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DFT Calculations on the Effect of Solvation on the Tautomeric Reactions for Wobble Gua-Thy and Canonical Gua-Cyt Base-Pairs

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Journal of Modern Physics 2013年第3期4卷 422-431页

作者： Kazuya Nomura Ryota Hoshino Eisuke Shimizu Yasuhiro Hoshiba Victor I. Danilov Noriyuki Kurita Department of Computer Science and Engineering Toyohashi University of Technology Toyohashi Japan Department of Molecular and Quantum Biophysics Institute of Molecular Biology and Genetics National Academy of Sciences of Ukraine Kyiv Ukraine

To elucidate the reaction mechanism from wobble Guanine-Thymine (wG-T) to tautomeric G-T base-pairs, we investigate its transition state (TS) by density functional theory (DFT) calculations, in vacuum and in water approximated by continuum solvation model. From the comparison of these results, we attempt to elucidate the effect of solvation on the tautomeric reaction for wG-T. In addition, the same DFT calculations are performed for the canonical G-C base-pair, in order to reveal the difference in the activation energy for the reactions involving wG-T and G-C. The obtained TS structures between wG-T and G*-T/G-T* (asterisk is an enol-form of base) are almost the same in vacuum and in water. However, the activation energy is 16.6 and 19.1 kcal/mol in vacuum and in water, respectively, indicating that the effect of solvation enlarges the energy barrier for the reactions from wG-T to G-T*/G*-T. The activation energy for the tautomeric reaction from G-C to G*-C* is also evaluated to be 15.8 and 12.9 kcal/mol in vacuum and in water, respectively. Therefore, it is expected that the tautomeric reaction from wG-T to G*-T/G-T* can occur in vacuum with a similar probability as that from G-C to G*-C*. We furthermore investigate the TS structure for wG-BrU to reveal the effect of the BrU introduction into wG-T. The activation energy is 14.5 and 16.7 kcal/mol in vacuum and in water, respectively. Accordingly, the BrU introduction is found to increase the probability of the tautomeric reaction producing the enol-form G* and T* bases. Because G* prefers to bind to T rather than to C, and T* to G not A, our calculated results reveal that the spontaneous mutation from C to T or from A to G bases is accelerated by the introduction of wG-BrU base-pair.

关键词： DFT Wobble Base Pair Base Pair Tautomerization Transition State Activation Energy Solvation

Influence of percutaneous local therapy for hepatocellular carcinoma on gastric function

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World Journal of Gastroenterology 2013年第10期19卷 1618-1624页

作者： Mitsuyoshi Kobayashi Fumihiko Kinekawa kazuya Matsuda Shintaro Fujihara Noriko Nishiyama Takako nomura Joji Tani Hisaaki Miyoshi Hideki Kobara Akihiro Deguchi Hirohito Yoneyama Hirohito Mori Tsutomu Masaki Department of Gastroenterology and Neurology Faculty of MedicineKagawa UniversityMiki-choKita-gunKagawa 761-0793Japan Department of Internal Medicine Sanuki Municipal HospitalSanuki-cityKagawa 769-2393Japan Department of Internal Medicine Matsuda ClinicTakamatsu-cityKagawa 760-0071Japan

AIM:To investigate the influence of percutaneous local therapy on gastric myoelectrical activity in patients with hepatocellular carcinomas.METHODS:Forty-four patients with hepatocellular carcinoma(HCC) [27 males and 17 females,ranging in age from 49 to 81 years old(69.7 ± 8.01 years)] who were admitted for percutaneous local therapy were enrolled in this study.We examined clinical abdominal symptoms using the Gastrointestinal Symptom Rating Scale(GSRS) before and 3 d after percutaneous local therapy.We also measured cutaneous fasting and postprandial electrogastrography(EGG) recordings before and 3 d after percutaneous local therapy.RESULTS:We found that the percentage of normogastria in the fasting period was lower in the Child B group than in the Child A group(66.8% ± 8.6% vs 84.0% ± 3.8%).After percutaneous local therapy for HCC,the percentages of normogastria in the fasting period were significantly decreased(81.6% ± 3.5% vs 75.2% ± 4.5%).None of the postprandial EGG parameters changed significantly after percutaneous local therapy for HCC.Percutaneous local therapy for HCC reduced the power ratio(PR).In particular,the PR of tachygastria was significantly decreased after therapy(P < 0.01).However,no significant differences were found in the postprandial EGG parameters.Likewise,no significant differences were found in the calculated GSRS scores obtained from the questionnaire before and after therapy.CONCLUSION:Gastric slow-wave dysrhythmias were induced by percutaneous local therapy in HCC patients,even though the GSRS scores obtained from the questionnaire did not change significantly.

