Network


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

Hotspot


Dive into the research topics where Yoko Katsura is active.

Publication


Featured researches published by Yoko Katsura.


Respiratory investigation | 2016

Diagnostic significance of cerebrospinal fluid EGFR mutation analysis for leptomeningeal metastasis in non-small-cell lung cancer patients harboring an active EGFR mutation following gefitinib therapy failure

Shinichi Sasaki; Yasuko Yoshioka; Ryo Ko; Yoko Katsura; Yukiko Namba; Takehito Shukuya; Kenji Kido; Shin-ichiro Iwakami; Shigeru Tominaga; Kazuhisa Takahashi

BACKGROUND Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been successfully used to treat patients with non-small cell lung cancer (NSCLC) harboring EGFR mutations. However, despite an initial excellent response, recurrence within one or two years is common. Diagnosis and treatment of leptomeningeal metastasis (LM), a form of NSCLC recurrence, remains particularly difficult. Here, we analyzed the EGFR mutation status of cerebrospinal fluid (CSF) directly using real-time polymerase chain reaction (PCR) and evaluated the efficacy of therapy with erlotinib, an EGFR TKI. PATIENTS AND METHODS Seven NSCLC patients harboring activating EGFR mutations who had developed LM during or after therapy with gefitinib, an EGFR TKI, were retrospectively analyzed. CSF was obtained and subjected to cytological examination and EGFR mutation analysis, including detection of the resistance-associated T790M mutation, using real-time PCR. RESULTS In all seven cases, the EGFR mutation detected in the CSF was the same as that detected in the primary tumor (sensitivity, 100%). Conversely, cytology results were positive in only two patients (sensitivity, 28.6%). No additional T790M mutations were detected. Erlotinib was efficacious in all cases, and improved performance status was achieved for five of the seven patients. The effect of erlotinib treatment was temporary, however, with time to treatment failure (TTF) ranging from 29 to 278 days (median, 65 days) and the interval between commencement of erlotinib treatment and death ranging from 45 to 347 days (median, 168 days). CONCLUSIONS Analysis of EGFR mutations in CSF using a highly sensitive real-time PCR assay is a potentially powerful diagnostic method for LM.


Experimental Lung Research | 2015

Characteristics of alveolar macrophages from murine models of OVA-induced allergic airway inflammation and LPS-induced acute airway inflammation

Yoko Katsura; Norihiro Harada; Sonoko Harada; Ayako Ishimori; Fumihiko Makino; Jun Ito; Fumitaka Kamachi; Ko Okumura; Hisaya Akiba; Ryo Atsuta; Kazuhisa Takahashi

ABSTRACT Background: Macrophages include the classically activated pro-inflammatory M1 macrophages (M1s) and alternatively activated anti-inflammatory M2 macrophages (M2s). The M1s are activated by both interferon-γ and Toll-like receptor ligands, including lipopolysaccharide (LPS), and have potent pro-inflammatory activity. In contrast, Th2 cytokines activate the M2s, which are involved in the immune response to parasites, promotion of tissue remodeling, and immune regulatory functions. Although alveolar macrophages (AMs) play an essential role in the pulmonary immune system, little is known about their phenotypes. Methods: Quantitative reverse transcription polymerase chain reaction and flow cytometry were used to define the characteristics of alveolar macrophages derived from untreated naïve mice and from murine models of both ovalbumin (OVA)-induced allergic airway inflammation and LPS-induced acute airway inflammation. AMs were co-cultured with CD4+ T cells and were pulsed with tritiated thymidine to assess proliferative responses. Results: We characterized in detail murine AMs and found that these cells were not completely consistent with the current M1 versus M2-polarization model. OVA-induced allergic and LPS-induced acute airway inflammation promoted the polarization of AMs towards the current M2-skewed and M1-skewed phenotypes, respectively. Moreover, our data also show that CD11c+ CD11b+ AMs from the LPS-treated mice play a regulatory role in antigen-specific T-cell proliferation in vitro. Conclusions: These characteristics of AMs depend on the incoming pathogens they encounter and on the phase of inflammation and do not correspond to the current M1 versus M2-polarization model. These findings may facilitate an understanding of their contributions to the pulmonary immune system in airway inflammation.


