JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Rhizobacter bergeniae sp. nov., isolated from the root of Bergenia scopulosa.
Int. J. Syst. Evol. Microbiol.
PUBLISHED: 11-13-2014
Show Abstract
Hide Abstract
A yellowish-pigmented bacterium, designated strain PLGR-1T, was isolated from the root of Bergenia scopulosa collected from Taibai Mountain in Shaanxi Province, north-west China, and was subjected to a taxonomic study by using a polyphasic approach. Cells of strain PLGR-1T were Gram-negative, strictly aerobic, rod-shaped, non-spore-forming and motile with a single polar flagellum. Growth occurred at 7-33 °C (optimum, 25-28 °C), at pH 5.0-10.0 (optimum, pH 6.0-7.0) and with 0-0.5 % (w/v) NaCl (optimum, 0 %). The predominant respiratory quinone was ubiquinone-8 (Q-8) and the major cellular fatty acids were summed feature 3 (comprising C16:1?7c and/or C16:1?6c), C16:0 and summed feature 8 (comprising C18:1?7c and/or C18:1?6c). The major polyamines are putrescine and 2-hydroxyputrescine and the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The DNA G+C content was 69.8 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain PLGR-1T belonged to the class Betaproteobacteria and formed a tight phyletic lineage with members of the genus Rhizobacter. Strain PLGR-1T was most closely related to Rhizobacter dauci DSM 11587T and Rhizobacter fulvus DSM 19916T, with 16S rRNA gene sequence similarities of 98.5 % and 98.0 %, respectively. The DNA-DNA relatedness values between strain PLGR-1T and the type strains of R. dauci and R. fulvus were 46.3 and 14.7 %, respectively. Based on the phenotypic, phylogenetic and genotypic data, strain PLGR-1T is considered to represent a novel species of the genus Rhizobacter, for which the name Rhizobacter bergeniae sp. nov. is proposed. The type strain is PLGR-1T (= CCTCC AB 2013018T = KCTC 32299T = LMG 27607T).
Related JoVE Video
Exendin-4 promotes endothelial barrier enhancement via PKA-and Epac1-dependent Rac1 activation.
Am. J. Physiol., Cell Physiol.
PUBLISHED: 11-08-2014
Show Abstract
Hide Abstract
Among emerging anti-diabetic candidates, glucagon like peptide-1 (GLP-1) based therapies carry special cardiovascular implications, exerting both direct as well as indirect effects. The control of vascular permeability is of pivotal importance in vascular pathologies. The objective of the present study was to determine the effect of GLP-1 on endothelial barrier function and assess the underlying mechanism (s). Here we show for the first time that the stable GLP-1 analogue Exendin-4 attenuated the leakage of subcutaneous blood vessels in mice indexed by dye extravasation caused by injections of thrombin. Moreover, in cultured endothelial cells, Exendin-4 significantly prevented the thrombin-induced FITC-dextran permeability of endothelial monolayers via GLP-1 receptor. Immunofluorescence microscopy reveals that Exendin-4 abrogates detrimental effects of thrombin on adherens junctions (VE-cadherin) and the F-actin cytoskeleton, with decreased stress fiber and gap formation. Importantly, Exendin-4 reduced thrombin-induced tyrosine phosphorylation of of VE-cadherin at Y731. Moreover, small GTPase Rac1 was significantly activated as a result of Exendin-4 treatment. The efficacy of Exendin-4 to counteract the barrier compromising effect of thrombin was blunted when Rac1 was inactivated by Rac1 inhibitor NSC23766. Inhibition of PKA activity, or small interfering RNA for exchange protein directly activated by cAMP 1 (Epac1) decreased Exendin-4-induced Rac1 activation and barrier enhancement, indicating the participation of both PKA and Epac1 in the barrier stabilizing effect of Exendin-4 elicited on thrombin-impared barrier function. Thus, our findings have uncovered an unpredicted role for Exendin-4 in the coordination of vascular permeability and clarified the molecular underpinings that contribute to barrier restoration initiated by Exendin-4.
Related JoVE Video
Designing a Cu(II)-ArCu(II)-ArCu(III)-Cu(I) Catalytic Cycle: Cu(II)-Catalyzed Oxidative Arene C-H Bond Azidation with Air as an Oxidant under Ambient Conditions.
J. Org. Chem.
PUBLISHED: 11-05-2014
Show Abstract
Hide Abstract
On the basis of our recent discovery of high valent organocopper compounds, we have designed and achieved efficient copper(II)-catalyzed oxidative arene C-H bond azidation under very mild aerobic conditions by using NaN3 as an azide source. In the presence of a Cu(II) catalyst, a number of azacalix[1]arene[3]pyridines underwent direct arene C-H bond cupration through an electrophilic aromatic metalation pathway to form an arylcopper(II) intermediate. Oxidized by a free copper(II) ion, the arylcopper(II) intermediate was transformed into an arylcopper(III) species that subsequently cross-coupled with azide to furnish the formation of aryl azide products with the release of a copper(I) ion. Under ambient catalytic reaction conditions, the copper(I) species generated was oxidized by air into copper(II), which entered into the next catalytic cycle. Application of the method was demonstrated by the synthesis of functional azacalix[1]arene[3]pyridines by means of simple and practical functional group transformations of azide. The showcase of the Cu(II)-ArCu(II)-ArCu(III)-Cu(I) catalytic cycle would provide a new strategy for the design of copper(II)-catalyzed aerobic oxidative arene C-H bond activation and transformations.
Related JoVE Video
Catalytic Asymmetric Difunctionalization of Stable Tertiary Enamides with Salicylaldehydes: Highly Efficient, Enantioselective, and Diastereoselective Synthesis of Diverse 4-Chromanol Derivatives.
Org. Lett.
PUBLISHED: 10-30-2014
Show Abstract
Hide Abstract
Catalyzed by a chiral BINOL-Ti(OiPr)4 complex, various stable tertiary enamides reacted with salicylaldehydes to afford diverse cis,trans-configured 4-chromanols that contain three continuous stereogenic centers in good yields with excellent diastereoselectivity and enantioselectivity. The reaction proceeded through the addition of enamide to aldehyde followed by the intramolecular interception of the resulting iminium by the hydroxy group. Oxidation of the resulting 4-chromanols yielded almost quantitatively chroman-4-one derivatives which underwent diastereospecific reduction with NaBH4 to produce cis,cis-configured 4-chromanols.
Related JoVE Video
Magnetic resonance study of the structure and function of the hippocampus and amygdala in patients with depression.
Chin. Med. J.
PUBLISHED: 10-16-2014
Show Abstract
Hide Abstract
The hippocampus and amygdala exhibit structural and functional alterations in patients with depression. The objective of this study was to investigate the structural and functional relationships between these core regions.
Related JoVE Video
Exendin-4 alleviates angiotensin II-induced senescence in vascular smooth muscle cells by inhibiting Rac1 activation via a cAMP/PKA-dependent pathway.
Am. J. Physiol., Cell Physiol.
PUBLISHED: 10-10-2014
Show Abstract
Hide Abstract
Vascular aging has been implicated in the progression of diabetes and age-related cardiovascular disorders. Glucagon-like peptide-1 (GLP-1) is an incretin hormone capable of cytoprotective actions in addition to its glucose-lowering effect. The present study was undertaken to examine whether Exendin-4, a specific ligand for GLP-1 receptor, could prevent angiotensin (Ang) II-induced premature senescence in vascular smooth muscle cells (VSMCs) and to determine the underlying mechanism involved. Senescence-associated ?-galactosidase (SA ?-gal) assay showed that Ang II induced premature senescence of VSMCs. Pretreatment with Exendin-4 significantly attenuated Ang II-induced generation of H2O2 and the subsequent VSMC senescence. These effects were, however, reversed in the presence of exendin fragment 9-39, a GLP-1 receptor antagonist, or PKI14-22. Moreover, a marked increase in the levels of p53 and p21 induced by Ang II was blunted by the treatment with Exendin-4. Nevertheless, Exendin-4 failed to decrease Ang II-induced expression of NAD(P)H oxidase 1(Nox 1), NAD(P)H oxidase 4 (Nox 4), p22(phox), or p47(phox) in VSMCs. Mechanistically, Exendin-4 blocked Ang II-induced Rac1 activation through the cAMP/PKA signaling cascade. Specifically, NSC23766, a Rac1 inhibitor, abrogated the suppressive effects of Exendin-4 on Ang II-induced premature senescence and H2O2 generation, respectively. Thus, Exendin-4 confers resistance to Ang II-induced superoxide anion generation from NAD(P)H oxidase and the resultant VSMC senescence by inhibiting Rac1 activation via a cAMP/PKA-dependent pathway. These findings demonstrate that GLP-1 as well as its analogues (GLP-1- related reagents) may hold therapeutic potential in the treatment of diabetes with cardiovascular disease.
Related JoVE Video
Dragline silk: a fiber assembled with low-molecular-weight cysteine-rich proteins.
Biomacromolecules
PUBLISHED: 10-09-2014
Show Abstract
Hide Abstract
Dragline silk has been proposed to contain two main protein constituents, MaSp1 and MaSp2. However, the mechanical properties of synthetic spider silks spun from recombinant MaSp1 and MaSp2 proteins have yet to approach natural fibers, implying the natural spinning dope is missing critical factors. Here we report the discovery of novel molecular constituents within the spinning dope that are extruded into dragline silk. Protein studies of the liquid spinning dope from the major ampullate gland, coupled with the analysis of dragline silk fibers using mass spectrometry, demonstrate the presence of a new family of low-molecular-weight cysteine-rich proteins (CRPs) that colocalize with the MA fibroins. Expression of the CRP family members is linked to dragline silk production, specifically MaSp1 and MaSp2 mRNA synthesis. Biochemical data support that CRP molecules are secreted into the spinning dope and assembled into macromolecular complexes via disulfide bond linkages. Sequence analysis supports that CRP molecules share similarities to members that belong to the cystine slipknot superfamily, suggesting that these factors may have evolved to increase fiber toughness by serving as molecular hubs that dissipate large amounts of energy under stress. Collectively, our findings provide molecular details about the components of dragline silk, providing new insight that will advance materials development of synthetic spider silk for industrial applications.
