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Dive into the research topics where Hiroaki Dobashi is active.

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Featured researches published by Hiroaki Dobashi.


Annals of the Rheumatic Diseases | 2000

Sequential changes of KL-6 in sera of patients with interstitial pneumonia associated with polymyositis/dermatomyositis

Shuji Bandoh; Jiro Fujita; Yuji Ohtsuki; Yutaka Ueda; Satoko Hojo; Michiaki Tokuda; Hiroaki Dobashi; Noriyuki Kurata; Takeo Yoshinouchi; Nobuoki Kohno; Jiro Takahara

OBJECTIVE KL-6 is a mucin-like high molecular weight glycoprotein, which is strongly expressed on type II alveolar pneumocytes and bronchiolar epithelial cells. It has been demonstrated that the KL-6 antigen is a useful marker for estimating the activity of interstitial pneumonia. In this study, it is hypothesised that serum KL-6 is a useful marker to evaluate the activity of interstitial pneumonia associated with polymyositis/dermatomyositis (PM/DM). METHODS KL-6 was measured in sera in 16 patients diagnosed with PM/DM. Five had non-specific interstitial pneumonia (NSIP), three had diffuse alveolar damage (DAD), and eight had no pulmonary involvement, and 10 were normal non-smokers as a control group. The correlation was also evaluated between the KL-6 level and each clinical course in patients with pulmonary involvement associated with PM/DM. Immunohistochemical analysis using monoclonal anti-KL-6 antibody was also performed. RESULTS KL-6 concentrations in sera of patients with interstitial pneumonia associated with PM/DM were significantly high compared with those of PM/DM without interstitial pneumonia, and normal non-smokers. KL-6 concentrations in sera in patients with DAD significantly increased compared with those of other groups. KL-6 values in sera changed according to the progression or improvement of interstitial pneumonia. Immunohistochemical study using pulmonary tissues obtained from patients with DAD demonstrated that the hyaline membrane, proliferating type II pneumocytes, bronchial epithelial cells and some endothelial cells in pulmonary veins were stained by antihuman KL-6 antibody. CONCLUSION These data demonstrate that measurement of serum KL-6 was a useful marker to evaluate the activity of acute interstitial pneumonia associated with PM/DM.


World journal of clinical oncology | 2014

Paraneoplastic syndromes associated with lung cancer

Nobuhiro Kanaji; Naoki Watanabe; Nobuyuki Kita; Shuji Bandoh; Akira Tadokoro; Tomoya Ishii; Hiroaki Dobashi; Takuya Matsunaga

Paraneoplastic syndromes are signs or symptoms that occur as a result of organ or tissue damage at locations remote from the site of the primary tumor or metastases. Paraneoplastic syndromes associated with lung cancer can impair various organ functions and include neurologic, endocrine, dermatologic, rheumatologic, hematologic, and ophthalmological syndromes, as well as glomerulopathy and coagulopathy (Trousseaus syndrome). The histological type of lung cancer is generally dependent on the associated syndrome, the two most common of which are humoral hypercalcemia of malignancy in squamous cell carcinoma and the syndrome of inappropriate antidiuretic hormone secretion in small cell lung cancer. The symptoms often precede the diagnosis of the associated lung cancer, especially when the symptoms are neurologic or dermatologic. The proposed mechanisms of paraneoplastic processes include the aberrant release of humoral mediators, such as hormones and hormone-like peptides, cytokines, and antibodies. Treating the underlying cancer is generally the most effective therapy for paraneoplastic syndromes, and treatment soon after symptom onset appears to offer the best potential for symptom improvement. In this article, we review the diagnosis, potential mechanisms, and treatments of a wide variety of paraneoplastic syndromes associated with lung cancer.


Arthritis Care and Research | 2014

Association of Higher Methotrexate Dose With Lymphoproliferative Disease Onset in Rheumatoid Arthritis Patients

Tomohiro Kameda; Hiroaki Dobashi; Masayuki Inoo; Ikuko Onishi; Noriyuki Kurata; Hiroki Mitsunaka; Kimihiro Kawakami; Tetsuya Fukumoto; Kentaro Susaki; M. Izumikawa; S. Nakashima; H. Shimada; Y. Takeuchi; Reiji Haba; Shohei Mano; Hiroaki Onishi; Osamu Imataki; Takuya Matsunaga

Methotrexate (MTX) is used as an anchor drug for rheumatoid arthritis (RA). Lymphoproliferative disease (LPD) occasionally develops in patients treated with MTX, and is known as MTX‐associated LPD (MTX‐LPD). Although MTX‐LPD occurs mainly in RA patients, it has not been established if MTX administration is an independent risk factor for LPD in RA patients. We examined the clinical characteristics of MTX‐LPD in Japanese RA patients and attempted to determine the risk factors for MTX‐LPD development.


