Publications by authors named "Samantha Chen"

Radiation therapy (RT), a mainstay treatment for head and neck squamous cell carcinoma (HNSCC), kills cancer cells and modulates the tumor immune microenvironment. We sought to assess the effect of RT in combination with PD-L1/TGF-β dual blockade in squamous cell carcinomas (SCC) and analyze the underlying mechanisms. We transplanted mouse SCC cells derived from keratin-15 (K15) stem cells harboring Kras/Smad4 mutations into syngeneic recipients and irradiated tumors followed by PD-L1/TGF-β dual blockade.

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Article Synopsis
  • * A mixed methods approach was employed, collecting both quantitative ratings and qualitative feedback from 47 student participants on the game features and their perceived utility for sleep health.
  • * While Hero's Sleep Journey was the most popular, Sleep Tamagotchi was seen as the most beneficial for improving sleep health; the analysis emphasized the importance of relevance in design, leading to recommendations for future sleep game development.
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The current research evaluates the Perfectionism Social Disconnection Model (PSDM) by considering the links between measures of trait perfectionism and perfectionistic self-presentation and measures of social support, loneliness, and distress in cross-sectional research. A particular focus is on perfectionism and levels of social support as assessed by the Social Provisions Scale. The current study also uniquely evaluates levels of perfectionism and perfectionistic self-presentation in undergraduate students, medical students, and law students.

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Background: Upon infection, mucosal tissues activate a brisk inflammatory response to clear the pathogen, i.e., resistance to disease.

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Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment; however, the responses to ICI treatment are highly variable in different individuals and the underlying mechanisms remain poorly understood. Here, we employed a mouse squamous cell carcinoma (SCC) model where tumor-bearing recipients diverged into responders (R) versus non-responders (NR) upon anti-PD-L1 treatment. We performed in-depth TCRβ sequencing with immunoSEQ platform to delineate the differences in CD8 tumor-infiltrating lymphocytes (TILs).

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Background: De-escalation of axillary surgery for lymph node (LN) positive breast cancer is facilitated by marking involved nodes which, when removed with sentinel nodes constitute risk-adapted targeted axillary dissection (TAD). Whether after chemotherapy or for primary surgery, selected patients with biopsy-proven involvement of nodes may be eligible for axillary conservation. Likewise, impalpable recurrence or stage 4 patients with localised axillary disease may benefit.

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Differential responses to immune checkpoint inhibitors (ICI) may be attributed to tumor-intrinsic factors or environmental cues; however, these mechanisms cannot fully explain the variable ICI responses in different individuals. Here, we investigate the potential contribution of immunological heterogeneity with a focus on differences in T-cell receptor (TCR) repertoire to ICI responses, which has not been defined previously. To reveal additional factors underlying heterogeneous responses to ICI, we employed a squamous cell carcinoma (SCC) mouse model in which tumor-bearing recipients unambiguously diverged into responders (R) or non-responders (NR) upon anti-PD-L1 treatment.

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Schistosomiasis is prevalent in some developing countries; however, it does not commonly affect the breast. Mammary schistosomiasis may present as suspicious microcalcification or a mass on mammography. Image-guided biopsy is necessary to exclude malignancy and identify calcified Schistosoma ova on histology.

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Background: While immune checkpoint inhibitors (ICI) were approved for head and neck squamous cell carcinomas (HNSCCs), the response rate remains relatively low. Mechanisms underlying ICI unresponsiveness versus sensitivity are not fully understood.

Method: To better delineate differential responses to ICI treatment, we employed mouse SCC models, termed KPPA tumors that were caused by deleting p53 and hyperactivating PIK3CA, two most frequently mutated genes in human HNSCCs.

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Vaccine-induced protective T cell immunity is necessary for HIV-1 functional cure. We previously reported that rhesus PD1-Gag-based DNA vaccination sustained simian-human immunodeficiency virus (SHIV) suppression by inducing effector-memory CD8 T cells. Here, we investigated a human PD1-Gag-based DNA vaccine, namely, ICVAX, for clinical translation.

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HIV-1 functional cure requires sustained viral suppression without antiretroviral therapy. While effector-memory CD8+ T lymphocytes are essential for viremia control, few vaccines elicit such cellular immunity that could be potently recalled upon viral infection. Here, we investigated a program death-1 (PD1)-based vaccine by fusion of simian immunodeficiency virus capsid antigen to soluble PD1.

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Background: Antitumor immunity is highly heterogeneous between individuals; however, underlying mechanisms remain elusive, despite their potential to improve personalized cancer immunotherapy. Head and neck squamous cell carcinomas (HNSCCs) vary significantly in immune infiltration and therapeutic responses between patients, demanding a mouse model with appropriate heterogeneity to investigate mechanistic differences.

Methods: We developed a unique HNSCC mouse model to investigate underlying mechanisms of heterogeneous antitumor immunity.

