PubMed HealthSearch

Biomedical subjects

F Moore

Publications and source records attributed to F Moore.

18 recordsLinked to original sources

Effects of n-3 fatty acids on postprandial triacylglycerol and hormone concentrations in normal subjects.

The present study reports results from two investigations to determine effects of a 6-week period of moderate n-3 fatty acid supplementation (2.7 g/d) on fasting and on postprandial triacylglycerol and metabolic hormone concentrations in response to standard test meals. In the first study postprandial responses were followed for 210 min after an early morning test meal challenge; in the second study responses to an evening test meal were followed during the evening and overnight for a total period of 12 h. In both studies postprandial triacylglycerol responses to the test meals were significantly reduced after compared with before fish-oil supplementation. In the second study the triacylglycerol peak response seen between 200 and 400 min in subjects studied before supplementation with fish oils was almost completely absent in the same subjects after 6 weeks of n-3 fatty acid supplementation. Analysis of fasting concentrations of metabolites and hormones was carried out on the combined data from the two studies. There were no significant differences in total, low-density-lipoprotein- or high-density-lipoprotein-cholesterol concentrations during fish-oil supplementation, although there was considerable individual variation in cholesterol responses to the supplement. Concentrations of Apo-B and Apo-A1 were unchanged during supplementation with fish oils. Fasting and early morning postprandial GIP concentrations were lower in subjects taking fish oils, possibly due to acute effects of fish-oil capsules taken on the evening before the studies. In both studies fasting insulin and glucose and postprandial insulin concentrations remained unchanged following fish-oil supplementation. The results do not support the view that triacylglycerol-lowering effects of n-3 fatty acids are due to modulation of insulin secretion mediated via the enteroinsular axis. Further studies are required to determine the precise mechanism by which fish oils reduce both fasting and postprandial triacylglycerol concentrations.

Adult

Evidence that AMP triggers phosphorylation as well as direct allosteric activation of rat liver AMP-activated protein kinase. A sensitive mechanism to protect the cell against ATP depletion.

1. In freshly isolated rat hepatocytes, the activity of the AMP-activated protein kinase is high, but decreases by 5-10-fold during incubation of the cells for 60 min. The expressed activity of acetyl-CoA carboxylase is initially very low, then rises in a reciprocal manner to the AMP-activated protein kinase activity. For both enzymes, treatment of partially purified preparations under dephosphorylating conditions abolishes the difference in activity between freshly isolated and preincubated cells. Thus, both the high activity of the AMP-activated protein kinase and the low activity of acetyl-CoA carboxylase in freshly isolated cells can be explained by phosphorylation. 2. Immediately after isolation, the hepatocytes have AMP/ATP ratios that are unphysiologically high (approximately 1:1.5). During incubation of the cells for 60 min, AMP levels fall and ATP levels rise so that the ratio becomes about 1:15, close to previous estimates of the ratio in freeze-clamped liver. The fall in AMP/ATP ratio precedes the decrease in AMP-activated protein kinase activity. 3. In cells which have been incubated for 60 min, treatment with 20 mM fructose, which causes a large but transient increase in the AMP/ATP ratio, also causes concomitant activation of the AMP-activated protein kinase and inactivation of acetyl-CoA carboxylase. 4. In all cases described above, the increases in activity of acetyl-CoA carboxylase were blocked by treatment with the cell-permeable protein phosphatase inhibitor, okadaic acid. However, the decreases in activity of the AMP-activated protein kinase were not blocked by this inhibitor. This is consistent with the finding that okadaic-acid-insensitive protein phosphatase 2C is the most effective at dephosphorylating the kinase in cell-free assays. 5. The results above suggested that AMP either promotes phosphorylation, or inhibits dephosphorylation, of the kinase. Studies in a partially purified cell-free system suggested that the former hypothesis was correct; reactivation of dephosphorylated AMP-activated protein kinase by kinase kinase was completely dependent on the presence of AMP. 6. Our results, obtained in both intact cells and a cell-free system, suggest that rises in the AMP/ATP ratio promote phosphorylation of the AMP-activated protein kinase by the kinase kinase, as well as causing direct allosteric activation. This represents a very sensitive system for switching off lipid biosynthetic pathways when ATP levels are limiting. The results with okadaic acid also suggest that protein phosphatase 2C is mainly responsible for dephosphorylation of the AMP-activated protein kinase in intact hepatocytes.

AMP-Activated Protein Kinase Kinases

Roles of the AMP-activated and cyclic-AMP-dependent protein kinases in the adrenaline-induced inactivation of acetyl-CoA carboxylase in rat adipocytes.

1. In isolated rat adipocytes, acetyl-CoA carboxylase is inactivated by treatment of the cells with adrenaline or the beta-agonist isoproterenol, but not by the alpha-agonist phenylephrine. The inactivation is stable during purification in the presence of protein phosphatase inhibitors, and is associated with a 30-40% increase in the labelling of enzyme isolated from 32P-labelled cells. 2. Increased phosphorylation occurs within peptide T1, which was identified by sequencing to be the peptide Ser-Ser77-Met-Ser79-Gly-Leu-His-Leu-Val-Lys, containing Ser-77 (phosphorylated by cyclic-AMP-dependent protein kinase) and Ser-79 (phosphorylated by the AMP-activated protein kinase). Analysis of the release of radioactivity as free phosphate during Edman degradation of peptide T1 revealed that all of the phosphate was in Ser-79 in both basal and hormone- or agonist-stimulated cells. Treatment of adipocytes with various agents which activate cyclic-AMP-dependent protein kinase by receptor-independent mechanisms (forskolin, cyclic AMP analogues, isobutylmethylxanthine) also produced inactivation of acetyl-CoA carboxylase and increased phosphorylation at Ser-79. 3. The (Rp)-[thio]phosphate analogue of cyclic AMP, which is an antagonist of binding of cyclic AMP to the regulatory subunit of cyclic-AMP-dependent protein kinase, opposes the effect of adrenaline on phosphorylation and inactivation of acetyl-CoA carboxylase. Together with the effects of isobutylmethylxanthine and the stimulatory cyclic AMP analogues, this strongly indicates that cyclic-AMP-dependent protein kinase is an essential component of the signal transduction pathway, although clearly it does not directly phosphorylate acetyl-CoA carboxylase. 4. As shown by okadaic acid inhibition, greater than 95% of the acetyl-CoA carboxylase phosphatase activity in extracts of rat adipocytes or liver is accounted for by protein phosphatase-2A, with less than 5% attributable to protein phosphatase-1. Inhibition of protein phosphatase-1 via phosphorylation of inhibitor-1 is therefore unlikely to be the mechanism by which cyclic-AMP-dependent protein kinase indirectly increases phosphorylation of acetyl-CoA carboxylase. Various other potential mechanisms are discussed.

