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Dive into the research topics where Yuichi Ozawa is active.

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Featured researches published by Yuichi Ozawa.


Respirology | 2009

Cumulative incidence of and predictive factors for lung cancer in IPF.

Yuichi Ozawa; Takafumi Suda; Tateaki Naito; Noriyuki Enomoto; Dai Hashimoto; Tomoyuki Fujisawa; Yutaro Nakamura; Naoki Inui; Hirotoshi Nakamura; Kingo Chida

Background and objective:  Previous studies have indicated a high incidence of lung cancer in IPF, and some have identified its risk factors. However, those studies were retrospective and the clinical characteristics of IPF patients developing lung cancer were evaluated only when those patients had developed the cancer. The true cumulative incidence of lung cancer after the diagnosis of IPF and its predictive factors at the initial diagnosis of IPF remain unknown. The present study was conducted to elucidate the cumulative incidence and risk factors for lung cancer in IPF patients by retrospective longitudinal cohort analysis.


Respirology | 2008

Possible therapeutic effect of direct haemoperfusion with a polymyxin B immobilized fibre column (PMX-DHP) on pulmonary oxygenation in acute exacerbations of interstitial pneumonia.

Noriyuki Enomoto; Takafumi Suda; Tomohiro Uto; Masato Kato; Yusuke Kaida; Yuichi Ozawa; Hiroo Miyazaki; Shigeki Kuroishi; Dai Hashimoto; Tateaki Naito; Tomoyuki Fujisawa; Takashi Matsui; Naoki Inui; Yutaro Nakamura; June Sato; Tomoaki Mizuguchi; Akihiko Kato; Kingo Chida

Background and objective:  Acute exacerbations of interstitial pneumonias (IP) can occasionally occur, and have an extremely poor prognosis. Recently, direct haemoperfusion with a polymyxin B immobilized fibre column (PMX‐DHP) was shown to have a beneficial effect in acute exacerbations of IPF. However, little is known about the efficacy of PMX‐DHP in acute exacerbations of other IP. This study investigated the effectiveness and safety of PMX‐DHP in acute exacerbations of IP.


Cancer Immunology, Immunotherapy | 2011

Enhanced anti-tumor immunity by superantigen-pulsed dendritic cells

Masato Kato; Yutaro Nakamura; Takafumi Suda; Yuichi Ozawa; Naoki Inui; Naohiro Seo; Toshi Nagata; Yukio Koide; Pawel Kalinski; Hirotoshi Nakamura; Kingo Chida

Staphylococcal enterotoxins A (SEA) and B (SEB) are classical models of superantigens (SAg), which induce potent T-cell-stimulating activity by forming complexes with MHC class II molecules on antigen-presenting cells. This large-scale activation of T-cells is accompanied by increased production of cytokines such as interferon-γ (IFN-γ). Additionally, as we previously reported, IFN-γ-producing CD8+ T cells act as “helper cells,” supporting the ability of dendritic cells to produce interleukin-12 (IL-12)p70. Here, we show that DC pulsed with SAg promote the enhancement of anti-tumor immunity. Murine bone marrow-derived dendritic cells (DC) were pulsed with OVA257–264 (SIINFEKL), which is an H-2Kb target epitope of EG7 [ovalbumin (OVA)-expressing EL4] cell lines, in the presence of SEA and SEB and were subcutaneously injected into naïve C57BL/6 mice. SAg plus OVA257–264-pulsed DC vaccine strongly enhanced peptide-specific CD8+ T cells exhibiting OVA257–264-specific cytotoxic activity and IFN-γ production, leading to the induction of protective immunity against EG7 tumors. Furthermore, cyclophosphamide (CY) added to SAg plus tumor-antigens (OVA257–264, tumor lysate, or TRP-2) pulsed DC immunization markedly enhanced tumor-specific T-cell expansion and had a significant therapeutic effect against various tumors (EG7, 2LL, and B16). Superantigens are potential candidates for enhancing tumor immunity in DC vaccines.


