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Find video protocols related to scientific articles indexed in Pubmed.
Fast estimation of first-order scattering in a medical x-ray computed tomography scanner using a ray-tracing technique.
J Xray Sci Technol
PUBLISHED: 11-20-2014
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This study describes a deterministic method for simulating the first-order scattering in a medical computed tomography scanner. The method was developed based on a physics model of x-ray photon interactions with matter and a ray tracing technique. The results from simulated scattering were compared to the ones from an actual scattering measurement. Two phantoms with homogeneous and heterogeneous material distributions were used in the scattering simulation and measurement. It was found that the simulated scatter profile was in agreement with the measurement result, with an average difference of 25% or less. Finally, tomographic images with artifacts caused by scatter were corrected based on the simulated scatter profiles. The image quality improved significantly.
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Detector response function of an energy-resolved CdTe single photon counting detector.
J Xray Sci Technol
PUBLISHED: 11-20-2014
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While spectral CT using single photon counting detector has shown a number of advantages in diagnostic imaging, knowledge of the detector response function of an energy-resolved detector is needed to correct the signal bias and reconstruct the image more accurately.
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Content discovery and retrieval services at the European Nucleotide Archive.
Nucleic Acids Res.
PUBLISHED: 11-19-2014
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The European Nucleotide Archive (ENA; http://www.ebi.ac.uk/ena) is Europe's primary resource for nucleotide sequence information. With the growing volume and diversity of public sequencing data comes the need for increased sophistication in data organisation, presentation and search services so as to maximise its discoverability and usability. In response to this, ENA has been introducing and improving checklists for use during submission and expanding its search facilities to provide targeted search results. Here, we give a brief update on ENA content and some major developments undertaken in data submission services during 2014. We then describe in more detail the services we offer for data discovery and retrieval.
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Expanded-core waveguides written by femtosecond laser irradiation in bulk optical glasses.
Opt Express
PUBLISHED: 11-18-2014
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Expanded-core structures based on layered increased index (type I) waveguiding traces are fabricated by ultrafast laser photoinscription in bulk optical glasses, with examples for fused silica and chalcogenide glasses. The expanded-core waveguides can serve for large-mode-area guiding concepts and their feasibility is experimentally investigated. A parametric study of the geometry, number of traces and index contrast indicates the possibility to design guided modes characteristics as exemplified in fused silica. A specific arrangement consisting of 8 traces of guiding layers with 6µm separation exhibit single-mode transport properties with mode field area of ~805µm2. The condition of single mode operation is also discussed in the frame of the dispersion relation of light guiding in periodical dielectric structures. The supported supermode of expanded-core structures can be controlled by careful design of the refractive index change, the number of guiding layers and the thickness of the interlayers. Inspection of the propagation characteristics shows equally low loss features. A Y-branching splitter based on expanded-core concept conserving single mode characteristics is fabricated. The optical design is equally successfully tested in chalcogenide Gallium Lanthanum Sulfide glass. Ultrafast laser inscribed expanded-core waveguiding provides therefore an interesting path of fabricating large mode area waveguides usable in near infrared and mid-infrared region beneficial for applications requiring high power or large mode dimensions.
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Assessing Steatotic Liver Function after Ischemia-reperfusion Injury by In Vivo Multiphoton Imaging of Fluorescein Disposition.
Drug Metab. Dispos.
PUBLISHED: 11-09-2014
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Ischemia-reperfusion injury is a common complication during liver surgery, where steatotic livers are more prone to the injury and may become more prevalent in the growing obese population. This study aimed to characterize liver morphology and understand changes in subcellular function in steatotic livers exposed to ischemia-reperfusion injury through quantitative description of fluorescein distribution obtained by minimally-invasive in vivo multiphoton microscopy using a physiological pharmacokinetic model. Rats were fed a high fat diet for 7 days to induce liver steatosis. Partial ischemia was induced, following reperfusion for 4 hours, when fluorescein (10 mg/kg) was injected intravenously. Liver images, bile and blood were collected up to 180 min following injection. Ischemia-reperfusion injury was associated with an increase in alanine transaminase levels and apoptosis. In addition, steatosis had the presence of lipid droplets and an increase in the fluorescein associated fluorescence observed in the hepatocytes by multiphoton imaging. Analysis of the hepatic concentration-time profiles suggests that the steatosis induced increase in fluorescein associated fluorescence mainly arises by inducing the hepatic fluorescein metabolism. The combination of ischemia-reperfusion with steatosis exacerbates these effects further. This was confirmed by fluorescence lifetime imaging microscopy showing a decreased average fluorescence lifetime of the liver, indicative of increased production of the metabolite. Our results show the potential of non-invasive imaging of a dye to further improve our understanding of liver disease induced subcellular changes in vivo by also providing further quantitative measures of metabolic and biliary liver function and, hence, extending the qualitative liver function tests now available.
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Insight into Deactivation of Commercial SCR Catalyst by Arsenic: An Experiment and DFT Study.
Environ. Sci. Technol.
PUBLISHED: 11-08-2014
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Fresh and arsenic-poisoned V2O5-WO3/TiO2 catalysts are investigated by experiments and DFT calculations for SCR activity and the deactivation mechanism. Poisoned catalyst (1.40% of arsenic) presents lower NO conversion and more N2O formation than fresh. Stream (5%) could further decrease the activity of poisoned catalyst above 350 °C. The deactivation is not attributed to the loss of surface area or phase transformation of TiO2 at a certain arsenic content, but due to the coverage of the V2O5 cluster and the decrease in the surface acidity: the number of Lewis acid sites and the stability of Brønsted acid sites. Large amounts of surface hydroxyl induced by H2O molecules provide more unreactive As-OH groups and give rise to a further decrease in the SCR activity. N2O is mainly from NH3 unselective oxidation at high temperatures since the reducibility of catalysts and the number of surface-active oxygens are improved by As2O5. Finally, the reaction pathway seems unchanged after poisoning: NH3 adsorbed on both Lewis and Brønsted acid sites is reactive.
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The Forest Filter Effect vs. Cold Trapping Effect on the Altitudinal Distribution of PCBs: A Case Study of Mt. Gongga, Eastern Tibetan Plateau.
Environ. Sci. Technol.
PUBLISHED: 11-08-2014
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High mountains are priority trapping zones of persistent organic pollutants (POPs) due to the cold condensation effect. Forest soils characterized by high organic carbon are important for terrestrial storage of POPs. To investigate the dominant factor controlling the altitudinal distribution of POPs in mountainous areas, we measured concentrations of polychlorinated biphenyls (PCBs) in different environmental matrices (surface soil, moss, and air) from nine elevations on the eastern slope of Mt. Gongga, the highest mountain in Sichuan Province on the Tibetan Plateau. The concentrations of 24 measured PCBs ranged from 41 to 510 pg/g dry weight (dw) (mean: 260 pg/g dw) in the surface soil, 280 to 1200 pg/g dw (mean: 740 pg/g dw) in moss, and 33 to 60 pg/m3 (mean: 47 pg/m3) in air. Soil organic carbon was a key determinant explaining 75% of the variation in concentration along the altitudinal gradient. Across all of the sampling sites, the average contribution of the forest filter effect (FFE) was greater than that of the mountain cold trapping effect based on principal components analysis and multiple linear regression. Our results deviate from the thermodynamic theory involving cold condensation at high altitudes of mountain areas and highlight the importance of the FFE.
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Stability analysis and design of time-domain acoustic impedance boundary conditions for lined duct with mean flow.
J. Acoust. Soc. Am.
PUBLISHED: 11-07-2014
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This work develops the so-called compensated impedance boundary conditions that enable stable time domain simulations of sound propagation in a lined duct with uniform mean flow, which has important practical interest for noise emission by aero-engines. The proposed method is developed analytically from an unusual perspective of control that shows impedance boundary conditions act as closed-loop feedbacks to an overall duct acoustic system. It turns out that those numerical instabilities of time domain simulations are caused by deficient phase margins of the corresponding control-oriented model. A particular instability of very low frequencies in the presence of steady uniform background mean flow, in addition to the well known high frequency numerical instabilities at the grid size, can be identified using this analysis approach. Stable time domain impedance boundary conditions can be formulated by including appropriate phaselead compensators to achieve desired phase margins. The compensated impedance boundary conditions can be simply designed with no empirical parameter, straightforwardly integrated with ordinary linear acoustic models, and efficiently calculated with no need of resolving sheared boundary layers. The proposed boundary conditions are validated by comparing against asymptotic solutions of spinning modal sound propagation in a duct with a hard-soft interface and reasonable agreement is achieved.
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Astemizole Arrests the Proliferation of Cancer Cells by Disrupting the EZH2-EED Interaction of Polycomb Repressive Complex 2.
J. Med. Chem.
PUBLISHED: 11-05-2014
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Polycomb Repressive Complex 2 (PRC2) modulates the chromatin structure and transcriptional repression by trimethylation lysine 27 of histone H3 (H3K27me3), a process that necessitates the protein-protein interaction (PPI) between the catalytic subunit EZH2 and EED. Deregulated PRC2 is intimately involved in tumorigenesis and progression, making it an invaluable target for epigenetic cancer therapy. However, until now, there have been no reported small molecule compounds targeting the EZH2-EED interactions. In the present study, we identified astemizole, an FDA-approved drug, as a small molecule inhibitor of the EZH2-EED interaction of PRC2. The disruption of the EZH2-EED interaction by astemizole destabilizes the PRC2 complex and inhibits its methyltransferase activity in cancer cells. Multiple lines of evidence have demonstrated that astemizole arrests the proliferation of PRC2-driven lymphomas primarily by disabling the PRC2 complex. Our findings demonstrate the chemical tractability of the difficult PPI target by a small molecule compound, highlighting the therapeutic promise for PRC2-driven human cancers via targeted destruction of the EZH2-EED complex.
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Stable anode performance of vanadium oxide hydrate semi-microspheres and their graphene based composite microspheres in sodium-ion batteries.
Dalton Trans
PUBLISHED: 10-31-2014
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A simple and versatile method for preparation of new crystalline vanadium oxide hydrate semi-microspheres is developed via a simple hydrothermal route, which are tested as a novel high-energy anode materials for sodium-ion batteries. The enhancement of electrochemical performance for the vanadium oxide hydrate electrode is offered by addition of graphene. The graphene-based vanadium oxide hydrate microsphere composite shows a high discharge capacity of 336.1 mA h g(-1) for the second cycle between a 0.05-3.0 V voltage limit at a discharge current density of 10 mA g(-1). A reversible capacity of 303.1 mA h g(-1) is retained after 20 cycles.
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Phenylobacterium kunshanense sp. nov., isolated from the sludge of pesticide manufacturing factory.
Int. J. Syst. Evol. Microbiol.
PUBLISHED: 10-30-2014
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A novel aerobic, Gram-negative, motile bacterium strain, designated BUT-10T, was isolated from the sludge of a pesticide manufacturing factory in Kunshan, China. Cells were rod-shaped (0.4-0.45×0.9-1.4 ?m) and colonies were white, circular with entire edges and had a smooth surface. The strain grew at 25-37 °C, pH 6.0-8.0 and 0 %-0.5 % of NaCl. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain BUT-10T was a member of the genus Phenylobacterium, and showed the highest sequence similarities to Phenylobacterium muchangponense A8T (97.49%), Phenylobacterium immobile DSM 1986T (97.14%) and Phenylobacterium lituiforme Fail3T (96.34%). Major fatty acids (>5 %) were summed feature 8 (comprising C18:1 ?7c and/or C18:1 ?6c), C16:0 and summed feature 3 (comprising C16:1 ?7c and/or C16:1 ?6c). The major isoprenoid quinone was ubiquinone-10. The DNA G+C content was 71.85 mol%. Strain BUT-10T showed low DNA-DNA relatedness with P. muchangponense A8T (15.7±2.9 %) and P. immobile DSM 1986T (12.8±1.1 %). On the basis of phenotypic, phylogenetic and genotypic data, strain BUT-10T is considered to represent a novel species of the genus Phenylobacterium, for which the name Phenylobacterium kunshanense sp. nov. is proposed. The type strain is BUT-10T (=CCTCC AB 2013085T = KCTC 42014T).
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[Experimental study of canine bone marrow mesenchymal stem cells combined with calcium phosphate cement for repair of mandibular bone defects in Beagle dogs].
Shanghai Kou Qiang Yi Xue
PUBLISHED: 10-24-2014
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To evaluate the effects of bone marrow mesenchymal stem cells (BMSCs) combined with calcium phosphate cement (CPC) scaffold for repair of mandibular defect in Beagle dogs.
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[Extracellular HMGB1 Promotes the Migration of Cord Blood CD34(+) Cells via SDF-1/CXCR-4 Axis].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 10-24-2014
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This study was aimed to investigate the effect of high mobility group box1(HMGB1) and/or stromal cell derived factor-1(SDF-1) on the migration of cord blood CD34(+) cells, and to explore whether HMGB1 promotes cord blood CD34(+) cell migration via SDF-1/CXCR4 axis. Cord blood mononuclear cells were isolated by Ficoll-Paque density centrifugation, CD34(+) cells were collected by a positive immunoselection procedure (CD34 MicroBeads) according to the manufacturer's instructions, the purity of the isolated CD34(+) cells was detected by flow cytometry. In vitro chemotaxis assays were performed using Transwell cell chambers to detect cells migration. 1×10(5) cells/well cord blood CD34(+) cells were added into the upper chambers. Different concentrations of HMGB1 and/or SDF-1 (0, 10, 25, 50, 100, 200 ng/ml) were used to detect the optimal concentrations of HMGB1 and/or SDF-1 for inducing migration of cord blood CD34(+) cells. Freshly isolated cord blood CD34(+) cells express CXCR4 (SDF-1 receptor), and HMGB1 receptor TLR-2,TLR-4 and RAGE. To explore which receptors were required for the synergy of HGMB1 and/or SDF-1 on cells migration, the anti-SDF-1, anti-CXCR4 and anti-RAGE antibodies were used to detect the effect of HGMB1 alone or with SDF-1 on cord blood CD34(+) cells migration. The results showed that the purity of CD34(+) cells isolated from cord blood mononuclear cells by magnetic cell sorting was 97.40 ± 1.26%, the 25 ng/ml SDF-1 did not induce migration of cord blood CD34(+) cells, whereas the optimal migration was observed at 100 ng/ml. HMGB1 alone did not induce migration up to 100 ng/ml. The dose test found that the the best synergistic concentrations for cells migration were 100 ng/ml HMGB1 combined with 50 ng/ml SDF-1. The blocking test showed that both the anti-SDF-1 (4 µg/ml) and anti-CXCR4 (5 µg/ml) antibodies could block cell migration induced by HMGB1 or combined with SDF-1, but the cord blood CD34(+) cells in the presence of anti-RAGE, anti-TLR-2 and anti-TLR-4 antibodies did not modify the response to SDF-1 in the presence of HMGB1. It is concluded that both HMGB1 and SDF-1 can induce cord blood CD34(+) cells migration, HMGB1 enhances SDF-1-induced migration exclusively via CXCR4 and in a RAGE and TLR receptors-independent manner, the exact mechanism needs to be further explored.
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[Effects of Sorafenib on Proliferation and Apoptosis of Human Multiple Myeloma Cell RPMI 8226].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 10-24-2014
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This study was aimed to investigate the effects of sorafenib on proliferation and apoptosis of MM cell line RPMI-8226, and to explore the its potential anti-tumor mechanism. The inhibitory rate of multiple myeloma cell proliferation was tested by MTT. Transmission electron microscopy was used to observe morphological and ultrastructural changes of RPMI-8226 cells treated with sorafenib. The effects of sorafenib on the apoptosis and cell cycle of RPMI-8226 cells was detected by flow cytometry. The effects of sorafenib on the expression of caspase-3, BCL-2 and MCL-1 mRNA and protein were assayed by RT-PCR and Western blot respectively. The results showed that sorafenib (0-10.0 µmol/L) could obviously inhibit the proliferation of RPMI-8226 cells in time and dose-dependent manner. Flow cytometry results showed that sorafenib could induce apoptosis of RPMI-8226 cells, the difference was statistical significance (P < 0.05). Sorafenib mainly arrested RPMI-8226 cells in the G1 phase (P < 0.05). Typical apoptotic morphological and ultrastructural changes of MM cells could be observed under transmission electron microscope, Examination of cellular signaling pathways showed that sorafenib induced upregulation of cleaved-caspase-3 expression, and simultaneous downregulation of BCL-2 and MCL-1 expression. It is concluded that sorafenib displays anti-myeloma activity. Activating the death receptor pathway and arresting cell cycle may be two of the relatated mechanisms.
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Proteomic Investigation of Signatures for Geniposide-Induced Hepatotoxicity.
J. Proteome Res.
PUBLISHED: 10-23-2014
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Evaluating the safety of traditional medicinal herbs and their major active constituents is critical for their widespread usage. Geniposide, a major active constituent with a defined structure from the traditional medicinal herb Gardenia jasminoides ELLIS fruit, exhibits remarkable anti-inflammatory, antiapoptotic, and antifibrotic properties and has been used in a variety of medical fields, mainly for the treatment of liver diseases. However, geniposide-induced hepatotoxicity and methods for the early detection of hepatotoxicity have yet to be reported. In this study, geniposide-induced hepatotoxicity was investigated. In addition, candidate biomarkers for the earlier detection of geniposide-induced hepatotoxicity were identified using a label-free quantitative proteomics approach on a geniposide overdose-induced liver injury in a rat model. Using an accurate intensity-based, absolute quantification (iBAQ)-based, one-step discovery and verification approach, a candidate biomarker panel was easily obtained from individual samples in response to different conditions. To determine the biomarkers' early detection abilities, five candidate biomarkers were selected and tested using enzyme-linked immunosorbent assays (ELISAs). Two biomarkers, glycine N-methyltransferase (GNMT) and glycogen phosphorylase (PYGL), were found to indicate hepatic injuries significantly earlier than the current gold standard liver biomarker. This study provides a first insight into geniposide-induced hepatotoxicity in a rat model and describes a method for the earlier detection of this hepatotoxicity, facilitating the efficient monitoring of drug-induced hepatotoxicity.
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Polyyne Hybrid Compounds from Notopterygium incisum with Peroxisome Proliferator-Activated Receptor Gamma Agonistic Effects.
