Secular trends of age at menarche and age at menopause in women born since 1951 from a county of Shandong Province, China / 北京大学学报(医学版)

OBJECTIVE@#To describe the secular trends of age at menarche and age at natural menopause of women from a county of Shandong Province.@*METHODS@#Based on the data of the Premarital Medical Examination and the Cervical Cancer and Breast Cancer Screening of the county, the secular trends of age at menarche in women born in 1951 to 1998 and age at menopause in women born in 1951 to 1975 were studied. Joinpoint regression was used to identify potential inflection points regarding the trend of age at menarche. Average hazard ratios (AHR) of early menopause among women born in different generations were estimated by performing multivariate weighted Cox regression.@*RESULTS@#The average age at menarche was (16.43±1.89) years for women born in 1951 and (13.99±1.22) years for women born in 1998. The average age at menarche was lower for urban women than that for rural women, and the higher the education level, the lower the average age at menarche. Joinpoint regression analysis identified three inflection points: 1959, 1973 and 1993. The average age at menarche decreased annually by 0.03 (P < 0.001), 0.08 (P < 0.001), and 0.03 (P < 0.001) years respectively for women born during 1951-1959, 1960-1973, and 1974-1993, while it remained stable for those born during 1994-1998 (P=0.968). As for age at menopause, compared with women born during 1951-1960, those born during 1961-1965, 1966-1970 and 1971-1975 showed a gradual decrease in the risk of early menopause and a tendency to delay the age at menopause. The stratified analysis presented that the risk of early menopause gradually decreased and the age of menopause showed a significant delay among those with education level of junior high school and below, but this trend was not obvious among those with education level of senior high school and above, where the risk of early menopause decreased and then increased among those with education level of college and above, and the corresponding AHRs were 0.90 (0.66-1.22), 1.07 (0.79-1.44) and 1.14 (0.79-1.66).@*CONCLUSION@#The age at menarche for women born since 1951 gradually declined until 1994 and leveled off, with a decrease of nearly 2.5 years in these years. The age at menopause for women born between 1951 and 1975 was generally delayed over time, but the trend of first increase and then decrease was observed among those with relatively higher education levels. In the context of the increasing delay in age at marriage and childbearing and the decline of fertility, this study highlights the necessity of the assessment and monitoring of women' s basic reproductive health status, especially the risk of early menopause.

Effects of gestational weight on the association between serum high sensitivity C reaction protein and gestational diabetes mellitus among twin gestations: A cohort study / 北京大学学报(医学版)

OBJECTIVE@#To investigate the association between serum high sensitivity C-reaction protein (hsCRP) in early pregnancy and gestational diabetes mellitus (GDM) among twin pregnant women, and to explore the effects of the pre-pregnant body mass index (BMI) and gestational weight gain (GWG) status on such association.@*METHODS@#Twin pregnant women with pre-pregnant BMI greater than or equal to 18.5 kg/m2 were recruited at Department of Obstetrics and Gynecology of Peking University Third Hospital from March 2017 to December 2020. Serum samples collected in early pregnancy were analyzed for hsCRP using particle-enhanced immunoturbidimetric method. In the following visits, the information about GWG and GDM were prospectively collected in every trimester. The association effect between hsCRP tertiles and GDM were estimated using Logistic regression, and further converted into risk ratio (RR). Cochran-Mantel-Haenszel test and mediation analysis were used to explore the effects of BMI and GWG status on the association.@*RESULTS@#Among the included 570 twin pregnant women, 31.6% deve-loped GDM, 26.1% were pre-pregnant overweight or obesity, and 49.5% with GWG out of referenced range. After adjustment for confounding factors, risk of developing GDM in twin gestations with the middle tertile and highest tertile of serum hsCRP in early pregnancy were 1.42 fold (95%CI: 1.02-1.89) and 1.54 fold (95%CI: 1.12-2.02), respectively, compared with the lowest tertile of serum hsCRP, and there existed significantly linear trend (P=0.022). Findings from mediation analysis illustrated that pre-pregnant BMI had partial mediating effect on the association, and BMI accounted for 23.84% (P < 0.001) of the increasing GDM risks with elevated hsCRP. Joint analysis with hsCRP and GWG found that those who were with GWG out of referenced range accompanied with the higher hsCRP tertiles (>1.21 mg/L) had significantly 2.31 fold increased risk according to those who were with GWG in the referenced range accompanied with the lowest hsCRP tertile (≤1.21 mg/L, P < 0.01).@*CONCLUSION@#Elevated hsCRP in early pregnancy significantly increased GDM risk among twin pregnant women. The hsCRP-GDM association was dependent on GWG status, and pre-pregnant BMI had partial mediating effect on such association. It is suggested that twin pregnant women should consider systemic inflammation and gestational weight at the same time to reduce GDM risk.

