ABSTRACT
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Subject(s)
Humans , Sex Factors , Plants , Genes, Tumor Suppressor , Genes, APC , Oncogenes , Genetic Predisposition to Disease , Carcinogens , Colonic Diseases , DNA Repair , Dietary Fats , Fruit , Colorectal Neoplasms , Dietary FiberSubject(s)
Colorectal Neoplasms/etiology , Carcinogens/adverse effects , Colonic Diseases/complications , Colorectal Neoplasms/epidemiology , Colorectal Neoplasms/prevention & control , DNA Repair/genetics , Dietary Fats/adverse effects , Dietary Fiber , Fruit , Genes, APC , Genes, Tumor Suppressor , Genetic Predisposition to Disease/genetics , Humans , Oncogenes , Sex Factors , VegetablesSubject(s)
Dietary Fats/administration & dosage , Fibroblasts/metabolism , Lipoproteins, HDL/metabolism , Lipoproteins, LDL/metabolism , Cells, Cultured , Cholesterol/metabolism , Fatty Acids/physiology , Fibroblasts/ultrastructure , Humans , Lipoproteins, HDL/administration & dosage , Lipoproteins, LDL/administration & dosage , Phospholipids/pharmacology , Receptors, Cell Surface/physiology , Receptors, LDL/physiology , Receptors, LipoproteinABSTRACT
A possible mechanism of action of probucol on low density lipoprotein uptake was examined in 7 type IIa hypercholesterolemic subjects. Probucol administration effectively lowered plasma cholesterol. Both apo B-associated cholesterol and HDL cholesterol were decreased but a great inter-patient variability was noted. Plasma triglycerides were unchanged and phospholipids decreased. The composition of the isolated LDL was unaffected. The LDL displaceable activity of reference [125I]LDL measured by competition assays in control fibroblasts, was increased in 3 subjects, decreased in 1 subject and unchanged in the other 3. No correlation was found between the change in apo B-associated cholesterol and the change in the in vitro catabolism of LDL of treated patients. The results did not allow a simple mechanism of action to be ascribed to the drug, but questioned the origin of the hypercholesterolemia.
Subject(s)
Hyperlipoproteinemia Type II/blood , Lipoproteins, LDL/blood , Phenols/therapeutic use , Probucol/therapeutic use , Skin/metabolism , Adult , Aged , Cells, Cultured , Female , Fibroblasts/metabolism , Humans , Hyperlipoproteinemia Type II/drug therapy , Lipoproteins, LDL/metabolism , Male , Middle AgedABSTRACT
The [3H]cholesterol efflux from cultured skin fibroblasts was investigated in 12 patients, clinically heterozygous for familial hypercholesterolemia (FH). The [3H]cholesterol efflux from fibroblasts was studied in the presence of high-density lipoproteins, isolated either from control sera or from the patient's own serum. The [3H]cholesterol efflux from fibroblasts of 3 patients was increased; it was decreased for 4 patients and similar to that of control cells for 5 patients. This study indicates that in some patients with heterozygous FH, abnormalities of [3H]cholesterol efflux from fibroblasts can be detected. The heterogeneity of the results is consistent with the heterogeneity of the low-density lipoprotein receptor activity and with the variability of the clinical picture found in this disease.
Subject(s)
Cholesterol/metabolism , Hyperlipoproteinemia Type II/metabolism , Adolescent , Adult , Cells, Cultured , Child , Child, Preschool , Female , Fibroblasts/metabolism , Heterozygote , Humans , Hyperlipoproteinemia Type II/genetics , Lipoproteins, HDL/blood , Male , Proteins/metabolism , Triglycerides/bloodABSTRACT
The purpose of this work was to determine whether the changes induced by dietary manipulations in the chemical composition of high-density lipoproteins (HDL) (particularly phospholipid fatty acid composition) modified their capacity to promote [3H]cholesterol efflux from cultured fibroblasts. Plasma HDL were obtained from subjects fed for six successive long periods on diets consisting of one predominant fat: peanut oil, corn oil, olive oil, soybean oil, low erucic acid rapeseed oil or milk fats. The [3H]cholesterol efflux from cells in the presence of plasma HDL was studied by means of normal adult human fibroblasts in culture. The [3H]cholesterol efflux from fibroblasts appeared to be independent of the overall composition of HDL and of the degree of saturation of the HDL phospholipid fatty acids, but it was correlated with the phospholipid fatty acid chain length. The [3H]cholesterol efflux from fibroblasts is highly and positively correlated with the sum of the HDL phospholipid C20, C22, C24 fatty acids, and negatively correlated with the sum of the HDL phospholipid C18 fatty acids.
