JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Photoelectric Activity of Bi2O3/Bi2WO6-xF2x Hererojunction Prepared by Simple One-step Microwave-Hydrothermal Method.
ACS Appl Mater Interfaces
PUBLISHED: 11-18-2014
Show Abstract
Hide Abstract
NH4F/Bi2WO6 powders were prepared by a simple one-step microwave-hydrothermal method at different reaction temperatures, using Bi(NO3)3)•5H2O and Na2WO4•2H2O as raw materials, NH4F as additive agent. Their photoelectric activities were also investigated by the degradation of rhodamine B (RhB). The results indicate that when the reaction temperature increases to 220? and 240?, the orthorhombic Bi2WO6 phase with Pca21 space group and cubic Bi2O3 phase with Pn-3m space group appear. Raman spectroscopy, SEM, TEM and XPS results also confirm the existence of Bi2O3/Bi2WO6-xF2x heterojunction at higher temperature. Above 95% photodegradation of RhB under the exposure of simulated sunlight is achieved within 90min with the Bi2O3/Bi2WO6-xF2x heterojunction prepared at 220?, which displays remarkably promoted photocatalytic activities. The electrochemical impedance spectra and photocurrent results also prove that efficient charge separation and better electron transport properties are achieved by the Bi2O3/Bi2WO6-xF2x heterojunction film prepared at 220?. In addition, the mechanism of the crystal growth and formation of the p-n junction between p-type Bi2O3 and n-type Bi2WO6 were also discussed.
Related JoVE Video
An additive-free synthesis of In2O3 cubes embedded into graphene sheets and their enhanced NO2 sensing performance at room temperature.
ACS Appl Mater Interfaces
PUBLISHED: 11-18-2014
Show Abstract
Hide Abstract
In this report, we developed an additive-free synthesis of In2O3 cubes embedded into graphene networks with InN nanowires (InN-NWs) and graphene oxide (GO) as precursors by a facile one-step microwave-assisted hydrothermal method. In absence of GO, the InN-NWs maintained their chemical composition and original morphology upon the same treatment. At varying mass ratios of InN-NWs and GO, the different morphologies and distributions of In2O3 could be obtained on graphene sheets. The uniform distribution, which is usually considered favorable for enhanced sensing performance, was observed in In2O3 cubes/reduced graphene oxide (rGO) composites. The room-temperature NO2 sensing properties of the In2O3 cubes/rGO composites-based sensor were systematically investigated. The results revealed that the sensor exhibited a significant response to NO2 gas with a concentration lower to 1 ppm, and an excellent selectivity, even though the concentrations of interferential gases were 1000 times that of NO2. The enhanced NO2 sensing performances were attributed to the synergistic effect of uniformly distributed In2O3 cubes and graphene sheets in the unique hybrid architectures without the interfering of extra additives.
Related JoVE Video
Super-resolution reconstruction for 4D computed tomography of the lung via the projections onto convex sets approach.
Med Phys
PUBLISHED: 11-06-2014
Show Abstract
Hide Abstract
The use of 4D computed tomography (4D-CT) of the lung is important in lung cancer radiotherapy for tumor localization and treatment planning. Sometimes, dense sampling is not acquired along the superior-inferior direction. This disadvantage results in an interslice thickness that is much greater than in-plane voxel resolutions. Isotropic resolution is necessary for multiplanar display, but the commonly used interpolation operation blurs images. This paper presents a super-resolution (SR) reconstruction method to enhance 4D-CT resolution.
Related JoVE Video
Effect of Diesel Leakage in Circulating Cooling Water System on Preponderant Bacteria Diversity and Bactericidal Effect of Biocides.
Environ Technol
PUBLISHED: 11-04-2014
Show Abstract
Hide Abstract
Petroleum products leakage results in adverse effect on the normal operation of circulating cooling water system. However, relatively little research has been done to explore the effect of petroleum products leakage on circulating cooling water quality and biofilm preponderant bacteria diversity. Also, normal biocides application modes can't fulfill the need for biofilm control. In this study, diesel oil was used as the experimental subject representing leaking petroleum products, effect of diesel addition on biofilm preponderant bacteria diversity and the bactericidal effect of chlorine dioxide and Tetradecyl Dimethyl Benzyl Ammonium Chloride (1427) was investigated. Bacterial community structures were examined by PCR- denaturing gradient gel electrophoresis and PCR cloning of 16S rDNA genes. Expect for 100?mg/L diesel, increasing diesel concentration enhanced biofilm detachment ratio comparing with the control test. The microstructure of biofilm samples with 0, 300?mg/L and 900?mg/L diesel addition was observed. The species of preponderant bacteria in the biofilm sample with 300?mg/L diesel addition were more and the bacteria distribution was more even than those in biofilm sample with 900?mg/L diesel addition. With ClO2 and 1427 addition, COD increased, lipid phosphorus and bacterial count first decreased and then kept stable, bactericidal ratio first increased and then kept stable. Diesel addition variation has more obvious effect on ClO2 than 1427.
Related JoVE Video
Structure and Dynamics of Apical Membrane Antigen 1 from Plasmodium falciparum FVO.
Biochemistry
PUBLISHED: 11-01-2014
Show Abstract
Hide Abstract
Apical membrane antigen 1 (AMA1) interacts with RON2 to form a protein complex that plays a key role in the invasion of host cells by malaria parasites. Blocking this protein-protein interaction represents a potential route to controlling malaria and related parasitic diseases, but the polymorphic nature of AMA1 has proven to be a major challenge to vaccine-induced antibodies and peptide inhibitors exerting strain-transcending inhibitory effects. Here we present the X-ray crystal structure of AMA1 domains I and II from Plasmodium falciparum strain FVO. We compare our new structure to those of AMA1 from P. falciparum 3D7 and Plasmodium vivax. A combination of normalized B factor analysis and computational methods has been used to investigate the flexibility of the domain I loops and how this correlates with their roles in determining the strain specificity of human antibody responses and inhibitory peptides. We also investigated the domain II loop, a key region involved in inhibitor binding, by comparison of multiple AMA1 crystal structures. Collectively, these results provide valuable insights that should contribute to the design of strain-transcending agents targeting P. falciparum AMA1.
Related JoVE Video
3D-QSAR, molecular docking and molecular dynamics studies of a series of ROR?t inhibitors.
J. Biomol. Struct. Dyn.
PUBLISHED: 10-25-2014
Show Abstract
Hide Abstract
The discovery of clinically relevant inhibitors of retinoic acid receptor-related orphan receptor-gamma-t (ROR?t) for autoimmune diseases therapy has proven to be a challenging task. In the present work, to find out the structural features required for the inhibitory activity, we show for the first time a three-dimensional quantitative structure-activity relationship (3D-QSAR), molecular docking and molecular dynamics (MD) simulations for a series of novel thiazole/thiophene ketone amides with inhibitory activity at the ROR?t receptor. The optimum CoMFA and CoMSIA models, derived from ligand-based superimposition I, exhibit leave-one-out cross-validated correlation coefficient (R(2)cv) of .859 and .805, respectively. Furthermore, the external predictive abilities of the models were evaluated by a test set, producing the predicted correlation coefficient (R(2)pred) of .7317 and .7097, respectively. In addition, molecular docking analysis was applied to explore the binding modes between the inhibitors and the receptor. MD simulation and MM/PBSA method were also employed to study the stability and rationality of the derived conformations, and the binding free energies in detail. The QSAR models and the results of molecular docking, MD simulation, binding free energies corroborate well with each other and further provide insights regarding the development of novel ROR?t inhibitors with better activity.
Related JoVE Video
[Effects of TIEG1 on K562 Cell Apoptosis and Expression of BCL-2/BAX, PTEN].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 10-24-2014
Show Abstract
Hide Abstract
The aim of this study was to investigate the effect of TIEG1 on K562 cell apoptosis and expression of BCL-2/BAX, PTEN. The different concentration(0, 1, 5, 10, 20 ng/ml) of TIEG1 were used to treat K562 cells, the cell growth inhibition rate was detected by using MTT method. After treating K562 cells with 10.00 ng/ml TIEG1, the cell apoptosis was detected with flow cytometry. The RT-PCR was used to detected the expression levels of BCL-2 /BAX and PTEN. The results showed that TIEG1 displays inhibitory effect on proliferation of K562 cells in time-and dose-dependent manner (r = 0.52, P < 0.05) ; after K562 cells were treated for 6, 12, 24 and 48 h, the IC50 of TIEG1 were 48.19, 18.72, 9.5 and 3.85 ng/ml respectively. After treating K562 cells with 10.00 ng/ml TIEG1 for 0, 6, 12, 24, 48 h, the apoptosis rate were (2.13 ± 0.42)%, (7.79 ± 0.71)%, (11.17 ± 1.37)%, (24.66 ± 0.29)% and (48.60 ± 1.38)% respectively, and there was significant difference between groups(P < 0.05). In process of K562 cell apoptosis, the expression level of BCL-2 gradually decreased (r = 0.48, P < 0.05), meanwhile the expression levels of BAX (r = 0.69, P < 0.05) and PTEN (r = 0.57, P < 0.05) gradually increased. It is concluded that TIEG1 can indue apoptosis of K562 cells and inhibit K562 cell proliferation in time-and dose-dependent manner. In apoptosis process of K562 cells induced by TIEG1, the expression changes of BCL-2/BAX and PTEN associate with the K562 cell apoptosis.
Related JoVE Video
Native and Thermally Modified Protein-Polyphenol Coassemblies: Lactoferrin-Based Nanoparticles and Submicrometer Particles as Protective Vehicles for (-)-Epigallocatechin-3-gallate.
