[Determination of six benzene homologues in human blood by purge and trap-gas chromatography-mass spectrometry].

Objective: To establish a purge and trap-gas chromatography-mass spectrometry method based on soil analysis model for the determination of six benzene homologues (benzene, toluene, ethylbenzene, m-xylene, p-xylene and o-xylene) in human blood. Methods: From September 2020 to May 2021, diatomite was used as a dispersant to add 2.0 ml blood sample and fully mixed. The sample was directly injected into the purging and collecting bottle after purging. The gas chromatography column was used for separation. The retention time locking was used for qualitative analysis and the selected ion scanning mode (SIM) was used for detection. The detection limit and recovery rate of the method were analyzed. Results: The linear range of the method for the determination of six benzene homologues in human blood was 0.02-10.00 ng/ml, the correlation coefficient was 0.9927-0.9968, the detection limit was 0.006-0.016 ng/ml, the recovery rate of sample spiking was 84.39%-102.41%, and the precision of the method was 3.06%-6.90%. Conclusion: Purge and trap-gas chromatography-mass spectrometry can simultaneously determine the contents of six benzene homologues in human blood. The pretreatment method is simple, time-saving, and the method has low detection limit, which provides a scientific basis for the detection of benzene homologues in human body.

[Determination of 6 BTEXs in urine by purge and trap with gas chromatography-mass spectrometry].

Objective: To establish a method for detection of 6 BTEXs in urine by Purge and Trap-Gas Chromatography-Mass Spectrometry. Methods: The urine sample need not be diluted, but directly purge and trap in the bottle, separated by gas chromatography column, then simultaneously analyzed by retention time locking (RTL) method and selective ion scanning mode (SIM) . Results: The linear range of 6 BTEXs in urine was good, the correlation coefficient was between 0.997 4 and 0.998 9. The minimum quantification limits was 0.010-0.036 µg/L. The precision was 1.9%-4.7%, and the recovery was 93.1%-101.9%. Conclusion: The method has the advantages of wide linear range, high sensitivity and recovery. It is suitable for the determination of 6 BTEXs in urine of low level occupational-exposed or non-exposed population.

[Effects of parity on nutrition and health status of Chinese women of childbearing age].

Objective: To analyze effects of parity on women's nutrition and health status. Methods: This study was based on the data bank of "Chinese Nutrition and Health Surveillance of Children and Adolescents Aged 0-17 years old and Lactating Mothers from 2016 to 2017". Using a multi-stage stratified random sampling method, 17 771 women at 0 to 24 months postpartum from 31 provinces in Mainland China were included in this study. Questionnaires were used to collect data on women's general demographic characteristics, parity, mode of delivery, pre-pregnancy weight, pre-delivery weight, diseases before and during pregnancy, postpartum hemorrhage. Current body height, body weight, waist circumference, and blood pressure were measured. Blood hemoglobin, blood glucose and blood lipids were detected. Pre-pregnancy BMI, gestational weight gain, postpartum weight retention, postpartum BMI, the rates of anemia, hypertension, diabetes, and dyslipidemia were calculated. Survey sample weights were calculated according to the sampling design and number of children under 2 years old from the sixth population census data of China. Effects of parity on the observational indicators after adjusting for confounding factors were analyzed by multivariate linear regression and multivariate logistic regression. Results: The age of 17 771 women was (29.5±5.0) years old, 12.2% (2 172) were over 35 but less than 40 years old, and 3.2% (563) were over 40 years old; the women with one parity, two parities, and three parities accounted for 47.3% (8 413), 48.5% (8 620) and 4.2% (738), respectively; urban women accounted for 49.9% (8 875), and rural women accounted for 50.1% (8 896). The results from multivariate linear regression showed that the pre-pregnancy BMI of women with two and three parities was 0.55 kg/m2 and 0.76 kg/m2 higher than women with one parity, respectively; the results of multivariate logistic regression showed that the OR(95%CI) of pre-pregnancy anemia was 1.45(1.04-2.02) for women with three parities compared with women with one parity, and the OR(95%CI) of anemia during pregnancy for women with two parities was 1.20(1.06-1.35) compared with women with one parity. Conclusion: Parity is associated with pre-pregnancy BMI and risk of anemia before and during pregnancy in women of reproductive age.

