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Biomedical subjects

C Janson

Publications and source records attributed to C Janson.

At least 37 records · Page 2Linked to original sources
PubMed2000

Onset and remission of allergic rhinitis and asthma and the relationship with atopic sensitization and smoking.

The aim of this study was to assess the influence of some risk factors for onset and remission of allergic rhinitis and asthma in Swedish adults. A random sample of 1,370 subjects, age 20 to 44 yr was investigated by means of postal questionnaires in 1990 and 1993. Skin prick tests were conducted in 1991-1992. The association between risk factors and onset or remission of allergic rhinitis and asthma was estimated using multivariate logistic regression analysis. Onset of allergic rhinitis was associated with sensitization to birch (odds ratio [OR] = 6.5), Parietaria (OR = 7.4); and pets (OR = 3.0) and with female sex (OR = 1.9). Onset of asthma was associated with allergic rhinitis (OR = 4.9), sensitization to pets (OR = 2.4); and with smoking (OR = 3.0). Onset of asthma was strongly associated with allergic rhinitis among atopics (OR = 5.7), but onset of asthma and rhinitis also tended to be related among nonatopics (OR = 3.5). A strong association between smoking and onset of asthma was found among nonatopics (OR = 5.7). In conclusion, sensitization to pollens and pets were risk factors for onset of allergic rhinitis, whereas allergic rhinitis, sensitization to pets, and smoking were risk factors for onset of asthma.

Adult↗
PubMed2000

Inflammation and structural changes in the airways of patients with atopic and nonatopic asthma. BHR Group.

The aim of the present study was to compare the cellular pattern and structural changes in the airway walls of atopic and nonatopic patients with asthma. Bronchial biopsy specimens were obtained from 13 atopic subjects with asthma, nine nonatopic patients with asthma, and seven healthy control subjects and investigated using immunohistochemical methods. The number of eosinophils increased in both asthma groups, but significantly more in the atopic group. The number of mast cells increased similarly in the two asthma groups, whereas the number of neutrophils increased only in the nonatopic asthma group. The number of T-lymphocytes (CD3-, CD4-, CD8-, CD-25-positive cells) was higher in patients with atopic asthma compared with nonatopic asthma. Interleukin-4 (IL-4) and IL-5-positive cells were more frequently found in the atopic asthma group, whereas cells staining for IL-8 were more frequent in the nonatopic group. The degree of epithelial damage was significantly higher in the atopic asthma group compared with the control subjects and the nonatopic asthmatics. The tenascin and laminin layer was significantly thicker in the atopic group compared with the group of nonatopic asthmatics. In the atopic group, there was a significant negative correlation between epithelial integrity (defined as the relative length of intact epithelium) and the eosinophil count and also between the number of CD25-positive cells and epithelial integrity. The number of mast cells correlated positively with the thickness of tenascin- and laminin-positive layers. In conclusion, we provide evidence of different patterns of involvement of inflammatory cells in atopic and nonatopic patients with asthma. There were also structural differences in the bronchial mucous membrane between atopic asthma and nonatopic asthma. This suggests that there are differences in the extent of the immunopathologic response of these clinically distinct forms of asthma.

Adolescent↗
PubMed1999

Association between atopic sensitization and asthma and bronchial hyperresponsiveness in swedish adults: pets, and not mites, are the most important allergens.

BACKGROUND: Atopic sensitization is a well-known risk factor for asthma and bronchial hyperresponsiveness (BHR). Mites have been regarded as the most important allergens, but the prevalence of sensitization to mites is relatively low in Sweden. OBJECTIVE: The aim of the study was to investigate possible associations between sensitization to various allergens and asthma and BHR in adults. METHODS: A random sample of 1859 subjects, aged 20 to 46 years, was investigated in a cross-sectional study by using a questionnaire, skin prick tests (SPTs), specific and total IgE measurements, and methacholine bronchial challenge tests. Possible associations were analyzed univariately and by using multivariate logistic regression analysis and proportional hazard regression analysis. RESULTS: Positive SPT and specific IgE results were more common in subjects with asthma and BHR than in subjects without these conditions for all allergens. The independent associations between positive SPT responses and asthma and BHR are given as adjusted prevalence ratios (PRRs): pets and asthma, PRR = 3.6; pets and BHR, PRR = 2.0; grass and asthma, PRR = 2.0; grass and BHR, PRR = 1.7; mites and asthma, PRR = 1.4; and mites and BHR, PRR = 1.2. The use of specific IgE measurements instead of SPTs showed essentially similar results. CONCLUSION: Cats and dogs were the sensitizing allergens most closely associated with asthma and BHR. The relationships with sensitization to grass and mites were less pronounced.

