Involvement of nitric oxide (NO) in cough reflex sensitivity between non-sensitized and OVA-sensitized guinea pigs

Background: Exhaled nitric oxide (ENO) is elevated in bronchial asthma patients, and inhaled corticosteroid therapy lowers the elevated ENO levels in such patients. ENO appears to be an inflammatory marker, but its role in the pathophysiology of cough remains unclear. This study aimed to elucidate the relationship between NO and increased cough reflex sensitivity induced by allergic airway reactions.Methods: Cough reflex sensitivity to inhaled capsaicin was observed under NO depletion caused by NO synthase (NOS) inhibitors in non-sensitized and ovalbumin (OVA)-sensitized guinea pigs. The bronchoalveolar lavage fluid (BALF) was analyzed in an NO depletion setting using the inducible NOS (iNOS) inhibitor ONO1714 in OVA-sensitized guinea pigs.Results: NO depletion by the non-selective NOS inhibitor L-NAME suppressed cough reflex sensitivity in non-sensitized guinea pigs and OVA-induced increase in cough reflex sensitivity in sensitized guinea pigs; however, iNOS inhibition caused by ONO1714 partially suppressed the OVA-induced increase in cough reflex sensitivity, but not the normal cough response in non-sensitized guinea pigs. ONO1714 did not change BAL cell components in OVA-sensitized guinea pigs.Conclusions: The results suggest that NO may be involved not only in the normal cough reflex circuit, but also in the OVA-induced increase in cough reflex sensitivity, possibly via a different mechanism of action. Further studies are needed to clarify the precise mechanism. © 2011 Hori et al; licensee BioMed Central Ltd

Effects of macrolides on antigen-induced increases in cough reflex sensitivity in guinea pigs

金沢大学医薬保健研究域医学系Background: Macrolides are antibiotics that have anti-inflammatory activities. Hence, they are used for both acute and chronic inflammatory airway diseases. However, the effects of these agents on allergic airway disorders presenting with an isolated chronic cough, such as non-asthmatic eosinophilic bronchitis and eosinophilic tracheobronchitis with cough hypersensitivity (atopic cough), still remain to be elucidated. Objective: To determine if macrolides are effective in the management of chronic cough caused by eosinophilic airway inflammation. Methods: The cough reflex sensitivity to inhaled capsaicin was measured at 48 h after challenge with an aerosolized antigen in actively sensitized guinea pigs. The 14-, 15- or 16-membered macrolides (erythromycin, azythromycin, or josamycin, respectively) were given intraperitoneally every 12 h after the antigen challenge. Bronchoalveolar lavage and the resection of the tracheal tissue were performed immediately after the measurement of the cough response to capsaicin. Results: The antigen-induced increase in the number of coughs elicited by capsaicin inhalation was significantly reduced by treatments with erythromycin and azythromycin, but not with josamycin. Erythromycin dose-dependently inhibited the increases in the substance P, prostaglandin E2 and leukotriene B4 levels, but not the histamine levels, in the bronchoalveolar lavage fluid. However, erythromycin did not influence the antigen-induced decrease in the neutral endopeptidase (NEP) activity in the tracheal tissue. Conclusions: Both 14- and 15-membered, but not 16-membered, macrolides could reduce the antigen-induced cough reflex hypersensitivity by inhibiting the antigen-induced release of the afferent sensory nerve sensitizers. These macrolides may be therapeutically useful for the treatment of isolated chronic cough based on cough reflex hypersensitivity in allergic airway diseases such as non-asthmatic eosinophilic bronchitis and atopic cough. © 2009 Elsevier Ltd. All rights reserved

Asthma exacerbations after the East Japan Disaster

On March 11, 2011, a 9.0-magnitude earthquake struck east Japan, following tsunami. Many people are forced to live in evacuation shelters without enough life-saving drugs. Asthma control for management of health crisis is required, because asthma exacerbation is a major cause of morbidity, can need acute care and results in death. However, it remains obscure what parameter should be used in primary clinic of evacuation shelters. The objective of this study is to elucidate the practical efficacy of asthma assessment tool in primary clinic for victims of this disaster. Asthma control test (ACT), a brief and patient-based tool to evaluate asthma control, was conducted for 17 patients with asthma in evacuation shelters at Tohoku district. Total sum of ACT scores were significantly decreased after this disaster. Significant decreases were observed for the items ; “Asthma keeps you from getting much done at work”, “Shortness of breath”, “Asthma symptoms wake you up” and “Patient rating of control”. ACT, an easy and practicable tool, clearly demonstrated the asthma exacerbation in evacuation shelters without the use of lung function testing. ACT may contribute to the management of health crisis not only for this East Japan disaster but also for the other forthcoming unavoidable disasters

Exhaled nitric oxide levels in patients with atopic cough and cough variant asthma

