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)

An aged male roseate flamingo, in a private collection in the British Virgin Islands, was found acutely "down." After four days of supportive therapy, the flamingo succumbed. At necropsy gross lesions included emaciation; collapsed and thickened, yellow abdominal air sac; dark red liver, partially covered by friable yellow material; and a raised, intimal plaque in the aorta near the iliac trifurcation. Histologic examination revealed severe, diffuse, pyogranulomatous air sacculitis with associated locally extensive pleuroperitonitis/perihepatitis. Pansystemic, predominantly periarteriolar distribution of amyloid deposition was evident, as was massive intrahepatocellular accumulation of iron pigment (hemachromatosis/hemosiderosis). A locally extensive, nonobstructive, fibroatheromatous plaque was present in the distal aorta. Amyloidosis, hemochromatosis/hemosiderosis, and atherosclerosis have been recognized in Phoenicopteriformes and other marine or aquatic birds. Their pathogenesis and pathogenicity remain a matter of debate.
 ...
PMID:Amyloidosis, hemochromatosis, and atherosclerosis in a roseate flamingo (Phoenicopterus ruber). 162 69

Low density lipoprotein (LDL) is routinely isolated and stored in buffers containing ethylene-diaminetetra-acetic acid (EDTA) to inhibit its autoxidation. We have investigated the effect of EDTA on LDL oxidation by both copper ions and macrophages. LDL oxidation by macrophages in Ham's F-10 medium containing 6 microM iron showed a large and concentration-dependent increase when EDTA was added up to about 10 microM. EDTA concentrations above about 10 microM progressively inhibited LDL oxidation as measured by macrophage degradation, thiobarbituric acid-reactive substances and electrophoretic mobility. The oxidation of LDL by 1 microM copper in Ham's F-10 medium, measured by macrophage degradation, also showed a large increase with low concentrations of EDTA (1-3 microM), with higher concentrations (10 microM or above) strongly inhibiting the oxidation. In a simple phosphate buffer, however, EDTA simply inhibited the oxidation of LDL by copper with equimolar amounts of EDTA to copper giving a complete inhibition. The results of this study indicate that when LDL oxidation by cells or by copper in Ham's F-10 medium is investigated, more oxidation may be obtained if the EDTA is not previously removed from the LDL preparation.
Atherosclerosis 1992 May
PMID:The effect of EDTA on the oxidation of low density lipoprotein. 163 57

The long-term tolerance to and effectiveness of heparin-induced extracorporeal LDL precipitation (HELP) in combination with lipid reducing drugs and diet was tested in six patient (5 males, 1 female; mean age 48 +/- 4 years). Follow-up period was over 50 months, in one patient over 24 months, while one man had a sudden cardiac death 57 weeks after starting treatment. The study was divided into three phases. In phase I (24 months) treatment consisted of HELP and conventional lipid-reducing drugs; in phase II (12 months) of lovastatin (80 mg daily) and cholestyramine (12-24 g daily); and phase III (14 months) of HELP, lovastatin and cholestyramine. In phase I it was possible to lower the pre-treatment level of LDL-cholesterol from 306 +/- 18 mg/dl to 173 +/- 13 mg/dl (43.5%). A similar effect (from 307 +/- 21 mg/dl to 155 +/- 17 mg/dl [-49.5%]) was obtained in phase II. The resumption of HELP reduced the pre-treatment LDL concentration to 136 +/- 9 mg/dl (-55.7%). The various treatment regimens were well tolerated. Biochemical data remained unchanged except for iron loss requiring substitution. Thus combined HELP, lovastatin and ion exchange offer for the first time an effective and reliable means in familial hypercholesterolaemia of clearly reducing long-term the mean LDL cholesterol level below the atherosclerosis threshold of 120 mg/dl.
 ...
PMID:[The long-term therapy of familial hypercholesterolemia with heparin-induced extracorporeal LDL precipitation]. 163 60

In this study the correlation between hemispherical ischemic symptoms and the presence of intraplaque hemorrhage in carotid plaques has been evaluated. 38 patients who had undergone carotid endarterectomy were examined clinically and the specimens obtained from operation were studied morphologically. The patients were divided into two groups, asymptomatic and symptomatic regarding the territory of the supplying carotid artery. The presence of intraplaque hemorrhage, shown by Ladewig's Trichrom stain, as well as evidence of iron, immunohistochemical stain of hemoglobin and native fluorescence microscopy was noted, and, according to their extension, classified into three degrees. As a result, there was neither a correlation between history of ischemic brain symptoms and the presence of intraplaque hemorrhage, nor between clinical symptoms and extension of hemorrhage. The plaques were high degree stenotic (greater than 80%) in most of the patients and showed various degenerative changes. In 97% of all plaques with hemorrhages surface defects were seen. Our results confirm that intraplaque hemorrhage is one out of a series of pathological events which occurs during advanced atherosclerosis. Blood inflow from the lumen through an already damaged plaque surface is a common event and a correlation with the onset of symptoms is unlikely.
 ...
PMID:Clinical relevance of intraplaque hemorrhage in the internal carotid artery. 167 27

