Effects of school myopia management measures on myopia onset and progression among Chinese primary school students.

BACKGROUND: Schools play an organizational role in managing myopia-related behavioral habits among students. We evaluated the effects of school myopia management measures on myopia onset and progression in a school-based prospective 1-year observational study. METHODS: In total, 8319 children from 26 elementary schools were included. Online questionnaire completed by a parent, in which school myopia management experience including outdoor activities in recess or physical education class, teachers' supervision, and teaching facilities. Variables were defined as implemented well or poorly, according to the Comprehensive Plan to Prevent Myopia among Children and Teenagers. Children underwent ophthalmic examinations, and the incidence and progression of myopia from 2019 to 2020 were estimated. Multilevel logistic regression models were constructed to analyze the association between school management measures and myopia development in 8,9 years and 10,11 years students. RESULTS: From 2019 to 2020, the incidence of myopia among primary school students was 36.49%; the mean difference of spherical equivalent in myopic children was - 0.29 ± 1.22 diopters. The risk of incident myopia was reduced by 20% in 8,9 years participants with well-implemented class recess compared with those with poorly implemented class recess (adjusted odds ratio [aOR]: 0.80, p = 0.032). PE outdoor time was significantly associated with myopia incidence in 10,11 years students (aOR: 0.76, p = 0.043). Compared with poorly implemented reading and writing posture, desk and chair height, 10,11 participants with well-implemented desk and chair height were less likely to have rapid myopic progression (p = 0.029, p = 0.022). CONCLUSION: In Shanghai, children's myopia is associated with better implementation of school myopia management measures. The present findings suggest that outdoor activities during class recess or PE class, providing suitable desks and chairs, and adequate instruction in reading and writing postures might protect against pathological eye growth. An age-specific myopia prevention and control programs in school is of primary importance.

Maternal affective and stress-related factors during pregnancy affect the occurrence of childhood allergic diseases: A Shanghai MCPC study.

OBJECTIVE: To investigate the association between exposures to maternal affective and stress-related factors during pregnancy and allergies in children from birth to 2 years of age. METHODS: We enrolled a total of 4178 children from the Shanghai Maternal-Child Pairs Cohort and measured maternal stress, anxiety, and depression during pregnancy by applying the Life Events Scale for Pregnant Women, Self-Rating Anxiety Scale, and the Center for Epidemiologic Studies-Depression Scale, respectively. Children's allergies were assessed by community physicians at 2, 6, 12, and 24 months, respectively; these included eczema, atopic dermatitis, food allergy, wheezing, asthma, and atopic rhinitis. We applied a latent class analysis (LCA) to these factors and analyzed the impacts of maternal affective and stress-related factors on childhood allergies by exploiting multivariate logistic regression. RESULTS: Three distinct classes of children were revealed by LCA: healthy (79.8%), transient allergy (15.2%), and persistent allergy (4.9%). High maternal stress in both early and late pregnancy was associated with an increased risk of infant eczema at 2 months (aOR = 1.30, 95% CI = 1.01-1.67; aOR = 1.64, 95% CI = 1.14-2.36). Moreover, high maternal stress in late pregnancy was also associated with food allergy at 6 months, rhinitis at 2 years of age, and persistent allergy (aOR = 3.22, 95% CI = 1.27-8.12; aOR = 1.78, 95% CI = 1.01-3.15; and aOR = 1.93, 95% CI = 1.10-3.40). CONCLUSIONS: The associations of maternal affective and stress-related factors during pregnancy with childhood allergies may vary by type and disease onset. We postulate that maternal stress in late pregnancy may exert a sustained negative effect on early childhood allergic diseases.

Longitudinal Associations Between Maternal Glucose Levels and Ultrasonographic Fetal Biometrics in a Shanghai Cohort.

