The aim of the present study is to investigate the correlation between microbial activity, i.e., biological stability measured by aerobic (OD(20) test) and anaerobic tests (ABP test), and odour emissions of organic fraction of municipal solid waste during anaerobic digestion in a full-scale treatment plant considering the three stages of the process (input, digested and post-digested waste). The results obtained indicated that the stabilization of the treated material reduces the odour impact measured by the olfactometric approach. Successive application of gas chromatography mass spectrometry (GC-MS) and electronic nose (EN) allowed the characterization of the different groups of volatile organic compounds (VOCs) responsible of odour impacts determining, also, their concentration. Principal component and partial least squares analyses applied to the EN and GC-MS data sets gave good regression for the OD(20) vs the EN and OD(20) vs the GC-MS data. Therefore, OD(20) reduction could be used as an odour depletion indicator.

The potential influence of dietary caffeine on bronchoprovocation challenges with carbachol was examined in 7 patients with asymptomatic asthma. In a double-blind fashion placebo or caffeine (6 mg/kg body weight; equivalent to approximately 4 cups of coffee) solved in orange juice was administered, and carbachol challenges were performed. The average peak serum concentration achieved 60 min after dosing was 7.6 +/- SD 2.1 mg/l. These caffeine levels did not produce any appreciable attenuation of the bronchoconstrictor response to carbachol inhalations. It thus appears that dietary caffeine is barely a cause of erroneous interpretations of bronchoprovocation challenges with carbachol.

In 50 patients with persistent cough suspected to be of asthmatic origin and in 16 healthy subjects, the bronchoconstrictor response to carbachol inhalation was determined by the method of Orehek. Data analysis yielded the following results: on average, the bronchial reactivity of patients was significantly higher than that of normal subjects (p less than 0.005), in healthy subjects, the spectrum of airway responsiveness showed a log-normal distribution, the patients' bronchial reactivities also showed a log-normal distribution, but with larger variance than in healthy subjects, both distributions overlapped to a considerable extent. These distribution patterns, and the difficulties in estimating the probability of errors, call for a cautious interpretation of the results of provocation testing in patients with chronic cough. Increased airway reactivity is an additional sign, rather than proof, of the asthmatic origin of chronic cough.

The case histories of more than 5000 outpatients with respiratory diseases were stored in free text from 1974 untill 1977. The retrieval efficiency was tested using STAIRS-IBM program product with the syntax operators "or", "and", "not", "with", and "adj". Chronic bronchitis in lung cancer patients was chosen as an example. The first word constellation was compiled as a retrieval argument for chronic bronchitis. The second word constellation was used as a retrieval argument for chronic bronchitis subsisting for more than 5 years before the diagnosis of lung cancer. The third word constellation retrieved documents without clear time relationship between chronic bronchitis and lung cancer. The review of each history of the 473 lung cancer patients issued a first group of 219 cases composed of lung cancer patients with histories of chronic bronchitis for more than 5 years. A second group of 180 patients had no history of preexisting chronic bronchitis. This manual selection of cases (reading of all 473 case histories) took 3 months compared to 4 h by computer dialogue selection. 87% of the first group (preexisting chronic bronchitis for more than 5 years) and 74% of the second group (no history of chronic bronchitis) were correctly obtained by the brief computer dialogue. This efficiency of the computer dialogue was further improved without difficulty by slight modifications of the dialogue strategy, so that only approximately 10% of documents remained falsely classified. It can be seen that free text analysis of case histories is possible by the STAIRS-IBM program and enables a doctor to observe new clinically important correlations in a very short time. Final deductions, however, must be followed by careful checking of all individual histories.