Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In rats, a single administration of acrylonitrile (vinyl cyanide) produces a rapidly occurring bilateral adrenal apoplexy. Structure-activity studies have shown that a close derivative, propionitrile (ethyl cyanide), causes duodenal ulcer without markedly affecting the adrenal glands. Prolonging the two-carbon chain of propionitrile by a methyl group (n-butyronitrile) enhances, replacing the methyl by bromide or nitrile decreases, while substitution by an amino group abolistes the ulcerogenic potency and variably affects the adrenocorticolytic action. On assaying a large number of nonnitrile compounds as well for ulcerogenic effect, such as thiols and amines, this effect was found to be related to a two-carbon structure bearing electronegative radicals on one or both ends of the chain.
 ...
PMID:Structure-activity relationships for ulcerogenic and adrenocorticolytic effects of alkyl nitriles, amines, and thiols. 117 50

Longitudinal stretch of the rabbit basilar artery produces local injury followed by prolonged circular constriction. After stretching and rapid release in vitro localized constrictions promptly occurred. This could be prevented by prior treatment with cyanide or calcium-free solution. Once produced, constrictions persisted for more than 72 hours. Previously induced constriction was not reversed by treatment for two hours with cyanide or by removing calcium. Histological observation indicated that constricted areas were associated with a discrete circumferential rupture of the internal elastic lamina and disruption and thinning of the underlying media. Specific catecholamine fluorescence at the adventitio-medial junction was unchanged in constricted areas. The relationship between smooth muscle cell length and resting tension of artery segments with and without constrictions was compared. Segments with constrictions had a shorter muscle length for any given resting tension, which confirms that constriction was not due to passive collapse of the vessel wall. These findings suggest that injury of cerebrovascular smooth muscle may result in essentially irreversible vasoconstriction. Such a mechanism could contribute to the pathogenesis of prolonged cerebral vasospasm after SAH or traumatic injury to the cerebrum.
Stroke
PMID:An in vitro study of prolonged vasospasm of a rabbit cerebral artery. 126 10

Myonecrosis has been reported to occur in patients with carbon monoxide (CO) poisoning, and last year we reported a case of non-traumatic rhabdomyolysis in a patient with CO poisoning secondary to smoke inhalation. We prospectively studied the association between CO poisoning and rhabdomyolysis by obtaining serum creatine kinase (CPK) levels on 65 of 81 consecutive patients (range 20-1315 IU/L) who presented to the University of Illinois Hospital Emergency Room during a 3-month period with CO levels greater than 5.0% (range 5.0%-63.9%). Thiocyanate levels were obtained on 45 patients (range 0-3.5 mg/dl). We found no statistically significant correlation by linear regression analysis between CO level and CPK level in these patients. A subjective complaint of weakness was obtained in 4 patients and physical evidence of weakness was found in 1 of these (this was felt to be secondary to a cerebrovascular accident). In none of these 4 patients was an elevated CPK level noted. We did, however, note an association between thiocyanate level and CPK level by linear regression analysis (p less than 0.02). A power curve was a better fit for this data (r2 = 0.7). This data suggests that serum CPK levels should not be routinely obtained on patients with CO poisoning and that cyanide may play a more important role in non-traumatic rhabdomyolysis associated with toxic inhalation than had previously been suspected.
 ...
PMID:Carbon monoxide and myonecrosis: a prospective study. 292 21

From 1975 to 1993, our University Hospital performed 2789 graft procedures. During the same period, 12 poisoned, "brain-dead" patients were considered as organ donors. The toxic substances involved were: methaqualone (n = 1), benzodiazepine alone (n = 1), benzodiazepine plus tricyclic antidepressants (n =1), tricyclic antidepressants alone (n = 1), barbiturates (n = 2), insulin (n = 2), carbon monoxide (n = 1), cyanide (n = 1), methanol (n = 1), and acetaminophen (n = 1). From these intoxicated persons, 32 organ transplants were obtained, but only 23 could be followed for 1 month and only 20 for 1 year. The outcome at 1 month was favorable in 20 of the 23 patients. Two heart transplant patients died with 24h after grafting from stroke and acute heart failure, respectively. Preoperative hepatic encephalopathy was not corrected after grafting and was directly responsible for the death of a liver transplant patient. After 1 year, 15 of the 20 recipients were still alive. Chronic hepatic graft rejection led to a fatal outcome in one recipient and to second grafting in another. Finally, one recipient died from delayed neoplasia. Based on our experience, organ procurement may be considered in a few select cases of acute poisoning. Attention should, however, be drawn to possible graft damage due to some poisons.
 ...
PMID:Outcome following organ removal from poisoned donors: experience with 12 cases and a review of the literature. 762 77

