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Find video protocols related to scientific articles indexed in Pubmed.
An Extensive Antigenic Footprint Underpins Immunodominant TCR Adaptability against a Hypervariable Viral Determinant.
J. Immunol.
PUBLISHED: 10-29-2014
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Mutations in T cell epitopes are implicated in hepatitis C virus (HCV) persistence and can impinge on vaccine development. We recently demonstrated a narrow bias in the human TCR repertoire targeted at an immunodominant, but highly mutable, HLA-B*0801-restricted epitope ((1395)HSKKKCDEL(1403) [HSK]). To investigate if the narrow TCR repertoire facilitates CTL escape, structural and biophysical studies were undertaken, alongside comprehensive functional analysis of T cells targeted at the natural variants of HLA-B*0801-HSK in different HCV genotypes and quasispecies. Interestingly, within the TCR-HLA-B*0801-HSK complex, the TCR contacts all available surface-exposed residues of the HSK determinant. This broad epitope coverage facilitates cross-genotypic reactivity and recognition of common mutations reported in HCV quasispecies, albeit to a varying degree. Certain mutations did abrogate T cell reactivity; however, natural variants comprising these mutations are reportedly rare and transient in nature, presumably due to fitness costs. Overall, despite a narrow bias, the TCR accommodated frequent mutations by acting like a blanket over the hypervariable epitope, thereby providing effective viral immunity. Our findings simultaneously advance the understanding of anti-HCV immunity and indicate the potential for cross-genotype HCV vaccines.
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An investigation into the effects of temporal resolution on hepatic dynamic contrast-enhanced MRI in volunteers and in patients with hepatocellular carcinoma.
Phys Med Biol
PUBLISHED: 05-27-2014
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This study investigated the effect of temporal resolution on the dual-input pharmacokinetic (PK) modelling of dynamic contrast-enhanced MRI (DCE-MRI) data from normal volunteer livers and from patients with hepatocellular carcinoma. Eleven volunteers and five patients were examined at 3 T. Two sections, one optimized for the vascular input functions (VIF) and one for the tissue, were imaged within a single heart-beat (HB) using a saturation-recovery fast gradient echo sequence. The data was analysed using a dual-input single-compartment PK model. The VIFs and/or uptake curves were then temporally sub-sampled (at interval ?t = [2-20] s) before being subject to the same PK analysis. Statistical comparisons of tumour and normal tissue PK parameter values using a 5% significance level gave rise to the same study results when temporally sub-sampling the VIFs to HB < ?t <4 s. However, sub-sampling to ?t > 4 s did adversely affect the statistical comparisons. Temporal sub-sampling of just the liver/tumour tissue uptake curves at ?t ? 20 s, whilst using high temporal resolution VIFs, did not substantially affect PK parameter statistical comparisons. In conclusion, there is no practical advantage to be gained from acquiring very high temporal resolution hepatic DCE-MRI data. Instead the high temporal resolution could be usefully traded for increased spatial resolution or SNR.
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Clinical significance of hepatitis B virion and SVP productivity: relationships between intrahepatic and serum markers in chronic hepatitis B patients.
United European Gastroenterol J
PUBLISHED: 01-30-2014
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Clinical use of hepatitis B viral (HBV) quantitative seromarker\s remains questionable since it is not precisely known whether they represent intrahepatic viral replication. Covalently closed circular DNA (cccDNA), relaxed circular DNA (rcDNA), and pregenomic RNA (pgRNA) are more likely to represent active HBV replication and their measurement can be used to derive virion productivity (VP; rcDNA/cccDNA), subviral particle (SVP) productivity (quantitative HBsAg/cccDNA), and replicative activity (RA; pgRNA/cccDNA). These can be used to compare relative HBV replication between HBeAg-negative and -positive patients.
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Diversity and distribution of deep-sea shrimps in the Ross Sea region of Antarctica.
PLoS ONE
PUBLISHED: 01-01-2014
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Although decapod crustaceans are widespread in the oceans, only Natantia (shrimps) are common in the Antarctic. Because remoteness, depth and ice cover restrict sampling in the South Ocean, species distribution modelling is a useful tool for evaluating distributions. We used physical specimen and towed camera data to describe the diversity and distribution of shrimps in the Ross Sea region of Antarctica. Eight shrimp species were recorded: Chorismus antarcticus; Notocrangon antarcticus; Nematocarcinus lanceopes; Dendrobranchiata; Pasiphaea scotiae; Pasiphaea cf. ledoyeri; Petalidium sp., and a new species of Lebbeus. For the two most common species, N. antarcticus and N. lanceopes, we used maximum entropy modelling, based on records of 60 specimens and over 1130 observations across 23 sites in depths from 269 m to 3433 m, to predict distributions in relation to environmental variables. Two independent sets of environmental data layers at 0.05° and 0.5° resolution respectively, showed how spatial resolution affected the model. Chorismus antarcticus and N. antarcticus were found only on the continental shelf and upper slopes, while N. lanceopes, Lebbeus n. sp., Dendrobranchiata, Petalidium sp., Pasiphaea cf. ledoyeri, and Pasiphaea scotiae were found on the slopes, seamounts and abyssal plain. The environmental variables that contributed most to models for N. antarcticus were depth, chlorophyll-a concentration, temperature, and salinity, and for N. lanceopes were depth, ice concentration, seabed slope/rugosity, and temperature. The relative ranking, but not the composition of these variables changed in models using different spatial resolutions, and the predicted extent of suitable habitat was smaller in models using the finer-scale environmental layers. Our modelling indicated that shrimps were widespread throughout the Ross Sea region and were thus likely to play important functional role in the ecosystem, and that the spatial resolution of data needs to be considered both in the use of species distribution models.
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Radiology of eating disorders: a pictorial review.
Radiographics
PUBLISHED: 07-12-2013
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Eating disorders are a major challenge for health professionals, with many patients receiving ineffective care due to underdiagnosis or poor compliance with treatment. The incidence of eating disorders is increasing worldwide, producing an increasing burden on healthcare systems, and they most often affect young patients, with significant long-term complications. The effects of long-term malnutrition manifest in almost every organ system, and many can be detected radiologically, even without overt clinical findings. Musculoskeletal complications including osteoporosis result in a high incidence of insufficiency fractures, with long-term implications for bone health and growth, while respiratory complications are often recognized late due to disordered physiologic responses to infection. Gastrointestinal complications are numerous and in extreme cases may result in fatal outcomes after acute gastric dilatation and rupture subsequent to binge eating. In patients with severely disordered eating, in particular anorexia nervosa, marked derangement of electrolyte levels may result in refeeding syndrome, which requires emergent management. Recognition of such complications is critical to effective patient care and requires radiologists to be aware of the spectrum of imaging abnormalities that may be seen. Since many patients are reluctant to disclose their underlying condition, radiologists also play a critical role in identifying previously undiagnosed eating disorders.
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The molecular epidemiology of hepatitis B in the Indigenous people of northern Australia.
J. Gastroenterol. Hepatol.
PUBLISHED: 02-02-2013
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The hepatitis B surface antigen was first described in the blood of an Indigenous Australian man, yet little is known about its molecular epidemiology in this population, in which it is endemic. The study aimed to determine the clinical and molecular epidemiology of hepatitis B virus (HBV) in Indigenous people from northern Australia.
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Cold seep epifaunal communities on the hikurangi margin, new zealand: composition, succession, and vulnerability to human activities.
PLoS ONE
PUBLISHED: 01-01-2013
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Cold seep communities with distinctive chemoautotrophic fauna occur where hydrocarbon-rich fluids escape from the seabed. We describe community composition, population densities, spatial extent, and within-region variability of epifaunal communities at methane-rich cold seep sites on the Hikurangi Margin, New Zealand. Using data from towed camera transects, we match observations to information about the probable life-history characteristics of the principal fauna to develop a hypothetical succession sequence for the Hikurangi seep communities, from the onset of fluid flux to senescence. New Zealand seep communities exhibit taxa characteristic of seeps in other regions, including predominance of large siboglinid tubeworms, vesicomyid clams, and bathymodiolin mussels. Some aspects appear to be novel; however, particularly the association of dense populations of ampharetid polychaetes with high-sulphide, high-methane flux, soft-sediment microhabitats. The common occurrence of these ampharetids suggests they play a role in conditioning sulphide-rich sediments at the sediment-water interface, thus facilitating settlement of clam and tubeworm taxa which dominate space during later successional stages. The seep sites are subject to disturbance from bottom trawling at present and potentially from gas hydrate extraction in future. The likely life-history characteristics of the dominant megafauna suggest that while ampharetids, clams, and mussels exploit ephemeral resources through rapid growth and reproduction, lamellibrachid tubeworm populations may persist potentially for centuries. The potential consequences of gas hydrate extraction cannot be fully assessed until extraction methods and target localities are defined but any long-term modification of fluid flow to seep sites would have consequences for all chemoautotrophic fauna.
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Angiogenesis imaging in neoplasia.
J Clin Imaging Sci
PUBLISHED: 05-03-2011
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Angiogenesis plays a key role in physiological and pathophysiological processes and is recognized as being essential for tumor growth and metastases. The recent oncological development of anti-angiogenic drugs brings with it a need for angiogenesis quantification and monitoring of response. The nature of these agents means that traditional anatomical methods of assessing morphologic change are outmoded and functional imaging techniques and/or agents are necessary. Herein, we describe the various imaging techniques that can be employed to assess angiogenesis, along with their inherent advantages and disadvantages and discuss the current and future developments in the field.
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Antigen-driven patterns of TCR bias are shared across diverse outcomes of human hepatitis C virus infection.
J. Immunol.
PUBLISHED: 12-15-2010
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Hepatitis C virus (HCV) infection causes significant morbidity and mortality worldwide. T cells play a central role in HCV clearance; however, there is currently little understanding of whether the disease outcome in HCV infection is influenced by the choice of TCR repertoire. TCR repertoires used against two immunodominant HCV determinants--the highly polymorphic, HLA-B*0801 restricted (1395)HSKKKCDEL(1403) (HSK) and the comparatively conserved, HLA-A*0101-restricted, (1435)ATDALMTGY(1443) (ATD)--were analyzed in clearly defined cohorts of HLA-matched, HCV-infected individuals with persistent infection and HCV clearance. In comparison with ATD, TCR repertoire selected against HSK was more narrowly focused, supporting reports of mutational escape in this epitope, in persistent HCV infection. Notwithstanding the Ag-driven divergence, T cell repertoire selection against either Ag was comparable in subjects with diverse disease outcomes. Biased T cell repertoires were observed early in infection and were evident not only in persistently infected individuals but also in subjects with HCV clearance, suggesting that these are not exclusively characteristic of viral persistence. Comprehensive clonal analysis of Ag-specific T cells revealed widespread use of public TCRs displaying a high degree of predictability in TRBV/TRBJ gene usage, CDR3 length, and amino acid composition. These public TCRs were observed against both ATD and HSK and were shared across diverse disease outcomes. Collectively, these observations indicate that repertoire diversity rather than particular V? segments are better associated with HCV persistence/clearance in humans. Notably, many of the anti-HCV TCRs switched TRBV and TRBJ genes around a conserved, N nucleotide-encoded CDR3 core, revealing TCR sequence mosaicism as a potential host mechanism to combat this highly variant virus.
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Association between aneurysm shoulder stress and abdominal aortic aneurysm expansion: a longitudinal follow-up study.
Circulation
PUBLISHED: 10-18-2010
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Aneurysm expansion rate is an important indicator of the potential risk of abdominal aortic aneurysm (AAA) rupture. Stress within the AAA wall is also thought to be a trigger for its rupture. However, the association between aneurysm wall stresses and expansion of AAA is unclear.
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Submarine canyons: hotspots of benthic biomass and productivity in the deep sea.
Proc. Biol. Sci.
