[Association between development of hypertension and nutrition in school-age children in Fengdu County of Chongqing, China].

OBJECTIVE: To investigate the association between the development of hypertension and nutrition in school-age children in Fengdu County of Chongqing, China. METHODS: A total of 8 033 children from 2 public primary schools in Fengdu County of Chongqing, whose registered residence was in the subdistricts where the two schools were located, were selected as study subjects using cluster random sampling. Body height, body weight, and blood pressure were measured, and the semi-quantitative food frequency questionnaire was used for dietary survey. The association between body mass index (BMI), dietary nutrients, and the development of hypertension in children was analyzed. RESULTS: A total of 7 538 children were enrolled for analysis. The detection rates of obesity, overweight, and hypertension were 9.11%, 12.27%, and 11.83% respectively. In children with obesity and overweight, the detection rate of hypertension was 33.62% and 17.84% respectively, 4.02 and 2.13 times that in normal children. The multivariate logistic stepwise regression analysis revealed that increased intake of calcium and sodium increased the risk of hypertension (OR=1.003 and 1.002 respectively), while the increased iron intake and calcium intake per unit body weight reduced the risk of hypertension (OR=0.979 and 0.926 respectively). CONCLUSIONS: The prevalence of hypertension and obesity in school-age children in Fengdu County of Chongqing is high. BMI and dietary nutrients are closely associated with the development of hypertension in children. Active control of body weight, adjustment of dietary structure, and limitation of sodium intake should be adopted to reduce the development of hypertension in school-age children.

[Effect of dietary vitamin A intake on plasma vitamin A concentration in preschool children of Banan district, Chongqing, China].

OBJECTIVE: To study the relationship between dietary vitamin A intake and plasma vitamin A concentration, and establish the theoretical basis for dietary intake predicting vitamin A nutritional status. METHODS: By using cluster sampling, 492 children aged 2-7 years in kindergartens in Banan district of Chongqing were selected. A cross-sectional nutrition and health survey was conducted, including the clinical examination, anthropometry, laboratory test and dietary survey. RESULTS: Among the children surveyed, 229 were boys, and 263 girls, the mean age was (4.54 ± 0.87) years, height (107.50 ± 7.20) cm, and weight (18.42 ± 3.41) kg, the mean value of plasma vitamin A was (1.04 ± 0.30) µmol/L. The prevalence of marginal vitamin A deficiency (MVAD) was 43.5%. No cases of severe clinical vitamin A deficiency were found (plasma vitamin A ≤ 0.35 µmol/L). Clinical examination found no conjunctiva, corneaor skin abnormalities, and no Bitot's spots. Prevalence of the last two weeks colds were 27.4% (135/492), no diarrhea and other gastrointestinal or digestive diseases were found. The proportion of insufficient dietary vitamin A intake (<600 µg RE/d) was as high as 50.0%. By using correlation analysis, plasma retinol concentrations were related to dietary vitamin A intake (r=0.162, P<0.001), and to dietary energy intake (r=0.107, P=0.017). After adjustment for the effects of other non-dietary factors on vitamin A deficiency, the multivariate logistic regression showed that vitamin A-rich foods of liver intake=0 g/d (OR=1.95, 95% CI: 1.05-3.61, P=0.034), vitamin A-rich fruits intake=0 g/d (OR=1.55, 95% CI: 1.03-2.33, P=0.034), vitamin A-rich vegetables intake<200 g/d (OR=3.47, 95% CI: 1.37-8.75, P=0.009) were important risk factors of vitamin A deficiency. But we had not found the correlation between the intake of meat, eggs and milk and vitamin A deficiency. CONCLUSION: Dietary factors may be the major risk factor of vitamin A deficiency in the three kindergartens. The dietary vitamin A intakes are significantly related to plasma retinol concentrations, and the vitamin A-rich foods intakes can predict the body's vitamin A nutritional status.

Effects of vitamin A, vitamin A plus zinc, and multiple micronutrients on anemia in preschool children in Chongqing, China.

This study is to clarify the impact of vitamin A or vitamin A combined with other micronutrients supplementation on anemia and growth in preschoolers. In the present study, a total of 290 preschoolers, aged 36-72 months old were randomly assigned to 3 treatment groups: vitamin A (A group), vitamin A plus zinc (AZ group), and vitamin A combined with additional multiple-micronutrient (AMM group). After 6-month supplementation, the height and height-for-age z-score gains of the AZ group were significantly higher than the other groups; the weight gain of the AMM group was greater than the other groups. Compared with baseline values, the concentrations of hemoglobin, and zinc at the end significantly increased in all 3 groups. The incremental concentrations of hemoglobin in the AMM group were significant higher than in the other two groups. Furthermore, the incremental concentrations of serum retinol in the AMM group, and the increase in serum zinc concentrations in the AZ group were significantly higher, respectively, than in the other groups. These 3 kinds of supplements in the present study are effective in enhancing height gains and are effective in reducing the prevalence of anemia. Supplementation of zinc plus vitamin A is a better way for improving children's height and height-for-age z-score. Vitamin A combined with multiple-micronutrient is more effective in improving the hemoglobin concentrations in preschool children.