Case-control study on the treatment of single-segment lumbar spinal stenosis with modified interlaminar approach and traditional approach / 中国骨伤

OBJECTIVE@#To explore the clinical effect of modified interlaminar approach for the treatment of single-segment lumbar spinal stenosis.@*METHODS@#From February 2015 to August 2017, 80 patients with single-segment lumbar spinal stenosis planned to undergo endoscopic surgery were selected, including 38 males and 42 females;aged 33 to 69 (47.6±9.5) years old. Using random number table method, the patients were divided into study group and traditional group, 40 cases in each group, and underwent surgical treatment through modified translaminar approach and traditional approach respectively. The operation time, intraoperative blood loss, and hospital stay were recorded;visual analogue scale (VAS) and Oswestry Disability Index (ODI) before and after operation were compared between two groups;spinal canal arca, spinal canal diameter, disc yellow space and surgical complications were observed.@*RESULTS@#All 80 patients were followed up for at least 3 months. Two patients had incision infection, both of them were in traditional group;there was no significant difference in operation time between two groups(@*CONCLUSION@#Compared with the traditional approach, the modified interlaminar approach has advantages of less trauma, faster recovery and better postoperative spinal space recovery in the treatment of single-segment lumbar spinal stenosis.

Bioaccessibility Measurement and Safety Evaluation of Elements in Decoction of Zhebawei Traditional Chinese Medicines / 中国药学杂志

OBJECTIVE: To study the bioaccessibility and evaluate the safety of inorganic elements in decoction of "Zhebawei" traditional Chinese medicines (TCMs). METHODSE: The bioaccessibility of inorganic elements in decoction of "Zhebawei" TCMs was measured based on in vitro digestion and inductively coupled plasma atomic emission spectrometer (ICP-AES) and the safety of these elements were evaluated by comparing with the safe limits issued by the FAO and WHO. RESULTS: The bioaccessibility of the inorganic elements was less than 1, and varied among different elements of the same herbal medicine or for the same element among different herbal medicines. Cd, V, Se, Cr, Sn, and As were not detected in the dialysate of some TCMs' decoction after in vitro digestion because of the total content being low or undetected in decoction. The result of safety evaluation showed that the daily intakes of Ni, Fe, Mn, Se, Cu, Zn, Co, V, Cr from the decoction of "Zhebawei" TCMs were all within safe limits. The daily intakes of Cd and Sn did not exceed the level of personal acceptable daily intake instituted by the FAO and WHO. The total content in the decoction of Rhizoma Corydalis was more than the level of personal acceptable daily intake instituted by FAO and WHO, however the amount in the dislysate of "Zhebawei" TCMs' decoction after in vitro digestion were under the standard. The analysis of total content may exaggerate the risk of toxicity. CONCLUSION: The results will provide the basis for further researches such as bioavailability and safety of inorganic elements in "Zhebawei" TCMs, and will provide references for ensuring the rational use of TCM according to the analysis of inorganic elements.

Relationship of plasma vitamin A levels between neonates and pregnant women in third trimester / 北京大学学报(医学版)

OBJECTIVE@#To study the correlation of plasma vitamin A (VitA) levels between neonates and pregnant women in third trimester.@*METHODS@#A total of 688 pregnant women were recruited in Yuanshi and Laoting counties of Hebei Province, from May to June 2009. Venous blood samples of women before delivery and cord blood samples of newborns were collected and measured for retinol (retinol concentration was used to reflect VitA level) using high performance liquid chromatography assay. According to venous blood plasma retinol concentration, maternal VitA nutritional status was divided into deficiency (<0.70 μmol/L), marginal deficiency (0.70-<1.05 μmol/L), and sufficiency (≥1.05 μmol/L). According to cord blood plasma retinol concentration, neonatal VitA nutritional status was divided into deficiency (<0.35 μmol/L), marginal deficiency (0.35-<0.70 μmol/L), and sufficiency (≥0.70 μmol/L); neonatal VitA relative deficiency was further defined as cord blood plasma retinol concentration lower than the 10th percentile. VitA placental transport ratio was defined as retinol concentration in the neonates divided by that in pregnant women. Multivariable fractional polynomials (MFP) model and Pearson correlation were used to study the dose-response relationship between maternal and neonatal plasma VitA levels, Logistic regression model to estimate the effect of maternal VitA nutritional status on neonatal VitA deficiency, and MFP model and Spearman correlation to describe the relationship between maternal VitA level and VitA placental transport ratio.@*RESULTS@#The average retinol concentration of the pregnant women was (1.15±0.30) μmol/L, and the prevalence of VitA deficiency and marginal deficiency were 4.5% and 37.8%, respectively. Average retinol concentration of the neonates was (0.78±0.13) μmol/L, and no neonates were VitA deficiency, 28.2% of the neonates were marginal deficiency. After multivariable adjustment, the VitA level of the neonates was positively and linearly related to maternal VitA level (pm=1, P<0.05), with the corresponding Pearson correlation coefficient of 0.13 (P<0.01). As compared with the women with sufficient VitA, those with VitA deficiency (crude OR=2.20, 95%CI:1.04-4.66) and marginal deficiency (crude OR=1.43, 95%CI:1.01-2.02) had higher risks to deliver neonates with VitA marginal deficiency; while the risks turned to be non-significant after multivariable adjustment. The pregnant women with VitA deficiency had higher risk to deliver neonates with relative VitA deficiency before and after multivariable adjustment (crude OR=3.02, 95%CI:1.21-7.50; adjusted OR=2.76, 95%CI:1.05-7.22). The maternal VitA level was negatively and non-linearly correlated with placental transport ratio (pm= -0.5, P<0.05), with corresponding adjusted Spearman correlation coefficient of -0.82 (P<0.001).@*CONCLUSION@#There was a positive linear dose-response relationship between VitA levels of newborns and pregnant women in third trimester, indicating that neonatal VitA storing levels at birth was affected by maternal VitA nutritional status.

