N Hirata

Kumamoto University, Kumamoto-shi, Kumamoto Prefecture, Japan

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Publications (12)39.41 Total impact

  • Article: Human bronchial intraepithelial T cells produce interferon-gamma and stimulate epithelial cells.
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    ABSTRACT: Intraepithelial lymphocytes (IELs) can be identified among epithelial cells in systemic mucosal tissues. Although intestinal IELs play a crucial role in mucosal immunity, their bronchial counterparts have not been well studied. The purpose of this study was to determine the immunological functions of human bronchial IELs, which interact directly with epithelial cells, unlike lamina propria lymphocytes (LPLs). We isolated successfully bronchial IELs and LPLs using a magnetic cell separation system from the T cell suspensions extracted from bronchial specimens far from the tumours of resected lungs. Human bronchial IELs showed an apparent type 1 cytokine profile and proliferated more actively in response to CD2 signalling than did bronchial LPLs. CD8(+) IELs were identified as the most significant sources of interferon (IFN)-gamma. Human bronchial epithelial cells constitutively produced the T cell growth factors interleukin (IL)-7 and IL-15, and levels of those factors increased when cells were stimulated by IFN-gamma. Bronchial epithelial cells expressed cell surface proteins CD58 and E-cadherin, possibly enabling adhesion to IELs. In summary, human bronchial IELs have immunological functions distinct from bronchial LPLs and may interact with epithelial cells to maintain mucosal homeostasis.
    Clinical & Experimental Immunology 12/2008; 155(2):266-74. · 3.36 Impact Factor
  • Article: The role of substance P release in the lung with esophageal acid.
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    ABSTRACT: To investigate whether tachykinins are released in the airways by stimulating the esophagus, airway plasma extravasation induced by intraesophageal hydrochloric acid (HCl) in the presence or absence of the neutral endopeptidase (NEP) inhibitor phosphoramidon and the neurokinin-1-receptor antagonist FK888 was studied in anesthetized guinea pigs. Airway plasma extravasation also was studied in the presence of the NEP inhibitor in guinea pigs pretreated with capsaicin or bilateral vagotomy. Propranolol and atropine were used in all animals to block adrenergic and cholinergic nerve effects. Airway plasma leakage was evaluated by measuring extravasated Evans blue dye. One normal HCl infusion into the esophagus significantly increased plasma extravasation in the trachea. Phosphoramidon significantly potentiated plasma extravasation induced by HCl infusion into the esophagus in the trachea and main bronchi, and FK888 significantly inhibited extravasation in a dose-related manner. In capsaicin-treated animals, airway plasma extravasation was completely inhibited even in the presence of phosphoramidon. Tracheal plasma extravasation potentiated by phosphoramidon was significantly inhibited in the bilaterally vagotomized animals. These results suggest that locally acting substances are released by intraesophageal HCl stimulation that cause airway plasma extravasation. These substances are generated through activation of neural pathways, including some that traffic through the vagus nerves that link the esophagus or airways.
    The American Journal of Medicine 01/2002; 111 Suppl 8A:25S-30S. · 5.43 Impact Factor
  • Article: [Prevalence of asthma in adults in Menda town rural-mountain area in Japan].
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    ABSTRACT: Several reports have suggested that the prevalence of asthma in adults is currently increasing. However, recent prevalence of asthma has not reported in Japan, especially in rural-mountain areas. To investigate the prevalence of asthma in adults in Japan, we conducted clinical epidemiological research on 5066 inhabitants of Menda town, in a rural-mountain area of Japan. The study population comprised 98.7% of adults in the town, including senior high school students whose age were more than 15 years old. The prevalence of asthma among adults was 3.6%. The ratio of prevalence in males to prevalence in females was 1.44. Peaks prevalences were observed in the age ranges of 15-19 and > 70 years old in males, and 15-19, 40-49 and > 70 years old in females.
    Arerugī = [Allergy] 12/2001; 50(12):1163-70.
  • Article: Dyspnoea and hyperventilation induced by synthetic progesterone chlorpromadinone acetate for the treatment of prostatic hypertrophy.
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    ABSTRACT: We describe a 74-year-old patient with dyspnoea and tachypnoea induced by chlorpromadinone acetate, a synthetic progesterone used to treat prostatic hyperplasia. The dyspnoea, tachypnoea and hypocapnia improved after discontinuing the chlorpromadinone acetate. It is important to recognize that synthetic progesterones can cause dyspnoea and hyperventilation.
    Respirology 10/2001; 6(3):265-7. · 2.42 Impact Factor
  • Article: Human bronchial intraepithelial T lymphocytes as a distinct T-cell subset: their long-term survival in SCID-Hu chimeras.
