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Sapporo, Japan

The basic model for chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection during therapy enables us to analyze short-term viral kinetics. However, the model is not useful for analyzing long-term viral kinetics. Here, I suggest a new model that was obtained by introducing Michaelis-Menten kinetics into the basic model. The new model can exhibit long-term viral kinetics without rebound and oscillation, unlike the basic model. The value of the parameter K in the new model is analogous to the Michaelis constant Km and is predicted to be approximately less than 1010/ml. © 2013 Elsevier Ltd.

Cell-mediated cytotoxicity assays are widely implemented to evaluate cell-mediated cytotoxic activity, and some assays are analyzed using the analogy of enzyme kinetics. In the analogy, the effector cell is regarded as the enzyme, the target cell as the substrate, the effector cell-target cell conjugate as the enzyme-substrate complex and the dead target cell as the product. However, the assumptions analogous to those of enzyme kinetics are not always true in cell-mediated cytotoxicity assays, and the parameter analogous to the Michaelis-Menten constant is not constant but is dependent on the number of effector cells. Therefore I present novel mathematical models for cell-mediated cytotoxicity assays without applying enzyme kinetics. I instead use combinations and probability, because analysis of cell-mediated cytotoxicity assays by applying enzyme kinetics seems controversial. With my original models, I demonstrate simulations of the data in previously published papers. The results are exhibited in the same forms as the corresponding data. Comparing the simulation results with the published data, the results seem to agree well with the data. From simulations of cytotoxic assays with bulk effector cells, it appears that bystanders in bulk effector cells increase both the cytotoxic activity and the motility of effector cells. © 2011 Elsevier Ireland Ltd.

Nakajima F.,Nemuro City Hospital | Matsuoka K.,Nemuro City Hospital | Ogawa T.,Nemuro City Hospital | Nomura H.,Kushiro Koujinkai Memorial Hospital | Araya J.,Sapporo Ryokuai Hospital
Japanese Journal of Cancer and Chemotherapy | Year: 2011

A 42-year-old female underwent surgery for cancer of the left breast (T3N2M0) in February 2003, and FEC 70, followed by CMF, was administered as adjuvant therapy. In January 2009, second-line chemotherapy with weekly paclitaxel therapy was started after multiple pleural and bone metastatic lesions had been found. Despite this treatment, she required radiation therapy for the growth of bone metastatic lesions. As paclitaxel apparently had no useful effect on the lesions, S-1 chemotherapy, given as third-line therapy starting in December 2009, was considered useful for disease control without progression demonstrated by PET evaluation.

Araya J.,Sapporo Ryokuai Hospital | Nomura H.,Hoshigaura Hospital | Nakajima F.,Betsukai Municipal Hospital
Journal of Japanese Society of Gastroenterology | Year: 2016

A 79-year-old woman was admitted for investigation of epigastric pain and jaundice. Abdominal computed tomography showed a common bile duct stone with a needle-like calcification. Endoscopic sphincterotomy was performed, and the stone was extracted from the common bile duct After endoscopic sphincterotomy, laparoscopic cholecystectomy was performed. Pathological findings and component analysis of the stone suggested that it was formed from a fish bone. We report a rare case of a common bile duct stone formed from a fish bone.

Fujishiro M.,University of Tokyo | Higuchi K.,Osaka Medical College | Kato M.,Hokkaido University | Kinoshita Y.,The University of Shimane | And 78 more authors.
Journal of Clinical Biochemistry and Nutrition | Year: 2015

A 24-week, double-blind, clinical trial of rabeprazole for the prevention of recurrent peptic ulcers caused by low-dose aspirin (LDA) has been reported, but trials for longer than 24 weeks have not been reported. The aim of this study is to assess the long-term efficacy and safety of rabeprazole for preventing peptic ulcer recurrence on LDA therapy. Eligible patients had a history of peptic ulcers on long-term LDA (81 or 100 mg/day) therapy. Patients with no recurrence of peptic ulcers at the end of the 24-week double-blind phase with rabeprazole (10- or 5-mg once daily) or teprenone (50 mg three times daily) entered the extension phase. Rabeprazole doses were maintained for a maximum of 76 weeks, including the double-blind 24-week period and the extension phase period (long-term rabeprazole 10- and 5-mg groups). Tepre-none was randomly switched to rabeprazole 10 or 5 mg for a maximum of 52 weeks in the extension phase (newly-initiated rabeprazole 10- and 5-mg groups). The full analysis set consisted of 151 and 150 subjects in the long-term rabeprazole 10- and 5- mg groups, respectively, and the cumulative recurrence rates of peptic ulcers were 2.2 and 3.7%, respectively. Recurrent peptic ulcers were not observed in the newly-initiated rabeprazole 10- and 5-mg groups. No bleeding ulcers were reported. No clinically significant safety findings, including cardiovascular events, emerged. The use of long-term rabeprazole 10- and 5-mg once daily prevents the recurrence of peptic ulcers in subjects on low- dose aspirin therapy, and both were well-tolerated. © 2015 JCBN.

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