Importance: Evidence on the timing of fetal growth alterations associated with gestational diabetes or on the association of the maternal glycemic trajectory with fetal growth during pregnancy remains lacking. Objective: To examine the associations between maternal glucose levels and offspring intrauterine growth. Design, Setting, and Participants: This cohort study used data from 4574 eligible pregnant women and their offspring in the Shanghai Maternal-Child Pairs Cohort collected from April 10, 2016, to April 30, 2018. Group-based trajectory modeling was used to classify fasting plasma glucose levels during pregnancy into 3 glycemic trajectories (trajectory 1, consistently normal glucose levels in all 3 trimesters; trajectory 2, hyperglycemia only in late pregnancy; and trajectory 3, hyperglycemia in all 3 trimesters [ie, consistently high glucose levels]). Statistical analysis was performed from April 25, 2020, to October 1, 2021. Exposures: Gestational diabetes, which was defined using the results of an oral glucose tolerance test. Main Outcomes and Measures: Longitudinal fetal biometrics during gestational weeks 11 to 40 and birth outcomes were obtained from medical records. Pregnancy was partitioned into 3 periods (<24, 24-34, and >34 weeks' gestational age). The differences in offspring growth (log-transformed) and maternal glucose levels were compared using generalized linear mixed models. Results: A total of 4121 pregnant women had oral glucose tolerance test results (mean [SD] age, 28.8 [4.1] years), 3746 of whom had glycemic trajectory data (mean [SD] age, 28.6 [4.1] years); 983 women (23.8%) had gestational diabetes. Throughout the pregnancy period and compared with the women without gestational diabetes or with women in the trajectory 1 group, the fetal biometrics for the women with gestational diabetes or for those in the trajectory 3 group were significantly higher (except for biparietal diameter), with an estimated increase in fetal weight in the group with gestational diabetes (ß = 1.82; 95% CI, 1.03-2.61) and in the trajectory 3 group (ß = 1.50; 95% CI, 0.54-2.47; P = .002). Fetal biometric alterations among women with gestational diabetes appeared before 24 weeks' gestational age, with neonatal birth weight significantly higher than in the group without gestational diabetes at 40.4 g (95% CI, 9.8-71.1 g) along with an increased risk of large size for gestational age (odds ratio, 1.36; 95% CI, 1.05-1.75) and macrosomia (odds ratio, 1.47; 95% CI, 1.12-1.94). However, pregnant women in the trajectory 2 group manifested significantly reduced fetal biometrics, and abdominal circumference was significantly augmented after 34 weeks' gestational age (increase, ß = 1.92; 95% CI, 0.87-2.99). Conclusions and Relevance: In this cohort study, pregnant women who received a diagnosis of gestational diabetes in midpregnancy or had hyperglycemia during all 3 trimesters showed an association with altered fetal growth patterns, including increased estimated fetal weight that appeared before 24 weeks' gestational age, increased birth weight, and the risk for large size for gestational age and macrosomia.

Longitudinal association between the timing of adiposity peak and rebound and overweight at seven years of age.

BACKGROUND: The timing of adiposity peak (AP) or adiposity rebound (AR) is a determinant of overweight or obesity in adolescence and adulthood. However, limited studies have reported the association in young school-age children. We aimed to evaluate this association and explore the role of health behaviours in it. METHODS: Routinely collected, sequential, anthropometric data from the 1st to 80th months of age were used to estimate AP and AR timings in 2330 children born in Shanghai between 2010 and 2013. Multivariate regression analyses were applied to identify the associations between the AP or AR timings and the risk of developing overweight or obesity in first-grade school children. The roles of health behaviours, including dietary patterns, physical activity level, sleep and snacking habits, and screen time, were also evaluated. RESULTS: Children with a late AP or an early AR were at higher risk of overweight but not obesity or central obesity in their first grade. A high physical activity level was associated with a lower risk of having overweight in children with a late AP, and limited screen time was associated with a decreased risk of having overweight or obesity in children with an early AR. The absence of a late-night snacking habit in children with a non-early AR indicated a decreased risk of having overweight. However, this association was not observed among children with an early AR. CONCLUSION: The timings of AP and AR are tied to overweight in middle childhood. Prevention strategies are suggested to move forward to control late AP and early AR.

A Longitudinal Study of the Effects of Bed-Sharing Experience in Infancy on Sleep Outcomes at 2 Years Old.

