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Biomedical subjects

D Jarvis

Publications and source records attributed to D Jarvis.

At least 55 records · Page 3Linked to original sources
PubMed1997

The distribution of total and specific serum IgE in the European Community Respiratory Health Survey.

BACKGROUND: Variations in the prevalence of atopy could provide important clues to the etiology of atopy and asthma. Although estimates of prevalence are available from different studies, a lack of standardization makes comparisons difficult. OBJECTIVE: This study was conducted to estimate the variation of geometric mean levels of serum IgE and the prevalence of specific IgE to common allergens between populations as part of the European Community Respiratory Health Survey (ECRHS), a multicenter survey of asthma and risk factors for asthma. METHODS: Random samples of subjects living in 37 centers in 16 countries who had answered a questionnaire about their respiratory symptoms were invited for further assessment including total serum IgE and the presence of specific IgE against house dust mite (Dermatophagoides pteronyssinus), timothy grass, cat, Cladosporium herbarum, and a local allergen. Sera were tested from 13,883 persons. RESULTS: The estimated prevalence of atopy, defined as the presence of at least one positive specific IgE, ranged from 16% in Albacete (Spain) to 45% in Christchurch (New Zealand). The geometric mean total serum IgE varied from 13 kU/L in Reykjavik (Iceland) to 62 kU/L in Bordeaux (France). There was no relation between the geometric mean total serum IgE in a center and the prevalence of atopy. CONCLUSIONS: There are substantial variations in the prevalence of atopy and the level of serum IgE. These variations are independent of each other and likely to be largely environmental in origin.

Allergens↗
PubMed1997

Physician-diagnosed asthma and drug utilization in the European Community Respiratory Health Survey.

The aim of this analysis was to estimate the geographical variation in the prevalence of physician-diagnosed asthma and treatment practice for asthma in young adults. The results are based on an ecological analysis of 34 centres in 14 countries, in which a total of 17,029 randomly selected subjects (52% females, age 20-48 yrs) underwent a structured interview and spirometry as part of the European Community Respiratory Health Survey. The sample was enriched with 2,903 symptomatic subjects when investigating treatment in subjects with physician-diagnosed asthma. The prevalence of physician-diagnosed asthma was highest in New Zealand and Australia (11-13%) and lowest in Erfurt, Germany (1.2%) and Spain (1.5-3.0%). The reported use of antiasthma medication in the last 12 months was also highest in New Zealand and Australia (12-16%) and correlated closely with the prevalence of diagnosed asthma (r=0.89, p<0.001). Herbal remedies against breathing problems had been used by 13% of subjects in Hamburg but the reported use of alternative remedies for breathing problems was low in most other centres. The use of inhaled anti-inflammatory drugs in subjects with physician-diagnosed asthma ranged from 49% in the UK to 17% in Italy and correlated with the prevalence of doctors' consultations within the last 12 months (r=0.66, p<0.05). The prevalence of anti-inflammatory treatment was positively related to the prevalence of nocturnal asthma symptoms (p<0.05). We conclude that there is a wide geographical variation in the prevalence of physician-diagnosed asthma and use of antiasthma medication. The geographical variation in the use of anti-inflammatory drugs among individuals with diagnosed asthma may be related to variations in asthma severity, as well as differences in treatment practices between countries.

Adult↗
PubMed1997

Variation in bronchial responsiveness in the European Community Respiratory Health Survey (ECRHS).

Attempts to compare bronchial responsiveness between populations have been hampered by between-study differences in the pharmacological agent of provocation, the method of administration and the summary statistic employed. The European Community Respiratory Health Survey used methacholine challenge delivered by Mefar dosimeter according to a standardized protocol used in 35 centres in 16 countries. Data were obtained from 13,161 men and women, aged 20-44 yrs at the start of the study. The dose of methacholine producing a 20% fall in forced expiratory volume in one second (FEV1) (PD20) and the regression coefficient of percentage decline in FEV1 with log dose, were calculated ("slope", after transformation), with and without calibration of nebulizers by weight and adjustment for nonresponse bias. Standardization for baseline lung function and variation in smoking prevalence was applied to slope. Results were robust to whichever summary measure was used, and to the various adjustments. Responsiveness was low in Iceland and Switzerland, and in most centres in Sweden, Italy and Spain, and high in New Zealand, Australia, the USA, Britain, France, Denmark and Germany. Bronchial responsiveness varies considerably in Europe, and high levels are not confined to the English-speaking world.

Adult↗
PubMed1997

The association of family size with atopy and atopic disease.

