False-positive MDA findings in HRMS-based screening of putrefied postmortem blood samples-Identification of the interference as N-acetyltyramine.

An unidentified compound in putrefied postmortem blood samples showed identical accurate mass and chromatographic behavior as 3,4-methylenedioxyamphetamine (MDA) and led to false-positive preliminary screening results. The aim of the study was to identify this unknown interference. Postmortem blood samples were analyzed after protein precipitation on a QExactive Focus high-resolution mass spectrometer (Thermo Fisher, Germany) coupled to a RP C18 column (Macherey-Nagel, Germany).

A liquid chromatographic-mass spectrometric procedure for analysis of pentaerythrityl tetranitrate metabolites - Development, validation and application to ovine serum and human plasma samples.

Pentaerythrityl tetranitrate (PETN) is an established drug in the treatment of coronary heart disease and heart failure. It is assumed, that the vasodilative and vasoprotective effects of PETN also have a positive impact on pregnant patients with impaired placental perfusion and studies evaluating the effect of PETN in risk pregnancies have been carried out. In the context of these clinical trials, measuring of serum levels of PETN and its metabolites pentaerythrityl trinitrate (PETriN), pentaerythrityl dinitrate (PEDN), pentaerythrityl mononitrate (PEMN) and pentaerythritol (PE) were required.

Evaluation of biochemical assays and optimization of LC-MS-MS analysis for the detection of synthetic urine.

Ensuring specimen validity is an essential aspect of toxicological laboratories. In recent years, substituting authentic urine specimens for synthetic urine (SU) has become increasingly popular. Such SU products consist of components expected in normal urine and show physiological values for specific gravity and pH.

Advances in testing for sample manipulation in clinical and forensic toxicology - Part A: urine samples.

In many countries, adherence testing is used to monitor consumption behavior or to prove abstinence. Urine and hair are most commonly used, although other biological fluids are available. Positive test results are usually associated with serious legal or economic consequences.

Advances in testing for sample manipulation in clinical and forensic toxicology-part B: hair samples.

As a continuation of part A, focusing on advances in testing for sample manipulation of urine samples in clinical and forensic toxicology, part B of the review article relates to hair, another commonly used matrix for abstinence control testing. Similar to urine manipulation, relevant strategies to manipulate a hair test are lowering drug concentrations in hair to undercut the limits of detection/cut-offs, for instance, by forced washout effects or adulteration. However, distinguishing between usual, common cosmetic hair treatment and deliberate manipulation to circumvent a positive drug test is often impossible.

Long time stability of 35 small endogenous biomolecules in dried urine spotted on various surfaces and environmental conditions.

Analysis of endogenous biomolecules is an important aspect of many forensic investigations especially with focus on DNA analysis for perpetrator/victim identification and protein analysis for body fluid identification. Recently, small endogenous biomolecules have been used for differentiation of synthetic "fake" urine from authentic urine and might be also useful for biofluid identification. Therefore, the aim of this study was to adapt and optimize a method for analysis of small EBs and to investigate long time stability of 35 small endogenous biomolecules (including acylcarnitines with their isomers and metabolites as well as amino acids with their metabolites) in spotted urine samples.

Liquid Chromatography High-Resolution Mass Spectrometry in Forensic Toxicology: What are the Specifics of Method Development, Validation and Quality Assurance for Comprehensive Screening Approaches?

The use of high-resolution mass spectrometry (HRMS) has increased over the past decade in clinical and forensic toxicology, especially for comprehensive screening approaches. Despite this, few guidelines in this field have specifically addressed HRMS issues concerning compound identification, validation, measurement uncertainty and quality assurance. To fully implement this technique, certainly in an era in which the quality demands for laboratories are ever-increasing due to various norms (e.

HPLC-MS identification of acid degradation products of dolutegravir.

Dolutegravir is an integrase strand transfer inhibitor used for the treatment of human immuno-deficiency virus infections. The present study was conducted in order to identify degradation products formed in acidic solution upon heating. The structures were assigned based on low resolution collision-induced dissociation tandem mass spectra as well as high resolution higher-energy collisional dissociation tandem mass spectra.

Ethnomedicinal survey and in vitro confirmation of anti-inflammatory and antispasmodic properties of the termite strain Macrotermes bellicosus used in traditional medicine in the Republic of Benin.

Ethnopharmacological Relevance: Insects and insect-derived products play a vital role in traditional medicine in many parts of the world since ancient times. Among these insects, fungus-growing termites like Macrotermes bellicosus (M. bellicosus) are widely used in nutrition and traditional medicine in various societies of sub-Saharan Africa.

Gastric bypass surgery in a rat model alters the community structure and functional composition of the intestinal microbiota independently of weight loss.

Background: Roux-en-Y gastric bypass (RYGB) surgery is a last-resort treatment to induce substantial and sustained weight loss in cases of severe obesity. This anatomical rearrangement affects the intestinal microbiota, but so far, little information is available on how it interferes with microbial functionality and microbial-host interactions independently of weight loss.

Methods: A rat model was employed where the RYGB-surgery cohort is compared to sham-operated controls which were kept at a matched body weight by food restriction.

Liquid chromatography-mass spectrometry-based determination of ergocristine, ergocryptine, ergotamine, ergovaline, hypoglycin A, lolitrem B, methylene cyclopropyl acetic acid carnitine, N-acetylloline, N-formylloline, paxilline, and peramine in equine hair.

Ingestion of hypoglycin A (HGA) in maple seeds or alkaloids produced by symbiotic fungi in pasture grasses is thought to be associated with various syndromes in grazing animals. This article describes analytical methods for monitoring long-term exposure to HGA, its metabolite MCPA-carnitine, as well as ergocristine, ergocryptine, ergotamine, ergovaline, lolitrem B, N-acetylloline, N-formylloline, peramine, and paxilline in equine hair. After extraction of hair samples separation was achieved using two ultra high performance liquid chromatographic systems (HILIC or RP-C18, ammonium formate:acetonitrile).