Experience with organ procurement from poisoned donors in brain death status is still limited in comparison with other etiologies. From 1963 to 1993, 2769 grafts (heart 141, kidney 1922, liver 623, pancreas 43) were performed in our University Hospital. Since 1975, among 1174 patients admitted to the ICU for acute poisoning, 12 patients who developed brain death status were considered for organ donation. The toxics involved were: methaqualone (1), benzodiazepines (1), benzodiazepines plus tricyclic antidepressants (2), barbiturates (2), insulin (2), carbon monoxide (1), cyanide (1), methanol (1), and acetaminophen (1). Exclusion criteria for organ removal were applied according to the nature of the toxin and the general criteria used for organ donation. The organs removed were: heart 5, heart valves for graft bank 2, kidneys 22, liver 4, pancreas 2, pancrease islet cells 2. Pertinent follow-up was obtained in 23 of 32 recipients. Immediate outcome was favorable in 20/23 patients (85%). Three patients died either from stroke, heart failure or preexisting encephalopathy. Two patients died from either chronic hepatic or renal graft rejection. None of these events could be directly related to a toxic origin. The one year survival rate of 75% is similar to that observed in the population who received organs from nonpoisoned donors. Organ procurement can be considered in few selected cases of acute poisoning. The accuracy of the diagnosis of irreversible brain damage is essential in this setting.
 ...
PMID:Outcome following organ removal from poisoned donors in brain death status: a report of 12 cases and review of the literature. 852 98

Uric acid is a well-known natural antioxidant present in fluids and tissues throughout the body. Oxyradical production and cellular calcium overload are believed to contribute to the damage and death of neurons that occurs following cerebral ischemia in victims of stroke. We now report that uric acid protects cultured rat hippocampal neurons against cell death induced by insults relevant to the pathogenesis of cerebral ischemia, including exposure to the excitatory amino acid glutamate and the metabolic poison cyanide. Confocal laser scanning microscope analyses showed that uric acid suppresses the accumulation of reactive oxygen species (hydrogen peroxide and peroxynitrite), and lipid peroxidation, associated with each insult. Mitochondrial function was compromised by the excitotoxic and metabolic insults, and was preserved in neurons treated with uric acid. Delayed elevations of intracellular free calcium levels induced by glutamate and cyanide were significantly attenuated in neurons treated with uric acid. These data demonstrate a neuroprotective action of uric acid that involves suppression of oxyradical accumulation, stabilization of calcium homeostasis, and preservation of mitochondrial function. Administration of uric acid to adult rats either 24 hr prior to middle cerebral artery occlusion (62.5 mg uric acid/kg, intraperitoneally) or 1 hr following reperfusion (16 mg uric acid/kg, intravenously) resulted in a highly significant reduction in ischemic damage to cerebral cortex and striatum, and improved behavioral outcome. These findings support a central role for oxyradicals in excitotoxic and ischemic neuronal injury, and suggest a potential therapeutic use for uric acid in ischemic stroke and related neurodegenerative conditions.
 ...
PMID:Uric acid protects neurons against excitotoxic and metabolic insults in cell culture, and against focal ischemic brain injury in vivo. 972 32

Studies utilizing gene delivery to the nervous system indicate that various strategies are protective following acute neurological insults such as seizure and stroke. We have found that inhibitors of apoptosis are protective against excitotoxicity and heat stress but not energetic impairment in vitro. Here we studied the neuroprotective efficacy in vivo of these mediators: viral genes (crmA, p35, gamma34.5 KsBcl-2) that have evolved to suppress suicidal host responses to infection, by inhibiting apoptosis. We investigated these effects by utilizing modified herpes vectors to deliver the anti-apoptotic agents intracerebrally and examined them in the face of excitotoxic and metabolic insults. We found that p35 and gamma34.5 reduced by 45% a hippocampal CA3 lesion caused by kainic acid, while crmA and KsBcl-2 did not. None of the inhibitors protected the dentate gyrus of the hippocampus following 3-acetylpyridine, a hypoglycemia model, but we found crmA to worsen the damage. These data are similar to our results in neuronal cultures where the inhibitors protected against the excitotoxin domoic acid, but not against the metabolic poison, cyanide. Together, the results suggest that inhibitors of various apoptotic elements are capable of protecting under acute insult conditions both in vitro and in vivo, suggesting possible future therapeutic applications.
 ...
PMID:HSV-mediated delivery of virally derived anti-apoptotic genes protects the rat hippocampus from damage following excitotoxicity, but not metabolic disruption. 1185 25