Mobile terminal-based survey on the birth characteristics for Chinese newborns / 北京大学学报(医学版)

OBJECTIVE@#To describe the birth characteristics for Chinese newborns, to assess the feasibility of collecting basic data on maternal and child health, and to conduct relevant epidemiological studies by using mobile terminals.@*METHODS@#From June 2016 to January 2017, pregnant women who delivered in hospitals were recruited in 166 hospitals scattered across 23 provinces of China. The data on their maternal and child health including delivery mode, gestational age and birth weight, were collected by self-administered questionnaires embedded in a mobile application. The incidences or means of cesarean section, preterm birth, birth weight, length and head circumference were calculated and compared with recognized national data, including 2005 Growth Standards for Chinese Children Under 7 Years of Age, 2006 World Health Organization Child Growth Standards and 2014 Chinese Neonatal Birth Weight Standards by Gestational Age.@*RESULTS@#A total of 9 986 women were investigated, among whom those aged ≥35 years accounted for 11.7% and those received well education (college and above) accounted for 70.2%. The rate of cesarean section, preterm delivery, low birth weight and macrosomia were 38.1%, 4.5%, 2.2%, and 7.8%, respectively. The means were (3.33±0.44) kg [male (3.36±0.44) kg, female (3.29±0.43) kg] for birth weight, (50.97±2.32) cm [male (51.04±2.32) cm, female (50.89±2.32) cm] for birth length, and (33.99±1.56) cm [male (34.01±1.57) cm, female (33.97±1.55) cm] for head circumference, respectively. As compared with the national data, the cesarean section rate and birth weights by gestational age for term-born neonates were similar to the latest national data in 2014, while the means of birth weight and length were obviously higher than those of the 2005 Growth Standards for Chinese Children Under 7 Years of Age and 2006 World Health Organization Child Growth Standards.@*CONCLUSION@#As compared with the national data 10 years ago, the mean birth weights for male and female newborns were increased by 40 g and 80 g respectively and mean lengths by 0.6 cm and 1.3 cm, but changes for mean head circumferences were negligible, indicating that the physical health condition for Chinese newborns improved significantly over past 10 years and emerging information technology likely provided a new approach for epidemiological research.

N-acetyl-L-cysteine reduces the ozone-induced lung inflammation response in mice / 生理学报

In this study, we investigated the protective effect of the antioxidant N-acetyl-L-cysteine (NAC) on the lung inflammation caused by ozone (O) exposure in mice. Thirty-two C57BL/6 mice were randomly divided into control group, Ogroup, O+NAC group and NAC group. Mice were exposed to O(1.0 ppm) or fresh air for 3 h on the day 1, day 3 and day 5, respectively. NAC (100 mg/kg) was intraperitoneally applied to the mice 1 h before each exposure. At 24 h after the 3-time exposure, the alveolar wall structure was severely damaged and the infiltrated inflammatory cells were apparent perivascularly and peribronchiolarly. Significant increases in the total white blood cell count, macrophage, lymphocyte and neutrophil counts, as well as total protein concentration were observed in the bronchoalveolar lavage fluid (BALF) (P < 0.05). The IL-6, IL-8 (P < 0.01) and MDA levels (P < 0.05) in the lung homogenates were elevated coherently. Administration of NAC could attenuate the alveolar wall structure damage induced by Oexposure and reduce the amount of infiltrated inflammatory cells, total and differential leukocyte counts (P < 0.05), as well as the IL-6, IL-8 (P < 0.01) and MDA release (P < 0.05). Western blotting results showed that the Oexposure up-regulated the p38 MAPK and NF-κB p65 protein expression in the lung tissue of mice (P < 0.05), which could be alleviated by NAC (P < 0.05). These results indicated that NAC could protect against O-induced pulmonary inflammation in mice. The beneficial effect of NAC might be related with the p38 MAPK and NF-κB p65 signal pathway.