| For medical practitioners and the general public - Cholesterol Journal Article Catalog. |
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| Cholesterol removal from homogenized milk with beta-cyclodextrin Lee, D. K., J. Ahn, et al. (1999), J Dairy Sci 82(11): 2327-30. Abstract: This study was carried out to determine optimum conditions of five different factors (beta-cyclodextrin concentration, mixing temperature, mixing time, centrifugal force, and centrifugation time) in reduction of cholesterol in 3.6% fat, homogenized milk by application of beta-cyclodextrin. beta-Cyclodextrin at 0.5 to 1.5% provided 92.2 to 95.3% removal of cholesterol when mixed at 10 degrees C for 10 min. Among other factors, mixing time (5 to 20 min) did not significantly affect cholesterol removal. Removal was enhanced with increasing centrifugal forces up to 166x g (95.9%) but decreased thereafter. Various centrifugation times (5 to 20 min) did not have significant effects. Based on these results, we suggest that the optimum conditions for the process are addition of 1.5% beta-cyclodextrin, mixing temperature of 10 degrees C, 10-min mixing time, and centrifugation at 166x g for 10 min. |
| Cholesterol removal from media by lactococci Kimoto, H., S. Ohmomo, et al. (2002), J Dairy Sci 85(12): 3182-8. Abstract: Elevated serum cholesterol in humans is generally a risk factor correlated with the development of coronary heart disease. It has been reported that a culture of Lactobacillus acidophilus actively taking up cholesterol from a laboratory medium would function in vivo to exert a hypocholesterolemic effect. In the present study, seven strains of the genus Lactococcus were examined for their ability to remove cholesterol from laboratory media during growth. All strains of lactococci tested could remove cholesterol from media without degrading cholesterol. The amount of cholesterol removed was strain specific. Among them, Lc. Lactis subsp. lactis biovar diacetylactis N7 could remove as much cholesterol as L. acidophilus ATCC 43121, which had a beneficial influence on serum cholesterol levels in pigs. The manner of cholesterol removal by strain N7 corresponded to the manner of its growth. The growth of strain N7 (growth yield and growth efficiency) was enhanced. The fatty acid composition of the cells of strain N7 was altered by removing cholesterol from the media. The ability to remove cholesterol was also observed in the heat-killed cells of strain N7. However, the amount of cholesterol removed by the cells during growth was significantly higher than that removed by the heat-killed cells. Thus, strain N7 has the ability to remove cholesterol from media independently of whether cells are viable. These results indicate that administration of strain N7 in vivo may well be promising on the hypocholesterolemic effect. |
| Cholesterol requirement and metabolism in Entamoeba histolytica Lujan, H. D. and L. S. Diamond (1997), Arch Med Res 28 Spec No: 96-7. |
| Cholesterol requirement for cation-independent mannose 6-phosphate receptor exit from multivesicular late endosomes to the Golgi Miwako, I., A. Yamamoto, et al. (2001), J Cell Sci 114(Pt 9): 1765-76. Abstract: The regulation of endocytic traffic of receptors has central importance in the fine tuning of cell activities. Here, we provide evidence that cholesterol is required for the exit of cation-independent mannose 6-phosphate receptor (CI-MPR) from the endosomal carrier vesicle/multivesicular bodies (ECV/MVBs) to the Golgi. A previously established Chinese hamster ovary cell mutant, LEX2, exhibits arrested ECV/MVBs in which CI-MPR and lysosomal glycoprotein-B (lgp-B) are accumulated. The abnormal accumulation of CI-MPR within the ECV/MVBs in LEX2 cells was corrected in a post-translational manner by the supplementation of medium with cholesterol. Furthermore, it was shown that, by expression cloning using LEX2 mutant, the introduction of the NAD(P)H steroid dehydrogenase-like protein, an enzyme involved in the later stage of cholesterol biosynthesis, allows the exit of CI-MPR from the MVBs to the Golgi and reduces the number of arrested ECV/MVBs in LEX2 cells. The recovery of the exit transport of CI-MPR from the ECV/MVBs was associated with the restoration of the normal cellular free cholesterol level and segregation between CI-MPR and lgp-B, both of which had been localized at the internal small vesicles of the arrested ECV/MVBs. By contrast, the restoration of cholesterol failed to correct the defective processing of endocytosed LDL to a degradative compartment in LEX2 cells. These results suggest that cholesterol is required for ECV/MVB reorganization that drives the sorting/transport of materials destined for the Golgi out of the pathways towards lysosomes. |
