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Dive into the research topics where Bjørn Johansen is active.

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Featured researches published by Bjørn Johansen.


Toxicology | 1998

Airborne house dust elicits a local lymph node reaction and has an adjuvant effect on specific IgE production in the mouse

Heidi Ormstad; Per Ivar Gaarder; Bjørn Johansen; Martinus Løvik

Indoor suspended particulate matter (SPM) consists of many different types of particles, the vast majority of which are less than 2.5 microm in diameter. An important question is how these particles, being inhalable, contribute to asthma and respiratory symptoms. One possibility is that these particles have an adjuvant effect on the immune response and increase the IgE production, or cause a non-specific irritation in the airways, contributing to bronchial hyper-responsiveness. In this study, the adjuvant activity of indoor SPM on the response to the model allergen ovalbumin (OA) in BALB/c mice was investigated, using the popliteal lymph node (PLN) assay. The adjuvant activity on the local lymph node response was determined by measuring the PLN weight, cell numbers and cell proliferation, and the adjuvant activity on the IgE production by measuring the levels of serum IgE specific to OA. SPM was found to give a significant PLN response, both when injected alone and together with OA. SPM was also found to enhance the production of specific IgE to OA when injected together with OA, after reinjection with OA, compared with immunisation with OA alone.


Annals of the Rheumatic Diseases | 2011

Pulmonary outcome in juvenile dermatomyositis: a case-control study

Helga Sanner; Trond Mogens Aaløkken; Jan Tore Gran; Ivar Sjaastad; Bjørn Johansen; Berit Flatø

Objectives To compare pulmonary function in patients with juvenile dermatomyositis (JDM) with that of matched controls; and to examine associations between pulmonary function impairment, high-resolution CT (HRCT) abnormalities and other disease variables in patients with JDM. Methods A total of 59 patients with JDM clinically examined a median 16.8 years (range 2–38 years) after disease onset were compared with 59 age-matched and sex-matched controls. Pulmonary function tests included spirometry, diffusing capacity for carbon monoxide (DLCO) and body plethysmography. In patients with JDM, HRCT scans were performed and cumulative organ damage and patient-reported health status assessed. Results Patients with JDM had lower total lung capacity (TLC) and DLCO compared to controls (p=0.003 and <0.001, respectively). A low TLC was found in 26% of patients versus 9% of controls (p=0.026), and a low DLCO in 49% of patients versus 9% of controls (p<0.001). HRCT abnormalities were found in 37% of patients, and included interstitial lung disease (ILD) (14%), chest wall calcinosis (14%) and airway disease (15%). Three patients were diagnosed as having ILD prior to the follow-up visit. A low TLC was more often found in patients with than without abnormal HRCT (50% vs 12%, p=0.002). HRCT abnormality correlated with cumulative organ damage (rs=0.346, p=0.008) and patient-reported health status at follow-up (p<0.005). Conclusions Patients with JDM had smaller lung volumes than controls; a restrictive ventilatory defect was found in 26% and HRCT abnormality in 37% of the patients, and these findings were associated. Although mostly subclinical, the relatively high frequency of pulmonary involvement highlights the systemic nature of JDM.


Annals of Allergy Asthma & Immunology | 2010

Development of pulmonary abnormalities in patients with common variable immunodeficiency: associations with clinical and immunologic factors

Stina Gregersen; Trond Mogens Aaløkken; Georg Mynarek; Børre Fevang; Are Martin Holm; Thor Ueland; Pål Aukrust; Johny Kongerud; Bjørn Johansen; Stig S. Frøland

BACKGROUND Patients with common variable immunodeficiency (CVID) have low serum IgG, IgA, and/or IgM levels and recurrent airway infections. Radiologic pulmonary abnormalities and impaired function are common complications. It is unclear to what extent IgG replacement treatment prevents further pulmonary damage and how factors beside infections may contribute to progression of disease. OBJECTIVES To study the development of pulmonary damage and determine how clinical and immunologic factors, such as serum IgG, may contribute to possible changes. METHODS In a retrospective, longitudinal study of 54 patients with CVID already treated with immunoglobulins, we examined changes of lung function and findings on high-resolution computed tomography (HRCT), obtained at 2 time points (the date of the last pulmonary function measurement before April 2005 [T1] and the date of the measurement performed closest to 5 years earlier [T0]) 2 to 7 years apart and explored possible relations to clinical and immunologic factors such as levels of IgG, tumor necrosis alpha (TNF-alpha), and mannose-binding lectin (MBL) in serum. RESULTS Despite a mean (SD) serum IgG level of 7.6 (2.3) g/L for all the patients during the entire study period, lung function decreased from T0 to T1. The combination of a low serum IgA level and serum MBL was associated with the presence of bronchiectasis and lower lung function and with worsening of several HRCT abnormalities from T0 to T1. Increased serum levels of TNF-alpha were related to deterioration of gas diffusion. A mean serum IgG level less than 5 g/L between T0 and T1 was associated with worsening of linear and/or irregular opacities seen on HRCT. CONCLUSION For a period of 4 years, lung function and HRCT deteriorated in CVID patients treated with immunoglobulins.


