Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Yoshiki Ishii is active.

Publication


Featured researches published by Yoshiki Ishii.


Journal of Thoracic Oncology | 2014

Effectiveness of Gefitinib against Non-Small-Cell Lung Cancer with the Uncommon EGFR Mutations G719X and L861Q

Satoshi Watanabe; Yuji Minegishi; Hirohisa Yoshizawa; Makoto Maemondo; Akira Inoue; Shunichi Sugawara; Hiroshi Isobe; Masao Harada; Yoshiki Ishii; Akihiko Gemma; Koichi Hagiwara; Kunihiko Kobayashi

Introduction: In non–small-cell lung cancer, an exon 19 deletion and an L858R point mutation in the epidermal growth factor receptor (EGFR) are predictors of a response to EGFR-tyrosine kinase inhibitors. However, it is uncertain whether other uncommon EGFR mutations are associated with sensitivity to EGFR-tyrosine kinase inhibitors. Methods: A post-hoc analysis to assess prognostic factors was performed with the use of patients with EGFR mutations (exon 19 deletion, L858R, G719X, and L861Q) who were treated with gefitinib in the NEJ002 study, which compared gefitinib with carboplatin-paclitaxel as the first-line therapy. Results: In the NEJ002 study, 225 patients with EGFR mutations received gefitinib at any treatment line. The Cox proportional hazards model indicated that performance status, response to chemotherapy, response to gefitinib, and mutation types were significant prognostic factors. Overall survival (OS) was significantly shorter among patients with uncommon EGFR mutations (G719X or L861Q) compared with OS of those with common EGFR mutations (12 versus 28.4 months; p = 0.002). In the gefitinib group (n = 114), patients with uncommon EGFR mutations had a significantly shorter OS (11.9 versus 29.3 months; p < 0.001). By contrast, OS was similar between patients with uncommon mutations and those with common mutations in the carboplatin-paclitaxel group (n = 111; 22.8 versus 28 months; p = 0.358). Conclusions: The post-hoc analyses clearly demonstrated shorter survival for gefitinib-treated patients with uncommon EGFR mutations compared with the survival of those with common mutations and suggest that the first-line chemotherapy may be relatively effective for non–small-cell lung cancer with uncommon EGFR mutations.


European Respiratory Journal | 2012

A neutrophil elastase inhibitor prevents bleomycin-induced pulmonary fibrosis in mice

Akihiro Takemasa; Yoshiki Ishii; Takeshi Fukuda

Neutrophil elastase plays pivotal roles in the pathogenesis of pulmonary fibrosis. The neutrophil elastase inhibitor, sivelestat, could alleviate pulmonary fibrosis; however, the antifibrotic mechanisms have not yet been clarified. We examined the antifibrotic mechanisms, mainly focusing on a key fibrotic cytokine, transforming growth factor (TGF)-&bgr;1, in this study. To elucidate the antifibrotic mechanisms of sivelestat, we examined a murine model of bleomycin-induced early-stage pulmonary fibrosis. After intratracheal instillation of bleomycin, sivelestat was administered intraperitoneally once a day for 7 or 14 days. Bronchoalveolar lavage fluid and lung samples were examined on day 7 or day 14 after bleomycin instillation. In the bleomycin-induced early-stage pulmonary fibrosis model, the neutrophil elastase level was increased in the lungs. Sivelestat significantly inhibited the increase in lung collagen content, fibrotic changes, the numbers of total cells (including macrophages, neutrophils and lymphocytes), the levels of the active form of TGF-&bgr;1 and phospho-Smad2 in bleomycin-induced early-stage pulmonary fibrosis. The total TGF-&bgr;1 levels and relative changes of TGF-&bgr;1 mRNA expression, however, were not decreased significantly by sivelestat. These results suggest that sivelestat alleviated bleomycin-induced pulmonary fibrosis via inhibition of both TGF-&bgr; activation and inflammatory cell recruitment in the lung.


