| For medical practitioners and the general public - Cholesterol Journal Article Catalog. |
| First Page | Previous Page | Next Page | Last Page |
| More on the Chinese red-yeast-rice supplement and its cholesterol-lowering effect Bliznakov, E. G. (2000), Am J Clin Nutr 71(1): 152-4. |
| More ordered, convex ganglioside-enriched membrane domains: the effects of GM1 on sphingomyelin bilayers containing a low level of cholesterol Pei, B. and J. W. Chen (2003), J Biochem (Tokyo) 134(4): 575-81. Abstract: The special physical state of the sphingolipid-enriched membranes with characteristic lipid composition, presently one of the most controversial foci in cell biology, provides the essential environment for the proteins inside to be involved in the related physiological processes. The role of gangliosides, an important component of the membranes, deserves attention. The present investigation using several biophysical techniques indicates that ganglioside GM(1) induces the phase separation in the sphingomyelin membrane with 5 mol% cholesterol and regulates the membrane structure. The results of differential scanning calorimetry show that a higher T(m), GM(1)-rich phase emerges behind the lower T(m), sphingomyelin-rich phase with the incorporation of GM(1) into the sphingomyelin/cholesterol bilayers; and the GM(1)-rich phase dominates the membrane when the proportion of GM(1) reaches about 20 mol%. Fluorescence quenching further shows that the separation of the two domains is independent of temperature, occurring both in the gel phase and in the liquid phase. Laser Raman spectroscopy and fluorescence polarization suggest that the order of hydrocarbon chains increases and membrane fluidity decreases with increase in GM(1) content. Use of the fluorescence probe merocyanine-540 and electron microscopy reveals that the insertion of GM(1) leads to an increase in the spatial density of the lipid headgroups and a decrease in the curvature of the sphingomyelin/cholesterol bilayers. In sums, both the hydrophilic sugar heads and the hydrophobic hydrocarbon chains of GM(1) contribute to the regulation of membrane architecture. We suggest that the convex curvature of ganglioside-enriched membrane could be involved in forming and maintaining the characteristic flask-shaped invagination of caveolae. |
| More than cholesterol: the complexity of coronary artery disease Ijem, J. and C. Granlie (2000), S D J Med 53(11): 489-91. Abstract: There have been many recent articles published that emphasize the fact that cholesterol deposits are only one of many mechanisms through which acute coronary artery disease develops. Recently, a meta-analysis shows that only 14% of acute coronary events occur in stenotic lesions in coronary arteries that are greater than 70% occluded. The majority of acute coronary events (68%) occur in coronary arteries that have less than 50% stenotic lesions. The acute coronary syndrome is a very complex and unpredictable disease. Recent information now points to the endothelium as a modulating factor in the pathogenesis of coronary artery disease through the production of nitric oxide and angiotensin-II which maintain the homeostatic environment influencing the progression of coronary artery disease. With dysfunctional endothelium there seems to be an imbalance in terms of angiotensin production with regards to the nitric oxide production. This imbalance tends to promote coronary artery disease in individuals who have multiple risk factors. Furthermore, it has been suggested that certain inflammatory compounds are produced in a very dysfunctional endothelium, thereby propagating or leading to acute coronary syndromes. Specifically, this includes C-reactive protein which promotes chronic inflammation at various sites. There are also other acute phase reactants, such as fibrinogen, which may play a role in atherogenesis. Certain statin drugs, as they are called, tend to ameliorate the levels of the above acute phase reactants, while other statins do not. This reduction of coronary events by statins is independent of the LDL lowering benefits from statin drugs. This article delineates some of the beneficial effects of the different