金沢大学大学院医薬保健研究域医学系Background and objective: Atopic cough (AC) is an established clinical entity in Japan, in which patients present with a chronic persistent non-productive cough. Exhaled nitric oxide (NO) is a biomarker of eosinophilic airway inflammation. The present study examined whether exhaled NO levels were increased in AC in comparison with cough variant asthma (CVA) and bronchial asthma (BA). Methods: Consecutive patients presenting with an isolated cough lasting at least 8 weeks were enrolled in the study. The aetiology of the chronic cough was determined according to the Japanese Respiratory Society guidelines for management of cough. Exhaled NO, capsaicin cough sensitivity (capsaicin concentration eliciting five or more coughs (C5)) and bronchial reversibility were measured at the patients\u27 first visit. Bronchial responsiveness (PC20 to methacholine) was measured at their second visit following a 6-day course of bronchodilator therapy. Results: There were 58 patients recruited and fully investigated; of these 9 and 11 patients were diagnosed with AC and CVA, respectively, as single causes of chronic cough. Ten patients with BA who had not received corticosteroid therapy in the previous 4 weeks and who attended the same clinic in the same time period acted as controls. Exhaled NO levels in patients with AC were significantly lower than those in patients with CVA and BA. There was no significant difference in the exhaled NO levels between patients with CVA and BA. Conclusions: Exhaled NO may reflect eosinophilic inflammation of peripheral airways and its measurement may be useful in differentiating CVA from AC and other causes of chronic non-productive cough. © 2008 The Authors

Bronchial thermoplasty for severe asthma

Despite the relatively short follow-up period in our previous study, we had reported that increased cough reflex sensitivity (CRS) may predict the efficacy of bronchial thermoplasty (BT) for treating asthma. Herein, we examined whether CRS predicts the efficacy of BT 2 years after the final BT treatment. We also investigated the influence of BT on CRS. We reviewed 10 patients 2 years after their final BT treatment. CRS, asthma-related symptoms, asthma exacerbations, and cough-related quality of life were assessed at baseline and 2 years after BT. Five patients responded positively to BT (BT responders) and their asthma control improved. No significant difference in CRS at baseline was detected between the BT responders and nonresponders. In contrast, BT responders exhibited significant improvements in CRS 2 years after BT. CRS at baseline could not predict the BT efficacy after 2 years. This is the first report demonstrating BT desensitized CRS in consecutive case series

N-Propionyl-Cysteaminylphenol-Magnetite Conjugate (NPrCAP/M) Is a Nanoparticle for the Targeted Growth Suppression of Melanoma Cells

A magnetite nanoparticle, NPrCAP/M, was produced for intracellular hyperthermia treatment of melanoma by conjugating N-propionyl-cysteaminylphenol (NPrCAP) with magnetite and used for the study of selective targeting and degradation of melanoma cells. NPrCAP/M, like NPrCAP, was integrated as a substrate in the oxidative reaction by mushroom tyrosinase. Melanoma, but not non-melanoma, cells incorporated larger amounts of iron than magnetite from NPrCAP/M. When mice bearing a B16F1 melanoma and a lymphoma on opposite flanks were given NPrCAP/M, iron was observed only in B16F1 melanoma cells and iron particles (NPrCAP/M) were identified within late-stage melanosomes by electron microscopy. When cells were treated with NPrCAP/M or magnetite and heated to 43°C by an external alternating magnetic field (AMF), melanoma cells were degraded 1.7- to 5.4-fold more significantly by NPrCAP/M than by magnetite. Growth of transplanted B16 melanoma was suppressed effectively by NPrCAP/M-mediated hyperthermia, suggesting a clinical application of NPrCAP/M to lesional therapy for melanoma. Finally, melanoma cells treated with NPrCAP/M plus AMF showed little sub-G1 fraction and no caspase 3 activation, suggesting that the NPrCAP/M-mediated hyperthermia induced non-apoptotic cell death. These results suggest that NPrCAP/M may be useful in targeted therapy for melanoma by inducing non-apoptotic cell death after appropriate heating by the AMF

Asthma-COPD overlap : prevalence and features

Background Asthma-COPD overlap (ACO) is a disease that shares clinical features of both asthma and COPD. The purpose of this study is to investigate the prevalence and clinical features of ACO. Methods We retrospectively reviewed data for 170 patients with persistent airflow limitation and diagnosed them according to “The Japanese Respiratory Society Guidelines for the Management of ACO 2018”. Results Of the 170 patients, 111 were diagnosed as follows : COPD (74 patients, 66.6%), ACO (34 patients, 30.6%), and asthma (3 patients, 2.8%). There was no significant difference in clinical features between ACO and COPD patients. The following pulmonary function tests were significantly lower in ACO than in COPD patients : forced expiratory volume in 1 second/forced vital capacity, peak expiratory flow, maximal mid-expiratory flow, and the maximum expiratory flow at 50% and 75%. The following respiratory impedance parameters were significantly higher in ACO than in COPD patients : respiratory resistance (Rrs) at 5 Hz (R5), Rrsat 20 Hz (R20), R5-R20, and low-frequency reactance area. Conclusions About 30% of patients with persistent airflow limitation were diagnosed with ACO. ACO patients had lower lung function and higher respiratory impedance compared with COPD patients