[Optimal time of the day for measuring peak expiratory flow rates in patients with asthma]

Regular measurement of peak expiratory flow rate (PEF) has been recommended as an aid in the management of asthma, but the time of the day when PEF should be measured remains unclear. We therefore sought to determine the optimal time for measuring PEF in untreated patients with mild to moderate asthma. PEF was measured in 11 patients four times daily: on waking, around noon, in the evening, and at bedtime. Significant (p < 0.05) rhythms were detected by single cosinor analysis in all patients. Analysis by the population mean cosinor method showed that the mesor was 381 +/- 120 l/m, the amplitude was 52 +/- 21 l/m, and the acrophase was at 16:28 +/- 0:55. These data indicate that, in general, PEF is lowest at 4:30 a.m. and highest at 4:30 p.m. in patients with mild to moderate asthma. We conclude that PEF should be measured early in the morning and at 4:30 p.m. in such patients.

[Circadian rhythms in peak expiratory flow rate of asthmatic patients before and after treatment with beclomethasone dipropionate]

Asthmatic patients have a circadian rhythm in peak expiratory flow rate (PEFR). The present study was done to measure the effect of inhaled beclomethasone dipropionate (BDP) on the circadian rhythm of PEFR in asthmatic patients. After two weeks of observation, BDP (400 micrograms) was given by metered dose inhaler to nine asthmatic patients. The dose of inhaled BDP (800-1200 micrograms) was increased every two weeks until PEFR varied by no more than 20% each day. PEFR was measured four times daily: on waking, around noon, in the evening, and at bedtime. Nine asthmatic patients had a significant (p < 0.05) rhythm detectable by single cosinor analysis, both during the observation period and during treatment. Analysis by the group mean-cosinor method showed that the mean mesor was 397.3 +/- 6.8 l/min, the mean amplitude was 54.3 +/- 7.1 l/min, and the mean acrophase was at 16:31 +/- 0.27 before treatment. After treatment, the mean mesor was 543.8 +/- 4.4 l/min, the mean amplitude was 30.5 +/- 4.9 l/minm, and the mean acrophase was at 16:25 +/- 0.31. The mean mesor had increased significantly (p < 0.05), and the mean amplitude had decreased significantly (p < 0.05) after treatment. The mean acrophase did not change. These data indicate that inhaled BDP increases PEFR at a constant acrophase in asthmatic patients.

[Dynamics of pleural liquid in hydrothorax]

The basics of pleural liquid dynamics are summarized. The normal pleural cavity contains a small amount of pleural liquid (0.1-0.3 ml/kg). Its protein concentration is about 1.0 g/dl and its pH is 7.6. The normal flow of pleural liquid is gravity dependent, and pleural liquid flows from the costal to the mediastinal region. In experimental hydrothorax, the pleural liquid was removed mainly via lymphatics. The turnover of the pleural liquid is rapid, and it depends on the area of contact between pleural liquid and pleural and on the blood flow to the pleura.

[Detection of intratumoral DNA heterogeneity in primary lung cancer using a multiple sampling method]

The nuclear DNA contents of 18 freshly resected specimens of primary lung cancer tissue were determined by flow cytometry with a multiple sampling method. A DNA aneuploidy pattern was observed in all cases. In three cases, a diploid DNA pattern was observed along with abnormal DNA stem lines. Twelve cases (66%) had two or more abnormal DNA stem lines, and were classified as DNA multiploidy. The frequencies of DNA aneuploidy and DNA multiploidy were higher than in previously reported studies. Intratumoral DNA heterogeneity was observed in 10 cases (55%). Three of these were a mixture of DNA diploidy and DNA aneuploidy, and the other seven were a mixture of DNA aneuploidy and DNA multiploidy. If multiple sampling had not been performed in these cases, their ploidy patterns would have been misinterpreted. We conclude that multiple sampling is important in determining the precise DNA ploidy patterns of primary lung cancers.

[A case of thymic cyst showing elevated CEA, SLX and CA125 levels in the cystic fluid associated with non-invasive thymoma]

A 66-year-old woman, who had complained of left ptosis and been diagnosed as having myasthenia gravis (ocular type) 9 years previously, was admitted to our hospital for further examination of an abnormal mass shadow on chest X-ray film. Chest computerized tomography (CT) revealed a cystic tumor in the anterior mediastinum and thoracotomy was performed to make a definitive diagnosis. The tumor could be removed completely and was diagnosed histologically as a thymic cyst with thymoma. The cyst was 32 x 30 x 28 mm in size and contained about 10 ml of brown turbid fluid. The levels of CEA (61.3 ng/ml), SLX (24,000 U/ml) and CA125 (1300 U/ml) were markedly increased in the cystic fluid, while those in serum were not elevated. Immunohistochemical staining demonstrated the epithelial cells lining the cyst to contain SLX. The findings suggest that SLX was produced in the epithelial cells of the cyst. However, neither CEA nor CA125 was positive in the epithelial cells. From our review of reported cases of thymic cyst showing elevated levels of tumor markers in the cystic fluid, the main mechanism of marked elevation of tumor markers seems to be condensation in the cystic fluid rather than increased production in epithelial cells lining the cyst. Cases of thymic cyst with thymoma are extremely rare, but our case was concluded to be incidentally associated with non-invasive thymoma.