Subject(s)
Cholesterol/metabolism , Dietary Fats/administration & dosage , Fatty Acids/analysis , Lipoproteins, HDL/analysis , Phospholipids/analysis , Adult , Aged , Biological Transport , Cells, Cultured , Dietary Fats/pharmacology , Female , Fibroblasts/metabolism , Humans , Middle Aged , Structure-Activity RelationshipABSTRACT
The chemical composition and metabolism of low-density lipoproteins (LDLs) in a population of Benedictine nuns were studied after 5-month periods during which the predominant dietary fats were sunflower oil, fluid of palm, peanut oil, milk fats, low erucic acid rapeseed (LEAR) oil, corn oil, olive oil, soybean oil. The population was divided into three groups. The control group (C) included 12 subjects selected at random by taking 2 subjects per age pool among those with plasma cholesterol less than 230 mg/dl. Groups H1 and H2 were selected in the same way among those with plasma cholesterol less than 230 mg/dl. Groups H1 and H2 comprised 6 subjects and differed from each other in the amount of plasma cholesteryl esters, i.e., below and above the mean value of group C. Changes in LDL composition, according to the dietary fat, were associated with changes in LDL catabolism studied in fibroblast cultures, but no significant differences were found between the three groups.
Subject(s)
Dietary Fats/administration & dosage , Fatty Acids/analysis , Fibroblasts/drug effects , Lipoproteins, LDL/metabolism , Cell Communication/drug effects , Cells, Cultured , Fatty Acids/physiology , Female , Fibroblasts/metabolism , Humans , Lipoproteins, LDL/analysis , Lipoproteins, LDL/blood , Lipoproteins, LDL/physiologyABSTRACT
The chemical composition and metabolism of lipoproteins in a population of Benedictine nuns were studied after 5-month periods during which the predominant dietary fats were sunflower oil, peanut oil, palm oil, or milk fats (butter and cream). The population was divided into three groups. The control group (C) included twelve subjects selected at random by taking two subjects per age pool among those with plasma cholesterol less than 230 mg/dl. Groups H1 and H2 were selected at random in the same way, among those with plasma cholesterol greater than 230 mg/dl. Each group comprised six subjects and differed from each other in the amount of plasma cholesteryl esters, i.e., below and above the mean value of group C, for H1 and H2, respectively. Changes in the degree of saturation of the predominant fat of the diet were associated with changes in both the chemical composition of lipoproteins and their cellular metabolism studied in fibroblast cultures. No significant difference between the normocholesterolemic subjects of group C and the "high risk" subjects of groups H1 and H2 was found.
Subject(s)
Dietary Fats/metabolism , Lipoproteins, HDL/blood , Lipoproteins, LDL/blood , Plant Oils , Adult , Aged , Cells, Cultured , Cholesterol/biosynthesis , Cholesterol/blood , Cholesterol, LDL , Esterification , Female , Fibroblasts/metabolism , Humans , Lipoproteins, VLDL/blood , Middle Aged , Oils/pharmacology , Palm Oil , Peanut Oil , Sunflower OilABSTRACT
The effects of 3 dietary fats (olive oil, canbra oil and butter) on the fatty acids of blood lipids and on serum lipoproteins were compared in 6 healthy adult outpatients, after a 6-day normocaloric diet including 35% of the studied fat. Important, although incomplete, changes appeared in the fatty acid composition of the various serum lipids and in the composition and distribution of serum lipoproteins. These changes probably result from the degree of saturation of the fat ingested. Moreover, differences were observed among individual subjects. Genetic differences, which are important in clinical practice, are stressed in connection with risks of vascular diseases and hyperlipidemia and affect intestinal fat absorption and lipoprotein metabolism.
