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Biomedical subjects

T Kimoto

Publications and source records attributed to T Kimoto.

At least 163 records · Page 9Linked to original sources

Tumor cell phagocytosis and cytotoxicity of lymphoblastoid cells following concanavalin A treatment.

Cell-to-cell interaction was investigated in various malignant tumor cells (human ovarial tumor, lung cancer, carcinoma of larynx and hamster melanoma cell) and in human lymphoblastoid cells (T-cell (MOLT-4 cell), thymoma cells and B-cells (Burkitt lymphoma cell)). Live lymphoblastoid cells did not adhere to the cell surfaces of tumor cells nor the lymphoblastoid cells were ingested by tumor cells without immunologic and specific treatment. Tumor cells as well as T-cells and B-cells had receptors to concanavalin A on their surfaces, and they showed marked cell binding of tumor cells and lymphoblastoid cells. Moreover, tumor cells that phagocytized lymphoblasts underwent marked cell destruction within 4 hours of cell binding. The cytolytic mechanism of the target tumor cell was probably related to contact with the lymphoblastoid cells and was increased by ingestive activity, and metabolic disturbance by lymphotoxin in tumor cells.

Animals↗

Scanning electron microscopy of the ischaemic kidney--changes in the surface microstructure of glomerular epithelial cells.

Domestic rabbits were used to study the changes that occur during ischaemic conditions in the kidney. With a scanning electron microscope, the microcellular changes at the surface of gomerular epithelial cells were observed regularly from the onset of ischaemia until five hours later. After one hour of ischaemia, the surface of the glomerular epithelial cells showed mild swelling and some change in its smooth appearance. One part had taken on a sponge-like appearance. After 2.5 hours of ischaemia, the epithelial cells had atrophied and the entire cell surface was clearly sponge-like. It was no longer possible to distinguish the small pore-like structures that had been seen on the cell surface in the normal. Moreover, 2.5 hours of ischaemia was the time when, biochemically, cell metabolism had completely ceased and the permeability of the cell membrane had altered. The cell was considered to have undergone irreversible change by this stage. After 5 hours of ischaemia, cells were markedly atrophied and the appearance of the surface had become even more sponge-like.

Animals↗

Carcinogenesis in tissue culture. 29: Neoplastic transformation of a normal human diploid cell strain, WI-38, with Co-60 gamma rays.

WI-38 normal human diploid fibroblasts were exposed to Co-60 gamma rays 4 times at a total dose of 1400 rads and transformed into neoplastic cells in culture. The transformed WI-38 cells which are growing steadily without showing aging phenomena at the present time showed epithelial-like morphology, abnormal karyology, B-type isoenzyme pattern of glucose-6-phosphate dehydrogenase (G6PD), and produced sarcomas when transplanted into cheek pouches of hamsters treated with anti-hamster thymocyte serum.

Animals↗

Establishment and characteristics of a human pancreatic cancer cell line (HCG-25).

A floating cell line (HCG-25) was established from the metastatic ascitic fluid of a human pancreatic adenocarcinoma of ductal cell origin. The cell line was characterized by the growth in suspension with a doubling time of 15.6 hr, a high cloning efficiency in soft agar and a modal chromosome number of 72. Electron microscopic examination revealed terminal bars in a small number of cells. Production of mucin and immunoglobulins and phagocytosis were not demonstrated. Heterotransplantation of the cells produced tumors, being undifferentiated carcinoma histologically. These characteristics mentioned above confirm that HGC-25 cell line is a human pancreatic cancer cell line.

Adenocarcinoma↗

Carcinogenesis in tissue culture. 28. Comparison of various effects of a chemical carcinogen, 4-nitroquinoline I-oxide, on normal human cells and on normal mouse cells in culture.

A comparison of the effects on cultured cells of a chemical carcinogen, 4-nitroquinoline 1-oxide (4NQO), between normal human cells which were resistant to malignant transformation with 4NQO and normal mouse cells rather easily transformable was carried out. We studied the following effects of 4NQO on normal human and normal rodent cells; 1) cytotoxicity, 2) DNA, RNA and protein synthesis, 3) incorporation of 4NQO into cells and time course changes of the drug bound with macromolecular substances in cells, 4) DNA repair synthesis, and 5) chromosomal changes. Our results demonstrated that there were no differences in cytotoxicity and inhibition of cellular macromolecular syntheses between human and mouse cells. On the other hand, significant differences were noted in DNA repair synthesis and chromosomal aberrations between human and rodent cells. These differences suggest that mouse cells are easily transformed into neoplastic cells with chemical carcinogens as compared with human cells.

4-Nitroquinoline-1-oxide↗