Publications by authors named "P-J Chiu"

Pseudoachondroplasia (PSACH), a severe dwarfing condition characterized by impaired skeletal growth and early joint degeneration, results from mutations in cartilage oligomeric matrix protein (COMP). These mutations disrupt normal protein folding, leading to the accumulation of misfolded COMP in chondrocytes. The MT-COMP mouse is a murine model of PSACH that expresses D469del human COMP in response to doxycycline and replicates the PSACH chondrocyte and clinical pathology.

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  • One in ten COVID-19 infections lead to long COVID, characterized by prolonged symptoms, but the underlying mechanisms remain unclear.
  • In a study of 657 individuals, certain inflammatory markers were linked to long COVID symptoms, revealing connections to cardiorespiratory issues, fatigue, anxiety, gastrointestinal problems, cognitive impairments, and potential nerve tissue repair disturbances.
  • Findings suggest that targeting specific inflammatory pathways could offer new therapeutic options for treating different subtypes of long COVID in future clinical trials.*
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SLC15A4 is an endolysosome-resident transporter linked with autoinflammation and autoimmunity. Specifically, SLC15A4 is critical for Toll-like receptors (TLRs) 7-9 as well as nucleotide-binding oligomerization domain-containing protein (NOD) signaling in several immune cell subsets. Notably, SLC15A4 is essential for the development of systemic lupus erythematosus in murine models and is associated with autoimmune conditions in humans.

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Cell-free DNA (cfDNA) fragmentation is nonrandom, at least partially mediated by various DNA nucleases, forming characteristic cfDNA end motifs. However, there is a paucity of tools for deciphering the relative contributions of cfDNA cleavage patterns related to underlying fragmentation factors. In this study, through non-negative matrix factorization algorithm, we used 256 5' 4-mer end motifs to identify distinct types of cfDNA cleavage patterns, referred to as "founder" end-motif profiles (F-profiles).

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  • Neutrophil migration is essential for managing inflammation, with Mac-1 being a key integrin that facilitates their adhesion and movement through blood vessels.
  • PDI (protein disulfide isomerase) plays a significant role in regulating Mac-1's affinity for ICAM-1, impacting neutrophil migration under fluid shear conditions.
  • The research demonstrated that PDI localizes with high-affinity Mac-1 in neutrophils, and specific disulfide bond cleavage by PDI leads to conformational changes in Mac-1 that modulate its interaction with ICAM-1 during neutrophil crawling.
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Background: Although cold snare polypectomy (CSP) is considered effective in reducing delayed postpolypectomy bleeding risk, direct evidence supporting its safety in the general population remains lacking.

Objective: To clarify whether CSP would reduce delayed bleeding risk after polypectomy compared with hot snare polypectomy (HSP) in the general population.

Design: Multicenter randomized controlled study.

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Background: MRI-guidance techniques that dynamically adapt radiation beams to follow tumor motion in real time will lead to more accurate cancer treatments and reduced collateral healthy tissue damage. The gold-standard for reconstruction of undersampled MR data is compressed sensing (CS) which is computationally slow and limits the rate that images can be available for real-time adaptation.

Purpose: Once trained, neural networks can be used to accurately reconstruct raw MRI data with minimal latency.

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Cell-free DNA (cfDNA) fragmentation patterns contain important molecular information linked to tissues of origin. We explored the possibility of using fragmentation patterns to predict cytosine-phosphate-guanine (CpG) methylation of cfDNA, obviating the use of bisulfite treatment and associated risks of DNA degradation. This study investigated the cfDNA cleavage profile surrounding a CpG (i.

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Orthostatic hypotension affects roughly 10% of individuals with hypertension and is associated with several adverse health outcomes, including dementia, cardiovascular disease, stroke, and death. Among adults with hypertension, orthostatic hypotension has also been shown to predict patterns of blood pressure dysregulation that may not be appreciated in the office setting, including nocturnal nondipping. Individuals with uncontrolled hypertension are at particular risk of orthostatic hypotension and may meet diagnostic criteria for the condition with a smaller relative reduction in blood pressure compared with normotensive individuals.

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Urinary cell-free DNA (ucfDNA) is a potential biomarker for bladder cancer detection. However, the biological characteristics of ucfDNA are not well understood. We explored the roles of deoxyribonuclease 1 (DNASE1) and deoxyribonuclease 1-like 3 (DNASE1L3) in the fragmentation of ucfDNA using mouse models.

