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Jae-Kyu Roh

Publications and source records attributed to Jae-Kyu Roh.

49 records · Page 3Linked to original sources
PubMed2003

Human neural stem cell transplantation promotes functional recovery in rats with experimental intracerebral hemorrhage.

BACKGROUND AND PURPOSE: Cell transplantation has been used to reduce behavioral deficit in cerebral ischemia. However, there is no report about cell transplantation in experimental intracerebral hemorrhage (ICH). We hypothesize that intravenously transplanted human neural stem cells (NSCs) can migrate and differentiate into neurons or glial cells, thereby improving functional outcome in ICH. METHODS: Experimental ICH was induced by intrastriatal administration of bacterial collagenase in adult rats. One day after surgery, the rats were randomly divided into 2 groups to receive intravenously either immortalized Lac z-positive human NSCs (5x10(6) cells in 500 microL, n=12) or the same amount of saline (n=13). The animals were evaluated for 8 weeks with modified limb placing and rotarod tests. Transplanted NSCs were detected by X-gal histochemistry or beta-gal immunohistochemistry with double labeling of GFAP, NeuN, neurofilament, or CNPase. RESULTS: Intravenously transplanted NSCs migrated selectively to the perihematomal areas and differentiated into neurons (approximately 10% of beta-gal+ cells) and astrocytes (approximately 75%). The NSC-transplanted group showed better functional performance on rotarod test after 2 weeks and on modified limb placing test after 5 weeks compared with the control group (P<0.05), and these effects persisted for up to 8 weeks. There was no difference in the final hemispheric area between the 2 groups. CONCLUSIONS: Intravenously transplanted NSCs can enter the rat brain with ICH, survive, migrate, and improve functional recovery. Transplantation of human NSCs can be used to restore neurological deficits in experimental ICH.

Animals↗
PubMed2003

A case of multiple brain infarctions associated with Erysipelothrix rhusiopathiae endocarditis.

A 63-year-old woman was admitted to our hospital because of fever and altered mentality. Brain magnetic resonance imaging showed multiple infarctions at the basal ganglia, cerebellum, and subcortical white matter with petechial hemorrhage, which was more easily seen on gradient echo images. Erysipelothrix rhusiopathiae was cultured from her blood, and echocardiography showed septic vegetations in the mitral valve. She recovered fully after 6 weeks of appropriate antibiotic treatment.

Brain Infarction↗
PubMed2003

POEMS syndrome associated with ischemic stroke.

BACKGROUND: A syndrome variously combining peripheral neuropathy, visceromegaly, endocrinopathy, monoclonal gammopathy, and skin changes (POEMS syndrome) is a rare variant of plasma cell dyscrasia with multisystemic manifestations. Acute ischemic strokes in patients with POEMS syndrome have rarely been reported, and the pathophysiologic mechanism of this disease is unknown. Fibrinogen is reported to be an independent risk factor for cerebrovascular disease and is correlated with the interleukin 6 level in the plasma. The serum level of interleukin 6 is high in the active stage of POEMS syndrome. OBJECTIVE: To describe the neuroimaging findings and fibrinogen levels in patients with POEMS syndrome. DESIGN: Case series. SETTING: The neurology department of a tertiary referral center. METHODS: Three patients with an acute cerebral infarction associated with POEMS syndrome underwent magnetic resonance imaging, diffusion-weighted imaging, magnetic resonance angiography, transcranial Doppler ultrasonography, and serum fibrinogen level and serum C-reactive protein level analysis. The serum fibrinogen level before the stroke was collected retrospectively from the hospital medical records. RESULTS: There was an elevated fibrinogen level in all of the patients. In 2 patients, unilateral or bilateral end artery border-zone infarcts were observed on the brain magnetic resonance imaging scan. The serum fibrinogen level was high before the stroke in 2 patients. CONCLUSIONS: The POEMS syndrome can be associated with stroke, particularly end artery border-zone infarctions. We suggest that an elevated fibrinogen level might play a role in the pathogenesis of stroke.

Adult↗
PubMed2003

A case of cortical vein thrombosis with the cord sign.

