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Find video protocols related to scientific articles indexed in Pubmed.
Intramolecular annulation of aromatic rings with N-sulfonyl 1,2,3-triazoles: divergent synthesis of 3-methylene-2,3-dihydrobenzofurans and 3-methylene-2,3-dihydroindoles.
Chem. Commun. (Camb.)
PUBLISHED: 11-12-2014
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The controllable synthesis of 3-methylene-2,3-dihydrobenzofurans 2 and 3-methylene-2,3-dihydroindoles 5 has been developed through Rh-catalyzed intramolecular annulation of aromatic rings with azavinyl carbenes.
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Unprecedented synthesis of aza-bridged benzodioxepine derivatives through a tandem Rh(ii)-catalyzed 1,3-rearrangement/[3+2] cycloaddition of carbonyltriazoles.
Chem. Commun. (Camb.)
PUBLISHED: 11-10-2014
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Rh(ii)-catalyzed novel tandem intramolecular cycloisomerizations of aldehydes or ketones with 1-sulfonyl 1,2,3-triazoles have been disclosed, providing a facile protocol to access a series of functionalized aza-bridged benzodioxepine heterocycles.
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One-pot tandem diastereoselective and enantioselective synthesis of functionalized oxindole-fused spiropyrazolidine frameworks.
Chemistry
PUBLISHED: 08-28-2014
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A highly efficient palladium(0)-catalyzed asymmetric [3+2] cycloaddition using 3-diazooxindoles serving as dipolarophiles affords functionalized pyrazolidine derivatives in an atom-economical way. In addition, by trapping the pyrazolidine derivatives with maleimides, the corresponding spiropyrazolidine oxindoles containing multiple stereogenic centers have been obtained in high yields along with moderate to good levels of diastereoselectivity and enantioselectivity under mild conditions. Thus, a novel three-component one-pot tandem reaction has been developed.
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One-step synthesis of mussel-inspired molecularly imprinted magnetic polymer as stationary phase for chip-based open tubular capillary electrochromatography enantioseparation.
J Chromatogr A
PUBLISHED: 08-20-2014
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A facile approach for preparation of molecularly imprinted polymers was developed and successfully used as chiral stationary phase for rapid enantioseparation by open tubular capillary electrochromatography (OT-CEC). In this work, molecularly imprinted polymers were one-step prepared employing Fe3O4 nanoparticles (NPs) as the supporting substrate and dopamine as the functional monomer. By simply mixing Fe3O4 NPs with template molecules in a weak alkaline solution of dopamine, a thin adherent polydopamine (PDA) film imprinted with template molecules was formed by the self-polymerization of dopamine on the surface of Fe3O4 NPs. After extracting the embedded template molecules, the produced imprinted Fe3O4@PDA NPs are of three dimensional shape of template molecules favoring high binding capacity and magnetism property for easy manipulation. The imprinted Fe3O4@PDA NPs prepared with l-tryptophan, l-tyrosine, Gly-l-Phe or s-ofloxacin as template molecules were packed in the PDMS microchannel via magnetic field as novel stationary phase for the successful enantioseparation of corresponding target analysts. In addition, the imprinted Fe3O4@PDA NPs-based OT-CEC system exhibited excellent reproducibility, stability and repeatability, which provides a powerful protocol for separation enantiomers within a short analytical time and opens up a promising avenue for high-throughput screening of chiral compounds.
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Phosphine-catalyzed annulations of 4,4-dicyano-2-methylenebut-3-enoates with maleimides and maleic anhydride.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 08-19-2014
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A novel phosphine-catalyzed [4+1] annulation of maleimides with 4,4-dicyano-2-methylenebut-3-enoates has been developed to afford spirocyclic products, and the maleimides serves as C1 ?synthons. Moreover, a phosphine-catalyzed formal [3+2] annulation between 4,4-dicyano-2-methylenebut-3-enoates and maleic anhydride has been also achieved, and maleic anhydride behaved as a C3 ?synthon in the reaction, thus efficiently affording the functionalized cyclopentenones. A stable phosphinium-containing zwitterionic compound is the key reactive intermediate in both annulations and was successfully isolated. Plausible mechanisms have been proposed on the basis of control experiments and deuterium-labeling experiments.
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Preparation and antitumor effect of a toxin-linked conjugate targeting vascular endothelial growth factor receptor and urokinase plasminogen activator.
Exp. Biol. Med. (Maywood)
PUBLISHED: 08-14-2014
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The aberrant signaling activation of vascular endothelial growth factor receptor (VEGFR) and urokinase plasminogen activator (uPA) is a common characteristic of many tumors, including lung cancer. Accordingly, VEGFR and uPA have emerged as attractive targets for tumor. KDR (Flk-1/VEGFR-2), a member of the VEGFR family, has been recognized as an important target for antiangiogenesis in tumor. In this study, a recombinant immunotoxin was produced to specifically target KDR-expressing tumor vascular endothelial cells and uPA-expressing tumor cells and mediate antitumor angiogenesis and antitumor effect. Based on its potent inhibitory effect on protein synthesis, Luffin-beta (L?) ribosome-inactivating protein was selected as part of a recombinant fusion protein, a single-chain variable fragment against KDR (KDRscFv)-uPA cleavage site (uPAcs)-L?-KDEL (named as KPLK). The KDRscFv-uPAcs-L?-KDEL (KPLK) contained a single-chain variable fragment (scFv) against KDR, uPAcs, L?, and the retention signal for endoplasmic reticulum proteins KDEL (Lys-Asp-Glu-Leu). The KPLK-expressing vector was expressed in Escherichia coli, and the KPLK protein was isolated with nickel affinity chromatography and gel filtration chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis test demonstrated KPLK was effectively expressed. Result of in vitro cell viability assay on non-small cell lung cancer (NSCLC) H460 cell line (uPA-positive cell) revealed that KPLK significantly inhibited cell proliferation, induced apoptosis, and accumulated cells in S and G2/M phases, but the normal cell line (human submandibular gland cell) was unaffected. These effects were enhanced when uPA was added to digest KPLK to release L?. For in vivo assay of KPLK, subcutaneous xenograft tumor model of nude mice were established with H460 cells. Growth of solid tumors was significantly inhibited in animals treated with KPLK up to 21 days, tumor weights were decreased, and the expression of angiogenesis marker CD31 was downregulated; meanwhile, the apoptosis-related protein casspase-3 was upregulated. These results suggested that the recombinant KPLK may have therapeutic applications on tumors, especially uPA-overexpressing ones.
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Total aglycones from Marsdenia tenacissima increases antitumor efficacy of paclitaxel in nude mice.
Molecules
PUBLISHED: 08-06-2014
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Marsdeniae tenacissimae Caulis (MTC) is a Chinese herbal medicine used mainly for treatment of cancer, whose pharmacologically active constituents responsible for its in vivo activity and clinical efficacy have not been clearly elucidated. In this study, total aglycones of MTC (ETA) showed the ability to sensitize KB-3-1, HeLa, HepG2 and K562 cells to paclitaxel treatment. More inspiringly, ETA markedly enhanced the antitumor activity of paclitaxel in nude mice bearing HeLa or KB-3-1 xenografts. Compared to treatment with paclitaxel alone, treatment with combination of paclitaxel and ETA achieved significant reduction in volume and weight of HeLa tumors (p<0.05), and remarkable inhibition to the growth of KB-3-1 tumors (p<10??). ETA was characterized by the presence of a group of tenacigenin B ester derivatives, among which four reference compounds, 11?-O-tigloyl-12?-O-acetyltenacigenin B, 11?,12?-di-O-tigloyltenacigenin B, 11?-O-2-methylbutanoyl-12?-O-tigloyltenacigenin B, and 11?-O-(2-methylbutanoyl)-12?-O-benzoyltenacigenin B, accounted for 42.14% of the total peak area of 19 detectable components assayed by HPLC. Our study has identified ETA as a promising sensitizer for cancer chemotherapy.
