| 1. |
- Norlin, Nils, et al.
(författare)
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Extended Förster theory for determining intraprotein distances : Part III. Partial donor–donor energy migration among reorienting fluorophores
- 2008
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 10, s. 6962-70
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Tidskriftsartikel (refereegranskat)abstract
- An extended Förster theory (EFT) is derived and outlined for electronic energy migration between two fluorescent molecules which are chemically identical, but photophysically non-identical. These molecules exhibit identical absorption and fluorescence spectra, while their fluorescence lifetimes differ. The latter means that the excitation probability becomes irreversible. Unlike the case of equal lifetimes, which is often referred to as, donor–donor energy migration (DDEM), the observed fluorescence relaxation is then no longer invariant to the energy migration process. To distinguish, the present case is therefore referred to as partial donor–donor energy migration (PDDEM). The EFT of PPDEM is described by a stochastic master equation (SME), which has been derived from the stochastic Liouville equation (SLE) of motion. The SME accounts for the reorienting as well as the translational motions of the interacting chromophores. Synthetic fluorescence lifetime and depolarisation data that mimics time-correlated single photon counting experiments have been generated and re-analysed. The rates of reorientation, as well as the orientational configurations of the interacting D-groups were examined. Moreover the EFT of PPDEM overcomes the classical 2-problem and the frequently applied approximation of 2 = 2/3 in the data analyses. An outline for the analyses of fluorescence lifetime and depolarisation data is also given, which might prove applicable to structural studies of D-labelled macromolecules, e.g. proteins. The EFT presented here brings the analyses of PDDEM data to the same level of molecular detail as that used in ESR- and NMR-spectroscopy.
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| 2. |
- 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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| 3. |
- Bergquist, Jonas, et al.
(författare)
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Mass spectrometry of proteins - Uppsala perspectives on past and present : Paper in honor of Prof. Peter Roepstorff's 65th birthday
- 2007
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Ingår i: International Journal of Mass Spectrometry. - : Elsevier BV. - 1387-3806 .- 1873-2798. ; 268:2-3, s. 73-82
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Tidskriftsartikel (refereegranskat)abstract
- The development of biological mass spectrometry has been rapid in the past three to four decades. In particular, the possibility to detect and identify peptides and proteins from biologically and medically relevant samples has revolutionized life sciences. The development has gone from a stage where the detection of insulin in a mass spectrum was a major event to one in which the recording of mass spectra with more than 104 resolved and calibrating peaks in each spectrum is a routine task.In this paper, the evolution of protein mass spectrometry will be discussed from the Uppsala horizon with special emphasis on the unique coupling between ion induced desorption of biomolecules and ion track physics.
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| 4. |
- Fjaertoft, Gustav, et al.
(författare)
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CD64 (Fcgamma receptor I) cell surface expression on maturing neutrophils from preterm and term newborn infants.
- 2005
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Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 94:3, s. 295-302
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The expression of CD64 (FcgammaRI) is increased from an almost negligible to a marked level on neutrophils in patients with bacterial infections. CD64 expression on neutrophils might therefore be a potential candidate for the diagnosis of bacterial infections in infants. AIM: This study was performed to monitor changes of neutrophil expression of CD64 during the postpartum period to further evaluate the usefulness of this analysis. The possible influence on the expression of this receptor by other factors was also investigated, including respiratory distress syndrome (RDS) and preterm rupture of the membranes (PROM). METHODS: Cell surface expression of CD64 on neutrophils from preterm and term newborn infants and healthy adults was analysed by flow cytometry. The expression of the other Fcgamma receptors, CD32 and CD16, and the complement receptors CD11b/CD18 and CD35 was also analysed for comparison. RESULTS: Neutrophils from preterm newborn infants showed a moderately increased level of CD64 expression that, during their first month of life, was reduced to the level observed on neutrophils from term newborn infants and adults. In contrast, the level of neutrophil expression of CD32 and CD16 was significantly lower in preterm than term newborn infants and adults. Neutrophils from all groups indicated similar levels of CD11b expression, but the expression on neutrophils from newborn infants increased after birth. CONCLUSION: Our results showed that neutrophil expression of CD64 is moderately increased in preterm newborn infants at birth. It seems not to be influenced by RDS, PROM or other factors related to preterm birth but by bacterial infection.
