TY  - JOUR
A1  - Zwirner, Johann
A1  - Anders, Sven
A1  - Bohnert, Simone
A1  - Burkhardt, Ralph
A1  - Da Broi, Ugo
A1  - Hammer, Niels
A1  - Pohlers, Dirk
A1  - Tse, Rexson
A1  - Ondruschka, Benjamin
T1  - Screening for fatal traumatic brain injuries in cerebrospinal fluid using blood-validated CK and CK−MB immunoassays
JF  - Biomolecules
N2  - A single, specific, sensitive biochemical biomarker that can reliably diagnose a traumatic brain injury (TBI) has not yet been found, but combining different biomarkers would be the most promising approach in clinical and postmortem settings. In addition, identifying new biomarkers and developing laboratory tests can be time-consuming and economically challenging. As such, it would be efficient to use established clinical diagnostic assays for postmortem biochemistry. In this study, postmortem cerebrospinal fluid samples from 45 lethal TBI cases and 47 controls were analyzed using commercially available blood-validated assays for creatine kinase (CK) activity and its heart-type isoenzyme (CK–MB). TBI cases with a survival time of up to two hours showed an increase in both CK and CK–MB with moderate (CK–MB: AUC = 0.788, p < 0.001) to high (CK: AUC = 0.811, p < 0.001) diagnostic accuracy. This reflected the excessive increase of the brain-type CK isoenzyme (CK–BB) following a TBI. The results provide evidence that CK immunoassays can be used as an adjunct quantitative test aid in diagnosing acute TBI-related fatalities.
KW  - cerebrospinal fluid
KW  - creatine kinase
KW  - fatal traumatic brain injury
KW  - postmortem biochemistry
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-242769
SN  - 2218-273X
VL  - 11
IS  - 7
ER  - 
TY  - JOUR
A1  - Becker, Manuel
A1  - Sperlich, Billy
A1  - Zinner, Christoph
A1  - Achtzehn, Silvia
T1  - Intra-Individual and Seasonal Variation of Selected Biomarkers for Internal Load Monitoring in U-19 Soccer Players
JF  - Frontiers in Physiology
N2  - The aim of this study was to investigate inter-day and -week as well as intra- and inter-individual variation of selected biomarkers in high-performance youth soccer players to assist practitioners interpreting player’s internal load to counteract underperformance and unwanted health risks. Eleven male youth soccer players were tested multiple times during two 3-week periods at midpoint (3-wkmid) and at the end (3-wkend) of the first half of a German under-19 1. Bundesliga season. The levels of creatine kinase (CK), urea, and C-reactive protein (CRP) were measured during 3-wkmid and 3-wkend each Monday, Wednesday, and Friday. In 3-wkmid the CK median was 14% higher (241 vs. 212 U/L) compared to 3-wkend (P = 0.26, ES = 0.16). Overall, the medians of CK, urea (P = 0.59, ES = 0.08), and CRP (P = 0.56, ES = 0.10) during 3-wkmid did not differ to the values of 3-wkend. Daily coefficient of variations (CVs) ranged from 22 to 71% (CK), 17 to 37% (urea), and 9 to 164% (CRP). Individual medians ranged from 101 to 350 U/L (CK), 23 to 50 mg/dL (urea), and 0.6 to 1.1 mg/L (CRP). High intra-individual variability was demonstrated by large intra-individual CVs (medians: CK 50%, urea 18%, and CRP 45%). Our data show (i) large inter-day and inter-week variability of all biomarkers, depending on the external load and (ii) considerable inter- and intra-individual parameter variations. Creatine kinase concentrations could sensitively reflect soccer-specific loads during the season.
KW  - biomarker variability
KW  - creatine kinase
KW  - soccer
KW  - youth soccer
KW  - internal load
KW  - monitoring
KW  - point of care testing
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-209616
SN  - 1664-042X
VL  - 11
IS  - 838
ER  -