Japanese Journal of Clinical Oncology | 2011

Phase II Study of Erlotinib as Third-line Monotherapy in Patients with Advanced Non-small-cell Lung Cancer without Epidermal Growth Factor Receptor Mutations

Shun Matsuura; Naoki Inui; Yuichi Ozawa; Yutaro Nakamura; Mikio Toyoshima; Kazumasa Yasuda; Takashi Yamada; Toshihiro Shirai; Hideki Suganuma; Koji Yokomura; Takafumi Suda; Kingo Chida

OBJECTIVE There are few standard therapeutic options beyond second-line treatment. We aimed to evaluate the efficacy and safety of erlotinib monotherapy as third-line chemotherapy in patients with advanced non-small-cell lung cancer without epidermal growth factor receptor mutations. METHODS In this phase II trial, patients who did not have epidermal growth factor receptor mutations and who had previously received two cytotoxic chemotherapy regimens containing platinum were treated with erlotinib (150 mg, per os) until disease progression or unacceptable toxicity. RESULTS Twenty patients were eligible for the assessment of efficacy and safety. Three cases showed a partial response, and eight cases showed stable disease with an overall response rate of 15.0% (95% confidence interval: 5.2-36.0%) and a disease control rate of 55.0% (95% confidence interval: 34.2-74.2%). Median progression-free survival and overall survival time were 2.1 and 6.7 months, respectively. Although dose reduction was required in one patient because of skin toxicity, grade 3/4 toxicity or pulmonary disease was not observed. CONCLUSIONS Erlotinib as third-line therapy showed an acceptable response rate, survival time and toxicity. It could be a potential third-line therapy for patients without epidermal growth factor receptor mutations.


PLOS ONE | 2015

Impact of Preexisting Interstitial Lung Disease on Acute, Extensive Radiation Pneumonitis: Retrospective Analysis of Patients with Lung Cancer.

Yuichi Ozawa; Takefumi Abe; Minako Omae; Takashi Matsui; Masato Kato; Hirotsugu Hasegawa; Yasunori Enomoto; Takeaki Ishihara; Naoki Inui; Kazunari Yamada; Koshi Yokomura; Takafumi Suda

Introduction This study investigated the clinical characteristics and predictive factors for developing acute extended radiation pneumonitis with a focus on the presence and radiological characteristics of preexisting interstitial lung disease. Methods Of 1429 irradiations for lung cancer from May 2006 to August 2013, we reviewed 651 irradiations involving the lung field. The presence, compatibility with usual interstitial pneumonia, and occupying area of preexisting interstitial lung disease were retrospectively evaluated by pretreatment computed tomography. Cases of non-infectious, non-cardiogenic, acute respiratory failure with an extended bilateral shadow developing within 30 days after the last irradiation were defined as acute extended radiation pneumonitis. Results Nine (1.4%) patients developed acute extended radiation pneumonitis a mean of 6.7 days after the last irradiation. Although preexisting interstitial lung disease was found in 13% of patients (84 patients), 78% of patients (7 patients) with acute extended radiation pneumonitis cases had preexisting interstitial lung disease, which resulted in incidences of acute extended radiation pneumonitis of 0.35 and 8.3% in patients without and with preexisting interstitial lung disease, respectively. Multivariate logistic analysis indicated that the presence of preexisting interstitial lung disease (odds ratio = 22.6; 95% confidence interval = 5.29–155; p < 0.001) and performance status (≥2; odds ratio = 4.22; 95% confidence interval = 1.06–20.8; p = 0.049) were significant predictive factors. Further analysis of the 84 patients with preexisting interstitial lung disease revealed that involvement of more than 10% of the lung field was the only independent predictive factor associated with the risk of acute extended radiation pneumonitis (odds ratio = 6.14; 95% confidence interval = 1.0–37.4); p = 0.038). Conclusions Pretreatment computed tomography evaluations of the presence of and area size occupied by preexisting interstitial lung disease should be assessed for safer irradiation of areas involving the lung field.


