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- Alehagen, Urban, 1951-, et al.
(author)
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Utility of the amino-terminal fragment of pro-brain natriuretic peptide in plasma for the evaluation of cardiac dysfunction in elderly patients in primary health care
- 2003
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In: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 49:8, s. 1337-1346
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Journal article (peer-reviewed)abstract
- Background: The aims of this study were to measure the N-terminal fragment of pro-brain natriuretic peptide (proBNP) in plasma in medical conditions commonly found in primary care and to evaluate the utility of these measurements in identifying impaired cardiac function in elderly patients with symptoms associated with heart failure.Methods: We studied 415 patients (221 men and 194 women; mean age, 72 years) who had contacted a primary healthcare center for dyspnea, fatigue, and/or peripheral edema. One cardiologist evaluated the patients in terms of history, physical examination, functional capacity, electrocardiography, and suspicion of heart failure. Plasma N-terminal proBNP was measured by an in-house RIA. An ejection fraction ≤40% by Doppler echocardiography was regarded as reduced cardiac function. Abnormal diastolic function was defined as an abnormal mitral inflow defined as reduced ratio of peak early diastolic filling velocity to peak filling velocity at atrial contraction (E/A ratio), or as abnormal pulmonary venous flow pattern.Results: Patients with impaired functional capacity, impaired systolic function, and/or impaired renal function had significantly increased N-terminal proBNP concentrations. By multiple regression analysis, N-terminal proBNP concentrations were also influenced by ischemic heart disease, cardiac enlargement, and certain medications but not by increased creatinine. No gender differences were observed. Patients with isolated diastolic dysfunction attributable to relaxation abnormali-ties had lower concentrations than those with normal cardiac function, whereas those with pseudonormal E/A ratios or restrictive filling patterns had higher concentrations.Conclusions: Plasma N-terminal proBNP concentrations increase as a result of impaired systolic function, age, impaired renal function, cardiac ischemia and enlargement, and certain medications. Values are high in diastolic dysfunction with pseudonormal patterns, but not in patients with relaxation abnormalities. An increase in plasma N-terminal proBNP might be an earlier sign of abnormal cardiac function than abnormalities identified by currently used echocardiographic measurements.
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| 2. |
- Helander, A, et al.
(author)
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Improved HPLC method for carbohydrate-deficient transferrin in serum
- 2003
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In: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 49:11, s. 1881-1890
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Journal article (peer-reviewed)abstract
- Background: There is need for a reference method for transferrin glycoforms in serum to which routine immunologic methods for the alcohol marker carbohydrate-deficient transferrin (CDT) can be traceable. We describe an improved HPLC method for transferrin glycoforms. Methods: Transferrin was iron-saturated by mixing the serum with ferric nitrilotriacetic acid, and lipoproteins were precipitated with dextran sulfate and calcium chloride. Separation of glycoforms was performed on a SOURCE 15Q anion-exchange column using salt gradient elution. Quantification relied on selective absorbance of the iron-transferrin complex at 470 run. The relative amount of each glycoform was calculated as a percentage of the area under the curve, using baseline integration. Results: The HPLC system provided reproducible separation and quantification of the asialo-, monosialo-, disialo-, trisialo-, tetrasialo-, pentasialo-, and hexasialotransferrin glycoforms. Most importantly, disialo- and trisialotransferrin were almost baseline separated. The intra- and interassay CV for disialotransferrin were <5%. Serum and the pretreated samples were stable for at least 2 days at 22 or 4 degreesC. Sera from 132 healthy controls contained [mean (SD)] 1.16 (0.25)% disialotransferrin, 4.77 (1.36)% trisialotransferrin, 80.18 (2.01)% tetrasialotransferrin, and 13.88 (1.69)% pentasialo- + hexasialotransferrin. In some cases of a high (>6%) trisialotransferrin, monosialotransferrin was detected at <0.25%. Asialotransferrin was not detected in control sera, but was detected in 57% of chronic heavy drinkers and in 62% of sera with greater than or equal to2% disialotransferrin. Conclusions: The HPLC method fulfills the requirements of a preliminary reference method for CDT and should work for any combination of serum transferrin glycoforms. This method could also be useful for confirming positive CDT results by immunoassays in medico-legal cases. (C) 2003 American Association for Clinical Chemistry.