OBJECTIVE: To assess the effects of bed-sharing experiences in infancy on sleep patterns and sleep problems at 2 years of age. STUDY DESIGN: A total of 1564 children from an ongoing Shanghai Maternal-Child Pairs Cohort were included. Bed-sharing experiences were collected when children were 2, 6, and 24 months old via caregiver-completed questionnaires (whether caregivers shared a bed with children during the night), and children's bed-sharing experiences were classified as follows: no bed-sharing, early-only bed-sharing, late-onset bed-sharing, and persistent bed-sharing. Sleep outcomes at month 24 were assessed using the Brief Infant Sleep Questionnaire. Sleep patterns and problems were compared among the 4 types of bed-sharing experiences. RESULTS: Of the 1564 infants, 10.10% had no bed-sharing, 18.35% had early-only, 27.94% had late-onset, and 43.61% had persistent bed-sharing. Compared with children with no bed-sharing, children with late-onset and persistent bed-sharing had shorter nighttime sleep durations and longer daytime sleep durations (P < .05) and were more likely to snore (aOR 1.87 [95% CI 1.25-2.79]; aOR 1.68 [95% CI 1.14-2.47]) and have sleep onset difficulty (aOR 2.06 [95% CI 1.37-3.09]; aOR 2.07 [95% CI 1.41-3.05]). However, caregivers of infants in the late-onset and persistent bed-sharing groups perceived less problematic sleep (aOR 0.38 [95% CI 0.26-0.56] and aOR 0.40 [95% CI 0.28-0.58]). CONCLUSIONS: Bed-sharing is a common experience among Chinese children. Although bed-sharing may reduce caregivers' perception of children's problematic sleep, late-onset or persistent bed-sharing in infancy is associated with sleep problems at 2 years of age.

Ideal physical activity in association with incident ankylosing spondylitis: a community-based, prospective cohort study.

OBJECTIVES: Only limited risk factors for ankylosing spondylitis (AS) have been identified to date. Therefore, we aimed to explore whether cardiovascular health (CVH) behaviours and factors are associated with the risk of developing AS. METHODS: Patients with incident AS were identified in cohorts from two ongoing prospective studies. Assessments were made of the association of AS with individual baseline cardiovascular health lifestyle behaviours (including smoking status, body mass index, physical activity and diet) and cardiovascular health factors (including total cholesterol levels, blood pressure levels and fasting plasma glucose levels), and with a cardiovascular health metric determined by the number of ideal behaviours and factors. Cox regression analysis was used for the estimation of hazard ratios (HRs) for AS. RESULTS: Among 124,303 participants, incident AS was identified in 53 individuals within the 8 years of follow-up. For participants with ideal physical activity (>80 min/week) the HR was 0.21 (95% CI 0.05-0.89) compared with participants without ideal physical activity after adjusting for potential confounders. No signi cant risk of developing AS was associated with baseline smoking, diet, body mass index, blood pressure, fasting blood glucose or total cholesterol status, nor did cardiovascular health metrics. CONCLUSIONS: Adherence to ideal physical activity may reduce the risk of developing AS.

Association of serum uric acid and risk of hypertension in adults: a prospective study of Kailuan Corporation cohort.

Whether hyperuricemia is an independent risk factor for hypertension in adults is still under debate. To determine the association between serum uric acid and risk of hypertension in the Chinese population, we conducted a prospective study using the "Kailuan Corporation cohort." A total of 39,233 adult subjects with available data on serum uric acid were enrolled from 2006 to 2007. Subjects with established hypertension were excluded and were then grouped based on the gender and baseline quartile serum uric acid into F1-4 for women and M1-4 for men with F1 and M1 being the lowest quartiles. Incidence of newly described primary hypertension was reevaluated in 2010-2011. The median (interquantile range) baseline uric acid (UA) was 290 (243-344) µmol/L in men and 230 (194-274) µmol/L in women. During a 4-year follow-up period, 12,844 subjects (31.31 %) were newly diagnosed with hypertension. The incidence of hypertension was 14.36, 16.57, 19.06, and 22.35 % in F1 to F4 and 33.64, 33.97, 36.54, and 40.74 % in M1 to M4, respectively. Multiple logistic regression analysis showed that the odds ratios (ORs) of incident hypertension were 1.17 [95 % confidence interval (CI) 1.00-1.37, P = 0.055], 1.24 (95 % CI 1.06-1.45, P = 0.009), and 1.20 (95 % CI 1.02-1.41, P = 0.027) in F2 to F4 compared to the F1 and 0.98 (95 % CI 0.91-1.05, P = 0.534), 1.05 (95 % CI 0.98-1.13, P = 0.190), and 1.13 (95 % CI 1.05-1.22, P = 0.002) in M2 to M4 compared to the M1. Elevated level of serum uric acid is associated with an increased risk of hypertension in adults.

