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Dive into the research topics where Seigo Kitada is active.

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Featured researches published by Seigo Kitada.


PLOS ONE | 2012

Ghrelin Treatment of Cachectic Patients with Chronic Obstructive Pulmonary Disease: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

Keisuke Miki; Ryoji Maekura; Noritoshi Nagaya; Masamitsu Nakazato; Hiroshi Kimura; Shinsuke Murakami; Shunsuke Ohnishi; Toru Hiraga; Mari Miki; Seigo Kitada; Kenji Yoshimura; Yoshitaka Tateishi; Yasuji Arimura; Nobuhiro Matsumoto; Masanori Yoshikawa; Kenichi Yamahara; Kenji Kangawa

Background Pulmonary cachexia is common in advanced chronic obstructive pulmonary disease (COPD), culminating in exercise intolerance and a poor prognosis. Ghrelin is a novel growth hormone (GH)-releasing peptide with GH-independent effects. The efficacy and safety of adding ghrelin to pulmonary rehabilitation (PR) in cachectic COPD patients were investigated. Methodology/Principal Findings In a multicenter, randomized, double-blind, placebo-controlled trial, 33 cachectic COPD patients were randomly assigned PR with intravenous ghrelin (2 µg/kg) or placebo twice daily for 3 weeks in hospital. The primary outcomes were changes in 6-min walk distance (6-MWD) and the St. George Respiratory Questionnaire (SGRQ) score. Secondary outcomes included changes in the Medical Research Council (MRC) scale, and respiratory muscle strength. At pre-treatment, serum GH levels were increased from baseline levels by a single dose of ghrelin (mean change, +46.5 ng/ml; between-group p<0.0001), the effect of which continued during the 3-week treatment. In the ghrelin group, the mean change from pre-treatment in 6-MWD was improved at Week 3 (+40 m, within-group p = 0.033) and was maintained at Week 7 (+47 m, within-group p = 0.017), although the difference between ghrelin and placebo was not significant. At Week 7, the mean changes in SGRQ symptoms (between-group p = 0.026), in MRC (between-group p = 0.030), and in maximal expiratory pressure (MEP; between-group p = 0.015) were better in the ghrelin group than in the placebo group. Additionally, repeated-measures analysis of variance (ANOVA) indicated significant time course effects of ghrelin versus placebo in SGRQ symptoms (p = 0.049) and MEP (p = 0.021). Ghrelin treatment was well tolerated. Conclusions/Significance In cachectic COPD patients, with the safety profile, ghrelin administration provided improvements in symptoms and respiratory strength, despite the lack of a significant between-group difference in 6-MWD. Trial Registration UMIN Clinical Trial Registry C000000061


Journal of Clinical Microbiology | 2004

Rapid Serodiagnosis of Active Pulmonary Mycobacterium tuberculosis by Analysis of Results from Multiple Antigen-Specific Tests

Yoshinari Okuda; Ryoji Maekura; Atsusi Hirotani; Seigo Kitada; Kenji Yoshimura; Touru Hiraga; Yuoko Yamamoto; Masami Itou; Takeshi Ogura; Toshio Ogihara

ABSTRACT We have prospectively analyzed three antigens for serodiagnosis of tuberculosis (TB). These antigens were tuberculous glycolipid antigen, lypoarabinomannan polysaccharide antigen, and antigen 60 (A60), which was derived from purified protein derivatives. Of the 131 patients with active pulmonary TB, 57 were both smear and culture negative and 14 had chronic active pulmonary TB that remained smear positive for >12 months of chemotherapy. One hundred twenty healthy adults were controls. The percentages of patients positive in all three tests were 58.8% for smear-positive active pulmonary TB and 71.4% for chronic active pulmonary TB. When the results of the three serodiagnostic tests were evaluated in combination, the sensitivity increased to 91.5% in patients with active pulmonary TB and to 86.0% in smear- and culture-negative patients. The false-positive rate of the three-test combination was 12.5% in the healthy control groups. In conclusion, it was not possible to detect all of the antibodies against antigenic substances in the cell walls of the tuberculous bacilli in the sera of all TB patients by using available serodiagnostic tests. However, the combined use of tests with three separate antigens maximizes the effectiveness of serodiagnosis.


Clinical Infectious Diseases | 2002

Serodiagnosis of pulmonary disease due to Mycobacterium avium complex with an enzyme immunoassay that uses a mixture of glycopeptidolipid antigens.