[A study on the correlation of phthalate metabolites in umbilical cord blood of 161 newborns with birth indicators in Beijing].

Objective: To analyze the correlation of phthalate metabolites in neonatal umbilical cord blood with birth indicators in Beijing, 2015. Method: From February to July in 2015, 161 pregnant women and their newborns who met the criteria were recruited from the Maternal and Child Health Hospital in Haidian District, Beijing. Questionnaires were used to collect the demographic information of pregnant women such as age, smoking, drinking, and cord blood after delivery. An ultra-high performance liquid chromatography-tandem mass spectrometry was used to determine the concentration of phthalate metabolites in umbilical cord blood. The multiple linear regression model was used to analyze the correlation of phthalate metabolites in umbilical cord blood with the neonatal weight, length, and ponderal index. Result: The age of 161 pregnant women was (30.3±3.0) years. The weight, length and ponderal index of 161 newborns were (3 447.2±413.0) kg, (50.2±1.1) cm, and (26.7±2.2) kg/m3; 51.6% of newborns (83 cases) were boys. The concentrations of seven phthalate metabolites detected in umbilical cord blood, i.e., mono-methyl phthalate (MMP), mono-ethyl phthalate (MEP),mono-(2-isobutyl) phthalate (MiBP), mono-n-butyl phthalate (MBP), mono-ethylhexyl phthalate (MEHP), mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), was (3.50±0.28), (2.65±0.47), (4.31±0.55), (6.26±0.57), (1.71±0.13), (1.10±0.09) and (0.47±0.06) ng/ml, respectively. The result of multiple linear regression model analysis showed that the concentrations of seven phthalate metabolites were not related to the neonatal weight, length, and ponderal index (all P values> 0.05). Conclusion: The concentrations of phthalate metabolites in neonatal umbilical cord blood are low, and they are not related to the neonatal weight, length, and ponderal index.

[Introduction to Guidelines for Salt Reduction in Chinese Food Industry].

Excessive salt intake is an important risk factor of diseases such as hypertension, stroke, and stomach cancer. China is one of countries with high salt intake in the world. Recently, the intake of sodium from pre-packaged foods in China has been increasing, and the situation of salt control is rigorous. Based on the summary of the domestic and international experience of salt reduction, the "Guidelines for Salt Reduction in Chinese Food Industry" presents the basic principles, targets at different stages within various categories, technical routes, steps and measures, and social environment co-construction of salt reduction in Chinese food industry. This article focuses on the background, basis, process, key content and promotion of the guideline. The implementation of this guideline will contribute to the vigorous advancement of salt reduction action in Chinese food industry.

[Analysis on maternal anemia rate and related factors in Taicang of Jiangsu Province in 2014-2016].

