Cholesterol Journal Articles

Record 10361 to 10380

Pyrene cholesterol reports the transient appearance of nonlamellar intermediate structures during fusion of model membranes
Malinin, V. S. and B. R. Lentz (2002), Biochemistry 41(18): 5913-9.
Abstract: We have hypothesized that modulating the free energy of hydrophobic mismatch (HM) might be a principal means to control the fusion process and that it may be a role of cholesterol to counteract HM and make membranes fusogenic. To test these hypotheses, we examined the ability of cholesterol 1-pyrenebutyrate (PY-Ch) and other pyrene-containing fluorescent probes to report interstices formed during the L(alpha)-H(II) transition of DiPoPE in terms of changes in excimer/monomer (E/M) fluorescence ratios. We found a significant (>150%) increase in the PY-Ch E/M in the hexagonal phase relative to the lamellar phase, presumably resulting from redistribution of PY-Ch from the curved lamellar leaflets to coexisting HMs that constitute 20 vol % of this phase. All other probes showed a much smaller or even an opposite (PY-hexadecanoic acid) effect. The time course of the PY-Ch E/M ratio during fusion of DOPC/PE/Ch small unilamellar vesicles showed a transient increase with a subsequent decrease, consistent with fusion proceeding through intermediates with significant HM. The amplitude and position of the maximum in E/M correlated with the rate of contents mixing. An increase in E/M was not seen when lipid mixing occurred in the absence of contents mixing. Our results suggest that PY-Ch provides a tool for monitoring fusion intermediates that occur after the initial fusion intermediate but prior to pore formation, possibly by accumulating in regions associated with HM.

Pyridoxine reduces cholesterol and low-density lipoprotein and increases antithrombin III activity in 80-year-old men with low plasma pyridoxal 5-phosphate
Brattstrom, L., L. Stavenow, et al. (1990), Scand J Clin Lab Invest 50(8): 873-7.
Abstract: We have previously observed that pyridoxine treatment reduced plasma total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol concentrations and increased antithrombin III (AT III) activity in atherosclerotic patients with subnormal plasma pyridoxal 5-phosphate (PLP) levels. In order to confirm these results, we selected 17 males with low plasma PLP levels from a group of 122 80-year-old males in whom PLP has been determined. After supplementation with 120 mg of pyridoxine per day for 8 weeks their mean plasma TC and LDL cholesterol concentrations were decreased by 10% (p less than 0.01) and 17% (p less than 0.001), respectively. There was no effect on high-density lipoprotein cholesterol and triglycerides but plasma AT III activity was increased by 6% (p less than 0.05). The mechanism by which pyridoxine acts is unclear but it is hypothesized that pyridoxine-derived PLP may enhance the catabolism of LDL and the activity of AT III by inhibiting their glycosylation.

Pyruvate supplementation of a low-cholesterol, low-fat diet: effects on plasma lipid concentrations and body composition in hyperlipidemic patients
Stanko, R. T., H. R. Reynolds, et al. (1994), Am J Clin Nutr 59(2): 423-7.
Abstract: The effects of the three-carbon compound pyruvate on plasma lipid concentrations and body composition were evaluated in hyperlipidemic patients consuming a low-cholesterol (165-180 mg), low-fat (22-24% of energy; 18-20% of energy as saturated fatty acid) diet (0.091-0.099 MJ.kg body wt-1 x d-1). After consuming the above diet for 4 wk, during which time plasma lipid concentrations decreased, 34 subjects were randomly assigned to receive either 22-44 g pyruvate (n = 17) or 18-35 g polyglucose (placebo, Polycose, n = 17), iso-energetically substituted for a portion of carbohydrate energy for 6 wk. Despite greater weight and fat losses with pyruvate (P < 0.05), plasma concentrations of cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride were not different between the two groups of subjects. We conclude that subsequent to diet-induced reduction in plasma lipid concentrations, pyruvate supplementation of a low-cholesterol, low-fat diet providing 6.7-7.6 MJ/d for 6 wk has no effect on plasma lipid concentrations but enhances body weight and fat losses.