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    ABSTRACT: Intestinal intraepithelial T lymphocytes (i-IELs) show features different from those of conventional T cells and play specific roles in the mucosal immunity. To investigate whether human bronchial intraepithelial T lymphocytes (IELs) are a distinct entity, we examined T cells in human bronchial xenografts transplanted on mice with severe combined immune deficiency (SCID). We transplanted human bronchi subcutaneously into mice with SCID, resected the xenografts after various incubation periods (7-174 d), and examined them for CD3(+), CD4(+), CD8(+), and CD45(+) cells by immunohistochemistry. The number of CD3(+) cells in the lamina propria decreased significantly in the first month (from 308.7 +/- 60.2 to 70.9 +/- 49. 4/mm(2); P < 0.05), and xenografts more than 5 mo of age had scant T cells in the lamina propria (5.2 +/- 2.0/mm(2)). However, there was no significant difference between the number of CD3(+) IELs in freshly isolated bronchi and in xenografts maintained for more than 5 mo. In freshly isolated bronchi, the number of CD4(+) IELs was significantly lower than that of CD8(+) cells (2.35 +/- 0.62 versus 4.56 +/- 1.32/mm basement membrane; P < 0.01). After transplantation, the mean CD4-to-CD8 ratio of all xenografts was significantly higher than that of freshly isolated bronchi (5.2 +/- 0.9 versus 0.6 +/- 0.2; P < 0.005). The IELs were positive for CD45, which is specific for human leukocytes, and they were eliminated by irradiation before the transplantation. Almost all IELs (99.5%) in the xenografts expressed alphabeta T-cell receptor, and 35.8% of IELs expressed alpha(e)beta7 integrin. Bronchial epithelial cells in the xenografts expressed interleukin (IL)-7, stem cell factor, intercellular adhesion molecule (ICAM)-1, and human leukocyte antigen-DR (HLA-DR). We conclude that in the SCID-Hu chimera model, human bronchial IELs survive for more than 5 mo, unlike the T cells in the lamina propria, and we suggest that human bronchial IELs may be stimulated by bronchial epithelial cells expressing IL-7, stem cell factor, ICAM-1, and HLA-DR.
    American Journal of Respiratory Cell and Molecular Biology 04/2000; 22(4):405-11. · 5.13 Impact Factor
  • Article: The role of cysteinyl leukotrienes in the pathogenesis of asthma: clinical study of leukotriene antagonist pranlukast for 1 year in moderate and severe asthma.
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    ABSTRACT: Clinical studies have shown that pranlukast (Ono Pharmaceutical Co., Osaka, Japan) is effective for mild and moderate asthma. However, it is not well known that pranlukast is also effective on moderate and severe persistent asthma in the long term. We studied the effect of pranlukast on moderate and severe asthmatics by evaluating the change of peak expiratory flow (PEF) and therapeutic scores for 1 year before and during pranlukast therapy. We gave pranlukast 225 mg twice daily orally to 25 patients who were receiving more than 400 micrograms/day beclomethasone inhalation and beta 2 stimulant inhalation with or without oral corticosteroid. Pranlukast increased PEF more than 10 L/min in 14 patients in the first 4 weeks. In these 14 patients, 10 patients continued to monitor PEF and kept asthma diaries for 1 year. We compared the data for 1 year before and during the pranlukast therapy. During the pranlukast therapy, PEF significantly increased, puffs of beta 2 stimulant inhalation significantly decreased. The incidence of oral corticosteroid rescue therapy reduced, and the mean daily dose of oral corticosteroid decreased; however, they were not statistically significant. During treatment with pranlukast, no side effect was observed. From these results, we suggest that pranlukast is effective for more than half of the moderate and severe persistent asthmatics, and that the effectiveness continues for more than 1 year.
    Respirology 10/1999; 4(3):319-23. · 2.42 Impact Factor
  • Article: Allergen exposure induces the expression of endothelial adhesion molecules in passively sensitized human bronchus: time course and the role of cytokines.
