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T Andoh

Publications and source records attributed to T Andoh.

At least 253 records · Page 14Linked to original sources
PubMed1984

[Delayed radiation necrosis in the optochiasmatic region--report of two cases and review of the literature].

Two cases with delayed radiation necrosis of the chiasmatic region following irradiation of the hypophysis for treatment of Cushing's disease were presented. Case 1 was a 36-year-old female who had reduction of visual acuity and bitemporal hemianopsia 2 years after 60Co-irradiation therapy (total 8000 rads) for Cushing's disease. CT scans showed low density in the pituitary fossa and irregular contrast-enhanced suprasellar mass, and metrizamide CT cisternography revealed the pituitary fossa filled with contrast medium. From those findings, secondary empty sella syndrome was suspicious. Case 2 was a 35-year-old male who had progressive visual disturbance 3 years after 60Co-irradiation therapy (total 9050 rads) for Cushing's disease. The right visual acuity was 0.05 and the left one was 0.1. Examination of visual field showed left homonymous hemianopsia. CT scans showed the contrast enhanced suprasellar mass extending to the right anterior thalamic region, and metrizamide CT cisternography detected secondary empty sella as same as that of Case 1. Both cases were treated by administration of steroid hormone intrathecally and orally which was not effective. Right frontotemporal craniotomies were performed. Intraoperative findings of the chiasmatic region revealed diffuse adhesions and thickening of arachnoid membrane with mesh-work of fine vascular proliferations and adhesiotomies were performed in both cases. On the postoperative course, visual disturbance did not improved in both cases. Histological examinations of the thicked arachnoids obtained intraoperatively showed the fibrous connective tissues with round cells infiltrations in both cases, and in Case 2, the small vessel in the arachnoid was occluded by organized thrombi. Authors reviewed and analyzed literatures of delayed radiation necrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Rapid purification and characterization of DNA topoisomerase I from cultured mouse mammary carcinoma FM3A cells.

We have previously shown that a DNA topoisomerase I from mouse mammary carcinoma cells is inhibited by heparin. Taking advantage of this enzyme-heparin interaction, we developed a rapid and efficient method of purification of this enzyme to near homogeneity by extraction of chromatin with 0.15 M phosphate buffer followed by two-step column chromatography on heparin-Sepharose and phenyl-Sepharose. Electrophoresis on sodium dodecyl sulfate-polyacrylamide gels revealed that the final preparation is composed of two polypeptides with apparent Mr approximately 98,000 (p98) and 102,000 (p102), p98 comprising 70% and p102 30%. Extraction and renaturation of the polypeptides from the gel shows that both p98 and p102 seem to possess topoisomerase activity. Partial proteolytic digestion of p98 and p102 with Staphylococcus aureus V8 and chymotrypsin yielded a series of identical peptides, indicating that the two polypeptides are structurally related. The enzyme sedimented through sucrose density gradient with s20,w of 4.0 S, and thus is monomeric in solution.

Animals↗
PubMed1982

Purification of folding proteins of DNA from cultured mouse mammary carcinoma cells.

We described methods of preparation of folding proteins of DNA in quantity for further characterization. In principle folding proteins were first isolated as a specific DNA-protein complex from the bulk cellular proteins by centrifugation through a sucrose density gradient, followed by dissociation or by passage through a SH-Sepharose column. The overall yield was 105 micrograms of folding proteins from 1.5 x 10(9) cells. The folding protein preparation was shown to be composed of a mixture of a few kinds of SH-containing proteins, the main components being of molecular weight of 52 K and 60 K.

Animals↗
PubMed1980

Further characterization of a thermosensitive transformation variant of mouse fibroblasts.