Qualitative and quantitative comparison of gallbladder proteins from patients with and without cholesterol gallstones
Yu, L. and Z. Guan (1990), Dig Dis Sci 35(1): 47-9.
Abstract: Amino acid analysis and protein electrophoretic techniques were used to determine whether qualitative and quantitative gallbladder protein abnormalities exist in patients with cholesterol gallstones in Inner Mongolia. Gallbladder bile osmotic pressure measurement was determined and correlations were sought between the protein concentration and osmotic pressure of gallbladder bile. Protein concentrations and bile osmolality were higher in patients with cholesterol gallstones than in controls without biliary tract disease. A correlation between the protein concentration and osmotic pressure was found in gallbladder patients but not in controls (patients: r = 0.83, P less than 0.05; controls: r = 0.74, P less than 0.1).

Quality control of liposomal lipids with special emphasis on peroxidation of phospholipids and cholesterol
Lang, J. K. and C. Vigo-Pelfrey (1993), Chem Phys Lipids 64(1-3): 19-29.
Abstract: The usefulness of various assays for the determination of phospholipid and cholesterol peroxidation in liposome formulations was studied on model liposomes prepared as small unilamellar vesicles (SUV) and multilamellar vesicles (MLV) from either native egg phosphatidylcholine (EPC), partially hydrogenated egg phosphatidylcholine (PHEPC) or fully hydrogenated egg phosphatidylcholine (HEPC) and cholesterol in 65/35 molar ratio at a total lipid concentration of 10 mumol/ml in phosphate buffered saline pH 7.2. Liposomes were incubated at 50 degrees C for a total of 3 months. Fatty acid and cholesterol peroxidation were monitored after 1, 2 and 3 months by quantitative measurement of fatty acids and cholesterol and as well as peroxidation products. Fatty acid peroxidation products malondialdehyde, lipidhydroperoxides, conjugated dienes, conjugated trienes were poor predictors of actual fatty acid loss. Among the cholesterol peroxidation products 7-hydroxy-cholesterols, 7-keto-cholesterol and 4-cholesten-3-one were measured quantitatively. Only the formation of 7-keto-cholesterol correlated well with cholesterol disappearance.

Quality control practices for calcium, cholesterol, digoxin, and hemoglobin: a College of American Pathologists Q-probes study in 505 hospital laboratories
Steindel, S. J. and G. Tetrault (1998), Arch Pathol Lab Med 122(5): 401-8.
Abstract: OBJECTIVE: To assess quality control (QC) practices and their impact on hospital laboratories using the College of American Pathologists (CAP) Q-Probes process. DESIGN: Self-directed data gathering, using a questionnaire to determine QC practices, data input forms for 6 months retrospective quality control use and run failure rates, and input forms for 3 months prospective data concerning QC failure rates and corrective steps taken. Participants submitted data for four analytes: calcium, cholesterol, digoxin, and hemoglobin. PARTICIPANTS: Laboratories enrolled in the 1994 CAP Q-Probes program. MAIN OUTCOME MEASURES: Retrospective and prospective QC failure rates compared with QC protocols and the corrective steps. RESULTS: Five hundred five hospital laboratories returned various components of the study. Median retrospective run rejection rates per 1000 runs: calcium, 4.3; cholesterol, 3.6; digoxin, 4.3; and hemoglobin, 2.4. Corresponding median prospective run rejection rates per 1000 runs: calcium, 5.8; cholesterol, 5.6; digoxin, 6.5; and hemoglobin, 3.6. Participants resolved most out-of-control events in less than 20 minutes, with no patient samples repeated. More than 95% of the time, participants resolved out-of-control events simply by repeating controls. Most participants used a single control rule based on a target mean plus or minus a multiple of the standard deviation. A few laboratories used multirule systems. CONCLUSIONS: Current testing methods yield few out-of-control events, which usually are resolved rapidly, with little impact on laboratory operation. We recommend modification and simplification of laboratory QC practices to decrease false rejection rates and to use modern instrumentation more efficiently.

