Cholesterol Articles and Abstracts

For medical practitioners and the general public - Cholesterol Journal Article Catalog.

Cholesterol Journal Articles



Record 13381 to 13400
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Vacuolar uptake of host components, and a role for cholesterol and sphingomyelin in malarial infection
Lauer, S., J. VanWye, et al. (2000), Embo J 19(14): 3556-64.
Abstract: Erythrocytes, which are incapable of endocytosis or phagocytosis, can be infected by the malaria parasite Plasmodium falciparum. We find that a transmembrane protein (Duffy), glycosylphosphatidylinositol (GPI)-anchored and cytoplasmic proteins, associated with detergent-resistant membranes (DRMs) that are characteristic of microdomains in host cell membranes, are internalized by vacuolar parasites, while the major integral membrane and cytoskeletal proteins are not. The internalized host proteins and a plasmodial transmembrane resident parasitophorous vacuolar membrane (PVM) protein are detected in DRMs associated with vacuolar parasites. This is the first report of a host transmembrane protein being recruited into an apicomplexan vacuole and of the presence of vacuolar DRMs; it establishes that integral association does not preclude protein internalization into the P.FALCIPARUM: vacuole. Rather, as shown for Duffy, intracellular accumulation occurs at the same rate as that seen for a DRM-associated GPI-anchored protein. Furthermore, novel mechanisms regulated by the DRM lipids, sphingomyelin and cholesterol, mediate (i) the uptake of host DRM proteins and (ii) maintenance of the intracellular vacuole in the non-endocytic red cell, which may have implications for intracellular parasitism and pathogenesis.

VA-HIT Study Veterans Affairs High-Density Lipoprotein Cholesterol Intervention Trial Study
Noto, H. and M. Kinoshita (2001), Nippon Rinsho 59 Suppl 3: 442-7.

Validation and standardization of cholesterol measurements
McQueen, M. and P. H. Petersen (1990), Scand J Clin Lab Invest Suppl 198: 49-50.

Validation of a short questionnaire to qualitatively assess the intake of total fat, saturated, monounsaturated, polyunsaturated fatty acids, and cholesterol
Rohrmann, S. and G. Klein (2003), J Hum Nutr Diet 16(2): 111-7.
Abstract: BACKGROUND: To validate a self-administered 20-item short questionnaire (SQ) for classifying individuals according to their intake of total fat, saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA), as well as cholesterol. METHODS: The SQ was sent to a randomly selected subsample of 300 participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) in Heidelberg. The SQ was sent back by 244 participants (52.5% women, 47.5% men). Intake of total fat, SFA, MUFA, PUFA, and cholesterol was calculated from a 148-item food frequency questionnaire (FFQ). The intake was compared with the scores computed from the SQ. RESULTS: Spearman's correlation coefficient between the intake estimated from the FFQ and the score from the SQ ranged from r = 0.29 (PUFA) to r = 0.56 (cholesterol). When the participants were assigned to quartiles of intake according to both methods 29-42% were classified into the same quartile, 1-7% of the participants were grossly misclassified. CONCLUSIONS: The SQ demonstrated a good validity with respect to SFA and cholesterol and an acceptable validity with respect to total fat and MUFA, while the results are less good for PUFA. The SQ can be used to classify persons according to their intake into categories of intake.

Validation of a single-isotope-labeled cholesterol tracer approach for measuring human cholesterol absorption
Wang, Y., C. A. Vanstone, et al. (2004), Lipids 39(1): 87-91.
Abstract: Cholesterol absorption is frequently determined using the plasma dual stable-isotope ratio method (PDSIRM). However, this method involves intravenous injection of stable-isotope-labeled cholesterol with simultaneous oral administration of differently labeled cholesterol, which results in high study costs and involves additional ethical considerations. The objective of the present study was to validate a simpler single-isotope method for determining cholesterol absorption against PDSIRM by using data from two previous studies. Enrichments of carbon-13 (13C and deuterium in red blood cells were analyzed by using differential isotope ratio MS. The area under the curve of 13C-enrichment in the plasma free-cholesterol pool was found to be significantly correlated with cholesterol absorption measured by using PDSIRM for study 1 (r = 0.85, P < 0.0001) and study 2 (r = 0.81, P < 0.0001). Average 13C-enrichment correlated with the area under the curve of 13C-enrichment in the plasma free cholesterol for both study 1 (r = 0.98, P < 0.0001) and study 2 (r = 1.00, P < 0.0001). Study 1 examined the efficacy and mechanisms of unesterified plant sterols and stanols on lipid profiles in hypercholesterolemic men and women, while study 2 investigated the effects of phytosterol vs. phytostanol esters on plasma lipid levels and cholesterol kinetics in hyperlipidemic men. Experimental approaches to determine cholesterol absorption were identical between the two studies. Consequently, in both studies, correlations (r = 0.88, P < 0.0001 for study 1, and r = 0.82, P < 0.0001 for study 2) were found between the average 13C-enrichment of plasma free cholesterol and cholesterol absorption measured by PDSIRM. These results suggest that a single-isotope-labeled cholesterol tracer approach can be used as a reliable noninvasive method to replace PDSIRM for examining changes in cholesterol absorption.

