Physical performance of migrant schoolchildren with marginal and severe iron deficiency in the suburbs of Beijing / 生物医学与环境科学（英文）

<p><b>OBJECTIVES</b>To investigate relationship between iron deficiency of different degrees and physical performance and habitual activity of migrant schoolchildren at the age of 11-14 years.</p><p><b>METHODS</b>Ninety one randomly selected schoolchildren were divided into three groups according to their iron status. Iron status including hemoglobin (Hb), serum ferritin (SF), serum iron (SI) and sTfR was determined. Physical performance tests included maximum oxygen consumption (VO2max) and maximum work time. Energy expenditure (EE) and daily physical activity were estimated by recording 24-h heart rate (HR). Dietary intake was assessed with frequency questionnaires, and physical activity level was estimated with frequency and physical activity questionnaires.</p><p><b>RESULTS</b>Severe iron deficiency (IDA) impaired the aerobic capacity and habitual physical activity. When fat-free mass (FFM) was considered, VO2max (VO2max/FFM) was significantly lower in the iron-marginal group than in the iron-adequate groups among girls (P = 0.02), but such a deference was not found among boys (P = 0.28). Aerobic activity and EE at leisure were significantly lower in the severe iron deficient group than in the marginal iron deficient and iron adequate groups. Net HR at leisure time was correlated with Hb, log SF, body weight, and FFM (P < 0.05).</p><p><b>CONCLUSION</b>The functional effect of iron deficiency on physical performance and habitual physical activity rely on the degree of current iron deficiency. Severe iron deficiency significantly impairs both aerobic capacity and habitual physical activity. Iron-marginal deficiency impairs VO2max/FFM in girls, rather than in boys.</p>

Antioxidation properties and mechanism of action of dihydromyricetin from Ampelopsis grossedentata / 药学学报

<p><b>AIM</b>To assess the antioxidative properties and the mechanism of action of dihydromyricetin (DMY) from Ampelopsis grossedentata.</p><p><b>METHODS</b>The antioxidative properties of DMY were measured by scavenging 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and inhibiting lipid peroxidation induced by FeSO4-edetic acid in linoleic acid. The mechanism of antioxidative properties of DMY was tested by measuring the chelating activities of DMY for Fe2+ with ultraviolet spectrum (UV) method.</p><p><b>RESULTS</b>The specific absorption of DPPH radical solution at 517 nm was reduced 73.3%-91.5% when DMY was added into the reaction solution in the concentration range from 0.01% to 0.04%. DMY was shown to greatly inhibit the increase of lipid peroxidation (LPO) values in linolei acid system catalyzed by FeSO4-edetic acid. The reaction rates (A532.min-1) of lipid peroxidation were 0.0021-0.0004 in the concentration range from 0.01% to 0.04% and the inhibition activities of DMY was found to be in a concentration-dependent manner. The mechanism of antioxidative properties of DMY was chelating Fe2+ in the Fe(2+)-dependent lipid peroxidation system.</p><p><b>CONCLUSION</b>DMY showed great antioxidative effect and would be a good natural antioxidant.</p>