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Biomedical subjects

G Boman

Publications and source records attributed to G Boman.

At least 19 recordsLinked to original sources

The extracellular deposition of mast cell products is increased in hypertrophic airways smooth muscles in allergic asthma but not in nonallergic asthma.

BACKGROUND: Bronchial asthma is characterized by airways smooth muscle hypertrophy and infiltration of mast cells in the bronchial mucosa. The aim of this investigation was to study the distribution of mast cells in different compartments in the bronchial mucosa of allergic and nonallergic asthma in relation to airways remodeling. METHODS: Bronchial biopsies were obtained from 29 subjects with allergic and nonallergic asthma and healthy controls. The biopsies were stained for mast cells by means of the tryptase specific antibody AA1. Extracellular deposition of mast cell products were judged on a semi-quantitative scale. Mast cells per mm(2) were counted in epithelium, lamina propria and the smooth muscle compartment. Smooth muscle was visualized by actin antibodies and the proportion of staining of the biopsy estimated. Laminin and tenascin layers were visualized by their respective antibodies. RESULTS: Airways smooth muscle thickness was greater in allergic vs nonallergic asthma (P < 0.001). Mast cells were increased in all three compartments in both allergic and nonallergic asthma, with significantly higher numbers in smooth muscles in allergic asthma (P < 0.03). The extracellular deposition of mast cell products was more common in allergic than nonallergic asthma in lamina propria and smooth muscles (P = 0.025; P = 0.002, respectively). In patients with allergic asthma the numbers of mast cells with extracellular deposition of mast cell products were significantly correlated to the thickness of the laminin and tenascin layers. CONCLUSION: Our results suggest that there are large differences between allergic and nonallergic asthmatics as to mast cell activation and airways smooth muscle thickness. Our data implies that mast cells are causally involved in structural alterations in allergic asthma.

Adult↗

Obesity and nocturnal gastro-oesophageal reflux are related to onset of asthma and respiratory symptoms.

Several studies have identified obesity as a risk factor for asthma in both children and adults. An increased prevalence of asthma in subjects with gastro-oesophageal reflux (GOR) and obstructive sleep apnoea syndrome has also been reported. The aim of this investigation was to study obesity, nocturnal GOR and snoring as independent risk factors for onset of asthma and respiratory symptoms in a Nordic population. In a 5-10 yr follow-up study of the European Community Respiratory Health Survey in Iceland, Norway, Denmark, Sweden and Estonia, a postal questionnaire was sent to previous respondents. A total of 16,191 participants responded to the questionnaire. Reported onset of asthma, wheeze and night-time symptoms as well as nocturnal GOR and habitual snoring increased in prevalence along with the increase in body mass index (BMI). After adjusting for nocturnal GOR, habitual snoring and other confounders, obesity (BMI >30) remained significantly related to the onset of asthma, wheeze and night-time symptoms. Nocturnal GOR was independently related to the onset of asthma and in addition, both nocturnal GOR and habitual snoring were independently related to onset of wheeze and night-time symptoms. This study adds evidence to an independent relationship between obesity, nocturnal gastro-oesophageal reflux and habitual snoring and the onset of asthma and respiratory symptoms in adults.

Adult↗

Bronchial hyperresponsiveness in two populations with different prevalences of atopy.

SETTING: Random population samples of young adults from Tartu, Estonia (n = 307) and Uppsala, Sweden (n = 498) in the framework of the European Community Respiratory Health Survey (ECRHS). OBJECTIVE: To compare the prevalence and risk factors for bronchial hyperresponsiveness (BHR) to methacholine in two centres with similar climate and ethnicity but differences in the prevalence of atopy, asthma and respiratory symptoms. DESIGN: General population-based cross-sectional survey. RESULTS: The prevalence of BHR using the cut-off points 1.5, 1.0 and 0.5 mg was 19%, 12% and 8% in Tartu and 11%, 7% and 2%, respectively, in Uppsala. Current smoking was a common risk factor for BHR in both centres. Female sex (odds ratio [OR] 2.9), sensitisation to cat (OR 5.9) and visible mould in the home (OR 2.4) were independent risk factors for BHR in Tartu. In Uppsala, BHR was significantly associated with total IgE levels (OR 2.0) and exposure to environmental tobacco smoke (OR 3.3). CONCLUSION: The high prevalence of BHR can explain the high prevalence of respiratory symptoms in Tartu and indicates that causes other than asthma and atopy can be responsible for the high prevalence of BHR in a population.

