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Biomedical subjects

S Tokuda

Publications and source records attributed to S Tokuda.

At least 37 records · Page 2Linked to original sources
PubMed1984

Changes in erythrocyte carbonic anhydrase activity due to physical exercise.

Changes in erythrocyte carbonic anhydrase (RBC-CA) activity due to physical exercise were investigated using a measuring apparatus based on the electrometric method. RBC-CA activities were slightly changed due to transient aerobic (20-min run) or anaerobic (200-m run) exercise in moderately trained subjects, but there were no fixed trends. In 3 weeks of weight training, there were no differences in RBC-CA activities between before training and after 1 day of recovery in both trained and untrained subjects. However, after 1 week of recovery, RBC-CA activities slightly decreased in both types of subjects. The trained subjects showed higher levels of RBC-CA activity than the untrained subjects before and after training. The rest values of RBC-CA activity were higher in trained subjects than in untrained subjects. It was evident that RBC-CA activities were higher in subjects (especially in long-distance runners, swimmers etc.) who had undergone long-term strenuous aerobic training.

Adolescent↗
PubMed1984

Production of d-Tagatose from Dulcitol by Arthrobacter globiformis.

A process for the bacterial oxidation of dulcitol to d-tagatose has been developed. The strain Arthrobacter globiformis ST48 used in this fermentation was isolated from soil. The yield of d-tagatose accumulated in the medium from dulcitol was as high as 85%. About 14 g of d-tagatose crystals was isolated from 1 liter of 2% dulcitol medium.

Journal Article↗
PubMed1983

Hypocholesterolemic effect of triterpene alcohols with soysterol on plasma cholesterol in rats.

To identify the synergistic hypocholesterolemic substance found in soybean oil unsaponifiable matter, rats were fed diets containing various fractions of the unsaponifiable matter prepared by silicic acid column chromatography. The plasma cholesterol level of the group fed the alcohol fraction, which mainly consisted of triterpene alcohols, was significantly lower and the effect was synergistic with soysterol. So the effect of cycloartenol and 24-methylenecycloartanol, which are main constituents of triterpene alcohols in soybean oil unsaponifiable matter, was investigated. Both compounds were prepared from gamma-oryzanol (ferulate) and were added (0.05%) respectively to the experimental diet containing 0.5% cholesterol and 1% soysterol. It was observed that both cycloartenol and 24-methylenecycloartanol in combination with soysterol greatly reduced the plasma cholesterol and enhanced cholesterol excretion. This suggests that the hypocholesterolemic activity of dietary vegetable oils may account for not only their fatty acid compositions and sterol contents but also the synergistic hypocholesterolemic effect of triterpene alcohols.

Alcohols↗
PubMed1983

[Case of synovial sarcoma in an infant].

The case of a 4-month old boy with monophasic synovial sarcoma of the left thigh is reported. He died of pulmonary metastasis 11 months after surgical removal of the primary tumor. Histologically, the tumor was composed of densely packed, small spindle cells; there were occasional islands and clusters of polygonal cells. Ultrastructurally, the closely packed polygonal cells displayed occasional desmosomelike attachments between apposing cytoplasmic membranes of neighboring cells. Many small abortive duct-like intercellular spaces with elongated cytoplasmic filopodias were seen. These findings were suggestive of epithelial differentiation of some of the tumor cells. In general, synovial sarcoma is a disease of young adults and is rare in children.

Diagnosis, Differential↗
PubMed1982

Surgical results of intracranial ruptured aneurysms in the acute stage.

To evaluate the operative mortality and morbidity of definitive intracranial microsurgical aneurysm obliteration as a function of timing of early operative intervention and as a function of clinical condition at the acute state, we retrospectively review 164 consecutive patients who underwent surgery within 72 hours following haemorrhage. The series was divided into four operation periods (0-6, 6-12, 12-24, 24-72 hours), and patients were graded according to five clinical conditions described by Hunt and Hess. The mortality of the individual clinical condition at each operation period was to great extent independent of the timing of operation, and there was a distinct correlation between the surgical results and the form of bleeding visualized by C.T. In poor condition (grade 3, 4, and 5) patients, satisfactory surgical results were obtained in patients in whom cisternal blood clots, intracerebral haematoma, and subdural haematoma had been shown by C.T. The optimum operation times for each group were suggested.

Acute Disease↗
PubMed1982

Radiation-induced augmentation of the response of A/J mice to SaI tumor cells.

