89 research outputs found

    Proceedings of the 11th Annual Meeting, Southern Soybean Disease Workers (March 27-29, 1984, Ft. Walton Beach, Florida): Economics of Soybean Disease

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    Contents 1984 Southern Soybean Disease Workers Officers 1984 Southern Soybean Disease Workers Program Committee 1984 Southern Soybean Disease Workers Committee Chairmen Workshop Diagnosing early season soybean disorders. D Stuckey and A Wrather General session Presidential address. HJ Walters Southern United States Soybean Disease Loss Estimate for 1983. Southern Soybean Disease Workers, Soybean Disease Loss Estimate Committee. RP Mulrooney Soybean nematodes. R Dunn presiding A New Publication on the Soybean Cyst Nematode. WF Moore Soybean Cultivars and Development of Populations of Meloidogyne incognita in Soil: A Concept of Tolerance. R Rodríguez-Kábana and DB Weaver A Comparison of Soybean Cultivars for Their Resistance to Meloidogyne incognita and M. arenaria. RA Kinloch Ethylene Dibromide and Alternative Nematicides for Soybeans. RA Dunn Involvement of Fungi in Phytonematode Pathology. G Morgan-Jones and R Rodríguez-Kábana Graduate student presentations. EC McGawley presiding Interaction Between Heterodera glycines and Glomus macrocarpus on Soybeans as Affected by Aldicarb. DP McCormack, DP Schmitt, and KR Barker Phomopsis sp. and Soybean Seedling Emergence: Influence of Soil Water Potential. M Gleason and RS Ferriss Soybean seed, seedling and soil-borne diseases. WS Gazaway presiding Report of Southern Soybean Disease Workers Seed Treatment Committee, 1983. MC McDaniel Effects of Soil Source, Soil Moisture, Seed Quality and Seed Treatment on Soybean Emergence. RE Stuckey, RS Ferriss, and MR Siegel Epidemiological and Mycofloral Relationships in Soybean Seedling Disease. JF Killebrew and KW Roy Seed Treatments for Control of Seedling Diseases and Rhizoctonia Root Rot in No-Till Soybeans. AY Chambers Soybean foliar, pod and stem diseases. JW Shriver presiding Southern Soybean Disease Workers Standardized Foliar Fungicide Test, 1983. AY Chambers and MA Newman Stem Canker in the Southeastern United States. WS Gazaway Timings of Foliar Fungicide Applications on Soybeans in Louisiana. JS Gershey, GT Berggren, and ME Pace Levels of Chlorine in Leaves and Seed Causing Leaf Scorch of Soybeans. MB Parker, TP Gaines, and GJ Gascho Incidence and Yield Loss Estimates on Stem and Foliar Diseases as Affected by Row Spacing and Overhead Irrigation. MC Hirrell and MC McDaniel Foliar Fungicides in Georgia: A Ten-Year Summary. DV Phillips New developments. E Barrett presiding The Use of Microcomputers in Soybean Disease Research. ME Pace, GT Berggren, Jr, and JS Gershey Aerial Web Blight in Mississippi in 1983. JA Fox SSDW Treasurer\u27s repor

    What is the clinical and ethical importance of incidental abnormalities found by knee MRI?

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    INTRODUCTION: Magnetic resonance imaging (MRI) is increasingly used to examine joints for research purposes. It may detect both suspected and unsuspected abnormalities. This raises both clinical and ethical issues, especially when incidental abnormalities are detected. The prevalence of incidental, potentially clinically significant abnormalities identified by MRI and their clinical significance in a population undergoing knee MRI in research studies are unknown. METHODS: We examined the prevalence of such lesions in healthy asymptomatic adults and those with symptomatic knee osteoarthritis (OA) undergoing knee MRI with limited sequences for the purpose of research. The MRI findings in 601 asymptomatic subjects and 132 with knee OA who underwent at least one limited knee MRI scan for cartilage volume measurement were examined by an MRI radiologist for the presence of potentially clinically significant abnormalities. RESULTS: These were present in 2.3% of healthy and 2.3% of OA subjects. All required further investigation to exclude non-benign disease, including four with bone marrow expansion (0.7%), requiring further investigation and management. A single potentially life-threatening lesion, a myeloma lesion, was identified in a subject with symptomatic knee OA on their second MRI scan in a longitudinal study. CONCLUSION: As musculoskeletal MRI is increasingly used clinically and for research purposes, the potential for detecting unsuspected abnormalities that require further investigation should be recognized. Incorporating a system to detect these, to characterize unexpected findings, and to facilitate appropriate medical follow-up when designing studies using this technology should be considered ethical research practice

