974 research outputs found

    Application of quality by design tools to upstream processing of platelet precursor cells to enable in vitro manufacture of blood products

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    Annually 4.5 million platelet units are transfused in Europe and the United States. These are obtained solely from allogeneic donations and have a shelf life of 5-7 days. To address the corresponding supply challenge, Moreau et al.1 devised a novel process for producing megakaryocytes (MKs, the platelet precursor cell) in vitro. A transcription-factor driven, forward-programming (FOP) approach converts human pluripotent stem cells into MKs. This strategy has the unique advantage of generating high yields of pure MKs in chemically defined medium which could lead to the production of a consistent, reliable supply of platelets which overcomes the logistical, financial and biosafety challenges for health organisations worldwide. Here we follow a Quality by Design (QbD) approach to enable improvements to the upstream processing of FOPMKs. Firstly, we created a process flow diagram for production of in vitro platelets for transfusion, which segregated processes into individual unit operations for control and optimisation. Next, we developed a Quality Target Product Profile (QTPP) and identified Critical Quality Attributes (CQAs) for each stage. We conducted a range of experiments utilising Design of Experiments (DOE) and mechanistic modelling2 tools to link Critical Process Parameters (CPPs) to CQAs. For adherent culture, we identified a productivity limit related to surface area available for growth and a cell loss phase which was dependent on cell seeding density, RhoK inhibitor usage and seed density. Using suspension cultures of FOPMK. We noted that TPO and Doxycycline concentration were CPPs as these impacted cell net growth rate and phenotype trajectory. Furthermore, we noted that medium exhaustion led to a 30% loss of viable cells over 8 hours. Proof of concept studies also showed that FOPMKs can be cultured in scaled-down suspension systems (ambr-15 and spinner flask culture) whilst retaining CQAs. 1. Moreau, T. et al. Large-scale production of megakaryocytes from human pluripotent stem cells by chemically defined forward programming. Nat. Commun. 7, 1–15 (2016). 2. Stacey, A. J., Cheeseman, E. A., Glen, K. E., Moore, R. L. L. & Thomas, R. J. Experimentally integrated dynamic modelling for intuitive optimisation of cell-based processes and manufacture. Biochem. Eng. J. 132, 130–138 (2018)

    Müllerian Adenosarcoma of the Urinary Bladder: Clinicopathologic and Immunohistochemical Features with Novel Genetic Aberrations

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    Müllerian adenosarcoma is a biphasic neoplasm most commonly of the uterus and less frequently of the ovary. It has been rarely described to occur in other sites such as peritoneum and liver. In this study, we report the clinicopathologic, immunohistochemical and molecular features of a primary müllerian adenosarcoma of the urinary bladder in a 62-year-old woman. To our knowledge, this is the first report of müllerian adenosarcoma primary to the urinary bladder in the literature. Light microscopy showed a biphasic epithelial and stromal tumor with benign-appearing glands surrounded by endometrial-type stroma that is densely cellular with increased mitotic figures. The stroma surrounding the glands is more cellular than the intervening areas, which are more loose and edematous. Immunohistochemistry profile included positive staining for Pax2/8 within the glands, for CD10 and WT-1 within the spindled stroma, and for estrogen and progesterone receptors in both. Staining for desmin, GATA3, p63, and human papilloma virus (HPV) is negative. Molecular analyses identified mutations in AKT1 E17K, FLT3 D835N, KRAS G12D and HRAS G12S. These novel molecular aberrations have yet to be reported in the medical literature. X chromosome inactivation analysis revealed a clonal pattern in the stromal component and a non-clonal pattern in the epithelial component. Currently, the patient is disease/recurrence-free after regular follow-up of approximately 84 months. This case represents the first reported diagnosis of müllerian adenosarcoma arising in the urinary bladder with extensive clinicopathologic, immunohistochemical, and molecular analyses

    The Epigenetic Regulatory Protein CBX2 Promotes mTORC1 Signalling and Inhibits DREAM Complex Activity to Drive Breast Cancer Cell Growth