J. Nat. Prod.
PUBLISHED: 10-22-2014
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In the search for peroxisome proliferator-activated receptor gamma (PPAR?) active constituents from the roots and rhizomes of Notopterygium incisum, 11 new polyacetylene derivatives (1-11) were isolated. Their structures were elucidated by NMR and HRESIMS as new polyyne hybrid molecules of falcarindiol with sesquiterpenoid or phenylpropanoid moieties, named notoethers A-H (1-8) and notoincisols A-C (9-11), respectively. Notoincisol B (10) and notoincisol C (11) represent two new carbon skeletons. When tested for PPAR? activation in a luciferase reporter assay with HEK-293 cells, notoethers A-C (1-3), notoincisol A (9), and notoincisol B (10) showed promising agonistic activity (EC50 values of 1.7 to 2.3 ?M). In addition, notoincisol A (9) exhibited inhibitory activity on NO production of stimulated RAW 264.7 macrophages.
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Involvement of Endoplasmic Reticulum Stress in All-trans-retinal Induced Retinal Pigment Epithelium Degeneration.
Toxicol. Sci.
PUBLISHED: 10-20-2014
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Excess accumulation of endogenous all-trans-retinal (atRAL) contributes to degeneration of the retinal pigment epithelium (RPE) and photoreceptor cells, and plays a role in the etiologies of age-related macular degeneration (AMD) and Stargardt's disease. In this study, we reveal that human RPE cells tolerate exposure of up to 5 ?M atRAL without deleterious effects, but higher concentrations are detrimental and induce cell apoptosis. atRAL treatment significantly increased production of intracellular reactive oxygen species (ROS) and up-regulated mRNA expression of Nrf2, HO-1, and ?-GCSh within RPE cells, thereby causing oxidative stress. ROS localized to mitochondria and endoplasmic reticulum (ER). ER resident molecular chaperone BiP, a marker of ER stress, was up-regulated at the translational level, and meanwhile, the PERK-eIF2?-ATF4 signaling pathway was activated. Expression levels of ATF4, CHOP, and GADD34 in RPE cells increased in a concentration-dependent manner after incubation with atRAL. Salubrinal, a selective inhibitor of ER stress, alleviated atRAL-induced cell death. The antioxidant N-acetylcysteine (NAC) effectively blocked RPE cell loss and ER stress activation, suggesting that atRAL-induced ROS generation is responsible for RPE degeneration and is an early trigger of ER stress. Furthermore, the mitochondrial transmembrane potential was lost after atRAL exposure, and was followed by caspase-3 activation and PARP cleavage. The results demonstrate that atRAL-driven ROS overproduction induced ER stress is involved in cellular mitochondrial dysfunction and apoptosis of RPE cells.
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Nickel exposure is associated with the prevalence of type 2 diabetes in Chinese adults.
Int J Epidemiol
PUBLISHED: 10-18-2014
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Nickel exposure can induce hyperglycaemia in rodents, but little is known about its association with abnormal glucose metabolism in humans. We aimed to investigate the association of nickel exposure with the prevalence of type 2 diabetes in Chinese adults.
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Monitoring and risk assessment of 74 pesticide residues in Pu-erh tea produced in Yunnan, China.
Food Addit Contam Part B Surveill
PUBLISHED: 10-14-2014
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A number of 100 Pu-erh tea samples from the 2013 harvest in Yunnan Province (China) were analyzed for 74 pesticides. A total of 11 pesticides were detected. At least 1 pesticide was detected in 56% of the samples. None of the samples contained the 74 monitored pesticides at concentrations above Chinese maximum residual levels. Imidacloprid, bifenthrin and acetamiprid were most frequently found, with percentages of 53%, 46%, and 31%, respectively. These were also the top 3 pesticides with maximum concentrations of 140 ?g kg(-1), 246 ?g kg(-1) and 672 ?g kg(-1), respectively. Residual levels of the monitored pesticides showed no significant correlation with the production time or area of Pu-er tea. Whereas a high incidence of pesticide residues was detected in Pu-erh tea, the contamination levels observed do not pose serious health risks.
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Enhanced performance from a hybrid quenchometric deoxyribonucleic Acid (DNA) silica xerogel gaseous oxygen sensing platform.
Appl Spectrosc
PUBLISHED: 10-01-2014
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A complex of salmon milt deoxyribonucleic acid (DNA) and the cationic surfactant cetyltrimethylammonium (CTMA) forms an organic-soluble biomaterial that can be readily incorporated within an organically modified silane-based xerogel. The photoluminescence (PL) intensity and excited-state luminescence lifetime of tris(4,7'-diphenyl-1,10'-phenanathroline) ruthenium(II) [(Ru(dpp)3](2+), a common O2 responsive luminophore, increases in the presence of DNA-CTMA within the xerogel. The increase in the [Ru(dpp)3](2+)excited-state lifetime in the presence of DNA-CTMA arises from DNA intercalation that attenuates one or more non-radiative processes, leading to an increase in the [Ru(dpp)3](2+) excited-state lifetime. Prospects for the use of these materials in an oxygen sensor are demonstrated.
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Quantum Anomalous Hall Effect in Magnetically Doped InAs/GaSb Quantum Wells.
Phys. Rev. Lett.
PUBLISHED: 09-29-2014
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The quantum anomalous Hall effect has recently been observed experimentally in thin films of Cr-doped (Bi,Sb)_{2}Te_{3} at a low temperature (?30??mK). In this work, we propose realizing the quantum anomalous Hall effect in more conventional diluted magnetic semiconductors with magnetically doped InAs/GaSb type-II quantum wells. Based on a four-band model, we find an enhancement of the Curie temperature of ferromagnetism due to band edge singularities in the inverted regime of InAs/GaSb quantum wells. Below the Curie temperature, the quantum anomalous Hall effect is confirmed by the direct calculation of Hall conductance. The parameter regime for the quantum anomalous Hall phase is identified based on the eight-band Kane model. The high sample quality and strong exchange coupling make magnetically doped InAs/GaSb quantum wells good candidates for realizing the quantum anomalous Hall insulator at a high temperature.
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Facile synthesis of graphite nitrate-like ammonium vanadium bronzes and their graphene composites for sodium-ion battery cathodes.
Dalton Trans
PUBLISHED: 09-27-2014
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A simple and versatile method for preparation of new crystalline graphite nitrate-like ammonium vanadium bronze (NH4)0.19V2O5·0.44H2O nano-microstructures is developed via a simple hydrothermal route following heat treatment. (NH4)0.19V2O5·0.44H2O platelets are tested as a novel high-energy cathode material for sodium-ion batteries. The enhancement of electrochemical performance for a (NH4)0.19V2O5·0.44H2O platelet electrode is offered by addition of graphene and using graphite nitrate-like ammonium vanadium bronze microflowers. A graphene-based graphite nitrate-like vanadium bronze microflower composite shows a higher discharge capacity of 208.9 A h g(-1) for the second cycle in a 1.5-3.4 V voltage limit at a discharge current density of 20 mA g(-1). The reversible capacity of 141.5 A h g(-1) remained after 40 cycles.
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A real-time fluorescence polarization activity assay to screen for inhibitors of bacterial ribonuclease P.
Nucleic Acids Res.
PUBLISHED: 09-23-2014
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Ribonuclease P (RNase P) is an essential endonuclease that catalyzes the 5' end maturation of precursor tRNA (pre-tRNA). Bacterial RNase P is an attractive potential antibacterial target because it is essential for cell survival and has a distinct subunit composition compared to the eukaryal counterparts. To accelerate both structure-function studies and discovery of inhibitors of RNase P, we developed the first real-time RNase P activity assay using fluorescence polarization/anisotropy (FP/FA) with a 5' end fluorescein-labeled pre-tRNA(Asp) substrate. This FP/FA assay also detects binding of small molecules to pre-tRNA. Neomycin B and kanamycin B bind to pre-tRNA(Asp) with a Kd value that is comparable to their IC50 value for inhibition of RNase P, suggesting that binding of these antibiotics to the pre-tRNA substrate contributes to the inhibitory activity. This assay was optimized for high-throughput screening (HTS) to identify specific inhibitors of RNase P from a 2880 compound library. A natural product derivative, iriginol hexaacetate, was identified as a new inhibitor of Bacillus subtilis RNase P. The FP/FA methodology and inhibitors reported here will further our understanding of RNase P molecular recognition and facilitate discovery of antibacterial compounds that target RNase P.
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Elimination of sulphur odours at landfills by bioconversion and the corona discharge plasma technique.
Environ Technol
PUBLISHED: 09-23-2014
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Hydrogen sulphide (H2S) contributes a lot to odours at landfills, which is a threat to the environment and the health of the staff therein. To mitigate its emission, the bioconversion within landfill cover soils (LCSs) was introduced. H2S emission and concentration both in the field air above the landfill and in microcosm testing were surveyed. Results indicated that H2S emission and concentration in the landfill varied with landfill seasons and sites. There existed relationship between H2S concentration and fluxes spatially and temporally. To characterize and assess the spatial and temporal diversity of sulphur-oxidizing bacteria (SOB) and sulphate-reducing bacteria (SRB) in the LCSs, the terminal-restriction fragment length polymorphism technique was employed. Using the functional genes of dsrB and soxB, SOB, including Halothiobacillus, Rhodothalassium, Paracocccus, Allochromatium, and Thiobacillus, and SRB, including Desulfovibrio, Syntrophobacter, Desulfomonile and Desulfobacca, were identical and exhibited the dominant role in the LCSs. By employing an alternative available corona reactor, more than 90% removal efficiencies of sulphides were demonstrated, suggesting that the LCSs for eliminating odours in a lower concentration would be feasible.
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Efficacy, safety and tolerability of linezolid for the treatment of XDR-TB: a study in China.
Eur. Respir. J.
