H Koto

Kyushu University, Hukuoka, Fukuoka, Japan

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Publications (53)173.05 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Elucidating the prevalence of asthma and chronic obstructive pulmonary disease (COPD) is important for designing a public health strategy. Recent studies have discriminated a phenotype of COPD with variable airflow limitation (COPD-VAL) associated with asthma–COPD overlap syndrome. Its prevalence remains uncertain. The age and occupational distributions in the town of Hisayama and in Japan are nearly identical. Each disease׳s prevalence was estimated for the town׳s residents. Methods In 2008, town residents (≥40 years) were solicited to participate in a health checkup. Individuals with abnormal spirometry (forced expiratory volume in 1 s/forced vital capacity [FEV1/FVC]<70% and/or %FVC<80%) were recommended for further evaluations. Two pulmonologists in a blinded fashion reviewed their medical records, including bronchodilator reversibility. Individuals with airflow limitation were classified as having asthma, COPD, COPD-VAL, or other diseases. The prevalence of each disease was then estimated. Results A total of 2100 residents (43.4% of residents in the age group) completed spirometry. In 455 residents with abnormal spirometry, 190 residents had further evaluations, and the medical records of 174 residents were reviewed. The prevalence of asthma with airflow limitation, COPD, and COPD-VAL, were 2.0%, 8.4%, and 0.9%, respectively. The prevalence of COPD and COPD-VAL were higher in men and smokers than in women and never-smokers. The prevalence of COPD, but not COPD-VAL or asthma, increased with age. Conclusion The prevalence of asthma with airflow limitation, COPD, and COPD-VAL were estimated in a population of residents (≥40 years) in Hisayama.
    01/2014; DOI:10.1016/j.resinv.2014.08.002
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    ABSTRACT: Airway hyperresponsiveness is a cardinal feature of asthma. Although the modulation of cholinergic neuroeffector transmission may play a role in airway responsiveness, in vivo evidence remains scarce. It is well known that histamine causes bronchoconstriction partly via vagal reflex, whereas methacholine does not. To investigate the significance of modulating neuroeffector transmission, we compared the effect of low-dose salbutamol-a β2-adrenoceptor agonist-on airway responsiveness to histamine with that to methacholine. We enrolled 12 subjects with stable asthma. After screening confirmed that inhalation of low-dose salbutamol (1μg) did not change their basic pulmonary function, subjects underwent measurement of airway responsiveness to inhaled histamine and methacholine with or without pretreatment with low-dose salbutamol, in a randomized, crossover fashion. Airway responsiveness was measured by an astograph by which respiratory conductance (Grs) was assessed by the forced oscillation method during continuous inhalation of histamine or methacholine in stepwise incremental concentrations. Airway responsiveness was calculated as the cumulative dose of bronchoconstrictors that induced a decrease of 35% in Grs. Inhalation of 1μg of salbutamol significantly attenuated airway responsiveness to histamine but not methacholine. This selective attenuation was observed irrespective of disease severity or phenotype, namely atopy or non-atopy. Low-dose salbutamol suppresses airway responsiveness to histamine but not methacholine in subjects with asthma. The present study may provide a novel insight into the bronchoprotective mechanism of β2-adorenoceptor agonist in clinical settings.
    09/2013; 51(3):158-65. DOI:10.1016/j.resinv.2013.03.001
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    ABSTRACT: beta-Adrenoceptor agonists reportedly decrease spontaneous apoptosis of peripheral blood eosinophils; however, its signaling pathway is unknown. Survival signals can be elicited by the activation of phosphatidylinositol 3-kinase (PI3K) and Akt, both of which are known to be potent regulators of apoptosis, and Akt in turn inactivates Forkhead transcription factors, including FKHR (Forkhead in rhabdomyosarcoma). We have investigated the effect of beta-agonists on apoptosis of local eosinophils isolated from the airways and the involvement of PI3K, Akt, and FKHR in its survival signal. Eosinophils obtained from immunized mice by bronchoalveolar lavage after allergen provocation underwent apoptosis in a time-dependent manner. Incubation of eosinophils with isoproterenol or formoterol dose-dependently inhibited both spontaneous eosinophil apoptosis and apoptosis induced by Fas receptor activation. Incubation with cAMP or forskolin also inhibited eosinophil apoptosis. The PI3K inhibitors wortmannin and LY-294002 and an Akt inhibitor, 1-L-6-hydroxymethyl-chiro-inositol 2-(R)-2-O-methyl-3-O-octadecylcarbonate, but not a mitogen-activated protein kinase kinase inhibitor PD-98059, blocked isoproterenol-mediated eosinophil survival. Wortmannin also inhibited cAMP-mediated eosinophil survival. Isoproterenol rapidly induced phosphorylation of Akt and FKHR in eosinophils in a PI3K-dependent manner. These findings indicate that the PI3K-Akt-FKHR pathway conveys a critical survival signal induced by beta-agonists in airway eosinophils.
