Cholesterol Journal Articles

Record 2781 to 2800

Cholesterol pericarditis. A specific but rare cause of pericardial disease
Fernandes, F., G. S. Vieira, et al. (2001), Arq Bras Cardiol 76(5): 391-4.
Abstract: During a diagnostic investigation in a 40-year-old male with pericardial effusion associated with hypothyroidism, cholesterol pericarditis was detected. We report a brief review on the etiopathogeny, clinical findings, and therapeutical possibilities of this entity.

Cholesterol peroxidation potential as influenced by dietary fat type
Bhadra, S., S. D. Banavali, et al. (1993), Int J Vitam Nutr Res 63(3): 223-8.
Abstract: Oxidation of lipoproteins is believed to play a key role in atherogenesis. In this study, influence of two fat vehicles, corn oil (unsaturated) or beef tallow (saturated), on cholesterol induced effects in terms of a) plasma lipoprotein peroxidation and b) aortic accumulation of cholesterol, cholesterol oxide and malonaldehyde was investigated in weanling rabbits. Although the increase in plasma cholesterol induced by cholesterol feeding was similar in both the groups Cu2+ ion induced peroxidation of lipoprotein cholesterol to oxysterols was significantly higher in corn oil group. This difference persisted even at 5 weeks after switching to chow diet. Aortic content of cholesterol and cholesterol oxides was also significantly higher in corn oil group at the end of chow diet period. Aortic accumulation of malonaldehyde (detected by immunocytochemistry) appeared to be greater in corn oil group at the end of the study. These results suggest that fatty acid composition of a given diet during exposure to high dietary cholesterol can influence cholesterol peroxidation to oxysterols and its accumulation in aorta.

Cholesterol perturbing agents inhibit NMDA-dependent calcium influx in rat hippocampal primary culture
Frank, C., A. M. Giammarioli, et al. (2004), FEBS Lett 566(1-3): 25-9.
Abstract: The present study was carried out to investigate the potential involvement of cholesterol-rich membrane microdomains in the mobilization of calcium induced by NMDA-receptors (NMDA-R). We herein provide evidence that agents interfering with plasma membrane cholesterol (namely, filipin and methyl-beta-cyclodextrin (Cdex)) inhibit the NMDA-stimulated influx of calcium in hippocampal cells in culture. Filipin-treated cells maintained their morphology and were able to respond with a calcium influx to high K(+) challenge, whereas Cdex altered both cellular parameters. These results suggest that the NMDA-R can be located in cholesterol-rich membrane microdomains or alternatively that the mechanisms coupling their dynamics in the post-synaptic membrane are dependent on the integrity of the microdomains.

Cholesterol phosphate derivatives: synthesis and incorporation into a phosphatase and calcium-sensitive triggered release liposome
Davis, S. C. and F. C. Szoka, Jr. (1998), Bioconjug Chem 9(6): 783-92.
Abstract: A series of cholesterol derivatives that position a phosphate monoester at increasing distance from the sterol ring system was synthesized, and their utility as a triggered release liposome tested. Stable anionic liposomes consisting of the novel cholesterol phosphate derivatives and dioleoylphosphatidylethanolamine (DOPE) can be induced to collapse upon phosphatase-catalyzed removal of the phosphate group. Control liposomes containing DOPE and cholesterol phosphate or phosphatidic acid, which are not phosphatase substrates, do not undergo phosphatase-mediated collapse. The phosphatase-sensitive liposomes also collapse in the presence of calcium. The precise concentration of calcium that induces the collapse is controlled by the structure of the cholesterol phosphate derivative. Plasmid DNA encoding luciferase, encapsulated in the cholesterol derivative/DOPE liposomes, transfected cells in vitro. The level of transfection is dependent upon the cholesterol derivative and is mediated by both a calcium-independent and a calcium-dependent pathway; however, the involvement of phosphatase in the latter mechanism is not yet resolved. The transfection efficiency is between 10(6) and 10(7) of luciferase activity in relative light units per milligram of protein, which is similar to transfection values reported using other triggered release liposomes.

