Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0004153 (atherosclerosis)
 77,401 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A logical argument can be made for the hypothesis that lack of silicon may be an important aetiological factor in atherosclerosis. As silicic acid or its derivatives, silicon is essential for growth. It is found mainly in connective tissue, where it functions as a cross-linking agent. Unusually high amounts of bound silicon are present in the arterial wall, especially in the intima. Various kinds of dietary fibre have been reported to be effective in preventing experimental models of atherosclerosis, reducing cholesterol and blood-lipid levels, and binding bile acids in vitro. Exceptionally large amounts of silicon (1000 to 25 000 p.p.m.) were found in fibre products of greatly varying origin and chemical composition which were active in these tests. Inactive materials, such as different types of purified cellulose, contained only negligible quantities of the element. It is concluded that silicate-silicon may be the active agent in dietary fibre which affects the development of atherosclerosis. Two out of three samples of bran also had relatively low levels, which could explain why bran does not lower serum-cholesterol. The fact that atherosclerosis has a low incidence in less developed countries may be related to the availability of dietary silicon. Two instances are presented where silicon is reduced by industrial treatment: white flour and refined soy products were much lower in silicon than--their respective crude natural products. The chemical nature of silicon in different types of fibre is not known. It could exist as orthosilic acid, polymeric silicic acid, colloidal silica (opal), dense silica concentrations, or in the form of organically bound derivatives of silicic acid (silanolates). Possible mechanisms of action are discussed.
 ...
PMID:Silicon, fibre, and atherosclerosis. 6 65

Silicon is a constituent of connective and elastic tissues. Administered intravenously or per os in rabbits, it inhibits experimental atheromas normally induced by an atheromatous diet, making atheromatous plaques much rarer and lipid deposits more superficial. Though the mechanism of silicon's antiatheromatous action remains shadowy, the impermeability's rise of the arterial wall is probably not the only influencing factor, because the arterial walls of animals under silicon do show a higher lipid concentration with respect to control animals. The preservation of the structure of elastic fibers, as well as of ground substance, and the absence of an increase in oleic acid in the aortic wall may also explain the rareness of atheromatous plaques.
Atherosclerosis 1979 Aug
PMID:The antiatheromatous action of silicon. 50 83

BALT magic catheter (PURSIL catheter) is a new catheter which is more flexible and plaint than the TRACKER-18 catheter because its mid-section and distal portion are made from polyurethane and silicon rather than polyethylene. Because the PURSIL catheter is flexible, it cannot be inserted with a guide wire, although it can be inserted into circulation during injection of contrast medium. Its inner diameter, 3.5mm, is smaller than that (5mm) of the TRACKER. There are few reports of embolization with the PURSIL catheter, and these describe only embolization using adhesive liquid embolus material. Embolization using small particles through the PURSIL catheter has never been reported. We report the catheterization using the PURSIL catheter of 26 arteries in 15 patients. The catheter was used for superselective angiography to clarify feeder and amytal tests in 5 patients with AVM, and embolization using PVA particles (150-250 microns) was performed in 1 patient with AVM, 3 patients with dural AVM, 4 cases with meningioma and 1 patient with vertebral aneurysm. Small PVA particles were easily injected without resistance through this catheter. In only one patient with dural AVM, was catheterization with this catheter not successful, and that was because the distal portion of the internal maxillar artery was extremely tortuous because of severe atherosclerosis. No complications associated with the use of this catheter were observed. We think that the greatest advantage of this catheter is the safety afforded by not using a guide wire. A disadvantage of this catheter is that, because of its small inner diameter, only small particles, or liquid embolus material can be injected through it.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Experience with BALT magic catheter (PURSIL catheter); especially investigation about advantage, disadvantage and the applications]. 150 11

