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Cost of a recurrent vs. cost of first-ever stroke over an 18-month period.

When assessing the cost-effectiveness of the secondary prevention of stroke, it is not well known whether the cost of a recurrent brain infarction (BI) is different from a first-ever BI. In a cohort of 435 consecutive prevalent cases of BI (including both recurrent and first-ever BI) we collected medical and socio-economic variables. Handicap was measured with the Rankin scale. Only the direct medical costs were considered over an 18-month period from a societal perspective. We compared first-ever to recurrent BI. Of the 435 patients 20.5% had a recurrent BI. The length of the initial hospitalization and the distribution of the patients into the three classes of handicap (Rankin 0-2, 3, and 4-5) were similar in the first-ever and recurrent BI groups. The average total cost of a first-ever BI was euro 19 725 (95% CI, 17 950-21 501) and euro 18 560 (95% CI, 15 798-21 322) for a recurrent BI (P = 0.48). There were no differences between the two groups when the costs were compared by handicap levels (P = 0.17) or when the costs were compared for each type of expenditure (initial hospitalization, rehabilitation, ambulatory services) except for long-term care, because of the small number of cases. This study suggests that the costs of recurrent BI are roughly similar to the costs of first-ever BI, which may be helpful when studying the cost-effectiveness of secondary stroke prevention trials.

Adolescent↗

The transcription factor E2F1 modulates apoptosis of neurons.

The transcription factor E2F1 is known to mediate apoptosis in isolated quiescent and postmitotic cardiac myocytes, and its absence decreases the size of brain infarction following cerebral ischemia. To demonstrate directly that E2F1 modulates neuronal apoptosis, we used cultured cortical neurons to show a temporal association of the transcription and expression of E2F1 in neurons with increased neuronal apoptosis. Cortical neurons lacking E2F1 expression (derived from E2F1 -/- mice) were resistant to staurosporine-induced apoptosis as evidenced by the significantly lower caspase 3-like activity and a lesser number of cells with apoptotic morphology in comparison with cortical cultures derived from wild-type mice. Furthermore, overexpressing E2F1 alone using replication-deficient recombinant adenovirus was sufficient to cause neuronal cell death by apoptosis, as evidenced by the appearance of hallmarks of apoptosis, such as the threefold increase in caspase 3-like activity and increased laddered DNA fragmentation, in situ endlabeled DNA fragmentation, and numbers of neuronal cells with punctate nuclei. Taken together, we conclude that E2F1 plays a key role in modulating neuronal apoptosis.

Adenoviridae↗

Heart rate variability parameters correlate with functional independence measures in ischemic stroke patients.

This study gives quantitative information regarding the effect of brain infarction on the regulation of the cardiovascular system. Electrocardiograms of 16 patients, ranging from 54 to 85 years old, admitted for rehabilitation after an ischemic supratentorial stroke, all without a history of cardiac disease or rhythm disturbances, were recorded during physiotherapy effort. All patients were evaluated for the functional independence measure (FIM) score 48 to 72 hours following admission and repeated at one week before discharge. The heart rate variability (HRV) parameters: standard deviation (SD) of the RR series, the power spectrum of the RR intervals for the low frequency range (LF: 0.04-0.15 Hz), and the high frequency range (HF: 0.15-0.4 Hz) were calculated. The results showed that all heart rate variability parameters had statistically significant relationship with the FIM on admission and discharge scores. In conclusion, the HRV parameters correlate with the clinical measures of function: the greater the HRV parameter the higher the FIM score. The presented technique may prove useful as a prognostic tool providing a simple way for determining functional performance of stroke patients.

Aged↗

Neuroprotective activity of a nanoparticulate formulation of the glycineB site antagonist MRZ 2/576 in transient focal ischaemia in rats.

