Evaluation of Erythrocyte Iron Incorporation in Beijing Prepubertal Children Using a Single Stable Isotope Tracer Method / 生物医学与环境科学（英文）

Objective@#To analyze the rate of erythrocyte iron incorporation and provided guidance for the iron nutrition for prepubertal children.@*Methods@#Fifty-seven prepubertal children of Beijing were involved in this study and each subject was orally administered 3 mg of Fe twice daily to obtain a total of 30 mg Fe after a 5-d period. The stable isotope ratios in RBCs were determined in 14th day, 28th day, 60th day, and 90th day. The erythrocyte incorporation rate in children was calculated using the stable isotope ratios, blood volume and body iron mass.@*Results@#The percentage of erythrocyte Fe incorporation increased starting 14 th day, reached a peak at 60 d (boys: 19.67% ± 0.56%, girls: 21.33% ± 0.59%) and then decreased. The erythrocyte incorporation rates of Fe obtained for girls in 60th day was significantly higher than those obtained for boys ( < 0.0001).@*Conclusions@#The oral administration of Fe to children can be used to obtain erythrocyte iron incorporation within 90 d. Prepubertal girls should begin to increase the intake of iron and further studies should pay more attention to the iron status in prepubertal children.

Zinc Absorption from Representative Diet in a Chinese Elderly Population Using Stable Isotope Technique / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To determine the dietary zinc absorption in a Chinese elderly population and provide the basic data for the setting of zinc (Zn) recommended nutrient intakes (RNI) for Chinese elderly people.</p><p><b>METHODS</b>A total of 24 elderly people were recruited for this study and were administered oral doses of 3 mg 67Zn and 1.2 mg dysprosium on the fourth day. The primary macronutrients, energy, and phytic acid in the representative diet were examined based on the Chinese National Standard Methods. Fecal samples were collected during the experimental period and analyzed for zinc content, 67Zn isotope ratio, and dysprosium content.</p><p><b>RESULTS</b>The mean (± SD) zinc intake from the representative Chinese diet was 10.6 ± 1.5 mg/d. The phytic acid-to-zinc molar ratio in the diet was 6.4. The absorption rate of 67Zn was 27.9% ± 9.2%. The RNI of zinc, which were calculated by the absorption rate in elderly men and women, were 10.4 and 9.2 mg/d, respectively.</p><p><b>CONCLUSION</b>This study got the dietary Zn absorption in a Chinese elderly population. We found that Zn absorption was higher in elderly men than in elderly women. The current RNI in elderly female is lower than our finding, which indicates that more attention is needed regarding elderly females' zinc status and health.</p>

Clustering of Non-communicable Diseases Risk Factors in Healthy Adults Aged 35 Years and Older in Shenzhen, China / 生物医学与环境科学（英文）

We assessed the prevalence of non- communicable diseases (NCDs) risk factors with a focus on their clustering among healthy adults in Shenzhen, China. Data from the 2011 China Health and Nutrition Survey, comprising a regionally representative sample of 806 healthy adults aged 35 years or older, were obtained to determine the prevalence of five risk factors for NCDs. The prevalence of current smoking, central obesity, impaired fasting glucose, borderline hypertension, and borderline high total cholesterol was 19.97%, 28.29%, 4.47%, 10.55%, and 36.10%, respectively. A total 63.77% of participants had at least one risk factor. Upon examination of risk factor clustering, we observed that 7.57% of participants had at least three risk factors. Using this threshold as a cutoff, clustering of risk factors was associated with sex [odds ratio (OR) = 3.336, 95% confidence interval (CI): 1.782 to 6.246], physical activity (OR = 1.913, 95% CI: 1.009 to 3.628), and BMI (OR = 7.376, 95% CI: 3.812 to 14.270). The prevalence of risk factors for NCDs is fairly high among healthy adults in Shenzhen, with a clustering tendency.

Cut-off Values of Diagnostic Indices to Detect Iron Deficiency in Chinese Breast-fed Infants / 生物医学与环境科学（英文）

Iron deficiency anemia is one of the most prevalent nutritional deficiency worldwide. The commonly used cut-off values for identifying iron deficiency are extrapolated from older children and may not be suitable for infants. Therefore, our study aimed to establish appropriate cut-off values for the evaluation of iron status in Chinese infants. Pregnant women who delivered at ⋝37 gestational weeks with normal iron status were recruited. Later, infants with normal birth weight and who were breastfed in the first 4 months were selected. Blood samples were collected to assess hemoglobin, serum ferritin, soluble transferrin receptor, mean corpuscular volume and free erythrocyte protoporphyrin. Cut-offs of all iron indices were determined as the limit of 95% confidence interval.

