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Biomedical subjects

J Crane

Publications and source records attributed to J Crane.

At least 127 records · Page 7Linked to original sources
PubMed1995

International Study of Asthma and Allergies in Childhood (ISAAC): rationale and methods.

The aetiology of asthma and allergic disease remains poorly understood, despite considerable research. The International Study of Asthma and Allergies in Childhood (ISAAC), was founded to maximize the value of epidemiological research into asthma and allergic disease, by establishing a standardized methodology and facilitating international collaboration. Its specific aims are: 1) to describe the prevalence and severity of asthma, rhinitis and eczema in children living in different centres, and to make comparisons within and between countries; 2) to obtain baseline measures for assessment of future trends in the prevalence and severity of these diseases; and 3) to provide a framework for further aetiological research into genetic, lifestyle, environmental, and medical care factors affecting these diseases. The ISAAC design comprises three phases. Phase 1 uses core questionnaires designed to assess the prevalence and severity of asthma and allergic disease in defined populations. Phase 2 will investigate possible aetiological factors, particularly those suggested by the findings of Phase 1. Phase 3 will be a repetition of Phase 1 to assess trends in prevalence.

Adolescent↗
PubMed1995

The future of research utilization.

The need for utilization of scientifically based knowledge in clinical practice was recognized long ago. This article discusses the future of research utilization in nursing, emphasizing the role of nurse administrators, health care organizations, educational programs, and professional organizations. A futuristic view of research utilization is presented.

Diffusion of Innovation↗
PubMed1994

The self reported prevalence of asthma symptoms amongst adult New Zealanders.

AIMS: To examine the prevalence of asthma symptoms in a random population sample of New Zealand adults aged 20-44 years drawn from the general and Maori electoral rolls as phase I of an international study of asthma prevalence. METHODS: Subjects aged 20-44 years in Auckland, Hawkes Bay, Wellington and Christchurch, were selected randomly from the electoral rolls and sent a one page screening questionnaire, asking about respiratory symptoms, asthma attacks and asthma treatment. They were also asked to record their ethnic affiliation. Nonresponders were subsequently sent two written reminders followed by a telephone questionnaire where possible. RESULTS: A response rate of 84% was achieved. The study found a high prevalence of asthma symptoms, with 26% reporting wheezing in the last year, 8% experiencing an attack of asthma in the last year and 9% currently using asthma medication. Females were more likely to have had wheezing in the last year (26.6%) and be on treatment for asthma (9.8%) compared with males (24.7% and 7.5% respectively). Small regional differences were found with more reported symptoms and asthma treatment in Wellington and Christchurch, compared with Auckland and Hawkes Bay. Maori were more frequently symptomatic (35.2%) than nonPolynesian (24.8%) but were no more likely to report an attack of asthma (Maori 9.0%, nonPolynesian 7.7%) or be currently receiving asthma treatment (Maori 10.0%, nonPolynesian 8.6%). Asthma symptoms tended to decline with age in non Maori but increased with age in Maori. Adjustment of prevalence rates by two independent methods suggests that nonresponse bias has not significantly inflated these rates. CONCLUSIONS: The symptoms of asthma and their treatment are common in young New Zealanders, affecting one in three Maori and one in four nonMaori. One in ten of this adult population currently receive asthma treatment.

Adult↗
PubMed1994

Risk factors for asthma symptoms in Kawerau children.

