| 61. |
- Anckarsäter, Rolf, 1956, et al.
(författare)
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Cerebrospinal fluid protein reactions during non-neurological surgery.
- 2007
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Ingår i: Acta neurologica Scandinavica. - : Hindawi Limited. - 0001-6314 .- 1600-0404. ; 115:4, s. 254-9
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To study changes in cerebrospinal fluid (CSF) protein markers of blood-CSF barrier integrity and immunological reactions during surgical stress. SUBJECTS AND METHODS: Thirty-five patients without neurological or psychiatric disorders undergoing knee replacements had CSF and serum samples drawn from spinal and arterial catheters before, 3 h after and the morning after surgery. RESULTS: Serum albumin decreased during surgery and CSF albumin decreased during and after surgery, and, as a consequence, the CSF/serum albumin ratio decreased significantly during the study period, especially after the intervention. In contrast, CSF concentrations of beta-2-microglobuline (beta2M) increased significantly during surgery and remained high. The CSF general marker beta-trace protein (betaTP) remained unchanged. CONCLUSIONS: Central nervous system protein reactions to a non-neurological surgical intervention include sharply decreased permeability of albumin into the CSF and signs of intrathecal inflammatory activity.
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| 62. |
- Anderberg, Elsie, et al.
(författare)
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Micro processes of learning : Exploring the interplay between conceptions, meanings and expressions
- 2009
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Ingår i: Higher Education. - : Springer Science and Business Media LLC. - 0018-1560 .- 1573-174X. ; 58:5, s. 653-668
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Tidskriftsartikel (refereegranskat)abstract
- The article describes qualitative variation in micro processes of learning, focusing the dynamic interplay between conceptions, expressions and meanings of expressions in students' learning in higher education. The intentional-expressive approach employed is an alternative approach to the function of language use in learning processes. In the empirical investigation, a dialogue model was used that both stimulates and documents students' ways of processing meaning. Results were grouped into three descriptive categories: vague, stabilising and developing ways of processing. Educational implications include, firstly, two distinct types of vague constitution of meaning in learning: one connected to fragmentary relationships between expressions and meanings, and another that triggers and creates close relationships and changes in relationships. Secondly, the categories display different unexplored ways of processing, related to deep and surface approaches in students' learning.
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| 63. |
- Anderlund, Magnus F., et al.
(författare)
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Redox chemistry of a dimanganese(II,III) complex with an unsymmetric ligand : Water binding, deprotonation and accumulative light-induced oxidation
- 2006
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Ingår i: European Journal of Inorganic Chemistry. - : Wiley. - 1434-1948 .- 1099-1948 .- 1099-0682. ; :24, s. 5033-5047
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Tidskriftsartikel (refereegranskat)abstract
- A dinuclear manganese complex {[(Mn2L)-L-II,IIII(mu-OAc)(2)]-ClO4} has been synthesised, where L is the dianion of 2-{[bis-(pyrid-2-ylmethyl)amino]methyl}-6-{[(3,5-di-tert-butyl-2- hydroxybenzyl)(pyrid-2-ylmethyl)amino]methyl)-4-methylphenol, an unsymmetric binucleating ligand with two coordinating phenol groups. The two manganese ions, with a Mn-Mn distance of 3.498 angstrom, are bridged by the two bidentate acetate ligands and the 4-methylphenolate group of the ligand, resulting in a N3O3 and N2O4 donor set of Mn-II and Mn-II, respectively. Electrochemically [Mn2(II,III)L(mu-OAc)(2)](+) is reduced to [(Mn2L)-L-II,II(mu-OAc)(2)] at E-1/2(1)=-0.53 V versus Fc(+/0) and oxidised to [(Mn2L)-L-III,III(mu-OAC)(2)](2+) at E-1/2(2)=0.38 V versus Fc(+/0). All three redox states have been characterised by EPR, IR and UV/Vis spectroscopy. Subsequent oxidation of [(Mn2L)-L-II,III(mu-OAc)(2)](2+) [E-1/2(3)=0.75 V vs. Fc(+/0)] in dry acetonitrile results in an unstable primary product with a lifetime of about 100 ins. At high scan rates quasireversible voltammetric behaviour is found for all three electrode processes, with particularly slow electron transfer for the II,III/II,II [k(o)(1) = 0.002 cms(-1) and III,III/II,III [k(o)(2) = 0.005 cms(-1)] couples, which can be rationalised in terms of major distortions of the Mn-II centres. In aqueous media the bridging acetates are replaced by water-derived ligands. Deprotonation of these stabilises higher valence states, and photo-induced oxidation of the manganese complex results in a (Mn2L)-L-IlI,IV complex with oxo or hydroxo bridging ligands, which is further oxidised to an EPR-silent product. These results demonstrate that a larger number of metal-centred oxidations can be compressed in a narrow potential range if build up of charge is avoided by charge-compensating reactions.
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| 64. |
- Anderot, Maria, et al.
