Prevalence and causes of chronic cough in Japan.

BACKGROUND: Chronic cough is one of the most common symptoms of respiratory diseases and can adversely affect patients' quality of life and interfere with social activities, resulting in a significant social burden. A survey is required to elucidate the frequency and treatment effect of chronic cough. However, clinical studies that cover all of Japan have not yet been conducted. METHODS: Patients who presented with a cough that lasted longer than 8 weeks and visited the respiratory clinics or hospitals affiliated with the Japan Cough Society during the 2-year study period were registered. RESULTS: A total of 379 patients were enrolled, and those who did not meet the definition of chronic cough were excluded. A total of 334 patients were analyzed: 201 patients had a single cause, and 113 patients had two or more causes. The main causative diseases were cough variant asthma in 92 patients, sinobronchial syndrome (SBS) in 36 patients, atopic cough in 31 patients, and gastroesophageal reflux (GER)-associated cough in 10 patients. The time required to treat undiagnosed patients and those with SBS was significantly longer and the treatment success rate for GER-associated cough was considerably poor. CONCLUSIONS: We confirmed that the main causes of chronic cough were cough variant asthma, SBS, atopic cough, and their complications. We also showed that complicated GER-associated cough was more likely to become refractory. This is the first nationwide study in Japan of the causes and treatment effects of chronic cough.

Ascending speed and nocturnal activity of adult masu salmon (Oncorhynchus masou Brevoort) during upstream migration.

We released five adult masu salmon (Oncorhynchus masou) tagged with external transmitters to track their ascending behaviour. The signals of all specimens were recorded in the upper area of the river system. Two patterns of ascending behaviour were recognized: ascending upward immediately after release and ascending during increased river discharge. The fastest ascending speed was about 1000 m h-1 . Active movements were detected at night. The signal recording duration at each receiver for each fish was generally brief. Most fish did not stay at the pools where the receivers were installed.

Antitussive effects of the H1-receptor antagonist epinastine in patients with atopic cough (eosinophilic bronchitis).

Chronic cough is the only symptom of eosinophilic bronchitis (EB). There is considerable overlap between EB and atopic cough. To investigate the antitussive effects of a histamine H1-recetor antagonist, epinastine hydrochloride (epinastine, CAS 80012-43-7, Alesion; 20 mg/day, once daily), cough scores, pulmonary function, capsaicin cough threshold, and bronchial hyperresonsiveness (BHR) to methacholine (MCh) were evaluated before and after a 4-week treatment with epinastine in patients with EB. In the epinastine group, the cough scores were decreased significantly (18.3 +/- 6.1 in week 1, 17.4 +/- 6.7 in week 2, 15.1 +/- 6.2 in week 3, 14.0 +/- 4.8 in week 4) in comparison with the value of 35.3 +/- 8.7 in week -2). The cough threshold for capsaicin improved from 1.70 +/- 3.04 micromol/l to 12.7 +/- 17.6 micromol/l in the epinastine group (p < 0.05; baseline vs. week 4) The bronchial hyperresponsiveness to MCh (Dmin) did not change significantly either in the epinastine or the placebo groups. The morning and evening peak expiratory flow rate (PEFR, L/min) did not change from the baseline period in either the epinastine or the placebo groups. These results suggested that epinastine may be useful for treating patients with EB and that histamine H1-receptor is related to the pathophysiology of coughing in EB.

Characterization of the anandamide induced depolarization of guinea-pig isolated vagus nerve.

