Hair Mercury Levels and Their Relationship with Seafood Consumption among Preschool Children in Shanghai / 生物医学与环境科学（英文）

Mercury is a global pollutant. Children are vulnerable to environmental toxicants. Seafood consumption is a major source of methylmercury exposure. In order to ascertain children's mercury exposure levels and study their relationship with seafood consumption, we conducted a cross-sectional study among preschool children in Shanghai. According to our data, the geometric mean of the mercury levels in children's hair was 191.9 (95% CI: 181.8, 202.4) μg/kg. These results indicate that high income may be a predictor of elevated mercury levels in children's hair. Intake of marine fish, especially tuna and pomfret, was documented in our study and found to increase the risk of high mercury levels. Frequency of fish consumption was positively related with hair mercury levels. Our study is the first to provide baseline data for hair mercury concentration among preschool children in Shanghai.

Comparative study of children's sleep evaluation methods / 中华儿科杂志

<p><b>OBJECTIVE</b>To compare the compliance of using Actiwatch, parent report of sleep diary and sleep questionnaire in school age children, and to further evaluate agreement rates between actigraphy, diary, and questionnaire for children's sleep patterns.</p><p><b>METHOD</b>Two primary schools in Luwan District were selected and first grade students without obvious physical and mental illnesses or sleep disorders were enrolled in the study. Each student was home-monitored with an Actiwatch for 7 days, meanwhile parents were asked to complete a detailed sleep diary during the Actiwatch monitoring days. Sleep questionnaires were distributed to their parents who were asked to fill in these on the last monitoring day.</p><p><b>RESULT</b>Forty-five children participated in the study, 36 children completed sleep assessments by all the three methods, and among them 20 were boys and 16 were girls. The mean age of those children was (7.26±0.42) years. The completion rate of questionnaire was 100%, of diary was 86.7% (39/45) and of Actiwatch was 93.3% (42/45). The completion rate between sleep diary and sleep questionnaire was significantly different (P<0.05). The satisfactory agreement between Actiwatch and sleep diary was reached with sleep diary overestimating weekday and weekend sleep duration by 26 minutes and 25 minutes respectively. The agreement rates between Actiwatch and questionnaire was insufficient for all variables with sleep questionnaire overestimating weekday and weekend sleep duration by 37 minutes and 38 minutes respectively.</p><p><b>CONCLUSION</b>Sleep questionnaire is an easy and high compliance method for evaluating children's sleep pattern while sleep diary showed high agreement with Actiwatch. Using either of these methods for evaluating children's sleep pattern should be judged by research aim and sample size, and limitation of those methods should be considered when they are used in practice.</p>

The association of sleep hygiene and sleep quality among school-age children / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the association between sleep hygiene and sleep duration and quality among school-age children, and to explore the risk factors related to poor sleep hygiene.</p><p><b>METHODS</b>Totally 2019 grade-five children were sampled by stratified cluster random sampling from 10 primary schools in Shanghai, during November and December 2009. Questionnaires were used to investigate children and their parents. Adolescent Sleep Hygiene Scale (ASHS) was used to inquiry sleep hygiene of children; Children Sleep Habits Questionnaire (CSHQ) was used to assess their sleep duration and quality; Family and Social Environment Questionnaire was used to collect demographic and socio-economic information. T-test, one-way ANOVA and multiple linear regression model were established to identify the risk factors for sleep hygiene.</p><p><b>RESULTS</b>The age of subjects was (10.81 ± 0.38) years old, 49.0% (989/2019) were boys. The ASHS total score was 125.43 ± 15.17, girls with better sleep hygiene than boys (127.05 ± 14.41 vs 123.74 ± 15.75, P < 0.05). The sleep duration was (9.47 ± 0.58)h/d, children slept less than 9 h/d had lower ASHS total score than those slept 9 - 10 h/d or over 10 h/d (121.69 ± 16.09 vs 126.17 ± 14.62 vs 126.50 ± 15.36, P < 0.05). Children with poor sleep quality had worse sleep hygiene than those with good sleep quality (121.00 ± 15.84 vs 128.36 ± 13.92, P < 0.05). Children with television set in bedroom had lower ASHS total score than the others (122.40 ± 15.76 vs 126.74 ± 14.66, P < 0.05). Children from single parent family had lower ASHS total score (117.90 ± 16.80 vs 125.94 ± 14.89, P < 0.05). Children whose father had irregular sleep or wake pattern had lower ASHS total score (122.65 ± 15.30 vs 125.89 ± 14.90 vs 127.79 ± 14.71, P < 0.05). The regression model confirmed that existence of television set in children's bedroom, single-parent family and father's irregular sleep pattern were the risk factors of poor sleep hygiene.</p><p><b>CONCLUSION</b>Sleep hygiene was closely associated with sleep duration and quality among school-age children. Children with television set in bedroom, male, from single parent family and whose father had irregular sleep or wake pattern had worse sleep quality.</p>

