18 research outputs found

    A Molecular Basis for Estrogen-Induced Cryptorchidism

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    AbstractMale sexual differentiation relies upon testicular secretion of the hormones testosterone, Mullerian inhibiting substance, and insulin-3 (Insl3). Insl3 is responsible for testicular descent through virilization and outgrowth of the embryonic gubernaculum. In mouse, prenatal exposure to 17β-estradiol and the nonsteroidal synthetic estrogen diethylstilbestrol (DES) disturbs the endocrine balance, causing demasculinizing and feminizing effects in the male embryo, including impaired testicular descent (cryptorchidism). In the current study, we show that maternal exposure to estrogens, including 17α- and β-estradiol, as well as DES, specifically down regulates Insl3 expression in embryonic Leydig cells, thereby providing a mechanism for cryptorchidism. These experiments may have implications for the widespread use of estrogenic substances in agriculture and the environment

    Visual Function Questionnaire as an outcome measure for homonymous hemianopia: subscales and supplementary questions, analysis from the VISION trial

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    Background: We conduct supplementary analyses of the NEI VFQ-25 data to evaluate where changes occurred within subscales of the NEI VFQ-25 leading to change in the composite scores between the three treatment arms, and evaluate the NEI VFQ-25 with and without the Neuro 10 supplement. Methods: A prospective, multicentre, parallel, single-blind, three-arm RCT of fourteen UK acute stroke units was conducted. Stroke survivors with homonymous hemianopia were recruited. Interventions included: Fresnel prisms for minimum 2 h, 5 days/week over 6-weeks (Arm a), Visual search training for minimum 30 min, 5 days/week over 6-weeks (Arm b) and standard care-information only (Arm c). Primary and secondary outcomes (including NEI VFQ-25 data) were measured at baseline, 6, 12 and 26 weeks after randomisation. Results: Eighty seven patients were recruited (69% male; mean age (SD) equal to 69 (12) years). At 26 weeks, outcomes for 24, 24 and 22 patients, respectively, were compared to baseline. NEI VFQ-25 (with and without Neuro 10) responses improved from baseline to 26 weeks with visual search training compared to Fresnel prisms and standard care. In subscale analysis, the most impacted across all treatment arms was ‘driving’ whilst the least impacted were ‘colour vision’ and ‘ocular pain’. Conclusions: Composite scores differed systematically for the NEI VFQ-25 (Neuro 10) versus NEI VFQ-25 at all time points. For subscale scores, descriptive statistics suggest clinically relevant improvement in distance activities and vision-specific dependency subscales for NEI VFQ-25 scores in the visual search treatment arm. Trial Registration: Current Controlled Trials ISRCTN05956042

    A Nuclear Surveillance Pathway for mRNAs with Defective Polyadenylation

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    The pap1-5 mutation in poly(A) polymerase causes rapid depletion of mRNAs at restrictive temperatures. Residual mRNAs are polyadenylated, indicating that Pap1-5p retains at least partial activity. In pap1-5 strains lacking Rrp6p, a nucleus-specific component of the exosome complex of 3′-5′ exonucleases, accumulation of poly(A)(+) mRNA was largely restored and growth was improved. The catalytically inactive mutant Rrp6-1p did not increase growth of the pap1-5 strain and conferred much less mRNA stabilization than rrp6Δ. This may indicate that the major function of Rrp6p is in RNA surveillance. Inactivation of core exosome components, Rrp41p and Mtr3p, or the nuclear RNA helicase Mtr4p gave different phenotypes, with accumulation of deadenylated and 3′-truncated mRNAs. We speculate that slowed mRNA polyadenylation in the pap1-5 strain is detected by a surveillance activity of Rrp6p, triggering rapid deadenylation and exosome-mediated degradation. In wild-type strains, assembly of the cleavage and polyadenylation complex might be suboptimal at cryptic polyadenylation sites, causing slowed polyadenylation