BACKGROUND: Studies in children have shown that family size is negatively associated with atopy and atopic disease. OBJECTIVE: To describe the association of family size with atopy and atopic disease in young adults. METHODS: A randomly selected sample of 1159 men and women aged 20-44 years provided information on respiratory symptoms, hay fever and eczema. Blood samples were taken for assessment of total IgE and specific IgE to house dust mite, grass, cat, Cladosporium and birch. The association of family size and birth order with respiratory symptoms, atopy and total IgE was assessed by multiple logistic and linear regression. RESULTS: There was a negative association between family size and the reporting of 'wheeze with breathlessness' (adjusted odds ratio for an increase of one sibling 0.85; 95% confidence interval 0.75-0.98), 'wheeze without a cold' (adjusted odds ratio for an increase of one sibling 0.85; 95% confidence interval 0.75-0.98) and 'asthma attacks' in the last 12 months (adjusted odds ratio for an increase of one sibling 0.77; 95% confidence interval 0.61-0.97), current 'hayfever and nasal allergies' (adjusted odds ratio for an increase of one sibling 0.84; 95% confidence interval 0.75-0.94) and sensitization to grass (adjusted odds ratio for an increase of one sibling 0.87; 95% confidence interval 0.76-0.99). Birth order was negatively associated with 'hayfever and nasal allergies' only. A decreased risk of sensitization to grass in those from large families did not fully explain the negative association between family size and hayfever. No statistically significant (P > 0.05) association of family size or birth order with the reporting of other respiratory symptoms, eczema, sensitization to the other allergens or total IgE was observed. CONCLUSION: There is a negative association between family size and some symptoms suggestive of asthma, 'hayfever and nasal allergies' and sensitization to grass in young adults. There is no consistent, significant association between family size and eczema, total IgE or sensitization to other allergens.

Adult↗
PubMed1996

Association of respiratory symptoms and lung function in young adults with use of domestic gas appliances.

BACKGROUND: There is evidence from some studies that people living in homes with gas stoves and other unvented gas appliances experience more respiratory symptoms than those who use other fuels for cooking and heating, but other studies have found no such association. We have investigated whether the use of gas appliances is associated with an increased risk of respiratory symptoms and whether sensitisation to common environmental allergens modifies any such association. METHODS: A stratified random sample of 15,000 adults aged 20-44 years, living in three towns in East Anglia, UK, were sent a questionnaire on asthma and hayfever. From those who responded, a random sample of 1864 were invited to complete an extended questionnaire that included questions on use of gas appliances, to give blood samples for measurements of total IgE and specific IgE to common allergens, and to undergo tests of respiratory function, 659 women and 500 men agreed to an interview. The association of the use of gas appliances with respiratory symptoms, total IgE, specific IgE, and respiratory function was assessed by logistic and multiple regression models. FINDINGS: Women who reported they mainly used gas for cooking had an increased risk of several asthma-like symptoms during the past 12 months including wheeze (odds ratio 2.07 [95% CI 1.41-3.05]), waking with shortness of breath (2.32 [1.25-4.34]), and asthma attacks (2.60 [1.20 -5.6]). Gas cooking increased the risk of symptoms more in women who were atopic than in non-atopic women but the difference did not reach significance (p . 0.05). Women who used a gas stove or had an open gas fire had reduced lung function (forced expiratory volume in 1 s [FEV1]) and increased airways obstruction (FEV1 as a percentage of forced vital capacity) compared with women who did not. These associations were not observed in men. INTERPRETATION: In East Anglia, the use of gas cooking is significantly associated with subjective and objective markers of respiratory morbidity in women but not in men. Women may be more susceptible than men to the products of gas combustion or they may have greater exposure to high concentrations of these products because they cook more frequently than men.

Adult↗
PubMed1996

Measuring atopy in a multi-centre epidemiological study.

Skin prick tests are used as a measure of atopy in epidemiological studies, but results may be influenced by the fieldworker performing the test. In a multi-centre epidemiological study the method of reporting the results should consider the need for comparability of findings from different centres. Data on over 1000 subjects from three English centres of the European Community Respiratory Health Survey were analysed to determine whether allergen wheal should be adjusted for histamine wheal, and what cutoff diameter gave the most comparable results. No consistent relation between allergen wheal diameter and histamine wheal diameter was found for any fieldworker or allergen. A cutoff of > 0 mm for a positive result gave a more consistent relation with the corresponding specific IgE value between fieldworkers than either a cutoff of > or = 3 mm or the use of the mean wheal diameter. While this result is not immediately generalisable to studies using different skin prick test reagents, the method of analysis to determine the appropriate criterion of reporting can be used in other epidemiological studies.

