92 research outputs found
Fuel Element Structural Design and Manufacture for the Consolidated Edison Thorium Reactor Plant
The design of the fuel-element structure for the CETR is described. Component parts of the assembly comprise the fuel-bundle assembly, the fuel-can assembly, the upper transition, the fuel-element spring, and the upper nozzle and seal assembly. (J.R.D.
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HRP2 Determines the Efficiency and Specificity of HIV-1 Integration in LEDGF/p75 Knockout Cells but Does Not Contribute to the Antiviral Activity of a Potent LEDGF/p75-Binding Site Integrase Inhibitor
The binding of integrase (IN) to lens epithelium-derived growth factor (LEDGF)/p75 in large part determines the efficiency and specificity of HIV-1 integration. However, a significant residual preference for integration into active genes persists in Psip1 (the gene that encodes for LEDGF/p75) knockout (KO) cells. One other cellular protein, HRP2, harbors both the PWWP and IN-binding domains that are important for LEDGF/p75 co-factor function. To assess the role of HRP2 in HIV-1 integration, cells generated from Hdgfrp2 (the gene that encodes for HRP2) and Psip1/Hdgfrp2 KO mice were infected alongside matched control cells. HRP2 depleted cells supported normal infection, while disruption of Hdgfrp2 in Psip1 KO cells yielded additional defects in the efficiency and specificity of integration. These deficits were largely restored by ectopic expression of either LEDGF/p75 or HRP2. The double-KO cells nevertheless supported residual integration into genes, indicating that IN and/or other host factors contribute to integration specificity in the absence of LEDGF/p75 and HRP2. Psip1 KO significantly increased the potency of an allosteric inhibitor that binds the LEDGF/p75 binding site on IN, a result that was not significantly altered by Hdgfrp2 disruption. These findings help to rule out the host factor-IN interactions as the primary antiviral targets of LEDGF/p75-binding site IN inhibitors
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Reprogramming human T cell function and specificity with non-viral genome targeting.
Decades of work have aimed to genetically reprogram T cells for therapeutic purposes1,2 using recombinant viral vectors, which do not target transgenes to specific genomic sites3,4. The need for viral vectors has slowed down research and clinical use as their manufacturing and testing is lengthy and expensive. Genome editing brought the promise of specific and efficient insertion of large transgenes into target cells using homology-directed repair5,6. Here we developed a CRISPR-Cas9 genome-targeting system that does not require viral vectors, allowing rapid and efficient insertion of large DNA sequences (greater than one kilobase) at specific sites in the genomes of primary human T cells, while preserving cell viability and function. This permits individual or multiplexed modification of endogenous genes. First, we applied this strategy to correct a pathogenic IL2RA mutation in cells from patients with monogenic autoimmune disease, and demonstrate improved signalling function. Second, we replaced the endogenous T cell receptor (TCR) locus with a new TCR that redirected T cells to a cancer antigen. The resulting TCR-engineered T cells specifically recognized tumour antigens and mounted productive anti-tumour cell responses in vitro and in vivo. Together, these studies provide preclinical evidence that non-viral genome targeting can enable rapid and flexible experimental manipulation and therapeutic engineering of primary human immune cells
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The Society for Immunotherapy of Cancer consensus statement on immunotherapy for the treatment of non-small cell lung cancer (NSCLC)
Lung cancer is the leading cause of cancer-related mortality worldwide, with non-small cell lung cancer (NSCLC) accounting for over 85% of all cases. Until recently, chemotherapy – characterized by some benefit but only rare durable responses – was the only treatment option for patients with NSCLC whose tumors lacked targetable mutations. By contrast, immune checkpoint inhibitors have demonstrated distinctly durable responses and represent the advent of a new treatment approach for patients with NSCLC. Three immune checkpoint inhibitors, pembrolizumab, nivolumab and atezolizumab, are now approved for use in first- and/or second-line settings for selected patients with advanced NSCLC, with promising benefit also seen in patients with stage III NSCLC. Additionally, durvalumab following chemoradiation has been approved for use in patients with locally advanced disease. Due to the distinct features of cancer immunotherapy, and