    Baryon masses in a chiral expansion with meson-baryon form factors

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    The chiral expansion of the one-loop corrections to baryon masses is examined in a generic meson-cloud model with meson-baryon form factors. For pion loops, the expansion is rapidly convergent and at fourth order in mπm_\pi accurately reproduces the full integral. In contrast, the expansion is found to converge very slowly for kaon loops, raising questions about the usefulness of chiral expansions for kaon-baryon physics. Despite the importance of high-order terms, relations like that of Gell-Mann and Okubo are well satisfied by the baryon masses calculated with the full integral. The pion cloud cloud makes a significant contribution to the πN\pi N sigma commutator, while kaon cloud gives a very small strangeness content in the nucleon.Comment: 20 pages (RevTeX), 2 figures (attached

    A novel mechanism for the scission of double-stranded DNA: BfiI cuts both 3′–5′ and 5′–3′ strands by rotating a single active site

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    Metal-dependent nucleases that generate double-strand breaks in DNA often possess two symmetrically-equivalent subunits, arranged so that the active sites from each subunit act on opposite DNA strands. Restriction endonuclease BfiI belongs to the phospholipase D (PLD) superfamily and does not require metal ions for DNA cleavage. It exists as a dimer but has at its subunit interface a single active site that acts sequentially on both DNA strands. The active site contains two identical histidines related by 2-fold symmetry, one from each subunit. This symmetrical arrangement raises two questions: first, what is the role and the contribution to catalysis of each His residue; secondly, how does a nuclease with a single active site cut two DNA strands of opposite polarities to generate a double-strand break. In this study, the roles of active-site histidines in catalysis were dissected by analysing heterodimeric variants of BfiI lacking the histidine in one subunit. These variants revealed a novel mechanism for the scission of double-stranded DNA, one that requires a single active site to not only switch between strands but also to switch its orientation on the DNA

    Efficacy of a Non-Hypercalcemic Vitamin-D2 Derived Anti-Cancer Agent (MT19c) and Inhibition of Fatty Acid Synthesis in an Ovarian Cancer Xenograft Model

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    BACKGROUND:Numerous vitamin-D analogs exhibited poor response rates, high systemic toxicities and hypercalcemia in human trials to treat cancer. We identified the first non-hypercalcemic anti-cancer vitamin D analog MT19c by altering the A-ring of ergocalciferol. This study describes the therapeutic efficacy and mechanism of action of MT19c in both in vitro and in vivo models. METHODOLOGY/PRINCIPAL FINDING:Antitumor efficacy of MT19c was evaluated in ovarian cancer cell (SKOV-3) xenografts in nude mice and a syngenic rat ovarian cancer model. Serum calcium levels of MT19c or calcitriol treated animals were measured. In-silico molecular docking simulation and a cell based VDR reporter assay revealed MT19c-VDR interaction. Genomewide mRNA analysis of MT19c treated tumors identified drug targets which were verified by immunoblotting and microscopy. Quantification of cellular malonyl CoA was carried out by HPLC-MS. A binding study with PPAR-Y receptor was performed. MT19c reduced ovarian cancer growth in xenograft and syngeneic animal models without causing hypercalcemia or acute toxicity. MT19c is a weak vitamin-D receptor (VDR) antagonist that disrupted the interaction between VDR and coactivator SRC2-3. Genome-wide mRNA analysis and western blot and microscopy of MT19c treated xenograft tumors showed inhibition of fatty acid synthase (FASN) activity. MT19c reduced cellular levels of malonyl CoA in SKOV-3 cells and inhibited EGFR/phosphoinositol-3kinase (PI-3K) activity independently of PPAR-gamma protein. SIGNIFICANCE:Antitumor effects of non-hypercalcemic agent MT19c provide a new approach to the design of vitamin-D based anticancer molecules and a rationale for developing MT19c as a therapeutic agent for malignant ovarian tumors by targeting oncogenic de novo lipogenesis

