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Biomedical subjects

M Iversen

Publications and source records attributed to M Iversen.

At least 19 recordsLinked to original sources
PubMed2006

Morphometric examination of native lungs in human lung allograft recipients.

The aim of the study was to estimate the degree of lung damage in patients with alpha(1)-antitrypsin (alpha1AT) deficiency, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) at the time of lung transplantation. Using unbiased stereological methods, lung-, bronchial- and vessel-volume, capillary length, and alveolar surface area and densities were estimated in recipient lungs from 21 consecutive patients with pre-transplant diagnoses including COPD (n=7), alpha1AT deficiency (n=6) and CF (n=8). Six unused adult donor lungs served as controls. Information relating to patient demography and pre-transplant lung function was obtained by retrospective chart review. Disease groups differed significantly with respect to demographics and pre-transplant lung function. Total lung volume was similar in all groups. Bronchial volume was significantly larger in CF patients compared to the control group (p<0.0001) and to the other two diagnostic groups: alpha1AT deficiency (p=0.0001) and COPD (p<0.0001). Alveolar surface density and capillary length density were significantly lower in patients with alpha1AT deficiency and COPD compared to controls (p<0.0001, respectively) and to patients with CF (p<0.0002, respectively). There were no correlations between clinical lung function and morphometric measurements. We conclude that unbiased microscopic stereological morphometry is an evolving science with the potential to elucidate pulmonary disease pathogenesis.

Adult↗
PubMed2005

The association between birth size and atopy in young North-European adults.

BACKGROUND: There is evidence that atopic disorders may begin in intra-uterine life; however, studies of birth characteristics and atopy show conflicting results. METHODS: We wanted to investigate the association of birth weight and head circumference with serum total or specific IgE, allergic rhinitis or eczema while addressing the influence of demographic and geographical factors. In this historic prospective cohort study, data were collected from birth records for 1683 men and women born in 1947-1973, from six Nordic-Baltic populations participating in the European Community Respiratory Health Survey. Blood tests for the measurement of serum total and specific IgE were available for 1494 subjects. In multiple regression analyses, adjustments were made for birth length, gender, age, study centre, adult body mass index, level of education, parental and adult smoking. RESULTS There was no association of birth weight (n=1230) and head circumference (n=285) with serum total IgE, specific IgE antibodies, allergic rhinitis or eczema. There were neither significant interactions by gender or age, nor heterogeneity between the study centres in the analyses of birth weight and adult atopy. CONCLUSION: Birth size was not associated with atopy among adults in this large Nordic-Baltic population study.

Adult↗
PubMed2005

Recurrent sarcoid granulomas in a transplanted lung derive from recipient immune cells.

From 1992-2004, single lung transplantation has been performed in seven patients with end-stage pulmonary sarcoidosis at the Danish National Centre for Lung Transplantation. The objective was to assess whether recurrent sarcoid granulomas in the lung graft are derived from recipient or donor immune cells. Three patients had sarcoid recurrence in the lung graft, but none had clinically overt extra-thoracic sarcoidosis. Graft sex-mismatch was present in one patient, a 52-yr-old female having a lung graft from a male donor. In order to discriminate between recipient and donor cells fluorescence in situ hybridisation (FISH), using probes for both X- and Y-chromosomes, was applied on transbronchial lung biopsies (TBB) from the lung graft containing sarcoid granulomas. The recipient's explanted lung contained multiple active sarcoid granulomas. TBB from the implanted donor lung 5 months after transplantation showed sarcoid granulomas. FISH showed that the immune cells in the granulomas were X-chromosome positive and Y-chromosome negative and, therefore, were derived from the recipient. In conclusion, the results indicate that recurrent sarcoid granulomas in the transplanted lung are derived from recipient's immune cells, having colonised the lung allograft.

Adult↗
PubMed2004

Is birth weight related to lung function and asthma symptoms in Nordic-Baltic adults?

Studies of birth characteristics and respiratory outcomes show contradictory findings. We wanted to investigate the association of birth weight with adult lung function as well as asthma symptoms while addressing the influence of demographic and environmental factors. Data was collected from the birth records of 1683 men and women born in 1947-1973 who were included in 6 Nordic-Baltic population samples investigated within the European Community Respiratory Health Survey (ECRHS). In the adults, an increase in birth weight from below 2500 g to above 4000 g was associated with an increase from 96% to 104% predicted one-second forced expiratory volume (P<0.01) and from 1.00% to 107% predicted forced vital capacity (P<0.01). However, birth weight was not associated with symptoms of asthma. After adjustment for birth length, gender, age, study centre, adult BMI, allergic rhinitis, parental and adult tobacco smoke exposure in multivariate regression analyses, birth weight was not associated with adult lung function or asthma symptoms. Further sub-sample analyses revealed no influence of gestational age, gender, age or geographical area. In this historic prospective cohort study an association was neither found between birth weight and adult lung function nor between birth weight and asthma symptoms.