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| 5. |
- Träger, Chatarina, 1962-, et al.
(author)
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Quantitative analysis of tyrosine hydroxylase mrna for sensitive detection of neuroblastoma cells in blood and bone marrow
- 2003
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In: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 49:1, s. 104-112
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Journal article (peer-reviewed)abstract
- Background: Sensitive monitoring of minimal residual disease may improve the treatment of neuroblastoma in children. To detect and monitor neuroblastoma cells in blood and bone marrow, we developed a quantitative method for the analysis of tyrosine hydroxylase mRNA. Methods: We used real-time reverse transcription-PCR. The calibrator was constructed from a segment of tyrosine hydroxylase mRNA that included the target. Blood and bone marrow samples from 24 children with neuroblastoma and 1 child with ganglioneuroma were analyzed. Controls were blood samples from the cords of 40 babies, from 58 children 6 months to 15 years of age, and from 34 healthy adults, as well as from 12 children with other diseases. Results: The detection limit was ~70 transcripts/mL. All 144 blood controls were below this limit. At diagnosis, blood tyrosine hydroxylase mRNA was higher in children with widespread disease (stage 4/4S, n = 6, range, 203-46 000 transcripts/mL) than in patients with localized disease (stages 1-3, n = 6, =83 transcripts/mL, P = 0.002). Bone marrow from all five children with localized disease had concentrations <72 transcripts/mL, whereas five of six stage 4 patients had increased concentrations (6000-8 000 000 transcripts/mL, P <0.05). In nine children in whom tyrosine hydroxylase mRNA was measured repeatedly, the results corresponded to the clinical course. Conclusion: Quantitative analysis of tyrosine hydroxylase mRNA in blood and bone marrow is reliable and easy to perform and may be used for upfront staging, prognostic assessment, and treatment monitoring of neuroblastoma.
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| 6. |
- Venge, Per, et al.
(author)
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Clinical and analytical performance of the liaison cardiac troponin I assay in unstable coronary artery disease, and the impact of age on the definition of reference limits : A FRISC-II substudy
- 2003
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In: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 49:6 Pt 1, s. 880-886
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Journal article (peer-reviewed)abstract
- BACKGROUND:Measurements of cardiac troponins are currently used as the standard for the detection of myocardial injury. None of the current assays complies with the new requirements on assay imprecision as proposed by the European Society of Cardiology/American College of Cardiology. Our aim was to evaluate the clinical and analytical performance of the Liaison cardiac troponin I (cTnI) assay.METHODS:EDTA-plasma was used, and cardiac troponins were assayed with the first-generation AxSYM assay, the second-generation AccuTnI assay, the third-generation Elecsys assay, and the first-generation Liaison assay.RESULTS:In a 6-day imprecision study, the Liaison cTnI assay had mean CV < or =10% at 0.027 microg/L and < or =20% at 0.015 microg/L. The 99th percentile of the upper reference limit (URL) of a reference population was 0.041 microg/L (age range, 41-76 years). Individuals <60 years had a significantly (P = 0.001) lower 99th percentile, 0.022 microg/L. The FRISC-II study participants with cTnI > or =0.041 microg/L had a poorer outcome relating to death/acute myocardial infarction than those with cTnI <0.041 microg/L (P <0.001). Treatment with low-molecular-weight heparin (dalteparin) or an invasive strategy reduced cardiac events only in patients with concentrations >0.041 microg/L (P = 0.002 and 0.02, respectively). Comparison with the AccuTnI assay showed that a large cohort of the patients with poor prognosis was identified by the AccuTnI assay but not by the Liaison cTnI assay.CONCLUSION:The Liaison cTnI assay is a sensitive assay with a CV < or =10% at the 99th percentile URL. The ability to detect age-related differences among apparently healthy individuals is unique among today's commercial assays. The results indicate that different assays seem to identify different patient cohorts for cardiac risk in the lower range of cTnI concentrations.
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