Quantitation of ortho-cresyl phosphate adducts to butyrylcholinesterase in human serum by immunomagnetic-UHPLC-MS/MS

Tri-ortho-cresyl phosphate (ToCP) is an anti-wear, flame retardant additive used in industrial lubricants, hydraulic fluids and gasoline. The neurotoxic effects of ToCP arise from the liver-activated metabolite 2-(o-cresyl)-4H-1,3,2-benzodioxaphosphoran-2-one (cresyl saligenin phosphate or CBDP), which inhibits esterase enzymes including...

Modified AZ80 magnesium alloys for biomedical applications

Magnesium and its alloys are light weight, biodegradable materials. They can be used as metal implants which maintain strength and integrity for the time of recovery, followed by natural dissolution in the body preventing the necessity of implant removal. In addition to the general biocompatibility and biodegradability requirements, these...

Bioconversion of red ginseng saponins in the gastro-intestinal tract in vitro model studied by high-performance liquid chromatography-high resolution Fourier transform ion cyclotron resonance mass spectrometry

A high-performance liquid chromatography-high resolution Fourier transform ion cyclotron resonance mass spectrometry (HPLC-FTICR-MS) method was developed to investigate the metabolism of ginsenosides in in vitro models of the gastro-intestinal tract. The metabolites were identified by high-resolution tandem mass spectrometry. Degradation and...

Alkaloid profiling of the Chinese herbal medicine Fuzi by combination of matrix-assisted laser desorption ionization mass spectrometry with liquid chromatography-mass spectrometry

A matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) method was developed for the high throughput and robust qualitative profiling of alkaloids in Fuzi-the processed lateral roots of the Chinese herbal medicine Aconitum carmichaeli Debx (A. carmichaeli). After optimization, powdered roots - without any further sample...

Performance and population analysis of a non-sterile trickle bed reactor inoculated with caldicellulosiruptor saccharolyticus, a thermophilic hydrogen producer

Non-axenic operation of a 400 L trickle bed reactor inoculated with the thermophile Caldicellulosiruptor saccharolyticus, yielded 2.8 molH 2mol hexose converted. The reactor was fed with a complex medium with sucrose as the main substrate, continuously flushed with nitrogen gas, and operated at 73°C. The volumetric productivity was 22 mmolH2(L...

Quantitative profiling of bile acids in biofluids and tissues based on accurate mass high resolution LC-FT-MS: Compound class targeting in a metabolomics workflow

We report a sensitive, generic method for quantitative profiling of bile acids and other endogenous metabolites in small quantities of various biological fluids and tissues. The method is based on a straightforward sample preparation, separation by reversed-phase high performance liquid-chromatography mass spectrometry (HPLC-MS) and electrospray...

Validation of transferability of DBA derivatization and LC-MS/MS determination method for isocyanates via an interlaboratory comparison

An adapted method for the quantitative determination of isocyanates in air was implemented and validated in-house. The method was based on air sampling using an impinger flask containing di-n-butylamine (DBA) in toluene and a glass fibre filter in series. The DBA derivatives were determined using liquid chromatography and tandem mass...

TGFbeta affects collagen cross-linking independent of chondrocyte phenotype but strongly depending on physical environment

Transforming growth factor beta (TGFbeta) is often used in cartilage tissue engineering to increase matrix formation by cells with various phenotypes. However, adverse effects of TGFbeta, such as extensive cross-linking in cultured fibroblasts, have also been reported. Our goal was to study effects of TGFbeta on collagen cross-linking and...

Lost in translation? Role of metabolomics in solving translational problems in drug discovery and development

Too few drug discovery projects generate a marketed drug product, often because preclinical studies fail to predict the clinical experience with a drug candidate. Improving the success of preclinical-to-clinical translation is of paramount importance in optimizing the pharmaceutical value chain. Here, we advance the case for a molecular systems...

Detection of a soluble form of BACE-1 in human cerebrospinal fluid by a sensitive activity assay

Background: Formation of deposits of the insoluble amyloid β-peptide is believed to be causally related with neurodegeneration in Alzheimer disease (AD). The β-peptide originates from a larger amyloid precursor protein (APP) by the action of proteolytic enzymes. The first proteolytic event leading to amyloid formation is the cleavage of APP by...

Confirmation of synthetic glucocorticoids with liquid chromatography/mass spectrometry: Organization and results of an international interlaboratory comparison test

Within the framework of a European Union (EU) research project entitled "Food Safety Screening: Synthetic Glucocorticoids (QLK1-1999-00122)," an international interlaboratory ring test was organized to compare and evaluate different liquid chromatography/mass spectrometry (LC/MS) confirmatory methods that are applied in European monitoring...

Detection of zilpaterol (Zilmax®) in calf urine and faeces with liquid chromatography-tandem mass spectrometry

Zilpaterol is a new powerful beta-agonist, which is officially registered for fattening purposes in cattle in Mexico and South Africa. Its chemical structure is different from the well-known beta-agonists. Therefore, the routinely used screening methods are not likely to be suited for the analysis of zilpaterol. Also gas chromatography-mass...

Generic solid phase extraction-liquid chromatography-tandem mass spectrometry method for fast determination of drugs in biological fluids

A generic method was developed for the fast determination of a wide range of drugs in serum or plasma. The methodology comprises generic solid-phase extraction, on-line coupled to gradient HPLC with tandem mass spectrometric detection (SPE-LC-MS/MS). The individual components of the SPE-LC-MS/MS system were optimized in an integrated approach to...

Mobilization of PCBs and lindane from soil during in vitro digestion and their distribution among bile salt micelles and proteins of human digestive fluid and the soil

Children can take up contaminated soil via hand-to-mouth behavior. The contaminants can be mobilized from the soil by digestive juices and thus become available for intestinal absorption (i.e. become bioaccessible). In the present study components of an in vitro digestion model were varied to study their effect on the mobilization of several...

Body fluid markers to monitor multiple sclerosis: The assays and the challenges

The need for reliable markers of disease activity in multiple sclerosis (MS) to better guide basic research, diagnosis, treatment, and monitoring of therapy is well-recognized. A recent European Charcot Foundation Symposium (Body fluid markers for course and activity of disease in multiple sclerosis (Madrid, Spain, October 2-4, 1997) organized...

A sensitive bioimmunoassay for thrombin-cleaved two-chain urokinase-type plasminogen activator in human body fluids

Thrombin cleaves single-chain urokinase-type plasminogen activator (scu-PA) into a two-chain form (tcu-PA/T), which is virtually inactive in plasminogen activator assays. Little is known about the physiological importance of tcu-PA/T. To examine the occurrence of tcu-PA/T in vivo, we developed a sensitive and specific bioimmunoassay (BIA) for...

Immunological characterization of plasminogen activator activities in human tissues and body fluids

Human plasminogen activators were compared immunologically in both a double-diffusion technique and quenching experiments on the fibrinolytic activities of the activators. Antisera against HMW and LMW urokinase and an antiserum against highly purified tissue plasminogen activator from human uterus were used. It was found that uterine tissue...