Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0917798 (cerebral ischemia)
 17,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cerebral blood flow (CBF) was determined by the 123I-IMP SPECT reference sample method in 39 patients with subarachnoid hemorrhage (SAH) due to ruptured cerebral aneurysm. They were examined according to the time lapse after onset, severity, CT findings, and prognosis. These 39 patients were admitted to our medical center within 36 hours after the onset, and SAH and ruptured aneurysm were diagnosed by CT scan and angiography, respectively. Patients with intraventricular hemorrhage, intracerebral hematoma, and other severe complications were excluded. The stage of SAH was divided into three, by designating the day of onset as day 0: day 0-4 as the acute stage, day 5-20 as the subacute stage, and day 21 and after that as the chronic stage. Acute stage surgery was conducted within 48 hours after the onset on principle. Hyperdynamic therapy and cisternal drainage were conducted in severe case of SAH. The prognosis was evaluated with Glasgow outcome scale (GOS). The average CBF was 33.39, 29.44, and 33.15 in the acute, subacute, and chronic stages, respectively. These are values lower than the reference sample value, 43.39 (ml/100 g/min). Only a small number of cases, however, revealed vasospasm by angiography conducted in the acute stage. There was a correlation between the CT severity in the acute stage and the decrease in CBF. In the group with low density area (LDA) on CT due to delayed cerebral ischemia in the subacute stage, the average CBF was 28.28 and 23.95 in the acute and subacute stages, respectively. These values were significantly lower than 35.97 and 32.45, respectively, in the group without LDA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Time-related changes in the cerebral blood flow in subarachnoid hemorrhage due to ruptured cerebral aneurysm]. 157 54

To compare the merits of 123I-isopropyl-iodoamphetamine (123I-IMP) and 99mTc-HMPAO in showing abnormal brain uptake distribution during cerebral ischemia, we studied ten patients during the subacute phase of their stroke, a period where metabolism and blood flow are frequently uncoupled. SPECT imaging was performed using both radiopharmaceuticals in the 10 patients from 48 h to 4 weeks after onset of symptoms. Two patients out of the 10 had similar defects with 123I-IMP and 99mTc-HMPAO SPECT, the location of the defects corresponding to the area of infarction observed on CT. Six patients had normal 99mTc-HMPAO SPECT and abnormal 123I-IMP SPECT with defects in the area of infarction shown by CT. The remaining 2 patients had hyperactive abnormalities on 99mTc-HMPAO in areas corresponding to defects on the 123I-IMP images. Two of the patients with SPECT mismatches were studied again more than 1 month after onset. On reexamination, 99mTc-HMPAO SPECT which was previously normal or hyperactive became hypoactive with a focal area of decreased activity corresponding to the defect on 123I-IMP. Crossed cerebellar diaschisis was found in 7 patients with 99mTc-HMPAO and was absent for both 123I-IMP and 99mTc-HMPAO in 3. We suggest that SPECT with 99mTc-HMPAO could show transient hyperemia not demonstrated by 123I-IMP whereas in some cases cerebral infarction would be more difficult to demonstrate with 99mTc-HMPAO than with 123I-IMP. SPECT with both tracers is recommended to follow the evolution of strokes in terms of regional cerebral blood flow and tissue metabolism.
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PMID:"Luxury perfusion" with 99mTc-HMPAO and 123I-IMP SPECT imaging during the subacute phase of stroke. 230 69

A novel chrono-autoradiographic technique (sequential double label autoradiography) was established in order to evaluate regional cerebral blood flow (CBF) changes utilizing N-isopropyl-p-123I-iodoamphetamine (123I-IMP) and 14C-iodoantipyrine (14C-IAP). With sequential administration of 123I-IMP and 14C-IAP, two CBF images were obtained from the same brain section. By applying this method to focal cerebral ischemia, two sequential CBF images, one during ischemia and one after recirculation, were obtained. These results show that this method is useful in topographical evaluation of CBF changes. From a pathophysiological point of view, the result demonstrates a heterogeneous tissue perfusion after a transient ischemic insult.
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PMID:Sequential cerebral blood flow study by chrono-autoradiography. 373 11