statin agents and points out that all statins are not equal in terms of their known lipid beneficial effects. For the practicing physician, choosing a particular statin agent is important. Some have more drug/drug interaction potential as compared with the others because of their inability to be metabolized through the cytochrome P450 system. There are also some, because of their lipophilic and hydrophilic nature, that tend to enter cells more readily than other statin agents. The effects conferred by these subtle differences among the currently available statins tend to be beneficial in patients with low to moderate levels of LDL cholesterol. |
| Morphologic changes in human carcinoma cells (A-431) stimulated by epidermal growth factor: effect of cholesterol and low-density lipoproteins on the ruffling response Jackowski, M. M., L. L. Swift, et al. (1990), J Cell Physiol 142(3): 458-68. Abstract: Stimulation of A-431 carcinoma cells with epidermal growth factor (EGF) causes dramatic morphologic responses including ruffling, rounding, and bulk-phase pinocytosis. In attempts to explore the mechanisms responsible for changes in plasmalemma topography, we have investigated the effects of exogenous sterols thought to alter membrane fluidity. Light and scanning electron microscopy revealed a time- and concentration-dependent inhibition of ruffling (greater than 90%) by cholesterol. This effect could be duplicated by preincubation of the cells with comparable levels of low-density lipoproteins (LDL). EGF-stimulated bulk-phase endocytosis also is inhibited by treatment with cholesterol. No alteration of EGF binding, kinase stimulation, or internalization was detected in cells incubated in cholesterol-enriched medium (175 micrograms/ml in 0.5% ethanol), nor did cholesterol or LDL have any effect on EGF-stimulated rounding. Morphometry of electron micrographs from cholesterol-treated cells revealed a selective depletion of interdigitating lateral surface membrane that normally appears to be recruited to generate apical ruffles. Thus, the sterol inhibition of ruffling may be due to redistribution of plasmalemma rather than to changes in membrane viscosity. Together with previous observations, these data suggest that EGF-stimulated ruffling and bulk-phase pinocytosis are related phenomena, whereas EGF-stimulated cell rounding is an independent process. |
| Morphological aspects of the effect of magnesium orotate therapy on changes in the vascular walls induced by cholesterol-rich diet Jellinek, H. and E. Takacs (1997), Orv Hetil 138(36 Suppl 2): 2276-80. Abstract: Heart and blood vessel disease are one of the leading causes of death, so their prevention and therapy are very important. In the present study the effects of magnesium chloride, magnesium orotate and orotic acid were tested. New Zealand rabbits were fed with enriched (2%) cholesterol diet during 112 days: starting with day 56 all rabbits were treated with MgCl2, Mg-orotate or orotic acid (orally). Aortas, coronaries, renal and femoral arteries were removed and evaluated by morphological and morphometric methods. Atherosclerotic alterations in each vessel could be influenced moderately by Mg-chloride, quite well by orotic acid and excellently by Mg-orotate. From these results one can conclude that orotic acid and Mg-orotate have a beneficial effect in the prevention and therapy of heart and vessels diseases. |
| Morphological changes of human erythrocytes induced by cholesterol sulphate Przybylska, M., M. Faber, et al. (1998), Clin Biochem 31(2): 73-9. Abstract: OBJECTIVES: Morphological alterations of human erythrocytes induced by cholesterol sulphate (5-cholesten-3 beta-ol sulphate, CS) were studied. DESIGN AND METHODS: Influence of CS on red blood cell stability (in isotonic conditions) by simultaneous application of flow cytometry and scanning electron microscopy was studied. RESULTS: In isotonic medium CS induces erythrocyte size and shape changes in dose-and time-dependent manner. Incubation (in vitro) of erythrocytes with CS concentrations from 4 x 10(-5) mol/dm3 to 8 x 10(-5) mol/dm3 led to a progressive sphero-echinocitic shape transformation accompanied by a cell size