Atypical imaging appearances of intracranial meningiomas.

Meningiomas are the commonest primary, non-glial intracranial tumours. The diagnosis is often correctly predicted from characteristic imaging appearances. This paper presents some examples of atypical imaging appearances that may cause diagnostic confusion.

Twice daily slow-release theophylline vs placebo for 'morning-dipping' in asthma.

We report the results of a double-blind control crossover trial of slow release theophylline Nuelin S.A. in improving symptoms of 'morning-dipping' in twelve asthmatic patients. Sleep disturbance was lessened and 'morning-dipping', though not abolished, was improved by 24% (P less than 0.01). Mean peak expiratory flow-rate (PEFR) on waking was significantly higher on active drug (262 l/min vs 226 l/min, P less than 0.001) as were the evening PEFRs (316 l/min vs 285 l/min, P less than 0.05). Seven of the 12 patients achieved 26% improvement in mean PEFR (P less than 0.05) with plasma theophylline levels in the range 28-44 mumol/l. The other five patients improved by 9% (P less than 0.02) with levels in the range 55-66 mumol/l. Mean plasma cyclic AMP 4-6 h after theophylline was significantly higher than with placebo (27.0 nmol/l vs 17.6 nmol/l, P less than 0.05) but significant correlations between cyclic AMP and theophylline levels, and cyclic AMP and PEFR were not demonstrated. A total of nine patients, 33% of those originally recruited for this study, withdrew prior to the double-blind phase because of unacceptable side-effects of theophylline, namely nausea and headache.

Tracheal obstruction presenting as asthma.

A case is reported in which a tracheal tumour presented with symptoms suggestive of bronchial asthma. In the assessment and management of airways obstruction and wheeze, it is important to bear in mind that disease other than asthma and chronic bronchitis may present in this way.

Inhalation challenge with specific grass pollen antigens in asthmatics and the effect of lodoxamide tromethamine.

Highly purified species-specific grass pollen antigens were used for inhalation bronchial challenge in 12 patients with atopic asthma. This was found to result in reproducible experimental asthma. Lodoxamide tromethamine was administered by inhalation in two different doses, 0.01 mg and 0.1 mg, to each patient, in double-blind, random, placebo-controlled manner, 15 minutes before pollen inhalation. It was found to have a significant protective action at both doses (p less than 0.05), but it produced troublesome side effects at the higher dose of 0.1 mg.

Serum beta-2-microglobulin and angiotensin-converting enzyme activity in sarcoidosis.

Angiotensin-converting enzyme activity in sarcoidosis is regarded both as a diagnostic feature and as an index of disease activity. Increased activity of this enzyme is thought to parallel macrophage and epithelioid cell activity. Beta-2-microglobulin, a low-molecular-weight protein associated with the histocompatibility antigens, is thought to reflect activation of immunocompetent cells, particularly lymphocytes. In 132 patients with known sarcoidosis no close association was found to exist between the results of the two assays (r = 0.53). Angiotensin-converting enzyme activity was raised in 33% and beta 2-microglobulin concentrations in 63% of patients with sarcoidosis. When analysed prospectively, the results of the two assays showed no correlation in 29 patients over periods of up to 19 months. Stage, duration of disease, and corticosteroid treatment showed no significant effect on levels of either angiotensin-converting enzyme or beta 2-microglobulin. The disparity between indices of macrophage and lymphocyte activation requires further study in sarcoidosis.

Time-dependent effect of prostaglandin E2 inhalation on airway responses to bronchoconstrictor agents in normal subjects.

Studies were performed to investigate whether hyperresponsiveness of the airways could be induced in normal subjects by inhalation of prostaglandin E2 (PGE2). During the initial bronchodilator phase of PGE2 action the bronchoconstrictor effect of inhaled histamine was significantly antagonised. When bronchoconstrictor challenges were started shortly after the end of the bronchodilator response to PGE2, however, significant enhancement of the effects of both inhaled histamine and methacholine occurred. It was predominantly sensitivity to these agents that was increased, with a parallel shift of the dose-response curves towards increased bronchoconstriction. Thus PGE2 may be protective in the acute phase of a bronchoconstrictor challenge, but in a chronic inflammatory condition its net effect may be a balance between this beneficial action and a non-specific potentiation of the activity of bronchoconstrictor agents.

Induction of bronchial hypersensitivity: evidence for a role for prostaglandins.

Bronchial hyper-responsiveness is a particular feature of asthma, but also occurs in normal subjects after a viral upper respiratory tract infection or ozone inhalation. Such stimuli would be expected to result in the release of chemical mediators of inflammation. In this study, the effects of one of these, prostaglandin F2 alpha (PGF2 alpha), on the response of normal subjects to inhaled histamine has been investigated. Nine normal volunteers took 10 inhalations of increasing concentrations of PGF2 alpha at 15-minute intervals from a Wright's nebuliser under standard conditions until a change in sGaw could be detected. The next lowest serial dilution of PGF2 alpha was subsequently inhaled by each subject every 15 min for 90 min to ensure the absence of a cumulative effect. Inhalation dose-response curves to histamine diphosphate were constructed on two separate occasions using the same standardised technique. Doses were administered every 15 min and sGaw determined five minutes after each. On one occasion each dose of histamine was immediately preceded by the non-active test dose of PGF2 alpha and on the second by saline as placebo. The study was performed double-blind and in random order. After pretreatment with PGF2 alpha the histamine dose-response curve was significantly shifted to the left in a parallel fashion (p less than 0.001). There was a significant decrease in the doses of histamine required to cause a 20% fall in sGaw (p less than 0.0015) but no significant change in the slopes of the dose-response regression lines, indicating that bronchial muscle sensitivity rather than reactivity had been predominantly affected.