Vitamin A deficiency impairs postnatal cognitive function via inhibition of neuronal calcium excitability in hippocampus.

Vitamin A (VA) is important for postnatal brain development, and VA deficiency (VAD) can cause learning and spatial memory deficits in rats. Most of the biological functions of VA are mediated by retinoic acid (RA). To investigate the mechanisms underlying VA deficits, mother rats were fed elemental diets to achieve blood VA levels classified as normal, deficient or severely deficient. Shuttle box and Morris water maze tests revealed impairments in learning ability and spatial memory, respectively, in adolescent VAD rats (p 30-35). Electrophysiology showed weaker long-term potentiation in VAD rats compared to VA normal rats. Examination of NMDA-induced calcium (Ca(2+) ) excitability revealed decreased excitability in hippocampal slices from VAD rats during postnatal development. Relative to VA normal rats, VAD rats also had decreased NMDA receptor NR1 mRNA and protein expression in later stages of postnatal development (p 10-30), as well as differences in retinoic acid receptor (RARα) mRNA and protein expression. Furthermore, primary hippocampal neurons in culture showed increased neuronal Ca(2+) excitability in response to all-trans-RA or 9-cis-RA, coupled with increases in RARα and NR1 expression similar to those observed in vivo. We also found weaker calcium excitability and lower expression of NR1 mRNA and protein after specific silencing of RARα. Finally, we found that RA signals affected the expression of NR1 do not directly through transcriptional regulation. These data support the new idea that continuous postnatal VAD inhibits RARα expression, which decreases NR1 expression via no direct transcriptional regulation and then inhibits hippocampal neuronal Ca(2+) excitability which affects long-term potentiation, finally producing deficits in active learning and spatial memory in adolescence.

[Impact of antioxidant vitamins and heavy metal levels at birth on neurodevelopment of children assessed at two years of age].

OBJECTIVE: Epidemiologic study on the perinatal interaction of antioxidant vitamins and heavy metals on offspring's intellectual development is extremely limited. The aim of this prospective cohort study was to investigate the status of maternal and cord blood antioxidant vitamins (Vitamin A, E and C) and heavy metals (lead, cadmium and mercury) at delivery and correlations between these antioxidant vitamins or metals and neurodevelopment of early childhood, and to explore the protective effect of antioxidant vitamins against the injure of heavy metals to intellectual development in children in Tongliang, Chongqing, China. METHOD: A total of 150 pairs of mothers-neonates were recruited. Serum concentrations of vitamin(V) A, vitamin E, vitamin C, lead, cadmium and mercury in maternal and cord blood after delivery were determined and intellectual development was evaluated by Gesell Development Schedule (GDS) at two years of age. RESULT: A total of 111 pairs of maternal-neonatal subjects with completed data were included into statistical analysis. After adjusting for potential confounders, cord blood mercury level was found negatively associated with all the development quotients (DQs) (ß = -0.486, ß = -0.716, ß = -0.846, ß = -0.935, ß = -0.702, P < 0.05). Cord VE level was positively correlated with motor, adaptation, language and average DQ (ß = 0.475, ß = 0.458, ß = 0.403, ß = 0.395, P < 0.05). When antioxidant vitamins and heavy metals levels were all included into the multiple regression model, cord vitamin E level was statistically positively related with motor, adaptation and average DQs (ß = 0.449, ß = 0.412, ß = 0.349, P < 0.05). While cord blood mercury level was negatively correlated with adaptation, language, social and average DQ (ß = -0.397, ß = -0.727, ß = -0.935, ß = -0.628, P < 0.05), the relationship between cord mercury level and motor DQ was not statistically significant (P = 0.0890). The motor, adaptation, language and average DQs in high cord VE group were higher than those in low VE group (t = 2.93, t = 2.06, t = 2.13, t = 2.27, P < 0.05). Social DQ in high cord lead group was significantly lower than that in low lead group (χ(2) = 5.56, P = 0.015). Cord VC level in high cadmium group was significantly lower than that in low cadmium group (χ(2) = 7.62, P = 0.006). VA placental transport ratio in high mercury group was significantly lower than those in low mercury group (χ(2) = 8.02, P = 0.005). CONCLUSION: Our data suggested that there may be certain interaction between antioxidant vitamin A, E, C and heavy metals lead, cadmium, mercury. Antioxidant vitamins at delivery may have protective effect on the early neurodevelopment via interaction with the heavy metals.