Quality status of serum cholesterol analysis in Iceland
Olafsdottir, E. and T. V. Gudmundsson (1993), Ups J Med Sci 98(3): 401-4.
Abstract: Eight laboratories participated in the first Icelandic quality assessment survey of serum cholesterol analysis in 1989. Quality control material, lyophilized animal serum and frozen human serum, was distributed three times over a period of one year and analyzed each time over 10 consecutive days. After two distributions of control material the laboratories were advised to start using a common calibrator from the U.S. National Bureau of Standards, and six months later the third lot of control material was analyzed. All laboratories use the same enzymatic methods for estimating serum cholesterol. Average total imprecision within and between laboratories improved throughout the survey, but did not reach the quality goal of the U.S. National Cholesterol Education Panel of +/- 3% for imprecision and +/- 3% for bias leaving scope for further improvement.

Quantification in situ of crystalline cholesterol and calcium phosphate hydroxyapatite in human atherosclerotic plaques by solid-state magic angle spinning NMR
Guo, W., J. D. Morrisett, et al. (2000), Arterioscler Thromb Vasc Biol 20(6): 1630-6.
Abstract: Because of renewed interest in the progression, stabilization, and regression of atherosclerotic plaques, it has become important to develop methods for characterizing structural features of plaques in situ and noninvasively. We present a nondestructive method for ex vivo quantification of 2 solid-phase components of plaques: crystalline cholesterol and calcium phosphate salts. Magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of human carotid endarterectomy plaques revealed (13)C resonances of crystalline cholesterol monohydrate and a (31)P resonance of calcium phosphate hydroxyapatite (CPH). The spectra were obtained under conditions in which there was little or no interference from other chemical components and were suitable for quantification in situ of the crystalline cholesterol and CPH. Carotid atherosclerotic plaques showed a wide variation in their crystalline cholesterol content. The calculated molar ratio of liquid-crystalline cholesterol to phospholipid ranged from 1.1 to 1.7, demonstrating different capabilities of the phospholipids to reduce crystallization of cholesterol. The spectral properties of the phosphate groups in CPH in carotid plaques were identical to those of CPH in bone. (31)P MAS NMR is a simple, rapid method for quantification of calcium phosphate salts in tissue without extraction and time-consuming chemical analysis. Crystalline phases in intact atherosclerotic plaques (ex vivo) can be quantified accurately by solid-state (13)C and (31)P MAS NMR spectroscopy.

