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

Many cases of age-related cognitive dementia are caused by cerebrovascular lesions, and various vascular syndromes can lead to cognitive impairment and dementia. Repeated cortical infarcts due to embolic disease of the heart or major cerebral vessels can cause progressive deterioration towards dementia and incapacitation. In classic multi-infarct dementia, cognitive deterioration is stepwise rather than smoothly progressive. While diagnostic technologies have vastly improved and added to general knowledge of the pathology of cerebrovascular disease, MRI, PET, and transcranial Doppler scans have demonstrated that significant white matter change is possible without clinically recognized TIA or completed stroke. In addition, patients may have initial complaints that are not serious enough to produce changes on mental status examination. Many patients have mixed dementia, exhibiting aspects of both degenerative brain disease and clinical evidence of strokes or significant changes on MRI scan. The overlap between vascular and degenerative disease is significant, yet the exact interaction of the pathophysiology of the vascular lesions and the degenerative changes is not known. The treatment of vascular or mixed dementia involves control of the risk factors for continued vascular events and treatment with the cholinesterase inhibitors.
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PMID:Vascular dementia. 2247 Feb 55

Butyrylcholinesterase (BChE) is the major acetylcholine hydrolyzing enzyme in peripheral mammalian systems. It can either reside in the circulation or adhere to cells and tissues and protect them from anticholinesterases, including insecticides and poisonous nerve gases. In humans, impaired cholinesterase functioning is causally involved in many pathologies, including Alzheimer's and Parkinson's diseases, trait anxiety, and post stroke conditions. Recombinant cholinesterases have been developed for therapeutic use; therefore, it is important to follow their in vivo path, location, and interactions. Traditional labeling methods, such as fluorescent dyes and proteins, generally suffer from sensitivity to environmental conditions, from proximity to different molecules or special enzymes which can alter them, and from relatively fast photobleaching. In contrast, emerging development in synthesis and surface engineering of semiconductor nanocrystals enable their use to detect and follow molecules in biological milieus at high sensitivity and in real time. Therefore, we developed a platform for conjugating highly purified recombinant human BChE dimers (rhBChE) to CdSe/CdZnS quantum dots (QDs). We report the development and characterization of highly fluorescent aqueous soluble QD-rhBChE conjugates, present maintenance of hydrolytic activity, inhibitor sensitivity, and adherence to the membrane of cultured live cells of these conjugates, and outline their advantageous features for diverse biological applications.
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PMID:Quantum dot labeling of butyrylcholinesterase maintains substrate and inhibitor interactions and cell adherence features. 2277 63

Vascular dementia (VaD) is a common dementing illness. There are no pharmacological agents with a regulatory approval for its treatment or prevention. Review of published clinical trial reports indicates that early treatment of hypertension, a risk factor for stroke, reduces VaD risk and slows progression. However, unlike stroke, treatment of hyperlipidemia with statin class drugs or treatment of blood clotting abnormalities with acetylsalicylic acid do not appear to have an effect on VaD incidence or progression. Pharmacological agents for treatment of Alzheimer's dementia (AD) such as memantine or acetylcholinesterase inhibitors have small positive effects on cognition in VaD, which are likely due to their action on co-existing AD-related neuropathology. Drug development efforts using novel approaches such as patient stratification by their genotype are needed in order to address the increasing need for effective VaD therapeutics.
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PMID:Pharmacological prevention and treatment of vascular dementia: approaches and perspectives. 2279 25

There is increasing evidence that hypercholesterolemia during midlife may represent a predictor of subsequent mild cognitive impairments and dementia decades later. However, the exact mechanism underlying this phenomenon remains unknown since plasmatic cholesterol is not able to cross the blood-brain barrier. In the present study, we evaluated the hypothesis that cognitive impairments triggered by hypercholesterolemia during aging may be related to brain oxidative stress and altered brain acetylcholinesterase (AChE) activity. We also performed a neuropathological investigation in order to analyze whether the cognitive impairments may be associated with stroke-related features. To address these questions we used three- and fourteen-month-old low-density lipoprotein receptor-deficient mice (LDLr-/-). The current findings provide new evidence that aged LDLr-/- mice, exposed to over three-fold cholesterol levels from early life, show working, spatial reference, and procedural memory impairments, without alterations in motor function. Antioxidant imbalance and oxidative damage were evidenced by a marked increase in lipid peroxidation (thiobarbituric acid reactive substances levels) and glutathione metabolism (increase in glutathione levels, glutathione reductase, and glutathione peroxidase activities) together with a significant increase in the AChE activity in the prefrontal cortex of aged hypercholesterolemic LDLr-/- mice. Notably, hypercholesterolemia was not related to brain infarcts and neurodegeneration in mice, independent of their age. These observations provide new evidence that hypercholesterolemia during aging triggers cognitive impairments on different types of learning and memory, accompanied by antioxidant imbalance, oxidative damage, and alterations of cholinergic signaling in brain areas associated with learning and memory processes, particularly in the prefrontal cortex.
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PMID:Age-related cognitive decline in hypercholesterolemic LDL receptor knockout mice (LDLr-/-): evidence of antioxidant imbalance and increased acetylcholinesterase activity in the prefrontal cortex. 2281 96

