Kumamoto University

About: Kumamoto University is a education organization based out in Kumamoto, Kumamoto, Japan. It is known for research contribution in the topics: Population & Cancer. The organization has 19602 authors who have published 35513 publications receiving 901260 citations. The organization is also known as: Kumamoto Daigaku.

Genome-wide analysis of deoxyadenosine methyltransferase-mediated control of gene expression in Escherichia coli.

Abstract: Deoxyadenosine methyltransferase (Dam) methylates the deoxyadenine residues in 5'-GATC-3' sequences and is important in many cellular processes in Escherichia coli. We performed a computational analysis of the entire E. coli genome and confirmed that GATC sequences are distributed unevenly in regulatory regions, which suggests that Dam might regulate gene transcription. To test this, a high-density DNA microarray of 4097 E. coli genes was constructed and used to assess the gene expression profiles of the wild type and the dam-16::kam mutant strain grown under four different conditions. We also used two-dimensional electrophoretic analysis of the proteome to assess the protein profiles. The expression of a large number of genes was affected by the dam deficiency. Genes involved in aerobic respiration, stress and SOS responses, amino acid metabolism and nucleotide metabolism were expressed at higher levels in the mutant cells, especially in aerobic conditions. In contrast, transcription of genes participating in anaerobic respiration, flagella biosynthesis, chemotaxis and motility was decreased in the dam mutant strain under both aerobic and low aerobic conditions. Thus, Dam-controlled genes are involved in adjusting the metabolic and respiratory pathways and bacterial motility to suit particular environmental conditions. The promoters of most of these Dam-controlled genes were also found to contain GATC sequences that overlap with recognition sites for two global regulators, fumarate nitrate reduction (Fnr) and catabolite activator protein (CRP). We propose that Dam-mediated methylation plays an important role in the global regulation of genes, particularly those with Fnr and CRP binding sites.

Indications for EMR/ESD in cases of early gastric cancer: relationship between histological type, depth of wall invasion, and lymph node metastasis

Abstract: Background Limited surgery by endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) for gastric cancer is frequently performed in many institutions. These techniques do preserve gastric function and maintain a high quality of life but may compromise survival. The treatment strategy for early tumors should therefore be based on a complete cure, and limited surgery must thus have clear indications.

Rate Dependence of Serrated Flow During Nanoindentation of a Bulk Metallic Glass

Abstract: Plastic deformation of Pd–40Ni–20P bulk metallic glass (BMG) was investigated by instrumented nanoindentation experiments over a broad range of indentation strain rates. At low rates, the load–displacement curves during indentation exhibited numerous serrations or pop-ins, but these serrations became less prominent as the indentation rate was increased. Using the tip velocity during pop-in as a gauge of serration activity, we found that serrated flow is only significant at indentation strain rates below about 1–10/s. This result suggests a transition in plastic flow behavior at high strain rates, in agreement with prior studies of BMGs under different modes of loading.