Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004153 (atherosclerosis)
77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Atherosclerosis is the leading obstacle to long-term survival in cardiac transplant patients. Increases in plasma triglycerides and lipoprotein cholesterol levels occur after transplantation that may contribute to transplant atherosclerosis. The etiology of this increase is unclear. We investigated the interaction of immunosuppressive medications with plasma triglycerides, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, the HDL subclasses HDL2 and HDL3 cholesterol, and hepatic and lipoprotein lipase activity in 72 consecutive cardiac transplant patients compared to 51 healthy control subjects. In the transplantation group, greater concentrations of plasma triglyceride (80%, p less than 0.001), LDL cholesterol (16%, p less than 0.005) and hepatic lipase activity (100%, p less than 0.001) were noted, whereas lipoprotein lipase activity was noted to be significantly lower (124%, p less than 0.001). No difference was detected in HDL, HDL2, or HDL3 cholesterol. Cyclosporine dose was significantly associated with hepatic lipase activity (r = 0.33, p less than 0.02) and inversely associated with lipoprotein lipase activity (r = -0.28, p less than 0.05). Lipoprotein lipase activity after transplantation correlated inversely with triglycerides (r = -0.36, p less than 0.002) and positively with HDL cholesterol (r = 0.23, p less than 0.05) and HDL2 cholesterol (r = 0.29, p less than 0.05). Hepatic lipase activity correlated inversely with LDL cholesterol (r = -0.21, p less than 0.08). In multiple regression analysis, cyclosporine dose was the major source of variation in hepatic lipase activity.
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PMID:Lipoprotein and hepatic lipase activity and high-density lipoprotein subclasses after cardiac transplantation. 222 Jun 41

The arterial wall is a complex organ system with respect to carbohydrate-protein macromolecules, particularly proteoglycans. Proteoglycans in the arterial wall display polydispersity and heterogeneity even in the same family. At least two major types are known: chondroitin sulphate-dermatan sulphate type and heparan sulphate type. These proteoglycans have varied biological properties, and some of these properties are implicated in the development of atherosclerosis. The chondroitin sulphate-dermatan sulphate proteoglycans are capable of forming complexes with serum low-density lipoproteins, a process conductive to lipid accumulation in the extracellular space of the arterial wall. Also, such reactions render low-density lipoprotein particles electronegative aggregates. These altered low-density lipoproteins are taken up by macrophages (and possibly by proliferative smooth muscle cells) through a high-affinity receptor pathway devoid of feedback regulation, which results in intracellular lipid accumulation and foam-cell formation, a hallmark of atherosclerosis. On the other hand, heparan sulphate proteoglycan located on the cell surface and internal elastic lamina is antithrombogenic, and facilitates binding of the lipid-clearing enzyme, lipoprotein lipase, to endothelium. Thus, chondroitin sulphate and heparan sulphate proteoglycans with divergent biological properties play a crucial role in the pathogenesis of atherosclerosis.
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PMID:Arterial wall proteoglycans--biological properties related to pathogenesis of atherosclerosis. 222 23

Dyslipidemias are frequent in diabetic subjects: they increase the risk for atherosclerosis, in addition to the risk of diabetes mellitus per se. The pathogenesis of dyslipidemias differs between type I and type II diabetes: untreated type I diabetic subjects demonstrate frequently increased triglyceride concentrations due to diminished removal of triglyceride-containing particles, as a result of diminished activity of lipoprotein lipase. In addition, more triglycerides are produced due to increased lipolysis and increased free fatty acid supply to the liver. Type II diabetic subjects demonstrate very low density lipoprotein (VLDL) over-production due to obesity, insulin resistance and caloric overconsumption. In addition, triglyceride removal may be diminished due to diminished lipoprotein lipase activity when diabetes mellitus is poorly controlled. In addition, high density lipoprotein (HDL) is frequently lowered. During decompensation low density lipoprotein (LDL) concentrations may also increase. LDL particle composition is frequently abnormal. A severe dyslipidemia in diabetes mellitus is frequently a combined effect of diabetes mellitus and a congenital lipoprotein abnormality. The evaluation and treatment of dyslipidemias in diabetic subjects should be performed similarly to non-diabetics according to the guidelines published recently by the Working Group 'Lipids' of the Swiss Foundation of Cardiology. Additional accents in diabetic subjects are necessary. It is recommended that serum cholesterol, triglycerides and HDL are determined in every patient when diabetes mellitus is diagnosed. If serum cholesterol is greater than 6.5 mmol/l and the cholesterol/HDL-ratio is greater 6.5, dietary treatment should be reinforced; if its effect is insufficient, drug therapy should be considered.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Dyslipidemia in diabetes mellitus: significance, diagnosis and treatment]. 223 46