J. Agric. Food Chem.
PUBLISHED: 10-21-2014
Show Abstract
Hide Abstract
The interactions between native, thermally modified lactoferrin (LF) and (-)-epigallocatechin-3-gallate (EGCG) at pH 3.5, 5.0, and 6.5 were investigated. Turbidity, particle size, and charge of LF-EGCG complexes were mainly dominated by pH value and secondary structure of protein. At pH 3.5 and 5.0, LF-EGCG complexes were nanoparticles which had high ?-potential, small size, and soluble state. At pH 6.5, they were submicrometer particles which exhibited low ?-potential, large size, and insoluble state. The infrared spectra of freeze-dried LF-EGCG complexes showed that they were different from LF and EGCG alone. Far-UV CD results indicated that heat denaturation might irreversibly alter the secondary structure of LF and EGCG induced a progressive increase in the proportion of ?-helix structure at the cost of ?-sheet and unordered coil structure of LF at pH 3.5, 5.0, and 6.5. EGCG exhibited a strong affinity for native LF but a weak affinity for thermally modified LF at pH 5.0 and 6.5. An inverse result was observed at pH 3.5. These results could have potential for the development of food formulations based on LF as a carrier of bioactive compounds.
Related JoVE Video
High-Sensitivity Troponin T and N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP) and Risk of Incident Heart Failure in Patients with CKD: The Chronic Renal Insufficiency Cohort (CRIC) Study.
J. Am. Soc. Nephrol.
PUBLISHED: 10-02-2014
Show Abstract
Hide Abstract
High-sensitivity troponin T (hsTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) strongly predict heart failure (HF) in the general population. However, the interpretation of levels of these biomarkers as predictors of HF is uncertain among patients with CKD. Here, we investigated whether hsTnT and NT-proBNP are associated with incident HF among patients with CKD. In a prospective cohort analysis, we studied 3483 people with CKD in the Chronic Renal Insufficiency Cohort (CRIC) Study recruited from June of 2003 to August of 2008 who were free of HF at baseline. We used Cox regression to examine the association of baseline levels of hsTnT and NT-proBNP with incident HF after adjustment for demographic factors, traditional cardiovascular risk factors, markers of kidney disease, pertinent medication use, and mineral metabolism markers. At baseline, hsTnT levels ranged from ?5.0 to 378.7 pg/ml, and NT-proBNP levels ranged from ?5 to 35,000 pg/ml. Compared with those who had undetectable hsTnT, participants in the highest quartile (>26.5 ng/ml) had a significantly higher rate of HF (hazard ratio, 4.77; 95% confidence interval, 2.49 to 9.14). Similarly, compared with those in the lowest NT-proBNP quintile (<47.6 ng/ml), participants in the highest quintile (>433.0 ng/ml) experienced a substantially higher rate of HF (hazard ratio, 9.57; 95% confidence interval, 4.40 to 20.83). In conclusion, hsTnT and NT-proBNP were strongly associated with incident HF among a diverse cohort of individuals with mild to severe CKD. Elevations in these biomarkers may indicate subclinical changes in volume and myocardial stress that subsequently contribute to clinical HF.
Related JoVE Video
Payoffs, not tradeoffs, in the adaptation of a virus to ostensibly conflicting selective pressures.
PLoS Genet.
PUBLISHED: 10-01-2014
Show Abstract
Hide Abstract
The genetic architecture of many phenotypic traits is such that genes often contribute to multiple traits, and mutations in these genes can therefore affect multiple phenotypes. These pleiotropic interactions often manifest as tradeoffs between traits where improvement in one property entails a cost in another. The life cycles of many pathogens include periods of growth within a host punctuated with transmission events, such as passage through a digestive tract or a passive stage of exposure in the environment. Populations exposed to such fluctuating selective pressures are expected to acquire mutations showing tradeoffs between reproduction within and survival outside of a host. We selected for individual mutations under fluctuating selective pressures for a ssDNA microvirid bacteriophage by alternating selection for increased growth rate with selection on biophysical properties of the phage capsid in high-temperature or low-pH conditions. Surprisingly, none of the seven unique mutations identified showed a pleiotropic cost; they all improved both growth rate and pH or temperature stability, suggesting that single mutations even in a simple genetic system can simultaneously improve two distinct traits. Selection on growth rate alone revealed tradeoffs, but some mutations still benefited both traits. Tradeoffs were therefore prevalent when selection acted on a single trait, but payoffs resulted when multiple traits were selected for simultaneously. We employed a molecular-dynamics simulation method to determine the mechanisms underlying beneficial effects for three heat-shock mutations. All three mutations significantly enhanced the affinities of protein-protein interfacial bindings, thereby improving capsid stability. The ancestral residues at the mutation sites did not contribute to protein-protein interfacial binding, indicating that these sites acquired a new function. Computational models, such as those used here, may be used in future work not only as predictive tools for mutational effects on protein stability but, ultimately, for evolution.
Related JoVE Video
Palladium-catalyzed difunctionalization of alkynes via C-N and S-N cleavages: a versatile approach to highly functional indoles.
Org. Lett.
PUBLISHED: 09-23-2014
Show Abstract
Hide Abstract
Palladium-catalyzed intramolecular addition of C-N and S-N bond to alkynes with the migration of functional groups has been achieved. A wide range of functional groups including acyl, pyruvoyl, amide, and sulfonyl groups can migrate smoothly and be conveniently introduced at the C-3 postion of indoles in our catalytic system. The operational simplicity and broad substrate scope demonstrate the great potential of this method for the synthesis of highly functional indoles.
Related JoVE Video
Tumor-targeted in vivo gene silencing via systemic delivery of cRGD-conjugated siRNA.
Nucleic Acids Res.
PUBLISHED: 09-15-2014
Show Abstract
Hide Abstract
RNAi technology is taking strong position among the key therapeutic modalities, with dozens of siRNA-based programs entering and successfully progressing through clinical stages of drug development. To further explore potentials of RNAi technology as therapeutics, we engineered and tested VEGFR2 siRNA molecules specifically targeted to tumors through covalently conjugated cyclo(Arg-Gly-Asp-d-Phe-Lys[PEG-MAL]) (cRGD) peptide, known to bind ?v?3 integrin receptors. cRGD-siRNAs were demonstrated to specifically enter and silence targeted genes in cultured ?v?3 positive human cells (HUVEC). Microinjection of zebrafish blastocysts with VEGFR2 cRGD-siRNA resulted in specific inhibition of blood vessel growth. In tumor-bearing mice, intravenously injected cRGD-siRNA molecules generated no innate immune response and bio-distributed to tumor tissues. Continuous systemic delivery of two different VEGFR2 cRGD-siRNAs resulted in down-regulation of corresponding mRNA (55 and 45%) and protein (65 and 45%) in tumors, as well as in overall reduction of tumor volume (90 and 70%). These findings demonstrate strong potential of cRGD-siRNA molecules as anti-tumor therapy.
Related JoVE Video
Two new dimeric naphthoquinones with neuraminidase inhibitory activity from Lithospermum erythrorhizon.
Nat. Prod. Res.
PUBLISHED: 09-05-2014
Show Abstract
Hide Abstract
The crude methanol extract of roots of Lithospermum erythrorhizon was subjected to successive chromatographic fractionation which afforded two new dimeric naphthoquinone derivatives shikometabolin E (2) and shikometabolin F (3) as well as one known compound shikometabolin A (1). The structures of compounds 1-3 were elucidated by using UV, MS, 1D and 2D NMR spectroscopic analysis. The two new dimeric naphthoquinone derivatives showed significant neuraminidase inhibitory activities.
Related JoVE Video
A Custom Correlation Coefficient (CCC) Approach for Fast Identification of Multi-SNP Association Patterns in Genome-Wide SNPs Data.
Genet. Epidemiol.
PUBLISHED: 08-28-2014
Show Abstract
Hide Abstract
Complex diseases are often associated with sets of multiple interacting genetic factors and possibly with unique sets of the genetic factors in different groups of individuals (genetic heterogeneity). We introduce a novel concept of custom correlation coefficient (CCC) between single nucleotide polymorphisms (SNPs) that address genetic heterogeneity by measuring subset correlations autonomously. It is used to develop a 3-step process to identify candidate multi-SNP patterns: (1) pairwise (SNP-SNP) correlations are computed using CCC; (2) clusters of so-correlated SNPs identified; and (3) frequencies of these clusters in disease cases and controls compared to identify disease-associated multi-SNP patterns. This method identified 42 candidate multi-SNP associations with hypertensive heart disease (HHD), among which one cluster of 22 SNPs (six genes) included 13 in SLC8A1 (aka NCX1, an essential component of cardiac excitation-contraction coupling) and another of 32 SNPs had 29 from a different segment of SLC8A1. While allele frequencies show little difference between cases and controls, the cluster of 22 associated alleles were found in 20% of controls but no cases and the other in 3% of controls but 20% of cases. These suggest that both protective and risk effects on HHD could be exerted by combinations of variants in different regions of SLC8A1, modified by variants from other genes. The results demonstrate that this new correlation metric identifies disease-associated multi-SNP patterns overlooked by commonly used correlation measures. Furthermore, computation time using CCC is a small fraction of that required by other methods, thereby enabling the analyses of large GWAS datasets.
Related JoVE Video
Aqueous Extract of Chrysanthemum morifolium ( Jú Hu?) Enhances the Antimelanogenic and Antioxidative Activities of the Mixture of Soy Peptide and Collagen Peptide.
J Tradit Complement Med
PUBLISHED: 08-28-2014
Show Abstract
Hide Abstract
The possible synergistic effect between the aqueous extract of Chrysanthemum morifolium ( Jú Hu?) (AECM) and the peptide mixture (PM) containing soy peptide and collagen peptide was investigated in an ultraviolet (UV) irradiation-induced skin damage mouse model. The irradiated mice were treated with the PM or PM + AECM (containing PM and AECM), respectively. Both PM and PM + AECM groups displayed an apparent photoprotective effect on the UV-irradiated skin damage of mice. Histological evaluation demonstrated that the epidermal hyperplasia and melanocytes in the basal epidermal layer of the UV-irradiated skin in mice decreased when treated with either PM or PM + AECM. Further study showed that soy peptide, collagen peptide, and AECM also inhibited the activities of mushroom tyrosinase with IC50 values of 82.3, 28.2, and 1.6 ?g/ml, respectively. Additionally, PM + AECM reduced melanogenesis by 46.2% at the concentration of 10 mg/ml in B16 mouse melanoma cells. Meanwhile, the UV-induced increase of antioxidative indicators, including glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and malondialdehyde (MDA), was reduced significantly after treatment with 1.83 g/kg/dbw of PM + AECM. This evidence supported the synergistic antioxidative effect of AECM with PM. These results demonstrated that oral intake of PM and AECM had synergistic antimelanogenic and antioxidative effects in UV-irradiated mice.
