Essential Insight of Direct Electron Transfer-Type Bioelectrocatalysis by Membrane-Bound d-Fructose Dehydrogenase with Structural Bioelectrochemistry

電極を基質認識できる酵素の反応メカニズムを解明 --次世代バイオセンシングにつながる基盤技術--. 京都大学プレスリリース. 2023-10-16.Flavin adenine dinucleotide-dependent d-fructose dehydrogenase (FDH) from Gluconobacter japonicus NBRC3260, a membrane-bound heterotrimeric flavohemoprotein capable of direct electron transfer (DET)-type bioelectrocatalysis, was investigated from the perspective of structural biology, bioelectrochemistry, and protein engineering. DET-type reactions offer several benefits in biomimetics (e.g., biofuel cells, bioreactors, and biosensors) owing to their mediator-less configuration. FDH provides an intense DET-type catalytic signal; therefore, extensive research has been conducted on the fundamental principles and applications of biosensors. Structural analysis using cryo-electron microscopy and single-particle analysis has revealed the entire FDH structures with resolutions of 2.5 and 2.7 Å for the reduced and oxidized forms, respectively. The electron transfer (ET) pathway during the catalytic oxidation of d-fructose was investigated by using both thermodynamic and kinetic approaches. Structural analysis has shown the localization of the electrostatic surface charges around heme 2c in subunit II, and experiments using functionalized electrodes with a controlled surface charge support the notion that heme 2c is the electrode-active site. Furthermore, two aromatic amino acid residues (Trp427 and Phe489) were located in a possible long-range ET pathway between heme 2c and the electrode. Two variants (W427A and F489A) were obtained by site-directed mutagenesis, and their effects on DET-type activity were elucidated. The results have shown that Trp427 plays an essential role in accelerating long-range ET and triples the standard rate constant of heterogeneous ET according to bioelectrochemical analysis

Nursing Support Increases the Efficacy of Interferon Therapy in Patients with Chronic Hepatitis C

Nursing support might help patients with chronic hepatitis C (CHC) remain in good mental and physical condition during interferon (IFN) therapy. However, the effects of nursing support have not been studied adequately in this context. This case-control study evaluated the effects of nursing support during IFN therapy. Twenty-four CHC patients who received pegylated IFN and ribavirin were enrolled. Nurses advised patients on the maintenance of their mental and physical condition at weekly visits, based on the results of written questionnaires. An additional 24 patients who received IFN therapy without nursing support and who were matched for age, sex, platelet count, viral serogroup and IFN regimen were selected with propensity score matching as controls. The patients with nursing support during IFN therapy achieved higher sustained virological responses (79%) than those without nursing support (58%). Adherence to the IFN and ribavirin regimens at 24 weeks of therapy were slightly higher in the patients with nursing support than those without it, but these differences were not statistically significant. Adherence to ribavirin after 24 weeks of therapy was significantly higher in those with nursing support than those without it (93% and 66%, p＝0.045). These results suggested that nursing support services could contribute to the virological responses of CHC patients by promoting drug-regimen adherence

Recurrence of Proliferative Glomerulonephritis with Monoclonal Immunoglobulin G Deposits with a Striated Ultrastructure

This is the peer-reviewed but unedited manuscript version of the following article: Nephron 2020;144(suppl 1):43–48 (DOI: 10.1159/000512330)]. The final, published version is available at http://www.karger.com/?doi=10.1159/000512330

Laparoscopic Rectosigmoid Colon Vaginoplasty in Male-to-Female Transsexuals: Experience in Japan

Intestinal vaginoplasty has several advantageous features, such as scarless surgery, low incidence of contraction of the reconstructed vagina, maintenance of vaginal depth, spontaneous mucus production, and a low rate of complications. Therefore, this technique is becoming popular in many countries. Following the global trend, the demand for intestinal vaginoplasty for transsexuals is also increasing in Japan. However, there are few reports on intestinal vaginoplasty in Japan. In this study, we examined the safety and effectiveness of rectosigmoid colon vaginoplasty in the Japanese population. We retrospectively surveyed 18 male-to-female transsexuals who underwent laparoscopic rectosigmoid colon vaginoplasty at the Okayama University Hospital Gender Center between October 2012 and December 2017. One patient had developed an anastomotic leak and 2 patients experienced vaginal prolapse, which needed revision surgery. Both adverse outcomes were comparable with those from previous studies. The anastomotic leak was managed adequately with conservative treatment. To avoid vaginal prolapse, it is important to decide the length of the rectosigmoid segment so that a pull on it does not cause it to become lax, while excessive stress on the feeder vessels is avoided. Based on our study, we concluded that rectosigmoid vaginoplasty was a reliable technique in the Japanese population