Objective: To investigate anemia rate and to analyze related factors in maternal women in Taicang of Jiangsu province. Methods: There were 13 278 pregnant women who had prenatal care and gave birth in 25 hospitals during 2014-2016 in Taicang of Jiangsu Province. We excluded 1 179 women who registered after 12 weeks of gestation, 144 women who did not test hemoglobin during gestation, and 25 women whose gestational weeks were incorrect. Finally, data from 11 930 pregnant women were analyzed. From the electronical medical record system of maternal and child health care, we obtained basic information of these pregnant women, their hemoglobin levels and related data during gestation and postpartum. Anemia rate was descripted, and factors associated with anemia were identified using multiple unconditional logistic regression. Results: Age of the 11 930 pregnant women was (27.0±4.5) years old, and the P(50) (P(25)-P(75)) of BMI at the first trimester was 21.4 (19.6-23.7) kg/m(2). The anemia rate during gestation was 37.2% (4 434/11 930). The anemia rate was 5.5% (276/5 035), 24.4% (1 802/7 377), and 47.8% (3 328/6 966) at the first, second and third trimesters, respectively. Anemia rate at 42 days postpartum was 19.9% (680/3 418). Multiple unconditional logistic regression indicated that anemia during gestation was related with maternal age <21 years old at prenatal registration (OR (95%CI): 1.28 (1.07-1.53)), body mass index(BMI) <18.5 kg/m(2) at the first trimester (OR (95%CI): 1.14 (1.00-1.29)), non-local residence (OR (95%CI): 1.35 (1.20-1.52)), education of middle school and lower (OR (95%CI): middle school: 1.24 (1.05-1.47), primary school: 1.36 (1.01-1.82)), occupation of housewife or farmer (OR (95%CI): housewife: 1.21 (1.06-1.38), farmer: 1.21 (1.03-1.44)). Anemia at 42 days postpartum was associated with multipara (OR(95%CI): 1.59 (1.12-2.27)), anemia at the first trimester (OR(95%CI): 3.26 (1.92-5.55)), no folic acid supplementation at the first trimester (OR(95%CI): 1.34 (1.00-1.80)), and hemorrhage≥500 ml during 24 h postpartum (OR(95%CI): 2.26 (1.02-4.97)). Conclusion: Anemia rate was low for maternal women in Taicang of Jiangsu Province. The factors associated with gestational anemia included pregnant women's age, BMI, local or non-local residence, occupation, and education. The factors associated with postpartum anemia included multipara, anemia at the first trimester, no folic acid supplementation at the first trimester, and hemorrhage 24 h postpartum.

[Status and related factors for gestational weight gain of Chinese pregnant women during 2010-2012].

Objective: To examine the status and related factors for gestational weight gain of Chinese pregnant women at different trimesters in 2010-2012. Methods: Participants were from Chinese National Nutrition and Health Surveillance in 2010-2012. Using a multi-stage stratified cluster random sampling method, we recruited 2 805 singleton pregnant women with gestational age 13 weeks or more from 31 provinces of China. A standard questionnaire was used to collect general information and pre-pregnancy weight; body weight and height of pregnant women were measured using a unified weighing scale and stadiometer, dietary intake during the previous year was collected using a food frequency questionnaire. A multiple logistic regression was used to analyze potential factors associated with appropriate gestational weight gain. Results: Among 2 805 pregnant women, 1 441 were in the second (13-27 weeks) and 1 364 in the third trimesters (≥28 weeks) . In the 2(nd) trimester, 229 cases (15.9%), 440 cases (30.5%) and 772 cases (53.6%) were insufficient gestational weight gain, appropriate gestational weight gain and excessive gestational weight gain respectively. So were 256 cases (18.8%), 474 cases (34.8%), 634 cases (46.5%) in the 3(rd) trimester respectively. In the multivariate unconditional logistic model, less fruit intake was associated with insufficient weight gain for women in the 2(nd) trimester (OR (95%CI): 1.58 (1.06-2.34)). Pregnant women with Han ethnicity who live in the small/medium city had lower risk of insufficient weight gain in the 3(rd) trimester (OR (95%CI): 0.58 (0.34-0.98)). Those pregnant women with physical activity <1 hour/day had a higher risk of excessive weight gain (OR (95%CI): 1.33 (1.02-1.73)). Conclusion: The prevalence of appropriate gestational weight gain was low in China. Our study suggests that pregnant weight gain is associated with fruit intake, types of residential area and physical activity.

[Gestational weight gain and optimal ranges in Chinese mothers giving singleton and full-term births in 2013].

