Blood lead levels during pregnancy and its influencing factors in Nanjing, China.

OBJECTIVE: To investigate the blood lead levels (BLLs) in the duration of pregnancy and 6-12 weeks after delivery, and analyze the influencing factors of BLLs in healthy pregnant women. METHODS: Pregnant women were recruited from September 2009 to February 2010 at the prenatal clinic in Nanjing Maternity and Child Health Care Hospital. Altogether 174 healthy pregnant women without pregnant or obstetric complications or abnormal pregnancy outcomes were enrolled as the gravida group, and 120 healthy non-pregnant women as the control group. BLLs during pregnancy were determined by flame atomic absorption spectroscopy. RESULTS: BLLs in all the three pregnancy trimesters and postpartum were 59.8±24.3, 55.4±20.1, 55.9±19.7, and 67.6±17.4 µg/L, respectively, and the mean BLL in control group was 67.5±21.3 µg/L. BLLs during all the three trimesters were lower in the gravida group than in the control group (P=0.043, 0.021, and 0.028). Furthermore, occupations, nutrients supplementation, and time of house/apartment painted were associated with BLLs in pregnant women. Lead-related occupations, cosmetics use, and living in a house painted less than 1 year before are risk factors of high BLLs among pregnant women, while calcium, iron, zinc, and milk supplements are protective factors. CONCLUSION: Supplementing calcium, iron, zinc, and milk, or avoiding contact with risk factors may help people, especially pregnant women, to reduce lead exposure.

TNF-alpha induces mitochondrial dysfunction in 3T3-L1 adipocytes.

TNF-alpha was the first proinflammatory cytokine identified linking obesity, insulin resistance and chronic inflammation. However, the mechanism of TNF-alpha in the etiology of insulin resistance is still far from clear. Because the mitochondria play an important role in energy metabolism, we investigated whether mitochondrial dysfunction is involved in pathogenesis of TNF-alpha-mediated insulin resistance. First, a fully differentiated insulin-resistant 3T3-L1 adipocyte model was established by incubating with 4 ng/ml TNF-alpha for 4 d, and then the mitochondrial morphology and functions were observed. TNF-alpha treatment induced pronounced morphological changes in the mitochondria, which became smaller and condensed, and some appeared hollow and absent of cristae. Mitochondrial dynamics changes were observed as increased mitofusion protein mfn1 and mitofission protein Drp1 levels compared with controls. No obvious effects on mitochondrial biogenesis were found. PGC-1alpha levels decreased, but no significant changes were found in mtTFA mRNA expression, NRF1mRNA expression and mitochondrial DNA (mtDNA). TNFalpha treatment also led to decreased mitochondrial membrane potential and reduced production of intracellular ATP, as well as accumulation of significant amounts of reactive oxygen species (ROS). Further research is required to determine if mitochondrial dysfunction is involved in the inflammatory mechanism of insulin resistance and may be a potential target for the treatment of insulin resistance.

[Effects of infant formula containing palm oil on the nutrient absorption and defecation in infants: a meta-analysis].

OBJECTIVE: To evaluate the effects of infant formula containing palm oil on the nutrient absorption and defecation in infants. METHODS: A search in Cochrane Library, PubMed, OVID, Springer, China National Knowledge Infrastructure, Vip Chinese Periodical Database, Wanfang Chinese Periodical Database and Chinese Bio-medicine Database was performed to identify relevant English and Chinese language articles between January 1990 and March 2009. Two reviewers independently performed data extraction and appraised using Jadad instrument. Double data were input and analyzed by software of Review Manager 4.2 recommended by Cochrane Collaboration. Intestinal nutrient absorption, electrolyte content of fecal excretion, in vivo calcium deposition, and defecation were included as the target outcomes. These outcomes were evaluated as the combined standardized mean difference (SMD) and relative risk (RR) value and 95% CI of them. RESULTS: Thirteen articles were included. Three articles meeting inclusion criteria were analyzed for the effects between infant formula containing palmitic acid at the Sn-2 positions and palmitic acid at the Sn-1, 3 positions; five articles were analyzed for the effects between infant formula containing palmitic acid at the Sn-1, 3 and without palmitic acid; another five articles were analyzed for the effects between infant formula containing palmitic acid at the Sn-2 positions and without palmitic acid. Absorption of fat and calcium was higher, the Ca(2+) of fecal excretion was lower when the infant formula provided palmitic acid at the Sn-2 positions or without palmitic acid than that determined when formula containing palmitic acid at the Sn-1 and Sn-3 positions was given (P < 0.01). The bone mineral content (BMC) and bone mineral density (BMD) increased at 3, 6 months when the infant formula without palmitic acid as compared with using the formula containing palmitic acid at the Sn-1 and Sn-3 positions (P < 0.01). The formation of calcium soaps in stool was reduced, the BMC increased when the infant formula provided palmitic acid at the Sn-2 positions as compared with using the infant formula without palmitic acid (P < 0.01). The incidence of soft stools was higher, and the incidence of hard stools was lower when the infant formula provided palmitic acid at the Sn-2 positions or without palmitic acid than that when formula containing palmitic acid at the Sn-1 and Sn-3 positions was used (P < 0.01). CONCLUSION: Absorption of fat and calcium was lower, the Ca(2+) of fecal excretion was higher, the BMC was reduced, the incidence of hard stools increased when the infant formula provided the palmitic acid at the Sn-1 and Sn-3 positions as compared with using formula contained palmitic acid at the Sn-2 positions or without palmitic acid. However, this conclusion should be used cautiously because of the limited quality of studies included into the analysis.