Related JoVE Video
MicroRNA-130b Promotes Cell Aggressiveness by Inhibiting Peroxisome Proliferator-Activated Receptor Gamma in Human Hepatocellular Carcinoma.
Int J Mol Sci
PUBLISHED: 08-25-2014
Show Abstract
Hide Abstract
MircroRNA-130b (miR-130b) is proposed as a novel tumor-related miRNA and has been found to be significantly dysregulated in tumors. In this study, the expression level of miR-130b was found to be obviously higher in hepatocellular carcinoma (HCC) tissues than that in nontumor tissues. Further, miR-130b was expressed at significantly higher levels in aggressive and recurrent tumor tissues. Clinical analysis indicated that high-expression of miR-130b was prominently correlated with venous infiltration, high Edmondson-Steiner grading and advanced tumor-node-metastasis (TNM) tumor stage in HCC. Elevated miR-130b expression was observed in all HCC cell lines (HepG2, SMMC-7721, Huh7, Hep3B and MHCC97H) as compared with that in a nontransformed hepatic cell line (LO2). Furthermore, an inverse correlation between miR-130b and E-cadherin and a positive correlation between miR-130b and Vimentin were observed in HCC tissues. Down-regulation of miR-130b expression reduced invasion and migration in both Hep3B and MHCC97H cells. Peroxisome proliferator-activated receptor gamma (PPAR-?) was inversely correlated with miR-130b expression in HCC tissues. In addition, down-regulation of miR-130b restored PPAR-? expression and subsequently suppressed epithelial-mesenchymal transition (EMT) in HCC cells. We identified PPAR? as a direct target of miR-130b in HCC in vitro. Notably, PPAR-? knockdown abolished down-regulation of miR-130b-inhibited EMT in MHCC97H cells. In conclusion, miR-130b may promote HCC cell migration and invasion by inhibiting PPAR-? and subsequently inducing EMT.
Related JoVE Video
A jogged dislocation governed strengthening mechanism in nanotwinned metals.
Nano Lett.
PUBLISHED: 08-22-2014
Show Abstract
Hide Abstract
Atomistic simulations reveal a new and unique strengthening mechanism in nanotwinned metals governed by the collective motion of multiple necklace-like extended jogged dislocations. This mechanism prevails in a columnar-grained nanotwinned metal subject to an external stress parallel to the twin planes, provided the twin boundary spacing falls below a critical value. A theoretical model based on the depinning of unit jogs on twin planes is proposed to determine the flow stress associated with this deformation mechanism and is shown to be in agreement with atomistic simulations.
Related JoVE Video
Anomalous high adsorption energy of H2O on fluorinated graphenes: a first principles study.
Phys Chem Chem Phys
PUBLISHED: 08-20-2014
Show Abstract
Hide Abstract
Polytetrafluoroethylene (PTFE) has been well-known for the surface superhydrophobicity, while its two-dimensional stable analogues, CF and C4F, possess distinct surface wettability. The CF inherits the hydrophobicity from PTFE since the van der Waals interaction is mitigated by the high electronegativity of fluorine. Surprisingly, a high adsorption energy (?550 meV per molecule) of water has been unveiled on C4F via density functional theory studies, implying anomalous superhydrophilicity of C4F. The abrupt transition from hydrophobicity of CF to superhydrophilicity of C4F can be reconciled with the difference in their molecular orbitals. The high adsorption energy of C4F is mainly attributed to the Coulomb attraction among the non-bonding interactions, as proposed by our theoretical model. Since the surface chemical inertness of CF inhibits it from being widely adopted in device fabrication, the present finding suggests that C4F can be a promising candidate in graphene-based electronic devices.
Related JoVE Video
Differential modulation by IL-17A of Cholangitis versus Colitis in IL-2R? deleted mice.
PLoS ONE
PUBLISHED: 08-18-2014
Show Abstract
Hide Abstract
IFN-? is a signature Th1 cell associated cytokine critical for the inflammatory response in autoimmunity with both pro-inflammatory and potentially protective functions. IL-17A is the hallmark of T helper 17 (Th17) cell subsets, produced by ??T, CD8+ T, NK and NKT cells. We have taken advantage of our colony of IL-2R?-/- mice that spontaneously develop both autoimmune cholangitis and inflammatory bowel disease. In this model CD8+ T cells mediate biliary ductular damage, whereas CD4+ T cells mediate induction of colon-specific autoimmunity. Importantly, IL-2R?-/- mice have high levels of interferon ? (IFN-?), and interleukin-17A (IL-17A). We produced unique double deletions of mice that were either IL-17A-/-IL-2R?-/- or IFN-?-/-IL-2R?-/- to specifically address the precise role of these two cytokines in the natural history of autoimmune cholangitis and colitis. Of note, deletion of IL-17A in IL-2R?-/- mice led to more severe liver inflammation, but ameliorated colitis. In contrast, there were no significant changes in the immunopathology of double knock-out IFN-?-/- IL-2R?-/- mice, compared to single knock-out IL-2R?-/- mice with respect to cholangitis or colitis. Furthermore, there was a significant increase in pathogenetic CD8+ T cells in the liver of IL-17A-/-IL-2R?-/- mice. Our data suggest that while IL-17A plays a protective role in autoimmune cholangitis, it has a pro-inflammatory role in inflammatory bowel disease. These data take on particular significance in the potential use of anti-IL-17A therapy in humans with primary biliary cirrhosis.
Related JoVE Video
Isolation, characterization, and antitumor activity of a novel heteroglycan from cultured mycelia of Cordyceps sinensis.
Planta Med.
PUBLISHED: 08-15-2014
Show Abstract
Hide Abstract
A novel heteroglycan, Cordyceps sinensis polysaccharide 1 (molecular weight 1 17 × 10(5) Da), was isolated and purified from mycelia of the fungus C. sinensis obtained by solid-state culture. Structural characterization by chemical analysis, GC-MS, FTIR, and NMR spectroscopy showed that C. sinensis polysaccharide 1 was mainly composed of (1???6)-linked ?-D-Glc and ?-D-Gal, with minor ?-(1???4)-D-Xyl and ?-(1???4)-D-Man residues probably located in the side chains with a trace amount of ?-(1???3)-L-Rha residue. In biological assays, C. sinensis polysaccharide 1 significantly inhibited proliferation of sarcoma 180 cells and induced apoptosis in a dose-dependent manner. Further studies will elucidate the antitumor mechanism of C. sinensis polysaccharide 1 and promote its utilization for the development of novel, effective anticancer drugs.
Related JoVE Video
[Identification of three novel frameshift mutations in the RUNX2 gene in three sporadic Chinese cases with cleidocranial dysplasia].
Zhonghua Yi Xue Yi Chuan Xue Za Zhi
PUBLISHED: 08-15-2014
Show Abstract
Hide Abstract
To investigate the molecular etiology of three patients with sporadic cleidocranial dysplasia (CCD) and to provide genetic counseling and prenatal diagnosis for the family members based on the identified mutations.
Related JoVE Video
A case study of pulmonary embolism from the right atrial shunt after acute type a aortic dissection surgery.
J Cardiothorac Surg
PUBLISHED: 08-14-2014
Show Abstract
Hide Abstract
This is one case report of a 46-year-old Chinese male with type A acute aortic dissection. It is an emergent surgery including Bentall procedure, interposition graft replacement of aortic arch, stented descending aorta with the modified right atrial shunt technique. In the early post operation period, the patient was complicated with pulmonary embolism. Pulmanary arteriography showed that the right main pulmonary embolism without an extrinsic compression. After the anticoagulant therapy, the patient was well recovered and discharged from hospital 1 month later. The origin of pulmonary embolism in the patient was believed to be the thrombosis in the shunt fistula. The right atrial shunt-related complications haven¿t been reported for more than thirty years. Pulmonary embolism could be a severe complication after the right atrial shunt in acute type A aortic dissection.
Related JoVE Video
Chemical ablation therapy of recurrent mediastinal nodal metastasis in post-radiotherapy cancer patients.
Med. Oncol.
PUBLISHED: 08-11-2014
Show Abstract
Hide Abstract
The aim of our study was to evaluate the treatment of post-radiotherapy recurrent mediastinal nodal metastasis. Post-radiotherapy esophageal cancer patients with mediastinal lymph node recurrence were enrolled in this study. Patients were randomized into the radiation (±chemotherapy) or the chemoablation group. Patients randomized to the chemoradiotherapy group received additional radiotherapy, second-line chemotherapy, or both. Patients randomized to the chemoablation group received CT-guided percutaneous chemical ablation. Clinical remission was assessed at 1 month by contrast CT. Reirradiation dose ranged from 2,200 to 3,600 cGy depending on dose-limiting constraints in consideration of prior radiotherapy dose. The RECIST criteria were used in the evaluation of response to therapy. The median length of follow-up is 6 months. Thirty-one patients were enrolled in the study. In the chemoradiation group, all patients underwent CT imaging at 1-month follow-up. Among these patients, seven had progressive disease, five had stable disease (SD), and four had partial response (PR). The 6-month survival rate was 12.5%. In the chemoablation group at 1-month follow-up, 12 patients had SD and three patients had PR, and the 6-month survival rate was 46.6%. Our results suggest that chemoablation therapy as salvage treatment after post-radiotherapy relapse is efficacious and safe.
Related JoVE Video
Prognostic significance of miR-218 in human hepatocellular carcinoma and its role in cell growth.
Oncol. Rep.