Follow-up study of school-age children's sleep quality in Shanghai / 中华儿科杂志

<p><b>OBJECTIVE</b>China has undergone massive socioeconomic change during the past several years, and its impact on children's sleep is still unrecognized. Shanghai, as one of typical economically fast-developing cities, was chosen as observational city in this study, which was designed to explore trends in sleep quality in Shanghai school-aged children and related high risk factors on sleep quality.</p><p><b>METHOD</b>Totally 884 fifth grade school-aged students were sampled by stratified cluster random sampling method from 10 primary schools of Shanghai in 2005, then four years later in 2009, 2161 same grade students were sampled from the same schools. Chinese version of Children's Sleep Habits Questionnaire (CSHQ) was used to evaluate 8 sleep quality parameters among those children, and high risk factors on school-aged children's sleep quality were investigated as well.</p><p><b>RESULT</b>The prevalence of poor sleep quality decreased from 29.2% in 2005 to 27.9% in 2009, and among 8 sleep quality parameters, bedtime resistance decreased from 33.1% to 28.7%, sleep anxiety from 50.6% to 39.8%, night waking from 25.2% to 21.5%, and parasomnia from 51.2% to 45.8%. The factors, such as heavier homework burden, longer daily computer use, bright light during sleep, cosleeping, existence of chronic disease and irregular sleep habits of parents, were associated with poor sleep quality of school-aged children after adjusting for children's age, gender, and family social-economic status.</p><p><b>CONCLUSION</b>Part of sleep quality parameters improved during the past 4 years, but current situation is still tough with more than 1/4 poor sleep quality children. Helping children to develop good sleep hygiene as well as educating parents how to shape children's regular sleep habits might be effective methods to improve children's sleep quality.</p>

Exposure level and risk factors of heavy metal in prenatal period among Shanghai infants / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the exposure level and risk factors of heavy metal among Shanghai infants in their prenatal period.</p><p><b>METHODS</b>A total of 1652 pregnant or puerperal women were recruited from 10 midwifery-qualified hospitals in Shanghai since October 2008 to October 2009, by the stratified cluster sampling method. They answered the questionnaire and their umbilical cord blood and serum were collected to detect the content of Pb, Hg, Mn, Cd, As and Tl. The risk factors were analyzed by single and multiple regression methods respectively.</p><p><b>RESULTS</b>The median value of the content of Pb, Hg, Mn, Cd, As and Tl were 41.00, 1.88, 4.10, 0.03, 0.86 and 0.02 µg/L respectively. The Hg concentration of pregnant women who ate fish for 4 - 7 times per week (9.7% (160/1652)) was 2.76 µg/L, which was higher than that of pregnant women who only ate fish for 1-3 times per week (49.3% (814/1652)) and those who seldom ate fish (40.0% (661/1652)); the Hg concentration in the two groups above were 2.41 and 2.03 µg/L separately. The difference had statistical significance (χ(2) = 36.40, P < 0.001). Meanwhile, the concentrations of Pb and Tl in the group of pregnant women whose houses were remodeled by PVC pipe (85.0% (1404/1652)) was higher than the concentrations in group of pregnant women whose houses were remodeled by galvanized pipe (15.0% (248/1652)); the Pb concentration in the two groups above were 45.54 and 40.00 µg/L (Z = 2.54, P < 0.05) and the Tl concentration in the two groups above were 0.021 and 0.018 µg/L (Z = 2.97, P < 0.05). However, the As concentration in the group of PVC pipe remodeled was 4.33 µg/L, which was lower than that in the group of galvanized pipe (9.37 µg/L). The difference had statistical significance (Z = 3.99, P < 0.01). The concentrations of Mn, Cd and Tl in the groups of pregnant women whose house had been remodeled in the last 3 years (38.0% (628/1652)) were 14.78, 0.51 and 0.022 µg/L separately, which were all significantly higher than those in the groups of women whose houses' were not remodeled (62.0% (1024/1652)), whose concentrations were 11.01, 0.29 and 0.02 µg/L respectively. The differences had statistical significance (Mn: Z = 2.46, P < 0.05; Cd: Z = 2.38, P < 0.05; Tl: Z = 2.81, P < 0.01).</p><p><b>CONCLUSION</b>The infants in Shanghai were exposed to heavy metals in their prenatal period. The main sources of the exposure were daily diet and remodeled pollution.</p>