Immunology Letters | 2009

Expression of Th2-skewed pathology mediators in monocyte-derived type 2 of dendritic cells (DC2)

Mitsumi Hata; Seiji Takahara; Hidetoshi Tsuzaki; Yoshiki Ishii; Koh Nakata; Kiyoko S. Akagawa; Kazuki Satoh

The information conveyed from dendritic cells (DCs) to naïve CD4(+) T cells has crucial influence on their differentiation toward effector T cells. In an effort to identify DC-derived molecules directly contributing to T cell differentiation, we searched for molecules distinctively expressed between two DC subtypes, which were differentiated from peripheral monocytes by cultivation with GM-CSF (for DC1) or IL-3 (for DC2) in the presence of IL-4 and had the ability to induce naïve T cells to differentiate into Th1 or Th2 cells, respectively. As the first step to address this issue, we subtracted DC1 transcripts from those of DC2 and compiled the gene profile dominantly expressed in DC2, whose products are known to reside in other than the nucleus. Intriguingly, many of them were molecules involved in Th2-skewed disease pathologies, such as FN1, ITGAE, GPNMB, PLAUR, FPRL2, LILRB4, SERPINE1, ALOX15, TBXAS1, NCF2, CCL3, IL1RN, SPARC, and STAB1, suggesting that DCs function not only as antigen presenting cells but also as producers of Th2 pathology specific milieus leading to disease deteriorations. We also found that expressions of CYP27A1, PPAP2B, RSAD2, and ABCC3 were up-regulated in DC2, implying their significant function in Th2-deviated states. The identification of differentially expressed genes between DC subtypes provides new insights into their functions and our comparative gene expression profile will be highly useful for the identification of DC-derived key molecules for T cell differentiation.


Respiratory Research | 2016

Dipeptidyl peptidase-4 is highly expressed in bronchial epithelial cells of untreated asthma and it increases cell proliferation along with fibronectin production in airway constitutive cells

Taichi Shiobara; Kazuyuki Chibana; Taiji Watanabe; Ryo Arai; Yukiko Horigane; Yusuke Nakamura; Yumeko Hayashi; Yasuo Shimizu; Akihiro Takemasa; Yoshiki Ishii

AbstractBackgroundType 2 helper T-cell cytokines including IL-13 play a central role in the pathogenesis of bronchial asthma (BA). During the course of our research, our attention was drawn to dipeptidyl peptidase-4 (DPP4) as one of the molecules that were induced from bronchial epithelial cells (BECs) by IL-13 stimulation. DPP4 could become a new biomarker or therapeutic target. The aim of this study was to investigate the expression of DPP4 in the asthmatic airway, and its role in the pathophysiology of asthma.MethodsBECs were isolated from patients with inhaled corticosteroid-treated asthma (stBA) and inhaled corticosteroid-naïve asthma (snBA) using bronchoscopy.n DPP4 mRNA expression in freshly isolated BECs and primary cultured BECs with or without IL-13 stimulation was investigated by microarray analysis and quantitative real-time PCR (qPCR). The distribution of DPP4 protein was determined by immunostaining of transbronchial lung biopsy specimens from asthma patients. The effect of recombinant human (rh) DPP4 on the proliferation of lung fibroblasts (HFL-1) and bronchial smooth muscle cells (BSMCs) was examined, as well as its effect on the production of fibronectin (FN).ResultsDPP4 mRNA was strongly expressed in freshly isolated BECs in snBA, and its expression was significantly enhanced by IL-13 stimulation. DPP4 mRNA expression in BECs of snBA significantly correlated with exhaled nitric oxide. Biopsied tissues of the asthmatic airway revealed strong expression of DPP4 protein in BECs from snBA subjects. rhDPP4 stimulated the proliferation of HFL-1 and BSMCs, and it also enhanced production of FN from these airway cells.ConclusionDPP4 may be involved in the pathologic features of asthmatic airway inflammation and cell proliferation and FN production.