Effect of marginal vitamin A deficiency during pregnancy on retinoic acid receptors and N-methyl-D-aspartate receptor expression in the offspring of rats.

This study examined whether pregnancy-related marginal vitamin A deficiency (MVAD) influences postnatal development of retinoic acid receptors (RARs) and N-methyl-D-aspartate (NMDA) receptor subunit 1 (NR1) in hippocampus of rat pups. Sixteen female rats were randomized equally into control and MVAD groups. Dams and pups were fed with either a normal control diet or one deficient in vitamin A. Eight female pups in each group were killed at 1 day, 2 weeks, 4 weeks and 8 weeks after birth, respectively. Serum retinol levels were monitored. The messenger RNA (mRNA) and protein expressions and subcellular localization of RARα, RARß and NR1 in postnatal hippocampus were detected. At 1 day, 2 weeks and 8 weeks after birth, serum retinol levels in the MVAD group were significantly lower than those in the control group. Results of Morris water maze test at 7 weeks of age showed that spatial learning and memory in the MVAD group were affected. Vitamin A deficiency resulted in decreased mRNA levels of RARα, RARß and NR1 (P<.05). The protein level of RARα and NR1 in the MVAD group was lower than that of the control group (P<.05). There was no significant difference in RARß between the groups (P>.05). A mass of RARα and NR1 colocalized in hippocampal cell cytoplasm on postnatal day 1. Our data suggested that vitamin A deficiency in pregnancy may affect the postnatal expression of RARα and NR1, affecting learning and memory function in the hippocampus and synaptic plasticity of the calcium signaling pathway.

The pattern of retinoic acid receptor expression and subcellular, anatomic and functional area translocation during the postnatal development of the rat cerebral cortex and white matter.

Retinoic acid (RA), which is an important modulator of brain development, neural cell proliferation, neurite outgrowth, and synaptic plasticity, is regulated via changes in RA receptors. The pattern of RA receptor changes in the rat cerebral cortex and white matter during postnatal development has not been extensively studied. Therefore, we studied the mRNA expression patterns of 6 RA receptors in the postnatal rat cerebral cortex and white matter at 1, 3, 7, 10, 14, 21, 28, and 35days. We found that RARß, RXRα and RXRß mRNA levels gradually increased during postnatal development. RARα presented a nearly unimodal trend, but RARγ and RXRγ were generally bimodal. RARα, RARγ, and RXRγ mRNA levels peaked at postnatal day 21 (P21). The pattern of RARα expression was consistent with that of its mRNA levels. RARα and RXRγ mRNA levels were the highest among those of all RA receptors during postnatal development. Interestingly, RARα expression was mainly located in the cytoplasm in the postnatal development apart from P3d. We further showed that RARα is expressed mainly in layers 2 and 3, partly in layers 1 and 4, and in a limited manner in layers 5 and 6 in the parietal cortex. Most RARα expression occurs in layers 2, 3, and 4 in the temporal lobe cortex. We realized that the M1 S2 region of RARα is highly expressed and that the position of RARα changes dynamically to meet the needs of different regions during development. These results support the idea that the RA receptor plays an important role in the cerebrum during postnatal development and implementation of these functions may be mainly dependent on the non-transcriptional or post- transcriptional regulation.

[Effects of vitamin A, vitamin A plus iron and multiple micronutrient-fortified seasoning powder on iron metabolic homeostasis].

