Biomedical subjects
Publications and source records attributed to N Yasui.
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A cervical cord tumor was examined with positron emission tomography using L-methyl-[11C]methionine. The radioactive tracer accumulated in the solid parts (but not in the associated cysts) of the neoplasm, which at histology was found to be an ependymoma.
After the stereotactic treatment of patients with Parkinson's disease, a correlative study between the site of the deep subcortical lesions and subsequent cerebellar signs (dysmetria and hypotonia) was made. Cerebellar signs appeared in 27 cases (40.8%) of subthalamotomy and in 3 cases (8.6%) of VIM thalamotomy 2 weeks after an operation. The appearance of these signs after an operation was independent from the operative effect on tremor. Thus, we concluded that VIM thalamotomy might be better than subthalamotomy for the relief of tremor in Parkinson's disease.
A combined antitumor activity of mitomycin C (MMC) and interferon gamma-1a (IFN-gamma) was evaluated to be synergistic by the 3-(4, 5-dimethylthiazol-2yl)-2,5-diphenyl-2H tetrazolium bromide assay and human tumor xenografts/severe combined immunodeficient (SCID) mouse system using colon cancer cell lines. The experimental metastasis of WiDr cells in SCID mouse was inhibited by MMC and IFN-gamma with their synergism. Intracellular uptake of MMC in WiDr cells in vitro was significantly increased by IFN-gamma, suggesting the mode of synergism of these agents. This model may also partly explain the antitumor activity of combined MMC, 5-fluorouracil and interleukin-2 treatment on hepatic metastasis of colon cancer.
Combined treatment of interleukin-2 (IL-2), 5-fluorouracil (5-FU) and mitomycin C (MMC) is reported to be effective against hepatic metastasis of colon carcinoma. To clarify this modality, we investigated lymphokine activated killer (LAK) activity of human peripheral lymphocytes on colon cancer cell lines by 51Cr release assay. LAK activity against Colo 205 cells by untreated lymphocytes was 12%, which increased to 25% upon the addition of 5-FU, but remained unchanged upon the addition of MMC. The combined antitumour activity of MMC or 5-FU with or without LAK-supernatant was evaluated by MTT assay; antitumour activity of MMC was increased by the addition of LAK-supernatant. The concentration of interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) was increased in LAK-supernatant, and the antitumour activity of combined IFN-gamma and MMC was synergistic. The mechanism of this therapy seemed to be associated with both increased LAK activity by 5-FU and increased antitumour activity of MMC with IFN-gamma.
BACKGROUND: Fibronectin (FN) acts in many fundamental biological processes including cell adhesion, migration, proliferation and apoptosis. Although FN shows an ubiquitous expression pattern, alternative mRNA splicing modulates tissue-specific molecular heterogeneity at three regions: extra domain-B, extra domain-A and variable region. MATERIALS AND METHODS: In the present study, we analyzed the FN mRNA splicing in osteochondrogenic tumors as well as in various normal tissues using the RT-PCR method. RESULTS: Normal cartilage almost exclusively contained short mRNA lacking alternative exons in all regions. However, 14 osteochondrogenic tumors including osteochondroma, enchondroma, chondroblastoma, chondrosarcoma and osteosarcoma uniformly contained long mRNA with various patterns of alternative exons in the three regions. CONCLUSION: These results indicated that the lack of regulation excluding the alternative exons may be associated with tumorigenesis in chondrocytes.
Using positron computed tomography (PCT) and the 15O labeled gas steady-state inhalation technique, regional cerebral blood flow (rCBF), cerebral oxygen consumption (rCMRO2), and oxygen extraction fraction (rOEF) can be measured quantitatively in humans. We quantitatively examined the relationship between focal ischemic lesions and intact regions as detected by X-ray CT in such areas as the territory of the contralateral middle cerebral artery (MCA), thalami, pons, and cerebellar hemispheres. Twenty-three PCT measurements in 13 patients with unilateral ischemic infarction in the MCA territory as detected by X-ray CT were performed. Remote effects from cerebral infarction of the MCA territory were observed in the contralateral MCA territory, ipsilateral thalamus, brainstem, and contralateral cerebellar hemisphere. Slight depression of rCBF and rCMRO2 was also observed in the contralateral thalamus and ipsilateral cerebral hemisphere; rOEF was normal in these areas. Though the depression of rCBF and rCMRO2 due to remote effects was detected in all periods, it was mildly observed 0 to 6 days after onset. The reduction of rCBF and rCMRO2 due to remote effects was less than the morphological as well as the functional threshold. The phenomenon is probably caused by neuronal deactivation, and the regions with depressed blood flow and metabolism may be in a "resting" state.
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