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Biomedical subjects

H Fukuyama

Publications and source records attributed to H Fukuyama.

At least 217 records · Page 12Linked to original sources
PubMed1988

Biochemical aspects of Parkinson-dementia complex.

Positron emission tomography of a parkinsonian patient with dementia revealed a decreased cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) in the cerebral cortex and deep gray matter, whereas a parkinsonian patient without dementia showed a decrease in CBF and CMRO2 in the deep gray matter, but not in the cerebral cortex. The ratio of 3,4-dihydroxyphenylacetic acid/L-dopa in the plasma after L-dopa administration was significantly increased in parkinsonian patients with hallucinations, indicating an accelerated metabolism of L-dopa. The concentration of 5-hydroxyindoleacetic acid (5HIAA) was decreased in the cerebrospinal fluid of parkinsonian patients with psychiatric symptoms, especially with visual hallucinations. The serotonin level in mouse striatum was significantly reduced 1 week after methylphenyltetrahydropyridine (MPTP) injection, though returned to normal in 4 weeks. The 5HIAA level increased at both 1 and 4 weeks. The activity of tryptophan hydroxylase was increased in the striatum 1-4 weeks after MPTP injection, but was unchanged in the cerebral cortex. The choline acetyltransferase (ChAT) activity was significantly decreased in the hippocampus 1 week, but not 4 weeks after MPTP. The ChAT activity was not changed in the frontal cortex at either 1 or 4 weeks.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1988

[Cerebral circulation and oxygen metabolism in children's "moyamoya" diseases].

Regional (r) CBF, rOEF, rCMRO2, rCBV in five cases of "moyamoya" disease in children were studied with PET scan, using 15O steady-state methods. All cases showed ischemic symptoms such as TIA, RIND and minor stroke. Intervals from the latest ictus to PET ranged from 3 days to 3 years 6 months. Control data were obtained through PET studies in 8 normal volunteers. Physiological parameters described above, in cerebral gray matter, white matter and basal ganglia were calculated and were carefully compared with normal control. Apparently low density area in X-ray CT were excluded from this analysis. Although rCBF showed a little bit higher value in all gray, white and basal ganglia, it was not statistically significant. rCBV of "moyamoya" disease significantly increased in gray, white and basal ganglia. The calculated value of CBF/CBV is considered to be an index of perfusion pressure and is the reversed value of transit time. This value was significantly decreased in "moyamoya" disease in every three region. Under the normal autoregulation, further decrease of perfusion pressure initiate increase of rOER and also decrease of rCBF. In spite of reduction of CBF/CBV, rOER was not significantly increased in every three region. Hence the cerebral circulation in children's "moyamoya" disease of ischemic type appears to be characterized by the mild decrease of perfusion pressure, dilated resistant vessels and prolonged circulation time.

Adolescent↗
PubMed1987

Pontine ataxic hemiparesis studied by a high-resolution magnetic resonance imaging system.

Using a high-resolution magnetic resonance imaging system, we studied 3 patients who had exhibited pontine ataxic hemiparesis. In each patient, the ischemic lesions responsible for the contralateral ataxia were located in the dorsomedial basis pontis. The isointensity bands in the ischemic area on T2-weighted images showed the spared transverse fibers originating from the contralateral pontine nuclei, and this may explain the cause of the unilateral ataxia.

Ataxia↗
PubMed1987

Acute-onset amnestic syndrome with localized infarct on the dominant side--comparison between anteromedial thalamic lesion and posterior cerebral artery territory lesion.

Among 39 cases with acute-onset amnestic syndrome having unilateral localized infarct, 8 cases with anteromedial thalamic infarct ("thalamic" amnesia), and 18 cases with medial temporal lobe infarct including hippocampus in the posterior cerebral artery territory ("PCA" amnesia) were studied in terms of X-CT and MRI findings and neuropsychological examinations. Results were as follows: 7 out of 8 cases with thalamic amnesia (88%), and 15 of 19 cases with PCA amnesia (78%) showed left side lesions on CT scan. All groups showed a prolonged recent memory loss with little loss of immediate recall and remote memory, and disorientation and dyscalculia. In both types of amnesia, patients having a left sided lesion showed recent memory loss with new learning disabilities of verbal materials. Patients having a right sided lesion showed recent memory loss with new learning disabilities of both verbal and visuospatial materials. Judging from the X-CT and MRI findings, the lesions most probably causing amnesia in these cases seemed to be the anterior and dorsomedial nuclei of the thalamus in thalamic amnesia and hippocampus in PCA amnesia. Differential diagnosis in amnestic syndrome with localized infarct is also discussed.

Adult↗