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Novel zinc alloys for biodegradable surgical staples

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World Journal of Clinical Cases 2020年第3期8卷 504-516页

作者： Hizuru Amano koichi Miyake Akinari Hinoki Kazuki Yokota Fumie Kinoshita Atsuko nakazawa Yujiro Tanaka Yasuhiro Seto Hiroo Uchida Department of Pediatric Surgery Graduate School of MedicineThe University of TokyoTokyo 113-8655Japan Mitsui Mining and Smelting Co. Ltd.Tokyo 141-0032Japan Department of Pediatric Surgery Nagoya University Graduate School of MedicineNagoya 466-8550Japan Department of Advanced Medicine Nagoya University HospitalNagoya 466-8560Japan Department of Clinical Research Saitama Children’s Medical CenterSaitama 330-8777Japan

BACKGROUND The development of biodegradable surgical staples is desirable as non-biodegradable Ti alloy staples reside in the human body long after wound healing, which can cause allergic/foreign-body reactions, adhesion, or other adverse effects. In order to develop a biodegradable alloy suitable for the fabrication of surgical staples, we hypothesized that Zn, a known biodegradable metal, could be alloyed with various elements to improve the mechanical properties while retaining biodegradability and biocompatibility. Considering their biocompatibility, Mg, Ca, Mn, and Cu were selected as candidate alloying elements, alongside Ti, the main material of clinically available surgical *** To investigate the in vitro mechanical properties and degradation behavior and in vivo safety and feasibility of biodegradable Zn alloy *** Tensile and bending tests were conducted to evaluate the mechanical properties of binary Zn alloys with 0.1–6 wt.% Mg, Ca, Mn, Cu, or Ti. Based on the results,three promising Zn alloy compositions were devised for staple applications(wt.%): Zn-1.0Cu-0.2Mn-0.1Ti(Zn alloy 1), Zn-1.0Mn-0.1Ti(Zn alloy 2), and Zn-1.0Cu-0.1Ti(Zn alloy 3). Immersion tests were performed at 37℃ for 4 wk using fed-state simulated intestinal fluid(Fe SSIF) and Hank’s balanced salt solution(HBSS). The corrosion rate was estimated from the weight loss of staples during immersion. Nine rabbits were subjected to gastric resection using each Zn alloy staple, and a clinically available Ti staple was used for another group of nine rabbits. Three in each group were sacrificed at 1, 4, and 12 wk *** Additions of ≤1 wt.% Mn or Cu and 0.1 wt.% Ti improved the yield strength without excessive deterioration of elongation or bendability. Immersion tests revealed no gas evolution or staple fracture in any of the Zn alloy staples. The corrosion rates of Zn alloy staples 1, 2, and 3 were 0.02 mm/year in HBSS and 0.12, 0.11, and 0.13 mm/year, respective

关键词： Zinc alloy Surgical staple Gastric resection Biodegradability,Biocompatibility Mechanical Strength

Alterations in the human epidermal growth factor receptor 2-phosphatidylinositol 3-kinase-v-Akt pathway in gastric cancer

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World Journal of Gastroenterology 2012年第45期18卷 6577-6586页

作者： Yasutaka Sukawa Hiroyuki Yamamoto Katsuhiko Nosho Hiroaki Kunimoto Hiromu Suzuki Yasushi Adachi Mayumi nakazawa Takayuki Nobuoka Mariko Kawayama Masashi Mikami Takashi Matsuno Tadashi Hasegawa koichi Hirata Kohzoh Imai Yasuhisa Shinomura First Department of Internal Medicine Sapporo Medical University School of MedicineSapporo 60-8543Japan Department of Molecular Biology Sapporo Medical University School of MedicineSapporo 60-8543Japan First Department of Surgery Sapporo Medical University School of MedicineSapporo 60-8543Japan Department of Gastroenterology JR Sapporo HospitalSapporo 60-8543Japan Department of Surgery Sapporo Gekakinen HospitalSapporo 60-8543Japan Department of Surgical Pathology Sapporo Medical University HospitalSapporo 60-8543Japan Division of Cancer Research The Institute of Medical ScienceThe University of TokyoTokyo 108-8639Japan

