Publications by authors named "Kirk Pappan"

Purpose: The Genomic Analysis of High-Risk Non-Muscle-Invasive Bladder Cancer (GARNER) study investigated FGFR alteration (ALT) frequency and the clinical outcome relationship with Bacillus Calmette-Guérin (BCG) treatment in high-risk non-muscle-invasive bladder cancer (HR-NMIBC). An FGFR predictive response signature (FGFR-PRS) was discovered that identifies patients with an activated FGFR pathway who could potentially benefit from FGFR-targeted therapy beyond those who are FGFR ALT (+).

Experimental Design: Pretreatment tumor samples and clinical data were analyzed from 582 BCG-treated patients with HR-NMIBC.

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  • Infection with Clostridium difficile (CDI) is the main cause of diarrhea acquired in hospitals, but current diagnostic methods like enzyme immunoassays and PCR have significant limitations.
  • A study used advanced technology to analyze exhaled breath samples from 17 CDI patients and control patients, identifying 9 specific volatile organic compounds (VOCs).
  • The resulting analysis demonstrated a 74% accuracy in distinguishing CDI cases, indicating that breath VOC testing could be a promising additional tool for diagnosing CDI, pending further research.
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Human breath offers several benefits for diagnostic applications, including simple, noninvasive collection. Breath is a rich source of clinically-relevant biological information; this includes a volatile fraction, where greater than 1,000 volatile organic compounds (VOCs) have been described so far, and breath aerosols that carry nucleic acids, proteins, signaling molecules, and pathogens. Many of these factors, especially VOCs, are delivered to the lung by the systemic circulation, and diffusion of candidate biomarkers from blood into breath allows systematic profiling of organismal health.

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Acylcholines are comprised of an acyl chain esterified to a choline moiety; acetylcholine is the best-characterized member of this class, functioning as a neurotransmitter in the central and peripheral nervous systems as well as an inhibitor of cytokine production by macrophages and other innate immune cells. Acylcholines are metabolized by a class of cholinesterases, including acetylcholinesterase (a specific regulator of acetylcholine levels) and butyrylcholinesterase (BChE, an enigmatic enzyme whose function has not been resolved by genetic knockout models). BChE provides reserve capacity to hydrolyze acetylcholine, but its importance is arguable given acetylcholinesterase is the most catalytically efficient enzyme characterized to date.

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  • Recent advancements in newborn screening have improved the detection of inborn errors of metabolism (IEMs), but many treatable conditions are still not included in standard panels or testing.* -
  • This study compares the effectiveness of traditional metabolic screening with untargeted metabolomics for diagnosing IEMs by analyzing data from two groups of clinical samples over several years.* -
  • Results showed a low diagnostic rate (1.3%) for traditional screening, while untargeted metabolomics identified additional IEMs not part of standard protocols, highlighting its potential as a more comprehensive screening method.*
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Face masks and personal respirators are used to curb the transmission of SARS-CoV-2 in respiratory droplets; filters embedded in some personal protective equipment could be used as a non-invasive sample source for applications, including at-home testing, but information is needed about whether filters are suited to capture viral particles for SARS-CoV-2 detection. In this study, we generated inactivated virus-laden aerosols of 0.3-2 microns in diameter (0.

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Feline obesity elicits a plethora of metabolic responses leading to comorbidities, with potential reversal during weight loss. The specific metabolic alterations and biomarkers of organ dysfunction are not entirely understood. Untargeted, high-throughput metabolomic technologies may allow the identification of biological components that change with weight status in cats, increasing our understanding of feline metabolism.

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Aims/hypothesis: This study aimed to examine if beta-aminoisobutyric acid (BAIBA) is (i) secreted by skeletal muscle in humans during exercise, (ii) associated with insulin secretory function in vivo, and (iii) directly linked with acute glucose-mediated insulin release by pancreatic beta cells .

Methods: Following 2-weeks of single-leg immobilization, plasma BAIBA concentrations were measured in the brachial artery and the femoral veins of each leg in healthy male subjects, at rest and during two-legged dynamic knee-extensor exercise. During a 2-h hyperglycamic clamp, insulin secretory function and levels of plasma BAIBA were assessed in non-diabetic individuals, non-diabetic individuals following 24-h hyperglycemia and patients with type 2 diabetes.

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Inborn errors of metabolism (IEM) involving the non-oxidative pentose phosphate pathway (PPP) include the two relatively rare conditions, transketolase deficiency and transaldolase deficiency, both of which can be difficult to diagnosis given their non-specific clinical presentations. Current biochemical testing approaches require an index of suspicion to consider targeted urine polyol testing. To determine whether a broad-spectrum biochemical test could accurately identify a specific metabolic pattern defining IEMs of the non-oxidative PPP, we employed the use of clinical metabolomic profiling as an unbiased novel approach to diagnosis.

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  • Whole-exome sequencing has enhanced the diagnosis of genetic diseases, leading to the development of a clinical metabolomics method that uses mass spectrometry to screen for metabolic disorders by measuring hundreds of metabolites in a single sample.
  • A precision study was conducted on human plasma to assess the reliability of four high-throughput metabolomics platforms, revealing a range of laboratory and inter-assay coefficient of variations (CVs) indicating good precision across samples.
  • The evaluation confirms that the method is robust and reproducible for identifying key metabolites related to inborn errors of metabolism (IEMs), demonstrating its effectiveness in patient screening through consistent analytical results.
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Methylmalonate semialdehyde dehydrogenase deficiency (MMSDD; MIM 614105) is a rare autosomal recessive defect of valine and pyrimidine catabolism. Four prior MMSDD cases are published. We present a fifth case, along with functional and metabolomic analysis.

