| 1. |
- Izumrudov, Vladimir, et al.
(författare)
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Factors Controlling Phase Separation in Water-Salt Solutions of DNA and Polycations.
- 2003
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 19:11, s. 4733-4739
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Tidskriftsartikel (refereegranskat)abstract
- Factors affecting phase separation in water-salt solutions of polyelectrolyte complexes (PECs), formed by DNA and integral or pendant polycations with a quaternary amino group in every monomer unit, have been studied. When no salt was added, quantitative DNA precipitation occurred at a stoichiometric charge ratio, = [+]/[-] 1. In DNA mixtures with poly(N,N'-dimethyldiallylammonium chloride) (PDMDAAC, a pendant polycation), insoluble PECs formed in the range 0.7 < < 2. This suggests the formation of soluble, negatively charged PECs at 0 < < 0.7 and soluble, positively charged PECs at > 2. For different aliphatic ionene bromides (integral polycations), the range of corresponding to insoluble PECs was significantly broader, mainly due to the poor ability of the ionenes to form soluble, positively charged PECs. The range was also relatively broad for poly(N-ethyl-4-vinylpyridinium bromide) (a pendant polycation) and became broader with decreasing degree of polymerization of the polycation. The formation of insoluble PECs was favored by the addition of salt (NaCl), and the effect was more pronounced when decreasing the relative content of the solubilizing component, i.e., the nucleic acid at < 1 and the polycation at > 1. At moderate ionic strength, 0.12 M < [NaCl] < 0.6 M, quantitative precipitation of DNA was attained by addition of PDMAAC in the whole region studied: 1 < < 4.5. The data obtained strongly suggest that phase separation in solutions of DNA-containing PECs follows general rules revealed by studying PECs formed by flexible vinyl polyanions. However, the high rigidity of the DNA double helix appears to be responsible for the key feature revealed in the phase diagrams, i.e., significant broadening of the region for insoluble PECs at the expense of the region in which soluble DNA-containing PECs are formed. This feature may severely limit the application of DNA-containing PECs in medicine and biology but could be beneficial in the development of simple and effective procedures for DNA separation in biotechnology.
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| 2. |
- Sjöberg, Mats, 1965-, et al.
(författare)
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Infliximab or cyclosporine as rescue therapy in hospitalized patients with steroid-refractory ulcerative colitis : a retrospective observational study
- 2012
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Ingår i: Inflammatory Bowel Diseases. - : John Wiley & Sons. - 1078-0998 .- 1536-4844. ; 18:2, s. 212-218
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cyclosporine (CsA) or infliximab (IFX) are used as rescue therapies in steroid-refractory, severe attacks of ulcerative colitis (UC). There are no data comparing the efficacy of these two alternatives. Methods: Outcome of rescue therapy was retrospectively studied in two cohorts of patients hospitalized due to steroid-refractory moderate to severe UC: 1) a Swedish-Danish cohort (n 49) treated with a single infusion of IFX; 2) an Austrian cohort (n 43) treated with intravenous CsA. After successful rescue therapy, maintenance immunomodulator treatment was given to 27/33 (82%) of IFX patients and to 31/40 (78%) of CsA patients. Endpoints were colectomy-free survival at 3 and 12 months. Kaplan-Meier and Cox regression models were used to evaluate the association between treatment groups and colectomy. Results: At 15 days, colectomy-free survival in the IFX cohort was 36/49 (73%) versus 41/43 (95%) in the CsA cohort (P = 0.005), at 3 months 33/49 (67%) versus 40/43 (93%) (P = 0.002), and at 12 months 28/49 (57%) versus 33/43 (77%) (P = 0.034). After adjusting for potential confounding factors, Cox regression analysis yielded adjusted hazard ratios for risk of colectomy in IFX-treated patients of 11.2 (95% confidence interval [CI] 2.4-53.1, P = 0.002) at 3 months and of 3.0 (95% CI 1.1-8.2, P = 0.030) at 12 months in comparison with CsA-treated patients. There were no opportunistic infections or mortality. Conclusions: Colectomy frequencies were significantly lower after rescue therapy with CsA than with a single infusion of IFX both at 3 and 12 months' follow-up. The superiority of CsA was seen principally during the first 15 days.
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| 3. |
- Wahlund, Per-Olof, et al.
(författare)
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Phase Separations in Water-Salt Solutions of Polyelectrolyte Complexes Formed by RNA and Polycations: Comparison with DNA Complexes.