Acta Obstetricia et Gynecologica Scandinavica | 2009

Association between aerobic fitness in late pregnancy and duration of labor in nulliparous women

Kristin R. Kardel; Bjørn Johansen; Nanna Voldner; Per Ole Iversen; Tore Henriksen

It is established that the level of physical activity in the population generally is too low, and data indicate that pregnant women are no exception. Studies of the effects of aerobic fitness on delivery outcomes are limited. In this observational study, we investigated the effect of aerobic fitness on duration of labor in nulliparous women who started labor spontaneously. Maximal oxygen uptake was measured in 40 nulliparous women at 35–37 weeks of gestation. Duration of labor was defined as the time between 3 cm cervical dilation with regular uterine contractions and delivery. The mean (SD) maximal oxygen uptake was 2.1 (0.3) L/min and duration of labor 583 (317) minutes. Duration of labor was inversely associated with maximal oxygen uptake after adjusting for birthweight (p = 0.034). We conclude that measurement of maximal oxygen uptake is safe in pregnancy at 35–37 weeks and that increased aerobic fitness was associated with shorter labor in nulliparous women who started labor spontaneously.


Respiratory Medicine | 2009

High resolution computed tomography and pulmonary function in common variable immunodeficiency.

Stina Gregersen; Trond Mogens Aaløkken; Georg Mynarek; Johny Kongerud; Pål Aukrust; Stig S. Frøland; Bjørn Johansen

Patients with common variable immunodeficiency (CVID) have impaired production of immunoglobulins and hence recurrent airway infections, which in turn may lead to radiological changes and impaired lung function. Uncertainty exists about the nature and frequency of the radiological and the physiological abnormalities, and how they relate to each other. We reassessed high resolution computed tomography (HRCT) images in 65 patients, reported results from previously measured lung function tests, and studied relations between radiology, function and clinical variables. Airway obstruction, ventilatory restriction and impaired gas diffusion was found in 40, 34 and 21% of the patients, respectively. HRCT abnormalities were present in 94% of the subjects, mild changes being the most common. Bronchial wall thickening, found in two thirds of the patients, was related to airway obstruction and impaired gas diffusion. Linear and/or irregular opacities, the most frequent interstitial abnormality, was related to impaired gas diffusion. Bronchiectasis was found in more than half, but only severe bronchiectasis was related to airway obstruction. Since bronchial wall thickening and linear and/or irregular opacities are both frequent and important determinants of impaired pulmonary function, more attention should be given to these features in the follow up of CVID patients.


Ultramicroscopy | 1982

Surface activation of carbon film supports for biological electron microscopy

Ellen Namork; Bjørn Johansen

The effect of glow-discharging on naked carbon-filmed grids has been evaluated. The effect of different locations of the grids within a DC discharge, operated in the normal glow, was analyzed by applying various biological specimens to the grids. Two locations were found to give consistent results: (a) in Crookes dark space, particulate specimens, negatively stained, spread evenly--suggesting a new negative surface charge of the support; (b) below the anode, nucleic acids, selectively (positively) stained, appeared as well spread filaments, indicating a net positive surface charge.


Journal of Immunological Methods | 1995

Scanning electron microscopy of immunogold labeled cat allergens (Fel d 1) on the surface of airborne house dust particles.

Heidi Ormstad; Ellen Namork; Per Ivar Gaarder; Bjørn Johansen

This study investigated the ability of an immunogold labeling technique to demonstrate the presence of Fel d 1 (domestic cat) allergens on the surface of particles in samples of airborne house dust. Suspended particulate matter was sampled from ten Norwegian households, five with and five without a domestic cat. The specimens were immunogold labeled and examined in the backscatter electron imaging mode of the scanning electron microscope and in the transmission electron microscope. X-ray microanalysis was also applied to execute element analysis of the suspended particular matter. The gold probe was mainly detected on carbon particles in the suspended particulate matter, both on small (< 1 microns) and larger carbon aggregates (1-10 microns). The present method may be useful in studying the localisation of different allergens on airborne house dust particles of various sizes and composition.


