Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Sandström Thomas) "

Sökning: WFRF:(Sandström Thomas)

Sortera/gruppera träfflistan
  • Barath, Stefan, et al. (författare)
  • Impaired vascular function after exposure to diesel exhaust generated at urban transient running conditions
  • 2010
  • Ingår i: Particle and fibre toxicology. - BioMed Central. - 1743-8977. ; 7:1, s. 19
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Traffic emissions including diesel engine exhaust are associated with increased respiratory and cardiovascular morbidity and mortality. Controlled human exposure studies have demonstrated impaired vascular function after inhalation of exhaust generated by a diesel engine under idling conditions.OBJECTIVES: To assess the vascular and fibrinolytic effects of exposure to diesel exhaust generated during urban-cycle running conditions that mimic ambient 'real-world' exposures.METHODS: In a randomised double-blind crossover study, eighteen healthy male volunteers were exposed to diesel exhaust (approximately 250 mug/m3) or filtered air for one hour during intermittent exercise. Diesel exhaust was generated during the urban part of the standardized European Transient Cycle. Six hours post-exposure, vascular vasomotor and fibrinolytic function was assessed during venous occlusion plethysmography with intra-arterial agonist infusions.MEASUREMENTS AND MAIN RESULTS: Forearm blood flow increased in a dose-dependent manner with both endothelial-dependent (acetylcholine and bradykinin) and endothelial-independent (sodium nitroprusside and verapamil) vasodilators. Diesel exhaust exposure attenuated the vasodilatation to acetylcholine (P < 0.001), bradykinin (P < 0.05), sodium nitroprusside (P < 0.05) and verapamil (P < 0.001). In addition, the net release of tissue plasminogen activator during bradykinin infusion was impaired following diesel exhaust exposure (P < 0.05).CONCLUSION: Exposure to diesel exhaust generated under transient running conditions, as a relevant model of urban air pollution, impairs vasomotor function and endogenous fibrinolysis in a similar way as exposure to diesel exhaust generated at idling. This indicates that adverse vascular effects of diesel exhaust inhalation occur over different running conditions with varying exhaust composition and concentrations as well as physicochemical particle properties. Importantly, exposure to diesel exhaust under ETC conditions was also associated with a novel finding of impaired of calcium channel-dependent vasomotor function. This implies that certain cardiovascular endpoints seem to be related to general diesel exhaust properties, whereas the novel calcium flux-related effect may be associated with exhaust properties more specific for the ETC condition, for example a higher content of diesel soot particles along with their adsorbed organic compounds.
  • Bolling, Anette Kocbach, et al. (författare)
  • Wood smoke particles from different combustion phases induce similar pro-inflammatory effects in a co-culture of monocyte and pneumocyte cell lines.
  • 2012
  • Ingår i: Particle and fibre toxicology. - 1743-8977. ; 9:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Exposure to particulate matter (PM) has been linked to several adverse cardiopulmonary effects, probably via biological mechanisms involving inflammation. The pro-inflammatory potential of PM depends on the particles' physical and chemical characteristics, which again depend on the emitting source. Wood combustion is a major source of ambient air pollution in Northern countries during the winter season. The overall aim of this study was therefore to investigate cellular responses to wood smoke particles (WSPs) collected from different phases of the combustion cycle, and from combustion at different temperatures. Results: WSPs from different phases of the combustion cycle induced very similar effects on pro-inflammatory mediator release, cytotoxicity and cell number, whereas WSPs from medium-temperature combustion were more cytotoxic than WSPs from high-temperature incomplete combustion. Furthermore, comparisons of effects induced by native WSPs with the corresponding organic extracts and washed particles revealed that the organic fraction was the most important determinant for the WSP-induced effects. However, the responses induced by the organic fraction could generally not be linked to the content of the measured polycyclic aromatic hydrocarbons (PAHs), suggesting that also other organic compounds were involved. Conclusion: The toxicity of WSPs seems to a large extent to be determined by stove type and combustion conditions, rather than the phase of the combustion cycle. Notably, this toxicity seems to strongly depend on the organic fraction, and it is probably associated with organic components other than the commonly measured unsubstituted PAHs.
  • Georgsson, Fredrik, et al. (författare)
  • Development of an Autonomous Path Tracking Forest Machine
  • 2005
  • Rapport (övrigt vetenskapligt)abstract
    • In many respects traditional automation in the forest-machine industry has reached an up- per limit, since the driver already has to deal with an excess of information and take too many decisions at a very high pace. To further automation still, introduction of semi-autonomous and autonomous functions are expected and considered necessary. This paper describes an ongoing project along these ideas. We describe the development of the hardware and software of an unmanned shuttle that shifts timber from the area of felling to the main roads for fur- ther transportation. A new path-tracking algorithm is introduced, and demonstrated as being superior to standard techniques, such as Follow-the-Carrot and Pure-Pursuit. To facilitate the research and development, a comprehensive software architecture for sensor and actuator interfacing is developed. Obstacle avoidance is accomplished by a new kind of radar, developed for and by the automotive industry. Localization is accomplished by a Kalman filter combining data from a Real-Time Kinematic Differential GPS/GLONASS and a gyro/compass. Tests conducted on a simulator and a small-scale robot show promising results. Tests on the real forest machine are ongoing, and will be completed before the end of 2005.
