Kouji Abe

Temporal and spatial differences of PSA-NCAM expression between young-adult and aged rats in normal and ischemic brains.

Highly polysialylated neural cell adhesion molecule (PSA-NCAM) is transiently expressed specifically in newly generated cells, and is important for migration and neurite outgrowth. To investigate the effect of aging on the migration of neural stem cell (NSC) after brain ischemia, the spatiotemporal expressions of immunoreactive PSA-NCAM were examined at 4 h or 1, 3 or 7 days after 90 min of middle cerebral artery occlusion (MCAO) in the young-adult or aged rats. In the sham control brain, PSA-NCAM staining was slightly observed both in dorsal and ventral parts of subventricular zone (SVZ) in the aged brain, but only in the dorsal part of SVZ in the young brain. After transient MCAO, immunoreactivity for PSA-NCAM increased in the number and the intensity in SVZ ipsilateral to MCAO in the young-adult brains and became the peak at 1 day, while that was at 3 days in the aged brains. These findings suggest that PSA-NCAM was located in different spatial distribution in normal condition between young and old rats. PSA-NCAM was induced after ischemia, and the temporal expression was also different after transient MCAO between young and older rats.

Fractal dimension analysis of static stabilometry in Parkinson's disease and spinocerebellar ataxia.

Abstract The static stabilometry patterns associated with Parkinson’s disease (PD, n = 15) and spinocerebellar ataxia (SCA, n = 15) were compared with those of normal control (n = 15) by measuring the fractal dimensions. Fractal dimensions were estimated using the modified pixel dilation (mPD) method. The fractal dimensions with closed eyes showed a significant correlation with Environmental area for SCA group (p<0.05). The fractal dimension for SCA group was significantly higher with closed eyes than that with open eyes (p<0.05). The fractal dimension with closed eyes was significantly higher in PD and SCA groups than that in normal group (p<0.05). The fractal dimension with closed eyes was higher when the clinical stage was more severe with PD and SCA group while Environmental and Longitude/Environmental areas were not. These findings suggest that the fractal dimension is more sensitive than traditional stabilometric analysis in an evaluation of postural instability in PD and SCA.

Nocturnal blood pressure dip in CADASIL.

The influence of a nocturnal blood pressure dip on cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) has not yet been clarified. We attempted to examine a correlation with the nocturnal blood pressure dip and CADASIL. We monitored circadian blood pressure patterns by the use of a portable blood pressure monitoring device in five patients with CADASIL and 10 age- and sex-matched control subjects. Based on nocturnal fall in mean arterial blood pressure (MABP), we classified patients into extreme dippers (nocturnal reduction of MABP > or =20%), dippers (> or =10% but <20%), nondippers (<10% but > or =0%), and inverted dippers (<0%). Three patients revealed non-dipper and two inverted dipper. Nighttime MABP fall was significantly lower in patients compared with control subjects (P<0.01). This study suggests that a lower nocturnal blood pressure fall may be partly associated with incidence and/or worsening of deep white matter lesions in CADASIL.

Attenuation of oxidative DNA damage with a novel antioxidant EPC-K1 in rat brain neuronal cells after transient middle cerebral artery occlusion

Abstract EPC-K1, L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-yl-hydrogen phosphate] potassium salt, is a novel antioxidant. In this study, we investigated a reduction of oxidative neuronal cell damage with EPC-K1 by immunohistochemical analysis for 8-hydroxy-2′-deoxyguanosine (8-OHdG) in rat brain with 60 min transient middle cerebral artery occlusion, in association with terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick end labeling (TUNEL) and staining for total and active caspase-3. Treatment with EPC-K1 (20mg kg-1 i.v.) significantly reduced infarct size (p < 0.05) at 24 h of reperfusion. There were no positive cells for 8-OHdG and TUNEL in sham-operated brain, but numerous cells became positive for 8-OHdG, TUNEL and caspase-3 in the brains with ischemia. The number was markedly reduced in the EPC-K1 treated group. These reductions were particularly evident in the border zone of the infarct area, but the degree of reduction was less in caspase-3 staining than in 8-OHdG and TUNEL stainings. These results indicate EPC-K1 attenuates oxidative neuronal cell damage and prevents neuronal cell death. [Neurol Res 2001; 23: 676-680]

Serial MRI findings in patient with chronic cryptococcus meningo-encephalitis

Abstract We describe the serial changes of magnetic resonance imaging (MRI) in a patient with chronic cryptococcus meningo-encephalitis. In the subacute phase, MRI revealed a focal lesion with hyperintensity on T2-weighted image (WI) in the left thalamus. At 11 months after the onset, MRI showed a focal lesion with hyperintensity on T2-WI in the right pons that was enhanced with gadolinium (Gd). At 13 months after the onset, the lesion in the left thalamus became rim enhanced with Gd. After antifungal therapy (amphotericin B and 5-flucytosine), the rim enhancement in the left thalamus and the high signal intensity area in the right pons decreased. Cryptococcoma should be in the differential from other ring enhancing lesions. [Neurol Res 2001; 23: 810-812]