Oxidized lipoproteins have been identified in atherosclerotic plaques and in early lesions in humans as well as in animals. There is accumulating evidence that such oxidized lipoproteins have an important role in atherosclerosis. Treatment of endothelial cells with altered lipoproteins stimulates monocyte binding as well as the production of chemotactic factors for monocytes. Both these findings could be relevant to the accumulation of monocytes-macrophages in the arterial wall during the early stages of lesion development. We now report that treatment of endothelial cells (EC) with modified low-density lipoproteins obtained by mild iron oxidation or by prolonged storage, results in a rapid and large induction of the expression of granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage CSF (M-CSF) and granulocyte CSF (G-CSF). These growth factors affect the differentiation, survival, proliferation, migration and metabolism of macrophages/granulocytes, and G-CSF and GM-CSF also affect the migration and proliferation of EC. Because EC and macrophages are important in the development of atherosclerosis, the expression of the CSFs by these cells could contribute to the disease.
 ...
PMID:Induction of endothelial cell expression of granulocyte and macrophage colony-stimulating factors by modified low-density lipoproteins. 169 Mar 54

The beneficial effects of combined estrogen-progestin-containing oral contraceptives (OCs) include prevention of pregnancy (less than 1 failure out of 100 regular users); the prevention of ectopic pregnancy; the reduction of preeclampsia (2.4 times lower risk compared with barrier methods); and reduction of pelvic inflammation to about one-half. The effects on menstruation include the reduction of sideropenic anemia (by lowering the incidence and duration of menstruation, OCs reduce the loss of iron to 50% or to as much as 33%); dysmenorrhea by 40% (symptoms receded in 90% of users); and premenstrual syndrome by 30%. OCs exert a favorable effect on menstrual epilepsy; reduce sports-related accidents in the premenstrual and menstrual periods; and reduce intermenstrual bleeding. The protection from cancer includes the lowering of endometrial cancer risk (every 2 years of use reduces the risk by 38%, 12 years of use by 70%, and the beneficial effects last 3-15 years); reduction of the risk of the ovarian cancer (already 3-6 months of use reduces the risk by 30%, and more than 5 years by 50% in women under 50 years of age with a longterm effect of 10 years or more, which drops sharply in women over 60 who are mostly at risk). Among other beneficial effects, they reduce benign mastopathy by 50-75%; reduce the risk of follicular ovarian cysts to 50% and the risk of corpus luteal ovarian cysts to 1/5; and they lessen bone loss which favorably affects osteoporosis. Low-dose OCs minimize the well-known risks of thrombotic and cerebrovascular accidents, myocardial infarction, hypertension, altered carbohydrate metabolism, gallbladder diseases, and liver cancer. A new OC with 30 mcg of ethinyl estradiol was tested with daily doses of 150 mcg of desogestrel. The high density lipoprotein (HDL) either increased or did not change with desogestrel: the HDL2 subfraction that protects from atherosclerosis did not change, and probably the HDL3 raised the HDL level.
 ...
PMID:[Favorable effects of oral estrogen-progestin contraception]. 181 41

The biochemical mechanisms by which hypertension accelerates atherosclerosis and increases the risk of aortic aneurysm rupture are poorly understood. This study evaluates the effects of hypertension on aortic trace element concentrations and antioxidant status in tissue removed from 26 normotensive (NT) and 20 hypertensive (HT) patients. Twenty-seven of 46 patients (59%) had aneurysmal (AA), and 19 of 46 (41%) had occlusive disease (OD). Aortic iron concentrations were markedly higher in both OD and AA tissue compared with controls. A similar trend was observed with copper concentrations, with the highest elevations observed in HT AA tissues. No significant differences were observed in zinc concentrations, except that HT AA aorta had significantly lower zinc levels than either OD or control tissue. Aortic ascorbic acid concentrations in diseased aorta were lower than those of controls, but independent of blood pressure. Copper-zinc-superoxide dismutase activity was similarly reduced, with the lowest activity observed in diseased aorta from HT patients. Only HT AA aorta had significantly higher manganese-superoxide dismutase activity than controls. The aortas of patients with AA had significantly lower amounts of elastin and greater elastase activity than either controls or those with OD. However, the differences were independent of blood pressure. Hypertensive patients with OD and AA had 31% more and 27% less aortic collagen, respectively, than their NT counterparts (P less than 0.05). These data suggest that the reduction in aortic collagen and elastin in HT patients with AA compared with their NT counterparts may explain the larger size of aneurysms and predispose to their eventual rupture. Furthermore, the diminished antioxidant status associated with HT predisposes to lipid peroxidation, which contributes to the acceleration of these processes. Our studies were conducted in patients with established aortic aneurysmal and occlusive disease. Whether these observations are pertinent to the pathogenesis of AA and OD remains unclear and merits further study.
 ...
PMID:Effects of hypertension on aortic antioxidant status in human abdominal aneurysmal and occlusive disease. 199 4