| Cholesterol requirement for growth of IR983F and P3X63-Ag8-U1 myeloma cells in serum-free medium Li, J. L., Y. J. Li, et al. (1991), Cytobios 68(272): 15-22. Abstract: Cholesterol, a major lipid component of the plasma membrane, is thought to have profound effects on the structure and function of cells. Most animal tissues are capable of synthesizing cholesterol de novo from acetate; however, there are relatively few mammalian cells in vitro expressing an absolute requirement for an exogenous source of cholesterol. In this paper, it was shown that both IR983F (983) rat myeloma cells and P3X63-Ag8-U1 (P3U1) mouse myeloma cells which had been cultivated in serum-free medium containing cholesterol for more than 6 months still required cholesterol in vitro for growth in serum-free medium. Optimal growth of 983 and P3U1 occurred in cholesterol concentrations of 15 and 5 micrograms/ml, respectively. Moreover, it was demonstrated that the cholesterol could be replaced by human low density lipoprotein in a concentration of 10 micrograms/ml but not by mevalonic acid lactone. In contrast to the parental myeloma cells, hybridoma cells derived from the mouse myeloma cells which had been cultivated in serum-free medium containing cholesterol for more than 6 months did not require cholesterol. |
| Cholesterol requirement of hepatitis B surface antigen (HBsAg) secretion Lin, Y. L., M. S. Shiao, et al. (2003), Virology 314(1): 253-60. Abstract: Hepatitis B virus-infected patients secrete enormous quantities (50-300 microg/ml) of hepatitis B surface antigen (HBsAg) in their serum. One hypothesis for this synthetic effort is that these lipoprotein particles serve to adsorb neutralizing antisurface antibodies. We have shown that insulin suppresses the expression of HBsAg in human hepatoma cell Hep3B cells. We further studied the signaling pathway of insulin on the inhibition of HBsAg. Using a fungal metabolite, lovastatin, to block the p21Ras signaling pathway of insulin, we found that lovastatin inhibited the secretion of HBsAg into culture medium in Hep3B cells; however, the involvement of p21Ras-MAPKs was excluded in this effect. The cholesterol depletion from the membrane, leading to the destabilization of rafts, was the mechanism for the lovastatin inhibition of HBsAg secretion. However, lovastatin has no effect on the secretion of infectious viral Dane particles. Herein, we show for the first time that cholesterol is required for HBsAg secretion. |
| Cholesterol reutilization during myelination of regenerating PNS axons is impaired in Niemann-Pick disease type C mice Goodrum, J. F. and P. G. Pentchev (1997), J Neurosci Res 49(3): 389-92. Abstract: Niemann-Pick C (NPC) disease is an autosomal recessive lipidosis characterized by lysosomal accumulations of unesterified cholesterol. Cultured NPC cells exhibit a defect in the intracellular trafficking of LDL-derived cholesterol that leads to lysosomal accumulations of unesterified cholesterol. We found in a preliminary study that the myelination of regenerating axons was retarded in the NPC mouse following sciatic nerve crush. Because lipoprotein-mediated cholesterol transport is involved in myelination during nerve regeneration, we investigated whether this cholesterol reutilization pathway was perturbed in the NPC mouse. Mice received intraneural injections of 3Hacetate to label myelin cholesterol, and 2 weeks later the injected nerves were crushed above the injection site. Four weeks after crush, the nerves were examined by electron microscopic autoradiography. In normal mice, regeneration was well advanced, with thick myelin sheaths surrounding the regenerated axons and very little myelin debris remaining. The new myelin sheaths were well labeled, indicative of efficient cholesterol reutilization. In NPC mice, the new myelin sheaths were thinner and contained little label, indicative of retarded regeneration and little or no cholesterol reutilization. These data suggest the possibility of a causal link between compromised cholesterol reutilization and delayed or slowed regeneration of myelin sheaths. |