  • Löndahl, Jakob, et al. (författare)
  • Experimental determination of the respiratory tract deposition of diesel combustion particles in patients with chronic obstructive pulmonary disease
  • 2012
  • Ingår i: Particle and Fibre Toxicology. - BioMed Central. - 1743-8977. ; 9
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Air pollution, mainly from combustion, is one of the leading global health risk factors. A susceptible group is the more than 200 million people worldwide suffering from chronic obstructive pulmonary disease (COPD). There are few data on lung deposition of airborne particles in patients with COPD and none for combustion particles. Objectives: To determine respiratory tract deposition of diesel combustion particles in patients with COPD during spontaneous breathing. Methods: Ten COPD patients and seven healthy subjects inhaled diesel exhaust particles generated during idling and transient driving in an exposure chamber. The respiratory tract deposition of the particles was measured in the size range 10-500 nm during spontaneous breathing. Results: The deposited dose rate increased with increasing severity of the disease. However, the deposition probability of the ultrafine combustion particles (< 100 nm) was decreased in COPD patients. The deposition probability was associated with both breathing parameters and lung function, but could be predicted only based on lung function. Conclusions: The higher deposited dose rate of inhaled air pollution particles in COPD patients may be one of the factors contributing to their increased vulnerability. The strong correlations between lung function and particle deposition, especially in the size range of 20-30 nm, suggest that altered particle deposition could be used as an indicator respiratory disease.
  • Rissler, Jenny, et al. (författare)
  • Experimental determination of deposition of diesel exhaust particles in the human respiratory tract
  • 2012
  • Ingår i: Journal of Aerosol Science. - Elsevier. - 0021-8502. ; 48, s. 18-33
  • Tidskriftsartikel (refereegranskat)abstract
    • Diesel emissions are a major contributor to combustion-generated airborne ambient particles. To understand the role of diesel particulate emissions on health effects, it is important to predict the actual particulate dose deposited in the human respiratory tract, with respect to number, surface area and mass. This is complicated by the agglomerate nature of some of these particles. In this study the respiratory tract deposition fraction in the size range 10-500 nm, was determined for 10 healthy volunteers during both idling and transient engine running conditions of a heavy duty diesel engine. The aerosol was characterized with respect to both chemical and physical properties including size resolved particle effective density. The dominating part of the emitted particles had an agglomerate structure. For those formed during transient running conditions, the relationship between particle mass and mobility diameter could be described by a power law function. This was not the case during idling, most likely because of volatile compounds condensing on the agglomerates. The respiratory tract particle deposition revealed large intra-subject variability with some subjects receiving a dose that was twice as high as that of others, when exposed to the same particle concentration. Associations were found between total deposited fractions (TDF), and breathing pattern. There was a difference between the idling and transient cycle with TDF being higher with respect to number during idling. The measured size-dependent deposition fraction of the agglomerated exhaust particles from both running conditions was nearly identical and closely resembled that of spherical hydrophobic particles, if plotted as a function of mobility diameter. Thus, for the size range covered, the mobility diameter could well describe the diameter-dependent particle respiratory tract deposition probability, regardless of the agglomeration state of the particles. Whilst mobility diameter well describes the deposition fraction, more information about particle characteristics is needed to convert this to volume equivalent diameter or estimate dose with respect to surface area or mass. A methodology is presented and applied to calculate deposited dose by surface area and mass of agglomerated particles. The methodology may be useful in similar studies estimating dose to the lung, deposition onto cell cultures and in animal studies. (C) 2012 Elsevier Ltd. All rights reserved.
  • Sehlstedt, Maria, 1979-, et al. (författare)
  • Antioxidant airway responses following experimental exposure to wood smoke in man
  • 2010
  • Ingår i: Particle and Fibre Toxicology. - Biomed Central Ltd. - 1743-8977. ; 7
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Biomass combustion contributes to the production of ambient particulate matter (PM) in rural environments as well as urban settings, but relatively little is known about the health effects of these emissions. The aim of this study was therefore to characterize airway responses in humans exposed to wood smoke PM under controlled conditions. Nineteen healthy volunteers were exposed to both wood smoke, at a particulate matter (PM2.5) concentration of 224 +/- 22 mu g/m(3), and filtered air for three hours with intermittent exercise. The wood smoke was generated employing an experimental set-up with an adjustable wood pellet boiler system under incomplete combustion. Symptoms, lung function, and exhaled NO were measured over exposures, with bronchoscopy performed 24 h post-exposure for characterisation of airway inflammatory and antioxidant responses in airway lavages. Results: Glutathione (GSH) concentrations were enhanced in bronchoalveolar lavage (BAL) after wood smoke exposure vs. air (p = 0.025), together with an increase in upper airway symptoms. Neither lung function, exhaled NO nor systemic nor airway inflammatory parameters in BAL and bronchial mucosal biopsies were significantly affected. Conclusions: Exposure of healthy subjects to wood smoke, derived from an experimental wood pellet boiler operating under incomplete combustion conditions with PM emissions dominated by organic matter, caused an increase in mucosal symptoms and GSH in the alveolar respiratory tract lining fluids but no acute airway inflammatory responses. We contend that this response reflects a mobilisation of GSH to the air-lung interface, consistent with a protective adaptation to the investigated wood smoke exposure.
