The effect of lifestyle on wheeze, atopy, and bronchial hyperreactivity in Asian and white children.

There is increasing evidence linking Western culture to increasing prevalence of asthma. We have measured the prevalence of symptoms of asthma, bronchial hyperreactivity, and atopy in a sample of white and Asian inner city schoolchildren aged 8-11 yr in the U.K. and assessed the influence of certain aspects of western culture on these variables. Bronchial reactivity was measured by methacholine challenge, atopy by allergen skin prick tests, and symptoms of asthma and aspects of lifestyle by questionnaire. Degree of Westernization was assessed from dietary habit categorized as exclusively Asian, mostly Asian, mixed, or exclusively English. The questionnaire was completed by 92% of children. The 308 white and 539 Asian children were of similar age (mean 9.3 yr versus 9.4 yr) with slightly more girls in the Asian group (52.6% versus 47.4%). The white children reported more wheeze within the past year (14.2% versus 8.8%, p = 0.01) but less were atopic (29.5% versus 38.4%, p = 0.01) with no significant difference in the prevalence of hyperreactivity (31.5% versus 29.6%, p = 0.57). Most Asians (97%) included Asian food in their diet; 35% ate a mostly Asian diet, 45% ate a mixed English and Asian diet, and 17% ate an exclusively Asian diet. After controlling for confounding factors whites were at higher risk of hyperreactivity and lower risk of atopy, and the risk of hyperreactivity and to a lesser extent atopy among Asian children was related to diet in a dose response fashion. The relative odds for hyperreactivity with an exclusively Asian, mostly Asian, or a mixed diet relative to an English diet were 0.31 (95% CI 0.15 to 0.62), 0.88 (0.56 to 1.37), and 0.99 (0.65 to 1.49), and for atopy were 1.22 (0.72 to 2.06), 1.47 (0.99 to 2.19), and 1.78 (1.23 to 2.58). These results suggest that diet or other closely related factors associated with Westernization are involved in the etiology of atopy and hyperreactivity.

Impact of respiratory virus infection in patients with chronic chest disease.

This study investigated the morbidity associated with respiratory virus infections in patients with well-documented chest disease, and the risk of transmission between close contacts. Patients informed the study team if they were exposed to a family member or colleague with a cold. Patients and symptomatic index cases recorded respiratory symptoms during the study period. Acute nasopharyngeal swabs and paired sera were obtained for viral diagnosis. Twenty-five (43%) of 58 recorded exposures resulted in a symptomatic illness and 16 (28%) patients developed lower respiratory tract symptoms. Sixteen (64%) of the 25 symptomatic patients contacted their general practitioner, 14 (56%) received antibiotics and 4 (16%) were hospitalized. Mean duration of illness was 10.6 days in symptomatic patients and 5.7 days in their corresponding index cases (P < 0.005). Mean symptom scores were 100.6 in symptomatic patients and 62.2 in index cases (P < 0.01). Respiratory viruses were identified in 19 (33%) episodes. Rhinovirus, coronavirus and respiratory syncytial virus infections were all associated with lower respiratory tract exacerbations. Respiratory tract symptoms following exposure to a cold were comparatively severe in these patients with chronic chest disease. This group of patients might gain particular benefit from the introduction of effective vaccines or antiviral therapy.

Effect of alterations of dietary sodium on the severity of asthma in men.

BACKGROUND: There is some evidence of a positive association between increased dietary salt consumption and both increased bronchial reactivity and mortality from asthma in men. This study assesses the effects of alterations in dietary salt consumption on the clinical severity of asthma in adult male asthmatic patients. METHODS: A randomised, double blind, placebo controlled, crossover design was employed. Twenty seven mild to moderate asthmatic patients were established on a low sodium diet (80 mmol/day) at the end of a 4-5 day run in period and then randomised to receive 200 mmol/day slow sodium or matching placebo for five weeks, crossing over to the alternative regime for a further five weeks. Patients used diary cards to record twice daily peak expiratory flow rates, daily symptom scores, and bronchodilator consumption. Spirometry and degree of bronchial responsiveness (methacholine challenge test) were measured at screening and at the end of each treatment period. Twenty four hour urinary sodium excretion was measured at screening and in duplicate for each treatment period. RESULTS: Twenty two patients completed the study. For these patients the mean (95% confidence interval (CI)) difference in 24 hour sodium excretion between treatments was 204 (175 to 235) mmol. Compared with placebo, sodium supplementation resulted in deleterious alterations of all measured parameters. Bronchial reactivity rose on slow sodium with a 0.73 (0.2 to 1.3) doubling dose methacholine difference compared with placebo. Estimated median (95% CI) difference in bronchodilator consumption was 1.3 (0.4 to 2.1) puffs per day, the estimated median difference in symptom score was 0.6 (0.2 to 0.9), and mean forced expiratory volume in one second fell by 0.21 (0.05 to 0.37) 1. The peak expiratory flow rate rose on placebo and fell on slow sodium. Median differences between treatments were 5.6% (2.2% to 9.8%) for morning and 7.8% (3.9% to 12.9%) for evening peak expiratory flow rate. CONCLUSIONS: Our results suggest that large increases in dietary sodium result in physiological deterioration and increased morbidity in male asthmatic patients.

