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S Tsuji

Publications and source records attributed to S Tsuji.

At least 559 records · Page 31Linked to original sources
PubMed1995

Dual-tracer autoradiography using 125I-iomazenil and 99Tcm-HMPAO in experimental brain ischaemia.

To investigate the utility of neuroreceptor imaging in ischaemic cerebrovascular disorders, dual-tracer autoradiography using 99Tcm-hexamethylpropyleneamine oxime (HMPAO) for the evaluation of cerebral blood flow and 125I-iomazenil for the evaluation of central-type benzodiazepine receptor density was performed in experimental brain ischaemia created by occlusion of the unilateral middle cerebral artery of the rat. In the acute phase of ischaemia, 125I-iomazenil accumulation showed less of a decrease than 99Tcm-HMPAO in the cerebral cortex of the lateral convexity and in the lateral segment of the caudate putamen in the lesioned cerebral hemisphere. In the sub-acute phase, both 125I-iomazenil and 99Tcm-HMPAO accumulation increased in the lesion compared with the acute phase. A large accumulation of 99Tcm-HMPAO and 125I-iomazenil in the lesion was considered to be due to luxury perfusion and penetration of 125I-iomazenil hydrophilic metabolites from the blood into the brain tissue through the altered blood-brain barrier. In the chronic phase, 125I-iomazenil accumulation showed a more marked decrease than 99Tcm-HMPAO in the lesion. Moreover, the ipsilateral thalamus, which is remote from the lesion, revealed decreased 125I-iomazenil accumulation despite normal 99Tcm-HMPAO accumulation. Since the central-type benzodiazepine receptors are principally located not on the glial cells but on the neurons, the receptor density may exhibit a change that parallels the neuron density. These results suggest that central-type benzodiazepine receptor imaging is useful for the evaluation of neuronal damage when used in conjunction with brain perfusion imaging in ischaemic cerebrovascular disorders, except in the sub-acute phase.

Acute Disease↗
PubMed1995

Does homozygosity advance the onset of dentatorubral-pallidoluysian atrophy?

We confirmed a homozygous type of relatively small expansion of CAG triplet repeats (57 repeats) in the short arm of chromosome 12 in a male patient with dentatorubral-pallidoluysian atrophy (DRPLA) by polymerase chain reaction. He showed early onset (age, 17 years) of DRPLA. There was good correlation of the age of onset with the number of triplet repeats. The homozygous state of the expansion of the triplet repeats was responsible for the early onset and severity of his DRPLA.

Adult↗
PubMed1995

Identification and minisatellite linkage analysis of SMXA recombinant inbred strains of mice by DNA fingerprinting.

SMXA recombinant inbred (RI) strains of mice were produced by systematic inbreeding from the F2 generation of a cross between two progenitor inbred strains, A/J and SM/J, which differ considerably with respect to many characteristics, and consists of 28 inbred strains. In this study, we investigated the applicability of DNA fingerprinting with M13 phage DNA to the identification of these closely related strains. DNA fingerprints of the SMXA RI strains and their progenitors, SM/J and A/J, showed strain-specific patterns, with the same banding patterns within each strain. Linkage analysis by using strain distribution patterns of minisatellite loci with 108 genetic markers containing microsatellites, biochemical and immunological marker genes allowed 23 minisatellite loci to be assigned to 11 chromosomes. The results suggested that DNA fingerprinting with M13 phage DNA is applicable not only for strain identification but also for genetic monitoring of RI strains on almost all chromosomes.

Animals↗
PubMed1995

Gastric blood flow in ulcer diseases.

BACKGROUND: Gastric blood circulation maintains the structure and functions of the stomach, and thereby is closely associated with the pathogenesis and the healing of gastrointestinal lesions. Gastric mucosal blood flow, regulated by systemic neural and humoral factors, is also modified by local metabolic factors such as prostaglandins, leukotrienes. PAF and other endogenous chemical mediators in mucosa. Endothelium-derived factors that are produced by vascular endothelial cells, inducing relaxation or contraction of the blood vessels, are also recognized as basic mediators that regulate the circulation in the stomach. RESULTS: The regionally disturbed gastric circulation in combination with the presence of acid is closely associated with the pathogenesis of NSAIDs and ethanol-induced gastric lesions. Blood flow and oxygenation in the surface mucosa surrounding the peptic ulcer change during healing, depending on the quality of the ulcer healing process: an increased blood circulation with increased oxygen supply to the ulcer margin is important for rapid ulcer healing shown by reflectance spectrophotometry. Factors altering the blood flow during the ulcer healing are discussed.