Related JoVE Video
Flush-mounted probe diagnostics for argon glow discharge plasma.
Rev Sci Instrum
PUBLISHED: 10-03-2014
Show Abstract
Hide Abstract
A comparison is made between plasma parameters measured by a flush-mounted probe (FP) and a cylindrical probe (CP) in argon glow discharge plasma. Parameters compared include the space potential, the plasma density, and the effective electron temperature. It is found that the ion density determined by the FP agrees well with the electron density determined by the CP in the quasi-neutral plasma to better than 10%. Moreover, the space potential and effective electron temperature calculated from electron energy distribution function measured by the FP is consistent with that measured by the CP over the operated discharge current and pressure ranges. These results present the FP can be used as a reliable diagnostic tool in the stable laboratory plasma and also be anticipated to be applied in other complicated plasmas, such as tokamaks, the region of boundary-layer, and so on.
Related JoVE Video
Hepatoprotective effect of Schisandra chinensis (Turcz.) Baill. lignans and its formula with Rubus idaeus on chronic alcohol-induced liver injury in mice.
Food Funct
PUBLISHED: 09-26-2014
Show Abstract
Hide Abstract
This study aimed to investigate the liver protection effect of Schisandra chinensis (Turcz.) Baill. (SC) lignans and its combination with Rubus idaeus (RI) on chronic alcohol-induced mice. A low level of SC lignans (SL) was prepared from the clear juice of sarcocarp. Lignans were further extracted from the SC seeds and added to the SL to form high-level SC lignans (SH). Moreover, RI clear juice lyophilized powder was mixed with SL (SR), and the liver protection effects of SL, SH and SR were investigated. Male ICR mice were administered with the corresponding samples and gastrically infused with 50% alcohol (1 h later) once per day for 60 d. In the in vitro study, the characteristic lignans in the SC clear juice and the seed extract were analyzed by high performance liquid chromatography (HPLC). The total phenolic content (TPC) and antioxidant capability of SL, SH, and SR were determined. The results of the in vivo study showed that SC lignans exhibited a dose-dependent effect on the regulation of hepatic antioxidant status, serum transaminases levels, hyperlipidemia and hepatic fat deposition in mice. However, hepatic lesions were observed in the SH mice, which indicated a potential side effect caused by long-term consumption of SH under chronic alcohol administration. By contrast, SR exhibited a similar hepatoprotective effect as SH without any abnormality found in the histological analysis. After analysis with HPLC, Schizandrol A and Schizandrol B were identified in the SC clear juice, and two more kinds of lignans, Schisandrin A and Schisandrin B, were identified in the seed extracts. The SR sample had the highest TPC and exhibited the best antioxidant capability. In conclusion, RI strengthened the liver protection effect of SC lignans effectively and safely, which was probably achieved by enhancing the antioxidant status and the positive effect of their combination was possibly attributed to both lignans and polyphenols. This study demonstrated that the combination of low-level SC lignans and RI might be used as a potential safe formula for beverage development to alleviate the adverse effects of long-term alcohol consumption.
Related JoVE Video
LIM and SH3 Protein 1 Induces TGF?-Mediated Epithelial-Mesenchymal Transition in Human Colorectal Cancer by Regulating S100A4 Expression.
Clin. Cancer Res.
PUBLISHED: 09-24-2014
Show Abstract
Hide Abstract
The expression of LIM and SH3 protein 1 (LASP1) was upregulated in colorectal cancer cases, thereby contributing to the aggressive phenotypes of colorectal cancer cells. However, we still cannot decipher the underlying molecular mechanism associated with colorectal cancer metastasis.
Related JoVE Video
[Pollution fingerprints and sources of perfluorinated compounds in surface soil of different functional areas].
Huan Jing Ke Xue
PUBLISHED: 09-24-2014
Show Abstract
Hide Abstract
In order to explore the effect of regional functions on the pollution fingerprints and levels of perfluorinated compounds (PFCs), principal components analysis was combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and solid phase extraction enrichment in this research to analyze the levels of 14 PFCs species in 76 surface soil samples, which were collected from 4 functional regions, namely parks, communities, crossroads and surroundings of factories, as well as the urban background of Shenzhen. The results showed that regional functions had significant effect on total PFCs (sigma PFCs), which ranked as the following: surroundings of factories (P < 0.001) > crossroads (P < 0.01) > communities (P < 0.05) > parks > urban background. The distribution of PFCs was in the order of medium- (P < 0.05) > long- > short-chain PFCs in surroundings of factories, communities and crossroads, while in the order of medium- approximately short- (P < 0.05) > long chain PFCs in crossroads. Over 81% of sigmaPFCs in the surface soil of Shenzhen could be attributed to the three principal components, represented by perfluorooctane sulfonate, perfluorooctane acid and perfluorotridecanoic acid, respectively. PFCs fingerprints were clearly shown in crossroads, as well as in surroundings of electroplating and paint factories.
Related JoVE Video
Gefitinib loaded folate decorated bovine serum albumin conjugated carboxymethyl-beta-cyclodextrin nanoparticles enhance drug delivery and attenuate autophagy in folate receptor-positive cancer cells.
J Nanobiotechnology
PUBLISHED: 09-17-2014
Show Abstract
Hide Abstract
BackgroundActive targeting endocytosis mediated by the specific interaction between folic acid and its receptor has been a hotspot in biological therapy of many human cancers. Various studies have demonstrated that folate and its conjugates could facilitate the chemotherapeutic drug delivery into folate receptor (FR)-positive tumor cells in vitro and in vivo. In order to utilize FA-FR binding specificity to achieve targeted delivery of drugs into tumor cells, we prepared Gefitinib loaded folate decorated bovine serum albumin conjugated carboxymethyl-ß-cyclodextrin nanoparticles for enhancing drug delivery in cancer cells. On this context, the aim of our study was to develop a novel nano-delivery system for promoting tumor-targeting drug delivery in folate receptor-positive Hela cells.ResultsWe prepared folic acid (FA)-decorated bovine serum albumin (BSA) conjugated carboxymethyl-ß-cyclodextrin (CM-ß-CD) nanoparticles (FA-BSA-CM-ß-CD NPs) capable of entrapping a hydrophobic Gefitinib. It was observed that nanoparticles are monodisperse and spherical nanospheres with an average diameter of 90.2 nm and negative surface charge of ¿18.6 mV. FA-BSA-CM-ß-CD NPs could greatly facilitate Gefitinib uptake and enhance the toxicity to folate receptor-positive Hela cells. Under the reaction between FA and FR, Gefitinib loaded FA-BSA-CM-ß-CD NPs induced apoptosis of Hela cells through elevating the expression of caspase-3 and inhibited autophagy through decreasing the expressing of LC3. It also confirmed that clathrin-mediated endocytosis and macropinocytosis exerted great influence on the internalization of both NPs.ConclusionsThese results demonstrated that FA may be an effective targeting molecule and FA-BSA-CM-ß-CD NPs provided a new strategy for the treatment of human cancer cells which over-expressed folate receptors.
Related JoVE Video
Asticcacaulis endophyticus sp. nov., a prosthecate bacterium isolated from the root of Geum aleppicum.
Int. J. Syst. Evol. Microbiol.
PUBLISHED: 09-11-2014
Show Abstract
Hide Abstract
A strictly aerobic, light-yellow-coloured, stalked bacterium, designated strain ZFGT-14T, was isolated from the root of Geum aleppicum Jacq. collected from Taibai Mountain in Shaanxi Province, north-west China, and was subjected to a taxonomic study by using a polyphasic approach. This novel isolate grew at 7-33 °C (optimum, 25-28 °C) and pH 6.0-10.0 (optimum, pH 7.0-8.0). Flexirubin-type pigments were not produced. Cells were Gram-reaction-negative, rod-shaped and motile with a single polar flagellum. The predominant respiratory quinone was Q-10. The major cellular fatty acids were summed feature 8 (comprising C18:1?7c/C18:1?6c), C16:0, C19:0 cyclo ?8c and summed feature 3 (comprises C16:1?7c and/or C16:1?6c) and the major polar lipids were phosphatidylglycerol and glycolipids. The DNA G+C content was 57.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ZFGT-14T was most closely related to the genus Asticcacaulis, exhibiting low sequence similarity (95.0-95.9 %) with all Asticcacaulis species with validly published names. Based on the phenotypic, phylogenetic and genotypic data, strain ZFGT-14T is considered to represent a novel species of the genus Asticcacaulis, for which the name Asticcacaulis endophyticus sp. nov. is proposed. The type strain is ZFGT-14T (=CCTCC AB 2013012T = KCTC 32296T=LMG 27605T).
Related JoVE Video
[Progression in metastasis of colorectal carcinoma].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 09-05-2014
Show Abstract
Hide Abstract
Globally, the incidence of colorectal carcinoma (CRC) ranks the third among all cancers. The incidence of CRC is continually increasing in China. Invasion and metastasis are the major causes of death. Metastasis is a complex multistep malignant process, including the detachment of tumor cells from the primary site, interaction of tumor cells with the surrounding extracellular matrix, entering into the circulation or lymph system, adhesion to the endothelial cells of vascular wall, migration of tumor cells into secondary sites, angiogenesis and formation of new metastases. This article reviews the recent research progress in aspects of the metastasis related genes, microRNAs, epithelial mesenchymal transition, tumor stem cells, and micro environment of colorectal cancer.
Related JoVE Video
Loss of PIKfyve in platelets causes a lysosomal disease leading to inflammation and thrombosis in mice.