OBJECTIVE: To evaluate the effect of vitamin A, vitamin A plus iron and "7 + 1" multiple micronutrient-fortified seasoning powder on iron metabolic homeostasis in preschool children. METHODS: This was a randomized, controlled and blinded interventional field trial. A total of 226 2 - 7 years old preschool children were recruited from three nurseries in the area, and they were randomly assigned into three different fortified diet groups for 6 months. The subjects in Group I were fortified with vitamin A; those in Group II and III were fortified with vitamin A plus iron and vitamin A plus iron, thiamine, riboflavin, folic acid, niacinamide, zinc and calcium (7 + 1), respectively. The concentration of serum vitamin A was measured by high-performance liquid chromatography (HPLC), serum ferritin (SF) was measured by enzyme-linked immunosorbent assay (ELISA), soluble transferrin receptor (sTfR) was measured by microparticle-enhanced, and hemoglobin (HB) by hemiglobincyanide, the sTfR-SF index (TFR-F index) and total body iron content were computed respectively before and after intervention. Simultaneously, children's demographic data, socio-economic status and eating habits, etc. were investigated by questionnaires. RESULTS: A total of 226 preschool children were included in the study with age ranged from 2 to 7 years with average age (4.0 ± 0.85) (means ± standard deviation). The prevalence of anemia, deficient iron storage, vitamin A deficiency (VAD) and suspect sub-clinical vitamin A deficiency (SSVAD) were 23.5%, 15.0%, 6.3% and 25.9%, respectively. The levels of SF and sTfR significantly decreased after intervention in all groups (χ(2) = 8.3298, χ(2) = 16.1471, χ(2) = 15.1371, χ(2) = 15.1171, χ(2) = 5.2617, χ(2) = 4.8844, P < 0.05) especially in group II and group III for SF (χ(2) = 16.1471, χ(2) = 15.1371, P < 0.05) and group I for sTfR (χ(2) = 15.1171, P < 0.05). No marked change of TFR-F index and total body iron contents was observed in group I (t = 0.1817, t = 1.7736, P > 0.05), while TFR-F index decreased and total body iron contents increased in group II and group III (t = 5.3561, t = 6.5979, t = 11.1663, t = 8.7306, P < 0.05) after intervention. CONCLUSION: Vitamin A intervention has significant effect on iron storage and mobilization but seldom effect on iron absorption in small intestine. The combination of vitamin A and other micronutrients might be a better intervention for the improvement of iron deficiency for preschool-children.

Effect of vitamin A, vitamin A plus iron and multiple micronutrient-fortified seasoning powder on infectious morbidity of preschool children.

OBJECTIVE: Improvement of hemoglobin and serum retinol and facilitation of the mobilization of iron storage were achieved with a multiple-micronutrient-fortified diet in preschoolers for 6 mo in a suburb of Chongqing, China. We investigated whether fortification with multiple micronutrients in a diet for preschool children results in changes in children's infectious morbidity compared with diets fortified solely with vitamin A and with vitamin A plus iron. METHODS: From December 2005 to June 2006, 226 2- to 6-y-old preschool children were recruited from three nurseries randomly assigned to three different fortified-diet groups for 6 mo. Group I was fortified with vitamin A; groups II and III were fortified with vitamin A plus iron and vitamin A plus iron, thiamine, riboflavin, folic acid, niacinamide, zinc, and calcium, respectively. The secondary functional outcomes, morbidity of diarrhea and respiratory infection, were collected during supplementation. RESULTS: The groups were comparable concerning compliance and loss to follow-up. There was evidence of a lower incidence rate of respiratory-related illnesses, diarrhea-related illness, fewer symptoms of runny nose, cough, and fever, and shorter duration of respiratory-related illnesses and cough for children in group III compared with children in groups I and II. However, there was no significantly or clinically important difference between children in groups I and II. CONCLUSION: The beneficial effects on infectious morbidity over 6 mo, in addition to some biochemical improvements, highlight the potential of this micronutrient-fortified seasoning powder supplied in a diet for preschool children.

[Primary culture of rat hippocampal neurons and detection of the neuronal excitability].

OBJECTIVE: To improve the efficiency of primary culture of hippocampal neurons and obtain highly purified neurons with good in vitro growth and minimal risk of contamination. METHODS: The hippocampal neurons of neonatal Wistar rats were isolated and the single cell suspension was prepared by mechanical trituration and sedimentation in stead of trypsin digestion and filteration. Twenty-four hours after the cell plating, the culture medium was removed and replaced by serum-free DMEM/F12 with B27 supplementation. Half of the culture medium was changed 2-3 times every week. The morphological changes of the neurons were observed under inverted phase-contrast microscope. Immunofluorescence staining for NSE was performed to identify the neurons, and the purity of neurons was calculated. The hippocampal neurons were stained with calcium-sensitive fluorescent dye to monitor the effect of KCl on neuronal excitability by a calcium imaging system. RESULTS AND CONCLUSION: This simplified method is time-saving and cost-effective for primary culture of hippocampal neurons with reduced risk of contamination, and the neurons obtained showed high uniformity, purity and long-term viability.

Effect of biscuits fortified with different doses of vitamin A on indices of vitamin A status, haemoglobin and physical growth levels of pre-school children in Chongqing.

