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K Nishitani

Publications and source records attributed to K Nishitani.

At least 55 records · Page 3Linked to original sources
PubMed1988

Multi-step neoplastic transformation of normal human fibroblasts by Co-60 gamma rays and Ha-ras oncogenes.

As reported previously (Namba et al., 1985; Namba, 1985), normal human fibroblasts were transformed into immortal cells with abnormal karyotypes by Co-60 gamma-ray irradiation. These immortally transformed cells (KMST-6) showed no clonability in soft agar and were not tumorigenic. However, by treatment with Ha-ras oncogenes derived from a human lung carcinoma or Harvey murine sarcoma virus, the KMST-6 cells acquired elevated clonability in soft agar and transplantability in nude mice. All the tumors produced grew progressively without showing regression and killed the mice. The tumors were also serially transplantable into other mice. The Ha-ras oncogene alone did not convert normal human fibroblasts into either immortal or tumorigenic cells. Our current data suggest that gamma rays worked as an initiator of carcinogenesis in normal human cells, giving rise to chromosome aberrations and immortality, and the Ha-ras oncogene played a role in the progression of the immortally transformed cell population to a neoplastic one showing enhanced colony formation in soft agar and tumorigenicity in nude mice.

Cell Line↗
PubMed1988

Enzymic Analysis of Feruloylated Arabinoxylans (Feraxan) Derived from Zea mays Cell Walls I : Purification of Novel Enzymes Capable of Dissociating Feraxan Fragments from Zea mays Coleoptile Cell Wall.

Three novel beta-xylan xylanohydrolases capable of dissociating ferulated arabinoxylan (Feraxan) from maize (Zea mays L. hybrid B73 x Mo17) coleoptile sections and two conventional beta-xylan xylanohydrolases (xylanases) were purified from a Bacillus subtilis industrial enzyme preparation (Novo Ban L-120). The Feraxan-dissociating enzymes (designated as feraxanases) exhibit optimum activities between pH 6.5 and 7.0 and have common molecular weights of 45 kilodaltons as studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two xylanases exhibit their optimum activities between pH 4.5 and 6.0 and have common molecular weights of 27 kilodaltons. Feraxanases liberate oligomeric fragments, which accounted for the following percentages of walls of Zea mays coleoptile sections that had been pretreated by boiling in 80% ethanol: 76% of the ferulic acid, 96% of the arabinose, 71% of the xylose, 27% of the galactose, 50% of the uronic acid, and 4% of the glucose. Monomers, dimers, trimers, or tetramers were not found among enzyme digestion products. The enzymes hydrolyzed both Feraxan in intact cell wall and maize arabinoxylans extracted from walls by alkaline solutions but did not degrade other substrates including larch arabinoxylan and Rhodymenia xylan. Structural analyses of the fragments released by the enzymes from the maize cell wall indicated the presence of 2,4/3,4-linked-xylopyranosyl, terminal-arabinofuranosyl, 5-linked-arabinofuranosyl, 4-linked-xylopyranosyl, terminal-glucuronopyranosyl, and ferulic acid as major components. This result is consistent with the idea that most of the fragments were derived from Feraxan. Because of high enzyme specificity and substantial recovery of digestion products from maize cell walls, these new enzymes offer opportunities not only for enhanced structural analyses of cell walls but also for assistance in protoplast preparation from cereals.

Journal Article↗
PubMed1986

Multistep process of neoplastic transformation of normal human fibroblasts by 60Co gamma rays and Harvey sarcoma viruses.