Quantification of atherosclerotic plaque composition in cholesterol-fed rabbits with 50-MHz acoustic microscopy
Shepard, R. K., J. G. Miller, et al. (1992), Arterioscler Thromb 12(10): 1227-34.
Abstract: To determine whether high-frequency ultrasound could distinguish normal from pathological vascular structure and to elucidate the determinants of ultrasonic backscatter in different layers of normal and atherosclerotic arteries, high-resolution acoustic microscopy at 50 MHz was used to characterize aortic plaque in six New Zealand White rabbits fed a 2% cholesterol diet for 3.5 months. Four rabbits were fed a standard diet for 3.5 months to provide normal control data. Segments of aortas were excised, fixed in formalin, opened longitudinally, and mounted flat for insonification. For each specimen, backscattered radio frequency (rf) data were acquired from 30 to 100 independent sites separated by 500 microns. Portions of rf data were gated from discrete layers of the vessel wall for computation of integrated backscatter. Results of histological and immunocytochemical analyses of vessel wall thickness and composition were compared with those of ultrasonic analysis. Normal aortas manifested prominent but homogeneous backscatter (average integrated backscatter, -28.5 +/- 2.9 dB) throughout the vessel wall, with no clear distinction between intimal and medial layers. The atherosclerotic aortas manifested substantially reduced integrated backscatter from the thickened intima (-47.5 +/- 3.2 dB, p < 0.0001) but relatively normal integrated backscatter from the media (-31.2 +/- 1.6 dB; p = NS versus normal aortas). The thickness of the media for both normal and atherosclerotic rabbits was approximately 300 microns. Histological characteristics of atherosclerotic aortas confirmed the presence of substantial intimal thickening, with prominent foam cell and lipid infiltration abutting a more normal medial layer.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantification of cholesterol in all lipoprotein classes by the VAP-II method
Kulkarni, K. R., D. W. Garber, et al. (1994), J Lipid Res 35(1): 159-68.
Abstract: We have developed a high resolution microvolume Vertical Auto Profile (VAP) method for the simultaneous measurement of cholesterol in all lipoprotein classes, including lipoproteina (Lpa) and intermediate density lipoprotein (IDL). This method, designated as VAP-II, uses a non-segmented continuous flow (controlled-dispersion flow) analyzer for the enzymatic analysis of cholesterol in lipoprotein classes separated by a short spin (47 min) single vertical ultracentrifugation. Cholesterol concentrations of high (HDL), low (LDL), very low (VLDL), and intermediate (IDL) density lipoproteins, as well as Lpa, are determined by decomposing the spectrophotometric absorbance curve, obtained from the continuous analysis of the centrifuged sample, into its components using software developed in this laboratory. Analysis by VAP-II is rapid and sensitive (as little as 40 microliters plasma is required per assay). The resolution of lipoprotein peaks is considerably enhanced in the present analyzer compared to the previous analyzer (VAP-I, which used the Technicon AutoAnalyzer); improvement is especially noticeable for Lpa and IDL. Total and lipoprotein cholesterol values obtained by VAP-II correlated well with the values obtained by Northwest Lipid Research Laboratories (NWLRL). VAP-II Lpa cholesterol values also correlated well with the Lpa mass values obtained by an immunoassay technique performed at NWLRL (r = 0.907). The reproducibility and accuracy of the method are within the requirements of the CDC-NHLBI (Centers for Disease Control-National Heart, Lung, and Blood Institute) Lipid Standardization Program.

Quantification of cholesterol in foods using non-aqueous capillary electrophoresis
Xu, X. H., R. K. Li, et al. (2002), J Chromatogr B Analyt Technol Biomed Life Sci 768(2): 369-73.
Abstract: A simple method for the rapid quantification of cholesterol in egg yolk and milk by non-aqueous capillary electrophoresis (NACE) is described in this paper. The samples were treated with saponification and then quantified by NACE, in which 100 mM sodium acetate-acetic acid in methanol was employed as the running buffer. The correlation coefficient between the cholesterol concentration and the corresponding peak area was 0.999. The detection limit of cholesterol was 5 microg/ml (twice the signal-to-noise ratio). This method can be used as a routine method for the rapid and sensitive determination of cholesterol in foods.

Quantification of cholesterol tracers by gas chromatography--negative ion chemical ionization mass spectrometry
Ostlund, R. E., Jr., F. F. Hsu, et al. (1996), J Mass Spectrom 31(11): 1291-6.
Abstract: Because of its high sensitivity, gas chromatography negative ion chemical ionization mass spectrometry (GC-NCI-MS) is a potentially valuable analytical tool for the study of cholesterol metabolism. Of several derivatives prepared for potential use in tracer studies pentafluorobenzoyl cholesterol was selected because it formed rapidly at ambient temperature and was stable for long periods, could be detected at a level of 1 fmol, and yielded a mass spectrum in which the molecular ion was the principal component. Hexadeuterated cholesterol tracer (26,26,26,27,27,27-2H6cholesterol) could be detected in dilutions up to 2700 in unlabeled cholesterol by selected ion monitoring with a coefficient of variation averaging 3.2%. In seven normal subjects tracer cholesterol was infused intravenously and plasma cholesterol enrichment was determined after 4 h. The measured rapidly miscible cholesterol pool was 391.0 +/- 38.6 mg cholesterol/kg. Negative ion mass spectrometry of pentafluorobenzyol cholesterol will facilitate analysis of both small amounts of natural cholesterol and labeled cholesterol in applications where sensitivity is critical.

