| 31. |
- Artemenko, Konstantin A., et al.
(författare)
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Optimization of immunoaffinity enrichment and detection : toward a comprehensive characterization of the phosphotyrosine proteome of K562 cells by liquid chromatography-mass spectrometry
- 2011
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Ingår i: The Analyst. - : Royal Society of Chemistry (RSC). - 0003-2654 .- 1364-5528. ; 136:9, s. 1971-1978
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Tidskriftsartikel (refereegranskat)abstract
- Phosphorylation of protein tyrosine residues regulates many cell functions and has also been proved to be involved in oncogenesis. Thus, the identification of the phosphotyrosine (pTyr) proteome of cells is a very important task. Since tyrosine phosphorylation represents only around 1% of the total human phosphoproteome, the study of pTyr proteins is rather challenging. Here we report the optimization study of the phosphotyrosine proteome using K562 cells as a model system. A substantial segment of the phosphotyrosine proteome of K562 cells was characterized by immunoaffinity enrichment with 4G10 and PYKD1 antibodies followed by LC-MS/MS analysis. 480 non-redundant pTyr peptides corresponding to 342 pTyr proteins were found. 141 pTyr peptides were not described elsewhere. The mass spectrometry approach involving high-resolving FTMS analysis of precursor ions and subsequent detection of CID fragments in a linear ion trap was considered as optimal. For detection of low abundant pTyr peptides pooling of individual immunoaffinity enrichments for one LC-MS/MS analysis was crucial. The enrichment properties of the monoclonal PYKD1 antibody were presented for the first time, also in comparison to the 4G10 antibody. PYKD1 was found to be more effective for protein enrichment (1.2 and 5% efficiency at peptide and protein level correspondingly), while 4G10 showed better results when peptide enrichment was performed (15% efficiency versus 3.6% at protein level). Substantially different subsets of the phosphoproteome were enriched by these antibodies. This finding together with previous studies demonstrates that comprehensive pTyr proteome characterization by immunoprecipitation requires multiple antibodies to be used for the affinity enrichment.
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| 32. |
- Barkholt, L M, et al.
(författare)
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Stool cultures obtained before liver transplantation are useful for choice of perioperative antibiotic prophylaxis
- 1997
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Ingår i: Transplant International. - : Frontiers Media SA. - 0934-0874 .- 1432-2277. ; 10:6, s. 432-438
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Tidskriftsartikel (refereegranskat)abstract
- Bacterial infections, especially cholangitis, are still common complications after liver transplantation (LTx). During recent years, multiresistant enterococci have become a nosocomial problem in transplant units. The present prospective study on 26 patients, including 24 patients with chronic liver disease, demonstrated that enterococci were the predominant micro-organism involved in post-LTx bacterial infections. They were cultured in the feces and in other sites of 10 out of 13 (77%) patients who underwent extensive examinations. Ampicillin-resistant Enterococcus faecium strains were isolated in urine or feces of 2 of the 13 patients prior to LTx. Similarly, resistance to ampicillin and gentamicin, the empirically used antibiotics for patients with fever of unknown origin, was found in E. faecium strains in 3 and 2 patients, respectively. Moreover, multiresistant E. faecium and E. faecalis strains were demonstrated in 46% of the patients in the postoperative period (3 months). However, no vancomycin-resistant enterococci were isolated. The use of antibiotics within 4 months prior to LTx significantly increased the risk of developing ampicillin-resistant bacteria at the time of LTx and of infections with bacteria of enteric origin after LTx (P = 0.03 and 0.01, respectively). We conclude that stool and urine cultures performed prior to LTX may be useful for selecting prophylactic antibiotic regimens.
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| 33. |
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| 34. |
- Baykut, Doan, et al.