We measured and manipulated intracellular potassium (K+) fluxes in cultured hippocampal neurons in an effort to understand the involvement of K+ in neuronal death under conditions of ischemia and exposure to apoptotic stimuli. Measurements of the intracellular K+ concentration using the fluorescent probe 1,3-benzenedicarboxylic acid, 4,4'-[1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diylbis(5-methoxy-6,2-benzofurandiyl)]bis-, tetrakis [(acetyloxy) methyl] ester (PBFI) revealed that exposure of neurons to cyanide (chemical hypoxia), glutamate (excitotoxic insult) or staurosporine (apoptotic stimulus) results in efflux of K+ and cell death. Treatment of neurons with 5-hydroxydecanoate (5HD), an inhibitor of mitochondrial K+ channels, reduced K+ fluxes in neurons exposed to each insult and increased the resistance of the cells to death. K+ efflux was attenuated, levels of oxyradicals were decreased, mitochondrial membrane potential was stabilized and release of cytochrome c from mitochondria was attenuated in neurons treated with 5HD. K+ was rapidly released into the cytosol from mitochondria when neurons were exposed to the K+ channel opener, diazoxide, or to the mitochondrial uncoupler, carbonyl cyanide 4(trifluoromethoxy)phenylhydrazone (FCCP), demonstrating that the intramitochondrial K+ concentration is greater than the cytosolic K+ concentration. The release of K+ from mitochondria was followed by efflux through plasma membrane K+ channels. In vivo studies showed that 5HD reduces ischemic brain damage without affecting cerebral blood flow in a mouse model of focal ischemic stroke. These findings suggest that intracellular K+ fluxes play a key role in modulating neuronal oxyradical production and cell survival under ischemic conditions, and that agents that modify K+ fluxes may have therapeutic benefit in stroke and related neurodegenerative conditions.
 ...
PMID:Involvement of mitochondrial K+ release and cellular efflux in ischemic and apoptotic neuronal death. 1288 94

Rapid and complete tissue reoxygenation is a prime goal of present stroke therapy. However, reoxygenation may trigger detrimental cascades that partially antagonize beneficial effects. It was our goal to investigate selective grading of reoxygenation with targeting of single mitochondrial complexes in murine hippocampal slices. Population spike amplitude (PSAP) and NADH were measured during hypoxic hypoxia (15 min) and recovery (45 min). With onset of reoxygenation, slices were treated for different times with amobarbital (1 mM), malonate (2 mM), or cyanide (1 mM), inhibitors of mitochondrial complex I, II, or IV, respectively. Other slices were treated with nicotinamide (1 mM). Posthypoxic recovery of PSAP increased from 32% +/- 43% of onset in control slices to 52% +/- 59% (P <.05) upon treatment with amobarbital for 1 min and to 62% +/- 37% (P <.05) upon treatment with malonate. With nicotinamide, posthypoxic recovery improved to 73% +/- 25% (P <.05). Oxidation of NADH was prolonged upon treatment with amobarbital, whereas no change in NADH oxidation was observed with malonate and nicotinamide. Thus, grading of reoxygenation with selective targeting of mitochondrial complex I or II but not of complex IV improves outcome upon reoxygenation in murine hippocampal slices.
 ...
PMID:Graded reoxygenation with chemical inhibition of oxidative phosphorylation improves posthypoxic recovery in murine hippocampal slices. 1474 58

The neuroprotective potency of N-PEP-12, a novel, proprietary compound consisting of biopeptides and amino acids was investigated. Lesion models have been applied in neuronal cultures of embryonic chicken cortex, pre-treated with N-PEP-12 from the first day onwards. On day 8 in vitro neurons were lesioned and cell viability was measured 24 and 48 hours later. To simulate acute brain ischemia, cytotoxic hypoxia was induced by sodium cyanide or by iodoacetate and excitotoxicity by L-glutamate. Ionomycin for up to 48 hours induced calcium overload. The cytoskeleton was disrupted by addition of colchicine. N-PEP-12 shows dose-dependent neuroprotection in all different models. The effect size depends on the recovery time but also on the extent of the lesion. In cases of mild to moderate lesion pronounced dose-dependent effects could be demonstrated. This indicates that chronic exposure to N-PEP-12 is able to prevent neuronal cell death associated to conditions occurring during normal aging and neurological disorders like ischemic stroke, hypoxia, brain trauma, or AD.
 ...
PMID:N-PEP-12--a novel peptide compound that protects cortical neurons in culture against different age and disease associated lesions. 1575 Jun 82


1 2 3 Next >>