OBJECTIVE: To investigate the efficacy of biscuits fortified with different doses of vitamin A on improving vitamin A deficiency (VAD), anaemia and physical growth of pre-school children. DESIGN: A randomised double-masked population-based field interventional trial with a positive control group. SETTING: Banan district of Chongqing, China. SUBJECTS: A total of 580 pre-school children aged 3-6 years were randomly recruited into four groups. Children in groups I and II were given biscuits fortified with vitamin A at 30 % of the recommended daily intake (RDA) and 100 % of the RDA once a day for 9 and 3 months, respectively. Children in group III received biscuits containing 20,000 IU of vitamin A once a week for 3 months. Initially, the children in group IV received a 200,000 IU vitamin A capsule just once. At the beginning and end of the study, blood samples were collected to measure Hb, serum retinol, retinol-binding protein and prealbumin, and weight and height were measured. RESULTS: All the fortification types significantly decreased the prevalence of VAD and anaemia in each group (P < 0.05). The effect of 9-month intervention on group I was the most efficient (P < 0.0045). After intervention, the Z-scores of height-for-age, weight-for-age and weight-for-height in all groups increased markedly compared with baseline (P < 0.05), but no significant difference was observed among the groups. CONCLUSIONS: Data indicated that consuming vitamin A-fortified biscuits with daily 100 % RDA for 3 months has the same effect on the improvement of VAD, anaemia and physical growth as did the weekly 20,000 IU and single 200,000 IU administration in pre-school children.

Co-assessment of iron, vitamin A and growth status to investigate anemia in preschool children in suburb Chongqing, China.

BACKGROUND: Anemia is a widespread public health problem, which is due to many factors, nutritional or non-nutritional. Iron, vitamin A and growth status were assessed to investigate anemia of preschool children in suburb Chongqing, China. METHODS: A descriptive, cross-sectional survey was performed on 459 preschool children aged 2 to 7 years randomly chosen from the kindergartens in 6 suburban districts of Chongqing. Weight and height levels, hemoglobin, erythrocyte protoporphyrin, serum retinol, and ferritin concentrations were measured to evaluate the anthropometric and nutritional status. RESULTS: The rates of stunt, underweight, overweight, wasting, obesity, anemia, iron deficiency, vitamin A deficiency (VAD), and marginal VAD were 6.3%, 3.9%, 3.7%, 1.5%, 3.1%, 23.5%, 15.0%, 6.3% and 25.9%, respectively. Serum retinol concentration was significantly lower in children with anemia than in those without anemia (P=0.003), and the retinol concentration was associated with hemoglobin (Pearson's correlation coefficient, r=0.22, P<0.01). Children with VAD had a significantly increased risk for anemia (odds ratio, 2.56; 95% confident interval, 1.15-5.70). In all 108 children with anemia, only 42 were related to VAD and 12 related to iron deficiency, suggesting that almost half of the anemia children cannot be explained solely by iron deficiency or VAD. CONCLUSIONS: Vitamin A and iron deficiency are still public health problems in some localities of China. Public health interventions in anemia control should be used to eliminate deficiencies of vitamin A, iron, and other micronutrients by deliberate supplementation. Attention must be paid to such deficiencies in high-risk groups, especially in preschool children.

Marginal vitamin A deficiency affects lung maturation in rats from prenatal to adult stage.

UNLABELLED: Mild or marginal vitamin A deficiency (MVAD) is still a serious and widespread public health problem in pregnant women and children in developing countries. This study investigated rat lung maturation from prenatal to adult stage during pregnancy and postnatal MVAD and the recovery after postnatal vitamin A supplementation (VAS). Adult female rats and their offspring were randomized into three groups. 1. CONTROL: the mothers and offspring received a normal diet.2. MVAD: The mothers and offspring received a MVAD diet.3. VAS: the mothers received MVAD diet till parturition, and then received the normal diet. The offspring of the VAS group were given low-dose vitamin A from postnatal day 1 to day 7 and received the normal diet after weaning. The lung development, structure, and collagen and elastic fiber of offspring were monitored by morphometric analysis at age 1 d, 2 and 8 wk, respectively. Lower body weight, lung weight, reduced numbers of alveoli and total alveolar surface area as well as increased alveoli septa thickness was observed in MVAD compared to that in the control animals. Increased collagen deposits and decreasing elastic fiber were found in MVAD rats. However, all of these were significantly improved in VAS-treated animals. These data suggest that the rat lung is sensitive to MVAD during the developing stage. Early postnatal vitamin A supplementation can partially restore the normal lung structure.

Antioxidant vitamin status during pregnancy in relation to cognitive development in the first two years of life.

