Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vascular and metabolic reserve were analyzed in probable Alzheimer's disease (AD) and vascular dementia (VaD). Cerebral blood flow (CBF), cerebral blood volume (CBV), cerebral metabolic rate of oxygen (CMRO(2)), and oxygen extraction fraction (OEF) were measured quantitatively with positron emission tomography (PET). Vascular reactivity (VR) was also calculated by comparing the CBF during 5% CO(2) inhalation with the CBF during normal breathing. Vascular transit time (VTT) that was calculated as a ratio of CBV/CBF and VR reflect vasodilating capacity of the small resistance vessels, whereas OEF designates metabolic (oxygen-extraction) reserve in threatening brain ischemia. Significant increase in OEF was seen in the parieto-temporal cortex and both VTT and VR were preserved in AD patients. By constrast, there was no significant increase in OEF whereas VTT was prolonged and VR was markedly depressed in VaD patients. The increase of OEF and preserved VTT and VR seen in AD patients indicate the possible participation of vascular factors in the pathogenesis of AD perhaps at the capillary level.
 ...
PMID:Vascular and metabolic reserve in Alzheimer's disease. 1086 15

Homonymous visual field defects usually occur with structural processes affecting retrochiasmal visual pathways. The responsible lesion is usually evident on magnetic resonance imaging or on other neuroimaging studies. When results of neuroimaging are normal, functional illness is often suspected. The authors report four patients with homonymous visual field defects who presented with no evident corresponding lesion on magnetic resonance or computed tomography imaging. Etiologies for the visual field defects included the Heidenhain variant of Creutzfeldt-Jacob disease, degenerative dementia, subtle occipital ischemia demonstrated only on positron-emission tomography scanning, and nonketotic hyperglycemia. Clinicians should be aware of the alternative etiologies of organic homonymous visual field loss in patients with normal neuroimaging.
 ...
PMID:Homonymous visual field defects in patients without corresponding structural lesions on neuroimaging. 1087 Sep 20

The effects of bis(7)-tacrine, a novel acetylcholinesterase inhibitor, on ischemia-induced cell death and apoptosis were investigated in primary cerebral cortical astrocytes of mice. Following a 6 h in vitro ischemic incubation of the cultures, a marked decrease in the percentage of viable cells was observed by lactate dehydrogenase (LDH) release assay. Furthermore, using bisbenzimide staining, we determined that approximately 65% of the cells underwent apoptosis. Treatment with bis(7)-tacrine (1-10 nM) during ischemic incubation effectively inhibited the ischemia-induced apoptosis, as demonstrated by morphological and biochemical tests. Our results demonstrated that bis(7)-tacrine could protect astrocytes against ischemia-induced cell injury, indicating that the drug might be beneficial for the treatment of vascular dementia, in addition to Alzheimer's disease.
 ...
PMID:Protection against ischemic injury in primary cultured mouse astrocytes by bis(7)-tacrine, a novel acetylcholinesterase inhibitor [corrected]. 1087 69

Dementia may result from complete or incomplete infarction of brain regions subserving memory and cognition. Several effective treatments reduce the risk of initial and recurrent stroke. Presumably, these interventions reduce the risk of vascular cognitive impairment. Incomplete infarction caused by recurrent, chronic, or subclinical ischemia appears to represent another important cause of ischemic brain injury, but has been relatively neglected. A shift in focus from the serendipitous clinical phenotype of vascular dementia to preventing and ameliorating the broad spectrum of ischemic brain injury is recommended.
 ...
PMID:Vascular dementia, a new beginning: shifting focus from clinical phenotype to ischemic brain injury. 1107 69