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[Effect of tetramethylpyrazine and rat CTGF miRNA plasmids on connective tissue growth factor, transforming growth factor-beta in high glucose stimulated hepatic stellate cells].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 07-22-2014
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The aim of this research is to evaluate the effect of tetramethylpyrazine (TMP) and connective tissue growth factor (CTGF) miRNA plasmids on the expressive levels of CTGF, transforming growth factor-beta (TGFbeta) and type I collagen of rat hepatic stellate cells (HSC) which are stimulated by high glucose. The rat HSCs which were successfully transfected rat CTGF miRNA plasmids and the rat HSCs which were successfully transfected negative plasmids were cultured in vitro. After stimulus of the TMP and the high glucose, the protein levels and gene expressive levels of CTGF, TGF-beta and type I collagen were tested. The results indicated that high glucose increased the expression of CTGF mRNA, CTGF protein, TGF-beta mRNA,TGF-beta protein and type I collagen (P < 0.05). The expressive levels of CTGF mRNA, CTGF protein, TGF-beta mRNA, TGF-beta and type I collagen in TMP group were lower than those in high glucose group and showed statistically significant differences (P < 0.05). Compared with high glucose group, the expressive levels of CTGF mRNA, CTGF protein, TGF-beta mRNA, TGF-beta and type I collagen in rat CTGF miRNA plasmid interference group were significantly lower (P < 0.05). However, no statistically significant difference was found in CTGF mRNA and CTGF protein levels between TMP group and CTGF miRNA group (P > 0.05), while type I collagen levels showed statistically significant differences (P < 0.05). It is concluded that high glucose could promote the expressions of CTGF, TGF-beta and type I collagen, and TMP and rat CTGF miRNA plasmids could reduce the expressions of CTGF, TGF-beta, type I collagen.
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[Comparative study on hyperspectral inversion accuracy of soil salt content and electrical conductivity].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 05-15-2014
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The objective of the present article is to ascertain the mechanism of hyperspectral remote sensing monitoring for soil salinization, which is of great importance for improving the accuracy of hyperspectral remote sensing monitoring. Paddy soils in Wensu, Hetian and Baicheng counties of the southern Xinjiang were selected. Hyperspectral data of soils were obtained. Soil salt content (S(t)) an electrical conductivity of 1:5 soil-to-water extracts (EC(1:5)) were determined. Relationships between S(t) and EC(1:5) were studied. Correlations between hyperspectral indices and S(t), and EC(1:5) were analyzed. The inversion accuracy of S(t) using hyperspectral technique was compared with that of EC(1:5). Results showed that: significant (p<0.01) relationships were found between S(t) and EC(1:5) for soils in Wensu and Hetian counties, and correlation coefficients were 0.86 and 0.45, respectively; there was no significant relationship between S(t) and EC(1:5) for soils in Baicheng county. Therefore, the correlations between S(t) and EC(1:5) varied with studied sites. S(t) and EC(1:5) were significantly related with spectral reflectance, first derivative reflectance and continuum-removed reflectance, respectively; but correlation coefficients between S(t) and spectral indices were higher than those between EC(1:5) and spectral indices, which was obvious in some sensitive bands for soil salinization such as 660, 35, 1229, 1414, 1721, 1738, 1772, 2309 nm, and so on. Prediction equations of St and EC(1:5) were established using multivariate linear regression, principal component regression and partial least-squares regression methods, respectively. Coefficients of determination, determination coefficients of prediction, and relative analytical errors of these equations were analyzed. Coefficients of determination and relative analytical errors of equations between S(t) and spectral indices were higher than those of equations between EC(1:5) and spectral indices. Therefore, the responses of high spectral information to St were more sensitive than those of high spectral information to EC(1:5). Accuracy of St predicted from high spectral data was higher than that of EC(1:5) estimated from high spectral data. The results of this study can provide a theoretical basis to improve hyperspectral remote sensing monitoring accuracy of soil salinization.
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Catalyst-dependent divergent synthesis of pyrroles from 3-alkynyl imine derivatives: a noncarbonylative and carbonylative approach.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 05-13-2014
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A novel Ru(0)- and Rh(I)-catalyzed noncarbonylative and carbonylative cycloisomerization of readily available 3-alkynyl imine derivatives has been developed to provide 3,4-fused or nonfused pyrrole derivatives efficiently in moderate to excellent yields. The key steps involve the formation of a ruthenium carbenoid intermediate or a rhodacycle intermediate, respectively. In these reactions, CO can serve as a ligand or a reagent.
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Brain aging and AD-like pathology in streptozotocin-induced diabetic rats.
J Diabetes Res
PUBLISHED: 05-05-2014
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Numerous epidemiological studies have linked diabetes mellitus (DM) with an increased risk of developing Alzheimer's disease (AD). However, whether or not diabetic encephalopathy shows AD-like pathology remains unclear.
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[Intracellular mechanisms of Porphyromonas gingivalis induced interleukin-8 upregulation in endothelial cells].
Beijing Da Xue Xue Bao
PUBLISHED: 04-19-2014
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To find out the mechanisms by which Porphyromonas gingivalis (P. gingivalis) regulates interleukin (IL)-8 expression in endothelial cells.
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Polycomb-group histone methyltransferase CLF is required for proper somatic recombination in Arabidopsis.
J Integr Plant Biol
PUBLISHED: 04-01-2014
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Homologous recombination (HR) is a key process during meiosis in reproductive cells and the DNA damage repair process in somatic cells. Although chromatin structure is thought to be crucial for HR, only a small number of chromatin modifiers have been studied in HR regulation so far. Here, we investigated the function of CURLY LEAF (CLF), a Polycomb-group (PcG) gene responsible for histone3 lysine 27 trimethylation (H3K27me3), in somatic and meiotic HR in Arabidopsis thaliana. Although fluorescent protein reporter assays in pollen and seeds showed that the frequency of meiotic cross-over in the loss-of-function mutant clf-29 was not significantly different from that in wild type, there was a lower frequency of HR in clf-29 than in wild type under normal conditions and under bleomycin treatment. The DNA damage levels were comparable between clf-29 and wild type, even though several DNA damage repair genes (e.g. ATM, BRCA2a, RAD50, RAD51, RAD54, and PARP2) were expressed at lower levels in clf-29. Under bleomycin treatment, the expression levels of DNA repair genes were similar in clf-29 and wild type, thus CLF may also regulate HR via other mechanisms. These findings expand the current knowledge of PcG function and contribute to general interests of epigenetic regulation in genome stability regulation.
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Towards understanding elastocapillarity: comparing wetting of soft and rigid plates.
J Phys Condens Matter
PUBLISHED: 03-27-2014
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Elastocapillarity plays a significant role in the buoyancy and water repellency of soft objects floating on water. In this paper, we analyze the wetting behavior of an elastic and circular plate pressing a liquid surface. The geometry and stability of axisymmetric infinite liquid menisci are investigated, and their qualitative difference from two-dimensional planar menisci is revealed. By comparing the wetting processes of rigid and elastic circular plates under pressing, we show that flexibility benefits both the maximal depth and buoyancy a plate can reach. The results are helpful not only for understanding the living behavior of some aquatic creatures but also for the design of biomimetic soft microrobotics.
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Transgenic expression of human cytoxic T-lymphocyte associated antigen4-Immunoglobulin (hCTLA4Ig) by porcine skin for xenogeneic skin grafting.
Transgenic Res.
PUBLISHED: 03-26-2014
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Porcine skin is frequently used as a substitute of human skin to cover large wounds in clinic practice of wound care. In our previous work, we found that transgenic expression of human cytoxicT-lymphocyte associated antigen4-immunoglobulin (hCTLA4Ig) in murine skin graft remarkably prolonged its survival in xenogeneic wounds without extensive immunosuppression in recipients, suggesting that transgenic hCTLA4Ig expression in skin graft may be an effective and safe method to prolong xenogeneic skin graft survival. In this work, using a transgene construct containing hCTLA4Ig coding sequence under the drive of human Keratine 14 (k14) promoter, hCTLA4Ig transgenic pigs were generated by somatic nuclear transfer. The derived transgenic pigs were healthy and exhibited no signs of susceptibility to infection. The hCTLA4Ig transgene was stably transmitted through germline over generations, and thereby a transgenic pig colony was established. In the derived transgenic pigs, hCTLA4Ig expression in skin was shown to be genetically stable over generations, and detected in heart, kidney and corneal as well as in skin. Transgenic hCTLA4Ig protein in pigs exhibited expected biological activity as it suppressed human lymphocyte proliferation in human mixed lymphocyte culture to extents comparable to those of commercially purchased purified hCTLA4Ig protein. In skin grafting from pigs to rats, transgenic porcine skin grafts exhibited remarkably prolonged survival compared to the wild-type skin grafts derived from the same pig strain (13.33 ± 3.64 vs. 6.25 ± 2.49 days, P < 0.01), further indicating that the transgenic hCTLA4Ig protein was biologically active and capable of extending porcine skin graft survival in xenogeneic wounds. The transgenic pigs generated in this work can be used as a reproducible resource to provide porcine skin grafts with extended survival for wound coverage, and also as donors to investigate the impacts of hCTLA4Ig on xenotransplantation of other organs (heart, kidney and corneal) due to the ectopic transgenic hCTLA4Ig expression.
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Zn/Mn-MOFs with `S-shaped' packing modes.
Acta Crystallogr C Struct Chem
PUBLISHED: 03-15-2014
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Two novel polymers exhibiting metal-organic frameworks (MOFs) have been synthesized by the combination of a metal ion with a benzene-1,3,5-tricarboxylate ligand (BTC) and 1,10-phenanthroline (phen) under hydrothermal conditions. The first compound, poly[[(?4-benzene-1,3,5-tricarboxylato-?(4)O:O':O'':O''')(?-hydroxido-?(2)O:O)bis(1,10-phenanthroline-?(2)N,N')dizinc(II)] 0.32-hydrate], {[Zn2(C9H3O6)(OH)(C12H8N2)2]·0.32H2O}n, denoted Zn-MOF, forms a two-dimensional network in which a binuclear Zn2 cluster serves as a 3-connecting node; the BTC trianion also acts as a 3-connecting centre. The overall topology is that of a 6(3) net. The phen ligands serve as appendages to the network and interdigitate with phen ligands belonging to adjacent parallel sheets. The second compound, poly[[(?6-benzene-1,3,5-tricarboxylato-?(7)O(1),O(1'):O(1):O(3):O(3'):O(5):O(5'))(?3-hydroxido-?(2)O:O:O)(1,10-phenanthroline-?(2)N,N')dimanganese(II)] 1.26-hydrate], {[Mn2(C9H3O6)(OH)(C12H8N2)]·1.26H2O}n, denoted Mn-MOF, exists as a three-dimensional network in which an Mn4 cluster serves as a 6-connecting unit, while the BTC trianion again plays the role of a 3-connecting centre. The overall topology is that of the rutile net. Phen ligands act as appendages to the network and form the `S-shaped' packing mode.
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Overexpression of miR-483-5p/3p cooperate to inhibit mouse liver fibrosis by suppressing the TGF-? stimulated HSCs in transgenic mice.
J. Cell. Mol. Med.
PUBLISHED: 03-10-2014
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The transition from liver fibrosis to hepatocellular carcinoma (HCC) has been suggested to be a continuous and developmental pathological process. MicroRNAs (miRNAs) are recently discovered molecules that regulate the expression of genes involved in liver disease. Many reports demonstrate that miR-483-5p and miR-483-3p, which originate from miR-483, are up-regulated in HCC, and their oncogenic targets have been identified. However, recent studies have suggested that miR-483-5p/3p is partially down-regulated in HCC samples and is down-regulated in rat liver fibrosis. Therefore, the aberrant expression and function of miR-483 in liver fibrosis remains elusive. In this study, we demonstrate that overexpression of miR-483 in vivo inhibits mouse liver fibrosis induced by CCl4 . We demonstrate that miR-483-5p/3p acts together to target two pro-fibrosis factors, platelet-derived growth factor-? and tissue inhibitor of metalloproteinase 2, which suppress the activation of hepatic stellate cells (HSC) LX-2. Our work identifies the pathway that regulates liver fibrosis by inhibiting the activation of HSCs.
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DNA-length-dependent fluorescent sensing based on energy transfer in self-assembled multilayers.
Biosens Bioelectron
PUBLISHED: 03-07-2014
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In this paper, a novel DNA-length-dependent fluorescent sensor was constructed based on the fluorescence resonance energy transfer. In the self-assembled multilayers (Quartz/GO/PDDA/Tx-DNA/PDDA/ZnO@CdS), ZnO@CdS and graphene oxide(GO) were employed as an energy donor and an energy acceptor, respectively. Single-stranded Tx-DNA (x represents different chain length of DNA) and poly(diallydimethylammonium) chloride (PDDA) were used as a linker. In the presence of complementary Px-DNA, the formation of double-stranded DNA leads to a change in chain length and achieves the purpose of changing the distance between ZnO@CdS and GO. Thereby, it enhances the efficiency of energy transfer between ZnO@CdS and GO resulting in the quench of fluorescence of ZnO@CdS, and thus different length DNA sequence was detected.
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JAB1 and phospho-Ser10 p27 expression profile determine human hepatocellular carcinoma prognosis.
J. Cancer Res. Clin. Oncol.
PUBLISHED: 03-06-2014
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To elucidate the clinicopathological significance and the role of Jun Activation Domain-Binding Protein 1 (JAB1), Ser10-phosphorylated p27 (p27S10), and total p27 in human hepatocellular carcinoma (HCC) prognosis.
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HMGB1-promoted and TLR2/4-dependent NK cell maturation and activation take part in rotavirus-induced murine biliary atresia.
PLoS Pathog.
PUBLISHED: 03-01-2014
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Recent studies show that NK cells play important roles in murine biliary atresia (BA), and a temporary immunological gap exists in this disease. In this study, we found high-mobility group box-1 (HMGB1) and TLRs were overexpressed in human and rotavirus-induced murine BA. The overexpressed HMGB1 released from the nuclei of rotavirus-infected cholangiocytes, as well as macrophages, activated hepatic NK cells via HMGB1-TLRs-MAPK signaling pathways. Immature NK cells had low cytotoxicity on rotavirus-injured cholangiocytes due to low expression of TLRs, which caused persistent rotavirus infection in bile ducts. HMGB1 up-regulated the levels of TLRs of NK cells and promoted NK cell activation in an age-dependent fashion. As NK cells gained increasing activation as mice aged, they gained increasing cytotoxicity on rotavirus-infected cholangiocytes, which finally caused BA. Adult NK cells eliminated rotavirus-infected cholangiocytes shortly after infection, which prevented persistent rotavirus infection in bile ducts. Moreover, adoptive transfer of mature NK cells prior to rotavirus infection decreased the incidence of BA in newborn mice. Thus, the dysfunction of newborn NK cells may, in part, participate in the immunological gap in the development of rotavirus induced murine BA.
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Rhodium(II)-catalyzed intramolecular cycloisomerizations of methylenecyclopropanes with N-sulfonyl 1,2,3-triazoles.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 02-25-2014
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A novel rhodium(II)-catalyzed tandem cycloisomerization of methylenecyclopropanes (MCPs) with N-sulfonyl 1,2,3-triazoles is disclosed. The reaction produces a series of highly functionalized polycyclic N?heterocycles via a rhodium imino carbene intermediate. A distinct feature of this divergent synthesis is that different types of substrates control the reaction pathways. Moreover, several interesting transformations of these products to construct diazabicyclo[3.2.1]octane derivatives are also reported.
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Hepatic, gastric, and intestinal first-pass effects of vitexin in rats.
Pharm Biol
PUBLISHED: 02-20-2014
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Recent research has demonstrated that vitexin exhibits a prominent first-pass effect. In this light, it is necessary to investigate the causes of this distinct first-pass effect.
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Complete genome sequence analysis identifies a new genotype of brassica yellows virus that infects cabbage and radish in China.
Arch. Virol.
PUBLISHED: 02-13-2014
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For brassica yellows virus (BrYV), proposed to be a member of a new polerovirus species, two clearly distinct genotypes (BrYV-A and BrYV-B) have been described. In this study, the complete nucleotide sequences of two BrYV isolates from radish and Chinese cabbage were determined. Sequence analysis suggested that these isolates represent a new genotype, referred to here as BrYV-C. The full-length sequences of the two BrYV-C isolates shared 93.4-94.8 % identity with BrYV-A and BrYV-B. Further phylogenetic analysis showed that the BrYV-C isolates formed a subgroup that was distinct from the BrYV-A and BrYV-B isolates based on all of the proteins except P5.
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Rhodium(II)-catalyzed intramolecular annulation of 1-sulfonyl-1,2,3-triazoles with pyrrole and indole rings: facile synthesis of N-bridgehead azepine skeletons.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 01-27-2014
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A convenient and efficient synthetic method has been developed to construct highly functionalized N-bridgehead azepine skeletons, which are of great importance in biological and pharmaceutical industry. The reaction proceeds through a rhodium(II) azavinyl carbene intermediate, which initiated the intramolecular C-H functionalization with pyrrolyl and indolyl rings. A variety of azepine derivatives were obtained in moderate to good yields under mild reaction conditions with high chemoselectivity. Several interesting derivatizations of the resulting products demonstrate that this method is synthetically valuable and useful.
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Toll-like receptor 4 polymorphisms to determine acute pancreatitis susceptibility and severity: a meta-analysis.
World J. Gastroenterol.
PUBLISHED: 01-24-2014
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To investigate the correlation of toll-like receptor 4 (TLR4) gene Asp299Gly and Thr399Ile polymorphisms and acute pancreatitis (AP) risk and severity.
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Amino acid sequence motifs essential for P0-mediated suppression of RNA silencing in an isolate of potato leafroll virus from Inner Mongolia.
Mol. Plant Microbe Interact.
PUBLISHED: 01-24-2014
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Polerovirus P0 suppressors of host gene silencing contain a consensus F-box-like motif with Leu/Pro (L/P) requirements for suppressor activity. The Inner Mongolian Potato leafroll virus (PLRV) P0 protein (P0(PL-IM)) has an unusual F-box-like motif that contains a Trp/Gly (W/G) sequence and an additional GW/WG-like motif (G139/W140/G141) that is lacking in other P0 proteins. We used Agrobacterium infiltration-mediated RNA silencing assays to establish that P0(PL-IM) has a strong suppressor activity. Mutagenesis experiments demonstrated that the P0(PL-IM) F-box-like motif encompasses amino acids 76-LPRHLHYECLEWGLLCG THP-95, and that the suppressor activity is abolished by L76A, W87A, or G88A substitution. The suppressor activity is also weakened substantially by mutations within the G139/W140/G141 region and is eliminated by a mutation (F220R) in a C-terminal conserved sequence of P0(PL-IM). As has been observed with other P0 proteins, P0(PL-IM) suppression is correlated with reduced accumulation of the host AGO1-silencing complex protein. However, P0(PL-IM) fails to bind SKP1, which functions in a proteasome pathway that may be involved in AGO1 degradation. These results suggest that P0(PL-IM) may suppress RNA silencing by using an alternative pathway to target AGO1 for degradation. Our results help improve our understanding of the molecular mechanisms involved in PLRV infection.
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Hydrogen sulfide synergistically upregulates Porphyromonas gingivalis lipopolysaccharide-induced expression of IL-6 and IL-8 via NF-?B signalling in periodontal fibroblasts.
Arch. Oral Biol.
PUBLISHED: 01-10-2014
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The periodontal pathogen Porphyromonas gingivalis produces hydrogen sulfide (H2S). H2S in the oral cavity is positively correlated with periodontitis but the mechanism by which H2S contributes to periodontal diseases is obscure. We investigated the effect of H2S in combination with P. gingivalis lipopolysaccharide (LPS) on expression of the pro-inflammatory cytokines interleukin (IL)-6 and IL-8 in periodontal fibroblasts and the underlying mechanism of action.
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Rhodium-catalyzed three-component reaction of 3-diazooxindoles with indoles and isatin-derived ketimines: a facile and versatile approach to functionalized 3,3',3''-trisindoles.
Org. Biomol. Chem.
PUBLISHED: 01-10-2014
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A simple, facile and efficient Rh2(OAc)4-catalyzed three-component reaction of 3-diazooxindoles with indoles and isatin-derived N-Boc ketimines towards a variety of functionalized 3,3',3''-trisindoles in high yields with moderate to excellent diastereoselectivities has been developed. This methodology provides an ideal approach for the direct introduction of indole and oxindole into an isatin moiety at the 3-position.
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Electric-field-induced patterns and their temperature dependence in a bent-core liquid crystal.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 01-06-2014
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Two kinds of electroconvection patterns in an ether-bridged bent-core nematic liquid crystal material (BCN), which appear in different frequency ranges, are examined and compared. One is a longitudinal pattern with the stripes parallel to the orientation of the BCN and with a periodicity of approximately the cell thickness, occurring in the high-frequency range of several hundreds Hz; the other one is oblique stripes, which results in a zigzag pattern, and appears in the low-frequency range of several tens Hz. In addition, within an intermediate-frequency range, transformations from oblique to longitudinal and then to normal stripes occur at increased ac voltages. In particular, we investigated the temperature behavior of longitudinal and oblique stripes: When the temperature T increases and approaches the clearing temperature Tc, the contrast of the domains is enhanced and the frequency range of existence becomes wider, while the onset voltages increase only moderately instead of diverging, thus suggesting an isotropic mechanism of pattern formation.
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The meganuclease I-SceI containing nuclear localization signal (NLS-I-SceI) efficiently mediated mammalian germline transgenesis via embryo cytoplasmic microinjection.
PLoS ONE
PUBLISHED: 01-01-2014
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The meganuclease I-SceI has been effectively used to facilitate transgenesis in fish eggs for nearly a decade. I-SceI-mediated transgenesis is simply via embryo cytoplasmic microinjection and only involves plasmid vectors containing I-SceI recognition sequences, therefore regarding the transgenesis process and application of resulted transgenic organisms, I-SceI-mediated transgenesis is of minimal bio-safety concerns. However, currently no transgenic mammals derived from I-SceI-mediated transgenesis have been reported. In this work, we found that the native I-SceI molecule was not capable of facilitating transgenesis in mammalian embryos via cytoplasmic microinjection as it did in fish eggs. In contrast, the I-SceI molecule containing mammalian nuclear localization signal (NLS-I-SceI) was shown to be capable of transferring DNA fragments from cytoplasm into nuclear in porcine embryos, and cytoplasmic microinjection with NLS-I-SceI mRNA and circular I-SceI recognition sequence-containing transgene plasmids resulted in transgene expression in both mouse and porcine embryos. Besides, transfer of the cytoplasmically microinjected mouse and porcine embryos into synchronized recipient females both efficiently resulted in transgenic founders with germline transmission competence. These results provided a novel method to facilitate mammalian transgenesis using I-SceI, and using the NLS-I-SceI molecule, a simple, efficient and species-neutral transgenesis technology based on embryo cytoplasmic microinjection with minimal bio-safety concerns can be established for mammalian species. As far as we know, this is the first report for transgenic mammals derived from I-SceI-mediated transgenesis via embryo cytoplasmic microinjection.
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Ultrasonographic features of Langerhans cell histiocytosis of the thyroid.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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Langerhans cell histiocytosis (LCH) is a rare disease, especially when it involves the thyroid gland. Awareness of ultrasonic features will be helpful for a clinician who should consider this disease in the differential diagnosis from other more common thyroid disorders, especially prior to surgery. Here, we report two patients who have histologically confirmed LCH of the thyroid and summarize the reported cases with ultrasonographic scans from the last 10 years (n=10). Ultrasonograms showed isolated or multiple hypoechoic nodules in unilateral or bilateral thyroid gland. Internal acoustic features of most nodules was heterogeneous (n=5) or hypoechoic (n=2).
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Gold-Catalyzed Tandem Reactions of Methylenecyclopropanes and Vinylidenecyclopropanes.
Acc. Chem. Res.
PUBLISHED: 10-30-2013
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Gold catalysis is often the key step in the synthesis of natural products, and is a powerful tool for tandem or domino reaction processes. Both gold salts and complexes are among the most powerful soft Lewis acids for electrophilic activation of carbon-carbon multiple bonds toward a variety of nucleophiles. The core of these reactions relies on the interaction between gold catalysts and ?-bonds of alkenes, alkynes, and allenes. Activation of functional groups by gold complexes provides a useful and important method for facilitating many different organic transformations with high atom efficiency. Although they are highly strained, methylenecyclopropanes (MCPs) and vinylidenecyclopropanes (VDCPs) are readily accessible molecules that have served as useful building blocks in organic synthesis. Because of their unique structural and electronic properties, significant developments have been made in the presence of transition metal catalysts such as nickel, rhodium, palladium, and ruthenium during the past decades. However, less attention has been paid to the gold-catalyzed chemistry of MCPs and VDCPs. In this Account, we describe gold-catalyzed chemical transformations of MCPs and VDCPs developed both in our laboratory and by other researchers. Chemists have demonstrated that MCPs and VDCPs have amphiphilic properties. When MCPs or VDCPs are activated by a gold catalyst, subsequent nucleophilic attack by other reagents or ring-opening (ring-expansion) of the cyclopropane moiety will occur. However, the C-C double bonds of MCPs and VDCPs can also serve as nucleophilic reagents while more electrophilic reagents are present and activated by gold catalyst, and then further cascade reactions take place as triggered by the release of ring strain of cyclopropane. Based on this strategy, both our group and others have found some interesting gold-catalyzed transformations in recent years. These transformations of MCPs and VDCPs can produce a variety of polycyclic and heterocyclic structures, containing different sized skeletons. Moreover, we have carried out some isotopic labeling experiments and computational studies for mechanistic investigation. These reactions always give the desired products with high level control of chemo-, regio-, and diastereoselectivities, making them highly valuable for the synthesis of natural products and to the pharmaceutical industry and medicine in general.
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[Effects of promoting blood circulation to remove meridian obstruction combined with medicinal guides on related osteogenesis factors in rabbits with femoral head necrosis].
Zhongguo Gu Shang
PUBLISHED: 10-19-2013
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To observe effects of blood circulation promoting compounds combined with medicinal guides on content of bone glaprotein (BGP), bone morphogenetic protein-2 (BPM-2) and expression of BMP-2 mRNA in rabbits with femoral head necrosis, and explore its mechanism.
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Assessment of the right and left ventricular function in patients with cor pulmonale using high-definition CT.
Chin. Med. J.
PUBLISHED: 10-12-2013
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Cor pulmonale is often associated with changes of structure and function of the right ventricle (RV) and thus further affects functional changes of the left heart. Our study aimed to assess the left ventricular (LV) and RV function in patients with cor pulmonale using high-definition CT (HDCT).
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[Identification of Env-specific monoclonal antibodies from Chinese HIV-1 infected person by magnetic beads separating B cells and single cell RT-PCR cloning].
Zhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi
PUBLISHED: 09-19-2013
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To establish a simple and practical method for screening of Env-specific monoclonal antibodies from HIV-1 infected individuals.
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Copper-catalyzed trifluoromethylation and cyclization of aromatic-sulfonyl-group-tethered alkenes for the construction of 1,2-benzothiazinane dioxide type compounds.
Chemistry
PUBLISHED: 09-13-2013
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A multi-talented system: An efficient copper-catalyzed tandem trifluoromethylation/annulation of an electron-deficient aromatic ring has been developed. This method provides a powerful and straightforward way to synthesize trifluoromethylated 1,2-benzothiazinane dioxides under mild conditions. The mechanism was investigated by a series of kinetic experiments and isotopic labeling studies.
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Diameters of left gastric vein and its originating vein on magnetic resonance imaging in liver cirrhosis patients with hepatitis B: Association with endoscopic grades of esophageal varices.
Hepatol. Res.
PUBLISHED: 08-16-2013
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To determine whether diameters of the left gastric vein (LGV) and its originating vein are associated with endoscopic grades of esophageal varices.
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Facile preparation of protein stationary phase based on polydopamine/graphene oxide platform for chip-based open tubular capillary electrochromatography enantioseparation.
J Chromatogr A
PUBLISHED: 08-10-2013
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A novel chip-based enantioselective open-tubular capillary electrochromatography (OT-CEC) was developed employing bovine serum albumin (BSA) conjugated polydopamine-graphene oxide (PDA/GO) nanocomposites (PDA/GO/BSA) as stationary phase. After the poly(dimethylsiloxane) (PDMS) microfluidic chip was filled with a freshly prepared solution containing dopamine and graphene oxide, PDA/GO nanocomposites were formed and deposited on the inner wall of microchannel as permanent coating via the oxidation of dopamine by the oxygen dissolved in the solution. The PDA/GO-coated PDMS microchips not only have the adhesion of PDA that make them easily immobilized in the microchannel, but also have the larger surface and excellent biocompatibility of graphene which can incorporate much more biomolecules and well maintain their biological activity. In addition, incorporation of GO in PDA film can make surface morphology more rough, which is beneficial for enhancing the loading capacity of proteins in the microchannels and increasing sample capacity of OT-CEC columns. BSA was stably immobilized in the PDMS microchannel to fabricate a protein-stationary phase. Compared with the native PDMS microchannels, the modified surfaces exhibited much better wettability, more stable electroosmotic mobility, and less nonspecific adsorption. The efficient separation of chiral amino acids (tryptophan and threonine) and chiral dipeptide demonstrate that the constructed OT-CEC columns own ideal enantioselectivity. The presented strategy using PDA/GO coating as a versatile platform for facile conjugation of proteins may offer new processing strategies to prepare a functional surface designed on microfluidic chips.
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[Relative factors of expectant management of ectopic pregnancy].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 08-02-2013
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To analyze select patients of ectopic pregnancy for expectant management.
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Construction of graphene oxide magnetic nanocomposites-based on-chip enzymatic microreactor for ultrasensitive pesticide detection.
J Chromatogr A
PUBLISHED: 07-24-2013
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A new strategy for facile construction of graphene oxide magnetic nanocomposites (GO/Fe3O4 MNCs)-based on-chip enzymatic microreactor and ultrasensitive pesticide detection has been proposed. GO/Fe3O4 MNCs were first prepared through an in situ chemical deposition strategy. Then, acetylcholinesterase (AChE) was adsorbed onto the GO/Fe3O4 surface to form GO/Fe3O4/AChE MNCs which was locally packed into PDMS microchannel simply with the help of external magnetic field to form an on-chip enzymatic microreactor. The constructed GO/Fe3O4/AChE MNCs-based enzymatic microreactor not only have the magnetism of Fe3O4 NPs that make them conveniently manipulated by an external magnetic field, but also have the larger surface and excellent biocompatibility of graphene which can incorporate much more AChE molecules and well maintain their biological activity. On the basis of the AChE inhibition principle, a novel on-chip enzymatic microreactor was constructed for analyzing dimethoate which is usually used as a model of organophosphorus pesticides. Under optimal conditions, a linear relationship between the inhibition rates of AChE and the concentration of dimethoate from 1 to 20 ?gL(-1) with a detection limit of 0.18 ?gL(-1) (S/N=3) was obtained. The developed electrophoretic and magnetic-based chip exhibited excellent reproducibility and stability with no decrease in the activity of enzyme for more than 20 repeated measurements over one week period, which provided a new and promising tool for the analysis of enzyme inhibitors with low cost and excellent performance.
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An intrinsic algorithm for parallel Poisson disk sampling on arbitrary surfaces.
IEEE Trans Vis Comput Graph
PUBLISHED: 07-13-2013
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Poisson disk sampling has excellent spatial and spectral properties, and plays an important role in a variety of visual computing. Although many promising algorithms have been proposed for multidimensional sampling in euclidean space, very few studies have been reported with regard to the problem of generating Poisson disks on surfaces due to the complicated nature of the surface. This paper presents an intrinsic algorithm for parallel Poisson disk sampling on arbitrary surfaces. In sharp contrast to the conventional parallel approaches, our method neither partitions the given surface into small patches nor uses any spatial data structure to maintain the voids in the sampling domain. Instead, our approach assigns each sample candidate a random and unique priority that is unbiased with regard to the distribution. Hence, multiple threads can process the candidates simultaneously and resolve conflicts by checking the given priority values. Our algorithm guarantees that the generated Poisson disks are uniformly and randomly distributed without bias. It is worth noting that our method is intrinsic and independent of the embedding space. This intrinsic feature allows us to generate Poisson disk patterns on arbitrary surfaces in IR(n). To our knowledge, this is the first intrinsic, parallel, and accurate algorithm for surface Poisson disk sampling. Furthermore, by manipulating the spatially varying density function, we can obtain adaptive sampling easily.
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The balance mediated by miRNAs and the heme oxygenase 1 feedback loop contributes to biological effects.
J. Cell. Biochem.
PUBLISHED: 07-02-2013
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Heme oxygenase-1 (HMOX1) is a ubiquitously expressed inducible enzyme that degrades heme to carbon monoxide, biliverdin, and free iron ions. Since 1950, many studies have revealed the role of HMOX1 in reducing the impact of oxidative stress in many types of diseases, such as Alzheimers disease, heart disease, and the development of tumors. These effects arise as a result of the removal of heme, the biological activities of the products of HMOX1 and the activity of HMOX1 itself. However, HMOX1 has some contradictory effects. The discovery of microRNAs (miRNAs) and their relationship with HMOX1 has provided a new direction for research in this field. Here, we discuss the role of a potential regulatory feedback loop between HMOX1 and miRNAs in pathological processes based on recently published data. We hope to describe a new mechanism for HMOX1 function based on miRNAs to address the contradictory results reported in the literature.
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A solid AND logic stimuli-responsive material with bright nondestructive performance designed by sensitive cuprophilicity.
Chem. Commun. (Camb.)
PUBLISHED: 06-28-2013
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A stimuli-responsive material with AND logic function was realized by modulating sensitive Cu-Cu interactions, which is quite different from traditional photoinduced electron transfer (PET) strategies. The obtained material not only gets rid of fluid media, but also displays nondestructive, high intensity optical signals and environmentally friendly performances.
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[Effect of adenovirus-mediated TXNIP overexpression on apoptosis and injury of H9C2 cardiomyocytes].