Phosphatic metabolite (perchloric acid extractable) concentrations of cerebral tissues were analyzed by phosphorus-31 nuclear magnetic resonance (P-31 NMR) spectroscopy following external perfusion of the isolated rat brain (30 min or 60 min) under the following conditions: (a) constant perfusion pressure with either fluorocarbon- or erythrocyte-based medium, and (b) constant perfusate flow rate (3 ml/min) with the erythrocyte-based medium. Metabolite concentrations of control perfused brains were compared with those in nonperfused controls to provide a basis for detecting any qualitative or quantitative changes in cerebral metabolite composition. Metabolic responses of perfused brains to ischemia (incomplete ischemia, 83% reduction in flow for 10 min; transient complete ischemia for 1.5 or 2 min) were evaluated immediately after the ischemic episode and at selected time points during reperfusion (3 and 15 min). Alterations in cerebral metabolite levels induced by hypoxia were analyzed using a nonperfused rat brain model. Irrespective of the perfusion method employed, the phosphatic metabolites of control perfused rat brains were identical quantitatively to those of the nonperfused controls. Cerebral ischemia resulted in significantly increased levels of ADP, AMP + IMP, Pi, fructose 1,6-diphosphate, and glycerol 3-phosphate (global ischemia only), whereas ATP and phosphocreatine (PCr) levels declined significantly. The magnitude of these changes varied with the severity of the ischemia; however, following 15 min of control reperfusion metabolite levels had reverted to preischemic values. Significant perturbations in tissue phosphoethanolamine (3.84 delta resonance) content were evident at various time points during ischemia and postischemic recovery, which varied according to the perfusion conditions. In contrast to the changes observed in response to ischemia, hypoxia affected only cerebral high-energy phosphate levels. ATP and PCr levels were reduced, while a concomitant, essentially equimolar, increase in Pi and ADP was observed. The present studies indicate that in terms of phosphatic metabolites, the control equilibrated isolated perfused rat brain is quantitatively and qualitatively indistinguishable from the nonperfused rat brain in vivo regardless of the perfusion conditions (constant flow versus constant pressure). The metabolic responses to ischemia and hypoxia, as measured by P-31 NMR, were consistent with the pattern of changes reported elsewhere. Overall, P-31 NMR spectroscopic evaluation of the intact rat brain provides a potential experimental context for dynamic measures of cerebral metabolism under exogenously controlled conditions. Th
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PMID:P-31 nuclear magnetic resonance analysis of brain: II. Effects of oxygen deprivation on isolated perfused and nonperfused rat brain. 609 45

A study was performed to compare the follow-up results of superficial temporal artery-middle cerebral artery anastomosis between a group of nine elderly patients (aged 70 years or over) and another group of 24 non-elderly patients (aged less than 70 years) with cerebral ischemia. The 33 patients, comprising 26 males and seven females, were evaluated pre- and postoperatively by four-vessel angiography, CT scan, MRI and cerebral blood flow (CBF) examination using either xenon inhalation or 123I-IMP SPECT. In some patients, additional evaluations were done. For those with dementia, the minimental scale (MMS), P300 event-related potential, the Hachinski ischemia score, and the vowel word counting test (Kaneko's KANAHIROI) were used, and for the hemiplegic, the Barthel index indicating ability of daily life (ADL) was employed. The results of follow-up for periods ranging from 12 to 55 months were "excellent" (returned to previous job) or "good" (able to perform self-care) in 27 of the 33 patients (81.8%) including six (66.6%) of the elderly group and 21 (87.5%) of the non-elderly group. There was no significant difference between the two groups by statistical evaluation. Among the nine patients with dementia (five under 70, four 70 years of age or over), eight (four under 70, four 70 or over) showed "rapid recovery" with improved postoperative MMS, P300, vowel word counting score and CBF. One patient under 70 (Case 5; a 47-year-old male) with a delayed 2-day recovery from general anesthesia, took as long as 6 months to obtain the self-care ability in daily life. Excluding this patient, all of the remaining eight patients responded quickly to surgery and were able to go home with their families after 2 to 4 weeks, there being no significant difference between the two age groups. In the 14 patients with hemiplegia/paresis (nine under 70, five 70 or over), a definitely better result was obtained for the non-elderly group. Eight of the nine non-elderly patients (89%) showed full ADL (Barthel index 100), whereas only one of three elderly patients (33.3%) showed almost full ADL (Barthel index 97). In five progressive stroke patients, (three under 70, two 70 or over) ultra-early bypass was performed within 8 hours postictus. Definitely better results were obtained in the patients aged less than 70, who showed rapid recovery and were able to return to their previous jobs 1 to 3 months after surgery. In contrast, the two patients aged 70 or over showed no improvement. In this report, we discuss the clinical and physiological variables that may be important for selection of elderly patients for cerebrovascular bypass surgery.
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PMID:[Results of superficial temporal artery-middle cerebral artery anastomosis for elderly and non-elderly patients with cerebral ischemia]. 782 13

