Hyperreactivity In Patients Research Articles

Bronchial hyperreactivity in patients who cough after receiving angiotensin converting enzyme inhibitors.

Angiotensin converting enzyme inhibitors cause cough in some patients, but the mechanism of this effect is not known. Six patients in whom these inhibitors had caused cough and a further two patients in whom they were suspected to have caused worsening of bronchial asthma were studied. Nine patients in whom angiotensin converting enzyme inhibitors had not been associated with cough served as controls. In the controls lung function and bronchial reactivity were measured once; for the study patients these and the cough index were measured twice before rechallenge for two weeks with an angiotensin enzyme inhibitor and once afterwards. Rechallenge with drug for two weeks caused a significant decrease in the mean concentration of histamine causing a 35% fall in airways conductance and a significant increase in the cough index. Patients with cough showed bronchial hyperactivity compared with the controls, which increased after rechallenge with the inhibitors. Cough associated with converting enzyme inhibitors may be a variant of the cough in asthma.

The magnitude of the spontaneous production of histamine-releasing factor (HRF) by lymphocytes in vitro correlates with the state of bronchial hyperreactivity in patients with asthma

In our previous studies we reported that lymphocytes from patients with asthma spontaneously produce histamine-releasing factor (HRF) in vitro. In an effort to examine whether spontaneous HRF production (SpHRF) by lymphocytes from patients with asthma is related to the state of bronchial hyperreactivity (BHR), 20 patients with mild to severe asthma were studied. Peripheral blood lymphocytes were cultured alone in a serum-free medium for 24 hours, and culture supernatant was assayed for HRF activity in two separate histamine-release tests with autologous basophils and normal basophils from known healthy donors. BHR was measured as bronchial reactivity to inhaled histamine and was expressed as a provocation concentration of histamine required to induce a 20% fall in FEV1 (PC20). The result of this study demonstrated that lymphocyte supernatant from all patients with asthma released significant amount of histamine from both autologous and normal basophils. Very high histamine release was usually induced by lymphocyte supernatant from severely ill patients who had PC20 less than 2 mg/ml. Statistical analysis demonstrated that the magnitude of the SpHRF significantly correlated (r = -0.86; p less than 0.001) with PC20. Since mast cell- and basophil-derived mediators have been implicated in the pathogenesis of BHR, high correlation between PC20 and SpHRF by lymphocytes suggests that the latter may contribute to the development of BHR. Further studies are required to disclose the exact relationship between SpHRF and BHR.

Cold air provocation of airway hyperreactivity in patients with cystic fibrosis.

Thirty-four patients with cystic fibrosis (CF) were assessed for baseline pulmonary functions before, and 5 and 15 minutes after cold air challenge (CACh). Most of the patients had no change in forced expiratory volume in 1 second (FEV1) and maximum expiratory flow at 25% vital capacity (Vmax25%VC) post-CACh. Five patients responded with reduced FEV1 and 13 with reduced Vmax25%VC. However, paradoxical increases were noted in 10 patients for FEV1 and in 5 for Vmax25%VC. Paradoxical responses were most frequent in patients with severe lung disease. The explanation for this variability may lie in the varying degrees of airway instability and volume of airway contribution (VAC) to early flows, resulting from the damage caused by chronic infection. Conventional challenges may be useless in determining the true incidence of bronchial hyperreactivity in patients with CF.

Type A behavior and blood pressure during general surgery.

The Type A behavior pattern (TABP) has been demonstrated as a risk factor for the development of coronary heart disease (CHD). Psychophysiologic studies suggest that the TABP may be associated with autonomic hyperreactivity to a variety of stressors. Recent studies report an association of TABP with autonomic hyperreactivity in patients under general anesthesia for coronary artery bypass surgery. The present study did not find a significant correlation between the TABP and intraoperative rise in blood pressure for 44 noncardiac patients undergoing anesthesia for elective general surgical procedures. Suggestive associations were found in sub-samples with family history of CHD or age greater than 60 years. Thus, the TABP may be correlated with heightened physiologic response under anesthesia only in selected populations.

Effect of aerosol fenoterol on the severity of bronchial hyperreactivity in patients with asthma.

Beta adrenergic agents given by aerosol decrease the responsiveness of the airways to histamine and methacholine in subjects with asthma, causing a shift of the dose response curve to the right. To find out whether the shift is related to the dose of beta adrenergic agent given and to determine the duration of the reduced responsiveness, eight subjects with asthma were given histamine inhalation tests after inhaled saline and after increasing doses of inhaled fenoterol on different days. The histamine inhalation tests were repeated at hourly intervals for five hours after a selected dose of fenoterol. Fenoterol caused a dose related shift to the right of the histamine dose response curve in each subject and in some the dose response relationship reached the "non-symptomatic range." The shift in the dose response curve was short lived and had returned towards the control position within three hours in all subjects. There was no change in shape of the curves at the time of maximal shift. The results show that inhaled fenoterol greatly reduces the airway responsiveness to histamine, but up to 400 micrograms of fenoterol every four to five hours may be needed to keep the responsiveness of the airways in the non-symptomatic range.

Vestibular hyperreactivity in patients with multiple sclerosis.

Vestibular hyperreactivity in patients with multiple sclerosis.

The frequency and importance of bronchial hyperreactivity in patients with allergic and non-allergic rhinitis.

A trial was undertaken to evaluate the occurrence of bronchial hyperreactivity, typical of bronchial asthma, in 50 patients with hay fever (rhinitis allergica) and 45 patients with rhinitis vasomotorica nonallergica, as opposed to a group of healthy subjects and patients with bronchial asthma. All the patients were subjected to spirographic examinations at rest (VC, FEV1, ETT, SI), after exercise (PWC170), and after histamine inhalation. The authors believe that it is expedient to study bronchial hyperreactivity in patients with hay fever and rhinitis vasomotorica nonallergica in that it affords possibilities for the prevision of the conceivable unfavourable evolution of the disease towards the atopic or non-atopic bronchial asthma, as well as for the taking of adequate preventive and therapeutic measures.

Contribution of airway collapse to supramaximal expiratory flows.

Contribution of airway collapse to supramaximal expiratory flows.