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Find video protocols related to scientific articles indexed in Pubmed.
Understanding the three-dimensional anatomy of the superficial lymphatics of the limbs.
Plast. Reconstr. Surg.
PUBLISHED: 10-28-2014
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There are minimal data in the current literature regarding the depth of the superficial lymphatic collectors of the limbs in relation to the various subcutaneous tissue layers.
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A continuous enzyme-coupled assay for triphosphohydrolase activity of HIV-1 restriction factor SAMHD1.
Antimicrob. Agents Chemother.
PUBLISHED: 10-22-2014
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Development of dNTP-based drugs requires a quantitative understanding of any inhibition, activation or hydrolysis by off-target cellular enzymes. SAMHD1 is a regulatory dNTP-triphosphohydrolase that inhibits HIV-1 replication in human myeloid cells. We describe a coupled-enzyme assay to quantify activation, inhibition and hydrolysis of dNTPs, nucleotide analogues and nucleotide analogue inhibitors by triphosphohydrolase enzymes. The assay facilitates mechanistic studies of triphosphohydrolase enzymes and quantification of off-target effects of nucleotide-based antiviral and chemotherapeutic agents.
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Structural studies of postentry restriction factors reveal antiparallel dimers that enable avid binding to the HIV-1 capsid lattice.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 06-16-2014
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Restriction factors (RFs) form important components of host defenses to retroviral infection. The Fv1, Trim5?, and TrimCyp RFs contain N-terminal dimerization and C-terminal specificity domains that target assembled retroviral capsid (CA) proteins enclosing the viral core. However, the molecular detail of the interaction between RFs and their CA targets is unknown. Therefore, we have determined the crystal structure of the B-box and coiled-coil (BCC) region from Trim5? and used small-angle X-ray scattering to examine the solution structure of Trim5? BCC, the dimerization domain of Fv1 (Fv1Ntd), and the hybrid restriction factor Fv1Cyp comprising Fv1NtD fused to the HIV-1 binding protein Cyclophilin A (CypA). These data reveal that coiled-coil regions of Fv1 and Trim5? form extended antiparallel dimers. In Fv1Cyp, two CypA moieties are located at opposing ends, creating a molecule with a dumbbell appearance. In Trim5?, the B-boxes are located at either end of the coiled-coil, held in place by interactions with a helical motif from the L2 region of the opposing monomer. A comparative analysis of Fv1Cyp and CypA binding to a preformed HIV-1 CA lattice reveals how RF dimerization enhances the affinity of interaction through avidity effects. We conclude that the antiparallel organization of the NtD regions of Fv1 and Trim5? dimers correctly positions C-terminal specificity and N-terminal effector domains and facilitates stable binding to adjacent CA hexamers in viral cores.
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Rigorous meta-analysis of life history correlations by simultaneously analyzing multiple population dynamics models.
Ecol Appl
PUBLISHED: 04-03-2014
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Correlations among life history parameters have been discussed in the ecological literature for over 50 years, but are often estimated while treating model estimates of demographic rates such as natural mortality (M) or individual growth (k) as "data." This approach fails to propagate uncertainty appropriately because it ignores correlations in estimation errors between parameters within a species and differences in estimation error among species. An improved alternative is multi-species mixed-effects modeling, which we approximate using multivariate likelihood profiles in an approach that synthesizes information from several population dynamics models. Simulation modeling demonstrates that this approach has minimal bias, and that precision improves with increased number of species. As a case study, we demonstrate this approach by estimating M/k for 11 groundfish species off the U.S. West Coast using the data and functional forms on which pre-existing, peer-reviewed, population dynamics models are based. M/k is estimated to be 1.26 for Pacific rockfishes (Sebastes spp.), with a coefficient of variation of 76% for M given k. This represents the first-ever estimate of correlations among life history parameters for marine fishes using several age-structured population dynamics models, and it serves as a standard for future life history correlation studies. This approach can be modified to provide robust estimates of other life history parameters and correlations, and requires few changes to existing population dynamics models and software input files for both marine and terrestrial species. Specific results for Pacific rockfishes can be used as a Bayesian prior for estimating natural mortality in future fisheries management efforts. We therefore recommend that fish population dynamics models be compiled in a global database that can be used to simultaneously analyze observation-level data for many species in life history meta-analyses.
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Hydrogen peroxide priming of the venous architecture: a new technique that reveals the underlying anatomical basis for venous complications of DIEP, TRAM, and other abdominal flaps.
Plast. Reconstr. Surg.
PUBLISHED: 02-27-2014
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Previous studies of venous anatomy lack the detail of their arterial counterparts because of (1) the technical challenge of retrograde perfusion against competent valves and (2) anterograde venous perfusion failing to adequately delineate the area of interest. We introduced a novel technique: retrograde hydrogen peroxide priming that dilates veins and renders valves incompetent, thereby facilitating complete cadaveric venous perfusion.
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FAN1 activity on asymmetric repair intermediates is mediated by an atypical monomeric virus-type replication-repair nuclease domain.
Cell Rep
PUBLISHED: 02-07-2014
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FAN1 is a structure-selective DNA repair nuclease with 5' flap endonuclease activity, involved in the repair of interstrand DNA crosslinks. It is the only eukaryotic protein with a virus-type replication-repair nuclease ("VRR-Nuc") "module" that commonly occurs as a standalone domain in many bacteria and viruses. Crystal structures of three representatives show that they structurally resemble Holliday junction resolvases (HJRs), are dimeric in solution, and are able to cleave symmetric four-way junctions. In contrast, FAN1 orthologs are monomeric and cleave 5' flap structures in vitro, but not Holliday junctions. Modeling of the VRR-Nuc domain of FAN1 reveals that it has an insertion, which packs against the dimerization interface observed in the structures of the viral/bacterial VRR-Nuc proteins. We propose that these additional structural elements in FAN1 prevent dimerization and bias specificity toward flap structures.
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A phase 2 trial of dacomitinib (PF-00299804), an oral, irreversible pan-HER (human epidermal growth factor receptor) inhibitor, in patients with advanced non-small cell lung cancer after failure of prior chemotherapy and erlotinib.
Cancer
PUBLISHED: 02-05-2014
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This phase 2 trial (ClinicalTrials.gov identifier NCT00548093) assessed the efficacy, safety, and impact on health-related quality of life of dacomitinib (PF-00299804), an irreversible tyrosine kinase inhibitor (TKI) of human epidermal growth factor receptors (EGFR)/HER1, HER2, and HER4, in patients with KRAS wild-type non-small cell lung cancer (NSCLC).
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True and Choke Anastomoses between Perforator Angiosomes: Part II. Dynamic Thermographic Identification.
Plast. Reconstr. Surg.
PUBLISHED: 11-28-2013
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Cadaveric studies have revealed that cutaneous perforators are linked by either reduced-caliber "choke" arteries, or by vessels without change in caliber, the true anastomoses. These true anastomotic vessels are often found in parallel with the cutaneous nerves and accompanying veins, and are associated both experimentally and clinically with larger areas of flap survival. The Doppler probe and computed tomographic angiography are already used preoperatively to determine perforator locations but currently cannot reveal the type of anastomotic connections.
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True and Choke Anastomoses between Perforator Angiosomes: Part I. Anatomical Location.
Plast. Reconstr. Surg.
PUBLISHED: 11-28-2013
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Reports of more than two cutaneous perforator angiosome territories being raised successfully in distally based sural flaps are appearing in the literature. Previous anatomical studies have noted that cutaneous arteries, connected by true anastomosis without change in caliber, frequently parallel cutaneous nerves.