Adult↗

Serum eosinophil cationic protein (S-ECP) in a population with low prevalence of atopy.

The study is a part of the European Community Respiratory Health Survey. A random sample (n = 351) of 20-44-year olds and persons of the same age with asthma-like symptoms or current asthma medication according to a postal questionnaire (n = 95) were studied. Interview was taken, methacholine challenge was done and ECP, total and specific IgE were measured from serum. The median S-ECP value was 8.0 micrograms/l in the random sample. The geometric mean of S-ECP was higher in subjects with, than without atopy (10.2 vs 8.9 micrograms/l, P < 0.01) and in subjects with bronchial hyperresponsiveness (BHR) than in subjects without BHR (9.9 vs 8.0 micrograms/l, P < 0.01). The levels correlated weakly to forced expiratory volume in one second (FEV1) (r = 0.13, P < 0.01) and were not independently correlated with respiratory symptoms, asthma or FEV1 after adjusting for BHR, IgE, sensitisation and smoking. Our results indicate that the level of eosinophil activation is low in a population with a low prevalence of atopy, even when BHR is common.

Adult↗

Obstructive sleep apnoea and urine catecholamines in hypertensive males: a population-based study.

Studies addressing the relationship between obstructive sleep apnoea (OSA) and sympathoadrenal activity have been criticized for poor control of factors known to confound sympathetic function, including hypertension. The aim of this study was to investigate the relationship between OSA and urinary catecholamines in a population-based sample of hypertensive males. In 1994, 2,668 males aged 40-79 yrs answered a questionnaire regarding sleep disorders and somatic diseases. Of those who reported hypertension, an age-stratified sample of 116 was selected for monitoring of breathing during sleep and overnight urine analysis. Subjects with OSA, defined as apnoea-hypopnoea index > or = 10 x h(-1), had higher concentrations of urinary normetanephrine (182+/-57 versus 141+/-45 micromol x mol(-1) creatinine, p<0.001) and metanephrine (70+/-28 versus 61+/-28 micromol mol(-1) creatinine, p<0.05) in comparison to subjects without OSA. In a multiple regression analysis, there was an association between variables of sleep-disordered breathing and normetanephrine and metanephrine concentrations, independent of major confounding factors. The authors concluded that, in a population-based sample of hypertensive males, obstructive sleep apnoea is associated with increased urinary concentrations of extraneuronal metabolites of catecholamines independent of major confounding factors, suggesting increased sympathoadrenal activity. Elevated sympathoadrenal activity may explain the increased cardiovascular morbidity associated with obstructive sleep apnoea.

Adult↗

Lung cancer risk in a population-based cohort of patients hospitalized for asthma in Sweden.

It has been suggested that asthma increases the risk of lung cancer in males but not in females. However, previous studies may suffer from report bias and are based on a small numbers of cases. The objective of the present study was to assess the incidence of lung cancer in males and females using a nationwide Swedish cohort of asthma patients. Patients (n=92,986) aged > or = 20 yrs with a hospital-discharge diagnosis of asthma and who were alive and free from malignancy I yr after first hospitalization were followed-up, for incidence of lung cancer during the period 1965-1994 (average duration of follow-up, 8.5 yrs). Their incidence of lung cancer was compared with that of the national population. The authors observed 713 lung cancers (standardized incidence ratio (SIR) 1.58, 95% confidence interval (CI) 1.47-1.70). The SIR was 1.51 in males (95% CI 1.38-1.65, 492 cases) and 1.78 in females (95% CI 1.55-2.03, 221 cases). The SIR decreased with duration of follow-up and increased with calendar period and age at first hospitalization. The risk of lung cancer was higher for squamous cell and small cell carcinoma than for adenocarcinoma, and it was higher in patients with other diseases as the main diagnosis and in patients hospitalized in departments other than internal and respiratory medicine. It was confirmed that asthma patients are at increased risk of lung cancer, but there is no heterogeneity in risk between the sexes. Several indirect arguments point towards a noncausal explanation of these findings; in particular, confounding by tobacco smoking is a plausible explanation.