CAD results from atherosclerosis, a chronic disease process that has its origin in childhood. Children and adolescents can be at higher risk for CAD by virtue of being from families with premature CAD or familial dyslipoproteinemias. The plasma lipid and lipoprotein levels result from a number of complex metabolic processes that are under the control of genetic and environmental (e.g., diet) influences. The normal ranges of plasma lipids and lipoproteins in children are known, and children and adolescents with dyslipoproteinemia are ordinarily defined as those having levels of plasma total, LDL, or triglyceride above the 95th percentile or with a low HDL cholesterol below the 5th percentile. Children of a parent with documented dyslipoproteinemia or with family history of premature CAD may be screened in the fasting state any time after 2 years of age. Following the exclusion of secondary causes of dyslipoproteinemia, the diagnosis of primary dyslipoproteinemia can be made. Lipoprotein patterns are not diagnostic for a given genotype. Efforts to determine further the biochemical defects responsible for a given phenotype have led to the investigation of gene coding for the apolipoproteins, the key enzymes in the lipoproteins pathways (LPL, HDL, and LCAT) and the receptors that process lipoproteins, such as the LDL receptor and the chylomicron remnant receptor. From a practical standpoint, the diagnosis of the kind of dyslipoproteinemia in a child will depend upon the nature and severity of the dyslipoproteinemia, both in the child (or adolescent) and in parents and siblings. Marked increases in plasma total and LDL cholesterol in the child and in at least one of the parents often reflect the presence of familial hypercholesterolemia, an inherited dominant condition due to a defect in the LDL receptor gene. The triglyceride levels are often normal. If the child has a different dyslipoproteinemia pattern from siblings and parents, then the diagnosis of familial combined hyperlipidemia or hyperapobetalipoproteinemia should be considered. Most children with mild or borderline elevations in total and LDL cholesterol will have polygenic hypercholesterolemia. Triglyceride problems in children and adolescents are relatively uncommon, particularly the more severe hypertriglyceridemia such as that found in lipoprotein lipase and apoC-II deficiency, dysbetalipoproteinemia, and type V hyperlipoproteinemia. High levels of Lp(a) lipoprotein, in isolation or in combination with other dyslipoproteinemia, accelerate risk for CAD. Low levels of HDL cholesterol in the absence of other abnormalities suggest the diagnosis of hypoalphalipoproteinemia.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Diagnosis and management of familial dyslipoproteinemia in children and adolescents. 225 50

Large (Sf greater than 100) and small (Sf 100-20) very low density lipoprotein (VLDL) particles were isolated by density gradient ultracentrifugation and characterized chemically in 8 patients with primary hypertriglyceridemia before and after 6 weeks treatment with 4 grammes daily of nicotinic acid (NA). Concomitant changes in high density lipoprotein (HDL) subclass distribution were determined by gradient gel electrophoresis. Small VLDL was subjected to lipolysis in vitro by incubation with bovine lipoprotein lipase before and after NA, and the change in the lipolytic end-product isolated in the low density lipoprotein (LDL) fraction was investigated. Reductions were achieved in the plasma levels of triglycerides, free and esterified cholesterol, phospholipids and proteins in the two VLDL subfractions. In all, the composition of both large and small VLDL particles changed towards potentially less atherogenic particles that were poorer in cholesteryl esters. The HDL cholesterol concentration increased and the HDL protein distribution on gradient gel electrophoresis changed towards larger particles. The mechanism behind the change in cholesterol distribution between VLDL and HDL after NA treatment is unclear, but it could possibly relate to decreased lipid transfer activity. NA reduced the content of apolipoprotein B in both VLDL subclasses and did not decrease the calculated particle size or the number of triglyceride molecules per particle, indicating a reduction of VLDL particle number rather than of particle size. The LDL density fraction isolated after lipolysis in vitro of small VLDL contained less total cholesterol and phospholipids and had a density profile more similar to native LDL after the patients had been treated with NA.
Atherosclerosis 1990 Oct
PMID:Normalisation of the composition of very low density lipoprotein in hypertriglyceridemia by nicotinic acid. 228