Nat Commun
PUBLISHED: 09-02-2014
Show Abstract
Hide Abstract
PIKfyve is essential for the synthesis of phosphatidylinositol-3,5-bisphosphate [PtdIns(3,5)P2] and for the regulation of endolysosomal membrane dynamics in mammals. PtdIns(3,5)P2 deficiency causes neurodegeneration in mice and humans, but the role of PtdIns(3,5)P2 in non-neural tissues is poorly understood. Here we show that platelet-specific ablation of PIKfyve in mice leads to accelerated arterial thrombosis, and, unexpectedly, also to inappropriate inflammatory responses characterized by macrophage accumulation in multiple tissues. These multiorgan defects are attenuated by platelet depletion in vivo, confirming that they reflect a platelet-specific process. PIKfyve ablation in platelets induces defective maturation and excessive storage of lysosomal enzymes that are released upon platelet activation. Impairing lysosome secretion from PIKfyve-null platelets in vivo markedly attenuates the multiorgan defects, suggesting that platelet lysosome secretion contributes to pathogenesis. Our findings identify PIKfyve as an essential regulator for platelet lysosome homeostasis, and demonstrate the contributions of platelet lysosomes to inflammation, arterial thrombosis and macrophage biology.
Related JoVE Video
Serum diamine oxidase as a hemorrhagic shock biomarker in a rabbit model.
PLoS ONE
PUBLISHED: 08-21-2014
Show Abstract
Hide Abstract
In prolonged hemorrhagic shock, reductions in intestinal mucosal blood perfusion lead to mucosal barrier damage and systemic inflammation. Gastrointestinal failure in critically ill patients has a poor prognosis, so early assessment of mucosal barrier injury in shock patients is clinically relevant. Unfortunately, there is no serum marker that can accurately assess intestinal ischemia-reperfusion injury.
Related JoVE Video
Carboxymethyl-?-cyclodextrin conjugated nanoparticles facilitate therapy for folate receptor-positive tumor with the mediation of folic acid.
Int J Pharm
PUBLISHED: 08-19-2014
Show Abstract
Hide Abstract
Currently, clinical operation treatments, chemotherapy and radiotherapy just could eliminate local tumor cells. However, chemotherapy and radiotherapy also injury normal cells and lead to serious side effects and toxicities. So, it is necessary to find an effective target cancer carrier that delivers the anticancer agents into tumor cells and reduces normal cells' injury. Folic acid (FA) is a classical targeting agent mediates internalization of chemical drugs into tumor cells which over-express folate receptor (FR) on their surface. We herein report that based on host-guest interaction, NPs decorated by novel folate enhance antitumor drug delivery. BSA-NPs were prepared by desolvation method and carboxymethyl-?-cyclodextrin (CM-?-CD) was conjugated to the surface of NPs by carbodiimide coupling to hold FA. From in vitro cytotoxicity assay, cell apoptosis study, intracellular ATP level assay and western blot, we can see that FA-CM-?-CD-BSA NPs as good monodispersity, negative charge, and homogenous particle size have a high encapsulation efficiency. The results showed that MTT and cell apoptosis demonstrated that FA-decorated NPs exhibit stronger inhibition rate and induce obvious apoptosis in FR positive Hela cells as compared to free drug and FA undecorated NPs. Moreover, 5-fluorouracil (5-Fu) loaded FA-CM-?-CD-BSA NPs down-regulate ATP levels and increase the expression of caspase-3. Taken together, FA-CM-?-CD-BSA NPs enhance FR receptor-mediated endocytosis and lead to more intracellular uptake of drug, inducing the higher apoptosis ratio of cells than free 5-Fu.
Related JoVE Video
Optimization of physicochemical properties and safety profile of novel bacterial topoisomerase type II inhibitors (NBTIs) with activity against Pseudomonas aeruginosa.
Bioorg. Med. Chem.
PUBLISHED: 08-04-2014
Show Abstract
Hide Abstract
Type II bacterial topoisomerases are well validated targets for antimicrobial chemotherapy. Novel bacterial type II topoisomerase inhibitors (NBTIs) of these targets are of interest for the development of new antibacterial agents that are not impacted by target-mediated cross-resistance with fluoroquinolones. We now disclose the optimization of a class of NBTIs towards Gram-negative pathogens, especially against drug-resistant Pseudomonas aeruginosa. Physicochemical properties (pKa and logD) were optimized for activity against P. aeruginosa and for reduced inhibition of the hERG channel. The optimized analogs 9g and 9i displayed potent antibacterial activity against P. aeruginosa, and a significantly improved hERG profile over previously reported analogs. Compound 9g showed an improved QT profile in in vivo models and lower clearance in rat over earlier compounds. The compounds show promise for the development of new antimicrobial agents against drug-resistant Pseudomonas aeruginosa.
Related JoVE Video
Endothelium-dependent and -independent vasorelaxant actions and mechanisms induced by total flavonoids of Elsholtzia splendens in rat aortas.
Environ. Toxicol. Pharmacol.
PUBLISHED: 08-04-2014
Show Abstract
Hide Abstract
Elsholtzia splendens (ES) is, rich in flavonoids, used to repair copper contaminated soil in China, which has been reported to benefit cardiovascular systems as folk medicine. However, few direct evidences have been found to clarify the vasorelaxation effect of total flavonoids of ES (TFES). The vasoactive effect of TFES and its underlying mechanisms in rat thoracic aortas were investigated using the organ bath system. TFES (5-200mg/L) caused a concentration-dependent vasorelaxation in endothelium-intact rings, which was not abolished but significantly reduced by the removal of endothelium. The nitric oxide synthase (NOS) inhibitor N(?)-nitro-l-arginine methyl ester (100?M) and the guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,2-?]quinoxalin-1-one (30?M) significantly blocked the endothelium-dependent vasorelaxation of TFES. Meanwhile, NOS activity in endothelium-intact aortas was concentration-dependently elevated by TFES. However, indomethacin (10?M) did not affect TFES-induced vasorelaxation. Endothelium-independent vasorelaxation of TFES was significantly attenuated by KATP channel blocker glibenclamide. The accumulative Ca(2+)-induced contraction in endothelium-denuded aortic rings primed with KCl or phenylephrine was markedly weakened by TFES. These results revealed that the NOS/NO/cGMP pathway is likely involved in the endothelium-dependent vasorelaxation induced by TFES, while activating KATP channel, inhibiting intracellular Ca(2+) release, blocking Ca(2+) channels and decreasing Ca(2+) influx into vascular smooth muscle cells might contribute to the endothelium-independent vasorelaxation conferred by TFES.
Related JoVE Video
Synthesis of Quaternary-Carbon-Containing and Functionalized Enantiopure Pentanecarboxylic Acids from Biocatalytic Desymmetrization of meso-Cyclopentane-1,3-Dicarboxamides.
Chem Asian J
PUBLISHED: 08-02-2014
Show Abstract
Hide Abstract
Catalyzed by Rhodococcus erythropolis AJ270, a nitrile hydratase-amidase containing microbial whole-cell catalyst under mild conditions, enantioselective desymmetrizations of meso-cyclopentane-1,3-dicarbonitriles and cyclopentane-1,3-dicarboxamides were studied. Although the nitrile hydratase was found to exhibit high enzymatic activity, but low 1R enantioselectivity toward dinitriles, a number of 2,2-unsymmetrically substituted meso-cyclopentane-1,3-dicarboxamide substrates were converted by the 1S enantioselective amidase into quaternary carbon-bearing enantiopure (1S,2R,3R)-3-carbamoylcyclopentanecarboxylic acids in yields up to 94?%. The application of the method was demonstrated by convenient and practical transformations of the resulting (1S,2R,3R)-2-allyl-3-carbamoylcyclopentanecarboxylic acid derivatives into functionalized cyclopentane-fused ?-lactam and ?-lactone compounds.
Related JoVE Video
Structure-function analysis of mouse Sry reveals dual essential roles of the C-terminal polyglutamine tract in sex determination.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 07-29-2014
Show Abstract
Hide Abstract
The mammalian sex-determining factor SRY comprises a conserved high-mobility group (HMG) box DNA-binding domain and poorly conserved regions outside the HMG box. Mouse Sry is unusual in that it includes a C-terminal polyglutamine (polyQ) tract that is absent in nonrodent SRY proteins, and yet, paradoxically, is essential for male sex determination. To dissect the molecular functions of this domain, we generated a series of Sry mutants, and studied their biochemical properties in cell lines and transgenic mouse embryos. Sry protein lacking the polyQ domain was unstable, due to proteasomal degradation. Replacing this domain with irrelevant sequences stabilized the protein but failed to restore Sry's ability to up-regulate its key target gene SRY-box 9 (Sox9) and its sex-determining function in vivo. These functions were restored only when a VP16 transactivation domain was substituted. We conclude that the polyQ domain has important roles in protein stabilization and transcriptional activation, both of which are essential for male sex determination in mice. Our data disprove the hypothesis that the conserved HMG box domain is the only functional domain of Sry, and highlight an evolutionary paradox whereby mouse Sry has evolved a novel bifunctional module to activate Sox9 directly, whereas SRY proteins in other taxa, including humans, seem to lack this ability, presumably making them dependent on partner proteins(s) to provide this function.
Related JoVE Video
Synthesis, Structure, and Properties of O6 -Corona[3]arene[3]tetrazines.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 07-28-2014
Show Abstract
Hide Abstract
O6 -Corona[3]arene[3]tetraazines, a new class of macrocyclic compounds, were synthesized efficiently in a one-pot reaction from the nucleophilic aromatic substitution reaction between 1,4-dihydroxybenzene derivatives and 3,6-dichlorotetrazine in warm acetonitrile. In the crystalline structure, the resulting macrocycles adopt highly symmetric structures of a regular hexagonal cavity with all bridging oxygen atoms and tetrazine rings located on the same plane with phenylene units orthogonally orientated. The constitutional aromatic rings are able to rotate around the macrocyclic annulus, depending on the steric effect of the substituents and temperature, in solution. The electron-deficient nature revealed by cyclic voltammetry, differential pulse voltammetry, and characteristic absorbances at a visible region show the O6 -corona[3]arene[3]tetrazines to be suitable macrocyclic receptors for electron-rich guests.