Does a positive Heaf test reaction in Asian schoolchildren predict later breakdown of tuberculosis?

BACKGROUND: Some authorities advise giving prophylactic antituberculosis treatment to those with a grade 3 or 4 reaction to Heaf tests performed as part of the schools' BCG programme. This is not done in Leicestershire, which because of its large Asian population would require considerable resources to do so. A calculation of the "breakdown" rate, and thus the potential value of chemoprophylaxis, in these children would therefore be valuable. METHOD: Lists of names of Asian children who had a grade 3 or 4 Heaf test reaction in 1982 and 1983 were compared with lists of notifications for the five years 1983 to 1987. Those who were on both lists were considered to have tuberculosis that had "broken down." RESULTS: Of the 760 children with positive Heaf test reactions, only four were on the subsequent notification lists. The chest radiograph obtained because of the Heaf test result showed evidence of active tuberculosis in only three of these. Only one child had infection that "broke down" later. CONCLUSION: The benefit of chemoprophylaxis seems likely to be limited in these Asian children, most of whom had received BCG early in life.

Normal pulmonary function in Botswana.

Forced vital capacity, forced expiratory volume in one second and peak expiratory flow rate were measured in 125 adult Batswana who were without evidence of pulmonary disease. Regression co-efficients suitable for the calculation of normal values for these parameters are presented. Results are similar to those in other Negroid populations but lower than in Caucasian subjects.

Auditing a research ethics committee.

Research ethics committees approve research on human subjects performed locally. They have been criticised for failing to perform this function adequately. I have, therefore, examined the structure and process of the committee for Leicestershire and compared it with the guidelines for these committees produced by the Royal College of Physicians and the Department of Health. The structure and function of the committee are described and conform well with the recommendations of the Royal College of Physicians and the Department of Health. An annual report to the health authority has not previously been produced but the need for this is now accepted. The suggestion for a lay chairman or vice-chairman has, however, been rejected. The workload has steadily increased over the past 10 years, from 66 protocols a year to 302. During a recent 12-month period, 277 research submissions were received; 143 of them were agreed without amendment, 93 with minor amendments, and 41 were rejected or required further information before they could be reconsidered. Assessment of outcome is more difficult. In future, the committee may ask for annual reports from investigators on their research and on any ethical problems encountered. Ethics committees need to foster good ethical research and inform researchers of ethical issues. Most of the latter are highlighted on the Leicestershire application form but are supplemented by short guidelines on particular topics. The committee consumes time and money; it is not clear if it will be adequately funded under the new NHS structure.

Prophylactic intranasal alpha 2 interferon and viral exacerbations of chronic respiratory disease.

BACKGROUND As respiratory virus infections often lead to exacerbations of chronic bronchitis and asthma an effective antiviral drug may be helpful in such patients. Alpha 2 interferon has been shown to give protection against rhinovirus infections in field studies. METHODS Patients with chronic respiratory disease exposed to close contacts with symptoms of upper respiratory tract infection were randomly allocated to receive nasal sprays of recombinant alpha 2 interferon (3 x 10(6) IU) or placebo twice daily for five days. Of the 123 patients recruited into the study, 69 took 117 courses of medication; 11 courses were excluded from analysis. RESULTS No important side effects were recorded and the incidence of possible adverse effects was similar in the two groups. Interferon treatment did not reduce the number or severity of symptomatic episodes; 11 of 48 patients given interferon and 16 of 58 given placebo developed lower respiratory symptoms. There were no differences in mean symptom scores (51 interferon and 52 placebo), number of symptomatic days (3.3 interferon and 5.0 placebo), peak flow values, number of general practitioner consultations, or use of antibiotics. CONCLUSION Alpha 2 interferon 3 x 10(6) IU taken twice daily for five days does not protect patients with chronic respiratory disease from exacerbations after they have been in contact with an upper respiratory tract infection.