PUBLISHED: 08-07-2014
Show Abstract
Hide Abstract
MicroRNA-218 (miR-218) is considered a tumor suppressor in human cancer. In the present study, miR-218 expression was found to be significantly lower in human hepatocellular carcinoma (HCC) than in normal tumor-adjacent tissues. miR-218 was clearly silenced or downregulated in five HCC cells (HepG2, Hep3B, SMMC-7721, Huh7 and Bel-7402) compared with normal hepatocytes (LO2). The low expression of miR-218 conferred a poor 5-year survival in HCC patients. Multivariate Cox regression analysis indicated that miR-218 was an independent prognostic factor in HCC. Ectopic expression of miR-218 inhibited proliferation and promoted apoptosis in HepG2 and SMMC-7721 cells. In tumor bearing mice, miR-218 slowed down tumor growth by inducing apoptosis and growth arrest. Restoring miR-218 expression resulted in downregulation of B lymphoma Mo-MLV insertion region 1 homolog (BMI-1) mRNA and protein level in HepG2 and SMMC-7721 cells. In addition, BMI-1 mRNA expression in HCC was significantly higher than that in non-cancerous tissues. BMI-1 mRNA was inversely correlated with miR-218 expression in HCC tissues. In conclusion, miR-218 may serve as a prognostic biomarker and induce apoptosis and growth arrest by downregulating BMI-1 in HCC.
Related JoVE Video
Dwell-time algorithm for polishing large optics.
Appl Opt
PUBLISHED: 08-05-2014
Show Abstract
Hide Abstract
The calculation of the dwell time plays a crucial role in polishing precision large optics. Although some studies have taken place, it remains a challenge to develop a calculation algorithm which is absolutely stable, together with a high convergence ratio and fast solution speed even for extremely large mirrors. For this aim, we introduced a self-adaptive iterative algorithm to calculate the dwell time in this paper. Simulations were conducted in bonnet polishing (BP) to test the performance of this method on a real 430??mm × 430??mm fused silica part with the initial surface error PV=1741.29??nm, RMS=433.204??nm. The final surface residual error in the clear aperture after two simulation steps turned out to be PV=11.7??nm, RMS=0.5??nm. The results confirm that this method is stable and has a high convergence ratio and fast solution speed even with an ordinary computer. It is notable that the solution time is usually just a few seconds even on a 1000??mm × 1000??mm part. Hence, we believe that this method is perfectly suitable for polishing large optics. And not only can it be applied to BP, but it can also be applied to other subaperture deterministic polishing processes.
Related JoVE Video
Emodin-loaded magnesium silicate hollow nanocarriers for anti-angiogenesis treatment through inhibiting VEGF.
Int J Mol Sci
PUBLISHED: 08-03-2014
Show Abstract
Hide Abstract
The applications of anti-VEGF (vascular endothelial growth factor) treatment in ophthalmic fields to inhibit angiogenesis have been widely documented in recent years. However, the hydrophobic nature of many agents makes its delivery difficult in practice. Therefore, the aim of the present study was to introduce a new kind of hydrophobic drug carrier by employing nanoparticles with a hollow structure inside. Followed by the synthesis and characterization of magnesium silicate hollow spheres, cytotoxicity was evaluated in retina capillary endothelial cells. The loading and releasing capacity were tested by employing emodin, and the effect on VEGF expression was performed at the gene and protein level. Finally, an investigation on angiogenesis was carried on fertilized chicken eggs. The results indicated that the magnesium silicate nanoparticles had low toxicity. Emodin-MgSiO3 can inhibit the expression of both VEGF gene and protein effectively. Angiogenesis of eggs was also reduced significantly. Based on the above results, we concluded that magnesium silicate hollow spheres were good candidates as drug carriers with enough safety.
Related JoVE Video
Investigation on pharmacokinetics, tissue distribution and excretion of 1-triacontanol in rats by gas chromatography-tandem mass spectrometry (GC-MS/MS).
Xenobiotica
PUBLISHED: 08-01-2014
Show Abstract
Hide Abstract
Abstract 1.? 1-Triacontanol (TA) recently shows promising anti-tumor activity. The present study was aimed to develop a sensitive gas chromatography-tandem mass spectrometry method to explore the pharmacokinetic profiles, distribution and excretion of TA in Sprague-Dawley rats after oral administration of TA. Chromatography separation was performed on a HP-5MS column. 1-Octacosanal was used as the internal standard (IS). Quantification of TA and IS was carried out at m/z 495.6???97.0 and m/z 467.5???97.0, respectively, in positive electron ionization and multiple reaction monitoring mode. The pharmacokinetic parameters were calculated by non-compartmental analysis. 2.? The area under concentration-time curve AUC0-6 h and AUC0-? for TA at 60?mg/kg were 87.737±13.574 and 93.617±17.62, respectively. The mean residence time was 3.25?±?0.17?h. In addition, the elimination half-lives (t1/2) were (2.37±1.23, 1.27±0.49, 2.07±0.93) h after single oral administration of 30, 60 and 120?mg/kg of TA. After oral administration, TA was extensively distributed in stomach and intestine. The majority of TA excreted via feces, and its accumulative excretion ratio during the period of 72?h was 26.68?±?7.14%, but only 0.0023?±?0.0015% and 0.0027?±?0.0006% for urines and bile, respectively. The absolute bioavailability (F, %) of TA was about 2.0%.
Related JoVE Video
Residential agricultural pesticide exposures and risk of selected congenital heart defects among offspring in the San Joaquin Valley of California.
Environ. Res.
PUBLISHED: 07-25-2014
Show Abstract
Hide Abstract
Pesticide exposures are ubiquitous and of substantial public concern. We examined the potential association of congenital heart defects with residential proximity to commercial agricultural pesticide applications in the San Joaquin Valley, California.
Related JoVE Video
Proanthocyanidins in wild sea buckthorn (Hippophaë rhamnoides) berries analyzed by reversed-phase, normal-phase, and hydrophilic interaction liquid chromatography with UV and MS detection.
J. Agric. Food Chem.
PUBLISHED: 07-25-2014
Show Abstract
Hide Abstract
A rapid and sensitive method for profiling of proanthocyanidins (PAs) of sea buckthorn (Hippophaë rhamnoides) berries was established based on aqueous, acidified acetone extraction. The extract was purified by Sephadex column chromatography and analyzed using reversed-phase, normal-phase, and hydrophilic interaction liquid chromatography (HILIC). Negative ion electrospray ionization mass spectrometry (ESI-MS) in single ion recording (SIR) and full scan modes combined with UV detection were used to define the combinations and ratios of PA oligomer classes. PAs with degree of polymerization from 2 to 11 were detected by HILIC-ESI-MS. Quantification of dimeric, trimeric, and tetrameric PAs was carried out with ESI-MS-SIR, and their molar proportions were 40, 40, and 20%, respectively. Only B-type PAs were found, and (epi)gallocatechins were the main monomeric units. More than 60 combinations of (epi)catechins and (epi)gallocatechins of proanthocyanidin dimers and trimers were found. A majority of the PAs were shown to be higher polymers based on the HILIC-UV analysis.
Related JoVE Video
Modeling the propagation of mobile phone virus under complex network.
ScientificWorldJournal
PUBLISHED: 07-15-2014
Show Abstract
Hide Abstract
Mobile phone virus is a rogue program written to propagate from one phone to another, which can take control of a mobile device by exploiting its vulnerabilities. In this paper the propagation model of mobile phone virus is tackled to understand how particular factors can affect its propagation and design effective containment strategies to suppress mobile phone virus. Two different propagation models of mobile phone viruses under the complex network are proposed in this paper. One is intended to describe the propagation of user-tricking virus, and the other is to describe the propagation of the vulnerability-exploiting virus. Based on the traditional epidemic models, the characteristics of mobile phone viruses and the network topology structure are incorporated into our models. A detailed analysis is conducted to analyze the propagation models. Through analysis, the stable infection-free equilibrium point and the stability condition are derived. Finally, considering the network topology, the numerical and simulation experiments are carried out. Results indicate that both models are correct and suitable for describing the spread of two different mobile phone viruses, respectively.
Related JoVE Video
A novel electronic nose based on porous In2O3 microtubes sensor array for the discrimination of VOCs.
Biosens Bioelectron
PUBLISHED: 07-11-2014
Show Abstract
Hide Abstract
We have innovatively developed an electronic nose consisting of only one type of semiconductor metal oxide (SMO) material. The representative SMO material, porous In2O3 microtubes in this work, offered great surface area and large gas penetration channels. By using a solvent casting process, different amounts of porous In2O3 microtubes were coated on Al2O3 substrate, forming a resistometric SMO sensor array-based electronic nose. Each sensing unit in the electronic nose exhibited independent response toward ethanol. We have successfully applied this electronic nose to distinguish four alcohols at the same concentrations (100ppm), and also utilized the electronic nose for the discrimination of 14 volatile organic compounds (VOCs). Clear differentiation among all the 14 VOCs both at their immediately dangerous to life or health (IDLH) and the permissible exposure limit (PEL) concentrations has been achieved with no errors or misclassifications. We expect that this method will expand the application of SMO sensor array-based electronic nose which has been largely limited by the selection of commercially available SMOs and dopants.
Related JoVE Video
SUMO proteomics to decipher the SUMO-modified proteome regulated by various diseases.
Proteomics
PUBLISHED: 06-30-2014
Show Abstract
Hide Abstract
Small ubiquitin-like modifier (SUMO1-3) conjugation is a posttranslational protein modification whereby SUMOs are conjugated to lysine residues of target proteins. SUMO conjugation can alter the activity, stability, and function of target proteins, and thereby modulate almost all major cellular pathways. Many diseases are associated with SUMO conjugation, including heart failure, arthritis, cancer, degenerative diseases, and brain ischemia/stroke. It is, therefore, of major interest to characterize the SUMO-modified proteome regulated by these disorders. SUMO proteomics analysis is hampered by low levels of SUMOylated proteins. Several strategies have, therefore, been developed to enrich SUMOylated proteins from cell/tissue extracts. These include proteomics analysis on cells expressing epitope-tagged SUMO isoforms, use of monoclonal SUMO antibodies for immunoprecipitation and epitope-specific peptides for elution, and affinity purification with peptides containing SUMO interaction motifs to specifically enrich polySUMOylated proteins. Recently, two mouse models were generated and characterized that express tagged SUMO isoforms, and allow purification of SUMOylated proteins from complex organ extracts. Ultimately, these new analytical tools will help to decipher the SUMO-modified proteome regulated by various human diseases, and thereby, identify new targets for preventive and therapeutic purposes.
