The study design was one-year cluster randomized controlled trial of physical activity intervention (20 min of daily exercise in the classroom) with an additional year of follow-up among 4 700 students aged 8-11 years at baseline.</p><p><b>RESULTS</b>After the one-year intervention, BMI increased by 0.56 kg/m(2) (SD 1.15) in the intervention group and by 0.72 kg/m(2) (SD 1.20) in the control group, with a mean difference of -0.15 kg/m(2) (95% CI: -0.28 to -0.02). BMI z score decreased by -0.05 (SD 0.44) in the intervention group, but increased by 0.01 (SD 0.46) in the control group, with a mean difference of -0.07 (-0.13 to -0.01). After another year of follow up, compared to the control group, children in the intervention group had significantly lower BMI (-0.13, -0.25 to -0.01), BMI z score (-0.05, -0.10 to -0.01), fat mass (-0.27 kg, -0.53 to -0.02) and percent body fat (-0.53, -1.00 to -0.05). The intervention had a more pronounced effect on weight, height, BMI, BMI z score, and body composition among obese children than among normal weight or overweight children. Compared to the control group, the intervention group had a significantly higher percentage of children who maintained or reduced their BMI z score at year 1 (P=0.008) and year 2 (P=0.04).</p><p><b>CONCLUSIONS</b>These findings suggest that 20 min of daily moderate to vigorous physical activity during the school year is a feasible and effective way to prevent excessive gain of body weight, BMI, and body fatness in primary school students.</p>

[ effects of soy consumption on markers of oxidative stress in postmenopausal women with the metabolic syndrome]

Postmenopausal women with the metabolic syndrome are at a high risk of oxidative stress. Several studies have suggested possible antioxidant properties of soy, but little evidence is available regarding the effect of soy on oxidative stress in postmenopausal women with the metabolic syndrome. The aim of this study was to determine the effects of consumption of soy and soy protein on the plasma total antioxidant capacity [TAC] and malondialdehyde [MDA] levels in postmenopausal women with the metabolic syndrome. This randomized cross-over trial was conducted on 42 postmenopausal women with the metabolic syndrome as defined by ATP III. Participants were randomly assigned to consume a control diet, a soy-protein diet, or a roasted soy diet. Dietary Approaches to Stop Hypertension [DASH] was used in all three intervention periods. Red meat [1 serving/day] was substituted by soy protein or roasted soy in the respective diets. Each intervention period was 8 weeks and each wash-out period 4 weeks. Means of the variables were calculated by the repeated measures analysis of variance. There were significant differences among the control, soy-protein and roasted soy diets as regards the final MDA values [0.70, 0.64, and 0.63, micro mol/L, respectively; global P<0.01]. The final TAC values were also different among the 3 groups in the same order [1.95, 2.03, and 2.11 micro mol/ml, respectively; P<0.01]. As compared to the control values, the final TAC values for TAC increased by +4.5% on the roasted soy diet [p<0.01] and by +5.8% on the soy-protein regimen [p<0.01], while MDA levels decreased [7.9% in the roasted soy group; p<0.01, and 9.4% in the soy protein group; p<0.01]. Soy consumption reduced plasma MDA and increased plasma TAC levels in postmenopausal women with the metabolic syndrome