Cholesterol photodynamic oxidation by ultraviolet irradiation and cholesterol ozonization by ozone exposure
Osada, K. and A. Sevanian (2000), Methods Enzymol 319: 188-96.

Cholesterol pleuritis
Sekine, K. (1994), Ryoikibetsu Shokogun Shirizu(3): 815-8.

Cholesterol plus methionine feeding do not induce lipid peroxidation and atherosclerotic changes in the rat aorta
Dogru-Abbasoglu, S., C. Basaran-Kucukgergin, et al. (2002), Int J Vitam Nutr Res 72(2): 109-13.
Abstract: The purpose of this study was to investigate whether cholesterol plus methionine feeding may be a convenient model to produce atherosclerosis in rats, and also to examine the contribution of oxidative stress to this development. For this reason, lipid peroxide levels and antioxidant enzyme activities in the liver and aorta as well as histopathological findings were determined in male Wistar-albino rats fed a diet supplemented with cholesterol plus cholic acid and methionine for six months. This diet was found to increase lipid peroxide levels in the liver of rats. Hepatic glutathione peroxidase (GSH-Px) and catalase (CAT) activities increased, but superoxide dismutase (SOD) activity remained unchanged. In conclusion, cholesterol and methionine feeding in rats did not cause oxidative stress and atherosclerotic changes in the aorta, although hepatic prooxidant-antioxidant balance was affected by this diet.

Cholesterol policy and the primary prevention of coronary disease: reflections on clinical and population strategies
Naylor, C. D. and J. M. Paterson (1996), Annu Rev Nutr 16: 349-82.
Abstract: Despite billions of dollars spent on targeted and population-wide strategies aimed at reducing human consumption of saturated fat and cholesterol, aspects of the diet-heart connection remain a source of debate. At least part of the uncertainty arises from a growing appreciation that the relationship between dietary habits, serum lipids, and atherosclerosis is more complex than was previously thought. While we wait for answers from clinical and basic research, what is to be done? This review examines evidence about clinical policies and population strategies for the primary prevention of coronary disease, with specific reference to diet and dyslipidemias. It also summarizes some current policies and offers conclusions about broad directions for further policy development.

Cholesterol polyp
Taira, A. and K. Tanaka (1996), Ryoikibetsu Shokogun Shirizu(9): 280-2.

Cholesterol polyp of the common bile duct
Ikoma, A., T. Ueno, et al. (1995), Am J Gastroenterol 90(9): 1534-5.

Cholesterol polyp of the gallbladder showing rapid growth and atypical changes--a case report
Ukai, K., Y. Akita, et al. (1992), Hepatogastroenterology 39(4): 371-3.
Abstract: We report on a case of resected cholesterol polyp with typical ultrasonic findings that became atypical, with a 40% increase in diameter, over a period of about 10 months. The resected specimen revealed a black polyp with a large-nodular appearance. The pathological diagnosis was cholesterol polyp with marked glandular proliferation, and the glandular cavity showed cystic dilatations filled with dark brown fluid. It is suspected that the aggregation of large numbers of these dilated glands explained the black color, the rapid growth, and the development leading to the atypical ultrasonic findings.

