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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The properties of fatty acyl coenzyme A: estradiol-17 beta acyl transferase in microsomes derived from pooled human mammary cancer tissue have been examined. A pH optimum of 5.5 was found and addition of long-chained fatty acyl CoAs increased estradiol-17 beta (E2) 17-monoacyl ester synthesis; the apparent Km for E2 being 8 microM when oleoyl CoA, linolenoyl CoA or palmitoyl CoA were employed. Testosterone, dehydroepiandrosterone, and 5-androsterone-3 beta, 17 beta-diol acted as competitive inhibitors with Ki values of 36, 36 and 46 microM, respectively. The composition of E2 fatty acyl esters (E2-L) formed by incubation of [3H]E2 with human mammary cancer tissue and human mammary cancer cell lines has been determined by HPLC. Although the composition of E2-L in estrogen receptor negative cell lines (MDA-MB-231 and MDA-MB-330) was generally similar to that found for MCF-7 cells (estrogen receptor positive) and pooled human mammary cancer tissue, the former cell lines contained a 3-fold higher relative concentration of E2-17 beta stearate. MCF-7 cells were exposed to 30 nM [3H]E2 and the composition of the isolated [3H]E2-L fraction studied at various time intervals. At 0.5 h, the intracellular concentration of E2-L was 1.8 +/- 0.4 (SEM) pmol/mg DNA which increased to values of 3.6 +/- 0.6 and 4.3 +/- 0.5 at 4 h and 16 h, respectively. In the subsequent 3 h following transfer to medium lacking [3H]E2, the concentration of E2-L declined to 3.7 +/- 0.3 pmol/mg DNA. The subfraction of E2-L composed of E2-17 beta arachidonate, linolenate and docosahexaenoate, was seen to decline in relative abundance after 0.5 h and to reach significantly lower relative levels at 16 h, and again in the 3 h period following estrogen withdrawal. The data suggests that these components, derived from essential fatty acids, are more metabolically active. This may then provide a new lead to link these novel estrogen derivatives with the established relationship between unsaturated fatty acids and an increased mammary cancer incidence.
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PMID:Selective turnover of the essential fatty acid ester components of estradiol-17 beta lipoidal derivatives formed by human mammary cancer cells in culture. 366 59

Total plasma fatty acids were measured in 101 cirrhotic inpatients (64 men, 37 women, aged 64.3 +/- 1.2 (SEM) yr; range, 34-80) who were subsequently followed for survival for a mean of 14.8 +/- 1.0 months. Data on plasma fatty acids have been published elsewhere. Individual values of these variables were categorized in a binary fashion using the 5th or the 95th percentiles of a group of 44 well-nourished healthy controls (24 men, 20 women, aged 51.3 +/- 2.1 yr; range, 32-76) as the cutoff limit. Forty-nine patients died during follow-up (2-yr cumulative probability of survival, 52%). Deficiency of palmitate, dihomo-tau-linolenate, and arachidonate (values below the 5th percentile) were univariately associated with death (long-rank test). However, after a multivariate analysis (Cox's proportional hazards regression), only the existence of plasma arachidonate deficiency was included in the final model (beta, 0.62; relative risk, 1.86; 95% CI, 1.06-3.25; p < 0.05). We conclude that arachidonic acid deficiency significantly increases the mortality risk in patients with advanced liver cirrhosis.
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PMID:The relationship of plasma polyunsaturated fatty acid deficiency with survival in advanced liver cirrhosis: multivariate analysis. 848 Jul 37