Adult↗
PubMed2003

[Respiratory diseases in European farmers-II. Part of the European farmers' project].

BACKGROUND: The aim of the European Farmers' Project was to estimate the prevalence of respiratory diseases in farmers across Europe. Furthermore, risk factors for respiratory symptoms in different parts of agricultural production should be assessed. METHODS: In the first part of the study, 7496 farmers from four European countries answered a written questionaire. Of these, 229 were visited at their farms in the second part of the survey. On site, spirometry, allergy tests, as well exposure measurements were performed. RESULTS: Farmers with animal production had a significantly lower prevalence of allergic diseases than the general population. In contrast, the prevalence of chronic phlegm was higher in animal farmers. Organic dust toxic syndrome (ODTS) was a major predictor of chronic bronchitis. It was indicated that allergens found in the working environment could be transfered to the living environment of the farmer. Poor ventilation as well as high temperatures inside the animal buildings were shown to have a negative impact on respiratory symptoms and lung function parameters. CONCLUSION: Animal farmers are at high risk of chronic bronchitis. Intervention studies on the efficacy of different types of ventilation are now warranted. Furthermore, prospective studies on the associaton between ODTS and COPD should be done.

Adult↗
PubMed2003

Region-related risk factors for respiratory symptoms in European and Californian farmers.

The aim of this study was to determine the prevalences and regional risk factors for respiratory symptoms in European and Californian farmers. Farmers participating in the 1993-1997 surveys performed in Europe (n = 7,188) and California (n = 1,839) were included in this cross-sectional study. Respiratory symptoms and farming characteristics were assessed by questionnaire and risk factors associated with symptoms using logistic regression. The prevalences of rhinitis and asthma were lower in European (12.7% and 2.8%) than in Californian farmers (23.9% and 4.7%), but chronic bronchitis and toxic pneumonitis were more prevalent in Europe (10.7% and 12.2%) than in California (4.41% and 2.7%). Respiratory symptoms were associated with poultry and rabbit farming, flower growing and the cultivation of grain and oil plants. Working in Europe was a statistically significant risk factor for chronic bronchitis and toxic pneumonitis. Chronic bronchitis was related to toxic pneumonitis, work inside confinement buildings and greenhouses. Chronic bronchitis and toxic pneumonitis are highly prevalent among European farmers and are mainly attributable to indoor work.

Adult↗
PubMed2001

Exposure assessment and lung function in pig and poultry farmers.

OBJECTIVES: To describe the relation between spirometric findings and farming characteristics and variables of exposure to organic dust measured during work in animal buildings. Farmers have traditionally been described as having one of the most dangerous occupations, so a large scale study on European farmers was carried out. This is the report of the second part of that study. METHODS: 40 pig farmers in Denmark and 36 poultry farmers in Switzerland were chosen randomly and were assessed over 1 working day. RESULTS: Mean (SD) baseline spirometric results in pig farmers were higher than in poultry farmers (forced expiratory volume in 1 second (FEV(1)) (% of reference value) 108.3 (16.7) v 100.2 (14.2); p=0.04). Baseline lung function results were significantly associated with ventilation of the animal houses. Furthermore, temperature was related to spirometric findings in pig farmers. CONCLUSIONS: Ventilation of the animal house and temperature might influence respiratory morbidity in farmers.

Adult↗
PubMed2001

Respiratory symptoms in European animal farmers.

Farmers are known to be at high risk for the development of occupational airway disease. The aim of this European study was to determine which airway symptoms predominate in different types of animal farmers (cattle, pigs, poultry, sheep) and to compare the prevalence of symptoms to the general population. A total of 6,156 randomly selected animal farmers in Denmark, Germany (Schleswig-Holstein, Niedersachsen), Switzerland, and Spain completed a questionnaire on respiratory symptoms and farming characteristics in 1995-1997. The prevalence of general respiratory symptoms was compared to the results of the European Community Respiratory Health Survey (ECRHS) obtained in the same regions. Pig farmers were at highest risk for the development of work-related symptoms. A significant dose-response relationship between daily hours worked inside animal houses and symptoms was established for pig and poultry farmers. Additionally, self-reported nasal allergies (odds ratio (95% confidence interval): 3.92 (3.26-4.71)) and nasal irritation during work (3.98 (3.35-4.73)) were shown to be associated with the development of chronic phlegm. The prevalence of wheezing, shortness of breath, asthma and nasal allergies was signficantly lower among all farmers in the age group 20-44 yrs than among the general population. However, the prevalence of usually bringing up phlegm in winter among farmers was significantly higher than in the general population (9.4 (8.3-10.5%) versus 7.5 (6.5-8.5%)). Individual factors have been shown to be related to the prevalence of chronic phlegm among farmers. Additionally, this study could support the hypothesis that farming could be negatively related to allergic diseases.