Effects of chronic partial sleep deprivation on growth and learning/memory in young rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>The effects of sleep deprivation on the immature brain remain unknown. Based on a computer controlled chronic sleep deprivation animal model, the effects of chronic partial sleep deprivation on growth, learning and memory in young rats were explored.</p><p><b>METHODS</b>Twelve weaned male Spraque-Dawley rats (3-week-old) were randomly divided into sleep deprivation, test control and blank control groups. Sleep deprivation was performed using computer-controlled "disc-over-water" technique at 8-11 am daily, for 14 days. The temperature and weights were measured every 7 days. Morris water maze was used to test spatial learning and memory abilities before and 7 and 14 days after sleep deprivation. After 14 days of sleep deprivation, the rats were sacrificed for weighting their major organs.</p><p><b>RESULTS</b>After 14 days of sleep deprivation, the rats' temperature increased significantly. During the sleep deprivation, the rate of weight gain in the sleep deprivation group was much slower than that in the test control and blank control groups. The thymus of the rats subjected to sleep deprivation was much lighter than that of the blank control group. After 7 days of sleep deprivation, the rats showed slower acquisition of reference memory, but were capable of successfully performing the task by repeated exposure to the test. Such impairment of reference memory was not seen 14 days after sleep deprivation.</p><p><b>CONCLUSIONS</b>Chronic sleep deprivation can affect growth of immature rats, as well as their abilities to acquire spatial reference memory.</p>

Primary study on executive function in children with Ping-Pong training and swimming training / 上海第二医科大学学报

Objective To investigate the executive function of children with different sports training. Methods Forty children with Ping-Pong training (Ping-Pong group) and 41 children with swimming training (swimming group), aged 6-9 years, completed GO/NOGO task. Behavioral data (reaction time and accuracy) and event related potential component N2 were collected and analyzed. Results The reaction time was significantly faster and accuracy significantly lower of GO task and NOGO task in swimming group than in Ping-Pong group (P<0.05 and P<0.01). There were significant differences in the amplitude of NOGO-N2 on site CPz between swimming group and Ping-Pong group[(-11.36±9.4) μV vs (-7.55±7.99) μV, P<0.05]. Conclusion The inhibitory function of children with Ping-Pong training is stronger than those with swimming training.

Impact of television-watching and computer-using on sleep patterns and sleep problems of school-aged children in Shanghai / 上海第二医科大学学报

Objective To investigate the effects of television-watching and computer-using on sleep/wake patterns, sleep duration and sleep problems of school-aged children in Shanghai. Methods A total of 4 108 school-aged children from 10 primary schools of Shanghai were enrolled by multi-stage cluster sampling and surveyed by questionnaires. The information of television-watching and computer-using, family and personal condition was investigated by self-prepared questionnaire, and the Chinese version of Children's Sleep Habits Questionnaire was employed to survey the sleep behaviors of children. The effects of television-watching and computer-using on sleep/wake patterns, sleep duration and sleep problems were analyzed by multiple linear regression analysis and Logistic regression analysis. Results The percentage of children who watched television≥2 h per day was 4.1% during weekdays, and that came to 49.2% during weekends. In terms of frequency of computer-using, most children reported "rarely" (88.2%, 0-1 time/week), followed by "often" (11.0%, 2-4 times/ week) and "usually" (0.8%, 5-7 times/week). With the age increase, the percentages of children who watched television≥2 h per day and those who "often" used computer gradually increased. It was revealed by multiple linear regression analysis and Logistic regression analysis that television-watching and computer-using were not only positively correlated with later bedtime, later wake time and shorter sleep duration but also significantly associated with sleep problems such as bedtime resistance, sleep onset delay, sleep duration disorder, sleep anxiety and parasomnia. Conclusion Television-watching and computer-using exert influences on sleep behaviors of sleep/wake patterns, sleep duration and sleep problems. Concerns about the potential negative effects of television-watching and computer-using on sleep behaviors may help to promote healthy sleep patterns and improve sleep quality.