Within the autonomic system, acetylcholine signaling contributes simultaneously and interactively to cognitive, behavioral, muscle and immune functions. Therefore, manipulating cholinergic parameters such as the activities of the acetylcholine hydrolyzing enzymes in body fluids or the corresponding transcript levels in blood leukocytes can change the global status of the autonomic system in treated individuals. Specifically, cholinesterase activities are subject to rapid and effective changes. The enzyme activity baseline increases with age and body mass index and depends on gender and ethnic origin. Also, the corresponding DNA (for detecting mutations) and RNA (for measuring specific mRNA transcripts) of cholinergic genes present individual variability. In leukocytes, acetylcholine inhibits the production of pro-inflammatory cytokines, suggesting relevance of cholinergic parameters to both the basal levels and to disease-induced inflammation. Inversely, acetylcholine levels increase under various stress stimuli, inducing changes in autonomic system molecules (e.g., pro-inflammatory cytokines) which can penetrate the brain; therefore, manipulating these levels can also effect brain reactions, mainly of anxiety, depression and pain. Additionally, neurodegenerative diseases often involve exacerbated inflammation, depression and anxiety, providing a focus interest group for cholinergic manipulations. In Alzheimer's disease, the systemic cholinergic impairments reflect premature death of cholinergic neurons. The decline of cholinesterases in the serum of Parkinson's disease and post- stroke patients, discovery of the relevant microRNAs and the growing range of use of anticholinesterase medications all call for critical re-inspection of established and novel approaches for manipulating cholinergic parameters.
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PMID:Cholinergic involvement and manipulation approaches in multiple system disorders. 2289 18

Epilepsy is a common neurological disorder characterized by an initial injury due to stroke, traumatic brain injury, brain infection, or febrile seizures causing status epilepticus (SE). This phenomenon precedes recurrent (secondary) seizures, the latent period (period without seizures) and downstream appearance of spontaneous recurrent seizures (SRS). Epilepsy inducers include the organophosphorous (OP) compounds modified as chemical warfare nerve agents, such as soman. SE induced by soman is a result of cholinergic system hyperactivity caused by the irreversible inhibition of acetylcholinesterase, and the subsequent increase in the amount of the neurotransmitter acetylcholine at central and peripheral sites. SE leads to profound, permanent, complex and widespread brain damage and associated cognitive and behavioral deficits, accompanied by impaired neurogenesis. Several anticonvulsant and neuroprotective strategies have been studied in order to avoid the epileptogenesis which occurs after SE caused by soman exposure. In recent studies, we showed that SRS occur post-soman exposure and neuropathology can be reduced with diazepam (DZP) and valproic acid (VPA) when administered in combination treatment. These effects are accompanied by neurogenesis seen 15 days post-exposure in the hippocampal dentate gyrus (DG). This review discusses several findings about epilepsy induced by soman exposure such as behavioral changes, EEG anomalies, neuropathology, neuroinflammation, neurogenesis, possible circuitry changes and current strategies for treatment. The soman seizure model is an important model of temporal lobe epilepsy (TLE) and comparable in certain respects with well studied models in the literature such as pilocarpine and kainic acid. All these models together allow for a greater understanding of the different mechanisms of seizure induction, propagation and options for treatment. These studies are very necessary for current military and civilian treatment regimens, against OP nerve agent exposure, which fail to prevent SE resulting in severe neuropathology and epilepsy.
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PMID:Exposure to nerve agents: from status epilepticus to neuroinflammation, brain damage, neurogenesis and epilepsy. 2300 13

Pharmacological enhancement of neurorehabilitation is based on the concept of neuroplasticity. Agents with probably unfavourable effects on recovery (e.g. classical antiepileptic drugs, butyrophenones) should be avoided. The findings of experimental studies in animal models, investigations in healthy subjects and the findings of neurophysiological studies indicate that there is scope for benefit from pharmacological enhancement in stroke rehabilitation in the clinical setting - in addition to rehabilitative therapies. Randomized controlled clinical trials have shown benefit of pharmacological enhancement in stroke rehabilitation for some agents. Nevertheless, the clinical evidence regarding benefits of this treatment approach is still considered weak for the following reason: First, the beneficial findings of some studies were not confirmed by others. Second, several studies were limited by small patient populations and narrow inclusion criteria. Third, there were concerns regarding safety of some agents (i.e., piracetam, and amphetamines). Dopaminergic agents, Selective Serotonin-Reuptake-Inhibitors (SSRI) and acetylcholinesterase-inhibitors are promising candidates. Their safety and efficacy should be further investigated; ideally in - sufficiently powered - large randomized controlled trials.
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PMID:Safety in pharmacological enhancement of stroke rehabilitation. 2343 54