关键词： Gastric myoelectrical activity Electrogastrography Hepatocellular carcinoma Percutaneous ethanol injection Radiofrequency ablation

Successful endoscopic hemostasis for gastric arterial bleeding due to invasion of malignant lymphoma

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World Journal of Gastroenterology 2005年第27期11卷 4285-4286页

作者： Kenichi nomura Shinya Yamada Daisuke Shimizu Takashi Okuda Yuri Kamitsuji Naohisa Yoshida Yosuke Matsumoto Naoki Wakabayashi kazuya Mikami Shigeo Horiike Takeshi Okanoue Masafumi Taniwaki Masafumi Taniwaki Molecular Gastroenterology and Hepatology Department of Urology Clinical Molecular Genetics and Laboratory Medicine

A 75-year-old male with malignant lymphoma (ML) accompanied with gastric lesion was treated with combination chemotherapy. The patient produced tarry stool on the 4th d, and emergency gastroscopy showed arterial bleeding from the lesion. Hemostasis was achieved by injecting pure ethanol and using hemostatic clips. There is only one previous report on endoscopic hemostasis being effective for bleeding due to lymphoma. Since gastric bleeding causes significant mortality, endoscopic hemostasis should be considered as first-line treatment for ML patients who were treated with chemotherapy.

关键词：内窥镜止血方法胃动脉淋巴瘤

A Case of Simultaneous Triple Primary Cancers of the Hypopharynx, Esophagus, and Stomach Which Were Dissected by Endoscopic Laryngo-Pharyngeal Surgery Combined with Endoscopic Submucosal Dissection

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Open Journal of Gastroenterology 2018年第3期8卷 94-102页

作者： Kenro Kawada Taro Sugimoto Ryuhei Okada kazuya Yamaguchi Yuudai Kawamura Masafumi Okuda Yuuichiro Kume Andres Mora Tairo Ryotokuji Takuya Okada Akihiro Hoshino Yutaka Tokairin Yasuaki Nakajima Yusuke Kiyokawa Fuminori nomura Yoshuke Ariizumi Shohei Tomii Takashi Ito Takahiro Asakage Yusuke Kinugasa Tatsuyuki Kawano Department of Gastrointestinal Surgery Tokyo Medical and Dental University Tokyo Japan Department of Head and Neck Surgery Tokyo Medical and Dental University Tokyo Japan Department of Human Pathology Tokyo Medical and Dental University Tokyo Japan

A 65-year-old man was admitted to our hospital following 6 months of dysphagia. At first, conventional endoscopy showed a reddish and depressed lesion in the stomach and an elevated lesion in the posterior wall of the hypopharynx. An endoscopic biopsy showed adenocarcinoma in the stomach, and squamous cell carcinoma in the hypopharynx. On the further examination, trans-nasal endoscopy with narrow band imaging (NBI) was performed. During the trumpet maneuver, a huge protruded lesion was observed and it reached to the orifice of the esophagus. Other superficial lesion located at left pyriform sinus was detected by NBI system as brownish area with brown dots. Furthermore, superficial esophageal cancer in the cervical esophagus was detected. Finally, 4 carcinomas in upper gastrointestinal tract were detected. Among them, the hypopharyngeal cancer was the most advanced (T3N0). The patient hoped to preserve his voice and swallowing function, endoscopic laryngo-pharyngeal surgery (ELPS) was performed for the hypopharyngeal cancer. Endoscopic mucosal resection (EMR) was performed for the esophageal cancer, and Endoscopic submucosal dissection (ESD) was performed for the gastric cancer. Under collaboration between a head and neck surgeon and an endoscopist, the tumor was resected en-bloc. The histopathological findings of hypopharyngeal cancer were squamous cell carcinoma, subeipthelial invasion, 29 × 28 × 4.2 mm. The others were diagnosed as mucosal cancers. The patient is currently alive with no recurrence at 28 months after the surgery;there is no stricture at the cervical esophagus. Endoscopic laryngopharyngeal surgery for the tumor of pharyngo-esophageal junction can provide a less invasive treatment.

关键词： Endoscopic Laryngopharyngeal Surgery Hypopharyngeal Cancer Multiple Primary Cancer Trumpet Maneuver Endoscopic Submucosal Dissection