decrease. In contrast to this, for CS content equal to 1 x 10(-5) mol/dm3 the maintenance of the normal biconcave shape of red blood cells was observed. CONCLUSIONS: The results suggest that CS, similarly to numerous evaginating amphiphilic agents, induces a transformation of the erythrocyte normal discoid shape to echinocytic form. This effect may be caused, at least partly, by an asymmetric expansion of the membrane lipid bilayer due to asymmetric distribution of CS incorporated into the membrane. The echinocytic shape transformation of erythrocytes indicated that CS intercalates in the outer hemileaflet of the lipid bilayer leading to membrane externalization. |
| Morphological study of cholesterol hepatolithiasis. Report of three cases Saito, K., Y. Nakanuma, et al. (1990), J Clin Gastroenterol 12(5): 585-90. Abstract: Three cases of pure cholesterol intrahepatic stones are compared morphologically to those of calcium bilirubinate stones. Cholesterol stones were found in the intrahepatic bile duct of the left lateral lobe in two cases and in both the left lateral and the right posterior lobe in one. Although the chronic inflammatory reaction and fibrous thickening of bile duct wall were similar in both types of hepatolithiasis, the proliferation of intrahepatic periductal glands and the production of mucin were rather mild, compared to that is the liner containing calcium bilirubinate stones. Multiple intramural cholesterol calculi and cholesterin granulomas (cholesterin crystals surrounded by foreign-body giant cells) were found within the cystically dilated small bile duct branches and/or conduits of periductal glands. The calculi and granulomas were characteristic for cholesterol hepatolithiasis. These findings suggest that the formation of the cholesterol stones differs from that of calcium bilirubinate stones; the perturbation of factors influencing cholesterol nucleation in the hepatic bile may be related to the changed microenvironment of the intrahepatic bile ducts, which is followed by the formation of cholesterol stones. |
| Mothers' attitudes toward nutrition are related to daughters' but not to sons' plasma cholesterol levels Messina, C. R., G. Weidner, et al. (2002), J Am Diet Assoc 102(5): 678-82. Abstract: OBJECTIVE: To examine the relationship between parents' attitudes toward nutrition and plasma lipid levels of their children. DESIGN: Parents' nutrition attitudes were assessed with the Nutritional Attitude Scale, a self-report questionnaire measuring attitudes toward the adoption of a low-fat, low-cholesterol diet. Parents' and children's plasma lipid and lipoprotein levels were obtained. Data were collected during the baseline period and a 1-year follow-up of the Family Heart Study, a small community study of cholesterol-lowering via dietary change. PARTICIPANTS/SETTING: Participants were 33 girls and 34 boys (aged 6 to 13 years), and their parents. They were a subsample of European-American, middle-class, Portland, Ore, families participating in the Family Heart Study. STATISTICAL ANALYSES: Associations between parents' nutrition attitudes and plasma lipid levels of their children were evaluated using multiple linear regression analyses, controlling for the contribution of parents' lipid levels to those of their children. RESULTS: Mothers' nutrition attitudes interacted with their daughters' ages, accounting for 14% of the variance in plasma total cholesterol level and 11% in low-density lipoprotein cholesterol level in their daughters. Mothers' unhealthful nutrition attitudes were associated with elevated levels of plasma total and low-density lipoprotein cholesterol levels among older daughters, but not among younger daughters nor their sons. Fathers' nutrition attitudes were unrelated to their children's plasma lipid levels. Mothers' nutrition attitudes assessed at baseline remained a significant predictor of their daughters' lipid levels measured 1 year later. APPLICATIONS/CONCLUSIONS: The previously reported relationships between adults' unhealthful nutrition attitudes and their own elevated plasma lipid levels appear to extend to that of their children. The association between mothers' nutrition attitudes and their daughters' lipid levels highlights the importance of focusing on nutrition attitudes when designing intervention programs to reduce plasma lipids and lipoproteins via dietary changes in the family. |