- 2003
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Ingår i: Macromolecular Bioscience. - : Wiley. - 1616-5195 .- 1616-5187. ; 3:8, s. 404-411
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Tidskriftsartikel (refereegranskat)abstract
- Formation of insoluble polyelectrolyte complexes (PECs) between RNA and polycations was followed by measuring the residual RNA absorbance in the solution after separation of the precipitate. The polycations studied were poly(N,N-dimethyldiallylammonium) chloride (pendant type) and 2,5-ionene bromide (integral type) with quaternary amino groups in every monomer unit. The data obtained were compared with the results of analogous studies of DNA-containing PECs. This study is a part of a project aimed at the specific separation of plasmid DNA from RNA, a major problem in the preparative isolation of plasmid DNA. We thus deliberately chose a heterogenous RNA sample as it represents the RNA present in a real cell extract. In contrast to the exhaustive precipitation of DNA observed at certain values, a significant part of RNA was nonprecipitated at any = [+]/[-], that is, at any ratio of positively charged quaternary amino groups and negatively charged phosphate groups. The addition of sodium chloride increased the nonprecipitated fraction of RNA. DNA, on the other hand, was completely precipitated by both polycations at > 0.7. The less effective precipitation of RNA was probably due to the presence of a considerable fraction of short-chained molecules, incapable of forming a sufficient cooperative system of salt bonds with the polycation. This assumption was supported by a separate experiment, in which the precipitation behavior of RNA fractions of different molecular masses was investigated. The same tendency, while less pronounced, was also ascertained for PECs formed by polycations with DNA fractions of different molecular masses. The possibility of using the revealed differences between DNA and RNA behavior for effective precipitation procedure useful in bioseparation is discussed. The difference in the precipitation behavior of nucleic acids of different molecular masses means there is a possibility for developing an enzymatic assay for DNAase and RNAase activity.
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| 4. |
- Wahlund, Per-Olof, et al.
(författare)
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Polyelectrolyte complexes as a tool for purification of plasmid DNA background and development
- 2004
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Ingår i: Journal of Chromatography. B. - : Elsevier BV. - 1873-376X .- 1570-0232. ; 807:1, s. 121-127
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Tidskriftsartikel (refereegranskat)abstract
- The demand for highly purified plasmids in gene therapy and plasmid-based vaccines requires large-scale production of pharmaceutical-grade plasmid. Plasmid DNA was selectively precipitated from a clarified alkaline lysate using the polycation poly(N,N'-dimethyldiallylammonium) chloride which formed insoluble polyelectrolyte complex (PEC) with the plasmid DNA. Soluble PECs of DNA with polycations have earlier been used for cell transformation, but now the focus has been on insoluble PECs. Both DNA and RNA form stable PECs with synthetic polycations. However, it was possible to find a range of salt concentration where plasmid DNA was quantitatively precipitated whereas RNA remained in solution. The precipitated plasmid DNA was resolubilised at high salt concentration and the polycation was removed by gel-filtration. (C) 2004 Elsevier B.V. All rights reserved.
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| 5. |
- Wahlund, Per-Olof, et al.
(författare)
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Precipitation by polycation as capture step in purification of plasmid DNA from a clarified lysate
- 2004
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Ingår i: Biotechnology and Bioengineering. - : Wiley. - 1097-0290 .- 0006-3592. ; 87:5, s. 675-684
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Tidskriftsartikel (refereegranskat)abstract
- The demand for highly purified plasmids in gene therapy and plasmid-based vaccines requires large-scale production of pharmaceutical-grade plasmid. Large-scale purification of plasmid DNA from bacterial cell culture normally includes one or several chromatographic steps. Prechromatographic steps include precipitation with solvents, salts, and polymers combined with enzymatic degradation of nucleic acids. No method alone has so far been able to selectively capture plasmid DNA directly from a clarified alkaline lysate. We present a method for selective precipitation of plasmid DNA from a clarified alkaline lysate using polycation poly(N,N'-dimethyldiallylammonium) chloride (PDMDAAC). The specific interaction between the polycation and the plasmid DNA resulted in the formation of a stoichiometric insoluble complex. Efficient removal of contaminants such as RNA, by far the major contaminant in a clarified lysate, and proteins as well as 20-fold plasmid concentration has been obtained with about 80% recovery. The method utilizes a inexpensive, commercially available polymer and thus provides a capture step suitable for large-scale production. (C) 2004 Wiley Periodicals, Inc.
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| 6. |
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| 7. |
- Blais, Curtis, et al.