Comparative study on the metabolism of the ergot alkaloids ergocristine, ergocryptine, ergotamine, and ergovaline in equine and human S9 fractions and equine liver preparations.

1. Ergopeptine alkaloids like ergovaline and ergotamine are suspected to be associated with fescue toxicosis and ergotism in horses. Information on the metabolism of ergot alkaloids is scarce, especially in horses, but needed for toxicological analysis of these drugs in urine/feces of affected horses.

Systematic investigations of novel validity parameters in urine drug testing and prevalence of urine adulteration in a two-year cohort.

Urinalysis is well established for drug screening. Various methods of urine adulteration such as dilution, addition of oxidative/reductive chemicals or detergents, and handing over urine-like fluids are used to circumvent a positive screen. Validity parameters such as determination of pH, gravidity, urine temperature, or testing for oxidative/reductive chemicals are therefore used to uncover adulterated urine specimens.

Development and validation of an ultrahigh performance liquid chromatography-high resolution tandem mass spectrometry assay for nine toxic alkaloids from endophyte-infected pasture grasses in horse serum.

Endophyte fungi (e.g. Epichloë ssp.

mediates the impact of prenatal bisphenol A exposure on long-term body weight development.

Background: Exposure to endocrine-disrupting chemicals can alter normal physiology and increase susceptibility to non-communicable diseases like obesity. Especially the prenatal and early postnatal period is highly vulnerable to adverse effects by environmental exposure, promoting developmental reprogramming by epigenetic alterations. To obtain a deeper insight into the role of prenatal bisphenol A (BPA) exposure in children's overweight development, we combine epidemiological data with experimental models and BPA-dependent DNA methylation changes.

Development and validation of an ultrahigh performance liquid chromatography-high resolution tandem mass spectrometry quantification method for hypoglycin A and methylene cyclopropyl acetic acid carnitine in horse serum in cases of atypical myopathy.

Atypical myopathy (AM) is a fatal disease in horses presumably caused by hypoglycine A (HGA) from ingested maple seeds and its active metabolite methylene cyclopropyl acetic acid (MCPA). The aim of this study was the development and validation of a rapid and simple assay for HGA and MCPA-carnitine in horse serum and its application to authentic samples. Identification and quantification were carried out by ultra high performance liquid chromatography-high resolution tandem mass spectrometry (UHPLC-HRMS/MS) with full-scan/data-dependent MS/MS.

Acidotolerant and Fungi as a Sink of Methanol-Derived Carbon in a Deciduous Forest Soil.

Methanol is an abundant atmospheric volatile organic compound that is released from both living and decaying plant material. In forest and other aerated soils, methanol can be consumed by methanol-utilizing microorganisms that constitute a known terrestrial sink. However, the environmental factors that drive the biodiversity of such methanol-utilizers have been hardly resolved.

Method Development in Forensic Toxicology.

Background: In the field of forensic toxicology, the quality of analytical methods is of great importance to ensure the reliability of results and to avoid unjustified legal consequences. A key to high quality analytical methods is a thorough method development.

Methods: The presented article will provide an overview on the process of developing methods for forensic applications.

Degradation of indoor limonene by outdoor ozone: A cascade of secondary organic aerosols.

In indoor air, terpene-ozone reactions can form secondary organic aerosols (SOA) in a transient process. 'Real world' measurements conducted in a furnished room without air conditioning were modelled involving the indoor background of airborne particulate matter, outdoor ozone infiltrated by natural ventilation, repeated transient limonene evaporations, and different subsequent ventilation regimes. For the given setup, we disentangled the development of nucleated, coagulated, and condensed SOA fractions in the indoor air and calculated the time dependence of the aerosol mass fraction (AMF) by means of a process model.

Recent advances of liquid chromatography-(tandem) mass spectrometry in clinical and forensic toxicology - An update.

Liquid chromatography (LC) coupled to mass spectrometry (MS) or tandem mass spectrometry (MS/MS) is a well-established and widely used technique in clinical and forensic toxicology as well as doping control especially for quantitative analysis. In recent years, many applications for so-called multi-target screening and/or quantification of drugs, poisons, and or their metabolites in biological matrices have been developed. Such methods have proven particularly useful for analysis of so-called new psychoactive substances that have appeared on recreational drug markets throughout the world.

Microdialysis Sampling from Wound Fluids Enables Quantitative Assessment of Cytokines, Proteins, and Metabolites Reveals Bone Defect-Specific Molecular Profiles.

Bone healing involves a variety of different cell types and biological processes. Although certain key molecules have been identified, the molecular interactions of the healing progress are not completely understood. Moreover, a clinical routine for predicting the quality of bone healing after a fracture in an early phase is missing.

Prenatal maternal stress and wheeze in children: novel insights into epigenetic regulation.

Psychological stress during pregnancy increases the risk of childhood wheeze and asthma. However, the transmitting mechanisms remain largely unknown. Since epigenetic alterations have emerged as a link between perturbations in the prenatal environment and an increased disease risk we used whole genome bisulfite sequencing (WGBS) to analyze changes in DNA methylation in mothers and their children related to prenatal psychosocial stress and assessed its role in the development of wheeze in the child.

Optimization of metabolomics of defined in vitro gut microbial ecosystems.

The metabolic functionality of a microbial community is a key to the understanding of its inherent ecological processes and the interaction with the host. However, the study of the human gut microbiota is hindered by the complexity of this ecosystem. One way to resolve this issue is to derive defined communities that may be cultured ex vivo in bioreactor systems and used to approximate the native ecosystem.