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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Trace metal contents of cerebral vessels in age-matched and sex-matched subjects from three population groups were estimated. The trace metals included calcium, manganese, zinc, magnesium, copper and iron. The American blacks in Washington, D.C., who are ethnologically related to Nigerian Africans, have different patterns of trace metal contents in their cerebral vessels and the observed levels also differed in some respects from Minnesota Caucasians living in a similar environment. The greatest amounts of calcium, zinc, and copper were found in the vessels of American blacks while the greatest amount of magnesium was found in vessels of Minnesota Caucasians. There was no statistically significant difference in the manganese content of the cerebral vessels in three population groups. Nigerian Africans had the least amounts of copper and magnesium but had the highest iron content. A similar high level of iron was observed in the vessels of American blacks. Since it has been shown that American blacks have the most extensive and severe degree of atherosclerosis among the three population groups, it would appear that iron, calcium and manganese in the cerebral vessels may not directly relate to the severity of cerebral atherosclerosis. Relatively high levels of copper and magnesium, which were observed in the cerebral vessels of American blacks and Caucasians, may be of significance in the pathogenesis of cerebral atherosclerosis. The low levels of the trace metals in Nigerians may be protective. The possible role of zinc requires further studies.
Stroke
PMID:Trace metal content of cerebral vessels in American Blacks, Caucasians and Nigerian Africans. 119 34

Optimization of the contrast-to-noise ratio (CNR) is described for microcirculation magnetic resonance (MR) imaging techniques based on flow-compensated/flow-dephased sequences, both with and without even-echo rephasing. The authors present the most advantageous manner of applying flow-dephased gradients, such that dephasing is maximal while diffusion losses are minimal. The theoretical considerations include phase, diffusion, echo time, and bandwidth in the determination of the optimal parameters for microcirculation imaging. Studies in phantoms consisting of stationary and flowing copper sulfate in Sephadex columns demonstrate the validity of the calculations. Optimized in vivo images of a rat stroke model demonstrate the potential of the flow-compensated/flow-dephased technique and the importance of optimizing CNR.
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PMID:Maximization of contrast-to-noise ratio to distinguish diffusion and microcirculatory flow. 180 29

The role of oxygen-derived free radicals, superoxide in particular, in the pathogenesis of neuronal cell death induced by glutamate was studied using cultured cortical neurons from transgenic mice overexpressing human copper-zinc-superoxide dismutase. Primary cortical neuron cultures were developed from 15-day-old fetuses of both transgenic mice and their normal littermates. Both human copper-zinc-superoxide dismutase and host mouse copper-zinc-superoxide dismutase activities in cultured neurons were identified by native gel electrophoresis followed by nitroblue tetrazolium staining. Cultured neurons grown for 10-12 days in vitro were exposed briefly to 0.5 mM glutamate for 5 minutes, followed by biochemical and morphological examinations at 2, 4, and 24 hours. Our data have demonstrated that glutamate neurotoxicity is significantly reduced in transgenic neurons at 2 and 4 hours following exposure to glutamate, as measured by the efflux of lactate dehydrogenase, the 3-O-methyl glucose space, and by phase-contrast and bright-field trypan blue staining. These data indicate that transgenic neurons containing twofold to threefold the normal amount of copper-zinc-superoxide dismutase activity as the result of expression of the human copper-zinc-superoxide dismutase transgene are protected against glutamate neurotoxicity in vitro. Our results suggest that oxidative stress, at least in part, plays an important role in the biochemical pathways amplifying N-methyl-D-aspartate receptor-mediated neurotoxicity.
Stroke 1990 Nov
PMID:Reduced neurotoxicity in transgenic mice overexpressing human copper-zinc-superoxide dismutase. 223 89