Validation of deuterium incorporation against sterol balance for measurement of human cholesterol biosynthesis
Jones, P. J., L. M. Ausman, et al. (1998), J Lipid Res 39(5): 1111-7.
Abstract: To examine the validity of the deuterium (D) incorporation technique for measurement of human cholesterol synthesis rates, D uptake from D2O into cholesterol was compared to sterol balance in 13 subjects each under three controlled diet settings. Subjects (age 62 +/- 3.6 yr, body weight 74 +/- 4.0 kg, BMI 27 +/- 1.4) consumed weight maintenance diets enriched in either corn oil, beef tallow, or stick corn oil margarine over a 5-week period. During the final week of the study period, subjects were given 1.2 g/D2O per kg body water. D enrichment was measured in plasma water and total cholesterol over 24 h. Also, during the final week, dietary intake and fecal elimination rates of cholesterol were assessed over one 6-day period to calculate sterol balance. There was no significant difference (t = 0.858, P = 0.397) between D incorporation into cholesterol (1,183 +/- 92 mg/day) and sterol balance (1,316 +/- 125 mg/day). Among diets, net cholesterol biosynthesis measured by D incorporation agreed (r = 0.745, P = 0.0001) with values derived from sterol balance. The degree of association between methods was not influenced by the wide range of fatty acid composition of the diet fat. These data demonstrate the utility of the simple, non-restrictive deuterium incorporation method as a reliable means of determining cholesterol biosynthesis in free-living humans.

Validation of the dietary risk assessment food frequency questionnaire against the Keys score for saturated fat and cholesterol
Cheng, C., C. Graziani, et al. (2005), J Nutr Educ Behav 37(3): 152-3.
Abstract: OBJECTIVE: The objective of this pilot study was to validate the Dietary Risk Assessment (DRA) food frequency questionnaire against the Keys score obtained from 2 2-day dietary recalls in a sample of subjects. DESIGN: Cross-sectional study design. SETTING: Urban university-based family practice. PARTICIPANTS: The 105 subjects included outpatients, medical students, and staff. MAIN OUTCOME MEASURE: Correlation between the DRA and Keys score. ANALYSIS: Pearson correlation analysis. RESULTS: We found that the correlation between the DRA and Keys score derived from the dietary recalls was.62 (P <.001). CONCLUSIONS AND IMPLICATIONS: The simplicity of the DRA and its correlation with dietary recall may make this a useful dietary analysis and nutrition education tool for both patients and physicians.

Validation of the Friedewald formula for the determination of low-density lipoprotein cholesterol compared with beta-quantification in a large population
Tremblay, A. J., H. Morrissette, et al. (2004), Clin Biochem 37(9): 785-90.
Abstract: Lipoprotein data from 9477 subjects, covering a wide range of total plasma cholesterol levels, were used to examine the validity of the Friedewald formula for estimating plasma concentrations of low-density lipoprotein cholesterol (LDL-C) using high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) concentrations. Values of LDL-C obtained from the Friedewald formula were compared with values of LDL-C derived from preparative ultracentrifugation used as a reference method. We found that the bias associated with the Friedewald formula was not related to plasma LDL-C levels and was smaller than -4.0% even for plasma LDL-C values <3.0 mmol/l. Moreover, in the subgroup of individuals with plasma TG levels < or =4.5 mmol/l, the Friedewald formula underestimated LDL-C levels with a bias between -3.1% and -1.9% according to TG quartiles. Interestingly, the Friedewald formula showed no significant bias in patients with plasma TG levels between 4.51 and 8.82 mmol/l, suggesting that the calculated LDL-C are reliable and could be clinically useful in patients with plasma TG levels higher than 4.5 mmol/l which is the reference cut-point value used by most clinical laboratories. Finally, multiple regression analyses showed that the very low-density lipoprotein cholesterol (VLDL-C)/TG ratio represented nearly 63% (P < 0.0001) of the variance of the bias associated with the Friedewald formula. We concluded that the Friedewald formula may be reliable at low LDL-C levels and at TG levels up to 9 mmol/l but may be used with caution when the VLDL-C/TG ratio is high as observed in patients with type III dysbetalipoproteinemia.