The objective of the present study was to characterise the neuroprotective activity of the novel glycineB site NMDA (N-methyl-D-aspartate) receptor antagonist MRZ 2/576 (8-chloro-4-hydroxy-l-oxo- 1,2-dihydropyridazino[4,5-b]quinolin-5-oxide choline salt, CAS 202807-80-5) in a rodent model of focal cerebral ischaemia. Since the solubility of MRZ 2/576 at a physiological pH, is minimal and adequate concentrations can be achieved only at relatively high basic pH the in vivo use of the substance is substantially limited. Therefore, a special nanoparticle formulation was developed to provide means for lengthy i.v. administration of experimentally relevant doses within the physiological range of pH. Focal ischaemia of 75 min duration was induced in rats by a reversible occlusion of the middle cerebral artery (MCAo). MRZ 2/576 (18 mg/kg over 10 min followed by 18 mg/kg/h over 6 h) or placebo treatment was initiated immediately after onset of MCAo. Neurological deficit was evaluated daily for 3 consecutive days and then brain infarct analysis was performed. MRZ 2/576 significantly improved the neurological score at 24 h and 72 h post stroke (p < 0.05 vs. placebo). It also produced a 53.0% reduction of total infarct size, 60.4% of cortical and 42.3% of striatal infarction (p < 0.05 vs. placebo). Temporary drug-induced hypothermia and ataxia were observed during infusions. This leads to the conclusion that prolonged administration of the glycineB site antagonist MRZ 2/576 in form of the nanoparticle suspension ameliorates ischaemic damage induced by the transient MCAo in rats. The results suggest that nanoparticles hold promise as an effective strategy e.g. for substances with physico-chemical characteristics that otherwise would preclude them from pre-clinical development and/or clinical application.

Animals↗

Nimodipine evoked dilation of cerebral arteries early during the development of late vasospasm in subarachnoid hemorrhage.

In subarachnoid hemorrhage (SAH) late cerebral ischemia may develop without significant visible narrowing of arteries at angiography, but in severe ischemic conditions "vasospasm" invariably seems to be present. The majority of patients with aneurysm rupture develop some degree of vasospasm, whereas relatively few suffer from ultimate brain infarction. The prophylactic use of the calcium antagonist Nimodipine is linked to a beneficial anti-ischemic effect in SAH, although narrowing of large bore arteries still seems to develop despite administration of this drug. Attenuation of vascular spasm, mainly in the arterioles has been implicated as the major mechanism of action, although a neuronprotective effect of Nimodipine has been suggested as well. The present paper presents fragmentary evidence that Nimodipine does elicit a vasoactive response in the cerebral vasculature early during the development of late cerebral vasospasm, and that this response seems closely linked to reversal of attendant ischemic symptoms.

Aged↗

The causes and risk of stroke in patients with asymptomatic internal-carotid-artery stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators.

BACKGROUND: The causes of stroke in patients with asymptomatic carotid-artery stenosis have not been carefully studied. Information about causes might influence decisions about the use of carotid endarterectomy in such patients. METHODS: We studied patients with unilateral symptomatic carotid-artery stenosis and asymptomatic contralateral stenosis from 1988 to 1997. The causes, severity, risk, and predictors of stroke in the territory of the asymptomatic artery were examined and quantified. RESULTS: The risk of stroke at five years after study entry in a total of 1820 patients increased with the severity of stenosis. Among 1604 patients with stenosis of less than 60 percent of the luminal diameter, the risk of a first stroke was 8.0 percent (1.6 percent annually), as compared with 16.2 percent (3.2 percent annually) among 216 patients with 60 to 99 percent stenosis. In the group with 60 to 99 percent stenosis, the five-year risk of stroke in the territory of a large artery was 9.9 percent, that of lacunar stroke was 6.0 percent, and that of cardioembolic stroke 2.1 percent. Some patients had more than one stroke of more than one cause. In the territory of an asymptomatic occluded artery (as was identified in 86 patients), the annualized risk of stroke was 1.9 percent. Strokes with different causes had different risk factors. The risk factors for large-artery stroke were silent brain infarction, a history of diabetes, and a higher degree of stenosis; for cardioembolic stroke, a history of myocardial infarction or angina and hypertension; for lacunar stroke, age of 75 years or older, hypertension, diabetes, and a higher degree of stenosis. CONCLUSIONS: The risk of stroke among patients with asymptomatic carotid-artery stenosis is relatively low. Forty-five percent of strokes in patients with asymptomatic stenosis of 60 to 99 percent are attributable to lacunes or cardioembolism. These observations have implications for the use of endarterectomy in asymptomatic patients. Without analysis of the risk of stroke according to cause, the absolute benefit associated with endarterectomy may be overestimated.