Cholesterol pools in rat adrenal mitochondria: use of cholesterol oxidase to infer a complex pool structure
Stevens, V. L., T. Xu, et al. (1992), Endocrinology 130(3): 1557-63.
Abstract: ACTH stimulates the side-chain cleavage of cholesterol in the adrenal cortex in a cycloheximide-inhibitable manner. Its mechanism involves mobilizing cholesterol to a "steroidogenic pool" where the sterol can be metabolized to pregnenolone. This pool has been proposed to be in the inner mitochondrial membrane where cytochrome P-450scc resides, and regulation may involve transport of cholesterol from the outer to the inner membrane. To investigate the structure of the mitochondrial cholesterol pools, cholesterol oxidase has been used as a membrane-impermeant probe which should have selective access to outer membrane cholesterol. At 37 C, almost all the cholesterol in mitochondria from ether-stressed rats was metabolized by cholesterol oxidase. Depletion of an intermembrane space but not a matrix marker enzyme indicated partial disruption of the outer membrane. However, at 16 C, mitochondria remained largely intact, and cholesterol oxidase identified a unique pool of cholesterol, which was about two-thirds of the total. In experiments using mitochondria from ether-stressed rats, the size of the 16 C cholesterol oxidase accessible and inaccessible pools was compared with that of the steroidogenic pool. The steroidogenic pool was enhanced by pretreatment of some animals with aminoglutethimide (a P-450scc inhibitor) or eliminated with cycloheximide, both of which increased the total mitochondrial cholesterol. This approach reveals that the steroidogenic pool is not equivalent to the cholesterol oxidase-inaccessible pool. Rather, it overlaps both the cholesterol oxidase accessible and inaccessible pools. These results are not consistent with a simple two pool model, but can be explained by assuming a minimum of three cholesterol pools.

Cholesterol precipitation from cholesterol-supersaturated bile models
Fudim-Levin, E., A. Bor, et al. (1995), Biochim Biophys Acta 1259(1): 23-8.
Abstract: Bile-model systems containing cholesterol (CH), phosphatidylcholine (PC) and sodium cholate (NaC) at concentrations similar to those found in supersaturated human gall bladder bile (CH/PC = 0.60 +/- 0.01; CH saturation index, CSI = 1.58 +/- 0.03) were prepared by mixing PC-CH vesicles with NaC micellar solutions. Following mixing, the dispersion became transparent and gave rise to high resolution 1H-NMR spectra typical of mixed micellar systems. Cryo-transmission electron micrographs of specimens vitrified at that stage support the conclusion that the vesicles had become completely micellized. Following micellization, the metastable (cholesterol-supersaturated) bile-models spontaneously underwent a series of reorganizational steps: first, cholesterol-rich vesicles with a CH/PC ratio of 1.57 +/- 0.69 were formed, in co-existence with a mixed micellar system with CH/PC = 0.43 +/- 0.01 and CSI = 1.12 +/- 0.03. The resultant cholesterol-rich vesicles subsequently aggregated and cholesterol crystals of varying sizes and shapes appeared within the aggregates: needle-like structures were first observed, followed by clusters of those crystals and of helical crystals. Eventually, typical plate-like cholesterol crystals appeared, at which time some of the PC returned to the non-particulate (isotropic) phase. Consequently, the system contained cholesterol crystals coexisting with mixed micelles, whose composition was close to the limit of saturation (CSI = 1.08). These findings confirm the sequence of events preceding the appearance of cholesterol crystals, as previously proposed in our less detailed studies ((1990) Hepatology 12, 149S) and support the relevance of the morphologically similar results of Konikoff et al. ((1992) J. Clin. Invest. 90, 1155) obtained in a very dilute supersaturated bile-model.

Cholesterol precursor concentration in plasma from patients with chronic renal failure or kidney grafts
Sutherland, W. H., R. J. Walker, et al. (1995), Clin Nephrol 43(6): 392-8.
Abstract: Plasma lathosterol concentration which is an index of cholesterol synthesis rate was measured in 36 patients with chronic renal failure (CRF) including 13 who were dialysis independent, 12 receiving hemodialysis and 11 on continuous ambulatory peritoneal dialysis (CAPD), 17 renal transplant recipients and 27 healthy control subjects. Concentrations of plasma lathosterol were significantly (ANOVA p = 0.03) lower in all categories of renal patients excepting those treated by CAPD, compared with control values. In normolipidemic subjects (cholesterol < or = 6.50 mmol/l and triglycerides < or = 2.0 mmol/l) plasma lathosterol levels in hemodialysis patients and renal transplant recipients were still significantly (ANOVA p = 0.02) lower than control values. In transplant recipients, the plasma lathosterol/cholesterol ratio was significantly (p = 0.02) lower than those treated with azathioprine and prednisone compared with those treated with these drugs and cyclosporin. Significant (p < 0.001) positive correlations were recorded between plasma lathosterol concentration and plasma levels of apolipoprotein B (apoB) and very low density lipoprotein (VLDL) lipids in the renal patients. These data suggest that the rate of cholesterol synthesis may be low in undialysed and hemodialysed patients with CRF and in renal transplant recipients, particularly those treated with double therapy, and may be linked to the metabolism of apoB and VLDL.