BACKGROUND: Computed tomography is performed in suspicious cases of cerebral venous thrombosis. Although an empty delta sign is not uncommonly reported, a cord sign is rarely reported. But this is, if present, pathognomonic, especially in the case of cortical vein thrombosis. CASE DESCRIPTION: A young man with antithrombin III deficiency sought emergency treatment for headache and seizure. Noncontrast computed tomography showed a typical cord sign in multiple sections. It seemed to be independent from the adjacent pathologic findings in most sections. Brain magnetic resonance imaging verified it as a thrombosed vein in conjunction with acute venous infarction. CONCLUSION: The cord sign should be considered for early and accurate diagnosis of cortical vein thrombosis.

Adult↗
PubMed2003

Huntingtin is degraded to small fragments by calpain after ischemic injury.

The gene defect in Huntington's disease (HD) causes a polyglutamine expansion in the N-terminal region of huntingtin (N-htt). In vitro studies suggest that mutant N-htt fragments can aggregate and cause cell death in HD. The physiological and pathological conditions that affect htt proteolysis in the brain are unclear. We examined htt expression by Western blot in the rat brain after transient ischemic injury, which causes striatal neurodegeneration similar to that seen in HD and activates proteases including calcium-dependent calpains. Focal brain ischemia reduced levels of full-length htt in the infarcted cortex and striatum and increased expression of a 55-kDa N-htt fragment that was also produced by treating control brain extracts with calpain. N-htt fragments between 65 and 80 kDa also rose after injury, but these fragments were not as long-lived as the 55-kDa N-htt fragment. The results suggest that after ischemic injury full-length htt is degraded in degenerating neurons and an N-htt fragment accumulates.

Animals↗
PubMed2003

Nonpulsatile cerebral perfusion in Takayasu's arteritis.

A nonpulsatile cerebral perfusion may be encountered in an artificial cardiopulmonary bypass used in cardiac surgery, which is exceptional in physiological conditions. The authors report on a 37-year-old woman with Takayasu's arteritis (TA) who had been suffering from progressive visual loss and recurrent seizures. Ocular findings of chronic ischemia and multiple, subcortical, high-signal lesions in magnetic resonance (MR) imaging were indicative of significant hemodynamic impairment. MR angiography showed the complete occlusion of the innominate artery, the left common carotid artery (CCA), and the subclavian artery from the orifice of the aortic arch. The patient's transcranial Doppler (TCD) waveform was flat throughout all segments of the intracranial arteries. Intravenous acetazolamide injection confirmed the severe impairment of vasoreactivity. After a bypass graft from the aorta to the left CCA, flow velocity and pulsatility were dramatically increased without postoperative complications. A nonpulsatile cerebral perfusion indicates severe hemodynamic impairment and is partially reversible by a surgical bypass graft. TCD seems to be useful to detect "high-risk" patients and to follow up in TA.

Adult↗
PubMed2002

Ischemic intensity influences the distribution of delayed infarction and apoptotic cell death following transient focal cerebral ischemia in rats.

The aim of this study was to investigate whether the apoptotic process contributes to the delayed infarction that follows a middle cerebral artery (MCA) occlusion of 20 min (mild ischemia group) and to compare this with the delayed component of infarct following 2 h of MCA occlusion (severe ischemia group). Adult male Sprague-Dawley rats underwent left MCA occlusion for either 20 min or 2 h and were reperfused for 12, 24 and 72 h. On 2,3,5-triphenyltetrazolium chloride-stained coronal sections, delayed infarction was observed to develop in the whole MCA territory after mild ischemia, and also in the frontoparietal cortex after severe ischemia. At 24 h after 20 min of MCA occlusion, characteristic apoptotic features, including chromatin condensation and apoptotic bodies were frequently observed by electron microscopy. In both ischemic groups, Hoechst 33342 staining showed typically condensed and fragmented nuclei in the area showing delayed infarction, where TdT-dUTP nick end labeling (TUNEL)-positive cells were also significantly increased. Caspase-3 activity was also found to be elevated 24 and 72 h after reperfusion and this peaked at 24 h in both groups. These findings suggest that ischemic severity may influence the distribution of delayed infarction, and that apoptosis is the underlying pathophysiologic mechanism.

Animals↗
PubMed2002

Lesion patterns and mechanism of ischemia in internal carotid artery disease: a diffusion-weighted imaging study.