Validity of animal models for the cholesterol-raising effects of coffee diterpenes in human subjects
de Roos, B., J. K. Sawyer, et al. (1999), Proc Nutr Soc 58(3): 551-7.
Abstract: Cafestol and kahweol, coffee lipids present in unfiltered coffee brews, potently increase LDL-cholesterol concentration in human subjects. We searched for an animal species in which cafestol similarly increases LDL-cholesterol. Such an animal model could be used subsequently as a model to study the mechanism of action of cafestol and kahweol. Cafestol and kahweol increased serum lipids in African green monkeys (Cercopithecus aethiops), cebus (Cebus apella) and rhesus (Macaca mulatta) monkeys, hamsters, rats and gerbils differently from the increase in human subjects. In African green monkeys, the rise in total cholesterol was less pronounced than that in human subjects. In addition, the increase in total cholesterol was predominantly due to a rise in HDL-cholesterol rather than LDL-cholesterol. Thus, the rise in plasma lipids might illustrate the mechanism in these monkeys rather than the mechanism in human subjects. In other animal species, cafestol and kahweol did not raise cholesterol consistently. The variability in effects on serum lipids could not be explained by the mode of administration or dose of diterpenes, nor by the amount of cholesterol in the diet. In conclusion, we did not find an animal model in which cafestol and kahweol elevate plasma lipoproteins to the same extent as in human subjects. For the time being, therefore, studies on the mechanism of action should be done preferably in human subjects.

Validity of studies on distribution and transbilayer movement of erythrocyte membrane cholesterol
Muriana, F. J., A. Alonso, et al. (1996), J Hypertens 14(11): 1379-80.

Value of a new method of LDL cholesterol assay in case of moderate hypertriglyceridemia
Lefevre, F. and P. Gillery (2000), Ann Biol Clin (Paris) 58(5): 618-23.

Value of ascitic fibronectin and cholesterol concentration in the differentiation between malignancy-related and non-malignant ascites
Archimandritis, A., D. Kapsalas, et al. (1996), Ann Med Interne (Paris) 147(3): 145-50.
Abstract: In this prospective study, we tried to evaluate various "humoral tests of malignancy" regarding their efficiency of discriminating between malignancy-related and non-malignant ascites. Fibronectin, total protein, number of cells, LDH, pH, specific gravity and cytology were compared in the ascitic fluid of 51 patients with malignancy-related and 52 patients with non-malignant ascites; patients with tuberculous peritonitis were not included. Ascitic fluid cholesterol was determined in 36 of 51 malignancy-related and in 37 of 52 non-malignant ascites. Cytology and fibronectin were found 100% specific with diagnostic efficiency 87.5% and 94.2% respectively under optimal conditions. Cholesterol was neither sensitive nor specific. It is concluded that fibronectin was a valuable test for malignancy-associated ascites.

Value of carcinoembryonic antigen (CEA) and cholesterol assays of ascitic fluid in cases of inconclusive cytology
Gulyas, M., A. D. Kaposi, et al. (2001), J Clin Pathol 54(11): 831-5.
Abstract: AIM: To determine whether assays of carcinoembryonic antigen (CEA) and cholesterol in ascites add diagnostic value to cytology. METHODS: The additional diagnostic efficacy of the biochemical assays was studied in the ascitic fluid from 130 patients, of whom 57 had peritoneal carcinomatosis. All diagnoses were verified by subsequent necropsy and/or histology. RESULTS: CEA concentrations over 5 ng/ml indicated carcinomas, occasionally without peritoneal involvement of the tumour. However, increased values were significantly more common in cancer with peritoneal involvement (p < 0.01), giving a sensitivity of 51% and specificity of 97% for carcinomatosis. A cholesterol value exceeding 1.21 mmol/litre was found in 93% of cancers with peritoneal involvement, but it was not entirely specific (96%) for carcinomatosis. Simultaneous increases in CEA and cholesterol concentrations were specific for carcinomatosis and this combination increased the sensitivity for diagnosing carcinomatosis from 77% with cytology alone to 88%. The correct diagnosis could thus be made in five of 12 cases with inconclusive cytology. CONCLUSIONS: The measurements of both CEA and cholesterol concentrations in ascites give additional specific information about peritoneal carcinomatosis and can therefore be a useful adjunct to cytology-in particular, in inconclusive cases.