The white matter lesions in dementia of Alzheimer type (DAT) with and without multiple lacunar infarctions were studied relative to a normal control group. The frequency and distribution of white matter (WM) lesions in DAT (22 cases; mean age +/- standard deviation (SD), 88.1 +/- 5.8), DAT with multiple lacunar infarctions (DAT + CVD, 18 cases; mean age +/- SD, 87.8 +/- 6.0), and in a normal control group (17 cases; mean age +/- SD, 85.2 +/- 4.8) were evaluated. The frequency of myelin pallor (frontal, parietal and occipital lobes) was significantly higher in the DAT + CVD group than in the other groups (DAT and controls). There was no significant difference in the frequency of myelin pallor between the DAT and control groups. Therefore, it was concluded that the WM lesions in DAT are the result of ischemia rather than wallerian degeneration.
 ...
PMID:Dementia of Alzheimer type with and without multiple lacunar infarctions: evaluation of white matter lesions. 1113 36

The number of studies on Ginkgo biloba leaves is rapidly increasing. A variety of effects of Ginkgo biloba leaf extract (GBLE) have been identified. GBLE contains many different flavone glycosides and terpenoides. GBLE has an antioxidant action as a free radical scavenger, a relaxing effect on vascular walls, an antagonistic action on platelet-activating factor, an improving effect on blood flow or microcirculation, and a stimulating effect on neurotransmitters. Besides a direct scavenging action on active oxygen species, GBLE exerts an anti-inflammatory effect on inflammatory cells by suppressing the production of active oxygen and nitrogen species. GBLE inhibited the increase in the products of the oxidative decomposition low-density lipoprotein (LDL), reduced the cell death in various types of neuropathy, and prevented the oxidative damage to mitochondria, suggesting that GBLE exhibits beneficial effects on neuron degenerative diseases by preventing chronic oxidative damage. The study using a model of ischemia-reperfusion injury has also demonstrated the protective effect of GBLE on cardiac muscle and its antioxidative action in vivo. Favorable results have been obtained in double-blind, placebo-controlled, comparative trials of patients with memory disorders, obstructive arteriosclerosis, and dementia. We review the recent studies on GBLE with respect to its various pharmacological actions, such as a scavenging activity on free radicals and an inhibitory action on lipid peroxidation. GBLE shows a very strong scavenging action on free radicals, and is thus considered to be useful for the treatment of diseases related to the production of free radicals, such as ischemic heart disease, cerebral infarction, chronic inflammation, and aging.
 ...
PMID:Ginkgo biloba leaf extract: review of biological actions and clinical applications. 1123 45

This epidemiological study was carried out as a 3-year follow-up project to assess the incidence of transient ischemic attacks (TIAs) and strokes; 8,846 treated hypertensive patients (mean BP, 149/84 mm Hg) aged 65 years or over (mean age, 73.7 +/- 6.3 years), devoid of symptoms of dementia and with documented vascular risk factors were recruited from January 1994 to August 1995, by 1,598 general practitioners in connection with 36 referral university neurology units throughout metropolitan France. Among these patients, 506 (5.7%) had at least one cerebrovascular event during the follow-up period: 309 (3.5%) experienced one or more isolated TIAs, and 197 (2.2%) had a stroke with or without a preceding TIA. A total of 510 TIAs were reported. The stroke subtypes were ischemia, hemorrhage, and unclassified in 70, 16, and 15% of the cases, respectively. The estimated annual stroke incidence was 7.42 per thousand. Of the 197 patients who developed strokes, 51 (26%) died. This case-fatality rate should be compared with the 4.5% mortality rate observed in the whole population during the study period. The 3 subgroups (with isolated TIAs, strokes, or no events during the study) were found to differ regarding age, sedentary lifestyle, past history of cardiovascular events, duration of hypertension, and evidence of complicated hypertension (univariate analysis). The factors identified as predictive of a stroke (multivariate analysis) were: the patient's age; sedentary lifestyle; pulse pressure (SBP-DBP); identification of TIA at baseline, and presence of arrhythmias.
 ...
PMID:Incidence and predictive factors of cerebrovascular events in 8,846 elderly treated hypertensive patients during a 3-year follow-up: the PRESAGE study. 1124 71