| Motivation for cholesterol screening Klevay, L. M. (1990), J Lab Clin Med 115(2): 263-4. |
| Motivational effect of cholesterol measurement in general practice health checks Robertson, I., A. Phillips, et al. (1992), Br J Gen Pract 42(364): 469-72. Abstract: A randomized trial was conducted in five general practices in and around Aylesbury, Buckinghamshire to assess the motivational effect of cholesterol measurement on compliance with advice to reduce dietary fat intake and to stop smoking. The advice was given by practice nurses during health checks for cardiovascular risk factors. A total of 578 patients were recruited to the study and randomized into two groups. Both groups were given the same advice and were followed up after a median of three months, but the intervention group was also given immediate feedback on their cholesterol concentration. Follow up was completed for 88.2% of subjects, and those who were not followed up were assumed not to have changed their behaviour. The mean fall in total cholesterol at follow up was 0.11 mmol l-1 (95% confidence interval 0.03 to 0.18) in the intervention group who were told their cholesterol result and 0.02 mmol l-1 (95% CI -0.06 to 0.10) in the control group who were not. The proportion of smokers who were not smoking at follow up was 10.7% and 10.1% in the two groups, respectively. Patients in the intervention group with an initial total cholesterol level of 6.50 mmol l-1 or greater showed a mean fall of 6.2% in cholesterol level whereas those with an initial cholesterol level of less than 5.20 mmol l-1 experienced a mean increase of 3.6%, but as differences of this magnitude were also seen in the control group they probably reflect regression to the mean rather than an effect of knowledge of cholesterol level.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Mouse Disp1 is required in sonic hedgehog-expressing cells for paracrine activity of the cholesterol-modified ligand Tian, H., J. Jeong, et al. (2005), Development 132(1): 133-42. Abstract: Previous studies have demonstrated that Disp1 function is essential for Shh and Ihh signaling in the mouse, and Disp1 gene dose regulates the level of Shh signaling activity in vivo. To determine whether Disp1 activity is required in Shh-producing cells for paracrine signaling in Shh target fields, we used a ShhGFP-Cre (here shortened to ShhCre) knock-in allele and a Disp1 conditional allele to knock down Disp1 activity specifically within Shh-producing cells. The resulting facial and neural tube phenotypes support the conclusion that the primary and probably exclusive role for Disp1 is within hedgehog protein-producing cells. Furthermore, using an allele that produces N-Shh (a noncholesterol modified form of the Shh protein), we demonstrate that N-Shh is sufficient to rescue most of the early embryonic lethal defects in a Disp1-null mutant background. Thus, Disp1 activity is only required for paracrine hedgehog protein signaling by the cholesterol modified form of Shh (N-Shhp), the normal product generated by auto-processing of a Shh precursor protein. In both respects, Disp function is conserved from Drosophila to mice. |
| Movement of zymosterol, a precursor of cholesterol, among three membranes in human fibroblasts Lange, Y., F. Echevarria, et al. (1991), J Biol Chem 266(32): 21439-43. Abstract: Where examined, cholesterol is synthesized in the endoplasmic reticulum; however, its precursor, zymosterol, is found mostly in the plasma membrane. The novel implication of these disparate findings is that zymosterol circulates within the cell. In tracing its movements, we have now established the following: (a) in human fibroblasts, zymosterol is converted to cholesterol solely in the rough ER. (b) Little or no zymosterol or cholesterol accumulates in the rough ER in vivo. (c) Newly synthesized zymosterol moves to the plasma membrane without a detectable lag and with a half-time of 9 min, about twice as fast as cholesterol. (d) The