Adult↗
PubMed2000

Working in swine-confinement buildings causes an accelerated decline in FEV1: a 7-yr follow-up of Danish farmers.

Work in swine confinement units causes exposure to high levels of organic dust and is associated with a high prevalence of work-related respiratory symptoms and probably with accelerated decline in forced expiratory volume in one second (FEV1). A 7-yr follow-up on FEV1, forced vital capacity (FVC), bronchial reactivity, and respiratory symptoms was performed on 181 Danish farmers. The participation rate was 76.3% and nonparticipants had more symptoms, were more likely to be current-smokers and had lower lung function in the first survey than participants in both surveys. Farmers who worked exclusively with pigs in the follow-up had an accelerated decline in FEV1 but not in FVC compared with dairy farmers, where the observed decline in FEV1 was close to the expected. For a nonsmoking pig farmer compared to a nonsmoking dairy farmer the mean additional decline in FEV1 was 17 mL x yr(-1) (53.0 mL x yr(-1) versus 36.1 mL x yr(-1)). The authors conclude that working in swine confinement units causes an accelerated decline in forced expiratory volume in one second but not in forced vital capacity. The mean decline is approximately 0.5 L during a working life and some farmers will develop clinically significant airway obstruction due to work in swine confinement units.

Adult↗
PubMed2000

Respiratory symptoms of obstructive lung disease in European crop farmers.

Crop farming as a risk factor for respiratory symptoms of obstructive lung disease was assessed. Random samples of crop farmers from four European countries were studied following a cross-sectional design. A questionnaire on respiratory symptoms and occupation was administered to determine prevalences, and the roles of the various crops as risk factors for respiratory symptoms were assessed through logistic regression modeling. The 4,793 crop farmers included in the study (response rate: 85.3%) reported the following respiratory symptoms: wheezing (14.9%), asthma (3.3%), nasal allergy (14.4%), chronic phlegm (12.4%), organic dust toxic syndrome (ODTS) (15.2%), and symptoms at work (22.0%). In the multivariate analysis, adjusting for age, sex, smoking, country, and exposure to other plants or livestock, flower growing was a risk factor for asthma (odds ratio [OR] 2.1, 95% confidence interval [CI] 1.1-3.9) and cultivating oil plants was associated with ODTS (OR 1.5, 95% CI 1.3-1.9), symptoms at work (OR 1.4, 95% CI 1.2- 1.7), and chronic phlegm (OR 1.3, 95% CI 1.1-1.6). Working inside greenhouses was a marginal risk factor for asthma (OR 2.1, 95% CI 0.9-4.5). We conclude that flower and oil plant production is associated with increased risk of respiratory symptoms in European crop farmers.

Adult↗
PubMed2000

Human health effects of dust exposure in animal confinement buildings.

Work in swine and poultry units is associated with exposure to significant levels of organic dust and endotoxins with the highest concentrations found in poultry houses, whereas values found in dairy and in cattle farming are much lower. Corresponding to this is an excess of work-related respiratory symptoms in swine farmers. A dose-response relationship exists between symptoms and number of working hours. Longitudinal studies have demonstrated an accelerated decline of lung function in swine farmers large enough to cause clinically significant disease in some farmers. Because of the large number of people needed in swine farming and the long working hours, swine farming has emerged as the major respiratory problem in farming. Experimental studies indicate that exposure has to be lowered substantially to avoid acute effects and longitudinal studies demonstrate that loss of lung function occurs in non-smoking swine farmers without respiratory symptoms and that accelerated decline in lung function occurs below endotoxin concentrations in dust (100 ng/m3) proposed as a safe threshold.

Agricultural Workers' Diseases↗
PubMed2000

Examination of serum IgE specific to pig protein in pig farmers by histamine release test.