Related JoVE Video
Interferon-? Safeguards Blood-Brain Barrier during Experimental Autoimmune Encephalomyelitis.
Am. J. Pathol.
PUBLISHED: 06-24-2014
Show Abstract
Hide Abstract
The function of blood-brain barrier is often disrupted during the progression of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). However, the molecular mechanism of blood-brain barrier modulation during neuroinflammation remains unclear. Herein, we show that the expression of interferon-? (IFN?) receptor on endothelial cells (ECs) protected mice from the brain inflammation during EAE. IFN? stabilized the integrity of the cerebral endothelium and prevented the infiltration of leukocytes into the brain. Further analysis revealed that IFN? increased the expression of tight junction proteins zonula occludens protein 1 and occludin, as well as membranous distribution of claudin-5, in brain ECs. Silencing claudin-5 abolished the IFN?-mediated improvement of EC integrity. Taken together, our results show that IFN?, a pleiotropic proinflammatory cytokine, stabilizes blood-brain barrier integrity and, therefore, prevents brain inflammation during EAE.
Related JoVE Video
Design, synthesis and biological evaluation of 4-anilinothieno[2,3-d]pyrimidine-based hydroxamic acid derivatives as novel histone deacetylase inhibitors.
Bioorg. Med. Chem.
PUBLISHED: 06-11-2014
Show Abstract
Hide Abstract
A series of 4-anilinothieno[2,3-d]pyrimidine-based hydroxamic acid derivatives as novel HDACs inhibitors were designed, synthesized and evaluated. Most of these compounds displayed good to excellent inhibitory activities against HDAC1, 3, 6. The IC50 values of compound 10r against HDAC1, HDAC3, HDAC6 was 1.14±0.03nM, 3.56±0.08nM, 11.43±0.12nM. Compound 10r noticeably up-regulated the level of histone H3 acetylation compared to the SAHA. Most of the compounds showed the strong anti-proliferative activity against human cancer cell lines including RMPI8226 and HCT-116. The IC50 values of Compounds 10r and 10t against RPMI8226 was 2.39±0.20?M, 1.41±0.44?M, respectively, and the HCT-116 was sensitive to the compounds 10h, 10m, 10r, 10w with the IC50 values <1.9?M.
Related JoVE Video
Breast implant-associated anaplastic large cell lymphoma: sensitivity, specificity, and findings of imaging studies in 44 patients.
Breast Cancer Res. Treat.
PUBLISHED: 06-10-2014
Show Abstract
Hide Abstract
Breast implant-associated anaplastic large cell lymphoma (BIA ALCL) is a newly described clinicopathologic entity. The purpose of this study is to describe the imaging findings of patients with BIA ALCL and determine their sensitivity and specificity in the detection of the presence of an effusion or a mass related to BIA ALCL. A retrospective search was performed of our files as well as of the world literature for patients with pathologically proven BIA ALCL who had been assessed by any imaging study including ultrasound (US), computerized tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET)-CT, as well as mammography. The sensitivity and specificity of each imaging modality in the detection of an effusion or a mass around breast implants was determined. We identified 44 patients who had BIA ALCL and imaging studies performed between 1997 and 2013. The sensitivity for detecting an effusion was 84, 55, 82, and 38 %, and for detecting a mass was 46, 50, 50, and 64 %, by US, CT, MRI, and PET, respectively. The sensitivity of mammography in the detection of an abnormality without distinction of effusion or mass was 73 %, and specificity 50 %. Progression-free survival was worse in patients with an implant-associated mass (p = 0.001).
Related JoVE Video
Exposure to airborne polycyclic aromatic hydrocarbons during pregnancy and risk of preterm birth.
Environ. Res.
PUBLISHED: 06-03-2014
Show Abstract
Hide Abstract
Preterm birth is an important marker of health and has a prevalence of 12-13% in the U.S. Polycyclic aromatic hydrocarbons (PAHs) are a group of organic contaminants that form during the incomplete combustion of hydrocarbons, such as coal, diesel and gasoline. Studies suggest that exposure to PAHs during pregnancy is related to adverse birth outcomes. The aim of this study is to evaluate the association between exposure to PAHs during the pregnancy and preterm birth.
Related JoVE Video
Tissue distribution and ontogeny of multidrug resistance protein 2, a phosphatidylcholine translocator, in rats.
Eur J Drug Metab Pharmacokinet
PUBLISHED: 05-22-2014
Show Abstract
Hide Abstract
Multidrug resistance protein 2 (Mdr2), encoded by ATP-binding cassette b4 (Abcb4), serves as a phospholipid flippase that is indispensable for phosphatidylcholine translocation. However, little was known about the regulation of Mdr2 in Sprague-Dawley rats, although they are commonly used for pre-clinical investigation as well as mechanistic study. Present study aims at determining the tissue distribution, gender difference and ontogeny of Mdr2 in rats on both gene and protein levels. Results showed that Mdr2 was highly expressed in liver, modestly enriched in brain and testis, and less distributed in gastrointestinal tracts. Gender-divergent and male-dominated distribution was observed in the Mdr2 mRNA expression of liver and generative organs. Developmental pattern of rat Mdr2 on protein level was not exactly consistent with that on mRNA level. In conclusion, there was a considerable distribution of rat Mdr2 in the brain, testis and intestine besides liver, and the ontogeny of Mdr2 performed in an age-dependent pattern with the post-transcriptional regulation.
Related JoVE Video
Integration of proteomic and transcriptomic profiles identifies a novel PDGF-MYC network in human smooth muscle cells.
Cell Commun. Signal
PUBLISHED: 05-14-2014
Show Abstract
Hide Abstract
BackgroundPlatelet-derived growth factor-BB (PDGF-BB) has been implicated in the proliferation, migration and synthetic activities of smooth muscle cells that characterize physiologic and pathologic tissue remodeling in hollow organs. However, neither the molecular basis of PDGFR-regulated signaling webs, nor the extent to which specific components within these networks could be exploited for therapeutic benefit has been fully elucidated.ResultsExpression profiling and quantitative proteomics analysis of PDGF-treated primary human bladder smooth muscle cells identified 1,695 genes and 241 proteins as differentially expressed versus non-treated cells. Analysis of gene expression data revealed MYC, JUN, EGR1, MYB, RUNX1, as the transcription factors most significantly networked with up-regulated genes. Forty targets were significantly altered at both the mRNA and protein levels. Proliferation, migration and angiogenesis were the biological processes most significantly associated with this signature, and MYC was the most highly networked master regulator. Alterations in master regulators and gene targets were validated in PDGF-stimulated smooth muscle cells in vitro and in a model of bladder injury in vivo. Pharmacologic inhibition of MYC and JUN confirmed their role in SMC proliferation and migration. Network analysis identified the diaphanous-related formin 3 as a novel PDGF target regulated by MYC and JUN, which was necessary for PDGF-stimulated lamellipodium formation.ConclusionsThese findings provide the first systems-level analysis of the PDGF-regulated transcriptome and proteome in normal smooth muscle cells. The analyses revealed an extensive cohort of PDGF-dependent biological processes and connected key transcriptional effectors to their regulation, significantly expanding current knowledge of PDGF-stimulated signaling cascades. These observations also implicate MYC as a novel target for pharmacological intervention in fibroproliferative expansion of smooth muscle, and potentially in cancers in which PDGFR-dependent signaling or MYC activation promote tumor progression.
Related JoVE Video
Histopathologic Correlation of Residual Mammographic Microcalcifications After Neoadjuvant Chemotherapy for Locally Advanced Breast Cancer.
Ann. Surg. Oncol.
PUBLISHED: 05-12-2014
Show Abstract
Hide Abstract
This study was designed to determine the histopathologic correlation at surgery of residual mammographic calcifications in patients after neoadjuvant chemotherapy (NAC) for locally advanced breast cancer (LABC).
Related JoVE Video
The complex jujube genome provides insights into fruit tree biology.
Nat Commun
PUBLISHED: 03-21-2014
Show Abstract
Hide Abstract
The jujube (Ziziphus jujuba Mill.), a member of family Rhamnaceae, is a major dry fruit and a traditional herbal medicine for more than one billion people. Here we present a high-quality sequence for the complex jujube genome, the first genome sequence of Rhamnaceae, using an integrated strategy. The final assembly spans 437.65?Mb (98.6% of the estimated) with 321.45?Mb anchored to the 12 pseudo-chromosomes and contains 32,808 genes. The jujube genome has undergone frequent inter-chromosome fusions and segmental duplications, but no recent whole-genome duplication. Further analyses of the jujube-specific genes and transcriptome data from 15 tissues reveal the molecular mechanisms underlying some specific properties of the jujube. Its high vitamin C content can be attributed to a unique high level expression of genes involved in both biosynthesis and regeneration. Our study provides insights into jujube-specific biology and valuable genomic resources for the improvement of Rhamnaceae plants and other fruit trees.
Related JoVE Video
Multimodal brain-tumor segmentation based on Dirichlet process mixture model with anisotropic diffusion and Markov random field prior.
Comput Math Methods Med
PUBLISHED: 03-14-2014
Show Abstract
Hide Abstract
Brain-tumor segmentation is an important clinical requirement for brain-tumor diagnosis and radiotherapy planning. It is well-known that the number of clusters is one of the most important parameters for automatic segmentation. However, it is difficult to define owing to the high diversity in appearance of tumor tissue among different patients and the ambiguous boundaries of lesions. In this study, a nonparametric mixture of Dirichlet process (MDP) model is applied to segment the tumor images, and the MDP segmentation can be performed without the initialization of the number of clusters. Because the classical MDP segmentation cannot be applied for real-time diagnosis, a new nonparametric segmentation algorithm combined with anisotropic diffusion and a Markov random field (MRF) smooth constraint is proposed in this study. Besides the segmentation of single modal brain-tumor images, we developed the algorithm to segment multimodal brain-tumor images by the magnetic resonance (MR) multimodal features and obtain the active tumor and edema in the same time. The proposed algorithm is evaluated using 32 multimodal MR glioma image sequences, and the segmentation results are compared with other approaches. The accuracy and computation time of our algorithm demonstrates very impressive performance and has a great potential for practical real-time clinical use.
