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.
Anion A- • HX Clusters with Reduced Electron Binding Energies: Proton vs Hydrogen Atom Relocation Upon Electron Detachment.
J. Am. Chem. Soc.
PUBLISHED: 11-20-2014
Show Abstract
Hide Abstract
Clustering an anion with one or more neutral molecules is a stabilizing process that enhances the oxidation potential of the complex relative to the free ion. Several hydrogen bond clusters (i.e., A- • HX, where A- = H2PO4- and CF3CO2- and HX = MeOH, PhOH, and Me2NOH or Et2NOH) are examined by photoelectron spectroscopy and M06-2X and CCSD(T) computations. Remarkably, these species are experimentally found to have adiabatic detachment energies that are smaller than those for the free ion and reductions of 0.47 to 1.87 eV are predicted computationally. Hydrogen atom and proton transfers upon vertical photodetachment are two limiting extremes on the neutral surface in a continuum of mechanistic pathways that account for these results, and the whole gamut of possibilities are predicted to occur.
Related JoVE Video
Detection of posteriorly located breast tumors using gold nanoparticles: A breast-mimicking phantom study.
J Xray Sci Technol
PUBLISHED: 11-20-2014
Show Abstract
Hide Abstract
Accurately depicting breast tumors located posteriorly, close to the chest wall musculature, with conventional mammography is a technical challenge.OBJECTIVE: This study demonstrates the proof of concept of an x-ray fluorescence mapping (XFM) technique to address this issue.METHODS: A tissue-equivalent gel phantom is designed to mimic structures in the central part of a compressed breast. The posterior aspect of the breast and adjacent pectoralis major muscle are represented by another 10-mm-thickness breast tissue simulation phantom (BR12) that is attached to the back of the gel phantom as a region of interest (ROI). Two gold nanoparticle (GNP) solutions are embedded into the ROI to simulate varying GNP uptake within breast lesions. The ROI is imaged through performing the XFM technique with an x-ray pencil-beam and a single spectrometer.RESULTS: A 2D mapping of the middle plane in the ROI demonstrates feasibility and matches well the known spatial distribution and different GNP concentrations. 3D reconstruction of the ROI is easily rendered by repeating the 2D mapping process.CONCLUSION: XFM system geometry and its insensitivity to attenuation coefficients of breast tissue components are unique characteristics that may complement conventional mammography and improve the detection of breast cancers located posteriorly, adjacent to or overlying the chest wall musculature.
Related JoVE Video
Fullerene cyanation does not always increase electron affinity: an experimental and theoretical study.
Phys Chem Chem Phys
PUBLISHED: 11-20-2014
Show Abstract
Hide Abstract
The electron affinities of C70 derivatives with trifluoromethyl, methyl and cyano groups were studied experimentally and theoretically using low-temperature photoelectron spectroscopy (LT PES) and density functional theory (DFT). The electronic effects of these functional groups were determined and found to be highly dependent on the addition patterns. Substitution of CF3 for CN for the same addition pattern increases the experimental electron affinity by 70 meV per substitution. The synthesis of a new fullerene derivative, C70(CF3)10(CN)2, is reported for the first time.
Related JoVE Video
p53-mediated Regulation of Phosphoglycerate Dehydrogenase (PHGDH) is crucial for the Apoptotic Response Upon Serine Starvation.
J. Biol. Chem.
PUBLISHED: 11-19-2014
Show Abstract
Hide Abstract
Although p53 is frequently mutated in human cancers, about 80% of human melanomas retain wild-type p53. Here, we report that PHGDH, the key metabolic enzyme that cata-lyzes the rate-limiting step of serine biosynthesis pathway, is a target of p53 in human melanoma cells. p53 suppresses its expression and inhibits de novo serine biosynthesis. Notably, upon serine starvation, p53-mediated cell death is dramatically enhanced in response to Nutlin-3 treatment. Moreover, PHGDH is recently found to be frequently amplified in human melanomas. We found that PHGDH overexpression significantly suppresses the apoptotic response, whereas RNAi-mediated knock-down of endogenous PHGDH promotes apoptosis under the same treatment. These results demonstrate an important role of p53 in regulating serine biosynthesis pathway through suppressing PHGDH expression and reveal serine deprivation as a novel approach to sensitize p53-mediated apoptotic responses in human melanoma cells.