We have previously shown that long-term potentiation (LTP) decreases the sensitivity of glutamate receptors in the rat hippocampal CA1 region to exogenously applied glutamate agonists. Since the pathophysiology of hypoxia/ischemia involves increased concentration of endogenous glutamate, we tested the hypothesis that LTP could reduce the effects of hypoxia in the hippocampal slice. The effects of LTP on hypoxia were measured by the changes in population spike potentials (PS) or field excitatory post-synaptic potentials (fepsps). Hypoxia was induced by perfusing the slice with (i) artificial CSF which had been pre-gassed with 95%N2/5% CO2; (ii) artificial CSF which had not been pre-gassed with 95% O2/5% CO2; or (iii) an oxygen-glucose deprived (OGD) medium which was similar to (ii) and in which the glucose had been replaced with sucrose. Exposure of a slice to a hypoxic medium for 1.5-3.0 min led to a decrease in the PS or fepsps; the potentials recovered to control levels within 3-5 min. Repeat exposure, 45 min later, of the same slice to the same hypoxic medium for the same duration as the first exposure caused a reduction in the potentials again; there were no significant differences between the degree of reduction caused by the first or second exposure for all three types of hypoxic media (P>0.05; paired t-test). In some of the slices, two episodes of LTP were induced 25 and 35 min after the first hypoxic exposure; this caused inhibition of reduction in potentials caused by the second hypoxic insult which was given at 45 min after the first; the differences in reduction in potentials were highly significant for all the hypoxic media used (P<0.01; paired t-test). The neuroprotective effects of LTP were not prevented by cyclothiazide or inhibitors of NO synthetase compounds that have been shown to be effective in blocking the effects of LTP on the actions of exogenously applied AMPA and NMDA, respectively. The neuroprotective effects of LTP were similar to those of propentofylline, a known neuroprotective compound. We conclude that LTP causes an appreciable protection of hippocampal slices to various models of acute hypoxia. This phenomenon does not appear to involve desensitisation of AMPA receptors or mediation by NO, but may account for the recognised inverse relationship between educational attainment and the development of dementia.
 ...
PMID:Long-term potentiation protects rat hippocampal slices from the effects of acute hypoxia. 1143 Aug 97

Ischemic vascular disease (IVD) is the second most common cause of dementia in the Western world. This article focuses on dementia resulting from subcortical ischemic vascular disease (SIVD), a subtype of IVD, which in many cases may be prevented. Hypertension and diabetes are the leading causes of small-artery disease, subcortical brain ischemia, and stepwise or slowing progressive decline in cognitive function. The pattern of cognitive impairment in SIVD, as compared with Alzheimer's disease, is characterized by greater impairment of executive function but better preservation of recognition memory. Structural neuroimaging studies, such as computed tomography and especially magnetic resonance imaging, are more sensitive than the clinical examination and can enable detection of subcortical lacunes and deep white matter changes that are clinically silent. Often the brain can be protected against SIVD by early diagnosis and management of risk factors. Once end-organ damage has occurred, however, treatment outcome is less satisfactory. The most common risk factors for SIVD--hypertension and diabetes mellitus--are best detected and managed in primary care settings.
 ...
PMID:Dementia due to subcortical ischemic vascular disease. 1143 21

In the present study we examined cognitive function, radiographic features, and functional ability in individuals with vascular dementia (VaD). Subjects were subdivided into individuals with only white matter involvement (WM) and individuals with evidence of a cortical infarction in addition to white matter ischemic change (C+WM). Results revealed that both groups of subjects were impaired across cognitive functions. Cognitive performance was more severely impaired among the C+WM group, but the general pattern of deficits did not differ between the two groups. Hachinski scores were significantly higher and instrumental activities of daily living were more severely affected in the C+WM group compared to the WM group. No significant differences were evident between the two groups on overall dementia severity or the extent of white matter involvement. These findings indicate that cognitive function in VaD may be globally impaired, and that cortical infarction in addition to white matter ischemia results in greater impairment, but the differences are largely quantitative rather than qualitative.
 ...
PMID:Cognitive and functional status in two subtypes of vascular dementia. 1145 96


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