Incorporation of the chemical warfare agent sulfur mustard (SM) produces a covalent adduct with human serum albumin (HSA) representing an established plasma biomarker of poisoning. Bioanalytical verification requires both plasma generation from whole blood and shipping to specialized laboratories following strict guidelines for complex packaging. These needs often push the infrastructural boundary in crisis regions and war zones. Therefore, we herein originally introduce different reliable bioanalytical procedures using filter paper as well as novel volumetric microsampling tools (Mitra devices and Noviplex DUO cards) to generate dried plasma samples not liable to the shipping constraints. In addition, the Noviplex device enables in-transit separation of plasma from whole blood without the need of a centrifuge. Plasma-loaded and dried devices were subjected to pronase treatment yielding the alkylated dipeptide hydroxyethylthioethyl-CysPro (HETE-CP) derived from the HSA-SM adduct that was detected by microbore liquid chromatography-electrospray ionization tandem-mass spectrometry (μLC-ESI MS/MS). For all devices, samples exposed to SM yielded excellent linearity (0.025-50 μM SM) and good precision (≤13%) and fulfilled forensic quality criteria for ion ratios of qualifying and quantifying product ions. Stability of the HSA-SM adduct in dried and liquid plasma is shown under conditions of three climatic zones (temperate climate, hot and dry climate, and hot and humid climate) for at least 9 days simulating the period of delayed sample shipping. Our results originally document that dried plasma is appropriate for storage and shipping at ambient temperature and that novel microsampling tools are of essential benefit when targeting the HSA-SM adduct for verification analysis.

Continuous cell culture monitoring as a way of investigating growth, proliferation, and kinetics of biological experiments is in high demand. However, commercially available solutions are typically expensive and large in size. Digital inline-holographic microscopes (DIHM) can provide a cost-effective alternative to conventional microscopes, bridging the gap towards live-cell culture imaging. In this work, a DIHM is built from inexpensive components and applied to different cell cultures. The images are reconstructed by computational methods and the data are analyzed with particle detection and tracking methods. Counting of cells as well as movement tracking of living cells is demonstrated, showing the feasibility of using a field-portable DIHM for basic cell culture investigation and bringing about the potential to deeply understand cell motility.

L-3,4-Dihydroxyphenylalanin (l-DOPA or levodopa) is currently the most used drug to treat symptoms of Parkinson’s disease (PD). After crossing the blood–brain barrier, it is enzymatically converted to dopamine by neuronal cells and restores depleted endogenous neurotransmitter levels. l-DOPA is prone to auto-oxidation and reactive intermediates of its degradation including reactive oxygen species (ROS) have been implicated in cellular damage. In this study, we investigated how oxygen tension effects l-DOPA stability. We applied oxygen tensions comparable to those in the mammalian brain and demonstrated that 2% oxygen almost completely stopped its auto-oxidation. l-DOPA even exerted a ROS scavenging function. Further mechanistic analysis indicated that l-DOPA reprogrammed mitochondrial metabolism and reduced oxidative phosphorylation, depolarized the mitochondrial membrane, induced reductive glutamine metabolism, and depleted the NADH pool. These results shed new light on the cellular effects of l-DOPA and its neuro-toxicity under physiological oxygen levels that are very distinct to normoxic in vitro conditions.

Background Alterations in mitochondrial dysfunction have been implicated in the pathogenesis of Parkinson's disease (PD). Mitochondrial energy production is linked to glucose metabolism, and diabetes is associated with PD. However, studies investigating glucose metabolism in vivo in genetically stratified PD patients and controls have yet to be performed. Objectives The objectives of this study were to explore glucose production, gluconeogenesis, and the contribution of gluconeogenesis to glucose production in idiopathic and PRKN PD compared with healthy controls with state‐of‐the‐art biochemical methods. Methods We applied a dried‐blood sampling/gas chromatography/mass spectrometry approach to monitor fluxes in the Cori cycle in vivo. Results The contribution of gluconeogenesis to total glucose production is increased in idiopathic PD patients (n = 33), but not in biallelic PRKN mutation carriers (n = 5) compared with healthy controls (n = 13). Conclusions We provide first‐time in vivo evidence for alterations in glucose metabolism in idiopathic PD, in keeping with the epidemiological evidence for an association between PD and diabetes. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Sulfur mustard (SM, bis[2-chloroethyl]-sulfide) is a banned chemical warfare agent deployed in the violent conflict in the Middle East poisoning humans and animals.For legal reasons, bioanalytical methods are mandatory proving exposure to SM. Reaction products (adducts) of SM with endogenous proteins, for example, serum albumin (SA), are valuable long-lived targets for analysis. Whereas nearly all methods known so far focus on human proteins, we address for the first time neat chicken SA and avian serum from chicken, duck, and ostrich. After proteolysis, protein precipitation, evaporation of the supernatant, and re-dissolution analysis were performed by micro-liquid chromatography-electrospray ionization tandem-mass spectrometry in the selected reaction monitoring mode, μLC-ESI MS/MS (SRM), for detection of the hydroxyethylthioethyl product ion [HETE] + at m/z 105.0. After in vitro incubation with SM and pronase-catalyzed proteolysis, the alkylated amino acids Glu(-HETE) and His(-HETE) were detected. Both borne the SM-characteristic HETE-moiety bound to their side chain. The eightfold deuterated SM analog (d8-SM) was also applied to support adduct identification. Proteolysis conditions were optimized with respect to pH (8.0), temperature (50 C), and time to maximize the yield of Glu(-HETE) (30 min) and His(-HETE) (180 min). Amino acid adducts were stable in the autosampler for at least 24 h. Protein-adducts were stable in serum at À30 C for at least 33 days and for three freeze-and-thaw cycles. At the body temperature of chicken (+40 C), Glu(-HETE) was degraded in serum (period of half-change 3 days), whereas His(-HETE) remained stable. The presented method broadens the toolbox of procedures to document poisoning with SM.