    Upgrading of biomass: alternative ways for biomass treatment

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    As the world population and wealth increases it is necessary to look for sustainable alternatives to guarantee modern living standards. With depleting resources and the threat of global warming, biomass is emerging as a promising alternative to lay the basis for a bio-based sustainable economy. New biomass upgrading trends lead to the concept of biorefinery, where a large array of chemicals, fuels and energy can be produced, maximizing the value of biomass. The aim of the present work is to find industrial biorefinery processes developed to produce chemicals and fuels but that at the same time yield considerable amounts of combustible by-products that can be employed as a fuel in Vattenfall´s power plants. This paper is focused on lignocellulosic biomass as a feedstock. A comprehensive review of existing technologies at different maturity levels to upgrade biomass is done. The review covers biomass pretreatment operations, thermochemical, chemical and biochemical processes. It starts by describing simple unitary operations that are used to build complex biorefinery systems. A selection of some of the possible biorefinery schemes is briefly described. After listing and describing different biomass upgrading processes, three process were selected for further analysis. Two biorefinery processes with different maturity levels were selected: the Biofine process and Lignocellulosic Ethanol. A process to produce a solid fuel, Hydrothermal Carbonization, was selected as well. The process selection was done according to Vattenfall´s interests. The three processes selected were further analyzed performing a mass and energy balance. To achieve these tasks, a model of the processes using Microsoft Excel was done. The estimation of the product yields and energy usage was done assuming woodchips as a feedstock. Sensitive operating conditions where the energy usage can be improved are identified. After the mass and energy balance an economical evaluation by means of OPEX and CAPEX calculations was done to determine the profitability of the processes. Opportunities for each process are identified and conditions to achieve or improve the profitability of the processes were pinpointed. The biorefinery concept is an emerging technology and as any new technology there are obstacles that need to be surpassed for being introduced into the market. A discussion on these issues was made as they will drive R&D efforts, industrial development and policies in the upcoming years. The importance of innovation in technology through R&D and market push policy measures was analyzed as it plays a fundamental role in the industrial dynamics of emerging technologies. Synergies and cooperation between the pulp and paper, forest, petrochemical and energy industries should be seek to tackle the challenges these technologies present and endorse a sustainable bio-based economy

    Humanized neurofibroma model from induced pluripotent stem cells delineates tumor pathogenesis and developmental origins

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    Neurofibromatosis type 1 (NF1) is a common tumor predisposition syndrome caused by NF1 gene mutation, in which affected patients develop Schwann cell lineage peripheral nerve sheath tumors (neurofibromas). To investigate human neurofibroma pathogenesis, we differentiated a series of isogenic, patient-specific NF1-mutant human induced pluripotent stem cells (hiPSCs) into Schwannian lineage cells (SLCs). We found that, although WT and heterozygous NF1-mutant hiPSCs-SLCs did not form tumors following mouse sciatic nerve implantation, NF1-null SLCs formed bona fide neurofibromas with high levels of SOX10 expression. To confirm that SOX10+ SLCs contained the cells of origin for neurofibromas, both Nf1 alleles were inactivated in mouse Sox10+ cells, leading to classic nodular cutaneous and plexiform neurofibroma formation that completely recapitulated their human counterparts. Moreover, we discovered that NF1 loss impaired Schwann cell differentiation by inducing a persistent stem-like state to expand the pool of progenitors required to initiate tumor formation, indicating that, in addition to regulating MAPK-mediated cell growth, NF1 loss also altered Schwann cell differentiation to promote neurofibroma development. Taken together, we established a complementary humanized neurofibroma explant and, to our knowledge, first-in-kind genetically engineered nodular cutaneous neurofibroma mouse models that delineate neurofibroma pathogenesis amenable to future therapeutic target discovery and evaluation

    Schwannoma development is mediated by Hippo pathway dysregulation and modified by RAS/MAPK signaling

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    Schwannomas are tumors of the Schwann cells that cause chronic pain, numbness, and potentially life-threatening impairment of vital organs. Despite the identification of causative genes, including NF2 (Merlin), INI1/SMARCB1, and LZTR1, the exact molecular mechanism of schwannoma development is still poorly understood. Several studies have identified Merlin as a key regulator of the Hippo, MAPK, and PI3K signaling pathways; however, definitive evidence demonstrating the importance of these pathways in schwannoma pathogenesis is absent. Here, we provide direct genetic evidence that dysregulation of the Hippo pathway in the Schwann cell lineage causes development of multiple schwannomas in mice. We found that canonical Hippo signaling through the effectors YAP/TAZ is required for schwannomagenesis and that MAPK signaling modifies schwannoma formation. Furthermore, cotargeting YAP/TAZ transcriptional activity and MAPK signaling demonstrated a synergistic therapeutic effect on schwannomas. Our new model provides a tractable platform to dissect the molecular mechanisms underpinning schwannoma formation and the role of combinatorial targeted therapy in schwannoma treatment
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