Rare Tumors | 2009

Synchronous malignant B-cell lymphoma and gastric tubular adenocarcinoma associated with paraneoplastic cutaneous vasculitis: hypereosinophilic syndrome with mixed cryoglobulinemia is an important sign of paraneoplastic syndrome.

Kazuhisa Nozawa; Hiroshi Kaneko; Tomoyasu Itoh; Yoko Katsura; Masaaki Noguchi; Fujihiko Suzuki; Yoshinari Takasaki; Hideoki Ogawa; Kenji Takamori; Iwao Sekigawa

Gastric adenocarcinoma developing concomitantly with a lymphoma is rare. Furthermore, B-cell lymphoma, originating from lymph nodes, with eosinophilia is extremely rare. We report here a case with a synchronous diffuse large B-cell lymphoma (DLBCL) and an early adenocarcinoma of the stomach. In addition, this case seemed to be associated with paraneoplastic cutaneous vasculitis caused by hypereosinophilic syndrome (HES) with mixed cryoglobulinemia (MC). Many neoplastic diseases that affect internal organs display cutaneous manifestations, which may be the presenting signs and symptoms of the underlying malignancy. In particular, the association between cutaneous vasculitis and malignancy has been widely reviewed, and recently neoplasms have been suggested to produce antigens and the resultant immune complex formations, activating the serum complement, thus cause paraneoplastic vasculitis. In this case, severe eosinophilia and cryoglobulinemia with low complements were observed in a laboratory test. A biopsy specimen from a skin lesion revealed leukocytoclastic vasculitis with severe perivascular infiltration of eosinophils. The cutaneous vasuculitis was considered to be a manifestation of HES with MC, although there were no etiological factors of HES and MC. Therefore, the vasculitis seems to be a symptom of paraneoplastic syndrome in this case. Our finding suggests that the potential presence of malignancies should be kept in mind as a possible underlying disorder especially in the presence of HES with MC; this possibility is interesting also as regards at least part of the pathogenesis for paraneplastic syndrome.


Journal of Asthma | 2016

Evaluation of switching low-dose inhaled corticosteroid to pranlukast for step-down therapy in well-controlled patients with mild persistent asthma

Sonoko Harada; Norihiro Harada; Yukinari Itoigawa; Yoko Katsura; Fumiko Kasuga; Ayako Ishimori; Fumihiko Makino; Jun Ito; Ryo Atsuta; Kazuhisa Takahashi

Abstract Objective: Treatment guidelines for asthma recommend step-down therapy for well-controlled asthma patients. However, the precise strategy for step-down therapy has not been well defined. We investigated whether well-controlled patients with mild persistent asthma can tolerate a step-down therapy of either a reduced dose of inhaled corticosteroid (ICS) or a switch to a leukotriene receptor antagonist (LTRA), pranlukast hydrate. Methods: We recruited 40 adult patients with mild persistent asthma who were well-controlled for at least 3 months with a low-dose ICS therapy. The patients were randomly assigned to either an ICS dose reduction or a switch to pranlukast for 6 months. Results: FeNO levels in the pranlukast group were significantly increased over that in the ICS group. There were no significant differences between the two groups for lung function, FOT, at the endpoint. The percentage of patients with controlled asthma was 72.2% in the pranlukast group and 90% in the ICS group. No statistically significant difference between the two groups in the percentages of patients with treatment failure was observed. Conclusions: Patients with mild persistent asthma that is well-controlled by a low dose of ICS can be switched to pranlukast safely for at least 6 months. However, 27.8% of the pranlukast group failed to maintain well-control, and FeNO levels increased with the switch to pranlukast at 6 months. This study was been limited by the small sample size and should therefore be considered preliminary. Further studies are needed to investigate the therapeutic efficacy of LTRA monotherapy as a step-down therapy.