Single photon emission computed tomography (SPECT) using 99mTc-bicisate and N-isopropyl-p-[123I]iodoamphetamine ([123I]IMP) was compared in 25 patients suffering cerebral ischemia during the subacute phase (7-14 days) of stroke. Patients were classified as cortical strokes (15) and subcortical strokes (10) according to clinical and CT data. Images were analyzed by five independent blinded observers. Then, using a cross-matching method between normal and abnormal brain areas, we evaluated the sensitivity and specificity for 99mTc-bicisate and [123I]IMP and inter- and intraobserver reproducibility. A semiquantitative analysis was performed to compare abnormal hypoactive areas versus the corresponding contralateral areas for 99mTc-bicisate and [123I]IMP in the two patient groups. There was no significant difference for sensitivity and specificity between 99mTc-bicisate and [123I]IMP. Matching was approximately 90% in the two groups. The kappa-concordance index was satisfactory and slightly better for 99mTc-bicisate (0.485) than for [123I]IMP (0.435). Level of hypoactivity in the abnormal areas was significantly higher for 99mTc-bicisate (p < 0.03, n = 25) than for [123I]IMP, especially for cortical strokes. This comparative study demonstrates that 99mTc-bicisate is a very useful tracer for the detection of focal cerebral ischemia by SPECT during the subacute phase of stroke.
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PMID:Comparison of brain SPECT using 99mTc-bicisate (L,L-ECD) and [123I]IMP in cortical and subcortical strokes. 826 76

A 65-year-old man who had a history of diabetes mellitus visited a hospital for recent memory disturbance. MR angiography showed stenoses of the main trunks of the intracranial arteries. He was admitted to our hospital, and angiography revealed occlusion of the left cervical internal carotid and right middle cerebral arteries, and stenoses of the right internal carotid, right anterior cerebral, left vertebral, and right posterior cerebral arteries. There was collateral circulation formed from the left external carotid and left posterior cerebral arteries. Basal moyamoya vessels were also observed. 123I-IMP SPECT showed low perfusion of the right cerebral hemisphere, and response to acetazolamide was poor. Based on the angiographical findings and the presence of diabetes mellitus, the patient was diagnosed as having quasi-moyamoya disease. Vascular reconstructive surgery was indicated. Since there was no recipient artery adequate for STA-MCA anastomosis, encephalo-duro-arterio-synangiosis was performed on the right side. Postoperatively, the patient's recent memory improved gradually, and angiography performed 7 months after the operation revealed neovascularization from the superficial and deep temporal arteries. Although indirect bypass surgery has been applied mainly to child moyamoya disease, its effectiveness for cerebral ischemia in adult patients has also been reported, particularly in cases with misery perfusion. Neovascularization with indirect bypass surgery can be expected if the patient is under misery perfusion, even in elderly patients.
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PMID:[Neovascularization after encephalo-duro-arterio-synangiosis in elderly quasi-moyamoya disease: a case report]. 930 Apr 48

A variety of recent studies suggest a role for both inflammatory cytokines such as interleukin-1 beta (IL-1 beta), and apoptosis in ischemic brain injury. Because IL-1 beta converting enzyme (ICE) is required for the conversion of proIL-1 beta to its biologically active form, and has homology with proteins that regulate apoptosis in invertebrates, we studied the effect of cerebral ischemia on brain injury in mutant mice deficient in the ICE gene (ICE knockout [KO] mice). Focal cerebral ischemia, produced by occlusion of the middle cerebral artery, resulted in brain edema (increased water and sodium content) at 4 hours and a histologically defined brain lesion at 24 hours. Both of these markers of brain injury were significantly reduced in the ICE KO mice as compared to wild-type C57BL/6 mice. Regional cerebral blood flow, determined using the flow tracer, N-isopropyl [methyl 1,3-(14)C] p-iodoamphetamine (14C-IMP), was similar in the two strains of mice, indicating that the reduced brain injury in the KO mice was not a result of a lesser degree of ischemia. These data show that ICE contributes to the development of ischemic brain damage, and that it plays a role at an early time in the pathologic process. Although the mechanism of this effect is uncertain, our results suggest that pharmacologic inhibition of ICE may be a useful treatment for stroke.
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PMID:Reduced ischemic brain injury in interleukin-1 beta converting enzyme-deficient mice. 946 61