AIM:To investigate human epidermal growth factor receptor 2(HER2)-phosphatidylinositol 3-kinase(PI3K)-vAkt murine thymoma viral oncogene homolog signaling ***:We analyzed 231 formalin-fixed,paraffinembedded gastric cancer tissue specimens from Japanese patients who had undergone surgical *** patients' age,sex,tumor location,depth of invasion,pathological type,lymph node metastasis,and pathological stage were determined by a review of the medical *** of HER2 was analyzed by immunohistochemistry(IHC) using the HercepTest TM *** criteria for HER2 positivity(0,1+,2+,and 3+) were *** that scored 3+ were considered *** of phospho Akt(pAkt) was also analyzed by *** were considered pAkt-positive when the percentage of positive tumor cells was 10% or ***3K,catalytic,alpha polypeptide(PIK3CA) mutations in exons 1,9 and 20 were analyzed by ***-Barr virus(EBV) infection was analyzed by in situ hybridization targeting EBV-encoded small RNA(EBER) with an EBER-RNA *** instability(MSI) was analyzed by polymerase chain reaction using the mononucleotide markers BAT25 and ***:HER2 expression levels of 0,1+,2+ and 3+ were found in 167(72%),32(14%),12(5%) and 20(8.7%) samples,***2 overexpression(IHC 3+) significantly correlated with intestinal histological type(15/20 vs 98 /205,P = 0.05).PIK3CA mutations were present in 20 cases(8.7%) and significantly correlated with MSI(10/20 vs 9/211,P < 0.01).The mutation frequency was high(21%) in T4 cancers and very low(6%) in T2 *** in exons 1,9 and 20 were detected in 5(2%),9(4%) and 7(3%) cases,*** new types of PIK3CA mutation,R88Q and R108H,were found in *** PIK3CA mutations were heterozygous missense singlebase substitutions,the most common being H1047R(6/20,30%) in *** cancers(8%) were EBV-positive and this positivity significantly correlated with a diffu

关键词： Human epidermal growth factor receptor 2 Phosphatidylinositol 3-kinase Catalytic Alpha polypep-tide Epstein-Barr virus Aid: Gastric cancer

Relationship of Lifestyle Habits with Sleep Quality among Japanese in Their 20s

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Health 2019年第1期11卷 1-8页

作者： Tomohide Yagyu Kohei Akazawa Minami Ebihara Junta Ishikawa koichi Ouchi Koji Kobayashi Kyoko nakazawa Department of Health Informatics Suzuka University of Medical Science Suzuka Japan Department of Medical Informatics Niigata University Medical & Dental Hospital Niigata Japan Department of Medical Informatics and Statistics Niigata University Graduate School of Medical & Dental Sciences Niigata Japan

The purpose of this study was to analyze the effects of lifestyle on sleep quality in young Japanese adults. A cross-sectional study was conducted on the web. We analyzed 637 eligible subjects (316 men and 321 women) aged 20 - 29 years. Information on diet and individual lifestyle characteristics, including sleep quality, which was assessed using the Pittsburgh Sleep Quality Index Japanese version (PSQI-J). Results were obtained by participants completing an online questionnaire. The participants were divided into two groups based on whether they were students (“student group”) or not (“not student group”). The participants with a PSQI-J global score of 6 or higher were evaluated as low-sleep-quality. Logistic regression analyses were performed to evaluate associations of lifestyle habits with low-sleep-quality. Logistic regression analyses were applied for “student group” and “not student group”. The results showed that days of eating out at dinner (OR: 1.11, CI: 1.00 - 1.22) and skipping dinner (OR: 1.21, CI: 1.05 - 1.42) were significant and independent predictors for low-sleep-quality among the “not student group”. There were no significant and independent predictors for low-sleep-quality among “student group”. Our results suggested that excessive intake by eating out and deficient intake by skipping dinner might lead to a high PSQI-J score. It is necessary for young people to receive education on the importance of cooking their own meals for traditional and daytime eating. The implication of this study lies in the fact that we have analyzed the effects of lifestyle habits on quality of sleep.

关键词： Sleep Quality Eating Out Skipping Meal Cross-Sectional Study Pittsburgh Sleep Quality Index

The Reproducibility of Patient Setup for Head and Neck Cancers Treated with Image-Guided and Intensity-Modulated Radiation Therapies Using Thermoplastic Immobilization Device

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2013年第4期2卷 117-124页

作者： Akihiro Nakata Kunihiko Tateoka Kazunori Fujimoto Yuichi Saito Takuya nakazawa Tadanori Abe Masaki Yano koichi Sakata 1Department of Medical Physics Graduate School of Medicine Sapporo Medical University Sapporo Japan 4Radiation Therapy Research Institute Social Medical Corporation Teishinkai Sapporo Japan Department of Medical Physics Graduate School of Medicine Sapporo Medical University Sapporo Japan Department of Medical Physics Graduate School of Medicine Sapporo Medical University Sapporo Japan Department of Radiology Sapporo Medical University Sapporo Japan Department of Medical Physics Graduate School of Medicine Sapporo Medical University Sapporo Japan Nikko Memorial Hospital Muroran Japan