Pig farmers are susceptible to a number of occupational hazards which may lead to respiratory symptoms. Therefore, inhalation allergy to pig was examined in pig farmers, including 40 farmers with work-related respiratory symptoms and 40 farmers without these symptoms. The presence in serum of IgE specific to pig protein was examined by the histamine release test, based on passive sensitization of basophil leukocytes with the farmers' serum. This test showed pig-specific IgE in a highly selected group of pig farmers in a previous study. In the present study of nonselected farmers, no swine-specific IgE was found in their serum. The results are thus in accordance with previous studies of nonselected populations of pig farmers tested by RAST and skin prick test. It can therefore be concluded that IgE-sensitization to pig protein is not a common phenomenon in pig farmers.

Adult↗
PubMed1997

Predictors of early- and late-phase reactions to bronchial allergen challenge.

The influence of inhaled steroids and predictive factors on the response to bronchial allergen challenge (BCA) was evaluated in 80 asthmatics allergic to Dermatophagoides pteronyssinus (Der p). All underwent BCA with Der p and measurement of early (EAR) and late asthmatic reaction (LAR). The cumulative dose of allergen producing 20% fall in FEV1 in the EAR (PD20) was calculated. Bronchial histamine provocation, conjunctival provocation test (CPT), and skin prick test with Der p extract were performed. Specific IgE to Der p in serum (RAST), blood eosinophil (EOS) count, serum eosinophil cationic protein, and eosinophil protein X were measured. Thirty patients (38%) were treated with inhaled steroids. All patients had at least a 20% fall in FEV1 in EAR. Some 42% of nonsteroid- and 33% of steroid-treated patients had LAR with fall in peak flow of at least 20%. For patients not treated with steroid, 35% of variation in PD20 was explained by RAST and histamine reactivity, and 53% of variation of observed PD20 could be predicted. The baseline FEV1, EOS, and EAR explained 28% of variation in LAR, and 28% of variation in observed LAR could be predicted. For patients treated with steroids, 38% of variation in PD20 was explained by EOS and histamine reactivity, and only 18% of variation of observed PD20 could be predicted. For patients treated with steroids, it was impossible to predict LAR. We conclude that to achieve a quantitative estimation of allergen-specific EAR and LAR, BCA cannot be replaced by the tests used in this study. Treatment with inhaled steroids modifies the response to BCA, making quantitative prediction of EAR less accurate and prediction of the magnitude of LAR impossible.

Administration, Inhalation↗
PubMed1997

Summer osmoregulatory capacity of the world's northernmost living salmonid.

Anadromous Arctic charr (Salvelinus alpinus L.) were caught on their way to and from the sea with the use of a fish trap placed in the Dieset watercourse located on the Spitsbergen Island (79 degrees 10' Northern latitude) within the high-Arctic Svalbard archipelago. When subjected to a seawater challenge test (34 parts/thousand at 4-5 degrees C), charr on their way to the sea showed only minor and temporary changes in blood plasma osmolality and Na+ and Mg2+ concentrations. The seawater tests also revealed good hypoosmoregulatory capacity for Arctic charr returning from the marine environment 4 wk later. A progressive decrease in seawater tolerance was first documented 7-11 days after their return to the freshwater habitat. Thus the Svalbard charr, being the northernmost anadromous salmonid and probably a direct descendant from the first Salvelinus immigrants to freshwater systems, undergoes a preparatory increase of hypoosmoregulatory capacity (smoltification) before entering the oceanic water bodies. Furthermore, the termination of their short annual seawater stay is probably elicited by factors controlling body systems other than osmoregulation.

Animals↗
PubMed1997

Predictors of long-term decline of lung function in farmers.

Farmers are exposed to high levels of organic dust with a high content of bacteria, fungi and endotoxins. The main exposure takes place during the many hours of work in closed animal confinement buildings, and working in swine confinement buildings gives the highest exposure. Corresponding to this, farmers have a high prevalence of respiratory symptoms and cross-sectional studies show evidence of airways obstruction. Swine farming seems to be an important risk factor for this in the farming community. Allergy plays a minor role in the development of symptoms, the most important allergy being towards storage mites. Longitudinal studies suggest that exposure to high concentrations of organic dust is associated with an accelerated decline in forced expiratory volume in one second.

Agricultural Workers' Diseases↗
PubMed1996

[Asthma symptoms and anti-asthma drugs in 4 Scandinavian countries].

A study of the occurrence of asthma in six areas in four Nordic countries showed 18-25 percent of the populations investigated to have had wheezing or whistling in the airways during the previous 12-month period, and 2-3 percent to have had asthma attacks. The use of anti-asthmatics was found to have differed from one to another of the areas included in the study, and the result suggest the difference to depend upon corresponding differences in the extent to which an active approach to treatment was adopted for the care of patients with asthmatic problems.

Adult↗