262 research outputs found

    Detection of the argonaute protein Ago2 and microRNAs in the RNA induced silencing complex (RISC) using a monoclonal antibody

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    MicroRNAs (miRNAs) are short RNA molecules responsible for post-transcriptional gene silencing by the degradation or translational inhibition of their target messenger RNAs (mRNAs). This process of gene silencing, known as RNA interference (RNAi), is mediated by highly conserved Argonaute (Ago) proteins which are the key components of the RNA induced silencing complex (RISC). In humans, Ago2 is responsible for the endonuclease cleavage of targeted mRNA and it interacts with the mRNAbinding protein GW182, which is a marker for cytoplasmic foci referred to as GW bodies (GWBs). We demonstrated that the antiAgo2 monoclonal antibody 4F9 recognized GWBs in a cell cycle dependent manner and was capable of capturing miRNAs associated with Ago2. Since Ago2 protein is the effector protein of RNAi, anti-Ago2 monoclonal antibody may be useful in capturing functional miRNAs

    Spectrum of centrosome autoantibodies in childhood varicella and post-varicella acute cerebellar ataxia

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    BACKGROUND: Sera from children with post-varicella infections have autoantibodies that react with centrosomes in brain and tissue culture cells. We investigated the sera of children with infections and post-varicella ataxia and related conditions for reactivity to five recombinant centrosome proteins: Ī³Ī³-enolase, pericentrin, ninein, PCM-1, and Mob1. METHODS: Sera from 12 patients with acute post-varicella ataxia, 1 with post-Epstein Barr virus (EBV) ataxia, 5 with uncomplicated varicella infections, and other conditions were tested for reactivity to cryopreserved cerebellum tissue and recombinant centrosome proteins. The distribution of pericentrin in the cerebellum was studied by indirect immunofluorescence (IIF) using rabbit antibodies to the recombinant protein. Antibodies to phospholipids (APL) were detected by ELISA. RESULTS: Eleven of 12 children with post-varicella ataxia, 4/5 children with uncomplicated varicella infections, 1/1 with post-EBV ataxia, 2/2 with ADEM, 1/2 with neuroblastoma and ataxia, and 2/2 with cerebellitis had antibodies directed against 1 or more recombinant centrosome antigens. Antibodies to pericentrin were seen in 5/12 children with post-varicella ataxia but not in any of the other sera tested. IIF demonstrated that pericentrin is located in axons and centrosomes of cerebellar cells. APL were detected in 75% of the sera from children with post-varicella ataxia and 50% of children with varicella without ataxia and in none of the controls. CONCLUSION: This is the first study to show the antigen specificity of anti-centrosome antibodies in children with varicella. Our data suggest that children with post-varicella ataxia have unique autoantibody reactivity to pericentrin

    Documenting Surface and Sub-surface Volatiles While Drilling in Frozen Lunar Simulant

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    NASA's Resource Prospector (RP) mission is intended to characterize the three-dimensional nature of volatiles in lunar polar regions and permanently shadowed regions. RP is slated to carry two instruments for prospecting purposes. These include the Neutron Spectrometer System (NSS) and Near-Infrared Volatile Spectrometer System (NIRVSS). A Honybee Robotics drill (HRD) is intended to sample to depths of 1 m, and deliver a sample to a crucible that is processed by the Oxygen Volatile Extraction Node (OVEN) where the soil is heated and evolved gas is delivered to the gas chromatograph / mass spectrometer of the Lunar Advanced Volatile Analysis system (LAVA). For several years, tests of various sub-systems have been undertaken in a large cryo-vacuum chamber facility (VF-13) located at Glenn Research Center. In these tests a large tube (1.2 m high x 25.4 cm diameter) is filled with lunar simulant, NU-LHT-3M, prepared with known abundances of water. There are thermo-couples embedded at different depths, and also across the surface of the soil tube. The soil tube is placed in the chamber and cooled with LN2 as the pressure is reduced to approx.5-6x10(exp -6) Torr. Here we discuss May 2016 tests where two soil tubes were prepared and placed in the chamber. Also located in the chamber were 5 crucibles, an Inficon mass spectrometer, and a trolly permitting x-y translation, where the HRD and NIRVSS, were mounted. The shroud surrounding the soil tube was held at different temperatures for each tube to simulate a warm and cold lunar environment

    PR3-ANCA:a promising biomarker in primary sclerosing cholangitis (PSC)

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    BACKGROUND AND AIMS:The only recognized biomarker for primary sclerosing cholangitis (PSC) is atypical anti-neutrophil cytoplasmic antibodies (aANCA), which, in addition to having low sensitivity and specificity, is an indirect immunofluorescence (IIF) test lacking the advantages of high throughput and objectivity. Recent reports have shown that antibodies to proteinase-3 (PR3-ANCA) might add diagnostic value in inflammatory bowel disease (IBD), specifically in ulcerative colitis (UC). As PSC is associated with IBD, the objective of this study was to evaluate the frequency and clinical significance of PR3-ANCA in a large cohort of patients. METHODS:A total of 244 PSC and 254 control [autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), hepatitis C viral infection (HCV), hepatitis B viral infection (HBV), and healthy controls] sera and their clinical correlations were retrospectively analyzed for PR3-ANCA determined by ELISA and a new chemiluminescence immunoassay (CIA). Testing was also performed for aANCA by IIF. RESULTS:When measured by CIA, PR3-ANCA was detected in 38.5% (94/244) of PSC patients compared to 10.6% (27/254) controls (p<0.0001). By ELISA, PR3-ANCA was detected in 23.4% (57/244) of PSC patients compared to 2.7% (6/254) controls (p<0.0001). PR3-ANCA in PSC patients was not associated with the presence or type of underlying IBD, and, in fact, it was more frequent in Crohn's disease (CD) patients with PSC than previously reported in CD alone. PR3-ANCA in PSC measured by CIA correlated with higher liver enzymes. CONCLUSION:PR3-ANCA is detected in a significant proportion of PSC patients compared to other liver diseases including PBC and AIH. PR3-ANCA is associated with higher liver enzyme levels in PSC, and is not solely related to underlying IBD