Respiratory Research | 2013

Comparative analysis of circulating dendritic cell subsets in patients with atopic diseases and sarcoidosis

Yumeko Hayashi; Yoshiki Ishii; Mitsumi Hata-Suzuki; Ryo Arai; Kazuyuki Chibana; Akihiro Takemasa; Takeshi Fukuda

BackgroundDendritic cells (DCs) are professional antigen-presenting cells that play a crucial role in the initiation and modulation of immune responses. Human circulating blood DCs are divided into two major subsets: myeloid DCs (mDCs); and plasmacytoid DCs (pDCs). Furthermore, mDCs are subdivided into two subsets: Th1-promoting mDCs (mDC1s); and Th2-promoting mDCs (mDC2s). Although CD1a, CD1c, and CD141 are generally used for classifying mDC subsets, their adequacy as a specific marker remains unclear. We performed this study to compare circulating mDC, pDC, mDC1, and mDC2 subsets between Th1- and Th2-mediated diseases using CD1a and CD141, and to analyze the adequacy of CD1a and CD141 as a marker for mDC1s and mDC2s, respectively.MethodsThirty patients with sarcoidosis, 23 patients with atopic diseases, such as atopic bronchial asthma, and 23 healthy subjects as controls were enrolled in this study. Peripheral blood DC subsets were analyzed with flow cytometry according to expressions of CD11c, CD123, CD1a, and CD141. For functional analysis, we measured interleukin (IL) 12p40 levels produced by the sorted mDC subsets.ResultsThe sarcoidosis group showed decreased total DC (Pu2009<u20090.05) and mDC counts (Pu2009<u20090.05) compared to controls. The atopy group showed decreased CD1a+mDC count (Pu2009<u20090.05), and increased CD1a-mDC count (Pu2009<u20090.05) compared to controls. CD141+mDC count in the atopy group was higher than controls (Pu2009<u20090.05). Sorted CD1a+mDCs produced higher levels of IL-12p40 than CD1a-mDCs (Pu2009=u20090.025) and CD141+mDCs (Pu2009=u20090.018).ConclusionsWe conclude that decreased count of CD1a+mDC and increased count of CD141+mDC may reflect the Th2-skewed immunity in atopic diseases. The results of IL-12 levels produced by the sorted mDC subsets suggested the adequacy of CD1a and CD141 as a marker for mDC1 and mDC2, respectively, in vivo.


Journal of Infection and Chemotherapy | 2015

Disseminated Mycobacterium gordonae and Mycobacterium mantenii infection with elevated anti-IFN-γ neutralizing autoantibodies

Isano Hase; Kozo Morimoto; Takuro Sakagami; Yuko Kazumi; Yoshiki Ishii; Jakko van Ingen

A case of disseminated nontuberculous mycobacteria(l) (NTM) infection in a patient with positive neutralizing anti-interferon-γ (IFN-γ) autoantibodies involving bone, bronchus, systemic lymph nodes, and skin is reported. The causative NTMs were two different strains: Mycobacterium gordonae, which rarely causes true disease, and Mycobacterium mantenii, which is extremely rare. Anti-mycobacterial treatment successfully ameliorated all disseminated lesions. Although the concentration of anti-IFN-γ autoantibodies increased during the pre-treatment period, it gradually decreased after anti-mycobacterial treatment was started.


Journal of Clinical Biochemistry and Nutrition | 2015

Co-localization of iron binding on silica with p62/sequestosome1 (SQSTM1) in lung granulomas of mice with acute silicosis.