    AJP Lung Cellular and Molecular Physiology 06/2005; 288(5):L860-7. DOI:10.1152/ajplung.00131.2004
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    ABSTRACT: Inhaled steroids are currently the most important drugs for asthma patients, but compliance tends to be low. Compliance could be improved by reducing the number of daily administrations. In the present study, we compared once- and twice-daily administration of fluticasone propionate (FP) to determine the differences in efficacy. Subjects were 40 patients diagnosed with bronchial asthma with stable symptoms and pulmonary functions who were on twice-daily FP administration of 100 microg. There were 14 men and 26 women ranging from 29 to 72 years of age. After a 4-week observation period, subjects were randomized into two administration groups by the envelope method and followed for 8 weeks: group A, once-daily administration (200 microg of FP at night), and group B, twice-daily administration (100 microg of FP in the morning and at night). Clinical symptoms, pulmonary functions and airway responsiveness were compared between these two groups. No significant deterioration in clinical symptoms, pulmonary functions and airway responsiveness were observed in group A compared with group B. These results demonstrate that once-daily FP administration is as effective as twice-daily administration, and that it may improve the compliance for inhaled steroids.
    Respiration 01/2005; 72(5):480-5. DOI:10.1159/000087671
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    ABSTRACT: A 52-year-old man was admitted to our department because of hypercapnic respiratory failure. His illness had begun with scleritis 5 years before, followed by swelling of the fingers and auricular cartilages and saddle nose 3 years before, when a clinical diagnosis of relapsing polychondritis was made. His chest CT after intubation revealed diffuse airway narrowing with complete collapse of both main bronchi on expiration. Though his clinical status was stabilized after initiation of mechanical ventilation and pulse-dose corticosteroid treatment, he was difficult to wean from the ventilator with a conventional on-off trial. We therefore assessed the diameters of the central airways using dynamic CT under application of bilevel PAP, which confirmed an improvement in airway patency. He was then successfully weaned from artificial ventilation using bilevel PAP, initially through tracheotomy and subsequently via a nasal mask. To our knowledge, this is the first report that confirms the advantage of bilevel PAP objectively for a patient with labile airways.
    03/2004; 42(2):185-90.
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    ABSTRACT: A 56-year-old man was admitted to our hospital because of bilateral pleural effusion. Computed tomography revealed solitary mediastinal lymphadenopathy, splenomegaly and a small amount of ascites. No lung parenchymal lesion was seen. Although lymphocyte predominance without atypia and a high adenocine deaminase concentration in the pleural fluid were compatible with tuberculous pleurisy, no mycobacteria could be detected either with Ziehl-Nielsen stain or with PCR. Because the serum soluble interleukin 2 receptor (sIL-2 R) level was unexpectedly high (> 8,000 U/ml), and a level not previously reported in benign diseases, we performed thoracoscopy- and mediastinoscopy-assisted biopsies, both of which eventually confirmed the diagnosis of tuberculosis. After a 4-drug anti-tuberculous regimen was initiated, pleural effusion and ascites subsided, with a marked decrease in the sIL-2R level. This case indicates that in tuberculous pleurisy, serum sIL-2R can rise to a level suggestive of hematological malignancies, it and also illustrates the validity of thoracoscopy-assisted pleural biopsy in such situations.