Heart failure (HF) is characterized by elevated sympathetic activity and reduced parasympathetic control of the heart. Experimental evidence suggests that the increase in parasympathetic function can be a therapeutic alternative to slow HF evolution. The parasympathetic neurotransmission can be improved by acetylcholinesterase inhibition. We investigated the long-term (4 wk) effects of the acetylcholinesterase inhibitor pyridostigmine on sympathovagal balance, cardiac remodeling, and cardiac function in the onset of HF following myocardial infarction. Myocardial infarction was elicited in adult male Wistar rats. After 4 wk of pyridostigmine administration, per os, methylatropine and propranolol were used to evaluate the cardiac sympathovagal balance. The tachycardic response caused by methylatropine was considered to be the vagal tone, whereas the bradycardic response caused by propranolol was considered to be the sympathetic tone. In conscious HF rats, pyridostigmine reduced the basal heart rate, increased vagal, and reduced sympathetic control of heart rate. Pyridostigmine reduced the myocyte diameter and collagen density of the surviving left ventricle. Pyridostigmine also increased vascular endothelial growth factor protein in the left ventricle, suggesting myocardial angiogenesis. Cardiac function was assessed by means of the pressure-volume conductance catheter system. HF rats treated with pyridostigmine exhibited a higher stroke volume, ejection fraction, cardiac output, and contractility of the left ventricle. It was demonstrated that the long-term administration of pyridostigmine started right after coronary artery ligation augmented cardiac vagal and reduced sympathetic tone, attenuating cardiac remodeling and left ventricular dysfunction during the progression of HF in rats.
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PMID:Increase in parasympathetic tone by pyridostigmine prevents ventricular dysfunction during the onset of heart failure. 2394 74

Various potential molecules with putative positive role in stroke pathology have failed to confer neuro-protection in animal models due to their insufficient bioavailability in brain. Efflux of these molecules by P-glycoprotein (P-gp), on blood brain barrier (BBB) is one of the reasons of their poor bioavailability. Berberine, have anti-inflammatory, antioxidant, anti-apoptotic properties, but also having low oral bioavailabilty. Verapamil, which increased the central nervous system uptake of few drugs, when concomitantly administered with berberine was evaluated in this animal model. Wistar rats were subjected to bilateral common carotid artery occlusion to induce acute cerebral ischemia for 15 min followed by reperfusion resulting in transient global cerebral ischemia. For 19 days berberine (5, 10, 20mg/kg, p.o.) alone and in similar doses concomitantly with verapamil (2mg/kg, p.o.) was evaluated employing various neuro-behavioral test, biochemical parameters and molecular estimations. The adjunction of berberine with verapamil improved the neurological outcome in a battery of behavioral paradigms, improved spatial memory in Morris water maze task, ameliorated the oxidative-nitrosative stress, increased acetylcholinesterase (AChE) activity, as well as improved mitochondrial complex (I, II, and IV) activity, reducing tumor necrosis factor-alpha, interleukin-1 beta and caspase-3 levels in brain tissues as compared to berberine alone group in ischemic rats. There is a strong possibility of improved brain bioavailabity of berberine when combined with verapamil. The findings suggested that the combination of berberine with verapamil, which could enhance its brain uptake, will surely provide a greater impact in neroprotection drug discovery for search of such combination.
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PMID:Verapamil augments the neuroprotectant action of berberine in rat model of transient global cerebral ischemia. 2417 87

[Purpose] In the present study, we investigated the effects of treadmill training on limb motor function and acetylcholinesterase activity following focal cerebral ischemia injury. [Methods] Focal cerebral ischemia was examined in adult male Sprague-Dawley rats by using a middle cerebral artery occlusion model. Rats were randomly divided into 3 groups. Group I included untreated normal rats (n=12), Group II included untreated rats with focal cerebral ischemia (n=12), and Group III included rats that performed treadmill exercise (20 m/min) training after focal cerebral ischemia (n=12). We determined the limb placement test score for each rat on days 1,7, 14, and 21; acetylcholinesterase activity in the hippocampus was examined at the end of the experiment. [Results] We observed that the motor behavior index improved in the treadmill group, and hippocampal acetylcholinesterase activity was decreased. [Conclusion] These results indicated that treadmill training after focal cerebral ischemia exerts a neuroprotective effects against ischemic brain injury by improving motor performance and decreasing the levels of acetylcholinesterase activity. Furthermore, these results suggest that treadmill training at an appropriate intensity is critical for post-stroke rehabilitation.
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PMID:Effects of treadmill training on limb motor function and acetylcholinesterase activity in rats with stroke. 2425 63


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