Aged↗

The effect of the Val34Leu polymorphism in the factor XIII gene in infants with a birth weight below 1500 g.

OBJECTIVES: The 34Leu polymorphism of the factor XIII gene is associated with a low rate of brain infarction and a higher incidence of primary intracerebral hemorrhage in adults. We evaluated the effect of the polymorphism on the subsequent development of isolated intracranial hemorrhage and white matter disease in preterm infants with a birth weight <1500 g (very low birth weight [VLBW] infants). STUDY DESIGN: We studied 531 VLBW infants and 301 control infants born at term. The factor XIII 34Leu polymorphism was detected by polymerase chain reaction and restriction enzyme digestion. RESULTS: Allele frequencies were not different from term and VLBW infants (Val/Val, 53.1% and 57.8%; Val/Leu, 38.8% and 37.6%; Leu/Leu, 8.0% and 4.5%, respectively). VLBW infants carrying the Leu/Val or Leu/Leu allele had a significant reduced risk of the development of white matter disease (3.6% vs 10.4% in infants without the polymorphism, P =.003). In a multivariate logistic regression analysis, only gestational age <28 weeks (odds ratio, 3.8; 95% confidence interval, 1.9-7.5; P <.001), and the factor XIII 34Leu allele (odds ratio, 0.3; 95% confidence interval, 0.1-0.7; P =.005) had significant prognostic value in predicting subsequent white matter disease. However, VLBW infants who carried the factor XIII 34Leu allele also had a moderately increased risk of the subsequent development of isolated intraventricular hemorrhage (14.3% vs 10.1% in infants without the mutation, P =.17). CONCLUSIONS: VLBW infants carrying the factor XIII 34Leu polymorphism had a decreased risk for white matter disorders.

Alleles↗

Transcription of the NR1 subunit of the N-methyl-D-aspartate receptor is down-regulated by excitotoxic stimulation and cerebral ischemia.

The N-methyl-D-aspartate (NMDA) type of glutamate receptor (NMDAR) plays central roles in normal and pathological neuronal functioning. We have examined the regulation of the NR1 subunit of the NMDAR in response to excessive activation of this receptor in in vitro and in vivo models of excitotoxicity. NR1 protein expression in cultured cortical neurons was specifically reduced by stimulation with 100 microM NMDA or glutamate. NMDA decreased NR1 protein amounts by 71% after 8 h. Low NMDA concentrations (< or = 10 microM) had no effect. NR1 down-regulation was inhibited by the general NMDAR antagonist DL-AP5 and also by ifenprodil, which specifically antagonizes NMDARs containing NR2B subunits. Arrest of NMDAR signaling with DL-AP5 after brief exposure to NMDA did not prevent subsequent NR1 decrease. Down-regulation of NR1 did not involve calpain cleavage but resulted from a decrease in de novo synthesis consequence of reduced mRNA amounts. In contrast, NMDA did not alter the expression of NR2A mRNA or newly synthesized protein. In neurons transiently transfected with an NR1 promoter/luciferase reporter construct, promoter activity was reduced by 68% after 2 h of stimulation with NMDA, and its inhibition required extracellular calcium. A similar mechanism of autoregulation of the receptor probably operates during cerebral ischemia, because NR1 mRNA and protein were strongly decreased at early stages of blood reperfusion in the infarcted brains of rats subjected to occlusion of the middle cerebral artery. Because NR1 is the obligatory subunit of NMDARs, this regulatory mechanism will be fundamental to NMDAR functioning.

Animals↗

Redox regulation of 4-hydroxy-2-nonenal-mediated endothelial barrier dysfunction by focal adhesion, adherens, and tight junction proteins.