Adenocarcinoma↗

[Can asthma deaths in young people be predicted and prevented?].

UNLABELLED: In spite of increased asthma prevalence, the mortality in the disease has decreased during the last two decades in Sweden and in some other countries. However, in the age group 15-24 years an increased death rate was noted at the end of the 1980s. Therefore we started a prospective study from 1994 with the aim of trying to analyse the precipitating factors of all deaths in the ages 1-34 years in which the death certificate alleged asthma or anaphylaxis as the main or contributing cause of death. We conducted a confidential telephone enquiry of the next of kin of the deceased using a modified questionnaire developed by the British Thoracic Association. When available, patient records and post mortem protocols were obtained. RESULTS: The mortality in asthma in the ages 1-34 years has decreased from around 5 per million/year to 0.5/million/year over the period 1987-1998. The main preventable factors found in this analysis are undertreatment, non-compliance, psychosocial factors including alcohol/drug abuse, food allergy and inhalation allergy. Lacking awareness of the risks and underestimation of the severity of the asthma both by the physician and the patient seem to be dominating factors.

Adolescent↗

[Great geographic variations in the prevalence of asthma and allergy. International population studies to explain the associative factors].

During the 1990's the international variation in the prevalence of asthma and allergy was studied in young adults (European Community Respiratory Health Survey, ECRHS) and in children (International Study of Asthma and Allergy in Children, ISAAC). The prevalence of asthma and allergy was highest in the United Kingdom, North America, Australia and New Zealand, lower in the Baltic countries and very low in some of the poorest republics of the former USSR. Children that lived in the countryside during the first year of life had a lower prevalence of atopic disease as teenager while in adults farmers had the highest prevalence of occupational asthma. In both investigations a negative association was found between having pets as a child and atopic sensitisation. This association could, however, be related to selection mechanisms. In a three year follow-up of the Swedish part of the ECRHS the incidence of asthma was higher in smokers than non-smokers. Passive smoking was associated with respiratory symptoms in both children and adults. Follow-ups of both studies are being planned or performed. Further analyses of the geographic differences may explain the reason for the rapid increase of asthma and allergy in the Western world.

Adolescent↗

Risk of adenocarcinomas of the oesophagus and gastric cardia in patients hospitalized for asthma.

In the first cohort study of the question we followed 92 986 (42 663 men and 50 323 women) adult patients hospitalized for asthma in Sweden from 1965 to 1994 for an average of 8.5 years to evaluate their risk of oesophageal and gastric cardia adenocarcinoma. Standardized incidence ratio (SIR) adjusted for gender, age and calendar year was used to estimate relative risk, using the Swedish nationwide cancer incidence rates as reference. Asthmatic patients overall had a moderately elevated risk for oesophageal adenocarcinoma (SIR = 1.5, 95% confidence interval CI, 0.9-2.5) and gastric cardia cancer (SIR = 1.4, 95% CI, 1.0-1.9). However, the excess risks were largely confined to asthmatic patients who also had a discharge record of gastro-oesophageal reflux (SIR = 7.5, 95% CI, 1.6-22.0 and SIR = 7.1, 95% CI, 3.1-14.0, respectively). No significant excess risk for oesophageal squamous-cell carcinoma or distal stomach cancer was observed. In conclusion, asthma is associated with a moderately elevated risk of developing oesophageal or gastric cardia adenocarcinoma. Special clinical vigilance vis-à-vis gastro-esophageal cancers seems unwarranted in asthmatic patients, but may be appropriate in those with clinically manifest gastro-oesophageal reflux.

Adenocarcinoma↗

Insomnia in men-a 10-year prospective population based study.

