Biomedical subjects

Yuji Miyamoto

Publications and source records attributed to Yuji Miyamoto.

40 records · Page 3Linked to original sources

PubMed2002

HOX gene clusters are hotspots of de novo methylation in CpG islands of human lung adenocarcinomas.

CpG island methylation results in the silencing of the associated gene and is an important step in tumorigenesis. Following a comprehensive isolation of CpG islands that were methylated in human lung adenocarcinoma, we found that in cancer cells de novo CpG island methylation generally occurred in a sporadic manner. However, some methylated CpG islands appeared to cluster in discrete chromosomal regions. In this study, we have investigated the methylation status of CpG islands located at such chromosomal loci. We have found that many CpG islands at the HOXA and HOXD loci were methylated in human lung adenocarcinoma. The de novo methylation of these CpG islands was also observed in patient's DNA from noncancerous portions of lung tissue. These results indicate the presence of specific chromosomal regions that are susceptible to de novo methylation.

Adenocarcinoma↗

PubMed2002

Cloning and characterization of a glycosyltransferase gene involved in the biosynthesis of anthracycline antibiotic beta-rhodomycin from Streptomyces violaceus.

A glycosyltransferase gene, rhoG, involved in the biosynthesis of the anthracycline antibiotic beta-rhodomycin was isolated as a 4.1-kb DNA fragment containing rhoG and its flanking region from Streptomyces violaceus by degenerate and inverse PCR. Sequencing analysis showed that rhoG was located in a gene cluster involved in the biosynthesis of the constitutive deoxysugar of beta-rhodomycin. The function of rhoG was verified by gene disruption, which was generated by replacing the internal 0.9-kb region of S. violaceus chromosome with a fragment including the SacI-blunted region. The rhoG disruption resulted in complete loss of beta-rhodomycin productivity, along with the accumulation of a non-glycosyl intermediate epsilon-rhodomycinone. In addition, the complementation test demonstrated that rhoG restored beta-rhodomycin production in this gene disruptant. These results indicated that rhoG is the glycosyltransferase gene responsible for the glycosylation of epsilon-rhodomycinone in beta-rhodomycin biosynthesis.

Anthracyclines↗

PubMed2002

Arch-first technique for aortic arch aneurysm repair through median sternotomy.

We describe a modified arch-first technique for total arch replacement through median sternotomy. This technique involves a short period of circulatory arrest (less than 30 minutes) and subsequent anterior cerebral perfusion. It does not require cannulation of the carotid vessels, which can cause cerebral thromboembolism, and it enables anterior cerebral perfusion to be resumed after a relatively short period of circulatory arrest. This appears to be a useful technique to reduce cerebral complications in complicated arch reconstruction operation for patients with severely atherosclerotic carotid vessels.

Aorta, Thoracic↗

PubMed2002

Intraoperative transfection of vein grafts with the NFkappaB decoy in a canine aortocoronary bypass model: a strategy to attenuate intimal hyperplasia.

BACKGROUND: The nuclear transcriptional factor NFkappaB is reported to play an important role in the expression of genes for neutrophil and macrophage chemotactic factors, adhesion molecules, and cell cycle-regulating proteins. In aortocoronary bypass surgery, the saphenous vein often develops vein graft disease. Here, we investigated whether transfection of a cis element decoy oligodeoxynucleotide of NFkappaB (NFkappaB decoy) into the vein graft wall suppresses neointimal hyperplasia and the differentiation of medial smooth muscle cells. METHODS: We established a canine aortocoronary bypass grafting model that has a saphenous vein graft between the left anterior descending coronary artery and the descending aorta. Pressure-mediated transfection of a scrambled (SD group; n = 5) or NFkappaB decoy (ND group; n = 5) into the graft wall was performed intraoperatively. The grafts were gently harvested at 4 weeks postoperative, and the middle portion of the graft was examined histopathologically. RESULTS: The average neointimal area of the ND group was significantly suppressed (SD group, 2.63 +/- 1.00 mm2 vs ND group, 0.88 +/- 0.66, p < 0.05), and the differentiation and proliferation of the medial smooth muscle cells in the ND group were also suppressed (proliferating cell nuclear antigen index: SD group, 56 +/- 24 vs ND, 13 +/- 4, p < 0.05). CONCLUSIONS: These results demonstrated the efficacy of intraoperative transfection of the NFkappaB decoy into the vein graft wall for attenuation of neointima formation.

Animals↗