The cytotoxic effect of hypertriglyceridemic (HTG) serum and triglyceride-rich lipoprotein (TG-rich lipoprotein) lipolyzed in vitro by purified lipoprotein lipase on cultured human umbilical vein endothelial cells (HUVECs) was studied. When confluent cultures of HUVECs (8.4 x 10(4)/cm2) were incubated in the presence of control (non-lipolyzed HTG serum) or lipolyzed HTG serum or TG-rich lipoprotein, the lipolyzed HTG serum or TG-rich lipoprotein was cytotoxic to the HUVECs as indicated by their detachment from the culture dish; the lipolyzed serum at 10% of the culture medium or lipolyzed TG-rich lipoprotein at 75 micrograms cholesterol/ml caused the detachment of all (100%) of the cells from the culture dish after a 24 h incubation. Control (non-lipolyzed) HTG serum or non-lipolyzed TG-rich lipoprotein at the same or higher concentration was not cytotoxic to the cells. The HUVECs incubated for 48 h with low (sublethal) doses of lipolyzed TG-rich lipoprotein (10-50 micrograms cholesterol/ml) contained massive lipid inclusions; no lipid inclusions were seen within the cells when the culture medium contained control non-lipolyzed TG-rich lipoproteins. Finally, when high density lipoprotein (HDL) was added to the culture medium at the same concentration as the cytotoxic lipolyzed TG-rich lipoprotein (75 micrograms cholesterol/ml), the cytotoxic effect of the lipolyzed TG-rich lipoprotein was inhibited. These data suggest that the interaction of endothelial cells with lipolytic remnants of TG-rich lipoprotein may play a role in the pathogenesis of atherosclerosis and that HDL may play an important role in inhibition of the endothelial cell injury produced by the lipolytic remnants of TG-rich lipoprotein.
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PMID:Lipolyzed hypertriglyceridemic serum and triglyceride-rich lipoprotein cause lipid accumulation in and are cytotoxic to cultured human endothelial cells. High density lipoproteins inhibit this cytotoxicity. 235 39

Small (Sf 20-100) very low density lipoprotein (VLDL) particles were prepared by density gradient ultracentrifugation of plasma from normolipidemic and type IV hypertriglyceridemic post-infarction patients and healthy controls. The small VLDL separated from the plasma of severely hypertriglyceridemic post-infarction patients were found to contain twice the amount of cholesteryl esters per particle, compared with small VLDL from normolipidemic patients and healthy controls. There was a linear increase in the percentage of cholesterol that was esterified in the small VLDL with the serum VLDL triglyceride concentration (r = 0.66). When incubated for two hours with bovine lipoprotein lipase in excess and bovine albumin as a free fatty acid acceptor at one and the same triglyceride concentration in the medium, the end-product isolated by ultracentrifugation varied as a function of the serum VLDL triglyceride level. The amount of glyceride-glycerol recovered after two hours of incubation with lipoprotein lipase was 13.3 +/- 1.3% (mean +/- SEM) of the initial values and did not correlate with the VLDL triglyceride level. With rising serum VLDL triglyceride concentration, the product isolated in the low density lipoprotein (LDL) density region (1.006 less than d less than 1.063 kg/l) contained more total cholesterol and phospholipids. The linear correlation coefficients for these relations were 0.65 and 0.58 for cholesterol and phospholipids respectively. The ratio of total cholesterol to insoluble protein in the LDL density range after lipolysis rose with increasing serum VLDL triglyceride level (r = 0.68). The end-product was further characterized by density gradient ultracentrifugation of the incubate. In vitro LDL derived by lipolysis of normolipidemic small VLDL was denser than in vitro LDL of hypertriglyceridemic small VLDL. A significant relation was found between the percentage of cholesteryl esters of total cholesterol in the substrate and the relative amount of total cholesterol recovered in the LDL density fraction after lipolysis (r = 0.69). We suggest that the enrichment with cholesteryl esters of small VLDL from type IV hypertriglyceridemic patients is caused by lipid transfer from LDL and high density lipoprotein (HDL) and that the change in VLDL particle composition influences the precursor-product relationship to LDL.
Atherosclerosis 1990 May
PMID:Abnormalities of composition and of in vitro lipolysis products of human small very low density lipoproteins in hypertriglyceridemia. 236 Sep 14

