Biomedical subjects

E Igata

Publications and source records attributed to E Igata.

4 recordsLinked to original sources

PubMed2002

Interconnected reversible lab-on-a-chip technology.

Interconnected lab-on-a-chip modules with minimal dead volume have been developed resulting in the 'plug and play' concept based upon a reversible bonding process. This paper describes the detail of a chip to chip interconnection method, where devices have been aligned and bonded within 15 min and rapidly disassembled in under 5 min. The transport of fluorescein between the chip modules was used as a model microfluidic system and analysed in order to demonstrate the electrophoretic performance of the device and the interconnected junction. Using this technology, in the future different modules for various applications can be developed and interconnected, depending on the required applications. In addition, this simple but rapid method of chip to chip connection overcomes potential problems associated with integrating incompatible materials on one device.

Journal Article↗

PubMed1999

Molecular cloning and functional characterization of the upstream promoter region of the human p73 gene.

The p73 gene encodes a protein that shares structural and functional homologies with the p53 tumor suppressor protein. To investigate the mechanism of transcriptional regulation of the p73 gene, we isolated a genomic DNA fragment spanning the 5' upstream region of the human p73 gene and characterized the promoter region. Unlike the p53 gene promoter, the human p73 gene promoter contained a putative TATA-box, and did not exhibit any extended homology to the p53 gene. Two CpG islands were located in the 5' upstream region. Transient transfection assays using progressive truncations of the p73 promoter showed that deletion from -119 to +19 relative to exon 1 resulted in a 13- to 20-fold reduction in the p73 promoter activity, suggesting that the elements for basal promoter activity exist in this region, where putative Sp1, AP-2 and Egr-1, 2, 3 sites are located and CpG dinucleotides are especially concentrated.

Base Composition↗

PubMed1999

Molecular cloning and functional analysis of the murine bax gene promoter.

Bcl-2-associated X protein (Bax) is a proapoptotic protein and is suggested to have an important role in carcinogenesis. To investigate the mechanism of bax gene transcriptional regulation, we isolated and sequenced the genomic DNA fragment of the 5' flanking region of the murine bax gene, and subcloned its promoter region into a luciferase reporter construction. The murine bax promoter is TATA-less, and the sequence is only partially homologous to that of the human bax promoter. Transient transfection into NIH 3T3 cells using unidirectionally deleted promoters and mutants of Sp1 sites revealed that two Sp1 sites were partially responsible for the basal activity. The murine bax promoter was not responsive to exogenous p53, suggesting that the p53-responsive element may not exist in the region used in our current experiments.

3T3 Cells↗

PubMed1997

Molecular cloning and characterization of the human p27Kip1 gene promoter.

p27Kip1 is an inhibitor of multiple cyclin-dependent kinases (cdk), and can arrest the cell-cycle progression by inhibiting the phosphorylation of the retinoblastoma gene family products. Tumor formation in p27Kip1 knockout mice clearly shows that p27Kip1 plays an important role in inhibiting tumor formation and progression. To investigate the mechanism of transcriptional p27Kip1 gene expression, we isolated the genomic DNA fragment of the 5' flanking region of the human p27Kip1 gene and characterized its promoter region. The human p27Kip1 promoter is TATA-less, and the sequence is highly homologous to the murine p27Kip1 promoter sequence. In the promoter assay, deletion from -774 to -435 relative to the initiating codon resulted in a 15-20-fold reduction of the p27Kip1 promoter activity, suggesting that the elements for basal promoter activity exist in this highly conserved 340 bp region, where putative CTF and ATF sites are conserved.

Animals↗