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Biomedical subjects

Y Kodama

Publications and source records attributed to Y Kodama.

At least 397 records · Page 22Linked to original sources
PubMed1979

Chromosome markers in 12 inbred strains of the Norway rat, Rattus norvegicus.

Morphological details of metaphase chromosomes were compared among 12 inbred strains of rats (Rattus norvegicus) by means of conventional Giemsa staining and by a sequential Q- and C-banding method. Inter-strain variations were found in seven pairs, as identified on the basis of size differences in the short arms and/or satellites of chromosomes 3 and 12 and the X chromosome and in the centromeric C-bands of chromosomes 4, 5, 7, and 9. All pairs were homomorphic in the inbred strains, while F1 hybrids between two inbred strains showed certain heteromorphic pairs expected from the parents. These chromosome markers appear to be useful for characterization of inbred strains as well as for various genetic studies, including linkage analyses.

Animals↗
PubMed1979

Tumor cell aggregation and mode of cancer spread in linitis plastica type of gastric carcinoma.

Spread of tumor cells in linitis plastica type of gastric carcinoma was studied in relation to features of tumor cell aggregation which were classified into two types: free-cell type and small nest type. Free-cell type was accompanied by a larger amount of fibrous stroma in submucosal layers than in small nest type. In the gastric wall lymphatics and regional lymph nodes, small nest types was more prominent than the free-cell type. Lymphatic permeation was noted predominantly in the submucosa. In the mucosa, both free-cell and small nest types were frequently present. In carcinoma with free-cell type predominance, diffuse infiltration with infrequent lymphogenous spread was noted, while in carcinoma with small nest type predominance, spread via the lymphogenous route was observed more frequently. The mode of cancer spread in this type of carcinoma appeared to be affected by the type of tumor cell aggregation dominant in the mucosa.

Adenocarcinoma, Scirrhous↗
PubMed1978

Thromboplastic and fibrinolytic activities of V2 and V7 carcinomas of rabbit, with special reference to fibrin deposition and thrombus formation in the tumors.

Thromboplastic and fibrinolytic activities of V2 and V7 carcinomas, the two transplantable rabbit tumors of the same viral origin, were studied in relation to fibrin deposition and thrombus formation in the tumors. Thromboplastic activity of V7 carcinoma was comparatively high, while that of V2 carcinoma was as low as that of muscle tissue. More fibrin deposits in the stroma and more thrombi in the small vessels were found at the advancing border of V7 carcinoma than that of V2 carcinoma. These differences might be associated with higher thromboplastic activity of V7 carcinoma than that of V2 carcinoma. Fibrinolytic activity of both tumors was high and it was confirmed to be localized in the tumor cells by Todd's method. Fibrin deposits in the stroma were found more abundantly somewhat apart from the advancing border of the tumor nests of both tumors. It was suggested that plasmin activated by plasminogen activator released locally from the tumor cells might digest fibrin deposited in the stroma just close to the tumor nests.

Animals↗
PubMed1978

Effects of ambient temperatures on induction of transmissible gastroenteritis in feeder pigs.

Experiments were carried out to investigate the effects of ambient temperatures on the induction of transmissible gastroenteritis in feeder pigs 2 to 3 months old. Pigs maintained at a high temperature (30 +/- 2 degrees C) and exposed to the virulent transmissible gastroenteritis virus did not show clinical signs of the disease during their maintenance at the high temperature. On the other hand, a sudden decrease in the ambient temperature, either before or after virus inoculation, induced severe disease in feeder pigs exposed to the virus. However, continuous maintenance of pigs at the low temperature (4 +/- 1 degrees C) tended to somewhat reduce the frequency of occurrence of signs in proportion to the length of the maintenance periods at that temperature. Pigs raised at temperatures that fluctuated between 20 +/- 2 and 4 +/- 1 degrees C every 24 h developed profuse diarrhea. The duration of clinical signs was longer in pigs maintained under the fluctuating temperatures than in those at the constantly low temperature. With one exception, antibody against transmissible gastroenteritis virus was demonstrated in sera collected from pigs both with and without clinical signs. Antibody titers obtained, however, were somewhat higher in sera collected from pigs that had developed clinical signs than in those from pigs that had endured the infection without showing signs.

Animals↗
PubMed1978

Effect of urokinase on growth and metastases of rabbit V2 carcinoma.

Effect of urokinase on the tumor growth and metastasis formation of rabbit V2 carcinoma, having low thromboplastic and high fibrinolytic activities, was examined. Weight of the tumor and lymphogenous metastases tended to increase, but the number of metastatic foci in the lungs was unchanged by the administration of urokinase. Diminution of fibrin deposits and connective tissue reaction in association with increase in the pattern of invasive growth was recognized at the advancing border of the tumors in the urokinase-treated group. In the intravenously induced pulmonary metastases, the number of metastatic foci decreased significantly in the urokinase-treated group. Fibrin was demonstrated at the site of tumor cell embolism by the conjugated anti-rabbit fibrinogen antibody. The growth of metastatic foci in the lungs was not affected by the treatment with urokinase. Enhancing effect of urokinase on fibrin resolution might promote the local tumor growth and release of tumor cells into the vessels, but interfere with the lodgement of tumor cells in remote organs.

