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Query: UMLS:C0020473 (hyperlipidemia)
 15,891 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lipids, which serve as a source of energy and are an important constituent of cell membrane structure, are readily stored in the body. By definition they are insoluble in water. Specific proteins called apolipoproteins interact with lipids to form soluble lipid-protein complexes called lipoproteins. It is in this form that the major lipids--cholesterol, triglyceride and phospholipid--circulate in plasma. Unesterified fatty acids, another major lipid group, are bound to albumin in the circulation. The plasma lipoproteins are complex macromolecules composed of lipids, apolipoproteins and carbohydrates. The relative proportions of these components differ markedly between lipoprotein classes. Hyperlipidemia is a term used for increased concentrations of plasma cholesterol and/or triglycerides. Any one plasma lipid is present in several types of lipoproteins. Thus, hyperlipidemia implies the presence of hyperlipoproteinemia. The latter has important therapeutic implications. Most of the recent attempts at classification have been directed at the lipoprotein level of plasma lipid organization. Decreased concentrations of lipids in plasma can be achieved by altering the rates of metabolism of lipoproteins. Decrease in lipoprotein synthesis, increased catabolism or impaired release from cells into the blood stream may all result in a decrease of plasma lipids. Drugs which affect one or more of these factors are used to treat hyperlipoproteinemia. In order to elucidate the mechanism of action of hypolipidemic drugs it is necessary to understand the lipoprotein defect at the molecular level. This requires a more detailed knowledge of lipoprotein metabolism than is presently available for most of the hyperlipoproteinemias. This paper will review some of the generally accepted properties of the plasma lipoproteins, describe some difficulties which hamper the understanding of lipoprotein metabolism, and identify possible mechanisms by which drugs may affect lipoprotein metabolism.
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PMID:Importance of apolipoproteins in lipid metabolism. 20 49

The aim of this study was to discover which of three major abnormalities of the genetically obese Zucker rat (fa/fa), namely hyperphagia, excess adiposity, and hyperlipidemia, is the first to appear prior to manifest obesity, i.e., before weaning. Suckling fa/fa rats, bred from heterozygous parents, were detected by sizing fat cells obtained from an inguinal fat pad biopsy. Cell hypertrophy was observed in fa/fa rats, compared to Fa/-littermates of the same sex, as soon as 5-7 days after birth. Prediction of fa/fa genotype at this age by this method was assessed using a series of 80 pups and proved to be totally successful. The identity of the "predicted" obese pups was confirmed morphologically at 6 weeks of age. Food (milk) intake was estimated from water turnover rates determined on 86 pups aged 2-8 days using tritiated water. The results show that 7-day-old fa/fa rats had heavier inguinal fat pads with larger adipocytes and higher lipoprotein lipase activity than their lean controls. There was no genotype effect on water intake adjusted to body weight during the first week of life. Moreover weight of stomach contents and triglyceridemia were similar in all animals at 7 days. These results show that excess adiposity develops in the fa/fa rat during the first week of life, before hypertriglyceridemia and hyperphagia, and raises the question of whether this adiposity results from a defect in energy expenditure or an abnormality of fat cell storage capacity, or both.
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PMID:Onset of genetic obesity in the absence of hyperphagia during the first week of life in the Zucker rat (fa/fa). 29 Jul 21

The nephrotic syndrome may be associated with several complications caused by severe proteinuria. The consequences of severe renal protein loss are disturbances of water and electrolyte metabolism, thromboses and thromboembolic complications, hyperlipidemia with accelerated atherosclerosis and, finally, some other complications due to the decreased oncotic pressure and the renal loss of transport globulins and immunoglobulins. Diagnosis and treatment of these complications are important in the management of patients with nephrotic syndrome. In the present study, the frequency and localization of thromboses and thromboembolic complications in 11 patients with nephrotic syndrome are described. In addition, factors which are known to be responsible for the hypercoagulable state in nephrotic syndrome were evaluated and correlated to the thromboembolic complications in these patients. An important finding was that in all patients with thromboses and thromboembolic complications, the serum albumin concentrations were below 2 g/100 ml, whereas, with one exception, serum albumin levels were above 2 g/100 ml in cases without thromboembolic complications. Our results indicate that serum albumin levels may be used as an indirect parameter to assess the risk of thromboembolic complications in patients with nephrotic syndrome.
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PMID:[Complications of nephrotic syndrome with special reference to thromboembolic accidents]. 37 Sep 77