    Near-Infrared Monitoring of Volatiles in Frozen Lunar Simulants While Drilling

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    In Situ Resource Utilization (ISRU) focuses on using local resources for mission consumables. The approach can reduce mission cost and risk. Lunar polar volatiles, e.g. water ice, have been detected via remote sensing measurements and represent a potential resource for both humans and propellant. The exact nature of the horizontal and depth distribution of the ice remains to be documented in situ. NASA's Resource Prospector mission (RP) is intended to investigate the polar volatiles using a rover, drill, and the RESOLVE science package. RP component level hardware is undergoing testing in relevant lunar conditions (cryovacuum). In March 2015 a series of drilling tests were undertaken using the Honeybee Robotics RP Drill, Near-Infrared Volatile Spectrometer System (NIRVSS), and sample capture mechanisms (SCM) inside a 'dirty' thermal vacuum chamber at the NASA Glenn Research Center. The goal of these tests was to investigate the ability of NIRVSS to monitor volatiles during drilling activities and assess delivery of soil sample transfer to the SCMs in order to elucidate the concept of operations associated with this regolith sampling method

    Antinuclear Antibodyā€“Negative Systemic Lupus Erythematosus in an International Inception Cohort

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    Objectives: The spectrum of antinuclear antibodies (ANA) is changing to include both nuclear staining as well as cytoplasmic and mitotic cell patterns (CMPs) and accordingly a change in terminology to antiā€cellular antibodies. This study examined the prevalence of indirect immunofluorescence (IIF) antiā€cellular antibody staining using the Systemic Lupus International Collaborating Clinics inception cohort. / Methods: Antiā€cellular antibodies were detected by IIF on HEpā€2000 substrate utilizing the baseline serum. Three serological subsets were examined: 1) ANAā€positive (presence of either nuclear or mixed nuclear/CMP staining), 2) antiā€cellular antibodyā€negative (absence of any intracellular staining), and 3) isolated CMP staining. The odds of being antiā€cellular antibodyā€negative versus ANA or isolated CMPā€positive was assessed by multivariable analysis. / Results: 1137 patients were included; 1049/1137 (92.3%) were ANAā€positive, 71/1137 (6.2%) were antiā€cellular antibodyā€negative, and 17/1137 (1.5%) had isolated CMP. The isolated CMP group did not differ from the ANAā€positive or antiā€cellular antibodyā€negative group in clinical, demographic or serologic features. Patients who were older (OR 1.02 [95% CI: 1.00, 1.04]), of Caucasian race/ethnicity (OR 3.53 [95% CI: 1.77, 7.03]), or on high dose glucocorticoids at or prior to enrolment (OR 2.39 [95% CI: 1.39, 4.12]) were more likely to be antiā€cellular antibodyā€negative. Patients on immunosuppressants (OR 0.35 [95% CI: 0.19, 0.64]) or with antiā€SSA/Ro60 (OR 0.41 [95% CI: 0.23, 0.74]) or antiā€UIā€RNP (OR 0.43 [95% CI: 0.20, 0.93]) were less likely to be antiā€cellular antibodyā€negative. / Conclusions: In newly diagnosed SLE, 6.2% of patients were antiā€cellular antibodyā€negative and 1.5% had isolated CMP. The prevalence of antiā€cellular antibodyā€negative SLE will likely decrease as emerging nomenclature guidelines recommend that nonā€nuclear patterns should also be reported as a positive ANA

    Report on the second International Consensus on ANA Pattern (ICAP) workshop in Dresden 2015

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    The second meeting for the International Consensus on Antinuclear antibody (ANA) Pattern (ICAP) was held on 22 September 2015, one day prior to the opening of the 12th Dresden Symposium on Autoantibodies in Dresden, Germany. The ultimate goal of ICAP is to promote harmonization and understanding of autoantibody nomenclature, and thereby optimizing ANA usage in patient care. The newly developed ICAP website www.ANApatterns.org was introduced to the more than 50 participants. This was followed by several presentations and discussions focusing on key issues including the two-tier classification of ANA patterns into competent-level versus expert-level, the consideration of how to report composite versus mixed ANA patterns, and the necessity for developing a consensus on how ANA results should be reported. The need to establish on-line training modules to help users gain competency in identifying ANA patterns was discussed as a future addition to the website. To advance the ICAP goal of promoting wider international participation, it was agreed that there should be a consolidated plan to translate consensus documents into other languages by recruiting help from members of the respective communities
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