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Biomedical subjects

J F O'Brien

Publications and source records attributed to J F O'Brien.

65 records · Page 4Linked to original sources
PubMed1974

Incorporation of (2-3H)glycerol into rat brain 1,2-diacyl-sn-glycero-3-phosphorylcholine and 1,2-diacyl-sn-glycerol molecular species in vivo.

Rat brain 1,2-diacyl-sn-glycerols (diglycerides) and 1,2-diacyl-sn-glycerols obtained from 1,2-diacyl-sn-glycero-3-phosphorylcholine after treatment with phospholipase C differ markedly in carbon number distribution. 70% of the 1,2-diacyl-sn-glycerols had a total of 38 fatty acid carbon atoms, and there was no detectable change in the 1,2-diacyl-sn-glycerol mass pattern between 7 and 23 days of age. In contrast, 1,2-diacyl-sn-glycero-3-phosphorylcholine contained at most 10% of this molecular species in the brains of rats of comparable age. A small increase in the C(36) species of 1,2-diacyl-sn-glycero-3-phosphorylcholine, which is associated with myelination, was noted between 10 and 17 days. The incorporation of intracranially injected [2-(3)H]glycerol into 1,2-diacyl-sn-glycero-3-phosphoryl-choline species with polyunsaturated fatty acids containing 20 or 22 carbon atoms was greater than into the species containing only saturated and/or monoenoic fatty acids between 30 min and 24 hr. The 1,2-diacyl-sn-glycerol fractions containing polyunsaturated fatty acids had the lowest specific activity at 30 min. The specific activity of the particular 1,2-diacyl-sn-glycerol fraction containing the stearate-arachidonate pair is the lowest for 4 hr after intracranial injection of the isotope. Thus, molecular species of 1,2-diacyl-sn-glycerol and 1,2-diacyl-sn-glycero-3-phosphorylcholine differed considerably in their labeling patterns, and a direct precursor-product relationship could not be demonstrated during the time period studied.

Animals↗
PubMedDate not supplied

Selenium status in patients receiving home parenteral nutrition.

Selenium (Se) status was evaluated in patients with intestinal failure requiring home parenteral nutrition (HPN). Ninety-two percent of patients (11 of 12) studied just prior to starting HPN had low serum Se values, and the mean value was 42 ng/ml, significantly less than mean values in disease controls with Crohn's disease not on HPN (76 ng/ml) and healthy controls (88 ng/ml). Eighty-five percent of patients (22 of 26) already on HPN for 2 to 109 months when studied had low serum Se levels (mean 38.4 ng/ml). The mean 24-hr urinary Se values were 3.7 micrograms in patients on HPN who did not have Crohn's disease, 10.9 micrograms in HPN patients with Crohn's, and 17.9 micrograms in healthy controls. In patients with Crohn's disease on HPN, a significant direct correlation existed between serum Se and the activity of whole blood glutathione peroxidase, a selenoprotein ; and a significant inverse correlation was found between serum Se and months of HPN. This study confirms that Se deficiency is very common in patients before starting and during HPN. These data and recent reports of cardiomyopathies associated with Se deficiencies in patients on HPN increase the importance of proper Se replacement and maintenance.

Crohn Disease↗