Publications by authors named "Jonathan J Chen"

Radiotherapy is used in the treatment of prostate cancer in a variety of disease states with significant reliance on imaging to guide clinical decision-making and radiation delivery. In the definitive setting, the choice of radiotherapy treatment modality, dose, and fractionation for localized prostate cancer is determined by the patient's initial risk stratification and other clinical considerations. Radiation is also an option as salvage therapy in patients with locoregionally recurrent disease after prior definitive radiation or surgery.

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Introduction: Bladder preservation with concurrent chemoradiotherapy after maximum transurethral resection of bladder tumor is an alternative to radical cystectomy in select patients with muscle invasive bladder cancer (MIBC). Concurrent administration of radio-sensitizing chemotherapy and radiation therapy (RT) has been shown to have superior disease control compared with RT alone and can often be administered with modest added toxicity. We sought to describe national patterns of chemotherapy use.

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Localized renal cell carcinoma is primarily managed surgically, but this disease commonly presents in highly comorbid patients who are poor operative candidates. Less invasive techniques, such as cryoablation and radiofrequency ablation, are effective, but require percutaneous or laparoscopic access, while generally being limited to cT1a tumors without proximity to the renal pelvis or ureter. Active surveillance is another management option for small renal masses, but many patients desire treatment or are poor candidates for active surveillance.

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Hematopoietic stem cells (HSC) and downstream lineage-biased multipotent progenitors (MPP) tailor blood production and control myelopoiesis on demand. Recent lineage tracing analyses revealed MPPs to be major functional contributors to steady-state hematopoiesis. However, we still lack a precise resolution of myeloid differentiation trajectories and cellular heterogeneity in the MPP compartment.

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Introduction: The paradigm of focal therapy's role in metastatic patients is being challenged by evolving attitudes and emerging data. At the current time, specifically regarding prostate cancer, does the evidence indicate this is more hype or hope?

Areas Covered: We searched the literature via PubMed, MEDLINE, and Embase for studies from 2014 to the present addressing focal therapy with non-palliative intent in metastatic prostate cancer patients, emphasizing prospective trials when available. We sought to address all common clinical scenarios: de novo synchronous diagnosis, oligorecurrence, oligoprogression, and mCRPC disease.

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Purpose: We conducted a prospective pilot study to evaluate safety and feasibility of TraceIT, a resorbable radiopaque hydrogel, to improve image guidance for bladder cancer radiation therapy (RT).

Methods And Materials: Patients with muscle invasive bladder cancer receiving definitive RT were eligible. TraceIT was injected intravesically around the tumor bed during maximal transurethral resection of bladder tumor.

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Purpose: Our purpose was to compare dosimetric parameters and late gastrointestinal outcomes between patients treated with proton beam therapy (PBT) for localized prostate cancer with rectal balloon immobilization versus a hydrogel rectal spacer.

Methods And Materials: Patients with localized, clinical stage T1-4 prostate adenocarcinoma were treated at a single institution using conventionally fractionated, dose-escalated PBT from 2013 to 2018. Patient-reported gastrointestinal toxicity was prospectively collected, and the incidence of rectal bleeding was retrospectively reviewed from patient records.

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Secreted proteins play important roles in mediating various biological processes such as cell-cell communication, differentiation, migration, and homeostasis at the population or tissue level. Here, we review bioanalytical technologies and devices for detecting protein secretions from single cells. We begin by discussing conventional approaches followed by detailing the latest advances in microengineered systems for detecting single-cell protein secretions with an emphasis on multiplex measurement.

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Glycolysis with PK-M2 occurs typically in anaerobic conditions and atypically in aerobic conditions, which is known as the Warburg effect. The Warburg effect is found in many oncogenic situations and is believed to provide energy and biomass for oncogenesis to persist. The work presented targets human PK-M2 (hPK-M2) in a virtual high-throughput screen to identify new inhibitors and leads for further study.

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Protein modification can have far-reaching effects. NEDDylation, a protein modification process with the protein NEDD8, stabilizes and modifies how the targeted protein interacts with other proteins. Its role in system regulation makes it a prime therapeutic target, and virtual high-throughput screening has already identified new NEDD8 inhibitors.

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Blood Clotting Factor XI is an important actor in the clotting mechanism: it activates downstream zymogen involved in the clotting process. It can be targeted for activation or inhibition depending on treatment goals to enhance or inhibit clotting. In terms of antithrombosis treatment, Factor XI has emerged as a promising target to focus on.

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When excessively activated, C1 is insufficiently regulated, which results in tissue damage. Such tissue damage causes the complement system to become further activated to remove the resulting tissue damage, and a vicious cycle of activation/tissue damage occurs. Current Food and Drug Administration approved treatments include supplemental recombinant C1 inhibitor, but these are extremely costly and a more economical solution is desired.

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Tumor progression and resistance to treatment are often accompanied by the polarization of malignant cells towards a mesenchymal or poorly differentiated state. Such a transition generates an accrued vulnerability to the induction of ferroptosis, potentially paving the way to novel therapeutic strategies for targeting residual disease in patients with cancer.

