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Find video protocols related to scientific articles indexed in Pubmed.
PARP-14 combines with tristetraprolin in the selective post-transcriptional control of macrophage tissue factor expression.
Blood
PUBLISHED: 10-09-2014
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Tissue factor (TF, CD142) is a 47 kDa transmembrane cell surface glycoprotein which triggers the extrinsic coagulation cascade and links thrombosis with inflammation. Although macrophage TF expression is known to be regulated at the RNA level, very little is known about the mechanisms involved. Poly(ADP-ribose)-polymerase (PARP)-14 belongs to a family of intracellular proteins that generate ADP-ribose post-translational adducts. Functional screening of PARP-14 deficient macrophages mice revealed that PARP-14 deficiency leads to increased tissue factor (TF) expression and functional activity in macrophages following challenge with bacterial lipopolysaccharide. This was related to an increase in TF mRNA stability. Ribonucleoprotein complex immunoprecipitation and biotinylated RNA pull-down assays demonstrated that PARP-14 forms a complex with the mRNA-destabilizing protein tristetraprolin (TTP) and a conserved AU-rich element in the TF mRNA 3' untranslated region. TF mRNA regulation by PARP-14 was selective, as TNF? mRNA, which is also regulated by TTP, was not altered in PARP-14 deficient macrophages. Consistent with the in vitro data, TF expression and TF activity, but not TNF? expression, were increased in Parp14(-/-) mice in vivo. Our study provides a novel mechanism for the post-transcriptional regulation of TF expression, indicating that this is selectively regulated by PARP-14.
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Transcriptional diversity during lineage commitment of human blood progenitors.
Science
PUBLISHED: 09-27-2014
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Blood cells derive from hematopoietic stem cells through stepwise fating events. To characterize gene expression programs driving lineage choice, we sequenced RNA from eight primary human hematopoietic progenitor populations representing the major myeloid commitment stages and the main lymphoid stage. We identified extensive cell type-specific expression changes: 6711 genes and 10,724 transcripts, enriched in non-protein-coding elements at early stages of differentiation. In addition, we found 7881 novel splice junctions and 2301 differentially used alternative splicing events, enriched in genes involved in regulatory processes. We demonstrated experimentally cell-specific isoform usage, identifying nuclear factor I/B (NFIB) as a regulator of megakaryocyte maturation-the platelet precursor. Our data highlight the complexity of fating events in closely related progenitor populations, the understanding of which is essential for the advancement of transplantation and regenerative medicine.
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Randomised trials of human albumin for adults with sepsis: systematic review and meta-analysis with trial sequential analysis of all-cause mortality.
BMJ
PUBLISHED: 08-08-2014
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To assess the efficacy and safety of pooled human albumin solutions as part of fluid volume expansion and resuscitation (with or without improvement of baseline hypoalbuminaemia) in critically unwell adults with sepsis of any severity.
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Ischaemic strokes in patients with pulmonary arteriovenous malformations and hereditary hemorrhagic telangiectasia: associations with iron deficiency and platelets.
PLoS ONE
PUBLISHED: 01-01-2014
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Pulmonary first pass filtration of particles marginally exceeding ?7 µm (the size of a red blood cell) is used routinely in diagnostics, and allows cellular aggregates forming or entering the circulation in the preceding cardiac cycle to lodge safely in pulmonary capillaries/arterioles. Pulmonary arteriovenous malformations compromise capillary bed filtration, and are commonly associated with ischaemic stroke. Cohorts with CT-scan evident malformations associated with the highest contrast echocardiographic shunt grades are known to be at higher stroke risk. Our goal was to identify within this broad grouping, which patients were at higher risk of stroke.
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Specific N-linked glycosylation sites modulate synthesis and secretion of von Willebrand factor.
Blood
PUBLISHED: 04-23-2010
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We examined the role that N-linked glycans play in the synthesis and expression of von Willebrand Factor (VWF). Blocking the addition of N-linked glycans (NLGs) or inhibiting initial glycan processing prevented secretion of VWF. To determine whether specific glycosylation sites were important, the 16 VWF N-linked glycosylation sites were mutated followed by expression in HEK293T cells. Four NLG mutants affected VWF expression: N99Q (D1 domain), N857Q (D domain), N2400Q (B1 domain), and N2790Q (CK domain) either abolished or reduced secretion of VWF and this was confirmed by metabolic labeling. Multimer analysis of mutant N2790Q cell lysate revealed an increase in VWF monomers, which was also observed when the isolated CK domain was expressed with N2790 mutated. Immunofluorescence microscopy showed that mutants N99Q, N857Q, and N2790Q were primarily retained within the ER, producing only few pseudo Weibel-Palade bodies over longer time periods compared with wtVWF. All the variants also showed an increase in free thiol reactivity. This was greatest with N857Q and D4-C2 NLG mutants, which had approximately 6-fold and 3- to 4-fold more free thiol reactivity than wtVWF. These data provide further evidence of the critical role that individual N-linked glycans play in determining VWF synthesis and expression.