Seigo Kitada; Ryoji Maekura; Naomi Toyoshima; Nagatoshi Fujiwara; Ikuya Yano; Takeshi Ogura; Masami Ito; Kazuo Kobayashi

It is difficult to distinguish pulmonary disease due to Mycobacterium avium complex (MAC) from that due to other mycobacteria, such as Mycobacterium tuberculosis and Mycobacterium kansasii. We developed an enzyme immunoassay (EIA) for diagnosis of MAC pulmonary diseases that uses glycopeptidolipid (GPL) antigens specific for MAC, and we used it for diagnosis in immunocompetent patients. The mean optical densities (+/- standard deviation) of serum immunoglobulin G antibodies to GPLs in patients with MAC disease, MAC colonization, M. kansasii disease, and tuberculosis and in healthy subjects were 0.778+/-0.784, 0.042+/-0.035, 0.059+/-0.035, 0.071+/-0.035, and 0.030+/-0.027, respectively. A significant increase in the level of anti-GPL antibodies was detected in patients with MAC disease. The level of anti-GPL antibodies reflected disease activity, because the level was decreased in culture-negative patients who had conversion of culture results. When a cutoff level of seropositivity (0.119) was defined, the sensitivity of EIA for diagnosis of MAC disease was 92.3%, and the specificity was 96.7%. Measurement of serum anti-GPL antibodies is useful for both the diagnosis of and assessment of activity in MAC disease.


Clinical Physiology and Functional Imaging | 2003

Prognostic predictors for survival in patients with COPD using cardiopulmonary exercise testing

Toru Hiraga; Ryoji Maekura; Yoshinari Okuda; Takashi Okamoto; Atsushi Hirotani; Seigo Kitada; Kenji Yoshimura; Soichiro Yokota; Masami Ito; Takeshi Ogura

We studied the relationship between physiologic parameters in cardiopulmonary exercise testing (CPET) and prognosis in terms of survival time in patients with chronic obstructive pulmonary disease (COPD) in order to accurately assess the severity of the disease. From a group of 195 patients with COPD who had consecutively undergone CPET between July 1989 and October 1997, we enrolled 120 subjects (mean age 67·6 years, 104 males) with exertional dyspnoea into a cohort protocol. Of these subjects, 34 (28·3%) died during the 3–5‐year follow‐up period after CPET. By univariate analysis, the following factors were significantly associated with survival time: age, body mass index, %FVC, %FEV1, FEV1%, Paco2 at rest, severity of exercise‐induced hypoxemia evaluated by ΔPao2/ΔV̇o2 (Pao2‐slope), oxygen uptake, ventilation, tidal volume, Paco2 and oxygen pulse at maximum exercise, as well as prescribing long‐term oxygen therapy. By multivariate analysis, age and the Pao2‐slope showed significance as independent prognostic factors, and the Pao2‐slope was most closely associated with the survival time. These results reveal that CPET is a useful technique to accurately assess the relationship between the functional impairments and the prognosis of patients with COPD.


Clinical and Vaccine Immunology | 2005

Use of Glycopeptidolipid Core Antigen for Serodiagnosis of Mycobacterium avium Complex Pulmonary Disease in Immunocompetent Patients

Seigo Kitada; Ryoji Maekura; Naomi Toyoshima; Takashi Naka; Nagatoshi Fujiwara; Masami Kobayashi; Ikuya Yano; Masami Ito; Kazuo Kobayashi

ABSTRACT We report the development of a serodiagnostic method for Mycobacterium avium complex (MAC) disease with an enzyme immunoassay (EIA) with the MAC-specific glycopeptidolipid (GPL) core as the antigen. In this study, we confirmed by EIA that the GPL core antibody was in the sera of immunocompetent patients with MAC disease. The EIA for quantifying the GPL core antibody was evaluated as a clinical tool for serodiagnosis of pulmonary MAC disease. A significant increase in GPL core antibodies (immunoglobulins G, A, and M) was detected in sera of patients with MAC pulmonary diseases when they were compared to patients who were colonized with MAC, patients with Mycobacterium kansasii disease or tuberculosis, and healthy subjects. The sensitivities and specificities of the GPL core-based EIA for diagnosis of MAC pulmonary disease were 72.6% and 92.2%, respectively, for IgG, 92.5% and 95.1%, respectively, for IgA, and 78.3% and 91.0%, respectively, for IgM. The best sensitivity and specificity were obtained by measuring immunoglobulin A antibodies against GPL core antigen. The level of GPL core antibodies reflected disease activity, since it decreased in cured MAC patients who had responded to chemotherapy. Measurement of serum antibodies against GPL core is useful for both diagnosis and assessment of disease activity in MAC disease of the lung.


