42 research outputs found

    Sensitization to molecular dog allergens in an adult population : Results from the West Sweden Asthma Study

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    Background: As the prevalence of dog allergy rises, component resolved diagnosis might improve the diagnosis, understanding of the clinical outcomes and the effectiveness of immunotherapy. Considering the paucity of data in adults, the current study characterized the patterns of sensitization to dog molecular allergens in an adult population. Methods: Data were derived from the West Sweden Asthma Study, a population-based and representative sample of adults from western Sweden. Of the 2006 subjects clinically examined, 313 participants sensitized to whole dog allergen extract were measured for specific immunoglobulin E (sIgE) levels to Can f 1, Can f 2, Can f 3, Can f 4, Can f 5 and Can f 6 using ImmunoCAPℱ. Polysensitization was defined as sensitization to ≄3 components. Overlapping sensitization was defined as having concomitant sensitization to at least two dog molecular allergen families (lipocalin, albumin or prostatic kallikrein). Results: Of 313, 218 (70%) subjects tested positive to at least one dog allergen component. Sensitization to Can f 1 (43%) was the most common, followed by Can f 5 (33%) among molecular allergens, while sensitization to lipocalins (56%) was the most common among component families. Polysensitization was found in 22% of all participants and was more common in participants with than in those without asthma. Subjects with asthma were less likely to be monosensitized to Can f 5 than those without asthma. Subjects with asthma had higher IgE levels of Can f 3, Can f 4 and Can f 6 than those without asthma. Overlapping sensitizations also differed between those with asthma and allergic rhinitis and those without. Conclusion: Increased knowledge about the sensitization patterns of dog allergen components can aid in defining their role in asthma and rhinitis. In complex clinical cases of dog allergy, a detailed analysis of dog allergen components can provide additional information on the nature of sensitization.publishedVersionPeer reviewe

    Controlled Exposures to Air Pollutants and Risk of Cardiac Arrhythmia

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    BACKGROUND: Epidemiological studies have reported associations between air pollution exposure and increases in cardiovascular morbidity and mortality. Exposure to air pollutants can influence cardiac autonomic tone and reduce heart rate variability, and may increase the risk of cardiac arrhythmias, particularly in susceptible patient groups. OBJECTIVES: We investigated the incidence of cardiac arrhythmias during and after controlled exposure to air pollutants in healthy volunteers and patients with coronary heart disease. METHODS: We analyzed data from 13 double-blind randomized crossover studies including 282 participants (140 healthy volunteers and 142 patients with stable coronary heart disease) from whom continuous electrocardiograms were available. The incidence of cardiac arrhythmias was recorded for each exposure and study population. RESULTS: There were no increases in any cardiac arrhythmia during or after exposure to dilute diesel exhaust, wood smoke, ozone, concentrated ambient particles, engineered carbon nanoparticles, or high ambient levels of air pollution in either healthy volunteers or patients with coronary heart disease. CONCLUSIONS: Acute controlled exposure to air pollutants did not increase the short-term risk of arrhythmia in participants. Research employing these techniques remains crucial in identifying the important pathophysiological pathways involved in the adverse effects of air pollution, and is vital to inform environmental and public health policy decisions

    Cardiovascular effects of diesel exhaust : mechanistic and interventional studies