Effects of forepaw sensorimotor deprivation in early life on spatial learning and memory in rats / 上海第二医科大学学报

Objective To explore the effects of forepaw sensorimotor deprivation in early life on hippocampus-dependent spatial reference learning and memory in rats. Methods Newborn SD rats were randomly assigned to experiment group (deprivation of forepaw sensorimotor function, n=53) and control group(n=55). Rats of postnatal day 13 (PN13) in experiment group were seleeted, and models of forepaw sensorimotor deprivation were established by microsurgical technique. Open field tests and Morris water maze tests were performed during the time periods of PN25(PN21-31), PN35 (PN31-39), PN45(PN41-50) and PN60(PN56-64) to evaluate the locomotor activity and spatial reference learning and memory, respectively. Results In open field tests, there was no significant difference in parameters of locomotor activity and exploratory behavior between the two groups (P>0.05). In Morris water maze tests, eontrol group performed significantly better than experiment group during training sessions and probe tests on PN25 and PN35 (P<0.05). While on PN45, although there was no significant difference between the two groups during training sessions, control group performed significantly better than experiment group during probe tests (P<0.05). Conclusion The deprivation of forepaw sensorimotor in early life has no signifieant effect on the locomotor activity and exploratory behavior of rats, but can impair the spatial reference learning and memory.

Effects of chelation therapy with succimer in young rabbits of moderate lead poisoning / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the effect of chelation therapy with succimer (DMSA) in male rabbits of moderate lead poisoning during juvenile stage.</p><p><b>METHODS</b>Twenty-four 45-day-old male New Zealand rabbits were randomly divided into three groups (therapy group, TG; positive control group, PG and negative control group, NG, n=8). The TG and PG were orally exposed to lead acetate (5 mg x kg(-1) x d(-1)) for 6 weeks. Rabbits in TG were orally supplied DMSA 1050 mg/m2 in the first week and 700 mg/m2 in the next two weeks, while the other two groups wren't blood and urinary samples of all rabbits were collected per week. The tissues and organs of all rabbits were collected after 12 weeks. The blood lead levels (BLLs) were determined by atomic absorption spectrometer. The urine lead levels and the lead contents of tissue and organ were determined by inductively coupled plasma-mass spectrometry. Histopathology of tissue and organ was observed by light microscope.</p><p><b>RESULTS</b>Compared with PG, the lead level in the morning urine of TG with DMSA chelating was increased significantly. The level was peaked at (1246.96 +/- 157.91) microg/L on the first day after chelating. While the base line was (40.97 +/- 1.77) microg/L before chelating. Meanwhile, the BLLs were sharply declined from (429.63 +/- 10.82) microg/L to (238.50 +/- 11.82) microg/L. The urine lead levels of TG decreased through the 3-week chelating and 3-week discontinuation. The urine lead levels of these two groups were significantly different (F=2934.35, P<0.01). Compared to each two groups in these three groups, there were significant difference (P<0.01). The authors found the reversion of BLLs in first week after stop chelating. The BLLs of PG presented the slow course of declining in the same time, were (135.50 +/- 7.09) microg/L, very close to the level of TG for (149.88 +/- 11.39) microg/L. Compared with treatment discontinuation for 3 weeks, the urine lead levels and the body weight gain of the therapy group increased more than that of PG, and the BLLs and the lead concentrations in tissues and organs decreased more than that of PG, and histopathology in the liver tissues and testicle tissues were improved.</p><p><b>CONCLUSION</b>DMSA chelating for the rodent models of moderate lead poisoning might reduce the BLLs and soft tissue lead contents quickly and effectively, decrease toxic effects of lead in a short period of time, thus alleviate the impairment of lead poisoning on tissues and organs by decreasing lead burden, and bring out improvement on the growth retardation caused by lead poisoning.</p>