    02/2004; 42(2):191-4.
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    ABSTRACT: Interleukin (IL)-13 induces important features of bronchial asthma such as eosinophilic infiltration, airway hyperresponsiveness (AHR), and mucus hypersecretion. Although glucocorticoids suppress airway inflammation and remain the most effective therapy for asthma, the effects of glucocorticoids on the IL-13-dependent features are unknown. We studied the effects of dexamethasone on eotaxin production, eosinophil accumulation, goblet cell hyperplasia, and AHR after IL-13 administration into the airways of mice in vivo. MUC5AC gene expression, a marker of goblet cell hyperplasia, was also analyzed. IL-13 alone dose dependently induced AHR. Treatment with dexamethasone inhibited eotaxin expression and completely abolished eosinophil accumulation, but it did not affect AHR, MUC5AC overexpression, or goblet cell hyperplasia induced by IL-13. The effects of tumor necrosis factor-alpha on IL-13-induced AHR were also examined. Tumor necrosis factor-alpha did not affect AHR despite marked enhancement of eosinophil infiltration in IL-13-treated mice. These findings suggest that glucocorticoid is not sufficient to suppress IL-13-induced AHR or goblet cell hyperplasia and that eotaxin expression and eosinophilic inflammation do not have a causal relationship to the induction of AHR or goblet cell hyperplasia by IL-13. Control of steroid-resistant features induced by IL-13, including AHR and mucus production, may provide new therapeutic modalities for asthma.
    American Journal of Respiratory and Critical Care Medicine 02/2003; 167(1):50-6. DOI:10.1164/rccm.2110084
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    ABSTRACT: Because eosinophilic airway inflammation is a characteristic of bronchial asthma, the treatment of such inflammation is important in the management of this disease. Suplatast tosilate is a novel anti-asthma drug that suppresses eosinophil proliferation and infiltration through selective inhibition of Th2 cytokine synthesis. We investigated the effect of oral suplatast tosilate therapy in patients with mild and moderate asthma. Twenty-eight asthma patients were randomized into two groups with or without suplatast tosilate treatment (100 mg t.i.d. for 28 days). We examined the blood eosinophil counts, eosinophilic cationic protein level, sputum eosinophil count, exhaled nitric oxide level, and airway responsiveness before and after treatment. In patients treated with suplatast tosilate, the eosinophil count in the blood and sputum was significantly decreased after treatment, while there was no such change in the patients without suplatast treatment. The exhaled nitric oxide level and airway responsiveness (measured using an Astograph) were also decreased after treatment with suplatast tosilate, while there were no significant changes in patients without suplatast tosilate. These results strongly suggest that oral administration of suplatast tosilate suppresses airway hyperresponsiveness in asthma patients by reducing eosinophilic inflammation in the airways.
    Journal of Asthma 10/2002; 39(6):545-52. DOI:10.1081/JAS-120004925
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    ABSTRACT: We reviewed the clinical features of 5 cases of Langerhans' cell histiocytosis that had been referred because of pulmonary lesions. The most frequent symptom was persistent dry cough. Chest radiographs showed bilateral, symmetric reticulonodular infiltrates and accompanying cystic changes with an upper-field predominance. Pulmonary function testing (PFT) revealed moderate restrictive impairment in 3 patients. All the above features were in accordance with previous reports. The incidence of complications was, however, higher in the present cases than reported in the literature. Four cases were complicated with diabetes insipidus (DI), which caused polydipsia and polyuria on the initial presentation and was subsequently managed with intranasal desmopressin. In 4 cases, bone lesions were detected. A bone scintigram at 99mTc proved to be useful for surveillance. All patients had been followed up closely for longer than 2 years (median duration 2.8 years). Their clinical courses were generally stable without apparent decline in PFT, except that one patient with a psychiatric problem died from hypernatremia due to misuse of desmopressin. Immunosuppressive agents were given in only 2 patients including the one who died. Four transbronchial biopsies (TBB) were performed in 4 cases and at least 3 specimens were sampled from each. Histological diagnoses were made from TBB specimens in 3 patients, while the remaining 2 patients underwent an open lung biopsy. We conclude that TBB is acceptable as an initial diagnostic attempt. Multiple sampling may also contribute to preferable yield. Regarding patient management, we suggest that DI and bone lesions should be sought extensively as their incidence may be much higher than previously estimated.