Experimental in situ thrombosis of the middle cerebral artery was produced in dogs by use of intravasally placed copper coils, which subsequently gave rise to an obstructing autologous thromboembolus. The resulting thrombosis was produced in the middle or rostral cerebral artery within 5-15 minutes after delivery of the thrombogenic device. The correlation of location of the coil in the intracranial vasculature of the internal carotid artery with the anatomic distribution of resulting cerebral infarcts suggests that this experimental model can produce a selective acute local occlusion of cerebral vessels in a high proportion of dogs without violating the cranium. The composition of the autologous thromboembolus, the low mortality rate, and the excellent reproducibility will make the correlative study of thrombolytic agents and their therapeutic efficacy possible.
Stroke 1988 Jun
PMID:New model of cerebral thrombosis in dogs. 337 66

Male rabbits received 20 micrograms/ml of cadmium in drinking water for nine months. At the end of the treatment aortic vascular resistance was increased, whereas maximum rate of increase in left ventricular pressure, aortic blood flow, stroke volume, cardiac output, left ventricular minute work, and left ventricular stroke work were reduced. Arterial blood pressure, heart rate, and the index of myocardial oxygen consumption were not modified. The exposed rabbits also showed reduced pressor responses to vagotomy, increased cardiovascular responses to angiotensin I and II and isoprenaline, and lower responses to serotonin and guanethidine; the bradycardia induced by clonidine was augmented; the cardiovascular effects of bilateral carotid occlusion, hexamethonium, phenylephrine, histamine, acetylcholine, tyramine, papaverine and verapamil were unaltered. In the treated rabbits cadmium was appreciably higher in the kidney than in the heart; however, renal concentrations of cadmium were lower than those reported as critical for workers exposed to cadmium. Zinc was increased in the kidney but not in the heart, whereas copper remained unchanged in the examined organs. In rabbits treated with cadmium the increased aortic vascular resistance and the reduced myocardial contractility contribute to preserve a haemodynamic equilibrium without alteration of blood pressure and heart rate; the question of whether a similar condition may be present in people exposed to cadmium with normal cardiovascular parameters is discussed.
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PMID:Mechanisms of cardiovascular regulation in male rabbits chronically exposed to cadmium. 375 11

To study the mechanism of dyslipoproteinemia, lipoproteins [very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL)] were isolated from stroke patients and healthy persons by ultracentrifugation. Lipoproteins were dialyzed into copper dichloride solution to study the effects of soycreme administration on lipoprotein peroxidation. Blood was drawn from 15 patients with cerebral thrombosis who were not administered soycreme, 10 patients with cerebral thrombosis who were administered soycreme and 11 healthy persons. The lipoproteins were dialyzed into 5 mol/l copper dichloride solution for various lengths of time, and then lipid constituents in the lipoproteins were measured by thin-layer chromatography. After the dialysis, percentages of cholesteryl ester and triglyceride in various lipoproteins decreased significantly (P < 0.05 or 0.01) in both patient groups and in healthy persons. Spot X1 was found between triglyceride and free fatty acid on the thin-layer chromatography, and spot X2 was located between free fatty acid and free cholesterol after dialysis. Spots X1 and X2 reflect lipoprotein peroxidation. Percentages of these spots were higher in VLDL, LDL and HDL in the patient groups than in the healthy subjects. Soycreme administration suppressed the appearance of spots X1 and X2. Furthermore, blood cholesterol concentrations were reduced by the administration of soy protein. Thus, soy may be useful in the prevention and/or treatment of atherosclerosis.
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PMID:Protective effects of soy protein on the peroxidizability of lipoproteins in cerebrovascular diseases. 788 46

The increased production of reactive oxygen metabolites in the central nervous system may result in cellular damage and vascular-parenchymal injury. Vascular injury is also a cause of the vasoregulation deficiency. In this case report, a 60-year-old woman was admitted to the department of neurology, with a diagnosis of cerebrovascular accident. During 18 days of follow-up, the status of the antioxidant system was determined by measuring red cell superoxide dismutase and catalase activity. Red cell and plasma copper, zinc and magnesium concentrations were also measured. Red cell superoxide dismutase activity increased markedly by Day 2, reached a peak on Day 6 before decreasing to normal 18 days after the injury. Red cell catalase activity was below normal values during the whole of the 18-day study period and was at its lowest between days 6 and 7. Plasma copper, zinc and magnesium concentrations showed corresponding alterations.
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PMID:Antioxidant defence system in a patient with cerebrovascular accident. 885 93