Effectiveness analysis on the physical activity and the health benefit of a community population based program / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To evaluate the community-based health promotion effect of physical activity.</p><p><b>METHODS</b>The residents aged 18 and above from two communities in Gongshu District of Hangzhou City, Zhejiang province, were randomly selected and recruited for the multi-strategy and comprehensive physical activity intervention. Questionnaire survey, physical check up and blood biochemistry were conducted.</p><p><b>RESULTS</b>After this two-year intervention, the time of the participant spent on weekly physical activity of moderate intensity increased from 464 min to 542 min (P<0.05), with an average increase of 78 min. Time spent in walking every week increased from 533 min to 678 min (P<0.05), with an average increase of 145 min. The body weight, waistline, blood pressure and heart rate all reduced significantly (P<0.05); the vital capacity increased significantly (P<0.05); and the related biochemical indicators were also improved.</p><p><b>CONCLUSION</b>Comprehensive and evidence-based physical activity interventions targeting community population can improve the levels of physical activity, related body measurement and biochemical indicators.</p>

The influence of preventive iron supplementation to iron nutritional status in breastfed infants / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze the effects to iron status who were given preventive iron supplements for two months from when they were breast-fed to four-month-old.</p><p><b>METHODS</b>A total of 123 infants in four-month-old age who were breast-fed were randomly divided into iron supplementation group (63 cases) and control group (60 cases), iron supplementation group was supplied with low-dose iron (1 mg×kg⁻¹×d⁻¹) for two months with no intervention for control group. Blood samples were collected to test C reactive protein and iron status indicators in six-month-old age group infants, and the growth indices were measured and compared on the gender difference of iron status at and 6 months.</p><p><b>RESULTS</b>After 2 months of low-dose iron supplementation, the hemoglobin of iron supplementation group (26 cases) increased about 5.5 g/L while the control group (34 cases) increases about 0.0 g/L (median), 95% confidence intervals were -7.0 - 13.0 g/L and -9.0 - 15.0 g/L, respectively. The hemoglobin increase of iron supplementation group was higher than the control group, the difference was statistically significant (u = -2.326, P < 0.05). The other iron nutritional status and the growth did not show any significant difference between iron supplementation group and control group (P > 0.05). At age 6 month, the MCV of the boys were (75.89 ± 3.34) fl, while the girls were (77.20 ± 3.17) fl. The boys had lower values of MCV than the girls, and the gender difference was statistically significant (t = 4.73, P < 0.05). The other iron nutritional status did not show any significant gender difference (P > 0.05).</p><p><b>CONCLUSION</b>Low-dose iron supplementation of breast-fed infants at 4-month-old can increase the hemoglobin level when they were 6-month-old, and had no measurable side effect on growth.</p>

The effects of iron stores and growth of delayed umbilical cord clamp timing on term breastfed infants at 4 months / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore whether delayed umbilical cord clamp timing of newborn can improve iron stores of infant period and growth and development.</p><p><b>METHODS</b>Mother-infant pairs were randomly assigned to early clamping (94 cases, < 15 s after delivery) and delayed clamping (64 cases, 1 min after delivery) by draw lots, and followed up until 4 months postpartum. Infant hematological status, iron status, the level of growth and development of infants after 4 months were measured respectively. Transcutaneous bilirubin at the third day after delivery was also measured.</p><p><b>RESULTS</b>At 4 month age, the median of serum ferritin and mean of corpuscular volume value in delayed group were 87.30 µg/L and (79.62 ± 4.13) fl, significantly higher than the values in early group (64.3 µg/L, (78.21 ± 4.38) fl), respectively (Z = -2.36, t = 2.23, both P values < 0.05). The hematocrit value was (33.59 ± 2.48)%, higher than that in early group (32.76 ± 2.69)% (t = 1.95, P = 0.05). There was no statistically significant difference at other iron nutrition indicators and infants' weight and body length at 4 month (P > 0.05). Under the different cut-off values (hemoglobin (Hb) < 105 g/L and Hb < 110 g/L, respectively), the prevalence of anemia in delay and early clamping group were 6.25% (4/64), 21.86% (14/64), and 12.77% (12/94), 34.04% (32/94), respectively (both P values > 0.05).</p><p><b>CONCLUSION</b>Delayed umbilical cord clamp timing until 1 min can improve iron stores of breastfed infants at 4 month; there is no significant adverse effects to growth.</p>