Related JoVE Video
[Morphological changes of corneal subbasal nerve plexus in patients with ocular blunt trauma by in vivo confocal microscope].
Zhonghua Yan Ke Za Zhi
PUBLISHED: 11-12-2014
Show Abstract
Hide Abstract
To evaluate morphological changes of corneal subbasal nerve plexus in patients with ocular blunt trauma using in vivo confocal microscope.
Related JoVE Video
Feature selection for the automated detection of metaphase chromosomes: Performance comparison using a receiver operating characteristic (ROC) method.
Anal Cell Pathol (Amst)
PUBLISHED: 10-02-2014
Show Abstract
Hide Abstract
The purpose of this study is to identify a set of features for optimizing the performance of metaphase chromosome detection under high throughput scanning microscopy. In the development of computer-aided detection (CAD) scheme, feature selection is critically important, as it directly determines the accuracy of the scheme. Although many features have been examined previously, selecting optimal features is often application-oriented.
Related JoVE Video
Clinical Evaluation of Rigid Gas Permeable Contact Lenses and Visual Outcome After Repaired Corneal Laceration.
Eye Contact Lens
PUBLISHED: 09-18-2014
Show Abstract
Hide Abstract
To evaluate the clinical value of rigid gas permeable contact lenses (RGPCLs) in patients with traumatic corneal scarring and address implications of primary corneal repair.
Related JoVE Video
[Protein interaction site of Toxoplasma gondii microneme protein 6 and aldolase determined by site-directed mutagenesis].
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi
PUBLISHED: 09-17-2014
Show Abstract
Hide Abstract
To identify the protein interaction site of Toxoplasma gondii microneme protein 6 (MIC6) and aldolase by using site-directed mutagenesis.
Related JoVE Video
Automated identification of retinal vessels using a multiscale directional contrast quantification (MDCQ) strategy.
Med Phys
PUBLISHED: 09-05-2014
Show Abstract
Hide Abstract
A novel algorithm is presented to automatically identify the retinal vessels depicted in color fundus photographs.
Related JoVE Video
Synthesis of the 6-azaindole containing HIV-1 attachment inhibitor pro-drug, BMS-663068.
J. Org. Chem.
PUBLISHED: 09-05-2014
Show Abstract
Hide Abstract
The development of a short and efficient synthesis of a complex 6-azaindole, BMS-663068, is described. Construction of the 6-azaindole core is quickly accomplished starting from a simple pyrrole, via a regioselective Friedel-Crafts acylation, Pictet-Spengler cyclization, and a radical-mediated aromatization. The synthesis leverages an unusual heterocyclic N-oxide ?-bromination to functionalize a critical C-H bond, enabling a highly regioselective copper-mediated Ullmann-Goldberg-Buchwald coupling to install a challenging triazole substituent. This strategy resulted in an efficient 11 step linear synthesis of this complex clinical candidate.
Related JoVE Video
[Value of admission electrocardiogram for predicting multivessel disease in acute anterior and anterior-inferior myocardial infarction].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 08-26-2014
Show Abstract
Hide Abstract
The correlation between admission Electrocardiogram (ECG) and coronary angiography findings have the responsibility for culprit vessel in predicting the infarct or multivessel disease (MVD) in acute anterior or anterior-inferior ST segment elevation myocardial infarction.
Related JoVE Video
Biomass-directed synthesis of 20 g high-quality boron nitride nanosheets for thermoconductive polymeric composites.
ACS Nano
PUBLISHED: 08-25-2014
Show Abstract
Hide Abstract
Electrically insulating boron nitride (BN) nanosheets possess thermal conductivity similar to and thermal and chemical stabilities superior to those of electrically conductive graphenes. Currently the production and application of BN nanosheets are rather limited due to the complexity of the BN binary compound growth, as opposed to massive graphene production. Here we have developed the original strategy "biomass-directed on-site synthesis" toward mass production of high-crystal-quality BN nanosheets. The strikingly effective, reliable, and high-throughput (dozens of grams) synthesis is directed by diverse biomass sources through the carbothermal reduction of gaseous boron oxide species. The produced BN nanosheets are single crystalline, laterally large, and atomically thin. Additionally, they assemble themselves into the same macroscopic shapes peculiar to original biomasses. The nanosheets are further utilized for making thermoconductive and electrically insulating epoxy/BN composites with a 14-fold increase in thermal conductivity, which are envisaged to be particularly valuable for future high-performance electronic packaging materials.