OBJECTIVE: To investigate the correlation of the antioxidant vitamins status (vitamins A, E and C) during pregnancy and the intellectual development of early childhood. METHOD: A total of 150 paired maternal-neonatal subjects were recruited into the present study. The serum concentrations of antioxidant vitamins (vitamins A, E and C) in maternal blood and cord blood after delivery were determined by high performance liquid chromatography and the intellectual development was evaluated by Gesell Development Schedules (GDS) at two-years-old. RESULT: Children with higher cord serum vitamin E level showed higher scores of motor, adaptive domain and average compared to children with lower cord serum vitamin E level (p<0.01 or 0.05), respectively. Cord serum vitamin A level had significant positive correlation with effect on motor DQs (beta=4.227, p<0.05), and vitamin E level in cord blood showed a positive relation with motor DQ and average DQ (beta=0.329 and 0.1875, respectively, p<0.05) in multiple linear regression model. The language and social DQs were influenced by placental vitamin E transport rate (beta=3.1968 and 3.0194, respectively, p<0.05). The placental transport rate of vitamin E also was a protective factor for the prevalence of motor behavior developmental delay [OR: 0.118, 95% confident interval (95% CI), 0.018-0.765, p=0.0251], personal and social behavior developmental delay (OR: 0.052, 95% CI: 0.004-0.610, p=0.0185) and average developmental delay (OR: 0.041, 95% CI: 0.003-0.642, p=0.0229) in logistic multiple regression model. CONCLUSION: Data suggested that vitamin A, E status and vitamin E transfer rate at delivery had beneficial influence on children's cognitive and behavior development quotients.

Perinatal vitamin A status in relation to neurodevelopmental outcome at two years of age.

UNLABELLED: Information about the effect of antioxidant vitamins nutrition during pregnancy on offsprings intellectual development is extremely limited. OBJECTIVE: To investigate the correlation of antioxidant vitamins (Vitamin A, E and C) at delivery and the neurodevelopment of early childhood. METHOD: A total of 158 paired maternal-neonatal subjects were recruited. The serum concentrations of vitamin A, E and C in maternal and cord blood after delivery were determined and intellectual development was evaluated by Gesell Development Schedule (GDS) at two years old. RESULT: After adjusting for potential confounders, vitamin A placental transport ratio (VA-PTR) was positively associated with motor area development quotients (DQ) and average DQ(p<0.01). Cord VA level was positively related with language area and social area DQ (p<0.05). Nevertheless, there was no significant association between cord VE, VC levels, VE PTR or VC PTR and GDS. The adaptive area and average DQ in high cord VA group was higher than those in low VA group (p<0.05). Cord VA level and VA-PTR were positively associated with birth head circumference and birth weight, respectively. CONCLUSION: Our data suggested that adequate vitamin A at delivery had beneficial influence on neonatal birth outcomes and children's neurodevelopment in later childhood.

[Effects of bone marrow mesenchymal stem cells on learning and memory functional recovery in neonatal rats with hypoxic-ischemic brain damage].

OBJECTIVE: Neonatal hypoxic-ischemic brain damage (HIBD) causes acute death and chronic nervous system sequelae in newborn infants and children. Whereas there have been no specific treatment towards it up to now. Studies have shown that bone marrow mesenchymal stem cells (MSCs) have the therapeutic potential in many nervous system diseases and the authors previously found that retinoid acid (RA), which plays an important role in brain development, could enhance the neural differentiation of rat MSCs (rMSCs) in vitro. This study aimed to examine effects of rMSCs and RA-preinduced rMSC on learning and memory functional recovery after HIBD in neonatal rats in order to explore a new treatment strategy for clinical application, and explore the mechanism of action of rMSCs. METHODS: Rat MSCs were isolated and purified from the whole bone marrow of juvenile Wistar rats by removing the non-adherent cells in primary and passage cultures. Neonatal hypoxic-ischemic brain damage rat models were built according to the methods described by Rice: the right carotid artery of 7-day-postnatal Wistar rats was ligated under anesthesia, and then the rats were exposed to 8% - 9% O2 in a container. At 5 days after hypoxia-ischemia, the HIBD neonatal rats were randomly divided into 3 groups and respectively transplanted with saline, BrdU marked rMSCs (1 - 2 x 10(5)) or RA-preinduced rMSCs (1 - 2 x 10(5)) into their lateral cerebral ventricle. Immunohistochemistry for nestin, neuron-specific enolase (NSE), neurofilament protein-heavy chain (NF-H) and glial fibrillary acidic protein (GFAP) were used to identify cells derived from rMSCs at 14 days and 42 days after transplantation. Shuttle box test was performed to evaluate the condition of learning and memory functional recovery when animals were 7 weeks old. Neurotrophin and receptors cDNA microarray were also employed at 14 days after transplantation to investigate the underlying action mechanisms of rMSCs treatment. Real-time PCR was used to confirm some of the remarkably changed genes. RESULTS: (1) The neonatal rat model of HIBD was successfully established. (2) Immunohistochemistry showed rMSCs-derived cells survived, migrated into the hypoxic-ischemic brain tissue and a few of them expressed protein characteristic of neurons and astrocytes (NF-H and GFAP) in RA-preinduced group 14 days and 42 days after transplantation, while no positive expression of nestin and NSE were detected. (3) The shuttle box test showed that the average learning times in rats transplanted with saline, rMSC and RA-preinduced rMSCs were (94.10 +/- 38.18), (74.60 +/- 29.21) and (47.90 +/- 21.13), respectively. The difference between the former two was not significant (P > 0.05), while the latter one exhibited significant improvement (P < 0.05). (4) The cDNA microarray analysis showed that compared with normal control group, IL-6, Fas and BDNF genes of the saline control group significantly up-regulated (the ratios of the three genes were 11.4, 2.4 and 6.6 respectively). Compared with saline group, the three genes in rMSC group were down-regulated (the ratios were all 0.1), while the levels of IL-6 and Fas genes (the ratios were 0.3 and 0.4 respectively) in RA-preinduced rMSCs group were higher than rMSCs group after down-regulating, but the level of BDNF remained at the saline group level. Real-time PCR analysis suggested that the results of IL-6 and Fas genes were at equal level with microarray results on the whole, while the level of BDNF gene in RA-preinduced rMSC group was significantly down-regulated (with ratio of 0.34), but higher than rMSCs group (the ratio was 0.25) as well. CONCLUSION: Transplantation of rMSC and RA-preinduced rMSCs into lateral cerebral ventricle can improve learning and memory functional recovery after HIBD in neonatal rats, especially RA-preinduced rMSCs. Regulating the levels of IL-6, Fas and BDNF in the brain to maintain at reasonable levels may be the mechanism.

