| 1. |
- Sott, Kristin, 1974, et al.
(författare)
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Micropipet Writing Technique for Production of Two-Dimensional Lipid Bilayer Nanotube-Vesicle Networks on Functionalized and Patterned Surfaces
- 2003
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 19:9, s. 3904-3910
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Tidskriftsartikel (refereegranskat)abstract
- We present a micropipet-assisted writing technique for formation of two-dimensional networks of phospholipid vesicles and nanotubes on functionalized and patterned substrates. The substrates are patterned with vesicle-adhesive circular spots (5-7.5 µm in diameter) consisting of a basal layer of biotin on gold and an apical coating of NeutrAvidin in a sandwich manner. The area surrounding the adhesive spots is coated with a phosphatidylcholine bilayer membrane, preventing protein and liposome adhesion. Networks were formed by aspirating a biotin-functionalized giant unilamellar or multilamellar liposome (5-50 µm in diameter) into a ~3 µm inner diameter borosilicate glass micropipet. By using a pressurized-air microejection system, a portion of the liposome is then ejected back into the solution while forming a first vesicle ~3 µm in diameter. This vesicle is placed on an adhesive spot. When the micropipet is moved, a nanotube connection is formed from the first vesicle and is pulled to the next adhesive spot where a second vesicle is ejected. This procedure can then be repeated until the lipid material is consumed in the pipet. The method allows for formation of networks with a large number of nodes and vertexes with well-defined geometry and surface adhesion, and represents a first step toward very large scale integration of nanotube-vesicle networks in, for example, nanofluidic applications.
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| 2. |
- Olofsson, Jessica, 1975, et al.
(författare)
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A microfluidics approach to the problem of creating separate solution environments accessible from macroscopic volumes
- 2004
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 76:17, s. 4968-4976
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Tidskriftsartikel (refereegranskat)abstract
- We report on a microfluidic device that generates separate solution environments in macroscopic volumes. Spatially distinct patterns are created by emitting fluids from 16 different sources (closely spaced microchannels) into a solution-filled macroscopic chamber. The fluid in neighboring microchannels couples viscously in the macroscopic container, generating one single interdigitated stream. Scanning nanoelectrode amperometry was used for characterizing the concentration landscape and the diffusion zones between solutions running in parallel at different coordinates in the stream. These experiments were complemented by finite element simulations of the Navier-Stokes and mass transport equations to describe the velocity distributions and the diffusion behavior. For in channel flow velocities of 50 mm·s -1 , patterns could persist on the order of millimeters to centimeters in the open volume. The most narrow diffusion zones with widths less than 10 μm (5-95% concentration change) were found some tens of micrometers out in the macroscopic container. We demonstrate that a 14-μm-diameter nearly spherical object (biological cell) attached to a micropipet can be moved from one solution environment to another by a lateral displacement of only 8 μm. The device is suitable for applications where the solution environment around a microscopic or nanoscopic sensor needs to be changed multiple times, i.e., in order to build layered structures, for obtaining binding isotherms, and kinetic information, for example, on ion channels, enzymes, and receptors as well as in applications where different loci on an object need to be exposed to different environments or where complex solution environments need to be created for studies of interfacial chemistry between two streaming layers.
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| 3. |
- Pihl, Johan, 1975, et al.
(författare)
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Microfluidic gradient-generating device for pharmacological profiling
- 2005
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 77:13, s. 3897-3903
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Tidskriftsartikel (refereegranskat)abstract
- We describe an on-chip microfluidic gradient-generating device that generates concentration gradients spanning nearly 5 orders of magnitude starting from a single concentration. The exiting stream of drugs held at different concentrations remains laminar in a recording chamber and can be presented as 24 discrete solutions to a cell-based sensor. The high-performance characteristics of the device are demonstrated by pharmacological screening of voltage-gated K + channels (hERG) and ligand-gated GABAA receptors using scanning-probe patch-clamp measurements. Multiple data point dose-response curves and IC 50 and EC 50 values were rapidly obtained, typically in less than 30 min, through its combined functionality of gradient generation and open-volume laminar flow. The device facilitates rapid pharmacological profiling of ion channel and GPCR effectors and enables the acquisition of large numbers of data points with minute sample consumption and handling. © 2005 American Chemical Society.
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| 4. |
- Torell, Agnes, 1993, et al.
(författare)
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Low CD4+T cell count is related to specific anti-nuclear antibodies, IFNα protein positivity and disease activity in systemic lupus erythematosus pregnancy.