Adult↗
PubMed1999

Inflammatory markers in acute exacerbations of obstructive pulmonary disease: predictive value in relation to smoking history.

The aim of this study was to investigate the relationship between the effect of emergency treatment and inflammatory markers in patients with acute exacerbations of obstructive pulmonary disease, especially with respect to smoking history. We investigated 50 unselected patients with acute bronchial obstruction. Blood, urine and sputum samples were taken and analysed for eosinophil and neutrophil markers. The patients were observed for at least 2 h and recordings of forced expiratory volume in 1 s (FEV1) were taken. They were re-examined after 1 and 4 weeks. The absolute levels of inflammatory markers did not differ significantly between non- or short-term smokers (< or = 5 pack-years) and long-term smokers (> 5 pack-years) with the exception of myeloperoxidase in serum (S-MPO), which was higher in long-term smokers. The patients with higher levels of eosinophil markers before emergency treatment experienced a greater improvement in lung function. In non- or short-term smokers this relationship was found in blood and urine, whereas in long-term smokers it was seen in sputum. No correlation was found between neutrophil markers and changes in lung function. We conclude that patients with obstructive pulmonary disease with acute exacerbations and high levels of eosinophil markers respond well to treatment.

Acute Disease↗
PubMed1999

Exhaled nitric oxide and its relationship to airway responsiveness and atopy in asthma. BHR-Study Group.

Exhaled nitric oxide (NO) has attracted increasing interest as a non-invasive marker of airway inflammation. The purpose of this study was to determine whether exhaled nitric oxide in subjects with asthma varied according to their atopic status and to examine its correlation with airway hyperresponsiveness and lung function measurements. Forty patients with asthma and 13 controls participated in the study. Nitric oxide was measured on three occasions with intervals of at least 3 days, using a chemiluminescence method. Airway responsiveness was assessed with methacholine challenge and lung function measurements were made. All subjects recorded peak expiratory flow and kept a symptom diary during a 17-day period. There was no significant difference in lung function measurements, peak expiratory flow or symptom score between the two asthma groups. Atopic patients with asthma had a significantly higher mean amount of exhaled NO than non-atopic subjects with asthma (162 +/- 68 vs. 113 +/- 55 nl min-1; P = 0.03) and the control group (88 +/- 52 nl min-1; P = 0.004). No significant difference was found in the amount of exhaled NO between non-atopic patients with asthma and the controls. In atopic subjects with asthma the mean exhaled NO was significantly correlated to the dose-response slope for methacholine (r = -0.52; P = 0.02), while no such correlation was found in the non-atopic group. In conclusion; in this study, atopic subjects with asthma had higher levels of exhaled NO than non-atopic subjects. Atopic status should be taken into account when measuring levels of exhaled NO in subjects with asthma.

Adolescent↗
PubMed1999

Sensitization to airborne and food allergens in Reykjavík (Iceland) and Uppsala (Sweden) - a comparative study.

BACKGROUND: The aim of this study was to compare the prevalence of atopic sensitization and possible risk factors for allergies in two ethnically similar but geographically widely separated urban populations. METHODS: Data from two centers of the European Community Respiratory Health Survey, Reykjavik, Iceland, and Uppsala, Sweden, were utilized. This included a structured interview, skin prick tests, and blood samples for total and specific IgE for common aeroallergens. Additional measurements of specific IgE antibodies to common food antigens were performed. Furthermore, data on social environment, lifestyle, air pollution, and meteorologic variables were compared. RESULTS: Skin prick tests were done on 540 individuals in Reykjavik and 527 in Uppsala. The overall prevalence of at least one positive prick test was 20.5% in Reykjavik and 34.2% in Uppsala (P<0.001). Total and specific IgE were measured in serum from 521 subjects in Reykjavik and 472 in Uppsala. The geometric mean value for total IgE was significantly lower in Reykjavik (13.4 kU/l) than in Uppsala (24.7 kU/l) (P<0.001). Similarly, the overall prevalence of at least one specific IgE to airborne allergens was 23.6% in Reykjavik and 32.3% in Uppsala (P<0.01). Specific IgE to a food panel (fx5) was measured in 502 subjects in Reykjavik, and 434 in Uppsala. In Reykjavik, 20 individuals (4.0%) were positive to one or more of the allergens in the food panel compared to 27 (6.0%) in Uppsala. When the single allergens present in the food panel were measured, altogether 16 positive reactions were found in Reykjavik compared to 47 in Uppsala (P<0.05). CONCLUSIONS: The prevalence of sensitization to both airborne and food allergens was lower in Reykjavik than in Uppsala. The difference may be due to environmental and/or dietary differences or to some yet undefined factor.