Annals of the Rheumatic Diseases | 2012

Drug retention rates and relevant risk factors for drug discontinuation due to adverse events in rheumatoid arthritis patients receiving anticytokine therapy with different target molecules

Ryoko Sakai; Michi Tanaka; Toshihiro Nanki; Kaori Watanabe; Hayato Yamazaki; Ryuji Koike; Hayato Nagasawa; Koichi Amano; Kazuyoshi Saito; Yoshiya Tanaka; Satoshi Ito; Takayuki Sumida; Atsushi Ihata; Yoshiaki Ishigatsubo; Tatsuya Atsumi; Takao Koike; Atsuo Nakajima; Naoto Tamura; Hiroaki Dobashi; Shigeto Tohma; Takahiko Sugihara; Yukitaka Ueki; Akira Hashiramoto; Atsushi Kawakami; Noboru Hagino; Nobuyuki Miyasaka; Masayoshi Harigai

Objective To compare reasons for discontinuation and drug retention rates per reason among anticytokine therapies, infliximab, etanercept and tocilizumab, and the risk of discontinuation of biological agents due to adverse events (AE) in patients with rheumatoid arthritis (RA). Method This prospective cohort study included Japanese RA patients who started infliximab (n=412, 636.0 patient-years (PY)), etanercept (n=442, 765.3 PY), or tocilizumab (n=168, 206.5 PY) as the first biological therapy after their enrolment in the Registry of Japanese Rheumatoid Arthritis Patients for Long-term Safety (REAL) database. Drug retention rates were calculated using the Kaplan–Meier method. To compare risks of drug discontinuation due to AE for patients treated with these biological agents, the Cox proportional hazard model was applied. Results The authors found significant differences among the three therapeutic groups in demography, clinical status, comorbidities and usage of concomitant drugs. Development of AE was the most frequent reason for discontinuation of biological agents in the etanercept and tocilizumab groups, and the second most frequent reason in the infliximab group. Discontinuation due to good control was observed most frequently in the infliximab group. Compared with etanercept, the use of infliximab (HR 1.69; 95% CI 1.14 to 2.51) and tocilizumab (HR 1.98; 95% CI 1.04 to 3.76) was significantly associated with a higher risk of discontinuation of biological agents due to AE. Conclusions Reasons for discontinuation are significantly different among biological agents. The use of infliximab and tocilizumab was significantly associated with treatment discontinuation due to AE compared with etanercept.


Cerebrovascular Diseases | 2009

Predictors of Intracerebral Hemorrhage Severity and Its Outcome in Japanese Stroke Patients

Naohisa Hosomi; Takayuki Naya; Hiroyuki Ohkita; Mao Mukai; Takehiro Nakamura; Masaki Ueno; Hiroaki Dobashi; Koji Murao; Hisashi Masugata; Takanori Miki; Masakazu Kohno; Shotai Kobayashi; James A. Koziol

Objective: The aim of this investigation was to determine the factors influencing acute intracerebral hemorrhage severity on admission and clinical outcomes at discharge. Methods: Sixty acute stroke hospitals throughout Japan participated in the Japan Standard Stroke Registry Study (JSSRS), documenting the in-hospital course of 16,630 consecutive patients with acute stroke from January 2001 to March 2004. We identified 2,840 adult patients from the JSSRS who had intracerebral hemorrhage. Results: Intracerebral hemorrhage severity on admission was strongly related to age, previous stroke history, and hemorrhage size in a monotone fashion [χ2(9) = 374.5, p < 0.0001]. Drinking history was also predictive of intracerebral hemorrhage severity on admission, but the association was not monotone. Interestingly, intracerebral hemorrhage severity on admission was increased in nondrinking and heavy drinking compared to mild drinking (p < 0.05). Unsuccessful outcome (modified Rankin scale score = 3–6) was related to age, previous stroke history, hemorrhage size, and intracerebral hemorrhage severity on admission [χ2(9) = 830.4, p < 0.0001]. Mortality was related to hemorrhage size, intraventricular hemorrhage, intracerebral hemorrhage severity on admission, and surgical operation [χ2(7) = 540.4, p < 0.0001]. Conclusion: We could find four varied factors associated with intracerebral hemorrhage severity and its outcomes. Interestingly, intracerebral hemorrhage severity tended to be greater in nondrinking and heavy drinking than mild drinking. Additionally, surgical operation decreased intracerebral hemorrhage mortality.


