JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
From deep sequencing to actual clones.
Protein Eng. Des. Sel.
PUBLISHED: 09-01-2014
Show Abstract
Hide Abstract
The application of deep sequencing to in vitro display technologies has been invaluable for the straightforward analysis of enriched clones. After sequencing in vitro selected populations, clones are binned into identical or similar groups and ordered by abundance, allowing identification of those that are most enriched. However, the greatest strength of deep sequencing is also its greatest weakness: clones are easily identified by their DNA sequences, but are not physically available for testing without a laborious multistep process involving several rounds of polymerization chain reaction (PCR), assembly and cloning. Here, using the isolation of antibody genes from a phage and yeast display selection as an example, we show the power of a rapid and simple inverse PCR-based method to easily isolate clones identified by deep sequencing. Once primers have been received, clone isolation can be carried out in a single day, rather than two days. Furthermore the reduced number of PCRs required will reduce PCR mutations correspondingly. We have observed a 100% success rate in amplifying clones with an abundance as low as 0.5% in a polyclonal population. This approach allows us to obtain full-length clones even when an incomplete sequence is available, and greatly simplifies the subcloning process. Moreover, rarer, but functional clones missed by traditional screening can be easily isolated using this method, and the approach can be extended to any selected library (scFv, cDNA, libraries based on scaffold proteins) where a unique sequence signature for the desired clones of interest is available.
Related JoVE Video
TGP, an extremely stable, non-aggregating fluorescent protein created by structure-guided surface engineering.
Proteins
PUBLISHED: 07-17-2014
Show Abstract
Hide Abstract
In this paper we describe the engineering and X-ray crystal structure of Thermal Green Protein (TGP), an extremely stable, highly soluble, non-aggregating green fluorescent protein. TGP is a soluble variant of the fluorescent protein eCGP123, which despite being highly stable, has proven to be aggregation-prone. The X-ray crystal structure of eCGP123, also determined within the context of this paper, was used to carry out rational surface engineering to improve its solubility, leading to TGP. The approach involved simultaneously eliminating crystal lattice contacts while increasing the overall negative charge of the protein. Despite intentional disruption of lattice contacts and introduction of high entropy glutamate side chains, TGP crystallized readily in a number of different conditions and the X-ray crystal structure of TGP was determined to 1.9 Å resolution. The structural reasons for the enhanced stability of TGP and eCGP123 are discussed. We demonstrate the utility of using TGP as a fusion partner in various assays and significantly, in amyloid assays in which the standard fluorescent protein, EGFP, is undesirable because of aberrant oligomerization. © Proteins 2014;. © 2014 Wiley Periodicals, Inc.
Related JoVE Video
Optimal aggregation of Fc?RI with a structurally defined trivalent ligand overrides negative regulation driven by phosphatases.
ACS Chem. Biol.
PUBLISHED: 05-15-2014
Show Abstract
Hide Abstract
To investigate why responses of mast cells to antigen-induced IgE receptor (Fc?RI) aggregation depend nonlinearly on antigen dose, we characterized a new artificial ligand, DF3, through complementary modeling and experimentation. This ligand is a stable trimer of peptides derived from bacteriophage T4 fibritin, each conjugated to a hapten (DNP). We found low and high doses of DF3 at which degranulation of mast cells sensitized with DNP-specific IgE is minimal, but ligand-induced receptor aggregation is comparable to aggregation at an intermediate dose, optimal for degranulation. This finding makes DF3 an ideal reagent for studying the balance of negative and positive signaling in the Fc?RI pathway. We find that the lipid phosphatase SHIP and the protein tyrosine phosphatase SHP-1 negatively regulate mast cell degranulation over all doses considered. In contrast, SHP-2 promotes degranulation. With high DF3 doses, relatively rapid recruitment of SHIP to the plasma membrane may explain the reduced degranulation response. Our results demonstrate that optimal secretory responses of mast cells depend on the formation of receptor aggregates that promote sufficient positive signaling by Syk to override phosphatase-mediated negative regulatory signals.
Related JoVE Video
A new family of ?-helix proteins with similarities to the polysaccharide lyases.
Acta Crystallogr. D Biol. Crystallogr.
PUBLISHED: 05-07-2014
Show Abstract
Hide Abstract
Microorganisms that degrade biomass produce diverse assortments of carbohydrate-active enzymes and binding modules. Despite tremendous advances in the genomic sequencing of these organisms, many genes do not have an ascribed function owing to low sequence identity to genes that have been annotated. Consequently, biochemical and structural characterization of genes with unknown function is required to complement the rapidly growing pool of genomic sequencing data. A protein with previously unknown function (Cthe_2159) was recently isolated in a genome-wide screen using phage display to identify cellulose-binding protein domains from the biomass-degrading bacterium Clostridium thermocellum. Here, the crystal structure of Cthe_2159 is presented and it is shown that it is a unique right-handed parallel ?-helix protein. Despite very low sequence identity to known ?-helix or carbohydrate-active proteins, Cthe_2159 displays structural features that are very similar to those of polysaccharide lyase (PL) families 1, 3, 6 and 9. Cthe_2159 is conserved across bacteria and some archaea and is a member of the domain of unknown function family DUF4353. This suggests that Cthe_2159 is the first representative of a previously unknown family of cellulose and/or acid-sugar binding ?-helix proteins that share structural similarities with PLs. Importantly, these results demonstrate how functional annotation by biochemical and structural analysis remains a critical tool in the characterization of new gene products.
Related JoVE Video
An improved Protein G with higher affinity for human/rabbit IgG Fc domains exploiting a computationally designed polar network.
Protein Eng. Des. Sel.
PUBLISHED: 03-14-2014
Show Abstract
Hide Abstract
Protein G is an IgG binding protein that has been widely exploited for biotechnological purposes. Rosetta protein modeling identified a set of favorable polar mutations in Protein G, at its binding interface with the Fc domain of Immunoglobulin G, that were predicted to increase the stability and tighten the binding relative to native Protein G, with only a minor perturbation of the binding mode seen in the crystal structure. This triple mutant was synthesized and evaluated experimentally. Relative to the native protein G, the mutant showed a 3.5-fold enhancement in display level on the surface of yeast and a 5-fold tighter molar affinity for rabbit and human IgG. We attribute the improved affinity to a network of hydrogen bonds exploiting specific polar groups on human and rabbit Fc. The relative specificity increased as well since there was little affinity enhancement for goat and mouse Fc, while the affinity for rat Fc was poorer by half. This designed Protein G will be useful in biotechnological applications as a recombinant protein, where its improved affinity, display and specificity will increase antibody capture sensitivity and capacity. Furthermore, the display of this protein on the surface of yeast introduces the concept of the use of yeast as an affinity matrix.
