[Analysis for the blood mineral content of children aged 3 to 12 years in 7 cities and 2 towns in China].

OBJECTIVE: To investigate the status of blood mineral content of children aged 3 to 12 years in Chinese cities and countryside and explore the possible related influencing factors. METHODS: The multistage stratified cluster random sampling was used to select one kindergarten and one primary school in seven cities (Beijing and Guangzhou and so on) and two towns randomly. Firstly, we selected one bottom class, middle class, top class in one kindergarten and one second grade and fifth grade in one primary school randomly. Then all of the healthful students of these classes were investigated and the blood mineral content of calcium, magnesium, lead, iron, copper, and zinc were detected. RESULTS: In the research, 1 842 students were investigated. The means of calcium, magnesium, lead, iron, copper, and zinc were in the standard range. The blood lead content of the boys was higher than that of the girls. The blood mineral content of different ages had statistical significance. The blood calcium and blood copper contents of the preschool children were higher than those of the school children. However, the school children had significantly higher blood lead, iron, and zinc contents in comparison with those of the preschool children. The incidences of iron deficiency and zinc deficiency were 35.5% and 39.6%, respectively. The incidence of iron deficiency and zinc deficiency of different ages had statistical significance, and with the age increasing, the incidence showed a decreasing trend. The incidences of iron deficiency and zinc deficiency of children whose age was more than or equal to 3 years and less than 4 years were up to 47.1% and 64.6%, respectively. The incidence of iron deficiency of the children in the countryside area was significantly higher than those in the first-tier cities. However, the incidence of zinc deficiency of the children in the countryside area was significantly lower than those in the first-tier cities and second-tier cities. CONCLUSION: The status of iron deficiency and zinc deficiency of children aged 3 to 12 years in Chinese cities and countryside were still serious. We should pay more attention to the nutrition interventional research on iron and zinc.

The chemical composition of human milk from Inner Mongolia of China.

In Inner Mongolia, China, the chemical composition of 66 breast milk samples at three lactation stages was analysed. Except for total nitrogen content, the contents of total solid, fat, NPN, lactose and ash were not significantly different between colostral, transitional and mature milk. Fatty acids did not vary over the three lactation stages, while unsaturated fatty acids accounted for 59.95-63.22% of the total fatty acids. Relatively low contents of vitamins were in the milk because the volunteer mothers did not take any vitamin supplementation over the entire lactation period. Besides sodium and phosphate, the concentrations of most minerals in the breast milk remained fairly constant across the three lactation stages.

[Application of solid sampling graphite furnace atomic absorption spectrophotometry to mensuration of brain iron content in rats].

In the present study, the authors performed the solid sampling and detected the iron levels in cortex, hippocampus and striatum of rat brain by GFAAS. The authors' results showed that there are no remarkable difference between the data obtained by solid sampling graphite furnace atomic absorption and liquid sampling graphite furnace atomic absorption. Compared to liquid sampling graphite furnace atomic absorption, the sample pre-treatment stage was obviously simplified, the cost was reduced significantly, and the time was shortened significantly in the solid sampling GFAAS. This study will be beneficial to the mensuration of iron content in micro-tissue of animal by solid sampling GFASS.

Amino acid composition of lactating mothers' milk and confinement diet in rural North China.

This study was designed to investigate the amino acids composition of lactating mothers' milk and their confinement diet in a town in Northern China, as well as to assess the relation of amino acids content in human milk and diet. Forty lactating mothers age 19 to 35 years participated in the study. They were 4 to 180 days postpartum. A 24-hour dietary recall was done and amino acids content of maternal milk was analyzed. The main findings are as follows: (1) The protein content of human milk is 1.58 g/dL and the ratio of EAA to NEAA is about 1:2. The most abundant amino acids in human milk are GLU (16.0%), PRO (10.2%), LEU (8.67%) and the lowest two are MET (1.76%) and TRP (0.91%). (2)The diet contains enough energy and protein, but lacks vitamins A, B and C, indicating that it is a characteristic confinement diet. Grain and eggs are the main source of protein, and soy and fish were consumed less frequently. (3) Amino acids composition in diet and milk are similar; and the correlation of the amino acids patterns between diet and milk is 0.989, demonstrating that the amino acid composition of diet is the foundation of that in human milk. However, almost no relation is found between the amino acids concentration in maternal diet and milk, suggesting that the amino acids content of the diet does not have a direct relation with that of human milk.

Purification and characterization of an immunomodulatory Peptide from bovine placenta water-soluble extract.

An immunomodulatory peptide was isolated from bovine placenta water-soluble extract and purified by consecutive chromatography on DEAE Sepharose CL-6B, Sephadex G-25, and Sephasil C18 column using lymphocyte proliferation assay to identify the active fractions. The immunomodulatory peptide showed a dose-dependent stimulating effect on lymphocyte proliferation. The isoelectric point of the immunodulatory peptide was determined to be 3.82 by capillary isoelectric focusing electrophoresis. The molecular mass of the immunomodulatory peptide was determined to be 2133.52 Da by mass spectrometry. The first 10 amino acid sequence of the immunomodulatory peptide was Tyr-X-Phe-Leu-Gly-Leu-Pro-Gly-X-Thr. This immunomodulatory peptide showed no significant homology with other immunomodulatory peptides. Additionally, it was thermostable, retaining about 60% of immune activity after incubating at 80 degrees C for 30 min.