Prevalence of pneumonia due to Legionella pneumophila and Mycoplasma pneumoniae in a population admitted to a department of internal medicine.

We studied 177 patients with pneumonia admitted to an internal medicine department over a period of 3 years to determine the incidence of two emerging pathogens, Legionella pneumophila and Mycoplasma pneumoniae. Clinical, radiological and laboratory tests were performed and included blood cultures, serology, gram staining and sputum cultures. L. pneumophila was the agent involved in 9 patients (5.1%) and M. pneumoniae in 12 (6.8%). These prevalences were about in the middle of the range of previously published figures. Legionella pneumonia is a rare illness, which even in the absence of suggestive clinical signs must be considered because of its possibly serious course and to allow appropriate therapeutic decisions to be made.

The effect of adrenoceptor agonists and antagonists on histamine-induced wheal response in the skin of normal subjects and atopic patients.

The role of the adrenergic mechanism in the pathogenesis of atopic diseases is controversial. Recent experimental and clinical reports have suggested that beta-2 adrenergic stimulation impairs and beta-2 adrenergic blockade enhances the histamine effect on vascular permeability. This led us to study the effect of salbutamol and of propranolol on histamine-induced cutaneous response in 13 healthy subjects and in 16 patients with allergic oculo-rhinitis. Both in normal subjects and in atopic patients salbutamol attenuated the whealing response to histamine and the protective effect of salbutamol was counteracted by propranolol. The ability, however, of salbutamol to inhibit histamine-induced response was significantly reduced in 50% of atopic patients. These findings suggest that beta-2 adrenergic hyporesponsiveness is present in some allergic patients.

Evaluation of the intensity and duration of the bronchodilatory action of fenoterol-ipratropium bromide in combination compared with terbutaline and placebo in patients with chronic obstructive lung disease.

The effect obtained using terbutaline and Duovent was studied in a group of 16 patients with chronic obstructive lung disease. The drugs were administered by aerosol in doses based on spirometric indices of flow and lung capacity. The results obtained confirm the efficacy of the two drugs in improving gas flow. This improvement persisted for 6-7 h after administration. Comparison of the two drugs has shown that as far as FVC is concerned, the improvement obtained with Duovent is longer-lasting than that with terbutaline. There were no side-effects.

The effect of intravenously administered salbutamol on serum potassium in asthmatic and nonasthmatic atopic subjects.

The role of adrenergic mechanism in the pathogenesis of allergic disease is controversial. Recent experimental and clinical reports have suggested that beta-adrenergic blockade impairs and beta stimulation enhances extrarenal potassium uptake in humans. This led us to study the effect of the intravenous administration of salbutamol, a specific beta-2-adrenergic agonist, on serum potassium in 9 healthy subjects and in 23 patients with allergic asthma and/or rhinitis. Serum potassium fell significantly and reached a peak decline at the end of venous infusion in all the normal subjects. Seventeen atopic subjects showed a lower or absent serum K+ decrement: there was no difference between asthmatic and rhinitic patients. There was no relation among the salbutamol-induced serum potassium decrement, serum glucose increment, blood pressure and heart-rate changes, and nonspecific bronchial reactivity. These findings suggest that beta-2-adrenergic hyporesponsiveness is present only in some allergic patients.

Potassium tolerance and bronchial reactivity in asthmatic and nonasthmatic atopic subjects.

Abnormal autonomic nervous system responsiveness may contribute to the pathogenesis of allergic diseases. Therefore, we measured the beta-adrenergic systemic (metabolic) responsiveness by means of acute potassium load in 10 normal healthy subjects and in 19 patients with allergic asthma and/or rhinitis. Ten allergic patients showed a greater potassium increment, as in normal subjects, when potassium was infused in the presence of propranolol. There was no difference between asthmatic and rhinitic patients. We then examined the relation between the response to potassium tolerance and the nonspecific, nonpharmacological bronchial reactivity in response to inhalation of ultrasonically nebulized distilled water. Some allergic patients showed bronchial hyperreactivity, while others did not show a difference compared with the controls; there was no significant difference between asthmatics and rhinitics, and there was no relation between nonspecific bronchial reactivity and potassium load tolerance. These findings suggest that systemic beta-adrenergic hyporesponsiveness may be present only in some allergic patients. There is no demonstrable relation among atopic state, nonspecific, nonpharmacological bronchial reactivity, and systemic beta-adrenergic hyporesponsiveness.