Effects of moderate lead poisoning on the hippocampus tissue of rabbits in juvenile stage / 中华预防医学杂志

<p><b>OBJECTIVE</b>To understand the effects of moderate lead poisoning on the hippocampus tissue of rabbits in juvenile stage.</p><p><b>METHODS</b>Sixteen 45-day-old male New Zealand rabbits were randomly divided into blank group and lead-exposed group,8 for each group. Rabbits in the lead-exposed group were treated with 5 mg x kg(-1) x d(-1) lead acetate in their forage for 6 weeks to establish a moderate lead poisoning animal model. The blood lead levels and the lead contents in the hippocampus were determined by atomic absorption spectrometer and inductively coupled plasma-mass spectrometry respectively. Histopathology and ultra-microstructure in the hippocampus tissue were observed by light microscope and electron microscope. The NR1, NR2A and NR2B protein expressions in the CA1 hippocampal region were analyzed through immunohistochemical method.</p><p><b>RESULTS</b>Compared with those of blank group, the blood lead levels of lead-exposed group were significant increased, (428.63 +/- 9.46) vs (66.38+/-3.93) microg/L (t = 100.08, P<0.01); and lead contents of hippocampus was significantly increased, (44.57+/-2.03) vs (21.20+/-1.53) ng/g, (t = 26.05, P<0.01); the hippocampus wet weight were significant decreased, (0.735 +/-0.012) vs (0.808+/-0.010), (t =12.97, P<0.01); the coefficient of hippocampus wet weight, was (0.458 +/-0.004) vs (0.476+/-0.005), (t =7.87, P<0.01). The significant declines in both the positive rate of NR1 and NR2A in the CA1 hippocampal region for NR1: (37.44 +/- 2.05)% vs (41.81+/-2.50)% (t = 3.82, P<0.01) and for NR2A: 21.97+/-1.08 vs 25.48+/-1.30 (t =5.89, P<0.01) were also observed. With light microscope and electron microscope, the histopathology and ultra-microstructure of neuron and glial cell in the hippocampus tissue were changed.</p><p><b>CONCLUSION</b>The impairment of hippocampus of rabbits in juvenile stage with chronic moderate lead poisoning were observed, and the histopathology and N-methyl-D-aspartate receptor protein expressions in the hippocampus tissue were changed.</p>

Sleep habits and sleep disturbance in school-age children of China / 中华儿科杂志

<p><b>OBJECTIVE</b>To survey the sleep habits (bedtime, wake time), sleep duration, and sleep problems in school-age children of China.</p><p><b>METHOD</b>From November to December, 2005, a total of 19,299 school-age children from 55 elementary schools of 9 cities entered the study by a cross-sectional survey. A parent-administered questionnaire and the Chinese version of the Children's Sleep Habits Questionnaire were applied to investigate children's sociodemographic characteristics and sleep behaviors, respectively.</p><p><b>RESULTS</b>The mean sleep duration was 9 hours and 10 minutes (9:10, SD:48 min) during the weekdays and 9:48 (SD: 63 min) during the weekends. In about 71.4% and 41.8% school-aged children the sleep duration per day did not reach the lowest criterion of 10 hours recommended by the Ministry of Education of China during weekdays and weekends, respectively. Sleep problems were common with prevalence ranging from 14.5% for sleep-disordered breathing to 75.3% for daytime sleepiness. Parasomnia (chi(2) = 13.76, P < 0.01) and sleep-disordered breathing (chi(2) = 119.83, P < 0.01) were more prevalent in boys than in girls; however, sleep anxiety was more prevalent in girls than in boys (chi(2) = 19.42, P < 0.01). Except for night waking, other types of sleep problems were significantly associated with age.</p><p><b>CONCLUSIONS</b>Inadequate sleep duration and sleep problems prevail among school-age children, which indicates that children's sleep health may be a major public health concern in China.</p>