AIMS: To study risk factors for asthma prevalence in Kawerau children aged 8-13 years. METHODS: Questionnaires on asthma symptoms and risk factors were completed in 1992 by parents of 708 Kawerau schoolchildren aged 8-13 years, a response rate of 82.0%; for a subgroup of children, stored serum samples from a 1984 survey were also analysed. RESULTS: The overall prevalence of current wheeze (21.3%) was similar to that observed in other New Zealand surveys. The prevalence of current wheeze was elevated in males (odds ratio (OR) = 1.7, 95% CI 1.2-2.5), in those who had been passively exposed to cigarette smoke from the primary caregiver (OR = 1.4, 95% CI 1.0-2.1), in those who had had pets in the home at age 0-5 years (OR = 1.9, 95% CI 1.2-2.9) and in those with one or more birth parents with asthma (OR = 2.1, 95% CI 1.4-3.1); current wheeze was less common in those with older children living in the same household (for 2 or more older children in the same household, OR = 0.5, 95% CI 0.2-1.0). In a small nested case-control study it was found that current wheeze was more common in those with high levels of IgE (OR = 6.4, 95% CI 1.3-36.4) or low levels of selenium (OR = 3.1, 95% CI 0.9-11.8) in stored serum collected 8 years previously. There was no difference in the proportions with current wheeze, or with diagnosed asthma between Maori and European children, but Maori children were more likely to have current frequent nocturnal wheeze (OR = 2.2, 95% CI 1.0-5.1), current severe wheeze (OR = 1.8, 95% CI 0.8-3.7) or to have been admitted to hospital with asthma (OR = 2.4, 95% CI 1.2-4.8). Passive exposure to tobacco smoke was more common among Maori children, but this only partially accounted for the greater asthma severity in Maori children, and the lower prescribing of prophylactic medications in this group may also have contributed. CONCLUSIONS: Multiple factors were associated with asthma symptoms in children in this age-group, including a family history of asthma, male gender, environmental tobacco smoke, environmental allergen exposure, atopy, and low selenium status. Further studies are required to assess the relative contributions of these factors to the prevalence of asthma in New Zealand.

Adolescent↗
PubMed1994

The influence of increased health care costs on general practitioner consultations and prescription collection.

AIM: Increased health service charges have led to concern that some patients may be unable to meet these costs, which could compromise their care. Increased costs may affect general practitioner attendance, and/or the collection of a prescription. This study examines both of these factors. METHODS: Between 18 August and 14 September 1992, questionnaires were sent to the consenting patients of 19 general practitioners from the Hutt Valley requesting information regarding the general practice (GP) visit and the prescription. The information included the reason for the GP visit, whether there was any delay and its duration, the reason for any delay, the cost of the visit and whether a prescription was received. Data regarding the prescription included the cost and whether all, some, or none of the items were uplifted, and whether the patient had a community service card. RESULTS: 489 (86%) returned completed questionnaires and 426 received a prescription. Of these, 164 were group 1 community service card holders; one was a group 2 community service card holder; 186 were group 3; 59 did not specify their group; 18 had a chronic-user card. Forty percent (194 patients), delayed going to their doctor, 118 by more than 3 days. The most common reasons for delay were hope that their condition may improve spontaneously and the cost of the consultation or prescription. Possession of a community service card was a significant factor in delay with group 3 (high wage earners) more likely to delay than group 1 (p < 0.0005). Only two patients did not present their prescription. Ninety-three percent of those receiving a prescription presented for dispensing within 24 hours. Ninety-two percent of patients paid for all their prescription items. CONCLUSIONS: Delay in obtaining treatment is common and occurs primarily at the general practitioner consultation. It primarily affects those individuals who were classified as group 3, the group that has taken the burden of recent health service charges increases.

Adolescent↗
PubMed1994

Pattern of injury in those dying from traumatic amputation caused by bomb blast.

Traumatic amputation of limbs caused by bomb blast carries a high risk of mortality. This paper describes 73 amputations in 34 deaths from bomb blast in Northern Ireland. The principal aim was to determine the sites of traumatic amputation to provide a biophysical basis for the development of protective measures. Few amputations were through joints; nearly all were through the bone shafts. The most common site in the tibia was the upper third. The distribution of femoral sites resulting from car bombs differed from that characterizing other types of explosion. For car bombs the principal site of amputation was the upper third; for other types of device it was the lower third. It is concluded that flailing is not a notable contributor to limb avulsion. The pattern of amputation is consistent with direct local pressure loads leading to bone fracture; the amputation itself is a secondary event arising from the flow of combustion products.

Amputation, Traumatic↗
PubMed1994

The effect of hypercapnia and hypoxemia on the cardiovascular responses to isoproterenol.