Related JoVE Video
Suppression of AKT expression by miR-153 produced anti-tumor activity in lung cancer.
Int. J. Cancer
PUBLISHED: 07-22-2014
Show Abstract
Hide Abstract
Lung cancer is one of the leading causes of cancer death worldwide. microRNAs have been shown to be a novel class of regulators in lung cancer. Here, we explored the role of miR-153 in the pathogenesis of lung cancer and its therapeutic potential. miR-153 was significantly decreased in lung cancer tissues than the adjacent tissues. The protein and mRNA levels of protein kinase B (AKT), which were shown to promote tumor growth, were both increased in lung cancer tissues than adjacent tissues. Overexpression of miR-153 significantly inhibited AKT protein expression, which were abrogated by co-transfection of AMO-153, the specific inhibitor of miR-153. Luciferase assay showed that transfection of miR-153 markedly suppressed the fluorescent intensity of chimeric vectors carrying the 3'UTR of AKT1, while produced no effect on the mutant construct, indicating that AKT is regulated by miR-153. Overexpression of miR-153 significantly inhibited the proliferation and migration, and promoted apoptosis of cultured lung cancer cells in vitro, and suppressed the growth of xenograft tumors in vivo. Interestingly, lung cancer cells with lower endogenous miR-153 expression are more sensitive to ectopic overexpressed miR-153. The IC50 of miR-153 on lung cancer cells is positive correlated with the endogenous miR-153 level, while negative correlated with AKT level. Knockdown of AKT expression suppressed lung cancer cell proliferation. In summary, miR-153 exerted anti-tumor activity in lung cancer by targeting on AKT. The sensitivity of lung cancer cells to miR-153 is determined by its endogenous miR-153 level.
Related JoVE Video
[Effects of total flavones of Elsholtzia splendens in isolated ischemia/reperfusion rat hearts].
Zhongguo Ying Yong Sheng Li Xue Za Zhi
PUBLISHED: 07-15-2014
Show Abstract
Hide Abstract
To investigate the influence of total flavonoids of Elsholtzia splendens (TFES) on isolated ischemia/reperfusion rat hearts and its underlying mechanisms.
Related JoVE Video
Tumor suppressor miR-1 restrains epithelial-mesenchymal transition and metastasis of colorectal carcinoma via the MAPK and PI3K/AKT pathway.
J Transl Med
PUBLISHED: 07-11-2014
Show Abstract
Hide Abstract
Aberrant expression of miR-1 has been implicated in various cancers. However, the mechanisms underlying the role of miR-1 in CRC progression still have not been clarified clearly. Here, we showed the decreased expression of miR-1 in colorectal carcinoma (CRC) tissues and cell lines. Ectopic introduction of miR-1 suppressed cell proliferation and migration, whereas miR-1 inhibitor performed contrary functions in CRC cells. Stable overexpression of miR-1 was sufficient to inhibit tumor growth and homing capacity in vivo. Proteomic analysis revealed that miR-1 modulated the expression of key cellular molecules and involved in the MAPK and PI3K/AKT pathways by inhibiting phosphorylation of ERK and AKT. Meanwhile, miR-1 also reversed epithelial¿mesenchymal transition (EMT), which played a pivotal role in the initiation of metastasis. Further studies found that miR-1 can target the 3' untranslated region (3'UTR) of LIM and SH3 protein 1 (LASP1) mRNA and suppress the expression of LASP1, identified as a CRC-associated protein. In contrast to the phenotypes induced by miR-1 restoration, LASP1-induced cell proliferation and migration partly rescued miR-1-mediated biological behaviors. Our results illustrated that miR-1 play a critical role in CRC progression, which suggests its potential role in the molecular therapy of cancer.
Related JoVE Video
Superatoms (Li3O and BeF3) induce phenalenyl radical ?-dimer: fascinating interlayer charge-transfer and large NLO responses.
Dalton Trans
PUBLISHED: 07-11-2014
Show Abstract
Hide Abstract
Recently, the well-known phenalenyl radical ?-dimer with its fascinating 2-electron/12-center (2e/12c) bond has attracted our attention. In this work, we designed two molecules, Li3OC13H9 () and BeF3C13H9 (). Interestingly, owing to the inductive effect of superatoms, an electron is transferred from Li3O to phenalenyl in , while an electron is transferred from phenalenyl to BeF3 in . Further, we employed and as building blocks to assemble two novel molecules with 2e/12c bonds: Li3O(C13H9)2BeF3 () and Li3O(C13H9)2BeF3 (). Remarkably, and with novel 2e/12c bonds exhibit a dramatic interlayer charge-transfer character, which results in a significant difference of dipole moments (??: 2.6804 for and 3.8019 Debye for ) between the ground state and the crucial excited state. As a result, the static first hyperpolarizabilities (?0: 5154 for and 12?500 au for ) are considerably larger than the values of 347 for and 328 au for . It is our expectation that the results of the present work might provide beneficial information for further theoretical and experimental studies on the fascinating properties of molecules with interlayer charge-transfer character.
Related JoVE Video
Tightly bound excitons in monolayer WSe(2).
Phys. Rev. Lett.
PUBLISHED: 07-10-2014
Show Abstract
Hide Abstract
Exciton binding energy and excited states in monolayers of tungsten diselenide (WSe(2)) are investigated using the combined linear absorption and two-photon photoluminescence excitation spectroscopy. The exciton binding energy is determined to be 0.37 eV, which is about an order of magnitude larger than that in III-V semiconductor quantum wells and renders the exciton excited states observable even at room temperature. The exciton excitation spectrum with both experimentally determined one- and two-photon active states is distinct from the simple two-dimensional (2D) hydrogenic model. This result reveals significantly reduced and nonlocal dielectric screening of Coulomb interactions in 2D semiconductors. The observed large exciton binding energy will also have a significant impact on next-generation photonics and optoelectronics applications based on 2D atomic crystals.
Related JoVE Video
Percutaneous transcatheter closure of congenital coronary artery fistulae with patent ductus arteriosus occluder in children: focus on patient selection and intermediate-term follow-up results.
J Invasive Cardiol
PUBLISHED: 07-05-2014
Show Abstract
Hide Abstract
The prognostic implications of clinically silent coronary artery fistula (CAF) and its intermediate/long-term outcomes after transcatheter closure have not been well studied, especially in children.
Related JoVE Video
An 8-GW long-pulse generator based on Tesla transformer and pulse forming network.
Rev Sci Instrum
PUBLISHED: 07-03-2014
Show Abstract
Hide Abstract
A long-pulse generator TPG700L based on a Tesla transformer and a series pulse forming network (PFN) is constructed to generate intense electron beams for the purpose of high power microwave (HPM) generation. The TPG700L mainly consists of a 12-stage PFN, a built-in Tesla transformer in a pulse forming line, a three-electrode gas switch, a transmission line with a trigger, and a load. The Tesla transformer and the compact PFN are the key technologies for the development of the TPG700L. This generator can output electrical pulses with a width as long as 200 ns at a level of 8 GW and a repetition rate of 50 Hz. When used to drive a relative backward wave oscillator for HPM generation, the electrical pulse width is about 100 ns on a voltage level of 520 kV. Factors affecting the pulse waveform of the TPG700L are also discussed. At present, the TPG700L performs well for long-pulse HPM generation in our laboratory.
Related JoVE Video
The effects and underlying mechanism of excessive iodide on excessive fluoride-induced thyroid cytotoxicity.
Environ. Toxicol. Pharmacol.
PUBLISHED: 06-27-2014
Show Abstract
Hide Abstract
In many regions, excessive fluoride and excessive iodide coexist in groundwater, which may lead to biphasic hazards to human thyroid. To explore fluoride-induced thyroid cytotoxicity and the mechanism underlying the effects of excessive iodide on fluoride-induced cytotoxicity, a thyroid cell line (Nthy-ori 3-1) was exposed to excessive fluoride and/or excessive iodide. Cell viability, lactate dehydrogenase (LDH) leakage, reactive oxygen species (ROS) formation, apoptosis, and the expression levels of inositol-requiring enzyme 1 (IRE1) pathway-related molecules were detected. Fluoride and/or iodide decreased cell viability and increased LDH leakage and apoptosis. ROS, the expression levels of glucose-regulated protein 78 (GRP78), IRE1, C/EBP homologous protein (CHOP), and spliced X-box-binding protein-1 (sXBP-1) were enhanced by fluoride or the combination of the two elements. Collectively, excessive fluoride and excessive iodide have detrimental influences on human thyroid cells. Furthermore, an antagonistic interaction between fluoride and excessive iodide exists, and cytotoxicity may be related to IRE1 pathway-induced apoptosis.
Related JoVE Video
Inhibition of glycogen synthase kinase-3? attenuates acute kidney injury in sodium taurocholate?induced severe acute pancreatitis in rats.
Mol Med Rep
PUBLISHED: 06-11-2014
Show Abstract
Hide Abstract
The aim of the present study was to investigate the efficacy of 4?benzyl?2?methyl?1,2,4?thiadiazolidine?3,5?dione (TDZD?8), the selective inhibitor of glycogen synthase kinase?3? (GSK?3?), on the development of acute kidney injury in an experimental model of sodium taurocholate?induced severe acute pancreatitis (SAP) in rats. The serum amylase, lipase, interleukin?1? and interleukin?6 levels, and the pancreatic pathological score were examined to determine the magnitude of pancreatitis injury. The serum creatinine and blood urea nitrogen levels, myeloperoxidase (MPO) activity and renal histological grading were measured to assess the magnitude of SAP?induced acute kidney injury. The activation of nuclear factor??B (NF??B) was examined using an immunohistochemistry assay. The expression of GSK?3?, phospho?GSK?3? (Ser9), tumour necrosis factor?? (TNF??), intercellular adhesion molecule?1 (ICAM?1) and inducible nitric oxide synthase (iNOS) protein in the kidney was characterised using western blot analysis. TDZD?8 attenuated (i) serum amylase, lipase and renal dysfunction; (ii) the serum concentrations of proinflammatory cytokines; (iii) pancreatic and renal pathological injury; (iv) renal MPO activity and (v) NF??B activation and TNF??, ICAM?1 and iNOS protein expression in the kidney. The results obtained in the present study suggest that the inhibition of GSK?3? attenuates renal disorders associated with SAP through the inhibition of NF??B activation and the downregulation of the expression of proinflammatory cytokines, TNF??, ICAM?1 and iNOS in rats. Blocking GSK?3? protein kinase activity may be a novel approach to the treatment of this in?ammatory condition.