CONTEXT: Although embolism and low-flow phenomenon are the 2 main mechanisms of stroke in internal carotid artery (ICA) occlusive disease, the mechanism of border-zone infarction remains controversial. Diffusion-weighted imaging (DWI) can more easily detect small or multiple ischemic lesions than conventional imaging. OBJECTIVES: To investigate the ischemic lesion patterns on DWI and to discuss the mechanisms of stroke in ICA disease. DESIGN: Case series. SETTING: A tertiary referral center. PATIENTS: We enrolled 35 consecutive patients who had an acute ischemic stroke and (> or = 70%) stenosis or an occlusion of the extracranial ICA confirmed by cerebral angiography and an acute relevant stroke lesion on DWI within 1 week of onset, but without cardiac sources of embolism and tandem intracranial arterial disease. MAIN OUTCOME MEASURES: The lesion pattern on DWI was categorized as territorial or border zone. Multiple ischemic lesions were defined as noncontiguous lesions on DWI in more than 1 vascular territory. RESULTS: There were 3 distinctive stroke lesion patterns. (1) A territorial lesion without a border-zone lesion was found in 21 patients: superficial and superficial territorial in 9, superficial and deep territorial in 7, and single in 5. (2) A border-zone lesion with or without a territorial lesion was found in 10 patients: border zone and territorial in 9 and border zone alone in 1. (3) Bilateral hemispheric lesions were found in 4 patients. Multiple ischemic lesions were found in 29 (82.9%) of the 35 patients. No patient had episodes of hemodynamic compromise. CONCLUSIONS: An acute ischemic lesion in ICA occlusive disease is mainly multiple. Border-zone infarction was mostly associated with territorial infarction. These results support the fact that embolism is the predominant stroke mechanism in ICA occlusive disease.

Aged↗
PubMed2002

Gradient echo magnetic resonance imaging in the prediction of hemorrhagic vs ischemic stroke: a need for the consideration of the extent of leukoariosis.

BACKGROUND: Multifocal signal loss lesion (MSLL) on gradient echo magnetic resonance imaging (GE-MRI) may reflect bleeding-prone microangiopathy. However, MSLLs are also known to be associated with leukoariosis; leukoariosis is commonly associated with occlusive-type vascular lesions. OBJECTIVE: To determine whether MSLL on GE-MRI is significantly associated with the type of stroke--intracerebral hemorrhagic (ICH) stroke more often than an ischemic stroke (infarction)--regardless of the extent of leukoariosis. PATIENTS AND METHODS: We studied 91 patients who had an acute stroke and were admitted to the Department of Neurology, Seoul National University Hospital, Seoul, South Korea, from March 1, 1997, to July 31, 1998. These patients underwent both conventional MRI and GE-MRI. The GE-MRI was used to count MSLLs. We also counted lacunae and classified leukoariosis (none or mild and advanced). Multiple logistic regression analysis was used to test for MSLL-leukoariosis interaction association with the type of stroke (ICH over infarction) and to evaluate the relative contribution of an MSLL--adjusted for age, sex, and lacunae--in discriminating the type of stroke. RESULTS: The association between MSLL and ICH statistically significantly differed by leukoariosis (P =.003 for MSLL-leukoariosis interaction term). The MSLL count on GE-MRI was significantly associated with the type of stroke (ICH over infarction; odds ratio, 2.46; 95% confidence interval, 1.38-4.39) when leukoariosis was classified as none or mild. When leukoariosis was classified as advanced, there was a decrease in the odds ratio of MSLL to 0.99 (95% confidence interval, 0.94-1.04). CONCLUSIONS: Our findings indicate that MSLL on GE-MRI is a predictor of ICH vs infarction in patients with no or mild leukoariosis, but not in patients with advanced leukoariosis. Therefore, in the evaluation of GE-MRI for a bleeding-prone microangiopathy, the extent of leukoariosis should be considered.

Adult↗
PubMed2002

Diffusion-weighted and gradient echo magnetic resonance findings of hemichorea-hemiballismus associated with diabetic hyperglycemia: a hyperviscosity syndrome?