STUDY OBJECTIVES: to prospectively analyze changes in the prevalence of insomnia and the relationship between insomnia, aging, lifestyle, and medical disorders DESIGN: a longitudinal population survey. PARTICIPANTS: a randomly selected population sample of 2,602 men (age 30-69 years) from Uppsala in Sweden. INTERVENTION: all participants answered a questionnaire on sleep disturbances, lifestyle factors, and medical disorders in 1984 and again in 1994. MEASUREMENTS AND RESULTS: The prevalence of INSOMNIA was 10.3% in 1984 and 12.8% in 1994. No significant correlation was found between age and insomnia in any of the two time periods. Insomnia in 1994 was independently related to having insomnia in 1984 (OR=6.45), being over-weight (BMI> 27 kg/m2) (OR=1.35), physical inactivity (OR=1.42), alcohol dependence (OR=1.75), psychiatric disorders (OR=8.27) and joint/low back disorders (OR=2.95). The number of subject with reported insomnia in 1984 but not 1994 was 149. Subjects that quit smoking during the time period had an increased likeliness of remission (OR=2.70) while men who were overweight were less likely to remit (OR=0.43). CONCLUSIONS: We conclude that in men insomnia is related to lifestyle factors such as obesity, physical inactivity and alcohol dependency but not to aging. Medical disorders such as joint and low back disorders and psychiatric illnesses also increase the risk of reporting insomnia. This study demonstrates the close relationship between quality of sleep and overall health status.

Adult↗

Sleep-disordered breathing and glucose metabolism in hypertensive men: a population-based study.

OBJECTIVES: Diabetes mellitus and obstructive sleep apnoea (OSA) are two prevalent medical problems. Both are strongly associated with obesity and hypertension. The aim of this study was to investigate whether the association between OSA and diabetes is entirely dependent on obesity in hypertensive men. DESIGN: A population-based study. SETTING: The municipality of Uppsala, Sweden. Subjects and methods. In 1994, 2668 men aged 40-79 years answered a questionnaire regarding snoring, sleep disturbances and somatic diseases. An age-stratified sample of 116 hypertensive men was selected for a whole-night sleep study. Twenty-five of them had diabetes, defined as reporting regular medical controls for diabetes or having a fasting blood glucose > or =6.1 mmol L(-1). RESULTS: The prevalence of severe OSA, defined as apnoea-hypopnoea index (AHI) > or =20 h(-1) was significantly higher in diabetic patients than in normoglycaemic subjects (36 vs. 14.5%, P < 0.05). The sample was divided into four groups based on the presence or absence of severe OSA and the presence or absence of central obesity, defined as waist-to-hip ratio (WHR) > or =1.0. In a logistic regression model with the non-OSA, WHR <1.0 as the reference group, the adjusted odds ratio (95% confidence interval) for diabetes was 11.8 (2.0-69.8) in the OSA, WHR > or =1.0 group, whilst it was 3.6 (0.9-14.8) in the non-OSA, WHR > or =1.0 group and 5.7 (0.3-112) in the OSA, WHR <1.0 group. In a linear regression model, after adjustment for WHR, there was a significant relationship between variables of sleep-disordered breathing and fasting insulin, glucose and haemoglobin A1c. CONCLUSIONS: We conclude that, in hypertensive men, although obesity is the main risk factor for diabetes, coexistent severe OSA may add to this risk. Sleep breathing disorders, independent of central obesity, may influence plasma insulin and glycaemia.

Adult↗

Inflammation and structural changes in the airways of patients with primary Sjögren's syndrome.

