Publications by authors named "Helen Yu"

Background: Sarcopenia, a group of muscle-related disorders, leads to the gradual decline and weakening of skeletal muscle over time. Recognizing the pivotal role of gastrointestinal conditions in maintaining metabolic homeostasis within skeletal muscle, we hypothesize that the effectiveness of the myogenic programme is influenced by the levels of gastrointestinal hormones in the bloodstream, and this connection is associated with the onset of sarcopenia.

Methods: We first categorized 145 individuals from the Emergency Room of Taipei Veterans General Hospital into sarcopenia and non-sarcopenia groups, following the criteria established by the Asian Working Group for Sarcopenia.

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Objective: Maladaptive personality traits have been implicated in romantic relationship dissatisfaction, but the etiology of those links and the degree to which they extend to other types of relationships are unclear. The purpose of this study was to examine associations between maladaptive personality traits and satisfaction in various relationships using a co-twin control design to identify potential environmental contributions.

Method: The sample consisted of 1340 older adult twin participants from the Minnesota Twin Registry (M = 70.

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Biomechanical cues could effectively govern cell gene expression to direct the differentiation of specific stem cell lineage. Recently, the medium viscosity has emerged as a significant mechanical stimulator that regulates the cellular mechanical properties and various physiological functions. However, whether the medium viscosity can regulate the mechanical properties of human mesenchymal stem cells (hMSCs) to effectively trigger osteogenic differentiation remains uncertain.

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Sarcopenia, a prevalent muscle disease characterized by muscle mass and strength reduction, is associated with impaired skeletal muscle regeneration. However, the influence of the biomechanical properties of sarcopenic skeletal muscle on the efficiency of the myogenic program remains unclear. Herein, we established a mouse model of sarcopenia and observed a reduction in stiffness within the sarcopenic skeletal muscle in vivo.

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Protease inhibitors (PIs) remain an important component of antiretroviral therapy for the treatment of HIV-1 infection due to their high genetic barrier to resistance development. Nevertheless, the two most commonly prescribed HIV PIs, atazanavir and darunavir, still require co-administration with a pharmacokinetic boosting agent to maintain sufficient drug plasma levels which can lead to undesirable drug-drug interactions. Herein, we describe GS-9770, a novel investigational non-peptidomimetic HIV PI with unboosted once-daily oral dosing potential due to improvements in its metabolic stability and its pharmacokinetic properties in preclinical animal species.

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Article Synopsis
  • A challenge in drug design is optimizing ligands, which are small molecules that bind to target biomolecules, by adding chemical groups called fragments to enhance their properties.
  • The researchers developed a machine learning framework named FRAME that identifies where to add these fragments, chooses the fragments, and predicts their geometry.
  • On testing, FRAME outperformed existing methods by improving ligand affinity and selectivity while generating more drug-like properties, making it a valuable tool for medicinal chemists in drug discovery and design processes.
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Lenacapavir (LEN) is a picomolar first-in-class capsid inhibitor of human immunodeficiency virus type 1 (HIV-1) with a multistage mechanism of action and no known cross resistance to other existing antiretroviral (ARV) drug classes. LEN exhibits a low aqueous solubility and exceptionally low systemic clearance following intravenous (IV) administration in nonclinical species and humans. LEN formulated in an aqueous suspension or a PEG/water solution formulation showed sustained plasma exposure levels with no unintended rapid drug release following subcutaneous (SC) administration to rats and dogs.

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Background: Pancreatic trauma is an uncommon injury that occurs usually in a young population and is frequently overlooked and not readily appreciated on initial examination. Nowadays, the diagnosis and management of pancreatic trauma are still controversial, and there is no gold standard for the treatment. The aim of this study is to describe our experience in the management of blunt pancreatic trauma with a laparoscopic approach and review the literature on laparoscopic management of pancreatic trauma.

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Remdesivir (GS-5734; VEKLURY) is a single diastereomer monophosphoramidate prodrug of an adenosine analog (GS-441524). Remdesivir is taken up by target cells and metabolized in multiple steps to form the active nucleoside triphosphate (GS-443902), which acts as a potent inhibitor of viral RNA-dependent RNA polymerases. Remdesivir and GS-441524 have antiviral activity against multiple RNA viruses.

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Non-nucleoside reverse transcriptase inhibitors (NNRTIs) represent cornerstones of current regimens for treatment of human immunodeficiency virus type 1 (HIV-1) infections. However, NNRTIs usually suffer from low aqueous solubility and the emergence of resistant viral strains. In the present work, novel bicyclic NNRTIs derived from etravirine (ETV) and rilpivirine (RPV), bearing modified purine, tetrahydropteridine, and pyrimidodiazepine cores, were designed and prepared.

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Chronic hepatitis B (CHB) is a global health care challenge and a major cause of liver disease. To find new therapeutic avenues with a potential to functionally cure chronic Hepatitis B virus (HBV) infection, we performed a focused screen of epigenetic modifiers to identify potential inhibitors of replication or gene expression. From this work we identified isonicotinic acid inhibitors of the histone lysine demethylase 5 (KDM5) with potent anti-HBV activity.

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Within the heterogeneous tissue architecture, a comprehensive understanding of how cell shapes regulate cytoskeletal mechanics by adjusting focal adhesions (FAs) signals to correlate with the lineage commitment of mesenchymal stromal cells (MSCs) remains obscure. Here, via engineered extracellular matrices, we observed that the development of mature FAs, coupled with a symmetrical pattern of radial fiber bundles, appeared at the right-angle vertices in cells with square shape. While circular cells aligned the transverse fibers parallel to the cell edge, and moved them centripetally in a counter-clockwise direction, symmetrical bundles of radial fibers at the vertices of square cells disrupted the counter-clockwise swirling and bridged the transverse fibers to move centripetally.