Related JoVE Video
Association of Gestational Diabetes Mellitus (GDM) with subclinical atherosclerosis: a systemic review and meta-analysis.
BMC Cardiovasc Disord
PUBLISHED: 06-11-2014
Show Abstract
Hide Abstract
Gestational diabetes mellitus (GDM) is associated with an elevated risk of adverse health outcomes such as type 2 diabetes and cardiovascular diseases. Carotid intima-media thickness (cIMT) is increasingly used as a noninvasive marker for subclinical atherosclerosis. Whether there is a direct correlation between GDM and elevated cIMT is still controversial.
Related JoVE Video
[Ginsenoside Rh2 inhibits proliferation and promotes apoptosis of leukemia KG1-? cells].
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
PUBLISHED: 06-10-2014
Show Abstract
Hide Abstract
To investigate the effect of ginsenoside Rh2 on leukemia KG1-? cells.
Related JoVE Video
Enhanced biocompatibility of PLGA nanofibers with gelatin/nano-hydroxyapatite bone biomimetics incorporation.
ACS Appl Mater Interfaces
PUBLISHED: 06-10-2014
Show Abstract
Hide Abstract
The biocompatibility of biomaterials is essentially for its application. The aim of current study was to evaluate the biocompatibility of poly(lactic-co-glycolic acid) (PLGA)/gelatin/nanohydroxyapatite (n-HA) (PGH) nanofibers systemically to provide further rationales for the application of the composite electrospun fibers as a favorable platform for bone tissue engineering. The PGH composite scaffold with diameter ranging from nano- to micrometers was fabricated by using electrospinning technique. Subsequently, we utilized confocal laser scanning microscopy (CLSM) and MTT assay to evaluate its cyto-compatibility in vitro. Besides, real-time quantitative polymerase chain reaction (qPCR) analysis and alizarin red staining (ARS) were performed to assess the osteoinductive activity. To further test in vivo, we implanted either PLGA or PGH composite scaffold in a rat subcutaneous model. The results demonstrated that PGH scaffold could better support osteoblasts adhesion, spreading, and proliferation and show better cyto-compatibility than pure PLGA scaffold. Besides, qPCR analysis and ARS showed that PGH composite scaffold exhibited higher osteoinductive activity owing to higher phenotypic expression of typical osteogenic genes and calcium deposition. The histology evaluation indicated that the incorporation of Gelatin/nanohydroxyapatite (GH) biomimetics could significantly reduce local inflammation. Our data indicated that PGH composite electrospun nanofibers possessed excellent cyto-compatibility, good osteogenic activity, as well as good performance of host tissue response, which could be versatile biocompatible scaffolds for bone tissue engineering.
Related JoVE Video
TiO2/CdSe core-shell nanofiber film for photoelectrochemical hydrogen generation.
Nanoscale
PUBLISHED: 05-30-2014
Show Abstract
Hide Abstract
We report on a novel core-shell TiO2/CdSe nanofiber photoanode for photoelectrochemical hydrogen generation. The core-shell nanofiber films, with a hierarchical network structure, are prepared on fluorine-doped tin oxide coated substrates via electrospinning pyrolysis and chemical bath deposition. The hierarchical network structure shows significantly improved photoelectrochemical properties due, we believe, to possessing more active sites for the oxidation reaction and a larger TiO2/CdSe interface area for photogenerated charges' separation. The synthesis details are discussed to provide a generic route for preparing other similar photoanodes with hierarchical network structures.
Related JoVE Video
Clinical endpoint sensitivity in rheumatoid arthritis: modeling and simulation.
J Pharmacokinet Pharmacodyn
PUBLISHED: 05-29-2014
Show Abstract
Hide Abstract
The commonly used efficacy endpoints in Rheumatoid Arthritis (RA) clinical trials are American College of Rheumatology 20 % improvement criteria (ACR20), ACR50, and ACR70 response rates, and the 28-joint disease activity score (DAS28). Longitudinal models to quantitate the exposure-response relationships for ACRs and DAS28 score were developed for four biologics used for the management of RA. The models were then used to simulate the clinical outcome at various time points following different treatment regimens. Discriminative sensitivity of these endpoints was assessed using a power analysis. The trial simulation and subsequent power analysis showed that both ACR20 and DAS28 exhibit much lower power in distinguishing between two doses investigated compared with distinguishing treatment effect over placebo/Methotrexate (MTX) control. ACR20 response rate is generally more powerful in detecting treatment effect over placebo/MTX control as compared to DAS28. The findings of current study provide useful information which will help future clinical trial design for the treatment of patients with RA.
Related JoVE Video
Action representations activated by task-irrelevant information: Is it really irrelevant?
Scand J Psychol
PUBLISHED: 05-16-2014
Show Abstract
Hide Abstract
Accessing action knowledge is believed to rely on the activation of action representations through the retrieval of functional, manipulative, and spatial information associated with objects. However, it remains unclear whether action representations can be activated in this way when the object information is irrelevant to the current judgment. The present study investigated this question by independently manipulating the correctness of three types of action-related information: the functional relation between the two objects, the grip applied to the objects, and the orientation of the objects. In each of three tasks in Experiment 1, participants evaluated the correctness of only one of the three information types (function, grip or orientation). Similar results were achieved with all three tasks: "correct" judgments were facilitated when the other dimensions were correct; however, "incorrect" judgments were facilitated when the other two dimensions were both correct and also when they were both incorrect. In Experiment 2, when participants attended to an action-irrelevant feature (object color), there was no interaction between function, grip, and orientation. These results clearly indicate that action representations can be activated by retrieval of functional, manipulative, and spatial knowledge about objects, even though this is task-irrelevant information.
Related JoVE Video
Single nucleotide polymorphisms in TNFAIP3 were associated with the risks of rheumatoid arthritis in northern Chinese Han population.
BMC Med. Genet.
PUBLISHED: 05-07-2014
Show Abstract
Hide Abstract
Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic destructive inflammation in synovial joints. It is well known that genetic and environmental risk factors and their interaction contribute to RA pathogenesis. This study aimed to investigate the association between the critical polymorphisms in the tumor necrosis factor ? (TNF?)-induced protein 3(TNFAIP3) gene and the risk of RA in a large northern Chinese Han population.
Related JoVE Video
A piggyBac transposon- and gateway-enhanced system for efficient BAC transgenesis.
Dev. Dyn.
PUBLISHED: 05-05-2014
Show Abstract
Hide Abstract
Bacterial artificial chromosomes (BACs) have become increasingly popular vectors for making transgenic mice, as they are able to carry large genomic DNA fragments that in many cases are needed to reproduce the endogenous gene expression pattern. However, the efficiency of BAC transgenesis is generally low, and gene transfer to BAC vectors by recombination-mediated engineering (recombineering) is time-consuming and technically demanding.
Related JoVE Video
Rhizobium smilacinae sp. nov., an endophytic bacterium isolated from the leaf of Smilacina japonica.
Antonie Van Leeuwenhoek
PUBLISHED: 05-04-2014
Show Abstract
Hide Abstract
During a study of endophytic bacteria from traditional Chinese medicinal plants, a bacterial strain, designated PTYR-5(T), was isolated from the leaf of Smilacina japonica A. Gray collected from Taibai Mountain in Shaanxi Province, north-west China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain PTYR-5(T) is a member of the genus Rhizobium, exhibiting the highest sequence similarities to R. cellulosilyticum LMG 23642(T) (97.2%), R. huautlense LMG 18254(T) (97.2%) and R. alkalisoli CCBAU 01393(T) (97.1%). The levels of 16S rRNA gene sequence similarity with respect to other Rhizobium species with validly published names were less than 97.0%. Phylogenies of the housekeeping genes atpD, recA and glnII confirmed its distinct position, showing low similarity with respect to those of recognized Rhizobium species (no more than 94.1, 90.0 and 88.0% similarity, respectively). The DNA-DNA relatedness values of strain PTYR-5(T) with R. cellulosilyticum LMG 23642(T), R. huautlense LMG 18254(T) and R. alkalisoli CCBAU 01393(T) were 33.6, 21.4 and 29.5 %, respectively. Based on phenotypic, phylogenetic and genotypic data, strain PTYR-5(T) is considered to represent a novel species of the genus Rhizobium, for which the name Rhizobium smilacinae sp. nov. is proposed. The type strain is PTYR-5(T) (=CCTCC AB 2013016(T)=KCTC 32300(T)=LMG 27604(T)).
Related JoVE Video
Nutritional status modulates box C/D snoRNP biogenesis by regulated subcellular relocalization of the R2TP complex.
Genome Biol.
PUBLISHED: 04-23-2014
Show Abstract
Hide Abstract
Box C/D snoRNPs, which are typically composed of box C/D snoRNA and the four core protein components Nop1, Nop56, Nop58, and Snu13, play an essential role in the modification and processing of pre-ribosomal RNA. The highly conserved R2TP complex, comprising the proteins Rvb1, Rvb2, Tah1, and Pih1, has been shown to be required for box C/D snoRNP biogenesis and assembly; however, the molecular basis of R2TP chaperone-like activity is not yet known.