Objective: To analyze the status of gestational weight gain (GWG) among Chinese mothers who gave singleton and full-term births, and to look at optimal GWG ranges. Methods: In 2013, using the multi-stage stratified and population proportional cluster sampling method, we investigated 8 323 mother-child pairs at their 0-24 months postpartum from 55 counties (cities/districts) of 30 provinces (except Tibet) in mainland China. Questionnaire was used to collect data on body weight before pregnancy and delivery, diseases during gestation, hemorrhage or not at postpartum, child birth weight and length, and other information about pregnant outcomes. We measured mother's body weight and height, and child's body weight and length. Based on 'Chinese Adult Body Weight Standard', we divided mothers into four groups according to their body weight before pregnancy: low weight (BMI<18.5 kg/m(2)), normal weight (BMI 18.5-23.9 kg/m(2)), overweight (BMI 24.0-27.9 kg/m(2)) and obesity (BMI≥28.0 kg/m(2)). The status of GWG was assessed by IOM optimal GWG guidelines. Chinese optimal GWG ranges were calculated according to the association of GWG with pregnant outcomes and anthropometry of mothers and children, and according to P25-P75 of GWG among mothers who had good pregnant outcomes and good anthropometry, and whose children had good anthropometry. The status of GWG was assessed by the new optimal ranges. Results: P50 (P25-P75) of GWG among the 8 323 mothers was 15.0 (10.0-19.0) kg. According to the proposed optimal GWG ranges of IOM, the proportions of inadequate, optimal and excessive GWG accounted for 27.2% (2 263 mothers), 36.2% (3 016 mothers) and 36.6% (3 044 mothers). The optimal GWG ranges for low weight, normal weight, overweight and obesity were 11.5-18.0, 10.0-15.0, 8.0-14.0 and 5.0-11.5 kg. Based on these optimal GWG ranges established in this study, the rates of inadequate, optimal and excessive GWG were 15.7% (1 303 mothers), 45.0% (3 744 mothers) and 39.3% (3 276 mothers), and these rates were significantly different from that defined by the IOM standards (χ2=345.36, P<0.001). Conclusion: The median of GWG among Chinese mothers is 15.0 kg, which is at a relatively higher level. This study suggests the optimal GWG ranges for Chinese women who give singleton and full-term babies, which appears lower than IOM's.

[Nutritional status and influence of vitamin D among Chinese lactating women in 2013].

Objective: To analyze serum vitamin D levels in Chinese lactating women, in 2013, and to evaluate their vitamin D nutritional status and influencing factors. Methods: Data were from the Chinese National Nutrition and Health Surveillance in 2013. Using the multistage stratified cluster sampling method, serum samples from lactating women, at 0-24 months postpartum, were obtained from 55 sites in 30 provinces of China, excluding the Tibet Autonomous Region. The concentration of serum vitamin D was determined by mass spectroscopy. A standard questionnaire was used to obtain basic information and the season of blood collection. Dietary information for one recent month was collected using a food frequency questionnaire. A total of 1 981 lactating women were included in the study. A multiple logistic regression model was used to analyze the factors related to vitamin D levels among lactating women. Results: The mean vitamin D level was (16.6±6.5) ng/ml, the prevalence of vitamin D deficiency (VDD) (vitamin D<12 ng/ml) was 25.2% (499 cases) and the prevalence of vitamin D inadequacy (12 ng/ml≤vitamin D<20 ng/ml) was 45.4% (900 cases). Compared with in the Han ethnic group, the OR value of VDD was 13.37 for Muslim ethnic women. Compared with women having a junior high school education or below, the OR value of VDD was 1.40 for those women with an educational level of senior high, middle school or above. Compared with housewives or nonworking women, the OR value of VDD was 1.62 for professional women. Compared with women living in general rural settings, the OR values of VDD for women living in large cities, medium and small cities or poor rural settings were 1.99, 1.46 and 2.66 respectively. Compared with the women surveyed in the fall, the OR value of VDD was 2.19 for the women surveyed in winter or spring. The VDD prevalence increased with higher latitude (OR=1.12) and decreased with increased meat consumption per day (OR= 0.73). (P<0.05 for all comparisons). Conclusion: Vitamin D deficiency and vitamin D inadequacy were common in lactating women in China. Those with increased risk of VDD included lactating women who were ethnic Muslims, with higher education levels, engaged in a professional occupation, living in higher latitude region and were surveyed in winter and spring.

[The status of postpartum weight retention and its associated factors among Chinese lactating women in 2013].

