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Biomedical subjects

S Okamura

Publications and source records attributed to S Okamura.

At least 253 records · Page 14Linked to original sources
PubMed1987

Stimulatory effect of forphenicinol on normal human bone marrow granulocyte-macrophage progenitor cells mediated by T-lymphocytes.

Forphenicinol, L-2-(4-formyl-3-hydroxymethylphenyl) glycine, is a newly discovered low molecular weight immunomodifier. Its effects on normal human bone marrow granulocyte-macrophage progenitor cells (CFU-C) were studied in vitro. Addition of forphenicinol to cell cultures resulted in a significant (p less than 0.05) increase in the number of, and preservation of the ability to form CFU-C colonies per fixed number of human non-adherent bone marrow cells. This effect was not observed in T-lymphocyte depleted fractions of human non-adherent bone marrow cells. Furthermore, colony stimulating factor was released when T-lymphocytes were incubated with forphenicinol. These data suggested that T-lymphocytes mediated the stimulatory effect of forphenicol on human bone marrow CFU-C.

Adjuvants, Immunologic↗
PubMed1987

[Clinicopathological study of colorectal cancer in young adults including a case of cancer family syndrome].

During the last 6 years, we examined 402 cases (including 5 cases in their 20's and 17 cases in their 30's) of colorectal cancer. We compared three groups (cases in their 20's, cases in their 30's, and cases over 40 years old), and had the following results. Cases in their 20's had a higher rate of familial history of colorectal cancer, and the cancer was located mainly in the proximal colon. Well differentiated and moderately differentiated adenocarcinoma was dominant in the cases in their 30's and in those over 40 years old. On the other hand mucinous adenocarcinoma and signet ring cell carcinoma was dominant in the cases in their 20's. A case of cancer family syndrome is also presented.

Adenocarcinoma↗
PubMed1986

Immunohistological study of histiocytic necrotizing lymphadenitis.

Immunohistological study of 18 cases of histiocytic necrotizing lymphadenitis (HNL) demonstrated numerous helper/inducer cells (OKT-4) and suppressor/cytotoxic cells (OKT-8) with activation (Tac) and proliferation (OKT-9) markers, and histiocytes (lysozyme, alpha-1 anti-chymotrypsin, OK-M1) in the affected areas. However, B cells (B-1), NK cells (Leu-7 and Leu-11), complement proteins and receptor (C4 and C3d receptor), and neutrophils (chloroacetate esterase) were scanty or absent in these foci. Activity of NK cells was also decreased in the peripheral blood of 2 cases examined. The results suggest that HNL might be induced by the abnormal T cell-histiocyte response against some causative agents which induce a similar reaction of delayed hypersensitivity type.

Adolescent↗
PubMed1986

Visualization of moving fluid: quantitative analysis of blood flow velocity using MR imaging.

A new method for the measurement of blood flow using magnetic resonance imaging has been developed. The flow velocities are calculated from the distances that the fluid has moved. The distances are directly visualized by a new pulse sequence. In a phantom study, the measured flow rates showed very good correlation with actual flow rates of up to 20 l/min (3 m/sec). In a volunteer study, pulsatile flow velocities of a large artery were measured with electrocardiographic gating. The flow pattern of a cardiac cycle at the abdominal aorta is similar to that revealed by other methods of measurement, such as Doppler ultrasound. This method allows reasonably accurate quantitative analysis of blood flow in the large arteries.

Blood Flow Velocity↗
PubMed1986

[Establishment and characterization of TA-4 producing cell line (OMC-1) originating from a human squamous cell carcinoma of the uterine cervix].

A new human cell line designated OMC-1 was established from a metastatic lesion of Virchow lymph node of a large cell non-keratinizing squamous cell carcinoma of the uterine cervix. OMC-1 was successively subcultured 30 times in about 15 months. The monolayer cultured cells appeared to be epithelial with a pavement-like arrangement and tendency to pile up without contact inhibition. Electronmicroscopy showed desmosomes and well-developed tonofilaments. The population doubling time was 43-70 hours, the saturation density was 1.3-1.7 X 10(5) cells/cm2, the plating efficiency was 23-25% and the mitotic index was 3.3-4.8%. Chromosome studies showed aneuploidy and a modal number of 45. After subcutaneous transplantation into nude mice, the cells grew into solid large cell non-keratinizing squamous cell carcinomas. By the flow cytometric analysis, the phase fractions of the cells was G1 + G0 = 40.1%, S = 24.9% and G2 + M = 35.0%. The OMC-1 cells produced TA-4 in culture media. TA-4 was also demonstrated immunohistochemically in the original tumor tissue, cultured cells and tumors in nude mice.

Animals↗
PubMed1986

[Sensitivity to etoposide in cultured cells from cervical squamous cell carcinoma].

The anti-cancer effect of Etoposide was tested in in vitro in cultures of cells taken from a squamous cell carcinoma of the uterine cervix (SKG-IIIb). Growth inhibition was tested by the regrowth assay method, inhibition of DNA synthesis by the uptake of 3H-thymidine, and morphological changes by the method of Limburg et al. The concentrations of Etoposide used were similar to the blood levels recommended for clinical use. The regrowth assay showed that the effective concentration of Etoposide for 50% cell kill was 7.5 micrograms/ml in 2-hour and 1.0 microgram/ml in 24-hour cultures. The 3H-thymidine uptake test showed that a concentration of 13 micrograms/ml for 2 hours or of 3.5 micrograms/ml for 24 hours resulted in 50% inhibition of DNA synthesis. Morphological changes were much greater in the 2-hour cultures at the higher concentration of Etoposide than in the 24-hour cultures at the lower concentration. Investigation of the drug sensitivity by cell kinetics disclosed prolongation of the cell cycle occurring after 96 hours at 1.0 microgram/ml and inhibition of cell cycle progression occurring after 24 hours at 10.0 micrograms/ml and after 4 or 8 hours at 50.0 mu/ml. Thus, the anti-cancer effect of Etoposide on SKG-IIIb depends on both the concentration and exposure time and is related to its ability to inhibit cell growth and DNA synthesis and to cause morphological changes in the cancer cells.

Carcinoma, Squamous Cell↗
PubMed1985

Properties of purified colchicine-binding protein from a cultured carrot cell extract.

Colchicine-binding protein (CBP) was purified from a cultured carrot cell extract by DEAE-Sephacel, phosphocellulose and Sephadex G200 column chromatographies. The purified CBP separated into three bands on SDS-polyacrylamide gel electrophoresis. One of them reacted with a monoclonal antibody against chick brain alpha-tubulin and the other two with that against beta-tubulin. Colchicine-binding activity of the purified protein was enhanced by tartrate and inhibited little by an excess of podophyllotoxin. It decayed following first order kinetics, but was more stable than the CBP in the crude extract. The binding constant of the purified CBP for colchicine was 0.57 microM-1 and the number of binding sites of colchicine per mg protein was about 2 nmol. This binding constant is about ten times lower than that of porcine brain tubulin under identical conditions.

Animals↗
PubMed1985

B cell activity and regulatory T cell function in systemic lupus erythematosus by human B cell colony formation.

We have examined the ability of B cells from patients with systemic lupus erythematosus (SLE) to form colonies in vitro. Significantly more B cell colonies growing in the absence of irradiated T cells were observed in patients with active SLE. Helper T cell function of active SLE was normal. Culture supernatants of SLE T cells had significantly less activity to support the B cell colony formation. Our results suggest that the hyperactivity of B cells in SLE may reside in the lupus B cells themselves and that SLE T cells are defective in releasing the soluble factor.

Adolescent↗