Related JoVE Video
Monitoring the AML1/ETO fusion transcript to predict outcome in childhood acute myeloid leukemia.
Pediatr Blood Cancer
PUBLISHED: 04-23-2014
Show Abstract
Hide Abstract
To determine the prognostic significance of the detection of the minimal residual disease (MRD) in children with AML1/ETO AML, we compared the results of reverse-transcription polymerase chain reaction (RT-PCR) and quantitative reverse-transcription polymerase chain reaction (RQ-PCR).
Related JoVE Video
Distributed power-line outage detection based on wide area measurement system.
Sensors (Basel)
PUBLISHED: 04-16-2014
Show Abstract
Hide Abstract
In modern power grids, the fast and reliable detection of power-line outages is an important functionality, which prevents cascading failures and facilitates an accurate state estimation to monitor the real-time conditions of the grids. However, most of the existing approaches for outage detection suffer from two drawbacks, namely: (i) high computational complexity; and (ii) relying on a centralized means of implementation. The high computational complexity limits the practical usage of outage detection only for the case of single-line or double-line outages. Meanwhile, the centralized means of implementation raises security and privacy issues. Considering these drawbacks, the present paper proposes a distributed framework, which carries out in-network information processing and only shares estimates on boundaries with the neighboring control areas. This novel framework relies on a convex-relaxed formulation of the line outage detection problem and leverages the alternating direction method of multipliers (ADMM) for its distributed solution. The proposed framework invokes a low computational complexity, requiring only linear and simple matrix-vector operations. We also extend this framework to incorporate the sparse property of the measurement matrix and employ the LSQRalgorithm to enable a warm start, which further accelerates the algorithm. Analysis and simulation tests validate the correctness and effectiveness of the proposed approaches.
Related JoVE Video
Characterization of zebrafish Pax1b and Pax9 in fin bud development.
Biomed Res Int
PUBLISHED: 04-03-2014
Show Abstract
Hide Abstract
Both Pax1 and Pax9 belong to the important paired box gene family (PAX), which mainly participates in animal development and sclerotome differentiation. To date, the precise molecular mechanism and related signaling pathway of Pax1 remain unclear. In our study, microinjection of morpholino- (MO-) modified antisense oligonucleotides against pax1b induced pectoral fin bud defects. Furthermore, we demonstrate that the phenotypes caused by the knockdown of Pax1b in zebrafish could not be phenocopied by pax9 MO and could not be rescued by either Pax1a or Pax9 overexpression. We further find that Pax1b affects the expression of col2a1, Uncx4.1, Noggin3, and aggrecan, confirming the role of Pax1b in chondrocyte differentiation and bone maturation. Moreover, we identify an interaction between PAX1 and FOXO1 and find that the interaction was enhanced under hypoxia stress. Together, this evidence for cell death caused by pax1b knockdown provides new insight into the role of the Pax protein family in cell fate determination and tissue specification.
Related JoVE Video
The context dependence of beneficiary feedback effects on benefactors in plant facilitation.
New Phytol.
PUBLISHED: 03-25-2014
Show Abstract
Hide Abstract
Facilitative effects of some species on others are a major driver of biodiversity. These positive effects of a benefactor on its beneficiary can result in negative feedback effects of the beneficiary on the benefactor and reduced fitness of the benefactor. However, in contrast to the wealth of studies on facilitative effects in different environments, we know little about whether the feedback effects show predictable patterns of context dependence. We reanalyzed a global data set on alpine cushion plants, previously used to assess their positive effects on biodiversity and the nature of the beneficiary feedback effects, to specifically assess the context dependence of how small- and large-scale drivers alter the feedback effects of cushion-associated (beneficiary) species on their cushion benefactors using structural equation modelling. The effect of beneficiaries on cushions became negative when beneficiary diversity increased and facilitation was more intense. Local-scale biotic and climatic conditions mediated these community-scale processes, having indirect effects on the feedback effect. High-productivity sites demonstrated weaker negative feedback effects of beneficiaries on the benefactor. Our results indicate a limited impact of the beneficiary feedback effects on benefactor cushions, but strong context dependence. This context dependence may help to explain the ecological and evolutionary persistence of this widespread facilitative system.
Related JoVE Video
Spatial and temporal variability of polycyclic aromatic hydrocarbons in sediments from yellow river-dominated margin.
ScientificWorldJournal
PUBLISHED: 02-28-2014
Show Abstract
Hide Abstract
Polycyclic aromatic hydrocarbons (PAHs) were analyzed for surface sediments and a sediment core from the Yellow River-dominated margin. The concentration of 16 USEPA priority PAHs in surface sediments ranged from 5.6 to 175.4?ng?g(-1) dry weight sediment (dws) with a mean of 49.1?ng?g(-1)?dws. From 1930 to 2011, the distribution of PAHs (37.2 to 210.6?ng?g(-1)?dws) was consistent with the socioeconomic development of China. The PAHs' concentration peaked in 1964 and 1986, corresponding to the rapid economic growth in China (1958-1965) and the initiation of the "Reform and Open" policy in 1978, respectively. The applications of molecular diagnostic ratios and principal component analysis suggest that PAHs are predominantly produced by the coal and biomass combustion, whereas the contribution of petroleum combustions slightly increased after the 1970s, synchronous with an increasing usage of oil and gas in China.
Related JoVE Video
Biofeedback-guided pelvic floor exercise therapy for obstructive defecation: an effective alternative.
World J. Gastroenterol.
PUBLISHED: 02-26-2014
Show Abstract
Hide Abstract
To compare biofeedback-guided pelvic floor exercise therapy (BFT) with the use of oral polyethylene glycol (PEG) for the treatment of obstructive defecation.
Related JoVE Video
Theoretical characterization and design of highly efficient iridium (III) complexes bearing guanidinate ancillary ligand.
J. Mol. Graph. Model.
PUBLISHED: 02-25-2014
Show Abstract
Hide Abstract
A density functional theory/time-depended density functional theory was used to investigate the synthesized guanidinate-based iridium(III) complex [(ppy)2Ir{(N(i)Pr)2C(NPh2)}] (1) and two designed derivatives (2 and 3) to determine the influences of different cyclometalated ligands on photophysical properties. Except the conventional discussions on geometric relaxations, absorption and emission properties, many relevant parameters, including spin-orbital coupling (SOC) matrix elements, zero-field-splitting parameters, radiative rate constants (kr) and so on were quantitatively evaluated. The results reveal that the replacement of the pyridine ring in the 2-phenylpyridine ligand with different diazole rings cannot only enlarge the frontier molecular orbital energy gaps, resulting in a blue-shift of the absorption spectra for 2 and 3, but also enhance the absorption intensity of 3 in the lower-energy region. Furthermore, it is intriguing to note that the photoluminescence quantum efficiency (?PL) of 3 is significantly higher than that of 1. This can be explained by its large SOC value(n=3-4) and large transition electric dipole moment (?S3), which could significantly contribute to a larger kr. Besides, compared with 1, the higher emitting energy (ET1) and smaller (2) value for 3 may lead to a smaller non-radiative decay rate. Additionally, the detailed results also indicate that compared to 1 with pyridine ring, 3 with imidazole ring performs a better hole injection ability. Therefore, the designed complex 3 can be expected as a promising candidate for highly efficient guanidinate-based phosphorescence emitter for OLEDs applications.
Related JoVE Video
Foliar water uptake of Tamarix ramosissima from an atmosphere of high humidity.
ScientificWorldJournal
PUBLISHED: 02-18-2014
Show Abstract
Hide Abstract
Many species have been found to be capable of foliar water uptake, but little research has focused on this in desert plants. Tamarix ramosissima was investigated to determine whether its leaves can directly absorb water from high humidity atmosphere and, if they can, to understand the magnitude and importance of foliar water uptake. Various techniques were adopted to demonstrate foliar water uptake under submergence or high atmospheric humidity. The mean increase in leaf water content after submergence was 29.38% and 20.93% for mature and tender leaves, respectively. In the chamber experiment, obvious reverse sap flow occurred when relative humidity (RH) was persistently above 90%. Reverse flow was recorded first in twigs, then in branches and stems. For the stem, the percentage of negative sap flow rate accounting for the maximum value of sap flow reached 10.71%, and its amount accounted for 7.54% of diurnal sap flow. Small rainfall can not only compensate water loss of plant by foliar uptake, but also suppress transpiration. Foliar uptake can appear in the daytime under certain rainfall events. High atmospheric humidity is beneficial for enhancing the water status of plants. Foliar uptake should be an important strategy of water acquisition for desert plants.
Related JoVE Video
Simultaneous determination of oleanolic acid, ursolic acid, quercetin and apigenin in Swertia mussotii Franch by capillary zone electrophoresis with running buffer modifier.
Biomed. Chromatogr.
PUBLISHED: 02-17-2014
Show Abstract
Hide Abstract
The method of capillary zone electrophoresis (CZE) with direct UV detection was developed for the determination of oleanolic acid, ursolic acid, quercetin and apigenin. and then for the first time successfully applied to the analysis of four analytes in Swertia mussotii Franch and its preparations. Various factors affecting the CZE procedure were investigated and optimized, and the optimal conditions were: 50?×?10(-3) ?mol/L borate-phosphate buffer (pH?9.5) with 5.0?×?10(-3) ?mol/L ?-cyclodextrin, 15?kV separation voltage, 20?°C column temperature, 250?nm detection wavelength and 5?s electrokinetic injection time (voltage 20?psi). Under the conditions, oleanolic acid, ursolic acid, quercetin and apigenin could be determined within the test ranges with a good correlation coefficient (r(2) ?>?0.9991). The limits of detection for conditions, oleanolic acid, ursolic acid, quercetin and apigenin were 0.3415, 0.2003, 0.0062 and 0.2538?µg/mL, respectively, and the intra- and inter-day relative standard deviations were no more than 4.72%. This procedure provided a convenient, sensitive and accurate method for simultaneous determination of oleanolic acid, ursolic acid, quercetin and apigenin in S. mussotii Franch. Copyright © 2014 John Wiley & Sons, Ltd.
