Stillmonitoring in Deutschland – aktueller Handlungsbedarf und Perspektiven

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Stillmonitoring bezeichnet die systematische Erhebung aktueller, umfassender und genauer Daten zu Stillquoten, Stillverhalten und...     

Standardized peptidome profiling of human urine by magnetic bead separation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

BACKGROUND: Peptidome profiling of human urine is a promising tool to identify novel disease-associated biomarkers; however, a wide range of preanalytical variables influence the results of peptidome analysis. Our aim was to develop a standardized protocol for reproducible urine peptidome profiling by means of magnetic bead (MB) separation followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). METHODS: MBs with defined surface functionalities (hydrophobic interaction, cation exchange, and metal ion affinity) were used for peptide fractionation of urine. Mass accuracy and imprecision were calculated for 9 characteristic mass signals (M(r), 1000-10,000). Exogenous variables (instrument performance, urine sampling/storage conditions, freezing conditions, and freeze-thaw cycles) and endogenous variables (pH, urine salt and protein concentrations, and blood and bacteria interferences) were investigated with urine samples from 10 male and 10 female volunteers. RESULTS: We detected 427 different mass signals in the urine of healthy donors. Within- and between-day imprecision in relative signal intensities ranged from 1% to 14% and from 4% to 16%, respectively. Weak cation-exchange and metal ion affinity MB preparations required adjustment of the urinary pH to 7. Storage time, storage temperature, the number of freeze-thaw cycles, and bacterial and blood contamination significantly influenced urine peptide patterns. Individual urine peptide patterns differed significantly within and between days. This imprecision was diminished by normalization to a urinary protein content of 3.5 microg. CONCLUSION: This reliable pretreatment protocol allows standardization of preanalytical modalities and facilitates reproducible peptidome profiling of human urine by means of MB separation in combination with MALDI-TOF MS.     

Interim thymus and activation regulated chemokine versus interim 18F-fluorodeoxyglucose positron-emission tomography in classical Hodgkin lymphoma response evaluation

Serum thymus and activation regulated chemokine (TARC) levels reflect classical Hodgkin lymphoma (cHL) disease activity and correspond with treatment response. We compared mid-treatment interim TARC (iTARC) with interim ¹⁸F-fluorodeoxyglucose positron-emission tomography (iPET) imaging to predict modified progression-free survival (mPFS) in a group of 95 patients with cHL. High iTARC levels were found in nine and positive iPET in 17 patients. The positive predictive value (PPV) of iTARC for a 5-year mPFS event was 88% compared to 47% for iPET. The negative predictive value was comparable at 86% for iTARC and 85% for iPET. Serum iTARC levels more accurately reflect treatment response with a higher PPV compared to iPET.