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Reconstruction of the nasolabial fold using a fascia lata sheet graft: a modified technique.
Plast. Reconstr. Surg.
PUBLISHED: 10-30-2013
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A refinement over existing static facial sling techniques to reconstruct the nasolabial fold in longstanding facial palsy is presented. The innovative use of fascia lata sheet graft instead of strips facilitates greater intraoperative control over the contour of the reconstructed fold and provides a wide area of attachments of the graft. This technique has a reduced incidence of complications and can be adjusted with minimal scarring as a secondary procedure if necessary.
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Structural basis of lentiviral subversion of a cellular protein degradation pathway.
Nature
PUBLISHED: 07-11-2013
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Lentiviruses contain accessory genes that have evolved to counteract the effects of host cellular defence proteins that inhibit productive infection. One such restriction factor, SAMHD1, inhibits human immunodeficiency virus (HIV)-1 infection of myeloid-lineage cells as well as resting CD4(+) T cells by reducing the cellular deoxynucleoside 5-triphosphate (dNTP) concentration to a level at which the viral reverse transcriptase cannot function. In other lentiviruses, including HIV-2 and related simian immunodeficiency viruses (SIVs), SAMHD1 restriction is overcome by the action of viral accessory protein x (Vpx) or the related viral protein r (Vpr) that target and recruit SAMHD1 for proteasomal degradation. The molecular mechanism by which these viral proteins are able to usurp the host cells ubiquitination machinery to destroy the cells protection against these viruses has not been defined. Here we present the crystal structure of a ternary complex of Vpx with the human E3 ligase substrate adaptor DCAF1 and the carboxy-terminal region of human SAMHD1. Vpx is made up of a three-helical bundle stabilized by a zinc finger motif, and wraps tightly around the disc-shaped DCAF1 molecule to present a new molecular surface. This adapted surface is then able to recruit SAMHD1 via its C terminus, making it a competent substrate for the E3 ligase to mark for proteasomal degradation. The structure reported here provides a molecular description of how a lentiviral accessory protein is able to subvert the cells normal protein degradation pathway to inactivate the cellular viral defence system.
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A cluster randomized controlled trial of strategies to increase adolescents physical activity and motivation in physical education: results of the Motivating Active Learning in Physical Education (MALP) trial.
Prev Med
PUBLISHED: 05-07-2013
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Physical education (PE) programs aim to promote physical activity (PA) and reach most school-aged youth. However, PA levels within PE lessons are often low. In this cluster-randomized controlled trial, we examined the effects of three self-determination theory-based motivational strategies on PA and sedentary behavior, as well as their hypothesized antecedents during PE lessons.
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A unique spumavirus Gag N-terminal domain with functional properties of orthoretroviral matrix and capsid.
PLoS Pathog.
PUBLISHED: 05-01-2013
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The Spumaretrovirinae, or foamyviruses (FVs) are complex retroviruses that infect many species of monkey and ape. Although FV infection is apparently benign, trans-species zoonosis is commonplace and has resulted in the isolation of the Prototypic Foamy Virus (PFV) from human sources and the potential for germ-line transmission. Despite little sequence homology, FV and orthoretroviral Gag proteins perform equivalent functions, including genome packaging, virion assembly, trafficking and membrane targeting. In addition, PFV Gag interacts with the FV Envelope (Env) protein to facilitate budding of infectious particles. Presently, there is a paucity of structural information with regards FVs and it is unclear how disparate FV and orthoretroviral Gag molecules share the same function. Therefore, in order to probe the functional overlap of FV and orthoretroviral Gag and learn more about FV egress and replication we have undertaken a structural, biophysical and virological study of PFV-Gag. We present the crystal structure of a dimeric amino terminal domain from PFV, Gag-NtD, both free and in complex with the leader peptide of PFV Env. The structure comprises a head domain together with a coiled coil that forms the dimer interface and despite the shared function it is entirely unrelated to either the capsid or matrix of Gag from other retroviruses. Furthermore, we present structural, biochemical and virological data that reveal the molecular details of the essential Gag-Env interaction and in addition we also examine the specificity of Trim5? restriction of PFV. These data provide the first information with regards to FV structural proteins and suggest a model for convergent evolution of gag genes where structurally unrelated molecules have become functionally equivalent.
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Anatomy of the superficial lymphatics of the abdominal wall and the upper thigh and its implications in lymphatic microsurgery.
J Plast Reconstr Aesthet Surg
PUBLISHED: 03-04-2013
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The recent advent in the surgical treatment of lymphedema necessitates a more detailed understanding of the anatomy of the lymphatic system. Lymphovenous anastomosis (LVA) requires a precise knowledge of the anatomy of the superficial lymphatic collectors in relation to the superficial veins. In vascularized lymph node transfer (VLNT), donor site lymphatic function must be preserved.
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Anemia and performance status as prognostic markers in acute hypercapnic respiratory failure due to chronic obstructive pulmonary disease.
Int J Chron Obstruct Pulmon Dis
PUBLISHED: 01-01-2013
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In patients with acute hypercapnic respiratory failure (AHRF) during exacerbations of COPD, mortality can be high despite noninvasive ventilation (NIV). For some, AHRF is terminal and NIV is inappropriate. However there is no definitive method of identifying patients who are unlikely to survive. The aim of this study was to identify factors associated with inpatient mortality from AHRF with respiratory acidosis due to COPD.
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Impact of health care reform on academic medical centers.
Gastrointest. Endosc. Clin. N. Am.
PUBLISHED: 10-08-2011
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The impact of health care reform on academic medical centers will be just as great as it is on community practices. The economics of academic medical centers and training programs has been challenging, and will become even more so as funding is cut and the demand for regional integrated systems mounts. This article is one of the first to articulate these challenges and is written by authors well positioned to understand this arena.
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A longitudinal examination of coach and peer motivational climates in youth sport: implications for moral attitudes, well-being, and behavioral investment.
Dev Psychol
PUBLISHED: 07-25-2011
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Embedded in achievement goal theory (Ames, 1992; Meece, Anderman, & Anderman, 2006), this study examined how perceptions of coach and peer motivational climate in youth sport predicted moral attitudes, emotional well-being, and indices of behavioral investment in a sample of British adolescents competing in regional leagues. We adopted a longitudinal perspective, taking measures at the middle and the end of a sport season, as well as at the beginning of the following season. Multilevel modeling analyses showed that perceptions of task-involving peer and coach climates were predictive of more adaptive outcomes than were perceptions of ego-involving peer and coach climates. Predictive effects differed as a function of time and outcome variable under investigation. The results indicate the importance of considering peer influence in addition to coach influence when examining motivational climate in youth sport.
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Diffuse scattering resulting from macromolecular frustration.
Acta Crystallogr., B
PUBLISHED: 06-28-2011
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Distinctive diffuse scattering in the form of diffuse rings around Bragg positions has been observed in the diffraction patterns of a crystal of the N-terminal fragment of the Gag protein from Feline Foamy Virus. It is shown that these are caused by geometric frustration as molecules try to pack on the triangular b-c mesh of the space group P6(1)22. In order to explain the strong diffuse scattering it is necessary for the crystal to contain occupational disorder such that each unit cell contains one or other of two different molecular arrangements, A and B. The frustration arises because the nearest-neighbour packing prefers neighbouring cells to be AB or BA, which cannot be achieved on all three sides of a triangle simultaneously. To explain the observation that reciprocal sections hk5n, where n = integer, contain only Bragg peaks it is necessary that A and B are identical molecular arrangements differing only by a translation of 0.2c. The implications of the disorder for solving the structure of the protein by conventional techniques as well as the possibility of using the diffuse scattering for this purpose are discussed.