Neuroimmunomodulation | 2001

Growth Hormone Prevents Fas-Induced Apoptosis in Lymphocytes through Modulation of Bcl-2 and Caspase-3

Hiroki Mitsunaka; Hiroaki Dobashi; Makoto Sato; Terukazu Tanaka; Akira Kitanaka; Genji Yamaoka; Michiaki Tokuda; Kenichiro Matoba; Takashi Hiraishi; Toshihiko Ishida

Objective: Growth hormone (GH) has been reported to have a potent effect on the immune system. However, the detailed mechanism of the effect of GH on the immune system has not yet been clarified. This study was designed to investigate the nature of this mechanism. Methods: In the present study, we investigated the effects of GH on the susceptibility of both human CEM/C7 lymphocytes and human IM-9 lymphocytes to Fas-induced apoptosis. Results: Both cell lines expressed GH receptor mRNA. GH rescued Fas-induced suppression of [3H]-thymidine incorporation into each cell line. GH prevented Fas-induced apoptosis in each cell line without changing Fas antigen expression. We next investigated the mechanisms of the prevention of Fas-induced apoptosis, by focusing on intracellular molecules related to the apoptotic signal. Bcl-2 expression was increased by GH treatment in both CEM/C7 and IM-9 lymphocytes. GH also downregulated caspase-3 expression and inhibited activation of caspase-3 in both cell lines. Conclusion: These findings suggest that GH regulates the human immune system through inhibition of Fas-induced apoptosis in activated T and B lymphocytes.


The FASEB Journal | 2001

Growth hormone restores glucocorticoid-induced T cell suppression

Hiroaki Dobashi; Makoto Sato; Terukazu Tanaka; Michiaki Tokuda; Toshihiko Ishida

Growth hormone (GH) is a potent anabolic hormone, and its clinical use has been extended to the improvement of metabolic imbalance in many disease,s including autoimmune disorders treated with glucocorticoids (GCs). GH has, however, a potential action on the immune system, and this might be a demerit in GH therapy for those diseases. We report here the anti‐GC effects of GH on T lymphocytes. Human peripheral T lymphocytes (HPTLs) expressed GH receptor mRNA. GH stimulated tyrosine phosphorylation of cellular proteins, including JAK2 and STAT5b in HPTLs. GH and IGF‐I alleviated dexamethasone (Dex)‐induced suppression of [3H]thymidine incorporation into HPTLs. GH alleviated Dex‐induced apoptosis in CD4+ (positive) HPTLs. GH increased Bcl‐2 expression in CD4+ HPTLs but not in CD8+ HPTLs. In vivo, GH raised the CD4/8 ratio of T lymphocytes in rats chronically administered with Dex. These findings indicate that GH may inhibit GC‐induced apoptosis predominantly in CD4+ T lymphocytes and present important implications of GH therapy, especially for autoimmune disorders treated with GCs.


Japanese Journal of Radiology | 2010

Clinical value of 18F-fluorodeoxyglucose positron emission tomography in patients with connective tissue disease.

Yoshihiro Nishiyama; Yuka Yamamoto; Hiroaki Dobashi; Tomohiro Kameda

Connective tissue diseases represent a heterogeneous group of immunologically mediated inflammatory disorders with a large variety of affected organs other than the lung. 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) is widely used in oncology but may also be valuable in patients with infections or inflammatory disease. The purpose of this article was to assess the clinical value of 18F-FDG PET in patients with connective tissue disease. Our experience demonstrates that 18F-FDG PET is a unique imaging technique for assessing the metabolic activity throughout the body in those with a connective tissue disease. The technique appears to be a promising imaging modality for detecting coexistent neoplastic diseases and other autoimmune disorders.