The reproducibility of patient setup is an important issue for head and neck cancers treated with intensity-modulated radiation therapy (IMRT). In this study, an image-guided radiation therapy (IGRT) system has been used to minimize the uncertainty of patient setup while standard thermoplastic masks were used to provide adequate immobilization for the head and neck. However, they do not provide sufficient immobilization of the shoulders, which is an important requirement in comprehensive nodal irradiation. Therefore, we investigated the setup and rotational shifts in head and neck cancer patients undergoing IMRT for which this immobilization device had been used together with an IGRT system. The setup and rotational shifts of patients were analyzed using the ExacTrac X-ray 6D IGRT system. The patients were classified as having head and neck tumors in the upper or lower regions. The upper neck nodes included lymph nodal level II while the lower neck nodes included lymph nodal levels III and IV. Clinical data from 227 treatment sessions of 12 head and neck cancer patients were analyzed. The random translational error in inter-and intra-fraction errors of the anterio-posterior (AP) direction might influence the rotational errors of pitch and roll in the upper region. At the same time, the random translational error in the inter-and intra-fraction errors of the AP direction might influence the rotational error of roll in the lower region. We believe that these random translational errors should be considered during treatment. We found variability in random translational errors for different regions in the anatomy of head and neck cancer patients due to rotational shifts. Depending on the location of the primary lesion or the selected nodal treatment targets, these relative positional variations should be considered when setup and rotational shifts are corrected with IGRT systems before treatment.

关键词： IMRT IGRT Radiation Therapy Immobilization Head and Neck Cancer

Method for Converting Cone-Beam CT Values into Hounsfield Units for Radiation Treatment Planning

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2017年第4期6卷 361-375页

作者： Tadanori Abe Kunihiko Tateoka Yuichi Saito Takuya nakazawa Masaki Yano Kensei Nakata Masanori Someya Masakazu Hori koichi Sakata Depertment of Radiation Oncology and Medical Physics Graduate School of Medicine Sapporo Medical University Sapporo Japan Department of Radiology KKR Sapporo Medical Center Sapporo Japan Preparatory Office for Proton Therapy Center Radiation Therapy Research Institute Social Medical Corporation Teishinkai Sapporo Japan Department of Radiology National Hospital Organization Hokkaido Cancer Center Sapporo Japan Department of Radiology Kushiro City General Hospital Kushiro Japan Department of Radiation Oncology School of Medicine Sapporo Medical University Sapporo Japan

Cone-beam CT (CBCT) images acquired during radiation treatment can be used to recalculate the dose distribution as well as to confirm the treatment location. However, it is difficult to obtain the electron densities (EDs) necessary for dose calculation from CBCT images because of the effects of scatter contamination during CBCT image acquisition. This paper presents a mathematical method for converting the pixel values of CBCT images (CBCT values) into Hounsfield units (HUs) of radiation treatment simulation CT (simCT) images for use in radiation treatment planning. CBCT values are converted into HUs by matching the histograms of the CBCT values with the histograms of the HUs for each slice via linear scaling of the CBCT values. For prostate cancer and head-and-neck cancer patients, the EDs obtained from converted CBCT values (mCBCT values) show good agreement with the EDs obtained from HUs, within approximately 3.0%, and the dose calculated on the basis of CBCT images shows good agreement with the dose calculated on the basis of the simCT images, within approximately 2.0%. Because the CBCT values are converted for each slice, this conversion method can account for variation in the CBCT values associated with differences in body size, body shape, and inner tissue structures, as well as in longitudinally displaced positions from the isocenter, unlike conventional methods that use electron density phantoms. This method improves on conventional CBCT-ED conversion and shows considerable potential for improving the accuracy of radiation treatment planning using CBCT images.

关键词： Cone-Beam Computed Tomography Hounsfield Unit Electron Density Ra-diation Treatment Planning

Effects of Beam Startup Characteristics on Dose Delivery Accuracy at Low Monitor Units in Step-and-Shoot Intensity Modulated Radiation Therapy

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2013年第1期2卷 1-5页

作者： Kazunori Fujimoto Kunihiko Tateoka Yuji Yaegashi Katsumi Shima Junji Suzuki Yuichi Saito Akihiro Nakata Takuya nakazawa Tadanori Abe Masaki Yano Masanori Someya Kensei Nakata Masakazu Hori Masato Hareyama koichi Sakata Department of Medical Physics Graduate School of Medicine Sapporo Medical University Sapporo Japan Department of Radiology Sapporo Medical University Sapporo Japan Radiation Therapy Research Institute Social Medical Corporation Teishinkai Sapporo Japan

Intensity modulated radiation therapy (IMRT) is a highly accurate technique that is usually implemented in either dynamic or step-and-shoot fashion with many segments each having low monitor units (MUs). The present study evaluated the effects of beam startup characteristics on the dose delivery accuracy for each segment at low MUs for step-and-shoot IMRT with an Elekta Precise accelerator at the highest dose rates. We used a two-dimensional semi-conductor detector for the dose measurements. The field size of each segment was assumed to be 20 ×20 cm2 and each segment was set to deliver 1 - 10 MUs. Our results show a variation in dose delivery accuracy between segments for the same IMRT beam, which can be attributed to the beam startup characteristics. This variability is attributed to the changes in the transient changes in the temperatures of the electron gun filament and the magnetron. That is, the transient increase in the temperature of the filament leads to increasing doses with time and that of the magnetron leads to decreasing doses with time during the first few MUs.

关键词： Startup Performance Step-and-Shoot IMRT Low Monitor Units