Value of determining serum cholesterol levels in patients with coronary heart disease
Stalenhoef, A. F. (1997), Ned Tijdschr Geneeskd 141(52): 2545-8.
Abstract: Cholesterol synthesis (HMG-CoA reductase) inhibitors have proven their value in preventing cardiovascular events, especially in patients with manifest coronary heart disease. Besides cholesterol lowering a number of effects have been described which may contribute to the beneficial influence of these agents on the process of atherosclerosis. Measurement of serum lipids is still necessary for various reasons, namely, to know the degree of elevation in serum cholesterol and specific disturbances in lipid metabolism, the extent to which serum lipids must be lowered and the compliance with cholesterol lowering therapy.

Value of HDL cholesterol, apolipoprotein A-I, lipoprotein A-I, and lipoprotein A-I/A-II in prediction of coronary heart disease: the PRIME Study. Prospective Epidemiological Study of Myocardial Infarction
Luc, G., J. M. Bard, et al. (2002), Arterioscler Thromb Vasc Biol 22(7): 1155-61.
Abstract: OBJECTIVE: We have examined the association between the incidence of coronary heart disease (CHD) and plasma high density lipoprotein (HDL) cholesterol, apolipoprotein A-I (apoA-I), and 2 HDL fractions, lipoprotein A-I and lipoprotein A-I:A-II. METHODS AND RESULTS: These parameters were measured in subjects recruited in France and in Northern Ireland in the Prospective Epidemiological Study of Myocardial Infarction (PRIME) Study, a prospective cohort study. Among the subjects free of CHD on entry, 176 in France and 113 in Northern Ireland suffered an ischemic attack (CHD patients) during the 5-year follow-up, whereas 6612 French and 2172 Northern Irish men showed no CHD symptoms (CHD-free subjects). All 4 HDL parameter levels were lower in CHD patients than in CHD-free subjects. After the cohort was divided into quintiles based on the distribution of HDL parameter levels, a significant (P<0.0001) linear increase in relative risk was observed for each HDL parameter level. However, regression logistic analyses showed that apoA-I was the strongest predictor (more powerful than HDL cholesterol) and that lipoprotein A-I and lipoprotein A-I:A-II did not supplement apoA-I in predicting CHD. CONCLUSIONS: Among the parameters related to HDL, apoA-I appears to be the strongest independent risk factor.

Values of serum cholesterol in the Mexican population
Posadas-Romero, C., J. Sepulveda, et al. (1992), Salud Publica Mex 34(2): 157-67.
Abstract: The National Seroepidemiologic survey was carried out by the General Directorate of Epidemiology of the Ministry of Health from March 1987 to May 1988. One of the objectives of this survey was to know the mean cholesterol levels in the whole country and in each of the different states of the Mexican Republic by sex and in the different age groups. Of the 68,257 individuals studied, 39,990 (58.6%) were females and 28,267 (41.1%) males. The blood samples were processed at the Lipid Laboratory in the Endocrinology Department of the National Institute of Cardiology "Ignacio Chavez". The mean serum cholesterol levels were for the entire country 184 and 185 mg/dl in adult males and females, respectively, and 145 in males and 149 mg/dl in females in the age group below 20 years old. The northern states and two states in the southeast (Yucatan and Campeche) had the highest mean values of the country, and were found to be very similar to those observed in the United States population. When the values seen during childhood were compared with those attained on adult age, an increment of around 33 percent in the mean cholesterol levels was disclosed. This finding was similar in the different regions of Mexico as well as in the USA population. Also, the states with the highest mean cholesterol values in the young population had the highest values during adulthood (R2 = 0.90 and 0.91, for males and females). This information can be of great value for developing public health strategies to diminish the incidence of coronary heart disease.