Respirology | 1996

When to suspect and how to diagnose pulmonary lymphangioleiomyomatosis

Anne Naalsund; Bjørn Johansen; Arnold Foerster; Alf Kolbenstvedt

Abstract The objective of this study was to present clinical and radiological data of eight women with histologically proven lymphangioleiomyomatosis (LAM) diagnosed between 1984 and 1994, and to suggest a diagnostic strategy when LAM is suspected. A review of case reports, including results of biopsies, lung function and radiological procedures was undertaken. The mean age of the women at start of symptoms was 36 years, and the mean age at time of diagnosis 42 years. The most frequent presenting complaint was dyspnea, either in conjunction with pneumothorax (3), chylothorax (2) or on exertion (2). All patients had airflow limitation and markedly reduced gas transfer. Five patients had 16 episodes of pneumothorax. In seven patients multiple cysts were observed on the surface of the lung during thoracotomy while computerized tomography (CT) scans revealed numerous cysts evenly distributed throughout the lung parenchyma. The procedures that confirmed the diagnosis included transbronchial lung biopsy (4), open lung biopsy (2), thoracoscopy (1), thoracotomy (3) and autopsy (1). Three specimens had to be revised before the histological diagnosis was confirmed. It was concluded that the important clues to a diagnosis of LAM are recurrent episodes of pneumothoraces in fertile women, progressive air‐flow limitation, markedly reduced gas transfer and characteristic findings on thoracic CT scans. A specific request to the pathologist to stain lung tissue specimens for smooth muscle cells is mandatory.


Scandinavian Journal of Clinical & Laboratory Investigation | 2013

Lung disease, T-cells and inflammation in common variable immunodeficiency disorders

Stina Gregersen; Are Martin Holm; Børre Fevang; Thor Ueland; Liv Ingunn Bjoner Sikkeland; Trond Mogens Aaløkken; Georg Mynarek; Johny Kongerud; Pål Aukrust; Bjørn Johansen; Stig S. Frøland

Abstract Introduction. Besides hypogammaglobulinemia and recurrent infections, abnormalities of T-cells might contribute to lung damage in common variable immunodeficiency disorders (CVID). Materials and methods. In 16 adult patients, the majority of whom had pulmonary abnormalities, we studied T-cell subsets and markers of inflammation in bronchoalveolar lavage fluid (BALF) and blood and their relations with pulmonary function and high resolution computed tomography (HRCT). Results. We demonstrated that some of the lymphocyte abnormalities previously demonstrated in peripheral blood from CVID patients, such as low CD4/CD8 T-cell ratio, were also present in BALF. Moreover, low BALF CD4/CD8 ratio (≤ 1), found in seven patients, was significantly associated with higher blood CD8+ cell count and to lower values of the lung function variables; forced expiratory volume (FVC), total lung capacity (TLC), vital capacity (VC) and residual volume (RV) in % of predicted. The expression of the inflammatory markers HLA-DR and CCR5 on T-cells was significantly higher, and the expression of CCR7 significantly lower, in BALF compared to blood, possibly reflecting an inflammatory/cytotoxic T-cell phenotype within pulmonary tissue in CVID. Furthermore, patients with bronchiectasis had higher concentrations of the pro-inflammatory cytokine TNFα in plasma, compared to those without. Conclusion. Our findings suggest that inflammation and T-cell activation may be involved in the immunopathogenesis of pulmonary complications in CVID.


Micron | 1980

Electron microscopy of nucleic acids: The effect of different post-treatments on contour-length measurements

Ellen Namork; Bjørn Johansen

Abstract The contour-length of the DNA plasmid Colicin E1 was measured when the specimens were given three commonly used treatments, after the molecules were mounted onto nitrocellulose (Collodion) supports. Significant variations in contour-length and standard deviation were observed and related to the specimen post-preparative treatments of the specimen.

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Ellen Namork

Norwegian Institute of Public Health

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Georg Mynarek

Oslo University Hospital

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Pål Aukrust

Oslo University Hospital

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Børre Fevang

Oslo University Hospital

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