Cholesterol precursors and plant sterols in children with food allergy
Joki, P., H. Suomalainen, et al. (2003), Am J Clin Nutr 77(1): 51-5.
Abstract: BACKGROUND: The data on lipid metabolism in allergic children is limited. OBJECTIVE: We investigated lipid and sterol metabolism in young children whose diets were restricted because of food allergy. DESIGN: Children in group A n = 21; mean (+/- SD) age: 1.78 +/- 0.73 y were allergic to fish, eggs, and either cow milk or cereals; those in group B (n = 31, aged 1.45 +/- 0.58 y) were allergic to fish, eggs, and both cow milk and cereals. Cholesterol precursor and plant sterol to cholesterol ratios (10(2) x micro mol/mmol cholesterol) and apolipoprotein E phenotype distributions were analyzed in 36 subjects. The control group for cholesterol precursor and plant sterol measurements consisted of 18 healthy age-matched children. RESULTS: The mean serum cholesterol concentration was 3.6 +/- 0.6 mmol/L, and HDL cholesterol was 1.03 +/- 0.3 mmol/L in group A. Corresponding values in group B were 3.4 +/- 0.7 and 1.09 +/- 0.2 mmol/L. The daily cholesterol intake was low: 61.3 +/- 36.0 mg in group A and 50.7 +/- 48.5 mg in group B. Cholesterol precursor plant sterol concentrations were significantly higher in allergic subjects than in control subjects. CONCLUSIONS: Allergic children with restricted diets have a low intake of cholesterol and relatively low serum cholesterol concentrations. Dietary intake of plant sterols was obviously increased because of supplementation with rapeseed oil, which is rich in plant sterols, leading to elevated plant sterol concentrations. Plant sterols may have inhibited cholesterol absorption, which in turn stimulated cholesterol synthesis in compensation, also explaining the increased precursor sterol ratios in serum in our subjects.

Cholesterol predicts stroke mortality in the Women's Pooling Project
Horenstein, R. B., D. E. Smith, et al. (2002), Stroke 33(7): 1863-8.
Abstract: BACKGROUND AND PURPOSE: Cholesterol is emerging as a risk factor for stroke; however, few data are available regarding the relation of cholesterol and stroke mortality in women and ethnic minorities. METHODS: We evaluated the risk of death caused by total stroke, nonhemorrhagic stroke, and hemorrhagic stroke by race, age, and cholesterol quintile in 24 343 women with no previous cardiovascular disease who were participating in 8 US longitudinal, prospective, cohort studies included in the Women's Pooling Project. RESULTS: We observed 568 stroke deaths (461 nonhemorrhagic, 83 hemorrhagic) for women > or =30 years of age without previous cardiovascular disease during 339 215 person-years of follow-up. In multivariate models, black women <55 years of age had a 76% increased risk of death caused by stroke compared with white women relative risk (RR), 1.76; 95% confidence interval (CI), 1.10 to 2.81. For black women <55 years of age, the top compared with the lowest cholesterol quintile (Q5 versus Q1) remained an independent predictor of stroke mortality (RR, 2.58; 95% CI, 1.05 to 6.32) in multivariate models. For white women <55 years of age, Q5 versus Q1 cholesterol did not predict stroke mortality with significance (RR, 1.47; 95% CI, 0.57 to 3.76). In analogous multivariate models, we found a positive relation between continuous cholesterol and nonhemorrhagic stroke death in women <55 years of age (RR, 1.23; 95% CI, 1.02 to 1.49). CONCLUSIONS: Our results show that cholesterol is a risk factor for nonhemorrhagic stroke death in women <55 years of age and is more strongly associated with mortality in black women <55 years of age than in white women. These data document the importance of cholesterol in addition to established risk factors for predicting stroke mortality in young women and may guide prevention strategies.