Vanadium and ascorbate effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase, cholesterol and tissue minerals in guinea pigs fed low-chromium diets
Seaborn, C. D., E. D. Mitchell, et al. (1991), Magnes Trace Elem 10(5-6): 327-38.
Abstract: Vanadium has been reported to affect numerous physiological processes; however, a demonstration that vanadium deficiency consistently impairs biological function is lacking. The purpose of this study was to determine if the activity of hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, the rate-limiting enzyme in cholesterol synthesis, is affected by dietary supplementation of vanadate and/or chronic ascorbic acid deficiency. To determine if vanadium and/or ascorbic acid affected mineral metabolism, tissue minerals also were analyzed. Weanling male guinea pigs were assigned randomly to groups of 10 in a 2 x 2 factorial design. The dietary variables were ascorbate, 0.5 or 10 mg/day, and vanadium < 0.01 microgram or 0.5 microgram/g diet as NH4VO3 in a low Cr diet containing < 0.07 microgram Cr/g diet. After 21 weeks on this diet, guinea pigs receiving more ascorbate had lower liver weight/body weight ratios and increased bone copper. Testes weight/body weight ratios, hepatic glycogen and bone copper decreased while hepatic lipids, fecal bile acids, plasma cortisol and bone calcium and magnesium were increased by vanadium supplementation. An interaction between vanadium and ascorbate affected cholesterol excretion in feces, hepatic iron, plasma cholesterol concentration and the activity of HMG CoA reductase. This study provides evidence of increased bone mineral concentrations with vanadium supplementation and of an interaction between vanadium and ascorbate which affected cholesterol metabolism.

Variability in cholesterol content and physical properties of lipoproteins containing apolipoprotein B-100
Abate, N., G. L. Vega, et al. (1993), Atherosclerosis 104(1-2): 159-71.
Abstract: The primary objective of this study was to determine the variability in cholesterol carrying capacity of low density lipoproteins (LDLs) and other apolipoprotein B (apo B)-containing lipoproteins in normolipidemic men. One hundred and fifty-nine normolipidemic men, ages 21 to 73 years, were enrolled. In addition to determining plasma lipids and lipoproteins, three primary measurements were made: ratios of cholesterol to apo B in LDL; the electrophoretic pattern of LDL, i.e. pattern A, AB, or B; and levels of cholesterol in all lipoproteins other than high density lipoproteins (nonHDL-cholesterol) along with total apo B. First, the data revealed that about 85% of the variability of LDL-cholesterol levels can be accounted for by LDL-apo B levels, whereas the remaining 15% can be explained by differences in LDL-cholesterol/apo B ratios. Second, LDL electrophoretic pattern A was the predominant pattern in young adult men, but in older men the pattern shifted increasingly to AB and B. And third, there was a high correlation between nonHDL-cholesterol levels and total apo B levels, which suggests that nonHDL-cholesterol can be used as a relatively accurate surrogate for total apo B levels in normolipidemic individuals.

Variability in cholesterol content in serum and aortic tissue in apolipoprotein E-deficient mice is comparable in inbred (129/Sv) and outbred (mixed 129/Sv and C57BL/6) mice
van Ree, J. H., W. J. van den Broek, et al. (1995), Atherosclerosis 118(1): 165-7.

Variability in cholesterol measurements in a worksite cholesterol screening program
Stave, G. M., B. S. Winslow, et al. (1991), Am J Prev Med 7(6): 406-9.
Abstract: Worksite cholesterol screening programs are becoming increasingly prevalent. Variability in cholesterol measurements frequently renders the interpretation of single or repeated cholesterol determinations problematic, complicating employee counseling within screening programs. In the setting of a corporate cholesterol screening program, this study quantifies variability in cholesterol measurements and calculates a 90% confidence interval (CI) for cholesterol measurements. We chose 15 men and 15 women to represent a broad range of cholesterol values. We obtained duplicate samples of blood from each subject at one-week intervals for a total of three weeks. We performed total cholesterol measurements in duplicate twice weekly on each blood sample for three weeks, yielding a total of 36 measurements per subject. Components of variability were estimated using a hierarchical random effects analysis of variance (ANOVA) model. The coefficients of variation for biologic and analytic variation were 5.2% and 3.4% for men and 4.7% and 3.2% for women. CIs were +/- 10.2% for men and +/- 9.3% for women. As a result of this variation, we recommend the routine use of CIs when discussing cholesterol measurements with patients.


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