BACKGROUND: The reason for the increased risk of death with fenoterol and isoproterenol in asthma is unknown but may relate to their cardiovascular effects. Deaths from asthma usually occur outside hospital where hypoxemia, with or without hypercapnia, may exist. Both of these states can influence the cardiovascular system. We investigated whether different gas mixtures modified the cardiovascular effects of isoproterenol. METHOD: Nine healthy men were randomly assigned to receive each of three gas mixtures to achieve (1) normoxia-normocapnia, (2) hypercapnia (end-tidal PaCO2, 50 mm Hg), (3) hypoxemia-hypercapnia (arterial oxygen saturation, 90%; PaCO2, 50 mm Hg). Isoproterenol was administered with each of the gas mixtures. Cardiovascular measurements of heart rate, blood pressure, cardiac index, ejection fraction, fractional shortening, electromechanical systole, and the QTc interval were made before administration of the gases, as well as before and 5 minutes after isoproterenol administration. RESULTS: The changes after hypercapnia were not significantly different from those after normoxia-normocapnia. Hypoxemia-hypercapnia increased heart rate, systolic and diastolic blood pressure, QTc interval, cardiac index, ejection fraction, and fractional shortening. Isoproterenol increased heart rate, systolic blood pressure, QTc interval, cardiac index, ejection fraction, and fractional shortening while the subjects breathed the normoxia-normocapnia gas mixture. It caused similar changes with the other gas mixtures. The changes were additive. CONCLUSION: Isoproterenol and hypoxemia-hypercapnia will increase myocardial oxygen demand and could prove to be detrimental in severe asthma.

Adult↗
PubMed1994

Confounding by severity does not explain the association between fenoterol and asthma death.

Three recent case-control studies from New Zealand, and one from Saskatchewan, Canada, have found that fenoterol increases the risk of death in patients with severe asthma. It has been suggested that these findings may be due to confounding by severity, if fenoterol was selectively prescribed to more severe asthmatics. This 'confounding by severity' hypothesis has now been investigated in further analyses of data from the New Zealand case-control studies. This analysis found that among patients whose asthma was severe enough to require hospital admission (the population in whom the case-control studies were conducted), fenoterol was not preferentially prescribed to the more severe asthmatics. There was greater co-prescribing of other drugs with fenoterol (compared with salbutamol) during the later years of the epidemic, but these differences did not explain the excess risk associated with fenoterol, and there was little evidence of greater co-prescribing during the earlier years of the New Zealand epidemic of asthma deaths. There was no association between the prescription of fenoterol and markers of acute asthma severity or psychosocial problems. Patients were not selectively changed to fenoterol as a result of a severe attack resulting in a hospital admission. Most importantly, in the case-control studies of asthma deaths, the inhaled fenoterol relative risk increased when the analysis was restricted to sub-groups defined by markers of chronic asthma severity; whereas the relative risk would have decreased towards 1.0 in these sub-group analyses if the overall elevated risk for fenoterol was due to confounding by severity.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1994

The effects of sympathomimetics on the cardiovascular system of sheep.

1. Sheep hearts have been used to study the effects of beta-adrenoceptor (beta-AR) agonists in order to better understand the effects of common asthma treatment drugs on heart rate, cardiac power output and cardiac pathology. Hearts have been examined both in vivo and in vitro. 2. In whole anaesthetized sheep, isoprenaline, fenoterol and salbutamol induced dose-dependent increases in heart rate. Hypokalaemia in response to salbutamol was accentuated in hypoxia. Many of these hearts showed significant myocardial lesions. Hypoxia alone caused no significant cardiac response. 3. As expected, the beta 1-AR agonist dobutamine caused dose-dependent increases in heart performance (heart rate and cardiac power output). Both responses were blocked by metoprolol and propranolol. The beta 2-AR agonist salbutamol caused dose-dependent increases in heart rate and although cardiac output increased, cardiac power output remained unchanged as a consequence of the fall in peripheral resistance. The heart rate changes were blocked by metoprolol. Importantly, propranolol blocked both the heart rate response and the fall in peripheral resistance. 4. Isolated atrial strips showed a right shift of their dose-response curve to isoprenaline in the presence of the highly selective beta 2-AR antagonist ICI 118,551 at concentrations above 1 x 10(-8) mol/L. 5. We conclude that the sheep heart shows many pharmacological characteristics of the human heart which makes it a good pharmacological model in addition to its being amenable to many common techniques available for humans.