Mediating effect of anxiety and depression on the relationship between Attention-deficit/hyperactivity disorder symptoms and smoking/drinking.

Attention-deficit/hyperactivity disorder (ADHD) has been often found to be comorbid with other disorders, including anxiety, depression, and unhealthy behaviors such as drinking alcohol and smoking. These factors were often discussed separately, and the mediating effects of mental health on substance use are unknown. To study the mediating effects of anxiety and depression on the relationship between ADHD and drinking/smoking behaviors, we conducted a cross-sectional study of 1870 college students from Shanghai, China. The Adult ADHD Self-Report Scale (ASRS-v1.1) and Wender Utah Rating Scale (WURS) were used to identify the current and past ADHD. Structural Equation Modeling was carried out to clarify the mediating effect of anxiety and depression on the relationship between core ADHD symptoms and smoking/drinking behaviors. We found that inattention as one of the core symptoms of ADHD was associated with an increased risk of depression as a direct effect, as well as slightly increased risk of smoking/drinking behaviors by an indirect effect of depression. Hyperactivity-impulsivity, as another core symptom of ADHD had a robust impact on smoking and drinking behaviors, while being mediated by anxiety and depression. In conclusion, anxiety and depression was associated with further increased risk behaviors of smoking/drinking alcohol among those students with ADHD.

SUMOylation of KLF4 acts as a switch in transcriptional programs that control VSMC proliferation.

The regulation of vascular smooth muscle cell (VSMC) proliferation is an important issue due to its major implications for the prevention of pathological vascular conditions. The objective of this work was to assess the function of small ubiquitin-like modifier (SUMO)ylated Krϋppel-like transcription factor 4 (KLF4) in the regulation of VSMC proliferation in cultured cells and in animal models with balloon injury. We found that under basal conditions, binding of non-SUMOylated KLF4 to p300 activated p21 (p21(WAF1/CIP1))transcription, leading to VSMC growth arrest. PDGF-BB promoted the interaction between Ubc9 and KLF4 and the SUMOylation of KLF4, which in turn recruited transcriptional corepressors to the p21 promoter. The reduction in p21 enhanced VSMC proliferation. Additionally, the SUMOylated KLF4 did not affect the expression of KLF4, thereby forming a positive feedback loop enhancing cell proliferation. These results demonstrated that SUMOylated KLF4 plays an important role in cell proliferation by reversing the transactivation action of KLF4 on p21 induced with PDGF-BB.

miR-200c-SUMOylated KLF4 feedback loop acts as a switch in transcriptional programs that control VSMC proliferation.

The regulation of vascular smooth muscle cell (VSMC) proliferation is an important issue because it has major implications for the prevention of pathological vascular conditions. Using microRNA array screen, we found the expression levels of 200 unique miRNAs in hyperplasic tissues. Among them, miR-200c expression substantially was down-regulated. The objective of this work was to assess the function of miR-200c and SUMOylated Krϋppel-like transcription factor 4 (KLF4) in the regulation of VSMC proliferation in both cultured cells and animal models of balloon injury. Under basal conditions, we found that miR-200c inhibited the expression of KLF4 and the SUMO-conjugating enzyme Ubc9. Upon PDGF-BB treatment, Ubc9 interacted with and promoted the SUMOylation of KLF4, which allowed the recruitment of transcriptional corepressors (e.g., nuclear receptor corepressor (NCoR) and HDAC2) to the miR-200c promoter. The reduction in miR-200c levels led to increased target gene expression (e.g., Ubc9 and KLF4), which further repressed miR-200c levels and accelerated VSMC proliferation. These results demonstrate that induction of a miR-200c-SUMOylated KLF4 feedback loop is a significant aspect of the PDGF-BB proliferative response in VSMCs and that targeting Ubc9 represents a novel approach for the prevention of restenosis.