1-Methyl-3-isobutylxanthine

Unusual case.

Explore the source record for details and available documents.

Animals

Factors associated with cardiac mortality in developed countries with particular reference to the consumption of wine.

Deaths from ischaemic heart-disease in 18 developed countries are not strongly associated with health-service factors such as doctor and nurse density. There is a negative association with gross national product per capita and a positive but inconsistent association with saturated and monounsaturated fat intake. The principal finding is a strong and specific negative association between ischaemic heart-disease deaths and alcohol consumption. This is shown to be wholly attributable to wine consumption.

Adult

The mortality of men in the Rhondda Fach, 1950--1970.

A more detailed analysis of material from the 20-year follow-up of men in the Rhondda Fach confirms the similarity between the Standardised Mortality Ratios (SMRs) of miners and exminers with radiological categories 0, 1, 2, 3 and A (120.3, 116.5, 119.0, 115.7, and 120.1 respectively) as well as the difference between these SMRs and that of the non-moners (98.7). The specific death rates show a raised SMR for bronchitis and other respiratory diseases excluding pneumoconiosis for all categories including category 0, but little difference between those for category 0 and those for simple pneumoconiosis. The SMRs for ischaemic heart disease and other circulatory diseases for categories A, B and C combined are lower than those for simple pneumoconiosis and category 0 (84.2 and 85.0, compared with 109.8 and 121.8 for simple pneumoconiosis, and 117.5 and 114.6 for category 0). Fortunately the SMR for leukaemia is low. A comparison between the survival rates of men aged 55-64 in Leigh, Lancashire and those in the Rhondda Fach suggests that nonminers in the two areas have similar survival rates while the survival rates for category 0 and simple pneumoconiosis are lower in the Rhondda Fach.

Accidents

Medical rehabilitation unit--Palmerston North, the first four years.

The first four years of the Palmerston NORTH Medical Rehabilitation Unit are described. Reference is given to buildings, patients and staff considerations and organisation of the Unit. The outcome of the Unit's activities are discussed. Evaluation is attempted. Attention is drawn to the value of work assessment in a hospital setting.

Adolescent

Health service 'input' and mortality 'output' in developed countries.

The relationship between age-specific mortality rates and some indices of health facilities and some environmental and dietary factors has been studied in 18 developed couuntries. The indices of health care are not negatively associated with mortality, and there is a marked positive association between the prevalence of doctors and mortality in the younger age groups. No explanation of this doctor anomaly has so far been found. Gross national product per head is the principal variable which shows a consistently strong negative association with mortality.

Adolescent

Temperature and deaths from ischaemic heart disease.

Certain features of the relationship between 11 measurements of weekly temperature and the number of deaths from ischaemic heart disease (IHD) within age groups in Greater London between 1970 and 1974 are described. Firstly, the correlation coefficients between age-specific deaths from IHD and each of the temperature variables are of a similar order. Secondly, in contrast, the linear regression coefficients between deaths and temperature are more variable and depend upon the particular measurement of temperature chosen. Thirdly, the proportional changes in the number of deaths with the temperature variables are similar within specific age groups; consequently it is suggested that deaths from IHD and temperature may be directly related.

Adult

The hazard of old lead mines in Wales.

Two population surveys were conducted near old lead workings in Wales. The first, at Y Fan in the middle of Wales, gave evidence suggestive of a gradient in blood lead level, highest in subjects resident close to the contaminated spoil heaps, and lowest in those who lived in farms some distance away. However, the gradient was significant (P less than 0.05) only in males, and all but one of the blood lead levels were below 2.0 mumol/l. In the second survey, at Halkyn in North Wales, levels in subjects living in the area contaminated by spoil were compared with those in subjects living in a nearby industrial area, and with subjects in a market town some distance away. Mean blood lead in people living in the three areas were homogeneous. These studies give no evidence that old lead workings in Wales are a serious hazard to health.

Adult

Nursing student perceptions of public health issues in Ghana.

This article reports survey results to Ghanaian nursing students' perceptions of public health issues. Their views were ascertained through a questionnaire designed to capture ratings of educational curriculum concerns and perceptions of the importance of public health factors. Both frequency data and chi-square analysis were used to assess the ordinal position of health factors and gender differences, respectively. Chi-square analysis was also done to assess differences by age. Differences between men and women respondents existed on six of 15 health factors (p less than .05) including malaria, heart disease, measles, cancer, malnutrition and car accidents, while differences between age groups were found on two of the 15 factors (violence and cancer). Based on the ascertained student perceptions, current efforts in Ghana suggest that preventive health is an emerging concern to public health officials. As such, Ghanaian nursing students hold perceptions not dissimilar to those of U.S. health professions students.

Adult