The silicon (Si) content and glycosaminoglycans (GAG) of normal, fatty streaks and atheroma of human aortic intima was measured. The Si content in fatty streaks and/or atheroma was significantly higher than in normal human aortic intima (P less than 0.05). The GAG content in human aortic intima was inversely correlated with the severity of atherosclerosis as described in many reports. However, the percentage composition of dermatan sulphate (DS) in total GAG was found to increase with the advance of atherosclerosis, and was significantly higher than that in normal and fatty streaks (P less than 0.001, P less than 0.01, respectively). In human aortic intima, a significant negative correlation was seen between Si content and the content of each GAG except GlcUA-GalNAc-6-sulphate (CS-6-S), and a significant positive correlation was noted between Si content and the content of each lipid. Interestingly, the percentage composition of DS in total GAG showed a significant positive correlation with Si content in human aortic intima (r = 0.603, P less than 0.005). These results suggest the increase in Si in the aortic intima is related to the occurrences and/or progression of atherosclerosis, whether primary or secondary.
 ...
PMID:Silicon contents in normal, fatty streaks and atheroma of human aortic intima: its relationship with glycosaminoglycans. 397 Aug 27

Experiments on 50 rabbits examined the hemostatic effects of negative oxygen aeroions (AI). In control experiments, keeping the animals under hypodynamia led to 40% animal death, significant aortic atherosclerosis and myocardial infarction. The animals developed the thrombohemorrhagic syndrome with hypercoagulemia and drastically suppressed blood fibrinolytic activity. Keeping the animals in the excess AI-containing premise saved all rabbits' life and prevented arteriosclerosis and myocardial infarction. Unlike the controls, these animals failed to develop the thrombohemorrhagic syndrome. Clotting time, plasma recalcification time, and plasma silicon and kaolin time did not reduce, but prolonged. There was no drop in the content of antithrombin III or rise in values of paracoagulation tests. It is recommended that Chizhevsky's electroeffluvial chandeliers should be used to prevent hemostatic disorders and arteriosclerosis in hypodynamia.
 ...
PMID:[Effect of oxygen aeroions on hemostasis and development of arteriosclerosis in hypodynamia]. 875 44

The pathogenesis of arteriosclerosis and of restenosis after angioplasty is linked with an inflammatory and fibroproliferative response of the arterial tissue. We have induced a non-infectious inflammation by implanting a silicon-copper cuff around rat carotid arteries. The copper ions released from the oxidized copper initiate and mimic all morphological features of post-angioplasty restenotic and arteriosclerotic lesions. The copper-induced lesions were analyzed by electron and light microscopy, immunohistochemical methods and quantified by morphometry. During the first phase of copper-induced tissue reaction (3 days), macrophages and polymorphonuclear leucocytes invaded through the endothelium, accumulated in the subendothelial space and triggered the proliferation of smooth muscle cells which then migrated from the tunica media through the lamina elastica interna into the intima. Within 3 weeks, the accumulated smooth muscle cells, macrophages, leucocytes and newly synthesized extracellular matrix formed a circular mostly eccentric fibrotic thickening that narrows the vessel lumen by 30-40%. The accompanying structural disorganization of the medial layer led to focal rupture and aneurysm-like dilatation of the vessel wall in 3 of 11 animals between day 20 and 43. The neointima progressively increased in thickness over time leading to corresponding reduction of the vessel lumen. The carotid arteries of control animals and animals treated with copper-free silicon cuffs showed no abnormal pathological appearance. Our results show that inflammation-inducing agents can contribute to and simulate restenosis- and arteriosclerosis-like lesions and that the copper-cuff model may be useful in the exploration of new approaches to intervention.
Atherosclerosis 1997 Apr
PMID:Copper-induced inflammatory reactions of rat carotid arteries mimic restenosis/arteriosclerosis-like neointima formation. 912 45

Recent improvements in intravascular magnetic resonance imaging techniques mandate an accurate method of monitoring the introduction of MR catheter probes into the vessel of interest. For this purpose, a novel imaging protocol and a display method have been designed. First, a roadmap 3D image data set with standard pulse sequences is obtained using an external imaging coil. Subsequently, using very narrow rectangular-FOV fast-spoiled gradient recalled (SPGR), a movie of the percutaneous placement procedure of an MR catheter probe is acquired at a rate of 7.3 frames/second. In this protocol, the probe is used to transmit RF pulses and receive MR signal. A computer program was written for image unwrapping and for displaying the unwrapped movie frames on the roadmap image. In an alternative protocol, the movie frames in two projection angles were acquired in an interleaved fashion. Frames were unwrapped and combined with a 3D roadmap and displayed on a Silicon Graphics workstation equipped with stereovision goggles. Using these methods, percutaneous catheter placement in a phantom and a dog was examined. In conclusion, a new visualization technique for MR catheter placement is proposed. Combining this technique with high resolution intravascular MRI techniques may result in a very useful diagnostic tool for the evaluation of atherosclerosis and other vessel diseases.
 ...
PMID:Catheter-tracking FOV MR fluoroscopy. 984 Aug 31