PUBLISHED: 05-05-2010
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Submarine canyons are dramatic and widespread topographic features crossing continental and island margins in all oceans. Canyons can be sites of enhanced organic-matter flux and deposition through entrainment of coastal detrital export, dense shelf-water cascade, channelling of resuspended particulate material and focusing of sediment deposition. Despite their unusual ecological characteristics and global distribution along oceanic continental margins, only scattered information is available about the influence of submarine canyons on deep-sea ecosystem structure and productivity. Here, we show that deep-sea canyons such as the Kaikoura Canyon on the eastern New Zealand margin (42 degrees 01 S, 173 degrees 03 E) can sustain enormous biomasses of infaunal megabenthic invertebrates over large areas. Our reported biomass values are 100-fold higher than those previously reported for deep-sea (non-chemosynthetic) habitats below 500 m in the ocean. We also present evidence from deep-sea-towed camera images that areas in the canyon that have the extraordinary benthic biomass also harbour high abundances of macrourid (rattail) fishes likely to be feeding on the macro- and megabenthos. Bottom-trawl catch data also indicate that the Kaikoura Canyon has dramatically higher abundances of benthic-feeding fishes than adjacent slopes. Our results demonstrate that the Kaikoura Canyon is one of the most productive habitats described so far in the deep sea. A new global inventory suggests there are at least 660 submarine canyons worldwide, approximately 100 of which could be biomass hotspots similar to the Kaikoura Canyon. The importance of such deep-sea canyons as potential hotspots of production and commercial fisheries yields merits substantial further study.
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Cost-effectiveness analysis of endovascular versus open surgical repair of acute abdominal aortic aneurysms based on worldwide experience.
J. Endovasc. Ther.
PUBLISHED: 04-30-2010
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To present an economic evaluation of endovascular versus open surgical repair of ruptured abdominal aortic aneurysms (AAA).
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Diffusion-weighted magnetic resonance imaging for the detection of lipid-rich necrotic core in carotid atheroma in vivo.
Neuroradiology
PUBLISHED: 03-05-2010
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Research has shown that knowing the morphology of carotid atheroma improves current risk stratification for predicting subsequent thrombo-embolic events. Previous magnetic resonance (MR) ex vivo studies have shown that diffusion-weighted imaging (DWI) can detect lipid-rich necrotic core (LR/NC) and fibrous cap. This study aims to establish if this is achievable in vivo.
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Mycotic pseudoaneurysm of the superficial femoral artery in a patient with Cushing disease: case report and literature review.
Vascular
PUBLISHED: 05-30-2009
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Mycotic pseudoaneurysms of the peripheral arteries are rare and can occur as an extension of localized infection or from systemic sepsis. In some cases, no obvious source of infection may be identified. Both endovascular and open surgical management options are available for this important condition. We report a mycotic pseudoaneurysm of the superficial femoral artery in a patient associated with systemic immunosuppression secondary to Cushing disease that was successfully managed with open surgical repair and autologous bypass grafting. This unusual case highlights the potential for serious adverse cardiovascular sequelae of Cushing disease and the need for awareness of such complications in this patient group.
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Utility of high resolution MR imaging to assess carotid plaque morphology: a comparison of acute symptomatic, recently symptomatic and asymptomatic patients with carotid artery disease.
Atherosclerosis
PUBLISHED: 02-04-2009
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Compare carotid plaque morphology of acute symptomatic, recently symptomatic and asymptomatic patients (groups 1, 2 and 3 respectively) with carotid artery disease using high resolution magnetic resonance imaging (MRI), to identify high-risk plaque characteristics best associated with risk of recurrent thrombo-embolic events.
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Carotid endarterectomy performed in the morning is associated with increased cerebral microembolization.
J. Vasc. Surg.
PUBLISHED: 01-03-2009
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Platelet function exhibits circadian variation with highest levels of activity in the morning and plays a central role in arterial thrombotic events, including thrombotic stroke following carotid endarterectomy (CEA). Prior to the platelet-rich thrombus occluding the carotid artery, multiple embolic signals are detected in the middle cerebral artery using transcranial Doppler ultrasound. We hypothesized that patients undergoing CEA early in the day may be at an increased stroke risk and this would manifest as an increased postoperative embolic count.
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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.