pool of radiolabeled zymosterol in the plasma membrane turns over rapidly, faster than does intracellular cholesterol. Thus, plasma membrane zymosterol is not stagnant. (e) 3HZymosterol pulsed into intact cells is initially found in the plasma membrane. It is rapidly internalized and is then converted to 3H cholesterol. Half of the 3Hcholesterol produced returns to the plasma membrane within 30 min of the initial 3Hzymosterol pulse. (f) Nascent zymosterol accumulates in a buoyant sterol-rich intracellular membrane before it reaches the plasma membrane. This membrane also acquires nascent cholesterol, exogenous 3Hzymosterol pulsed into intact cells, and 3Hcholesterol synthesized from the exogenous 3H zymosterol. These results suggest that at least one sterol moves rapidly and in both directions among the rough endoplasmic reticulum, a sterol-rich intracellular membrane bearing nascent cholesterol, and the plasma membrane. |
| MR aortography and serum cholesterol levels in patients with long-term nonspecific lower back pain Kauppila, L. I., R. Mikkonen, et al. (2004), Spine 29(19): 2147-52. Abstract: STUDY DESIGN: A cross-sectional analysis of the feeding arteries of the lumbar spine and cholesterol levels on patients with long-term nonspecific lower back pain. OBJECTIVES: To evaluate whether occlusion of lumbar and middle sacral arteries or serum cholesterol levels are associated with lower back pain and/or with disc degeneration. SUMMARY OF BACKGROUND DATA: Atherosclerosis in the wall of the abdominal aorta usually develops at the ostia of branching arteries and the bifurcation, and may obliterate orifices of lumbar and middle sacral arteries. Obstruction of these arteries causes ischemia in the lumbar spine and may result in back symptoms and disc degeneration. METHODS: MR aortography and cholesterol blood tests were performed on 51 patients with long-term lower back pain without specific findings (i.e., spinal or nerve root compression) in regular lumbar MR images. The patients ranged from 35 to 70 years of age (mean age, 56 years). Serum cholesterol and low-density lipoprotein (LDL) cholesterol levels were measured. To assess symptoms and disability NASS low back Outcome Instrument was used. RESULTS: Twenty-nine (78%) of 37 men and 11 (77%) of 14 women showed occluded lumbar and/or middle sacral arteries. The prevalence of occluded arteries was 2.5 times more than in subjects of corresponding age group in a Finnish necropsy material. Twenty-three (62%) men and seven (50%) women had significant disc degeneration. Disc degeneration was associated with occluded lumbar/middle sacral arteries (P = 0.035). Patients with occluded arteries or significant disc degeneration did not complain more severe symptoms than those without, whereas patients with above normal serum LDL cholesterol scored higher in neurogenic symptoms (P = 0.031) and complained more often severe pain (P = 0.049) than those with normal LDL cholesterol. CONCLUSIONS: The study indicates that lumbar and middle sacral arteries are often occluded in patients with nonspecific long-term lower back pain. Occlusion of these arteries may also be associated with disc degeneration. |
| MRI of rabbit atherosclerosis in response to dietary cholesterol lowering McConnell, M. V., M. Aikawa, et al. (1999), Arterioscler Thromb Vasc Biol 19(8): 1956-9. Abstract: Direct imaging of the atherosclerotic plaque, rather than the angiographic lumen, may provide greater insight into the response of atherosclerosis to cholesterol-lowering therapy. Aortic plaque was studied in vivo by MRI in rabbits undergoing dietary cholesterol intervention. Thirty-one rabbits underwent aortic balloon injury and high-cholesterol diet for 4 months and then were assigned to low-cholesterol versus continued high-cholesterol diet for up to an additional 16 months. High-resolution (310 micrometer) fast spin-echo MRI of the abdominal aorta was performed at 4, 12, and 20 months and compared with histology. MRI demonstrated a significant reduction in % area stenosis in rabbits placed on low-cholesterol diet (44.6+/-2. 