Journal of Asthma | 2018

Difference between two exhaled nitric oxide analyzers, NIOX VERO® electrochemical hand-held analyzer and NOA280i® chemiluminescence stationary analyzer

Yuki Tanabe; Norihiro Harada; Jun Ito; Kei Matsuno; Tomohito Takeshige; Sonoko Harada; Mirano Takemasa; Masaki Kotajima; Ayako Ishimori; Yoko Katsura; Fumihiko Makino; Ryo Atsuta; Kazuhisa Takahashi

Abstract Background: Fractional exhaled nitric oxide (FENO) is useful for the evaluation of eosinophilic airway inflammation, including that seen in asthma. Although a new electrochemical hand-held FENO analyzer, the NIOX VERO® (Aerocrine AB, Solna, Sweden), is clinically convenient to use, it has not been fully compared with the chemiluminescence stationary electrochemical analyzer NOA280i® (Sievers Instruments, Boulder, CO, USA) in terms of the level of measured FENO. The aim of this study was to determine whether there is a difference between the two analyzers. Methods: The FENO levels measured with both NIOX VERO® and NOA280i® were evaluated in 1,369 adults at Juntendo University Hospital from May 2016 to October 2016. Results: The median FENO level measured with the NIOX VERO® was significantly lower than that measured with the NOA280i® (41 ppb, range 5–368 ppb vs. 29 ppb, range 5–251 ppb; p < 0.001). There was a strong positive correlation in the measurement of FENO level between the NOA280i® and the NIOX VERO® (r = 0.942, p < 0.001). The following conversion equation was calculated: FENO (NOA280i®) = 1.362 (SE, 0.661) + 1.384 (SE, 0.021) × FENO (NIOX VERO®). Conclusions: To our best knowledge, we have provided the first report showing that the measured FENO level with the NIOX VERO® was approximately 30% lower than that with the NOA280i® and that there was a significant correlation between the measurements of these two devices. The correction equation that we provided may help assess the data obtained by these two analyzers. AbbreviationsATS American Thoracic SocietyBMI Body mass indexERS European Respiratory SocietyFENO Fractional exhaled nitric oxideGINA Global Initiative for AsthmaNO Nitric oxideppb Parts per billionROC Receiver operating characteristicSD Standard deviation


Respiratory Research | 2015

TWEAK enhances TGF-β-induced epithelial-mesenchymal transition in human bronchial epithelial cells

Yukinari Itoigawa; Norihiro Harada; Sonoko Harada; Yoko Katsura; Fumihiko Makino; Jun Ito; Fariz Nurwidya; Motoyasu Kato; Fumiyuki Takahashi; Ryo Atsuta; Kazuhisa Takahashi


Nippon Ishinkin Gakkai Zasshi | 2011

Breakthrough lung Scedosporium prolificans infection with multiple cavity lesions in a patient receiving voriconazole for probable invasive aspergillosis associated with monoclonal gammopathy of undetermined significance (MGUS)

Rina Ohashi; Motoyasu Kato; Yoko Katsura; Hidenori Takekawa; Yoshito Hoshika; Tomonori Sugawara; Kaku Yoshimi; Shinsaku Togo; Tetsutaro Nagaoka; Kuniaki Seyama; Kazuhisa Takahashi; Koji Tsuchiya; Shigeki Misawa; Ken Kikuchi


Allergy, Asthma & Clinical Immunology | 2018

Characterization of tenascin-C as a novel biomarker for asthma: utility of tenascin-C in combination with periostin or immunoglobulin E

Mina Yasuda; Norihiro Harada; Sonoko Harada; Ayako Ishimori; Yoko Katsura; Yukinari Itoigawa; Kei Matsuno; Fumihiko Makino; Jun Ito; Junya Ono; Kazunori Tobino; Hisaya Akiba; Ryo Atsuta; Kenji Izuhara; Kazuhisa Takahashi


Respirology | 2013

the Effect of Chitin on Il-1β Production by Alveolar Macrophage : Ps058

Yoko Katsura; Norihiro Harada; Sonoko Harada; Yukinari Itoigawa; Kei Matsuno; Ayako Ishimori; Fumihiko Makino; Jun Ito; Osamu Nagashima; Ryo Atsuta; Kazuhisa Takahashi


順天堂医学 = Juntendo medical journal | 2012

Pulmonary Metastases from Carotid Body Paraganglioma : A Case Report

文美 奥住; Toru Kimura; Yoko Katsura; Atsuko Miyaji; Michihiro Hirama; Kenji Kido; Kanako Ogura; Makoto Hishii; Kazuhisa Takahashi

Collaboration


Dive into the Yoko Katsura's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge