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Biomedical subjects

A B Breslin

Publications and source records attributed to A B Breslin.

At least 37 records · Page 2Linked to original sources

Passive cigarette smoking and patients with asthma.

A study of the effect of passive smoking on patients with asthma is presented. Six patients were exposed for one hour to the air in a room in which tobacco smoke was produced mechanically over that period. The effects on symptoms, lung function and airways sensitivity to inhaled histamine were then measured and compared with the same patient's responses during a control day when they inhaled smoke-free air. All six patients developed chest tightness and symptoms similar to an attack of asthma. The findings of respiratory and sensitivity tests suggest: (i) that passive smoking may trigger asthma attacks in subjects who suffer from asthma and (ii) that the airways of such subjects show increased histamine reactivity four hours after the passive smoke exposure.

Adult↗

The role of alpha and beta adrenoceptors in airway hyperresponsiveness to histamine.

The effect of a specific alpha 1-adrenoceptor antagonist, prazosin, on histamine-induced bronchoconstriction was compared to a beta 2-adrenoceptor agonist, salbutamol, in 16 subjects with nonspecific bronchial hyperresponsiveness whose PC20H ranged from 0.10 to 5.12 mg/ml. PC20H was calculated from a histamine inhalation test performed before and after 0.5 mg of prazosin by dry powder inhalation and 200 mcg of salbutamol by pressurized aerosol. PC20H was also measured in six subjects before and after placebo (20 mg lactose) by dry powder inhalation in a randomized double-blind study with prazosin. Mean (+/- SE) PC20H before and after placebo was 1.77 (0.32) and 1.57 (0.38) mg/ml, respectively, an 0.89-fold change. Mean (+/- SE) PC20H before and after prazosin for the 16 subjects was 1.92 (0.34) and 3.10 (0.72) mg/ml, a 1.51-fold change (p less than 0.001), and PC20H before and after salbutamol was 2.08 (0.33) and 9.54 (2.51) mg/ml, a 4.08-fold change (p less than 0.001). There was a positive correlation between the prazosin and salbutamol responses (r = 0.55, p less than 0.05). A dose response for salbutamol was performed in eight subjects, and PC20H was determined by use of increasing doses of salbutamol until PC20H was more than 16 mg/ml. The dose of salbutamol required varied widely between subjects and did not relate to baseline PC20H. The results suggest a role for alpha-adrenoceptors in addition to beta-adrenoceptors in histamine-induced bronchoconstriction.

Adolescent↗

Experience with allergic bronchopulmonary aspergillosis: some unusual features.

The clinical and immunologic features of ten patients with allergic bronchopulmonary aspergillosis (ABPA), observed over periods varying from 12 months to 10 years, are reported. Acute attacks of ABPA were characterized by several, or all of: increased cough and sputum, haemoptysis, pleuritic pain, expectoration of sputum plugs, and increasing airways obstruction. Peripheral blood eosinophilia and acutely elevated serum IgE levels were seen in all patients during acute attacks, sputum eosinophilia and recovery of Aspergillus in sputum was less common. However, blood eosinophilia was not present in all attacks of ABPA and sputum eosinophilia varied similarly from one attack to another. Six patients with previously documented multiple precipitin lines have had no demonstrable precipitins to Aspergillus on several occasions between attacks, three of these patients have also been negative during attacks. Five of the six patients have again developed positive precipitin lines. The total number of episodes in these ten patients was fifty two, three patients have had more than nine acute attacks of ABPA. There is no seasonal variation in this group of patients. Since diagnosis, only three patients have had an attack-free interval longer than 12 months. Two patients are steroid-dependent because of severe asthma, and nine have symptoms of bronchiectasis.

Adult↗

Upper respiratory tract infections and airway reactivity in normal and asthmatic subjects.