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Following uncontrolled proliferation, a subset of primary tumour cells acquires additional traits/mutations to trigger phenotypic changes that enhance migration and are hypothesized to be the initiators of metastasis. This study reveals an adaptive mechanism that harnesses synergistic paracrine signalling via IL-6/8, which is amplified by cell proliferation and cell density, to directly promote cell migration. This effect occurs in metastatic human sarcoma and carcinoma cells- but not in normal or non-metastatic cancer cells-, and likely involves the downstream signalling of WASF3 and Arp2/3.

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Single-cell analysis of cytokine production is increasingly recognized as an important method to understand the inflammatory microenvironment and hematopoietic disease state. Certain cytokines are critical to the regulation of lineage specification, and the aberrant production of these cytokines can contribute to lineage reprogramming. Here, we describe of a platform combining subnanoliter microchambers and a high-density antibody barcode array for the study of single-cell cytokine secretions in hematopoietic cancer cell populations.

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Inorganic nanowires are among the most attractive functional materials, which have emerged in the past two decades. They have demonstrated applications in information technology and energy conversion, but their utility in biological or biomedical research remains relatively under-explored. Although nanowire-based sensors have been frequently reported for biomolecular detection, interfacing nanowire arrays and living mammalian cells for the direct analysis of cellular functions is a very recent endeavor.

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Objective: The purpose of this study was to investigate and compare the cause-specific survival (CSS) of stage I (tumor [T]1 node [N]0 metastasis [M]0) versus stage II (T2N0M0) glottic cancer in a large population cohort.

Study Design: We analyzed data from the Surveillance, Epidemiology, and End Results 18 database from 1973 to 2009, comprising patients diagnosed with T1N0M0 or T2N0M0 squamous cell glottic cancer. Kaplan-Meier survival analysis, multivariable Cox proportional hazards regression analysis, and competing-risks survival regression were used for statistical analysis.

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Unlabelled: The identification of JAK2/MPL mutations in patients with myeloproliferative neoplasms (MPN) has led to the clinical development of JAK kinase inhibitors, including ruxolitinib. Ruxolitinib reduces splenomegaly and systemic symptoms in myelofibrosis and improves overall survival; however, the mechanism by which JAK inhibitors achieve efficacy has not been delineated. Patients with MPN present with increased levels of circulating proinflammatory cytokines, which are mitigated by JAK inhibitor therapy.

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It is increasingly recognized that infiltrating immune cells contribute to the pathogenesis of a wide range of solid tumors. The paracrine signaling between the tumor and the immune cells alters the functional state of individual tumor cells and, correspondingly, the anticipated response to radiation or chemotherapies, which is of great importance to clinical oncology. Here we present a high-density microchip platform capable of measuring a panel of paracrine signals associated with heterotypic tumor-immune cell interactions in the single-cell, pair-wise manner.

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Secreted proteins including cytokines, chemokines, and growth factors represent important functional regulators mediating a range of cellular behavior and cell-cell paracrine/autocrine signaling, e.g., in the immunological system (Rothenberg, 2007), tumor microenvironment (Hanahan and Weinberg, 2011), or stem cell niche (Gnecchi etal.

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Secreted proteins dictate a range of cellular functions in human health and disease. Because of the high degree of cellular heterogeneity and, more importantly, polyfunctionality of individual cells, there is an unmet need to simultaneously measure an array of proteins from single cells and to rapidly assay a large number of single cells (more than 1000) in parallel. We describe a simple bioanalytical assay platform consisting of a large array of subnanoliter microchambers integrated with high-density antibody barcode microarrays for highly multiplexed protein detection from over a thousand single cells in parallel.

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Objectives: Incomplete hepatitis B virus (HBV) vaccine coverage and poor HBV-related knowledge in China leave millions of children unprotected from this life-threatening infection. To address these gaps, a pilot program for HBV education and vaccination was launched in rural China.

Methods: In 2006, public and private organizations in the US and China collaborated to provide HBV education and vaccination to 55,000 school-age children in the remote, highly HBV-endemic area of Qinghai Province.

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The objective of this study was to assess the correlation between blood lead levels (BLL) with both renal dysfunction and hyperuricemia among aboriginals and non-aboriginals in Taiwan. 1318 aboriginals and 1247 non-aboriginals over 40 years of age volunteered for this study. During routine health examinations at a clinic, blood samples were taken and a questionnaire was administered.

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Because fibromyalgia (FM) is often comorbid with anxiety, and monoamine oxidase A (MAOA) was reported to be associated with anxiety, we determine if there is MAOA gene polymorphism associated with FM patients. Moreover, interleukin 4 (IL-4) was found to be an important cytokine participating in the immunologic pathway of T-helper 2 (Th-2) cells, in this study, we search if the genetic polymorphism of IL-4 intron3 could be demonstrated in FM patients. The genotype of sixty-two FM patients was compared with that of control subjects.

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