When bezafibrate therapy was interrupted in patients who had been on continuous treatment for hyperlipoproteinemia for 4-10 years, there were significant increases in the serum cholesterol, triglyceride and apolipoprotein B concentrations corresponding to an increase of the very low density lipoprotein (VLDL) levels by approximately 50%. This increase of VLDL was accompanied by reduced levels of the post-heparin lipoprotein lipase activity (LPLA) (P = 0.07) and hepatic lipase (P = 0.05) activity with a significant reduction of the skeletal muscle LPLA (P less than 0.05), but not the adipose tissue LPLA, and a retarded removal of an i v injected fat emulsion (P less than 0.01). There were no significant changes of the low or high density lipoprotein cholesterol or the apolipoprotein A-I or A-II concentrations. Three months after bezafibrate treatment the content of linoleic and gammalinoleic acid in the plasma cholesterol ester had increased significantly, while the palmitoleic and oleic acids were reduced in spite of unchanged dietary treatment. Taken together, the data indicate that a lipid-lowering effect of bezafibrate, particularly on the VLDL lipids, is maintained throughout long treatment periods. One mechanism for the reduced level of the triglyceride-rich lipoproteins is an increased activity of the lipoprotein-lipase activity in the skeletal muscle, which decreased when the treatment was interrupted. The significance of the changes of the plasma lipid fatty acid spectrum during bezafibrate treatment remains unclear.
Atherosclerosis 1990 May
PMID:Interruption of long-term lipid-lowering treatment with bezafibrate in hypertriglyceridaemic patients. Effects on lipoprotein composition, lipase activities and the plasma lipid fatty acid spectrum. 236 Sep 15

Human plasma lipoproteins or human whole plasma have been incubated in vitro with canine hepatic lipase (HL) and bovine milk lipoprotein lipase (LPL) to determine the effects of lipases on the particle size distribution of HDL. Confirming previous reports, HL preferentially hydrolysed high density lipoprotein (HDL) triacylglycerol while LPL hydrolysed predominantly very low density lipoprotein (VLDL) triacylglycerol; however, neither lipase altered HDL particle size unless both VLDL and cholesteryl ester transfer protein (CETP) were present. Under these conditions HL promoted marked reduction in HDL particle size in a process dependent on the concentration of VLDL triacylglycerol while LPL was virtually without effect. When both LPL and HL were included in the same incubation, however, LPL prevented the effects of HL. These results are consistent with a proposition that HL has a direct effect on HDL particle size in a process which is dependent on concurrent lipid transfers between HDL and VLDL and that LPL reduces the effect of HL by reducing the concentration of VLDL triacylglycerol.
Atherosclerosis 1990 Jun
PMID:Lipoprotein lipase prevents the hepatic lipase-induced reduction in particle size of high density lipoproteins during incubation of human plasma. 237 81

Relationships between lipoprotein fractions, lipoprotein lipase activities, thyroid hormones, and coronary lesion growth were studied among 35 male patients with severe coronary atherosclerosis, who had participated in the Leiden Intervention Trial, a lipid-lowering dietary intervention program. Coronary arteriography was performed at the beginning of the study and again 2 years later at its termination. The lesions were quantified using a computer-based analysis system to assess the progression rate of coronary lesions based on absolute arterial dimensions in a patient's coronary tree. For this reason an absolute coronary score was computed. Based on absolute coronary scores, patients could be divided into a no-lesion growth group (14 patients) and a progression group (21 patients). Lipoprotein fractions, lipoprotein lipases, and thyroid hormones were determined at the end of the trial. No significant differences were found between the no-lesion growth and progression groups for total cholesterol and low-density lipoprotein (LDL) cholesterol. In the progression group very-low-density lipoprotein (VLDL) cholesterol and triglycerides were significantly higher (p less than 0.05) and high-density lipoprotein (HDL) cholesterol was almost significantly lower (p = 0.058). Hepatic lipase (HL) values were significantly higher in the no-lesion growth group, when compared with the progression group, whereas lipoprotein lipase (LPL) values were not significantly different. Triiodothyronine (T3) was significantly lower (p less than 0.01) in the progression group. Multivariate regression analysis showed HL to be the most important determinant of changes in coronary atherosclerotic lesions. T3 and HDL cholesterol were also independently inversely related to coronary lesion growth.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Diet and the role of lipoproteins, lipases, and thyroid hormones in coronary lesion growth. 244 40


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