東京大学 · 経済学
渡辺恒教授の研究室は、細菌における抗生物質耐性因子の遺伝子移動機構に注目し、特にエピソームを介した耐性遺伝子の転移とその分子機構を解明してきました。主な研究対象は、エシュェリチア・コリなどの腸内細菌に由来するR因子の性質、特にfi因子による性感染抑制機能や、ペルオキシソームやトランスダクションによる遺伝子移動のメカニズムです。また、耐性遺伝子の連鎖的挙動や、細菌間での遺伝子交換の効率に関する基礎的知見を多数得ています。
Figures are computed from collected data and may differ slightly.
Watanabe, Tsutomu (Keio University, Tokyo, Japan), Hiroshi Nishida, Chizuko Ogata, Toshihiko Arai, and Sachiko Sato. Episome-mediated transfer of drug resistance in Enterobacteriaceae. VII. Two types of naturally occurring R factors. J. Bacteriol. 88:716-726. 1964.-Naturally occurring R factors are classified into two types, fi(+) and fi(-), depending on their fi characters. The term fi is an abbreviation of fertility inhibition and fi(-) and fi(-) mean, respectively, the presence and absence of
Japan's government has taken a number of measures, including declaring a state of emergency, to combat the spread COVID-19. We examine the mechanisms through which the government's policies have led to changes in people's behavior. Using smartphone location data, we construct a daily prefecture-level stay-at-home measure to identify the following two effects: (1) the effect that citizens refrained from going out in line with the government's request, and (2) the effect that government announceme
Watanabe, Tsutomu (Keio University, Tokyo, Japan), and Toshio Fukasawa. Episome-mediated transfer of drug resistance in Enterobacteriaceae. III. Transduction of resistance factors. J. Bacteriol. 82:202-209. 1961.-Transmissible multiple drug resistance of Enterobacteriaceae, which includes resistance to streptomycin (SM), chloramphenicol (CM), tetracycline (TC), and sulfonamide (Su), was found to be transduced in the systems of Salmonella typhimurium strain LT-2 with phage P-22 and Escherichia co
R factors fi(+) and fi(-), with various combinations of drug-resistance markers and isolated from independent sources, were transduced by phage P1kc in Escherichia coli and by phage P22 in Salmonella typhimurium. Usually the entire R factor was transduced by P1kc in E. coli, as indicated by the absence of segregation of the drug-resistance markers from their conjugal transferability. In contrast, the patterns of segregation of the drug-resistance markers and their conjugal transferability differ
A half-filled-band Hubbard model on an anisotropic triangular lattice (t in two bond directions and t' in the other) is studied using an optimization variational Monte Carlo method, to consider the Mott transition and superconductivity arising in \kappa-BEDT-TTF_2X. Adopting wave functions with doublon-holon binding factors, we reveal that a first-order Mott (conductor-to-nonmagnetic insulator) transition takes place at U=U_c approximately of the band width, for a wide range of t'/t. This transi
A formula for the cross section of the ionization of an atom colliding with an excited atom, A*+B→A+B++e, was obtained. The calculations to the formula were restricted to the case where the transition A→A* is optically allowed and the excitation energy of A* exceeds the ionization potential of B as before. Here all degenerate states of A* and B+e were taken into account. The present formula gives a cross section which is 23% smaller than the previous result calculated by the use of the rotating-
Watanabe, T. (Keio University, Tokyo, Japan) and T. Fukasawa. Episome-mediated transfer of drug resistance in Enterobacteriaceae. IV. Interactions between resistance transfer factor and F-factor in Escherichia coli K-12. J. Bacteriol. 83:727-735. 1962. - Resistance transfer factor (RTF) present in F(+) and F'(+) strains was found to suppress completely the transfer of F-factor, F', and host chromosomes. On the other hand, the presence of RTF in Hfr strains was found to reduce the frequencies of
Abstract The relationship between stem cell mobilization with granulocyte colony-stimulating factor (G-CSF) and the endogenous production of interleukin-8 (IL-8), macrophage inflammatory protein-1 (MIP-1), tumor necrosis factor- (TNF-), and interferon-γ (IFN-γ) was studied in normal donors for allogeneic peripheral blood stem cell (PBSC) transplantation. G-CSF was administered to 20 normal donors at a dose of 10 μg/kg/d for 5 days with aphereses on days 5 and 6 of G-CSF treatment. Cytokine s
Human bone marrow mononuclear cells (BMMNCs) and enriched CD34 positive (CD34+) cells were transduced with adenovirus vectors encoding Escherichia coli beta-galactosidase gene. Tranductions were carried out by 24-hour coincubation with adenovirus vectors at different multiplicities of infections (moi). Efficacy of gene transfer into BM cells and expression of the gene product (ie, beta-galactosidase) were studied using X-Gal histochemical staining and flow cytometric analysis. X-Gal staining dem
IN 1959, in Japan, Ochiai and Akiba and their collaborators first discovered that resistance to several antimicrobial agents could be transferred among enteric bacteria in vitro. This phenomenon, which has become known as infectious drug resistance, is one of special interest to the microbial geneticist, but it is also of great potential importance in clinical medicine. This paper emphasizes the medical aspects of this subject and discusses some of the genetic data that are relevant to its medic
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