Related JoVE Video
The negative ion photoelectron spectrum of cyclopropane-1,2,3-trione radical anion, (CO)3(•-)--a joint experimental and computational study.
J. Am. Chem. Soc.
PUBLISHED: 08-22-2014
Show Abstract
Hide Abstract
Negative ion photoelectron (NIPE) spectra of the radical anion of cyclopropane-1,2,3-trione, (CO)3(•-), have been obtained at 20 K, using both 355 and 266 nm lasers for electron photodetachment. The spectra show broadened bands, due to the short lifetimes of both the singlet and triplet states of neutral (CO)3 and, to a lesser extent, to the vibrational progressions that accompany the photodetachment process. The smaller intensity of the band with the lower electron binding energy suggests that the singlet is the ground state of (CO)3. From the NIPE spectra, the electron affinity (EA) and the singlet-triplet energy gap of (CO)3 are estimated to be, respectively, EA = 3.1 ± 0.1 eV and ?EST = -14 ± 3 kcal/mol. High-level, (U)CCSD(T)/aug-cc-pVQZ//(U)CCSD(T)/aug-cc-pVTZ, calculations give EA = 3.04 eV for the (1)A1' ground state of (CO)3 and ?EST = -13.8 kcal/mol for the energy gap between the (1)A1' and (3)A2 states, in excellent agreement with values from the NIPE spectra. In addition, simulations of the vibrational structures for formation of these states of (CO)3 from the (2)A2? state of (CO)3(•-) provide a good fit to the shapes of broad bands in the 266 nm NIPE spectrum. The NIPE spectrum of (CO)3(•-) and the analysis of the spectrum by high-quality electronic structure calculations demonstrate that NIPES can not only access and provide information about transition structures but NIPES can also access and provide information about hilltops on potential energy surfaces.
Related JoVE Video
The use of a well-defined surface organometallic complex as a probe molecule: [(?SiO)Ta(V)Cl2Me2] shows different isolated silanol sites on the silica surface.
Chem. Commun. (Camb.)
PUBLISHED: 08-22-2014
Show Abstract
Hide Abstract
Ta(V)Cl2Me3 reacts with silica(700) and produces two different [(?SiO)Ta(V)Cl2Me2] surface organometallic species, suggesting a heterogeneity of the highly dehydroxylated silica surface, which was studied with a combined experimental and theoretical approach.
Related JoVE Video
Energy Stress Regulates Hippo-YAP Signaling Involving AMPK-Mediated Regulation of Angiomotin-like 1 Protein.
Cell Rep
PUBLISHED: 08-18-2014
Show Abstract
Hide Abstract
Hippo signaling is a tumor-suppressor pathway involved in organ size control and tumorigenesis through the inhibition of YAP and TAZ. Here, we show that energy stress induces YAP cytoplasmic retention and S127 phosphorylation and inhibits YAP transcriptional activity and YAP-dependent transformation. These effects require the central metabolic sensor AMP-activated protein kinase (AMPK) and the upstream Hippo pathway components Lats1/Lats2 and angiomotin-like 1 (AMOTL1). Furthermore, we show that AMPK directly phosphorylates S793 of AMOTL1. AMPK activation stabilizes and increases AMOTL1 steady-state protein levels, contributing to YAP inhibition. The phosphorylation-deficient S793Ala mutant of AMOTL1 showed a shorter half-life and conferred resistance to energy-stress-induced YAP inhibition. Our findings link energy sensing to the Hippo-YAP pathway and suggest that YAP may integrate spatial (contact inhibition), mechanical, and metabolic signals to control cellular proliferation and survival.
Related JoVE Video
Associations between AT-rich interactive domain 5B gene polymorphisms and risk of childhood acute lymphoblastic leukemia: a meta-analysis.
Asian Pac. J. Cancer Prev.
