Maternal and environmental determinants of breast-milk mercury concentrations.

We aimed to evaluate the maternal factors [including dietary habits, dental care, smoking, anemia, levels of breast-milk zinc (Zn) and iron (Fe), and levels of serum selenium (Se), Zn and copper (Cu)] that influence breast-milk mercury (Hg) concentrations and to investigate whether there is any relation between Hg concentrations and infant growth and development during the exclusive breastfeeding period and in the second year of life. Forty-four healthy mother-infant pairs in the 10-20-day postpartum period were enrolled in the study. Maternal history and blood samples for hemoglobin, Fe, Fe binding capacity, ferritin, Se, Zn, and Cu and breast-milk samples for Fe, Zn and Hg were taken. Infant growth and development during the exclusive breastfeeding period and in the second year of life were followed. The mean concentration of breast-milk Hg was 3.42 +/- 1.66 microg/L. Serum Se levels were negatively correlated with milk Hg levels. Multivariate analysis revealed that active/passive smoking and offal intake during pregnancy and presence of maternal anemia had an impact on increased milk Hg concentrations. Preventive strategies for mercury exposure should include management of iron deficiency anemia, cessation of smoking exposure and proper nutrition during the pregnancy period.

Zinc supplementation and TNF-α levels in vaccinated cardiac patients.

OBJECTIVE: To investigate whether zinc supplementation could affect serum tumor necrosis factor-alpha (TNF-α) levels in congenital and acquired cardiac patients attending for an influenza vaccine. METHODS: 9-18 years old, voluntary children with cardiac disease were weighed, measured height and blood samples for hemoglobin level, zinc level, IgA and IgG titers of influenza A and B serotypes and TNF-α levels were obtained. The children were randomly assigned to 1 of 2 groups: ZV group received both zinc supplementation and influenza vaccine; V group received influenza vaccine. Serum TNF-α levels were measured at 28 days after the immunization. RESULTS: Mean (±SD) serum zinc level was 100 (±20) µg/dL. Cases with congenital heart disease had lower serum zinc levels than acquired ones (93±17 µg/dL, 116±18 µg/dL; respectively, p<0.001). Median titers of serum TNF-α decreased after vaccination (78.9 pg/mL, 74.8 pg/mL; p<0.05) but this significant change occurred only in ZV group (77.1 pg/mL, 73.4 pg/mL; p=0.001). Vaccine associated adverse events were similar in ZV and V groups except malaise (0% in ZV and 23.8% in V group; p<0.05). Adverse events were similar in patients with congenital and acquired heart diseases. During the previous influenza season, 77.3% had more than two episodes of upper respiratory tract infection (URTI), however, after vaccination only 13.6% had more than two episode of URTI. CONCLUSION: Zinc supplementation has a beneficial effect on malaise, one of the influenza vaccine associated adverse events, and decrease serum TNF-α levels.