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    Chromobox 2 (CBX2) is a chromatin-binding component of polycomb repressive complex 1, which causes gene silencing. CBX2 expression is elevated in triple-negative breast cancer (TNBC), for which there are few therapeutic options. Here, we aimed to investigate the functional role of CBX2 in TNBC. CBX2 knockdown in TNBC models reduced cell numbers, which was rescued by ectopic expression of wild-type CBX2 but not a chromatin binding-deficient mutant. Blocking CBX2 chromatin interactions using the inhibitor SW2_152F also reduced cell growth, suggesting CBX2 chromatin binding is crucial for TNBC progression. RNA sequencing and gene set enrichment analysis of CBX2-depleted cells identified downregulation of oncogenic signalling pathways, including mTORC1 and E2F signalling. Subsequent analysis identified that CBX2 represses the expression of mTORC1 inhibitors and the tumour suppressor RBL2. RBL2 repression, in turn, inhibits DREAM complex activity. The DREAM complex inhibits E2F signalling, causing cell senescence; therefore, inhibition of the DREAM complex via CBX2 may be a key oncogenic driver. We observed similar effects in oestrogen receptor-positive breast cancer, and analysis of patient datasets suggested CBX2 inhibits RBL2 activity in other cancer types. Therapeutic inhibition of CBX2 could therefore repress mTORC1 activation and promote DREAM complex-mediated senescence in TNBC and could have similar effects in other cancer types

    CAST constraints on the axion-electron coupling

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    In non-hadronic axion models, which have a tree-level axion-electron interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton scattering, and axiorecombination, the "BCA processes." Based on a new calculation of this flux, including for the first time axio-recombination, we derive limits on the axion-electron Yukawa coupling gae and axion-photon interaction strength ga using the CAST phase-I data (vacuum phase). For ma <~ 10 meV/c2 we find ga gae < 8.1 × 10−23 GeV−1 at 95% CL. We stress that a next-generation axion helioscope such as the proposed IAXO could push this sensitivity into a range beyond stellar energy-loss limits and test the hypothesis that white-dwarf cooling is dominated by axion emission

    Large-amplitude driving of a superconducting artificial atom: Interferometry, cooling, and amplitude spectroscopy

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    Superconducting persistent-current qubits are quantum-coherent artificial atoms with multiple, tunable energy levels. In the presence of large-amplitude harmonic excitation, the qubit state can be driven through one or more of the constituent energy-level avoided crossings. The resulting Landau-Zener-Stueckelberg (LZS) transitions mediate a rich array of quantum-coherent phenomena. We review here three experimental works based on LZS transitions: Mach-Zehnder-type interferometry between repeated LZS transitions, microwave-induced cooling, and amplitude spectroscopy. These experiments exhibit a remarkable agreement with theory, and are extensible to other solid-state and atomic qubit modalities. We anticipate they will find application to qubit state-preparation and control methods for quantum information science and technology.Comment: 13 pages, 5 figure

    Regulating and Deregulating the Public Utilities 1830-2010

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    History can provide invaluable insights into important issues of the economic and social regulation of utilities, and offer lessons towards future debates. But the history of utility regulation – which speaks of changing, diverse and complex experiences around the world – was, unfortunately, sidelined or marginalised when economists and policymakers enthusiastically embraced the question of how to reform the utilities from the 1970s. This paper provides an overview of the three, overarching, `waves' of utility regulation from the nineteenth century to the present, documenting how, when and why the ways in which the roles of the state, the market and firms altered over time. It then contextualises and explains the main contributions of each of the papers included in this special issue of Business History, which cover energy, communications, water, transportation and other urban infrastructure regulation, across Western Europe, the United States and Australia

    Subcellular tracking reveals the location of dimethylsulfoniopropionate in microalgae and visualises its uptake by marine bacteria

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    Phytoplankton-bacteria interactions drive the surface ocean sulfur cycle and local climatic processes through the production and exchange of a key compound: dimethylsulfoniopropionate (DMSP). Despite their large-scale implications, these interactions remain unquantified at the cellular-scale. Here we use secondary-ion mass spectrometry to provide the first visualization of DMSP at sub-cellular levels, tracking the fate of a stable sulfur isotope (34S) from its incorporation by microalgae as inorganic sulfate to its biosynthesis and exudation as DMSP, and finally its uptake and degradation by bacteria. Our results identify for the first time the storage locations of DMSP in microalgae, with high enrichments present in vacuoles, cytoplasm and chloroplasts. In addition, we quantify DMSP incorporation at the single-cell level, with DMSP-degrading bacteria containing seven times more 34S than the control strain. This study provides an unprecedented methodology to label, retain, and image small diffusible molecules, which can be transposable to other symbiotic systems.This work was supported by ANNiMS (Australian Government, Department of Education, Employment and Workplace Relations), the AMMRF Centre for Microscopy, Characterisation and Analysis (UWA) and by Australian Research Council Grant DE160100636
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