Effects of vitamin A, vitamin A plus iron and multiple micronutrient-fortified seasoning powder on preschool children in a suburb of Chongqing, China.

Preschool children in developing countries are likely to have multiple, concurrent micronutrient deficiencies. This study was designed to evaluate the effectiveness of different combinations of nutritional fortified diet to improve the blood levels of iron, vitamin A and other essential micronutrients in the preschool population of Banan District of Chongqing, China. From December 2005 to June 2006, a total of 226 2-6 y old preschool children were recruited from three nurseries in the area, and they were randomly assigned to three different fortified diet groups for 6 mo. Group I was fortified with vitamin A; groups II and III were fortified with vitamin A plus iron and vitamin A plus iron, thiamine, riboflavin, folic acid, niacinamide, zinc and calcium, respectively. Subjects' weight and height were measured for assessing the children's growth and development. Blood samples were taken at the beginning and the end of the 6-mo study period for measuring serum levels of micronutrients. Group III with the multiple micronutrient fortified diet was the most effective to improve the serum level of retinol from [media (P25, P75): 1.06 (0.89, 1.32)] micromol/L to 1.29 (1.04, 1.39) micromol/L (p<0.05) and retinol binding protein from 17.0 (12.6, 25.6) mg/L to 31.6 (24.4, 44.0) mg/L (p<0.05) and to mobilize the stored iron in the liver (p<0.05). In addition, the three groups' hemoglobin levels were elevated from 117.0 (109.0, 124.1) g/L, 114.0 (109.2, 119.7) g/L and 115.0 (109.5, 122.7) g/L to 125.7 (119.2, 133.1) g/L, 126.5 (122.2, 135.9) g/L and 125.1 (119.8, 131.6) g/L over the 6 mo of intervention period, but there were no difference among the three groups (p>0.05). Nevertheless, unexpected results were obtained when comparing the effects on growth status among the different supplement groups. Our study has demonstrated that a multiple micronutrient fortified diet for 6 mo is more effective to improve the levels of hemoglobin, serum retinol, and RBP as well as to facilitate the mobilization of iron storage in preschool children.

[Effects of early intervention on learning and memory in young rats of marginal vitamin A deficiency and it's mechanism].

