Dietary exposure of lead in primary, middle and high school students in Pudong new area of Shanghai / 中国学校卫生

Objective@#To obtain the dietary exposure of lead in primary, middle and high school students, and to provide basic foundation for food safety risk assessment and management for children and adolecsents.@*Methods@#Weighing method, 3-days hour dietary survey, combining with the food frequency questionnaire, was applied to obtain basic dietary data in 616 primary, middle and high school students selected through multi-stage randdom sampling method from Pudong new area of shanghai. Data on lead concentrations were derived from the food safety risk monitoring system, which included 1 145 samples.@*Results@#Lead was detected in 568 of 1 145 samples (49.61%) from 10 categories of foods. The exceeding standard rate was 3.58% (41 samples exceeded). The average content of lead was (0.12±0.25) mg/kg, fungi and algae, beans and the aquatic products were found to be the primary food sources of lead exposure. The average dietary lead exposure in primary, middle and high school students was 9.94 μg/kg per week, accounted for 39.76% of PTWI. The lead exposure level at the 97.5th percentile which accounted for 118.24% of PTWI was 29.56 μg/kg. Vegetables, beans and cereal foods were the mainly source of dietary lead exposure, with average dietary lead exposure 2.57, 2.44 and 1.43 μg/kg peer week, accounted for 10.26%, 9.76% and 5.74% of PTWI, respectively.@*Conclusion@#Lead is present in some foods available in local markets in Pudong New Area, Shanghai. Low level of dietary exposure to lead is found in primary, middle and high school students, however, it depends on dietary pattern. Continued efforts are needed to reduce the dietary exposure of lead in school students.

[Effects of soybean isoflavone on reproductive development in SD rats].

OBJECTIVE: To assess the effects of soybean isoflavone on reproductive development in SD rats. METHODS: Forty 4 week-old SD rats (20 males and 20 females) were randomly divided into a control group and a soy isoflavone (SI) group according to their body mass, and were fed with normal diet or normal diet added with soy isoflavone (100 mg/kg BW), respectively. The body weight, daily food intake, estrous cycle, fertility index, pregnant index, gestation length, number of pups, blood hormone level, the weight of reproduction organ and the quality of sperm of the parental generation and the sex ratio, anogenital distance, vagina opening time, prepuce separation time of F1 generation were recorded. The data were analyzed by two independent t test, and the data of pups in each litter were analyzed as a unit. RESULTS: Compared with the control group, the body weight and food utilization of male and female rats in SI group were lower before copulation (P < 0.05). The total number of sperm of parental males was higher (P < 0.05). Serum luteinizing hormone (LH) level of parental male was lower (P < 0.05), serum luteinizing hormone (LH), prolactin (PRL) and progesterone (P) of parental female were lower in SI group (P < 0.05). There were no significant differences of other indices such as estrous cycle, mating index, fertility index between two groups. CONCLUSION: SI has certain effect on the bodyweight of parental males, food utilization of females, and the total number of sperm and the level of some hormones.

[Influence of infant formula on reproductive development of rats].

OBJECTIVE: To identify the effects of infant formula on the reproductive development of Spraque-Dawley rats. METHODS: A two-generation reproductive test was carried out. Forty 4 week-old SD rats were divided into two groups randomly by body weight and maintained on diet containing a kind of infant formula or an adjusted basal feeds. The body weight, dietary intake, hormone level, function of reproductive organs, and the development status of the P generation rats and F1 generation rats were measured. RESULTS: No significant growth-promoting effect was observed in the infant formula group; and no impairment on reproductive organ development or development status in the P generation and F1 generation rats was caused by the infant formula. The body weight at the 14th day of gestation and at the 0th and 4th day of lactation in infant formula group was significantly lower than that in control group (P < 0.05). The level of prolactin was significantly lower in the infant formula group. The AGD of F2a female rats was significantly shorter in the infant formula group. CONCLUSION: There was few effect of the infant formula on the reproductive development of SD rats, further study is required to determine the effects of infant formula on the body weight change during gestation period and lactation period, AGD and prolactin level.

[Effect of fructus corni polysaccharides on damaged sexual function of male rats].

OBJECTIVE: To observe the effects of Fructus Corni polysaccharides (FCP) on sexual function of hemicastrated rats. METHOD: 70 male SD rats are randomly divided into 7 groups with their right testis extirpated except for normal control group. Normal control group and negative control group are given saline (ig) while positive control group are injected hypodermically testosterone propionate at dose of 2 mg x kg(-1) x d(-1). FCP control groups are given FCP separately at dose of 10, 50, 100, 150 mg x kg(-1) x d(-1) (ig). Mating test and erective test are observed. The levels of serum sex hormone T, LSH, FSH, E2 are detected with the Radioimmunoassay (RIA). RESULT: Incubation period of penis erection and mounting are shortened in FCP control groups and positive control group, and the percentage of mounting rats is increased. The level of serum sex hormone T is increased, but estradiol level is reduced. The organ coefficient of foreskin gland and seminal vesicle-prostate gland as well as sperm count and vigor are increased significantly (P < 0.01 or P < 0.05). CONCLUSION: FCP can increase the sexual function of hemicastrated rats. The mechanism is probably through adjustment of the hypothalamus-pituitary-gonadal axis.