Sheng Li Xue Bao
PUBLISHED: 06-22-2013
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Adenovirus transfection technique was used in the current study to show if thioredoxin-interacting protein (TXNIP) overexpression can induce cell apoptosis and injury in H9C2 cardiomyocytes cultured in normal glucose condition. And the mechanisms were then investigated. Briefly, H9C2 cardiomyocytes in logarithmic growth phase were randomly divided into three groups: normal cultured group, empty adenovirus vector group (Ad-eGFP) and TXNIP overexpression group (Ad-TXNIP-eGFP). All cells were cultured in DMEM containing normal concentration of glucose (5 mmol/L) and lipid. 72 h after adenovirus transfection, cells and culture mediums were collected for further assay. The results showed that Ad-eGFP and Ad-TXNIP-eGFP adenovirus transfected H9C2 cells successfully, and the transfection efficiency reached the peak at 72 h. Compared with Ad-eGFP group, Ad-TXNIP-eGFP transfection significantly increased TXNIP mRNA (P < 0.05) and protein expression level (P < 0.01). TXNIP overexpression induced remarkable cell apoptosis and injury as evidenced by increased caspase-3 activity (P < 0.05), apoptotic rate (P < 0.01) and LDH activity (P < 0.01). To further analysis the mechanisms of TXNIP-induced cell apoptosis, we also determined Trx activity, Trx related free radical injury and p38 kinase activation, which are involved in free radical induced apoptosis. The results showed that, compared with those in Ad-eGFP group, Trx activity was significantly decreased (P < 0.01), while malondialdehyde (MDA), 3-nitrotyrosine contents and p38 kinase activity were significantly increased (P < 0.01) in TXNIP overexpression group. These results suggest that TXNIP overexpression alone can induce severe apoptosis and injury in H9C2 cardiomyocytes even they are cultured in normal glucose and lipid concentration conditions. The mechanism involved is that overexpressed TXNIP can bind and inhibit Trx, impairs its antioxidative and antiapoptotic function, and then increases free radical induced injury and p38 kinase dependent apoptosis.
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Rhodium(I)-catalyzed cycloisomerization of nitrogen-tethered indoles and alkylidenecyclopropanes: convenient access to polycyclic indole derivatives.
Chemistry
PUBLISHED: 06-19-2013
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At the end of its tether: A new synthetic protocol for the preparation of polycyclic indole derivatives has been developed from a rhodium(I)-catalyzed cycloisomerization of a nitrogen-tethered indole and alkylidenecyclopropane, affording the corresponding tetrahydro-?-carboline derivatives in moderate to good yields. Further transformations give a direct and rapid route to tetracyclic compounds through transition-metal catalysis.
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[Influence of soil iron oxide on VNIR diffuse reflectance spectroscopy].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 05-24-2013
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The influences of iron oxide on soil reflectance, soil line parameter, organic matter spectral characterization and the shape of soil reflectance spectra were studied in the present paper with thirteen samples in several soil types, which covered a range of iron oxide content obtained from various combination of original and iron-removing samples. The results highlight that (1) a decrease on 350-570 nm and an increase on 570-2 500 nm were showed in the reflectance spectra with increasing iron oxide content. However, there was no significant correlation between iron oxide and spectral reflectance quantitatively; (2) iron oxide content had a negative linear correlation with soil line slope and a positive linear correlation with intercept, both were significant, which illustrated the feasibility of iron oxide prediction using soil line parameter; (3) the spectral characteristics of soil organic matter could be covered by iron oxide on 622-851 nm; (4) iron oxide in soil had influence on the shape of reflectance spectra after continuum removal and calculating statistical F and spectral angle.
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Buoyancy of a thin plate pressing a floating oil film on water.
Langmuir
PUBLISHED: 05-24-2013
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Because of the superhydrophobicity of their legs, water striders and many other aquatic creatures can stand and walk effortlessly on water. Because of pollution, an oil film may exist on water in some practical situations. To date, however, it remains unclear how the presence of an oil film would affect the wetting behavior of an object floating on water. In this work, we investigated, both theoretically and experimentally, the buoyancy of a thin plate pressing the surface of a bilayered liquid system. In particular, the effect of the oil layer on the buoyancy force was examined. The critical depth and the corresponding buoyancy at the penetration of the plate into the liquids were obtained analytically. For a plate vertically pressing the liquid surface, the force-displacement loop during a complete advancing-receding cycle was analyzed. Experiments were also performed to verify the theoretical results.
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Purification and characterization of a gelatinolytic matrix metalloproteinase from the skeletal muscle of grass carp (Ctenopharyngodon idellus).
Food Chem
PUBLISHED: 05-22-2013
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A gelatinolytic matrix metalloproteinase (gMMP) from grass carp skeletal muscle was purified by 30-70% ammonium sulphate fractionation and a combination of chromatographic steps including ion exchange on DEAE-Sephacel, gel filtration on Sephacryl S-200, and affinity on gelatin-sepharose. The molecular weight of the proteinase as estimated by SDS-PAGE was 70 kDa under non-reducing conditions. The enzyme revealed high activity from 30 to 50 °C, and the gelatin hydrolysing activity was investigated at a slightly alkaline pH range using gelatin as substrate. Metalloproteinase inhibitor EDTA completely suppressed the gelatinolytic activity, while other proteinase inhibitors did not show any inhibitory effect. Divalent metal ion Ca(2+) was essential for the gelatinolytic activity. Further, peptide mass fingerprinting obtained four fragments with 45 amino acid residues, which were highly identical to MMP-2 from fish species. The gMMP could effectively hydrolyse type I collagen even at 4 °C, suggesting its involvement in the texture softening of fish muscle during the post-mortem stage.
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[Clinical observation of sunitinib treatment for refractory advanced breast cancer ulcer].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 05-08-2013
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To observe the preliminary efficacies and adverse events of sunitinib in the treatment of metastatic breast cancer ulcer.
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[Analysis of the factors affecting pathologic complete response to neoadjuvant chemotherapy in breast cancer patients].
Zhonghua Zhong Liu Za Zhi
PUBLISHED: 05-08-2013
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To analyze the factors affecting pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) in breast cancer patients.
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Cuscuta chinensis seeds water extraction protecting murine osteoblastic MC3T3-E1 cells against tertiary butyl hydroperoxide induced injury.
J Ethnopharmacol
PUBLISHED: 04-03-2013
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Cuscuta chinensis (C. chinensis) is a well-known traditional Chinese herb that has been used to treat heart disease, diabetes, liver injury, cancer, and aging.
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Association of inflammatory factors with occurrence and recurrence of atrial fibrillation: a meta-analysis.
Int. J. Cardiol.
PUBLISHED: 04-01-2013
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The role of circulating inflammatory factors in atrial fibrillation (AF) occurrence and recurrence remains inconclusive.
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An Intrinsic Algorithm for Parallel Poisson Disk Sampling on Arbitrary Surfaces.
IEEE Trans Vis Comput Graph
PUBLISHED: 03-20-2013
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Poisson disk sampling plays an important role in a variety of visual computing, due to its useful statistical property in distribution and the absence of aliasing artifacts. While many effective techniques have been proposed to generate Poisson disk distribution in Euclidean space, relatively few work has been reported to the surface counterpart. This paper presents an intrinsic algorithm for parallel Poisson disk sampling on arbitrary surfaces. We propose a new technique for parallelizing the dart throwing. Rather than the conventional approaches that explicitly partition the spatial domain to generate the samples in parallel, our approach assigns each sample candidate a random and unique priority that is unbiased with regard to the distribution. Hence, multiple threads can process the candidates simultaneously and resolve conflicts by checking the given priority values. It is worth noting that our algorithm is accurate as the generated Poisson disks are uniformly and randomly distributed without bias. Our method is intrinsic in that all the computations are based on the intrinsic metric and are independent of the embedding space. This intrinsic feature allows us to generate Poisson disk distributions on arbitrary surfaces. Furthermore, by manipulating the spatially varying density function, we can obtain adaptive sampling easily.
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Observation of the photorefractive effects in bent-core liquid crystals.
Opt Express
PUBLISHED: 03-14-2013
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We present a new observation of photorefractive (PR) effects in bent-core nematic (BCN) liquid crystal (LC) materials, where two kinds of optical-induced gratings are demonstrated and compared in pure and surface-doped BCN systems. The experimental results showed that these two kinds of gratings exhibit distinctive different polarization-dependent and angular-dependent behaviors, respectively. Furthermore, we supplied the pure and surface-doped rodlike LC systems for comparison, which revealed that V shape molecular structure of BCN can produce charge carrier more efficiently than rodlike molecular structure does. Thus BCN materials can offer an exciting potential for optical information processing.
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The expression of intronic miRNAs, miR-483 and miR-483*, and their host gene, Igf2, in murine osteoarthritis cartilage.
Int. J. Biol. Macromol.
PUBLISHED: 03-02-2013
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MicroRNAs (miRNAs) have been shown to be important regulators in the pathogenesis of osteoarthritis (OA). The objective of this study was to determine the expression levels of miR-483, miR-483*, their host gene (Igf2) and other cytokines in a murine model of OA. The expression of miR-483 was significantly up-regulated in old mouse and in all of the operation groups, particularly the group assessed 1 week after surgery. The expression of miR-483* was significantly increased in the old mouse group and the group assessed 5 weeks after surgery. The expression of miR-483 was negatively correlated with the expression of (mRNA) Bmp7 and TgfB and positively correlated with Mmp13 by Pearson correlation analysis, while miR-483* was positively correlated with Il1B. Surprisingly, there was no correlation between the expression of either miR-483 or miR-483* and Igf2. This study shows that the expression of miR-483 and miR-483* is up-regulated in murine OA. These data suggest that miR-483 and miR-483* may play critical roles in early and later pathogenesis of OA, respectively, without the involvement of their host gene Igf2.
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[Translational Medicine and its application in stem cell research for periodontal regeneration].
Beijing Da Xue Xue Bao
PUBLISHED: 02-16-2013
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Translational Medicine is an evolutional concept that encompasses the rapid translation of basic research for use in clinical disease diagnosis, prevention, treatment and finally in public health promotion. It follows the idea "from bench to bedside and back", and hence relies on cooperation between laboratory research and clinical care. Translation process is a complex process that requires both research and non-research activities. During the past ten years, there has been intense interest in the development of new clinical procedures, therapeutic molecules, and prototypes based on translational medicine concept including dentistry. Periodontitis is a globally prevalent inflammatory disease that causes the destruction of the tooth supporting apparatus. Current methods to reconstitute lost periodontal structures have been shown to have limited and variable outcomes. Stem cell therapy can be used for periodontal regeneration and it is also one of the hot topics in translational regenerative medicine. In this article, recent advances and current status of translational medicine in stem cell therapy in periodontal regeneration field were reviewed. However, a number of biological, technical and clinical hurdles must be overcome before stem cell therapy could be used in clinics.
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Over-expression of heme oxygenase-1 does not protect porcine endothelial cells from human xenoantibodies and complement-mediated lysis.
J. Huazhong Univ. Sci. Technol. Med. Sci.
PUBLISHED: 02-08-2013
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Accommodated organs can survive in the presence of anti-organ antibodies and complement. Heme oxygenase-1 (HO-1) is essential to ensure accommodation in concordant xenotransplant models. However, whether induction of HO-1 over-expression could protect porcine endothelial cells (PECs) against human xenoantibodies and complement-mediated lysis and induce an in vitro accommodation is still unknown. The SV40-immortalized porcine aorta-derived endothelial cell line (iPEC) was pre-incubated with 20, 50, or 80 ?mol/L of cobalt-protoporphyrins IX (CoPPIX) for 24 h, and the HO-1 expression in iPECs was analyzed by using Western blotting. CoPPIX-treated or untreated iPECs were incubated with normal human AB sera, and complement-dependent cytotoxicity (CDC) was measured by both flow cytometry and lactate dehydrogenase (LDH) release assay. In vitro treatment with CoPPIX significantly increased the expression of HO-1 in iPECs in a dose-dependent manner. Over-expression of HO-1 was successfully achieved by incubation of iPECs with either 50 or 80 ?mol/L of CoPPIX. However, HO-1 over-expression did not show any protective effects on iPECs against normal human sera-mediated cell lysis. In conclusion, induction of HO-1 over-expression alone is not enough to protect PECs from human xenoantibodies and complement-mediated humoral injury. Additionally, use of other protective strategies is needed to achieve accommodation in pig-to-primate xenotransplantation.
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Silver pyroarsonates obtained from Ag(I)-mediated in situ condensation of aryl arsonate ligands under solvothermal conditions.
Inorg Chem
PUBLISHED: 02-06-2013
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Four new layered silver(I) organoarsonates, namely, [Ag(3)(L(3))(CN)] (1) (H(2)L(3) = (PhAsO(2)H)(2)O), [Ag(3)(L(4))(CN)] (2) (H(2)L(4) = (2-NO(2)-C(6)H(4)-AsO(2)H)(2)O), [Ag(3)(HL(5))(H(2)L(5))] (3) (H(3)L(5) = 3-NO(2)-4-OH-C(6)H(3)-AsO(3)H(2)) and [Ag(2)(HL(5))] (4), were synthesized under solvothermal conditions. During the preparations of 1 and 2, condensation of organoarsonate ligands (H(2)L(1) = Ph-AsO(3)H(2); H(2)L(2) = 2-NO(2)-C(6)H(4)-AsO(3)H(2)) and the decomposition of acetonitrile molecules to cyanide anions occurred. Single crystals of H(2)L(4) ligand and compounds 1-4 were isolated, and their crystal structures have been determined by single crystal X-ray diffraction studies. In 1, the one-dimensional (1D) chains based on Ag(I) ions and {L(3)}(2-) anions are further interconnected by CN(-) into two-dimensional (2D) layers. In 2, adjacent Ag(I) ions within the silver(I) organoarsonate layer are further bridged by ?(4)-CN(-) anions with very short Ag···Ag contacts. In 3, the hexanuclear {Ag(6)O(12)} clusters are interconnected by bridging organoarsonate ligands into a silver(I) arsonate hybrid layer. In 4, the right-handed {Ag(4)O(4)} chains are further interconnected by organoarsonate ligands as well as additional Ag-O-Ag bridges into a novel silver(I) arsonate layer. Compounds 1 and 2 display red and orange-red emissions, respectively, which may be assigned to be an admixture of ligand-to-metal charge transfer (LMCT) and metal-centered (4d-5s/5p) transitions perturbed by Ag(I)···Ag(I) interactions. Upon cooling from room temperature to 10 K, compound 1 exhibits interesting temperature-dependent emissions.
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Xanthine microsensor based on polypyrrole molecularly imprinted film modified carbon fiber microelectrodes.
Anal. Biochem.
PUBLISHED: 02-04-2013
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A molecularly imprinted polymers (MIPs) microsensor was presented as a carbon fiber microelectrode (CFME) coating for specifically recognizing xanthine (Xan). The polymeric film was obtained based on the imprinted procedure of electropolymerization of pyrrole in the presence of the template molecule Xan by cyclic voltammetry, and template was removed by magnetic stirring. Under the optimum conditions, a satisfactory molecularly binding selectivity of Xan was obtained from the MIPs microsensor with an imprinting factor (IF) of 6.63 and a linear response to concentration in certain ranges. The ranges are from 4.0 × 10?? to 6.0 × 10?? M and from 8.0 × 10?? to 2.0 × 10?³ M with a detection limit of 2.5 × 10?? M. Meanwhile, good stability (relative standard deviation [RSD] = 3.2%, n = 10) and reproducibility (RSD = 2.0%, n = 10) were observed, and recoveries ranging from 96.9 to 102.5% were calculated when applied to Xan determination in real blood serum samples.
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The disturbance of hippocampal CaMKII/PKA/PKC phosphorylation in early experimental diabetes mellitus.
CNS Neurosci Ther
PUBLISHED: 02-01-2013
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Defining the impact of diabetes and related risk factors on brain cognitive function is critically important for patients with diabetes.
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Nitrogen/manganese oxides doped porous carbons derived from sodium butyl naphthalene sulfonate.
J Colloid Interface Sci
PUBLISHED: 01-19-2013
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High-performance porous carbons have been prepared as supercapacitor electrode materials by co-doped with nitrogen and MnOx via a direct carbonization method, using sodium butyl naphthalene sulfonate (abbr. BNS-Na) as carbon source. It is believed that the in situ formed Na6(SO4)2(CO3) in the product would probably serve as temporary template for producing porous structures. The impacts of nitrogen/MnOx contents as well as the structures upon the capacitive performances were emphatically discussed. It indicates that introducing nitrogen and/or MnOx into the carbon matrix can remarkably improve their capacitive performances based on the cyclic voltammetry and galvanostatic charge-discharge measurements in 6 mol L(-1) KOH aqueous solution. The specific capacitances of doped carbons can reach up to ca. 167.0-241.8 F g(-1) compared with that of the undoped carbon of ca. 105.6 F g(-1). Of these samples, the carbon-Mn-1:30-N-1:15 sample co-doped with nitrogen and MnOx exhibits the highest specific capacitance and energy density up to 241.8 F g(-1) and 33.6 Wh kg(-1), respectively. In particular, these carbons also exhibit high intrinsic capacitances (i.e., capacitance per surface area) up to ca. 0.66-1.92 F m(-2).
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Nimotuzumab enhances the radiosensitivity of cancer cells in vitro by inhibiting radiation-induced DNA damage repair.
PLoS ONE
PUBLISHED: 01-01-2013
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Nimotuzumab is a humanized IgG1 monoclonal antibody specifically targeting EGFR. In this study, we aimed to investigate the molecular mechanisms of nimotuzumab in its effects of enhancing cancer cell radiosensitivity.
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Discovery and Characterization of a Novel Carlavirus Infecting Potatoes in China.
PLoS ONE
PUBLISHED: 01-01-2013
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A new carlavirus, tentatively named Potato virus H (PVH), was found on potato plants with mild symptoms in Hohhot, Inner Mongolia Autonomous Region, China. PVH was confirmed by genome sequencing, serological reactions, electron microscopy, and host index assays. The PVH particles were filamentous and slightly curved, with a modal length of 570 nm. Complete RNA genomic sequences of two isolates of PVH were determined using reverse transcription-PCR (RT-PCR) and the 5 rapid amplification of cDNA ends (5 RACE) method. Sequence analysis revealed that PVH had the typical genomic organization of members of the genus Carlavirus, with a positive-sense single-stranded genome of 8410 nt. It shared coat protein (CP) and replicase amino acid sequence identities of 17.9-56.7% with those of reported carlaviruses. Phylogenetic analyses based on the protein-coding sequences of replicase and CP showed that PVH formed a distinct branch, which was related only distantly to other carlaviruses. Western blotting assays showed that PVH was not related serologically to other potato carlaviruses (Potato virus S, Potato virus M, and Potato latent virus). PVH systemically infected Nicotianaglutinosa but not Nicotiana tabacum, Nicotianabenthamiana, or Chenopodiumquinoa, which is in contrast with the other potato carlaviruses. These results support the classification of PVH as a novel species in the genus Carlavirus. Preliminary results also indicated that a cysteine-rich protein encoded by the smallest ORF located in the 3 proximal region of the genome suppressed local RNA silencing and enhanced the pathogenicity of the recombinant PVX.
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[Petroleum hydrocarbon pollution status in shellfish culture area of Sanggou Bay and effect on quality safety of shellfish].
Huan Jing Ke Xue
PUBLISHED: 12-29-2011
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Petroleum hydrocarbon concentrations in seawater, surface sediments and culture shellfish were investigated in shellfish culture area of Sanggou Bay from Jan. to Nov. in 2008. Investigation was conducted on the distribution and variation of petroleum hydrocarbon concentrations in seawater and sediments in the shellfish culture area of Sanggou Bay, as well as on the levels and the differences in petroleum hydrocarbon concentrations among the shellfish species. In addition, the petroleum hydrocarbon pollution status in the three media was evaluated and the effects of accumulated petroleum hydrocarbon in shellfish on the food safety risk were discussed. The results indicated: 1) Petroleum hydrocarbon concentrations in seawater in the shellfish culture area of Sanggou Bay were in the range of 3.61 - 98.21 microg/L; the mean values of petroleum hydrocarbon concentrations in sediments were in the range of 6.75-25.95 mg/kg; petroleum hydrocarbon concentrations in culture shellfish were in the range of 2.14- 42.87 mg/kg; and petroleum hydrocarbon concentrations in shellfish varied largely among different species, with the mean values in the sequence of clam Venerupis variegata > oyster > scallop; 2) Monthly petroleum hydrocarbon concentrations in seawater and surface sediments varied significantly in Sanggou Bay shellfish culture area, with the highest and the lowest values of petroleum hydrocarbon concentrations in seawater that occurred in July and in August, respectively, and with the highest and the lowest values of petroleum hydrocarbon concentrations in surface sediments that occurred in September and in March, respectively; 3) According to the corresponding evaluation criteria, the petroleum hydrocarbon pollution status in surface sediments in Sanggou Bay shellfish culture area was unpolluted but the status in surface seawater was polluted. The culture shellfish was also polluted by petroleum hydrocarbon with different degrees among three species, namely, the pollution degree of clam Venerupis variegata and oyster was more serious than that of scallop Chlamys farreri; 4) The results of linear regression analysis showed that petroleum hydrocarbon concentrations in shellfish had a significantly positive correlation with the concentrations in seawater, while the linear correlation between the concentrations in shellfish and surface sediments was not obvious; and 5) According to the pollution level of petroleum hydrocarbon in shellfish, the food safety risk of three culture shellfishes in Sanggou Bay was relatively low.
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PDMS microchip coated with polydopamine/gold nanoparticles hybrid for efficient electrophoresis separation of amino acids.
Electrophoresis
PUBLISHED: 12-03-2011
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In this paper, a novel, simple, economical and environmentally friendly method based on in situ chemically induced synthesis strategy was designed and developed for the modification of a poly(dimethylsiloxane) (PDMS) microchip channel with polydopamine/gold nanoparticles (PDA/Au NPs) to create a hydrophilic and biofouling resistant surface. Dopamine as a reductant and a monomer, and HAuCl(4) as an oxidant to trigger dopamine polymerization and the source of metallic nanoparticles, were filled into the PDMS microchannel to yield in situ a well-distributed and robust PDA/Au NP coating. Au NPs were highly and uniformly dispersed in/on the PDA matrix with a narrow size distribution, as verified by scanning electron microscopy and UV-vis spectra. Compared with the native PDMS microchannel, the modified surfaces exhibited much better wettability, high stability and suppressed electroosmotic mobility, and less nonspecific adsorption towards biomolecules. The water contact angle and EOF of PDA/Au NP-coated PDMS microchip were measured to be 13° and 4.17×10(-4) cm(2)/V s, compared to those of 111° and 5.33×10(-4) cm(2)/V s from the native one, respectively. Fast and efficient separations of five amino acids such as arginine, proline, histidine, valine and threonine suggested greatly improved electrophoretic performance of the PDA/Au NP-functionalized PDMS microchips. This one-step procedure offers an effective approach for a biomimetic surface design on microfluidic chips, which is promising in high-throughput and complex biological analysis.
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Preparation and biodistribution of 188Re-labeled folate conjugated human serum albumin magnetic cisplatin nanoparticles (188Re-folate-CDDP/HSA MNPs) in vivo.
Int J Nanomedicine
PUBLISHED: 11-30-2011
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The purpose of this study was to develop intraperitoneal hyperthermic therapy based on magnetic fluid hyperthermia, nanoparticle-wrapped cisplatin chemotherapy, and magnetic particles of albumin. In addition, to combine the multiple-killing effects of hyperthermal targeting therapy, chemotherapy, and radiotherapy, the albumin-nanoparticle surfaces were linked with radionuclide (188)Re-labeled folic acid ligand ((188)Re-folate-CDDP/HSA).
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Syntheses, crystal structures and luminescent properties of new lanthanide(III) organoarsonates.
Dalton Trans
PUBLISHED: 11-28-2011
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The first examples of lanthanide(III) organoarsonates, Ln(L(1))(H(2)O)(3) (Ln = La (1), H(3)L(1) = 4-hydroxy-3-nitrophenylarsonic acid), Ln(L(1))(H(2)O)(2) (Ln = Nd (2), Gd (3)), and mixed-ligand lanthanide(III) organoarsonates, Ln(2)(HL(1))(2)(C(2)O(4))(H(2)O)(2) (Ln = Nd (4), Sm (5), Eu (6)), were hydrothermally synthesized and structurally characterized. Compounds 1-3 feature a corrugated lanthanide arsonate layer, in which 1D lanthanide arsonate inorganic chains are further interconnected via bridging L(1)(3-) ligands. Compounds 4-6 exhibit a complicated 3D network. The interconnection of the lanthanide(III) ions by the bridging arsonate ligand leads to the formation of a novel 3D framework with long narrow 1D tunnels along the a-axis, with the oxalate anions are located at the above tunnels and bridging with lanthanide(III) ions. Compounds 2 and 4 exhibit the characteristic emission bands of the Nd(III) ion, whereas compound 6 displays the characteristic emission bands of the Eu(III) ion. The magnetic properties of compounds 3-6 were also investigated.
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Synthesis of blue fluorescence CdS quantum dots stabilized by L-cysteine in aqueous phase.
J Nanosci Nanotechnol
PUBLISHED: 11-23-2011
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In this paper we report a novel synthesis method of blue fluorescence CdS quantum dots stabilized by L-cysteine in aqueous phase. When pH value of the core/shell CdTe/CdS colloid solution changed from 11.6 to 1.5, blue fluorescence CdS QDs was obtained. The fluorescence emission wavelength yielded a hypsochromic shift from 540 nm to 438 nm corresponding to the absorption peak position gave a hypsochromic shift from 518 nm to 352 nm. The CdS QDs were characterized by XPS and TEM. And the photostability of CdS QDs solution irradiated with UV lamp under open air condition at room temperature was very stable.
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[Effects of n-hexane exposure on human serum myelin basic proteins].
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi
PUBLISHED: 11-22-2011
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To explore the effects of n-hexane on expression of serum myelin proteins (MBP) in workers occupationally exposed to n-hexane.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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