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BACKGROUND: The concentration of exhaled carbon monoxide (eCO) in young children with stable asthma and during acute asthma attack is not known. METHODS: A sampling bag was developed to collect the exhaled air of preschool children. A total of 257 preschool-age children (≥ 3 years and ≤ 6 years old) were studied; 111 had a diagnosis of asthma (43 suffering a mild asthma attack and 68 without active asthmatic symptom), 99 had upper respiratory infection (URI) and 47 were healthy. RESULTS: In preschool-age children, eCO levels of those with asthma attacks (mean ± SE, 2.7 ± 0.3 p.p.m., n= 43) were significantly higher than those of subjects with asymptomatic asthma (0.5 ± 0.1 p.p.m., P < 0.05), URI (0.8 ± 0.1 p.p.m., P < 0.05) and healthy children (0.4 ± 0.1 p.p.m., P < 0.05). A multivariate linear regression model showed that eCO was higher in children with asthma attacks independent of age and gender. In 33 asthmatic children followed before and after treatment, eCO levels during asthma attacks significantly decreased after inhalation therapy with a combination of salbutamol and sodium cromoglycate (before therapy, 2.9 ± 0.4 p.p.m.; after therapy, 0.6 ± 0.1 p.p.m., P < 0.0001). CONCLUSIONS: The measurement of eCO using a novel collecting system is useful in the recognition of asthma in preschool children.

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OBJECTIVES: To investigate whether proton pump inhibitor (PPI) therapy reduces the frequency of common colds and exacerbations in patients with chronic obstructive pulmonary disease (COPD). DESIGN: Twelve-month, randomized, observer-blind, controlled trial. SETTING: A university hospital and three city hospitals in Miyagi prefecture in Japan. PARTICIPANTS: One hundred patients with COPD (mean age +/- SD 74.9 +/- 8.2) participated. They were all ex-smokers and had received conventional therapies for COPD, including smoking cessation and bronchodilators. Patients with gastroesophageal reflux disease or gastroduodenal ulcer were excluded. INTERVENTION: Patients were randomly assigned to conventional therapies (control group) or conventional therapies plus PPI (lansoprazole 15 mg/d; PPI group) and observed for 12 months. MEASUREMENTS: Frequency of common colds and COPD exacerbations. RESULTS: The number of exacerbations per person in a year in the PPI group was significantly lower than that in the control group (0.34 +/- 0.72 vs 1.18 +/- 1.40; P<.001). The adjusted odds ratio with logistic regression for having exacerbation (> or =once/year) in the PPI group compared with the control group was 0.23 (P=.004). In contrast, there was no significant difference in the numbers of common colds per person per year between the PPI group and the control group (1.22 +/- 2.09 vs 2.04 +/- 3.07; P=.12). PPI therapy significantly reduced the risk of catching frequent common colds (> or =3 times/year), the adjusted odds ratio of which was 0.28 (P=.048). CONCLUSION: In this single-blind, nonplacebo-controlled trial, lansoprazole was associated with a significant decrease in COPD exacerbations. More definitive clinical trials are warranted.

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BACKGROUND: The down-regulation of the cough reflex in patients with aspiration pneumonia can involve both cortical facilitatory pathways for cough and medullary reflex pathways. In order to study the possible involvement of the supramedullary system in the down-regulation of cough reflex, we evaluated the urge-to-cough in patients with aspiration pneumonia. METHODS: Cough reflex sensitivity and the urge-to-cough to inhaled citric acid were evaluated in patients with at least a history of aspiration pneumonia and age-matched healthy elderly people. The cough reflex sensitivities were defined as the lowest concentration of citric acid that elicited two or more coughs (C2) and five or more coughs (C5). The urge-to-cough scores at the concentration of C2 and C5, and at the concentration of two times dilution of C2 (C2/2) and C5 (C5/2) were estimated for each subject. RESULTS: Both C2 and C5 in the control subjects were significantly greater than those for patients with aspiration pneumonia. There were no significant differences in the urge-to-cough at C2 and C5 between control subjects and patients with aspiration pneumonia. However, the urge-to-cough scores at both C2/2 and C5/2 in patients with aspiration pneumonia were significantly lower than those in control subjects. The number of coughs at C5/2 was significantly greater in the control subjects than those in the patients with aspiration pneumonia whereas the number of coughs at C2/2 did not show a significant difference between the control subjects and the patients with aspiration pneumonia. CONCLUSION: The study suggests the involvement of supramedullary dysfunction in the etiology of aspiration pneumonia in the elderly. Therefore, restoration of the cough motivation system could be a new strategy to prevent aspiration pneumonia in the elderly.

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We studied the mutations induced in skin by sunlight using transgenic Muta mice. Noon sunlight during summer at Sendai, Japan induced mutations efficiently in both epidermis and dermis. The mutant frequency (MF) in epidermis reached nearly 0.5% during the first 40 min irradiation but became saturated at this level with the appearance of skin inflammation after further irradiation. At the equivalent inflammatory dose, sunlight was twice as genotoxic as 313 nm-peak UVB. The 81 mutations detected in 80 lacZ transgene mutants isolated from the sunlight-exposed epidermis were dominated by C --> T transitions (89%), occurring exclusively at dipyrimidine sites, and also included a CC --> TT tandem substitution. Thus, the sunlight-induced mutation spectrum is highly UV-specific, quite similar to that induced by UVB but significantly different from that induced by UVA. Although oxidative damage-related C --> A transversions were detected only in five mutants (6%), their frequency was elevated to at least 15 times the background level, suggesting that the contribution of UVA-mediated oxidative stress is comparatively small but considerable. An analysis of bases adjacent to the mutated cytosines revealed that the sunlight-induced mutations prefer 5'-TC-3' dipyrimidine sites to 5'-CC-3' and 5'-CT-3'. The distribution of the frequent C --> T transition sites in the transgene was well associated with the CpG motif, which is known to be completely methylated in the gene, and quite similar to that induced by UVB rather than that by UVA. Thus, the UVB component contributes to the sunlight-induced mutations in the mammalian skin much more than the UVA component, whose influence through reactive oxygen species (ROS)-mediated mutagenesis is still appreciable.

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