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Dive into the research topics where Naoko Tojo is active.

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Featured researches published by Naoko Tojo.


Respiration | 1992

Changes of Circulating Atrial Natriuretic Peptide and Antidiuretic Hormone in Obstructive Sleep Apnea Syndrome

Masahiko Ichioka; Yukio Hirata; Naohiko Inase; Naoko Tojo; Masafumi Yoshizawa; Mamoru Chida; Itsuro Miyazato; Satoshi Taniai; Fumiaki Marumo

Patients with obstructive sleep apnea (OSA) syndrome are known to exhibit nocturnal natriuresis/diuresis. We studied plasma and urinary levels of atrial natriuretic peptide (ANP), a potent natriuretic hormone released from the heart, and plasma antidiuretic hormone (ADH) levels in patients with OSA during awake and sleeping periods, to compare with those of normal subjects. Seven patients with OSA and 6 normal subjects were studied. Arterial blood samples were drawn during the awake and the sleeping period, while in patients with OSA, blood samples were obtained during the apneic period. Urine samples were collected over two 12-hour periods (9 a.m.-9 p.m. and 9 p.m.-9 a.m.) In patients with OSA, plasma ANP as well as urinary ANP excretion increased during the apneic period compared with the awake period. There was a significant negative correlation between plasma levels of ANP and ADH in patients with OSA. On the other hand, normal subjects had no apparent differences in plasma and urinary ANP levels between the two periods. It is suggested that nocturnal increase in ANP and decrease in ADH are responsible for the nocturnal diuresis and natriuresis associated with OSA.


Lab on a Chip | 2011

Point-of-care testing system enabling 30 min detection of influenza genes

Tomoteru Abe; Yuji Segawa; Hidetoshi Watanabe; Tasuku Yotoriyama; Shinichi Kai; Akio Yasuda; Norio Shimizu; Naoko Tojo

We developed a portable and easy-to-use nucleic acid amplification test (NAT) system for use in point-of-care testing (POCT). The system shows sensitivity that is sufficiently higher than that of the currently available rapid diagnostic kit and is comparable to that of real-time reverse transcription polymerase chain reaction (RT-PCR) for influenza testing.


Respiratory Physiology & Neurobiology | 2002

Effect of chest wall vibration on dyspnea during exercise in chronic obstructive pulmonary disease

Toshihide Fujie; Naoko Tojo; Naohiko Inase; Nobuo Nara; Ikuo Homma; Yasuyuki Yoshizawa

To elucidate the effect of in-phase chest wall vibration (IPV) during exercise, 17 COPD male patients performed two constant-load exercise tests on a cycle ergometer with and without IPV. The Borg dyspnea score significantly decreased from IPV (-) to IPV (+) (from 13.6+/-2.9 to 12.5+/-2.9, P<0.01). IPV elicited a significant increase in V(O(2)) (P<0.005) and significant decreases in both VE/V(O(2)) (P<0.05) and respiratory frequency (P<0.05), but it did not elicit any changes in VE. The change in Borg score between IPV (+) and IPV (-) showed a significant positive correlation with % predicted V(O(2),max) (r=0.71) and FEV(1)/FVC (r=0.69). Patients in the responsive group (n=11) showed significantly lower FEV(1) (P<0.05) and higher DeltaN(2)/L (P<0.01) than patients in the non-responsive group (n=6). We conclude that IPV reduces dyspnea and improves respiratory efficiency during aerobic exercise in severe COPD.


Antimicrobial Agents and Chemotherapy | 2014

First Report of KPC-2 Carbapenemase-Producing Klebsiella pneumoniae in Japan

Ryoichi Saito; Rieko Takahashi; Etsuko Sawabe; Saho Koyano; Yutaka Takahashi; Mari Shima; Hiroto Ushizawa; Toshihide Fujie; Naoki Tosaka; Yuko Kato; Kyoji Moriya; Shuji Tohda; Naoko Tojo; Ryuji Koike; Tetsuo Kubota

ABSTRACT We investigated a novel Japanese isolate of sequence type 11 (ST11), the Klebsiella pneumoniae carbapenemase-2 (KPC-2)-producing K. pneumoniae strain Kp3018, which was previously obtained from a patient treated at a Brazilian hospital. This strain was resistant to various antibiotic classes, including carbapenems, and harbored the gene blaKPC-2, which was present on the transferable plasmid of ca. 190 kb, in addition to the blaCTX-M-15 gene. Furthermore, the ca. 2.3-kb sequences (ISKpn8-blaKPC-2–ISKpn6-like), encompassing blaKPC-2, were found to be similar to those of K. pneumoniae strains from China.