The present study investigated the effect of serum lipoproteins on sterol synthesis by isolated rat hepatocytes. These cells were maintained in culture medium for 24 hr and incubated for the same period of time with increasing concentrations of serum lipoproteins (5-150 microgram of lipoprotein-protein per ml) isolated from different animal species. The viability of the cells was ascertained by their ability to synthesize cholesterol and protein and to secrete serum proteins into the medium. Rat VLDL and LDL did not alter sterol synthesis, which was stimulated instead by HDL. Rat serum chylomicrons were also ineffective. Human LDL significantly reduced the synthesis of sterols from both acetate and tritiated water; this effect was also induced by human VLDL to a reduced extent. VLDL isolated from hypercholesterolemic rabbit (VLDLC) strongly inhibited sterol synthesis from acetate but not from mevalonate. Cholesteryl-ester-rich VLDL isolated from a patient with type III hyperlipidemia (type III VLDL) were more effective than normal VLDL in suppressing sterol synthesis from acetate. The implications of these findings are discussed with regard to the possible role of cholesteryl-ester-rich lipoproteins on the in vivo regulation of sterol synthesis in the liver.
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PMID:Cholesterol synthesis in isolated rat hepatocytes: effect of homologous and heterologous serum lipoproteins. 45 21

Results in animals and in man indicate that in many circumstances, lipemia is not closely related to the severity of atherosclerosis nor to the incidence of coronary heart disease (CHD) or the intake of saturated fats as observed in paired studies between farmers from Moselle and Var in France and from West and East Scotland. In rabbits, an increased response of platelets to thrombin occurs before any deposition of cholesterol, as a result of a saturated fat feeding. Under these conditions, the addition of alcohol to the drinking water decreases significantly both the platelet response to thrombin and the severity of atherosclerotic lesions without much affecting plasma cholesterol. In farmers from Moselle and Var (as well as from Scotland), platelet functions, namely the aggregation to thrombin and their clotting activity, i.e. PF3, are closely related to the intake of saturated fats, either as a result of the long-term feeding or of a 1 year change in the diet of Moselle farmers. Certain platelet functions appear to be the only blood parameter related to the incidence of CHD and significantly correlated on a group, as well as on an individual basis, with the intake of saturated fat, and inversely related with that of calcium. Saturated fats and calcium are known to be the two main dietary factors related to CHD. These results suggest that the intermediate link between dietary fats and CHD might be blood platelets rather than serum lipids, through an effect on both thrombosis and atherosclerosis.
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PMID:Dietary fats and platelet functions in relation to atherosclerosis and coronary heart disease. 51 Oct 11

We have experienced with 50 cases of parasellar tumors, four cases of which had persistent thirst, polydipsia, polyuria, and reversible temporary hyponatremia secondary to hypernatriuresis. The mechanism of the syndrome in these four cases could not be explained by either that of the syndrome of hypernatremia or of the so-called SIADH. We tentatively named this syndrome as "CEREBRAL POLYURIC HYPONATREMIA" and the criteria of this syndrome as as follows: 1) persistent thirst, polydipsia polyuria, 2) reversible temporary hyponatremia secondary to hypernatriuresis, 3) exception of the following items--administration of uretic drugs, renal and adrenal dysfunction, hyperglycemia, hyperlipemia, overadministration of water, and poor administration of NaCl. The mechanism of this syndrome is presumed as follows: 1) compression by a tumor or surgical attack to the anterior hypothalamus, 2) disturbance of the mechanism of ADH secret-on, 3) extrasecretion of natriuretic factor possibly produced in the anterior hypthalamus, and 4) preservation of the thirst center.
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PMID:[Cerebral polyuric hyponatremia--discussion of a new syndrome with disturbance of electrolyte balance of central origin (author's transl)]. 55 42

Hyponatremia may be due to relative excess of water or to sodium (Na+) depletion or may be artifactual due to hyperlipemia or excess osmotically active solute in plasma. The cause can be determined from the history, hydration status, and results of simple ancillary tests, eg, osmolality determinations and estimations of urine Na+ concentration. Hypernatremia almost always means water lack. The cause can be determined by correlating clinical findings with urine osmolality test results.
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PMID:Electrolyte studies. 1. Sodium and water. 70 3

