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Biomedical subjects

T Kimoto

Publications and source records attributed to T Kimoto.

At least 145 records · Page 8Linked to original sources
PubMed1982

Combined effects of 5-fluorouracil and interferon on proliferation of human neoplastic cells in culture.

The growth inhibitory effects of the combination of 5-fluorouracil (5-FU) and human fibroblast interferon on human neoplastic cell lines and normal human fibroblasts were examined. The neoplastic cell lines used were HeLa (cervical carcinoma), MCF-7 (mammary carcinoma), WI-38 CT-1 (embryonic lung fibroblasts transformed in culture by 60Co gamma-ray irradiation), KMM-1 (myeloma), and Raji (Burkitt's lymphoma). The normal human cell line used was WI-38. The growth inhibitory effects were determined by measuring colony formation for HeLa, MCF-7, WI-38 CT-1, and WI-38 cells, and by measuring cell growth for KMM-1 and Raji cells. Each cell line showed different sensitivities to 5-FU or interferon. The combination of 5-FU and interferon showed synergistic inhibitory effects on the growth of HeLa, WI-38 CT-1, KMM-1, and Raji cells. Neither synergistic nor additive growth inhibitory effects of the combination of 5-FU and interferon were observed in MCF-7 and WI-38 cells.

Animals↗
PubMed1982

[Combined effects of 5-fluorouracil and interferon on proliferation of human neoplastic cells in culture].

Potentiation of the cytotoxic effects of 5-fluorouracil (5-FU) by interferon on human tumor cells was examined. The human neoplastic cell lines used were HeLa (uterine cervical cancer), MCF-7 (mammary cancer), WI-38 CT-1 (embryonic lung fibroblasts transformed in culture by Co-60 gamma-ray irradiation), KMM-1 (myeloma), and Raji (Burkitt's lymphoma). As a normal human cell strain, WI-38 (embryonic lung fibroblasts) was used. The cytotoxic effects were determined by colony formation. Each cell line was different in sensitivity to interferon or 5-FU. Interferon potentiated synergistically the cytotoxic effects of 5-FU on HeLa, WI-38 CT-1, and KMM-1 cells. In the case of Raji cells, the cytotoxic effects of the combination of interferon and 5-FU were additive. Neither synergistic nor additive lethal effects of the combination of the two agents were observed in MCF-7 and WI-38 cells. The present results indicate a possibility that a combined treatment with interferon and 5-FU may be effective in certain types of human cancers.

Cell Division↗
PubMed1982

An improved short-term culture method for human mammary epithelial cells.

An improved short-term culture method for human mammary epithelial cells was developed and the details are presented. Briefly, after the digestion of biopsy tissues with 0.2% collagenase solution for 16 to 18 hr, 4 consecutive fractions were obtained by differential sedimentation. The last fraction, S-4, contained organoids having alveolar- or duct-like structures and gave rise to mammary epithelial cell growth with minimal contamination of fibroblasts.

Biopsy↗
PubMed1982

Collagen and stromal proliferation as preventive mechanisms against cancer invasion by purified polysaccharides from human tubercle bacillus (SSM).

The antitumor activity of SSM consists in the activation and intensification of collagen proliferation against carcinoma. The experiment in vitro and in vivo (xenografts) indicates that SSM did no direct damage to the cancer cells, but that it accelerated the proliferation of collagen fibers of the stroma. These collagen fibers enclosed the cancer cells and prevented cancer cell proliferation. It was also made clear that the proliferation of collagen fibers was accelerated remarkably by SSM under a certain condition of immunity. Therefore, one of the basic activities of SSM is to stimulate the proliferation of collagen fibers in the stroma invaded by cancer cells. Collagen serves in the composition of small blood vessels, blood capillaries, muscle fibers, and nerve fibers. Besides, the biosynthesis of collagen seems to be accelerated by carcinomatous infiltration, and it may also take place with fibroblasts, endothelial cells, and the amorphous matrix in the normal tissue or cancer cells themselves.

Adenocarcinoma↗
PubMed1981

Culture conditions for a human lymphoma cell line (Raji) and their application to mutation research.

Experimental systems for the detection of somatic cell mutation to hypoxanthine-guanine phosphoribosyl transferase (HGPRT) deficiency in human lymphoma cells were developed. The cell line used was the Raji line established from Burkitt's lymphoma. The cloning efficiency (CE) in soft agar of the cells was enhanced approximately 5-fold by addition of 2 x 10(-4) to 4 x 10(-4)M dithiothreitol (DDT) and 1% human serum, as compared with the CE in control medium. Other thiols such a mercaptoethanol and thioglycerin were also able to increase the CE but not as efficiently as DTT. Under these culture conditions, 10(6) cells per 55-mm dish could be seeded into soft agar medium containing 5 micrograms/ml 6-thioguanine (6-TG) to detect a forward mutation without any metabolic cooperation. The optimum expression time was determined by treating the cells with 125 micrograms/ml ethyl methanesulfonate (EMS) for 20 hr at 37 degrees. A significant increase of mutation frequency was observed approximately 10 days after the 6-TG treatment, by which time the cells had gone through about 10 population doublings. After determining these experimental conditions, a comparison of mutation frequency among three mutagens, EMS, N-methyl-N'-nitro-N-nitrosoguanidine and ICR-170, was carried out. ICr-170 was the most efficient mutagen among these chemicals.

Aminoacridines↗
PubMed1981

Lactate dehydrogenase isozyme patterns of normal human fibroblasts and their in vitro-transformed counterparts obtained by treatment with CO-60 gamma-rays, SV40 or 4-nitroquinoline 1-oxide.

Lactate dehydrogenase (LDH) isoenzyme patterns of normal human fibroblasts and their in vitro-transformed counterparts were studied. Normal human fibroblasts were derived from embryonic or adult skin or embryonic lung tissues. These cells were transformed into neoplastic cells having unlimited growth potential and abnormal karyotypes by treatment with CO-60 gamma-rays, SV40 or 4-nitroquinoline 1-oxide. No significant difference in LDH isoenzyme patterns was observed in growing or confluent cultures, in the process of in vitro aging of normal human fibroblasts, or in embryonic or adult skin fibroblasts, but there was a considerable difference in isozyme patterns between lung and skin fibroblasts cultured from embryos. All of the transformed fibroblast cell lines derived from lung or skin showed a distinctly increased ratio of B to A subunit (greater than 0.5), whereas normal human fibroblasts did not (less than 0.5). There was no significant difference in total activity of LDH in the various cells used for the present experiments. These findings suggest that the changes of LDH isozyme patterns may be useful as a marker of neoplastic transformation in cultures of normal human fibroblasts.

4-Nitroquinoline-1-oxide↗
PubMed1980

Myelin-like structures seen intracellularly in renal tubule cells subjected to ischemia.

Renal cortex was studied during experimentally induced ischemia. A transient increase in anerobic glycolysis occurred with concomitant swelling of both the Golgi apparatus and mitochondria. These intracytoplasmic organelles underwent marked changes in their intracellular positions. Infolding of cytoplasmic membrane at the basal side of proximal tubule cells increased in complexity and proceeded to enclose various intracytoplasmic microorganelles such as mitochondria and the Golgi apparatus. Piling up in layers was particularly marked around mitochondria. This piling up appeared as myelin-like structures on the free surface of, and within, proximal tubule cells, and followed disruption of the brush border at the free surface. Histological examination of thin sections showed that the fused portions of this brush border were actually brush border cytoplasmic membrane piled up in layers giving the appearance of myelin-like structures. After two hours of ischemia, parts of the membrane of these myelin-like structures were disrupted. Large vacuoles developed and these were thought to be related to the large vacuoles seen during cell degeneration.

Acid Phosphatase↗
PubMed1980

Effects of theophylline on the cell growth of normal and malignant human cells transformed in culture.

Proliferation of normal human diploid cell strains was inhibited to a greater extent by treatment with theophylline than the proliferation of neoplastic human cell lines transformed in culture with Co-60 gamma rays (WI-38 CT-1) or SV40 (WI-38 VA-13). Theophylline was added to cultures at final concentrations of 1 to 3 mM. Morphologically, normal fibroblasts became slender and small when grown in theophylline-containing medium, while little morphological change was observed in neoplastically transformed cells. Growth inhibition of theophylline was cytostatic rather than cytotoxic. No significant difference was detected in the uptake of theophylline between the normal and the transformed cells. Incorporation of 3H-thymidine into acid-insoluble fractions of cells began to decrease in the normal cells about 4 hr after adding theophylline to the culture medium. The intracellular contents of adenosine 3',5'-cyclic monophosphate increased linearly in the normal human cells with the time of treatment with theophylline, but no increase was observed in the transformed cells. The present results suggest that the use of theophylline might be useful for quantitative experiments on neoplastic transformation in cultures of normal human cells.

Cell Division↗
PubMed1980

Characteristics of WI-38 cells (WI-38 CT-1) transformed by treatment with Co-60 gamma rays.

The characteristics of WI-38 CT-1 cells, which had been transformed by treatment with Co-60 gamma rays, were compared with those of the control WI-38 cells in order to identify parameters of malignant transformation in cultures of normal human diploid cells. The transformed WI-38 CT-1 cells were different from the control WI-38 cells in the following respects: (1) epithelial-like morphology of the cells, (2) reduced serum requirement for cell proliferation, (3) increased colony formation in soft agar, (4) increased saturation density, and (5) resistance to the cytostatic effect of theophylline on cell proliferation. On the other hand, no appreciable difference was detected between the control and the transformed cells in (1) population doubling time and (2) sensitivity to Co-60 gamma rays.

Agar↗
PubMed1979

Differences in antibody responses in varicella, herpes zoster and after vaccination.

Difference in antibody responses between varicella and herpes zoster was reconfirmed by complement fixation (CF) test and by platelet aggregation (PA) test. Rise in PA antibody level was observed only in patients with herpes zoster, but not in patients with varicella, while the increase in CF antibody was demonstrated in both types of the diseases. Among 235 healthy children, CF antibody was detected in 42 children and out of these 25 also had PA antibody. Sera of 116 individuals who were vaccinated with a live vaccine comprised of varicella-herpes zoster virus (VZV) were tested for CF and PA antibodies. Within six months after vaccination, 81.3 per cent of the vaccinees demonstrated the rise in CF antibody alone, and only one vaccinee possessed low level of PA antibody. Six months to 1 year after vaccination, CF antibody in 12 out of 13 vaccinees fell to undetectable level. Later than 1 year after vaccination, 9 out of 28 vaccinees possessed CF antibody. Two out of these 9 vaccinees also had PA antibody. The PA antigens prepared from viruses isolated either from a varicella patient or a herpes zoster patient responded similarly to the sera of herpes zoster patients, but no response was detected with sera of varicella patients. PA and CF antibody titers of herpes zoster patients showed a high degree of correlation.

Adolescent↗
PubMed1979

An attempt for improving plating efficiency of human diploid fibroblasts.

An attempt was made to enhance the plating efficiency of normal human diploid skin fibroblasts by testing various culture media. Eagle's minimum essential medium (MEM), Dulbecco's MEM, William's medium E, DM-160, McCoy's 5a, RPMI-1640, Ham's F12, MCDB 102, Waymouth's MB 752/1, and L-15 synthetic media were examined. L-15 was the best among them. Plating efficiency with L-15 supplemented with 20% calf serum ranged from 20 to 60%. Plating efficiency decreased in the order of Eagle's MEM, Dulbecco's MEM, DM-160, and Ham's F12. Waymouth's MB 752/1, MCDB 102 McCoy's 5a, RPMI-1640, and William's medium E were not favorable for high plating efficiency. Although L-15 gave the best plating efficiency and Waymouth's MB 752/1 the worst, the Waymouth medium supported better cell proliferation than L-15, when cell proliferation was compared in mass culture with these two media. It was concluded that L-15 was better suited for culture of small number of cells, and especially for work involving colony formation.

Cell Division↗
PubMed1978

C3b and c3d receptor sites on human fibroblasts derived from several human tissues.

The C3b and C3d receptor sites on one cell line of human diploid fibroblasts (WI-38) were reported in previous papers [3, 4]. In this paper we describe that C3b and C3d receptor sites can also be detected in fibroblast cell lines derived from other human tissues. We consider that C3b and C3d receptors are normally found on the cell surfaces of all human fibroblasts.

Binding Sites↗