Animals↗
PubMed1995

Molecular cloning of a full-length cDNA for dentatorubral-pallidoluysian atrophy and regional expressions of the expanded alleles in the CNS.

Dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder characterized by genetic anticipation and variable combinations of symptoms including myoclonus, epilepsy, cerebellar ataxia, choreoathetosis, and dementia. Recently, we discovered that DRPLA is caused by unstable expansion of a CAG repeat of a gene on the short arm of chromosome 12. We determined the consensus DRPLA cDNA sequence containing the complete coding region for 1,185 amino acids. The CAG repeat, which is expanded in DRPLA, is located 1,462 bp downstream from the putative methionine initiation codon and encodes a poly-glutamine tract. Although poly-serine and proline tracts exist near the CAG repeats, these polyserine or proline tracts did not show any polymorphisms, which is in strong contrast to the high heterogeneity in the length of the CAG repeat. Northern blot analysis revealed a 4.7-kb transcript that is widely expressed in various tissues including heart, lung, kidney, placenta, skeletal muscle, and brain. Reverse transcription-PCR analysis revealed that the expanded alleles are transcribed to levels comparable to those of normal alleles. These results indicate that there is no difference in transcriptional efficiency between expanded and normal alleles. Furthermore, mRNA from cerebellar hemispheres of DRPLA patients showed smaller sizes of CAG repeats compared with other regions of the brain, which reflects somatic mosaicism of the expanded alleles of the DRPLA gene.

Alleles↗
PubMed1995

[Auditory comprehension in transcortical motor aphasia due to a medial lesions of the left frontal lobe].

We assessed the anatomical findings and auditory comprehension of six patients with transcortical motor aphasia due to medical lesions of the left frontal lobe. All patients were right-handed and were initially mute for several hours after the onset, and they exhibited mild paresis of the right lower extremity. Their spontaneous speech was sparse and not fluent, and sometimes accompanied by echolalia, but their articulation was normal and repetition was excellent. They had difficulty in recalling words. A diagnosis of transcortical motor aphasia was made on the basis of their clinical symptoms. All patients were found to have an infarct in the left medial frontal region by MRI and/or CT. We administered the Western Aphasia Battery and 50 line drawing pointing task in order to evaluate auditory comprehension. Based on the results we concluded that there is no impairment of auditory comprehension of single words when lesions are limited to the superior frontal gyrus, but that lesions extending to the middle frontal gyrus interfere with auditory comprehension of single words. Our observations indicate that the middle frontal gyrus plays an important role in auditory comprehension of single words. All of the patients displayed impaired auditory comprehension of sentences even when their lesions were strictly limited to the medial frontal lobe. This suggests that the medial frontal lobe plays some role in the auditory comprehension of sentences.

Aged↗
PubMed1995

[A case of pure alexia whose writing ability with eyes closed was superior to that with eyes open].

We compared the writing ability between eyes open (looking at one's writing) and eyes closed (without looking) in a case of pure alexia. The patient is a 84-year-old right handed man who developed pure alexia following an infarction in the distribution of the left posterior cerebral artery. He showed right homonymous hemianopsia, slight memory disorder and slight anomia. He could not read any kinds of letters and words at all though he could categorize letters: Kana (phonograms), Kanji (morphograms) and Arabic numbers, and he could distinguish the real letters from false ones. He could achieve almost 60-70% of Kana and Kanji dictation, though it was not perfect. He was often confused and could not continue writing correct letters once interrupted. He wrote poorly when looking at what he was writing. So we compared the ability of dictation with his eyes closed, and that with his eyes open. We found the former way never caused confusion and got better results, which was statistically significant (Fisher's exact test (p < 0.05)). It seemed that his visual feedback of his own writing rather caused trouble in his writing. Thus we concluded that input (reading) process and output (writing) process work simultaneously and bi-directionally. Slight impairment of writing in pure alexia patients might be caused by the effect of impairment of input (reading) process, which is simultaneously connected with the output (writing) process.

Aged↗
PubMed1995

Dentatorubral-pallidoluysian atrophy (DRPLA). Molecular basis for wide clinical features of DRPLA.