Relatively high bone mineral density in Chinese adolescent dancers despite lower energy intake and menstrual disorder / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>The effect of dietary restriction, intense exercise and menstrual dysfunction on bone mineral density remains controversial. The aim of this study was to assess the skeletal health status and relationship between bone mineral density and nutrient intake, menstrual status, estrogen level and other factos in Chinese adolescent dancers.</p><p><b>METHODS</b>Sixty dancers and 77 healthy controls underwent measurements of bone density, body composition, and estrogen level. Nutrient intake, menstrual status and physical activity were assessed with questionnaires. The correlation between these factors were analyzed.</p><p><b>RESULTS</b>The dancers under study had a significantly lean body mass index (18.3 +/- 1.4 kg/m2 vs. 21.7 +/- 3.1 kg/m2), lower percentage of body fat (0.25 +/- 0.05 vs. 0.34 +/- 0.04) and later age at menarche (14.0 +/- 0.9 y vs. 13.0 +/- 1.3 y), and the estrogen level, daily calorie and fat intake in them were also lower than in the controls. All the dancers undertook intensive physical activity every day and up to 69% of them suffered from irregular menarche. Yet they had relatively high BMD and BMC of the total body and legs than the controls after adjusting for BMI and age. Site-specific BMD was positively correlated to BMI, body composition and training hours per week and negatively correlated to the age at menarche and menstrual frequency.</p><p><b>CONCLUSIONS</b>The relatively high BMD and BMC of the dancers at the total body and legs were probably caused by high levels of weight-bearing physical activity. To ameliorate disordered eating, especially low energy intake might be helpful to prevent the Triad and to improve the bone health in adolescent dancers.</p>

Correlation of serum leptin level with bone mineral density and bone turnover markers in Chinese adolescent dancers / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate plasma leptin concentrations in adolescent female dancers and to determine whether leptin has some effects on their bone mineral density (BMD) and bone turnover markers.</p><p><b>METHODS</b>Sixty dancers aged 15-17 years and 77 healthy controls were enrolled in the study. Bone mineral density (BMD) and body composition were detected by dual energy X-ray absorptiometry. Serum leptin concentrations were measured by radioimmunoassay (RIA). Two bone turnover markers, bone-specific alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase(TRACP), were determined by ELISA.</p><p><b>RESULTS</b>The dancers had a lower fat mass and a lower leptin level than the controls, while they had a relatively higher BMD of the total body and legs after adjustment for BMI and age. The levels of bone resorption and formation of markers were higher in the dancers than in the controls. Leptin was positively correlated with BMI, body weight, fat mass, and percentage of body fat. In dancers, Leptin was positively correlated with the BMD of the total body and the left leg. However, after adjustment for BMI, no correlation of serum leptin concentrations with BMD values was found in either dancers or controls. Nor correlation was found between leptin and bone turnover markers after adjustment for BMI.</p><p><b>CONCLUSION</b>The leptin profile is different between the controls and the dancers with a lower BMI and a lower fat mass. Circulating plasma leptin level depends on BMI and is not a direct determinant of BMD in Chinese adolescent dancers.</p>

Association of estrogen receptor-alpha gene Pvull polymorphisms with the effect of calcium supplementation on skeletal development in Chinese pubertal girls / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the association of estrogen receptor alpha (ER-alpha) PvuII polymorphisms with the effect of calcium supplementation on bone development in Chinese pubertal girls, and to study the importance of calcium supplementation by maximizing the peak bone mass at their pubertal stage for bone development and osteoporosis prevention and the role of estrogen in regulating bone mass.</p><p><b>METHODS</b>Ninety-four pubertal girls were recruited in the study and divided into two groups and three sub-groups according to the ER-alpha PvuII polymorphisms. One year before and after calcium supplementation, bone mineral density (BMD) was measured by DEXA, while BGP, BAP, TRACP5b, and 25-OH-VitD(3), as well as estrogen were detected by ELISA. Analysis of covariance was used to examine the effect of ER-alpha polymorphisms on bone development.</p><p><b>RESULTS</b>The absolute increase and percentage change of BGP were significantly higher in the supplemented group than in the control group (P<0.05). In the intervened group, The increase and percentage change of the total body and radio distal 1/3 BMD were higher in PP than in PP genotype (P<0.05), and the increase of BAP in Pp was also higher than PP in the same group (P<0.05).</p><p><b>CONCLUSION</b>PP genotype shows a better response to calcium supplementation than the other PvuII polymorphisms.</p>

