Biomedical subjects

Y Tokuyama

Publications and source records attributed to Y Tokuyama.

58 records · Page 4Linked to original sources

PubMed1989

Bovine colostric transforming growth factor-beta-like peptide that induces growth inhibition and changes in morphology of human osteogenic sarcoma cells (MG-63).

TGF-beta like peptide, termed TGF(BC-1), was partially purified from defatted and decaseinated bovine colostrum by a sequence of DEAE-Sephacel chromatography and Sephadex G-50 gel filtration in 1M acetic acid. TGF(BC-1) was distinct from well-known 25K TGF-beta in chemical properties: TGF(BC-1) was sensitive to acid ethanol extraction (Roberts et al., 1980). Its apparent molecular weight ranged from 21k to 11k by gel filtration and it was composed of low MW peptides (15k, 13k, 10k and 7.3k but not 25k) as examined by SDS-PAGE under non-reducing conditions. However, TGF(BC-1) shares some biological properties with the prototype TGF-b. TGF(BC-1) remarkably suppressed growth of osteogenic sarcoma cells (MG-63), and this was intriguingly accompanied by a striking change in morphology.

Animals↗

PubMed1988

Mouse monoclonal antibodies with restricted specificity for human renal cell carcinoma and ability to modulate the tumor cell growth in vitro.

Three mouse monoclonal antibodies (MAbs), KRC-1, -2 and -3(IgG1) were produced against cultured cells of human renal cell carcinoma (RCC) cell lines. All of them had restricted specificity for subset of RCC, but did not react with other tumor cell lines, tumor and normal tissues including kidney. The effect of these MAbs on the tumor cell growth in vitro was examined both in soft agar and in plate culture systems. All of them showed modulator effect on the tumor cell growth: KRC-1 showed stimulation effect and others, KRC-2 and -3, suppression one in the both systems. The specificity was observed in the modulator effects. KRC-1 detected a 135 kd glycoprotein in immunoblotting. KRC-2 detected a high molecular weight antigen (ca. 1200 kd) in gel filtration. All the antigens showed affinity for Con A lectin. Molecular properties of the antigens appeared to be different from those of previously reported RCC-associated antigens. The three MAbs seem to be useful to study mechanism of growth regulation in transformed cells.

Animals↗

PubMed1987

Seasonal appearance and size of egg rafts of Culex halifaxii and Culex fuscanus in Okinawajima, the Ryukyu Archipelago, Japan.

The seasonal chronology of eggs of Culex halifaxii, Cx. fuscanus and their cohabitant Cx. quinquefasciatus were observed from March 1984 to early May 1985 in Okinawa prefecture, Japan. In Okinawajima, egg rafts of Cx. halifaxii and Cx. quinquefasciatus were found throughout the year. The greatest peak in eggs of Cx. halifaxii were observed in early June. The egg rafts of Cx. fuscanus were first collected on June 15, with the greatest peak of oviposition in early November. The egg raft of Cx. fuscanus was larger and both the maximum and mean numbers of eggs per raft were approximately two times greater than those of Cx. halifaxii.

Animals↗

PubMedDate not supplied

Retinoic acid and steroid hormones regulate IgA production by LPS-stimulated murine spleen cells.

We examined the regulatory effects of steroid hormones (beta-estradiol and glucocorticoids) on in vitro IgA production. Addition of retinoic acid (RA, 100-500 nM) to the LPS-stimulated spleen cell culture enhanced IgA production (8-22-fold). Simultaneous addition of beta-estradiol, but not testosterone, enhanced the effect of RA synergistically (a further 2-4-fold). In contrast, glucocorticoids inhibited the reaction. The concentration inhibiting IgA production by 50% was 1 nM, 6 nM and 10 nM for dexamethasone, prednisolone and hydrocortisone, respectively. None of the hormones tested alone affected IgA production by LPS-stimulated spleen cells. Hydrocortisone enhanced the IgG1 production by LPS-stimulated spleen cells. This effect was completely abolished by simultaneous addition of RA. These findings indicate that RA can direct the class-switching to IgA in LPS-stimulated spleen cells, and that beta-estradiol and glucocorticoids have positive and negative regulatory effects, respectively, on the IgA production.

Animals↗