Browsing by Autor "Joe M. McCord"

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    Potential role for elevated maternal enzymatic antioxidant status in Andean protection against altitude-associated SGA
    (Informa, 2011) Colleen G. Julian; Enrique Vargas; Vaughn A. Browne; Megan J. Wilson; Abigail W. Bigham; Carmelo Rodriguez; Joe M. McCord; Lorna G. Moore
    Oxidative stress has been implicated in the uteroplacental ischemia characteristic of preeclampsia and small-for-gestational-age (SGA) birth, both of which are more common at high (>2500 m) vs low altitude. Since Andeans are protected relative to Europeans from the altitude-associated rise in SGA, we asked whether alterations in maternal antioxidant status or oxidative stress contributed to their protection. Enzymatic antioxidant (erythrocyte catalase and superoxide dismutase [SOD]) activity and a plasma marker of lipid peroxidation (8-iso-PGF2α) were measured during pregnancy and in the non-pregnant state in Andean or European residents of low (400 m) or high altitude (3600-4100 m). Pregnancy and altitude increased catalase and/or SOD activity to a greater extent in Andeans than Europeans. 8-iso-PGF2α levels were independent of altitude and pregnancy. SOD was lower in mothers of SGA infants at weeks 20 and 36. Our findings are consistent with the possibility that elevated enzymatic antioxidant activity contributes to Andean protection against altitude-associated SGA.
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    The role of antioxidant & oxidative status in the protection against altitude‐associated reductions in uterine artery (UA) blood flow & fetal growth afforded by Andean ancestry
    (Wiley, 2008) Colleen G. Julian; Enrique Vargas; Joe M. McCord; Jennifer L. Hageman; R. Daniela Dávila; Henry Yamashiro; Megan J. Wilson; Carmelo Rodriguez; Armando Rodríguez; Vaughn A. Browne
    Objective: To determine the role of antioxidant & oxidative status in the protection of uterine artery blood flow (UAVF) & fetal growth at high altitude in Andean populations. Methods: Erythrocyte catalase (CAT) & superoxide dismutase (SOD), plasma isoprostanes (8‐ISO‐PGF‐2α) & UA VF were measured at 20 & 36w of pregnancy & and in the non‐pregnant state in Andean (AND) & European (EUR) women at low (LA, 416m) or high (HA, 3600m) altitude. CAT, SOD & 8‐iso‐PGF‐2α were assessed by spectrometry, UA VF by Doppler ultrasound & birth weight (BW) by medical records review. Data was analyzed by t‐tests, 1‐ & 2‐way ANOVA. Results: At LA, ancestry had no effect on CAT or SOD. AND had higher CAT (20 & 36w p<0.05) & SOD activity (36w p<0.05) than EUR at HA. At HA, UA diameter and UA VF were greater in AND than EUR. Altitude decreased BW in AND (p<0.05) and EUR (p<0.01), and at HA EUR ancestry reduced BW (β= − 0.238 p<0.05). Small‐for‐gestational age (SGA) infants occurred 2‐times more frequently at HA than LA in EUR. SOD was lower at 20w in SGA at both altitues, or HA alone (all p<0.05). In EUR, CAT tended to be lower at 20w in SGA. 8‐ISO‐PGF2α reduced UA diam (p<0.05) & UA VF (p<0.01) in all women. Conclusion: Elevated endogenous antioxidant activity may contribute to the protection against altitude‐associated reductions in UA blood flow & fetal growth afforded by Andean ancestry. NIH HL079647 ,AHA 0610129Z & NSF BCS‐064719.