OBJECTIVE: In recent years, some experiments on vitamin A-deprived animals reveal a progressive and ultimately profound impairment of hippocampal CA1 area's long-term potentiation and these losses are fully reversible by dietary vitamin A replenishment in vivo. Our previous study revealed that marginal vitamin A deficiency (MVAD) beginning from embryonic period impairs learning, memory and long-term potentiation (LTP) in young rats. But the losses might not be reversible if the vitamin A supplementation is late, especially when the critical period of hippocampus development is missed. The present study aimed to observe the recovery of learning and memory in vitamin A marginally deficient young rats after early intervention with vitamin A supplementation and begin to study the mechanism. METHODS: Rats were divided into control, MVAD, vitamin A intervention 1 (VAI1) and VAI2 groups in this study. In control group (10 young rats) the dams and pups were fed with normal diet (VA 6500 U/kg). In MVAD group (19 young rats) the dams and pups were fed with MVAD diet (VA 400 U/kg). In VAI1 group (10 young rats) the dams were fed with MVAD diet till day 14 of pregnancy, then were fed with normal diet and the pups were fed with normal diet. In VAI2 group (13 young rats) the dams were fed with MVAD diet till delivery, then were fed with normal diet and the pups were fed with normal diet too. All the young rats were killed at the age of 7 weeks. During the last week of the experiment, the shuttle box active avoidance reaction tests were carried out. At week 7, the hippocampal CA1 LTP was detected by electrophysiological technique. The expression of RAR-alpha, RAR-beta, RXR-beta, RXR-gamma, RC3 and tTG mRNA was detected by using semi-quantified RT-PCR in hippocampus. RESULTS: (1) The times to reach the learning standard in MVAD group (45.6 +/- 12.1) were more than those in control group (17.1 +/- 4.4) (P < 0.01), in both VAI1 group (20.8 +/- 3.1) and VAI2 group (22.1 +/- 4.0) were more than those in group MVAD (P < 0.01), and there were no significant differences among groups VAI1, VAI2 and control (P > 0.05) in active avoidance reaction tests. (2) The changes of field excitatory postsynaptic potentials (fEPSP) slope for MVAD group [(22.9 +/- 9.4)%] and VAI2 group [(39.1 +/- 4.33)%] were less than that of control group [(57.5 +/- 27.3)%], respectively (P < 0.05). No significant difference was found between VAI1 and control group (P > 0.05). (3) The expression of RAR-beta and RXR-beta mRNA decreased by 48.72% and 37.84% respectively (P < 0.05) compared with control, but the expression of RAR-beta mRNA in group VAI1 was higher than that in group MVAD (P = 0.065). The expression of RC3 mRNA in MVAD group was lower than that in control (P = 0.061) and RAR-alpha mRNA in MVAD group was higher than that in control (P = 0.061). The expression of RXR-gamma and tTG mRNA had no significant difference among different groups as determined with semi-quantified RT-PCR in hippocampus. CONCLUSION: Early vitamin A intervention may make the impaired learning and memory behavior due to marginal vitamin A deficiency recover to the normal level in young rats, but lip losses in group VAI2 might not be reversible. Vitamin A may modulate the expression of RC3 mRNA by affecting RAR-alpha, RAR-beta and RXR-beta to influence the LTP, learning and memory.

[Effects of marginal vitamin A deficiency and intervention on learning and memory in young rats].

OBJECTIVE: Previous studies have demonstrated that vitamin A and its active derivatives function as essential competence factors for long-term synaptic plasticity within the adult brain. But little is known if marginal vitamin A deficiency (MVAD) beginning from embryonic period affects the brain development and the ability of learning and memory in young rats. The aim of this study was to identify the effects of MVAD and vitamin A intervention (VAI) on learning, memory and the hippocampal CA1 long-term potentiation (LTP) in young rats. METHODS: Rats were divided into control, MVAD and VAI groups in this study. In control group (10 young rats) the dams and pups were fed with normal diet (VA 6500 IU/kg). In MVAD group (19 young rats) the dams and pups were fed with MVAD diet (VA 400 IU/kg). In VAI group (9 young rats) the dams were fed with MVAD diet and the pups were fed with normal diet from postnatal week 4. All the young rats were killed at the age of 7 weeks. During the last week of the experiment, the shuttle box active avoidance reaction tests were carried out. At week 7, the hippocampal CA1 LTP was detected by electrophysiological technique and relative intensity of fluorescence in cells in hippocampal slices was measured by confocal laser scanning microscopy labeled by fluo-3. RESULTS: (1) The times to reach the learning standard in both VAI group (28.8 +/- 4.1) and MVAD group (45.6 +/- 12.1) were more than control group (17.1 +/- 4.4) (P < 0.01), and that of MVAD group was more than VAI group (P < 0.05) in active avoidance reaction tests. (2) The changes of field excitatory postsynaptic potentials (fEPSP) slope for MVAD group (22.9% +/- 9.4%) and VAI group (29.5% +/- 13.7%) were less than that of control group (57.5% +/- 27.3%), respectively (P < 0.01). No significant difference was found between VAI and MVAD groups (P > 0.05). (3) No significant differences of relative intensity of fluorescence in cells were found among the three groups before the tetanus stimulation. However, the significantly low relative intensity of fluorescence in cells was seen in MVAD (65.1 +/- 17.0) and VAI (85.8 +/- 17.1) groups compared with control group (113.6 +/- 20.5) after the tetanus stimulation (P < 0.01), and that of VAI group was higher than that of MVAD group (P < 0.05). CONCLUSION: MVAD beginning from embryonic period impairs learning, memory and LTP in young rats. But the losses might not be reversible if the vitamin A supplementation is late especially missing the critical period of hippocampus development. According to the experimental data, it is speculated that vitamin A may modulate the influx of calcium ion to influence the LTP and lead to the change of learning and memory.