| Cholesterol rich apo B containing lipoproteins and smoking are independently associated with macrovascular disease in normotensive NIDDM patients Dean, J. D., S. B. Matthews, et al. (1994), Diabet Med 11(8): 740-7. Abstract: A cross-sectional study of macrovascular disease (MVD) and associated metabolic and other risk factors was conducted in 87 normotensive NIDDM patients. MVD was assessed by Rose questionnaire, 12 lead resting ECG, duplex scanning of carotid and peripheral vessels, and ankle:brachial systolic blood pressure ratio. Fasting serum total cholesterol, total triglycerides, LDL cholesterol, HDL cholesterol, apolipoproteins AI and B, lipoprotein (a), HbA1, plasma glucose, insulin, and C-peptide responses to a carbohydrate rich meal, body mass index (BMI), waist-hip ratio, urinary albumin excretion rate, blood pressure, smoking and family history were assessed as possible 'risk factors'. Apolipoprotein:lipid ratios were calculated to estimate lipoprotein composition. Thirty-six patients had demonstrable MVD. The presence of MVD was associated with higher total triglycerides (p < 0.05), BMI (p < 0.05), systolic blood pressure (p < 0.01), a lower apo B:non HDL cholesterol ratio (p < 0.001), and smoking (p < 0.005) but no other measures. Multiple regression analysis revealed smoking and a low apo B:non HDL cholesterol to be independently associated with MVD. The low apo B:non HDL cholesterol suggests a high cholesterol content of apo B containing lipoproteins. This lipoprotein abnormality is not a feature of NIDDM, but when present in these patients may be particularly atherogenic. |
| Cholesterol rules: direct observation of the coexistence of two fluid phases in native pulmonary surfactant membranes at physiological temperatures Bernardino de la Serna, J., J. Perez-Gil, et al. (2004), J Biol Chem 279(39): 40715-22. Abstract: Pulmonary surfactant, the lipid-protein material that stabilizes the respiratory surface of the lungs, contains approximately equimolar amounts of saturated and unsaturated phospholipid species and significant proportions of cholesterol. Such lipid composition suggests that the membranes taking part in the surfactant structures could be organized heterogeneously in the form of inplane domains, originating from particular distributions of specific proteins and lipids. Here we report novel results concerning the lateral organization of bilayer membranes made of native pulmonary surfactant where the coexistence of two distinct micrometer sized fluid phases (fluid ordered and fluid disordered-like phases) is observed at physiological temperatures by using fluorescence microscopy and atomic force microscopy. Additional experiments using fluorescent-labeled proteins SP-B and SP-C show that at physiological temperatures these hydrophobic proteins are located exclusively in the fluid disordered-like phase. Most interestingly, the microscopic coexistence of fluid phases is maintained up to 37.5 degrees C, where most fluid ordered phases melt. This observation suggests that the particular composition of this material is naturally designed to be at the "edge" of a lateral structure transition under physiological conditions, likely providing particular structural and dynamic properties for its mechanical function. The observed lateral structure in native pulmonary surfactant membranes is dramatically affected by the extraction of cholesterol, an effect not observed upon extraction of the surfactant proteins. Furthermore, the spreading properties of the native surfactant material at the air-liquid interface were also greatly affected by cholesterol extraction, suggesting a connection between the observed lateral structure and a physiologically relevant function of the material. We suggest that the particular lipid composition of surfactant could be finely tuned to provide, under physiological conditions, a structural scaffold for surfactant proteins to act at appropriate local densities and lipid composition. |