Journal of Clinical Microbiology | 2005

Clinical and Prognostic Importance of Serotyping Mycobacterium avium-Mycobacterium intracellulare Complex Isolates in Human Immunodeficiency Virus-Negative Patients

Ryoji Maekura; Yoshinari Okuda; Atsusi Hirotani; Seigo Kitada; Touru Hiraga; Kenji Yoshimura; Ikuya Yano; Kazuo Kobayashi; Masami Ito

ABSTRACT We studied whether the serotypes of Mycobacterium avium-Mycobacterium intracellulare complex (MAC) isolates determine the prognosis for pulmonary MAC disease. We prospectively monitored a cohort of 68 patients with pulmonary MAC disease for whom the serotype-specific glycopeptidolipids in isolates were identified using thin-layer chromatography and fast atom bombardment mass-spectrometry in 1990 and 1995. Serovar 4 Mycobacterium avium was detected in 40/68 patients (58.8%). Other serotypes were serotypes 1 (five cases), 6 (three cases), 8 (seven cases), 9 (three cases), 14 (four cases), and 16 (six cases). Patients with serovar 4 were significantly (P < 0.01) younger (63.0 ± 9.8 years) than patients with other serotypes (71.8 ± 10.3). Patients who failed treatment had a significantly poorer prognosis than other patients. There were no cases of MAC-related death in the cured group. Chest radiographic findings progressively worsened in 36 (90%) of patients with serotype 4, and 14/36 died from respiratory failure caused by pulmonary Mycobacterium avium disease. The patients with serotype 4 had a significantly poorer prognosis than patients with other serotypes. These results show that both the outcome of chemotherapy and the serotypes of MAC isolates are important for assessing the prognosis of pulmonary MAC disease.


Microbial Pathogenesis | 2009

Virulence of Mycobacterium avium complex strains isolated from immunocompetent patients

Yoshitaka Tateishi; Yukio Hirayama; Yuriko Ozeki; Yukiko Nishiuchi; Mamiko Yoshimura; Jing Kang; Atsushi Shibata; Kazuto Hirata; Seigo Kitada; Ryoji Maekura; Hisashi Ogura; Kazuo Kobayashi; Sohkichi Matsumoto

Mycobacterium avium complex (MAC) disease has been increasing worldwide not only in immunocompromised but also in immunocompetent humans. However, the relationship between mycobacterial strain virulence and disease progression in immunocompetent humans is unclear. In this study, we isolated 6 strains from patients with pulmonary MAC disease. To explore the virulence, we examined the growth in human THP-1 macrophages and pathogenicity in C57BL/6 mice. We found that one strain, designated 198, which was isolated from a patient showing the most progressive disease, persisted in THP-1 cells. In addition, strain 198 grew to a high bacterial load with strong inflammation in mouse lungs and spleens 16 weeks after infection. To our knowledge, strain 198 is the first isolated MAC strain that exhibits hypervirulence consistently for the human patient, human macrophages in vitro, and even for immunocompetent mice. Other strains showed limited survival and weak virulence both in macrophages and in mice, uncorrelated to disease progression in human patients. We demonstrated that there is a hypervirulent clinical MAC strain whose experimental virulence corresponds to the serious disease progression in the patients. The existence of such strain suggests the involvement of bacterial virulence in the pathogenesis of pulmonary MAC disease in immunocompetent status.


European Respiratory Journal | 2013

Serodiagnosis of Mycobacterium avium complex pulmonary disease in the USA

Seigo Kitada; Adrah Levin; Melissa Hiserote; Ron J. Harbeck; Chris A. Czaja; Gwen A. Huitt; Shannon H. Kasperbauer; Charles L. Daley

Diagnosis of Mycobacterium avium complex pulmonary disease (MAC-PD) can be difficult. A previous study from Japan reported the usefulness of a serodiagnostic test for MAC-PD. The objective of this study was to evaluate the usefulness of the test in similar patients in the USA. 100 patients with known or suspected MAC-PD and 52 healthy volunteers were enrolled into the study at National Jewish Health, Denver, CO, USA. Serum glycopeptidolipid core immunoglobulin A antibody levels were measured with an enzyme immunoassay (EIA) kit and routine clinical evaluations were performed. The patients were divided into two groups based on clinical evaluation: 87 patients with MAC-PD that met American Thoracic Society criteria, and 13 who did not meet the criteria. The sensitivity and specificity (cut-off point 0.3 U·mL−1) of the serodiagnostic test for diagnosing MAC-PD were 70.1% and 93.9%, respectively. Among the 44 patients in the MAC-PD group with two or more positive sputum cultures within the previous 6 months, sensitivity was 81.8%. The EIA kit demonstrated good sensitivity and specificity for the identification of MAC-PD, particularly in patients with two or more positive cultures, and may be useful for rapid MAC-PD diagnosis.