Effects of preweaning enrichment on activity-regulated cytoskeletal protein expression and long-term memory in rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the effects of preweaning enrichment on the expression of activity-regulated cytoskeletal protein (Arc), an immediate early gene, and on the long-term memory in rats.</p><p><b>METHODS</b>Forty neonatal Sprague-Dawley rats were randomly assigned to control group (standard environment, n=20) and experimental group (enriched environment, n=20). The experimental group received enriched environment exposure from postnatal day 10 until weaning (2 weeks, 20 minutes per day). The open field and novel object recognition tests were performed at postnatal day 28. Arc expression was detected by Western blotting and immunohistochemistry.</p><p><b>RESULTS</b>There was no significant difference in the open field test between the two groups. However, in the novel object recognition test, the experimental group rats performed significantly better than the control rats after 1 and 24-hr retention. The preference index in the experimental group after 1-hr (59.61%+/-9.61% vs 50.46%+/-9.34%; P<0.05) and 24-hr retention (62.72%+/-14.12% vs 52.39%+/-9.16%; P<0.05 ) was significantly higher than that in the control group. Arc expression in both areas CA1 and DG of hippocampus in the experimental group increased significantly compared with that in the control group (P<0.01).</p><p><b>CONCLUSIONS</b>Preweaning enrichment can up-regulate the expression of immediate early gene, Arc, in the hippocampus of the rats, and promote their long-term memory.</p>

Effects of prenatal exposure to stress and lead on spatial learning and memory development in rats / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the effects of prenatal exposure to stress and lead on spatial learning and memory development in rats.</p><p><b>METHODS</b>All 32 Sprague-Dawley (SD) pregnant rats were divided randomly into 4 groups, 8 per group in line with the Random Number Table. The four groups were: no maternal stress, no Pb exposure (NS/C); non-maternal stress, Pb exposure (NS/L), maternal stress, no Pb exposure (S/C), and maternal stress plus Pb exposure (S/L). The spatial learning and memory ability, the serum corticosterone level both pre and post-testing of 30-day old offsprings, and lead concentration in hippocampus were tested by means of Morris Water Maze, radioimmunoassay and Inductively Coupled Plasma Mass Spectrometry (ICP-MS).</p><p><b>RESULTS</b>The residence time of male and female in NS/L was (16.08+/-3.41) s, (15.72+/-3.33) s, which were significantly shorter than NS/L (25.42+/-4.76) s, (24.55+/-4.43) s and S/C (20.96+/-3.45) s, (20.65+/-2.98) s, and significant difference was observed in the joint exposure effect (F=5.478, P<0.05). The effect of the joint exposure was significant on post-testing serum corticosterone. The hippocampus lead concentrations of NS/L and S/L were (0.4378+/-0.1041) microg/g and (0.4679+/-0.1243) microg/g without significant differences (F=0.298, P>0.05).</p><p><b>CONCLUSION</b>Prenatal joint exposure to restraint stress and lead might increase the effects of single exposure on the spatial learning and memory ability and serum corticosterone level of offsprings, and the joint influence on corticosterone level might be one of the reasons of further impairment of learning and memory.</p>

Study on maternal-fetal status of Pb, As, Cd, Mn and Zn elements and the influence factors / 中华预防医学杂志

<p><b>OBJECTIVE</b>Trace and toxic elements have great influences on the fetus growth during the pregnancy. The status of Pb, As, Cd, Mn and Zn in maternal and umbilical cord blood and influence factors were analyzed.</p><p><b>METHODS</b>From September 2006 to April 2007, 130 pairs of maternal blood and cord blood in total were collected at the time of spontaneous delivery or cesarean section. At the same time, the development of newborn was measured immediately. The concentrations of elements were determined by inductively coupled plasma mass spectrometry, the relationship of these elements between maternal and cord blood were also analyzed.</p><p><b>RESULTS</b>The median (microg/L) concentration of blood Pb, As, Cd, Mn and Zn in maternal blood were 64.32, 3.81, 0.84, 54.26 and 6312.50. And the median (microg/L) of those elements in cord blood were 35.72, 2.84, 0.32, 78.99 and 2250. The levels of Cd (r=0.341, P=0.000) and As (r=0.552, P=0.000) in maternal blood were positively correlated with the elements in the cord blood. From the questionnaire we conclude that the occupational hazardous factors and room decorated were the risk factors for the blood As and Zn levels. After multilinear regression analysis we also found mother weight, occupational hazardous factors and mother systolic pressure might affect the levels of blood Mn, Zn, As and Cd.</p><p><b>CONCLUSIONS</b>The levels of these elements were affected by environmental and maternal factors. In this study, although the levels of all heavy metals in pregnant women were below those considered hazardous, however, they were still higher than those in the developed countries. The effects of heavy metals of maternal exposure on developing fetuses should deserve attention further.</p>

