Cholesterol deposition

Langmuir-Blodgett films (LB) and self assembled monolayers (SAM) deposited on metal surfaces have been studied by SERS spectroscopy in several investigations. For example, mono- and bilayers of phospholipids and cholesterol deposited on a rutile prism with a silver coating have been analyzed in contact with water. The study showed that in these models of biological membranes the second layer modified the fluidity of the first monolayer, and revealed the conformation of the polar head close to the silver [4.300]. 

We hear a lot these days about the relationships between saturated fats, cholesterol, and heart disease. What are the facts It s well established that a diet rich in saturated animal fats often leads to an increase in blood serum cholesterol, particularly in sedentary, overweight people. Conversely, a diet-lower in saturated fats and higher in polyunsaturated fats leads to a lower serum cholesterol level. Studies have shown that a serum cholesterol level greater than 240 mg/dL (a desirable value is <200 mg/dL) is correlated with an increased incidence of coronary artery disease, in which cholesterol deposits build up on the inner walls of coronary arteries, blocking the flow of blood to the heart muscles. 

Brown, M.S. and Goldstein, J.L., Lipoprotein metabolism in the macrophage Implications for cholesterol deposition in atherosclerosis, Annu. Rev. Biochem. 52, 223, 1983. 

Coronary heart disease A type of heart disease caused by narrowing of the coronary arteries that feed the heart, which needs a constant supply of oxygen and nutrients carried by the blood in the coronary arteries. When the coronary arteries become narrowed or clogged by fat and cholesterol deposits and cannot supply enough blood to the heart, CHD results. [NIH]... 

This is a dominant genetic disease affecting 1/500 (heterozygous) individuals in the United States. It is characterized by elevated LDL cholesterol and increased risk for atherosclerosis and coronary artery disease. Cholesterol deposits may be seen as ... 

Serious Diseases Result from Cholesterol Deposits High-Density Lipoproteins (HDLs) May Reduce Cholesterol Deposits... 

Serious Diseases Result from Cholesterol Deposits... 

Does Citrus Pectin Bind Bile Salts A possible mechanism by which dietary pectin may cause lowering of cholesterol levels in rats has been reported (1 9). In these in vitro studies, pectin was found to inhibit the transport of taurocholic acid from everted sacs of rat intestine. The absorption of labelled cholesterol was depressed by the addition of 5% pectin to the diet as evidenced by increased excretion of labelled cholesterol and diminished cholesterol deposition in the liver. It was concluded from these studies that pectin lowers cholesterol levels in cholesterol-fed rats primarily by binding bile salts and, consequently, by impairing cholesterol absorption. Results similar to those obtained with dietary pectin and described have also been reported for other non-nutritive substances such as guar gum, psyllium seed colloid and seruglucan (20). 

Low-density lipids in the blood cause cholesterol deposits. Their presence and nature, including the position and number of double bonds, can be analyzed by means of ESI-MS techniques <2000JMP224>. Reverse-phase HPLC microsamples containing phospholipids were treated with bis(trimethylsilyl) trifluoroacetamide, then with methoxy-amine, and then exposed for 8 min to ozone gas at room temperature ESI-MS followed and showed the fragments corresponding to ozonides. 

G20, G22). Evidence from the WHHL rabbit suggests that the focal deposition of cholesterol in the artery wall and in tendons (seen in the WHHL rabbit and in humans with FH) is a direct response to increased uptake of LDL, perhaps into traumatized tissues, by pathways other than B-100,E receptors. This is in contradistinction to the cholesterol-fed rabbit with a normal LDL receptor system, which develops an entirely different pattern of cholesterol deposition in liver, spleen, and other tissues (B60). 

Interaction and adhesion of biological surfaces are central considerations for other physiological conditions as well. Platelets, erythrocytes, the vascular endothelium and other tissues interact during thrombosis and hemostasis. Also, when erythrocytes come in contact with artificial surfaces, damage often occurs and blood trauma may result. Finally, the accumulation of cholesterol deposits on the interior walls of arteries is responsible for atherosclerosis. 

Yamaguchi et al. (1993) found that addition of 10 % linoleic acid to a high-cholesterol diet enhanced cholesterol deposition in the aorta of male ICR strain mice. 

Increase in LDL and lipoprotein Lipids providing increased substrate plaques representing cholesterol deposits (xanthelasma, progressing to xanthomas) may be noted... 

Increase in cholesterol deposition (see above) Retention of cholesterol normally excreted in the bile Xanthomas... 

High levels of circulating LDL, which are rich in cholesterol and cholesteryl esters, cause cholesterol deposition into the endothelium of the so-called lesion-prone sites of the arterial wall. These areas are characterized by increased permeability to albumin, fibrinogen and LDL cholesterol and by a high monocyte recruitment activity. Monocytes migrate from the endothelium to the intima, and differentiate into macrophages. Recruitment and migration are part of an inflammatory... 

Evidence is accumulating that inositol will reduce elevated hlood cholesterol levels. This in turn may prevent or mitigate cholesterol depositions in (he intima of blood vessels in humans and animals and. theiefore, be of value in atherosclerosis. Inositol has also been considered a lipotropic agent. Because humans can synthesixe inositol, the need for it as a nutritional requireinent has not been proved. ... 

Goldstein JL, Ho YK, Basu SK, Brown MS. Binding site on macrophages that mediates uptake and degradation of acetylated low density lipoprotein, producing massive cholesterol deposition. Proc Natl Acad Sci U S A 1979 76 333-7. 

It must be remembered that xanthelasma is associated with dyslipidemia in 50% of cases. It can also be symptomatic of hepatobiliary disorders (biliary atresia and biliary cirrhosis) when associated with cholesterol deposits that start to build up in the hands and feet before spreading. Monoclonal gammapathies have also been described in association with xanthelasma. 

Peterson and Diederich have recently synthesized a water-soluble macrocycle containing a large hydrophobic cavity (Figure 55) [77]. This molecule has been shown to increase the water solubility of steroids severalfold. A 1 mM solution of the host was found to increase the water solubility of cholesterol to 850 /zM (from 4.7/zM in pure water). It has been suggested by these authors that further studies along these lines might lead to the development of alternative drugs for the dissolution of cholesterol deposits in vivo. 

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