Related JoVE Video
Denoising of 3D magnetic resonance images by using higher-order singular value decomposition.
Med Image Anal
PUBLISHED: 03-13-2014
Show Abstract
Hide Abstract
The denoising of magnetic resonance (MR) images is important to improve the inspection quality and reliability of quantitative image analysis. Nonlocal filters by exploiting similarity and/or sparseness among patches or cubes achieve excellent performance in denoising MR images. Recently, higher-order singular value decomposition (HOSVD) has been demonstrated to be a simple and effective method for exploiting redundancy in the 3D stack of similar patches during denoising 2D natural image. This work aims to investigate the application and improvement of HOSVD to denoising MR volume data. The wiener-augmented HOSVD method achieves comparable performance to that of BM4D. For further improvement, we propose to augment the standard HOSVD stage by a second recursive stage, which is a repeated HOSVD filtering of the weighted summation of the residual and denoised image in the first stage. The appropriate weights have been investigated by experiments with different image types and noise levels. Experimental results over synthetic and real 3D MR data demonstrate that the proposed method outperforms current state-of-the-art denoising methods.
Related JoVE Video
Arbuscular mycorrhizal fungal community response to warming and nitrogen addition in a semiarid steppe ecosystem.
Mycorrhiza
PUBLISHED: 02-10-2014
Show Abstract
Hide Abstract
Understanding the response of arbuscular mycorrhizal (AM) fungi to warming and nitrogen (N) fertilization is critical to assess the impact of anthropogenic disturbance on ecosystem functioning under global climate change scenarios. In this study, AM fungal communities were examined in a full factorial design with warming and N addition in a semiarid steppe in northern China. Warming significantly increased AM fungal spore density, regardless of N addition, whilst N addition significantly decreased AM fungal extraradical hyphal density, regardless of warming. A total of 79 operational taxonomic units (OTUs) of AM fungi were recovered by 454 pyrosequencing of SSU rDNA. Warming, but not N addition, had a significant positive effect on AM fungal OTU richness, while warming and N addition significantly increased AM fungal Shannon diversity index. N addition, but not warming, significantly altered the AM fungal community composition. Furthermore, the changes in AM fungal community composition were associated with shifts in plant community composition indirectly caused by N addition. These findings highlight the different effects of warming and N addition on AM fungal communities and contribute to understanding AM fungal community responses to global environmental change scenarios in semiarid steppe ecosystems.
Related JoVE Video
Urine Neutrophil Gelatinase-Associated Lipocalin and Risk of Cardiovascular Disease and Death in CKD: Results From the Chronic Renal Insufficiency Cohort (CRIC) Study.
Am. J. Kidney Dis.
PUBLISHED: 02-08-2014
Show Abstract
Hide Abstract
Chronic kidney disease is common and is associated with increased cardiovascular disease risk. Currently, markers of renal tubular injury are not used routinely to describe kidney health and little is known about the risk of cardiovascular events and death associated with these biomarkers independent of glomerular filtration-based markers (such as serum creatinine or albuminuria).
Related JoVE Video
Novel markers of gonadectomy-induced adrenocortical neoplasia in the mouse and ferret.
Mol. Cell. Endocrinol.
PUBLISHED: 01-21-2014
Show Abstract
Hide Abstract
Gonadectomy (GDX) induces sex steroid-producing adrenocortical tumors in certain mouse strains and in the domestic ferret. Transcriptome analysis and DNA methylation mapping were used to identify novel genetic and epigenetic markers of GDX-induced adrenocortical neoplasia in female DBA/2J mice. Markers were validated using a combination of laser capture microdissection, quantitative RT-PCR, in situ hybridization, and immunohistochemistry. Microarray expression profiling of whole adrenal mRNA from ovariectomized vs. intact mice demonstrated selective upregulation of gonadal-like genes including Spinlw1 and Insl3 in GDX-induced adrenocortical tumors of the mouse. A complementary candidate gene approach identified Foxl2 as another gonadal-like marker expressed in GDX-induced neoplasms of the mouse and ferret. That both "male-specific" (Spinlw1) and "female-specific" (Foxl2) markers were identified is noteworthy and implies that the neoplasms exhibit mixed characteristics of male and female gonadal somatic cells. Genome-wide methylation analysis showed that two genes with hypomethylated promoters, Igfbp6 and Foxs1, are upregulated in GDX-induced adrenocortical neoplasms. These new genetic and epigenetic markers may prove useful for studies of steroidogenic cell development and for diagnostic testing.
Related JoVE Video
Cloning, purification, crystallization and preliminary X-ray studies of HMO2 from Saccharomyces cerevisiae.
Acta Crystallogr F Struct Biol Commun
PUBLISHED: 01-15-2014
Show Abstract
Hide Abstract
The high-mobility group protein (HMO2) of Saccharomyces cerevisiae is a component of the chromatin-remodelling complex INO80, which is involved in double-strand break (DSB) repair. HMO2 can also bind DNA to protect it from exonucleolytic cleavage. Nevertheless, little structural information is available regarding these functions of HMO2. Since determination of three-dimensional structure is a powerful means to facilitate functional characterization, X-ray crystallography has been used to accomplish this task. Here, the expression, purification, crystallization and preliminary crystallographic analysis of HMO2 from S. cerevisiae are reported. The crystal belonged to space group P222, with unit-cell parameters a = 39.35, b = 75.69, c = 108.03?Å, and diffracted to a resolution of 3.0?Å. The crystals are most likely to contain one molecule in the asymmetric unit, with a VM value of 3.19?Å(3)?Da(-1).
Related JoVE Video
Inactivation of TRPM2 Channels by Extracellular Divalent Copper.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Cu2+ is an essential metal ion that plays a critical role in the regulation of a number of ion channels and receptors in addition to acting as a cofactor in a variety of enzymes. Here, we showed that human melastatin transient receptor potential 2 (hTRPM2) channel is sensitive to inhibition by extracellular Cu2+. Cu2+ at concentrations as low as 3 µM inhibited the hTRPM2 channel completely and irreversibly upon washing or using Cu2+ chelators, suggesting channel inactivation. The Cu2+-induced inactivation was similar when the channels conducted inward or outward currents, indicating the permeating ions had little effect on Cu2+-induced inactivation. Furthermore, Cu2+ had no effect on singe channel conductance. Alanine substitution by site-directed mutagenesis of His995 in the pore-forming region strongly attenuated Cu2+-induced channel inactivation, and mutation of several other pore residues to alanine altered the kinetics of channel inactivation by Cu2+. In addition, while introduction of the P1018L mutation is known to result in channel inactivation, exposure to Cu2+ accelerated the inactivation of this mutant channel. In contrast with the hTRPM2, the mouse TRPM2 (mTRPM2) channel, which contains glutamine at the position equivalent to His995, was insensitive to Cu2+. Replacement of His995 with glutamine in the hTRPM2 conferred loss of Cu2+-induced channel inactivation. Taken together, these results suggest that Cu2+ inactivates the hTRPM2 channel by interacting with the outer pore region. Our results also indicate that the amino acid residue difference in this region gives rise to species-dependent effect by Cu2+ on the human and mouse TRPM2 channels.
Related JoVE Video
Aspirin for primary prevention of cardiovascular events: meta-analysis of randomized controlled trials and subgroup analysis by sex and diabetes status.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
To evaluate the benefits and harms of aspirin for the primary prevention of CVD and determine whether the effects vary by sex and diabetes status.
Related JoVE Video
?-Klotho is an acute phase protein and altered by restraint stress in mice.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
To identify whether ?-Klotho is a kind of acute phase protein and alternation in the level of protein and mRNA under restraint stress.
Related JoVE Video
Klotho protein lowered in elderly hypertension.
Int J Clin Exp Med
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
We intend to identify the relationship between Klotho protein and elderly hypertension. Serous Klotho protein and nitric oxide (NO) which gathered from 79 elderly hypertensive patients, 30 elderly non-hypertensive patients and 25 non-elderly hypertensive patients were detected by ELISA and nitro-reductase method, respectively; and the comparison came from the former group and the last two groups. The results were as follows: Klotho protein absorbance (0.303 ± 0.096) and NO concentrations (43.95 ± 21.85 ?mol/L) in elderly hypertensive group were lower than the elderly non-hypertensive group (0.489 ± 0.216) and (62.63 ± 21.26 ?mol/L). So it shows that there was significant difference between the two groups (P < 0.01). And the result suggested that, except of the contribution of Klotho protein to the calcification of vessel wall and reduction of vascular elasticity, elderly hypertension may partially attributes to the reduction of serous Klotho protein, which leads to the shrinkage of endothelial function companied with decrease of NO.
Related JoVE Video
Entry properties and entry inhibitors of a human H7N9 influenza virus.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
The recently identified human infections with a novel avian influenza H7N9 virus in China raise important questions regarding possible risk to humans. However, the entry properties and tropism of this H7N9 virus were poorly understood. Moreover, neuraminidase inhibitor resistant H7N9 isolates were recently observed in two patients and correlated with poor clinical outcomes. In this study, we aimed to elucidate the entry properties of H7N9 virus, design and evaluate inhibitors for H7N9 virus entry. We optimized and developed an H7N9-pseudotyped particle system (H7N9pp) that could be neutralized by anti-H7 antibodies and closely mimicked the entry process of the H7N9 virus. Avian, human and mouse-derived cultured cells showed high, moderate and low permissiveness to H7N9pp, respectively. Based on influenza virus membrane fusion mechanisms, a potent anti-H7N9 peptide (P155-185-chol) corresponding to the C-terminal ectodomain of the H7N9 hemagglutinin protein was successfully identified. P155-185-chol demonstrated H7N9pp-specific inhibition of infection with IC50 of 0.19 µM. Importantly, P155-185-chol showed significant suppression of A/Anhui/1/2013 H7N9 live virus propagation in MDCK cells and additive effects with NA inhibitors Oseltamivir and Zanamivir. These findings expand our knowledge of the entry properties of the novel H7N9 viruses, and they highlight the potential for developing a new class of inhibitors targeting viral entry for use in the next pandemic.
Related JoVE Video
Bioinspired Total Synthesis of (±)-Yezootogirin C.