PUBLISHED: 09-20-2014
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Linezolid may be effective in treating multidrug-resistant tuberculosis and extensively drug-resistant tuberculosis. We conducted a prospective, multicentre, randomised study to further evaluate the efficacy, safety and tolerability of linezolid in patients with extensively drug-resistant tuberculosis in China. 65 patients who had culture-positive sputum for extensively drug-resistant tuberculosis were randomly assigned to a linezolid therapy group or a control group. Patients in the two groups adopted a 2-year individually based chemotherapy regimen. The linezolid therapy group was given linezolid at a start dose of 1200 mg per day for a period of 4-6 weeks and this was then followed by a dose of 300-600 mg per day. The proportion of sputum culture conversions in the linezolid therapy group was 78.8% by 24 months, significantly higher than that in the control group (37.6%, p<0.001). The treatment success rate in linezolid therapy group was 69.7%, significantly higher than that in the control group (34.4%, p = 0.004). 27 (81.8%) patients had clinically significant adverse events in the linezolid group, of whom 25 (93%) patients had events that were possibly or probably related to linezolid. Most adverse events resolved after reducing the dosage of linezolid or temporarily discontinuing linezolid. Linezolid containing chemotherapy for treatment of extensively drug-resistant tuberculosis may significantly promote cavity closure, increase sputum culture-conversion rate and improve treatment success rate.
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Phylogeography and evolution of a fungal-insect association on the Tibetan Plateau.
Mol. Ecol.
PUBLISHED: 09-18-2014
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Parasitoidism refers to a major form of interspecies interactions where parasitoids sterilize and/or kill their hosts typically before hosts reach reproductive age. However, relatively little is known about the evolutionary dynamics of parasitoidism. Here, we investigate the spatial patterns of genetic variation of Chinese cordyceps, including both the parasitoidal fungus Ophiocordyceps sinensis and its host insects. We sampled broadly from alpine regions on the Tibetan Plateau and obtained sequences on seven fungal and three insect DNA fragments from each of the 125 samples. Seven and five divergent lineages/cryptic species were identified within the fungus and host insects, respectively. Our analyses suggested that O. sinensis and host insects originated at similar geographic regions in southern Tibet/Yunnan, followed by range expansion to their current distributions. Cophylogenetic analyses revealed a complex evolutionary relationship between O. sinensis and its host insects. Significant congruence was found between host and parasite phylogenies and the time estimates of divergence were similar, raising the possibility of the occurrence of cospeciation events, but the incongruences suggested that host shifts were also prevalent. Interestingly, one fungal genotype was broadly distributed, consistent with recent gene flow. In contrast, the high-frequency insect genotypes showed limited geographic distributions. The dominant genotypes from both the fungus and the insect hosts may represent ideal materials from which to develop artificial cultivation of this important Chinese traditional medicine. Our results demonstrate that both historical and contemporary events have played important roles in the phylogeography and evolution of the O. sinensis-ghost moth parasitoidism on the Tibetan Plateau.
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Telbivudine or lamivudine use in late pregnancy safely reduces perinatal transmission of hepatitis B virus in real-life practice.
Hepatology
PUBLISHED: 09-18-2014
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Little observational data exist describing telbivudine (LdT) or lamivudine (LAM) use in late pregnancy for preventing hepatitis B mother-to-child transmission (MTCT) in real-world settings. During the period of January 2009 to March 2011, we enrolled hepatitis B e antigen-positive mothers with HBV DNA >6 log10 copies/mL in China. At gestation week 28, the mothers received LdT or LAM until postpartum week 4 or no treatment (NTx). The study endpoints were the safety of LdT/LAM use and MTCT rates. Of the 700 mothers enrolled, 648 (LdT/LAM/NTx?=?252/51/345) completed the 52-week study with 661 infants (LdT/LAM/NTx?=?257/52/352). On treatment, viral rebound occurred in 1.6% of mothers, all resulting from medication noncompliance. There was no genotypic mutation detected. At delivery, significantly lower HBV DNA levels were noted in mothers who received LdT or LAM versus NTx. Alanine aminotransferase flares were observed in 17.1% of treated mothers versus 6.3% of untreated mothers (P?
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Spatial and Temporal Analysis on the Distribution of Active Radio-Frequency Identification (RFID) Tracking Accuracy with the Kriging Method.
Sensors (Basel)
PUBLISHED: 09-13-2014
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Radio frequency identification (RFID) technology has already been applied in a number of areas to facilitate the tracking process. However, the insufficient tracking accuracy of RFID is one of the problems that impedes its wider application. Previous studies focus on examining the accuracy of discrete points RFID, thereby leaving the tracking accuracy of the areas between the observed points unpredictable. In this study, spatial and temporal analysis is applied to interpolate the continuous distribution of RFID tracking accuracy based on the Kriging method. An implementation trial has been conducted in the loading and docking area in front of a warehouse to validate this approach. The results show that the weak signal area can be easily identified by the approach developed in the study. The optimum distance between two RFID readers and the effect of the sudden removal of readers are also presented by analysing the spatial and temporal variation of RFID tracking accuracy. This study reveals the correlation between the testing time and the stability of RFID tracking accuracy. Experimental results show that the proposed approach can be used to assist the RFID system setup process to increase tracking accuracy.
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RLIP76 Blockade by siRNA Inhibits Proliferation, Enhances Apoptosis, and Suppresses Invasion in HT29 Colon Cancer Cells.
Cell Biochem. Biophys.
PUBLISHED: 09-13-2014
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RLIP76, a multidomain protein which is a downstream effector of the small GTP ases RalA and RalB, is known to play a role in biological activities in a variety of malignant cancer cells. However, little study has been done on the role of RLIP76 in CRC. In this study, a RLIP76-targeted siRNA-containing vector was used to investigate the effect of RLIP76 knockdown on cellular functions in human CRC cell line HT29. Quantitative RT-PCR and Western blot analysis revealed that the expression levels of RLIP76 mRNA and protein in HT29 cells were significantly suppressed after transfection. Our results indicated that RLIP76 downregulation in HT29 CRC cells suppressed cell growth, enhanced cell apoptosis, induced cell cycle arrest, and inhibited cell invasion by decreasing MMP2 expression. Although the mechanisms through which RLIP76 regulates the cellular functions needs further investigation, our results indicate that RLIP76 may represent as a potential target of gene therapy for CRC treatment.
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[Experimental study on relationship between pungent-hot herb property express and calmodulin].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 09-11-2014
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To explain the essence of pungent-hot herb property express according to in vivo and in vitro studies on its effect on calmodulin on the base of the observation of the adjustment in hypothalamic-pituitary-gonad axis functions of Aconiti Lateralis Radix Praeparata, Curculiginis Rhizoma, Cinnamomi Cortex and bitter-cold herb Phellodendri Chinensis Cortex in rats under the state of yang deficiency.
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Activation of RhoA-ROCK-BMP signaling reprograms adult human corneal endothelial cells.
J. Cell Biol.
PUBLISHED: 09-08-2014
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Currently there are limited treatment options for corneal blindness caused by dysfunctional corneal endothelial cells. The primary treatment involves transplantation of healthy donor human corneal endothelial cells, but a global shortage of donor corneas necessitates other options. Conventional tissue approaches for corneal endothelial cells are based on EDTA-trypsin treatment and run the risk of irreversible endothelial mesenchymal transition by activating canonical Wingless-related integration site (Wnt) and TGF-? signaling. Herein, we demonstrate an alternative strategy that avoids disruption of cell-cell junctions and instead activates Ras homologue gene family A (RhoA)-Rho-associated protein kinase (ROCK)-canonical bone morphogenic protein signaling to reprogram adult human corneal endothelial cells to neural crest-like progenitors via activation of the miR302b-Oct4-Sox2-Nanog network. This approach allowed us to engineer eight human corneal endothelial monolayers of transplantable size, with a normal density and phenotype from one corneoscleral rim. Given that a similar signal network also exists in the retinal pigment epithelium, this partial reprogramming approach may have widespread relevance and potential for treating degenerative diseases.
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Telbivudine or lamivudine use in late pregnancy safely reduces perinatal transmission of hepatitis B virus in real-life practice.
Hepatology
PUBLISHED: 09-05-2014
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Little observational data exist describing telbivudine (LdT) or lamivudine (LAM) use in late pregnancy for preventing hepatitis B mother-to-child transmission (MTCT) in real-world settings. During the period of January 2009 to March 2011, we enrolled hepatitis B e antigen-positive mothers with HBV DNA >6 log10 copies/mL in China. At gestation week 28, the mothers received LdT or LAM until postpartum week 4 or no treatment (NTx). The study endpoints were the safety of LdT/LAM use and MTCT rates. Of the 700 mothers enrolled, 648 (LdT/LAM/NTx=252/51/345) completed the 52-week study with 661 infants (LdT/LAM/NTx=257/52/352). On treatment, viral rebound occurred in 1.6% of mothers, all resulting from medication noncompliance. There was no genotypic mutation detected. At delivery, significantly lower HBV DNA levels were noted in mothers who received LdT or LAM versus NTx. Alanine aminotransferase flares were observed in 17.1% of treated mothers versus 6.3% of untreated mothers (P < 0.001). At birth, hepatitis B surface antigen (HBsAg) was detected in 20% and 24% of newborns in the treated and NTx groups, respectively. At week 52, an intention-to-treat analysis indicated 2.2% (95% confidence [CI]: 0.6-3.8) of HBsAg+ infants from the treated group versus 7.6% (95% CI: 4.9-10.3) in the NTx group (P50.001) and no difference of HBsAg+ rate between infants in the LdT and LAM groups(1.9% vs. 3.7%; P=0.758). On-treatment analysis indicated 0% of HBsAg+ infants in the treated group versus 2.84% in the NTx group (P=0.002). There were no differences for gestational age or infants' height, weight, Apgar scores, or birth defect rates between infants from the treated and untreated groups.
