European journal of respiratory diseases最新文献

The separate effects of tar and nicotine on the cigarette smoking manoeuvre were investigated. Each of ten asymptomatic habitual smokers smoked three different commercially available cigarettes in a randomised order. The brands were chosen such that two had the same tar yield (10 mg) and two had the same nicotine yield (1.4 mg). The volume of smoke inhaled into the lungs was measured by tracing the smoke with the inert gas 81Krm. Puffing indices were recorded using an electronic smoking analyser and flowhead/cigarette holder. There was no difference in the total volume of smoke puffed from each of the cigarette brands. With cigarettes of the same tar level, the total inhaled smoke volume was lower with the higher nicotine cigarette (P less than 0.05): by contrast, with cigarettes of the same nicotine level, the total inhaled smoke volume was lower with the lower tar cigarette (P less than 0.02). Tar and nicotine appear to exercise independent control over the volume of smoke inhaled.

We studied the lymphocytes and serum suppressive factor in patients with Mycoplasma pneumoniae pneumonia. Skin testing for delayed hypersensitivity to tuberculin was performed in 44 patients with pneumonia associated with M. pneumoniae infection. These patients were tuberculin-positive. Twenty-five patients showed a transient negative tuberculin reaction in the acute stage and 19 had a positive reaction. In tuberculin-negative patients, peripheral blood T lymphocytes were not significantly reduced; however, the blastogenic lymphocyte response to purified protein derivative (PPD) and PPD-induced gamma-interferon production were significantly reduced when compared with those in tuberculin-positive patients and healthy tuberculin-positive controls. The lymphocyte response of healthy tuberculin-positive controls was not suppressed by adding the serum of the tuberculin-negative patients. These results suggest that tuberculin anergy in patients with M. pneumoniae pneumonia early after clinical onset is due to depressed lymphocyte functions and not to serum factors.

Twenty-six normal volunteers were exposed to rhinovirus or influenza B virus. Measurement of nasal mucociliary clearance, ciliary beat frequency, percent of epithelium ciliated, ciliary ultrastructure and nasal transmucosal potential difference were made before exposure, during viral incubation and at the time of expected overt infection. Ten volunteers failed to become infected, six were subclinically infected and nine were infected with symptoms. There were no significant differences between the results in volunteer groups during the incubation period or between uninfected and subclinical groups at the time of expected symptoms. Six of nine symptomatic infected volunteers had prolonged nasal clearance, and six of the seven biopsied had less than 50% of their epithelium ciliated. However, there was no significant reduction in ciliary beat frequency nor increase in ultrastructural ciliary abnormalities within this group of symptomatic volunteers. Of the two symptomatic infected (influenza B) volunteers tested, both showed significantly reduced transmucosal potential difference.

We investigated the bronchodilator effect of intravenous aminophylline given after a cumulative dose of nebulized fenoterol of 2.4 mg in 18 patients with acute severe asthma. The mean forced expiratory volume in 1 s (FEV1) +/- SD before treatment was 0.72 +/- 0.22 l. The mean improvement in FEV1 after fenoterol was 0.64 +/- 0.39 l (85% of total improvement) and after aminophylline 0.11 +/- 0.13 l (15% of total improvement). The improvement after aminophylline was statistically significant (p less than 0.01), though quantitatively small. Thirteen patients improved after aminophylline by less than 0.15 l, and in only five was the improvement 0.2-0.4 l. There was no significant change in heart rate and subjective tremor score with treatment, although observed tremor (0 = absent, 4 = maximum) increased from 0.4 +/- 0.6 to 1.3 +/- 1.0 after all treatment. For the majority of patients presenting with acute severe asthma, it is likely that high doses of nebulized beta-2 agonist alone will produce near maximal bronchodilation in the short term.

The study was designed to compare terbutaline inhaled via a 750 ml spacer (Nebuhaler) with subcutaneous adrenaline injection as a first-line treatment for acute severe asthma. Patients were randomly allocated to two treatment groups, receiving either 2 X 4 mg of inhaled terbutaline followed by 2 X 0.5 mg subcutaneous adrenaline (22 patients) or the same drugs in reverse order (24 patients). All patients received a further 2 mg inhaled terbutaline to assess remaining bronchodilator reversibility. Initial treatment with terbutaline produced near maximal bronchodilation (FEV1, FVC), whilst initial treatment with adrenaline did not. Terbutaline also reduced symptoms of dyspnoea and wheeze to a greater extent than adrenaline, and was better tolerated with respect to heart rate and side-effects such as tremor. In conclusion, terbutaline inhaled via Nebuhaler was at least as effective as subcutaneous adrenaline, produced fewer side-effects, and hence can be recommended for initial treatment of acute severe asthma.

A hospital self-admission service for asthmatic patients was started in December 1968. During a 15-year period, 195 asthmatic patients were responsible for 873 hospital self-admissions. During the last 3 years there were significantly more night admissions and shorter durations of asthma attacks prior to admission than during the first 3 years. Assisted ventilation was necessary on 36 occasions (4%), but one patient was responsible for 28 of these episodes. There were three hospital deaths. One patient died from a tension pneumothorax as mechanical ventilation was being started, and two patients were not actively resuscitated because of irreversible airways obstruction and ischaemic heart disease. There were six deaths outside hospital, one from myocardial infarction, four from asthma; one young female died on a holiday trip. The hospital death rate for patients admitted via this service is 0.34% (0.1% if the two patients who were electively not resuscitated are excluded). This low mortality rate suggests that this self-admission service saves lives. There are no costs and this service gives confidence to patients and general practitioners.

Circulating lymphocytes subpopulations and their function have been studied in 25 young adults with cystic fibrosis (CF) and 25 normal controls. Mean absolute numbers of all lymphocyte subsets in the CF group were not significantly different from the controls. Antibody-dependent cell cytotoxicity was significantly higher in the CF patients who had Pseudomonas aeruginosa in their sputum compared with those who had not and compared with the normal controls. Within the CF group the numbers of B cells, total T cells and OKT4+ helper cells fell as percent predicted peak expiratory flow (PEF) declined and similar significant positive correlations were found between lymphocyte subsets and percent predicted body weight. Serum albumin levels also showed a positive correlation with total T lymphocyte numbers (p less than 0.05). In vitro lymphocyte proliferative responses to mitogen were not significantly different from the control group, but again correlated positively with body weight in the CF patients. This provides further evidence that immune function in CF patients may become impaired as pulmonary disease and nutritional status deteriorate.

The effect of N-acetylcysteine (NAC), a free radical scavenger, was investigated in a microembolism rat model of adult respiratory distress syndrome (ARDS). Microembolism was induced by an intravenous injection of bovine thrombin and an intraperitoneal injection of a fibrinolysis inhibitor, trans-4-aminomethyl-cyclohexane-carboxylic acid (AMCA). NAC counteracted the experimentally induced increase in lung weight, the development of alveolar oedema, and the amount of fibrin in precapillary vessels. There was also a tendency to a decrease of the experimentally induced interstitial oedema caused by the NAC treatment, although it was not statistically significant. Surprisingly, NAC reduced plasma viscosity in both experimental and control animals. It also seemed to increase PaO2 in animals with pulmonary damage, but had a lowering effect on PaO2 in control animals. The results indicate that NAC has a significant preventive effect in this microembolism rat model of ARDS, and that this effect may be achieved through decreased deposition of fibrin, thus counteracting pulmonary oedema, and a decrease in plasma viscosity.