BMC Neurology | 2008

Plasma brain natriuretic peptide as a surrogate marker for cardioembolic stroke

Kazushi Yukiiri; Naohisa Hosomi; Takayuki Naya; Tsutomu Takahashi; Hiroyuki Ohkita; Mao Mukai; Hisashi Masugata; Koji Murao; Masaki Ueno; Takehiro Nakamura; Hiroaki Dobashi; Takanori Miki; Yasuhiro Kuroda; Masakazu Kohno

BackgroundCardioembolic stroke generally results in more severe disability, since it typically has a larger ischemic area than the other types of ischemic stroke. However, it is difficult to differentiate cardioembolic stroke from non-cardioembolic stroke (atherothrombotic stroke and lacunar stroke). In this study, we evaluated the levels of plasma brain natriuretic peptide in acute ischemic stroke patients with cardioembolic stroke or non-cardioembolic stroke, and assessed the prediction factors of plasma brain natriuretic peptide and whether we could differentiate between stroke subtypes on the basis of plasma brain natriuretic peptide concentrations in addition to patients clinical variables.MethodsOur patient cohort consisted of 131 consecutive patients with acute cerebral infarction who were admitted to Kagawa University School of Medicine Hospital from January 1, 2005 to December 31, 2007. The mean age of patients (43 females, 88 males) was 69.6 ± 10.1 years. Sixty-two patients had cardioembolic stroke; the remaining 69 patients had non-cardioembolic stroke (including atherothrombotic stroke, lacunar stroke, or the other). Clinical variables and the plasma brain natriuretic peptide were evaluated in all patients.ResultsPlasma brain natriuretic peptide was linearly associated with atrial fibrillation, heart failure, chronic renal failure, and left atrial diameter, independently (F4,126 = 27.6, p < 0.0001; adjusted R2 = 0.45). Furthermore, atrial fibrillation, mitral regurgitation, plasma brain natriuretic peptide (> 77 pg/ml), and left atrial diameter (> 36 mm) were statistically significant independent predictors of cardioembolic stroke in the multivariable setting (Χ2 = 127.5, p < 0.001).ConclusionIt was suggested that cardioembolic stroke was strongly predicted with atrial fibrillation and plasma brain natriuretic peptide. Plasma brain natriuretic peptide can be a surrogate marker for cardioembolic stroke.


The Journal of Rheumatology | 2015

Longterm Safety and Efficacy of Subcutaneous Tocilizumab Monotherapy: Results from the 2-year Open-label Extension of the MUSASHI Study

Atsushi Ogata; Koichi Amano; Hiroaki Dobashi; Masayuki Inoo; Tomonori Ishii; Tsuyoshi Kasama; Shinichi Kawai; Atsushi Kawakami; Tatsuya Koike; Hisaaki Miyahara; Toshiaki Miyamoto; Yasuhiko Munakata; Akira Murasawa; Noriyoshi Ogawa; Tomohiro Ojima; Hajime Sano; Kenrin Shi; Eisuke Shono; Eiichi Suematsu; Hiroki Takahashi; Yoshiya Tanaka; Hiroshi Tsukamoto; Akira Nomura

Objective. To evaluate the longterm safety and efficacy of subcutaneous tocilizumab (TCZ-SC) as monotherapy in patients with rheumatoid arthritis (RA). Methods. Of 346 patients who received 24 weeks of double-blind treatment with either TCZ-SC monotherapy, 162 mg every 2 weeks (q2w); or intravenous TCZ (TCZ-IV) monotherapy, 8 mg/kg every 4 weeks; 319 patients continued to receive TCZ-SC q2w in the 84-week open-label extension (OLE) of the MUSASHI study (JAPICCTI-101117). Efficacy, safety, and immunogenicity were evaluated for all patients treated with TCZ during 108 weeks. Results. The proportions of patients who achieved American College of Rheumatology 20/50/70 responses, low disease activity [28-joint Disease Activity Score (DAS28) ≤ 3.2], or remission (DAS28 < 2.6) at Week 24 were maintained until Week 108. The incidences of adverse events and serious adverse events were 498.3 and 16.9 per 100 patient-years (PY), respectively. The overall safety of TCZ-SC monotherapy was similar to that of TCZ-IV monotherapy. Rates of injection site reactions (ISR) through 108 weeks remained similar to rates through 24 weeks. ISR were mild and did not cause any patient withdrawals. No serious hypersensitivity events (including anaphylactic reactions) occurred. Anti-TCZ antibodies were present in 2.1% of patients treated with TCZ-SC monotherapy. Conclusion. TCZ-SC monotherapy maintained a favorable safety profile and consistent efficacy throughout the 108-week study. Like TCZ-IV, TCZ-SC could provide an additional treatment option for patients with RA.

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