(författare)
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Determination of dissociation constants between polyelectrolytes and proteins by affinity capillary electrophoresis
- 2009
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Ingår i: Journal of chromatography. B. - : Elsevier BV. - 1570-0232 .- 1873-376X. ; 877:10, s. 892-896
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Tidskriftsartikel (refereegranskat)abstract
- In this manuscript we report the binding affinity between two model proteins, human serum albumin (HSA) and ribonuclease A (RNase A), and negatively charged polyelectrolytes, two different heparin fractions and dextran sulfate, by means of partial filling and affinity capillary electrophoresis. The apparent dissociation constants, K-d, obtained by use of the partial-filling method, between HSA and heparin (17 kDa), heparin (3 kDa) and dextran sulfate (8 kDa) were 33 and 307 mu M, respectively. A new method was developed to determine affinities that take in account different migration directions between the protein and the polyelectrolyte, which was required to study RNase A. By use of this affinity capillary electrophoresis two K-d values were observed for the interaction between RNase A and heparin 17 kDa, yielding a high affinity binding with K-d1 0.0075 mu M, and a lower affinity binding with K-d2 8.7 mu M. For dextran sulfate 8 kDa these K-d values were 0.027 and 10.4 mu M, respectively. Heparin 3 kDa only showed a single K-d value of 0.52 mu M. The results show that the magnitude of the binding affinity depends on the type of polyelectrolyte and its molecular weight. (C) 2009 Elsevier B.V. All rights reserved.
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| 65. |
- Andersen, Birgit, et al.
(författare)
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A recruited protease is involved in catabolism of pyrimidines.
- 2008
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Ingår i: Journal of Molecular Biology. - : Elsevier BV. - 1089-8638 .- 0022-2836. ; 379:2, s. 243-250
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Tidskriftsartikel (refereegranskat)abstract
- In nature, the same biochemical reaction can be catalyzed by enzymes having fundamentally different folds, reaction mechanisms and origins. For example, the third step of the reductive catabolism of pyrimidines, the conversion of N-carbamyl-beta-alanine to beta-alanine, is catalyzed by two beta-alanine synthase (beta ASase, EC 3.5.1.6) subfamilies. We show that the "prototype" eukaryote beta ASases, such as those from Drosophila melanogaster and Arabidopsis thaliana, are relatively efficient in the conversion of N-carbamyl-beta A compared with a representative of fungal beta ASases, the yeast Saccharomyces kluyveri beta ASase, which has a high K(m) value (71 mM). S. kluyveri beta ASase is specifically inhibited by dipeptides and tripeptides, and the apparent K(i) value of glycyl-glycine is in the same range as the substrate K(m). We show that this inhibitor binds to the enzyme active center in a similar way as the substrate. The observed structural similarities and inhibition behavior, as well as the phylogenetic relationship, suggest that the ancestor of the fungal beta ASase was a protease that had modified its profession and become involved in the metabolism of nucleic acid precursors.
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| 66. |
- Andersen, C. E., et al.
(författare)
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Medical proton dosimetry using radioluminescence from aluminium oxide crystals attached to optical-fiber cables
- 2007
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576 .- 0167-5087. ; 580:1, s. 466-468
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Tidskriftsartikel (refereegranskat)abstract
- The prime objective of this study is to investigate if radioluminescence (RL) from carbon-doped aluminum oxide (Al2O3:C) crystals potentially can be used for absorbed dose-rate measurements during proton radiotherapy. The RL from two separate (2 mg) Al2O3:C crystals attached to optical-fiber cables were recorded during irradiations in water in a 175 MeV clinical proton beam. The RL response for low-LET protons in the plateau region of the Bragg curve was found to closely resemble that observed for a clinical 6 MV X-ray beam. An identical response was found in the Bragg peak (where the dose-averaged LET is about 4 keV/mu m) for absorbed doses less than 0.3 Gy. For doses in the range of 0.3-3Gy, we observed a significant decrease in luminescence efficiency with LET. At 3 Gy, the luminescence efficiency was about 60% in the Bragg-peak region. The study implies that the RL-signal from Al2O3:C could potentially be suitable for medical proton dosimetry in the 0-0.3 Gy range even without any LET-dependent correction factors.
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| 67. |
- Andersen, Gorm, et al.
(författare)
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A gene duplication led to specialized gamma-aminobutyrate and beta-alanine aminotransferase in yeast
- 2007
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Ingår i: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 274:7, s. 1804-1817
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Tidskriftsartikel (refereegranskat)abstract
- In humans, beta-alanine (BAL) and the neurotransmitter gamma-aminobutyrate (GABA) are transaminated by a single aminotransferase enzyme. Apparently, yeast originally also had a single enzyme, but the corresponding gene was duplicated in the Saccharomyces kluyveri lineage. SkUGA1 encodes a homologue of Saccharomyces cerevisiae GABA aminotransferase, and SkPYD4 encodes an enzyme involved in both BAL and GABA transamination. SkPYD4 and SkUGA1 as well as S. cerevisiae UGA1 and Schizosaccharomyces pombe UGA1 were subcloned, over-expressed and purified. One discontinuous and two continuous coupled assays were used to characterize the substrate specificity and kinetic parameters of the four enzymes. It was found that the cofactor pyridoxal 5'-phosphate is needed for enzymatic activity and alpha-ketoglutarate, and not pyruvate, as the amino group acceptor. SkPyd4p preferentially uses BAL as the amino group donor (V-max/K-m = 0.78 U.mg(-1).mM(-1)), but can also use GABA (V-max/K-m = 0.42 U.mg(-1).mM(-1)), while SkUga1p only uses GABA (V-max/K-m = 4.01 U.mg(-1).mM(-1)). SpUga1p and ScUga1p transaminate only GABA and not BAL. While mammals degrade BAL and GABA with only one enzyme, but in different tissues, S. kluyveri and related yeasts have two different genes/enzymes to apparently 'distinguish' between the two reactions in a single cell. It is likely that upon duplication similar to 200 million years ago, a specialized Uga1p evolved into a 'novel' transaminase enzyme with broader substrate specificity.
