Stroke; a journal of cerebral circulation
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Multicenter Study Clinical Trial
Effect of intravenous thrombolysis on MRI parameters and functional outcome in acute stroke <6 hours.
The goals of this study were to examine MRI baseline characteristics of patients with acute ischemic stroke (AIS) and to study the influence of intravenous tissue plasminogen activator (tPA) on MR parameters and functional outcome using a multicenter approach. ⋯ In this pilot study, tPA therapy had a beneficial effect on vessel recanalization and functional outcome. Multiparametric MRI delineates tissue at risk of infarction in AIS patients, which may be helpful for the selection of patients for tPA therapy. tPA therapy appeared safe and effective beyond a 3-hour time window. This study delivers the rationale for a randomized, MR-based tPA trial.
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Comparative Study Clinical Trial
Comparison between echo contrast agent-specific imaging modes and perfusion-weighted magnetic resonance imaging for the assessment of brain perfusion.
Contrast burst imaging (CBI) and time variance imaging (TVI) are new ultrasonic imaging modes enabling the visualization of intravenously injected echo contrast agents in brain parenchyma. The aim of this study was to compare the quantitative ultrasonic data with corresponding perfusion-weighted MRI data (p-MRI) with respect to the assessment of brain perfusion. ⋯ In contrast to PI, TPI and rTPI in US techniques are robust parameters for the evaluation of cerebral perfusion and may help to differentiate physiological and pathological perfusion in different parenchymal regions of the brain.
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Comparative Study Clinical Trial
Comparison of CT and CT angiography source images with diffusion-weighted imaging in patients with acute stroke within 6 hours after onset.
Although stroke MRI has advantages over other diagnostic imaging modalities in acute stroke patients, most of these individuals are admitted to emergency units without MRI facilities. There is a need for an accurate diagnostic tool that rapidly and reliably detects hemorrhage, extent of ischemia, and vessel status and potentially estimates tissue at risk. We sought to determine the diagnostic accuracy of the combination of non-contrast-enhanced CT, CT angiography (CTA), and CTA source images (CTA-SI, showing early parenchymal contrast enhancement) in comparison with a multiparametric stroke MRI protocol in patients with acute stroke within 6 hours after onset. ⋯ The combination of non-contrast-enhanced CT (exclusion of intracranial hemorrhage), CTA (vessel status), and early contrast-enhanced CTA-SI (demarcation of irreversible infarct) allows diagnostic assessment of acute stroke with a quality comparable to that of stroke MRI. Furthermore, it is possible to distinguish patients at risk of infarct growth from those who are not according to the collateral status, in analogy with the stroke MRI mismatch concept.
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Cells lacking the ATM (ataxia telangectasia mutated) gene are hypersensitive to DNA damage caused by a variety of insults. ATM may regulate oxidative stress-induced signaling cascades involving nuclear factor-kappaB (NF-kappaB), a transcription factor that is upstream of a wide variety of stress-responsive genes. We investigated the potential interaction of ATM and NF-kappaB after oxygen-glucose deprivation (OGD) in cerebral endothelial cells (CECs). ⋯ We conclude that ATM may play a cytoprotective role in OGD-induced CEC death via a NF-kappaB-dependent signaling pathway.
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In humans, intracerebral hemorrhage (ICH) causes marked perihematomal edema formation and neurological deficits. A rat ICH model, involving infusion of autologous blood into the caudate, has been used extensively to study mechanisms of edema formation, but an examination of behavioral outcome would improve its preclinical utility and provide a more rigorous assessment of the pathological cascade of events over time. The purpose of this study was to use a battery of sensorimotor function tests to examine the neurological effects of ICH in the rat and to examine which components of the hematoma are involved in generating those effects. ⋯ These tests allow continuous monitoring of neurological deficits after rat ICH and assessment of therapeutic interventions. The time course of the neurological deficit closely matched the time course of cerebral edema for both ICH and injection of blood components. There was marked recovery of function after ICH, which may be amenable to therapeutic manipulation.