| 1. |
- Ahmadian, Afshin, et al.
(författare)
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Pyrosequencing : History, biochemistry and future
- 2006
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Ingår i: Clinica Chimica Acta. - : Elsevier BV. - 0009-8981 .- 1873-3492. ; 363:02-jan, s. 83-94
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Forskningsöversikt (refereegranskat)abstract
- Background: Pyrosequencing is a DNA sequencing technology based on the sequencing-by-synthesis principle. Methods: The technique is built on a 4-enzyme real-time monitoring of DNA synthesis by bioluminescence using a cascade that upon nucleotide incorporation ends in a detectable light signal (bioluminescence). The detection system is based on the pyrophosphate released when a nucleotide is introduced in the DNA-strand. Thereby, the signal can be quantitatively connected to the number of bases added. Currently, the technique is limited to analysis of short DNA sequences exemplified by single-nucleotide polymorphism analysis and genotyping. Mutation detection and single-nucleotide polymorphisin genotyping require screening of large samples of materials and therefore the importance of high-throughput DNA analysis techniques is significant. In order to expand the field for pyrosequencing, the read length needs to be improved. Conclusions: Th pyrosequencing system is based on an enzymatic system. There are different current and future applications of this technique.
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| 2. |
- Aldén, Anna, et al.
(författare)
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HPLC analysis of carbohydrate deficient transferrin isoforms isolated by the Axis-Shield %CDT method
- 2005
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Ingår i: Clinica Chimica Acta. - : Elsevier BV. - 0009-8981 .- 1873-3492. ; 356:1-2, s. 143-146
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Tidskriftsartikel (refereegranskat)abstract
- Background: Carbohydrate-deficient transferrin (CDT) is elevated during prolonged overconsumption of alcohol and CDT is considered to be the most specific biochemical marker for alcohol overconsumption. However, an accurate method for analysing CDT is necessary because the test is frequently used for example in legal matters. Methods: Patient serum samples were analysed with the Axis-Shield %CDT and eluates were pooled together. Transferrin was purified from the pool by affinity chromatography and further analysed with HPLC to determine the ratios of different transferrin isoforms. Results: In the eluates using the Axis-Shield %CDT method, a substantial amount of trisialo transferrin was found, which is generally not considered a CDT isoform. Conclusions: The fact that trisialo transferrin is present may generate falsely elevated CDT results and it could at least partly explain the discrepancy between results of the Axis-Shield %CDT assay and HPLC in routine analysis. © 2005 Elsevier B.V. All rights reserved.
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| 3. |
- Alehagen, Urban, 1951-, et al.
(författare)
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Reference intervals and decision limits for B-type natriuretic peptide (BNP) and its precursor (Nt-proBNP) in the elderly
- 2007
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Ingår i: Clinica Chimica Acta. - : Elsevier BV. - 0009-8981 .- 1873-3492. ; 382:1-2
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Tidskriftsartikel (refereegranskat)abstract
- Background: Elderly patients have the highest prevalence of heart failure (HF). The aims of the study were to establish a reference interval for B-type natriuretic peptide (BNP) and (Nt-proBNP) in elderly people, and to identify clinically relevant decision limits based on long-term outcome. Methods: Plasma concentrations of BNP and Nt-proBNP were measured from two elderly populations: 218 healthy subjects (mean age 73 years, population I), and 474 patients (mean age 73 years, population II) with symptoms associated with HF. Study population II was followed for 6 years with registration of all cardiovascular mortality. Results: An association between both BNP and Nt-proBNP concentrations and age was found. The upper limit for the reference intervals in the healthy elderly (population I) was: BNP ≤ 28 pmol/L (≤ 97 ng/L), and Nt-proBNP ≤ 64 pmol/L (≤ 540 ng/L). Based on cardiovascular mortality, decision limits for BNP (∼ 50 pmol/L, ∼ 170 ng/L) and Nt-proBNP (∼ 200 pmol/L, ∼ 1700 ng/L) (population II) were determined. Conclusions: Besides establishing reference intervals for BNP and Nt-proBNP in an elderly population, a higher clinically relevant decision limit for BNP and Nt-proBNP was identified, indicating additive prognostic information of the peptides on top of measurements by echocardiography. Therefore, both reference intervals and decision limits should be included in clinical practice. © 2007.
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| 4. |
- Andersson, Annika, et al.
(författare)
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Development of parallel reaction monitoring assays for cerebrospinal fluid proteins associated with Alzheimer's disease
- 2019
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Ingår i: Clinica Chimica Acta. - : Elsevier B.V.. - 0009-8981 .- 1873-3492. ; 494, s. 79-93
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Tidskriftsartikel (refereegranskat)abstract
- Detailed knowledge of protein changes in cerebrospinal fluid (CSF) across healthy and diseased individuals would provide a better understanding of the onset and progression of neurodegenerative disorders. In this study, we selected 20 brain-enriched proteins previously identified in CSF by antibody suspension bead arrays (SBA) to be potentially biomarkers for Alzheimer's disease (AD) and verified these using an orthogonal approach. We examined the same set of 94 CSF samples from patients affected by AD (including preclinical and prodromal), mild cognitive impairment (MCI), non-AD dementia and healthy individuals, which had previously been analyzed by SBA. Twenty-eight parallel reaction monitoring (PRM) assays were developed and 13 of them could be validated for protein quantification. Antibody profiles were verified by PRM. For seven proteins, the antibody profiles were highly correlated with the PRM results (r > 0.7) and GAP43, VCAM1 and PSAP were identified as potential markers of preclinical AD. In conclusion, we demonstrate the usefulness of targeted mass spectrometry as a tool for the orthogonal verification of antibody profiling data, suggesting that these complementary methods can be successfully applied for comprehensive exploration of CSF protein levels in neurodegenerative disorders.