Yasuo Shimizu; Kunio Dobashi; Hiroyuki Nagase; Ken Ohta; Takaaki Sano; Shinichi Matsuzaki; Yoshiki Ishii; Takahiro Satoh; Masashi Koka; Akihito Yokoyama; Takeru Ohkubo; Yasuyuki Ishii; Tomihiro Kamiya

The cellular mechanisms involved in the development of silicosis have not been fully elucidated. This study aimed to examine influence of silica-induced lung injury on autophagy. Suspensions of crystalline silica particles were administered transnasally to C57BL/6j mice. Immunohistochemical examination for Fas and p62 protein expression was performed using lung tissue specimens. Two-dimensional and quantitative analysis of silica deposits in the lungs were performed in situ using lung tissue sections by an in-air microparticle induced X-ray emission (in-air micro-PIXE) analysis system, which was based on irrradiation of specimens with a proton ion microbeam. Quantitative analysis showed a significant increase of iron levels on silica particles (assessed as the ratio of Fe relative to Si) on day 56 compared with day 7 (p<0.05). Fas and p62 were expressed by histiocytes in granulomas on day 7, and the expressions persisted for day 56. Fas- and p62-expressing histiocytes were co-localized in granulomas with silica particles that showed an increase of iron levels on silica particles in mouse lungs. Iron complexed with silica induces apoptosis, and may lead to dysregulations of autophagy in histiocytes of granulomas, and these mechanisms may contribute to granuloma development and progression in silicosis.


Allergology International | 2014

Epidemiologic Investigation of Hornet and Paper Wasp Stings in Forest Workers and Electrical Facility Field Workers in Japan

Yumeko Hayashih; Hirokuni Hirata; Mineaki Watanabe; Naruo Yoshida; Tatsuya Yokoyama; Yoshiki Murayama; Kumiya Sugiyama; Masafumi Arima; Yasutsugu Fukushima; Takeshi Fukuda; Yoshiki Ishii

BACKGROUNDnForestry and field workers who work outdoors are at high risk for Hymenoptera stings and may develop occupation-related allergies from being stung. However, clinical and immunological surveys of Hymenoptera stings in the occupational setting have rarely been reported. We surveyed the natural history of Hymenoptera stings in Japanese forestry workers (FWs) and electrical facility field workers (EFFWs), and we assessed the utility of measuring specific (s)IgE Ab to Hymenptera venom.nnnMETHODSnQuestionnaires on hornet and paper wasp stings were completed by 999 FWs, 354 EFFWs, and 365 office workers as controls between July and November 2009. Sera from these participants were tested for sIgE Ab levels to Hymenptera venom with a CAP system using a fluoroenzyme immunoassay.nnnRESULTSnOf the participants who had experienced Hymenoptera stings, 914 (91.5%) were FWs, 293 (82.8%) were EFFWs, and 295 (80.8%) were controls. Of the participants who had experienced systemic reactions, 210 (21.0%) were FWs, 51 (14.4%) were EFFWs, and 39 (10.7%) were controls. sIgE Ab in response to hornet and wasp venom was positive (≥ class 2) in 42.4% and 41.4% of FWs, 30.1% and 31.4% of EFFWs, and 15.1% and 18.1% of controls, respectively. The likelihood of being sIgE-positive to wasp and hornet venom was significantly higher in FWs and EFFWs than in controls (P < 0.05).nnnCONCLUSIONSn21% of FWs and 14% of EFFWs had experienced systemic reactions to Hymenoptera stings with a higher frequency compared with office workers in the same area. 40% of FWs and 30% of EFFWs had sera that were sIgE positive to Hymenoptera venom.BACKGROUNDnForestry and field workers who work outdoors are at high risk for Hymenoptera stings and may develop occupation-related allergies from being stung. However, clinical and immunological surveys of Hymenoptera stings in the occupational setting have rarely been reported. We surveyed the natural history of Hymenoptera stings in Japanese forestry workers (FWs) and electrical facility field workers (EFFWs), and we assessed the utility of measuring specific (s)IgE Ab to Hymenptera venom.nnnMETHODSnQuestionnaires on hornet and paper wasp stings were completed by 999 FWs, 354 EFFWs, and 365 office workers as controls between July and November 2009. Sera from these participants were tested for sIgE Ab levels to Hymenptera venom with a CAP system using a fluoroenzyme immunoassay.nnnRESULTSnOf the participants who had experienced Hymenoptera stings, 914 (91.5%) were FWs, 293 (82.8%) were EFFWs, and 295 (80.8%) were controls. Of the participants who had experienced systemic reactions, 210 (21.0%) were FWs, 51 (14.4%) were EFFWs, and 39 (10.7%) were controls. sIgE Ab in response to hornet and wasp venom was positive (≥ class 2) in 42.4% and 41.4% of FWs, 30.1% and 31.4% of EFFWs, and 15.1% and 18.1% of controls, respectively. The likelihood of being sIgE-positive to wasp and hornet venom was significantly higher in FWs and EFFWs than in controls (P < 0.05).nnnCONCLUSIONSn21% of FWs and 14% of EFFWs had experienced systemic reactions to Hymenoptera stings with a higher frequency compared with office workers in the same area. 40% of FWs and 30% of EFFWs had sera that were sIgE positive to Hymenoptera venom.