The present study aimed to compare the cellular pattern and structural changes in the airways of patients with primary Sjögren's syndrome (pSS) with healthy controls. Bronchial biopsy specimens were obtained from seven subjects with pSS and seven healthy controls. All the patients with pSS had increased bronchial responsiveness to methacholine. In the biopsies inflammatory cells, cytokine-producing cells, tenascin and laminin were visual zed by immunostaining. Patients with pSS had a higher number of neutrophils and mast cells than healthy controls, while the number of eosinophils was similar in the two groups. The number of IL-8-positive cells was higher in pSS butthe numbers of IL-4-and IL-5-positive cells were not significantly different between pSS and healthy controls. The numbers of T cells in patients with pSS were higher than in healthy controls, while the numbers of CD25-positive cells were similar to the healthy controls. The degree of epithelial integrity in patients with pSS was significantly lower than in the control group and the tenascin and laminin layers were significantly thicker in the pSS group. There was a correlation between the number of mast cells and the thickness of the tenascin and laminin layers in pSS. In conclusion, we found that the cellular pattern in the bronchial mucosa of patients with pSS displayed large numbers of neutrophils, mast cells and T-lymphocytes. These changes in inflammatory cell numbers seemed to relate to the observed increased epithelial damage and structural changes of the subepithelium. The structural findings, but not the pattern of inflammatory cells, are shared with atopic asthma and may relate to the increased bronchial hyper-responsiveness seen in both diseases.

Adult↗

[Tuberculosis a threat again. Multiresistance in the Baltic States and in Russia; Nordic countries initiate cooperation to prevent transmission].

The incidence of tuberculosis (TB) has more than doubled in the Baltic States during the last decade and is now 10-15 times higher than in Sweden. It is also a serious problem in Russia. Strains resistant to one or several of the anti-tuberculous drugs are common as is multi-drug resistance (MDR), i.e. strains resistant to the two most effective drugs rifampicin and isoniazid. MDR-TB is very difficult to treat; the mortality rate is high. Initiatives have been taken in the Nordic countries in order to help to control and improve the situation by way of supportive measures.

Antitubercular Agents↗

[Shortages in Swedish tuberculosis care. Good results only in 71 percent of cases after 12-month treatment as shown in a current study].

During the period August 1994-December 1995 783 cases of active tuberculos (TB) were notified to the health authorities in Sweden. By means of questionnaires sent to the consulting physicians (92 per cent response rate) the treatment outcome was studied twelve months after the diagnosis. Out of 676 patients only 71 per cent were reported to have completed the treatment and be cured of TB. This indicates that there is room for improvement as regards monitoring patients, if necessary by Directly Observed Therapy (DOT), in order to make sure that prescribed treatment is adhered to.

Adolescent↗

Different airway responsiveness profiles in atopic asthma, nonatopic asthma, and Sjögren's syndrome. BHR Study Group. Bronchial hyperresponsiveness.

BACKGROUND: Different mechanisms may underlie bronchial hyperresponsiveness (BHR) in different diseases. The aim of this study was to investigate the bronchial responsiveness profile produced by three different challenge tests, methacholine, a direct stimulus, and two indirect stimuli, adenosine 5'-monophosphate (AMP) and cold air, in subjects with asthma and patients with Sjögren's syndrome. METHODS: The study population comprised 40 adult patients with asthma, 18 subjects with Sjögren's syndrome, and 20 controls. Blood samples were collected before each challenge for measurements of serum eosinophil peroxidase (S-EPO) and eosinophil cationic protein (S-ECP). The investigated subjects recorded peak expiratory flow and kept a symptom diary. RESULTS: Atopic subjects with asthma were significantly more hyperresponsive to AMP than nonatopic subjects with asthma (P=0.01) and subjects with Sjögren's syndrome (P=0.02). No difference was seen between atopic and nonatopic subjects with asthma in the case of challenges with methacholine or cold air. In atopic subjects with asthma, a significant correlation was found between challenges with methacholine and AMP (r=0.91, P=0.0001) and methacholine and cold air (r=0.83, P=0.004), but, in nonatopic subjects with asthma, no significant correlation was seen between methacholine and AMP or cold air challenges. In atopic subjects with asthma, the dose-response slope for AMP was correlated to S-EPO (r= -0.56; P = 0.01) and S-ECP (r= -0.51, P = 0.02), while no correlation between BHR and inflammation markers was found in the two other patient groups. CONCLUSIONS: The results of this study suggest that patients with asthma and subjects with Sjögren's syndrome display different bronchial responsiveness profiles for different challenge agents. Atopic subjects with asthma are more hyperresponsive to AMP than nonatopic subjects and patients with Sjögren's syndrome. More than one challenge may be required to detect different aspects of bronchial responsiveness.

Adenosine Monophosphate↗