Biomedical subjects

Yasuhiro Kuramitsu

Publications and source records attributed to Yasuhiro Kuramitsu.

21 records · Page 2Linked to original sources

PubMed2002

Lipoproteins modulate growth and differentiation of cultured human epidermal keratinocytes.

The effects of various lipoproteins on the growth and the differentiation of cultured normal human keratinocytes were investigated. Primary cultures of human epidermal keratinocytes were obtained from neonatal foreskin, and then added with lipoproteins, very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL). Cell growth potential was examined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. VLDL and LDL enhanced keratinocytes growth and LDL receptor expression at the plasma membrane level. These effects were more remarkably observed in cells cultured with VLDL than in cells cultured with LDL. Apolipoprotein E (ApoE) was highly increased in VLDL treated cells. These results suggest that VLDL binds with high affinity to cell surface receptors and induces cell proliferation.

Apolipoproteins E↗

PubMed2002

A signaling pathway by a new synthetic lipid A analog, ONO-4007, in RAW264.7 cells.

ONO-4007 is a new synthetic lipid A derivative with low endotoxic activities. We have reported that ONO-4007 could be a new bio-logical response modifier for the treatment of tumor necrosis factor (TNF)-alpha-sensitive tumors. In this study, we confirmed that ONO-4007 activated a murine macrophage cell line, RAW264.7, and that the activated RAW264.7 cells produced TNF-alpha. RAW264.7 cells stimulated for less than 15 min with ONO-4007 (40 g/ml) did not produce TNF-alpha (less than 4 U/ml). However, 24 h stimulation with ONO-4007 induced TNF-alpha production (more than 256 U/ml) in RAW264.7 cells. Although P38 in mitogen-activated protein kinase of the RAW264.7 cells was not tyrosine phosphorylated by ONO-4007 stimulation, ERK1 of the RAW264.7 cells was tyrosine phosphorylated for 5-15 min by ONO-4007 stimulation. Tyrosine phosphorylation of ERK1 decreased gradually from 15 min after stimulation and almost disappeared 60 min after stimulation. These findings indicate that ONO-4007 stimulates RAW264.7 cells immediately and induces tyrosine phosphorylation of ERK1 in the RAW264.7 cells for 5-15 min. These data suggest that the signal transduction pathway of ONO-4007 may be similar to that of lipopolysaccharide.

Animals↗

PubMedDate not supplied

Rapid subpicogram protein detection on a microchip without denaturing.

Protein size separation based on sodium dodecyl sulfate-gel electrophoresis (SDS-GE) requires denaturing, but we propose that denaturing is unnecessary for analysis by microchip electrophoresis (micro-CE). By omitting the protein denaturing process, we achieved not only shortened total analysis time, but also dramatically improved sensitivity without compromising size determination. The detection limit was improved to 0.1 ng/microL under conditions without denaturing and 600 pg (9.0 femtomol) of bovine serum albumin was detectable, which equals levels detectable by Silver stain, although a routine method by microchips in the Coomassie Blue detection level.

Databases, Protein↗