    Rif1 maintains telomeres and mediates DNA repair by encasing DNA ends

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    In yeast, Rif1 is part of the telosome, where it inhibits telomerase and checkpoint signaling at chromosome ends. In mammalian cells, Rif1 is not telomeric, but it suppresses DNA end resection at chromosomal breaks, promoting repair by nonhomologous end joining (NHEJ). Here, we describe crystal structures for the uncharacterized and conserved ∼125-kDa N-terminal domain of Rif1 from Saccharomyces cerevisiae (Rif1-NTD), revealing an α-helical fold shaped like a shepherd's crook. We identify a high-affinity DNA-binding site in the Rif1-NTD that fully encases DNA as a head-to-tail dimer. Engagement of the Rif1-NTD with telomeres proved essential for checkpoint control and telomere length regulation. Unexpectedly, Rif1-NTD also promoted NHEJ at DNA breaks in yeast, revealing a conserved role of Rif1 in DNA repair. We propose that tight associations between the Rif1-NTD and DNA gate access of processing factors to DNA ends, enabling Rif1 to mediate diverse telomere maintenance and DNA repair functions

    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care(1) or hospitalization(2-4) after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes-including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)-in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease. © 2022, The Author(s)

    Whole-genome sequencing reveals host factors underlying critical COVID-19

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    Critical Covid-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalisation2-4 following SARS-CoV-2 infection. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from critically-ill cases with population controls in order to find underlying disease mechanisms. Here, we use whole genome sequencing in 7,491 critically-ill cases compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical Covid-19. We identify 16 new independent associations, including variants within genes involved in interferon signalling (IL10RB, PLSCR1), leucocyte differentiation (BCL11A), and blood type antigen secretor status (FUT2). Using transcriptome-wide association and colocalisation to infer the effect of gene expression on disease severity, we find evidence implicating multiple genes, including reduced expression of a membrane flippase (ATP11A), and increased mucin expression (MUC1), in critical disease. Mendelian randomisation provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5, CD209) and coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of Covid-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication, or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between critically-ill cases and population controls is highly efficient for detection of therapeutically-relevant mechanisms of disease

    CSAR Benchmark Exercise of 2010: Selection of the Protein–Ligand Complexes

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    ABSTRACT: A major goal in drug design is the improvement of computational methods for docking and scoring. The Community Structure Activity Resource (CSAR) aims to collect available data from industry and academia which may be used for this purpose (www.csardock.org). Also, CSAR is charged with organizing community-wide exercises based on the collected data. The first of these exercises was aimed to gauge the overall state of docking and scoring, using a large and diverse data set of protein ligand complexes. Participants were asked to calculate the affinity of the complexes as provided and then recalculate with changes which may improve their specific method. This first data set was selected from existing PDB entries which had binding data (Kd or Ki) in Binding MOAD, augmented with entries from PDBbind. The final data set contains 343 diverse protein ligand complexes and spans 14 pKd. Sixteen proteins have three or more complexes in the data set, from which a user could start an inspection of congeneric series. Inherent experimental error limits the possible correlation between scores and measured affinity; R 2 is limited to ∼0.9 when fitting to the data set without over parametrizing. R 2 is limited to ∼0.8 when scoring the data set with a method trained on outside data. The details of how the data set was initially selected, and the process by which it matured t

    SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues

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    Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component. Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci (eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene), including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types
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