Quantification of HDL2 and HDL3 cholesterol by the Vertical Auto Profile-II (VAP-II) methodology
Kulkarni, K. R., S. M. Marcovina, et al. (1997), J Lipid Res 38(11): 2353-64.
Abstract: Of the several existing methods for quantification of major subspecies of high density lipoprotein (HDL), HDL2 and HDL3, the methods based upon double precipitation are particularly useful for large-scale studies or for routine assay because of their high speed and low cost. The Vertical Auto Profile-II (VAP-II) method developed in our laboratory primarily for the direct single test measurement of cholesterol (C) in all major lipoproteins, including Lpa and IDL, is rapid, highly sensitive, and suitable for large-scale studies. Here we describe the modification of this procedure so as to be able to quantify both HDL2- and HDL3-C in addition to all major lipoproteins without any additional assay steps, time, or cost. The VAP-II procedure was validated by comparison with four other methods using plasma samples obtained from 35 healthy subjects: 1) HDL-VAP-II (a variation of the VAP-II procedure designed specifically to separate HDL subspecies); 2) dextran sulfate (DS)/Mg2+ double precipitation method performed at Northwest Lipid Research Laboratories (NWLRL), Seattle, WA; 3) 4-30% polyacrylamide-agarose (4/30 PAA) nondenaturing gradient gel electrophoresis (GGE); and 4) analytical ultracentrifugation (AUC), with both GGE and AUC performed at the Donner Laboratory, University of California at Berkeley. Both HDL2- and HDL3-C measurements by VAP-II correlated well with the measurements by all comparison methods (r for HDL3-C: HDL-VAP-II, 0.948; NWLRL, 0.947; GGE, 0.861; and AUC, 0.706, and r for HDL2-C: HDL-VAP-II, 0.867; NWLRL, 0.854; GGE, 0.885; and AUC, 0.721). The measurements of HDL2- and HDL3-C by the VAP-II method are reproducible, with the long-term between-rotor CV of 5.0% for HDL3-C and 9.0% for HDL2-C.

Quantification of high-density-lipoprotein cholesterol in plasma from hamsters by differential precipitation
Weingand, K. W. and B. P. Daggy (1990), Clin Chem 36(3): 575.

Quantification of lipoprotein(a) in plasma by assaying cholesterol in lectin-bound plasma fraction
Seman, L. J., J. L. Jenner, et al. (1994), Clin Chem 40(3): 400-3.
Abstract: Lipoprotein(a) Lp(a) is a low-density lipoprotein (LDL)-like particle in which apolipoprotein(a) apo(a) is disulfide-linked to apolipoprotein B (apoB). High concentrations of Lp(a) in plasma are associated with an increased risk of coronary heart disease (CHD). Lp(a) has traditionally been measured by immunoassay and expressed as total mass of Lp(a). Measuring Lp(a) by its cholesterol content will provide a way to directly compare Lp(a) with other lipoproteins that are measured by cholesterol. We have developed an assay to quantify Lp(a) by its cholesterol content Lp(a)-C, using lectin affinity to isolate Lp(a) from other lipoproteins, and then measuring the cholesterol within the isolated fraction. We compared the Lp(a)-C assay with an ELISA for Lp(a) mass in 47 plasma samples from normotriglyceridemic, fasting individuals with high Lp(a) contents (mean +/- SD, 446 +/- 350 mg/L). The mean Lp(a)-C concentration was 110 +/- 89 mg/L and correlated very highly with Lp(a) mass (r = 0.9975). Lp(a)-C measurement is an alternative method to screen for this CHD risk factor.

