Publications by authors named "George Yu"

Article Synopsis
  • Glioblastoma (GBM) is the deadliest brain tumor in adults, and current therapies are largely ineffective, which drives the need for new treatment strategies based on the tumor's metabolic needs, specifically glucose and glutamine.
  • A ketogenic metabolic therapy (KMT) approach targets these metabolic pathways by combining dietary changes with specific drugs to limit glycolysis and glutaminolysis, while promoting the use of non-fermentable fuels like ketones and fatty acids.
  • The glucose-ketone index (GKI) serves as a biomarker to monitor treatment effectiveness, aiming to create a more hostile environment for tumor growth and improve outcomes in GBM as well as potentially other cancer types reliant on similar metabolic pathways.
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We adapted an existing, spaceflight-proven, robust "electronic nose" (E-Nose) that uses an array of electrical resistivity-based nanosensors mimicking aspects of mammalian olfaction to conduct on-site, rapid screening for COVID-19 infection by measuring the pattern of sensor responses to volatile organic compounds (VOCs) in exhaled human breath. We built and tested multiple copies of a hand-held prototype E-Nose sensor system, composed of 64 chemically sensitive nanomaterial sensing elements tailored to COVID-19 VOC detection; data acquisition electronics; a smart tablet with software (App) for sensor control, data acquisition and display; and a sampling fixture to capture exhaled breath samples and deliver them to the sensor array inside the E-Nose. The sensing elements detect the combination of VOCs typical in breath at parts-per-billion (ppb) levels, with repeatability of 0.

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The COVID-19 pandemic has triggered the first widespread vaccination campaign against a coronavirus. Many vaccinated subjects are previously naive to SARS-CoV-2; however, almost all have previously encountered other coronaviruses (CoVs), and the role of this immunity in shaping the vaccine response remains uncharacterized. Here, we use longitudinal samples and highly multiplexed serology to identify mRNA-1273 vaccine-induced antibody responses against a range of CoV Spike epitopes, in both phylogenetically conserved and non-conserved regions.

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The COVID-19 pandemic has triggered the first widespread vaccination campaign against a coronavirus. Most vaccinated subjects are naïve to SARS-CoV-2, however almost all have previously encountered other coronaviruses (CoVs) and the role of this immunity in shaping the vaccine response remains uncharacterized. Here we use longitudinal samples and highly-multiplexed serology to identify mRNA-1273 vaccine-induced antibody responses against a range of CoV Spike epitopes and in both phylogenetically conserved and non-conserved regions.

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Objectives: A specific and sensitive automated chemiluminescent immunoassay (CLIA) was developed to detect neutralizing antibody (NAb) levels. This assay can be used for the diagnosis of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, treatment and vaccine evaluation.

Methods: The SARS-CoV-2 receptor-binding domain (RBD) and a stabilized version of the spike ectodomain as antigens were detected by CLIA.

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Introduction: Testosterone promotes the initial development of androgen-dependent prostate cancer. This is the basis for androgen ablation treatment, which attenuates, but does not terminate, the malignancy. Instead, it leads to prolactin-dependent malignancy; in which patient death generally occurs within 5 years.

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Cytochrome oxidase (COX) is a hetero-oligomeric complex of the mitochondrial inner membrane that reduces molecular oxygen to water, a reaction coupled to proton transfer from the mitochondrial matrix to the intermembrane space. In the yeast , COX is composed of 11-13 different polypeptide subunits. Here, using pulse labeling of mitochondrial gene products in isolated yeast mitochondria, combined with purification of tagged COX subunits and ancillary factors, we studied the Cox2p assembly intermediates.

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Background: A shift from respiration to fermentation is a common metabolic hallmark of cancer cells. As a result, glucose and glutamine become the prime fuels for driving the dysregulated growth of tumors. The simultaneous occurrence of "Press-Pulse" disturbances was considered the mechanism responsible for reduction of organic populations during prior evolutionary epochs.

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Glutamate is a major excitatory neurotransmitter present in the central nervous system. The glutamate/cystine antiporter system x connects the antioxidant defense with neurotransmission and behaviour. Overactivation of ionotropic glutamate receptors induces neuronal death, a pathway called excitotoxicity.

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Unlabelled: Abstract Background: The prostate gland synthesizes a host of hormones, prostaglandins and growth factors. It is not clear if such biochemical factors modulate the hypothalamic/pituitary (H-P) gonadal axis.

Aim: To determine the influence of the prostate gland on the hypothalamic-pituitary axis feedback system and changes in circulating hormone levels before and after cryoablation of the entire prostate.

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Among the major physiological functions of steroid hormones is regulation of carbohydrate, fat, and protein metabolism. Mitochondria, through oxidative phosphorylation, play a critical role in modulating a host of complex cellular metabolic pathways to produce chemical energy to meet the metabolic demand for cellular function. Thus, androgens may regulate cellular metabolism and energy production by increased mitochondrial numbers, activation of respiratory chain components, and increased transcription of mitochondrial-encoded respiratory chain genes that code for enzymes responsible for oxidative phosphorylation.

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Over the past 60 years, androgen deprivation therapy has been the mainstay of treatment of metastatic prostate cancer. However, research findings suggest that androgen deprivation therapy inflicts serious adverse effects on overall health and reduces the quality of life. Among the adverse effects known to date are insulin resistance, diabetes, metabolic syndrome fatigue, erectile dysfunction, and cardiovascular disease.

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Background: Chemicals that store in lipid-rich compartments have the potential for long-term disruption of metabolic and endocrine processes. Given the evidence that persistent organic pollutants (POPs) also alter systemic metabolic, endocrine, and immune system functions, it follows that elevated chemical concentrations in intra-abdominal fat may alter function, through local chemical signaling, of visceral organs. Despite this potential, there has been little study defining POP concentrations in live human intra-abdominal fat.

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The utility and performance of label-free, oligonucleotide probes for reagentless detection of dilute target analytes was examined using a voltammetric transduction principle in an array format. Multistep, solid-state fabrication yielded preproduction arrays of 16 individually addressable, 30 μm diameter microelectrodes in a 30 mm × 6.5 mm × 0.

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When an object approaches a vibrating quartz crystal microbalance (QCM) the resonant frequency changes. This "proximity effect" was seen at the distance of 10 mm in air and became more pronounced as the distance decreased. This effect depends on the quality factor (Q-factor) value of a QCM, conductivity of the object, and electrical connection of the object to QCM electrodes.

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A new technique for measurement of magnetic properties of materials is demonstrated. It can be used for the measurement of thin magnetic films during their chemical modification. The resonance frequency of a quartz crystal microbalance (QCM) with conducting polymer (polyaniline) suspension in poly(ethylene glycol) was observed to increase with increasing the externally applied uniform dc magnetic field.

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