Determination of Age Dependent Reference Ranges for PT and aPTT

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.

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Multi-generational SIR modeling: Determination of parameters, epidemiological forecasting and age-dependent vaccination policies

Infectious Disease Modelling ◽

10.1016/j.idm.2021.05.003 ◽

2021 ◽

Vol 6 ◽

pp. 751-765

Author(s):

Eduardo Lima Campos ◽

Rubens Penha Cysne ◽

Alexandre L. Madureira ◽

Gélcio L.Q. Mendes

Keyword(s):

Age Dependent ◽

Determination Of Parameters

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Therapeutic Drug Monitoring of Lamotrigine, Lacosamide, and Levetiracetam in Dried Capillary Blood – Determination of Conversion Factors for Serum-Based Reference Ranges

Therapeutic Drug Monitoring ◽

10.1097/ftd.0000000000000890 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

Dennis Klimpel ◽

Anne Hagemann ◽

Christian G. Bien ◽

Bertin Dufaux ◽

Theodor W. May ◽

...

Keyword(s):

Therapeutic Drug Monitoring ◽

Drug Monitoring ◽

Capillary Blood ◽

Therapeutic Drug ◽

Reference Ranges ◽

Conversion Factors

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Direct determination of selenium in serum by graphite-furnace atomic absorption spectrometry with deuterium background correction and a reduced palladium modifier: age-specific reference ranges.

Clinical Chemistry ◽

10.1093/clinchem/34.4.709 ◽

1988 ◽

Vol 34 (4) ◽

pp. 709-714 ◽

Cited By ~ 93

Author(s):

B E Jacobson ◽

G Lockitch

Keyword(s):

Atomic Absorption ◽

Direct Method ◽

Graphite Furnace ◽

Direct Determination ◽

Background Correction ◽

Specific Reference ◽

Reference Ranges ◽

Term Infants ◽

Graphite Furnace Atomic Absorption

Abstract We describe the development of a direct method for determination of selenium in serum by graphite-furnace atomic absorption spectrophotometry with deuterium background correction. We include palladium modifier to stabilize selenium in the presence of a strong reducing agent. Spectral interferences from iron are not evident in this system. Because an analysis requires only 20 microL of serum or plasma, the method is applicable to neonatal populations. At a selenium concentration of 0.75 mumol/L (approximately the mean found in our pre-term infants), the within-run CV is 5.3%. For a concentration of 1.83 mumol/L, which approximates our normal adult mean, within-run and between-run CVs are 2.7% and 3.4%. Accuracy is demonstrated by analytical recoveries ranging from 96% to 102%. We present reference values for pre-term and term infants, and age-specific ranges for infants to adults.

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Quantification of carbohydrate-deficient transferrin by ion-exchange chromatography with an enzymatically prepared calibrator

Clinical Chemistry ◽

10.1093/clinchem/43.3.485 ◽

1997 ◽

Vol 43 (3) ◽

pp. 485-490 ◽

Cited By ~ 28

Author(s):

Florian Renner ◽

Rolf-Dieter Kanitz

Keyword(s):

Hplc Method ◽

Ion Exchange Chromatography ◽

Exchange Chromatography ◽

Reference Ranges ◽

Diagnostic Specificity ◽

Time Saving ◽

Iron Saturation ◽

Carbohydrate Deficient Transferrin ◽

Absolute Concentrations

Abstract The current HPLC method for the determination of carbohydrate-deficient transferrin (CDT) yields ratios of CDT isoforms in relation to total transferrin, whereas the use of absolute concentrations obtainable in routine analysis by RIA and the reference ranges based hereupon is more convenient. We describe a modified HPLC method that likewise gives absolute CDT concentrations by using a calibrator prepared by treatment of transferrin with neuraminidase. Separation of isoforms could be improved and analysis time reduced to ∼2 h. Iron saturation proved stable during chromatography. In contrast to a commercial RIA, the cheaper and more time-saving HPLC method excludes erroneous results caused by aged samples or genetic transferrin variants and enables the determination of asialo- and disialotransferrin. Both methods showed comparable precision and correlated with each other (y = 1.76 + 0.27x; Sy|x = 5.38); for the HPLC method precision was 1.3–9.8% (within assay) and 6.2–10.6% (between assay). The clinical evaluation with a cutoff concentration of 80 mg/L resulted in a diagnostic specificity of 100% and a sensitivity of 82.5%.

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Clinical evaluation of immunoinhibition determination of creatine kinase B subunits in coronary care.

Clinical Chemistry ◽

10.1093/clinchem/29.2.353 ◽

1983 ◽

Vol 29 (2) ◽

pp. 353-355 ◽

Cited By ~ 1

Author(s):

J Booth ◽

P J McCarthy ◽

R N Walmsley

Keyword(s):

Creatine Kinase ◽

Chest Pain ◽

Normal Values ◽

Clinical Findings ◽

Reference Ranges ◽

B Subunit ◽

Creatine Kinase B ◽

Coronary Care ◽

Total Creatine

Abstract One hundred patients with chest pain of cardiac origin were evaluated on the basis of clinical findings, electrocardiograph results, and total creatine kinase (CK) and creatine kinase B-subunit (CK-B) activity (as determined by immunoinhibition with the Boehringer CK-MB kit) in serum. All patients diagnosed as having had an acute myocardial infarction had increased values for both CK-B and total CK. In no case was normal total CK activity associated with an increased CK-B, nor was normal CK-B associated with an increased total CK. During collection of data for reference ranges, we found 10 patients who had no evidence of cardiac disease but had various other diseases, who exhibited high values for CK-B in serum; four of these had normal values for total CK. We conclude that estimations of CK-B in serum by this method added no more diagnostic information than did data on total CK in the evaluation of chest pain.

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