(författare)
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Design and Development of an Architecture for Demonstrating the Interplay of Emerging SISO Standards
- 2007
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Ingår i: Simulation Interoperability Standards Organization - Spring Simulation Interoperability Workshop 2007, 07 Spring SIW. - 9781604239232 ; , s. 302-309
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Konferensbidrag (refereegranskat)abstract
- The Simulation Interoperability Standards Organization (SISO) focuses on facilitating simulation interoperability across government and non-government applications worldwide. A number of standards are emerging that will individually have great impact on the development and operation of simulation systems, as well as interoperation across simulation systems and command and control systems. Taken together, however, the emerging standards represent a set of capabilities and technologies which can revolutionize the simulation industry, radically improving the way we develop and deliver interoperable systems.In the Fall 2006 Simulation Interoperability Workshop, an architecture for demonstrating the interplay of several current and emerging SISO standards was presented. The following standards were selected for development of an initial demonstration system: (1) the Coalition Battle Management Language (C-BML) for unambiguous expression of plans and orders for live, constructive, and robotic forces; (2) the Military Scenario Definition Language (MSDL) for describing a scenarios that can be shared across multiple systems; (3) Base Object Models (BOMs) for specifying building blocks for composing larger model sets; (4) the Simulation Reference Markup Language (SRML) for platform-independent representation of executable behavior models; and (5) the Distributed Interactive Simulation Extensible Markup Language (DIS-XML) initiative for representing DIS Protocol Data Units in XML to enhance interchange of dynamic entity state and entity interactions across diverse systems in web-based network centric architectures.This paper discusses how the framework can be used by the SISO community as a means for educating the community on emerging standards and as a platform for demonstration of new concepts and capabilities as a precursor to a new standardization effort. It describes work performed to design and develop an initial test case demonstrating the integration of these standards, including problems encountered, problem resolutions, lessons learned, and future work.
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| 8. |
- Bodin, Theo, et al.
(författare)
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Road traffic noise, air pollution and myocardial infarction: a prospective cohort study.
- 2016
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Ingår i: International Archives of Occupational and Environmental Health. - : Springer Science and Business Media LLC. - 1432-1246 .- 0340-0131. ; 89:5, s. 793-802
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Tidskriftsartikel (refereegranskat)abstract
- Both road traffic noise and air pollution have been linked to cardiovascular disease. However, there are few prospective epidemiological studies available where both road traffic noise and air pollution have been analyzed simultaneously. The aim of this study was to investigate the relation between road traffic noise, air pollution and incident myocardial infarction in both current (1-year average) and medium-term (3-year average) perspective.
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| 9. |
- Budnik, Lygia Therese, et al.
(författare)
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Diagnosis, monitoring and prevention of exposure-related non-communicable diseases in the living and working environment : DiMoPEx-project is designed to determine the impacts of environmental exposure on human health
- 2018
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Ingår i: Journal of Occupational Medicine and Toxicology. - : Springer Science and Business Media LLC. - 1745-6673. ; 13:1
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Forskningsöversikt (refereegranskat)abstract
- The WHO has ranked environmental hazardous exposures in the living and working environment among the top risk factors for chronic disease mortality. Worldwide, about 40 million people die each year from noncommunicable diseases (NCDs) including cancer, diabetes, and chronic cardiovascular, neurological and lung diseases. The exposure to ambient pollution in the living and working environment is exacerbated by individual susceptibilities and lifestyle-driven factors to produce complex and complicated NCD etiologies. Research addressing the links between environmental exposure and disease prevalence is key for prevention of the pandemic increase in NCD morbidity and mortality. However, the long latency, the chronic course of some diseases and the necessity to address cumulative exposures over very long periods does mean that it is often difficult to identify causal environmental exposures. EU-funded COST Action DiMoPEx is developing new concepts for a better understanding of health-environment (including gene-environment) interactions in the etiology of NCDs. The overarching idea is to teach and train scientists and physicians to learn how to include efficient and valid exposure assessments in their research and in their clinical practice in current and future cooperative projects. DiMoPEx partners have identified some of the emerging research needs, which include the lack of evidence-based exposure data and the need for human-equivalent animal models mirroring human lifespan and low-dose cumulative exposures. Utilizing an interdisciplinary approach incorporating seven working groups, DiMoPEx will focus on aspects of air pollution with particulate matter including dust and fibers and on exposure to low doses of solvents and sensitizing agents. Biomarkers of early exposure and their associated effects as indicators of disease-derived information will be tested and standardized within individual projects. Risks arising from some NCDs, like pneumoconioses, cancers and allergies, are predictable and preventable. Consequently, preventative action could lead to decreasing disease morbidity and mortality for many of the NCDs that are of major public concern. DiMoPEx plans to catalyze and stimulate interaction of scientists with policy-makers in attacking these exposure-related diseases.
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| 10. |
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