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Biomedical subjects

M R Sears

Publications and source records attributed to M R Sears.

At least 145 records · Page 8Linked to original sources
PubMed1984

Exercise-induced asthma: comparison of cromoglycate powder and aerosol four hours before exercise.

To establish whether sodium cromoglycate delivered by pressurised aerosol was more effective than sodium cromoglycate powder in preventing exercise-induced asthma four hours after drug administration, eight subjects known to be protected by sodium cromoglycate taken immediately pre-exercise, underwent delayed exercise challenge following double-blind premedication with sodium cromoglycate powder, sodium cromoglycate aerosol and placebo. The maximum fall in FEV1 induced by exercise four hours after inhaling sodium cromoglycate was modified slightly by sodium cromoglycate powder and by a smaller amount, sodium cromoglycate aerosol, compared with the unpremedicated run, but the calculated protection provided by sodium cromoglycate was not significantly different from that given by placebo. It was concluded that asthmatics should not expect significant suppression of exercise-induced bronchoconstriction four hours after the last dose of either cromoglycate powder or aerosol.

Adolescent↗
PubMed1984

Bronchial asthma: lack of relationships between allergic factors, illness severity and psychosocial variables in adult patients attending an asthma clinic.

The relationships between illness severity, allergy as indicated by serum total immunoglobulin E, and various psychological and social factors were studied in 66 adult asthmatics. No substantial relationships were found between these factors. An earlier onset of illness before 3 years was associated with a higher serum IgE. These results do not support the commonly held concept that asthma is a 'psychosomatic' disorder.

Adaptation, Psychological↗
PubMed1983

Comparison of conventional and ultrasonic nebulisation of bronchodilator drugs in asthmatic subjects.

The effects of ultrasonic and conventional nebulisation of bronchodilator drugs were compared in 20 adults with moderately severe asthma. The bronchodilating effect of fenoterol hydrobromide was not significantly enhanced by ultrasonic nebulisation, and ultrasonic nebulisation of ipratropium bromide gave significantly less bronchodilatation than conventional nebulisation. Despite theoretical reasons why ultrasonic nebulisation of bronchodilator might be more effective than conventional nebulisation, this was not borne out by this study.

Adolescent↗
PubMed1983

A double-blind comparison of ketotifen and disodium cromoglycate in atopic adult asthmatics.

The therapeutic effects of inhaled disodium cromoglycate (DSCG) and orally administered ketotifen were compared in thirty atopic asthmatics aged 15-34 years during a 22-week double-blind parallel group study. Ketotifen is a cycloheptathiophene with experimental antihistaminic, anti-allergic and anti-anaphylactic effects equal or superior to those of DSCG. During the first 6 weeks of treatment, mean airflow meter readings increased and bronchodilator use diminished in those receiving DSCG, but no improvement was seen in those given ketotifen. In the next 10 weeks, concomitant therapy was reduced in both groups, but this reduction was greater in the group receiving DSCG. No serious adverse effects occurred. Asthma worsened after abrupt discontinuation of DSCG but not ketotifen. Although a small number of patients may have benefited from ketotifen, its effect on asthma was not comparable with that of inhaled disodium cromoglycate.

Administration, Oral↗
PubMed1982

Asthma in seven year old children: a report from the Dunedin Multidisciplinary Child Development Study.

The prevalence of asthma between birth and seven years was determined by questionnaire in 875 children as part of the Dunedin Multidisciplinary Child Development Study. From the combinations of asthma and/or wheezing reported in association with bronchitis, hayfever, eczema and allergies, a diagnosis of certain or probable asthma was made in 12.6 percent of these children. A further 22.6 percent admitted to wheezing, but a diagnosis of asthma could not be made with any certainty. Bronchitis was reported frequently, usually associated with wheezing. Children with more obvious asthma showed a male preponderance and significant differences in body build and school attendance compared with asymptomatic children.

Absenteeism↗
PubMed1980

Serum theophylline levels in adult asthmatics: comparison of oral sustained-release and microcrystalline preparations.

Serial serum theophylline levels were measured in 20 inpatient asthmatics given tablets of either microcrystalline or sustained-release theophylline. The sustained-release preparation gave serum levels which were more consistently within the therapeutic range with a significantly higher trough concentration. No increase in adverse effects was encountered.

Administration, Oral↗
PubMed1980

Serum total IgE in normal subjects and the influence of a family history of allergy.