To assess the effect of an upper respiratory tract infection (URTI) on airway reactivity, histamine inhalation tests (HITs) were performed prospectively in 44 nonsmoking asthmatic (14) and nonasthmatic (30) volunteers. Fifteen of the subjects developed an URTI during the following 4 months. Pulmonary function-forced expiratory volume in one second (FEV1), maximal midexpiratory flow rates (MMEFR) and maximal flow at 50% vital capacity (V50), and HITs, were studied at onset and 2, 3, and 4 wk after infection. There were no significant changes in pulmonary function during the total study period. For the 15 subjects, the mean provocative concentration of histamine causing a 20% fall in FEV1, (PC20H) was 8.73 mg/ml prior to onset of URTI, and at 1, 2, 3, and 4 wk after URTI was 7.97, 8.68, 8.13, and 8.61 mg/ml. These were not significantly different for the group as a whole, nor for the subgroups of asthmatics and nonasthmatics. Small changes in PC20H outside the normal range of variability occurred in 5 of 15 subjects. These were short-lived and no predictive factor for change in PC20H was identified in this group. Thus, URTI was not associated with significant changes in PC20H in this group of asthmatic and nonasthmatic subjects.

Adult↗

Asthmatic reactions to a commonly used aerosol insect killer.

Seven patients with asthma and a history of chest tightness on exposure to aerosol insecticide sprays were studied. Under controlled conditions, objective measures of airways narrowing were taken before and after exposure to an aerosol insect killer (Mortein Pressure Pak). Chest tightness described as asthma was produced in all seven subjects, but only one showed a greater than 20% fall in FEV1, compared to baseline values. A further two subjects showed small changes in the maximum mid-expiratory flow rate. No changes were observed in the subjects' sensitivity to inhaled histamine before, and 24 hours after, exposure to the insecticide. Thus, exposure to a commonly used household insecticide spray produced marked symptoms in all subjects, but objective evidence of airways obstruction was present in only three, and no changes in bronchial reactivity to inhaled histamine occurred in any of the subjects.

Adult↗

Pulmonary cryptococcosis: atypical results in the serum test for cryptococcal antigen.

Two cases of pulmonary infection with Cryptococcus neoformans are reported. In both patients the cryptococcal antigen titres remained positive following initiation of effective therapy, and despite clinical evidence of resolution of disease. The possible causes for these findings are discussed and it is suggested why this atypical serological response does not necessarily indicate dissemination or active infection.

Adult↗

Ventilatory effects of aerosol gentamicin.

Bronchial provocation tests with gentamicin solution, 40 mg/ml, and with the drug vehicle solution alone were carried out in 29 subjects aged 19 to 66 years. There were 18 subjects with bronchial asthma, four with chronic bronchitis, four with primary carcinoma of the lung, and three with no chest disease. Two millilitres of each of the two test solutions was given to each subject, in duplicate, via a nebuliser driven by a Bird Mark 8 respirator. Ventilatory function (FEV1 and VC) was measured before and after each inhalation, and changes were expressed as percentage variations from baseline. Seven subjects, all from the asthmatic group, developed at least one immediate FEV1 fall of 20% or more. The reactions ranged up to 71% and occurred to both test solutions. There was a trend towards greater reactions to the vehicle. In two subjects pretreatment with salbutamol and sodium cromoglycate did not modify these reactions. In three of the seven, inhalation of 2 ml normal saline produced FEV1 falls of 25% to 30%, but these falls were not as great as each subject's reactions to the test solutions. Skin prick tests using the gentamicin solution were negative in all subjects. These results show that substantial obstructive reactions may occur in some asthmatic subjects after inhalation of gentamicin. The reactions appear to be non-immunological in nature and may be due to an irritant effect of the drug vehicle.

Adult↗

Effect of sodium cromoglycate on asthmatic reactions to environmental temperature changes.

Immediate asthmatic reactions, with falls in FEV1 of 16-42.5% were elicited by exposure in a cold room at 3 degrees C in five out of eight subjects with histories of asthma provoked by falls in environmental temperature. In four of the subjects pretreatment by inhalation of sodium cromoglycate gave complete inhibition of the asthmatic reaction in two, partial inhibition in one and had no effect in one case.

Administration, Intranasal↗