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  • The text refers to a correction of an article published with the DOI 10.3389/fnins.2019.00394.
  • This correction indicates that there were errors or updates needed for the original publication.
  • It emphasizes the importance of accuracy and transparency in scientific literature.
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Introduction: Shiga toxin 2a (Stx2a) induces hemolytic uremic syndrome (STEC HUS) by targeting glomerular endothelial cells (GEC).

Objectives: We investigated in a metabolomic analysis the response of a conditionally immortalized, stable glomerular endothelial cell line (ciGEnC) to Stx2a stimulation as a cell culture model for STEC HUS.

Methods: CiGEnC were treated with tumor necrosis factor-(TNF)α, Stx2a or sequentially with TNFα and Stx2a.

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Broad-scale untargeted biochemical phenotyping is a technology that supplements widely accepted assays, such as organic acid, amino acid, and acylcarnitine analyses typically utilized for the diagnosis of inborn errors of metabolism. In this study, we investigate the analyte changes associated with 4-aminobutyrate aminotransferase (ABAT, GABA transaminase) deficiency and treatments that affect GABA metabolism. GABA-transaminase deficiency is a rare neurodevelopmental and neurometabolic disorder caused by mutations in and resulting in accumulation of GABA in the cerebrospinal fluid (CSF).

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Article Synopsis
  • - Metabolomics involves the untargeted analysis of small molecules in biological samples, revealing a global biochemical profile influenced by genetics, environment, and microbiomes, linking it to health outcomes.
  • - The technology, used for over a decade in research, holds promise for clinical diagnostics across various fields, but its application must consider distinct challenges compared to research settings to ensure meaningful results.
  • - Future advancements are needed to integrate metabolomics into clinical practice and gain recognition in the medical and regulatory fields, focusing on aspects like test design, data accuracy, and individual biochemical analysis.
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Pancreatic β-cell expansion is a highly regulated metabolic adaptation to increased somatic demands, including obesity and pregnancy; adult β cells otherwise rarely proliferate. We previously showed that high-fat diet (HFD) feeding induces mouse β-cell proliferation in less than 1 wk in the absence of insulin resistance. Here we metabolically profiled tissues from a short-term HFD β-cell expansion mouse model to identify pathways and metabolite changes associated with β-cell proliferation.

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Background: Phenotyping technologies featured in the diagnosis of inborn errors of metabolism, such as organic acid, amino acid, and acylcarnitine analyses, recently have been supplemented by broad-scale untargeted metabolomic phenotyping. We investigated the analyte changes associated with aromatic amino acid decarboxylase (AADC) deficiency and dopamine medication treatment.

Methods: Using an untargeted metabolomics platform, we analyzed ethylenediaminetetraacetic acid plasma specimens, and biomarkers were identified by comparing the biochemical profile of individual patient samples to a pediatric-centric population cohort.

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The transplantation of human pancreatic islets is a therapeutic possibility for a subset of type 1 diabetic patients who experience severe hypoglycemia. Pre- and post-transplantation loss in islet viability and function, however, is a major efficacy-limiting impediment. To investigate the effects of inflammation and hypoxia, the main obstacles hampering the survival and function of isolated, cultured, and transplanted islets, we conducted a comprehensive metabolomics evaluation of human islets in parallel with dynamic glucose-stimulated insulin release (GSIR) perifusion studies for functional evaluation.

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  • The study aimed to analyze the molecular composition of human cerebrospinal fluid (CSF) to enhance untargeted screening for inborn errors of metabolism (IEMs) using advanced metabolomics techniques.
  • Utilizing an integrated workflow involving chromatographic methods and mass spectrometry, researchers identified 435 different biochemicals in CSF, noting that a significant portion of these were also found in urine and plasma samples.
  • The findings highlighted how CSF metabolomics could effectively reveal disrupted metabolic patterns, demonstrated through a case study on a patient with dihydropteridine reductase (DHPR) deficiency, paving the way for better screening methods for metabolic disorders in pediatrics.
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Metabolomics profiling and bioinformatics technologies were used to determine the relationship between exercise-induced increases in IL-6 and lipid-related metabolites. Twenty-four male runners (age 36.5 ± 1.

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Postmenopausal women (PMW) report marginal n-3 PUFA intakes and are at risk of chronic diseases associated with the skeletal, muscular, neuroendocrine, and cardiovascular systems. How n-3 PUFA affect the amounts of endocannabinoids (ECs) and oxylipins (OLs) of metabolic and physiologic importance in PMW is not clear. Based on our recent findings that dietary n-3 PUFA alter gene targets of the EC system and lower pro-inflammatory OL we proceeded to characterize these actions in blood of PMW.

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This study characterizes the metabolic profile of synovial fluid after intra-articular ankle fracture with an emphasis on changes in the lipid profile. Bilateral ankle synovial fluid from 19 patients with unilateral intra-articular ankle fracture was submitted for metabolic profiling. Contralateral ankle synovial fluid from each patient served as a matched control.

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The goal of this study was to provide insight into the mechanism by which bariatric surgical procedures led to weight loss and improvement or resolution of diabetes. Global biochemical profiling was used to evaluate changes occurring in nondiabetic and type 2 diabetic (T2D) patients experiencing either less extreme sleeve gastrectomy or a full gastric bypass. We were able to identify changes in metabolism that were affected by standard preoperation liquid weight loss diet as well as by bariatric surgery itself.

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Introduction: Alterations of serum metabolites may allow us to identify individuals with lung cancer and advance our understanding of the nature and treatment of their cancer. We aimed to identify serum metabolites that differentiate patients with lung cancer from at-risk controls.

Methods: Serum samples from patients with biopsy-confirmed untreated stage I through stage III non-small cell lung cancer and at-risk controls were divided into fractions for analysis by ultrahigh-performance liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry.

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