    08/2002; 40(7):545-9.
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    ABSTRACT: Ozone induces airway hyperresponsiveness, but there is controversy about effects of ozone on smooth muscle per se. We therefore investigated effects of in vivo ozone exposure on intracellular calcium mobilization in relation to tracheal smooth muscle contractility in the guinea pig in vitro. Guinea pigs underwent ozone exposure or sham exposure (3 ppm, 2 h). Then, a tracheal smooth muscle strip was mounted in an organ bath to record isometric tension. Effects of ozone exposure on acetylcholine-induced contraction of smooth muscle were as follows. Contraction was not altered in normal Krebs solution, but was increased in Ca(2+)-free solution in ozone-exposed animals. Decline of tension on repetitive application of acetylcholine in Ca(2+)-free solution was reduced, while the tension decline rate while acetylcholine was washed out with Ca(2+)-free solution was facilitated in ozone-exposed animals. Tension decline during the continuous administration of acetylcholine in Ca(2+)-free solution was slowed. Contraction occurred more quickly in Ca(2+)-free solution in ozone-exposed animals. Results suggest that ozone has a direct action on airway smooth muscle by changing Ca(2+) mobilization; Ca(2+) refilling via a Ca(2+) pump and Ca(2+) release via Ca(2+) channels in the sarcoplasmic reticulum were increased, while Ca(2+) extrusion via the plasma membrane Ca(2+) pump was unchanged.
    Pulmonary Pharmacology &amp Therapeutics 02/2002; 15(2):111-19. DOI:10.1006/pupt.2001.0324
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    ABSTRACT: A 60-year-old asthmatic woman was admitted to our department because of bloody sputum and pneumonia. She had been treated with inhaled becromethasone dipropionate (800 micrograms/day) on an outpatient basis for 3 years. Fiberoptic bronchoscopy revealed polypoid lesions in the trachea, most of which were removed with forceps during the procedure. Numerous lymphocytes were observed in the biopsy specimen. Because immunohistochemical staining denied a monoclonal origin for the accumulated lymphocytes, the lesion was diagnosed as an inflammatory polyp. The patient was treated successfully with antibiotics for her pneumonia, and on a follow-up bronchoscopy 6 months later, only a small remnant of the lesion was noted. This is the fourth report about inflammatory polyps in asthmatics. In the previous 3 cases, however, marked eosinophil infiltration was consistently reported. The lymphocyte predominance in the present case therefore suggests a distinct etiology rather than asthmatic airway inflammation.
    12/2001; 39(11):843-6.
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    ABSTRACT: A 64-year old woman presented with an asymptomatic occlusion of the intermediate bronchus associated with a peripheral mass occupying the entire middle and lower lobes. As malignancy was suspected, inferior bilobectomy was done. There was a complete atelectasis of both lobes, with massive parenchymal necrosis. Pathological examinations suggested a tuberculous granuloma in the bronchus and parenchyma although tuberculous bacilli were not found. This case was unusual as congenital anomaly, and was suspected as bronchial tuberculosis.
    Annals of thoracic and cardiovascular surgery: official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia 11/2001; 7(5):301-3.
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    ABSTRACT: There has hitherto been no report describing idiopathic interstitial pneumonia associated with diffuse alveolar hemorrhage, but we herein report one such rare case. A 75-year-old man who had received a diagnosis of idiopathic interstitial pneumonia had been followed in our hospital since 1995, and had been treated with cyclophosphamide since September 1999. He discontinued taking cyclophosphamide without informing us, and two months later he was admitted to our hospital with deterioration of dyspnea on September 13, 2000. Since chest radiography and CT findings demonstrated alveolar infiltrates in the right middle lung field, he was treated with antibiotic agents. Although no deterioration of symptoms occurred, on September 14 he began to suffer rapidly progressive dyspnea accompanied with production of bloody sputum, which eventually developed into full-blown hemoptysis in the evening of September 15. He died of respiratory failure early the next morning. The autopsy findings demonstrated diffuse alveolar hemorrhage, diffuse alveolar damage, interstitial pneumonia, and pulmonary fibrosis.
