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G Powell

Publications and source records attributed to G Powell.

65 records · Page 4Linked to original sources
PubMed1971

Phenobarbital-induced alterations in phosphatidylcholine and triglyceride synthesis in hepatic endoplasmic reticulum.

Biosynthetic pathways of phosphatidylcholine and triglyceride were studied in proliferating hepatic endoplasmic reticulum of rats pretreated with phenobarbital. Phosphatidylcholine accounted for the major increment in membrane phospholipid. In vitro measurements of hepatic microsomal enzymes which catalyze phosphatidylcholine biosynthesis revealed a significant increase in specific activity of the enzyme governing phosphatidylcholine synthesis by sequential methylation of phosphatidylethanolamine. The specific activity of phosphorylcholine-glyceride transferase, which catalyzes phosphatidylcholine synthesis from d-1,2-diglyceride and CDP-choline, was not altered. Specific activity of diglyceride acyltransferase, which catalyzes triglyceride biosynthesis, was increased to a degree comparable to the increase in specific activity found in the phenobarbital-induced drug-metabolizing enzyme which oxidatively demethylates aminopyrine. In vivo incorporation of methyl-(3)H from l-methionine-methyl-(3)H into microsomal phosphatidylcholine was significantly increased, resulting in an increased methyl-(3)H to choline-1,2-(14)C incorporation ratio of more than three times that found in control animals. A comparable increase in this incorporation ratio was noted in serum phospholipids. The in vitro enzyme studies, in agreement with in vivo incorporation data, indicate that the increase in phosphatidylcholine content of phenobarbital-induced proliferating endoplasmic reticulum is related to increased activity of the pathway of phosphatidylcholine biosynthesis involving the sequential methylation of phosphatidylethanolamine.

Acyltransferases↗
PubMed1970

Enzyme specificity as a factor in regulation of fatty acid chain length in Escherichia coli.

Various acyl-acyl carrier protein intermediates in saturated and unsaturated fatty acid biosynthesis were tested as substrates for beta-ketoacyl-acyl carrier protein synthetase. With both classes of substrates the condensing enzyme in fatty biosynthesis demonstrates specificities which indicate that it might be an important factor in determining fatty acid chain length in Escherichia coli.

Acyltransferases↗
PubMedDate not supplied

Coping and psychosocial function after brain injury.

A total of 74 brain-injured patients and 46 non-neurological matched controls consecutively admitted to a specialist medical rehabilitation unit were administered the 'Ways of Coping' checklist and the 'Headley Court psychosocial rating scale'. The relatives of all participants were sent the psychosocial rating scale. An analysis of the 'Ways of Coping' checklist showed the brain-injured patients used four strategies for coping, namely problem-focused, emotion-focused, avoidance, and wishful thinking. Correlations between these four factors and the responses on the 'Headley Court psychosocial rating scale' showed that less use of emotion-focused, avoidance, and wishful thinking coping strategies predicts better psychosocial functioning in the brain-injured group, a result similar to those reported for a wide variety of other health problems. The implications for treatment and management are discussed.

Activities of Daily Living↗
PubMedDate not supplied

Epidural sufentanil for analgesia for labor and delivery.

Six groups of ten women each in active labor at term had epidural catheters placed in the usual manner and received a 3 mL test dose of 2% lidocaine with epinephrine. Groups 1-6 received, respectively, 5, 10, 20, 30, 40 and 50 micrograms of sufentanil diluted to 10 mL with normal saline. Significantly effective analgesia was provided at all sufentanil doses studied, with pain scores decreasing from 8.1 +/- 0.2 at baseline to 2.9 +/- 0.3 at 10 minutes and 1.1 +/- 0.2 at 30 minutes (mean +/- SEM, average for all groups). The duration of analgesia showed a significant (p less than 0.05) relation to sufentanil dose, increasing from 79.1 +/- 11.3 minutes (5-micrograms group) to 137.8 +/- 17.2 minutes (50-micrograms group). There were no serious maternal side effects, although ten patients developed pruritus, four became dizzy, two experienced mild sedation, and one had transient hypotension. No neonatal side effects occurred. Maternal serum sufentanil levels remained below the sensitivity of the assay, or 0.1 ng/ml.

Adult↗