  • Andersen, Grethe Neumann, et al. (författare)
  • Bronchoalveolar matrix metalloproteinase 9 relates to restrictive lung function impairment in systemic sclerosis.
  • 2007
  • Ingår i: Respiratory Medicine. - 0954-6111. ; 101:10, s. 2199-2206
  • Tidskriftsartikel (refereegranskat)abstract
    • Systemic sclerosis (SSc) is frequently associated with interstitial lung disease (ILD) often leading to lung fibrosis. In this study we investigated whether matrix metalloproteinase 9 (MMP-9) and its natural inhibitor; the tissue inhibitor of matrix metalloproteinase 1 (TIMP-1), would be associated with remodelling in ILD in SSc. Levels of total MMP-9, pro-MMP-9 and TIMP-1 were measured in bronchoalveolar lavage (BAL) fluid from nine SSc patients with ILD, seven SSc patients without ILD and 16 age- and sex-matched healthy controls. Total MMP-9 and pro-MMP-9 levels were significantly elevated in SSc patients with ILD, compared to levels in SSc patients without ILD and healthy controls. In SSc patients with ILD calculated active MMP-9 levels were significantly higher than in SSc patients without ILD and tended to be higher than in healthy controls. TIMP-1 levels were elevated in both patient groups compared to healthy controls. Total-, pro- and active MMP-9 levels as well as pro-MMP-TIMP-1 and active MMP-9/TIMP-1 ratios were inversely associated with total lung capacity. The present study suggests that MMP-9 plays a pathophysiological role in the remodelling in ILD and lung fibrosis associated with SSc, and may represent a new therapeutic target in this condition.
Skapa referenser, mejla, bekava och länka
fritt online (15)
Typ av publikation
tidskriftsartikel (129)
annan publikation (25)
konferensbidrag (21)
rapport (14)
bokkapitel (3)
forskningsöversikt (2)
visa fler...
bok (1)
visa färre...
Typ av innehåll
refereegranskat (145)
övrigt vetenskapligt (43)
populärvet., debatt m.m. (7)
Sandström, Thomas, (121)
Blomberg, Anders, (72)
Boman, Christoffer, (33)
Pourazar, Jamshid, (32)
Swietlicki, Erik (22)
Mills, Nicholas L. (21)
visa fler...
Löndahl, Jakob (20)
Newby, David E (19)
Pagels, Joakim (17)
Rissler, Jenny (14)
Sandström, Alfred, (11)
Sandstrom, T (11)
Barath, Stefan, (11)
Donaldson, Ken (11)
Helleday, Ragnberth, (11)
Bosson, Jenny, (11)
Langrish, Jeremy P (10)
Massling, Andreas (10)
Nyström, Robin, (10)
Westerholm, Roger, (9)
Axenrot, Thomas, (9)
Stenfors, Nikolai, (9)
Törnqvist, Håkan, (9)
Sandström, Thomas, 1 ... (9)
Nolte, Thomas, (8)
Söderberg, Stefan, (8)
Mudway, Ian S (8)
Sandström, Kristian, (8)
Kelly, Frank J (8)
Cassee, Flemming R (8)
Muala, Ala, (8)
Ragnarsson Stabo, He ... (7)
Blomberg, Anders, 19 ... (7)
Bosson, Jenny A., (7)
Kelly, F J (7)
Unosson, Jon (7)
Bucht, Anders, (6)
Behnam, Moris, (6)
Bohgard, Mats (6)
Lundbäck, Magnus, 19 ... (6)
Bengtsson, Agneta (6)
Pettersson, Esbjörn, (6)
Boon, Nicholas A (6)
Pegg, D. J. (5)
Stemme, Göran, (5)
van der Wijngaart, W ... (5)
Rönmark, Eva, (5)
Lundbäck, Bo, (5)
Ädelroth, Ellinor, (5)
Lucking, Andrew J (5)
visa färre...
Umeå universitet (116)
Lunds universitet (23)
Sveriges Lantbruksuniversitet (21)
Karolinska Institutet (13)
Kungliga Tekniska Högskolan (11)
Göteborgs universitet (10)
visa fler...
Uppsala universitet (9)
Stockholms universitet (8)
Mälardalens högskola (8)
Linköpings universitet (7)
Luleå tekniska universitet (7)
Chalmers tekniska högskola (4)
Örebro universitet (1)
visa färre...
Engelska (161)
Svenska (20)
Ämne (HSV)
Naturvetenskap (6)
Medicin och hälsovetenskap (5)


pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy