医学部附属病院

小澤 義人

Yoshihito Ozawa

基本情報

所属
千葉大学 医学部附属病院 臨床試験部 生物統計室 特任助教

J-GLOBAL ID
201901020807640034
researchmap会員ID
B000370681

研究分野

 1

論文

 40
  • Noriko Takeuchi, Bin Chang, Naruhiko Ishiwada, Yoshiaki Cho, Junichiro Nishi, Kenji Okada, Mikiya Fujieda, Megumi Oda, Akihiko Saitoh, Mitsuaki Hosoya, Nobuhisa Ishiguro, Kohei Takahashi, Yoshihito Ozawa, Shigeru Suga
    Vaccine 54 127138-127138 2025年4月18日  
    BACKGROUND: Nationwide surveillance was conducted in Japan to clarify the status of pediatric invasive pneumococcal diseases (IPD) after introducing a 13-valent pneumococcal conjugate vaccine (PCV13). METHODS: Detailed clinical and epidemiologic information of IPD cases in children aged <15 years was collected from 10 of 47 prefectures in Japan from January 2014 to December 2022. Streptococcus pneumoniae strains isolated from sterile body sites were analyzed including capsular serotypes, multi-locus sequence typing (MLST), and antimicrobial susceptibility testing. The serotype-specific IPD incidence was calculated by imputing the serotypes for missing isolates to serotypes assumed based on the distribution of known serotypes. RESULTS: During the study period, 1033 IPD cases were reported. The incidence rate of total IPD in patients aged <5 years from 2014 to 2019 declined by 21.3 % compared with the rate from 2011 to 2013 before the introduction of PCV13. Compared with the incidence of total IPD from 2014 to 2019 and from 2020 to 2022, during the COVID-19 pandemic, the incidence of IPD among children aged <5 years declined by 49.7 %. In total, 932 IPD cases were identified as capsular serotypes. Among children aged <5 years, the most frequent serotype was 24F, followed by 15 A, 12F, 15C, 15B, and 10 A. Since 2014, after replacement with PCV13 in 2013, the rate of IPD by PCV13 minus PCV7 serotypes decreased, and non-PCV13 serotypes further increased. The serotype causing IPD in children aged <5 years, with PCV15-unique serotypes and PCV20-unique serotype were 8.6 % and 22.5 %, respectively. In terms of antimicrobial susceptibility, strains resistant to penicillin and cefotaxime decreased, whereas the meropenem non-susceptible strains increased in the post-PCV13 era. CONCLUSION: PCV13 introduction and the COVID-19 pandemic have had a significant impact on pediatric IPD in Japan. It is important to continuously monitor the epidemiological characteristics of pediatric IPD after the introduction of PCV20.
  • Manato Horii, Kohei Takahashi, Seiji Kimura, Ryuichiro Akagi, Shotaro Watanabe, Satoshi Yamaguchi, Yoshihito Ozawa, Seiji Ohtori, Takahisa Sasho
    Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2025年3月22日  
    BACKGROUND: The ability to perform deep squats in children and adolescents is an essential component of lower extremity function. Especially for school-aged children and adolescents, the ability to perform deep squats is related to their daily life and school activities. Few reports have investigated the factors associated with deep squats ability in this population. This study aimed to identify the factors associated with deep squat ability in healthy Japanese children and adolescents. METHODS: A retrospective cohort study was conducted with children and adolescents aged 8-14 years in Japan from 2017 to 2019. Data on height, weight, ability to perform deep squats, general joint laxity, lower limb tightness, and the Hospital for Special Surgery Pediatric Functional Activity Brief Scale score were collected at the beginning of each year. Participants who were able to squat during their musculoskeletal screening were divided into two groups: those who could deep squat the following year and those who could not. Logistic regression analysis with variable selection was performed to calculate the odds ratio for each predicted risk factor associated with the inability to perform a deep squat. RESULTS: A total of 636 children and adolescents were included in the analysis, with 7.5 % of them being unable to perform deep squats the following year. The risk of being unable to deep squats significantly decreased with increasing age (odds ratio 0.66, 95 % confidence interval 0.50-0.87). In addition, higher weight (odds ratio 1.12, 95 % confidence interval 1.07-1.17) and higher Hospital for Special Surgery Pediatric Functional Activity Brief Scale score (odds ratio 1.05, 95 % confidence interval 1.01-1.10) were identified as risk factors associated with the inability to perform a deep squat. Other physical factors did not significantly contribute to the occurrence of deep squat abnormalities. CONCLUSIONS: Age, body weight, and physical activity levels were found to be associated with the ability to perform deep squats in healthy Japanese children and adolescents.
  • Yukiyo Mamiya, Takashi Taida, Jun Kato, Keisuke Matsusaka, Yoshiki Matsubara, Tomomi Ozaki, Takuya Ohashi, Toshiyuki Ito, Syohei Mukai, Nobuaki Syu, Yushi Koshibu, Yusuke Ozeki, Makoto Furuya, Yuhei Oyama, Hayato Nakazawa, Ryosuke Horio, Chihiro Goto, Satsuki Takahashi, Yoshihito Ozawa, Yuki Shiko, Akane Kurosugi, Michiko Sonoda, Tatsuya Kaneko, Tsubasa Ishikawa, Yuki Ohta, Kenichiro Okimoto, Keiko Saito, Tomoaki Matsumura, Jun-Ichiro Ikeda, Naoya Kato
    Digestive diseases and sciences 2025年1月27日  
    PURPOSE: The performance of endoscopic evaluation of ulcerative colitis (UC) using conventional scoring, including Mayo endoscopic subscore (MES) and ulcerative colitis endoscopic index of severity (UCEIS), is not satisfactory. Recently, the usefulness of novel image-enhanced endoscopy (IEE) such as texture and color enhancement imaging (TXI) and red dichromatic imaging (RDI) has been reported in the endoscopic evaluation of UC. We evaluated the performance of IEEs in UC, particularly focusing on the correlation with MES and UCEIS, and prediction of relapse. METHODS: This is a prospective, observational study. UC patients in clinical remission who underwent colonoscopy with evaluation of IEEs and follow-up for > 3 months were analyzed. TXI and RDI were evaluated using the previously reported scoring system (TXI 0-2 and RDI 1-4). The IEE scores were compared with the conventional scoring, fecal calprotectin levels, and histological findings using Geboes score, and patient's clinical relapse rate stratified by each IEE score was examined. RESULTS: Both TXI and RDI scores were well-correlated with MES and UCEIS (both p < 0.001), fecal calprotectin levels (p = 0.015 and p = 0.006), and histology evaluated with Geboes score. In the Geboes subscore, the subscore 2B (neutrophil infiltration in lamina propria) was the most correlated with each endoscopic scoring. RDI 3-4 was significantly correlated with subsequent relapse (hazard ratio 3.56, 95% confidence interval 1.13-11.24), but TXI scoring did not predict relapse significantly. CONCLUSION: The assessment using RDI could be a convenient and useful endoscopic evaluation method for predicting the prognosis of UC.
  • Jun Ikari, Megumi Katsumata, Akira Urano, Takuro Imamoto, Yuri Suzuki, Akira Nishiyama, Hajime Yokota, Kojiro Ono, Kentaro Okamoto, Eriko Abe, Tomoko Kamata, Shota Fujii, Kenichiro Okumura, Joji Ota, Eiko Suzuki, Naoko Kawata, Yoshihito Ozawa, Yoshitada Masuda, Kazuyuki Matsushita, Seiichiro Sakao, Takashi Uno, Koichiro Tatsumi, Takuji Suzuki
    BMJ open respiratory research 11(1) 2024年8月5日  
    INTRODUCTION: To date, there is limited evidence on the effects of bronchodilators on respiratory dynamics in chronic obstructive pulmonary disease (COPD). Dynamic chest radiography (DCR) is a novel radiographic modality that provides real-time, objective and quantifiable kinetic data, including changes in the lung area (Rs), tracheal diameter, diaphragmatic kinetics and pulmonary ventilation during respiration, at a lower radiation dose than that used by fluoroscopic or CT imaging. However, the therapeutic effect of dual bronchodilators on respiratory kinetics, such as chest wall dynamics and respiratory muscle function, has not yet been prospectively evaluated using DCR. AIM: This study aims to evaluate the effects of bronchodilator therapy on respiratory kinetics in patients with COPD using DCR. METHODS AND ANALYSIS: This is an open-label, prospective, single-centre, non-controlled, comparative study. A total of 35 patients with COPD, aged 40-85 years, with a forced expiratory volume in the first second of 30-80%, will be enrolled. After a 2-4 weeks washout period, patients will receive tiotropium/olodaterol therapy for 6 weeks. Treatment effects will be evaluated based on DCR findings, pulmonary function test results and patient-related outcomes obtained before and after treatment. The primary endpoint is the change in Rs after therapy. The secondary endpoints include differences in other DCR parameters (diaphragmatic kinetics, tracheal diameter change and maximum pixel value change rate), pulmonary function test results and patient-related outcomes between pre-therapy and post-therapy values. All adverse events will be reported. ETHICS AND DISSEMINATION: Ethical approval for this study was obtained from the Ethics Committee of Chiba University Hospital. The results of this trial will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: jRCTs032210543.
  • Kohei Shikano, Jun Ikari, Takahiro Nakajima, Masayuki Ota, Yuki Shiko, Akira Naito, Mitsuhiro Abe, Takeshi Kawasaki, Jun-Ichiro Ikeda, Yoshihito Ozawa, Takuji Suzuki
    Japanese journal of clinical oncology 2024年6月12日  
    BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has been used to diagnose and stage lung cancer. Acquire™ Pulmonary and Expect™ Pulmonary dedicated EBUS-TBNA needles were introduced as the Franseen and Lancet needles, respectively. It is still unclear whether the Franseen or Lancet needles yield a higher quality specimen especially focusing on next-generation sequencing-based molecular testing. METHODS: A single-center, prospective study performed at the Chiba University Hospital randomly assigned patients to two groups: Group A, wherein the first and second EBUS-TBNA were performed using Lancet and Franseen needles, respectively, and Group B, wherein the first and second EBUS-TBNA were performed using Franseen and Lancet needles, respectively. Each specimen was compared and analyzed pathologically. The primary outcome was the histological tissue area except blood clot and the cellularity of each sample. We also examined the success rate of molecular testing. RESULTS: Twelve patients who underwent EBUS-TBNA between November 2022 and February 2023 were enrolled in this study. The tissue area of the specimens obtained by the Franseen and Lancet needles was 13.3 ± 6.4 mm2 and 10.6 ± 6.3 mm2, respectively (P = .355). The tumor cellularity in the specimens obtained using the Franseen and Lancet needles was 54.0 ± 30.3 and 46.2 ± 36.3%, respectively (P = .608). The success rate of molecular testing using the single-pass sample by Franseen needle was 85.7 and 57.1% by Lancet needle. No serious complications were reported. CONCLUSIONS: The Franseen needle tended to show a greater amount of specimen with higher tumor cellularity than the Lancet needle which may contribute higher success rate of molecular testing. Further studies must be conducted to validate the results of this study. KEY FINDINGS: What is known and what is new?  What is the implication, and what should change now?

MISC

 33