Lung Cancer | 2009

Phase II study of combination chemotherapy with S-1 and weekly cisplatin in patients with previously untreated advanced non-small cell lung cancer

Yuichi Ozawa; Naoki Inui; Tateaki Naitoh; Kazumasa Yasuda; Masaharu Nagayama; Toshihiro Shirai; Hideki Suganuma; Masato Fujii; Hirotoshi Nakamura; Takafumi Suda; Kingo Chida

We aimed to evaluate the efficacy and safety of combination chemotherapy with S-1 and low-dose weekly cisplatin in patients with advanced non-small cell lung cancer (NSCLC). In this phase II trial, previously untreated patients with stage IIIB/IV NSCLC were treated with oral administration of S-1 at 80 mg/m(2) for 21 days and three consecutive weekly low doses of cisplatin (25 mg/m(2)) followed by a 2-week rest period. Twenty-six patients were eligible for the assessment of efficacy and safety. Six partial responses were observed with an overall response rate of 23.1% (95% confidence interval: 12.3-31.6%). The median survival time and median progression-free survival were 13.4 months and 5.4 months, respectively. Grade 3/4 hematologic toxicities were observed in 9 patients (34.6%), including one grade 4 neutropenia and thrombocytopenia. As for non-hematologic adverse reactions, although grade 3 events were observed in 4 patients (15.3%), no severe renal toxicity or vomiting was found. S-1 and weekly low-dose cisplatin combination chemotherapy in patients with advanced NSCLC showed an acceptable response rate, overall survival time, and toxicity. Because this regimen can be performed in an outpatient setting, it might be an alternative useful and convenient option. Further investigations with a large population are required to confirm our results.


American Journal of Respiratory Cell and Molecular Biology | 2009

Mucosal vaccine using CTL epitope-pulsed dendritic cell confers protection for intracellular pathogen.

Yuichi Ozawa; Takafumi Suda; Toshi Nagata; Dai Hashimoto; Yutaro Nakamura; Noriyuki Enomoto; Naoki Inui; Yukio Koide; Hirotoshi Nakamura; Kingo Chida

Effective protective immunity against respiratory infections with intracellular pathogens requires pathogen-specific cytotoxic T cells (CTL) in the lung. However, vaccines that induce pathogen-specific CTL in the lung are poorly explored. Dendritic cells (DC) have increasingly been exploited as vaccines against infections. However, few studies have investigated the ability of mucosal DC vaccines to elicit protective CTL responses in the lung. Our objective was to develop an efficacious mucosal DC vaccine to generate protective CTL against respiratory infections with intracellular pathogens. Bone marrow-derived DC (BM-DC) pulsed with a single immunodominant CTL epitope, listeriolysin O (LLO) 91-99, of Listeria monocytogenes (LM) were intratracheally administered into mice. The frequency and function of epitope-specific CTL in mediastinal lymph nodes (MLN) and spleen were assessed for their ability to protect against LM infection. After intratracheal administration, lipopolysaccharide (LPS)-treated LLO 91-99-loaded BM-DC (LPS-LLO DC) more frequently migrated to MLN than LPS-untreated LLO 91-99-loaded BM-DC (LLO DC). Using tetrameric H2-K(d)/LLO 91-99 peptide complex, specific CD8(+) T cells were found in MLN as well as the spleen in LPS-LLO DC-immunized mice, but not in LLO-DC-immunized mice. Both MLN and spleen cells obtained from LPS-LLO DC-immunized mice produced large amounts of IFN-gamma in response to LLO 91-99 with high epitope-specific CTL activities. Vaccination with LPS-LLO DC, but not LLO DC, protected mice against lethal respiratory infection with LM. These data suggest that mucosal vaccination with LPS-treated immunodominant CTL epitope-loaded DC is a promising strategy for generating protective CTL against respiratory infections with intracellular pathogens.