Dentatorubral-pallidoluysian atrophy (DRPLA) is a rare autosomal dominant neurodegenerative disorder characterized clinically by various combinations of myoclonus, epilepsy, cerebellar ataxia, choreoathetosis, dementia and psychiatric symptoms. Based on the phenomenon of anticipation, the gene for DRPLA was recently identified. DRPLA is caused by unstable expansion of a CAG repeat in the gene located on the short arm of chromosome 12. As have been observed in Huntington's disease and SCA1, there is a strong correlation between the age of onset and the size of CAG repeats. Furthermore, patients with larger repeats tend to show a PME (progressive myoclonus epilepsy) phenotype as well as earlier ages of onset. More prominent anticipation and larger intergenerational increase of CAG repeats in paternal transmission can be accounted for by the meiotic instability of CAG repeats in male gametogenesis. Comparison of size distributions of CAG repeats in Japanese, African-American and white populations revealed that 7.4% of the Japanese alleles had greater than 19 repeats, whereas none of the whites and 1% of the African-American alleles were of this size. The results may account for the ethnic predilection of DRPLA.

Adult↗
PubMed1995

Ethanol induces heterogeneous reduction of cytochrome aa3 within perfused rat liver lobule assessed using microspectroscopy.

The redox state of cytochrome aa3 was measured at microspots (20 microns diameter) within the lobule of perfused rat livers, using reflectance microspectroscopy, and the effect of ethanol infusion on sublobular distribution of the redox states was evaluated. A sigmoidal relationship was observed between oxygen delivery and the reduction of cytochrome aa3 in both the periportal and pericentral regions of the liver lobule when the influent O2 concentration was decreased in a graduated manner. This sigmoidal curve was shifted to the more reduced state by ethanol infusion, with ethanol (25-100 mM) increasing the degree of cytochrome aa3 reduction in a dose-dependent manner according to the distance from the periportal region along a sinusoid. This increase was spatially heterogeneous within a liver lobule. These data indicate that ethanol accelerates cytochrome aa3 reduction, with a distinct gradient of reduction along sinusoids but a heterogeneous distribution within the liver lobule.

Animals↗
PubMed1995

[A sporadic dentatorubral-pallidoluysian atrophy (DRPLA) diagnosed by gene analysis].

We report a 48-year-old woman with dentatorubral-pallidoluysian atrophy (DRPLA). She is the only patient in her 15 family members in two generations. She developed cerebellar ataxia and epilepsy at age 43. On admission at 48, she showed mild dementia and choreic movement in her face and extremities as well as truncal and limb ataxia. Routine laboratory examinations were normal. The point mutations in the tRNALys gene of mitochondrial DNA specific for MERRF were not found. A cranial CT scan and MRI showed mild atrophy of the cerebellum and prominent atrophy in the pons, especially in the tegmentum. Although she was thought to have DRPLA from the clinical point of view, absence of family history made the diagnosis difficult. Her parents were healthy until their 80's and died of cerebrovascular diseases and her 5 siblings had no symptoms. Hereditary DRPLA is known as an autosomal dominant disorder, with a high rate of penetrance and low rate of new mutation. According to our recent findings of a CAG repeat expansion in the DRPLA gene, this patient was diagnosed as a sporadic DRPLA. Considering the wide varieties of clinical manifestations, it is essential to examine this gene abnormality for diagnosing sporadic DRPLA.

Atrophy↗
PubMed1995

[Familial posterior cortical atrophy with visual agnosia and Bálint's syndrome].

We report a patient of posterior cortical atrophy with progressive visual agnosia, Bálint's syndrome and dementia in which posterior cortical atrophy with similar characteristics on CT and progressive dementia were found in a sister. The patient was a 75-year-old woman who noted the onset of a progressive visual disorder at the age of 70, and whose family first noticed disoriented behavior at around the same period. Ophthalmologic examinations revealed mild cataract but no evidence of peripheral optic nerve or retinal lesions. Neuropsychological examination showed right homonymous hemianopia, visual agnosia, Bálint's syndrome, mild transcortical sensory aphasia, Gerstmann's syndrome, constructional apraxia, mild ideomotor apraxia and memory disorder. MRI showed marked dilatation of both lateral ventricles, especially the posterior horns, and severe atrophy of the occipital lobes, hippocampus, and the parahippocampal gyrus. Assessment of regional cerebral blood flow by IMP-SPECT revealed a generalized decrease in the temporo-parieto-occipital region bilaterally. The patient's sister began to show evidence of progressive dementia at 80 years of age and CT of the brain revealed marked atrophy, predominantly in the occipital lobes, similar to that of the patient. We believe this to be the first report of posterior cortical atrophy with a positive family history, suggesting the possibility of a hereditary syndrome.

Aged↗