As reported previously (Namba et al., 1985), normal human fibroblasts were transformed by 60Co gamma-ray irradiation into immortal cells with abnormal karyotypes. These transformed cells (KMST-6), however, showed a low cloning efficiency in soft agar and no transplantability. However, upon treatment with Harvey murine sarcoma virus (Ha-MSV), the cells acquired elevated clonability in soft agar and transplantability in nude mice. Ha-MSV alone, however, did not convert normal human fibroblasts into either immortal or tumorigenic cells. The Ha-MSV-transformed KMST-6 cells showed an enhanced expression of the ras oncogene, but normal and 60Co gamma-ray-transformed cells did not. Our current data suggest that gamma rays worked against normal human cells as an initiator, giving rise to chromosome aberrations and immortality, and that Ha-MSV, probably through its ras oncogene, played a role in the progression of the malignant cell population to a more malignant one showing enhanced colony formation in soft agar and tumorigenicity in nude mice.

Animals↗
PubMed1986

Phototropism in Hypocotyls of Radish : II. Role of cis- and trans-Raphanusanins, and Raphanusamide in Phototropism of Radish Hypocotyls.

When etiolated radish (Raphanus sativus var. hortensis f. gigantissimus Makino) hypocotyls were subjected to a continuous unilateral illumination with white fluorescent light (0.1 watt per square meter), the growth rate at the lighted side was strongly inhibited for the first 2 hours, while that at the shaded side showed no change. After 2.5 hours growth on the lighted side recovered gradually, while that on the shaded side was slightly inhibited. The neutral growth inhibitors, cis- and trans-raphanusanins and raphanusamide, were determined in the lighted and shaded sides from 1 hour before until 2 hours after the start of unilateral illumination. In the lighted side, cis- and trans-raphanusanins increased by 0.5 hour after the start of illumination, reached 3 to 3.5-fold greater concentrations than in the shaded side after 1 hour, and then decreased gradually. Raphanusamide increased in the lighted side to a 3-fold greater concentration than that in the shaded one 2 hours after the start of the illumination. Unilateral applications of cis- and trans-raphanusanins and raphanusamide suppressed the growth of the hypocotyl on the applied side more than that on the opposite one, causing the hypocotyls to bend towards the site of application. The data suggest that phototropic curvature in radish is caused by the light-induced synthesis of growth-inhibiting cis- and trans-raphanusanins, and raphanusamide at the site of illumination.

Journal Article↗
PubMed1985

Neoplastic transformation of human diploid fibroblasts (KMST-6) by treatment with 60Co gamma rays.

Normal fibroblasts (KMS-6) derived from a human embryo were transformed in culture into neoplastic cells (KMST-6) by repeated treatment with 60Co gamma ray irradiation. Repeated treatment was necessary to obtain transformation. Control normal cells exhibited normal karyotype (46, XX) and stopped dividing due to cellular ageing at the 40th passage. The transformed cells are presently growing indefinitely (140th passage) and exhibit prominent karyologic aberrations, both numerical and structural. These 2 characteristics, indefinite growth and abnormal karyotype, are thought to be the most important parameters for neoplastic transformation of human fibroblasts. Other indispensable parameters are the presence of active mitotic figures on confluent cell sheets and colony-type morphology. Transformed cells grow into colonies with relatively smooth edges, while normal fibroblasts form colonies with jagged edges, due to the protrusion of growing fibroblasts. Other parameters, such as elevated plating efficiency, enhanced colony formation in soft agar, low serum requirement for growth, high saturation density, and acquisition of transplantability, are not reliable in the early stages of transformation. These parameters probably appear at rather later stages of transformation following several cell divisions. Among other characteristics, the transformed KMST-6 cells exhibit a B-type isozyme pattern of glucose-6-phosphate dehydrogenase, lactate-dehydrogenase isozyme pattern of human origin, no evidence of viral infection and no production of C-type virus particles.

Cell Line↗
PubMed1985

The analysis of systolic and diastolic time intervals: a more sensitive non-invasive method in the assessment of left ventricular dysfunction in the patients with essential hypertension.