The purpose of this study was to establish the range of serum total immunoglobulin E (IgE) in a healthy population free of personal and family history of allergy, and to determine whether a family history of allergy influenced serum IgE levels. Using commercially available Phadebas reagents, the mean serum IgE in eighty-four adults aged 17-30 years with no personal or family history of allergy was found to be 38.8 iu/ml. Seventy-five percent of subjects had a serum IgE below 50 iu/ml and in only one subject was serum IgE in excess of 150 iu/ml, which we suggest be taken as the upper limit of normal. When healthy subjects with no personal history but with a family history of allergy were included with this normal population, the mean serum IgE in 207 subjects was 95.4 iu/ml and the upper limit of the distribution curve over 200 iu/ml, suggesting an influence of genetic factors on IgE production.

Adolescent↗
PubMed1979

A study of asthma in a Dunedin suburban area.

Asthma was reported by 6.2 percent of 2347 inhabitants of a Dunedin residential area. Symptoms occurred within the past two years in 4.2 percent. In this group the majority showed evidence of atopy by skin reactivity and elevation of serum immunoglobulin E. Airways obstruction was detected by spirometry in 62 percent and 56 percent demonstrated increased bronchial reactivity to histamine aerosols. Less than half used bronchodilator aerosols for relief and only 18 per cent were treated with prophylactic disodium cromoglycate.

Adolescent↗
PubMed1976

Evaluation of the airflowmeter in the assessment of airways obstruction.

The airflowmeter, a new inexpensive instrument measuring severity of airways obstruction in arbitrary units, was found to correlate well with standard respiratory function tests, and to be more sensitive than FEV1 in detecting changes in obstruction. Despite the distortion of maximal expiratory flow-volume relationship induced by the resistance of the meter, and the considerable variability between instruments, the airflowmeter should prove useful for regular monitoring of patients with variable airways obstruction.

Airway Obstruction↗
PubMed1974

Effect of experimental pneumococcal meningitis on respiration and circulation in the rabbit.

Pathophysiological studies in bacterial meningitis in man have been limited by clinical variability and the necessity for immediate therapy. After the development of a reliable animal model of pneumococcal meningitis, we studied respiration and circulation in 25 anesthetized New Zealand white rabbits during untreated pneumococcal meningitis and in 33 healthy controls. In meningitis, we found increased lactic acid in cerebrospinal fluid (CSF). Increased ventilation, perhaps due to CSF lactic acid accumulation, resulted in respiratory alkalosis; the concomitant lowering of Pco(2) acted as a homeostatic mechanism to restore pH toward normality in the CSF. Hyperventilation increased with the duration of the illness. Cardiac output was also increased with decreased peripheral vascular resistance but with only slight reduction in mean systemic and pulmonary arterial pressures. In the final hour of life, peripheral vascular resistance fell further; ventilation declined and then abruptly ceased while cardiac activity continued. Lactic acid accumulation in the CSF, found in both experimental and human pneumococcal meningitis, may cause the hyperventilation found in this disease and may contribute to death.

Acidosis↗
PubMedDate not supplied

What is new since the last (1999) Canadian Asthma Consensus Guidelines?

The objective of the present document is to review the impact of new information on the recommendations made in the last (1999) Canadian Asthma Consensus Guidelines. It includes relevant published studies and observations or comments regarding what are considered to be the main issues in asthma management in children and adults in office, emergency department, hospital and clinical settings. Asthma is still insufficiently controlled in a large number of patients, and practice guidelines need to be integrated better with current care. This report re-emphasises the need for the following: objective measures of airflow obstruction to confirm the diagnosis of asthma suggested by the clinical evaluation; identification of contributing factors; and the establishment of a treatment plan to rapidly obtain and maintain optimal asthma control according to specific criteria. Recent publications support the essential role of asthma education and environmental control in asthma management. They further support the role of inhaled corticosteroids as the mainstay of anti-inflammatory therapy of asthma, and of both long acting beta2-agonists and leukotriene antagonists as effective means to improve asthma control when inhaled corticosteroids are insufficient. New developments, such as combination therapy, and recent major trials, such as the Children's Asthma Management Project (CAMP) study, are discussed.

Adrenergic beta-Agonists↗
PubMedDate not supplied

Nicotine replacement combined with a novel compound (ProBAN) for smoking cessation: a pilot study.