Org. Lett.
PUBLISHED: 12-30-2013
Show Abstract
Hide Abstract
The first and protective group-free total synthesis of (±)-yezootogirin C has been achieved from 3-methyl-4-prenylcyclohex-2-enone in eight steps with 23% overall yield. The tricyclic core of (±)-yezootogirin C was established via a bioinspired oxidative cascade cyclization strategy using Mn(II)/Mn(III) and O2, followed by reduction of the peroxy-bridged intermediate using thiourea in refluxing methanol.
Related JoVE Video
[Engineering Saccharomyces cerevisiae for sclareol production].
Sheng Wu Gong Cheng Xue Bao
PUBLISHED: 12-25-2013
Show Abstract
Hide Abstract
Sclareol is a member of labdane type diterpenes mostly used as fragrance ingredient. To enable microbial production of sclareol, synthetic pathways were constructed by incorporating labdenediol diphosphate synthase (LPPS) and terpene synthase (TPS) of the plant Salvia sclarea into Saccharomyces cerevisiae. It was found that sclareol production could be benefited by overexpression of key enzyme for precursor biosynthesis, construction of fusion protein for substrate channeling, and removal of signal peptides from LPPS and TPS. Under optimal shake flask culture conditions, strain S6 produced 8.96 mg/L sclareol. These results provided useful information for development of heterologous hosts for production of terpenoids.
Related JoVE Video
Vibration responses of h-BN sheet to charge doping and external strain.
J Chem Phys
PUBLISHED: 12-11-2013
Show Abstract
Hide Abstract
Based on density functional theory and density functional perturbation theory calculations, we systematically investigate the vibration responses of h-BN sheet to charge doping and external strains. It is found that under hole doping, the phonon frequencies of the ZO and TO branches at different wave vector q shift linearly with different slopes. Under electron doping, although the phonon frequencies shift irregularly, the shifting values are different at different phonon wave vectors. Interestingly, we find that external strain can restrain the irregular vibration responses of h-BN sheet to electron doping. The critical factor is revealed to be the relative position of the nearly free electron and boron pz states of h-BN sheet. Under external strains, the vibration responses of h-BN sheet are also found to be highly dependent on the phonon branches. Different vibration modes at different q points are revealed to be responsible for the vibration responses of h-BN sheet to charge doping and external strain. Our results point out a new way to detect the doping or strain status of h-BN sheet by measuring the vibration frequencies at different wave vector.
Related JoVE Video
Computer-aided Drug Design: Using Numbers to your Advantage.
ACS Med Chem Lett
PUBLISHED: 12-07-2013
Show Abstract
Hide Abstract
Computer-aided drug design could benefit from a greater understanding of how errors arise and propagate in biomolecular modeling. With such knowledge, model predictions could be associated with quantitative estimates of their uncertainty. In addition, novel algorithms could be designed to proactively reduce prediction errors. We investigated how errors propagate in statistical mechanical ensembles and found that free energy evaluations based on single molecular configurations yield maximum uncertainties in free energy. Furthermore, increasing the size of the ensemble by sampling and averaging over additional independent configurations reduces uncertainties in free energy dramatically. This finding suggests a general strategy that could be utilized as a post-hoc correction for improved precision in virtual screening and free energy estimation.
Related JoVE Video
ISRNA: an integrative online toolkit for short reads from high-throughput sequencing data.
Bioinformatics
PUBLISHED: 12-03-2013
Show Abstract
Hide Abstract
Integrative Short Reads NAvigator (ISRNA) is an online toolkit for analyzing high-throughput small RNA sequencing data. Besides the high-speed genome mapping function, ISRNA provides statistics for genomic location, length distribution and nucleotide composition bias analysis of sequence reads. Number of reads mapped to known microRNAs and other classes of short non-coding RNAs, coverage of short reads on genes, expression abundance of sequence reads as well as some other analysis functions are also supported. The versatile search functions enable users to select sequence reads according to their sub-sequences, expression abundance, genomic location, relationship to genes, etc. A specialized genome browser is integrated to visualize the genomic distribution of short reads. ISRNA also supports management and comparison among multiple datasets.
Related JoVE Video
Hidden Conformation Events in DNA Base Extrusions: A Generalized Ensemble Path Optimization and Equilibrium Simulation Study.
J Chem Theory Comput
PUBLISHED: 11-20-2013
Show Abstract
Hide Abstract
DNA base extrusion is a crucial component of many biomolecular processes. Elucidating how bases are selectively extruded from the interiors of double-strand DNAs is pivotal to accurately understanding and efficiently sampling this general type of conformational transitions. In this work, the on-the-path random walk (OTPRW) method, which is the first generalized ensemble sampling scheme designed for finite-temperature-string path optimizations, was improved and applied to obtain the minimum free energy path (MFEP) and the free energy profile of a classical B-DNA major-groove base extrusion pathway. Along the MFEP, an intermediate state and the corresponding transition state were located and characterized. The MFEP result suggests that a base-plane-elongation event rather than the commonly focused base-flipping event is dominant in the transition state formation portion of the pathway; and the energetic penalty at the transition state is mainly introduced by the stretching of the Watson-Crick base pair. Moreover to facilitate the essential base-plane-elongation dynamics, the surrounding environment of the flipped base needs to be intimately involved. Further taking the advantage of the extended-dynamics nature of the OTPRW Hamiltonian, an equilibrium generalized ensemble simulation was performed along the optimized path; and based on the collected samples, several base-flipping (opening) angle collective variables were evaluated. In consistence with the MFEP result, the collective variable analysis result reveals that none of these commonly employed flipping (opening) angles alone can adequately represent the base extrusion pathway, especially in the pre-transition-state portion. As further revealed by the collective variable analysis, the base-pairing partner of the extrusion target undergoes a series of in-plane rotations to facilitate the base-plane-elongation dynamics. A base-plane rotation angle is identified to be a possible reaction coordinate to represent these in-plane rotations. Notably, these in-plane rotation motions may play a pivotal role in determining the base extrusion selectivity.
Related JoVE Video
Characterization of the ubiquitin-modified proteome regulated by transient forebrain ischemia.
J. Cereb. Blood Flow Metab.
PUBLISHED: 09-17-2013
Show Abstract
Hide Abstract
Ubiquitylation is a posttranslational protein modification that modulates various cellular processes of key significance, including protein degradation and DNA damage repair. In animals subjected to transient cerebral ischemia, ubiquitin-conjugated proteins accumulate in Triton-insoluble aggregates. Although this process is widely considered to modulate the fate of postischemic neurons, few attempts have been made to characterize the ubiquitin-modified proteome in these aggregates. We performed proteomics analyses to identify ubiquitylated proteins in postischemic aggregates. Mice were subjected to 10?minutes of forebrain ischemia and 4?hours of reperfusion. The hippocampi were dissected, aggregates were isolated, and trypsin-digested after spiking with GG-BSA as internal standard. K-?-GG-containing peptides were immunoprecipitated and analyzed by label-free quantitative liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. We identified 1,664 peptides to 520 proteins containing at least one K-?-GG. Sixty-six proteins were highly ubiquitylated, with 10 or more K-?-GG peptides. Based on selection criteria of greater than fivefold increase and P<0.001, 763 peptides to 272 proteins were highly enriched in postischemic aggregates. These included proteins involved in important neuronal functions and signaling pathways that are impaired after ischemia. Results of this study could serve as an important platform to uncover the mechanisms linking insoluble ubiquitin aggregates to the functions of postischemic neurons.Journal of Cerebral Blood Flow & Metabolism advance online publication, 4 December 2013; doi:10.1038/jcbfm.2013.210.
Related JoVE Video
Neuritogenic Monoglyceride Derived from the Constituent of a Marine Fish for Activating the PI3K/ERK/CREB Signalling Pathways in PC12 Cells.
Int J Mol Sci
PUBLISHED: 09-16-2013
Show Abstract
Hide Abstract
A neuritogenic monoglyceride, 1-O-(myristoyl) glycerol (MG), was isolated from the head of Ilisha elongate using a PC12 cell bioassay system, and its chemical structure was elucidated using spectroscopic methods. MG significantly induced 42% of the neurite outgrowth of PC12 cells at a concentration of 10 ?M. To study the structure-activity relationships of MG, a series of monoglycerides was designed and synthesised. Bioassay results indicated that the alkyl chain length plays a key role in the neuritogenic activity of the monoglycerides. The groups that link the propane-1,2-diol and alkyl chain were also investigated. An ester linkage, rather than an amido one, was found to be optimal for neuritogenic activity. Therefore, 1-O-(stearoyl) glycerol (SG), which induces 57% of the neurite outgrowth of PC12 cells at 10 ?M, was determined to be a lead compound for neuritogenic activity. We then investigated the mechanism of action of neurite outgrowth induced by SG on PC12 cells using protein specific inhibitors and Western blot analysis. The mitogen-activated kinase/ERK kinase (MEK) inhibitor U0126 and the phosphatidylinositol-3 kinase (PI3K) inhibitor LY294002 significantly decreased neurite outgrowth. At the same time, SG increased phosphorylation of CREB in protein level. Thus, SG-induced neuritogenic activity depends on the activation of the extracellular-regulated protein kinase (ERK), cAMP responsive element-binding protein (CREB) and PI3K signalling pathways in PC12 cells.
Related JoVE Video
DNA Damage and Effects on Antioxidative Enzymes in Earthworm (Eisenia fetida) Induced by Flumorph.
Appl. Biochem. Biotechnol.
PUBLISHED: 09-06-2013
Show Abstract
Hide Abstract
Flumorph is an Oomycete fungicide, which is used extensively as an effective fungicide in vegetables and fruits, but little is known about its effect on nontarget soil organisms. In the present study, biochemical responses including changes in the activity of antioxidative enzymes catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST), malondialdehyde (MDA), and DNA damage induced by flumorph were investigated in earthworms (Eisenis fetida). The CAT concentrations were stimulated at 5.0 mg kg(-1) over 28 days and inhibited at 10 and 20 mg kg(-1), except 10 mg kg(-1) on days 21 and 28 compared with the controls. The overall SOD activities were inhibited except 5 mg kg(-1) on day 28 and 10 mg kg(-1) on days 7 and 14. Meanwhile, the GST activities were stimulated on day 7 and decreased on the other days in summary. The MDA activities were increased notably at 5, 10, and 20 mg kg(-1) after 14 days. Clear dose-dependent DNA damage to Eisenia fetida was observed by olive tail moments in comet assay compared with controls. The results demonstrate that flumorph induces oxidative stress and DNA damage to earthworms, and the effects may be the important mechanisms of its toxicity.