PUBLISHED: 08-16-2014
Show Abstract
Hide Abstract
Previous genome-wide association studies (GWAS) have implicated several single nucleotide polymorphisms (SNPs) in the AT-rich interactive domain 5B (ARID5B) gene with childhood acute lymphoblastic leukemia (ALL). However, replicated studies reported some inconsistent results in different populations. Using meta-analysis, we here aimed to clarify the nature of the genetic risks contributed by the two polymorphisms (rs10994982, rs7089424) for developing childhood ALL. Through searches of PubMed, EMBASE, and manually searching relevant references, a total of 14 articles with 16 independent studies were included. Odds ratios (ORs) with 95% confidence intervals (95%CI) were calculated to assess the associations. Both SNPs rs10994982 and rs7089424 showed significant associations with childhood ALL risk in all genetic models after Bonferroni correction. Furthermore, subtype analyses of B-lineage ALL provided strong evidence that SNP rs10994982 is highly associated with the risk of developing B-hyperdiploid ALL. These results indicate that SNPs rs10994982 and rs7089424 are indeed significantly associated with increased risk of childhood ALL.
Related JoVE Video
[Severe fever with thrombocytopenia syndrome virus nucleoprotein specifically binds to 60kD SSA/Ro protein in host cells].
Bing Du Xue Bao
PUBLISHED: 08-15-2014
Show Abstract
Hide Abstract
This study aims to investigate whether the nucleoprotein (NP) of severe fever with thrombocytopenia syndrome virus (SFTSV) can impact the cellular immunity of host cells. Gene segments that encode the NP and non-structural protein (NSs) of SFTSV were inserted into eukaryotic expression vector VR1012. Host proteins that interact with NP and affect immunity were identified with co-immunoprecipitation (IP), SDS-PAGE, mass spectrometry (MS), and Western blot. Co-localization of NP and the identified host proteins was confirmed by confocal microscopy. A 60kD SSA/Ro, a protein related to immunity, interacted with NP, as found by IP and MS. Confocal microscopy showed that NP and SSA/Ro were co-localized in cytoplasm. These results indicated that SFTSV NP may specifically bind to 60kD SSA/Ro and cause a series of immune responses and clinical symptoms.
Related JoVE Video
A new and fast image feature selection method for developing an optimal mammographic mass detection scheme.
Med Phys
PUBLISHED: 08-04-2014
Show Abstract
Hide Abstract
Selecting optimal features from a large image feature pool remains a major challenge in developing computer-aided detection (CAD) schemes of medical images. The objective of this study is to investigate a new approach to significantly improve efficacy of image feature selection and classifier optimization in developing a CAD scheme of mammographic masses.
Related JoVE Video
[Retrospective analysis of granted projects of the National Institute of Parasitic Disease, China CDC during 2002-2012].
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi
PUBLISHED: 07-29-2014
Show Abstract
Hide Abstract
In this paper, the granted projects of the National Institute of Parasitic Diseases (NIPD), China CDC, was analyzed. The results showed that from 2002 to 2012, 126 projects were granted to NIPD. 28.6% (36/126) of the projects were at the national level; 27% (34/126) were at provincial and ministrerial level. International cooperation projects and those supported by state key laboratory and enterprises accounted for 28.6% (36/126) and 15.8% (20/126), respectively. 94 projects belonged to applied researches and 32 belonged to basic researches. Most project leaders were young and middle-aged researchers with senior professional titles.
Related JoVE Video
A preorganized hydrogen bond network and its effect on anion stability.
J Phys Chem A
PUBLISHED: 07-25-2014
Show Abstract
Hide Abstract
Rigid tricyclic locked in all axial 1,3,5-cyclohexanetriol derivatives with 0-3 trifluoromethyl groups were synthesized and photoelectron spectra of their conjugate bases and chloride anion clusters are reported along with density functional computations. The resulting vertical and adiabatic detachment energies span 4.07-5.50 eV (VDE) and 3.75-5.00 (ADE) for the former ions and 5.60-6.23 eV (VDE) and 5.36-6.00 eV (ADE) for the latter species. These results provide measures of the anion stabilization due to the hydrogen bond network and inductive effects. The latter mechanism is found to be transmitted through space via hydrogen bonds, and the presence of three ring skeleton oxygen atoms and up to three trifluoromethyl groups enhance the ADEs by 1.61-2.88 eV for the conjugate bases and 1.01-1.60 eV for the chloride anion clusters. Computations indicate that the most favorable structures of the latter complexes have two hydrogen bonds to the chloride anion and one bifurcated interaction between the remote OH substituent and the two hydroxyl groups that directly bind to Cl(-).
Related JoVE Video
[SWOT analysis of laboratory certification and accreditation on detection of parasitic diseases].