Related JoVE Video
The antibody mining toolbox: an open source tool for the rapid analysis of antibody repertoires.
MAbs
PUBLISHED: 01-16-2014
Show Abstract
Hide Abstract
In vitro selection has been an essential tool in the development of recombinant antibodies against various antigen targets. Deep sequencing has recently been gaining ground as an alternative and valuable method to analyze such antibody selections. The analysis provides a novel and extremely detailed view of selected antibody populations, and allows the identification of specific antibodies using only sequencing data, potentially eliminating the need for expensive and laborious low-throughput screening methods such as enzyme-linked immunosorbant assay. The high cost and the need for bioinformatics experts and powerful computer clusters, however, have limited the general use of deep sequencing in antibody selections. Here, we describe the AbMining ToolBox, an open source software package for the straightforward analysis of antibody libraries sequenced by the three main next generation sequencing platforms (454, Ion Torrent, MiSeq). The ToolBox is able to identify heavy chain CDR3s as effectively as more computationally intense software, and can be easily adapted to analyze other portions of antibody variable genes, as well as the selection outputs of libraries based on different scaffolds. The software runs on all common operating systems (Microsoft Windows, Mac OS X, Linux), on standard personal computers, and sequence analysis of 1-2 million reads can be accomplished in 10-15 min, a fraction of the time of competing software. Use of the ToolBox will allow the average researcher to incorporate deep sequence analysis into routine selections from antibody display libraries.
Related JoVE Video
Using phage display selected antibodies to dissect microbiomes for complete de novo genome sequencing of low abundance microbes.
BMC Microbiol.
PUBLISHED: 08-31-2013
Show Abstract
Hide Abstract
Single cell genomics has revolutionized microbial sequencing, but complete coverage of genomes in complex microbiomes is imperfect due to enormous variation in organismal abundance and amplification bias. Empirical methods that complement rapidly improving bioinformatic tools will improve characterization of microbiomes and facilitate better genome coverage for low abundance microbes.
Related JoVE Video
Specific binder for Lightning-Link® biotinylated proteins from an antibody phage library.
J. Immunol. Methods
PUBLISHED: 05-20-2013
Show Abstract
Hide Abstract
Many applications required protein biotinylation. We routinely use biotinylated proteins to select single chain antibodies from phage and/or yeast display libraries. During phage selection the biotinylated antigens are bound to streptavidin coupled magnetic beads, while during yeast display, the biotinylated antigens are used during flow cytometry for both analysis and sorting. The Lightning-Link® Biotin kit, a rapid straightforward biotinylation kit that avoids the need for dialysis, is particularly useful when the amount of available protein is limiting. During routine screening of antibody libraries we identified a specific clone that bound a universal neo-epitope generated only when antigens are biotinylated with the commercial Lightning-Link® kit, with an affinity of ~10nM. Non-biotinylated proteins, and those biotinylated using alternative methods - the Thermo Fisher commercial kit or in vivo biotinylation using the Avitag (Ashraf et al., 2004) - were not recognized by this antibody. Using deep sequence analysis, the specific antibody was identified as being the most abundant in a number of different selections. This indicates the need for caution when using such modifying reagents, because of the possibility of selecting antibodies against the modification, rather than the target protein, and also highlights the value of deep sequencing analysis during display based selections. Furthermore, this antibody may have great utility in the analysis of proteins biotinylated using this method.
Related JoVE Video
Assessment of renal function by means of cystatin C following standard and fenestrated endovascular aneurysm repair.
Ann Vasc Surg
PUBLISHED: 03-31-2013
Show Abstract
Hide Abstract
Cystatin C (Cyst C) is more sensitive marker for early renal injury. However, serum creatinine (sCr) and estimated glomerular filtration rate (eGFR) are still used as the standard renal markers after endovascular aortic aneurysm repair (EVAR). The goal of this study was to compare the efficacy of Cyst C, sCr, and eGFR as markers of renal function after EVAR.
Related JoVE Video
Profiling celiac disease antibody repertoire.
Clin. Immunol.
PUBLISHED: 01-22-2013
Show Abstract
Hide Abstract
The aim of this study was to dissect the autoantibody response in celiac disease (CD) that remains largely unknown, with the goal of identifying the disease-specific autoantigenic protein pattern or the so called epitome. Sera from CD patients were used to select immunoreactive antigens from a cDNA phage-display library. Candidate genes were identified, the corresponding proteins produced and their immunoreactivity validated with sera from CD patients and controls. Thirteen CD-specific antigens were identified and further validated by protein microarray. The specificity for 6 of these antigens was confirmed by ELISA. Furthermore we showed that this antibody response was not abolished on a gluten free diet and was not shared with other autoimmune diseases. These antigens appear to be CD specific and independent of gluten induction. The utility of this panel extends beyond its diagnostic value and it may drive the attention to new targets for unbiased screens in autoimmunity research.
Related JoVE Video
Phanta: a non-fluorescent photochromic acceptor for pcFRET.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
We have developed an orange non-fluorescent photochromic protein (quantum yield, 0.003) we call Phanta that is useful as an acceptor in pcFRET applications. Phanta can be repeatedly inter-converted between the two absorbing states by alternate exposure to cyan and violet light. The absorption spectra of Phanta in one absorbing state shows excellent overlap with the emission spectra of a number of donor green fluorescent proteins including the commonly used EGFP. We show that the Phanta-EGFP FRET pair is suitable for monitoring the activation of caspase 3 in live cells using readily available instrumentation and a simple protocol that requires the acquisition of two donor emission images corresponding to Phanta in each of its photoswitched states. This the first report of a genetically encoded non-fluorescent acceptor for pcFRET.
Related JoVE Video
Discovery of DNA operators for TetR and MarR family transcription factors from Burkholderia xenovorans.