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Monitoring heparin anticoagulation in the acute phase response.
Br. J. Haematol.
PUBLISHED: 03-11-2010
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The anticoagulant effect of unfractionated heparin (UFH) is monitored using the activated partial thromboplastin time (APTT). An APTT of 1.5-2.5 times the control is usually taken as the therapeutic range and assumed to reflect an anti-activated factor X (anti-Xa) level of 0.35-0.7 u/ml. However, in some cases, despite administration of sufficient heparin to achieve a therapeutic anti-Xa assay level, the APTT remains sub-therapeutic. This apparent heparin resistance is commonly due to high levels of factor VIII (FVIII). In these situations, the anti-Xa is usually preferred for monitoring in order to avoid, what might be, dangerously high levels of heparin. We hypothesized that at high FVIII levels, the heparin resistance encountered may be genuine rather than apparent and that higher doses of heparin may indeed be needed for an equivalent anticoagulant effect. The relationship between heparin level, APTT and anticoagulant effect at different FVIII concentrations was determined using thrombelastography and the thrombin generation assay. Thromboelastographic and thrombin generation parameters concurred with APTT, demonstrating a genuine heparin resistance in the presence of high FVIII levels. This suggests that APTT may be a more accurate measure of anticoagulant effect in vivo than anti-Xa.
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Endothelial cell processing and alternatively spliced transcripts of factor VIII: potential implications for coagulation cascades and pulmonary hypertension.
PLoS ONE
PUBLISHED: 01-14-2010
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Coagulation factor VIII (FVIII) deficiency leads to haemophilia A. Conversely, elevated plasma levels are a strong predictor of recurrent venous thromboemboli and pulmonary hypertension phenotypes in which in situ thromboses are implicated. Extrahepatic sources of plasma FVIII are implicated, but have remained elusive.
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Clinical phenotype, laboratory features and genotype of 35 patients with heritable dysfibrinogenaemia.
Br. J. Haematol.
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Heritable dysfibrinogenaemia (HD) is a rare qualitative disorder of fibrinogen (FGN). To better describe the clinical, laboratory and genotypic spectrum of HD, we evaluated 35 subjects identified at two UK centres using laboratory criteria. 12/35(34%) subjects with HD experienced bleeding (bleeding score >1 at any site), 3/35(9%) thrombosis and 20/35(57%) were asymptomatic. Amongst subjects with bleeding, symptoms were typically mild, at one anatomical site and seldom occurred after invasive procedures. All subject showed dry clot weight within or above laboratory reference interval (median 3·2 g/l; range 1·9-5·1), reduced Clauss fibrinogen (median 0·52 g/l; range 0·21-1·3), and prolonged thrombin (median 30·7 s; range 21·3-45·7) and reptilase (median 42·0 s; range 20·0-68·0) times. In all subjects, the prothrombin time ratio (PTR), determined by Sysmex CA-1500 coagulometer and Innovin activator, was abnormal (median 1·42; range 1·22-1·61). The activated partial thromboplastin time ratio and PTR with other coagulometers and activators were comparatively insensitive to HD. All subjects with HD harboured heterozygous candidate nucleotide variations within known hotspots in the FGN genes. The HD variants identified in this cross-sectional study seldom have significant clinical manifestations and show similar laboratory features irrespective of genotype. Selection of coagulometer and PT activator may markedly affect the detection of new HD cases using coagulation screening tests.
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O-linked glycosylation of von Willebrand factor modulates the interaction with platelet receptor glycoprotein Ib under static and shear stress conditions.
Blood
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We have examined the effect of the O-linked glycan (OLG) structures of VWF on its interaction with the platelet receptor glycoprotein Ib?. The 10 OLGs were mutated individually and as clusters (Clus) on either and both sides of the A1 domain: Clus1 (N-terminal side), Clus2 (C-terminal side), and double cluster (DC), in both full-length-VWF and in a VWF construct spanning D to A3 domains. Mutations did not alter VWF secretion by HEK293T cells, multimeric structure, or static collagen binding. The T1255A, Clus1, and DC variants caused increased ristocetin-mediated GPIb? binding to VWF. Platelet translocation rate on OLG mutants was increased because of reduced numbers of GPIb? binding sites but without effect on bond lifetime. In contrast, OLG mutants mediated increased platelet capture on collagen under high shear stress that was associated with increased adhesion of these variants to the collagen under flow. These findings suggest that removal of OLGs increases the flexibility of the hinge linker region between the D3 and A1 domain, facilitating VWF unfolding by shear stress, thereby enhancing its ability to bind collagen and capture platelets. These data demonstrate an important functional role of VWF OLGs under shear stress conditions.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.