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
PUBLISHED: 07-24-2014
Show Abstract
Hide Abstract
This study analyzes the strength, weakness, opportunity and threat (SWOT) of laboratory certification and accreditation on detection of parasitic diseases by SWOT analysis comprehensively, and it puts forward some development strategies specifically, in order to provide some indicative references for the further development.
Related JoVE Video
Video Processing to Locate the Tooltip Position in Surgical Eye-Hand Coordination Tasks.
Surg Innov
PUBLISHED: 07-23-2014
Show Abstract
Hide Abstract
Introduction. Trajectories of surgical instruments in laparoscopic surgery contain rich information about surgeons' performance. In a simulation environment, instrument trajectories can be taken by motion sensors attached to the instruments. This method is not accepted by surgeons working in the operating room due to safety concerns. In this study, a novel approach of acquiring instrument trajectories from surgical videos is reported. Methods. A total of 12 surgical videos were obtained for this study. The videos were captured during simulated laparoscopic procedures where subjects were required to pick up and transport an object over 3 different targets using a laparoscopic grasper. An algorithm was developed to allow the computer to identify the tip of the grasper on each frame of video, and then compute the trajectories of grasper movement. Results. The newly developed algorithm successfully identified tool trajectories from all 12 surgical videos. To validate the accuracy of this algorithm, the location of the tooltip in these videos were also manually labeled. The rate of accurate matching between these 2 methods was 98.4% of all video frames. Discussion. Identifying tool movement from surgical videos creates an effective way to track instrument trajectories. This builds up the foundation for assessing psychomotor performance of surgeons in the operating room without jeopardizing patient safety.
Related JoVE Video
Reduction of false-positive recalls using a computerized mammographic image feature analysis scheme.
Phys Med Biol
PUBLISHED: 07-17-2014
Show Abstract
Hide Abstract
The high false-positive recall rate is one of the major dilemmas that significantly reduce the efficacy of screening mammography, which harms a large fraction of women and increases healthcare cost. This study aims to investigate the feasibility of helping reduce false-positive recalls by developing a new computer-aided diagnosis (CAD) scheme based on the analysis of global mammographic texture and density features computed from four-view images. Our database includes full-field digital mammography (FFDM) images acquired from 1052 recalled women (669 positive for cancer and 383 benign). Each case has four images: two craniocaudal (CC) and two mediolateral oblique (MLO) views. Our CAD scheme first computed global texture features related to the mammographic density distribution on the segmented breast regions of four images. Second, the computed features were given to two artificial neural network (ANN) classifiers that were separately trained and tested in a ten-fold cross-validation scheme on CC and MLO view images, respectively. Finally, two ANN classification scores were combined using a new adaptive scoring fusion method that automatically determined the optimal weights to assign to both views. CAD performance was tested using the area under a receiver operating characteristic curve (AUC). The AUC = 0.793? ± ?0.026 was obtained for this four-view CAD scheme, which was significantly higher at the 5% significance level than the AUCs achieved when using only CC (p = 0.025) or MLO (p = 0.0004) view images, respectively. This study demonstrates that a quantitative assessment of global mammographic image texture and density features could provide useful and/or supplementary information to classify between malignant and benign cases among the recalled cases, which may eventually help reduce the false-positive recall rate in screening mammography.
Related JoVE Video
Examining the amine functionalization in dicarboxylates: photoelectron spectroscopy and theoretical studies of aspartate and glutamate.
J Phys Chem A
PUBLISHED: 07-07-2014
Show Abstract
Hide Abstract
Aspartate (Asp(2-)) and glutamate (Glu(2-)), two doubly charged conjugate bases of the corresponding amino acids, were investigated using low-temperature negative ion photoelectron spectroscopy (NIPES) and ab initio calculations. The effect of amine functionalization was studied by a direct comparison to the parent dicarboxylate species ((-)CO2-(CH2)n-CO2(-), DCn(2-)), succinate (DC2(2-)) and propionate (DC3(2-)). Experimentally, the addition of the amine group for the n = 2 case (DC2(2-), Asp(2-)) significantly improves the stability of the resultant Asp(2-) dianionic species, albeit that NIPES shows only a small increase in adiabatic electron detachment energy (ADE) (+0.05 eV). In contrast, for n = 3 (DC3(2-), Glu(2-)), a much larger ADE increase is observed (+0.15 eV). Similar results are obtained through ab initio calculations. The latter indicates that increased stability of Asp(2-) can be attributed to the lowering of the energy of the singlet dianion state due to hydrogen bonding effects. The effect of the amino group on the doublet monoanion state is more complicated and results in the weakening of the binding of the adjacent carboxylate group due to electronic structure resonance effects. This conclusion is confirmed by the analysis of NIPES results that show enhanced production of near-zero kinetic energy electrons observed experimentally for amine-functionalized species.