| Cholesterol saturation rather than phospholipid/bile salt ratio or protein content affects crystallization sequences in human gallbladder bile Venneman, N. G., P. Portincasa, et al. (2004), Eur J Clin Invest 34(10): 656-63. Abstract: BACKGROUND: In model biles, cholesterol crystallization (an important factor in gallstone formation) mainly depends on phospholipid/bile salt ratios with characteristic sequences of plate-like (monohydrate) vs. non-plate-like (presumed anhydrous: arcs, needles, tubules, spirals) cholesterol crystals. We now investigate whether the same phenomenon occurs in human bile. METHODS: Appearances of plate-like and non-plate-like cholesterol crystals were determined in filtered bile of 80 cholesterol gallstone patients, and related to biliary lipid and pro-nucleating protein composition. RESULTS: Non-plate-like crystals appeared before plate-like crystals in 9 biles, on the same day in 24 biles, and after plate-like crystals in 31 biles. In 16 biles only plate-like crystals were observed. Crystal sequences did not depend on biliary lipid or protein composition. Cholesterol saturation indexes were higher in biles with than without non-plate-like crystals (150 +/- 6 vs. 125 +/- 12, P = 0.02). In contrast, phospholipid/(bile salt + phospholipid) ratios, bile salt species, phospholipid classes, concentrations of mucin, IgG, IgM, IgA, haptoglobin and alpha-1 acid glycoprotein did not differ. CONCLUSIONS: Cholesterol crystallization sequences in human bile depend on cholesterol saturation index rather than on phospholipid/bile salt ratio. |
| Cholesterol saturation, not proteins or cholecystitis, is critical for crystal formation in human gallbladder bile Miquel, J. F., L. Nunez, et al. (1998), Gastroenterology 114(5): 1016-23. Abstract: BACKGROUND & AIMS: Biliary proteins are promoters of cholesterol crystallization in artificial model bile. However, their pathogenic importance for cholesterol precipitation in native gallbladder bile (GB) is uncertain. The aim of this study was to evaluate the significance of biliary lipids and proteins on cholesterol crystal detection time (ChCDT) of GB in patients with gallstones. METHODS: ChCDT and concentrations of lipids, albumin, mucins, aminopeptidase N, alpha1-acid glycoprotein, haptoglobin, and immunoglobulins (Igs) were measured in GB of 92 patients, 52 of whom had cholesterol gallstones. RESULTS: ChCDT was markedly reduced in gallstone patients. Compared with patients without gallstones, they had a significant increase in cholesterol saturation and total protein, albumin, mucin, and IgG biliary concentrations. In univariate analysis, ChCDT of GB was significantly correlated with cholesterol saturation and total lipid, protein, Ig, aminopeptidase N, and alpha1-acid glycoprotein concentrations. However, stepwise logistic regression analysis showed that only cholesterol saturation independently correlated to ChCDT. Gallbladder inflammation correlated with the concentration of Igs, but subtraction of IgG from GB did not modify the ChCDT. CONCLUSIONS: Biliary cholesterol transport and saturation, but not proteins, appear critical for the cholesterol crystallization abnormality observed in native bile from patients with gallstones. |
| Cholesterol screening Brickfield, F. X. (1994), J Am Board Fam Pract 7(2): 183. |
| Cholesterol screening Christoffel, K. K., T. C. Griffin, et al. (1992), Pediatrics 89(4 Pt 1): 686-7. |
| Cholesterol screening Cooper, S. J. and S. H. Cocksedge (1992), Br J Gen Pract 42(359): 260-1. |
| Cholesterol screening Feeman, W. E., Jr. (1992), Pediatrics 89(4 Pt 1): 686. |
| Cholesterol screening Koffman, M. D. and S. Dai (2001), Bus Health 19(8): 42. |
| Cholesterol screening among children and their parents Muratova, V. N., S. S. Islam, et al. (2001), Prev Med 33(1): 1-6. Abstract: BACKGROUND: The Coronary Artery Risk Detection in Appalachian Communities (CARDIAC) project is designed to test the hypothesis that universal cholesterol screening of prepubertal schoolchildren is effective in identifying children and their parents at risk of developing premature coronary heart disease (CHD) in a high-risk rural population. METHODS: Seven hundred nine fifth-grade schoolchildren from seven rural Appalachian counties participated in a school-based cholesterol screening program. Family history of premature CHD, anthropometric and blood pressure measurement, tobacco smoke exposure, dietary