Related JoVE Video
Distribution and diversity of rhizobia associated with wild soybean (Glycine soja Sieb. & Zucc.) in Northwest China.
Syst. Appl. Microbiol.
PUBLISHED: 01-14-2014
Show Abstract
Hide Abstract
A total of 155 nodule isolates that originated from seven sites in Northwest China were characterized by PCR-RFLP of the 16S rRNA gene and sequence analysis of multiple core genes (16S rRNA, recA, atpD, and glnII) in order to investigate the diversity and biogeography of Glycine soja-nodulating rhizobia. Among the isolates, 80 were Ensifer fredii, 19 were Ensifer morelense, 49 were Rhizobium radiobacter, and 7 were putative novel Rhizobium species. The phylogenies of E. fredii and E. morelense isolates in a concatenate tree (assembly of all housekeeping genes) were generally consistent with those in individual gene trees. However, incongruence was found in the phylogenies of the different genes of Rhizobium isolates, indicating that lateral transfer or recombination possibly occurred in these gene loci. Despite their species identity, all the isolates in this study formed a single lineage related to E. fredii in nodAand nifH gene phylogenies, which also indicated that the symbiotic genes were laterally transferred between different species. Biogeographic patterns were found at the species and strain genomic type levels, as revealed by BOXA1R fingerprinting, demonstrating that the evolution of rhizobial populations in different geographic locations was related to soil types, altitude and spatial effects. This study is the first to report that E. morelense, R. radiobacter, and Rhizobium sp. are microsymbionts of G. soja, as well as showing that the diversity of G. soja rhizobia is enhanced and new rhizobia have evolved in Northwest China.
Related JoVE Video
Biomechanical analysis of a curvilinear distractor device for correcting mandibular symphyseal defects.
J. Oral Maxillofac. Surg.
PUBLISHED: 01-07-2014
Show Abstract
Hide Abstract
The local mechanical environment is a determinant of successful transport disc distraction osteogenesis. This study assessed the biomechanics of a curvilinear distractor device for correcting mandibular symphyseal defects.
Related JoVE Video
Impacts of Diffuse Radiation on Light Use Efficiency across Terrestrial Ecosystems Based on Eddy Covariance Observation in China.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Ecosystem light use efficiency (LUE) is a key factor of production models for gross primary production (GPP) predictions. Previous studies revealed that ecosystem LUE could be significantly enhanced by an increase on diffuse radiation. Under large spatial heterogeneity and increasing annual diffuse radiation in China, eddy covariance flux data at 6 sites across different ecosystems from 2003 to 2007 were used to investigate the impacts of diffuse radiation indicated by the cloudiness index (CI) on ecosystem LUE in grassland and forest ecosystems. Our results showed that the ecosystem LUE at the six sites was significantly correlated with the cloudiness variation (0.24?R2?0.85), especially at the Changbaishan temperate forest ecosystem (R2?=?0.85). Meanwhile, the CI values appeared more frequently between 0.8 and 1.0 in two subtropical forest ecosystems (Qianyanzhou and Dinghushan) and were much larger than those in temperate ecosystems. Besides, cloudiness thresholds which were favorable for enhancing ecosystem carbon sequestration existed at the three forest sites, respectively. Our research confirmed that the ecosystem LUE at the six sites in China was positively responsive to the diffuse radiation, and the cloudiness index could be used as an environmental regulator for LUE modeling in regional GPP prediction.
Related JoVE Video
Ultrasound guidance for radial artery catheterization: an updated meta-analysis of randomized controlled trials.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Since a previous meta-analysis reported that ultrasound guidance was associated with a higher first-attempt success rate in catheterization of the radial artery, a number of randomized controlled trials (RCTs) have reported inconsistent results. The aim of the present study is to conduct an updated meta-analysis to clarify the role of ultrasound guidance for radial artery catheterization.
Related JoVE Video
Unsupervised spatial event detection in targeted domains with applications to civil unrest modeling.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Twitter has become a popular data source as a surrogate for monitoring and detecting events. Targeted domains such as crime, election, and social unrest require the creation of algorithms capable of detecting events pertinent to these domains. Due to the unstructured language, short-length messages, dynamics, and heterogeneity typical of Twitter data streams, it is technically difficult and labor-intensive to develop and maintain supervised learning systems. We present a novel unsupervised approach for detecting spatial events in targeted domains and illustrate this approach using one specific domain, viz. civil unrest modeling. Given a targeted domain, we propose a dynamic query expansion algorithm to iteratively expand domain-related terms, and generate a tweet homogeneous graph. An anomaly identification method is utilized to detect spatial events over this graph by jointly maximizing local modularity and spatial scan statistics. Extensive experiments conducted in 10 Latin American countries demonstrate the effectiveness of the proposed approach.
Related JoVE Video
High homocysteine and blood pressure related to poor outcome of acute ischemia stroke in chinese population.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
To assess the association between plasma homocysteine (Hcy), blood pressure (BP) and poor outcome at hospital discharge among acute ischemic stroke patients, and if high Hcy increases the risk of poor outcome based on high BP status in a northern Chinese population.
Related JoVE Video
Solitary fibrous tumor of the central nervous system: report of 2 cases and review of literature.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Solitary fibrous tumors (SFTs) rarely occur in the central nervous system (CNS). Involvement of the brainstem and pineal gland is rarely recorded. Herein, we represent 2 cases of SFTs and firstly report SFT of the pineal gland. Cranial MR imaging showed isointense to hypointense signal intensity, and marked enhancement. Microscopically, the tumors showed characteristic "patternless-pattern" architecture. Elongated tumour cells formed fascicles alternating with hypocellular densely collagenous stroma. Immunohistochemistry for CD34, BCL2, and CD99 favors the definitive diagnosis of SFT. It is difficult to predict prognosis in patients with intraventricular SFT. In general, complete surgical resection may offer the best chance of a favorable clinical outcome.
Related JoVE Video
Association of TNF-? polymorphism with prediction of response to TNF blockers in spondyloarthritis and inflammatory bowel disease: a meta-analysis.
Pharmacogenomics
PUBLISHED: 11-07-2013
Show Abstract
Hide Abstract
To explore whether TNF-? promoter -308 A/G and -857 C/T polymorphisms have an association with responsiveness to TNF blockers in spondyloarthritis and inflammatory bowel disease.
Related JoVE Video
A Tesla-type repetitive nanosecond pulse generator for solid dielectric breakdown research.
Rev Sci Instrum
PUBLISHED: 11-05-2013
Show Abstract
Hide Abstract
A Tesla-type repetitive nanosecond pulse generator including a pair of electrode and a matched absorption resistor is established for the application of solid dielectric breakdown research. As major components, a built-in Tesla transformer and a gas-gap switch are designed to boost and shape the output pulse, respectively; the electrode is to form the anticipated electric field; the resistor is parallel to the electrode to absorb the reflected energy from the test sample. The parameters of the generator are a pulse width of 10 ns, a rise and fall time of 3 ns, and a maximum amplitude of 300 kV. By modifying the primary circuit of the Tesla transformer, the generator can produce both positive and negative pulses at a repetition rate of 1-50 Hz. In addition, a real-time measurement and control system is established based on the solid dielectric breakdown requirements for this generator. With this system, experiments on test samples made of common insulation materials in pulsed power systems are conducted. The preliminary experimental results show that the constructed generator is capable to research the solid dielectric breakdown phenomenon on a nanosecond time scale.
Related JoVE Video
Henle fiber layer phase retardation measured with polarization-sensitive optical coherence tomography.
Biomed Opt Express
PUBLISHED: 11-01-2013
Show Abstract
Hide Abstract
We developed a method based on polarization-sensitive optical coherence tomography (PS-OCT) to quantify the double pass phase retardation (DPPR) induced by Henle fiber layer in three subjects. Measurements of the retina were performed at a mean wavelength of 840 nm using two polarization states that were perpendicular in a Poincaré sphere representation and phase retardation contributions from tissue layers above and below the Henle fiber layer were excluded using appropriately placed reference and measurement points. These points were semi-automatically segmented from intensity data. Using a new algorithm to determine DPPR, the Henle fiber layer in three healthy subjects aged 50-60 years showed elevated DPPR in a concentric ring about the fovea, with an average maximum DPPR for the three subjects of 22.0° (range: 20.4° to 23.0°) occurring at an average retinal eccentricity of 1.8° (range: 1.5° to 2.25°). Outside the ring, a floor of approximately 6.8° was measured, which we show can mainly be attributed to phase noise that is induced in the polarization states. We also demonstrate the method can determine fast axis orientation of the retardation, which is found consistent with the known radial pattern of Henle fibers.
Related JoVE Video
Overexpression of RhoGDI, a novel predictor of distant metastasis, promotes cell proliferation and migration in hepatocellular carcinoma.
FEBS Lett.
PUBLISHED: 10-29-2013
Show Abstract
Hide Abstract
RhoGDI (Rho GDP-dissociation inhibitor alpha, or RhoGDI?) was identified as a regulator of Rho GTPases, but its role in cancer remains controversial. In this study, increased expression of RhoGDI was detected in hepatocellular carcinoma (HCC) cell lines and tissues with highly metastatic potential. RhoGDI overexpression correlated with postoperative distant metastasis. Enforced expression of RhoGDI in HCC cells significantly enhanced cell proliferation and migration. Conversely, knockdown of RhoGDI caused an inhibition of the aggressive phenotypes of HCC cells. Furthermore, RhoGDI up-regulated Rho, but not Rac, and enhanced PI3K/AKT and MAPK pathway activity. Our findings suggest that RhoGDI overexpression is a predictor of distant metastasis and plays an important role in the progression of HCC.
Related JoVE Video
The role of valvular regurgitation in catheter ablation outcomes of patients with long-standing persistent atrial fibrillation.