Internet addiction among Shanghai adolescents: prevalence and epidemiological features / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the prevalence of internet use and internet addiction in adolescents of Shanghai.</p><p><b>METHOD</b>From September to October 2007, a total of 5135 adolescents from 16 middle schools of 6 districts of Shanghai took part in the epidemiological study by a cross-sectional survey and 5123 adolescents finally enrolled in the study. A questionnaire of "DRM Adolescent Internet Use 52 Scale" was administrated to investigate the prevalence of internet use and internet addiction in adolescents of Shanghai. On this scale of 5-point rating, the scale includes seven parts of contents as tolerance, abstinence reaction, planning ability, self-control ability, whenness, sociability and hazard.</p><p><b>RESULTS</b>The rate of internet use among the surveyed adolescents was 94.32% (4673/5123), among which the incidence rate of internet addiction was 8.78% (450/5123). Boys, senior middle-school students were more susceptible to internet addiction than girls and junior middle-school students (male scores 122.42+/-43.46, female scores 116.92+/-38.10, F=23.22, P=0.00; senior middle-school students 125.24+/-39.02, junior middle-school students 110.30+/-42.35, F=164.68, P=0.00). Students from vocational senior middle-school were most susceptible (junior middle-school students 110.30+/-42.35, ordinary senior middle-school students 122.83+/-40.99, key senior middle-school students 120.05+/-37.87, vocational senior middle-school students 133.37+/-36.84, F=34.44, P=0.00). The 2nd grade students of senior middle-school have the highest risk for internet-addiction.</p><p><b>CONCLUSION</b>The prevalence of internet use and internet addiction in adolescents of Shanghai should be comparatively high in China, which indicates that great attention should be paid to the prevention and control.</p>

Development and psychometric properties of the Chinese version of Children's Sleep Habits Questionnaire / 中华儿科杂志

<p><b>OBJECTIVE</b>To develop the Chinese version of Children's Sleep Habits Questionnaire (CSHQ) by translating and retranslating the English version of CSHQ and to examine the reliability, content validity, construct validity of the Chinese version in a general population of school-age children.</p><p><b>METHODS</b>During November and December 2005, a total of 20 457 school-age children from 55 primary schools of 9 cities were recruited through cluster-stratified selection, using geographic location, economic standard, and population density as criteria. A parent-administered questionnaire and the Chinese version of CSHQ were completed to quantify sociodemographic characteristics and to characterize sleep patterns and sleep disturbances, respectively.</p><p><b>RESULTS</b>The internal consistency of overall questionnaire and the eight subscales of the Chinese version of CSHQ was good (Cronbach's alpha coefficient was 0.73 and ranged from 0.42 to 0.69, respectively). The consistency between mother and father was ICCs = 0.89 for overall questionnaire and ranged from ICCs = 0.83 to ICCs = 0.92 for subscales. The test-retest reliability was ICCs = 0.85 for overall questionnaire and range from ICCs = 0.60 to ICCs = 0.88 for subscales. Factor analysis revealed a three-factor structure, which could represent bedtime behavior problems, sleep disturbance, sleep duration and daytime sleepiness, respectively, and the three factors could be used to explain 58.63% of the total variance. The factor loading was above 0.5 for the corresponding subscale.</p><p><b>CONCLUSIONS</b>Reliability, content validity and construct validity of the Chinese version of CSHQ in a general population of school-age children are good. It appears to be a suitable instrument for measuring sleep patterns and screening for sleep problems in school-aged children.</p>