Minimally modified low density lipoprotein (MM-LDL), derived by mild iron oxidation or prolonged storage at 4 degrees C, has been shown to induce certain inflammatory responses in vascular cells in tissue culture. These include induction of monocyte (but not neutrophil) adherence to endothelial cells (EC), induction of EC production of colony stimulating factors (CSF), and induction of EC and smooth muscle cell production of monocyte chemotactic protein (MCP-1). To test for biologic activity in vivo, microgram quantities of MM-LDL were injected into mice, sera were assayed for CSF activity, and tissues were subjected to Northern analysis. After injection of MM-LDL, CSF activity increased approximately 7-26-fold but remained near control levels after injection of native LDL. Essentially all of the induced CSF activity was due to macrophage CSF as judged by antibody inhibition. Injection of MM-LDL into a mouse strain (C3H/HeJ) that is resistant to bacterial LPS gave similar results, indicating that the induction of CSF was not due to contaminating LPS and suggesting that there are differences in the pathways by which LPS and MM-LDL trigger cytokine production. In addition, after injection of MM-LDL, mRNA for JE, the mouse homologue of MCP-1, was markedly induced in various tissues, but was not induced after injection of native LDL. We conclude, therefore, that MM-LDL is biologically active in vivo and may contribute to the early stages of atherosclerosis by acting as an inflammatory agent.
 ...
PMID:Minimally modified low density lipoprotein is biologically active in vivo in mice. 204 Jul 5

Transitional metals, particularly iron, markedly potentiate oxidant damage to isolated cell organelles. However, determining the probable importance of iron in damage to intact cells is difficult because of our inability experimentally to increase the cell content of this transition metal. We now report that heme is a uniquely effective iron delivery vehicle, capable of loading large amounts of potentially reactive iron into intact cells. We find that endothelial cells in vitro rapidly incorporate free heme and this heme-loading sensitizes endothelium to oxidant-mediated cytotoxicity caused by hydrogen peroxide, the hypoxanthine/xanthine oxidase system, or phorbol-stimulated PMN. Although the precise mechanism of the heme-aggravated cytotoxicity is not yet known, it closely parallels amplified lipid peroxidation in endothelial cell membranes suggesting the importance of lipid injury. Hemopexin, by complexing heme, protects endothelial cells from activated PMN, but only if added simultaneously. The hydrophobic iron chelator and antioxidant, U74500A, abrogates heme-augmented hydrogen peroxide and PMN-mediated endothelial damage. Such compounds, therefore, may have therapeutic potential in one or more of the listed clinical syndromes. We speculate that exposure of endothelium to free heme may potentiate vascular damage in various clinical syndromes, including acute renal failure after massive intravascular hemolysis, crush injuries, reperfusion after myocardial infarction (perhaps secondary to cardiac myoglobin release), retrolental fibroplasia associated with neonatal hemopexin deficiency, and, perhaps, atherosclerosis involving sites of turbulence that may trigger minor red blood cell lysis.
 ...
PMID:Heme uptake by endothelium synergizes polymorphonuclear granulocyte-mediated damage. 213 29

Atherosclerosis and hypercholesterolemia have been produced in rabbits since 1913 by feeding them cholesterol. These experiments have a great influence on current thinking about the etiology and possible prevention of ischemic heart disease. Male, New Zealand White rabbits were fed 0.5% dietary cholesterol. Cholesterol and copper in plasma increased sixty-fold and 50%, respectively. Liver copper decreased 74% and hematocrit decreased 26%. Iron was unchanged in heart and liver, but was increased in kidney. Zinc was decreased in heart, but was unchanged in liver or kidney. Changes in organ iron and zinc were smaller than the decrease in liver copper. Similar experiments with higher doses of dietary cholesterol may have resulted in copper deficiency. It may be appropriate to revise interpretations of data from these experiments and to reformulate hypothesis based on the data. Results are consonant with the theoretical implication of copper metabolism and copper deficiency in the etiology and pathogenesis of ischemic heart disease.
 ...
PMID:Dietary cholesterol lowers liver copper in rabbits. 248 35


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>