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| 5. |
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| 6. |
- Beck, O., et al.
(författare)
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Study of measurement of the alcohol biomarker phosphatidylethanol (PEth) in dried blood spot (DBS) samples and application of a volumetric DBS device
- 2018
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Ingår i: Clinica Chimica Acta. - : Elsevier. - 0009-8981 .- 1873-3492. ; 479, s. 38-42
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Tidskriftsartikel (refereegranskat)abstract
- Phosphatidylethanol (PEth) is a group of phospholipids formed in cell membranes following alcohol consumption. PEth measurement in whole blood samples is established as a specific alcohol biomarker with clinical and medico-legal applications. This study further evaluated the usefulness of dried blood spot (DBS) samples collected on filter paper for PEth measurement. Specimens used were surplus volumes of venous whole blood sent for routine LC–MS/MS quantification of PEth 16:0/18:1, the major PEth homolog. DBS samples were prepared by pipetting blood on Whatman 903 Protein Saver Cards and onto a volumetric DBS device (Capitainer). The imprecision (CV) of the DBS sample amount based on area and weight measurements of spot punches were 23–28%. Investigation of the relationship between blood hematocrit and PEth concentration yielded a linear, positive correlation, and at around 1.0–1.5 μmol/L PEth 16:0/18:1, the PEth concentration increased by ~ 0.1 μmol/L for every 5% increase in hematocrit. There was a close agreement between the PEth concentrations obtained with whole blood samples and the corresponding results using Whatman 903 (PEthDBS = 1.026 PEthWB + 0.013) and volumetric device (PEthDBS = 1.045 PEthWB + 0.016) DBS samples. The CV of PEth quantification in DBS samples at concentrations ≥ 0.05 μmol/L were ≤ 15%. The present results further confirmed the usefulness of DBS samples for PEth measurement.
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| 7. |
- Bergquist, Jonas, et al.
(författare)
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Demonstration of immunoglobulin G with affinity for dopamine in cerebrospinal fluid from psychotic patients.
- 1993
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Ingår i: Clinica Chimica Acta. - 0009-8981 .- 1873-3492. ; 217:2, s. 129-42
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Tidskriftsartikel (refereegranskat)abstract
- Using an enzyme-linked immunosorbent assay, significantly raised concentrations of immunoglobulin G with affinity for the neurotransmitter dopamine were demonstrated in cerebrospinal fluid from psychotic patients. We have varied the antigen presentation in order to find a conjugate with low unspecific binding. The conjugation of dopamine to carbodiimide-activated poly-L-glutamic acid and that to activated succinimide ester of biotin are described. The use of glutaraldehyde conjugation is not recommended because of the risk of formation of tetrahydroisoquinolines. A strong correlation (r = 0.94, P < 0.001) between the results obtained with dopamine conjugated to poly-L-glutamic acid and dopamine conjugated to biotin was observed. Forty-two human cerebrospinal fluid samples from 20 psychotic patients, (12 with a bipolar disorder and 8 with schizophrenia) and 22 control patients, with various neurological diseases but no apparent psychiatric diseases were investigated. A significantly higher incidence (P < 0.001) of antibodies with affinity for dopamine were found in the group of psychotic patients compared with the neurological control group.
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| 8. |
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| 9. |
- Borén, Jan, 1963, et al.
(författare)
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Postprandial hypertriglyceridemia as a coronary risk factor.
- 2014
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Ingår i: Clinica chimica acta; international journal of clinical chemistry. - : Elsevier BV. - 1873-3492. ; 431, s. 131-42
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Forskningsöversikt (refereegranskat)abstract
- Postprandial hypertriglyceridemia is now established as an important risk factor for cardiovascular disease (CVD). This metabolic abnormality is principally initiated by overproduction and/or decreased catabolism of triglyceride-rich lipoproteins (TRLs) and is a consequence of predisposing genetic variations and medical conditions such as obesity and insulin resistance. Accumulation of TRLs in the postprandial state promotes the retention of remnant particles in the artery wall. Because of their size, most remnant particles cannot cross the endothelium as efficiently as smaller low-density lipoprotein (LDL) particles. However, since each remnant particle contains approximately 40 times more cholesterol compared with LDL, elevated levels of remnants may lead to accelerated atherosclerosis and CVD. The recognition of postprandial hypertriglyceridemia in the clinical setting has been severely hampered by technical difficulties and the lack of established clinical protocols for investigating postprandial lipemia. In addition, there are currently no internationally agreed management guidelines for this type of dyslipidemia. Here we review the mechanism for and consequences of excessive postprandial hypertriglyceridemia, epidemiological evidence in support of high triglycerides and remnant particles as risk factors for CVD, the definition of hypertriglyceridemia, methods to measure postprandial hypertriglyceridemia and apolipoproteins and, finally, current and future treatment opportunities.
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| 10. |
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