rapid progress in the field, clinical guidance is needed on the use of these agents, including appropriate patient selection, sequencing of therapies, response monitoring, adverse event management, and biomarker testing. The Society for Immunotherapy of Cancer (SITC) convened an expert Task Force charged with developing consensus recommendations on these key issues. Following a systematic process as outlined by the National Academy of Medicine, a literature search and panel voting were used to rate the strength of evidence for each recommendation. This consensus statement provides evidence-based recommendations to help clinicians integrate immune checkpoint inhibitors into the treatment plan for patients with NSCLC. This guidance will be updated following relevant advances in the field
Proof of concept, randomized, placebo-controlled study of the effect of simvastatin on the course of age-related macular degeneration
BACKGROUND: HMG Co-A reductase inhibitors are ubiquitous in our community yet their potential role in age-related macular degeneration (AMD) remains to be determined. METHODOLOGY/PRINCIPAL FINDINGS: OBJECTIVES: To evaluate the effect of simvastatin on AMD progression and the effect modification by polymorphism in apolipoprotein E (ApoE) and complement factor H (CFH) genes. DESIGN: A proof of concept double-masked randomized controlled study. PARTICIPANTS: 114 participants aged 53 to 91 years, with either bilateral intermediate AMD or unilateral non-advanced AMD (with advanced AMD in fellow eye), BCVA ≥ 20/60 in at least one eye, and a normal lipid profile. INTERVENTION: Simvastatin 40 mg/day or placebo, allocated 1:1. MAIN OUTCOME MEASURES: Progression of AMD either to advanced AMD or in severity of non-advanced AMD. Results. The cumulative AMD progression rates were 70% in the placebo and 54% in the simvastatin group. Intent to treat multivariable logistic regression analysis, adjusted for age, sex, smoking and baseline AMD severity, showed a significant 2-fold decrease in the risk of progression in the simvastatin group: OR 0.43 (0.18-0.99), p = 0.047. Post-hoc analysis stratified by baseline AMD severity showed no benefit from treatment in those who had advanced AMD in the fellow eye before enrolment: OR 0.97 (0.27-3.52), p = 0.96, after adjusting for age, sex and smoking. However, there was a significant reduction in the risk of progression in the bilateral intermediate AMD group compared to placebo [adjusted OR 0.23 (0.07-0.75), p = 0.015]. The most prominent effect was observed amongst those who had the CC (Y402H) at risk genotype of the CFH gene [OR 0.08 (0.02-0.45), p = 0.004]. No evidence of harm from simvastatin intervention was detected. CONCLUSION/SIGNIFICANCE: Simvastatin may slow progression of non-advanced AMD, especially for those with the at risk CFH genotype CC (Y402H). Further exploration of the potential use of statins for AMD, with emphasis on genetic subgroups, is warranted. TRIAL REGISTRATION: Australian New Zealand Clinical Trial Registry (ANZCTR) ACTRN1260500032065
Red wine and components flavonoids inhibit UGT2B17 in vitro
Background
The metabolism and excretion of the anabolic steroid testosterone occurs by glucuronidation to the conjugate testosterone glucuronide which is then excreted in urine. Alterations in UGT glucuronidation enzyme activity could alter the rate of testosterone excretion and thus its bioavailability. The aim of this study is to investigate if red wine, a common dietary substance, has an inhibitory effect on UGT2B17.
Methods
Testosterone glucuronidation was assayed using human UGT2B17 supersomes with quantification of unglucuronidated testosterone over time using HPLC with DAD detection. The selected red wine was analysed using HPLC and the inhibitory effects of the wine and phenolic components were tested independently in a screening assay. Further analyses were conducted for the strongest inhibitors at physiologically relevant concentrations. Control experiments were conducted to determine the effects of the ethanol on UGT2B17.
Results
Over the concentration range of 2 to 8% the red wine sample inhibited the glucuronidation of testosterone by up to 70% over 2 hours. The ethanol content had no significant effect. Three red wine phenolics, identified by HLPC analyses, also inhibited the enzyme by varying amounts in the order of quercetin (72%), caffeic acid (22%) and gallic acid (9%); using a ratio of phenolic:testosterone of 1:2.5. In contrast p-coumaric acid and chlorogenic acid had no effect on the UGT2B17. The most active phenolic was selected for a detailed study at physiologically relevant concentrations, and quercetin maintained inhibitory activity of 20% at 2 M despite a ten-fold excess of testosterone.