Adult↗
PubMed1996

Spectral analysis of an acoustic respiratory signal with a view to developing an apnoea monitor.

The movement of air through the air passages during normal respiration generates an acoustic signal which can be detected from the surface of the body at suitable sites with the aid of a microphone applied to the skin. The spectral characteristics of these sounds were analysed to see if they could be differentiated from other sources of sound. During normal respiration the other major source of sound was that transmitted from the heart, and this could be filtered out with a band pass filter. A prototype apnoea monitor was built which utilised these sound signals as an indicator of respiration and underwent preliminary testing. Although such acoustic signals have the potential to indicate respiration, and cardiac sounds can be effectively filtered, further work would be required to recognise and reject other extraneous sources of sound interfering with the respiratory signal.

Acoustics↗
PubMed1995

Adjustment of reported prevalence of respiratory symptoms for non-response in a multi-centre health survey.

BACKGROUND: Estimation of non-response bias by modelling prevalence as a function of the number of mailings required to achieve a response, or of the cumulative response, has been advocated, but the models have not incorporated age and sex, differential response rates by age and sex, or season of response. METHODS: The effect on age-sex standardized prevalence of estimating non-response bias using a variety of models was investigated using data on nine symptom and medication questions from 13,007 subjects in the three English centres of the European Community Respiratory Health Survey. Comparison was made of goodness of fit and the prediction of responses in a 25% follow-up sample with the observed values. RESULTS: Despite low response rates in Cambridge and significant decreases in prevalence with additional mailings or increasing cumulative response in Norwich, there were only small effects on estimated age-sex standardized prevalences. No model was consistently better for any centre or question. CONCLUSIONS: The models are useful for exploring the sensitivity of estimated prevalence to non-response bias, but should be used with caution to adjust estimates. Ideally first mailings should be staggered over the whole year so that mailing and season are not confounded, and sufficient mailings or other contacts carried out for the whole sample to ensure a high response rate.

Adult↗
PubMed1995

The association of age, gender and smoking with total IgE and specific IgE.

BACKGROUND: Smoking has been identified as a risk factor for atopy but there are difficulties in interpreting many of the previous studies because the subjects who have been studied have not been representative of the entire population and because there is confounding between gender and smoking. OBJECTIVE: To investigate the association of age, gender and smoking with total IgE and specific IgE to house dust mite, grass and cat. METHODS: A stratified random sample of 20-44 year olds living in three centres in East Anglia and registered with a local general practitioner had blood taken for total immunoglobulin E (IgE) and specific IgE. A smoking history was obtained from a structured interviewer-led questionnaire. RESULTS: Among non-smokers geometric mean total IgE was higher in men than women but unrelated to age. Smoking explained less than 1% of the variation in total IgE. Smoking was associated with an increased risk of sensitization to house dust mite (odds ratio 1.59; 95% confidence interval 1.02-2.48) but a decreased risk of sensitization to grass (odds ratio 0.45; 95% confidence interval 0.28-0.71) and cat (odds ratio 0.47; 0.24-0.94). CONCLUSION: Men aged 20-44 years have higher total IgE levels than women of the same age. In young adults smoking explains little of the variation in total IgE and its association with sensitization to common allergens varies between allergens.

Adult↗
PubMed1994

The European Community Respiratory Health Survey.

The European Community Respiratory Health Survey (ECRHS) was planned to answer specific questions about the distribution of asthma and health care given for asthma in the European Community. Specifically, the survey is designed to estimate variations in the prevalence of asthma, asthma-like symptoms and airway responsiveness; to estimate variations in exposures to known or suspected risk factors for asthma, and assess to what extent these variations explain the variations in the prevalence of disease; and to estimate differences in the use of medication for asthma. The protocol provides specific instructions on the sampling strategy adopted by the survey teams, as well as providing instructions on the use of questionnaires, the tests for allergy, lung function measurements, tests of airway responsiveness, and blood and urine collection. The principal data collection sheets and questionnaires are provided in the appendices, together with information on coding and quality control. The protocol is published as a reference for those who wish to know more of the methods used in the study, and also to give other groups who wish to collect comparable data access to the detailed methodology.

Asthma↗
PubMed1994

Prevalence of asthma and asthma-like symptoms in young adults living in three east Anglian towns.

BACKGROUND: The European Community respiratory health survey is examining the prevalence of asthma and risk factors for asthma. AIM: As part of this multinational survey, a study was undertaken to determine the prevalence of asthma and asthma-like symptoms in young adults living in Cambridge, Ipswich and Norwich using a postal questionnaire. METHOD: A previously validated symptom questionnaire was sent to 2500 men and 2500 women aged 20-44 years living in and registered with a general practitioner in each of the three towns. RESULTS: In total, approximately 9000 adults responded. The prevalence of symptoms suggestive of asthma was found to be similar in the three towns. Of respondents, 8% reported having been woken by an attack of shortness of breath at some time in the last 12 months, higher than previously reported. Five per cent reported having had an asthma attack. CONCLUSION: General practitioners wishing to examine asthma prevalence in their own practice population could use a similar methodology.

