Publications by authors named "Richard Yost"

Per- and polyfluoroalkyl substances (PFAS) are widespread, persistent environmental contaminants that have been linked to various health issues. Comprehensive PFAS analysis often relies on ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC HRMS) and molecular fragmentation (MS/MS). However, the selection and fragmentation of ions for MS/MS analysis using data-dependent analysis results in only the topmost abundant ions being selected.

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Meningiomas are among the most common brain tumors that arise from the leptomeningeal cover of the brain and spinal cord and account for around 37% of all central nervous system tumors. According to the World Health Organization, meningiomas are classified into three histological subtypes: benign, atypical, and anaplastic. Sometimes, meningiomas with a histological diagnosis of benign tumors show clinical characteristics and behavior of aggressive tumors.

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Bile acids (BAs) are a complex suite of clinically relevant metabolites that include many isomers. Liquid chromatography coupled to mass spectrometry (LC-MS) is an increasingly popular technique due to its high specificity and sensitivity; nonetheless, acquisition times are generally 10-20 min, and isomers are not always resolved. In this study, the application of ion mobility (IM) spectrometry coupled to MS was investigated to separate, characterize, and measure BAs.

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Traumatic brain injury (TBI) is a multidimensional damage, and currently, no FDA-approved medicine is available. Multiple pathways in the cell are triggered through a head injury (e.g.

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Building an accurate lipid inventory relies on coordinated information from orthogonal analytical capabilities. Integrating the familiar workflow of liquid chromatography (LC), high-resolution mass spectrometry (HRMS), and tandem mass spectrometry (MS/MS) with proton nuclear magnetic resonance spectroscopy (H NMR) would be ideal for building that inventory. For absolute lipid structural elucidation, LC-HRMS/MS can provide lower-level structural information with superior sensitivity, while H NMR can provide invaluable higher-order structural information for the disambiguation of isomers with absolute chemical specificity.

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Rationale: The triple quadrupole mass spectrometer, typically in combination with a gas or liquid chromatograph (GC/MS/MS and LC/MS/MS), is perhaps the most iconic example today of a tandem analytical instrument. Here I present the concepts of tandem or hyphenated techniques for trace analysis (that is, the detection and/or quantitation of one or more analytes present in a mixture at low levels).

Methods: This tutorial presents the principles of tandem trace analytical techniques such as GC/MS/MS and LC/MS/MS, including the capabilities and requirements for such tandem techniques, the role of sensitivity and selectivity in tandem techniques, ways to assess the "informing power" of these techniques, and a comparison of tandem techniques with individual techniques at high resolution.

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The vast majority of mass spectrometry (MS)-based metabolomics studies employ reversed-phase liquid chromatography (RPLC) to separate analytes prior to MS detection. Highly polar metabolites, such as amino acids (AAs), are poorly retained by RPLC, making quantitation of these key species challenging across the broad concentration ranges typically observed in biological specimens, such as cell extracts. To improve the detection and quantitation of AAs in microglial cell extracts, the implementation of a 4-dimethylaminobenzoylamido acetic acid N-hydroxysuccinimide ester (DBAA-NHS) derivatization agent was explored for its ability to improve both analyte retention and detection limits in RPLC-MS.

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Introduction: Intellectual disorders involving deletions of the X chromosome present a difficult task in the determination of a connection between symptoms and metabolites that could lead to treatment options. One specific disorder of X-chromosomal deletion, Fragile X syndrome, is the most frequently occurring of intellectual disabilities. Previous metabolomic studies have been limited to mouse models that may not have sufficiently revealed the full biochemical diversity of the disease in humans.

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Alcoholic fatty liver disease (AFLD) is characterized by lipid accumulation and inflammation and can progress to cirrhosis and cancer in the liver. AFLD diagnosis currently relies on histological analysis of liver biopsies. Early detection permits interventions that would prevent progression to cirrhosis or later stages of the disease.

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Traumatic brain injury (TBI) is a major neurological disorder without FDA-approved therapies. In this study, we have examined the concept that TBI might trigger global brain proteolysis in the acute post-injury phase. Thus, we conducted a systemic proteolytic peptidomics analysis using acute cerebrospinal fluid (CSF) samples from TBI patients and normal control samples.

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Article Synopsis
  • There's a critical need to validate biomarkers in biofluids for diagnosing and developing treatments for traumatic brain injury (TBI).
  • Four potential biomarkers identified are GFAP, S100B, UCH-L1, and Tau, which represent astroglial and neuronal damage.
  • Different assay formats showed inconsistent performance in detecting these biomarkers, highlighting the need for standardization to ensure accurate comparisons across platforms.
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One hundred and seventeen street sweeping samples were collected and analyzed for per- and polyfluoroalkyl substances (PFAS). Fifty-six samples were collected in one city (Gainesville, Florida) allowing for an in-depth city-wide characterization. Street sweepings from five other urban areas, (Orlando, n = 15; Key West, n = 15; Pensacola, n = 12; Tampa, n = 13; and Daytona Beach, n = 6) were analyzed to provide a city-to-city comparison of PFAS.