BACKGROUND: The magnetic resonance (MR) imaging findings of hemichorea-hemiballismus (HCHB) associated with hyperglycemia are characterized by hyperintensities in the striatum on T1-weighted MR images and computed tomographic scans, with a mechanism of petechial hemorrhage considered to be responsible. Diffusion-weighted MR imaging (DWI) has been reported to detect early ischemic damage (cytotoxic edema) as bright areas of high signal intensity and vasogenic edema as areas of heterogeneous signal intensity. We report various DWI findings in 2 patients with hyperglycemic HCHB. OBJECTIVES: To describe the DWI and gradient echo findings and characterize the types of edema in HCHB associated with hyperglycemia. SETTING: A tertiary referral center neurology department. DESIGN AND METHODS: Two patients with HCHB associated with hyperglycemia underwent DWI, gradient echo imaging, and conventional MR imaging with gadolinium enhancement. The patients had an elevated serum glucose level on admission and a long history of uncontrolled diabetes, and the symptoms were controlled by dopamine receptor blocking agents. Initial DWIs were obtained 5 to 20 days after symptom onset. Apparent diffusion coefficient (ADC) values were measured in the abnormal lesions with visual inspection of DWI and T2-weighted echo planar images. RESULTS: T1- and T2-weighted MR images and brain computed tomographic scans showed high signal intensities in the right head of the caudate nucleus and the putamen. Gradient echo images were normal. The DWIs showed bright high signal intensity in the corresponding lesions (patient 1), and the ADC values were decreased. The decrease in ADC and the high signal intensity on DWI persisted despite the disappearance of HCHB, even after 70 days. CONCLUSIONS: Gradient echo MR imaging findings were normal in HCHB with hyperglycemia, whereas DWI and the ADC map showed restricted diffusion, which suggests that hyperviscosity, not petechial hemorrhage, with cytotoxic edema can cause the observed MR abnormalities.

Aged↗
PubMed2002

Neurotrophin receptor immunoreactivity in severe cerebral cortical dysplasia.

PURPOSE: Cerebral cortical dysplasia (CD) is one of the important causes of intractable epilepsies and characterized histologically by disorganized cortical lamination and cytomegalic dysplastic neurons. Although it has been suggested that neurotrophins play an important role in differentiation, growth, and survival of developmental neurons, their pathogenetic role in CD has rarely been investigated. METHODS: To know the pathogenetic role of various neurotrophins on dysplastic neurons, immunohistochemical staining was performed using antibodies against NGFRp75, trkA, trkB, and trkC in surgical specimens of 20 patients with CD. RESULTS: TrkB and trkC were strongly expressed in dysplastic neurons of severe CD, and NGFRp75 was also expressed in some dysplastic neurons. CONCLUSIONS: It is known that brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) contribute to the differentiation of neuronal precursor cells, dendritic and axonal arborization, synaptic plasticity, and cellular hyperexcitability, so increased expression of trkB and trkC may have a critical pathogenetic role in cytoskeletal abnormalities and epileptogenicity in dysplastic neurons of CD.

Adolescent↗
PubMed2002

Low concentration of serum total cholesterol is associated with multifocal signal loss lesions on gradient-echo magnetic resonance imaging: analysis of risk factors for multifocal signal loss lesions.

BACKGROUND AND PURPOSE: Multifocal signal loss lesions (MSLLs) on T2*-weighted gradient-echo (GE) MRI are believed to be microbleeds histopathologically. Previous epidemiological studies suggested that low serum cholesterol is associated with the increased risk of intracerebral hemorrhage. We investigated risk factors of MSLLs and the relationship between lipid profiles and MSLLs on GE-MRI. METHODS: We included consecutively 172 patients who underwent brain MRI. MSLLs on GE-MRI were counted by 2 neurologists separately and graded by consensus. The concentrations of lipid profiles were categorized as quartiles, and the MSLLs were graded as absent (total count, 0), mild (1 to 2), moderate (3 to 10), and severe (>10). RESULTS: The mean concentrations of total cholesterol and low-density lipoprotein cholesterol were significantly lower in patients with a severe degree of MSLLs than in those without MSLL (P<0.05). By multivariate analysis, MSLLs were significantly correlated with hypertension (odds ratio [OR], 3.42; 95% CI, 1.17 to 9.97), leukoaraiosis (OR, 4.62; 95% CI, 2.87 to 7.41), the lowest quartile of serum total cholesterol (<4.27 mmol/L; OR, 10.91; 95% CI, 3.98 to 25.57), and the highest quartile of high-density lipoprotein (>1.47 mmol/L; OR, 3.5; 95% CI, 1.45 to 8.29). CONCLUSIONS: Our results suggest that both the lipid profile levels and the severity of hypertension may be closely associated with MSLLs on GE-MRI.

Adult↗