A DNA primer/probe system for the rapid and sensitive detection of Mycobacterium tuberculosis-complex pathogens.

A 1.5 kb EcoRI-BamHI restriction fragment from Mycobacterium tuberculosis was found to hybridize specifically with genomic DNA from M. tuberculosis-complex organisms. Primers were designed from the terminal sequences of this fragment and used to amplify uniquely M. tuberculosis-group DNA in a polymerase chain reaction. It is suggested that a combination of these primers and probe will prove a useful tool for the early diagnosis of tuberculous infections.

A comparison of inhaled beclomethasone dipropionate and nedocromil sodium as additional therapy in asthma.

We have compared the effects of inhaled beclomethasone dipropionate (BDP) 400 micrograms day-1 with inhaled nedocromil sodium (NDS) 16 mg day-1 as additional therapy in adults with asthma not fully controlled by regular beta-2-agonist inhalers with, or without, oral theophyllines. Seventeen subjects were entered into a 2-week baseline phase, and subsequently in a double-blind crossover fashion into two 8-week phases of daily BDP or NDS. Subjects recorded daily peak expiratory flow rates, morning and evening (PEF am and pm), symptom scores and beta-2-agonist inhaler use. Thirteen subjects completed the study and the last 2 weeks of each phase were analysed. Compared to baseline, both BDP and NDS caused a significant improvement in PEF am (P less than 0.05), PEF pm (P less than 0.05) and the 'amplitude % mean' (P less than 0.001). Both drugs gave a highly significant improvement in all symptom scores. There was no significant difference between BDP and NDS for PEF am, PEF pm, amplitude % mean, cough and daytime asthma score. However, beta-2-agonist inhaler use and scores for nocturnal asthma and morning tightness were all significantly better in the BDP phase, and may have contributed to its better overall subjective performance. Thus, both NDS and BDP resulted in a significant improvement in asthma control in the subjects studied, and both drugs caused a similar improvement in PEF.

High-dose inhaled albuterol in severe chronic airflow limitation.

Higher doses of inhaled albuterol have been shown to cause slightly more bronchodilatation than standard doses from a metered-dose inhaler in patients with severe chronic airflow limitation. Higher doses, however, carry an increased risk of side effects, and the optimum dose balancing benefit and adverse effects have yet to be established. We have therefore looked at objective and subjective evidence of beneficial and adverse effects after 4 doses of albuterol in 30 patients with chronic bronchitis, severe airflow limitation, and less than 200 ml increase in FEV1 after 200 micrograms inhaled albuterol. Subjects were given placebo, 400 micrograms, 1 mg, 2 mg, and 4 mg albuterol by dry powder inhaler in random order on separate days in a double-blind study, and FEV1, relaxed VC, PEFR, 12-min walk distance, finger tremor, oxygen saturation, heart rate, and arrhythmias were measured at intervals over 6 h. With increasing doses of albuterol, there was a significant dose-related increase in FEV1, VC, and PEFR, the maximal mean changes being 196 ml, 480 ml, and 50 L/min, respectively. The duration of effect was longer with the higher doses. There was a dose-related increase in heart rate, tremor amplitude, and supraventricular ectopic beats and a dose-related fall in oxygen saturation. There was no drug-related effect on the frequency of ventricular ectopic beats either at rest or during the walk tests. The largest increases in walk distance occurred after the 1 and 2 mg doses and the least after the 4 mg dose.(ABSTRACT TRUNCATED AT 250 WORDS)

A study of acute asthma in the accident and emergency department.

We have conducted a survey of all the asthmatic patients seen at the Leicester Royal Infirmary Accident and Emergency Department during a 1-year period. A significantly greater number of patients were seen in the 8-hour period 1600-2359 hours and a greater number of patients were seen on Sundays and bank holidays. Wheeze was recorded in only 43% of the patients and there was no record of any nocturnal asthmatic symptoms. Peak expiratory flow rate was only recorded in 26% of patients before treatment with nebulized salbutamol (the commonest treatment). Pulse rate, respiratory rate, time of day or month did not determine whether or not a patient was admitted. We conclude that the education of junior doctors in the management of asthma is still deficient.