Journal of Asthma | 2003

The Effect of Seratrodast on Eosinophil Cationic Protein and Symptoms in Asthmatics

Toshihiko Fukuoka; Shuji Miyake; Takeshi Umino; Naohiko Inase; Naoko Tojo; Yasuyuki Yoshizawa

Thromboxane A2 (TXA2), an arachidonate derivative, is a potent bronchoconstrictor; therefore, blocking TXA2 should attenuate airway narrowing. Seratrodast, a TXA2 receptor antagonist, is expected to be a potent antiasthmatic. It was reported that seratrodast reduced bronchial hyperresponsiveness. However, it is controversial whether it reduces airway inflammation. We studied some additional effects of oral seratrodast to inhaled corticosteroids on 10 adult asthmatics in an open-label, crossover design study. Eosinophil cationic protein (ECP) levels in serum and sputum, peak expiratory flow rate (PEF), clinical symptoms, and airway responsiveness were evaluated. Clinical symptom scores were improved by administration of seratrodast (p<0.05). The addition of seratrodast to asthmatic patients significantly improved mean PEF (p<0.05). In addition, withdrawal of seratrodast resulted in deterioration of PEF. Airway hyperresponsiveness to acetylcholine measured by Astograph was improved by administration of seratrodast (p<0.01), and returned to the level of “run-in period” after withdrawal. Administration of seratrodast decreased the concentration of ECP in sputum significantly (p<0.05), and sputum ECP significantly increased again after withdrawal of (p<0.05). These results suggest that seratrodast improves clinical symptoms and airway hyperresponsiveness by reducing airway inflammation. Seratrodast may be useful as an anti-inflammatory agent and beneficial when added to inhaled corticosteroids in the treatment of bronchial asthma.


Experimental and Therapeutic Medicine | 2012

Flow cytometric analysis of Notch1 and Jagged1 expression in normal blood cells and leukemia cells

Eriko Kanamori; Mai Itoh; Naoko Tojo; Takatoshi Koyama; Nobuo Nara; Shuji Tohda

Notch1 and its ligand Jagged1 are proteins with important roles in the growth of leukemia cells. Although the detection of Notch1 protein in acute lymphoblastic leukemia cells using immunoblot analysis has been previously reported, the expression patterns of Notch1 and Jagged1 detected by flow cytometry (FCM) in normal blood cells and various leukemia cells have not been well-characterised. In the present study, we examined the expression patterns of Notch1 and Jagged1 in 10 normal blood samples, 8 bone marrow samples, 11 leukemia/lymphoma cell lines and leukemia cells from 22 patients with acute myeloid leukemia (AML), mature T-cell neoplasms or B-cell chronic lymphocytic leukemia (B-CLL) using FCM. The results showed that Notch1 expression is relatively strong in monocytes and granulocytes but weak in lymphocytes. The expression of Notch1 is stronger in bone marrow cells than in the equivalent cells in blood. All the cell lines examined strongly expressed Notch1, and eight cell lines expressed Jagged1. In leukemia cells from patients, four AML samples expressed Notch1 and/or Jagged1. However, three samples expressed neither Notch1 and/or Jagged1 and none of the mature T-cell neoplasm samples expressed either protein. However, all B-CLL samples expressed high levels of both Notch1 and Jagged1. We found that the expression of Notch1 and Jagged1 is detected in various hematological malignancies by FCM. The examination of these proteins is likely to be useful in the characterisation of diseases and individual cases. Examination of these proteins may also be useful in the selection of patients most likely to benefit from novel molecular-targeted therapies using Notch inhibitors in the future.


Journal of Clinical Microbiology | 2014

Catheter-Related Bloodstream Infection by Tsukamurella inchonensis in an Immunocompromised Patient

Isao Takebe; Etsuko Sawabe; Kiyofumi Ohkusu; Naoko Tojo; Shuji Tohda

ABSTRACT We report a case of catheter-related bloodstream infection by Tsukamurella inchonensis, identified using 16S rRNA gene sequencing, in a patient with myelofibrosis who underwent a bone marrow transplant. Tsukamurella species infections are rare. To our knowledge, this is the first case of T. inchonensis bloodstream infection in an immunocompromised patient.