Microbiology (Reading, Engl.)
PUBLISHED: 11-24-2011
Show Abstract
Hide Abstract
Determining transcription factor (TF) recognition motifs or operator sites is central to understanding gene regulation, yet few operators have been characterized. In this study, we used a protein-binding microarray (PBM) to discover the DNA recognition sites and putative regulons for three TetR and one MarR family TFs derived from Burkholderia xenovorans, which are common to the genus Burkholderia. We also describe the development and application of a more streamlined version of the PBM technology that significantly reduced the experimental time. Despite the genus containing many pathogenically important species, only a handful of TF operator sites have been experimentally characterized for Burkholderia to date. Our study provides a significant addition to this knowledge base and illustrates some general challenges of discovering operators on a large scale for prokaryotes.
Related JoVE Video
Perioperative myocardial injury and hemostasis in patients undergoing endovascular aneurysm repair for asymptomatic infrarenal abdominal aortic aneurysm.
Vasc Endovascular Surg
PUBLISHED: 10-21-2011
Show Abstract
Hide Abstract
(1) To report the incidence of myocardial injury in patients undergoing endovascular aortic aneurysm repair (EVAR) through the routine measurement of perioperative cardiac troponin-T (cTnT) and (2) to investigate and correlate changes in perioperative cTnT levels with any concomitant hemostatic derangement.
Related JoVE Video
Filtering "genic" open reading frames from genomic DNA samples for advanced annotation.
BMC Genomics
PUBLISHED: 06-15-2011
Show Abstract
Hide Abstract
In order to carry out experimental gene annotation, DNA encoding open reading frames (ORFs) derived from real genes (termed "genic") in the correct frame is required. When genes are correctly assigned, isolation of genic DNA for functional annotation can be carried out by PCR. However, not all genes are correctly assigned, and even when correctly assigned, gene products are often incorrectly folded when expressed in heterologous hosts. This is a problem that can sometimes be overcome by the expression of protein fragments encoding domains, rather than full-length proteins. One possible method to isolate DNA encoding such domains would to "filter" complex DNA (cDNA libraries, genomic and metagenomic DNA) for gene fragments that confer a selectable phenotype relying on correct folding, with all such domains present in a complex DNA sample, termed the "domainome".
Related JoVE Video
Expression, purification, crystallization and preliminary X-ray analysis of eCGP123, an extremely stable monomeric green fluorescent protein with reversible photoswitching properties.
Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun.
PUBLISHED: 05-25-2011
Show Abstract
Hide Abstract
Enhanced consensus green protein variant 123 (eCGP123) is an extremely thermostable green fluorescent protein (GFP) that exhibits useful negative reversible photoswitching properties. eCGP123 was derived by the application of both a consensus engineering approach and a recursive evolutionary process. Diffraction-quality crystals of recombinant eCGP123 were obtained by the hanging-drop vapour-diffusion method using PEG 3350 as the precipitant. The eCGP123 crystal diffracted X-rays to 2.10 Å resolution. The data were indexed in space group P1, with unit-cell parameters a = 74.63, b = 75.38, c = 84.51 Å, ? = 90.96, ? = 89.92, ? = 104.03°. The Matthews coefficient (V(M) = 2.26 Å(3) Da(-1)) and a solvent content of 46% indicated that the asymmetric unit contained eight eCGP123 molecules.
Related JoVE Video
Development of phage-based single chain Fv antibody reagents for detection of Yersinia pestis.
PLoS ONE
PUBLISHED: 05-19-2011
Show Abstract
Hide Abstract
Most Yersinia pestis strains are known to express a capsule-like antigen, fraction 1 (F1)(.) F1 is encoded by the caf1 gene located on the large 100-kb pFra plasmid, which is found in Y. pestis but not in closely related species such as Yersinia enterocolytica and Yersinia pseudotuberculosis. In order to find antibodies specifically binding to Y. pestis we screened a large single chain Fv antibody fragment (scFv) phage display library using purified F1 antigen as a selection target. Different forms of the selected antibodies were used to establish assays for recombinant F1 antigen and Y. pestis detection.
Related JoVE Video
Changes in thrombin generation, fibrinolysis, platelet and endothelial cell activity, and inflammation following endovascular abdominal aortic aneurysm repair.
J. Vasc. Surg.
PUBLISHED: 05-18-2011
Show Abstract
Hide Abstract
Abdominal aortic aneurysm (AAA) is a chronic inflammatory condition associated with a prothrombotic, hypofibrinolytic diathesis that may increase the risk of cardiovascular events. The effect of endovascular aneurysm repair (EVAR) on this prothrombotic diathesis is not fully understood, especially over the medium and long term. A better understanding of these postintervention changes may improve the risk of cardiovascular complications in the long term. The purpose of this study was to examine thrombin generation, fibrinolysis, platelet and endothelial activation, and the inflammatory response during the 12 months following EVAR.
Related JoVE Video
Cryptic genetic gluten intolerance revealed by intestinal antitransglutaminase antibodies and response to gluten-free diet.
Gut
PUBLISHED: 04-06-2011
Show Abstract
Hide Abstract
Antitransglutaminase (anti-TG2) antibodies are synthesised in the intestine and their presence seems predictive of future coeliac disease (CD). This study investigates whether mucosal antibodies represent an early stage of gluten intolerance even in the absence of intestinal damage and serum anti-TG2 antibodies.
Related JoVE Video
Fluorescent labeling of antibody fragments using split GFP.
PLoS ONE
PUBLISHED: 03-24-2011
Show Abstract
Hide Abstract
Antibody fragments are easily isolated from in vitro selection systems, such as phage and yeast display. Lacking the Fc portion of the antibody, they are usually labeled using small peptide tags recognized by antibodies. In this paper we present an efficient method to fluorescently label single chain Fvs (scFvs) using the split green fluorescent protein (GFP) system. A 13 amino acid tag, derived from the last beta strand of GFP (termed GFP11), is fused to the C terminus of the scFv. This tag has been engineered to be non-perturbing, and we were able to show that it exerted no effect on scFv expression or functionality when compared to a scFv without the GFP11 tag. Effective functional fluorescent labeling is demonstrated in a number of different assays, including fluorescence linked immunosorbant assays, flow cytometry and yeast display. Furthermore, we were able to show that this split GFP system can be used to determine the concentration of scFv in crude samples, as well an estimate of antibody affinity, without the need for antibody purification. We anticipate this system will be of widespread interest in antibody engineering and in vitro display systems.
Related JoVE Video
Beyond natural antibodies: the power of in vitro display technologies.
Nat. Biotechnol.
PUBLISHED: 03-11-2011
Show Abstract
Hide Abstract
In vitro display technologies, best exemplified by phage and yeast display, were first described for the selection of antibodies some 20 years ago. Since then, many antibodies have been selected and improved upon using these methods. Although it is not widely recognized, many of the antibodies derived using in vitro display methods have properties that would be extremely difficult, if not impossible, to obtain by immunizing animals. The first antibodies derived using in vitro display methods are now in the clinic, with many more waiting in the wings. Unlike immunization, in vitro display permits the use of defined selection conditions and provides immediate availability of the sequence encoding the antibody. The amenability of in vitro display to high-throughput applications broadens the prospects for their wider use in basic and applied research.
Related JoVE Video
Endovascular aneurysm repair reverses the increased titer and the inflammatory activity of interleukin-1? in the serum of patients with abdominal aortic aneurysm.
J. Vasc. Surg.
PUBLISHED: 02-23-2011
Show Abstract
Hide Abstract
To examine serum cytokine/chemokine profiles before and 6 months after endovascular repair (EVAR) of abdominal aortic aneurysm (AAA) and to determine whether they correlate with serum inflammatory activity using an in vitro model of leukocyte recruitment.
Related JoVE Video
Coagulation, fibrinolysis, and platelet activation in patients undergoing open and endovascular repair of abdominal aortic aneurysm.
J. Vasc. Surg.
PUBLISHED: 01-30-2011
Show Abstract
Hide Abstract
Endovascular aneurysm repair (EVAR) is associated with an improved perioperative mortality compared to open surgical repair. This benefit may reflect reduced incidence of microvascular and macrovascular thrombotic complications after EVAR.
Related JoVE Video
High risk of peripheral arterial disease in the United Kingdom: 2-year results of a prospective registry.
Angiology
PUBLISHED: 01-12-2011
Show Abstract
Hide Abstract
We report a prospective 2-year, multicenter study of patients presenting with intermittent claudication (IC; ankle brachial blood pressure index, ABPI ? 0.9). Mean age of the 473 patients enrolled was 68 years, 20% were diabetics, 30% had prior symptomatic coronary heart disease (CHD), 7% had prior stroke, and 39% were current smokers. At baseline, 26.2% of patients had BP ? 140/85 mm Hg or lower and at 2 years this figure was 32.5% (P = .01). Current smokers had fallen to 27% (from 39%) at 2 years (P < .001). Use of antiplatelet agents, statins, and angiotensin converting enzyme inhibitors increased significantly during the course of the study as did claudication distance. Death and the composite of death, stroke or myocardial infarction (MI), occurred in 8.4% and 11.6% of patients, respectively. Prognosis was worse in patients with prior history of CHD, older age, those with diabetes and a lower ABPI.
Related JoVE Video
Epidemiology and aetiology of C4-6 disease.
Phlebology
PUBLISHED: 09-28-2010
Show Abstract
Hide Abstract
Although our understanding of chronic venous insufficiency (CVI) has improved, many important questions remain unanswered. Ensuring that patients are appropriately referred for specialist assessment and then receive evidence-based, cost-effective treatment continues to be challenging. The lifetime of risk of chronic venous ulceration (CVU) is around 1% with approximately 10% ulcers being open at any one time. The incidence skin changes disease is about 10 times greater (10%). However, many of the studies upon which these estimates are based are old and/or methodologically flawed. There is reason to believe that the incidence, prevalence and characteristics of CVI/CVU may have changed considerably over the last 10-20 years and that future change is likely. Further cross-sectional and longitudinal epidemiological studies are required to establish the size and nature of the health-care need going forward in developed and increasingly developing countries. CVI culminating CVU is primarily the result of sustained ambulatory venous hypertension, which in turn arises from superficial and/or deep venous reflux with or without deep vein obstruction. However, there are many other elements to this complex condition, for example, microvascular dysfunction; calf muscle pump efficiency; dermal inflammation; disordered fibroblast function and matrix production; failure of epithelialization; congenital and acquired thrombophilia; malnutrition, obesity and diet; and bacterial colonization. None of the currently available treatment modalities is entirely satisfactory and novel therapies based upon a clearer understanding of the disease at the psychological, genetic, mechanical, microvascular and microscopic level are required.
Related JoVE Video
Sequence analysis of the human tyrosylprotein sulfotransferase-2 gene in subjects with chronic pancreatitis.
Pancreatology
PUBLISHED: 05-12-2010
Show Abstract
Hide Abstract
Human trypsinogens are post-translationally sulfated on Tyr154 by the Golgi resident enzyme tyrosylprotein sulfotransferase-2 (TPST2). Tyrosine sulfation stimulates the autoactivation of human cationic trypsinogen. Because increased trypsinogen autoactivation has been implicated as a pathogenic mechanism in chronic pancreatitis, we hypothesized that genetic variants of TPST2 might alter the risk for the disease.
Related JoVE Video
The use of phage display in neurobiology.
Curr Protoc Neurosci
PUBLISHED: 04-08-2010
Show Abstract
Hide Abstract
Phage display has been extensively used to study protein-protein interactions, receptor- and antibody-binding sites, and immune responses, to modify protein properties, and to select antibodies against a wide range of different antigens. In the format most often used, a polypeptide is displayed on the surface of a filamentous phage by genetic fusion to one of the coat proteins, creating a chimeric coat protein, and coupling phenotype (the protein) to genotype (the gene within). As the gene encoding the chimeric coat protein is packaged within the phage, selection of the phage on the basis of the binding properties of the polypeptide displayed on the surface simultaneously results in the isolation of the gene encoding the polypeptide. This unit describes the background to the technique, and illustrates how it has been applied to a number of different problems, each of which has its neurobiological counterparts. Although this overview concentrates on the use of filamentous phage, which is the most popular platform, other systems are also described.
Related JoVE Video
Changes in health-related quality of life after ultrasound-guided foam sclerotherapy for great and small saphenous varicose veins.
J. Vasc. Surg.
PUBLISHED: 03-30-2010
Show Abstract
Hide Abstract
Health-related quality of life (HRQOL) improves after superficial venous surgery for varicose veins, but the effect of ultrasound-guided foam sclerotherapy on HRQOL is unknown. The aim of this study was to determine changes in HRQOL after ultrasound-guided foam sclerotherapy for varicose veins.
Related JoVE Video
Outcome in patients requiring renal replacement therapy after open surgical repair for ruptured abdominal aortic aneurysm.
Vasc Endovascular Surg
PUBLISHED: 03-24-2010
Show Abstract
Hide Abstract
To determine the relationship between postoperative renal replacement therapy (RRT) and patient survival after open surgical repair (OR) of ruptured abdominal aortic aneurysm (rAAA).
Related JoVE Video
Ultrasound-guided foam sclerotherapy is a safe and clinically effective treatment for superficial venous reflux.
J. Vasc. Surg.
PUBLISHED: 03-06-2010
Show Abstract
Hide Abstract
To test the hypothesis that ultrasound-guided foam sclerotherapy (UGFS) is a safe and durable treatment for superficial venous reflux (SVR) associated with CEAP clinical grade 2-6 disease.
Related JoVE Video
Rapid interactome profiling by massive sequencing.
Nucleic Acids Res.
PUBLISHED: 02-09-2010
Show Abstract
Hide Abstract
We have developed a high-throughput protein expression and interaction analysis platform that combines cDNA phage display library selection and massive gene sequencing using the 454 platform. A phage display library of open reading frame (ORF) fragments was created from mRNA derived from different tissues. This was used to study the interaction network of the enzyme transglutaminase 2 (TG2), a multifunctional enzyme involved in the regulation of cell growth, differentiation and apoptosis, associated with many different pathologies. After two rounds of panning with TG2 we assayed the frequency of ORFs within the selected phage population using 454 sequencing. Ranking and analysis of more than 120,000 sequences allowed us to identify several potential interactors, which were subsequently confirmed in functional assays. Within the identified clones, three had been previously described as interacting proteins (fibronectin, SMOC1 and GSTO2), while all the others were new. When compared with standard systems, such as microtiter enzyme-linked immunosorbant assay, the method described here is dramatically faster and yields far more information about the interaction under study, allowing better characterization of complex systems. For example, in the case of fibronectin, it was possible to identify the specific domains involved in the interaction.
Related JoVE Video
Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial: A survival prediction model to facilitate clinical decision making.
J. Vasc. Surg.
PUBLISHED: 01-24-2010
Show Abstract
Hide Abstract
An intention-to-treat analysis of the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial showed that in patients with severe lower limb ischemia (SLI) due to infrainguinal disease who survived for 2 years after intervention, initial randomization to a bypass surgery (BSX)-first vs balloon angioplasty (BAP)-first revascularization strategy was associated with improvements in subsequent overall survival (OS) and amputation-free survival (AFS) of about 7 and 6 months, respectively. This study explored the value of baseline factors to estimate the likelihood of survival to 2 years for the trial cohort (Cox model) and for individual BASIL trial patients (Weibull model) as an aid to clinical decision making.
Related JoVE Video
Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial: Health-related quality of life outcomes, resource utilization, and cost-effectiveness analysis.
J. Vasc. Surg.
PUBLISHED: 01-24-2010
Show Abstract
Hide Abstract
The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial showed that survival in patients with severe lower limb ischemia (rest pain, tissue loss) who survived postintervention for >2 years after initial randomization to bypass surgery (BSX) vs balloon angioplasty (BAP) was associated with an improvement in subsequent amputation-free and overall survival of about 6 and 7 months, respectively. We now compare the effect on hospital costs and health-related quality of life (HRQOL) of the BSX-first and BAP-first revascularization strategies using a within-trial cost-effectiveness analysis.
Related JoVE Video
Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial: A description of the severity and extent of disease using the Bollinger angiogram scoring method and the TransAtlantic Inter-Society Consensus II classification.
J. Vasc. Surg.
PUBLISHED: 01-24-2010
Show Abstract
Hide Abstract
The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial showed in patients with severe lower limb ischemia (rest pain, tissue loss) who survive for 2 years after intervention that initial randomization to bypass surgery, compared with balloon angioplasty, was associated with an improvement in subsequent amputation-free survival and overall survival of about 6 and 7 months, respectively. The aim of this report is to describe the angiographic severity and extent of infrainguinal arterial disease in the BASIL trial cohort so that the trial outcomes can be appropriately generalized to other patient cohorts with similar anatomic (angiographic) patterns of disease.
Related JoVE Video
Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial: Analysis of amputation free and overall survival by treatment received.
J. Vasc. Surg.
PUBLISHED: 01-24-2010
Show Abstract
Hide Abstract
An intention-to-treat analysis of randomized Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial data showed that initial randomization to a bypass surgery (BSX)-first strategy was associated with improvements in subsequent overall survival (OS) and amputation-free survival (AFS) of about 7 and 6 months, respectively. We describe the nature and timing of first, crossover, and reinterventions and examine AFS and OS by first treatment received. We also compare vein with prosthetic BSX and transluminal with subintimal balloon angioplasty (BAP) and examine outcomes from BSX after failed BAP.
Related JoVE Video
Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial: An intention-to-treat analysis of amputation-free and overall survival in patients randomized to a bypass surgery-first or a balloon angioplasty-first revascularization strategy.
J. Vasc. Surg.
PUBLISHED: 01-24-2010
Show Abstract
Hide Abstract
A 2005 interim analysis of the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial showed that in patients with severe lower limb ischemia (SLI; rest pain, ulceration, gangrene) due to infrainguinal disease, bypass surgery (BSX)-first and balloon angioplasty (BAP)-first revascularization strategies led to similar short-term clinical outcomes, although BSX was about one-third more expensive and morbidity was higher. We have monitored patients for a further 2.5 years and now report a final intention-to-treat (ITT) analysis of amputation-free survival (AFS) and overall survival (OS).
Related JoVE Video
Bypass versus angioplasty in severe ischaemia of the leg (BASIL) trial: what are its implications?
Semin Vasc Surg
PUBLISHED: 12-17-2009
Show Abstract
Hide Abstract
Lack of Level I evidence from randomized controlled trials (RCT) means that the relative merits of surgical and endovascular revascularization strategies for severe limb ischemia (SLI) due to infrainguinal disease remain unclear. The Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL) trial remains the only multicenter RCT to have compared the clinical and cost-effectiveness of bypass surgery (BSX)-first and balloon angioplasty (BAP)-first revascularization strategies for infrainguinal SLI. An intention to treat analysis shows that out to 2 years both strategies were associated with similar amputation-free (AFS) and overall survival (OS) rates, as well as improvements in health-related quality of life. In the short-term, BSX was significantly more morbid and expensive. However, for those patients who survived for 2 years after randomization, initial randomization to a BSX-first strategy was associated with a significant increase in subsequent OS of about 7 months and a nonsignificant increase in subsequent AFS of about 6 months. Vein BSX performed significantly better than prosthetic BSX in terms of AFS but not OS. For most patients BAP also appears preferable to prosthetic BSX. Patients who underwent BSX after a failed BAP-first strategy did not fare as well as those who received BSX as their first procedure. Patients who are expected to live less than 2 years should usually be offered BAP first, especially when the alternative is prosthetic BSX. Those expected to survive beyond this time horizon (approximately 75% of the BASIL cohort) should usually be offered BSX first, especially where vein is available. Further RCTs to confirm or refute these findings and recommendations are required.
Related JoVE Video
A comprehensive analysis of filamentous phage display vectors for cytoplasmic proteins: an analysis with different fluorescent proteins.
Nucleic Acids Res.
PUBLISHED: 12-02-2009
Show Abstract
Hide Abstract
Filamentous phage display has been extensively used to select proteins with binding properties of specific interest. Although many different display platforms using filamentous phage have been described, no comprehensive comparison of their abilities to display similar proteins has been conducted. This is particularly important for the display of cytoplasmic proteins, which are often poorly displayed with standard filamentous phage vectors. In this article, we have analyzed the ability of filamentous phage to display a stable form of green fluorescent protein and modified variants in nine different display vectors, a number of which have been previously proposed as being suitable for cytoplasmic protein display. Correct folding and display were assessed by phagemid particle fluorescence, and with anti-GFP antibodies. The poor correlation between phagemid particle fluorescence and recognition of GFP by antibodies, indicates that proteins may fold correctly without being accessible for display. The best vector used a twin arginine transporter leader to transport the displayed protein to the periplasm, and a coil-coil arrangement to link the displayed protein to g3p. This vector was able to display less robust forms of GFP, including ones with inserted epitopes, as well as fluorescent proteins of the Azami green series. It was also functional in mock selection experiments.
Related JoVE Video
Suggested objective performance goals and clinical trial design for evaluating catheter-based treatment of critical limb ischemia.
J. Vasc. Surg.
PUBLISHED: 09-14-2009
Show Abstract
Hide Abstract
To develop a set of suggested objective performance goals (OPG) for evaluating new catheter-based treatments in critical limb ischemia (CLI), based on evidence from historical controls.
Related JoVE Video
A community standard format for the representation of protein affinity reagents.
Mol. Cell Proteomics
PUBLISHED: 08-11-2009
Show Abstract
Hide Abstract
Protein affinity reagents (PARs), most commonly antibodies, are essential reagents for protein characterization in basic research, biotechnology, and diagnostics as well as the fastest growing class of therapeutics. Large numbers of PARs are available commercially; however, their quality is often uncertain. In addition, currently available PARs cover only a fraction of the human proteome, and their cost is prohibitive for proteome scale applications. This situation has triggered several initiatives involving large scale generation and validation of antibodies, for example the Swedish Human Protein Atlas and the German Antibody Factory. Antibodies targeting specific subproteomes are being pursued by members of Human Proteome Organisation (plasma and liver proteome projects) and the United States National Cancer Institute (cancer-associated antigens). ProteomeBinders, a European consortium, aims to set up a resource of consistently quality-controlled protein-binding reagents for the whole human proteome. An ultimate PAR database resource would allow consumers to visit one on-line warehouse and find all available affinity reagents from different providers together with documentation that facilitates easy comparison of their cost and quality. However, in contrast to, for example, nucleotide databases among which data are synchronized between the major data providers, current PAR producers, quality control centers, and commercial companies all use incompatible formats, hindering data exchange. Here we propose Proteomics Standards Initiative (PSI)-PAR as a global community standard format for the representation and exchange of protein affinity reagent data. The PSI-PAR format is maintained by the Human Proteome Organisation PSI and was developed within the context of ProteomeBinders by building on a mature proteomics standard format, PSI-molecular interaction, which is a widely accepted and established community standard for molecular interaction data. Further information and documentation are available on the PSI-PAR web site.
Related JoVE Video
Antibody library selection by the {beta}-lactamase protein fragment complementation assay.
Protein Eng. Des. Sel.
PUBLISHED: 08-11-2009
Show Abstract
Hide Abstract
Protein fragment complementation assay (PCA) is based on the interaction between two protein partners (e.g. target antigen and antibody), which are genetically fused to the two halves of a dissected marker protein. Binding of the two partners reassembles the marker protein and hence reconstitutes its activity. In this work we have developed the first application of beta-lactamase-based PCA for the isolation of single chain Fv fragments (scFvs) binding to the human receptor RON from a naïve library. Specific scFvs with the ability to immunoprecipitate could be isolated after a single round of PCA selection from an scFv repertoire previously pre-selected by phage display. Furthermore, the PCA was used to successfully map the epitopes recognized by the selected scFvs by screening them against a small library of random RON fragments.
Related JoVE Video
Reduction in the rate of methicillin-resistant Staphylococcus aureus acquisition in surgical wards by rapid screening for colonization: a prospective, cross-over study.
Clin. Microbiol. Infect.
PUBLISHED: 07-20-2009
Show Abstract
Hide Abstract
Identification of patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) and subsequent isolation and decolonization is pivotal to the control of cross infection in hospitals. The aim of this study was to establish if early identification of colonized patients using rapid methods alone reduces transmission. A prospective, cluster, two-period cross-over design was used. Seven surgical wards at a large hospital were allocated to two groups, and for the first 8 months four wards used rapid MRSA screening and three wards used a standard culture method. The groups were reversed for the second 8 months. Regardless of the method of detection, all patients were screened for nasal carriage on admission and then every 4 days. MRSA control measures remained constant. Results were analysed using a log linear Poisson regression model. A total of 12 682/13 952 patient ward episodes (PWE) were included in the study. Admission screening identified 453 (3.6%) MRSA-positive patient ward episodes, with a further 268 (2.2%) acquiring MRSA. After adjusting for other variables, rapid screening was shown to statistically reduce MRSA acquisition, with patients being 1.49 times (p 0.007) more likely to acquire MRSA in wards where they were screened using the culture method. Screening of surgical patients using rapid testing resulted in a statistically significant reduction in MRSA acquisition. This result was achieved in a routine surgical service with high bed occupancy and low availability of isolation rooms, making it applicable to the majority of health-care systems worldwide.
Related JoVE Video
Surgical versus endovascular reconstruction for chronic mesenteric ischemia: a contemporary UK series.
Vasc Endovascular Surg
PUBLISHED: 06-06-2009
Show Abstract
Hide Abstract
To assess the outcome of surgical (SR) and endovascular (ER) reconstruction for chronic mesenteric ischemia (CMI).
Related JoVE Video
Directed evolution of an extremely stable fluorescent protein.
Protein Eng. Des. Sel.
PUBLISHED: 04-15-2009
Show Abstract
Hide Abstract
In this paper we describe the evolution of eCGP123, an extremely stable green fluorescent protein based on a previously described fluorescent protein created by consensus engineering (CGP: consensus green protein). eCGP123 could not be denatured by a standard thermal melt, preserved almost full fluorescence after overnight incubation at 80 degrees C and possessed a free energy of denaturation of 12.4 kcal/mol. It was created from CGP by a recursive process involving the sequential introduction of three destabilizing heterologous inserts, evolution to overcome the destabilization and finally removal of the destabilizing insert by gene synthesis. We believe that this approach may be generally applicable to the stabilization of other proteins.
Related JoVE Video
Higher prevalence of thrombophilia in patients with varicose veins and venous ulcers than controls.
J. Vasc. Surg.
PUBLISHED: 03-25-2009
Show Abstract
Hide Abstract
Uncontrolled studies suggest that patients with chronic venous ulceration (CVU) have an increased prevalence of thrombophilia, similar to that observed in patients with deep vein thrombosis. This study compared the nature and prevalence of thrombophilia in patients with varicose veins (VV, CEAP clinical [C] grade C(2) to C(3)) and patients with CVU (C(5) to C(6)) with an age- and sex-matched population without clinical or duplex ultrasound evidence of venous disease.
Related JoVE Video
Multiplexed flow cytometry: high-throughput screening of single-chain antibodies.
Methods Mol. Biol.
PUBLISHED: 03-03-2009
Show Abstract
Hide Abstract
The development of high-throughput screening (HTS) technologies has become essential for initial characterization of recombinant antibodies and alternative affinity reagents, selected from large combinatorial libraries. Such binding ligands are routinely selected against a single antigen and screened for desired binding specificities. Recent progress with genome sequencing projects has led to widespread efforts to study corresponding proteomes; requiring selection of ligands against large numbers of gene products in a highly parallel manner. The capabilities of many routine HTS methods such as enzyme-linked immunosorbent assay (ELISA), or array-based methods, are limited to analysis of numerous different antibody clones against a single target or, individual antibody clones against many different targets. We have developed a multiplexed flow cytometry screening method that allows analysis of individual binding ligands against numerous targets in the same analytical sample. The method produces a complex analytical profile for each antibody clone in the primary screen, by allowing simultaneous determination of relative expression levels, identification of non-specific binding, and discrimination of fine specificities. The quality and quantity of data, combined with significant reductions in analysis time and antigen consumption, provide notable advantages over other standard screening methods, such as ELISA. By combining HT screening capabilities with multiplex technology, we have redefined the parameters for the initial identification of affinity reagents recovered from combinatorial libraries and removed a significant bottleneck in the generation of affinity reagents on a proteomic scale.
Related JoVE Video
A common African polymorphism abolishes tyrosine sulfation of human anionic trypsinogen (PRSS2).
Biochem. J.
PUBLISHED: 02-14-2009
Show Abstract
Hide Abstract
Human pancreatic trypsinogens undergo post-translational sulfation on Tyr(154), catalysed by the Golgi-resident enzyme tyrosylprotein sulfotransferase 2. Sequence alignments suggest that the sulfation of Tyr(154) is facilitated by a unique sequence context which is characteristically found in primate trypsinogens. In the search for genetic variants that might alter this sulfation motif, we identified a single nucleotide polymorphism (c.457G>C) in the PRSS2 (serine protease 2, human anionic trypsinogen) gene, which changed Asp(153) to a histidine residue (p.D153H). The p.D153H variant is common in subjects of African origin, with a minor allele frequency of 9.2%, whereas it is absent in subjects of European descent. We demonstrate that Asp(153) is the main determinant of tyrosine sulfation in anionic trypsinogen, as both the natural p.D153H variation and the p.D153N mutation result in a complete loss of trypsinogen sulfation. In contrast, mutation of Asp(156) and Glu(157) only slightly decrease tyrosine sulfation, whereas mutation of Gly(151) and Pro(155) has no effect. With respect to the biological relevance of the p.D153H variant, we found that tyrosine sulfation had no significant effect on the activation of anionic trypsinogen or the catalytic activity and inhibitor sensitivity of anionic trypsin. Taken together with previous studies, the observations of the present study suggest that the primary role of trypsinogen sulfation in humans is to stimulate autoactivation of PRSS1 (serine protease 1, human cationic trypsinogen), whereas the sulfation of anionic trypsinogen is unimportant for normal digestive physiology. As a result, the p.D153H polymorphism which eliminates this modification could become widespread in a healthy population.
Related JoVE Video
Using phage and yeast display to select hundreds of monoclonal antibodies: application to antigen 85, a tuberculosis biomarker.
