Impact of Zinc Supplementation on Respiratory and Gastrointestinal Infections: A Double-Blind, Randomized Trial Among Urban Iranian Schoolchildren

Abstract

INTRODUCTION:Vitamin A is an essential micronutrient for brain development. Marginal vitamin A deficiency (MVAD) remains a subclinical public health problem in children, but little is known about the mechanism by which it affects brain development beginning from embryonic period and early postnatal period. OBJECTIVE: The objective of this study was to study the effects of MVAD on the hippocampal CA1 long-term potentiation (LTP) in young rats. METHODS: The MVAD group was fed a vitamin A-deficient diet (400 IU/kg vitamin A), and the control group was fed a vitamin A-sufficient diet (6500 IU/kg vitamin A) at 3 weeks before coitus. Serum vitamin A was assessed by high-performance liquid chromatography. Hippocampal CA1 LTP was detected by electrophysiologic technique, and the ultrastructure of synapses was observed by electron microscope. RESULTS:The changes of field excitatory postsynaptic potentials slope (25.4% Ϯ 2.01%) in MVAD rats aged 7 weeks was much lower than that in the control group (57.5% Ϯ 8.6%). The changes of slope of field excitatory postsynaptic potentials induced by MVAD in young rats could be replenished after addition of retinoic acid (RA); however, LTP impairment was observed again after addition of RA antagonist into the solution of the control group. No differences of LTP were found after addition of FeSO 4 or ZnSO 4 . The curvature of the synaptic interface of the MVAD group was less than that of the MVAD group that was supplemented with RA and of the control group. CONCLUSIONS: MVAD during the embryonic and early postnatal period can directly impair the hippocampal CA1 LTP of young rats. EFFECT OF BCG VACCINATION ON SPLENIC DENDRITIC CELL DEVELOPMENT IN NEONATAL BALB/C MICE Submitted by Enmei Liu INTRODUCTION:As an immunoregulator, Mycobacterium BCG has the potential to be applied in allergic disease such as asthma prevention in clinic. Previous studies showed that neonatal BCG vaccination promoted mouse splenic T helper 1 development. OBJECTIVE: The objective of this study was to investigate further the impact of BCG vaccination on dendritic cell (DC) development in neonatal mice. METHODS: Neonatal and adult BALB/C mice were divided into 2 groups: the control group and the BCGtreated group in which BALB/C mice were inoculated with 1 ϫ 10 5 colony-forming units of BCG intraperitoneally. After 4 weeks, splenic cells were isolated and co-stimulatory molecules and major histocompatibility complex molecules were analyzed by flow cytometry on CD11c-positive cells. RESULTS: CD11c ϩ CD8␣ ϩ and CD11c ϩ CD8␣ Ϫ DCs were found in spleen cells of BALB/C mice. In comparison with the control group, the percentage of CD8␣ Ϫ DCs was significantly decreased (45.00 Ϯ 14.14 vs 67.00 Ϯ 8.27) and that of CD8␣ ϩ DCs was strikingly increased (55.00 Ϯ 14.14 vs 33.00 Ϯ 8.27) in BCGtreated neonatal mice. In contrast, the percentage of CD8␣ Ϫ DCs markedly increased from 57% to 70% and that of CD8␣ ϩ DCs noticeably decreased from 43% to 30% in adult mice that were vaccinated. BCG vaccination upregulated the expression ...