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- Bergquist, Jonas, et al.
(författare)
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Peptide Mapping of Proteins in Human Body Fluids using Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry
- 2002
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Ingår i: Mass spectrometry reviews (Print). - : Wiley. - 0277-7037 .- 1098-2787. ; 21:1, s. 2-15
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Tidskriftsartikel (refereegranskat)abstract
- Human body fluids have been rediscovered in the postgenomic era as great sources of biological markers and perhaps particularly as sources of potential protein biomarkers of disease. Analytical tools that allow rapid screening, low sample consumption, and accurate protein identification are of great importance in studies of complex biological samples and clinical diagnosis. Mass spectrometry is today one of the most important analytical tools with applications in a wide variety of fields. One of the fastest growing applications is in proteomics, or the study of protein expression in an organism. Mass spectrometry has been used to find post-translational modifications and to identify key functions of proteins in the human body. In this study, we review the use of human body fluids as sources for clinical markers and present new data that show the ability of Fourier transform ion cyclotron resonance (FTICR) mass spectrometry (MS) to identify, and characterize proteins in four human body fluids: plasma, cerebrospinal fluid (CSF), saliva, and urine. The body fluids were tryptically digested without any prior separation, purification, or selection, and the digest was introduced into a 9.4 T FTICR mass spectrometer by direct-infusion electrospray ionization (ESI). Even though these samples represent complex biological mixtures, the described method provides information that is comparable with traditional 2D-PAGE data. The sample consumption is extremely low, a few microliters, and the analysis time is only a few minutes. It is, however evident that the separation of proteins and/or peptides must be included in the methodology in order to detect low-abundance proteins and other proteins of biological relevance.
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| 2. |
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| 3. |
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| 4. |
- Palmblad, Magnus, et al.
(författare)
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Analysis of Enzymatically Digested Proteins and Protein Mixtures using a 9.4 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer
- 2000
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Ingår i: Rapid Communications in Mass Spectrometry. - 0951-4198 .- 1097-0231. ; 14:12, s. 1029-1034
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Tidskriftsartikel (refereegranskat)abstract
- A commercially available 9.4 Tesla Fourier transform ion cyclotron resonance (FTICR) mass spectrometer was applied in the analysis of tryptic digests of protein mixtures without any separation. First, the method was demonstrated on a mixture of tryptic digests of equine cytochrome c, equine myoglobin and bovine serum albumin. The same method was then applied to human plasma from a healthy blood donor. Computer programs were employed to simplify analysis of the complex spectra. The 2745 peaks in the human plasma electrospray ionization FTICR spectrum could be reduced to 1165 isotopic clusters and 669 unique masses. Out of these, 82 masses matched tryptic fragments of serum albumin with mass measurement errors less than 10 ppm, covering 93% of the sequence. Another 16 masses were assigned to tryptic fragments of transferrin, covering 41% of the sequence on the 10 ppm mass measurement error level (14 within 2 ppm). The mass measurement errors were approximately normal distributed with a standard deviation of 1.7 ppm. This demonstrates the feasibility of combining the ultra-high mass resolving power and accuracy of FTICR mass spectrometry with automated computer analysis for investigating complex biological matrices.
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| 5. |
- Amirkhani, Ardeshir, et al.
(författare)
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Comparison between different sheathless electrospray emitter configurations regarding the performance of nanoscale liquid chromatography time-of-flight mass spectrometry analysis
- 2004
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1033:2, s. 257-266
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Tidskriftsartikel (refereegranskat)abstract
- Four different sheathless electrospray ionization (ESI) configurations were investigated for a nano liquid chromatography (LC) system. The studied configurations were: a column with an integrated emitter, with the ESI potential applied before or after the column, and a column with separate emitter, with the ESI voltage applied at a union before the emitter or at the emitter tip. The results indicates that the efficiency of the LC system is rather independent of the configuration when using 95 μm i.d. columns, acetic mobile phase and standard peptides as a sample. Introduction of post column dead volume seems not to be a critical issue at least with flow rates down to 600 nl/min.
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| 6. |
- Bergquist, Björn, et al.
(författare)
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Provfiskeresultat år 2001
- 2002
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Vattendragsdelen i Naturvårdsverkets nationella effektuppföljningsprogram för kalkade vatten (IKEU-programmet), som startade 1989,omfattar för närvarande 12 kalkade vattendrag och 11 referensvattendrag fördelade på 5 geografiska regioner. I båda vattendragstyperna genomförs integrerade undersökningar med identiska undersökningsprogram som omfattar både vattenkemiska och biologiska undersökningar (bottenfauna och fisk). Programmets mål är att studera och analysera de långsiktiga effekterna av kalkning i försurade vatten och att bedöma om den svenska kalkningsverksamheten återskapar ekosystem med en artsammansättning, funktion och biologisk mångfald liknande situationen innan försurning. Uppföljningen görs också i syfte att kunna avgöra om kalkningsverksamheten leder till oönskade effekter i sjöar och vattendrag.