Quantification of menstrual and diurnal periodicities in rates of cholesterol and fat synthesis in humans
Faix, D., R. Neese, et al. (1993), J Lipid Res 34(12): 2063-75.
Abstract: The mass isotopomer distribution analysis (MIDA) technique is applied here in men and menstruating women to quantify periodicities in the biosynthesis of serum cholesterol and very low density lipoprotein (VLDL)-palmitate. The isotopic enrichment of the true biosynthetic precursor (intracellular acetyl-CoA) during oral or intravenous administration of sodium1-13C- or 2-13Cacetate was calculated from mass isotopomer fractional abundances in free cholesterol and VLDL-palmitate, determined by gas chromatography-mass spectrometry (GC-MS). To convert fractional into absolute cholesterol synthesis rates, decay rate constants of plasma cholesterol were determined from the die-away curves of endogenously labeled high-mass isotopomers. Oral 13Cacetate was a 3-4 times more efficient means of labeling the precursor pool for VLDL-palmitate than was intravenous 13Cacetate, consistent with a splanchnic site of VLDL-fatty acid synthesis, whereas the precursor for free cholesterol had an intermediate enrichment, suggesting a contribution from extra-splanchnic tissues as well. Endogenous synthesis of serum cholesterol was 8-11 mg/kg per day (an estimated 65-75% of input into serum cholesterol); it was 1.5- to 3-fold higher at night than during the day (37-49 mg/h at night compared to 9-23 mg/h during the day) and did not vary over the menstrual cycle (608-697 mg/day). In contrast, endogenous synthesis of fatty acids made a relatively minor contribution to body fat pools (1/10-1/20) of input into VLDL-palmitate) compared to dietary fat intake; it was greater in the day-time, and was influenced by menstrual cycle (3-fold elevated in the follicular phase compared to the luteal phase), and body composition (higher in obese men than normal weight men, r2 = 0.59 for lipogenesis vs. body mass index). Factors responsible for periodicities in endogenous lipid synthesis can be studied in humans using this approach.

Quantified increases of cholesterol, total lipid and globotriaosylceramide in filipin-positive Niemann-Pick type C fibroblasts
Harzer, K. and B. Kustermann-Kuhn (2001), Clin Chim Acta 305(1-2): 65-73.
Abstract: BACKGROUND: Niemann-Pick disease type C (NPC) is a neurovisceral lysosomal lipidosis caused in most cases by mutations in the NPC1 gene that codes for the cholesterol regulating NPC1 protein. METHODS: Cultured skin fibroblasts from 11 NPC patients aged 0.25 to 34 years at diagnosis with different severity of neurologic and visceral involvement, diagnosed by the cytochemical filipin test for lysosomally stored cholesterol, were analyzed for lipid composition. Cholesterol and other lipids were separated on thin-layer chromatography from fibroblast total lipid extracts, quantified by densitometry and compared with the total cell lipid mass. RESULTS: Cholesterol concentration in the patient cells was 1.5 to 5-fold higher than normal and total lipids up to 2.4-fold normal. Cholesterol and total lipids were particularly high in cells from NPC patients aged less than about 6 years, and for the whole patient series the abundance of fibroblast cholesterol was correlated with the tentatively assessed clinical disease severity. The findings in NPC suggested that NPC1 protein has a role not only in the balance of cholesterol but also the distribution of the total cell lipid mass. Another increase found in the NPC cells was that of a minor lipid fraction, globotriaosylceramide (Gb3, known as a cell signalling glycolipid). Gb3, in the average of its very variable individual concentrations, was about 2.5-fold higher in the NPC cell group as compared to normal or pathologic control group, but there was no correlation of Gb3 with the other lipid concentrations studied. CONCLUSIONS: For NPC diagnosis, the fibroblast cholesterol and total lipid quantification can be used as an alternative to the usual filipin test for lysosomal cholesterol, but both test methods are prone to equivocal results in cells from a small fraction of atypical NPC patients, where chemical testing in organ biopsies or mutational analysis of the NPC1 gene should be tried.