This in vitro study evaluated the wear resistance of a high-strength resin posterior denture tooth against eight opposing dental materials. The tooth specimen was cusp shaped and the opposing materials were formed as a 10 x 10 x 5 mm plate. All material combinations were tested using a machine designed to produce sliding contact 20 x 10(4) times at 60 cycles per minute and a 4-mm sliding distance per stroke in the buccolingual direction under a load of 1 kg. Wear analysis was measured as the total height loss of each material combination and the volume loss of each material. Wear against human enamel was evaluated as a control. The least loss was observed opposing a gold-silver-palladium-copper alloy, and the greatest loss was observed opposing porcelain. The volume loss of high-strength resin against gold-silver-palladium-copper alloy was as small as that against human enamel. High-strength resin wear was more significant against castable ceramics and porcelain. The volume losses of high-strength resin against high-strength resin, polycarbonate, or cobalt-chromium alloy were significantly larger than those against polyethersulfone, poly(methyl methacrylate), gold-silver-palladium-copper alloy, or human enamel. These findings suggest that the were resistance of high-strength resin is influenced considerably by opposing dental materials, and that the best combination was high-strength resin-gold-silver-palladium-copper alloy, and the poorest combination was high-strength resin-porcelain.
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PMID:An in vitro study of high-strength resin posterior denture tooth wear. 948 67

Dietary copper deficiency in animals is often associated with cardiac enlargement and anemia. In this study we examined the hypothesis that anemia leads to a high cardiac output state that results in work-induced (physiological) cardiac hypertrophy. Blood pressure was measured by carotid cannulation and cardiac output was measured by aortic flow probe in anesthetized, open-chested rats that had been subjected to various degrees of dietary copper deficiency for five weeks. Cardiac output was unaffected by dietary copper deficiency. However, the components of cardiac output were found to vary reciprocally, heart rate decreasing and stroke volume increasing with copper deficiency. Further, total peripheral resistance, calculated as the ratio of mean arterial blood pressure and cardiac output, was depressed by dietary copper deficiency. These findings suggest that bradycardia and depression of vascular resistance induced by copper deficiency contribute to increased venous filling and a resultant increase in stroke volume; these factors may lead to cardiac hypertrophy. A significant correlation between stroke volume and heart weight in rats of varying copper status supports this conclusion.
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PMID:Cardiovascular measurements relevant to heart size in copper-deficient rats. 1044 15

It has been reported in the epidemiological literature that cataract, stroke, and atherosclerosis risk is reduced by 50% in people consuming one alcoholic drink per day. Peroxide has been implicated as a causative agent in cataractogenesis, and LDL oxidation appears to play a role in atherosclerosis. The antioxidant activity of alcohol was measured by: (i) use of a luminescent assay developed in our laboratory, confirmed as appropriate; (ii) electron spin resonance (ESR) spin-trapping; and (iii) copper-catalysed oxidation of LDL and VLDL from hamsters fed 6% ethanol in their drinking water. Ethanol reduced the luminescent counts/min from peroxide and superoxide. It significantly reduced the spin-trapped signal of hydroxyl radical, but not the superoxide signal. Other alcohols also showed large reductions in counts from hydrogen peroxide. Plasma from hamsters fed 6% ethanol had lower lipid peroxides and the oxidizability of LDL and VLDL was significantly reduced compared to controls. These data provide a possible explanation for the effect of beverages containing ethanol in the reduction of cataract and atherosclerosis risk observed in human population studies.
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PMID:Is ethanol an important antioxidant in alcoholic beverages associated with risk reduction of cataract and atherosclerosis? 1049 11


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