Objective: To analyze the status of postpartum weight retention and its associated factors among Chinese lactating women in 2013. Methods: This study was based on the databank of Chinese National Nutrition and Health Surveillance in 2013. Using the multi-stage stratified cluster sampling method, we enrolled 12 514 women, at 0-24 months postpartum, from 55 sites in 30 provinces of China (excluding the Tibet Autonomous Region). Questionnaires were used to collect data on basic characteristics, physical activity, lifestyle, food intake, pre-pregnancy weight, weight before delivery, disease history during pregnancy, delivery date, delivery mode, parity and breastfeeding information. Current body weight and height of each subject were measured. Postpartum weight retention in each subject was calculated as the difference between pre-pregnancy and current weights. High postpartum weight retention was defined as ≥5 kg. Survey sample weights were calculated according to the sampling design and number of children under 2 years old from 2010 population census data of China. Associated factors of high postpartum weight retention were identified by multiple logistic regression analysis. Results: A total of 9 972 women were included in this study. P50 (P25-P75) of weight retention for participants was 3.6 (0.2-7.3) kg and high weight retention accounted for 41.5% of the subjects (4 134/9 972). The weighted means (SE) of weight retention was 3.5 (0.1) kg, and it was at 0 to <3, 3 to <6, 6 to <9, 9 to <12, 12 to <18 and 18 to <24 months postpartum were 5.3 (0.2), 4.5 (0.2), 3.8 (0.2), 3.1 (0.2), 2.8 (0.2) and 3.0 (0.2) kg, respectively. The weighted proportion of high postpartum weight retention was 37.4% (95%CI: 36.0%-38.9%). Compared with women aged under 25 years old, the odds ratio of high postpartum weight retention was 1.31 for women over 30 years old. Compared with women at 18 to <24 months postpartum, the odds ratio of high postpartum weight retention was 2.67, 1.61 and 1.31 for women at 0 to <3, 3 to <6 and 6 to <9 months postpartum, respectively. Compared with women having a pre-pregnant BMI from 18.5 to <25.0 kg/m2, the odds ratio of high postpartum weight retention was 1.30 and 0.67 for women having pre-pregnant BMI <18.5 kg/m2 and ≥25.0 kg/m2, respectively. Compared with women having appropriate gestational weight gain, the odds ratio of high postpartum weight retention was 0.47 and 2.24 for women having low and excessive gestational weight gains, respectively. Compared with farmers, the odds ratio of high postpartum weight retention was 1.44 for housewives. (P<0.05 for all comparisons). Conclusion: Postpartum weight retention in Chinese lactating women is at an intermediate level. High postpartum weight retention is primarily associated with age, postpartum period, pre-pregnant BMI, gestational weight gain and career. The key control factor for weight retention is gestational weight gain, and 1 year postpartum is critical period for weight recovery.

Liver involvement in epidemic haemorrhagic fever: in situ hybridization, immunohistochemical and pathological studies.

In the present study, liver biopsy specimens from 37 patients with epidemic haemorrhagic fever (EHF) were investigated by using light and electron microscopy, immunohistochemistry for the EHF virus envelope protein G2 and in situ hybridization (ISH) for EHF viral RNA. Immunostaining and in situ hybridization were both positive, and a few of the aetiological agents, the EHF virus (EHFV) particles, were found individually within the dilated Golgi cisternae and vesicles, and the dilated rough endoplasmic reticulum of the hepatocyte. The pathological alterations of the liver cells infected with EHFV were: hepatocellular degeneration, cytoplasmic vacuolation, and spotty necrosis; moreover, zonal necrosis was present and adjacent to the narrowed and occluded sinusoids. In degenerated and spotty necrotic cells, the positive signals from of ISH for EHFV RNA and those from immunostaining for the virus protein were both stronger than those in the zonal liver cell necrosis area. The results showed that hepatocellular degeneration and spotty necrosis might be directly related to the virus and its duplication inside the liver cells, while the zonal necrosis was ischaemic and thought to be caused by microcirculation dysfunction.