4-Hydroxy-2-nonenal (4-HNE), one of the major biologically active aldehydes formed during inflammation and oxidative stress, has been implicated in a number of cardiovascular and pulmonary disorders. 4-HNE has been shown to increase vascular endothelial permeability; however, the underlying mechanisms are unclear. Hence, in the current study, we tested our hypothesis that 4-HNE-induced changes in cellular thiol redox status may contribute to modulation of cell signaling pathways that lead to endothelial barrier dysfunction. Exposure of bovine lung microvascular endothelial cells (BLMVECs) to 4-HNE induced reactive oxygen species generation, depleted intracellular glutathione, and altered cell-cell adhesion as measured by transendothelial electrical resistance. Pretreatment of BLM-VECs with thiol protectants, N-acetylcysteine and mercaptopropionyl glycine, attenuated 4-HNE-induced decrease in transendothelial electrical resistance, reactive oxygen species generation, Michael protein adduct formation, protein tyrosine phosphorylation, activation of ERK, JNK, and p38 MAPK, and actin cytoskeletal rearrangement. Treatment of BLMVECs with 4-HNE resulted in the redistribution of FAK, paxillin, VE-cadherin, beta-catenin, and ZO-1, and intercellular gap formation. Western blot analyses confirmed the formation of 4-HNE-derived Michael adducts with the focal adhesion and adherens junction proteins. Also, 4-HNE decreased tyrosine phosphorylation of FAK without affecting total cellular FAK contents, suggesting the modification of integrins, which are natural FAK receptors. 4-HNE caused a decrease in the surface integrin in a time-dependent manner without altering total alpha5 and beta3 integrins. These results, for the first time, revealed that 4-HNE in redox-dependent fashion affected endothelial cell permeability by modulating cell-cell adhesion through focal adhesion, adherens, and tight junction proteins as well as integrin signal transduction that may lead dramatic alteration in endothelial cell barrier dysfunction during heart infarction, brain stroke, and lung diseases.

Adherens Junctions↗

Humanized anti-L-selectin monoclonal antibody DREG200 therapy in acute thromboembolic stroke.

Strategies directed against activated neutrophils have reduced ischemia-induced brain injury. However, therapies targeted specially against the neutrophil adhesion protein L-selectin have not yet been examined in stroke. This study therefore examined the effects of a monoclonal antibody directed against L-selectin in a rabbit model of thromboembolic stroke with (n = 16) or without (n = 10) concomitant t-PA therapy. Rabbits received either the humanized monoclonal antibody DREG200 directed against the L-selectin receptor or humanized control monoclonal antibody HuDREG55 which does not bind to rabbit L-selectin in addition to t-PA therapy (n = 8, each group). HuDREG200 (2 mg kg-1 i.v.) was given as a bolus 3 h following clot embolization, followed immediately by a 2 h intravenous infusion of t-PA (6.3 mg kg-1. Without t-PA therapy rabbits received HuDREG200 (2 mgkg-1, i.v.; n = 5) or HuDREG55 (n = 5) 1 h following clot embolization. The group receiving HuDREG200 in addition to t-PA demonstrated a moderate improvement in brain infarct size (8.4 +/- 2.4 vs. 13.5 +/- 3.5, %hemisphere, mean +/- sem), ICP (final reading 10.0 +/- 1.6 vs. 12.4 +/- 3.0 torr) and restoration in regional cerebral blood flow (30.2 +/- 7.8 vs. 21.6 +/- 10.9 cc 100 g-1 min-1) when compared to t-PA therapy alone although statistical significance was not achieved. No efficacy was demonstrated in the group receiving HUDREG200 without concomitant t-PA therapy. The results suggest the addition of a humanized anti-L-selectin monoclonal antibody HuDREG200 in combination with t-PA may further improve outcome in acute thromboembolic stroke, although future studies are necessary to support these findings.

Acute Disease↗

The effect of brain compression under venous circulatory impairment.