Adult↗
PubMed1992

Chemoprevention of chemically induced skin tumor development by diallyl sulfide and diallyl disulfide.

Garlic and onion oil have been shown to inhibit chemically induced skin tumor development in mice. In the present study, the effects of diallyl sulfide and diallyl disulfide, oil-soluble constituents of garlic and onion, on 7,12-dimethylbenz(a)anthracene-induced and 12,O-tetradecanoylphorbol-13-acetate-promoted skin tumor formation were examined in SENCAR mice. Topical application of diallyl sulfide or diallyl disulfide significantly inhibited skin papilloma formation from the ninth week of promotion and significantly increased the rate of survival in the murine model. Our findings support earlier evidence that these naturally occurring compounds may be useful for the chemoprevention of certain types of tumors.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1991

Substance P immunoreactive nerves in airways from asthmatics and nonasthmatics.

Substance P has been localized to nerves supplying smooth muscle, blood vessels and glands in the human lung and may play a major role in the pathophysiology of asthma. We performed a morphological study, using the avidin biotin peroxidase immunostaining technique, to examine sections of airway wall from subjects with and without asthma for the presence of substance P immunoreactive nerve fibres. Airways of 200 microns-12 mm were obtained from autopsy, lobectomy and bronchoscopy. Quantitative morphological analysis was performed on 3 mm diameter airways from three asthmatic and three nonasthmatic subjects collected at autopsy, and on biopsies of 10 mm diameter airways from eight asthmatic and thirteen nonasthematic subjects. There was an increase in both the number and the length of substance P immunoreactive nerve fibres, in airways from subjects with asthma when compared with airways from subjects without asthma. Fibres were found in the lamina propria and surrounding vessels and glands. The fibres were commonly seen as bundles rather than as single fibres. There was no difference in the number of substance P nerves between normal subjects and subjects with chronic airflow limitation (CAL). The difference in the number, length and morphological characteristics of the substance P immunoreactive nerves between asthmatic and nonasthmatic subjects were striking.

Adult↗
PubMed1989

Absence of immunoreactive vasoactive intestinal polypeptide in tissue from the lungs of patients with asthma.

Vasoactive intestinal polypeptide (VIP) is a neuropeptide present in the nerve fibers of normal lungs, where it acts to relax bronchial smooth muscle. To determine its presence or absence in the lungs of patients with asthma, we examined lung tissue obtained at autopsy or lobectomy from five patients with asthma and nine without asthma. The avidin-biotin-peroxidase complex technique was used to stain tissue for immunoreactivity to VIP. At least 80 tissue sections from each patient were examined microscopically; the airway diameter ranged from 100 microns to 1.2 cm. Immunoreactive VIP was seen within nerves in more than 92 percent of the sections from the lungs of patients without asthma. No VIP was seen in any of 468 sections we could evaluate that were obtained from the lungs of patients with asthma. As a control for the nonspecific destruction of neuropeptides, immunostaining for substance P was also carried out. Abundant amounts of this neuropeptide were seen within nerves in tissue from the lungs of all patients. We conclude that in patients with asthma there is a loss of VIP from the pulmonary nerve fibers that may diminish neurogenically mediated bronchodilation. Whether this loss is a cause or a result of asthma is unclear.

Adolescent↗
PubMed1988

Systemic air embolism during laser bronchoscopy.

We report a case of massive, fatal, systemic gas embolism which occurred during the course of laser bronchoscopic resection of a bronchial carcinoma. The clinical features of systemic air embolism are discussed.

Aged↗
PubMed1987

Viability and recovery from degranulation of isolated rat peritoneal mast cells.

Using a culture system that allows prolonged maintenance of purified populations of peritoneal mast cells, we have examined them following stimulation by non-immunologic or immunologic agents. Employing phase-contrast microscopy of living cells and various pharmacological manipulations, we have noted that the recovery process includes a reduction in cell size, the probable sealing of exocytotic cavities, a pronounced displacement of the cell nucleus and a resynthesis of histamine. During recovery, mast cells can entrap molecules from the extracellular fluid and later release these substances by a Ca-dependent mechanism. Our results suggest that microfilaments, calmodulin, Ca, and metabolic energy are necessary for recovery.

Animals↗