Publications by authors named "Sandra E Spencer"

Purpose: Preclinical data motivate clinical evaluation of inhibitors of mitogen-activated protein kinase-interacting kinases 1 and 2 (MNK1/2). We conducted a phase 1b clinical trial to study target engagement and safety of tomivosertib, a MNK1/2 inhibitor, alone and in combination with paclitaxel.

Methods: Eligible patients had metastatic breast cancer resistant to standard of care treatments.

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A thorough evaluation of the quality, reproducibility, and variability of bottom-up proteomics data is necessary at every stage of a workflow, from planning to analysis. We share vignettes applying adaptable quality control (QC) measures to assess sample preparation, system function, and quantitative analysis. System suitability samples are repeatedly measured longitudinally with targeted methods, and we share examples where they are used on three instrument platforms to identify severe system failures and track function over months to years.

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Article Synopsis
  • Low-grade serous ovarian carcinoma (LGSC) is a rare and dangerous type of ovarian cancer that is different from the more common high-grade version.
  • Researchers studied tissue samples from LGSC, high-grade serous ovarian carcinoma (HGSC), and serous borderline tumors (SBTs) to understand how they differ.
  • They found that the environment around the tumors was different in LGSC, including specific proteins and immune cells, which suggests that changing this environment could help develop new treatments.
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Mass spectrometry based targeted proteomics methods provide sensitive and high-throughput analysis of selected proteins. To develop a targeted bottom-up proteomics assay, peptides must be evaluated as proxies for the measurement of a protein or proteoform in a biological matrix. Candidate peptide selection typically relies on predetermined biochemical properties, data from semi-stochastic sampling, or by empirical measurements.

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Article Synopsis
  • * Longitudinal monitoring of system suitability samples on various instrument platforms helps identify failures and maintain consistent functionality over time.
  • * The integration of internal and external QC measures, along with tools for rapid analysis and data sharing, is proposed as an effective strategy for optimizing data quality and ensuring efficient use of experimental resources.
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  • Research highlights the key role of caspase-3 (CASP3) in both cell death and previously unknown survival functions in human cells.
  • Experiments showed that knocking down CASP3 led to cell cycle arrest and reduced survival, indicating its importance in maintaining normal and cancer cell health.
  • The study reveals that the protective effects of CASP3, including the removal of protein aggregates, do not rely on its usual enzyme activity, specifically identifying its N-terminal prodomain as crucial for these prosurvival functions.
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Background: Lung cancer is the leading cause of cancer related death worldwide, mainly due to the late stage of disease at the time of diagnosis. Non-invasive biomarkers are needed to supplement existing screening methods to enable earlier detection and increased patient survival. This is critical to -driven lung adenocarcinoma as it commonly occurs in individuals who have never smoked and do not qualify for current screening protocols.

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Optimizing the quality of proteomics data collected from a mass spectrometer (MS) requires careful selection of acquisition parameters and proper assessment of instrument performance. Software tools capable of extracting a broad set of information from raw files, including meta, scan, quantification, and identification data, are needed to provide guidance for MS system management. In this work, direct extraction and utilization of these data is demonstrated using RawTools, a standalone tool for extracting meta and scan data directly from raw MS files generated on Thermo Orbitrap instruments.

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As compared to conventional high-performance liquid chromatography (HPLC) techniques, nanoflow HPLC exhibits improved sensitivity and limits of detection. However, nanoflow HPLC suffers from low throughput due to instrument failure (e.g.

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Extractive electrospray ionization is an ambient ionization technique that allows real-time sampling of liquid samples, including organic aerosols. Similar to electrospray ionization, the composition of the electrospray solvent used in extractive electrospray ionization can easily be altered to form metal cationized molecules during ionization simply by adding a metal salt to the electrospray solvent. An increase in sensitivity is observed for some molecules that are lithium, sodium, or silver cationized compared with the protonated molecule formed in extractive electrospray ionization with an acid additive.

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The design and operation of an inexpensive, miniature low-temperature plasma ion source is detailed. The miniature low-temperature plasma ion source is operated in a "flow-through" configuration, wherein the gaseous or aerosolized analyte, caffeine or pyrolyzed ethyl cellulose, in a carrier gas is used as the plasma gas. In this flow-through configuration, the sensitivity for the caffeine standard and the pyrolysis products of ethyl cellulose is maintained or increased and the reproducibility of the ion source is increased.

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Low-temperature plasma ionization, a technique that causes minimal fragmentation during ionization, is investigated as an ionization technique for mass spectrometric detection of the compounds in ambient organic aerosols in real time. The experiments presented in this paper demonstrate that ions are generated from compounds in the aerosol particles. The utility of this technique for detection of both positive and negative ions from the pyrolysate of multiple natural polymers is presented.

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The use of condoms in sexual assault cases has become increasingly common due to the heightened awareness of the use of DNA as evidence in criminal investigations. The ability to identify and differentiate the polymers and additives found in lubricant residues can provide investigators leads and insights as to the perpetrator of a sexual assault. Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) is ideal for detecting condom lubricants and additives; the instrument is capable of surveying analytes across a wide mass range and is a preferred technique for the analysis of polymers.

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The negative ion mode ESI mass spectral analysis of antimony(III)-D- and -L-tartrate ("tartar emetic"), in association with leucine enantiomeric isotopomers, revealed remarkable proton-assisted enantioselective molecular recognition phenomena. The current study infers that recognition of amino acids by antimony(III)-D,L-tartrate complexes requires that the chiral selector associate a proton to become enantioselective. The dianionic selector itself failed to show enantiomeric discrimination capacity.

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