PubMed HealthSearch

Biomedical subjects

N C Thomson

Publications and source records attributed to N C Thomson.

11 recordsLinked to original sources

Asthma. Anti-inflammatory therapies.

It is likely that airway inflammation has an central role in the development and maintenance of the structural and functional abnormalities that characterise asthma. The recognition that asthma is a chronic inflammatory disorder of the airways has resulted in an increased emphasis on the use of anti-inflammatory drugs. The principal anti-inflammatory drugs are corticosteroids and to a lesser extent sodium cromoglycate and nedocromil sodium. Several other drugs and therapies may also have anti-inflammatory effects in asthma. The early use of prophylactic anti-inflammatory agents is advocated in the treatment of chronic asthma. It is hoped that this treatment scheme will result in a reduction in the morbidity and mortality from this common chronic condition.

Adult

Effect of dopamine on airways conductance in normals and extrinsic asthmatics.

1 Specific conductance was measured before and after infused and/or inhaled dopamine in nine normal subjects and twelve patients with extrinsic bronchial asthma. 2 There was no significant change in conductance in either group. 3 The alpha-adrenergic receptor antagonist thymoxamine infused in combination with dopamine had no significant effect on conductance in three asthmatics. 4 It is concluded that dopamine has no acute effect on airways resistance and that specific dopamine receptors are unlikely to exist in human airways.

Adolescent

Lymphocyte transformation in extrinsic bronchial asthma.

Lymphocytes from sixteen patients with extrinsic bronchial asthma and sixteen normals were investigated for their in vitro reactivity to stimulation with phytohaemagglutinin (PHA) and concanavalin A (Con A). No significant differences in maximum lymphocyte responses to PHA or Con A, either in the presence of foetal calf serum or autologous plasma, were found. The significance of these results in relation to T suppressor cell control of IgE formation is discussed.

Adolescent

Sodium cromoglycate and ipratropium bromide in exercise-induced asthma.

In thirteen patients with extrinsic asthma the effects of placebo, sodium cromoglycate, ipratropium bromide, and ipratropium bromide plus sodium cromoglycate were studied in a random double-blind fashion to assess their inhibitory action in exercise-induced asthma (EIA). Exercise testing consisted of steady state running on an inclined treadmill for up to eight minutes. In eight of the 13 patients studied the baseline ratio of expiratory flow at 50% vital capacity (VC) breathing helium-oxygen (V50He) to V50air was over 1.20 and they were called responders; the remaining five patients were called non-responders. There was a significantly lower baseline maximum mid-expiratory flow rate (MMEF) in non-responders (P less than 0.02) as compared to responders but no difference in forced expiratory volume in one second (FEV1) or forced vital capacity (FVC). Sodium cromoglycate (P less than 0.02), ipratropium bromide (P less than 0.01), and ipratropium bromide plus spdium cromoglycate (P less than 0.01) all significantly inhibited the percentage fall in FEV1 after exercise in the responders. Ipratropium bromide had no preventive action on non-responders, unlike sodium cromoglycate (P less than 0.05) and ipratropium bromide plus sodium cromoglycate (P less than 0.02). It is postulated that mediator release is an important factor in development of EIA in most extrinsic asthmatics, whereas cholinergic mechanisms are relevant only in those patients in whom the main site of airflow obstruction is in the large central airways.

Adolescent

Increase in peripheral blood 'null' cells in extrinsic bronchial asthma.

Lymphocyte subpopulations were measured in the peripheral blood of fifteen patients with extrinsic bronchial asthma and twenty-seven normal control subjects. No significant differences in the absolute numbers of relative proportions of T, B or K lymphocytes were found. Antibody-dependent lymphocyte-mediated cytotoxicity (K-cell activity) was also found to be normal. The proportion and absolute number of 'null' cells were significantly increased in the asthmatic group: this population did not correlate with serum IgE levels, the eosinophil count or the duration of disease. The significance of these results in relation to suppressor T-cell control of IgE formation is discussed.

Adolescent

Immunological studies in pre-eclamptic toxaemia.

Although five patients with severe pre-eclamptic toxaemia (PET) had increased anticomplementary activity in their serum, there was no evidence of complement activation in the plasma of four of the five patients. These results are not implicated in the pathogenesis of PET. No significant correlation was found between anticomplementary activity and pregnancy-associated alpha2-glycoprotein.

Antigen-Antibody Complex