history, and physical activity levels were collected. RESULTS: One-fourth (174) of the children were "presumptively" dyslipidemic upon measurement of nonfasting finger-stick blood cholesterol (FSC). Subsequent fasting lipid profile obtained for 63 of these children and 79 of their parents confirmed the presence of dyslipidemia in 37 children (59%) and 52 parents (66%). Among confirmed dyslipidemic children, family history was not a good predictor of dyslipidemia (sensitivity 21.6%). FSC levels were significantly correlated with fasting total cholesterol of children and their parents. CONCLUSIONS: Universal nonfasting FSC screening of prepubertal schoolchildren is effective in identifying dyslipidemic children and their parents, whereas family history has low sensitivity in predicting children with elevated blood cholesterol concentrations. |
| Cholesterol screening and cholesterol-lowering regimens examined Omenn, G. S. (1993), Am J Health Promot 7(6): 424-5. |
| Cholesterol screening and family history of vascular disease Primrose, E. D., J. M. Savage, et al. (1994), Arch Dis Child 71(3): 239-42. Abstract: Hypercholesterolaemia is a major risk factor for the development of coronary heart disease (CHD). Early detection and management of hypercholesterolaemia could retard the atherosclerotic process. Given that CHD and hypercholesterolaemia cluster within families, a screening strategy based on a family history of vascular disease has been advocated. Serum total cholesterol concentrations were measured in a random stratified sample of 1012 children aged from 12-15 years old participating in a coronary risk factor surveillance study in Northern Ireland. Information about vascular disease in close family members was obtained by means of a questionnaire. The study population was divided into two groups according to total cholesterol values: (i) normal, < 5.2 mmol/l (n = 822) and (ii) raised, > or = 5.2 mmol/l (n = 190). A family history identified 63 out of 190 individuals with hypercholesterolaemia yielding a sensitivity of 33.2% and specificity of 71.5%. Our data indicated that a strategy whereby only children from high risk families are screened for hypercholesterolaemia is ineffective. While primary prevention emphasising a healthy diet for all is essential, the role of universal screening deserves further appraisal. |
| Cholesterol screening and life assurance Neil, H. A. and D. Mant (1991), Bmj 302(6781): 891-3. Abstract: OBJECTIVES--To examine how insurance companies assess proposals for life assurance from applicants with raised cholesterol concentrations and to determine the excess mortality rating applied. DESIGN--Survey of 49 companies underwriting term life assurance. SETTING--United Kingdom. SUBJECTS--Four fictional men aged 30 seeking 20 year term policies paying benefit only on death. Two had total cholesterol concentrations of 6.4 and 8.1 mmol/l but no other cardiovascular risk factors; one was overweight, hypertensive, smoked 20 cigarettes daily, and had a total cholesterol concentration of 8.1 mmol/l; and one had possible familial hypercholesterolaemia and a total cholesterol concentration of 10.7 mmol/l after treatment. MAIN OUTCOME MEASURE--Percentage excess mortality rating. RESULTS--All companies used explicit criteria to assess the mortality risk associated with hyperlipidaemias, and 47 companies applied the same criteria to men and women. No excess mortality rating was imposed on an applicant with a total cholesterol concentration of 6.4 mmol/l, but a small excess was applied to an applicant with a concentration of 8.1 mmol/l (median excess 50%, range 0-75%). When multiple cardiovascular risk factors were present the same concentration of 8.1 mmol/l resulted in a substantial excess (median 135%, range 50-200%). A smaller but more variable excess was applied to an applicant with possible familial hypercholesterolaemia (median 75%, range 0-200%). CONCLUSIONS--Despite considerable differences among companies in the excess mortality ratings applied, increases in term life assurance premiums are likely to be restricted to patients with severe hypercholesterolaemia, in particular those with familial hypercholesterolaemia. In the absence of other cardiovascular risk factors milder hypercholesterolaemia is unlikely to result in higher premiums. |