European Respiratory Journal | 2007

Serological test and chest computed tomography findings in patients with Mycobacterium avium complex lung disease

Seigo Kitada; Y. Nishiuchi; Touru Hiraga; N. Naka; Hisako Hashimoto; Kenji Yoshimura; Keisuke Miki; Mari Miki; M. Motone; T. Fujikawa; Kazuo Kobayashi; Ikuya Yano; Ryoji Maekura

The present authors have previously reported the usefulness of a serodiagnostic test to detect serum glycopeptidolipid (GPL) core antibody in diagnosing Mycobacterium avium complex (MAC) lung disease in immunocompetent patients. The aim of the present study was to investigate correlations between the levels of antibody against GPL core and chest computed tomography (CCT) findings in patients with MAC lung disease. A total of 47 patients with MAC-positive culture from their sputum and who had radiographic abnormalities were investigated. Thirty-three patients met the American Thoracic Society criteria for MAC disease; 14 did not. All patients underwent both CCT examination and the serodiagnostic test for MAC at the same time. Small nodular shadows were seen on CCT in all 47 patients and bronchiectasis shadows were seen in 39 (83%) of them. There was a significant positive correlation between the extent of the disease and the level of GPL core immunoglobulin (Ig)A antibody. The levels of GPL core IgA antibody were significantly elevated in patients who had nodular shadows (10–30 mm) compared with patients who had small nodular shadows (<10 mm). The present results document that the levels of immunoglobulin A antibody against glycopeptidolipid core correlate with the chest computed tomography findings of Mycobacterium avium complex lung disease.


BMC Pulmonary Medicine | 2013

Effects of Ghrelin Treatment on Exercise Capacity in Underweight COPD Patients: a substudy of a multicenter, randomized, double-blind, placebo-controlled trial of ghrelin treatment

Keisuke Miki; Ryoji Maekura; Noritoshi Nagaya; Seigo Kitada; Mari Miki; Kenji Yoshimura; Yoshitaka Tateishi; Masaharu Motone; Toru Hiraga; Masahide Mori; Kenji Kangawa

BackgroundThe aim of this substudy of the ghrelin treatment, multicenter, randomized, double-blind, placebo-controlled trial was to investigate the effects of ghrelin administration on exercise capacity and the underlying mechanisms in underweight patients with chronic obstructive pulmonary disease (COPD) using cardiopulmonary exercise testing.MethodsTwenty underweight COPD patients were randomized to pulmonary rehabilitation with intravenous ghrelin (2 μg/kg, n = 10) or placebo (n = 10) twice daily for 3 weeks in a double-blind fashion. The primary outcome was changes in peak oxygen uptake V•o2. Secondary outcomes included changes in exertional cardio-respiratory functions: O2-pulse, physiologic dead space/tidal volume-ratio (VD/VT), ventilatory equivalent for oxygen V•E/V•o2, and ventilatory equivalent for carbon dioxide V•E/V•co2.ResultsWith incremental exercise, at peak exercise, there was a significant difference in the mean difference (ghrelin minus placebo), i.e., treatment effect in: i) peak V•o2 (1.2 mL/kg/min, 95% CI: 0.2-2.3 mL/kg/min, between-group p = 0.025); ii) V•E/V•o2 (-4.2, 95% CI: -7.9 to -0.5, between-group p = 0.030); iii) V•E/V•co2 (-4.1, 95% CI: -8.2 to -0.1, between-group p = 0.045); iv) VD/VT (-0.04, 95% CI: -0.08 to -0.00, between-group p = 0.041); and v) O2-pulse (0.7 mL/beat, 95% CI: 0.3 to 1.2 mL/beat, between-group p = 0.003). Additionally, repeated-measures analysis of variance (ANOVA) indicated a significant time-course effect of ghrelin versus placebo in the peak V•o2 (p = 0.025).ConclusionGhrelin administration was associated with improved exertional capacity and improvements in ventilatory-cardiac parameters.Trial registrationUMIN (University Hospital Medical Information Network in Japan) C000000061

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Masami Ito

Shiga University of Medical Science

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