Despite frequently good early successes the several therapeutic methods of obesity show in general unsatisfactory long-term results with large numbers of recidivations. Considering non-existing causal-therapeutic possibilities in the present paper in reported on a complex and differentiated therapeutic programme in 549 obese persons. After an initial subtotal fasting cure of ca. 100 kcal/a day with gradual increase of diet in more than half the obese persons an additional differentiated pharmacotherapy was performed. The indications resulted above all from the frequent syntropy with diabetes mellitus (28%), arterial hypertension (23%) and hyperlipidaemia (14%). In 122 test persons (adipose patients with hyperlipoproteinaemia and extremely obese patients without essential factors of risk, respectively) a treatment with 2 x 50 microgram tri-iodothyronine--partly in combination with diuretics--was performed in intermittent and gradually decreasing dosage. Apart from a vast normalisation of the lipid parameters a reduction of weight from 32.6 +/- 14.8 kg could be achieved after 31 +/- 14 months. Of 131 adipose hypertensive patients 74 received additionally diuretics on account of increased water retention with also good long-term results concerning the reduction of weight and normalisation of blood pressure. The biguanides were a therapeutic enrichment particularly in the treatment of adipose elderly diabetics with obligatory diet. Apart from an improvement of the carbohydrate tolerance regularly a more intensive reduction of weight was obtained.
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PMID:[Indications and results of an additional differentiated pharmacotherapy of obesity]. 73 44

The risks of the use of oral contraceptives (OC) or intrauterine devices (IUD) to the woman with significant cardiac disease are discussed. An increased risk of thromboembolic events, a hypertensive street, the retention of body fluids and water resulting in weight gain, and hyperlipidemia are some of the adverse effects of OCs reported in the literature. With the IUD, the risk of pelvic infection and the occurrence of the vagal syndrome at, or immediately after, insertion have serious implications for the woman with cardiac disease. It is concluded that OCs containing 50 mcg or more of estrogen should not be prescribed to women with cardiac disease, though combination OCs containing 20-30 mcg estrogen may be tried with caution. Very little risk is posed by the insertion of an IUD accompanied by antibiotic treatment. The conventional methods of contraception may be offered, but the greater risk of pregnancy should be carefully considered.
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PMID:Contraception for the woman with significant cardiac disease. 80 65

Destruction of the ventromedial hypothalamic nuclei (VMN) in the weanling rat without injury to the median eminence results in a series of somatic, endocrine, and metabolic changes that are characterized by normal food and water intake but decreased linear growth, normal body weight but increased carcass fat and reduced carcass protein, lean body mass, and water. The endocrine alterations comprise hyperinsulinemia in the face of normoglycemia, hypertriglyceridemia and hypercholesterolemia and reduced growth hormone levels. The metabolic changes include greater oxidation of glucose and incorporation into lipid and reduced palmitate oxidation but increased incorporation into lipid. Weanling rats with VMN lesions are normophagic in absolute terms, relative to body weight and per metabolic unit, but their nocturnal feeding and weight gain cycles are disrupted and their locomotor activity is reduced. The VMN are involved in the long-term control of feeding - as in the mature rat - as shown by intragastric preloading studies and dietary density manipulation, glucose preference tests and intraperitoneal injections with glucose. Hyperinsulinemia and hypertriglyceridemia are present four days after the VMN operation in the presence of subnormal food intake and plasma glucose levels. Manipulations of the fat content of the diet revealed that the hyperlipidemia is of both endogenous and exogenous origin and that lipoprotein lipase is increased; a 48-hour fast reduced the hyperlipidemia to control levels, however. This suggests that weanling VMN rat tissue may have an impaired ability to take up circulating lipid. An increased incorporation of glycerol into lipid may be due to induction of glycerokinase by hyperinsulinemia. Adipose tissue of weanling VMN rats showed glycerokinase by hyperinsulinemia. Adipose tissue of weanling VMN rats showed neither depressed lipolysis nor diminished lipolytic activity per milligram of tissue protein. Glucose oxidation and incorporation into adipose tissue is increased in several tissues in vitro and there is enhanced glucose disappearance from plasma and incorporation into tissue lipids in vivo. These changes develop within a short time after lesion production and persist at least partially up to six months: glucose utilization in liver increases already four hours after the operation whereas it takes 72 hours to commence in adipose tissue. Insulin resistance is not apparent either in vivo or in vitro. The decreased growth hormone levels are not critical to the metabolic changes, nor is the hyperinsulinemia totally necessary. The metabolic changes also appear on several different types of diet and persist with fasting. The latter does not reduce insulin sensitivity of VMN rat tissues, wheras it does so in normal rats. Mature rats developed the same metabolic changes even in the absence of hyperphagia. The metabolic alterations can be blocked by pharmacologic doses of glucocorticoids, but are enhanced by the administration of estrogen...
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PMID:Origin of endocrine-metabolic changes in the weanling rat ventromedial syndrome. 95 Jun 80


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