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| 5. |
- Fjaertoft, Gustav, 1951-
(författare)
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CD64 (FcγRI) Expression on Neutrophil Granulocytes : A Diagnostic Marker of Acute Bacterial Infections
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background. Newborn infants, especially preterm infants, have an increased susceptibility to serious and overwhelming bacterial as well as fungal infections. Symptoms of septicaemia in especially the very preterm neonates are vague and unspecific. No really good biochemical parameter exists today that can confirm or exclude the existence of neonatal septicaemia. The access to such a test in neonates would be most valuable, not only to assure early institution of effective antibiotic therapy when needed, but also to avoid unnecessary use of antibiotics, thereby reducing the risk of further development of antimicrobial resistance. Aim. To investigate the possible use of the expression of the phagocyte receptor CD64 (FcγRI) on neutrophils for early diagnosis of bacterial infections with special reference to neonatal septicaemia. Results. Neutrophils from preterm and term newborn infants, older infants, children, and adults examined during the early phase of a bacterial infection showed a significantly higher expression of CD64 compared with non-infected controls (p<0.001). Neutrophils from even extremely preterm infants expressed CD64 to the same extent as did neutrophils from children and adult patients. The expression of CD64 was not affected by the respiratory distress syndrome (RDS) or by such factors as premature rupture of the membranes, gestational age, steroid treatment before delivery, method of delivery, birth weight or postnatal age.Major surgery in adults (total hip replacement) did not affect the CD64 expression to an extent comparable to that found during bacterial infections. Indirectly CD64 was found to be at least equal to CRP for differentiation between Influenza A infection and bacterial infections in adults.Conclusion. CD64 was found to be a specific and reliable marker for early detection of bacterial infections in preterm and term newborn infants, as well as after surgery. For differentiation between bacterial and viral infections it is probably at least as effective as CRP.
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| 6. |
- Fjaertoft, Gustav, et al.
(författare)
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Cell surface expression of FcgammaRI (CD64) on neutrophils and monocytes in patients with influenza A, with and without complications
- 2005
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 37:11-12, s. 882-889
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Tidskriftsartikel (refereegranskat)abstract
- The expression of the Fcgamma-receptor I (FcgammaRI), CD64 on normal neutrophils is up-regulated during bacterial infections. CD64 is a promising diagnostic tool in the diagnosis of acute infections. The aim was to study surface expressions of CD64 on neutrophils and monocytes in patients with influenza A with and without complications and evaluate these as diagnostic tools in comparison with serum levels of HNL (human neutrophil lipocalin). CD64 expression on neutrophils and monocytes was evaluated by flow cytometry. HNL was assayed by a specific radioimmunoassay. 22 patients with influenza A with or without complications were included and the results compared with those of 29 patients with acute bacterial infections and 29 healthy subjects. Neutrophil expression of CD64 was increased in influenza A with raised proportion expressing CD64 in complicated compared to uncomplicated influenza. The expression was significantly higher in bacterial infections compared to both influenza groups. Serum levels of HNL were raised in all infection groups, but significantly more so in the group with bacterial infection. ROC-curve analysis showed that neutrophil expression of CD64 and the serum levels of HNL had similar diagnostic power in the discrimination between acute bacterial infections and influenza A. Monocyte expression of CD64 was raised in all infections with no differences between subgroups. We conclude that neutrophil expression of CD64 and serum levels of HNL are both promising assays in the distinction between infections caused by bacteria or influenza A, whereas CD64 could identify patients with complications of their influenza A infection.
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| 7. |
- Fjaertoft, Gustav, et al.