Related JoVE Video
Vascular calcification is coupled with phenotypic conversion of vascular smooth muscle cells through KLF5-mediated transactivation of the Runx2 promoter.
Biosci. Rep.
PUBLISHED: 07-02-2014
Show Abstract
Hide Abstract
Both KLF5 and Runx2 are involved in phenotypic switching of vascular smooth muscle cells (VSMC). However, the potential link between KLF5 and Runx2 in mediating vascular calcification remains unclear. The aim of the study was to elucidate the actual relationship between KLF5 and Runx2 in mediating VSMC calcification. We found that high phosphate increased the expression of KLF5, which is accompanied by loss of SM ?-actin and SM22?, as well as gain of Runx2 expression. Overexpression of KLF5 increased, while knockdown of KLF5 decreased, Runx2 expression and calcification. Further study showed that KLF5 bound directly to the Runx2 promoter and activated its transcription. KLF5 was also induced markedly in the calcified aorta of adenine-induced uremic rats. In conclusion, we demonstrate a critical role for KLF5-mediated induction of Runx2 in high phosphate-induced VSMC calcification.
Related JoVE Video
Tongxinluo inhibits vascular inflammation and neointimal hyperplasia through blockade of the positive feedback loop between miR-155 and TNF-?.
Am. J. Physiol. Heart Circ. Physiol.
PUBLISHED: 06-22-2014
Show Abstract
Hide Abstract
Tongxinluo (TXL), a traditional Chinese medicine, has multiple vasoprotective effects, including anti-inflammation. MicroRNA-155 (miR-155) is involved in vascular inflammation and atherosclerosis. However, a direct relationship between TXL and miR-155 in the development of vascular inflammation and remodeling had not yet been shown. The objective of the present study was to investigate whether TXL exerts an inhibitory effect on the vascular inflammatory response and neointimal hyperplasia by regulating miR-155 expression. Using the carotid artery ligation model in mice, we have shown that TXL dose dependently inhibited neointimal formation and reduced the vascular inflammatory response by inhibiting inflammatory cytokine production and macrophage infiltration. miR-155 was induced by carotid artery ligation, and neointimal hyperplasia was strongly reduced in miR-155(?/?) mice. In contrast, miR-155 overexpression partly reversed the inhibitory effect of TXL on neointimal hyperplasia. In bone marrow-derived macrophages, miR-155 and TNF-? formed a positive feedback loop to promote the inflammatory response, which could be blocked by TXL. Furthermore, TXL increased Akt1 protein expression and phosphorylation in TNF-?-stimulated marrow-derived macrophages, and knockdown of Akt1 abrogated the TXL-induced suppression of miR-155. In conclusion, TXL inhibits the vascular inflammatory response and neointimal hyperplasia induced by carotid artery ligation in mice. Suppression of miR-155 expression mediated by Akt1 and blockade of the feedback loop between miR-155 and TNF-? are important pathways whereby TXL exerts its vasoprotective effects.
Related JoVE Video
miR-182 attenuates atrophy-related gene expression by targeting FoxO3 in skeletal muscle.
Am. J. Physiol., Cell Physiol.