Prenatal phthalate exposure, infant growth, and global DNA methylation of human placenta.

Prenatal phthalate exposure has been shown to be associated with reduced fetal growth. Epigenetic changes such as DNA methylation might be a molecular mechanism through which phthalate exposure affects fetal growth. In this study, we examined associations between prenatal phthalate exposure, infant growth, and global DNA methylation in human placenta samples. We measured global DNA methylation of 119 subjects [55 fetal growth restriction (FGR) cases and 64 normal controls], as assessed by long interspersed nuclear element-1 (LINE-1) methylation, via quantitative polymerase chain reaction-pyrosequencing. Prenatal phthalate exposure was assessed by measuring maternal urinary phthalate metabolites concentrations using high-performance liquid chromatography-tandem mass spectrometry. Concentrations of mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP), and SumDEHP (molar sum of MEHP, MEHHP, and MEOHP) were significantly higher in FGR cases than those in normal controls (P = 0.002, 0.003, and 0.002, respectively). Placental LINE-1 methylation were found to be positively associated with fetal birth weight standard deviation scores, and negatively associated with urinary phthalate metabolites concentrations (MEHHP and SumDEHP). Every natural-log unit increase in urinary concentrations of MEHHP and SumDEHP was associated with 0.015 (ß = -0.015, P = 0.150) and 0.012 kg (ß = -0.012, P = 0.167) decrease in birth weight mediated through LINE-1 methylation. These findings suggest that changes in placental LINE-1 methylation might be part of the underlying biological pathway between prenatal phthalate exposure and adverse fetal growth.

Gender-specific relationship between prenatal exposure to phthalates and intrauterine growth restriction.

BACKGROUND: No study has examined the association between prenatal phthalate exposure and intrauterine growth retardation (IUGR). This study aimed to investigate whether prenatal exposure to phthalates was associated with increased risk of IUGR. METHODS: A total of 126 mother-newborn pairs, including 42 IUGR cases and 84 control newborns and their mothers, were enrolled in this case-control study. Spot urine samples were collected during the third trimester of pregnancy, and 5 phthalate metabolites (mono-n-butyl phthalate (MBP), monomethyl phthalate (MMP), mono-2-ethylhexyl phthalate (MEHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP)) were measured. RESULTS: Concentrations of MMP, MEHHP, MEOHP, and SumDEHP (MEHP, MEHHP, and MEOHP) were significantly higher in IUGR cases than in normal controls. In all subjects, urinary concentrations of MEHHP and MEOHP were significantly inversely associated with fetal growth indicators (birth weight and Quetelet's index). When mothers were stratified by infant sex, MEHHP and MEOHP concentrations were still negatively associated with fetal growth indicators, while no significant association was observed in females. In addition, exposure-response relationships were observed between MEHHP/SumDEHP concentrations in maternal urine and IUGR. CONCLUSION: Prenatal exposure to phthalates was associated with increased risk of IUGR, and male newborns were more sensitive to phthalates than females.

Recreational screen-time among Chinese adolescents: a cross-sectional study.