The differences in bone mineral content between female dancers and controls aged 15 - 17 years old and its relationship with physical activity level / 中华预防医学杂志

<p><b>OBJECTIVE</b>To assess bone mineral content (BMC) of 15 - 17 year-old dancers and high school females and analyze the relationship between physical activity status and BMC.</p><p><b>METHODS</b>Sixty dancers and 77 healthy controls aged 15 - 17 years old were enrolled in our study. BMC in the total body and forearm were measured by dual-energy X-ray absorptiometry (DEXA) while body weight and height were also measured. Physical activity information was collected by "one-year physical activity questionnaire".</p><p><b>RESULTS</b>The physical activity level (PAL) and the average daily energy expenditure (EE) of dancers were all higher than controls (PAL: 2.17 +/- 0.34 vs 1.63 +/- 0.34, t = 7.283; EE: (6876.43 +/- 1036.72) kJ vs (5388.43 +/- 920.83) kJ, t = 7.214, both P values < 0.01). The dancers showed lower BMC/height at total body and arms compared with the controls (the total body BMC/height was (13.896 +/- 1.308) vs (14.494 +/- 1.272) g/cm, F = -2.563); and the BMC/height of left and right arm were (0.779 +/- 0.088) vs (0.829 +/- 0.101) g/cm (F = -2.892) and (0.766 +/- 0.093) vs (0.829 +/- 0.097) g/cm (F = -3.650) respectively, all these P values were < 0.01.Yet after adjusting age and BMI, the dancers showed higher BMC/height at total body and legs, the corresponding values were (14.550 +/- 0.146) vs (13.947 +/- 0.131) g/cm (F = 7.868), (2.681 +/- 0.033) vs (2.389 +/- 0.030) g/cm (F = 36.520), (2.821 +/- 0.031) vs (2.450 +/- 0.028) g/cm (F = 65.279), all these P values were < 0.01. While no differences were found with controls at non-weight bearing sites (arms). Daily period (h) of training was significantly related to BMC/height of legs, total body (r value were 0.618, 0.448 and 0.554 respectively, all the P values < 0.01), while the history of training was also correlated with BMC/height of two legs (r value were 0.38 and 0.304 respectively, both P values < 0.05).</p><p><b>CONCLUSION</b>The adolescent dancers showed higher BMC after adjusting age and BMI, which was attributed to the long-term high level weight-bearing physical activity.</p>

Study on the association between estrogen receptor-alpha gene polymorphisms and pubertal skeletal developmental status in China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To investigate the association between estrogen receptor-alpha (ER-alpha) gene polymorphisms, pubertal bone mineral density (BMD) and bone turnover markers, to better understand the frequencies of ER-a genotypes.</p><p><b>METHODS</b>The ER-alpha Pvu II and Xba I genotypes were determined by PCR-RFLP in 158 healthy adolescent girls (12-14 years old) while BMD was measured by dual-energy X-ray absorptiometry (DEXA). The bone turnover markers (BAP, BGP, TRACP) and calcium adjust hormone (25-OH-VitD, E2) were detected by ELISA. The relationship among BMD, bone turnover markers, and polymorphisms of ER-a were examined.</p><p><b>RESULTS</b>(1) Although the bone turnover markers had a trend in ER-alpha Pvu II genotypes as pp>PP>Pp but no significant difference was found (P > 0.05). There were no significant differences found among Xba I genotypes and between Px haplotype and non-Px haplotype. (2) No association was noticed between ER-a genotype and BMD at any site of the forearm and the whole body. Compared with non-Px haplotype, the Px haplotype had lower BMD, but there was no significant difference noticed (P > 0.05).</p><p><b>CONCLUSION</b>ER-alpha gene Pvu II and Xba I polymorphism seemed not potentially influence on BMD and bone turnover markers in the pubertal girls in Beijing, suggesting that it might not be the major genetic factor regarding this population.</p>