- 2024
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Ingår i: Arthritis research & therapy. - : BioMed Central (BMC). - 1478-6362 .- 1478-6354. ; 26:1
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Tidskriftsartikel (refereegranskat)abstract
- Lymphopenia, autoantibodies and activation of the type I interferon (IFN) system are common features in systemic lupus erythematosus (SLE). We speculate whether lymphocyte subset counts are affected by pregnancy and if they relate to autoantibody profiles and/or IFNα protein in SLE pregnancy.Repeated blood samples were collected during pregnancy from 80 women with SLE and 51 healthy controls (HC). Late postpartum samples were obtained from 19 of the women with SLE. Counts of CD4+and CD8+T cells, B cells and NK cells were measured by flow cytometry. Positivity for anti-nuclear antibodies (ANA) fine specificities (double-stranded DNA [dsDNA], Smith [Sm], ribonucleoprotein [RNP], chromatin, Sjögren's syndrome antigen A [SSA] and B [SSB]) and anti-phospholipid antibodies (cardiolipin [CL] and β2 glycoprotein I [β2GPI]) was assessed with multiplexed bead assay. IFNα protein concentration was quantified with Single molecule array (Simoa) immune assay. Clinical data were retrieved from medical records.Women with SLE had lower counts of all lymphocyte subsets compared to HC throughout pregnancy, but counts did not differ during pregnancy compared to postpartum. Principal component analysis revealed that low lymphocyte subset counts differentially related to autoantibody profiles, cluster one (anti-dsDNA/anti-Sm/anti-RNP/anti-Sm/RNP/anti-chromatin), cluster two (anti-SSA/anti-SSB) and cluster three (anti-CL/anti-β2GPI), IFNα protein levels and disease activity. CD4+T cell counts were lower in women positive to all ANA fine specificities in cluster one compared to those who were negative, and B cell numbers were lower in women positive for anti-dsDNA and anti-Sm compared to negative women. Moreover, CD4+T cell and B cell counts were lower in women with moderate/high compared to no/low disease activity, and CD4+T cell count was lower in IFNα protein positive relative to negative women. Finally, CD4+T cell count was unrelated to treatment.Lymphocyte subset counts are lower in SLE compared to healthy pregnancies, which seems to be a feature of the disease per se and not affected by pregnancy. Our results also indicate that low lymphocyte subset counts relate differentially to autoantibody profiles, IFNα protein levels and disease activity, which could be due to divergent disease pathways.
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| 7. |
- Hugosson, Jonas, 1955, et al.
(författare)
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Mortality results from the Göteborg randomised population-based prostate-cancer screening trial.
- 2010
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Ingår i: The lancet oncology. - 1474-5488. ; 11:8, s. 725-32
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Tidskriftsartikel (refereegranskat)abstract
- Prostate cancer is one of the leading causes of death from malignant disease among men in the developed world. One strategy to decrease the risk of death from this disease is screening with prostate-specific antigen (PSA); however, the extent of benefit and harm with such screening is under continuous debate.
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| 8. |
- Hugosson, Jonas, 1955, et al.
(författare)
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Prostate Cancer Screening with PSA and MRI Followed by Targeted Biopsy Only.
- 2022
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Ingår i: The New England journal of medicine. - 1533-4406. ; 387:23, s. 2126-2137
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Tidskriftsartikel (refereegranskat)abstract
- Screening for prostate cancer is burdened by a high rate of overdiagnosis. The most appropriate algorithm for population-based screening is unknown.We invited 37,887 men who were 50 to 60 years of age to undergo regular prostate-specific antigen (PSA) screening. Participants with a PSA level of 3 ng per milliliter or higher underwent magnetic resonance imaging (MRI) of the prostate; one third of the participants were randomly assigned to a reference group that underwent systematic biopsy as well as targeted biopsy of suspicious lesions shown on MRI. The remaining participants were assigned to the experimental group and underwent MRI-targeted biopsy only. The primary outcome was clinically insignificant prostate cancer, defined as a Gleason score of 3+3. The secondary outcome was clinically significant prostate cancer, defined as a Gleason score of at least 3+4. Safety was also assessed.Of the men who were invited to undergo screening, 17,980 (47%) participated in the trial. A total of 66 of the 11,986 participants in the experimental group (0.6%) received a diagnosis of clinically insignificant prostate cancer, as compared with 72 of 5994 participants (1.2%) in the reference group, a difference of -0.7 percentage points (95% confidence interval [CI], -1.0 to -0.4; relative risk, 0.46; 95% CI, 0.33 to 0.64; P<0.001). The relative risk of clinically significant prostate cancer in the experimental group as compared with the reference group was 0.81 (95% CI, 0.60 to 1.1). Clinically significant cancer that was detected only by systematic biopsy was diagnosed in 10 participants in the reference group; all cases were of intermediate risk and involved mainly low-volume disease that was managed with active surveillance. Serious adverse events were rare (<0.1%) in the two groups.The avoidance of systematic biopsy in favor of MRI-directed targeted biopsy for screening and early detection in persons with elevated PSA levels reduced the risk of overdiagnosis by half at the cost of delaying detection of intermediate-risk tumors in a small proportion of patients. (Funded by Karin and Christer Johansson's Foundation and others; GÖTEBORG-2 ISRCTN Registry number, ISRCTN94604465.).
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| 9. |
- Karlsson, Per Erik, 1957, et al.
(författare)
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Evidence for Impacts of Near-ambient Ozone Concentrations on Vegetation in Southern Sweden
- 2009
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Ingår i: Ambio. - : Royal Swedish Academy of Sciences. ; 38:8, s. 425-431
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Tidskriftsartikel (refereegranskat)abstract
- Substantial impacts of near-ambient ozone concentrations on agricultural crops, trees, and seminatural vegetation are demonstrated for southern Sweden. Impacts of ambient ozone levels (2–15 μL L-¹ hr annual accumulated ozone exposure over a threshold of 40 nL L-¹ [AOT40]) range from a 2%–10% reduction for trees (e.g., leaf chlorophyll, tree growth) up to a 15% reduction for crops (e.g., yield, wheat/potato). Visible leaf injury on bioindicator plants caused by ambient ozone levels has been clearly demonstrated. The humid climatic conditions in Sweden promote high rates of leaf ozone uptake at a certain ozone concentration. This likely explains the comparatively large ozone impacts found for vegetation in southern Sweden at relatively low ozone concentrations in the air. It is important that the future methods used for the representation of ozone impacts on vegetation across Europe are based on the leaf ozone uptake concept and not on concentration-based exposure indices, such as AOT40.
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