Time indices and volumetric parameters were investigated in patients with essential hypertension subdivided into three groups according to the WHO stage classification. The ratio of ejection time (ET) and pre-ejection period (PEP), ET/PEP remained within normal range in WHO-I but decreased significantly in WHO-II and reached extremely low values in WHO-III. ET did not change in WHO-I and WHO-II but became significantly reduced in WHO-III. Prolongation of PEP in WHO-II and WHO-III increased with progression of hypertensive stage. Isovolumic relaxation time (IRT) showed the same pattern as the prolongation of PEP; positive correlation between PEP and IRT was observed (r=0.55). On the other hand, significant changes of volumetric parameters were only observed in WHO-III. These results indicated that the time indices were a more sensitive parameter than the volumetric ones in the assessment of left ventricular dysfunction in the patients with essential hypertension.

Adult↗
PubMed1983

Diagnostic significance of early diastolic time intervals in patients with hypertrophic cardiomyopathy and myocardial hypertrophy due to essential hypertension.

In order to differentiate hypertrophic cardiomyopathy (HCM) from myocardial hypertrophy due to essential hypertension (HT), echocardiogram, apexcardiogram and phonocardiogram were simultaneously recorded in patients with HCM (n = 22), HT (n = 34) and normal subjects (N) (n = 22). The following early diastolic time intervals were measured: 1) IIA-O time, 2) IIA-MVO time (IRT) and 3) MVO-O time. The IIA-O time was 119 +/- 9 msec in N, 159 +/- 31 in HT (p less than 0.001, vs N) and 228 +/- 57 in HCM (p less than 0.001, vs N and HT, respectively). The IIA-MVO time was 66 +/- 11 msec in N, 95 +/- 18 in HT (p less than 0.001, vs N) and 102 +/- 24 in HCM (p less than 0.001, vs N). The MVO-O time was 53 +/- 9 msec in N, 66 +/- 21 in HT and 126 +/- 48 in HCM (p less than 0.001, vs N and HT, respectively). These results showed that among the early diastolic time intervals HT was abnormal only in the IIA-MVO time. On the other hand, HCM had abnormalities not only in the IIA-MVO time but also in the MVO-O time. Both the IIA-MVO and the MVO-O times in hypertrophic non-obstructive cardiomyopathy were prolonged significantly as compared to those in obstructive one. Analysis of early diastolic time intervals may be very useful to differentiate HCM, especially of the non-obstructive type, from HT.

Cardiomegaly↗
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↗
PubMed1981

Hyperthermia in the treatment of psoriasis.

The effectiveness of commercially available, chemically generated, topical exothermic pads that elevate skin surface temperature from 42 to 43 degrees C was stressed in 22 patients with psoriasis. Control sites were treated with conventional modalities such as Goeckerman's regimen, as well as with occlusion with nonexothermic pads. Skin lesions in 19 patients disappeared after the use of hyperthermia. The average time required for complete regression in the treated areas was 27 days with hyperthermia, compared with 44 days with Goeckerman's regimen. There were no hyperthermic side effects. Seventeen patients whose skin lesions disappeared with the use of both hyperthermia and Goeckerman's regimen were subsequently reexamined. The hyperthermia produced an equal or longer duration of remission than did Goeckerman's regimen.

Adult↗
PubMed1980

Uptake and excretion of 67Ga-citrate in malignant tumors and normal cells.

Using in vivo and in vitro experimental models, the uptake and excretion of 67Ga-citrate in tumor cells and normal cells were studied. The time-lapse accumulation of 67Ga in the tumor of rats bearing Yoshida sarcoma reached its peak 24 h after the administration of 67Ga and gradually decreased thereafter. However, the excretion of 67Ga from the tumor was less than that from normal lung. For culture cells in vitro, the uptake of 67Ga increased with lapse of contact time between 67Ga and the cells, but there was no distinct difference between the results for tumor cells and normal skin fibroblasts. The excretion of 67Ga from the cells tended to decrease with prolongation of the contact time, the excretion from tumor cells being only about 10% after a contact time of 24 h. This indicated a significant delay in excretion in comparison with that of normal skin fibroblasts. This delay in the excretion of 67Ga may be an important factor in the tumor accumulation of 67Ga.

Animals↗
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↗