(författare)
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Molecular differentiation of ischemic and valvular heart disease by liquid chromatography/fourier transform ion cyclotron resonance mass spectrometry
- 2006
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Ingår i: European Journal of Medical Research. - 0949-2321 .- 2047-783X. ; 11:6, s. 221-226
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Tidskriftsartikel (refereegranskat)abstract
- Proteomic patterns of myocardial tissue in different etiologies of heart failure were investigated using a direct analytical approach with High Performance Liquid Chromatography (HPLC)/Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). Right atrial appendages from 20 patients, 10 with hemodynamically significant isolated aortic valve disease and 10 with symptomatic coronary artery disease were collected during elective cardiac surgery. After preparation of tissue samples and tryptic digestion of proteins, the peptide mixture was HPLC-separated and on-line analyzed by electrospray FT-ICR MS. Data obtained from HPLC / FT-ICR MS runs were compared for classification. To extract the classification features, the selection of best individual features was applied and the "nearest mean classifier" was used for the classification of test samples and the sample projection onto classification patterns. The pattern distribution characteristics of aortic and coronary diseases were clearly different. No interference between samples of both disease categories was registered, even if the distribution of unsupervised classified test samples were closer. Samples representing aortic valve disease showed a closer accumulation pattern of spots compared to the samples representing coronary disease, which indicated a more specific protein classification. Through selective identification of specific peptides and protein patterns with FTMS, valvular and coronary heart disease is for the first time clearly distinguished at molecular level. The described methodology could also be feasible in search for specific biomarkers in plasma or serum for diagnostic purposes.
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| 35. |
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| 36. |
- Bergquist, Ann-Kristin, 1972-, et al.
(författare)
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Understanding and Overcoming Roadblocks to Environmental Sustainability : Past Roads and Future Prospects
- 2019
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Ingår i: Business history review. - Boston : Cambridge University Press. - 0007-6805 .- 2044-768X. ; 93:1, s. 127-148
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Tidskriftsartikel (refereegranskat)abstract
- This article examines key barriers to business sustainability discussed at a multidisciplinary conference held at the Harvard Business School in 2018. Drawing on perspectives from both the historical and business literatures, speakers debated the historical success of and future opportunities for voluntary business actions to advance sustainability. Roadblocks include misaligned incentives, missing institutions, inertia of economic systems, and the concept of sustainability itself. Overcoming these roadblocks will require systematic interventions and alternative normative concepts.
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| 37. |
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| 38. |
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| 39. |
- Bergquist, Jonas, et al.
(författare)
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Discovery of endogenous catecholamines in lymphocytes and evidence for catecholamine regulation of lymphocyte function via an autocrine loop.
- 1994
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - 0027-8424 .- 1091-6490. ; 91:26, s. 12912-6
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Tidskriftsartikel (refereegranskat)abstract
- Evidence has been obtained that catecholamines and their metabolites are present in single lymphocytes and extracts of T- and B-cell clones by use of capillary electrophoresis with electrochemical detection. Pharmacological inhibition of tyrosine hydroxylase reduces observed catecholamine levels, suggesting catecholamine synthesis by lymphocytes. Intracellular dopamine levels are shown to be increased by extra-cellular dopamine, suggesting a cellular-uptake mechanism. Furthermore, incubation with either dopamine or L-dihydroxyphenylalanine, a precursor of dopamine, results in a dose-dependent inhibition of lymphocyte proliferation and differentiation. Together, these results suggest the presence of an autocrine loop whereby lymphocytes down-regulate their own activity.
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| 40. |
- Bergquist, Jonas, et al.
(författare)
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Measurements of catecholamine-mediated apoptosis of immunocompetent cells by capillary electrophoresis.
- 1997
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Ingår i: Electrophoresis. - : Wiley. - 0173-0835 .- 1522-2683. ; 18:10, s. 1760-6
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Tidskriftsartikel (refereegranskat)abstract
- Single cell analysis with capillary electrophoresis, a technique capable of detecting zeptomole quantities (10(-21) mole) of neurochemical species, has been used to demonstrate that lymphocytes are capable of active synthesis of dopamine and norepinephrine. Exposure of lymphocytes to catecholamines at concentrations as low as 10 nM leads to decreased proliferation and differentiation, e.g. interferon-gamma (IFN-gamma), interleukin-4 (IL-4) and immunoglobulin (Ig). In addition, both inhibition of dopamine uptake with nomifensine and inhibition of packing of catecholamines into vesicles with tetrabenazine, results in significantly lower levels of dopamine and norepinephrine (p < 0.01 and p < 0.05, respectively). The catecholamine-dependent inhibition of T- and B-lymphocyte activity is mediated via an induction of a Bcl-2/Bax and Fas/FasL involved apoptosis. These findings indicate a novel mechanism for regulation of lymphocyte activity in the central nervous system, whereby elevated regional levels of catecholamines might lead to the immunoprivilege of the brain.
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