Genes to Cells | 2013

YB1 binds to and represses the p16 tumor suppressor gene

Yojiro Kotake; Yuichi Ozawa; Masanori Harada; Kyoko Kitagawa; Hiroyuki Niida; Yasutaka Morita; Kenji Tanaka; Takafumi Suda; Masatoshi Kitagawa

Y box binding protein 1 (YB1) has multiple functions associated with drug resistance, cell proliferation and metastasis through transcriptional and translational regulation. Increased expression of YB1 is closely related to tumor growth and aggressiveness. We showed that YB1 protein levels were decreased through replicative and premature senescence and were correlated with increased expression levels of p16INK4A tumor suppressor gene. Depletion of YB1 was associated with increased levels of p16 in human and murine primary cells. Forced expression of YB1 in mouse embryonic fibroblasts resulted in decreased expression of p16 and increased cell proliferation. Senescence‐associated expression of β‐galactosidase was repressed in YB1‐over‐expressing cells. Chromatin immunoprecipitation assays showed that YB1 directly associates with the p16 promoter. Taken together, all our findings indicate that YB1 directly binds to and represses p16 transcription, subsequently resulting in the promotion of cell growth and prevention of cellular senescence.


Journal of Infection and Chemotherapy | 2015

Rhinosinusitis and disseminated cutaneous infection caused by Mycobacterium chelonae in an immunocompromised patient

Yasunori Enomoto; Misao Oba; Norihisa Ishii; Kazue Nakanaga; Yuki Yagi; Hirotsugu Hasegawa; Yuichi Ozawa; Takashi Matsui; Koshi Yokomura; Takafumi Suda

Mycobacterium chelonae frequently involves the skin, and the disseminated form can be observed in immunocompromised patients. In contrast, rhinosinusitis caused by the bacterium is a rare manifestation, which occurs independently of immune status. We report here a rare case of M. chelonae infection presenting as both disseminated cutaneous infection and rhinosinusitis in an immunocompromised patient. He had received systemic corticosteroids for 11 months due to cryptogenic organizing pneumonia. Before admission, he sustained injuries to his left arm and hand; those injuries succumbed to an infection that would subsequently spread to his other limbs, face, and even nasal cavities. This valuable case suggests that disseminated cutaneous infection by M. chelonae could spread to other organs.


Respiration | 2018

Efficacy and Tolerability of High-Flow Nasal Cannula Oxygen Therapy for Hypoxemic Respiratory Failure in Patients with Interstitial Lung Disease with Do-Not-Intubate Orders: A Retrospective Single-Center Study

Takafumi Koyauchi; Hirotsugu Hasegawa; Kei Kanata; Takuya Kakutani; Yusuke Amano; Yuichi Ozawa; Takashi Matsui; Koshi Yokomura; Takafumi Suda

Background: High-flow nasal cannula (HFNC) oxygen therapy may provide effective respiratory management of hypoxemic respiratory failure in patients with interstitial lung disease (ILD) with a do-not-intubate (DNI) order. Objectives: The aim was to assess the efficacy and tolerability of HFNC for these patients. Methods: We retrospectively reviewed the records of patients requesting a DNI order for hypoxemic respiratory failure associated with ILD, comparing treatment with HFNC and noninvasive positive pressure ventilation (NPPV). Outcomes measured were 30-day survival, in-hospital mortality, temporary interruption and discontinuation of the treatment at the patient’s request, adverse events, oral intake, and communication ability at the end of life. Results: A total of 84 patients (HFNC, n = 54; NPPV, n = 30) were analyzed. Neither 30-day survival (HFNC 31.5% vs. NPPV 30.0%; p = 0.86) nor in-hospital mortality (HFNC 79.6% vs. NPPV 83.3%; p = 0.78) differed significantly. The temporary interruption and discontinuation rates were significantly lower in the HFNC group than in the NPPV group (3.7 vs. 23.3%; p = 0.009 and 0 vs. 10%; p = 0.043, respectively), and that group had significantly fewer adverse events. Among patients who died in the hospital, those treated with HFNC had significantly better oral intake and ability to converse until just before death. Conclusion: HFNC had a survival rate equivalent to that of NPPV and was better tolerated by patients with hypoxemic respiratory failure associated with ILD who had a DNI order. HFNC allowed patients to eat and converse until just before death, suggesting that HFNC in these patients is a reasonable palliative treatment.

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