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    ABSTRACT: To study the mechanisms contributing to the recruitment of a selective leukocyte subset in allergic inflammation involving the airways as may occur in asthma, we examined whether allergic exposure induces the expression of cell adhesion molecules (CAMs) on the bronchial endothelium of passively sensitized human bronchi. Human bronchial tissue obtained from patients undergoing lung cancer surgery was passively sensitized with serum from patients with atopic asthma who were sensitive to house dust mite. We incubated the tissues for 30, 120, 240, and 480 min in the presence or absence of the dust mite allergen. The tissues were stained immunohistochemically for intercellular adhesion molecule 1 (ICAM-1), E-selectin, and vascular cell adhesion molecule 1 (VCAM-1). ICAM-1 was constitutively expressed in both the epithelium and endothelium in all tissues but after allergen stimulation significantly increased at 240 and 480 min. E-selectin expression also existed constitutively and increased significantly at 120 and 240 min with allergen exposure. The constitutive expression of VCAM-1 was less than that of ICAM-1 and E-selectin. Following allergen exposure, VCAM-1 expression increased significantly at 30, 120, 240, and 480 min, and at 480 min reached an almost 3.5-fold increase from baseline expression. The TNF-alpha level in the supernatants significantly increased at 120 min after allergen stimulation, and the interleukin (IL)-1beta level increased in 4 of 15 samples. We also examined the induction of CAMs by TNF-alpha, IL-1beta, and IL-4 on human bronchial tissue. TNF-alpha and IL-1beta increased the expression of ICAM-1, E-selectin, and VCAM-1, whereas IL-4 induced only that of VCAM-1. In addition, neutralizing antibody against TNF-alpha and IL-1beta partially blocked the upregulation of CAMs on passively sensitized bronchial tissue after allergen exposure. Thus, both an IgE-dependent allergic response and selected cytokines are able to upregulate endothelial CAMs in human bronchial tissue. These observations provide further evidence that leukocyte infiltration into the site of allergic inflammation as occurs in atopic asthma is in part regulated by the expression of ICAM-1, VCAM-1, and E-selectin.
    American Journal of Respiratory Cell and Molecular Biology 02/1998; 18(1):12-20. · 5.13 Impact Factor
  • Article: Novel phosphodiesterase 4 inhibitor T-440 reverses and prevents human bronchial contraction induced by allergen.
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    ABSTRACT: To study the roles of phosphodiesterase (PDE) 4 in the human airways, we examined the effect of the novel PDE4 inhibitor T-440 in the isolated human bronchus. T-440 inhibited PDE4 extracted from human bronchial smooth muscle. IC50 values for the effect of T-440, rolipram (a PDE4 inhibitor) and theophylline on PDE4 activity of the bronchial tissues were 0.08 microM, 2 microM and > 100 microM, respectively. T-440 (10(-6) M to 10(-5) M) and aminophylline (3.3 x 10(-5) M) significantly reversed the 10(-5) M histamine-induced contraction, the efficacy of 10(-6) M T-440 being almost the same as that of 3.3 x 10(-5) M aminophylline. T-440 (10(-6) M to 10(-5) M) and aminophylline (3.3 x 10(-5) M) significantly reversed the 10(-4) M ACh-induced contraction. But their reversal effects on the ACh-induced contraction were weaker than those on the histamine-induced contraction. T-440 (10(-5) M) significantly reversed the contraction induced by allergen in passively sensitized bronchi. The efficacy of the reversal effect of T-440 (10(-5) M) was significantly higher than that of aminophylline (10(-5) M). T-440 and aminophylline significantly relaxed the basal tension, but pretreatment with T-440 or aminophylline did not significantly prevent histamine- or ACh-induced contraction. In contrast, both T-440 (10(-5) M) and aminophylline (3.3 x 10(-5) M) prevented the contraction induced by allergen, which suggests that PDE4 inhibitor inhibits the release of chemical mediators probably from bronchial mast cells in the allergic response. T-440 (10(-6) M to 10(-5) M) caused the accumulation of cAMP at the concentration that relaxed histamine-induced contraction. Thus selective PDE4 inhibitor is a candidate for the treatment of asthma.
    Journal of Pharmacology and Experimental Therapeutics 01/1998; 284(1):162-9. · 3.83 Impact Factor
  • Article: Esophageal stimulation by hydrochloric acid causes neurogenic inflammation in the airways in guinea pigs.
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    ABSTRACT: To investigate whether tachykinins are released in the airways in response to stimulation of the esophagus, we studied the airway plasma extravasation induced by intraesophageal HCl in the presence or absence of neutral endopeptidase inhibitor phosphoramidon and NK1-receptor antagonist FK-888 in anesthetized guinea pigs. The airway plasma leakage was evaluated by measuring extravasated Evans blue dye in the animals pretreated with propranolol and atropine. Infusion of 1 N HCl into the esophagus significantly increased plasma extravasation in the trachea. Phosphoramidon significantly potentiated plasma extravasation in the trachea and main bronchi, whereas FK-888 significantly inhibited that extravasation in a dose-related manner. In the capsaicin-treated animals, airway plasma extravasation was completely inhibited even in the presence of phosphoramidon. Tracheal plasma extravasation potentiated by phosphoramidon was significantly inhibited in the bilateral vagotomized animals. These results suggest that 1) tachykinin-like substances are released to cause plasma extravasation in the airways as a result of intraesophageal HCl stimulation and 2) there are neural pathways communicating between the esophagus and airways, including the vagus nerve.