    11/2001; 39(10):787-91.
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    ABSTRACT: A 62-year-old woman treated with pranlukast for 2 months developed interstitial pneumonitis with a high fever. A lymphocyte stimulation test was reactive to pranlukast. Her clinical symptoms improved with discontinuation of pranlukast and administration of systemic corticosteroid. To our knowledge, this is the first reported case of drug-induced lung disease involving a leukotriene. The steps that can be taken to promptly reach a diagnosis and to successfully treat this life-threatening condition are described.
    Internal Medicine 09/2001; 40(8):791-4. DOI:10.2169/internalmedicine.40.791
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    ABSTRACT: Goblet cell metaplasia is an important morphological feature in the airways of patients with chronic airway diseases; however, the precise mechanisms that cause this feature are unknown. We investigated the role of endogenous platelet-activating factor (PAF) in airway goblet cell metaplasia induced by cigarette smoke in vivo. Guinea pigs were exposed repeatedly to cigarette smoke for 14 consecutive days. The number of goblet cells in each trachea was determined with Alcian blue-periodic acid-Schiff staining. Differential cell counts and PAF levels in bronchoalveolar lavage fluid were also evaluated. Cigarette smoke exposure significantly increased the number of goblet cells. Eosinophils, neutrophils, and PAF levels in bronchoalveolar lavage fluid were also significantly increased after cigarette smoke. Treatment with a specific PAF receptor antagonist, E-6123, significantly attenuated the increases in the number of airway goblet cells, eosinophils, and neutrophils observed after cigarette smoke exposure. These results suggest that endogenous PAF may play a key role in goblet cell metaplasia induced by cigarette smoke and that potential roles exist for inhibitors of PAF receptor in the treatment of hypersecretory airway diseases.
    AJP Lung Cellular and Molecular Physiology 04/2001; 280(3):L436-41.
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    ABSTRACT: A 26-year-old nurse consulted our department because of shortness of breath, wheezing and skin eruption after eating lunch several days before. At the consultation, the symptoms had disappeared, pulmonary function showed no abnormality, and there were no abnormal findings on chest auscultation. Latex allergy was suspected because of a history of wheezing and skin eruption after wearing latex gloves and an elevated serum IgE level specific to latex antigen. After a usage test of medical latex gloves, wheezing, skin eruption, and a decrease of FEV1.0 on pulmonary function testing were observed. The case was therefore diagnosed as latex allergy with bronchial asthma. Her symptoms were not observed after polymer coated gloves were substituted. Latex allergy is apt to complicate food allergy, an initial symptom of the present case. Specific IgE for several kinds of food was also elevated.
    12/2000; 38(11):850-3.
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    ABSTRACT: Cigarette smoke exposure causes bronchoconstriction in guinea pigs by stimulating cholinergic and excitatory nonadrenergic, noncholinergic (eNANC)-nerves in vagus system. The aim of this study is to elucidate the role of hydroxyl radical (OH(-)), contained in cigarette smoke, in bronchoconstriction. Anaesthetized animals were exposed to 80 puffs of smoke for 4 min. Pretreatment with dimethylthiourea, a OH(-) scavenger, significantly inhibited cigarette smoke-induced bronchoconstriction. To investigate its site of action, effects of dimethylthiourea were examined on vagally mediated bronchcoconstriction by electrical stimulation and on the bronchoconstriction by intravenous acetylcholine and neurokinin-A. Dimethylthiourea did not inhibit bronchoconstriction evoked by vagal stimulation, acetylcholine or neurokinin-A. These results suggest that dimethylthiourea inhibits cigarette smoke-induced bronchoconstriction by scavenging the smoke-derived OH(-), but not by inhibiting airway nerve function.