Temperature-sensitive (ts) variants that express phenotype at low (33 degrees) but not at high (38.5 degrees) temperature were isolated from a mouse fibroblast strain C3H2K cells. Among these variants, cloned ts-12B cells showed at 38.5 degrees a density-dependent inhibition of growth typical of normal fibroblasts cultured in vitro. However, at low temperature they lost this capacity and grew to a higher saturation density. The ts variant was also temperature-sensitive as regards serum requirement: it required a higher concentration of serum for growth at 38.5 degrees than at 33 degrees. However, the cells behaved at both temperatures like the parent strain, possessing anchorage-dependence for growth and fibronectin, whereas they were like transformed cells with respect to release of high fibrinolytic activity. No type-C virus core protein p30 was detected at either temperature. Thus, various parameters of transformation in vitro were independently regulated in these variant cells.

Animals↗
PubMed1978

Supercoiled DNA folded by nonhistone proteins in cultured mouse carcinoma cells.

Upon gentle lysis of exponentially growing mouse carcinoma cells FM3A by sodium dodecyl sulfate, DNA was released as a "DNA-protein complex" in a folded conformation. No histones could be detected in the DNA-protein complex. The proteins bound to DNA were found to be composed of several kinds of nonhistone proteins with a molecular weight range of 50,000 to 60,000; they appear to play a key role in stabilizing and maintaining the compact and folded structure of the complex. Removal of the proteins by Pronase or 2-mercaptoethanol produced a more relaxed structure sedimenting about half as fast as the original complex in a neutral sucrose gradient. DNA in the folded complex is supercoiled, as indicated by the characteristic biphasic response of its sedimentation rate to increasing concentration of various intercalating agents, actinomycin D, ethidium bromide and acriflavine, with which the cells were treated before lysis. Pronase- or 2-mercaptoethanol-treated relaxed DNA still possessed the characteristic of closed-circular structure as judged from its response to intercalating agents. Nicking with gamma-ray or 4NQO broke these superhelical turns and relaxed the folded complex to slower sedimenting forms equivalent to the relaxed DNA obtained on treatment with Pronase or 2-mercaptoethanol. Viscometric observations of DNA-protein complex were consistent with the above results. A tentative model for the structure of this DNA-protein complex is proposed in which supercoiled DNA is folded into loops by several kinds of nonhistone proteins. Autoradiographic examination of the complex appeared to support this model.

4-Nitroquinoline-1-oxide↗
PubMed1978

Aminopeptidase activities on the surface of mammalian cells and their alterations associated with transformation.

Activities of various hydrolytic enzymes were determined in rat organ homogenates and on the surface of cells from various sources, i.e., tumor cell strains, primary cultured cells, normal cells, and their transformants. Alanine, leucine, methionine, phenylalanine, and glycyl-proline aminopeptidases and esterase showed relatively high activities in all these organs and cells. In the kidney homogenate the aminopeptidase A activity was higher in other organs; i.e., the aminopeptidase A activity was lower than that of aminopeptidase B. Normal cells derived from kidneys showed the kidney-type pattern of amino-peptidases A and B on the surface of cells, whereas tumor cells from various origins were of another organ type. When cultured mouse fibroblast strain C3H2K and rat fibroblast strain 3Y1 cells were transformed by SV40 or by a ts A mutant and maintained at permissive temperature, aminopeptidase A activity was drastically decreased, and the ratio of aminopeptidase A to aminopeptidase B was reduced to the levels of tumor cells. If the ts A mutant-transformed cells were grown at the restrictive temperature, the ratio approached that of normal cells. In normal cells, however, cultivation at high or low temperature did not cause any change of the activities.

Aminopeptidases↗
PubMed1977

Isolation and some properties of temperature-sensitive mutants of mouse fibroblasts with respect to morphological transformation.

We have isolated from a mouse fibroblast strain C3H2K several temperature-sensitive mutants that express their transformed phenotype at low (33 degress C) but not at high (38 degrees C) temperature. The mutant clones exhibited a piled up and criss-cross pattern of growth and a high saturation density at 33 degrees C, but flat density-inhibited monolayer and a low saturation density at 38 degrees C. The temperature-dependent exprestion of transformed phenotype was fully reversible upon temperature shift, and seemed to require cell division. Plating efficiencies of the clones in liquid medium were slightly higher at 33 degrees C than at 38 degrees C, but the cells were unable to form colonies in soft agar medium.

Cell Division↗