Quantifying effect of statins on low density lipoprotein cholesterol, ischaemic heart disease, and stroke: systematic review and meta-analysis
Law, M. R., N. J. Wald, et al. (2003), Bmj 326(7404): 1423.
Abstract: OBJECTIVES: To determine by how much statins reduce serum concentrations of low density lipoprotein (LDL) cholesterol and incidence of ischaemic heart disease (IHD) events and stroke, according to drug, dose, and duration of treatment. DESIGN: Three meta-analyses: 164 short term randomised placebo controlled trials of six statins and LDL cholesterol reduction; 58 randomised trials of cholesterol lowering by any means and IHD events; and nine cohort studies and the same 58 trials on stoke. MAIN OUTCOME MEASURES: Reductions in LDL cholesterol according to statin and dose; reduction in IHD events and stroke for a specified reduction in LDL cholesterol. RESULTS: Reductions in LDL cholesterol (in the 164 trials) were 2.8 mmol/l (60%) with rosuvastatin 80 mg/day, 2.6 mmol/l (55%) with atorvastatin 80 mg/day, 1.8 mmol/l (40%) with atorvastatin 10 mg/day, lovastatin 40 mg/day, simvastatin 40 mg/day, or rosuvastatin 5 mg/day, all from pretreatment concentrations of 4.8 mmol/l. Pravastatin and fluvastatin achieved smaller reductions. In the 58 trials, for an LDL cholesterol reduction of 1.0 mmol/l the risk of IHD events was reduced by 11% in the first year of treatment, 24% in the second year, 33% in years three to five, and by 36% thereafter (P < 0.001 for trend). IHD events were reduced by 20%, 31%, and 51% in trials grouped by LDL cholesterol reduction (means 0.5 mmol/l, 1.0 mmol/l, and 1.6 mmol/l) after results from first two years of treatment were excluded (P < 0.001 for trend). After several years a reduction of 1.8 mmol/l would reduce IHD events by an estimated 61%. Results from the same 58 trials, corroborated by results from the nine cohort studies, show that lowering LDL cholesterol decreases all stroke by 10% for a 1 mmol/l reduction and 17% for a 1.8 mmol/l reduction. Estimates allow for the fact that trials tended to recruit people with vascular disease, among whom the effect of LDL cholesterol reduction on stroke is greater because of their higher risk of thromboembolic stroke (rather than haemorrhagic stroke) compared with people in the general population. CONCLUSIONS: Statins can lower LDL cholesterol concentration by an average of 1.8 mmol/l which reduces the risk of IHD events by about 60% and stroke by 17%.

Quantifying effect of statins on low density lipoprotein cholesterol, ischaemic heart disease, and stroke: systematic review and meta-analysis. Law MR, Wald NJ, Rudnicka AR. BMJ 2003; 326: 1407-408
Anand, S. S. (2003), Vasc Med 8(4): 289-90.

Quantitation by (1)H-NMR of dolichol, cholesterol and choline-containing lipids in extracts of normal and phathological thyroid tissue
Yoshioka, Y., J. Sasaki, et al. (2000), NMR Biomed 13(7): 377-83.
Abstract: Proton magnetic resonance spectroscopy at 1.9 T was used to quantify dolichols, cholesterols, choline-containing phospholipids and double bonds in unsaturated acyl chains in lipid extracts of four types of thyroid tissue normal (n = 27), papillary cancer (n = 15), adenoma (n = 13) and Basedow disease (n = 6). In normal thyroid the mean concentrations of dolichol, cholesterol and phospholipids were 1.2, 3.6 and 2.1 micromol/g wet weight, respectively. The concentrations of these lipids exhibited positive mutual correlations and positive correlations with patient age. The increase in dolichol in elderly human thyroid may be due to the accumulation of lysosomes and may help to compensate for the decrease in the activity of lysosomal enzymes and in thyroid hormone production and release. Dolichol concentrations were significantly lower in papillary cancer (0.4 micromol/g) and Basedow disease (0.3 micromol/g) compared to normal thyroid (p < 0.01 and p < 0.05, respectively), while cholesterol was enhanced only in cancer tissue (10.7 micromol/g). Benign adenoma exhibited normal levels of both dolichol and cholesterol. These results suggest that the synthesis and accumulation of isoprenoids are normal in adenoma but not in cancer.

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Cholesterol Journal Articles