    European Journal of Pharmacology 10/2000; 403(1-2):157-61. DOI:10.1016/S0014-2999(00)00511-2
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    ABSTRACT: To investigate the role of neutrophil elastase in ozone-induced airway hypersecretion, we measured goblet cell secretion by using a semiquantitative morphometric technique in guinea pigs. The magnitude of mucus discharge was estimated from the mucus score, which is inversely related to the degree of mucus discharge in histological sections of trachea stained for mucus glycoprotein with periodic acid Schiff/Alcian blue. Mucus hypersecretion of goblet cells was induced by ozone exposure and persisted for up to 5 h after exposure. Pretreatment with N-[2-¿4-(2,2-dimethyl-propionyloxy) phenyl-sulfonylamino¿ benzoyl] aminoacetic acid (ONO-5046), a specific neutrophil elastase inhibitor (200 mg/kg, intraperitoneally), significantly inhibited goblet cell hypersecretion both just after and 5 h after ozone-exposure, but the latter inhibition was not complete. In bronchoalveolar lavage fluid, ozone exposure significantly increased the number of neutrophils just after and 5 h after exposure, while ONO-5046 significantly inhibited the increase in neutrophils only 5 h after ozone-exposure. These results indicate that neutrophil elastase may play an important role in the ozone-induced tracheal goblet cell hypersecretion and influx of neutrophils.
    European Journal of Pharmacology 03/2000; 390(1-2):197-202. DOI:10.1016/S0014-2999(99)00921-8
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    ABSTRACT: Ozone-induced airway hyperresponsiveness occurs concurrently with neutrophilic inflammation and epithelial injury in various species including humans. The mechanism of neutrophil-induced airway hyperresponsiveness, however, has not yet been fully clarified. Neutrophil elastase (NE) is a multipotent protease released from activated neutrophils, which may play a role in ozone-induced airway hyperresponsiveness. In order to address this issue, the effects of ONO-5046, a specific NE inhibitor, were investigated in ozone-exposed guinea-pigs. Awake animals were exposed to ozone at 3 parts per million for 2 h, airway responsiveness to acetylcholine (ACh) measured and examination of bronchoalveolar lavage fluid (BALF) performed. Ozone exposure increased airway responsiveness to both inhaled and intravenous ACh, the concentration of NE in BALF and the number of neutrophils and airway epithelial cells in BALF. Although pretreatment with ONO-5046 (200 mg x kg(-1), i.p.) had no effect on these changes immediately after the exposure, it significantly inhibited airway hyperresponsiveness to inhaled ACh, whilst decreasing the number of neutrophils and epithelial cells in BALF 3-5 h after the exposure. In contrast, ONO-5046 showed no significant effect on airway hyperresponsiveness to intravenous ACh at any time. These results suggest that neutrophil elastase contributes to ozone-induced airway hyperresponsiveness developing during the hours after exposure, presumably by means of inducing epithelial injury.
    European Respiratory Journal 12/1999; 14(5):1088-94. DOI:10.1183/09031936.99.14510889
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    ABSTRACT: A 48-year-old man was admitted to our hospital because of shortness of breath and abnormal shadows on chest roentgenograms. Although he had been given a diagnosis of ankylosing spondylitis (AS) at the onset of his symptoms, a diagnosis of diffuse idiopathic skeletal hyperostosis (DISH) was made by our orthopedics department on the basis of bone X-ray findings. Spirograms demonstrated a restrictive pattern and residual volume was increased. Total lung capacity and respiratory muscle function were normal, suggesting that the abnormal spirogram findings were due to decreased thoracic cage compliance. Chest roentgenograms and computed tomographic scans showed apical fibrobullous changes in both lungs, similar to those observed in AS. To our knowledge, this is the first case of DISH with pulmonary involvement to be reported to date. The pulmonary manifestations were similar to those of AS, and it was speculated that they were due to limitation of the thoracic cage.
    11/1999; 37(10):823-8.

Publication Stats

750 Citations
173.05 Total Impact Points


  • 1994–2013
    • Kyushu University
      • • Graduate School of Medical Sciences
      • • Research Institute for Diseases of the Chest
      Hukuoka, Fukuoka, Japan
  • 1996–1999
    • Imperial College London
      Londinium, England, United Kingdom
  • 1996–1997
    • National Heart, Lung, and Blood Institute
      Maryland, United States