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Biomedical subjects

M Shimoyama

Publications and source records attributed to M Shimoyama.

At least 307 records · Page 17Linked to original sources
PubMed1982

A B-lymphoma cell line that forms rosettes with neuraminidase-treated sheep erythrocytes through monoclonal surface immunoglobulin.

Undifferentiated lymphoma from a 39-year-old female became serially xenotransplantable to preirradiated nude mice. The tumor cells (KT) possessed a monoclonal surface immunoglobulin (SIg mu, kappa) and formed rosettes with neuraminidase-treated sheep erythrocytes (SEn). Precise characterizations of the SEn rosette, however, revealed the following facts: (1) Neuraminidase-untreated or 2-aminoethylisothiuronium bromide (AET) treated sheep erythrocytes were not bound to the KT cells. (2) SEn rosettes on the KT cells did not show a temperature dependency. (3) Neuraminidase-treated erythrocytes from man, horse, mouse, and rabbit were not bound to the KT cells. (4) Preincubation of the KT cells with antipolyvalent immunoglobulin or anti-kappa-chain serum abolished the SEn rosette formation. (5) Trypsinization decreased both SEn rosettes and SIg on the KT cells. (6) SEn rosettes on the KT cells were too loose to be separated from nonrosetting cells by a Percoll gradient centrifugation method. Summarizing these results, the monoclonal SIg on the KT cells recognized sheep erythrocyte antigen(s) that were exposed only after the neuraminidase treatment. Therefore, this was considered to be a case with peculiar B-lymphoma cells that bound SEn through their SIg.

Adult↗
PubMed1982

A novel pre-T cell line derived from acute lymphoblastic leukemia.

A cultured cell line, P30/Ohkubo with pre-T cell phenotype, was established from an 11-year-old girl with acute lymphoblastic leukemia (ALL). According to the morphological, cytochemical and immunological analyses, P30/Ohkubo was found to have common-ALL antigen, Ia-like antigen, pan-T cell antigen, and L2 morphology with localized acid phosphatase staining, but not rosette-forming capacity with sheep erythrocytes, B1 antigen or surface immunoglobulins. Chromosome analysis revealed that P30/Ohkubo had two constant marker chromosomes [11q +, del (9)], but lacked 14q +. These findings indicate that P30/Ohkubo is a novel cultured cell line of pre-T cell phenotype. These characteristics have remained unchanged for more than 20 months since establishment of the cell line.

Antigens, Surface↗
PubMed1982

[A preliminary study of vincristine, methotrexate, and prednisolone (VM*P) combination chemotherapy for advanced adult non-Hodgkin's lymphoma].

The VM*P combination chemotherapy was administered to 13 patients with advanced (Stage III and IV) non-Hodgkin's lymphoma refractory to previous multiagent chemotherapy including cyclophosphamide (EX) and/or adriamycin (ADM). 1) Complete response was obtained in two patients with diffuse histiocytic lymphoma and one patient with diffuse undifferentiated (Burkitt type) lymphoma, and a response rate was 46.2%. 2) Tumor regression in responders was recognized within one week after administration of VM*P, but the duration of response was only 7(2-17) weeks in median (range). 3) Positive correlation was not seen between responsibility and dose of vincristine or methotrexate (MTX), but complete responders were obtained with only over 30 mg/dose of MTX. 4) In spite of resistant cases against EX and/or ADM, complete responders were obtained with VM*P therapy. Clinically, it was shown that cross resistance was minimal among MTX, EX and ADM. 5) Major side effects of VM*P therapy were myelosuppression (75%), hepatotoxicity (46%), and severe infection (23%). Neurotoxicity and nephrotoxicity were rare.

Adult↗
PubMed1981

Theophylline reduces poly (ADP-ribose) synthetase from chick embryo liver nuclei.

The effect of theophylline on poly(ADP-ribosyl)ation was investigated. The poly(ADP-ribose) synthetase activity in vitro was markedly reduced in the liver nuclei prepared from theophylline-treated chick embryo. This reduction was not due to the enzyme inhibition by theophylline contamination in the nuclear fraction. The hydroxyapatite column chromatographic analysis of [3H]adenosine-labelled poly(ADP-ribose)molecules formed in vivo revealed that the in vivo formation of poly(ADP-ribose)molecules was also decreased by theophylline administration. The theophylline-induced reduction of poly(ADP-ribose) synthesis was not due to either low NAD levels or to a decrease in the chain length of the poly(ADP-ribose) molecule, rather this reduction was derived from a decrease in the number of poly(ADP-ribose) molecule. Possible mechanisms related to reduction of poly(ADP-ribose) synthesis in vivo are discussed.

Animals↗
PubMed1981

Effect of polyamines on purified poly(ADP-ribose) synthetase from rat liver nuclei.

Using the purified enzyme system, we investigated the spermine-induced stimulation of poly(ADP-ribose) formation. In the presence of 2 microgram DNA and 10 mM Mg2+ in a reaction mixture of 0.2 ml, the optimal concentrations of spermine, spermidine and putrescine were 10, 12.5 and 35 mM, respectively. With the omission of Mg2+, there was an increase in optimal concentrations of polyamines without changes in the rate of poly(ADP-ribose) formation. The concentrations of spermine required for maximum synthesis of poly(ADP-ribose) were increased in proportion to the increase in the amount of DNA. Kinetic analysis of poly(ADP-ribose) formation showed a decrease in Km values for NAD with the addition of spermine. The possible relationship of polyions with regard to DNA, spermine and histone in the purified enzyme system was discussed.

Animals↗