BACKGROUND: Rapid urbanization in China has led to a proliferation of electronic entertainment media among youth. Prolonged screen time (ST; includes watching television and playing on computers, video game consoles, or mobile phones) is linked to poor health profiles. The aim of this study was to report recreational ST behaviors and ST correlates among Chinese adolescents living in two regions with different degrees of urbanization. METHODS: A cross-sectional, school-based survey (n = 3461 adolescents; aged 12-14 years old) living in inner-city Shanghai and a peri-urban region of Hangzhou. Students completed a questionnaire including family characteristics, daily ST, and information on family environment related to screen use. Recreational ST was categorized into two groups according to recommendations by the American Academy of Pediatrics (< or ≥2 h/day). Parents reported their own ST and also reported educational attainment as a proxy for socioeconomic status. RESULTS: ST was higher among boys than girls and on weekends than weekdays. Peri-urban girls were more likely to exceed 2 h/day ST compared to inner-city girls on weekends. Having a father with no university degree, mother's TV viewing ≥2 h/day, no ST rules at home, and eating meals in front of the TV were associated with higher ST on both weekdays and weekends, and regional differences were found for weekend ST. CONCLUSIONS: TV viewing and playing on the computer were the most prevalent ST behaviors among Chinese adolescents. Mobile phone playing was less prevalent but persistent throughout the week. More population-level surveillance and research is needed to monitor the trends in ST behaviors and to better understand the characteristics of those who are at risk.

High prevalence of overweight and obesity among inner city Chinese children in Shanghai, 2011.

BACKGROUND: In China, the prevalence of overweight and obesity appears to be increasing at unacceptable levels among young people living in major cities undergoing rapid economic growth. OBJECTIVE: To report the prevalence of overweight and obesity among Shanghai inner city youth using the recently published International Obesity Task Force (IOTF) Asian definition. METHODS: Secondary analysis of children aged 8-15 years who participated in the Shanghai Schools' Physical Fitness Examinations, a representative school-based survey. Height and weight were measured and body mass index (kg/m(2)) was calculated. The prevalence of overweight and obesity was determined using the IOTF children's BMI cut-points for Asian populations, equivalent to an adult BMI of 23 g/m(2) (overweight) and 27 kg/m(2) (obese). RESULTS: The prevalence of combined overweight and obesity was 49.1% for boys and 30.8% for girls aged 8-15-years. Almost one-in-five boys were obese, compared with 8.4% of girls. In boys the prevalence of overweight appeared to increase from age 10 years. CONCLUSION: The high prevalence of combined overweight and obesity among urban Chinese youth, especially among boys, requires immediate health promotion intervention.

Use of mobile phone text messaging to deliver an individualized smoking behaviour intervention in Chinese adolescents.

We evaluated the effectiveness of a mobile phone text-messaging based smoking cessation intervention package among Chinese adolescent smokers. Students aged 16-19 years were recruited from six vocational high schools located in Shanghai. We assigned the six schools to an intervention group or a control group by cluster randomization. The 92 participants in the intervention group were given tailored information via mobile phone text-messaging for 12 weeks. The 87 participants in the control group were provided with a self-help pamphlet about smoking cessation instead. After the intervention, attitudes towards the disadvantages of smoking were significantly improved, and the level of nicotine dependence and cigarette dependence significantly decreased in the intervention group. The intervention group had a relatively higher self-reported 7-day abstinence compared to the control group and 30-day abstinence, but the differences were not significant. However, the intervention group had a significantly higher rate of smoking reduction (66% vs. 35%) and moving forward in quitting stages (52% vs. 18%) compared to the control group. The interactive and tailored assistance provided by the mobile phone text-messaging was effective in smoking behaviour intervention in Chinese adolescent smokers.

[Applicability of self-rated pubertal development scale among urban Chinese adolescents].

OBJECTIVE: To explore the applicability of pubertal development scale in estimating sexual maturation among urban Chinese adolescents. METHODS: A cross-sectional survey was conducted among 2562 students of 4(th) to 12(th) grade in Shanghai, selected by stratified cluster sampling method. Self-reported pubertal maturation level was obtained by Pubertal Development Scale (PDS). Meanwhile, visual depiction of Tanner stages of breast, genital and pubic hair development were rated by a trained rater of the same gender. RESULTS: In 2562 students, the correlation between self-reported PDS and assessment from the raters were substantial, both in boys and girls (Pearson's correlation coefficients: 0.822 and 0.814, respectively). The overall agreement of pubertal development stages based on PDS and the rater's assessment were 35.24% and 51.42% for boys and girls, respectively, with Kendall's correlation coefficients as 0.713 and 0.685, respectively. Adolescents who were older, had relatively higher level of pubertal stages or adolescents from the richer families, tended to underestimate their actual level of pubertal maturation while those male subjects and overweight or obese subjects were even more likely to be so. CONCLUSION: Using the self-reported PDS, we could conveniently obtain the necessary information regarding sexual maturation among the urban adolescents. It seemed especially useful in the related epidemiological survey when physical examination was precluded by cost, privacy and other concerns.