Modern Rheumatology | 2016

Clinical features of organizing pneumonia associated with rheumatoid arthritis

Harutsugu Okada; Kazuhiro Kurasawa; Ryutaro Yamazaki; Ayae Tanaka; Satoko Arai; Takayoshi Owada; Reika Maezawa; Yoshiki Ishii

Abstract Objectives: To clarify the clinical features of organizing pneumonia (OP) associated with rheumatoid arthritis (RA) and to determine whether development of OP is related to RA activity. Methods: A cross-sectional study was conducted, in which medical records of 499 consecutive RA patients who visited our hospital during one month were reviewed. OP was diagnosed by pathological findings by trans-bronchial biopsy or by clinical features (typical computed tomography findings, no causative agents, good response to glucocorticoids, and lack of response to antibiotics). Results: Among 499 patients, OP was found in 19 patients and the estimated prevalence was 1.9–4.8%. No differences in clinical features were noted between the OP and non-OP groups. The mean age of OP development was 57.2 years and the period from the onset of RA to OP ranged from −4 to +34 years. Although 14 patients presented OP after the onset of RA, two developed OP before RA and three developed OP simultaneously with RA. Patients receiving tumor necrosis factor inhibitors also developed OP. RA disease activity just before onset of OP was low in 8 of 14 RA cases. At the onset of OP, only two patients showed exacerbations of arthritis, whereas most patients presented with fever and serum C-reactive protein (CRP) elevations. Glucocorticoids were effective for OP in all patients who received them. Relapse occurred in 4 of 19 cases. Conclusions: OP develops in approximately 4% of RA patients, which occurs independently from arthritis activity and at any time in RA patients.


Internal Medicine | 2016

Bronchoscopic Investigation of Atypical Drug-induced Hypersensitivity Syndrome Showing Viral Lung Involvement.

Isano Hase; Hiroaki Arakawa; Hideo Sakuma; Fumio Kaneko; Yuzuru Watanabe; Koichi Fujiu; Hideaki Miyamoto; Yoshiki Ishii

We herein report a case of atypical drug-induced hypersensitivity syndrome (DIHS) involving serological reactivation of cytomegalovirus induced by carbamazepine with pulmonary and skin manifestations. These lesions were not present on admission, but developed on virus reactivation as indicated by the presence of inclusion bodies and multinucleated giant cells in alveolar cells with CD8(+) T lymphocyte infiltration on a transbronchial lung biopsy. Although the precise mechanism of DIHS remains unknown, this case suggests the crucial role of viral reactivation in pulmonary lesions in DIHS.

Collaboration


Dive into the Yoshiki Ishii's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Ryo Arai

Dokkyo Medical University

View shared research outputs
Top Co-Authors

Avatar

Taichi Shiobara

Dokkyo Medical University

View shared research outputs
Top Co-Authors

Avatar

Taiji Watanabe

Dokkyo Medical University

View shared research outputs
Top Co-Authors

Avatar

Takeshi Fukuda

Dokkyo Medical University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Isano Hase

Dokkyo Medical University

View shared research outputs
Researchain Logo
Decentralizing Knowledge