Estrogen deficiency, hyperinsulinemia, type II diabetes, atherosclerosis, and a past history of elevated blood pressure may be associated with increased risk of Alzheimer's disease (AD). Common to all of these risk factors is a diminished capacity of vascular endothelium to generate nitric oxide (NO). Vascular NO has the potential to enhance the membrane polarization of cerebral neurons by increasing the open probability of calcium-activated potassium channels; this may protect neurons from the excessive calcium influx, potentiated by beta-amyloid peptides that is thought to mediate neuronal damage in AD. The possibility that NO/cyclic guanosine 3', 5'-phosphate (cGMP) may modulate the synthesis or processing of the amyloid precursor protein, also merits evaluation. Practical measures for promoting vascular NO production may include increased intakes of arginine, potassium, antioxidants, and fish-oil, as well as lifestyle measures that typically lower elevated blood pressure; potential benefits of chromium, glucosamine, and silicon should also be explored. In hypertensives, angiotensin-converting enzyme (ACE) inhibitors and sodium restriction may favorably influence endothelial function. Fish-oil should have the additional benefit of antagonizing the contribution of interleukin-1 to AD pathogenesis. Ancillary anti-excitotoxic measures such as magnesium, taurine, phenytoin, and vasodilators targeting ATP-dependent potassium (KATP) channels, may likewise reduce AD risk. Most of the nutritional measures suggested here would in any case be recommendable for preservation of vascular health.
 ...
PMID:Vascular nitric oxide may lessen Alzheimer's risk. 1005 65

Silicon is recognised as a protective trace element in atherosclerosis by epidemiologic and biochemical studies. The goal of the present work was the evaluation of the antiatheromatous effect of the natrium silicate in an experimental trial on 30 rabbits given a standard diet (control), an atherogenic diet (L1 lot) and a natrium silicate-supplemented atherogenic diet (L2 lot), by comparing the variation of the lipid pictures between each of the experimental lots and control. Levels of total lipids, cholesterol, triglycerides (TG), free fatty acids (FFA) and phospholipids indicated that the natrium silicate supplemented to the atherogenic diet minimised the lipid metabolism unbalance by keeping constant the level of FFA and TG in rabbits.
 ...
PMID:Serum lipid picture of rabbits fed on silicate-supplemented atherogenic diet. 1075 93

Cardiovascular disease is the primary cause of morbidity and mortality in the western world. Complex hemodynamics play a critical role in the development of atherosclerosis and the processes of aging, as well as many other disease processes. Biofluid mechanics play a major role in the cardiovascular system and it is important to understand the forces and movement of blood cells and whole blood as well as the interaction between blood cells and the vessel wall. Fundamental fluid mechanical, which are important for the understanding of the blood flow in the cardiovascular circulatory system of the human body aspects are presented. Measurement techniques for model studies such as LDA, ultrasound, and MRI studies will be discussed. Viscosity and flow behavior changes specifically the creation of vortices and flow disturbances can be used to show how medication can influence flow behavior. Experiments have shown that hemodynamics may have a strong influence on the creation of aneurysms and varicose veins. Other factors such as vessel wall structure are also important. In preliminary studies, it has been demonstrated that geometry and elasticity of vessel walls help determine flow behavior. High velocity fluctuations indicate flow disturbances that should be avoided. Health care practitioners must understand fluid dynamic factors such as flow rate ratio, pressure and velocity gradients, and flow behavior, velocity distribution, shear stress on the wall and on blood cells. These mechanical factors are largely responsible for the deposit of blood cells and lipids, a leading cause of atherosclerosis. The interaction between blood cells and of the cells with the vessel, leads to the formation of plaques and agglomerations. These deposits are found predominantly at arterial bends and bifurcations where blood flow is disturbed, where a secondary flow is created, and where flow separation regions are found. Experiments on hemodynamic effects in elastic silicon rubber models of the cardiovascular system with flow wire, stents, or patches for vessel surgery will be discussed. These studies can be important in improving diagnostics and therapeutic applications.
 ...
PMID:An introduction to biofluid mechanics--basic models and applications. 1193 11


1 2 3 4 Next >>