Albuterol↗
PubMed1994

Prescribed drug therapy and near-fatal asthma attacks.

Inhaled fenoterol has been associated with an increased risk of death in severe asthmatics, when compared to other adrenoceptor agonists. It is plausible that fenoterol may also increase the risk of near-fatal attacks. We have conducted a case-control study to investigate this hypothesis. The cases comprised Intensive Care Unit (ICU) admissions for asthma in the Wellington region during 1977-1988. For each of these cases, two age-matched controls were selected from asthma admissions to the same hospital during the same period. For the 155 cases and 305 controls, information on prescribed drug therapy was collected from the hospital admission records. The relative risk of a near-fatal asthma attack in patients prescribed inhaled fenoterol was 2.00 (95% confidence interval (CI) 1.35-2.97). An increased risk was also observed for oral theophylline (odds ratio (OR) = 1.88; 95% CI 1.26-2.79). For the 65 cases and 104 controls who had a previous admission for asthma in the previous 12 months, information relating to the previous admission was also collected; an increased risk was once again observed for inhaled fenoterol (OR = 2.18; 95% CI 1.10-4.33) and for oral theophylline (OR = 1.18; 95% CI 0.99-3.57). No other asthma drugs showed significantly increased risks. Although the ICU admission cases had generally been prescribed more asthma drugs than the hospital admission controls, and appeared to have more severe asthma, it is possible that the findings reported here are influenced by confounding by severity. We nevertheless estimate that our findings are consistent with the hypothesis that fenoterol increases the risk of near-fatal asthma attacks, and that they complement previous findings on fatal asthma attacks.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1994

Community-based asthma care: trial of a "credit card" asthma self-management plan.

Although asthma self-management plans are widely recommended as essential in the long-term treatment of adult asthma, there have been few studies examining their use. Our objective was to assess the effect of a "credit card" adult asthma self-management plan in a community experiencing major health problems from asthma, by means of a before and after intervention trial of the efficacy of the "credit card" plan, when introduced through community-based asthma clinics. The participants were 69 Maori people with asthma. The "credit card" plan consisted of written guidelines for the self-management of asthma, based on self-assessment of asthma severity, printed on a plastic card. On one side, management guidelines were based on the interpretation of peak expiratory flow rate (PEFR) recordings, whilst the reverse side was based on symptoms. The outcome measures used were before and after comparison of markers of asthma morbidity and requirement for acute medical treatment; and a structured questionnaire assessing the acceptability and use of the credit card plan. Following the introduction of the plan, the mean PEFR increased from 347 to 389 l.min-1, the percentage of nights woken fell from 30.4 to 16.9%, and the number of days "out of action" fell from 3.8 to 1.7%. The requirements for acute medical treatment also fell during the intervention period. Most participants commented favourably on the content and usefulness of the plan. In the situation of worsening asthma, 28% of subjects found the peak flow side of the card most helpful, 7% the symptoms side, and 48% found both sides equally helpful.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Comparison of two epidemiological protocols for measuring airway responsiveness and allergic sensitivity in adults.

In recent years, airway responsiveness has commonly been measured in epidemiological studies using one of two methods. In one method, histamine is administered via a handheld DeVilbiss nebulizer and in the other, methacholine is administered via a dosimeter. Allergic sensitivity has commonly been measured by either the allergen droplet method or by Phazet. We wanted to assess the comparability of airway responsiveness and of allergic sensitivity measured by both methods. A total of 48 volunteers, including normal and asthmatic subjects, participated in the study. Subjects first underwent one of the two tests of airway responsiveness and allergic sensitivity, and then returned within 10 days to undergo tests using the second protocol. Commencement protocol was allocated in random order. There was good agreement between both methods for assessing airway responsiveness and for assessing allergic sensitivity. The difference for dose response ratio (DRR) between histamine and methacholine was a 1.19 (95% (CI) 0.78, 1.82) fold changes, which was not statistically significant. Agreement between allergic sensitivity methods was perfect for Alternaria tenuis, good for rye-grass (kappa = 0.71) and moderate for cat and Dermatophagoides pteronyssinus (kappa approximately 0.5). It is possible to compare data from epidemiological studies which use these methods.

