Role of autonomic nervous system and the cough reflex in the increased responsiveness of airways in patients with obstructive airway disease.

Inhalation of aerosols of citric acid, histamine phosphate, or carbon dust, or air cooled to - 20 degrees C or rapid respiratory maneuvers (inspiration or expiration) results in an increase in airway resistance in some patients with asthma or bronchitis. It has been shown previously in animals that stimulation of cough receptors results in bronchoconstriction through efferent cholinergic pathways. In the patients studied, the administration of atropine sulfate, which would block such pathways, abolished the bronchoconstrictor effects of all the stimuli except large doses of histamine, which may exert a direct effect on airway smooth muscle. These data suggest that sensitized cough receptors may be involved in triggering reflex airway constriction in such patients.

Aryl hydrocarbon hydroxylase induction levels in patients with malignant tumors associated with smoking.

The levels of aryl hydrocarbon hydroxylase (AHH) inducibility were assessed in 173 patients with cancers statistically associated with smoking, i.e., squamous cell and transitional cell carcinomas, at various sites. In 34 patients with carcinomas of the oral cavity, 41 patients with laryngeal carcinomas, and 22 patients with pulmonary carcinomas there was a highly significant overrepresentation of high inducers, whereas 30 patients with carcinomas of the renal pelvis and ureter and 46 patients with urinary bladder carcinomas did not differ significantly in this respect from a control population comprising 92 subjects with no history of neoplastic disease. The results add further support to the concept of AHH as a major activator of carcinogens belonging to the group of polycyclic aromatic hydrocarbons (PAH) when these affect the oral cavity and/or the respiratory tract. The role of AHH in urothelial carcinogenesis seems to be less explicit.

Climate and environment change in patients with chronic airway obstruction.

Psychological, clinical, and pulmonary physiological measurements were studied in ten patients with weather-sensitive chronic airway obstruction during one month in Gothenburg, Sweden, and immediately after for one month in the Canary Islands, a change to a drier and warmer climate. All patients improved according to psychological tests and claimed to be better. Objective measurements including peak expiratory flow rate, airway conductance, static lung volumes, and elastic lung recoil showed improvement in eight of ten patients, a change that we believe is due to the effect of climate.

Clinical implications of bronchial hyperreactivity.

Bronchial hyperreactivity may be a primary internal factor needed for the occurrence of asthmatic symptoms when the atopic individual meets with allergens or the non-atopic individual inhales irritants causing inflammatory reactions in the bronchial tree. It can also be a secondary expression of allergy and occupational exposures. The hyperreactivity can be affected by treatment and is therefore a valuable tool to judge experimental studies of background and predictive factors, for follow up of specified airways disease and for treatment and drug effects. It is necessary to collect sufficient background factors and to use proper dose-response studies. We still lack knowledge as to why presumed normal subjects react, is it due to undetected small airways disease? Do we need to measure both sensitivity (as threshold values) and reactivity (as dose response-curves) in all kinds of tests of bronchial reactivity? We need simple ways to test larger populations in prospective studies of workers exposed to occupational irritants in order to solve the problems of primary versus secondary, acquired hyperreactivity.

Non-specific bronchial hyperreactivity: correlation to asthma and modifying factors.

Bronchial hyperreactivity can be induced and modified by allergic and non-allergic factors affecting the airways. Bronchospasm can also be induced by small amounts of many of these agents and by other factors as well. Allergic and non-allergic subjects can be affected. Bronchial obstruction in asthma due to allergic reactions is to a large extent dependent on the degree of nonspecific bronchial reactivity. This can be influenced by different modes of treatment.