1% at 20 months versus 55.8+/-1.5% at 4 months, P=0.0002). In contrast, % area stenosis increased in rabbits maintained on high-cholesterol diet (69.8+/-3.8% at 20 months versus 55.8+/-1.5% at 4 months, P=0.001). Similarly, plaque thickness decreased significantly in the low-cholesterol group (0.60+/-0.05 mm at 20 months versus 0.85+/-0.06 mm at 4 months, P=0.006), with a trend toward increase in the high-cholesterol group (1.02+/-0.08 mm at 20 months versus 0.85+/-0.06 mm at 4 months, P=0.1). Thus, in rabbits undergoing dietary cholesterol lowering, MRI detected regression of aortic atherosclerotic plaque in vivo. Plaque progression was seen with maintenance of high-cholesterol diet. MRI is a promising noninvasive technology for directly imaging atherosclerosis and its response to therapeutic interventions. |
| MspI polymorphism at +83 bp in intron 1 of the human apolipoprotein A1 gene is associated with elevated levels of HDL cholesterol and apolipoprotein A1 in nondiabetic subjects but not in type 2 diabetic patients with coronary heart disease Pulkkinen, A., L. Viitanen, et al. (2000), Diabetes Care 23(6): 791-5. Abstract: OBJECTIVE: Elevated HDL cholesterol and its principal carrier protein apolipoprotein a1 apo(a1) are associated with reduced risk of coronary heart disease (CHD). No studies are available on the impact of the -75-bp and/or +83-bp polymorphisms of the apo(a1) gene on HDL cholesterol and apo(a1) levels in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: We determined the prevalence of the: -75-bp and +83-bp polymorphisms of the apo(a1) gene by restriction fragment length polymorphism analysis among 308 unrelated nondiabetic subjects with CHD and among 251 unrelated patients with type 2 diabetes with CHD and in randomly selected 82 healthy men (CHD-). RESULTS: The rare M1- and M2- allele frequencies of the apo(a1) gene were 23 and 1.8%, respectively, among control subjects; 20 and 1.5%, respectively, among nondiabetic subjects with CHD; and 22 and 2.6%, respectively, among patients with type 2 diabetes and CHD (NS). Nonsmoking nondiabetic subjects with CHD having the M2+- genotype had higher HDL cholesterol (1.48 +/- 0.19 vs. 1.23 +/- 0.02 mmol/l, P < 0.01) and apo(a1) (1.43 +/- 0.10 vs. 1.36 +/- 0.02 g/l, P < 0.05) levels than subjects with the M2++ genotype, even after adjustment for confounding factors. This association was not found among patients with type 2 diabetes and CHD. CONCLUSIONS: We conclude that the +83-bp polymorphism of the apo(a1) gene is associated with elevated HDL cholesterol and apo(a1) levels in Finnish nondiabetic subjects but not in patients with type 2 diabetes. |
| MTP inhibitor decreases plasma cholesterol levels in LDL receptor-deficient WHHL rabbits by lowering the VLDL secretion Shiomi, M. and T. Ito (2001), Eur J Pharmacol 431(1): 127-31. Abstract: To examine whether a microsomal triglyceride transfer protein (MTP)-inhibitor is effective in patients with homozygous familial hypercholesterolemia, we administered (2S)-2-cyclopentyl-2-4-(2,4-dimethyl-9H-pyrido2,3-bindol-9-yl)methylp henyl-N-(1S)-2-hydroxy-1-phenylethylethanamide (Implitapide), a new MTP inhibitor, to low-density lipoprotein (LDL)-receptor-deficient Watanabe heritable hyperlipidemic (WHHL) rabbits at doses of 3, 6, and 12 mg/kg for 4 weeks. In the 12 mg/kg group, the plasma cholesterol and triglyceride levels were decreased by 70% and 45%, respectively, and the very low-density lipoprotein (VLDL) secretion rate was decreased by 80%. The composition of newly secreted VLDL was similar in each group. This suggests that Implitapide diminished the number of VLDL particles secreted from the liver. Although the ratio of vitamin E/LDL was not altered by Implitapide, triglyceride accumulation and a decrease in vitamin E were observed in the liver. In conclusion, an inhibition of VLDL secretion led to a decrease of plasma LDL in WHHL rabbits, and MTP inhibitors should have hypolipidemic effects against homozygous familial hypercholesterolemia. |