National estimates of the pubertal milestones among urban and rural Chinese girls.

PURPOSE: To provide clinically meaningful, normative reference data that describe pubertal timing indicators among urban and rural Chinese girls. METHODS: Girls of Chinese Han ethnicity from grade 1 in elementary schools through grade 12 in junior high schools in eight regions participated in China Puberty Research Collaboration from October 2010 to May 2011. At examination, stages of breast and pubic hair development were assessed by trained physicians. Data on menses were collected through questionnaire survey. RESULTS: A total of 15,388 girls aged 6.0-18.9 years participated in this collaboration study. Among them, approximately 53.5% (8,238) came from rural areas. The median ages at stage 2 of breast development of Chinese girls were 9.18 (95% confidence interval: 8.91-9.44) years and at stage 2 for pubic hair growth were 11.65 (95% confidence interval: 11.41-11.90) years. Girls with body mass index ≥85th percentile had earlier age for B2 (Tanner stage 2 for breast development), B3 (Tanner stage 3 for breast development), PH2 (Tanner stage 2 for pubic hair development), PH3 (Tanner stage 3 for pubic hair development), and menarche compared with girls with body mass index < 85th percentile. Urban girls achieved PH2, PH3, and menarche at a much earlier age than rural girls, except for B2 and B3 attainment. Mean menarcheal age is 12.43 years. CONCLUSIONS: This study presented up-to-date data on female pubertal timing in a national sample of Chinese Han ethnicity girls and separately for urban and rural areas.

KLF5 and hhLIM cooperatively promote proliferation of vascular smooth muscle cells.

Krüppel-like factor 5 (KLF5) plays an important role in cellular proliferation and differentiation. In this study, we show that adenovirus-mediated overexpression of KLF5 increased neointimal formation, while human heart LIM protein (hhLIM) decreased neointimal formation following vascular injury. Interestingly, neointimal formation was significantly increased in the animals where both hhLIM and KLF5 were introduced, suggesting that KLF5 can reverse hhLIM function in cell proliferation on the coexpression with hhLIM. These results were also confirmed the cellular level. Further mechanistic studies suggested that PDGF-BB promoted the interaction between hhLIM and KLF5 through stimulating hhLIM binding to TGF-ß control element (TCE) on the cyclin E promoter in a KLF5-dependent manner. Failure of KLF5 binding to the TCE, on the knockdown of KLF5 by transfecting siRNA, not only prevented the recruitment of hhLIM to the cyclin E promoter but also affected activation of the cyclin E promoter by KLF5. These data suggest that KLF5 reverses hhLIM function from anti-proliferation to pro-proliferation through its interaction with hhLIM on the cyclin E promoter.

Association between HLA-DRB1 and myasthenia gravis in a northern Han Chinese population.

The cause of myasthenia gravis (MG) is unknown, but it is widely believed to be an autoimmune disease occurring in genetically susceptible individuals. The human leukocyte antigen (HLA) region is considered to be the most important genetic region for MG susceptibility genes. To investigate the association between HLA-DRB1 and myasthenia gravis (MG) in a northern Han Chinese population, a polymerase chain reaction with sequence-specific oligonucleotide probe hybridization method was used to determine the HLA-DRB1 genotypes of 91 patients with MG and 171 healthy individuals. We found that the HLA-DRB1(*)09 allele was significantly more prevalent among patients with MG than among healthy controls, especially those who experienced early onset of the disease (≤40 years), those who were seronegative for acetylcholine receptor antibody, and those with ocular MG. The prevalence of the HLA-DRB1(*)08 allele was significantly lower among patients with MG than among controls. These results indicate that HLA-DRB1(*)09 might be positively associated and DRB1(*)08 negatively associated with MG in the northern Han Chinese population.