Stroke; a journal of cerebral circulation
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Edema formation after intracerebral hemorrhage has been linked to thrombin toxicity induced by the clot. However, thrombin at low concentrations actually protects neurons and astrocytes in culture from hypoglycemic and ischemic cell death. It is also known that a brief episode of brain ischemia increases neuronal tolerance to a subsequent severe ischemic episode. The objective of this study was to investigate whether pretreatment of the brain with low-dose thrombin induces tolerance to a subsequent large dose of thrombin injected into brain parenchyma. ⋯ OFF phenomenon of thrombin-induced tolerance of the brain to edema formation may be related to HSP27 induction.
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Although alteplase, a recombinant tissue plasminogen activator (tPA), is structurally identical to endogenous tPA and therefore should not induce allergy, single cases of acute hypersensitivity reactions have been reported. Until now, specific antibodies against alteplase were not detected in blood samples obtained in these patients. ⋯ The detection of specific IgE antibodies reactive with alteplase in this patient could provide the first evidence of an anaphylactic-type reaction to alteplase in man. Because previous exposure to alteplase can be excluded, the results suggest that this patient had preexisting antibodies that were cross-reactive with one or more epitopes of alteplase and therefore precipitated the anaphylactic-type reaction.
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Clinical Trial
Usefulness of transcranial color-coded sonography in the diagnosis of cerebral vasospasm.
The noninvasive diagnosis of cerebral vasospasm with the use of conventional transcranial Doppler ultrasonography (TCD) is based on a velocity study of the middle cerebral artery (MCA). The authors report a prospective comparative study between transcranial color-coded sonography (TCCS), conventional transcranial Doppler (TCD), and angiography in the diagnosis of cerebral vasospasm after surgical treatment for aneurysm. ⋯ The authors suggest that TCCS is useful for accurate monitoring of cerebral vasospasm in the MCA and ICA. In the ACA, TCCS monitors the hemodynamic state of the anterior part of the circle of Willis, which could expose the patient to a delayed ischemic deficit.
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The aim of our study was to compare outcome and its determinants in familial subarachnoid hemorrhage and in sporadic subarachnoid hemorrhage in a large and well-documented patient population. ⋯ Admission status, postoperative course, and outcome were similar in the familial and sporadic SAH groups in this Finnish population, in contrast to previous results. Familial SAH may not be a significant risk factor for poor outcome.
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Neutrophil (PMN) recruitment mediated by increased expression of intercellular adhesion molecule-1 expression (ICAM-1, CD54) in the cerebral microvasculature contributes to the pathogenesis of tissue injury in stroke. However, studies using blocking antibodies against the common beta2-integrin subunit on the PMN, the counterligand for ICAM-1 (CD18), have demonstrated equivocal efficacy. The current study tested the hypothesis that mice deficient in CD18 would be protected in the setting of reperfused but not nonreperfused stroke. ⋯ Deficiency for the CD18 gene confers cerebral protection in a murine model of reperfused stroke, but this benefit does not extend to CD18-deficient animals subjected to permanent MCA occlusion. These data suggest that anti-PMN strategies should be targeted to reperfused stroke and may perhaps be used in conjunction with thrombolytic therapy that establishes reperfusion.