Related JoVE Video
Characterization of the interleukin 1 receptor-associated kinase 4 (IRAK4)-encoding gene in salmonid fish: The functional copy is rearranged in Oncorhynchus mykiss and that factor can impair TLR signaling in mammalian cells.
Fish Shellfish Immunol.
PUBLISHED: 08-27-2013
Show Abstract
Hide Abstract
The interleukin 1 receptor-associated kinase 4 (IRAK4) is an essential factor for TLR-mediated activation of the hosts immune functions subsequent to pathogen contact. We have characterized the respective cDNA and gene sequences from three salmonid species, salmon, rainbow trout and maraena whitefish. The gene from salmon is structured into eleven exons, as is the mammalian homologue, while exons have been fused in the genes from the two other salmonid species. Rainbow trout expresses also a pseudogene at low levels. Its basic structure resembles more closely the primordial gene than the functional copy does. The N-terminal death domain and the C-terminal protein kinase domain of the factors are better conserved throughout evolution than the linker domain. The deduced amino acid sequences of the factors from all three species group together in an evolutionary tree of IRAK4 factors. Scrutinizing expression and function of IRAK4 from rainbow trout, we found its highest expression in head kidney and spleen and lowest expression in muscle tissue. Infecting fish with Aeromonas salmonicida did not modulate its expression during 72 h of observation. Expression of a GFP-tagged trout IRAK4 revealed, expectedly, its cytoplasmic localization in human HEK-293 cells. However, this factor significantly quenched in a dose-dependent fashion not only the pathogen-induced stimulation of NF-?B factors in the HEK-293 reconstitution system of TLR2 signaling, but also the basal NF-?B levels in unstimulated control cells. Our data unexpectedly imply that IRAK4 is involved in establishing threshold levels of active NF-?B in resting cells.
Related JoVE Video
Deoxynivalenol induced oxidative stress and genotoxicity in human peripheral blood lymphocytes.
Food Chem. Toxicol.
PUBLISHED: 08-21-2013
Show Abstract
Hide Abstract
Deoxynivalenol (DON) is one of the most common mycotoxins. The aim of this study consists in using diverse cellular and molecular assays to evaluate cytotoxicity, genotoxicity as well as oxidative damage and to investigate their mechanisms in human peripheral blood lymphocytes. The human lymphocytes were cultured in eight different doses of DON (0, 6.25, 12.5, 25, 50, 100, 250 and 500ng/mL) during 6; 12; and 24h. DON was able to decrease cell viability and cause damage to the membrane, the chromosomes or the DNA at all times of culture. It was also able to induce lipid peroxidation and raise the levels of 8-OHdG and ROS in 6, 12 and 24h. The results of the RT-PCR and the Western Blot indicated that DON is able to enhance mRNA or protein expressions of DNA repair genes and HO-1 in 6h and to inhibit these expressions in 24h. DON potentially triggers genotoxicity in human lymphocytes. This mechanism is probably related to depletion of antioxidase and oxidative damage to the DNA that reduced expression of HO-1, thereby inhibiting the ability of DNA repair.
Related JoVE Video
The draft genome of a socially polymorphic halictid bee, Lasioglossum albipes.
Genome Biol.
PUBLISHED: 07-17-2013
Show Abstract
Hide Abstract
Taxa that harbor natural phenotypic variation are ideal for ecological genomic approaches aimed at understanding how the interplay between genetic and environmental factors can lead to the evolution of complex traits. Lasioglossum albipes is a polymorphic halictid bee that expresses variation in social behavior among populations, and common-garden experiments have suggested that this variation is likely to have a genetic component.
Related JoVE Video
Correlation between TSP-1, TGF-? and PPAR-? expression levels and glioma microvascular density.
Oncol Lett
PUBLISHED: 04-25-2013
Show Abstract
Hide Abstract
Gliomas are the most common type of primary tumor in the central nervous system and are characterized by abundant capillary angiogenesis. It is important to study the underlying molecular mechanisms of angiogenesis in order to aid the identification of potential therapeutic targets. The aim of the current study was to investigate the expression levels of thrombospondin-1 (TSP-1), transforming growth factor-? (TGF-?) and peroxisome proliferator-activated receptor-? (PPAR-?) in gliomas, and determine their relationships with angiogenesis. Immunohistochemical methods were used to detect TSP-1, TGF-? and PPAR-? expression levels and to assess microvascular density (MVD) in 99 glioma tissue samples of various grades. The total positive expression rates of TSP-1 and PPAR-? were 78.4 and 94.1% in low-grade gliomas and 45.8 and 39.6% in high-grade gliomas. These values suggest that their expression negatively correlated with tumor grade. However, TGF-? expression positively correlated with tumor grade; the total positive expression rate of TGF-? in high-grade gliomas (93.8%) was significantly increased compared with that in low-grade gliomas (43.1%). The MVD in the low-grade group was 28±7.2 vessels/field, which was significantly lower than in the high-grade group (45±6.2 vessels/field). TSP-1 and PPAR-? expression levels were negatively correlated with MVD (P<0.05), while the TGF-? expression level was positively correlated with MVD (P<0.05). These results indicate that the TSP-1, TGF-? and PPAR-? expression levels in gliomas are correlated with MVD, which suggests that these proteins may be involved in the regulation of glioma angiogenesis.
Related JoVE Video
Source Apportionment of PAHs Using Unmix Model for Yantai Costal Surface Sediments, China.
Bull Environ Contam Toxicol
PUBLISHED: 04-20-2013
Show Abstract
Hide Abstract
16 Polycyclic aromatic hydrocarbons (PAHs) in 20 surface sediments from Yantai offshore area were measured. The total PAHs concentrations varied from 450.0 to 4,299.0 ng/g, with a mean of 2,492.9 ng/g. The high molecular weight (HMW) PAHs were most abundant and the ratio ranged from 54.9 % to 81.6 % in all sampling stations, indicating that pyrogenic sources were a predominant contribution to PAHs pollution. The source contributions of PAHs were estimated based on the EPA Unmix 6.0 receptor model. The data were well simulated due to a high correlation coefficient between predicted and measured PAHs concentration (R(2) = 0.99). A mixed source of coal combustion and traffic pollution contributed to 38.9 % of the measured PAHs, followed by diesel emission (38.8 %) and a mixed source of biomass combustion and gasoline engine emissions (22.3 %). The current findings further validated that Unmix model could be applied to apportion the sources of PAHs in sediments.
Related JoVE Video
EHR adoption across Chinas tertiary hospitals: A cross-sectional observational study.
Int J Med Inform
PUBLISHED: 03-15-2013
Show Abstract
Hide Abstract
EHR adoption across Chinas tertiary hospitals: a cross-sectional observation study OBJECTIVES: To assess electronic health record (EHR) adoption in Chinese tertiary hospitals using a nation-wide standard EHR grading model.
Related JoVE Video
Hydrogen Peroxide Is a Second Messenger in the Salicylic Acid-Triggered Adventitious Rooting Process in Mung Bean Seedlings.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
In plants, salicylic acid (SA) is a signaling molecule that regulates disease resistance responses, such as systemic acquired resistance (SAR) and hypertensive response (HR). SA has been implicated as participating in various biotic and abiotic stresses. This study was conducted to investigate the role of SA in adventitious root formation (ARF) in mung bean (Phaseolus radiatus L) hypocotyl cuttings. We observed that hypocotyl treatment with SA could significantly promote the adventitious root formation, and its effects were dose and time dependent. Explants treated with SA displayed a 130% increase in adventitious root number compared with control seedlings. The role of SA in mung bean hypocotyl ARF as well as its interaction with hydrogen peroxide (H2O2) were also elucidated. Pretreatment of mung bean explants with N, N-dimethylthiourea (DMTU), a scavenger for H2O2, resulted in a significant reduction of SA-induced ARF. Diphenyleneiodonium (DPI), a specific inhibitor of membrane-linked NADPH oxidase, also inhibited the effect of adventitious rooting triggered by SA treatment. The determination of the endogenous H2O2 level indicated that the seedlings treated with SA could induce H2O2 accumulation compared with the control treatment. Our results revealed a distinctive role of SA in the promotion of adventitious rooting via the process of H2O2 accumulation. This conclusion was further supported by antioxidant enzyme activity assays. Based on these results, we conclude that the accumulation of free H2O2 might be a downstream event in response to SA-triggered adventitious root formation in mung bean seedlings.
Related JoVE Video
Mutations in PRRT2 result in paroxysmal dyskinesias with marked variability in clinical expression.
J. Med. Genet.
PUBLISHED: 12-29-2011
Show Abstract
Hide Abstract
Paroxysmal dyskinesias (PDs), a clinically and genetically heterogeneous group of episodic movement disorders, include kinesigenic PD (PKD), exercise-induced PD (PED) and non-kinesigenic PD (PNKD). These disorders are all transmitted as autosomal dominant traits with incomplete penetrance. Several PD-related genetic disorders, including PKD and familial infantile convulsions with paroxysmal choreoathetosis (ICCA), mapped to the same region on chromosome 16. Independent genetic studies have recently revealed that PKD can be caused by loss-of-function mutations in the proline-rich transmembrane protein 2 gene (PRRT2). We tested the hypothesis that other forms of PDs are also due to PRRT2 mutations.
Related JoVE Video
[Genetic testing in a Chinese pedigree with Lowe syndrome].
Zhonghua Yan Ke Za Zhi
PUBLISHED: 12-20-2011
Show Abstract
Hide Abstract
To identify the pathogenic mutation underlying Lowe syndrome in a Chinese family.
Related JoVE Video

What is Visualize?

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

How does it work?

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

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

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