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The antibody response magnitude and kinetics may impact clinical severity, serological diagnosis and long-term protection of COVID-19, which may play a role in why children experience lower morbidity. We therefore tested samples from 122 children in Hong Kong with symptomatic (n = 78) and asymptomatic (n = 44) SARS-CoV-2 infections up to 200 days post infection, relative to 71 infected adults (symptomatic n = 61, and asymptomatic n = 10), and negative controls (n = 48). We assessed serum IgG antibodies to a 14-wide antigen panel of structural and accessory proteins by Luciferase Immuno-Precipitation System (LIPS) assay and circulating cytokines.

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Article Synopsis
  • * A new high-resolution analysis technique improved the determination of jagged end lengths by using methylation at non-CpG cytosine sites, overcoming limitations of previous methods.
  • * The research revealed that urinary DNA jagged ends showed a periodic pattern (10-nt) that was more prominent in patients with renal cell carcinoma and decreased with heparin treatment, indicating potential interaction with histones.
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In the field of circulating cell-free DNA, most of the studies have focused on short DNA molecules (e.g., <500 bp).

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Background: Mobile stroke units (MSUs) are ambulances with staff and a computed tomographic scanner that may enable faster treatment with tissue plasminogen activator (t-PA) than standard management by emergency medical services (EMS). Whether and how much MSUs alter outcomes has not been extensively studied.

Methods: In an observational, prospective, multicenter, alternating-week trial, we assessed outcomes from MSU or EMS management within 4.

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  • Checkpoint blockade therapies, particularly anti-PD-1 antibodies, show high effectiveness in Hodgkin lymphoma but low response rates in non-Hodgkin lymphomas like chronic lymphocytic leukemia (CLL).
  • Combining anti-PD-1 or PD-L1 therapies with avadomide, a cereblon E3 ligase modulator, enhances anti-CLL effects by stimulating immune responses and T-cell activation.
  • Clinical findings indicate that avadomide treatment leads to increased PD-L1 expression on T cells and better immune signaling in B-cell cancer patients, highlighting the need to boost T-cell inflammation for effective therapy.
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Plasma DNA fragmentomics is an emerging area in cell-free DNA diagnostics and research. In murine models, it has been shown that the extracellular DNase, DNASE1L3, plays a role in the fragmentation of plasma DNA. In humans, DNASE1L3 deficiency causes familial monogenic systemic lupus erythematosus with childhood onset and anti-dsDNA reactivity.

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We explored the presence of extrachromosomal circular DNA (eccDNA) in the plasma of pregnant women. Through sequencing following either restriction enzyme or Tn5 transposase treatment, we identified eccDNA molecules in the plasma of pregnant women. These eccDNA molecules showed bimodal size distributions peaking at ∼202 and ∼338 bp with distinct 10-bp periodicity observed throughout the size ranges within both peaks, suggestive of their nucleosomal origin.

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In many species, the offspring of related parents suffer reduced reproductive success, a phenomenon known as inbreeding depression. In humans, the importance of this effect has remained unclear, partly because reproduction between close relatives is both rare and frequently associated with confounding social factors. Here, using genomic inbreeding coefficients (F) for >1.

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Epstein-Barr virus (EBV) is associated with a number of diseases, including malignancies. Currently, it is not known whether patients with different EBV-associated diseases have different methylation profiles of circulating EBV DNA. Through whole-genome methylation analysis of plasma samples from patients with nasopharyngeal carcinoma (NPC), EBV-associated lymphoma and infectious mononucleosis, we demonstrate that EBV DNA methylation profiles exhibit a disease-associated pattern.

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Sesquizygotic multiple pregnancy is an exceptional intermediate between monozygotic and dizygotic twinning. We report a monochorionic twin pregnancy with fetal sex discordance. Genotyping of amniotic fluid from each sac showed that the twins were maternally identical but chimerically shared 78% of their paternal genome, which makes them genetically in between monozygotic and dizygotic; they are sesquizygotic.

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Circulating DNA in plasma consists of short DNA fragments. The biological processes generating such fragments are not well understood. DNASE1L3 is a secreted DNASE1-like nuclease capable of digesting DNA in chromatin, and its absence causes anti-DNA responses and autoimmunity in humans and mice.

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Background: Platelet-neutrophil interactions contribute to vascular occlusion and tissue damage in thromboinflammatory disease. Platelet glycoprotein Ibα (GPIbα), a key receptor for the cell-cell interaction, is believed to be constitutively active for ligand binding. Here, we established the role of platelet-derived protein disulfide isomerase (PDI) in reducing the allosteric disulfide bonds in GPIbα and enhancing the ligand-binding activity under thromboinflammatory conditions.

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Objective: Cell-free DNA (cfDNA) fragments in maternal plasma contain DNA damage and may negatively impact the sensitivity of noninvasive prenatal testing (NIPT). However, some of these DNA damages are potentially reparable. We aimed to recover these damaged cfDNA molecules using PreCR DNA repair mix.

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