Preparation of monoclonal antibody against HPT and its application to detecting marker protein in genetically modified rice / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To produce the monoclonal antibodies (mAbs) against hygromycin B phosphotransferase (HPT) and to develop immunoassay based on mAbs for biosafety assessment of HPT in genetically modified rice (GM rice).</p><p><b>METHODS</b>BALB/c mice were immunized with purified recombinant 6His. HPT protein, and the conventional hybridoma technology was used to generate the monoclonal hybridoma cells. ELISA and Western blot were used to analyze the specificity of mAbs recognizing HPT and the cross reaction with other proteins. A double-Ab sandwich ELISA method was established to detect HPT expression level in the sck gene-modified rice plants.</p><p><b>RESULTS</b>Four hybridomas, named F1, D4-2, D4-4, and D4-5, producing the mAbs against HPT were successfully obtained with the titer of ascetic mAbs ranging from 1x10(-4) to 1x10(-5). Identification of subclass showed that all the produced mAbs belonged to IgG1. Western blot showed specific binding reaction between the mAbs to the HPT proteins expressed in the GM rice. A double sandwich ELISA coated with anti-HPT polyclonal antibody was established with mAbs as sandwich antibody, which showed a sensitivity of 30ng/mL and did not crossreact with other proteins. The expression level of HPT in the leaves of sck-transformed lines was detected (80-150ng/mL). But HPT protein in the grain and seed of GM rice could not be detected using this ELISA assay.</p><p><b>CONCLUSION</b>Anti-HPT mAbs prepared herein have a high specificity and can be used for rapid assay of HPT antigen. The expression level of HPT in the GM rice grain and seed is lower than our ELISA detection limit.</p>

Purification and immunity analysis of recombinant 6His-HPT protein expressed in E. coli / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To obtain HPT protein (Hygromycin B Phosphotransferase), a kind of plant selective maker gene product expressed from E. coli and to prepare the polyclonal antibody (pAbs) against it.</p><p><b>METHODS</b>HPT cDNA fragment was obtained by PCR and was inserted into the prokaryotic expressing vector pBV222. Then the constructed recombinant plasmid pBV222-HPT was transferred into E. coli DH5alpha for HPT expression. The recombinant expressing system was confirmed by restriction endonuclease digestion, DNA sequencing and protein expression. E. coli cells were lysed by sonication and detergent dissolution. After cell membrane was extracted, the inclusion bodies were denatured by 8 mol/L Urea and purified with metal chelate affinity chromatography on Ni-NTA agarose under denaturing condition. The purified 6His-HPT was characterized by SDS-PAGE, and used to immunize rabbit. The titer and specificity of antisera were detected by ELISA and Western blot respecitively.</p><p><b>RESULTS</b>Analysis of DNA sequence and restricted enzymes showed that the sequence of PBV222-HPT plasmid was correct. The amount of recombinant HPT expressed in E. coli accounted for 30% of total cellular proteins. From 1 liter of fermentative bacteria about 22 milligrams of pure recombinant HPT was isolated with purity above 95%. The recombinant HPT protein could produce high titer antiserum in rabbits and show good immunity activity. Western blot showed specific binding reaction between the antiserum to the purified 6His-HPT protein and their expressed products (plants protein and bacterial protein).</p><p><b>CONCLUSION</b>HPT protein can be expressed and purified from E. coli by a relatively simple method, which has high immunity activity.</p>

Fusion expression, purification and bioactivity assay of CpTI in Escherichia coli / 生物工程学报

CpTI (Cowpea Trypsin Inhibitor) is a widely used insect resistance gene in the plant genetic engineering for its high insecticidal activity and the minimal ability of the insects to evolve resistance to it. To facilitate the safety assessment of genetically modified foods (GMFs) with CpTI protein, we need to produce gram quantities of this protein in microbes. With the pGEX fusion expression system, we expressed the GST-CpTI protein in E. coli BL21, which accounted for approximately 40% of germ proteins. By Glutathione Sephrose 4B affinity chromatography, GST-CpTI was obtained with the purity up to 90%. Overnight incubate the fusion proteins with Thrombin protease, we got the CpTI proteins cleavage of GST tag. Both of the GST-CpTI and CpTI proteins showed notable trypsin inhibitor activity. Immunization of rabbits with purified fusion protein generated high titer antibodies (> 20000), measuring by ELISA. Western Blotting also showed specific Ag-Ab binding band between the antiserum and the CpTI proteins no matter in the whole supersonic germ proteins or purified from the column. All these made a good ground for the further safety assessment of CpTI protein.