Journal of Clinical Microbiology | 2012

First Report of Sepsis Caused by Rhodococcus corynebacterioides in a Patient with Myelodysplastic Syndrome

Yuka Kitamura; Etsuko Sawabe; Kiyofumi Ohkusu; Naoko Tojo; Shuji Tohda

ABSTRACT We report a case of sepsis caused by Rhodococcus corynebacterioides, identified using 16S rRNA gene sequencing, in a myelodysplastic syndrome patient who had undergone hematopoietic stem cell transplantation. This is the first report of R. corynebacterioides infection in a human.


Acta Haematologica | 2014

A Case of Gray Platelet Syndrome Masked by Immune Thrombocytopenia at Presentation

Nana Mizuno; Eriko Kanamori; Hiroko Saito; Naomi Murakami; Naoko Tojo; Shuji Tohda

We report a case of gray platelet syndrome (GPS) associated with immune thrombocytopenia (ITP) at presentation. A 22-year-old male patient presenting with petechiae on his limbs was diagnosed with ITP due to a gradual decrease of his platelet count to a minimum of 26 × 109/liter and an elevated platelet-associated IgG (PA-IgG) level in the absence of any other specific cause of thrombocytopenia. Administration of prednisolone increased his platelet count, but this dropped again to approximately 50 × 109/liter as the dose was tapered, and remained at the same level after the treatment was terminated. Thirteen years later, we reassessed the cause of the thrombocytopenia because the PA-IgG level was found to be within the normal range. There were large hypogranular platelets on the blood film and a deficit of α-granules in the platelets on electron microscopy. On this basis, we diagnosed his thrombocytopenia as GPS. To our knowledge, this is the first report of a GPS case associated with ITP at presentation. This case illustrates the importance of carefully reviewing blood film results in the differential diagnosis of thrombocytopenia.


Immunological Medicine | 2018

Comparison of fluorescence optical imaging, ultrasonography and clinical examination with magnetic resonance imaging as a reference in active rheumatoid arthritis patients

Fumio Hirano; Waka Yokoyama-Kokuryo; Hayato Yamazaki; Michi Tsutsumino; Ryoko Sakai; Shiro Satoh; Tomo Kimura; Naoko Tojo; Hitoshi Kohsaka; Masayoshi Harigai

Abstract Background: Fluorescence optical imaging with indocyanine-green enhancement (FOI) is a new imaging modality for the assessment of hand arthritis. The objective of this study was to compare performance profiles of clinical examination (CE), US and FOI using MRI as a reference in the same active rheumatoid arthritis (RA) patients. Methods: CE, US, FOI and MRI were performed on six subjects with active RA. Each sequence of FOI was divided into three phases based on indocyanine-green dynamics and the joints were graded semi-quantitatively. Sensitivities and specificities of CE, US and FOI were calculated using the RAMRIS synovitis score >0 as a reference in a total of 30 joints (the second to fifth metacarpophalangeal (MCP) joints and the wrist of the clinically dominant hand). Results: FOI showed sensitivities and specificities, respectively, of 85% and of 94% for Phase-1 and 69% and 94% for Phase-2. Sensitivities and specificities were 100% and 35% for CE (tender or swollen), 92% and 41% for gray scale US, and 77% and 100% for color-Doppler US. Conclusions: The performance characteristics of FOI in detection of synovitis in patients with active RA are comparable to those of US and more specific than CE. FOI has a potential as an assessment modality of RA.

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Masahiko Ichioka

Tokyo Medical and Dental University

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Itsuro Miyazato

Tokyo Medical and Dental University

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Mamoru Chida

Tokyo Medical and Dental University

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Naohiko Inase

Tokyo Medical and Dental University

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Satoshi Taniai

Tokyo Medical and Dental University

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Shuji Tohda

Tokyo Medical and Dental University

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Fumiaki Marumo

Tokyo Medical and Dental University

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Etsuko Sawabe

Tokyo Medical and Dental University

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Masafumi Yoshizawa

Tokyo Medical and Dental University

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Nobuo Nara

Tokyo Medical and Dental University

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