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    Background: Air pollution is associated with negative health effects. Exposure to combustion-derived particulate matter (PM) air pollution has been related to increased incidence of cardiovascular and respiratory morbidity and mortality, specifically in susceptible populations. Ambient particles, with a diameter of less than 2.5 mm, have been suggested to be the strongest contributor to these health effects. Diesel exhaust (DE) is a major source of small combustion-derived PM air pollution world wide.  In healthy volunteers, exposure to DE, has been associated with airway inflammation and impaired vasomotor function and endogenous fibrinolysis. The aims of this thesis were to further elucidate the underlying mechanisms to the reported cardiovascular effects following exposure to DE, with specific focus on endothelin-1 (ET-1). Additionally, the vascular effects of the major gaseous component of DE, nitrogen dioxide (NO2), were assessed together with the impact of an exhaust particle trap to reduce the observed negative vascular effects after DE exposure. Methods: In all studies healthy, non-smoking male volunteers were included and exposed for one hour during intermittent exercise in a randomised double-blind crossover fashion. In studies I-III, subjects were exposed to DE at a particulate matter concentration of approximately 300 Όg/m3 and filtered air, on two different occasions. In study V an additional exposure was employed, during which DE was filtered through an exhaust particle trap. In study IV subjects were exposed to nitrogen dioxide (NO2) at 4 ppm or filtered air. In study I, thrombus formation and platelet activation were assessed using the Badimon ex vivo perfusion chamber and flow cytometry. Study II comprised the determination of arterial stiffness including pulse wave analysis and velocity. In studies III-V, vascular assessment was performed using venous occlusion plethysmography. In studies IV and V, the vascular responses to intra-arterially infused endothelial-dependent and endothelial-independent vasodilatators were registered. In study III, vascular responses to intra-arterial infusion of Endothelin-1 (ET-1) and ET-1-receptor antagonists were assessed. Venous occlusion phlethysmography was in all cases performed 4-6 hours following exposures. Blood samples for markers of inflammation, coagulation and platelet activation were collected before and throughout the study periods in studies III and V. Results: Exposure to DE increased ex vivo thrombus formation and arterial stiffness, in terms of augmentation index. DE inhalation impaired vasomotor function and endogenous fibrinolysis. The exhaust particle trap reduced the particle concentration by 98% and abolished the effects on vasomotor function, endogenous fibrinolysis and ex vivo thrombus formation. Plasma concentrations of ET-1 and its precursor big-ET-1 were unchanged following exposure. Dual endothelial receptor antagonism caused similar vasodilatation after both exposures, although vasodilatation to the endothelin-A receptor alone was blunted after DE exposure. ET-1 infusion induced vasoconstriction only following DE exposure. Exposure to nitrogen dioxide did not affect vascular function. Conclusion: Inhalation of diesel exhaust in young healthy men impaired important and complementary aspects of vascular function in humans; regulation of vascular tone and endogenous fibrinolysis as well as increased ex vivo thrombus formation. The use of an exhaust particle trap significantly reduced particle emissions and abolished the DE-induced vascular and prothrombotic effects. The adverse vascular effects following DE exposure do not appear to be directly mediated through the endothelin system. Neither is NO2 suggested to be a major arbiter of the DE-induced cardiovascular responses. Arterial stiffness is a non-invasive and easily accessible method and could thus be employed to address vascular function in larger field studies. Taken together, this thesis has given further knowledge about the mechanisms underlying the DE-induced vascular effects

    INTER-FIRM PRODUCT PLATFORM DEVELOPMENT IN THE AUTOMOTIVE INDUSTRY

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    The product platform development process becomes critical and of general interest when different brand name products are developed from inter-firm developed product platforms. The inter-firm platform adds perspectives not considered in previous research. In this article areas related to the inter-firm product platform integration process are described. The study is a longitudinal, deep, explorative study aimed at identifying managerial challenges to inter-firm platform development and how they can be dealt with. Analysis shows that the factory sequence is a critical factor when developing inter-firm platform architecture. Also, making architectural concessions without jeopardising brand uniqueness places new demands on managers involved in the development processes. Further, we found a reciprocal interdependence between technological and managerial factors that created a need for innovative organisational and managerial solutions. Finally, reciprocal interdependences add complementary theoretical knowledge on how to better control and understand areas that hamper inter-firm product development projects from attaining cost-effective solutions and economies of scale.Product platforms, product development integration, inter-firm, architecture

    Design engineering culture differences : FordÂŽs acquisition of Volvo Cars

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    The cultural issues of design engineering are important in the context of any interorganizational collaboration. The objective of this article is to describe and analyze the design engineering decision-making process at Ford Motor Company. It examines the area that concerns culture in the workplace, but does so in the context of how Volvo employees understand it one year after Ford's acquisition of Volvo Cars. It is clear that there are important differences in the way of conducting decisions between the companies, at least as the engineers at Volvo understand it. These differences will have a negatively impact on the speed of the integration process and future ability to co-operate.GodkÀnd; 2000; 20071006 (ysko

    Brief exposure to Swedish snus causes divergent vascular responses in healthy male and female volunteers

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    Introduction: The use of Swedish oral moist snuff, known as snus, has for a long time been limited to the Scandinavian countries. With declining cigarette sales in the western world, tobacco companies have looked to the development of alternative tobacco products. In 2006 snus products were launched in the US. Even though several studies have demonstrated negative health effects, snus is often depicted as harmless. The aim of the present study was to investigate acute vascular effects of snus as measured by arterial stiffness as well as blood pressure and heart rate. Methods: Two separate randomized double-blind crossover studies with the same study design were pooled for analysis. Twenty-nine healthy snus-users (17 females, 12 males) were included. Snus (Göteborgs Rapé) and tobacco free snus (Onico) were administered in a randomized order at two separate visits. Arterial stiffness, blood pressure and heart rate were measured at baseline as well as every five minutes for 40 minutes during exposure. Following snus removal, measurements continued for 30 minutes post exposure. Arterial stiffness was measured using pulse wave velocity (Vicorder) and pulse wave analysis (Sphygmocor). Results: Compared to placebo, snus significantly increased systolic and diastolic blood pressure as well as heart rate, however, only in females (p = 0.004, p = 0.006 and p<0.001 respectively). No changes were seen in arterial stiffness measurements in either gender. Conclusion: We observed an increase in blood pressure and heart rate only in females, but not in males due to snus usage as compared to placebo. This novel finding was surprising and needs to be further investigated considering most of the earlier studies have mainly focused on male snus users and the increasing usage of snus among females
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