Adolescent↗
PubMed1994

Nebulized beta 2-adrenoceptor agonists do not affect plasma selenium or glutathione peroxidase activity in patients with asthma.

We investigated whether the beta 2-agonists fenoterol and salbutamol decreased plasma selenium and glutathione peroxidase activity in patients with asthma as this may partially explain the findings of reduced selenium status in asthmatic patients. Nine patients with asthma were studied on 3 occasions and inhaled either fenoterol (5 mg), salbutamol (5 mg) or ipratropium bromide (0.5 mg) administered by nebulization using a randomized, double blind, crossover design. Plasma selenium, glutathione peroxidase activity and potassium were measured prior to drug administration and at 15, 30 and 60 minutes after drug. None of the drugs had any effect on plasma selenium or glutathione peroxidase activity. Ipratropium bromide did not affect plasma potassium. Both beta 2-agonists significantly decreased plasma potassium. The mean (SD) maximum decrease was -0.79 (0-18) mmol/l for fenoterol and -0.26 (0-03) mmol/l for salbutamol (both p < or = 0.01) confirming systemic absorption of the drugs. beta 2-agonists are unlikely to be responsible for the reduced selenium status found in some patients with asthma.

Adrenergic beta-2 Receptor Agonists↗
PubMed1994

The myocardial effects of fenoterol, isoprenaline and salbutamol in normoxic and hypoxic sheep.

Three groups, each of four sheep, were randomly allocated under blinded conditions to receive the beta-adrenoceptor agonists, salbutamol, fenoterol or isoprenaline, in doses of 0.5, 2, 8, 32 and 128 micrograms/kg intravenously at 15-minute intervals. A separate group of four animals received equal volumes of saline. Heart rate was recorded immediately prior to each drug administration and serum potassium was measured. Three to 4 days later the experiment was repeated during induced systemic hypoxia and the animals then necropsied. All the agonists produced significant increases in heart rate. During hypoxia, lower heart rates were recorded than in the normoxic experiments. Under conditions of hypoxia, all the beta-agonists produced significant hypokalaemia. Sterile saline had no effect on either heart rate or serum potassium levels. At necropsy, myocardial lesions were found in animals receiving all three beta-agonists. Subendocardial haemorrhage was consistently seen in all animals receiving fenoterol. Multifocal myonecrosis of 3-4 days duration was present in the left ventricle of all animals receiving fenoterol, in two receiving isoprenaline and in two receiving salbutamol. The lesions were most severe in the papillary muscle and were visible grossly in one animal given fenoterol and one given isoprenaline. No lesions were found in the control animals.

Adrenergic beta-Agonists↗
PubMed1994

Polymorphisms of the angiotensin-converting-enzyme gene in subjects who die from coronary heart disease.

It has been shown that myocardial infarction survivors are more likely to carry an insertion/deletion polymorphism (I/D) of the angiotensin-converting-enzyme (ACE) gene than age-matched population controls. To test whether the association with coronary risk had been under-estimated, the frequency of the ACE I/D was studied in 213 fatal cases of definite and possible myocardial infarction which came to autopsy in the Belfast MONICA Project area. In comparison to controls from the same population, the autopsy cases had an increased frequency of the ACE D allele (p < 0.02). The overall odds ratios were 2.2 for DD vs. II, and 1.8 for ID vs II (test for trend p = 0.01). The findings bear out the hypothesis that the ACE I/D polymorphism is a risk factor for fatal myocardial infarction and sudden cardiac death.

Adult↗