Cholesterol prevention. American and European positions
Cybulska, B. (1990), Wiad Lek 43(15-16): 808-20.

Cholesterol protects PC12 cells from beta-amyloid induced calcium disordering and cytotoxicity
Zhou, Y. and J. S. Richardson (1996), Neuroreport 7(15-17): 2487-90.
Abstract: THE neurotoxic action of beta-amyloid seems to play an important role in the pathogenesis of Alzheimer's disease. The disruption of calcium homeostasis by beta-amyloid has been suspected to be the mechanism of its neurotoxicity. We found that beta-amyloid 25-35 induces a rapid increase in cytosolic calcium of PC12 cells, and subsequently, a dramatic decrease in cell viability. The increase in cytosolic calcium induced by beta-amyloid is effectively blocked by cholesterol in a dose-dependent manner. Furthermore, pretreatment of PC12 cells with cholesterol also significantly attenuates the neurotoxicity induced by beta-amyloid. These findings suggest that extracellular free cholesterol can protect neurones from beta-amyloid neurotoxicity mediated by the disruption of calcium homeostasis.

Cholesterol protects the phospholipid bilayer from oxidative damage
Parasassi, T., A. M. Giusti, et al. (1995), Free Radic Biol Med 19(4): 511-6.
Abstract: The measurement of fluorescence lifetime distribution of 1,6-diphenyl-1,3,5-hexatriene is used for the detection of oxidative damage produced in phospholipid membranes by ionizing radiation. The recently developed method is based on the linear relationship between the width of the probe lifetime distribution and the logarithm of the dose. The molecular origin of the damage resides in the production of hydroperoxide residues at the level of acyl chains double bonds. A chemiluminescence assay was used to quantitate the amount of produced hydroperoxides. Consequences of the produced damages include an increased disorder in the upper portion of the bilayer, accompanied by the penetration of water molecules. In the presence of the physiological concentration of cholesterol in phopholipid bilayers, the amount of hydroperoxides produced by ionizing radiation is dramatically reduced. The packing effect of cholesterol in phopholipid bilayers is well recognized, as well as its influence on the reduction of water concentration in the bilayer. The dramatic reduction of hydroperoxides concentration observed when irradiation is performed in the presence of cholesterol probably originates from a steric hindrance to the radical chain reaction through the unsaturated lipids due to the presence of cholesterol.

Cholesterol quantitation by GLC: artifactual formation of short-chain steryl esters
Klansek, J. J., P. Yancey, et al. (1995), J Lipid Res 36(10): 2261-6.
Abstract: A simple and rapid method for the quantitation of total cholesterol in lipid extracts using gas-liquid chromatography is presented here as a modification of an earlier saponification procedure (Ishikawa, T. T., J. MacGee, J. A. Morrison, and C. J. Glueck. 1974. Quantitative analysis of cholesterol in 5 to 20 microliters of plasma. J. Lipid Res. 15: 286-291). Using the original method, as well as a slightly modified version, we found a systematic loss of cholesterol measured as total cholesterol that was attributable to the formation of a byproduct during the procedure. Depending on the nature of the solvent mixture used for extraction after saponification, different byproducts were produced that had longer retention times than cholesterol. The byproducts were identified as cholesteryl butyrate (produced when methyl butyrate was included in the solvent mix) and cholesteryl propionate (with ethyl propionate in the solvent mix) by comparison to authentic standards using gas chromatography-mass spectroscopy. Using mixtures of cholesterol standards, we compared several solvents in lieu of the solvent mixture used in the original extraction procedure to identify those that eliminate the formation of the byproducts. Our optimized microsaponification procedure uses a single solvent, tetrachloroethylene, to extract lipids after the saponification reaction, and improves the accuracy of the cholesterol determination.

Cholesterol Articles and Abstracts

Cholesterol Journal Articles