Europace
PUBLISHED: 10-25-2013
Show Abstract
Hide Abstract
The role of valvular regurgitation (VR) in outcomes of patients obtaining current ablation endpoints with long-standing persistent atrial fibrillation (LS-AF) was evaluated.METHODS AND RESULTS: In all, 216 consecutive patients obtaining current ablation endpoints with LS-AF were studied. A standard two-dimensional and Doppler transthoracic echocardiography (TTE) was performed in every patient before the procedure. The presentation and the grade of mitral regurgitation (MR), tricuspid regurgitation, and aortic regurgitation were evaluated. The clinical characteristics, TTE, and procedural characteristics were compared between the sinus rhythm group and the recurrent atrial tachyarrhythmia (ATa) group. After a follow-up of 18.9 ± 2.7 months, there were 48 patients in the ATa group. The patients in the ATa group had greater MR, longer AF duration, and larger left atrium (LA). In multivariate analyses, MR, LA size, and AF duration were independent predictors of recurrent ATa. The grades of MR severity were correlated with the rate of recurrent ATa, and more severe grade of MR indicated more recurrent ATa. Compared with the patients with organic MR, the patients with functional MR had a lower rate of recurrent ATa and lesser degrees of MR.CONCLUSION: In the three types of VR, MR was associated with recurrent ATa after AF ablation. Patients with ATa recurrence had more severe MR and greater organic MR.
Related JoVE Video
Ion-pairing chromatography on a porous graphitic carbon column coupled with time-of-flight mass spectrometry for targeted and untargeted profiling of amino acid biomarkers involved in Candida albicans biofilm formation.
Mol Biosyst
PUBLISHED: 10-23-2013
Show Abstract
Hide Abstract
Background: Candida albicans, the most common fungal pathogen related to colonization and biofilm formation on the surfaces of indwelling medical devices, shows high resistance to the most commonly used antifungal drugs. In this study, an ion-pairing chromatography-porous graphitic carbon column coupled with a time-of-flight mass spectrometry (IP-PGC-TOF/MS) system was developed for targeted and untargeted profiling of metabolites involved in biofilm and planktonic growth of C. albicans. Using untargeted profiling analysis, 16 differential metabolites were screened and identified as potential biomarkers, most of which were amino acids or related compounds. Based on untargeted profiling analysis, targeted quantitative analysis of 22 amino acids was established and carefully evaluated using stable isotope-labeled internal standards. Among them, 9 amino acids that were not screened by untargeted profiling were further characterized as new biomarkers. Finally, a total of 25 potential biomarkers were screened using the combined targeted and untargeted strategy, among which 16 were characterized for the first time. Our results confirmed that amino acid metabolism and polyamine metabolism were at a high level in biofilms, except for some new biomarkers including ornithine, arginine and proline that were directly related to ornithine. Further experiments were carried out on the ornithine decarboxylase-negative (spe1?) mutant, and the results showed that the consumption of ornithine for putrescine biosynthesis has a significant impact on biofilm formation and may prove to be a drug target for resolving drug resistance of C. albicans. This study provides a systematic view of changes in amino acid metabolism during C. albicans biofilm formation by a combination of targeted and untargeted profiling using an original IP-PGC-TOF/MS method. It is a feasible approach for characterizing subtle variations and screening novel biomarkers from the microbial metabolome.
Related JoVE Video
Evaluation of the Effects of Weaning Diets on Escherichia coli O157 Shedding, Body Weight, and Fecal Bacterial Communities in Beef Calves.
Foodborne Pathog. Dis.
PUBLISHED: 10-18-2013
Show Abstract
Hide Abstract
Abstract Cattle are considered to be one of the primary reservoirs of Escherichia coli O157. In this study, the effects of weaning diets on E. coli O157 shedding, body weight, and fecal bacterial communities in beef calves were evaluated. A total of 60 calves (28 heifers and 32 steers) were weaned and randomly assigned into two groups. A peanut/soy hull-based diet (Dry Feed, DF) and a corn silage-based diet (High Moisture, HM) were fed to the two groups, respectively, during the weaning and preconditioning period. Calf body weight was measured before weaning (BW) and 14 days after weaning (AW14), and a fecal sample was collected from each calf at BW, AW14, as well as 56 days after weaning (AW56). The prevalence of O157 in feces was determined by CHROMagar(™) O157 and polymerase chain reaction (PCR). Denaturing gradient gel electrophoresis (DGGE) was employed to analyze fecal bacterial communities. A significant decrease in body weight was observed during weaning, regardless of the calf diet (p<0.05). Calves fed the HM diet lost more weight than the DF-fed calves determined at 14 days after weaning (p<0.05). Both the CHROMagar(™) and PCR results showed that the overall prevalence of O157 increased significantly during weaning. Based on the CHROMagar(™) method, O157 increased from 16.6% at BW to 38.3% at AW14 (p<0.05) and stayed at the higher level during the preconditioning period (AW56). The increase in O157 prevalence was observed in HM-fed calves during weaning but not in DF-fed ones. Weaning also changed the profile of fecal bacterial communities (p<0.05). These results showed that weaning is a critical step in beef cattle production, not only because of its effects on body weight but also due to its impact on O157 shedding and gastrointestinal tract bacterial community establishment.
Related JoVE Video
The Cell Surface GRP78 Facilitates the Invasion of Hepatocellular Carcinoma Cells.
Biomed Res Int
PUBLISHED: 10-06-2013
Show Abstract
Hide Abstract
Invasion is a major characteristic of hepatocellular carcinoma and one of the main causes of refractory to treatment. We have previously reported that GRP78 promotes the invasion of hepatocellular carcinoma although the mechanism underlying this change remains uncertain. In this paper, we explored the role of the cell surface GRP78 in the regulation of cancer cell invasion in hepatocellular carcinoma cells. We found that neutralization of the endogenous cell surface GRP78 with the anti-GRP78 antibody inhibited the adhesion and invasion in hepatocellular carcinoma cell lines Mahlavu and SMMC7721. However, forced expression of the cell surface GRP78 facilitated the adhesion and invasion in SMMC7721. We further demonstrated that inhibition of the endogenous cell surface GRP78 specifically inhibited the secretion and activity of MMP-2 but did not affect the secretion and activity of MMP-9. We also found that inhibition of the cell surface GRP78 increased E-Cadherin expression and decreased N-Cadherin level. On the contrary, forced expression of the cell surface GRP78 increased N-Cadherin expression and decreased E-Cadherin level, suggesting that the cell surface GRP78 plays critical role in the regulation of EMT process. These findings suggest that the cell surface GRP78 plays a stimulatory role in the invasion process and may be a potential anti-invasion target for the treatment of hepatocellular carcinoma.
Related JoVE Video
Theoretical investigation on the 2e/12c bond and second hyperpolarizability of azaphenalenyl radical dimers: strength and effect of dimerization.
J Chem Phys
PUBLISHED: 10-05-2013
Show Abstract
Hide Abstract
An increasing number of chemists have focused on the investigations of two-electron/multicenter bond (2e/mc) that was first introduced to describe the structure of radical dimers. In this work, the dimerization of two isoelectronic radicals, triazaphenalenyl (TAP) and hexaazaphenalenyl (HAP) has been investigated in theory. Results show TAP2 is a stable dimer with stronger 2e/12c bond and larger interaction energy, while HAP2 is a less stable dimer with larger diradical character. Interestingly, the ultraviolet-visible absorption spectra suggest that the dimerization induces a longer wavelength absorption in visible area, which is dependent on the strength of dimerization. Significantly, the amplitude of second hyperpolarizability (?(yyyy)) of HAP2 is 1.36 × 10(6) a.u. that is larger than 7.79 × 10(4) a.u. of TAP2 because of the larger diradical character of HAP2. Therefore, the results indicate that the strength of radical dimerization can be effectively detected by comparing the magnitude of third order non-linear optical response, which is beneficial for further theoretical and experimental studies on the properties of complexes formed by radical dimerization.
Related JoVE Video
[Study on relationship between operation timing and clinical prognosis of cases with Bell palsy].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 10-01-2013
Show Abstract
Hide Abstract
To study on relationship between diverse handling time following onset and clinical prognosis of cases with Bell palsy.
Related JoVE Video
t4 Workshop Report: Pathways of Toxicity.
ALTEX
PUBLISHED: 09-26-2013
Show Abstract
Hide Abstract
Despite wide-spread consensus on the need to transform toxicology and risk assessment in order to keep pace with technological and computational changes that have revolutionized the life sciences, there remains much work to be done to achieve the vision of toxicology based on a mechanistic foundation. To this end, a workshop was organized to explore one key aspect of this transformation - the development of Pathways of Toxicity as a key tool for hazard identification based on systems biology. Several issues were discussed in depth in the workshop: The first was the challenge of formally defining the concept of a Pathway of Toxicity (PoT), as distinct from, but complementary to, other toxicological pathway concepts such as mode of action (MoA). The workshop came up with a preliminary definition of PoT as "A molecular definition of cellular processes shown to mediate adverse outcomes of toxicants". It is further recognized that normal physiological pathways exist that maintain homeostasis and these, sufficiently perturbed, can become PoT. Second, the workshop sought to define the adequate public and commercial resources for PoT information, including data, visualization, analyses, tools, and use-cases, as well as the kinds of efforts that will be necessary to enable the creation of such a resource. Third, the workshop explored ways in which systems biology approaches could inform pathway annotation, and which resources are needed and available that can provide relevant PoT information to the diverse user communities.
Related JoVE Video
[Anatomy study on micro transverse flap pedicled with superfical palmar branch of radial artery from palmar wrist].
Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi
PUBLISHED: 09-26-2013
Show Abstract
Hide Abstract
To study the anatomical basis of micro transverse flap pedicled with the superfical palmar branch of radial artery from the palmar wrist for using this free flap to repair soft tissue defect of the finger.
Related JoVE Video

What is Visualize?

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

How does it work?

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

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

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