Adult↗
PubMed1999

Adult asthmatics sensitized to cats and dogs: symptoms, severity, and bronchial hyperresponsiveness in patients with furred animals at home and patients without these animals.

BACKGROUND: Domestic furred animals are important sources of allergens in asthma, but few clinical studies have investigated the effects of exposure to or elimination of these allergens. The objective of this study was to investigate whether pet-sensitized asthmatics with pets at home have worsened asthma, compared with similar asthmatics without pets. METHODS: In a cross-sectional epidemiologic study, 129 adult asthmatics sensitized to cats or dogs were investigated by interviews, skin prick tests, specific IgE, eosinophil counts, and bronchial methacholine challenge tests. Patients with a cat or dog at home (n=39) were compared with subjects without pets (n=90). RESULTS: More subjects with pets had symptoms, inhaled or oral steroids, abnormal peak-flow records, higher eosinophil counts, and a higher degree of bronchial hyperresponsiveness than subjects without pets. Asthmatics with pets more frequently ascribed their symptoms to their home environment, but fewer of them reported that their symptoms were elicited by contact with cats or dogs. CONCLUSIONS: This study strongly indicates that living with a cat or a dog aggravates symptoms and biomarkers of airway inflammation in asthmatics sensitized to cats or dogs. The study indicates that avoidance of these allergens may be an important measure in the treatment of sensitized asthmatics.

Adolescent↗
PubMed1999

Increased nitric oxide in expired air in patients with Sjögren's syndrome. BHR study group. Bronchial hyperresponsiveness.

Nitric oxide has an important role in the regulation of airway function and can have pro-inflammatory effects. Bronchial hyperresponsiveness (BHR) and respiratory symptoms are common in patients with Sjögren's syndrome (SS). The aim of this study was to determine whether patients with SS have an increased amount of exhaled NO and whether this NO correlates with respiratory symptoms and BHR. Exhaled NO was measured in 18 patients with SS and 13 normal subjects on three different occasions with intervals of at least 3 days using a chemiluminescence method. Airway responsiveness was assessed with methacholine provocation. Serum levels of myeloperoxidase (MPO), human neutrophil lipocalin (HNL), eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO) were measured. Exhaled NO was significantly higher in patients with SS than in controls (147+/-82 versus 88+/-52 nL x min(-1); mean+/-SD; p=0.041). Exhaled NO was correlated with age (partial r=0.52, p=0.006) and serum HNL (partial r=0.46, p=0.014). There were no significant correlations between exhaled NO and respiratory symptoms, BHR or serum MPO, ECP or EPO. Disease duration was negatively associated with serum MPO (r=-0.47, p=0.043). In patients with SS, a positive correlation was found between symptom score and serum ECP (partial r=0.65, p=0.003) and EPO (partial r=0.62, p=0.004) and a negative correlation with age (partial r=-0.60, p=0.005). In conclusion, elevated levels of exhaled nitric oxide in patients with Sjögren's syndrome were demonstrated. The mechanism underlying this increase in exhaled nitric oxide in Sjögren's syndrome is not known.

Breath Tests↗
PubMed1999

Comparison of two methacholine challenge methods using Spira-2 or Mefar dosimeter.