| Mucins and calcium phosphate precipitates additively stimulate cholesterol crystallization van den Berg, A. A., J. D. van Buul, et al. (1998), J Lipid Res 39(9): 1744-51. Abstract: Human biliary mucin and calcium binding protein (CBP) influence formation of both calcium salt precipitates and cholesterol crystals and colocalize in the center of cholesterol gallstones. We investigated how physiological concentrations of these proteins regulate cholesterol crystallization in model biles, supersaturated with cholesterol and calcium salts, mimicking pathological human bile. Using polarizing light microscopy and nephelometry to assess cholesterol crystallization, the influence of calcium ions and calcium phosphate precipitates in the absence and presence of mucin, CBP, and human serum albumin was determined. Calcium phosphate precipitates stimulated cholesterol crystallization more strongly than soluble calcium. Mucin also stimulated, and with soluble calcium or calcium phosphate precipitates additively increased, the cholesterol crystal mass. In the absence of mucin, only human serum albumin plus CBP, not these proteins individually, decreased the stimulating effect of calcium phosphate precipitates but not of soluble calcium. However, seeding of calcium phosphate precipitates in biles with mucins resulted in near complete cholesterol crystallization within one day whether CBP and HSA were or were not also present. In conclusion, calcium salt precipitates plus human biliary mucins induce rapid and complete crystallization of cholesterol from model biles, little influenced by human biliary calcium binding proteins. |
| Mucin-vesicle interactions in model bile: evidence for vesicle aggregation and fusion before cholesterol crystal formation Afdhal, N. H., N. Niu, et al. (1995), Hepatology 22(3): 856-65. Abstract: Nucleation of cholesterol monohydrate crystals from bile is a critical step in the formation of cholesterol gallstones. Measurement of nucleation in model bile system and the characteristics of the initial nucleus have proven elusive. In this study we have used three separate physical chemical techniques to examine vesicle aggregation and fusion, including dynamic light scattering (DLS), transmission electron microscopy (TEM), and fluorescent biochemical assays. These assays enabled us to quantify the effect of biliary proteins, such as gallbladder mucin, on vesicle fusion and aggregation. In the absence of mucin, fusion is a relatively slow process occurring over 24 hours, whereas physiological concentrations of mucin are able to accelerate almost complete fusion of vesicles within 6 hours. Vesicle fusion and aggregation as characterized by TEM result in the formation of aggregates of multilamellar vesicles and giant fusion bodies associated with a background of mucin. These mucin-vesicle aggregate bodies may represent true nuclei and precede cholesterol monohydrate crystal nucleation. In future studies, these vesicle fusion assays can be used to quantitatively examine the effect of putative pro- and anti-nucleating proteins on the earliest steps of cholesterol crystal nucleation. |
| Mucolytic agents and cholesterol gallstones Mendez Sanchez, N. and M. Uribe Esquivel (1991), Gastroenterology 100(2): 581. |
| Multicenter evaluation of a homogeneous assay for HDL-cholesterol without sample pretreatment Nauck, M., W. Marz, et al. (1997), Clin Chem 43(9): 1622-9. Abstract: We evaluated a new homogeneous assay for the measurement of HDL-cholesterol (HDL-C) in six European laboratories. The assay includes two reagents and is applicable to most autoanalyzers, which allows full automation. The total CVs of the new method ranged between 1.3% and 6.7%. Thereby determined HDL-C values were in good agreement with those obtained by precipitation with phosphotungstic acid/MgCl2 or by a combination of ultracentrifugation and precipitation (0.956 < r < 0.994). The assay was linear up to at least 1500 mg/L HDL-C. Hemoglobin did not interfere, whereas icteric samples with bilirubin > 100 mg/L showed discrepancies between the homogeneous and the precipitation assay. Lipemia up to total triglyceride concentrations of 8000 mg/L did not interfere with the homogeneous HDL-C assay. The homogeneous HDL-C assay was easy to handle and produced similar results in all laboratories participating in this study. This method will significantly facilitate the screening of individuals at increased risk for cardiovascular disease. |