(författare)
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Neutrophil CD64 (FcgammaRI) expression is a specific marker of bacterial infection : A study on the kinetics and the impact of major surgery
- 2007
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Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 0036-5548 .- 1651-1980. ; 39:6-7, s. 525-535
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophil CD64 expression is a diagnostic marker for the early detection of bacterial infections. The aim was to investigate the kinetics of neutrophil CD64 expression during bacterial infection and the possible impact of surgical trauma. Blood samples were collected daily during 3 d after admission for analysis by flow cytometry of the surface expressions on neutrophils and monocytes of CD64, CD16, CD32, CD11b/CD18 and CD35, and analysis of serum CRP and blood WBC. Serum concentrations of IFNgamma, G-CSF, IL-6 and IL-8 were also analysed in adults. Eight children and 19 adult patients with bacterial infections, 12 patients admitted for hip-arthroplasty because of coxarthrosis and 30 healthy adults were studied. Neutrophil CD64 was increased all 3 d after start of treatment (p<0.0001) in children and adults with bacterial infections. The postoperative increase after surgery was less than the increase seen during bacterial infections (p<0.0001). CRP, G-CSF, IL-6 and IL-8 were raised both in bacterial infections and after surgery. Our results indicate that the expression of CD64 on neutrophils is a specific sign of bacterial infections. Neutrophil expression of CD64, therefore, seems to be a promising tool for the early detection of bacterial infections even during surgery.
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| 8. |
- Hagman, Charlotte, 1973-
(författare)
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Method Development in Quantitative and Structural Proteomics using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, methods for studying different aspects of proteomics were developed with Fourier Transform Ion Cyclotron Resonance, (FTICR), mass spectrometry. The FTICR technique provides ultra-high mass resolving power, mass accuracy at sub ppm level and sensitivity in the attomole region.Methods for quantifying biomarkers in body fluids such as cerebrospinal fluid, (CSF), and plasma were developed. Two sets of global markers with different properties were used for quantitative analysis; S-Methyl Thioacetimidate, (SMTA), and S-Methyl Thiopropionimidate, (SMTP), and [H4]- and [D4]-1-Nicotinoyloxy succinimide ester. Reduced ion suppression and higher sensitivity was obtained by coupling a High Performance Liquid Chromatography, (HPLC), system to the FTICR mass spectrometer.In body fluids, proteins and peptides are present in a broad dynamic concentration range. Therefore, depleting abundant proteins prior to analysis results in decreased ion suppression and increased sensitivity. Two commercial depletion kits were evaluated with the SMTA- and SMTP-markers.For both types of global markers, the experimental error for quantitative analysis of abundant proteins was less than 30%. This provides a lower limit for the protein up- and down regulations in complex solutions that can be monitored with HPLC-FTICR mass spectrometry.Together with the identity and quantity of selected proteins the structure, dynamics and interactions with other molecules are of great importance. The later can be elucidated with Hydrogen/Deuterium Exchange, (HDX), mass spectrometry. Structural information at high resolution can be obtained with Collision-Induced Dissociation, (CID), HDX mass spectrometry. In this thesis, exchange rates of amide hydrogens in peptides were in excellent agreement with NMR results.In some cases, the CID-fragments have different gas-phase exchange properties and as a consequence the solution phase exchange process can not be monitored. By applying Electron Capture Dissociation, (ECD), at ultra-high vacuum, the exchange process at a specific residue could be monitored.
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| 9. |
- Håkansson, Bo, et al.
(författare)
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A novel bone conduction implant (BCI)
- 2009
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Ingår i: 2<sup>nd</sup> Int Symposium on Bone Conduction Hearing – Craniofacial Osseointegration, Göteborg, Sweden.
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Konferensbidrag (refereegranskat)
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| 10. |
- Håkansson, David, et al.
(författare)
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Subjekt och topik i svenskan
- 2006
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Ingår i: Svenskans beskrivning 28. Förhandlingar vid Tjugoåttonde sammankomsten för svenskans beskrivning. - Örebro : Örebro universitet. - 9176685144 ; , s. 119-128
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Konferensbidrag (refereegranskat)
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