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HIV-1 restriction factor SAMHD1 is a deoxynucleoside triphosphate triphosphohydrolase.
Nature
PUBLISHED: 06-07-2011
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SAMHD1, an analogue of the murine interferon (IFN)-?-induced gene Mg11 (ref. 1), has recently been identified as a human immunodeficiency virus-1 (HIV-1) restriction factor that blocks early-stage virus replication in dendritic and other myeloid cells and is the target of the lentiviral protein Vpx, which can relieve HIV-1 restriction. SAMHD1 is also associated with Aicardi-Goutières syndrome (AGS), an inflammatory encephalopathy characterized by chronic cerebrospinal fluid lymphocytosis and elevated levels of the antiviral cytokine IFN-?. The pathology associated with AGS resembles congenital viral infection, such as transplacentally acquired HIV. Here we show that human SAMHD1 is a potent dGTP-stimulated triphosphohydrolase that converts deoxynucleoside triphosphates to the constituent deoxynucleoside and inorganic triphosphate. The crystal structure of the catalytic core of SAMHD1 reveals that the protein is dimeric and indicates a molecular basis for dGTP stimulation of catalytic activity against dNTPs. We propose that SAMHD1, which is highly expressed in dendritic cells, restricts HIV-1 replication by hydrolysing the majority of cellular dNTPs, thus inhibiting reverse transcription and viral complementary DNA (cDNA) synthesis.
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Antecedents of perceived coach autonomy supportive and controlling behaviors: coach psychological need satisfaction and well-being.
J Sport Exerc Psychol
PUBLISHED: 05-12-2011
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Within the self-determination theory (Deci & Ryan, 2000) framework, research has considered the consequences of coaches autonomy supportive and controlling behaviors on various athlete outcomes (e.g., motivation and performance). The antecedents of such behaviors, however, have received little attention. Coaches (N = 443) from a variety of sports and competitive levels completed a self-report questionnaire to assess their psychological need satisfaction, well-being and perceived interpersonal behaviors toward their athletes. Structural equation modeling demonstrated that coaches competence and autonomy need satisfaction positively predicted their levels of psychological well-being, as indexed by positive affect and subjective vitality. In turn, coaches psychological well-being positively predicted their perceived autonomy support toward their athletes, and negatively predicted their perceived controlling behaviors. Overall, the results highlight the importance of coaching contexts that facilitate coaches psychological need satisfaction and well-being, thereby increasing the likelihood of adaptive coach interpersonal behavior toward athletes.
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Directed evolution of a thermostable l-aminoacylase biocatalyst.
J. Biotechnol.
PUBLISHED: 04-21-2011
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Enzymes from extreme environments possess highly desirable traits of activity and stability for application under process conditions. One such example is l-aminoacylase (E.C. 3.5.1.14) from Thermococcus litoralis (TliACY), which catalyzes the enantioselective amide hydrolysis of N-protected l-amino acids, useful for resolving racemic mixtures in the preparation of chiral intermediates. Variants of this enzyme with improved activity and altered substrate preference are highly desirable. We have created a structural homology model of the enzyme and applied various two different directed evolution strategies to identify improved variants. Mutants P237S and F251Y were 2.4-fold more active towards N-benzoyl valine relative to the wild type at 65°C. F251 mutations to basic residues resulted in 4.5-11-fold shifts in the substrate preference towards N-benzoyl phenylalanine relative to N-benzoyl valine. The substrate preference of wild type decreases with increasingly branched and sterically hindered substrates. However, the mutant S100T/M106K disrupted this simple trend by selectively improving the substrate preference for N-benzoyl valine, with a >30-fold shift in the ratio of k(cat) values for N-benzoyl valine and N-benzoyl phenylalanine. Mutations that favoured N-benzoyl-phenylalanine appeared at the active site entrance, whereas those improving activity towards N-benzoyl-valine occurred in the hinge region loops linking the dimerization and zinc-binding domains in each monomer. These observations support a previously proposed substrate induced conformational transition between open and closed forms of aminoacylases.
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The anatomical (angiosome) and clinical territories of cutaneous perforating arteries: development of the concept and designing safe flaps.
Plast. Reconstr. Surg.
PUBLISHED: 04-05-2011
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Island "perforator flaps" have become state of the art for free-skin flap transfer. Recent articles by Saint-Cyr et al. and Rozen et al. have focused on the anatomical and the clinical territories of individual cutaneous perforating arteries in flap planning, and it is timely to compare this work with our angiosome concept.
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Ordered assembly of murine leukemia virus capsid protein on lipid nanotubes directs specific binding by the restriction factor, Fv1.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 03-21-2011
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The restriction factor Fv1 confers resistance to murine leukemia virus (MLV), blocking progression of the viral life cycle after reverse transcription, but before integration into the host chromosome. It is known that the specificity of restriction is determined by both the restriction factor and the viral capsid (CA), but a direct interaction between Fv1 and MLV CA has not yet been demonstrated. With the development of a previously unexplored method for in vitro polymerization of MLV CA, it has now been possible to display a binding interaction between Fv1 and MLV CA. C-terminally His-tagged CA molecules were assembled on Ni-chelating lipid nanotubes, and analysis by electron microscopy revealed the formation of a regular lattice. Comparison of binding data with existing restriction data confirmed the specificity of the binding interaction, with multiple positions of both Fv1 and CA shown to influence binding specificity.
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Novel escape mutants suggest an extensive TRIM5? binding site spanning the entire outer surface of the murine leukemia virus capsid protein.
PLoS Pathog.
PUBLISHED: 01-28-2011
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After entry into target cells, retroviruses encounter the host restriction factors such as Fv1 and TRIM5?. While it is clear that these factors target retrovirus capsid proteins (CA), recognition remains poorly defined in the absence of structural information. To better understand the binding interaction between TRIM5? and CA, we selected a panel of novel N-tropic murine leukaemia virus (N-MLV) escape mutants by a serial passage of replication competent N-MLV in rhesus macaque TRIM5? (rhTRIM5?)-positive cells using a small percentage of unrestricted cells to allow multiple rounds of virus replication. The newly identified mutations, many of which involve changes in charge, are distributed over the outer top surface of N-MLV CA, including the N-terminal ?-hairpin, and map up to 29 A(o) apart. Biological characterisation with a number of restriction factors revealed that only one of the new mutations affects restriction by human TRIM5?, indicating significant differences in the binding interaction between N-MLV and the two TRIM5?s, whereas three of the mutations result in dual sensitivity to Fv1(n) and Fv1(b). Structural studies of two mutants show that no major changes in the overall CA conformation are associated with escape from restriction. We conclude that interactions involving much, if not all, of the surface of CA are vital for TRIM5? binding.
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Phase I dose-escalation study of the pan-HER inhibitor, PF299804, in patients with advanced malignant solid tumors.
Clin. Cancer Res.
PUBLISHED: 01-10-2011
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PF299804 is a potent, orally available, irreversible inhibitor of tyrosine kinase human epidermal growth factor receptors (HER) 1 (EGFR), HER2, and HER4. This first-in-human study investigated the safety, tolerability, pharmacokinetics, and pharmacodynamics of PF299804 in patients with advanced solid malignancies.
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Testing a model of antecedents and consequences of defensive pessimism and self-handicapping in school physical education.