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Osmolytes are organic solutes that change the protein folding landscape shifting the equilibrium towards the folded state. Herein, we use osmolytes to probe the structuring and aggregation of the intrinsically disordered mutant Huntingtin (mHtt) vis-a-vis the pathogenicity of mHtt on transcription factor function and cell survival. Using an inducible PC12 cell model of Huntington's disease (HD), we show that stabilizing polyol osmolytes drive the aggregation of Htt103Q-EGFP from a diffuse ensemble into inclusion bodies (IBs), whereas the destabilizing osmolyte urea does not.

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Squamous cell carcinoma (SCC) is the second commonest type of skin cancer, and SCCs make up about 90% of head and neck cancers (HNSCCs). HNSCCs harbor two frequent molecular alterations, namely, gain-of-function alterations of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha ( and loss-of-function mutations of tumor protein p53 (). However, it remains poorly understood whether HNSCCs harboring different genetic alterations exhibit differential immune tumor microenvironments (TME).

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Sustained, drug-free control of HIV-1 replication is naturally achieved in less than 0.5% of infected individuals (here termed 'elite controllers'), despite the presence of a replication-competent viral reservoir. Inducing such an ability to spontaneously maintain undetectable plasma viraemia is a major objective of HIV-1 cure research, but the characteristics of proviral reservoirs in elite controllers remain to be determined.

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The BCR recognizes foreign Ags to initiate humoral immunity that needs isotype-switched Abs generated via class switch recombination (CSR); however, stimulating the BCR in the absence of costimulation (e.g., CD40) does not induce CSR; thus, it remains elusive whether and how the BCR induces CSR mechanistically.

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Aims: In the Northern Territory (NT) of Australia, Indigenous women have a lower incidence of breast cancer, but a higher mortality than Non-indigenous women. The aim of this study was to describe and compare breast cancer pathological features related to stage and biological aggression between the two groups.

Methods: Subjects were identified by extract from the NT Cancer Registry in two separate cohorts, cohort 1 (1991-2000) and cohort 2 (2001-2010).

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The suprachiasmatic nucleus (SCN) drives circadian rhythms in locomotion through coupled, single-cell oscillations. Global genetic deletion of the neuropeptide or its receptor results in profound deficits in daily synchrony among SCN cells and daily rhythms in locomotor behavior and glucocorticoid secretion. To test whether this phenotype depends on vasoactive intestinal polypeptide (VIP) neurons in the SCN, we ablated VIP SCN neurons in vivo in adult male mice through Caspase3-mediated induction of the apoptotic pathway in cre-expressing VIP neurons.

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AIDS Clinical Trials Group study A5308 found reduced T-cell activation and exhaustion in human immunodeficiency virus (HIV) controllers start antiretroviral therapy (ART). We further assessed HIV-specific T-cell responses and post-ART viral loads. Before ART, the 31% of participants with persistently undetectable viremia had more robust HIV-specific T-cell responses.

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Cancer cells can evade immune recognition by losing major histocompatibility complex (MHC) class I. Hence, MHC class I-negative cancers represent the most challenging cancers to treat. Chemotherapeutic drugs not only directly kill tumors but also modulate the tumor immune microenvironment.

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Immunotherapy has been applied successfully to treat B-cell lymphomas in preclinical models or clinical settings. However, immunotherapy resistance is a major challenge for B-cell lymphoma treatment. To overcome this issue, combinatorial therapeutic strategies have been pursued to achieve a better efficacy for treating B-cell lymphomas.

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Head and neck cancers are a heterogeneous group of tumors that are highly aggressive and collectively represent the sixth most common cancer worldwide. Ninety percent of head and neck cancers are squamous cell carcinomas (HNSCCs). The tumor microenvironment (TME) of HNSCCs consists of many different subsets of cells that infiltrate the tumors and interact with the tumor cells or with each other through various networks.

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Chromosomal integration of genome-intact HIV-1 sequences into the host genome creates a reservoir of virally infected cells that persists throughout life, necessitating indefinite antiretroviral suppression therapy. During effective antiviral treatment, the majority of these proviruses remain transcriptionally silent, but mechanisms responsible for viral latency are insufficiently clear. Here, we used matched integration site and proviral sequencing (MIP-Seq), an experimental approach involving multiple displacement amplification of individual proviral species, followed by near-full-length HIV-1 next-generation sequencing and corresponding chromosomal integration site analysis to selectively map the chromosomal positions of intact and defective proviruses in 3 HIV-1-infected individuals undergoing long-term antiretroviral therapy.

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The mammalian suprachiasmatic nucleus (SCN) functions as a master circadian pacemaker, integrating environmental input to align physiological and behavioral rhythms to local time cues. Approximately 10% of SCN neurons express vasoactive intestinal polypeptide (VIP); however, it is unknown how firing activity of VIP neurons releases VIP to entrain circadian rhythms. To identify physiologically relevant firing patterns, we optically tagged VIP neurons and characterized spontaneous firing over 3 days.

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