It is well known that surgical obliteration of the cerebral veins with additional brain compression by retractors is dangerous. To evaluate the mechanism, we studied the change in cerebral microcirculation and parenchymal damage following brain compression with venous circulatory impairment using a rat model. The animals were divided into the following four groups (each n = 5) (1) a sham-operated control; (2) group A, one cortical vein occlusion; (3) group B, a 30 mmHg compression pressure; and (4) group C, one cortical vein occlusion with 30 mmHg compression. The cortical vein was occluded photochemically. Local cerebral blood flow (l-CBF) in the compressed area was measured by stationary laser-Doppler (LD) flowmetry and regional CBF (r-CBF) in the surrounding area was also measured by LD scanning technique for 120 min. l-CBF in the compressed area decreased significantly in groups B and C. A gradual and significant increase in group B and decrease in group C in r-CBF of the surrounding area were observed. Histologically, more extensive damage was observed in group C than in group A and B. The degree of hypoperfusion of the affected brain correlated well with the subsequent brain damage in the experiments. We demonstrated that, compared with vein occlusion or brain compression alone, the accumulated episode caused severe ischemia, then increased the vulnerability of the rat brain to tissue damage.

Animals↗

Predicting syndromes of amnesia from a composite holographic associative recall/recognition model (CHARM).

The composite holographic associative recall/recognition model (CHARM) is used to predict the amnesia syndromes that are expected under conditions of discrete lesions to different components of the model. The components that are needed to allow recognition, recall, and rehearsal are: (1) perceptual/lexical processing and pattern identification, (2) consciousness or working memory, (3) association formation, (4) composite storage, (5) novelty monitoring and control, and (6) retrieval. Deficits in each of these components will have specific effects on memory, generating characteristic profiles of performance. Comparison of the profiles exhibited by patients to the component-based profiles predicted by the model identify the component impaired in a given patient, and connect the memory impairments to the underlying infarcted brain structures. The model, thus, relates the memory tasks to the particular memory components that allow enactment of those tasks, and shows how the dysfunction of particular components produces specific impairments.

Amnesia↗

Epidemiology of A3243G, the mutation for mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes: prevalence of the mutation in an adult population.

Mitochondrial diseases are characterized by considerable clinical variability and are most often caused by mutations in mtDNA. Because of the phenotypic variability, epidemiological studies of the frequency of these disorders have been difficult to perform. We studied the prevalence of the mtDNA mutation at nucleotide 3243 in an adult population of 245,201 individuals. This mutation is the most common molecular etiology of MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes), one of the clinical entities among the mitochondrial disorders. Patients with diabetes mellitus, sensorineural hearing impairment, epilepsy, occipital brain infarct, ophthalmoplegia, cerebral white-matter disease, basal-ganglia calcifications, hypertrophic cardiomyopathy, or ataxia were ascertained on the basis of defined clinical criteria and family-history data. A total of 615 patients were identified, and 480 samples were examined for the mutation. The mutation was found in 11 pedigrees, and its frequency was calculated to be >=16. 3/100,000 in the adult population (95% confidence interval 11.3-21. 4/100,000). The mutation had arisen in the population at least nine times, as determined by mtDNA haplotyping. Clinical evaluation of the probands revealed a syndrome that most frequently consisted of hearing impairment, cognitive decline, and short stature. The high prevalence of the common MELAS mutation in the adult population suggests that mitochondrial disorders constitute one of the largest diagnostic categories of neurogenetic diseases.

Acidosis, Lactic↗

Prevalence of heart disease in older women in a nursing home.

The prevalence of coronary artery disease (CAD) and the incidence of new coronary events are similar in older men and women. Independent risk factors for new coronary events in older women include age, prior CAD, cigarette smoking, hypertension, diabetes mellitus, high serum total cholesterol and triglycerides, and low serum high-density lipoprotein cholesterol. Older women have a higher prevalence of hypertension than older men. In older women with hypertension, echocardiographic left ventricular hypertrophy is a powerful independent predictor of new coronary events, atherothrombotic brain infarction, and congestive heart failure (CHF). Older women have a higher prevalence of rheumatic mitral stenosis and of mitral annular calcium than older men. Older women and men have a similar prevalence of valvular aortic stenosis, aortic regurgitation, mitral regurgitation, hypertrophic cardiomyopathy, and idiopathic dilated cardiomyopathy. The prevalence and incidence of CHF increase with age. The prevalence of normal left ventricular ejection fraction associated with CHF increases with age and is higher in older women than in older men. The prevalence of chronic atrial fibrillation increases with age and is similar in older men and women. Atrial fibrillation is an independent predictor of new coronary events and thromboembolic stroke in older women. Older women with unexplained syncope should have 24-hour ambulatory electrocardiograms to determine whether pauses > 3 seconds are present, requiring permanent pacemaker implantation.