PLoS ONE
Show Abstract
Hide Abstract
Current diagnostic methods for tuberculosis (TB), a major global health challenge that kills nearly two million people annually, are time-consuming and inadequate. During infection a number of bacterial molecules that play a role in the infective process are released and have been proposed as biomarkers for early TB diagnosis. Antigen 85 (Ag85) is the most abundant secreted TB protein, and a potential target for this diagnostic approach. One of the bottlenecks in the direct detection of such bacterial targets is the availability of robust, sensitive, specific antibodies.
Related JoVE Video
Effect of endovascular and open abdominal aortic aneurysm repair on thrombin generation and fibrinolysis.
J. Vasc. Surg.
Show Abstract
Hide Abstract
Abdominal aortic aneurysm (AAA) is associated with a prothrombotic diathesis that may increase the risk of cardiovascular events. This diathesis is exacerbated in the short term by open aneurysm repair (OAR) and endovascular aneurysm repair (EVAR). However, the effect of EVAR and OAR on coagulation and fibrinolysis in the medium and long term is poorly understood. The purpose of this study was to investigate the medium-term effects of EVAR and OAR on thrombin generation, neutralization, and fibrinolysis.
Related JoVE Video
IBCs 23rd Antibody Engineering and 10th Antibody Therapeutics Conferences and the Annual Meeting of The Antibody Society: December 2-6, 2012, San Diego, CA.
MAbs
Show Abstract
Hide Abstract
Now in its 23rd and 10th years, respectively, the Antibody Engineering and Antibody Therapeutics conferences are the Annual Meeting of The Antibody Society. The scientific program covers the full spectrum of challenges in antibody research and development from basic science through clinical development. In this preview of the conferences, the chairs provide their thoughts on sessions that will allow participants to track emerging trends in (1) the development of next-generation immunomodulatory antibodies; (2) the complexity of the environment in which antibodies must function; (3) antibody-targeted central nervous system (CNS) therapies that cross the blood brain barrier; (4) the extension of antibody half-life for improved efficacy and pharmacokinetics (PK)/pharmacodynamics (PD); and (5) the application of next generation DNA sequencing to accelerate antibody research. A pre-conference workshop on Sunday, December 2, 2012 will update participants on recent intellectual property (IP) law changes that affect antibody research, including biosimilar legislation, the America Invents Act and recent court cases. Keynote presentations will be given by Andreas Plückthun (University of Zürich), who will speak on engineering receptor ligands with powerful cellular responses; Gregory Friberg (Amgen Inc.), who will provide clinical updates of bispecific antibodies; James D. Marks (University of California, San Francisco), who will discuss a systems approach to generating tumor targeting antibodies; Dario Neri (Swiss Federal Institute of Technology Zürich), who will speak about delivering immune modulators at the sites of disease; William M. Pardridge (University of California, Los Angeles), who will discuss delivery across the blood-brain barrier; and Peter Senter (Seattle Genetics, Inc.), who will present his vision for the future of antibody-drug conjugates. For more information on these meetings or to register to attend, please visit www.IBCLifeSciences.com/AntibodyEng or call 800-390-4078. Members of The Antibody Society and mAbs journal subscribers receive a 20% discount for meeting registration. To obtain this discount, email kdostie@ibcusa.com. mAbs is the official therapeutics journal of The Antibody Society and offers a discounted subscription to Society members for $49.
Related JoVE Video
Time-resolved, confocal single-molecule tracking of individual organic dyes and fluorescent proteins in three dimensions.
ACS Nano
Show Abstract
Hide Abstract
We demonstrate following individual fluorescent protein constructs and individual organic dyes as they diffuse in 3-D in solution at rates up to 1 ?m(2)/s over distances of several micrometers in X, Y, and Z. Our 3-D tracking method is essentially a stage scanning confocal microscope that uses a unique spatial filter geometry and active feedback 200 times/s to follow fast 3-D motion. Here we detail simulations used to find optimal feedback parameters for following individual fluorescent proteins in 3-D and show that a wide range of parameters are capable of following individual proteins diffusing at 1 ?m(2)/s rates. In addition, we experimentally show that through 3-D single-molecule tracking of a protein oligomer series (monomer, dimer, and tetramer) of the fluorescent protein Azami Green one can determine the protein oligomerization state. We also perform time-resolved spectroscopy (photon pair correlation measurements) during the measured 3-D trajectories. The photon pair correlation measurements show clear fluorescence photon antibunching, demonstrating that the trajectories are of single fluorescent molecules. We note that the rates of single-molecule diffusive motion we follow (approximately 1 ?m(2)/s) are comparable to or faster than many intracellular transport processes.
Related JoVE Video
Intravenous naftidrofuryl for critical limb ischaemia.
Cochrane Database Syst Rev
Show Abstract
Hide Abstract
Peripheral arterial disease affects five per cent of men and women by late middle age. Approximately 25% of those affected will develop critical limb ischaemia (rest pain, ulceration and gangrene) within five years. Naftidrofuryl is a vasoactive drug which may be beneficial in the treatment of critical limb ischaemia.
Related JoVE Video
Recombinant antibodies and in vitro selection technologies.
Methods Mol. Biol.
Show Abstract
Hide Abstract
Over the past decade, the accumulation of detailed knowledge of antibody structure and function has enabled antibody phage display to emerge as a powerful in vitro alternative to hybridoma methods for creating antibodies. Many antibodies produced using phage display technology have unique properties that are not obtainable using traditional hybridoma technologies. In phage display, selections are performed under controlled, in vitro conditions that are tailored to suit demands of the antigen and the sequence encoding the antibody is immediately available. These features obviate many of the limitations of hybridoma methodology, and because the entire process relies on scalable molecular biology techniques, phage display is also suitable for high-throughput applications. Thus, antibody phage display technology is well suited for genome-scale biotechnology and therapeutic applications. This review describes the antibody phage display technology and highlights examples of antibodies with unique properties that cannot easily be obtained by other technologies.
Related JoVE Video
The relationship between aortic aneurysm sac thrombus volume on coagulation, fibrinolysis and platelet activity.
Thromb. Res.
Show Abstract
Hide Abstract
Abdominal aortic aneurysm (AAA) is associated with chronic mural inflammation and a pro-thrombotic diathesis. It has been suggested that both may be related to biologically active intra-sac thrombus. The aim of this study was to examine the relationship between thrombin generation, fibrinolysis, platelet activity and AAA sac thrombus volume.
Related JoVE Video

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.