Shotgun proteomics protocols are widely used for the identification and/or quantitation of proteins in complex biological samples. Described here is a shotgun protocol that can be to identify protein targets biologically relevant ligands mixtures. The combines quantitative platform with covalent modification strategy, termed Stability Proteins from Rates Oxidation (SPROX), which utilizes denaturant dependence hydrogen peroxide-mediated oxidation methionine side chains assess thermodynamic...

Described here is the development of a mass spectrometry-based covalent labeling protocol that utilizes reaction dimethyl(2-hydroxy-5-nitrobenzyl)sulfonium bromide (HNSB) with tryptophan (Trp) residues to measure protein folding free energies (ΔGf values). In protocol, chemical denaturant dependence rate at which globally protected Trp in react HNSB evaluated using either matrix assisted laser desorption ionization time-of-flight analysis intact or quantitative, bottom-up proteomics isobaric...

Only trace amounts of parent benzodiazepines are present in urine following extensive metabolism and conjugation. Thus, hydrolysis glucuronides is necessary for improved detection. Enzyme preferred to retain identification specificity, but can be costly time-consuming. The assessment a novel recombinant β-glucuronidase rapid benzodiazepine urinalysis presented. Glucuronide controls oxazepam, lorazepam temazepam were treated with IMCSzyme™ β-glucuronidase. Hydrolysis efficiency was assessed...

Designer drugs including synthetic cannabinoids and cathinones are an increasing problem due to the ease of access these compounds. They present analytical challenges inasmuch as compound structures numerous growing within each class. Typically class designer compounds is analyzed separately differences in chemistry, desired cut-offs or other reasons. Physicians treating "high-risk" patients typically order tests for all "illicit" substances which can span several test classes. Despite that...

Detection and quantitation of protein-ligand binding interactions is important in many areas biological research. Stability proteins from rates oxidation (SPROX) an energetics-based technique for identifying the targets ligands complex mixtures. Knowing false-positive rate protein target discovery proteome-wide SPROX experiments correct interpretation results. Reported here are results a control experiment which chemical denaturation data obtained on two samples that originated same yeast...

Adherence to prescribed antipsychotics is an ongoing problem. Traditionally, estimates of adherence have been made from patient interviews, pill counting and blood testing. A number methods for the analysis in reported both therapeutic drug monitoring postmortem testing toxicity. This report details a dilute shoot method 19 different metabolites. The takes advantage earlier reports demonstrating unique, prevalent urine metabolites aripiprazole, brexpiprazole, haloperidol lurasidone enhance...

Treatment adherence is often an issue with mental health patients. For those prescribed quetiapine (Seroquel®), the low levels of parent drug and plasma metabolite(s) (e.g., 7-hydroxyquetiapine) typically used in urine monitoring can result false negatives concomitant unfavorable impacts on patient care. Literature review coupled liquid chromatography/time-of-flight mass spectrometry analysis positive samples indicated presence carboxylic acid sulfoxide as significant urinary metabolites...

While earlier studies have attempted to resolve the challenges encountered when interpreting gamma-hydroxybutyric acid (GHB) concentrations in hair (primarily due its endogenous presence), few had large sample sizes. The first objective of this study was evaluate inter-individual variation GHB concentrations. second objective, be detailed another report, assess intra-individual and impact on exogenous discrimination. Over 2,000 segments from 141 women 73 men (all processed 3-12 cm long) were...

Epilepsy is a common neurologic disease that requires treatment with one or more medications. Due to the polypharmaceutical treatments, potential side effects, and drug-drug interactions associated these medications, therapeutic drug monitoring important. Therapeutic typically performed in blood due established clinical ranges. While provides benefit of determining ranges, urine less invasive collection method, which attractive for medication monitoring. As does not have it has become...

Abstract Background While validation of analytical (LC-MS/MS) methods has been documented in any number articles and reference texts, the optimal design subsequent a method for over 30 analytes presents special challenges. Conventional approaches to calibration curves, controls, run time are not tenable such methods. This report details practical aspects designing implementing accordance with College American Pathologists criteria. Methods criteria were followed 34 15 internal standards by...

Abstract The endogenous presence of gamma-hydroxybutyric acid (GHB) complicates the interpretation results in cases where an exogenous dosing is suspected. Due to GHB’s rapid metabolism and clearance following doses, hair has become a preferential matrix for confirmation GHB exposure drug-facilitated crimes. However, unlike blood urine agreed-upon cut-off concentration differentiation between been made, there no consensus on hair. This due part wide inter- intra-individual variation that...

Being able to communicate effectively is an essential skill for statisticians and data scientists. Despite this, communication skills are not frequently taught or emphasized in statistics science courses. In this article, we describe a series of four workshops that were developed enhance the written graduate students. We also present results survey administered prior first workshop after last assess changes attitudes towards writing obtain student feedback improve workshops. Lastly, discuss...

Reports have suggested that patients with mental health disorders including major depressive disorder and schizophrenia dramatically low adherence levels to prescribed medications. Patients on haloperidol (Haldol®) therapy, regardless of their disease, were found higher levels-though still strikingly low. This work shows high the glucuronidated form are present in patient urine samples. Time-of-Flight (TOF) mass spectrometry experiments consistent both presence glucuronide hydrolysis samples...

Benzodiazepines have been important drugs for the treatment of anxiety and pain since their introduction in 1950s.Urine drug testing (UDT) is often used to help establish whether patient adherent prescribed benzodiazepine or misusing drug.As such, it physicians recognize levels that are outside expected ranges.However, date there has little research into "normal" urine ranges patients benzodiazepines.This work designed present UDT results from a large population 6 months testing,...

The objective of this work was to study the results urine drug testing for ritalinic acid (RA), major urinary metabolite methylphenidate (MP) (e.g., Ritalin®). impact age from 4 65 years old and older on median levels RA investigated as well potential variations in pH, specific gravity creatinine content patient samples.Samples patients who were 1) prescribed MP found be positive RA, 2) but negative 3) not tested examined by liquid chromatography - mass spectrometry/mass spectrometry...

A recent paper regarding development and validation of a liquid chromatography/mass spectrometry mass (LC/MSMS) method for the analysis antipsychotics their respective metabolites in urine was published Journal Analytical Toxicology. 7This work by Kim, et al., focused on assessing adherence "mentally disordered probationers" to legally required antipsychotics.The authors note that repercussions "negative" test results could be severe thus they have taken very conservative approach declaring...