J Sports Sci
PUBLISHED: 11-09-2010
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There has been very limited research on the use of self-worth protection strategies in the achievement context of school physical education (PE). Thus the aim of the present study was to examine some antecedents and consequences of defensive pessimism and self-handicapping. The sample comprised 534 British pupils (275 females, 259 males) recruited from two schools who responded to established questionnaires. Results of structural equation modelling analysis indicated that self-handicapping and defensive pessimism were positively predicted by fear of failure and negatively predicted by competence valuation. In addition, defensive pessimism was negatively predicted by physical self-concept. In turn, defensive pessimism negatively predicted enjoyment in PE and intentions to participate in future optional PE programmes. Self-handicapping did not predict enjoyment or intentions. Results from multi-sample structural equation modelling showed the specified model to be largely invariant across males and females. The findings indicate that although both strategies aim to protect ones self-worth, some of their antecedents and consequences in PE may differ.
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Cultural differences in the relationships among autonomy support, psychological need satisfaction, subjective vitality, and effort in British and Chinese physical education.
J Sport Exerc Psychol
PUBLISHED: 10-29-2010
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Using basic psychological needs theory (BPNT; Ryan & Deci, 2000) as our guiding framework, we explored cultural differences in the relationships among physical education students perceptions of teacher autonomy support, psychological need satisfaction, subjective vitality and effort in class. Seven hundred and fifteen students (age range from 13 to 15 years) from the U.K. and Hong Kong, China, completed a multisection inventory during a timetabled physical education class. Multilevel analyses revealed that the relationships among autonomy support, subjective vitality and effort were mediated by students perceptions of psychological need satisfaction. The relationship between autonomy support and perceptions of competence was stronger in the Chinese sample, compared with the U.K. sample. In addition, the relationship between perceptions of relatedness and effort was not significant in the Chinese students. The findings generally support the pan-cultural utility of BPNT and imply that a teacher-created autonomy supportive environment may promote positive student experiences in both cultures.
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Staphylococcus aureus TargetArray: comprehensive differential essential gene expression as a mechanistic tool to profile antibacterials.
Antimicrob. Agents Chemother.
PUBLISHED: 06-14-2010
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The widespread emergence of antibiotic-resistant bacteria and a lack of new pharmaceutical development have catalyzed a need for new and innovative approaches for antibiotic drug discovery. One bottleneck in antibiotic discovery is the lack of a rapid and comprehensive method to identify compound mode of action (MOA). Since a hallmark of antibiotic action is as an inhibitor of essential cellular targets and processes, we identify a set of 308 essential genes in the clinically important pathogen Staphylococcus aureus. A total of 446 strains differentially expressing these genes were constructed in a comprehensive platform of sensitized and resistant strains. A subset of strains allows either target underexpression or target overexpression by heterologous promoter replacements with a suite of tetracycline-regulatable promoters. A further subset of 236 antisense RNA-expressing clones allows knockdown expression of cognate targets. Knockdown expression confers selective antibiotic hypersensitivity, while target overexpression confers resistance. The antisense strains were configured into a TargetArray in which pools of sensitized strains were challenged in fitness tests. A rapid detection method measures strain responses toward antibiotics. The TargetArray antibiotic fitness test results show mechanistically informative biological fingerprints that allow MOA elucidation.
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Structural and functional analysis of prehistoric lentiviruses uncovers an ancient molecular interface.
Cell Host Microbe
PUBLISHED: 04-23-2010
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Lentiviruses are widespread in a variety of vertebrates, often associated with chronic disease states. However, until the recent discovery of the prehistoric endogenous lentiviruses in rabbits (RELIK) and lemurs (PSIV), it was thought that lentiviruses had no capacity for germline integration and were only spread horizontally in an exogenous fashion. The existence of RELIK and PSIV refuted these ideas, revealing lentiviruses to be present in a range of mammals, capable of germline integration, and far more ancient than previously thought. Using Gag sequences reconstructed from the remnants of these prehistoric lentiviruses, we have produced chimeric lentiviruses capable of infecting nondividing cells and determined structures of capsid domains from PSIV and RELIK. We show that the structures from these diverse viruses are highly similar, containing features found in modern-day lentiviruses, including a functional cyclophilin-binding loop. Together, these data provide evidence for an ancient capsid-cyclophilin interaction preserved throughout lentiviral evolution.
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Motivational predictors of physical education students effort, exercise intentions, and leisure-time physical activity: a multilevel linear growth analysis.
J Sport Exerc Psychol
PUBLISHED: 02-20-2010
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Grounded in self-determination theory (SDT; Deci & Ryan, 2000), the current study explored whether physical education (PE) students psychological needs and their motivational regulations toward PE predicted mean differences and changes in effort in PE, exercise intentions, and leisure-time physical activity (LTPA) over the course of one UK school trimester. One hundred and seventy-eight students (69% male) aged between 11 and 16 years completed a multisection questionnaire at the beginning, middle, and end of a school trimester. Multilevel growth models revealed that students perceived competence and self-determined regulations were the most consistent predictors of the outcome variables at the within- and between-person levels. The results of this work add to the extant SDT-based literature by examining change in PE students motivational regulations and psychological needs, as well as underscoring the importance of disaggregating within- and between-student effects.
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Profile of early occurring spontaneous tumors in Han Wistar rats.
Toxicol Pathol
PUBLISHED: 02-02-2010
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It is sometimes difficult to assess the relevance of tumors that occur in treated animals in short-term studies. This report is intended to establish a general profile of tumor occurrence in young Han Wistar rats. Data were collected and evaluated from 29 rat carcinogenicity studies and from a few 2-, 4-, 13-, and 26-week studies conducted between 1995 and 2009 at Huntingdon Life Sciences, UK. The route of administration was dietary, oral gavage, or inhalation, and the analysis was confined to sporadic deaths (decedents) in carcinogenicity studies. In Han Wistar rats, the most common and earliest occurring tumor was malignant lymphoma in both sexes, the earliest being seen in the 16th and 26th week in males and females, respectively. The incidence of malignant lymphoma was slightly higher in males than in females. The second most common type of tumor was brain tumors in males and mammary tumors in females. Compared with Sprague-Dawley rats, where the most common early tumor was pituitary tumor in females, the most common early tumor in Han Wistar rats was malignant lymphoma in both sexes. These early tumor profiles are consistent with the lifetime tumor occurrence in these strains.
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Structure of the Rna15 RRM-RNA complex reveals the molecular basis of GU specificity in transcriptional 3-end processing factors.
Nucleic Acids Res.
PUBLISHED: 01-21-2010
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Rna15 is a core subunit of cleavage factor IA (CFIA), an essential transcriptional 3-end processing factor from Saccharomyces cerevisiae. CFIA is required for polyA site selection/cleavage targeting RNA sequences that surround polyadenylation sites in the 3-UTR of RNA polymerase-II transcripts. RNA recognition by CFIA is mediated by an RNA recognition motif (RRM) contained in the Rna15 subunit of the complex. We show here that Rna15 has a strong and unexpected preference for GU containing RNAs and reveal the molecular basis for a base selectivity mechanism that accommodates G or U but discriminates against C and A bases. This mode of base selectivity is rather different to that observed in other RRM-RNA structures and is structurally conserved in CstF64, the mammalian counterpart of Rna15. Our observations provide evidence for a highly conserved mechanism of base recognition amongst the 3-end processing complexes that interact with the U-rich or U/G-rich elements at 3-end cleavage/polyadenylation sites.
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Evaluating anatomical research in surgery: a prospective comparison of cadaveric and living anatomical studies of the abdominal wall.
ANZ J Surg
PUBLISHED: 12-17-2009
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Cadaveric research has widely influenced our understanding of clinical anatomy. However, while many soft-tissue structures remain quiescent after death, other tissues, such as viscera, undergo structural and functional changes that may influence their use in predicting living anatomy. In particular, our understanding of vascular anatomy has been based upon cadaveric studies, in which vascular tone and flow do not match the living situation.
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The venous anatomy of the anterior abdominal wall: an anatomical and clinical study.
Plast. Reconstr. Surg.
PUBLISHED: 09-05-2009
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Despite improving outcomes, venous problems in the harvest of deep inferior epigastric artery perforator (DIEP) flaps remain the more common vascular complications. However, it is apparent that the venous anatomy of the anterior abdominal wall has not been described to the same extent as the arterial anatomy. Previous anatomical studies have focused on cadaveric anatomy or excisional specimens. The current study uses in vivo computed tomographic angiography to evaluate this anatomy, in combination with a cadaveric radiographic study.
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The effect of anterior abdominal wall scars on the vascular anatomy of the abdominal wall: A cadaveric and clinical study with clinical implications.
Clin Anat
PUBLISHED: 08-01-2009
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The anterior abdominal wall integument is frequently used in a range of reconstructive flaps. These tissues are supplied by the deep and superficial inferior epigastric arteries (DIEA and SIEAs) and the deep and superficial superior epigastric arteries (DSEA and SSEAs). Previous abdominal wall surgery alters this vascular anatomy and may influence flap design. One hundred and sixty-eight patients underwent abdominal wall computed tomographic angiography (CTA) for preoperative imaging. Fifty-eight of these patients had undergone previous abdominal surgery, and were assessed for scar pattern and relationship to the course and distribution of all major axial vessels and perforators. Two cadaveric abdominal wall specimens with midline abdominal scars underwent contrast injection of the DIEAs and DSEAs, with subsequent CTA. The course and distribution of all cutaneous vessels were assessed. In all clinical and cadaveric cases, the vasculature of the abdominal wall had been altered by previous surgery. In the clinical cases, vascular architecture was universally altered in the region of the scar, often modifying the filling patterns of the abdominal wall and occasionally precluding the use of an abdominal wall flap. In both cadaveric specimens, regions of non-filling were evident upon contrast injection, highlighting the angiosomes not supplied by the DIEA or DSEA. Previous abdominal wall surgery necessarily alters the vascular architecture of the abdominal wall, and may alter the source vessels supplying cutaneous tissues. CTA was useful in identifying and delineating these changes, and may be used as a preoperative tool in this role.
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Stability and uniformity of extemporaneous preparations of voriconazole in two liquid suspension vehicles at two storage temperatures.
Am. J. Vet. Res.
PUBLISHED: 07-02-2009
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To determine the stability and distribution of voriconazole in 2 extemporaneously prepared (compounded) suspensions stored for 30 days at 2 temperatures.
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Advances in the pre-operative planning of deep inferior epigastric artery perforator flaps: magnetic resonance angiography.
Microsurgery
PUBLISHED: 06-19-2009
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Imaging of the abdominal wall vasculature prior to deep inferior epigastric artery (DIEA) perforator (DIEP) flaps has been shown to significantly improve surgical outcomes. Although computed tomography angiography (CTA) has been shown to be highly accurate, it is associated with radiation exposure, and as such modalities without radiation exposure have been sought. Magnetic resonance angiography (MRA) has been proposed as such an option. We conducted a pilot study comparing MRA with CTA and with operative findings in six consecutive patients undergoing DIEP flaps for breast reconstruction. The DIEA, superficial inferior epigastric artery (SIEA) and perforators were all assessed with each modality. We found that the DIEA and SIEA were accurately imaged with both CTA and MRA, but that while MRA could identify some major perforators, CTA was more accurate than MRA for perforator mapping. As such, while MRA does have a role in the imaging of DIEA perforators, CTA is still the preferred modality. On the basis of these findings, a larger study into the role for MRA in this setting is warranted.
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Historical review of breast lymphatic studies.
Clin Anat
PUBLISHED: 06-02-2009
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The gross anatomy of the lymphatic system is one of the least studied areas of anatomy, primarily because of the technical difficulties encountered in demonstrating this almost invisible yet vast system. Similarly, there have been very few studies of the gross lymphatic anatomy of the adult human breast. Previous studies used young pregnant female cadavers. When mercury was injected into the lactiferous ducts or breast lymphatic channels, these cadavers enabled early anatomists to see the breast lymphatics. Both Cruikshank (1786) and Cooper (1840) located the axillary lymph pathway as well as accessory pathways directly from the breast. Sappey (1874) concluded that all lymphatics arising from the breast drained into the axilla via the subareolar plexus. Current descriptions of the breast lymphatics may be traced back to the diagram made by Poirier and Cuneo (1902). However, it is apparent that this diagram is a composite of adult breast studies by Sappey, their fetal studies and even clinical feedback. This study provides an historical perspective of the methods that have been previously used to study the lymphatics of the breast and introduces an update on current investigative approaches.
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NEMO oligomerization and its ubiquitin-binding properties.
Biochem. J.
PUBLISHED: 05-09-2009
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The IKK [IkappaB (inhibitory kappaB) kinase] complex is a key regulatory component of NF-kappaB (nuclear factor kappaB) activation and is responsible for mediating the degradation of IkappaB, thereby allowing nuclear translocation of NF-kappaB and transcription of target genes. NEMO (NF-kappaB essential modulator), the regulatory subunit of the IKK complex, plays a pivotal role in this process by integrating upstream signals, in particular the recognition of polyubiquitin chains, and relaying these to the activation of IKKalpha and IKKbeta, the catalytic subunits of the IKK complex. The oligomeric state of NEMO is controversial and the mechanism by which it regulates activation of the IKK complex is poorly understood. Using a combination of hydrodynamic techniques we now show that apo-NEMO is a highly elongated, dimeric protein that is in weak equilibrium with a tetrameric assembly. Interaction with peptides derived from IKKbeta disrupts formation of the tetrameric NEMO complex, indicating that interaction with IKKalpha and IKKbeta and tetramerization are mutually exclusive. Furthermore, we show that NEMO binds to linear di-ubiquitin with a stoichiometry of one molecule of di-ubiquitin per NEMO dimer. This stoichiometry is preserved in a construct comprising the second coiled-coil region and the leucine zipper and in one that essentially spans the full-length protein. However, our data show that at high di-ubiquitin concentrations a second weaker binding site becomes apparent, implying that two different NEMO-di-ubiquitin complexes are formed during the IKK activation process. We propose that the role of these two complexes is to provide a threshold for activation, thereby ensuring sufficient specificity during NF-kappaB signalling.
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A competition assay for DNA binding using the fluorescent probe ANS.
Methods Mol. Biol.
PUBLISHED: 04-21-2009
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Fluorescence spectroscopy is a technique frequently employed to study protein-nucleic acid interactions. Often, the intrinsic fluorescence emission spectrum of tryptophan residues in a nucleic-acid-binding protein is strongly perturbed upon interaction with a target DNA or RNA. These spectral changes can then be exploited in order to construct binding isotherms and the extract equilibrium association constant together with the stoichiometry of an interaction. However, when a protein contains many tryptophan residues that are not located in the proximity of the nucleic-acid-binding site, changes in the fluorescence emission spectrum may not be apparent or the magnitude too small to be useful. Here, we make use of an extrinsic fluorescence probe, the environmentally sensitive fluorophore 1-anilinonaphthalene-8-sulphonic acid (1,8-ANS). Displacement by DNA of 1,8-ANS molecules from the nucleic-acid-binding site of the Type I modification methylase EcoR124I results in red shifting and an intensity decrease of the 1,8-ANS fluorescence emission spectrum. These spectral changes have been used to investigate the interaction of EcoR124I with DNA target recognition sequences.
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The lumbar artery perforators: a cadaveric and clinical anatomical study.
Plast. Reconstr. Surg.
PUBLISHED: 04-02-2009
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The lumbar region has been scarcely explored as a donor site for free tissue transfer or as a free flap recipient site. The lumbar integument provides a versatile prospective flap site, with a potentially well-concealed scar. Similarly, defects of this region can require recipient vessels that may be difficult to identify. Although lumbar artery perforators have been described, the reliability of perforators in this region remains questionable.
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Structure of the capsid amino-terminal domain from the betaretrovirus, Jaagsiekte sheep retrovirus.
J. Mol. Biol.
PUBLISHED: 03-24-2009
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Jaagsiekte sheep retrovirus is a betaretrovirus and the causative agent of pulmonary adenocarcinoma, a transmissible lung tumour of sheep. Here we report the crystal structure of the capsid amino-terminal domain and examine the self-association properties of Jaagsiekte sheep retrovirus capsid. We find that the structure is remarkably similar to the amino-terminal domain of the alpharetrovirus, avian leukosis virus, revealing a previously undetected evolutionary similarity. Examination of capsid self-association suggests a mode of assembly not driven by the strong capsid carboxy-terminal domain interactions that characterise capsid assembly in the lentiviruses. Based on these data, we propose this structure provides a model for the capsid of betaretroviruses including the HML-2 family of endogenous human betaretroviruses.
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A Staphylococcus aureus fitness test platform for mechanism-based profiling of antibacterial compounds.
Chem. Biol.
PUBLISHED: 03-06-2009
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The emergence of drug-resistant bacteria coupled with the limited discovery of novel chemical scaffolds and druggable targets inspires new approaches to antibiotic development. Here we describe a chemical genomics strategy based on 245 Staphylococcus aureus antisense RNA strains, each engineered for reduced expression of target genes essential for S. aureus growth. Attenuation of gene expression can sensitize cells to compounds that inhibit the activity of a gene product or associated process. Pools of strains grown competitively in the presence of bioactive compounds generate characteristic profiles of strain sensitivities reflecting compound mechanism of action. Here, we validate this approach with a structurally and mechanistically diverse set of reference antibiotics and, in the accompanying paper in this issue of Chemistry & Biology (Huber et al., 2009), demonstrate its use in the discovery of new cell wall inhibitors.
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The N-end rule pathway promotes seed germination and establishment through removal of ABA sensitivity in Arabidopsis.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 03-02-2009
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The N-end rule pathway targets protein degradation through the identity of the amino-terminal residue of specific protein substrates. Two components of this pathway in Arabidopsis thaliana, PROTEOLYSIS6 (PRT6) and arginyl-tRNA:protein arginyltransferase (ATE), were shown to regulate seed after-ripening, seedling sugar sensitivity, seedling lipid breakdown, and abscisic acid (ABA) sensitivity of germination. Sensitivity of prt6 mutant seeds to ABA inhibition of endosperm rupture reduced with after-ripening time, suggesting that seeds display a previously undescribed window of sensitivity to ABA. Reduced root growth of prt6 alleles and the ate1 ate2 double mutant was rescued by exogenous sucrose, and the breakdown of lipid bodies and seed-derived triacylglycerol was impaired in mutant seedlings, implicating the N-end rule pathway in control of seed oil mobilization. Epistasis analysis indicated that PRT6 control of germination and establishment, as exemplified by ABA and sugar sensitivity, as well as storage oil mobilization, occurs at least in part via transcription factors ABI3 and ABI5. The N-end rule pathway of protein turnover is therefore postulated to inactivate as-yet unidentified key component(s) of ABA signaling to influence the seed-to-seedling transition.
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The pudendal thigh flap for vaginal reconstruction: optimising flap survival.
J Plast Reconstr Aesthet Surg
PUBLISHED: 02-26-2009
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The pudendal thigh fasciocutaneous (PTF) flap is a useful flap in perineal reconstruction, that is reliable when small but is traditionally unreliable when large flaps are raised. Large flaps in particular, are associated with an increased incidence of apical necrosis. Thorough descriptions of the vascular anatomy of this flap have been lacking from the literature, with the current study evaluating this anatomy, aiming to provide the anatomical basis for vascular problems and for techniques to maximise its survival.
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Dynamic modularity in protein interaction networks predicts breast cancer outcome.
Nat. Biotechnol.
PUBLISHED: 02-01-2009
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Changes in the biochemical wiring of oncogenic cells drives phenotypic transformations that directly affect disease outcome. Here we examine the dynamic structure of the human protein interaction network (interactome) to determine whether changes in the organization of the interactome can be used to predict patient outcome. An analysis of hub proteins identified intermodular hub proteins that are co-expressed with their interacting partners in a tissue-restricted manner and intramodular hub proteins that are co-expressed with their interacting partners in all or most tissues. Substantial differences in biochemical structure were observed between the two types of hubs. Signaling domains were found more often in intermodular hub proteins, which were also more frequently associated with oncogenesis. Analysis of two breast cancer patient cohorts revealed that altered modularity of the human interactome may be useful as an indicator of breast cancer prognosis.
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The arterial supply of the patellar tendon: anatomical study with clinical implications for knee surgery.
Clin Anat
PUBLISHED: 01-29-2009
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The middle-third of the patellar tendon (PT) is well-established as a potential graft for cruciate ligament reconstruction, but there is little anatomical basis for its use. Although studies on PT vascular anatomy have focused on the risk to tendon pedicles from surgical approaches and knee pathophysiology, the significance of its blood supply to grafting has not been adequately explored previously. This investigation explores both the intrinsic and extrinsic arterial anatomy of the PT, as relevant to the PT graft. Ten fresh cadaveric lower limbs underwent angiographic injection of the common femoral artery with radio-opaque lead oxide. Each tendon was carefully dissected, underwent plain radiography and subsequently schematically reconstructed. The PT demonstrated a well-developed and consistent vascularity from three main sources: antero-proximally, mainly by the inferior-lateral genicular artery; antero-distally via a choke-anastomotic arch between the anterior tibial recurrent and inferior medial genicular arteries; and posteriorly via the retro-patellar anastomotic arch in Hoffas fat pad. Two patterns of pedicles formed this arch: inferior-lateral and descending genicular arteries (Type-I); superior-lateral, inferior-lateral, and superior-medial genicular arteries (Type-II). Both types supplied the posterior PT, with the majority of vessels descending to its middle-third. The middle-third PT has a richer intrinsic vascularity, which may enhance its ingrowth as a graft, and supports its conventional use in cruciate ligament reconstruction. The pedicles supplying the PT are endangered during procedures where Hoffas fat pad is removed including certain techniques of PT harvest and total knee arthroplasty.
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The arterial anatomy of the Achilles tendon: anatomical study and clinical implications.
Clin Anat
PUBLISHED: 01-29-2009
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The Achilles tendon is the most frequently ruptured tendon in the lower limb and accounts for almost 20% of all large tendon injuries. Despite numerous published studies describing its blood supply, there has been no uniformity in describing its topography. The current study comprises a detailed anatomical study of both the intrinsic and extrinsic arterial supply of the Achilles tendon, providing the detail sought from studies calling for improved planning of surgical procedures where damage to the vascularity of the Achilles tendon is likely. A dissection, microdissection, histological, and angiographic study was undertaken on 20 cadaveric lower limbs from 16 fresh and four embalmed cadavers. The Achilles tendon is supplied by two arteries, the posterior tibial and peroneal arteries. Three vascular territories were identified, with the midsection supplied by the peroneal artery, and the proximal and distal sections supplied by the posterior tibial artery. The midsection of the Achilles tendon was markedly more hypovascular that the rest of the tendon. The Achilles tendon is at highest risk of rupture and surgical complications at its midsection. Individuals with particularly poor supply of the midsection may be at increased risk of tendon rupture, and approaches to the tendon operatively should consider the route of supply by the peroneal artery to this susceptible part of the tendon.
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The superficial venous drainage of the breast: a clinical study and implications for breast reduction surgery.
J Plast Reconstr Aesthet Surg
PUBLISHED: 01-24-2009
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An understanding of the vascular anatomy of the breast is paramount in breast reduction surgery in order to minimize vascular complications. While most vascular compromise in breast reduction is largely venous in nature, the venous anatomy of the breast has not been sufficiently explored in the literature, particularly the inferior pole of the breast. Developments in infrared photography have enabled the use of this noninvasive technique to evaluate the venous architecture of the breast.
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A study of the ultrastructure of fragile-X-related proteins.
Biochem. J.
PUBLISHED: 01-16-2009
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Fragile-X-related proteins form a family implicated in RNA metabolism. Their sequence is composed of conserved N-terminal and central regions which contain Tudor and KH domains and of a divergent C-terminus with motifs rich in arginine and glycine residues. The most widely studied member of the family is probably FMRP (fragile X mental retardation protein), since absence or mutation of this protein in humans causes fragile X syndrome, the most common cause of inherited mental retardation. Understanding the structural properties of FMRP is essential for correlating it with its functions. The structures of isolated domains of FMRP have been reported, but nothing is yet known with regard to the spatial arrangement of the different modules, partly because of difficulties in producing both the full-length protein and its multidomain fragments in quantities, purities and monodispersity amenable for structural studies. In the present study, we describe how we have produced overlapping recombinant fragments of human FMRP and its paralogues which encompass the evolutionary conserved region. We have studied their behaviour in solution by complementary biochemical and biophysical techniques, identified the regions which promote self-association and determined their overall three-dimensional shape. The present study paves the way to further studies and rationalizes the existing knowledge on the self-association properties of these proteins.
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The angiosomes of the thigh and buttock.
Plast. Reconstr. Surg.
PUBLISHED: 01-01-2009
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The angiosomes of the body were defined in 1987. The recent popularity of skin perforator and muscle flaps designed in the thigh, together with significant major vessel anomaly and disease, has necessitated a more detailed reevaluation of the blood supply to this region.
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Neurovascular anatomy of sartorius muscle flaps: implications for local transposition and facial reanimation.
Plast. Reconstr. Surg.
PUBLISHED: 01-01-2009
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The sartorius muscle is a superficial muscle of the thigh that possesses highly suitable qualities for many uses in local transposition and free muscle transfer. However, a paucity of description of the neurovascular anatomy of the sartorius has contributed to its infrequent use in these roles.
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Tribology and energy efficiency: from molecules to lubricated contacts to complete machines.
Faraday Discuss.
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The impact of lubricants on energy efficiency is considered. Molecular details of base oils used in lubricants can have a great impact on the lubricants physical properties which will affect the energy efficiency performance of a lubricant. In addition, molecular details of lubricant additives can result in significant differences in measured friction coefficients for machine elements operating in the mixed/boundary lubrication regime. In single machine elements, these differences will result in lower friction losses, and for complete systems (such as cars, trucks, hydraulic circuits, industrial gearboxes etc.) lower fuel consumption or lower electricity consumption can result.
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The tripartite efficacy framework in client-therapist rehabilitation interactions: implications for relationship quality and client engagement.
Rehabil Psychol
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Within supervised rehabilitation programs, Lent and Lopez (2002) proposed that clients and therapists develop a "tripartite" network of efficacy beliefs, comprising their confidence in their own ability, their confidence in the other persons ability, and their estimation of the other persons confidence in them. To date, researchers have yet to explore the potential relational outcomes associated with this model in rehabilitation contexts.
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An improved racemase/acylase biotransformation for the preparation of enantiomerically pure amino acids.
J. Am. Chem. Soc.
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Using directed evolution, a variant N-acetyl amino acid racemase (NAAAR G291D/F323Y) has been developed with up to 6-fold higher activity than the wild-type on a range of N-acetylated amino acids. The variant has been coupled with an enantiospecific acylase to give a preparative scale dynamic kinetic resolution which allows 98% conversion of N-acetyl-DL-allylglycine into D-allylglycine in 18 h at high substrate concentrations (50 g L(-1)). This is the first example of NAAAR operating under conditions which would allow it to be successfully used on an industrial scale for the production of enantiomerically pure ?-amino acids. X-ray crystal analysis of the improved NAAAR variant allowed a comparison with the wild-type enzyme. We postulate that a network of novel interactions that result from the introduction of the two side chains is the source of improved catalytic performance.
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Tumor location and nature of lymphatic vessels are key determinants of cancer metastasis.
Clin. Exp. Metastasis
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Tumor metastasis to lymph nodes is a key indicator of patient survival, and is enhanced by the neo-lymphatics induced by tumor-secreted VEGF-C or VEGF-D, acting via VEGFR-3 signalling. These targets constitute important avenues for anti-metastatic treatment. Despite this new understanding, clinical observations linking metastasis with tumor depth or location suggest that lymphangiogenic growth factors are not the sole determinants of metastasis. Here we explored the influence of tumor proximity to lymphatics capable of responding to growth factors on nodal metastasis in a murine VEGF-D over-expression tumor model. We found that primary tumor location profoundly influenced VEGF-D-mediated lymph node metastasis: 89 % of tumors associated with the flank skin metastasised, in contrast with only 19 % of tumors located more deeply on the body wall (p < 0.01). Lymphatics in metastatic tumors arose from small lymphatics, and displayed distinct molecular and morphological profiles compared with those found in normal lymphatics. Smaller lymphatic subtypes were more abundant in skin (2.5-fold, p < 0.01) than in body wall, providing a richer source of lymphatics for VEGF-D(+) skin tumors, a phenomenon also confirmed in human samples. This study shows that the proximity of a VEGF-D(+) primary tumor to small lymphatics is an important determinant of metastasis. These observations may explain why tumor location relative to the lymphatic network is prognostically important for some human cancers.
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The gammaretroviral p12 protein has multiple domains that function during the early stages of replication.
Retrovirology
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The Moloney murine leukaemia virus (Mo-MLV) gag gene encodes three main structural proteins, matrix, capsid and nucleocapsid and a protein called p12. In addition to its role during the late stages of infection, p12 has an essential, but undefined, function during early post-entry events. As these stages of retroviral infection remain poorly understood, we set out to investigate the function of p12.
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Precision in Diagnosing and Classifying COPD: Comparison of Historical Height with Current Height and Arm Span to Predict FEV(1).
Open Respir Med J
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Measured reductions in lung function, as a result of COPD, use a measured current value and make comparisons to a determined normal value arrived at using a regression equation based upon a patients height. Osteoporosis is a recognised co-morbidity in patients with chronic obstructive pulmonary disease (COPD) and may cause excessive height loss resulting in the normal values and disease progression being under-estimated.
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Antecedents of perceived coach interpersonal behaviors: the coaching environment and coach psychological well- and ill-being.
J Sport Exerc Psychol
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Embedded in the self-determination theory (Deci & Ryan, 2000) framework, we obtained self-report data from 418 paid and voluntary coaches from a variety of sports and competitive levels with the aim of exploring potential antecedents of coaches perceived autonomy supportive and controlling behaviors. Controlling for socially desirable responses, structural equation modeling revealed that greater job security and opportunities for professional development, and lower work-life conflict were associated with psychological need satisfaction, which, in turn, was related to an adaptive process of psychological well-being and perceived autonomy support toward athletes. In contrast, higher work-life conflict and fewer opportunities for development were associated with a distinct maladaptive process of thwarted psychological needs, psychological ill-being, and perceived controlling interpersonal behavior. The results highlight how the coaching context may impact upon coaches psychological health and their interpersonal behavior toward athletes. Moreover, evidence is provided for the independence of adaptive and maladaptive processes within the self-determination theory paradigm.
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Dacomitinib (PF-00299804), an irreversible Pan-HER inhibitor, inhibits proliferation of HER2-amplified breast cancer cell lines resistant to trastuzumab and lapatinib.
Mol. Cancer Ther.
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The human EGF (HER) family of receptors has been pursued as therapeutic targets in breast cancer and other malignancies. Trastuzumab and lapatinib are standard treatments for HER2-amplified breast cancer, but a significant number of patients do not respond or develop resistance to these drugs. Here we evaluate the in vitro activity of dacomitinib (PF-00299804), an irreversible small molecule pan-HER inhibitor, in a large panel of human breast cancer cell lines with variable expression of the HER family receptors and ligands, and with variable sensitivity to trastuzumab and lapatinib. Forty-seven human breast cancer and immortalized breast epithelial lines representing the known molecular subgroups of breast cancer were treated with dacomitinib to determine IC(50) values. HER2-amplified lines were far more likely to respond to dacomitinib than nonamplified lines (RR, 3.39; P < 0.0001). Furthermore, HER2 mRNA and protein expression were quantitatively associated with response. Dacomitinib reduced the phosphorylation of HER2, EGFR, HER4, AKT, and ERK in the majority of sensitive lines. Dacomitinib exerted its antiproliferative effect through a combined G(0)-G(1) arrest and an induction of apoptosis. Dacomitinib inhibited growth in several HER2-amplified lines with de novo and acquired resistance to trastuzumab. Dacomitinib maintained a high activity in lines with acquired resistance to lapatinib. This study identifies HER2-amplified breast cancer lines as most sensitive to the antiproliferative effect of dacomitinib and provides a strong rationale for its clinical testing in HER2-amplified breast cancers resistant to trastuzumab and lapatinib.
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Randomized phase II study of dacomitinib (PF-00299804), an irreversible pan-human epidermal growth factor receptor inhibitor, versus erlotinib in patients with advanced non-small-cell lung cancer.
J. Clin. Oncol.
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This randomized, open-label trial compared dacomitinib (PF-00299804), an irreversible inhibitor of human epidermal growth factor receptors (EGFR)/HER1, HER2, and HER4, with erlotinib, a reversible EGFR inhibitor, in patients with advanced non-small-cell lung cancer (NSCLC).
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Lymphatic vessel density in primary melanomas predicts sentinel lymph node status and risk of metastasis.
Histopathology
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Shayan R, Karnezis T, Murali R, Wilmott J S, Ashton M W, Taylor G I, Thompson J F, Hersey P, Achen M G, Scolyer R A & Stacker S A (2012) Histopathology 61, 702-710 Lymphatic vessel density in primary melanomas predicts sentinel lymph node status and risk of metastasis Aims:? Important prognostic factors in patients with cutaneous melanoma include primary tumour thickness/depth of invasion, ulceration and mitotic rate, and the presence of tumour cells in regional lymph nodes. More recently, features of stromal components, such as blood and lymphatic vessel density, have been suggested as additional indicators of metastatic potential. Our aim was to investigate the relationship between tumour lymphatic vessels and lymph node metastasis. Methods and results:? Metastasizing (n?=?11) and non-metastasizing (n?=?11) primary melanoma samples matched for depth/thickness, mitotic rate and ulceration were examined for lymphatic vessel density (LVD) in the primary tumour, using an antibody to podoplanin. Significant differences were found between LVD (vessels/unit area) in the peripheral (5.73?±?0.67) versus central (1.72?±?0.42) regions of the metastasizing tumour group (P?
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Large multimeric assemblies of nucleosome assembly protein and histones revealed by small-angle X-ray scattering and electron microscopy.
J. Biol. Chem.
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The nucleosome assembly protein (NAP) family represents a key group of histone chaperones that are essential for cell viability. Several x-ray structures of NAP1 dimers are available; however, there are currently no structures of this ubiquitous chaperone in complex with histones. We have characterized NAP1 from Xenopus laevis and reveal that it forms discrete multimers with histones H2A/H2B and H3/H4 at a stoichiometry of one NAP dimer to one histone fold dimer. These complexes have been characterized by size exclusion chromatography, analytical ultracentrifugation, multiangle laser light scattering, and small-angle x-ray scattering to reveal their oligomeric assembly states in solution. By employing single-particle cryo-electron microscopy, we visualized these complexes for the first time and show that they form heterogeneous ring-like structures, potentially acting as large scaffolds for histone assembly and exchange.
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Relational efficacy beliefs in physical activity classes: a test of the tripartite model.
J Sport Exerc Psychol
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This study explored the predictive relationships between students (N = 516, Mage = 18.48, SD = 3.52) tripartite efficacy beliefs and key outcomes in undergraduate physical activity classes. Students reported their relational efficacy perceptions (i.e., other-efficacy and relation-inferred self-efficacy, or RISE) with respect to their instructor before a class, and instruments measuring self-efficacy, enjoyment, and effort were administered separately following the class. The following week, an independent observer assessed student achievement. Latent variable path analyses that accounted for nesting within classes revealed (a) that students were more confident in their own ability when they reported favorable other-efficacy and RISE appraisals, (b) a number of direct and indirect pathways through which other-efficacy and RISE predicted adaptive in-class outcomes, and (c) that self-efficacy directly predicted enjoyment and effort, and indirectly predicted achievement. Although previous studies have examined isolated aspects within the tripartite framework, this represents the first investigation to test the full range of direct and indirect pathways associated with the entire model.
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Protein interaction networks in medicine and disease.
Proteomics
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The physical interaction of proteins is subject to intense investigation that has revealed that proteins are assembled into large densely connected networks. In this review, we will examine how signaling pathways can be combined to form higher order protein interaction networks. By using network graph theory, these interaction networks can be further analyzed for global organization, which has revealed unique aspects of the relationships between protein networks and complex biological phenotypes. Moreover, several studies have shown that the structure and dynamics of protein networks are disturbed in complex diseases such as cancer progression. These relationships suggest a novel paradigm for treatment of complex multigenic disease where the protein interaction network is the target of therapy more so than individual molecules within the network.
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The gracilis myocutaneous free flap: a quantitative analysis of the fasciocutaneous blood supply and implications for autologous breast reconstruction.
PLoS ONE
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Mastectomies are one of the most common surgical procedures in women of the developed world. The gracilis myocutaneous flap is favoured by many reconstructive surgeons due to the donor site profile and speed of dissection. The distal component of the longitudinal skin paddle of the gracilis myocutaneous flap is unreliable. This study quantifies the fasciocutaneous vascular territories of the gracilis flap and offers the potential to reconstruct breasts of all sizes.
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Muscle weakness, health status and frequency of exacerbations in chronic obstructive pulmonary disease.
Postgrad Med J
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Multiple factors contribute to muscle weakness and reduced muscle mass in chronic obstructive pulmonary disease (COPD) and this impacts patients quality of life. One factor implicated in this process is systemic inflammation, an accompaniment of acute exacerbations. Recurrent exacerbations are associated with lower health status. This study examines the relationship between muscle weaknesses, health status and exacerbation frequency in a cohort of patients with COPD.
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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.