Two bronchial challenge protocols with breath-actuated dosimeters, Spira Elektro-2 and Mefar, with similar cumulative dose steps were compared in 28 patients with mild to moderate asthma. Methacholine challenges were performed after two different protocols at the same time of day in random order 3 or 4 days apart. The provocative dose of methacholine producing a 20% fall in forced expiratory volume in 1 second (PD20) was lower when determined by Spira than with the Mefar dosimeter (P < 0.05). Transition equations calculated by linear regression analysis were: PD20mefar = exp10[0.897 + 0.678(logPD20spira)] (P < 0.05; r = 0.62) and PD20spira = exp10[0.759 + 0.559 (log PD20mefar)] (P < 0.05; r = 0.62). The slopes were calculated by regressing the percentage fall in FEV1 on log10 (dose) and transformed as slope = 100/(regression coefficient + 10). The mean slope (95% CI) for Spira was 3.1 (2.6-3.7) and for Mefar 4.4 (3.6-5.1) (P < 0.005). Regression equations calculated by linear regression analysis were: slope(mefar) = 2.126 + 0.712 slope(spira) (P < 0.05; r = 0.51) and slope(spira) = 1.551 + 0.365 slope(mefar) (P < 0.05; r = 0.51). In conclusion, PD20 was smaller and the decline in FEV1/log(dose) curve steeper using the Spira compared with the Mefar protocol. The dose-response curves should be validated and transition equations calculated when bronchial reactivity to inhaled agents is compared, even while using apparently similar well-standardized dosimeter methods.

Adolescent↗
PubMed1999

Evolution of sleep apnea syndrome in sleepy snorers: a population-based prospective study.

This study followed a small number of men previously studied polysomnographically 10 yr earlier to investigate the relationship between the development of sleep-disordered breathing and age, weight gain, and smoking. In 1984, 3,201 men answered a questionnaire including questions about snoring and excessive daytime sleepiness (EDS). Of those reporting symptoms related to obstructive sleep apnea syndrome (OSAS), a random sample of 61 men was investigated using whole-night polysomnography in 1985. Ten years later, 38 men participated in the present follow-up, which included a structured interview and polysomnography. During the 10-yr period, nine men had been treated for OSAS. Of the 29 untreated subjects, the number of men with OSAS, defined as an apnea-hypopnea index (AHI) of >/= 5/h, increased from four in 1985 to 13 in 1995 (p < 0.01). In this small sample, no significant associations were found between DeltaAHI (i.e., AHI 1995 - AHI 1985) and age, weight gain, or smoking. We conclude that, among this small group of individuals who were selected for original polysomnographic study and follow-up because they were thought to have symptoms of sleep apnea, sleep-disordered breathing became significantly worse over time.

Adult↗
PubMed1999

Asthma-related work disability in Sweden. The impact of workplace exposures.

Work disability due to respiratory disease, especially asthma, is common and costly among working age adults. The goal of this analysis was to characterize the risk factors for such disability. We analyzed data from the Swedish part of the European Community Respiratory Health Survey (ECRHS), a random population-based sample of adults age 20 to 44, enriched with symptomatic subjects at increased likelihood of having asthma. We analyzed structured interview data available for 2,065 subjects and further analyzed methacholine challenge and skin prick test data for 1,562 of these. We defined respiratory work disability as reported job change or work loss due to breathing affected by a job. We used binary generalized linear modeling with a log link to estimate disability risk. Eighty-four subjects (4%) reported such work disability. This increased to 13% among those with asthma (45 of 350 subjects). Adjusting for covariates, occupations at high risk for asthma were associated with disability (prevalence ratio [PR] 1.8; 95% confidence interval [CI] 1.1 to 3.0), as was self-reported regular exposure to environmental tobacco smoke (ETS) at work (PR 1.8; 95% CI 1.1 to 3.1) and self- reported job exposure to vapors, gases, dust, or fumes (VGDF) (PR 4.3; 95% CI 2.2 to 8.6). Workplace ETS exposure was also associated with methacholine challenge-positive asthma reported to be symptomatic at work among male subjects (PR 4. 2; 95% CI 1.8 to 9.8), whereas high asthma-risk occupations were associated with this outcome among female subjects (PR 2.7; 95% CI 1. 05 to 7.1). Respiratory work disability, defined as breathing-related job change due to work loss, was associated with workplace exposures themselves, even after taking into account other covariates. Better control of workplace exposures, including workplace ETS, may reduce work disability caused by respiratory conditions, especially adult asthma.

Adult↗
PubMed1999

Delayed type of hypersensitivity and late allergic reactions in patients with stable COPD.

BACKGROUND: Malnutrition, a common feature among patients with COPD, has adverse effects on the immune system. Delayed type of hypersensitivity (DTH) tests have been used to evaluate the nutritional and immune status of patients and to predict outcome in various conditions. DTH is known to be and late allergic reaction (LAR) has been suggested to be dependent on T-lymphocyte function. STUDY OBJECTIVES: To compare DTH and LAR tests in COPD patients and healthy controls, to investigate whether skin tests have any value in estimating nutritional status and outcome in COPD patients, and to see whether there is any relationship between DTH and LAR. METHODS: Twenty-five patients with stable COPD and 20 healthy controls were tested for DTH and LAR. The patients were investigated with spirometry and anthropometric measurements and were followed for 1 year. RESULTS: Both the LAR and DTH reactions were diminished in the patient group (p < 0.001) compared with controls. The skin tests did not correlate with anthropometric parameters. DTH correlated to lung function, which was expressed as FEV(1) (percent predicted) (r = 0.56; p < 0.01), and LAR correlated to the number of exacerbations (at 3 months, r = - 0.61; p < 0.01). No correlation was found between LAR and DTH reactions. CONCLUSIONS: We conclude that patients with COPD in stable condition have diminished DTHs and LARs. Our results indicate that the magnitude of the LAR may be a prognostic marker in patients with COPD.

Aged↗
PubMed1999

Current asthma and biochemical signs of inflammation in relation to building dampness in dwellings.

SETTING: Study of current asthma in adults in relation to the indoor environment. OBJECTIVES: To assess the effect of building dampness in dwellings on the occurrence of current asthma, and biochemical signs of inflammation. DESIGN: A nested case-control study with 98 prevalent cases of asthma and 357 controls, within a stratified random population sample (20-45 years) from the Uppsala, Sweden, part of the European Community Respiratory Health Survey (ECRHS). Current asthma was defined as a combination of bronchial hyperresponsiveness and at least one asthma symptom (wheeze or attacks of breathlessness). Statistical calculations were made by multiple linear or logistic regression, adjusting for age, sex and smoking. RESULTS: Building dampness was found in 27% of dwellings. Current asthma was more common among subjects living in damp dwellings (odds ratio [OR] 1.8; 95% confidence interval [CI] 1.1-3.0), particularly with dampness in the floor construction (OR = 4.6; 95% CI 2.0-10.5). The average forced expiratory flow in one second (FEV1) was lower and peak expiratory flow (PEF) variability was higher in subjects from dwellings with floor dampness, and blood eosinophil count was increased in damp dwellings. No relation was found between immediate type allergy to house dust mites and current asthma or building dampness. Immediate type allergy to moulds (Cladosporium or Alternaria) was more prevalent in damp dwellings (9.3% vs 3.9%), and was related to current asthma (OR = 3.4; 95% CI 1.4-8.5). CONCLUSIONS: Building dampness is common in dwellings in Sweden, and seems to be related to an increase in current asthma and biochemical signs of inflammation. Immediate type allergy to house dust mites does not seem to be the explanation, but immediate type allergy to moulds could explain some of the findings.

Adult↗
PubMed1998

Atopy and allergic disorders among adults in Tartu, Estonia compared with Uppsala, Sweden.

BACKGROUND: Recent studies in children and adults indicate that the prevalence of atopy and allergic disorders is lower in previously socialist countries in Eastern Europe compared with countries with a market economy while revealed risk factors are similar. OBJECTIVES: To estimate the prevalence of atopy among adults in Tartu, Estonia and to compare the prevalence of risk factors for atopy and allergic respiratory diseases in Estonia and Sweden. METHODS: As a part of cross-sectional study-European Community Respiratory Health Survey-random samples of 20-44 year olds (n = 351 in Tartu and n = 470 in Uppsala) and persons of the same age with asthma like symptoms or on current asthma medication according to a postal questionnaire (n = 95 in Tartu and n = 201 in Uppsala) were interviewed and circulating IgE antibodies were measured. RESULTS: The prevalence of atopy was 19% in Tartu and 32% in Uppsala (P < 0.001). The prevalence of sensitization to pollen was twice lower (11.5 vs 23.2; P<0.001) and the prevalence of pollen associated asthma symptoms was four times lower (1.7 vs 6.8; P<0.001) in Tartu than in Uppsala while sensitization to pollen was an equally large risk factor for asthma in both centres. Age was inversely related to cat and pollen associated symptoms of rhinoconjunctivitis in Uppsala (OR 0.6 and 0.7, respectively, P < 0.05) but not in Tartu. CONCLUSIONS: The prevalence of atopy was lower in Tartu, Estonia than in Uppsala Sweden. Perception of allergic disorders seemed to be lower in Tartu than in Uppsala. Age did not influence the prevalence of atopy nor allergic disorders in Tartu, while in Uppsala age was inversely related to clinical allergy. This could suggest a cohort effect underlying the increasing prevalence of allergy in Western Europe.

Adult↗
PubMed1998

Increased mortality among sleepy snorers: a prospective population based study.

BACKGROUND: The long term health consequences of snoring and sleep apnoea syndrome are still uncertain. This study was conducted to assess the mortality risk associated with snoring and excessive daytime sleepiness (EDS), the two main symptoms of sleep apnoea syndrome, in men. METHODS: In 1984 a sample of 3100 men aged 30-69 responded to a postal questionnaire including questions about snoring, EDS, and the prevalence of various diseases (response rate 77.1%). Mortality data for the period 1985-1995 were collected for the complete sample. RESULTS: During the 10 year follow up period 213 men died, 88 of cardiovascular diseases. Compared with subjects with no snoring or EDS in 1984, men with isolated snoring or EDS displayed no significantly increased mortality. The combination of snoring and EDS was associated with a significant increase in mortality. However, the relative rates decreased with increasing age, and in men aged 60 and above no effect on mortality was found. Men below the age of 60 with both snoring and EDS had an age adjusted total death rate which was 2.7 times higher than men with no snoring or EDS (95% CI 1.6 to 4.5). The corresponding age adjusted hazard ratio for cardiovascular mortality was 2.9 (95% CI 1.3 to 6.7) for subjects with both snoring and EDS. Further adjustment for body mass index and reported hypertension, cardiac disease, and diabetes reduced the relative mortality risk associated with the combination of snoring and EDS to 2.2 (95% CI 1.3 to 3.8) and the relative risk of cardiovascular mortality to 2.0 (95% CI 0.8 to 4.7). CONCLUSION: Snoring without EDS does not appear to carry an increased risk of mortality. The combination of snoring and EDS appears to be associated with an increased mortality rate, but the effects seems to be age dependent. The increased mortality is partly explained by an association between "snoring and EDS" and cardiovascular disease.

Adult↗
PubMed1998

Autoantibodies in Estonia and Sweden, populations with different responses to allergens.

BACKGROUND: There are substantial differences in immune-mediated disease prevalence between different countries and populations which cannot be explained by genetic variability. AIMS: To compare the prevalence of antinuclear (ANA), antimitochondrial, antireticulin, liver-kidney microsomal, parietal cell, thyroid microsomal and double-stranded DNA (dsDNA) antibodies among adults aged 20-44 years in two towns, i.e. in Tartu, Estonia (n = 448) and in Uppsala, Sweden (n = 532) with a low and a high prevalence of allergy. METHODS: For autoantibody detection, standard indirect immunofluorescence tests on tissue and Chritidia lucilia antigenic preparations were used (sera were diluted starting from 1:10). RESULTS: The prevalence of ANA was lower in Tartu than in Uppsala (3 vs. 10% among males and 11 vs. 16% among females; p<0.01 and p<0.1, respectively). Furthermore, dsDNA antibody-positive cases were only identified in Uppsala. The largest difference between the two populations was revealed for IgM type ANA, both among males (1 vs. 6%; p<0.02) and females (5 vs. 11%; p<0.01). In addition, the antibody titers were lower in Tartu than in Uppsala (p<0.05). The prevalence of other autoantibodies was similar in the two towns. CONCLUSIONS: The findings could support that Th2-like immune responses are commoner in Sweden than in Estonia, as previously suggested by the higher prevalence of allergy.

Adult↗