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Biomedical subjects

A Chisholm

Publications and source records attributed to A Chisholm.

30 records · Page 2Linked to original sources
PubMed1995

Trans fatty acids: a cause for concern?

The recommendation to reduce total and saturated fat is incorporated into the dietary guidelines for the general population in many western countries. In addition, dietary modification to reduce substantially the intake of saturated fats is a cornerstone of treatment in the hyperlipidaemias. Concern has recently been expressed regarding possible deleterious effects of trans isomers of unsaturated fatty acids on the lipoprotein profiles of both normo and hypercholesterolaemic persons. This review seeks to examine recent research in this area with a view to considering possible changes in the present dietary recommendations.

Coronary Disease↗
PubMed1995

Effects of coconut oil, butter, and safflower oil on lipids and lipoproteins in persons with moderately elevated cholesterol levels.

The physiological effects of coconut oil, butter, and safflower oil on lipids and lipoproteins have been compared in moderately hypercholesterolemic individuals. Twenty eight participants (13 men, 15 women) followed three 6-week experimental diets of similar macronutrient distribution with the different test fats providing 50% total dietary fat. Total cholesterol and low density lipoprotein cholesterol were significantly higher (P < 0.001) on the diet containing butter [6.8 +/- 0.9, 4.5 +/- 0.8 mmol/l] (mean +/- SD), respectively than on the coconut oil diet (6.4 +/- 0.8; 4.2 +/- 0.7 mmol/l) when levels were significantly higher (P < 0.01) than on the safflower diet (6.1 +/- 0.8; 3.9 +/- 0.7 mmol/l). Findings with regard to the other measures of lipids and lipoproteins were less consistent. Apolipoprotein A-I was significantly higher on coconut oil (157 +/- 17 mg/dl) and on butter (141 +/- 23 mg/dl) than on safflower oil (132 +/- 22 mg/dl). Apolipoprotein B was also higher on butter (86 +/- 20 mg/dl) and coconut oil (91 +/- 32 mg/dl) than on safflower oil (77 +/- 19 mg/dl). However gender differences were apparent. In the group as a whole, high density lipoprotein did not differ significantly on the three diets whereas levels in women on the butter and coconut oil diet were significantly higher than on the safflower oil diet. Triacylglycerol was higher on the butter diet than on the safflower and coconut oil diets but the difference only reached statistical significance in women. Cholesteryl ester transfer activity was significantly higher on butter than safflower oil in the group as a whole and in women.(ABSTRACT TRUNCATED AT 250 WORDS)

Butter↗
PubMed1994

The effect of dietary fat content on plasma noncholesterol sterol concentrations in patients with familial hypercholesterolemia treated with simvastatin.

The effects of a low-fat, low-cholesterol diet (LFD) or a higher-fat, higher-cholesterol diet (HFD) on plasma concentrations of lipids, lipoproteins, lathosterol (an index of cholesterol synthesis rate), and plant sterols were determined in 19 patients with familial hypercholesterolemia (FH) treated with simvastatin. The study followed a randomized crossover design including two 8-week diet periods. The LFD significantly decreased plasma lathosterol (-22%), cholesterol (-6%), low-density lipoprotein (LDL) cholesterol (-6%), and high-density lipoprotein (HDL) cholesterol (-7%) levels compared with the HFD. Decreases in plasma lathosterol and LDL cholesterol concentrations in patients during the LFD were significantly correlated (r = .522, n = 19, P < .05). These results suggest that a LFD may enhance the decrease in cholesterol synthesis induced by simvastatin treatment, and in this way might contribute to the decrease in plasma cholesterol levels when the fat content of the diet is reduced in simvastatin-treated FH patients.

Adult↗
PubMed1993

A homeotic gene cluster patterns the anteroposterior body axis of C. elegans.