BACKGROUND: Smoking cessation rates with available pharmacological therapies remain suboptimal. Anecdotal observations with a combination of sublingual pralidoxime and ipratropium (ProBAN) suggested that these agents in combination with nicotine gum improved quit rates. OBJECTIVE: To determine whether ProBAN together with nicotine replacement improves quit rates compared with nicotine replacement alone. DESIGN: A 12-week, prospective, double-blind, randomized, placebo controlled pilot study. SETTING: University-affiliated outpatient clinic. POPULATION STUDIED: Healthy adult smokers were recruited via advertisements. Of 107 subjects seen at the screening visit, 27 were excluded because of comorbid illness or concomitant medication use. INTERVENTIONS: Of 80 eligible subjects, 40 were randomly assigned to receive treatment with ProBAN sub- lingual tablets and nicotine gum (treatment group), and 40 to receive placebo tablets and nicotine gum (control group) for 12 weeks. The primary outcome was complete continuous abstinence of smoking from one through 12 weeks after the quit date. MAIN RESULTS: There were no adverse effects in the treatment group. At one week after the quit date, 35% of ProBAN-treated subjects had quit compared with 18% of control subjects (odds ratio [OR] 2.5, 95% CI 0.9 to 7.2). Corresponding quit rates at four weeks were 28% and 15% (OR 2.1, 95% CI 0.7 to 6.5), at eight weeks were 25% and 13% (OR 2.3, 95% CI 0.7 to 7.6), and at 12 weeks were 23% and 13% (OR 2.0, 95% CI 0.6 to 6.7), respectively. CONCLUSIONS: This pilot study indicated that ProBAN combined with nicotine replacement doubled the continuous sustained quit rate compared with nicotine replacement alone, with no adverse effects. Although not statistically significant due to the size of the study, this result suggests that it may be an effective therapy for smoking cessation, and larger studies are warranted.

Administration, Sublingual↗
PubMedDate not supplied

Short-acting beta-agonist research: a perspective. 1997.

Asthma mortality increased sharply in New Zealand in 1977, prompting a national investigation into circumstances of asthma deaths. Subsequent observations of improved asthma control in subjects withdrawn from regular beta(2)-agonist treatment raised the question of whether asthma severity and, therefore, mortality could relate to frequent beta-agonist use. A randomized controlled trial of regular inhaled fenoterol versus as-needed bronchodilator use showed worsened asthma control during regular treatment despite concomitant use of inhaled corticosteroids. Assessment of these findings led to delay in the publishing of the American Asthma Guidelines, which were modified to suggest caution in using beta(2)-agonist treatments. Simultaneously, case control studies in New Zealand suggested that prescription of fenoterol was a substantial risk factor for asthma mortality. The causal association was hotly debated, but increasing evidence pointed to an adverse effect of fenoterol on asthma severity and, hence, mortality. This was supported by dramatic decreases in both morbidity and mortality when fenoterol was effectively withdrawn from use in New Zealand. The link between worsening asthma morbidity and mortality, and the use of potent short-acting beta(2)-agonists fulfills the Bradford Hill criteria for attributing causality. Application of evidence from randomized, controlled trials of short-acting beta-agonist use has led to a major shift in therapy in asthma to the recommendation of as-needed use only of short-acting beta-agonists and decreased patient reliance on regular bronchodilator therapy.

Adrenergic beta-Agonists↗
PubMedDate not supplied

Is asthma a risk factor for dental caries? Finding from a cohort study.

It has been suggested that asthmatic children may have a higher caries risk, both as a result of their medical condition and the physical and physiological effects of their pharmacotherapy. By examining the association over time between asthma and caries increment, this study tested the hypothesis that childhood asthma is associated with an increased caries increment. In a long-standing New Zealand cohort study, participants' long-term asthma histories and the 3-year net caries increment between the ages of 15 and 18 years were examined. Of the 781 who were examined at 15 and 18 years, 39 participants were consistently taking anti-asthma medication at the ages of 9, 11, 13 and 15 years (and were labelled in this study as 'medication-determined asthmatics'), 56 were identified as consistent wheezers at the ages of 9, 11, 13 and 15 years ('wheeze-determined asthmatics') and 36 were members of both groups. A smaller group (n = 9) was identified as being very-long-term asthmatics (asthma at 5 years of age and at the ages of 9, 11, 13 and 15 years). Some 206 study members were identified as having no history of asthma, asthma medication or significant wheeze at any time up to and including 18 years. The overall mean net caries increment between the ages of 15 and 18 years was 2.06 surfaces (SD, 3.76). There were no significant differences in caries increment between the 206 asthma-free participants and any of the asthma groups. This study provides little evidence for an asthma-caries causative relationship.

Adolescent↗