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| 7. |
- Bergquist, Henrik, 1969, et al.
(författare)
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Functional long-term outcome of a free jejunal transplant reconstruction following chemoradiotherapy and radical resection for hypopharyngeal and proximal oesophageal carcinoma
- 2004
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Ingår i: Digestive surgery. ; :21, s. 426-433
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND/AIMS: To evaluate the functional outcome of a reconstruction by a free vascularized jejunal transplant combined with a voice prosthesis after chemoradiotherapy and surgery for proximal oesophageal or hypopharyngeal cancer. METHODS: Seven patients (6 men, mean age 52 years, range 28-70) with squamous cell cancer in the proximal oesophagus (n = 6) or the hypopharynx received preoperative chemoradiotherapy (40.8 Gy, cisplatinum and 5-FU) followed by a circumferential pharyngolaryngectomy and resection of the proximal oesophagus. A single-stage reconstruction was carried out with a free jejunal transplant using a microsurgical technique. A tracheojejunal puncture and insertion of a voice prosthesis (Provox I) was performed after 3 months in suitable cases. RESULTS: All operations had a per- and postoperative uneventful course. Five patients were alive after a mean follow-up time of 5 years and 7 months after surgery (range 3 years 4 months to 7 years 10 months), while 2 patients died from metastases within 2 years after surgery. Postoperative examination showed histopathological down-staging in all cases. Relief of dysphagia was achieved in most cases. Good or average speech was recorded in 3 patients. CONCLUSION: Reconstruction after radical resection for proximal oesophageal and hypopharyngeal cancer can be carried out with low mortality, acceptable morbidity and a promising functional outcome.
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| 8. |
- Bergquist, Magnus, 1960, et al.
(författare)
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Communication - From management to organizing
- 2000
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Ingår i: Braa, Kristin, Sørensen, Carsten and Dahlbom, Bo (eds) Planet Internet. - Lund : Studentlitteratur. - 9144013523 ; , s. 65-86
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 9. |
- Bergquist, Magnus, 1960, et al.
(författare)
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Practising Peer Review in Organizations: a Qualifier for Knowledge Dissemination and Legitimization
- 2001
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Ingår i: Journal of Information Technology. - London : SAGE Publications. ; 16:2, s. 99-112
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Tidskriftsartikel (refereegranskat)abstract
- A key issue in many organizations is how to disseminate information in an effective way and, more importantly, how to make use of this information in order to create new knowledge. One way of addressing this problem is to focus on how information is socially transformed into knowledge. This includes how knowledge is handled in practice and how the knowledge produced is quali ed as being something worth knowing and acting upon. Two well-established practices for doing this are the refereeing system and the peer review process. These are used in scienti c communities as a means of validating and legitimating knowledge, for example by reviewing journal papers before publishing or project proposals before granting funds, etc. This paper argues that peer review is a useful concept when looking at knowledge creation and legitimization in organizations. The social meaning of peer review is to legitimize new knowledge by organizationally sanctioning it and thereby creating a platform for collective sense making. This paper uses an example from a eld study in a pharmaceutical company in order to illustrate this argument. The study took place in a quality support department where the quality of health care products and processes was assessed. The organization had a need for fast and reliable updating of information that could in uence how the production process of pharmaceuticals should be carried out. In order to cope with these problems the department established an ‘evaluation loop’, which shared several characteristics with the peer review process.
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| 10. |
- Bergquist, Magnus, 1960, et al.
(författare)
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The Power of Gifts: Organizing Social Relationships in Open Source Communities
- 2001
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Ingår i: Information Systems Journal. - Chichester : Wiley. ; 11:4, s. 305-320
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Tidskriftsartikel (refereegranskat)abstract
- In writings on the open source software development model, it is often argued that it is successful as a result of the gift economy that embraces activities in online communities. However, the theoretical foundations for this argument are seldom discussed and empirically tested. Starting with the ‘classic’ theories of gift giving, we discuss how they need to be developed in order to explain giftgiving practices in digital domains. In this paper, we argue that the gift economy is important, not only because it creates openness, but also because it organizes relationships between people in a certain way. Open source software development relies on gift giving as a way of getting new ideas and prototypes out into circulation. This also implies that the giver gets power from giving away. This power is used as a way of guaranteeing the quality of the code. We relate this practice to how gifts, in the form of new scientific knowledge, are given to the research community, and how this is done through peer review processes.
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