In insects and vertebrates, clusters of Antennapedia class homeobox (HOM-C) genes specify anteroposterior body pattern. The nematode C. elegans also contains a small cluster of HOM-C genes, one of which has been shown to specify positional identity. Here we show that two additional C. elegans HOM-C genes also specify positional identity and that together these three HOM-C genes function along the anteroposterior axis in the same order as their homologs in other organisms. Thus, HOM-C-based pattern formation has been conserved in nematodes despite the many differences in morphology and embryology that distinguish them from other phyla. Each C. elegans HOM-C gene is responsible for a distinct body region; however, where their domains overlap, two HOM-C genes can act together to specify the fates of individual cells.

Amino Acid Sequence↗
PubMed1992

Should mono- or poly-unsaturated fats replace saturated fat in the diet?

The effects of diets differing in saturated, monounsaturated and polyunsaturated fatty acid composition (SAFA, MUFA and PUFA, respectively) on plasma lipoproteins and factor VIIc were investigated in 28 middle-aged men and women with mild to moderate hyperlipidaemia. The subjects were stabilized on a diet with a total fat content fairly typical of New Zealand, containing approximately 40% energy as fat, before entering a randomized cross-over trial of diets high in PUFA (20% energy; SAFA and MUFA 10% each) or a high MUFA diet (20% energy; SAFA and PUFA 10% each). After 6-week periods on each diet the subjects returned to a high SAFA diet. Body weight and blood pressure remained unchanged during the study. Total and LDL cholesterol, HDL cholesterol and the HDL2 subfraction were significantly lower on both the MUFA and the PUFA diet than on SAFA. However, there were no statistically significant differences in lipoprotein concentrations on the MUFA and PUFA diet. Factor VIIc concentrations were similar on the three diets. The proportion of PUFA in a MUFA diet appears to be a major determinant of the relative lipoprotein response to such a diet. In order to avoid a reduction in HDL-C when replacing SAFA with MUFA it may be necessary to ensure that PUFA does not provide more than about 8% total energy. Thus careful planning is needed to identify the most appropriate foods to replace those rich in SAFA in diets designed to reduce the lipoprotein-mediated risk of coronary heart disease.

Aged↗
PubMed1991

Control of cell fate in the tail region of C. elegans by the gene egl-5.

The tail region of C. elegans contains a number of blast cell and neuron types that either are found only in the tail, or are different from more anterior homologues. In egl-5 mutants, the fates of many of these tail cells are abnormal or transformed to those of anterior homologues. The affected cells are related only by position and not by ancestry. egl-5 is also required for normal development of the somatic gonad and sex muscles in males. The function of egl-5 in all these tissues is cell autonomous. By genetic mapping, egl-5 lies very close to mab-5, a gene with an analogous role in the immediately anterior body region. egl-5 and mab-5 may constitute a 'mini-cluster' of regional determination genes, similar to those described in other animal phyla.

Animals↗
PubMedDate not supplied

Dietary management of patients with familial hypercholesterolaemia treated with simvastatin.

The effect of diet on plasma lipids and lipoproteins was examined in 19 patients with familial hypercholesterolaemia treated with the HMGCoA reductase inhibitor, simvastatin. The study was a randomized double-blind cross-over trial of two diets: a low fat diet and a higher fat diet, and was performed to determine whether ongoing attention to diet is necessary for patients receiving this drug for the treatment of familial hypercholesterolaemia. Plasma cholesterol concentration was 6.5 per cent lower on the low fat diet than on the high fat diet. The difference was within the range predicted by the Jacobs modification of the Keys formula from the reported intake on the two diets. The fall on the low fat diet was principally accounted for by a reduction in low density lipoprotein cholesterol, although high density lipoprotein cholesterol and apolipoprotein A1 also fell. Patients taking HMGCoA reductase inhibitors for the treatment of familial hypercholesterolaemia respond to changes in dietary fat intake. They are thus likely to achieve further reduction in their coronary heart disease risk, and should remain on a low saturated fat low cholesterol diet even when taking these powerful lipid lowering drugs.

Adult↗