Comparison of sample materials for S100b analysis.

Head injury is a potentially lethal and frequently occurring condition in the emergency department (ED). Reliable and fast diagnosis is important both for patients and flow in the ED. Circulating S100B is used to rule out the need for head computer tomography in low-risk patients with mild head injury. The flow of these patients through the ED would benefit from shorter turn-around time. Standard serum clotting tubes require 30-60 min clotting time, followed by an analysis time of 45 min. Here, we evaluated the performance of two alternative blood collection tubes; a rapid serum tube (RST) with a recommend clotting time of 5 min and a hirudin tube (HIR) for instant anticoagulation. S100B measurement was performed on paired blood samples from 221 subjects using a Roche Cobas 602 analyser. The performances of the alternative tubes were evaluated by method comparison to the standard serum clotting tube, repeatability and agreement of results obtained from alternative tubes compared with the standard clotting tube. Both alternative tubes had a minor positive bias (RST = 0.011 µg/L, HIR = 0.008 µg/L). The repeatability was 2% for RST and 10% for HIR, while being 4% for the standard clotting tube. In the agreement analysis, the positive and negative predictive values for RST were 62% and 100% while being 73% and 99% for HIR respectively. Our study suggests that RST is a feasible alternative to reduce laboratory turn-around time in S100b analysis.

Disentangling hydroxynitrile glucoside biosynthesis in a barley (Hordeum vulgare) metabolon provides access to elite malting barleys for ethyl carbamate-free whisky production.

Barley produces several specialized metabolites, including five α-, ß-, and γ-hydroxynitrile glucosides (HNGs). In malting barley, presence of the α-HNG epiheterodendrin gives rise to undesired formation of ethyl carbamate in the beverage production, especially after distilling. Metabolite-GWAS identified QTLs and underlying gene candidates possibly involved in the control of the relative and absolute content of HNGs, including an undescribed MATE transporter. By screening 325 genetically diverse barley accessions, we discovered three H. vulgare ssp. spontaneum (wild barley) lines with drastic changes in the relative ratios of the five HNGs. Knock-out (KO)-lines, isolated from the barley FIND-IT resource and each lacking one of the functional HNG biosynthetic genes (CYP79A12, CYP71C103, CYP71C113, CYP71U5, UGT85F22 and UGT85F23) showed unprecedented changes in HNG ratios enabling assignment of specific and mutually dependent catalytic functions to the biosynthetic enzymes involved. The highly similar relative ratios between the five HNGs found across wild and domesticated barley accessions indicate assembly of the HNG biosynthetic enzymes in a metabolon, the functional output of which was reconfigured in the absence of a single protein component. The absence or altered ratios of the five HNGs in the KO-lines did not change susceptibility to the fungal phytopathogen Pyrenophora teres causing net blotch. The study provides a deeper understanding of the organization of HNG biosynthesis in barley and identifies a novel, single gene HNG-0 line in an elite spring barley background for direct use in breeding of malting barley, eliminating HNGs as a source of ethyl carbamate formation in whisky production.