Iodine-123 labelled iomazenil ([(123)I]IMZ) has been reported to be a useful marker of neuronal viability. The brain distribution of [(123)I]IMZ, however, has not been correlated with the pathophysiological response in detail after an ischaemic insult. To characterise [(123)I]IMZ as a marker of neuronal viability, we compared its brain distribution with cyclooxygenase-2 (COX-2) expression, DNA fragmentation and cellular integrity. [(123)I]IMZ and [(125)I]IMP were injected into rats with focal cerebral ischaemia for the purpose of dual-tracer autoradiography. COX-2 and microtubule-associated protein-2 (MAP-2, a marker of cellular integrity) were immunostained. In situ DNA polymerase-I-dependent dUTP incorporation into damaged DNA was used as an indicator of DNA fragmentation. Lesion to normal ratios (LNRs) for [(123)I]IMP and [(125)I]IMZ were calculated. [(123)I]IMZ accumulation was preserved in several regions with impaired [(123)I]IMP accumulation. COX-2 expression was occasionally observed, whereas neither DNA fragmentation nor MAP-2 denaturation was detected in these regions. DNA fragmentation and impaired MAP-2 immunostaining were observed only in the regions with reduced LNRs for both tracers. The LNR for [(123)I]IMZ was significantly lower in regions with impaired MAP-2 immunostaining (0.120+/-0.152, P<0.0001), in regions positive for dUTP incorporation (0.488+/-0.166, P<0.0001) and in regions positive for COX-2 expression (0.626+/-0.186, P<0.001) than in histologically normal regions (0.784+/-0.213). Thus, neuronal DNA is still intact and cellular integrity is maintained in the ischaemic regions with preserved [(123)I]IMZ accumulation. The impairment of [(123)I]IMZ accumulation precedes DNA fragmentation and denaturation of cellular integrity. These results provide the molecular basis of [(123)I]IMZ distribution.
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PMID:Characterisation of [123I]iomazenil distribution in a rat model of focal cerebral ischaemia in relation to histopathological findings. 1453 32

Compression of the brain by swollen temporal muscle used for indirect pial synangiosis is a rare complication after the revascularization surgery for moyamoya disease, and its mechanism and clinical presentation are undetermined. A 26-year-old woman, who had been suffering transient ischemic attack (TIA), underwent superficial temporal artery-middle cerebral artery anastomosis with encephalo-myo-synangiosis (EMS) on the affected hemisphere. The (123)I-IMP-SPECT 1 day after surgery demonstrated an improvement of cerebral blood flow (CBF) on the operated hemisphere. Two days later, however, she suffered fluctuating aphasia when computed tomography scan revealed marked swelling of the temporal muscle used for EMS. The (123)I-IMP-SPECT 4 days after surgery showed significant decrease in CBF by the compression of the brain. Then, we performed revision of EMS. The base of the temporal muscle was markedly compressed by the edge of the free bone flap, which resulted in swelling of the entire temporal muscle used for EMS. We drilled out the edge of the free bone flap for decompression. Her aphasia disappeared postoperatively, and CBF normalized 7 days after the initial surgery. Her TIA disappeared, and there was no deterioration during the follow-up period. The STA-MCA bypass has been patent since the initial surgery. Surgical revascularization including EMS has a substantial risk for cerebral ischemia owing to compression of the brain by temporal muscle swelling. Relative wide bone window for temporal muscle insertion is necessary to avoid this rare complication. Once the flow compromise is confirmed, we recommend early decompression by the revision of EMS.
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PMID:Cerebral ischemia owing to compression of the brain by swollen temporal muscle used for encephalo-myo-synangiosis in moyamoya disease. 1915 59


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