Animals↗
PubMed1977

Karyological characterization of a human lymphoblastoid cell line resistant to 6-thioguanine.

A mutant human lymphoblastoid cell line, Raji-TG, resistant to 10micron g 6-thioguanine (TG)/ml was produced from wild-type cells after exposure to ethylmethane sulfonate. The Raji-TG cells showed their failure to incorporate 3H-hypoxanthine, only 2% as much hypoxanthine guanine phosphoribosyl transferase (HPRT) activity as wild-type cells, and no revertant in HAT selective medium containing bypoxanthine, aminopterin, and thymidine. Raji-TG cells, which were maintained routinely in regular medium lacking TG for as long as 2 years, still retained resistance to the drug and inability to grow in HAT medium. A fusion of Raji-TG cells and mouse cells resistant to 5-bromodeoxyuridine and lacking thymidine kinase formed hybrids, and the resulting hybrid colonies proliferated in HAT medium. These observations strongly supported the hypothesis that Raji-TG line cells might be originated from a mutational event with deficiency of HPRT. Both parental and the mutant have a modal chromosome number of 49 with a remarkably stable karyotype. Excess chromosome materials are found in chromosomes 1, 5, 7, 14, and 16. Chromosome 8 is completely missing, but is represented by two respective isochromosomes of the short and long arms of No. 8. Five different marker chromosomes could be distinguished, and most of their origin has been determined. Isolation of Raji-TG X mouse hybrid clones which contained one of each marker chromosome is of considerable value in mapping human genes on regions within particular chromosomes.

Animals↗
PubMed1977

Importance of 5'-terminal blocking structure to stabilize mRNA in eukaryotic protein synthesis.

The 7-methylguanylic acid residue confronting the 5'-terminal nucleotide of mRNA through two pyrophosphate linkages was completely removed by tobacco pyrophosphatase from mRNAs of cytoplasmic polyhedrosis virus, tobacco mosaic virus (viral RNA), and globin without any scission in the inner part of the RNA chain. Protein synthesis ability in a wheat germ cell-free system was lost after this treatment of all three kinds of mRNA. The initiation complexes for protein synthesis of these three RNAs were not obtained after using tobacco phosphodiesterase-treated mRNA. On incubation of mRNA in a wheat germ extract, the mRNA lacking m7G was quickly degraded from the 5' terminus in an exonucleolytic way, whereas the intact mRNA remained stable. These results show that one of the confronting nucleotide structure's functions is to stabilize the mRNA, to prevent its degradation.

Animals↗
PubMed1977

Outbreak of chronic arsenic poisoning among retired workers from an arsenic mine in Japan.

Retired former workers of Matsuo Arsenic Mine of Miyazaki prefecture in Japan were subjected to extensive medical examination. The number of retired workers subjected to examination were 61 of 208 workers who were engaged in the works of the mine and were tracked down by the work rolls. These workers left the mine more than 15 years prior to the time of the examination. The main works in the mine were classified as mining, dressing of ores, refining, and clerical work. Several findings such as arsenodermatitis, depigmentation, performation of nasal septum, hyposmia, anosmia, and peripheral nervous disturbance attributed to exposure to arsenic were observed in 9 of 21 roasters who often worked in the arsenic kitchen. No characteristic findings of arsenic poisoning, that is, gastrointestinal disturbance, disorder of the cardiovascular system, hematopoietic disorders, or liver disturbance were observed in the retired workers. Another notable finding was that 8 cases diagnosed as pneumoconiosis were found in 18 miners.

Adult↗
PubMed1977

Preliminary experimental study on carcinogenicity of arsenic trioxide in rat lung.

To investigate carcinogenic or cocarcinogenic properties, copper ore (Kinkaseki) and flue dust collected from a metal refinery and arsenic trioxide (As2O3) were administered into the lung of male Wistar-King rats by an intratracheal instillation method. No squamous cell carcinoma of the lung was found among the rats given three arsenical substances, while adenoma or adenocarcinoma was observed. Squamous cell carcinoma of the lung was observed in rats, when copper ore, flue dust, and arsenic trioxide were instilled into the lung together with benzo[a]pyrene (B[a]P. The incidence of squamous cell carcinoma of the lung in rats exposed to Kinkaseki, flue dust, and As2O3 in addition to B[a]P was higher than that in rats given B[a]P alone. The results of this study indicate that solid arsenical substances, such as arsenic trioxide, metal ore and flue dust from a metal refinery, seemed to act on the carcinogenicity of B[a]P in a cocarcinogenic manner.

Adenocarcinoma↗
PubMed1977

[A case of deep sylvian meningioma (author's transl)].

So called intracerebral or subcortical meningioma with no relation to the ventricles is extremely rare. In 1938 Cushing and Eisenhardt reported two cases of this type of tumor as "Deep Sylvian Meningiomas" The authors reported a case of "deep sylvian meningioma" because of its rarity and interesting diagnostical questions, and 16 cases reported in the literature were reviewed.

Adult↗