Whole-body exposure of A/J mice to low doses (5-25 rads) of ionizing radiation immediately prior to the inoculation of 10(4) Sarcoma I (SaI) cells results in smaller tumors than are observed in sham-irradiated control animals. The irradiated group also contains a greater proportion of mice that fail to develop tumors or that demonstrate tumor regression. Low-dose augmentation is 1) less pronounced in recipients that have undergone splenectomy; 2) not evident in adult thymectomized-lethally irradiated-bone-marrow-restored (ATxXBM) animals, where the opposite effect is seen (eg, low-dose enhancement of tumor growth); and 3) abolished by the administration of normal syngeneic spleen cells unless the latter have been depleted of T cells. On this basis, a very radiosensitive T cell with suppressor activity is implicated in this phenomenon. Low-dose exposure at various times prior to tumor inoculation suggests that this cell regenerates in 5-10 days after irradiation.

Animals↗
PubMed1981

Molecular pathology of cancer cell adhesiveness.

A new cell surface-associated adhesive glycoprotein with a molecular weight of 70,000 was separated from differentiated rat ascites hepatoma cells forming cell islands in vivo (but not from undifferentiated rat ascites hepatoma cells present as single cells in vivo) and highly purified by chromatography; it was synthesized by the cells and localized on the cell surface. Its synthesis began to rise rapidly and reached its peak in 24 hr cultivation, i.e., a 10-fold increase. This substance induced not only aggregation but also adhesiveness of the cells characterized by junctional complexes including tight junctions, desmosomes, and intermediate junctions, closely resembling the frequency and distribution of junctional complexes observed on the above cell islands. Its potency was inhibited specifically by D-mannose and alpha-methyl-D-mannoside; the numbers of the binding sites per cell were calculated as 6 x 10(5). Its activity was concerned with the protein portion of the molecule, and not with the carbohydrate portion. Thus, it seemed reasonable that the adhesive glycoprotein may play a key role in the cell adhesiveness and island formation. In contrast, serum-associated adhesive glycoprotein, separated from normal rat serum, could aggregate the cells but not develop junctional complex.

Animals↗
PubMed1981

Suppression of parasite antigen-specific lymphoid blastogenesis in African trypanosomiasis.

Inbred C57BL/6J mice were infected with either Trypanosoma rhodesiense organisms of Walter Reed Army Trypanozoon antigenic type 3 or 5 (WRATat 3 or WRATat 5) or were immunized with soluble trypanosomal antigens. Spleen cells obtained from immunized hosts undergo blastogenesis, measured by thymidine incorporation, when exposed to trypanosomal antigens in vitro. Spleens obtained from mice infected with T. rhodesiense organisms do not respond or respond only minimally to trypanosomal antigens in vitro. Spleen cells of infected mice suppress the trypanosomal antigen-induced proliferative response of spleen cells from immunized mice in co-culture experiments. The suppressive activity was found in both the plastic adherent and plastic nonadherent spleen cell populations. The in vitro responses of normal spleen cells to LPS and Con A were also suppressed by spleen cells obtained from infected mice.

Animals↗
PubMed1978

Cellular and humoral immune responses of mice during immunological enhancement of an allogeneic tumor.

Spleen cells obtained from C57BL/Ks (Ks, H-2d) mice carrying passively enhanced Sarcoma I (Sa I, H-2a) tumors were tested for alloantibody formation, lymphocyte blastogenesis, antibody-dependent cellular cytotoxicity, and cell to cell cytotoxicity. Assays were usually performed approximately 6 weeks after tumor inoculation. The results of these assays indicate that spleen cells from tumor-bearing mice are actively synthesizing alloantibody, but have a depressed blastogenic response to phytohemagglutinin and allogeneneic cells, and manifest no detectable cytotoxic activity in 51Cr release assays for antibody-dependent or cell to cell cytotoxicity. The absence of cell to cell cytotoxicity was specific and could not be attributed to the activity of suppressor cells acting in vitro, or to immunoglobulin secreted during the in vitro assay. These results indicate that Ks mice carrying immunologically enhanced Sa I tumors have a strong humoral response but a defective cellular response to the alloantigens of their tumors. These results are compatible with a mechanism of immunological enhancement which involves suppression of the development of the cellular immune response throughout the course of tumor growth.

Animals↗
PubMed1976

Tumor immunity induced by preimmunization with BALB/c mouse myeloma protein.

Prior sc immunization of BALB/c mice with 1 mg isolated M component of MOPC-11 mouse myeloma resulted in significant relative immunity to subsequent sc or ip challenge with 10(4) living cells from the same plasmacytoma. However, challenges of 10(5) and 10(6) tumor cells overcame immune status engendered by preimmunization with M component. Despite evidence for the specificity of the immunity induced by one isolated M component as opposed to another, no clear cytotoxic antibody, cell-mediated tumor-cell lysis, or predominance of either humoral or cell-mediated immune mechanisms were demonstrated. These findings were compatible with a relatively slight tumor-specific antigenicity of M components expressed on tumor surfaces, compared with the tumor specificity of other tumor-related, cell-surface antigens.

Animals↗