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Sediment samples from 25 locations in the Pensacola Bay System (PBS) watershed were analyzed for the presence of 51 per- and polyfluoroalkyl substances (PFAS) using ultra high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) and selected reaction monitoring. Results revealed quantifiable concentrations of PFAS in all sampling locations. More specifically, perfluorobutanoic acid (PFBA) was present in every sediment sample with a minimum and maximum concentration of 0.

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Specific aspects of previously reported extraction workflows, for measurement of per- and polyfluoroalkyl substances (PFAS) in solid matrices, have not been adequately interrogated. The objective of this study was to explore the importance of each workflow step in providing the most appropriate extraction for a comprehensive set of PFAS (51 different species) in soil. We compared different procedures, including two pre-extraction set ups (overnight handling of samples prior to extraction), two extraction solvents (methanol (MeOH), and acetonitrile (ACN)), two extraction solvent volumes (10 mL and 8.

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Atmospheric pressure sampling mass spectrometric methods are ideal platforms for rapidly analyzing the metabolomes of biological specimens. Several liquid extraction-based techniques have been developed for increasing metabolome coverage in direct sampling workflows. Here, we report the construction of a dual-probe microsampling device (DPM), based on the design of the liquid microjunction surface sampling probe, for analyzing the metabolome of live microglial cells by drift-tube ion mobility spectrometry (IMS) quadrupole time-of-flight mass spectrometry.

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Tauopathies are a class of neurodegenerative disorders characterized by abnormal deposition of post-translationally modified tau protein in the human brain. Tauopathies are associated with Alzheimer's disease (AD), chronic traumatic encephalopathy (CTE), and other diseases. Hyperphosphorylation increases tau tendency to aggregate and form neurofibrillary tangles (NFT), a pathological hallmark of AD.

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Background: Understanding the interaction between organisms and the environment is important for predicting and mitigating the effects of global phenomena such as climate change, and the fate, transport, and health effects of anthropogenic pollutants. By understanding organism and ecosystem responses to environmental stressors at the molecular level, mechanisms of toxicity and adaptation can be determined. This information has important implications in human and environmental health, engineering biotechnologies, and understanding the interaction between anthropogenic induced changes and the biosphere.

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Lipidomics has great promise in various applications; however, a major bottleneck in lipidomics is the accurate and comprehensive annotation of high-resolution tandem mass spectral data. While the number of available lipidomics software has drastically increased over the past five years, the reduction of false positives and the realization of obtaining structurally accurate annotations remains a significant challenge. We introduce Lipid Annotator, which is a user-friendly software for lipidomic analysis of data collected by liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS).

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Novel synthetic anabolic androgenic steroids have been developed not only to dodge current antidoping tests at the professional sports level, but also for consumption by noncompetitive bodybuilders. These novel anabolic steroids are commonly referred to as "designer steroids" and pose a significant risk to users because of the lack of testing for toxicity and safety in animals or humans. Manufacturers of designer steroids dodge regulation by distributing them as nutritional or dietary supplements.

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Article Synopsis
  • - The current targeted metabolomic workflows have limitations that can result in loss of key metabolic process information due to the sequential isolation of analytes, leading to variability and reduced data points in mass spectrometry analysis.
  • - Using a wide-isolation window during fragmentation can enhance consistency in quantitation while maintaining faster scan rates, which helps in accurately representing chromatographic peaks for better analysis.
  • - This study applied a new method combining wide-isolation quantitative strategies and qualitative metabolomics to analyze tryptophan degradation in mouse serum, revealing important insights into the kynurenine pathway and its metabolites.
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Diets high in calories can be used to model metabolic diseases, including obesity and its associated comorbidities, in animals. fed high-sugar diets (HSDs) exhibit complications of human obesity including hyperglycemia, hyperlipidemia, insulin resistance, cardiomyopathy, increased susceptibility to infection, and reduced longevity. We hypothesize that lipid storage in the high-sugar-fed fly's fat body (FB) reaches a maximum capacity, resulting in the accumulation of toxic lipids in other tissues or lipotoxicity.

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Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta of the brain, as well as the degeneration of motor and nonmotor circuitries. The cause of neuronal death is currently unknown, although chronic neuroinflammation, aggregated α-synuclein, mitochondrial dysfunction, and oxidative stress have all been implicated. Gliosis has been shown to exacerbate neuroinflammation via secretion of proinflammatory cytokines, and there is a subsequent infiltration of T lymphocytes (T-cells), into the brain of PD patients.

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Tauopathy is a class of a neurodegenerative disorder linked with tau hyperphosphorylation, proteolysis, and aggregation. Tau can be subjected to proteolysis upon calpain activation in Alzheimer disease (AD), and traumatic brain injury (TBI). We and others have extensively researched calpain-mediated tau breakdown products (Tau-BDP; 45K, 35K, and 17K).

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