Age Distribution↗

Neuroprotection by Brazilian Green Propolis against In vitro and In vivo Ischemic Neuronal Damage.

We examined whether Brazilian green propolis, a widely used folk medicine, has a neuroprotective function in vitro and/or in vivo. In vitro, propolis significantly inhibited neurotoxicity induced in neuronally differentiated PC12 cell cultures by either 24 h hydrogen peroxide (H(2)O(2)) exposure or 48 h serum deprivation. Regarding the possible underlying mechanism, propolis protected against oxidative stress (lipid peroxidation) in mouse forebrain homogenates and scavenged free radicals [induced by diphenyl-p-picrylhydrazyl (DPPH). In mice in vivo, propolis [30 or 100 mg/kg; intraperitoneally administered four times (at 2 days, 1 day and 60 min before, and at 4 h after induction of focal cerebral ischemia by permanent middle cerebral artery occlusion)] reduced brain infarction at 24 h after the occlusion. Thus, a propolis-induced inhibition of oxidative stress may be partly responsible for its neuroprotective function against in vitro cell death and in vivo focal cerebral ischemia.

Journal Article↗

Treatment of older persons with hypercholesterolemia with and without cardiovascular disease.

Hypercholesterolemia is a risk factor for new coronary events in older men and women. Secondary prevention trials have demonstrated in persons with coronary artery disease (CAD) and hypercholesterolemia that statin drugs reduced in older persons all-cause mortality, cardiovascular mortality, coronary events, coronary revascularization, stroke, and intermittent claudication. Statins have also been shown to slow progression of coronary atherosclerotic plaques in persons with CAD, to reduce restenosis after coronary stent implantation, and to decrease myocardial ischemia in persons with CAD. Older men and women with CAD, prior atherothrombotic brain infarction, peripheral arterial disease, or extracranial carotid arterial disease and a serum low-density lipoprotein (LDL) cholesterol level higher than 125 mg/dl despite diet should be treated with statin drug therapy to lower the serum LDL cholesterol level below 100 mg/dl. Primary prevention trials have shown that statins were also effective in reducing cardiovascular events in older persons with hypercholesterolemia. On the basis of data from the Air Force/Texas Coronary Atherosclerosis Prevention Study, the physician should consider using statins in persons aged 65-80 years without cardiovascular disease with a serum LDL cholesterol level above 130 mg/dl and serum high-density lipoprotein cholesterol level below 50 mg/dl.

Aged↗

Distribution of tripeptidyl peptidase I in human tissues under normal and pathological conditions.

Tripeptidyl peptidase I (TPP I) is a lysosomal exopeptidase that cleaves tripeptides from the free N-termini of oligopeptides. Mutations in this enzyme are associated with the classic late-infantile form of neuronal ceroid lipofuscinosis (CLN2), an autosomal recessive disorder leading to severe brain damage. To gain more insight into CLN2 pathogenesis and the role of TPP I in human tissues in general, we analyzed the temporal and spatial distribution of TPP I in the brain and its localization in internal organs under normal and pathological conditions. We report that TPP I immunoreactivity appears in neurons late in gestation and increases gradually in the postnatal period, matching significantly the final differentiation and maturation of neural tissue. Endothelial cells, choroid plexus, microglial cells, and ependyma showed TPP I immunostaining distinctly earlier than neurons. Acquisition of the adult pattern of TPP I distribution in the brain at around the age of 2 years correlates with the onset of clinical signs in CLN2 subjects. In adults, TPP I was found in all types of cells in the brain and internal organs we studied, although the intensity of TPP I labeling varied among several types of cells and showed a noticeable predilection for cells and/or organs associated with peptide hormone and neuropeptide production. In addition, TPP I immunoreactivity was increased in aging brain, neurodegenerative and lysosomal storage disorders, and some differentiated neoplasms and was reduced in ischemic/anoxic areas and undifferentiated tumors. These findings suggest that TPP I is involved in general protein turnover and that its expression may be controlled by various regulatory mechanisms, which highlights the importance of this enzyme for normal function of cells and organs in humans.

Adolescent↗