PUBLISHED: 05-28-2014
Show Abstract
Hide Abstract
Skeletal muscle atrophy occurs in response to a variety of conditions including chronic kidney disease, diabetes, cancer, and elevated glucocorticoids. MicroRNAs (miR) may play a role in the wasting process. Activation of the forkhead box O3 (FoxO3) transcription factor causes skeletal muscle atrophy in patients, animals, and cultured cells by increasing the expression of components of the ubiquitin-proteasome and autophagy-lysosome proteolytic systems. To identify microRNAs that potentially modulate the atrophy process, an in silico target analysis was performed and miR-182 was predicted to target FoxO3 mRNA. Using a combination of immunoblot analysis, quantitative real-time RT-PCR, and FoxO3 3'-UTR luciferase reporter genes, miR-182 was confirmed to regulate FoxO3 expression in C2C12 myotubes. Transfection of miR-182 into muscle cells decreased FoxO3 mRNA 30% and FoxO3 protein 67% (P < 0.05) and also prevented a glucocorticoid-induced upregulation of multiple FoxO3 gene targets including MAFbx/atrogin-1, autophagy-related protein 12 (ATG12), cathepsin L, and microtubule-associated protein light chain 3 (LC3). Treatment of C2C12 myotubes with dexamethasone (Dex) (1 ?M, 6 h) to induce muscle atrophy decreased miR-182 expression by 63% (P < 0.05). Similarly, miR-182 was decreased 44% (P < 0.05) in the gastrocnemius muscle of rats injected with streptozotocin to induce diabetes compared with controls. Finally, miR-182 was present in exosomes isolated from the media of C2C12 myotubes and Dex increased its abundance. These data identify miR-182 as an important regulator of FoxO3 expression that participates in the control of atrophy-inducing genes during catabolic diseases.
Related JoVE Video
miR-20b suppresses Th17 differentiation and the pathogenesis of experimental autoimmune encephalomyelitis by targeting ROR?t and STAT3.
J. Immunol.
PUBLISHED: 05-19-2014
Show Abstract
Hide Abstract
The differentiation and function of IL-17-producing Th17 cells are tightly regulated by specific transcription factors and cytokines, which are the key participants in the pathogenesis of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). Although specific miRNAs have been shown to be involved in the development of MS and EAE, the potential role of miRNAs in the context of Th17-driven autoimmunity is just beginning to be clarified. miR-20b has been reported as a downregulated miRNA in blood cells of MS patients. In this report, it was further studied in greater detail because we found it was significantly downregulated during EAE, and, in the in vitro differentiation model, Th17 cells had lower expression of miR-20b than did Th1, Th2, or inducible T regulatory cells. Ectopic expression of miR-20b repressed Th17 differentiation in vitro. Using lentiviral vectors for miR-20b overexpression in vivo, we demonstrated that overexpression of miR-20b led to decreased Th17 cells and reduced severity of EAE. Furthermore, we also identified both RAR-related orphan receptor ?t and STAT3 as potential targets of miR-20b. Finally, we confirmed that the mild disease severity and low number of Th17 cells in LV-miR-20b-infected mice were largely reversed by coinfection of these mice with lentivirus-expressing RAR-related orphan receptor ?t or STAT3 3'-untranslated regions. Taken together, our results contribute to the importance of miRNAs in Th17 differentiation and pathogenesis of MS and EAE.
Related JoVE Video
Mastering instruments before operating on a patient: the role of simulation training in tool use skills.
Surg Innov
PUBLISHED: 05-12-2014
Show Abstract
Hide Abstract
Background. We examined the impact of tool complexity on surgeons' performance and evaluated the value of using a simulation-based program for reducing training cost. Methods. Three pairs of surgical graspers with increasing mechanical complexity, which were designed for open, laparoscopic, and endoscopic procedures, were used in performing a simple object transportation task. Task times and mental workload of 17 surgeons were compared using all 3 variations of the graspers to test the impact of tool complexity on surgical performance. Subsequently, 4 of these surgeons decided to enter a 3-week training phase and practiced with these 3 surgical instruments on a daily basis. Learning curves were plotted to examine the value of using simulation for proficiency training with these tools. Results. Task time was significantly prolonged as tool complexity increased. Practice in a simulated environment shortened the task time significantly and moderately reduced mental workloads. However, the difference in task time varied among the 3 types of tools. Between days 1 and 9, task times for each types of grasper were reduced by 55% (endoscopic), 42% (open), and 22% (laparoscopic). Conclusions. Tool complexity may degrade a surgeon's performance. Extensive simulation training programs are important for surgeons to gain proficiency in handling a tool before they practice on patients.
Related JoVE Video
Management of the pulmonary artery during video-assisted thoracoscopic left upper lobectomy.
World J Surg
PUBLISHED: 05-09-2014
Show Abstract
Hide Abstract
Complete video-assisted thoracoscopic surgery (c-VATS) for left upper lobectomy is difficult due to the branching pattern of the left pulmonary artery.
Related JoVE Video
Poly(trifluoromethyl)azulenes: structures and acceptor properties.
Chem. Commun. (Camb.)