Conclusion
This study reports that in an in vitro supersome-based assay, the key steroid-metabolising enzyme UGT2B17 is inhibited by a number of phenolic dietary substances and therefore may reduce the rate of testosterone glucuronidation in vivo. These results highlight the potential interactions of a number of common dietary compounds on testosterone metabolism. Considering the variety of foodstuffs that contain flavonoids, it is feasible that diet can elevate levels of circulating testosterone through reduction in urinary excretion. These results warrant further investigation and extension to a human trial to delineate the healt
Analysis of expression profiles of MAGE-A antigens in oral squamous cell carcinoma cell lines
<p>Abstract</p> <p>Background</p> <p>The immunological response to solid tumours is insufficient. Therefore, tumour specific antigens have been explored to facilitate the activation of the immune system. The cancer/testis antigen class of MAGE-A antigens is a possible target for vaccination. Their differential expression profiles also modulate the course of the cancer disease and its response to antineoplastic drugs.</p> <p>Methods</p> <p>The expression profiles of MAGE-A2, -A3, -A4, -A6 and -A10 in five own oral squamous cell carcinoma cell lines were characterised by rt-PCR, qrt-PCR and immunocytochemistry with a global MAGE-A antibody (57B) and compared with those of an adult keratinocyte cell line (NHEK).</p> <p>Results</p> <p>All tumour cell lines expressed MAGE-A antigens. The antigens were expressed in groups with different preferences. The predominant antigens expressed were MAGE-A2, -A3 and -A6. MAGE-A10 was not expressed in the cell lines tested. The MAGE-A gene products detected in the adult keratinocyte cell line NHEK were used as a reference.</p> <p>Conclusion</p> <p>MAGE-A antigens are expressed in oral squamous cell carcinomas. The expression profiles measured facilitate distinct examinations in forthcoming studies on responses to antineoplastic drugs or radiation therapy. MAGE-A antigens are still an interesting aim for immunotherapy.</p
The \u3cem\u3eChlamydomonas\u3c/em\u3e Genome Reveals the Evolution of Key Animal and Plant Functions
Chlamydomonas reinhardtii is a unicellular green alga whose lineage diverged from land plants over 1 billion years ago. It is a model system for studying chloroplast-based photosynthesis, as well as the structure, assembly, and function of eukaryotic flagella (cilia), which were inherited from the common ancestor of plants and animals, but lost in land plants. We sequenced the ∼120-megabase nuclear genome of Chlamydomonas and performed comparative phylogenomic analyses, identifying genes encoding uncharacterized proteins that are likely associated with the function and biogenesis of chloroplasts or eukaryotic flagella. Analyses of the Chlamydomonas genome advance our understanding of the ancestral eukaryotic cell, reveal previously unknown genes associated with photosynthetic and flagellar functions, and establish links between ciliopathy and the composition and function of flagella
The case for the continued use of the genus name Mimulus for all monkeyflowers
The genus Mimulus is a well-studied group of plant species, which has for decades allowed researchers to address a wide array of fundamental questions in biology (Wu & al. 2008; Twyford & al. 2015). Linnaeus named the type species of Mimulus (ringens L.), while Darwin (1876) used Mimulus (luteus L.) to answer key research questions. The incredible phenotypic diversity of this group has made it the focus of ecological and evolutionary study since the mid-20th century, initiated by the influential work of Clausen, Keck, and Hiesey as well as their students and collaborators (Clausen & Hiesey 1958; Hiesey & al. 1971, Vickery 1952, 1978). Research has continued on this group of diverse taxa throughout the 20th and into the 21st century (Bradshaw & al. 1995; Schemske & Bradshaw 1999; Wu & al. 2008; Twyford & al. 2015; Yuan 2019), and Mimulus guttatus was one of the first non-model plants to be selected for full genome sequencing (Hellsten & al. 2013). Mimulus has played a key role in advancing our general understanding of the evolution of pollinator shifts (Bradshaw & Schemske 2003; Cooley & al. 2011; Byers & al. 2014), adaptation (Lowry & Willis 2010; Kooyers & al. 2015; Peterson & al. 2016; Ferris & Willis 2018; Troth & al. 2018), speciation (Ramsey & al. 2003; Wright & al. 2013; Sobel & Streisfeld 2015; Zuellig & Sweigart 2018), meiotic drive (Fishman & Saunders 2008), polyploidy (Vallejo-Marín 2012; Vallejo-Marín & al. 2015), range limits (Angert 2009; Sexton et al. 2011; Grossenbacher & al. 2014; Sheth & Angert 2014), circadian rhythms (Greenham & al. 2017), genetic recombination (Hellsten & al. 2013), mating systems (Fenster & Ritland 1994; Dudash & Carr 1998; Brandvain & al. 2014) and developmental biology (Moody & al. 1999; Baker & al. 2011, 2012; Yuan 2019). This combination of a rich history of study coupled with sustained modern research activity is unparalleled among angiosperms. Across many interested parties, the name Mimulus therefore takes on tremendous biological significance and is recognizable not only by botanists, but also by zoologists, horticulturalists, naturalists, and members of the biomedical community. Names associated with a taxonomic group of this prominence should have substantial inertia, and disruptive name changes should be avoided. As members of the Mimulus community, we advocate retaining the genus name Mimulus to describe all monkeyflowers. This is despite recent nomenclature changes that have led to a renaming of most monkeyflower species to other genera.Additional co-authors: Jannice Friedman, Dena L Grossenbacher, Liza M Holeski, Christopher T Ivey, Kathleen M Kay, Vanessa A Koelling, Nicholas J Kooyers, Courtney J Murren, Christopher D Muir, Thomas C Nelson, Megan L Peterson, Joshua R Puzey, Michael C Rotter, Jeffrey R Seemann, Jason P Sexton, Seema N Sheth, Matthew A Streisfeld, Andrea L Sweigart, Alex D Twyford, John H Willis, Kevin M Wright, Carrie A Wu, Yao-Wu Yua
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