Effects of lead exposure on expression of mGluR5 in mRNA and protein levels of the cultured hippocampal neurons / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the effects on the expression of mGluR5 mRNA and protein levels in primarily cultured hippocampal neurons after lead exposure.</p><p><b>METHODS</b>Primary embryonic rat hippocampal neuronal culture was prepared. On the 3(rd) day of incubation, lead chloride solution was added into medium to produce four different lead exposure levels: 0, 1 x 10(-8) mol/L, 1 x 10(-6) mol/L, 1 x 10(-4) mol/L Pb(2+). After 10 days of incubation, the neurons were collected to measure the alteration of mGluR5 mRNA expression by real-time fluorescent quantity PCR and the expression of mGluR5 in protein level by Western blot.</p><p><b>RESULTS</b>The studies revealed that mGluR5 mRNA expression was down-regulated after lead exposure in a dose-dependent manner. The mGluR5 mRNA expression of the lower lead-exposed neurons (Pb(2+) 10(-8) mol/L), the medium lead-exposed neurons(Pb(2+) 10(-6) mol/L), the higher lead-exposed neurons(Pb(2+) 10(-4) mol/L) were 0.724, 0.421, 0.321 times less than that of the controls, respectively. The Western blot demonstrated that mGluR5 expression in protein level should be decreased after lead exposure.</p><p><b>CONCLUSION</b>The expression of mGluR5 in mRNA and protein levels should be down-regulated after lead exposure at different lead levels in a dose-dependent manner.</p>

Effect of zinc deficiency on the protein expression of vitamin D receptor and calcium binding protein in growth-stage rats duodenal mucosa / 中华儿科杂志

<p><b>OBJECTIVE</b>To study the effect of zinc deficiency on the protein expression of vitamin D receptor (VDR) and calcium binding protein (CaBP) in growth-term rats duodenal mucosa and to clarify the mechanism of zinc deficiency affecting the calcium absorption by gene transcription.</p><p><b>METHODS</b>Thirty weaning male rats were randomly divided into three groups: zinc deficiency (ZD), paired-fed (PF) and zinc adequation (ZA). The ZA group received a diet containing 29.5 microg/g diet ad libitum; the ZD group received a diet containing less than 0.4 microg zinc/g diet ad libitum. To eliminate the effect of zinc deficiency on appetite, the PF group received a zinc-adequate diet restricted to the quantity of food consumed the previous day by the ZD rats. After 15 days feeding, duodenal mucosa was taken to measure expression of the protein of VDR and of CaBP by immunohistochemistry and Western-blotting.</p><p><b>RESULTS</b>Immunohistochemistry demonstrated that the intestinal mucosal expression of both VDR protein and CaBP protein in ZD rats significantly decreased. Analysis of the photographs showed that the number of cells expressed VDR protein in ZD rats was significantly less than that of the PF and ZA rats (P < 0.001). The number of cells which expressed VDR protein in ZD, PF, and ZA groups was 52, 162, and 220, and the number of cells which expressed CaBP protein was 169, 240 and 280 (F = 132 and 22, P < 0.001). Western-blotting showed similar results.</p><p><b>CONCLUSIONS</b>Zinc deficiency, by changing the activity of VDR, changes the protein expression of VDR, and thus affects the transcription of the target gene CaBP, resulting in the absorption of calcium that causes allo-osteogenesis.</p>

Association between vitamin D receptor gene polymorphism and vitamin D deficiency rickets / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the genetic susceptibility of children to vitamin D deficiency rickets through studying the association between Vitamin D receptor (VDR) gene polymorphism and vitamin D deficiency rickets.</p><p><b>METHODS</b>One hundred and fifty-nine children (100 boys and 59 girls, aged 0 to 2 years), with new-onset vitamin D deficiency rickets were enrolled. The patients sampled from a community of Jiamusi City, Heilongjiang Province. Seventy-eight healthy age-matched children (46 boys and 32 girls) were used as the controls. VDR gene polymorphism (cleaved by restriction endonuclease Fok I) was analyzed by polymerase chase reaction-restriction fragment length polymorphism (PCR-RFLP). The frequencies of the VDR genotype and allele were compared between the two groups.</p><p><b>RESULTS</b>The frequencies of FF, Ff and ff genotypes were 37%, 51% and 12% in the Rickets group, and 18%, 55% and 27% in the Control group. A significant difference was found in the frequency distribution of the VDR genotype between the two groups (chi(2)(0.01(2))=9.210, chi(2)=13.3880, P < 0.01). In the Rickets group, f allele frequency was lower (37% vs 54%), while the F allele was more common than the Control group (63% vs 46%).</p><p><b>CONCLUSIONS</b>There is an association between the VDR gene Fok I polymorphism and vitamin D deficiency rickets. The individuals with the F allele are more susceptible to vitamin D deficiency rickets.</p>