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[Determination of sulfonamide potentiators in animal origin foods by ultra performance liquid chromatography-tandem mass spectrometry].
Se Pu
PUBLISHED: 09-05-2014
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A method for the determination of sulfonamide potentiators, trimethoprim (TMP), diaveridine (DVD) and ormetoprin (OMP), in different animal origin food matrices (including chicken muscle, fish muscle, chicken liver, egg and milk) has been developed by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The sample was extracted by formic acid-acetonitrile (1:9, v/v), cleaned-up by hexane, separated on an Acquity UPLC BEH C18 column (50 mm x 2.1 mm, 1.7 microm) with gradient elution. The determination was carried out with electrospray ion source under the positive mode and multiple reaction monitoring (MRM) mode. The extraction recoveries of three extraction solvents were observed. The purification condition and concentration condition were optimized. In addition, the mobile phase, column temperature and solid phase extraction column were studied. The calibration curves showed a good linearity in the range of 1.25-30.0 microg/L, and the correlation coefficients (r) were higher than 0.99. The limits of quantification (LOQ, S/N = 10) of the three potentiators were 5.0 microg/kg. At the spiked levels of 5.0, 10.0 and 20.0 microg/kg, the recoveries of the three potentiators were ranged from 61.2% to 108.5%, and the relative standard deviations (RSD, n = 6) ranged from 1.1% to 9.8%. The results indicate that the method is simple, rapid, sensitive and suitable for the qualitative and quantitative analysis of the three potentiators in multiple matrices.
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Combination of vaccine-strain measles and mumps virus synergistically kills a wide range of human hematological cancer cells: Special focus on acute myeloid leukemia.
Cancer Lett.
PUBLISHED: 09-01-2014
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Through combining vaccine-derived measles and mumps viruses (MM), we efficiently targeted a wide range of hematopoietic cancer cell lines. MM synergistically killed many cell lines including acute myeloid leukemia (AML) cell lines. Further investigation suggested that enhanced oncolytic effect of MM was due to increased apoptosis induction. In an U937 xenograft AML mouse model, MM displayed greater tumor suppression and prolonged survival. Furthermore, MM efficiently killed blasts from 16 out of 20 AML patients and elicited more efficient killing effect on 11 patients when co-administered with Ara-C. Our results demonstrate that MM is a promising therapeutic candidate for hematological malignancies.
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[Changes of regulatory T cells related to CCl?-induced liver fibrosis in mice].
Zhonghua Gan Zang Bing Za Zhi
PUBLISHED: 09-01-2014
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To investigate liver fibrosis-related changes of CD4?CD25?Foxp3+ regulatory T cells (Tregs) in peripheral blood and in liver-infiltrating lymphocytes (LILs) using a mouse model.
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[Study on reductive surgery for pelvic organ prolapse concomitant with anti-incontinence sling for treatment of occult stress urinary incontinence].
Zhonghua Fu Chan Ke Za Zhi
PUBLISHED: 08-30-2014
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To evaluate the clinical outcome of anti-incontinence sling in the treatment of occult stress urinary incontinence (OSUI) during reductive surgery for advanced pelvic organ prolapse (POP).
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[Anatomic investigation of the pedicle fat grafts with the third lumbar segmental artery and its application in reoperation for lumbar disc herniation].
Zhongguo Gu Shang
PUBLISHED: 08-30-2014
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To investigate the blood supply of the pedicle fat grafts with the third lumbar segmental artery and its clinical effects on reoperation for lumbar disc herniation.
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Tetrandrine induces G1/S cell cycle arrest through the ROS/Akt pathway in EOMA cells and inhibits angiogenesis in vivo.
Int. J. Oncol.
PUBLISHED: 08-29-2014
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Tetrandrine, a bisbenzylisoquinoline alkaloid, is known to inhibit tumor cell proliferation and induce apoptosis in cancer models in vitro and in vivo. In the present study, tetrandrine significantly inhibited the proliferation of mouse endothelial cells (EOMA cell) and induced G1/S arrest in EOMA cells, in which the expressions of cyclin D and cyclin E and CDKs were downregulated. Tetrandrine treatment also caused intracellular accumulation of reactive oxygen species (ROS). Pretreatment with NAC, which is a ROS inhibitor, blocked G1/S cell arrest and cyclin regulation induced by tetrandrine, implying that ROS generation plays an important role in tetrandrine-induced cell cycle arrest. Furthermore, a decreased phospho-Akt protein level after tetrandrine treatment was reversible with the removal of the intracellular ROS by NAC. Notably, overexpression of Akt decreased tetrandrine-induced G1/S arrest. Finally, we verified the antiangiogenic effects of tetrandrine in vivo in a liver cancer xenograft model in nude mice. In conclusion, tetrandrine inhibits EOMA cell growth through the ROS/Akt pathway, and it could be a promising compound for cancer therapy as an inhibitor of tumor vascular growth.
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Association of variants in KCNK17 gene with ischemic stroke and cerebral hemorrhage in a Chinese population.
J Stroke Cerebrovasc Dis
PUBLISHED: 08-29-2014
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KCNK17 (potassium channel, subfamily K, member17) has a role in the pathogenesis of stroke. We reported previously that rs10947803 single-nucleotide polymorphism (SNP) in KCNK17 is associated with cerebral hemorrhage in a Chinese population. The aim of the present study was to examine other SNPs in the KCNK17 gene that are associated with cerebral hemorrhage and other subtypes of stroke in the Chinese population.
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Dual role of photosensitizer and carrier material of fullerene in micelles for chemo-photodynamic therapy of cancer.
J Pharm Sci
PUBLISHED: 08-29-2014
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Derivatives of fullerene (C60) as photosensitizers have rarely been studied as delivery carrier materials. The focus of this study was to explore the potential advantages of diadduct malonic acid-fullerene (DMA-C60) as delivery carrier materials and combination of chemo-phototherapy of some tumors. In this study, DMA-C60 and docetaxel (DTX) were coentrapped in micelles (MCs) (DMA-C60/DTX-MC). The addition of DMA-C60 could obviously improve static stability and decrease critical MC concentration of DTX-MC without hemolysis. The sustained release of DTX and DMA-C60 could be achieved, following Higuichi and first-order model, respectively. DMA-C60 could still produce reactive oxygen species efficiently in HeLa cells after encapsulation in MC. The addition of DMA-C60 under irradiation caused DTX-MC more stronger cytotoxicity, cell cycle changes, and more early apoptotic cells in vitro. More importantly, after intravenous injection, the addition of DMA-C60 in DTX-MC could result in 2.25-fold and 4.57-fold longer mean residence time compared with DTX-MC and Duopafei(®) , increase drug intratumoral distribution and decrease drug distribution in heart and kidney, and enhance antitumor effect under irradiation without body weight loss. These results suggested tremendous promise of DMA-C60 as carrier materials of MC and significant advantages in combination of chemo-phototherapy of some tumors. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3225-3234, 2014.
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Maximal likelihood correspondence estimation for face recognition across pose.
IEEE Trans Image Process
PUBLISHED: 08-28-2014
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Due to the misalignment of image features, the performance of many conventional face recognition methods degrades considerably in across pose scenario. To address this problem, many image matching-based methods are proposed to estimate semantic correspondence between faces in different poses. In this paper, we aim to solve two critical problems in previous image matching-based correspondence learning methods: 1) fail to fully exploit face specific structure information in correspondence estimation and 2) fail to learn personalized correspondence for each probe image. To this end, we first build a model, termed as morphable displacement field (MDF), to encode face specific structure information of semantic correspondence from a set of real samples of correspondences calculated from 3D face models. Then, we propose a maximal likelihood correspondence estimation (MLCE) method to learn personalized correspondence based on maximal likelihood frontal face assumption. After obtaining the semantic correspondence encoded in the learned displacement, we can synthesize virtual frontal images of the profile faces for subsequent recognition. Using linear discriminant analysis method with pixel-intensity features, state-of-the-art performance is achieved on three multipose benchmarks, i.e., CMU-PIE, FERET, and MultiPIE databases. Owe to the rational MDF regularization and the usage of novel maximal likelihood objective, the proposed MLCE method can reliably learn correspondence between faces in different poses even in complex wild environment, i.e., labeled face in the wild database.
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Ageing related periostin expression increase from cardiac fibroblasts promotes cardiomyocytes senescent.
Biochem. Biophys. Res. Commun.
PUBLISHED: 08-27-2014
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Periostin, as an extracellular matrix (ECM) protein, plays a critical role in myocardial fibrosis and also might be involved in the heart inflammatory process since it is a downstream molecule of IL4 and IL13. Considering the possible important role of periostin in heart aging, this study explored periostin expression pattern in both rat and human, the effect of periostin expression on cardiomyocyte senescent and expression of three cytokines (IL13, IL4 and IL6) in different age groups of human. This study found heart aging is associated with increased expression of periostin from cardiac fibroblasts and serum inflammatory cytokines (IL13 and IL6). Excessive periostin expression contributed to cardiomyocyte senescent, which could be alleviated through blocking the Ang-II-TGF ?1-MAPK/ERK pathway. Thus, periostin might play an important role in a vicious circle (aging-fibrosis-inflammation-aging) of heart through promoting myocardial fibrosis and cardiomyocyte senescent simultaneously. It is a potential aging marker that could be directly measured in serum.
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Evidence of Preserved Oxidative Capacity and Oxygen Delivery in the Plantar Flexor Muscles With Age.
J. Gerontol. A Biol. Sci. Med. Sci.
PUBLISHED: 08-27-2014
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Studies examining the effect of aging on skeletal muscle oxidative capacity have yielded equivocal results; however, these investigations may have been confounded by differences in oxygen (O2) delivery, physical activity, and small numbers of participants. Therefore, we evaluated skeletal muscle oxidative capacity and O2 delivery in a relatively large group (N = 40) of young (22 ± 2 years) and old (73 ± 7 years) participants matched for physical activity. After submaximal dynamic plantar flexion exercise, phosphocreatine (PCr) resynthesis ((31)P magnetic resonance spectroscopy), muscle reoxygenation (near-infrared spectroscopy), and popliteal artery blood flow (Doppler ultrasound) were measured. The phosphocreatine recovery time constant (Tau) (young: 33 ± 16; old: 30 ± 11 seconds), maximal rate of adenosine triphosphate (ATP) synthesis (young: 25 ± 9; old: 27 ± 8 mM/min), and muscle reoxygenation rates determined by the deoxyhemoglobin/myoglobin recovery Tau (young: 48 ± 5; old: 47 ± 9 seconds) were similar between groups. Similarly, although tending to be higher in the old, there were no significant age-related differences in postexercise popliteal blood flow (area under the curve: young: 1,665 ± 227 vs old: 2,404 ± 357mL, p = .06) and convective O2 delivery (young: 293 ± 146 vs old: 404 ± 191 mL, p = .07). In conclusion, when physical activity and O2 delivery are similar, oxidative capacity in the plantar flexors is not affected by aging. These findings reveal that diminished skeletal muscle oxidative capacity is not an obligatory accompaniment to the aging process.
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[Early screening of developmental dysplasia of the hip among hospitalized children].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 08-23-2014
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To summarize retrospectively developmental dysplasia of the hip (DDH) screening of children within 36 months.
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Association of CVD candidate gene polymorphisms with ischemic stroke and cerebral hemorrhage in Chinese individuals.
PLoS ONE
PUBLISHED: 08-21-2014
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Contribution of cardiovascular disease related genetic risk factors for stroke are not clearly defined. We performed a genetic association study to assess the association of 56 previously characterized gene variants in 34 candidate genes from cardiovascular disease related biological pathways with ischemic stroke and cerebral hemorrhage in a Chinese population.
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Inhibition of lung tumor growth by targeting EGFR/VEGFR-Akt/NF-?B pathways with novel theanine derivatives.
Oncotarget
PUBLISHED: 08-21-2014
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The molecularly targeted agents, including anti-VEGF or anti-EGFR monoclonal antibody and some inhibitors of EGFR tyrosine kinase, are effective in the treatment of non-small-cell lung cancer (NSCLC) to a certain extent, but the benefit for a proportion of patients is still limited. Hence, it is necessary and urgent to develop more selective and effective molecular targeted agents against lung cancer. Here, we have synthesized novel theanine derivatives, methyl coumarin-3-carboxylyl L-theanine (TMC), ethyl coumarin-3-carboxylyl L-theanine (TEC), ethyl 6-fluorocoumarin- 3-carboxylyl L-theanine (TFC), and ethyl 6-nitrocoumarin-3-carboxylyl L-theanine (TNC), which are fluorescent small molecules, based on their parental compound theanine and studied their anticancer activities in vitro, ex vivo and in vivo models of human and mouse cancers. Our results show that the four theanine derivatives significantly inhibit the lung cancer cell migration and the growth of lung cancer and leukemia cell lines. TFC and TNC display enhanced effects with anticancer drugs cytarabine vincristine, andmethotrexate on inhibition of lung cancer cell growth and no toxicity to the normal human embryonic lung fibroblast and peripheral blood lymphocytes. TFC and TNC exhibit strong suppression of the highly metastatic Lewis lung cancer (LLC) and A549 tumor growth in tumor-bearing mice without toxicity to mice. TFC and TNC can effectively suppress the growth of lung cancer cells in vitro, ex vivo and in vivo by targeting EGFR/VEGFR-Akt/NF-?B pathways. Our study has suggested that TFC and TNC may have the therapeutic and/or adjuvant therapeutic applications in the treatment of lung cancers and other cancer.
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Cellular Requirements for Bovine Immunodeficiency Virus Vif-Mediated Inactivation of Bovine APOBEC3 Proteins.
J. Virol.
PUBLISHED: 08-20-2014
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Human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV) viral infectivity factor (Vif) form a CRL5 E3 ubiquitin ligase complex to suppress virus restriction by host APOBEC3 (A3) proteins. The primate lentiviral Vif complex is composed of the unique cofactor core binding factor ? (CBF-?) and canonical ligase components Cullin 5 (CUL5), Elongin B/C (ELOB/C), and RBX2. However, the mechanism by which the Vif protein of the related lentivirus bovine immunodeficiency virus (BIV) overcomes its host A3 proteins is less clear. In this study, we show that BIV Vif interacts with Cullin 2 (CUL2), ELOB/C, and RBX1, but not with CBF-? or CUL5, to form a CRL2 E3 ubiquitin ligase and degrade the restrictive bovine A3 proteins (A3Z2Z3 and A3Z3). RNA interference-mediated knockdown of ELOB or CUL2 inhibited BIV Vif-mediated degradation of these A3 proteins, whereas knockdown of CUL5 or CBF-? did not. BIV Vif with mutations in the BC box (Vif SLQ-AAA) or putative VHL box (Vif YI-AA), which cannot interact with ELOB/C or CUL2, respectively, lost the ability to counteract bovine A3 proteins. Moreover, CUL2 and UBE2M dominant negative mutants competitively inhibited the BIV Vif-mediated degradation mechanism. Thus, although the general strategy for inhibiting A3 proteins is conserved between HIV-1/SIV and BIV, the precise mechanisms can differ substantially, with only the HIV-1/SIV Vif proteins requiring CBF-? as a cofactor, HIV-1/SIV Vif using CUL5-RBX2, and BIV Vif using CUL2-RBX1.
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Recent advances of stem cell therapy for retinitis pigmentosa.
Int J Mol Sci
PUBLISHED: 08-20-2014
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Retinitis pigmentosa (RP) is a group of inherited retinal disorders characterized by progressive loss of photoreceptors and eventually leads to retina degeneration and atrophy. Until now, the exact pathogenesis and etiology of this disease has not been clear, and many approaches for RP therapies have been carried out in animals and in clinical trials. In recent years, stem cell transplantation-based attempts made some progress, especially the transplantation of bone marrow-derived mesenchymal stem cells (BMSCs). This review will provide an overview of stem cell-based treatment of RP and its main problems, to provide evidence for the safety and feasibility for further clinical treatment.
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[Anaplastic lymphoma kinase fusion gene expression, clinical pathological characteristics and prognosis in 95 Chinese patients with non-small cell lung cancer].
Beijing Da Xue Xue Bao
PUBLISHED: 08-19-2014
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To examine the prevalence of anaplastic lymphoma kinase (ALK) fusion gene in Chinese patients with non-small cell lung cancer (NSCLC).
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[JAK2V617F mutation and TNF-? expression in myeloproliferative neoplasms and their correlation].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 08-19-2014
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This study was aimed to explore the JAK2V617F mutation and TNF-? expression in patients with myeloproliferative neoplasm (MPN), and the relation between them so as to provide theoretical basis for clinical practice and target therapy. Sixty-two confirmed BCR-ABL-negative MPN patients and 15 healthy adults were enrolled in this study. The peripheral blood mononuclear cells of the patients and healthy controls were divided into two parts, one part was used to extract DNA, the other one was used to extract mRNA and reverse-transcribe into cDNA. Real-time fluorescent quantitative PCR was used to detect JAK2V617F mutation proportion and the expression level of TNF-?. The results showed that the positive rate of JAK2V617F mutation in MPN patients was 64.52% (40/62) , including 54.28% in essential thrombocythemia (ET) patients (19/35), 94.74% in polycythemia vera (PV) patients (18/19) and 37.50% in myelofibrosis (MF) (3/8) patients. Mutation proportions of JAK2V617F in ET, PV and MF patients were 0.838 ± 0.419, 4.417 ± 0.658, 2.746 ± 2.009 respectively. The expression of TNF-? in ET, PV and MF patients were higher than that in healthy controls: 1.7, 7.0, 8.2-fold (P < 0.05) respectively. In addition, TNF-? expression was correlated with JAK2V617F allele burden (Pearson r = 0.610,R(2) = 0.372,P = 0.005). It is concluded that TNF-? plays an important role in the pathogenesis of MPN, the TNF-? expression increases and is different in ET,PV and MF patients,which correlates with JAK2V617F allele burden.
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Controlled Growth of Few-Layer Hexagonal Boron Nitride on Copper Foils Using Ion Beam Sputtering Deposition.
Small
PUBLISHED: 08-18-2014
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Ion beam sputtering deposition (IBSD) is used to synthesize high quality few-layer hexagonal boron nitride (h-BN) on copper foils. Compared to the conventional chemical vapor deposition, the IBSD technique avoids the use of unconventional precursors and is much easier to control, which should be very useful for the large-scale production of h-BN in the future.
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Involvement of threonine deaminase FgIlv1 in isoleucine biosynthesis and full virulence in Fusarium graminearum.
Curr. Genet.
PUBLISHED: 08-17-2014
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In this study we characterized FgIlv1, a homologue of the Saccharomyces cerevisiae threonine dehydratase (TD) from the important Fusarium head blight fungus Fusarium graminearum. TD catalyzes the first step in the biosynthesis pathway of isoleucine (Ile) for conversion of threonine (Thr) to 2-ketobutyrate (2-KB). The FgILV1 deletion mutant ?FgIlv1-3 was unable to grow on minimal medium or fructose gelatin agar which lacked Ile. Exogenous supplementation of Ile or 2-KB but not Thr rescued the mycelial growth defect of ?FgIlv1-3, indicating the involvement of FgIlv1 in the conversion of Thr to 2-KB in Ile biosynthesis. Additionally, exogenous supplementation of Methionine (Met) could also rescue the mycelial growth defect of ?FgIlv1-3, indicating a crosstalk between Ile biosynthesis and Met catabolism in F. graminearum. Deletion of FgILV1 also caused defects in conidial formation and germination. In addition, ?FgIlv1-3 displayed decreased virulence on wheat heads and a low level of deoxynivalenol (DON) production in wheat kernels. Taken together, results of this study indicate that FgIlv1 is an essential component in Ile biosynthesis and is required for various cellular processes including mycelial and conidial morphogenesis, DON biosynthesis, and full virulence in F. graminearum. Our data indicate the potential of targeting Ile biosynthesis for anti-FHB management.
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Impact of cellular immune function on prognosis of lung cancer patients after cytokine-induced killer cell therapy.
Asian Pac. J. Cancer Prev.
PUBLISHED: 08-16-2014
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To investigate changes in cellular immune function of patients with lung cancer before and after cytokine- induced killer (CIK) cell therapy and to identify variation effects on overall survival (OS) and progression-free survival (PFS).
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E-cadherin and gastric cancer: cause, consequence, and applications.
Biomed Res Int
PUBLISHED: 08-12-2014
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E-cadherin (epithelial-cadherin), encoded by the CDH1 gene, is a transmembrane glycoprotein playing a crucial role in maintaining cell-cell adhesion. E-cadherin has been reported to be a tumor suppressor and to be down regulated in gastric cancer. Besides genetic mutations in CDH1 gene to induce hereditary diffuse gastric cancer (HDGC), epigenetic factors such as DNA hypermethylation also contribute to the reduction of E-cadherin in gastric carcinogenesis. In addition, expression of E-cadherin could be mediated by infectious agents such as H. pylori (Helicobacter pylori). As E-cadherin is vitally involved in signaling pathways modulating cell proliferation, survival, invasion, and migration, dysregulation of E-cadherin leads to dysfunction of gastric epithelial cells and contributes to gastric cancer development. Moreover, changes in its expression could reflect pathological conditions of gastric mucosa, making its role in gastric cancer complicated. In this review, we summarize the functions of E-cadherin and the signaling pathways it regulates. We aim to provide comprehensive perspectives in the molecular mechanism of E-cadherin and its involvement in gastric cancer initiation and progression. We also focus on its applications for early diagnosis, prognosis, and therapy in gastric cancer in order to open new avenues in this field.
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Neolignans, lignans and glycoside from the fruits of Melia toosendan.
Fitoterapia
PUBLISHED: 07-24-2014
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Four new neolignans, meliasendanins A-D (1-4), and a new glycoside, toosenoside A (5), together with ten known ones (6-15), were isolated from a n-BuOH partition of the fruits of Melia toosendan. Their structures were elucidated by analyses of extensive spectroscopic data and comparison of the NMR data with those reported previously. Meliasendanin A (1) was a rare neolignan containing isochroman moiety, and its absolute configuration was determined using a CD spectrum. Toosenoside A (5) was an unusual glycoside with a rare naturally occurring aglycone and its structure was confirmed by X-ray single crystal diffraction analysis. The antioxidant activity of the isolated neolignans and lignans was evaluated by ABTS radical-scavenging assay. Compounds 1 and 13 exhibited strong antioxidant activity, with IC50 values of 62.8 and 45.1?M, respectively.
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The Pro12Ala Polymorphism of PPAR-? Gene Is Associated with Sepsis Disease Severity and Outcome in Chinese Han Population.
PPAR Res
PUBLISHED: 07-20-2014
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Peroxisome proliferator-activated receptor-? (PPAR-?) is a ligand-binding nuclear receptor, and its activation plays a prominent role in regulating the inflammatory response. Therefore, PPAR-? has been suggested as a candidate gene for sepsis. In the present study, we investigated the association between the Pro12Ala polymorphism of PPAR-? and sepsis in a Han Chinese population. A total of 308 patients with sepsis and 345 healthy controls were enrolled in this study. Genotyping was performed using the polymerase chain reaction-ligation detection reaction (PCR-LDR) method. No significant differences were detected in the allele and genotype distributions of the PPAR-? Pro12Ala SNP between septic patients and controls (P = 0.622 for genotype; P = 0.629 for allele). However, stratification by subtypes (sepsis, septic shock, and severe sepsis) revealed a statistically significant difference in the frequency of the Ala allele and Ala-carrier genotype between the patients with the sepsis subtype and the healthy controls (P = 0.014 for allele and P = 0.012, for genotype). Moreover, significant differences were found in the frequency of the Ala allele and genotype between the sepsis survivors and nonsurvivors (all P = 0.002). In the survivors, the PPAR-? Pro12Ala genotype was significantly associated with decreased disease severity and recovery time (all P < 0.001). Thus, genetic polymorphism is thought to play a role in the development and outcome of sepsis.
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Detecting network communities beyond assortativity-related attributes.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 07-10-2014
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In network science, assortativity refers to the tendency of links to exist between nodes with similar attributes. In social networks, for example, links tend to exist between individuals of similar age, nationality, location, race, income, educational level, religious belief, and language. Thus, various attributes jointly affect the network topology. An interesting problem is to detect community structure beyond some specific assortativity-related attributes ?, i.e., to take out the effect of ? on network topology and reveal the hidden community structures which are due to other attributes. An approach to this problem is to redefine the null model of the modularity measure, so as to simulate the effect of ? on network topology. However, a challenge is that we do not know to what extent the network topology is affected by ? and by other attributes. In this paper, we propose a distance modularity, which allows us to freely choose any suitable function to simulate the effect of ?. Such freedom can help us probe the effect of ? and detect the hidden communities which are due to other attributes. We test the effectiveness of distance modularity on synthetic benchmarks and two real-world networks.
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Does an analysis of polychlorinated biphenyl (PCB) distribution in mountain soils across China reveal a latitudinal fractionation paradox?
Environ. Pollut.
PUBLISHED: 07-09-2014
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Organic and mineral soil horizons from forests in 30 mountains across China were analysed for polychlorinated biphenyl (PCB). Soil total organic carbon (TOC) content was a key determinant of PCB distribution explaining over 90% of the differences between organic and mineral soils, and between 30% and 60% of the variance along altitudinal and regional transects. The residual variance (after normalization by TOC) was small. Tri- to tetra-CB levels were higher in the South in relation to high source density and precipitation. Heavier congeners were instead more abundant at mid/high-latitudes where the advection pattern was mainly from long range transport. This resulted in a latitudinal fractionation opposite to theoretical expectations. The study showed that exposure to sources with different characteristics, and possibly accumulation/degradation trends of different congeners in soils being out-of-phase at different latitudes, can lead to an unsteady large scale distribution scenario conflicting with the thermodynamic equilibrium perception.
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Synthesis, Crystal Structure, and Biological Activities of Two Chiral Mononuclear Mn((III)) Complexes.
Chirality
PUBLISHED: 06-23-2014
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Two new chiral mononuclear Mn((III)) complexes, [MnL((R)) Cl (C2 H5 OH)]•C2 H5 OH (1) and [MnL((S)) (CH3 OH)2 ]Cl•CH3 OH (2), {H2 L?=?(R,R)-or (S,S)-N,N'-bis-(2-hydroxy-1-naphthalidehydene)-cyclohexanediamine} were synthesized and characterized by various physicochemical techniques. Bond valence sum (BVS) calculations and the Jahn-Teller effect indicate that the Mn centers are in a +3 oxidation state. The statuses of the two complexes in the solution were confirmed as a pair of enantiomers by electrospray ionization, mass spectrometry (ESI-MS) spectrum. The binding ability of the complexes with calf thymus CT-DNA was investigated by spectroscopic and viscosity measurements. Both of the complexes could interact with CT-DNA via an intercalative mode with the order of 1 (R-enantiomer) >2 (S-enantiomer). Under the physiological conditions, the two compounds exhibit efficient DNA cleavage activities without any external agent, which also follows the order of R-enantiomer?>?S-enantiomer. Interestingly, the concentration-dependent DNA cleavage experiments indicate an optimal concentration of 17.5??M. In addition, the interaction of the compounds with bovine serum albumin (BSA) was also investigated, which indicated that the complexes could quench the intrinsic fluorescence of BSA by a static quenching mechanism. Chirality 00:000-000, 2014. © 2014 Wiley Periodicals, Inc.
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LRP5 polymorphism-A potential predictor of the clinical outcome in advanced gastric cancer patients treated with EOF regimen.
Chin. J. Cancer Res.
PUBLISHED: 06-10-2014
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Wnt pathways control key biological processes that potentially impact on tumor progression and patient survival. The present study analyzed the polymorphism of lipoprotein-related receptor 5 (LRP5) (gene with key functions in Wnt signaling) and its impact on the response to chemotherapy and survival of patients with advanced gastric cancer (AGC).
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Preparation of oxidized agar and characterization of its properties.
Carbohydr Polym
PUBLISHED: 06-10-2014
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A series of oxidized agars with different carboxyl content were prepared, and their properties were determined and analyzed. The results showed that the gelling temperature, the optical rotation and the apparent viscosity of the agar solution, and the melting temperature, the strength, the hardness, the fracturability, the springiness, the chewiness and the gumminess of agar gel all decreased except that the cohesiveness increased after oxidation. The gel skeleton structures of agar before and after oxidation were all of the porous network structures, but the pores of gel skeleton structure became smaller and denser after oxidation.
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Suberoylanilide hydroxamic acid (SAHA) and cladribine synergistically induce apoptosis in NK-LGL leukaemia.
Br. J. Haematol.
PUBLISHED: 06-06-2014
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Natural killer (NK) large granular lymphocyte (LGL) leukaemia features a clonal proliferation of CD3(-) NK cells that can be classified into either aggressive or chronic categories. The NKL cell line, derived from an aggressive Asian NK cell leukaemia, and patient samples from chronic NK-LGL leukaemia were used in our study to probe for synergistic efficacy of the epigenetic drugs vorinostat (SAHA) and cladribine in this disease. We demonstrate that histone deacetylases (HDACs) are over-expressed in both aggressive and chronic NK leukaemia. Administration of the HDAC inhibitor SAHA reduces class I and II HDAC expression and enhances histone acetylation in leukaemic NK cells. In vitro combination treatment with SAHA and cladribine dose-dependently exerts synergistic cytotoxic and apoptotic effects on leukaemic NK cells. Expression profiling of apoptotic regulatory genes suggests that both compounds led to caspase-dependent apoptosis through activation of intrinsic mitochondrial and extrinsic death receptor pathways. Collectively, these data show that combined epigenetic therapy, using HDAC and DNA methyltransferase inhibitors, may be a promising therapeutic approach for NK-LGL leukaemia.
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Extraction, preliminary characterization and evaluation of in vitro antitumor and antioxidant activities of polysaccharides from Mentha piperita.
Int J Mol Sci
PUBLISHED: 05-26-2014
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This study describes the extraction, preliminary characterization and evaluation of the in vitro antitumor and antioxidant activities of polysaccharides extracted from Mentha piperita (MPP). The optimal parameters for the extraction of MPP were obtained by Box-Behnken experimental design and response surface methodology (RSM) at the ratio of water to raw material of 20, extraction time of 1.5 h and extraction temperature at 80 °C. Chemical composition analysis showed that MPP was mainly composed of glucuronic acid, galacturonic acid, glucose, galactose and arabinose, and the molecular weight of its two major fractions were estimated to be about 2.843 and 1.139 kDa, respectively. In vitro bioactivity experiments showed that MPP not only inhibited the growth of A549 cells but possessed potent inhibitory action against DNA topoisomerase I (topo I), and an appreciative antioxidant action as well. These results indicate that MPP may be useful for developing safe natural health products.
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Quantitative SERS detection of low-concentration aromatic polychlorinated biphenyl-77 and 2,4,6-trinitrotoluene.
J. Hazard. Mater.
PUBLISHED: 05-21-2014
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This paper reports a simple label-free high-sensitive method for detecting low-concentration persistent organic pollutants and explosive materials. The proposed method combines surface-enhanced Raman spectroscopy (SERS) and magnetomotive enrichment of the target molecules on the surface of Ag nanoparticles (NPs). This structure can be achieved through self-assembling integration of Ag NPs with ferromagnetic Fe3O4 microspheres, forming a hybrid SERS nanoprobe with both optical and magnetic properties. Moreover, the magnetic response of ferromagnetic Fe3O4 microspheres can be used to dynamically modulate the optical property of Ag NPs through controlling their geometric arrangement on the substrate by applying an external magnetic field. It is also demonstrated from the full-wave numerical simulation results that the maximum electromagnetic field enhancement can be greatly increased by shortening the distance of neighboring Ag NPs and therefore resulting in an improved SERS detecting limit. More importantly, by using the prepared substrate, the SERS signals from organic pollution substances, i.e. aromatic polychlorinated biphenyl-77 and 2,4,6-trinitrotoluene, were quantitatively analyzed.
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Using skin for drug delivery and diagnosis in critically ill.
Adv. Drug Deliv. Rev.
PUBLISHED: 05-19-2014
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Skin offers easy access, convenience and non-invasiveness for drug delivery and diagnosis. In principle, these advantages of skin appear to be attractive for critically ill patients given potential difficulties that may be associated with oral and parenteral access in these patients. However, the profound changes in skin physiology that can be seen in these patients provide a challenge to reliably deliver drugs or provide diagnostic information. Drug delivery through skin may be used to manage burn injury, wounds, infection, trauma and the multisystem complications that rise from these conditions. Local anaesthetics and analgesics can be delivered through skin and may have wide application in critically ill patients. To ensure accurate information, diagnostic tools require validation in the critically ill patient population as information from other patient populations may not be applicable.
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Enhanced Expression of Recombinant Elastase in Pichia pastoris through the Substitution of Thr for Ser in Asn-Xaa-Ser Sequons.
Appl. Biochem. Biotechnol.
PUBLISHED: 05-12-2014
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N-glycosylation usually occurs at the Asn-Xaa-Ser/Thr sequon of glycoproteins in Pichia pastoris, exerting great effects on expression efficiency; however, Asn-Xaa-Thr is more efficiently glycosylated than Asn-Xaa-Ser. In this study, the role of the two sequons in the expression of recombinant elastase (rPAE) was investigated. At N43, N212, and N280 of rPAE, Asn-Xaa-Thr was substituted for the native Asn-Xaa-Ser sequon through site-directed mutagenesis, and the two sequon forms were introduced into rPAE at N36 and N264. As expected, substitution at N36, N43, N212, and N280 enhanced the degree of N-glycosylation. At N212 or N280, substitution increased rPAE production effectively by 43 and 25 %, respectively. In comparison, at N36, N43, and N264, the change inhibited rPAE expression to varying extents; specifically, substitution at N36 resulted in a 31 % decrease, while substitution at N43 or N264 resulted in a decrease of less than 9 %. It is suggested that the effect of the substitution of Asn-Xaa-Thr for Asn-Xaa-Ser on rPAE expression is roughly related to the role of the original Asn-Xaa-Ser sequon. As the conversion of Ser to Thr at N-glycosylation sites through site-directed mutagenesis is easily achieved, it is a feasible means of improving the expression of recombinant proteins in P. pastoris.
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An evaluation of genotoxicity and cytotoxicity of melamine in combination with cyanuric Acid at three mass ratios.
Biomed. Environ. Sci.
PUBLISHED: 05-11-2014
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Melamine in combination with cyanuric acid has been considered to be more toxic than either melamine or cyanuric acid alone. The objective of this study was designed to evaluate the combined genotoxicity and cytotoxicity of melamine (M) and cyanuric acid (C) at three mass ratios (1:1, 1:2, 2:1). MC (1:1), MC (1:2), and MC (2:1) were evaluated for their potential genotoxic risk, at gene level by Ames test, and at chromosomal level by micronucleus test. In order to evaluate cytotoxicity in HEK-293 cells, the MTT assay was included. Western blot was also employed to investigate the renal injury molecule-1 (Kim-1) expression in HEK-293 cells exposed to MC. Neither genotoxicity at gene level nor at chromosomal level was observed for MC (1:1), MC (1:2), and MC (2:1). Based on MTT assay, three ratios of MC at 82.5 and 165 µg/mL slightly inhibited viability of HEK-293 cells (P<0.05). MC (1:1) at 41.25 and 82.50 µg/mL could elevate the Kim-1 expression in HEK-293 cells.
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Protein 4.1R attenuates autoreactivity in experimental autoimmune encephalomyelitis by suppressing CD4(+) T cell activation.
Cell. Immunol.
PUBLISHED: 05-03-2014
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Immune synapse components contribute to multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) pathogenesis as they play important role in autoreactive T cell activation. Protein 4.1R, a red cell membrane cytoskeletal protein, recently was identified as an important component of immunological synapse (IS) and acted as the negative regulator of CD4(+) T cell activation. However, the pathological role of 4.1R in the MS/EAE pathogenesis is still not elucidated. In this study, we investigated the potential role of protein 4.1R in pathologic processes of EAE by using 4.1R knockout mouse model. Our results suggest that 4.1R can prevent pathogenic autoimmunity in MS/EAE progression by suppressing the CD4(+) T cell activation.
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Efficient improvement of surface activity of tea saponin through Gemini-like modification by straightforward esterification.
Food Chem
PUBLISHED: 04-28-2014
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Novel strategy of Gemini-like modification has been applied in development of new nonionic surfactants, tea saponin esters, with enhanced surface activity by simple esterification. Tea saponin was treated with acyl chlorides of different chain length and different ratio of tea saponin and acyl chloride under alkaline condition. The structures of tea saponin esters were analysed and confirmed by FT-IR, NMR and ESI-MS. Surface activity investigation revealed that esterification with the chain length of C12 and C14 and the ratio of 1:4 to 1:6 produced superior surface activity compared with tea saponin. The exceptional surface activity of the new surfactants suggested their great potential application in food industry as green surfactants due to their environmental benign nature as well as simple and inexpensive preparation. The strategy of Gemini-like modification will facilitate development of green surfactants based on natural resources.
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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.