1. There is considerable interest in elucidating potential endogenously derived agonists of the vanilloid receptor and the role of anandamide in this regard has received considerable attention. In the present study, we have used an electrophysiological technique to investigate the mechanism of activation of vanilloid receptors in an isolated vagal preparation. 2. Both capsaicin and anandamide depolarized de-sheathed whole vagal nerve preparations that was antagonized by the VR1 antagonist, capsazepine (P<0.05) whilst this response was unaltered by the cannabinoid (CB1) selective antagonist SR141716A or the CB2 selective antagonist, SR144528, thereby ruling out a role for cannabinoid receptors in this response. 3. The PKC activator, phorbol-12-myristate-13-acetate (PMA) augmented depolarization to both anandamide and capsaicin and this response was significantly inhibited with the PKC inhibitor, bisindolylmaleimide (BIM) (P<0.05). 4. The role of lipoxygenase products in the depolarization to anandamide was investigated in the presence of the lipoxygenase inhibitor, 5,8,11-Eicosatriynoic acid (ETI). Depolarization to anandamide and arachidonic acid was significantly inhibited in the presence of ET1 (P<0.05). However, in the absence of calcium depolarization to anandamide was not inhibited by ETI. 5. Using confocal microscopy we have demonstrated the presence of vanilloid receptors on both neuropeptide containing nerves and nerves that did not stain for sensory neuropeptides. 6. These results demonstrate that anandamide evokes depolarization of guinea-pig vagus nerve, following activation of vanilloid receptors, a component of which involves the generation of lipoxygenase products. Furthermore, these receptors are distributed in both neuropeptide and non-neuropeptide containing nerves.

Effect of suplatast tosilate, a Th2 cytokine inhibitor, on cough variant asthma.

STUDY OBJECTIVE: Th2 cytokines play an important role in the pathogenesis of asthma. Our study objective was to determine the effect of suplatast tosilate, a Th2 cytokine inhibitor, on patients with cough-variant asthma. METHODS: Twenty patients with cough-variant asthma (CVA) were assigned to a suplatast tosilate (100 mg three times daily) group or a placebo group for 6 weeks in a double-blind randomized study. The cough scores, medication scores, pulmonary function, bronchial hyperresponsiveness to methacholine, cough threshold for capsaicin, percentage of eosinophils and concentrations of eosinophilic cationic protein (ECP) in hypertonic saline-induced (induced) sputum were evaluated. The main outcome measures were capsaicin cough threshold and concentrations of ECP in induced sputum. RESULTS: In the suplatast group, the cough scores and the medication scores decreased significantly over time. The percentage of eosinophils in induced sputum significantly decreased from 53.5+/-5.6% to 13.6+/-2.6%. The cough threshold for capsaicin improved significantly from 2.72+/-3.41 microM to 39.7+/-22.7 microM in the suplatast group. The concentrations of ECP in induced sputum decreased significantly from 435+/-123 microg/l to 56+/-34 microg/l in the suplatast group. The bronchial responsiveness to methacholine changed from 8.45+/-3.43 units to 11.4+/-3.76 units in the suplatast group. CONCLUSIONS: Suplatast improved the cough scores and the cough threshold for capsaicin in patients with CVA without significant side effects, suggesting the effectiveness of suplatast in the treatment of CVA. Suplatast also decreased the percentage of eosinophils and concentrations of ECP in induced sputum, suggesting improvement in eosinophilic inflammation in patients with CVA. Further pharmacodynamic research is needed to explain the precise mechanism.

[A case of pneumonia due to coinfection by Mycoplasma pneumoniae and Chlamydia pneumoniae].

Few cases of Mycoplasma pneumoniae and Chlamydia pneumoniae coinfection in pneumonia have been reported in adults. We report a case of such a double infection in a young adult. A 16-year-old boy was admitted to our hospital with dry cough and fever. Laboratory findings revealed elevated serum GOT and GPT levels. The patient had been administered a beta-lactam antibiotic before admission to our hospital. Antibodies to M. pneumoniae were significantly elevated. Titers of IgM and IgG specific for C. pneumoniae titer were high, as measured by the enzyme-linked immunosorbent assay method. The patient was treated with clarithromycin and discharged after a satisfactory recovery. M. pneumoniae and C. pneumoniae may act as cofactors in community-acquired pneumonia. Further studies are needed to clarify the relationships of these pathogens to community-acquired pneumonia.