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In response to the COVID-19 pandemic, significant public funds have been invested worldwide into the research, development, and manufacturing of pharmaceutical products to combat the novel coronavirus. Traditionally, intellectual property (IP) rights have been justified in the pharmaceutical sector because of the time and cost associated with drug discovery and development. However, if (a) the cost of research for COVID-19 related innovations have largely been subsidized by the public through public research grants; (b) the time for development has been significantly reduced through publicly funded initiatives; and (c) manufacturing has been de-risked through taxpayer funded advance purchase agreements, should IP rights be asserted on innovations that have largely already been paid for by the public?.

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Article Synopsis
  • Tirabrutinib is an irreversible, small-molecule BTK inhibitor approved in Japan for treating B-cell malignancies and is under investigation for inflammatory diseases.
  • A pharmacokinetic/pharmacodynamic (PK/PD) model was created to inform dose selection based on clinical data from two phase I studies, which effectively predicted drug behavior in the body.
  • The model suggested a minimum daily dose of 40 mg to achieve over 90% BTK occupancy, and a positive correlation was found between increased BTK occupancy duration and enhanced treatment efficacy for rheumatoid arthritis.
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Failure to share and make use of existing knowledge, particularly negative research outcomes, has been recognized as one of the key sources of waste and inefficiency in the drug discovery and development process. In the field of antibiotic research, providing a platform where negative outcomes could be shared to prevent the vicious cycle of duplicating costly studies that produce the same negative results would greatly de-risk and accelerate the development of new antibiotics. Providing a legally supported framework that recognizes negative outcomes as intellectual contributions, which can subsequently be translated into a revenue-sharing model, may lead to more openness and value creation in support of a sustainable and responsible transformation of research into socially and economically beneficial innovations.

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Oral antiretroviral agents provide life-saving treatments for millions of people living with HIV, and can prevent new infections via pre-exposure prophylaxis. However, some people living with HIV who are heavily treatment-experienced have limited or no treatment options, owing to multidrug resistance. In addition, suboptimal adherence to oral daily regimens can negatively affect the outcome of treatment-which contributes to virologic failure, resistance generation and viral transmission-as well as of pre-exposure prophylaxis, leading to new infections.

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Background: Research failures are one of the most significant costs associated with the estimated USD$2.6 billion price tag and 12-year time frame to bring a drug from discovery to market. The European Commission estimates that USD$20 billion are spent every year to develop innovations that have already developed elsewhere, highlighting the exorbitant cost of duplication.

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Toll-like receptor 8 (TLR8) recognizes pathogen-derived single-stranded RNA fragments to trigger innate and adaptive immune responses. Chronic hepatitis B (CHB) is associated with a dysfunctional immune response, and therefore a selective TLR8 agonist may be an effective treatment option. Structure-based optimization of a dual TLR7/8 agonist led to the identification of the selective TLR8 clinical candidate ()-2-((2-amino-7-fluoropyrido[3,2-]pyrimidin-4-yl)amino)-2-methylhexan-1-ol (GS-9688, ()-).

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Spleen tyrosine kinase (SYK) is a critical regulator of signaling in a variety of immune cell types such as B-cells, monocytes, and macrophages. Accordingly, there have been numerous efforts to identify compounds that selectively inhibit SYK as a means to treat autoimmune and inflammatory diseases. We previously disclosed GS-9973 (entospletinib) as a selective SYK inhibitor that is under clinical evaluation in hematological malignancies.

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Background: Cervical screening programs have had an important effect on the reduction of cervical cancer rates. Comprehensive programs require access to pathological review to improve the sensitivity of screening cytology and the specificity of diagnostic histology.

Aims: To determine the number of cases where cervical cytology or histology was amended at cytopathological review; whether amendments were 'upgrades' or 'downgrades', and how amendments aligned with follow-up results for these patients.

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USP16 (also known as UBP-M) has emerged as a histone H2AK119 deubiquitylase (DUB) implicated in the regulation of chromatin-associated processes and cell cycle progression. Despite this, available evidence suggests that this DUB is also present in the cytoplasm. How the nucleo-cytoplasmic transport of USP16, and hence its function, is regulated has remained elusive.

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People living with HIV (PLWH) have expressed concern about the life-long burden and stigma associated with taking pills daily and can experience medication fatigue that might lead to suboptimal treatment adherence and the emergence of drug-resistant viral variants, thereby limiting future treatment options. As such, there is strong interest in long-acting antiretroviral (ARV) agents that can be administered less frequently. Herein, we report GS-CA1, a new archetypal small-molecule HIV capsid inhibitor with exceptional potency against HIV-2 and all major HIV-1 types, including viral variants resistant to the ARVs currently in clinical use.

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Background: Circadian rhythms modulate growth and development in all organisms through interlocking transcriptional-translational feedback loops. The transcriptional loop involves chromatin modifications of central circadian oscillators in mammals and plants. However, the molecular basis for rhythmic epigenetic modifications and circadian regulation is poorly understood.

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Glioblastoma therapies have remained elusive due to limitations in understanding mechanisms of growth and survival of the tumorigenic population. Using CRISPR-Cas9 approaches in patient-derived GBM stem cells (GSCs) to interrogate function of the coding genome, we identify actionable pathways responsible for growth, which reveal the gene-essential circuitry of GBM stemness and proliferation. In particular, we characterize members of the SOX transcription factor family, SOCS3, USP8, and DOT1L, and protein ufmylation as important for GSC growth.

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