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Biomedical subjects

L G Moore

Publications and source records attributed to L G Moore.

153 records · Page 9Linked to original sources
PubMed1977

Pharmacologic stimulation of erythrocyte 2,3-diphosphoglycerate production in vivo.

The ability of phosphate alone and in combination with sodium bicarbonate, vitamin C and pyruvate to elevate 2,3-diphosphoglycerate (DPG) levels was examined in normal human subjects in vivo. Statistically significant increases in DPG levels were noted (P less than .001) for all regimens pooled. Average rise in DPG levels reached 6% above pretreatment levels after 2 to 3 days of treatment. No changes in DPG levels were detectable in a group of control subjects over the same time period. Variation among pharmacologic trials and among subjects within trials in the actual magnitude of DPG build-up was marked. Significant differences could not be detected among the pharmacologic regimens in their ability to produce DPG increases. Previous reports suggested the use of these agents to stimulate red cell glycolysis but it seems that their effects and the mechanisms of glycolytic control in vivo are considerably more complex than has been previously suggested.

Ascorbic Acid↗
PubMedDate not supplied

Tibetan protection from intrauterine growth restriction (IUGR) and reproductive loss at high altitude.

Chronic hypoxia at high altitude restricts fetal growth, reducing birth weight and increasing infant mortality. We asked whether Tibetans, a long-resident high-altitude population, exhibit less altitude-associated intrauterine growth restriction (IUGR) and prenatal or postnatal reproductive loss than Han (ethnic Chinese), a group that has lived there for a shorter period of time. A population sample was obtained, comprising 485 deliveries to Tibetan or Han women over an 18-month period at 8 general hospitals or clinics located at 2,700-4,700 m in the Tibet Autonomous Region, China. Birth weight, gestational age, and other information were recorded for each delivery. Prenatal and postnatal mortality were calculated using information obtained from all pregnancies or babies born to study participants. Tibetan babies weighed more than the Han, averaging 310 g heavier at altitudes 2,700-3,000 m (95% CI = 126, 494 g; P < 0.01) and 530 g heavier at 3,000-3,800 m (210, 750 g; P < 0.01). More Han than Tibetan babies were born prematurely. Prenatal and postnatal mortality rose with increasing elevation and were 3-fold higher across all altitudes in the Han than the Tibetans (P < 0.05). Tibetans experience less altitude-associated IUGR than Han and have lower levels of prenatal and postnatal mortality. When the relationships between birth weight and altitude are compared among these and other high-altitude populations, those living at high altitude the longest have the least altitude-associated IUGR. This may suggest the occurrence of an evolutionary adaptation.

Adult↗
PubMedDate not supplied

Secretion of neurophysins by the ovary in sheep.

Measurements of venoarterial concentration differences across the ovary in anesthetized sheep have demonstrated that the ovary secretes ovine neurophysin I/II (oNP I/II) and that this process is stimulated by the prostaglandin F2 alpha analogue, cloprostenol. A parallel increase in the secretion of oxytocin (OT) was observed in response to cloprostenol, and the mean molar ratio of oNP I/II to OT secreted was 1.2. There was no detectable ovarian secretion of oNP III. Secretion of oNP I/II and OT was absent after hysterectomy. The data support other evidence indicating that the corpus luteum synthesizes OT, and confirm that the neurophysin associated with OT in the sheep is oNP I/II.

Animals↗
PubMedDate not supplied

Low serum estradiol and high serum progesterone concentrations characterize hypertensive pregnancies at high altitude.

OBJECTIVE: Intrauterine growth retardation and preeclampsia are more common at high than at low altitude. Because altered hormonal profiles have been linked with these disorders, we asked whether placental steroid hormone concentrations were altered during pregnancy at high altitude. METHODS: We measured progesterone, unconjugated estradiol, and estriol (by radioimmunoassay) at weeks 20, 30, and 36 of pregnancy in 18 women at low altitude (1600 m) and 40 women at high altitude (3100 m). RESULTS: Women at 3100 m compared with 1600 m had lower serum estradiol concentrations at week 36 of pregnancy, and lower estriol and higher progesterone concentrations throughout pregnancy. As a result, the progesterone/estradiol ratio was greater in the high- versus the low-altitude women. Estradiol fell between weeks 30 and 36 in women who developed transient hypertension or preeclampsia. The fall in estradiol was accompanied by a marked increase in progesterone concentrations among the preeclamptic women. At 3100 m, estradiol correlated negatively (r = -0.37, P < .05) and progesterone positively (r = 0.46, P < .05) with mean arterial pressure at week 36 of pregnancy. CONCLUSIONS: We speculate that reduced placental oxygen pressure (PO2) at high altitude may decrease placental aromatase activity and thereby lower estradiol and estriol concentrations. The factor(s) responsible for the rise in progesterone is unknown. Possibly, high progesterone relative to estradiol concentrations contributes to the development of preeclampsia at high altitude.

Adult↗