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| 68. |
- Andersen, Gorm, et al.
(författare)
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Catabolism of pyrimidines in yeast: A tool to understand degradation of anticancer drugs
- 2006
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Ingår i: Nucleosides, Nucleotides & Nucleic Acids. - : Informa UK Limited. - 1525-7770 .- 1532-2335. ; 25:9-11, s. 991-996
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Tidskriftsartikel (refereegranskat)abstract
- The pyrimidine catabolic pathway is of crucial importance in cancer patients because it is involved in degradation of several chemotherapeutic drugs, such as 5-fluorouracil; it also is important in plants, unicellular eukaryotes, and bacteria for the degradation of pyrimidine-based biocides/antibiotics. During the last decade we have developed a yeast species, Saccharomyces kluyveri, as a model and tool to study the genes and enzymes of the pyrimidine catabolic pathway. In this report, we studied degradation of uracil and its putative degradation products in 38 yeasts and showed that this pathway was present in the ancient yeasts but was lost approximately 100 million years ago in the S. cerevisiae lineage.
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| 69. |
- Andersen, Niels S., et al.
(författare)
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Pre-Emptive Treatment With Rituximab of Molecular Relapse After Autologous Stem Cell Transplantation in Mantle Cell Lymphoma
- 2009
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Ingår i: Journal of Clinical Oncology. - 0732-183X .- 1527-7755. ; 27:26, s. 4365-4370
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Minimal residual disease (MRD) is predictive of clinical progression in mantle-cell lymphoma (MCL). According to the Nordic MCL-2 protocol we prospectively analyzed the efficacy of pre-emptive treatment using rituximab to MCL patients in molecular relapse after autologous stem cell transplantation (ASCT). Patients and Materials MCL patients enrolled onto the study, who had polymerase chain reaction (PCR) detectable molecular markers and underwent ASCT, were followed with serial PCR assessments of MRD in consecutive bone marrow and peripheral blood samples after ASCT. In case of molecular relapse with increasing MRD levels, patients were offered pre-emptive treatment with rituximab 375 mg/m(2) weekly for 4 weeks. Results Of 160 MCL patients enrolled, 145 underwent ASCT, of whom 78 had a molecular marker. Of these, 74 were in complete remission (CR) and four had progressive disease after ASCT. Of the CR patients, 36 underwent a molecular relapse up to 6 years (mean, 18.5 months) after ASCT. Ten patients did not receive pre-emptive treatment mainly due to a simultaneous molecular and clinical relapse, while 26 patients underwent pre-emptive treatment leading to reinduction of molecular remission in 92%. Median molecular and clinical relapse-free survival after pre-emptive treatment were 1.5 and 3.7 years, respectively. Of the 38 patients who remain in molecular remission for now for a median of 3.3 years (range, 0.4 to 6.6 years), 33 are still in clinical CR. Conclusion Molecular relapse may occur many years after ASCT in MCL, and PCR based pre-emptive treatment using rituximab is feasible, reinduce molecular remission, and may prevent clinical relapse.
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| 70. |
- Andersson, Anne, 1966-, et al.
(författare)
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Family history of cancer as a risk factor for second malignancies after Hodgkin's lymphoma
- 2008
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 98:5, s. 1001-1005
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Tidskriftsartikel (refereegranskat)abstract
- This study estimated the risk of second primary malignancies after Hodgkin's lymphoma (HL) in relation to family history of cancer, age at diagnosis and latency, among 6946 patients treated for HL in Sweden in 1965–1995 identified through the Swedish Cancer Register (SCR). First-degree relatives (FDRs) to the HL patients and their malignancies were then ascertained together with their malignancies through the Multi-Generation Registry and SCR. The HL patient cohort was stratified on the number of FDRs with cancer, and standardised incidence ratios (SIRs) of developing SM were analysed. In the HL cohort, 781 SM were observed 1 year or longer after HL diagnosis. The risk for developing SM increased with the number of FDRs with cancer, SIRs being 2.26, 3.01, and 3.45 with 0, 1, or ≥2 FDRs with cancer, respectively. Hodgkin's lymphoma long-term survivors treated at a young age with a family history of cancer carry an increased risk for developing SM and may represent a subgroup where standardised screening for the most common cancer sites could be offered in a stringent surveillance programme.
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