    Journal of Applied Physiology 04/1997; 82(3):738-45. · 3.75 Impact Factor
  • Article: Tachykinin antagonist FK224 inhibits neurokinin A-, substance P- and capsaicin-induced human bronchial contraction.
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    ABSTRACT: To determine the roles of endogenously released tachykinins (substance P [SP] and neurokinin A [NKA]) in the human bronchial tissues, we studied the effects of tachykinin antagonist FK224 on bronchial smooth muscle contraction induced by SP, NKA and capsaicin in an organ bath. FK224 (10(-6) M and 10(-5) M, respectively) significantly inhibited NKA-induced contraction and 10(-5) M FK224 shifted the dose-response curve to more than one log unit higher concentration. Because SP- and capsaicin-induced contractions were small, we pretreated the tissues with the neutral endopeptidase inhibitor phosphoramidon (10(-5) M), which inhibits degradation of exogenous tachykinins in order to potentiate the contractions. FK224 (10(-5) M) significantly inhibited SP-induced contraction and it shifted the dose-response curves to about one log unit higher concentration. FK224 (10(-5) M) also significantly inhibited capsaicin-induced contraction and it shifted the dose-response curves to more than one log unit higher concentration. In contrast, FK224 (10(-5) M) did not affect on acetylcholine-, histamine-, and leukotriene D4-induced contraction. These results suggest that FK224 is a tachykinin receptor antagonist in the human bronchial smooth muscle, and that capsaicin-induced contraction is due to endogenously released tachykinin-like substances in the human bronchus.
    Fundamental and Clinical Pharmacology 02/1997; 11(3):260-6. · 1.80 Impact Factor
  • Article: Inhibitory effect of tyrosine kinase inhibitors on antigen-induced tracheal contraction and histamine release in guinea pigs.
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    ABSTRACT: We examined the effect of two different types of tyrosine kinase inhibitor, herbimycin A and genistein, on antigen-induced tracheal contraction and antigen-induced histamine release from the trachea in sensitized guinea pigs in vitro. Herbimycin A (1-10 microM) and genistein (1-10 microM) significantly inhibited antigen-induced tracheal contraction, compared with control. Additionally, herbimycin A (1-10 microM) and genistein (3-10 microM) significantly inhibited antigen-induced histamine release from the trachea in a concentration-dependent manner, compared with control. On the contrary, herbimycin A and genistein did not suppress acetylcholine- and histamine-induced tracheal contraction. We concluded that herbimycin A and genistein inhibit antigen-induced tracheal contraction without inhibiting smooth muscle contractility, and these inhibitory effects are due to, at least partially, inhibiting histamine release from tracheal mast cells.
    International Archives of Allergy and Immunology 12/1996; 111(3):291-8. · 2.40 Impact Factor
  • Article: Evidence that PGF2 alpha-induced contraction of isolated guinea pig bronchi is mediated in part by release of tachykinins.
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    ABSTRACT: To investigate whether prostaglandin F2 alpha (PGF2 alpha) stimulates the release of tachykinins and whether the tachykinins play a role in the PGF2 alpha-induced bronchial contraction, we examined the contractile response to PGF2 alpha in the presence or absence of a neutral endopeptidase (NEP) inhibitor phosphoramidon in the guinea pig main bronchus in vitro. Because NEP effectively cleaves tachykinins, we hypothesized that the inhibition of NEP would enhance a PGF2 alpha-induced bronchial contraction if PGF2 alpha stimulates the release of tachykinins. Phosphoramidon significantly enhanced the concentration-response curve to PGF2 alpha. And it also significantly enhanced 10(-5) M PGF2 alpha-induced contraction. The enhancement was significantly attenuated in tissues where the tachykinins had been depleted by treatment with capsaicin. Furthermore, the enhancement of contraction was also significantly attenuated in the presence of tachykinin antagonist FK-224 (10(-5) M). Tetrodotoxin, a sodium-channel blocker that blocks nerve conduction, did not affect the enhancement. From these results we conclude that 1) PGF2 alpha causes the release of tachykinin-like substances, 2) these substances play a role in bronchial contraction in tissues where NEP activity is inhibited, and 3) nerve conduction is not necessary for the release of these substances in the guinea pig bronchus.
    Journal of Applied Physiology 12/1995; 79(5):1411-8. · 3.75 Impact Factor