PUBLISHED: 05-02-2014
Show Abstract
Hide Abstract
Six new poly(trifluoromethyl)azulenes prepared in a single high-temperature reaction exhibit strong electron accepting properties in the gas phase and in solution and demonstrate the propensity to form regular ?-stacked columns in donor-acceptor crystals when mixed with pyrene as a donor.
Related JoVE Video
Over-expression of P2X7 receptors in spinal glial cells contributes to the development of chronic postsurgical pain induced by skin/muscle incision and retraction (SMIR) in rats.
Exp. Neurol.
PUBLISHED: 04-26-2014
Show Abstract
Hide Abstract
Many patients suffer from chronic postsurgical pain (CPSP) following surgery, and the underlying mechanisms are poorly understood. In the present work, with use of the skin/muscle incision and retraction (SMIR) model, the role of P2X7 receptors (P2X7Rs) in spinal glial cells in the development of CPSP was evaluated. Consistent with previous reports, we found that SMIR decreased the ipsilateral 50% paw withdrawal threshold (PWT), lasting for at least 2weeks. No injury was done to L3 dorsal root ganglia (DRG) neurons and no axonal or Schwann cell damage at the retraction site in the saphenous nerve was observed 7days after SMIR. The results of immunofluorescence showed that both microglia and astrocytes were activated in the spinal dorsal horn following SMIR. In addition, both P2X7Rs and tumor necrosis factor-alpha (TNF-?) were up-regulated following SMIR. Double immunofluorescence staining revealed that the up-regulated P2X7R immunoreactivity was mainly located in microglia, and to a lesser extent in astrocytes, but not in neurons. Intrathecal delivery of specific P2X7R antagonist BBG (10?M in 10?l volume) or A438079 (10?M in 10?l volume), started 30min before the surgery and once daily thereafter for 7days, prevented the mechanical allodynia. Intrathecal injection of BBG inhibited the activation of microglia and astrocytes, and the up-regulation of TNF-? induced by SMIR. These data suggest that P2X7Rs in the spinal dorsal horn might mediate the development of CPSP via activation of glial cells and up-regulation of TNF-?.
Related JoVE Video
?-Adducin gene G614T polymorphisms in essential hypertension patients with high low density lipoprotein (LDL) levels.
Indian J. Med. Res.
PUBLISHED: 04-11-2014
Show Abstract
Hide Abstract
The association between ?-adducin gene G614T polymorphism and essential hypertension (EH) is not clear. The present study was carried out to examine a possible association between ?-adducin gene G614T mutation and essential hypertension in Chinese population.
Related JoVE Video
Direct assessment of lung function in COPD using CT densitometric measures.
Physiol Meas
PUBLISHED: 04-08-2014
Show Abstract
Hide Abstract
To investigate whether lung function in patients with chronic obstructive pulmonary disease (COPD) can be directly predicted using CT densitometric measures and assess the underlying prediction errors as compared with the traditional spirometry-based measures. A total of 600 CT examinations were collected from a COPD study. In addition to the entire lung volume, the extent of emphysema depicted in each CT examination was quantified using density mask analysis (densitometry). The partial least square regression was used for constructing the prediction model, where a repeated random split-sample validation was employed. For each split, we randomly selected 400 CT exams for training (regression) purpose and the remaining 200 exams for assessing performance in prediction of lung function (e.g., FEV1 and FEV1/FVC) and disease severity. The absolute and percentage errors as well as their standard deviations were computed. The averaged percentage errors in prediction of FEV1, FEV1/FVC%, TLC, RV/TLC% and DLco% predicted were 33%, 17%, 9%, 18% and 23%, respectively. When classifying the exams in terms of disease severity grades using the CT measures, 37% of the subjects were correctly classified with no error and 83% of the exams were either correctly classified or classified into immediate neighboring categories. The linear weighted kappa and quadratic weighted kappa were 0.54 (moderate agreement) and 0.72 (substantial agreement), respectively. Despite the existence of certain prediction errors in quantitative assessment of lung function, the CT densitometric measures could be used to relatively reliably classify disease severity grade of COPD patients in terms of GOLD.
Related JoVE Video
para-Quinodimethane-bridged perylene dimers and pericondensed quaterrylenes: the effect of the fusion mode on the ground states and physical properties.
Chemistry
PUBLISHED: 03-29-2014
Show Abstract
Hide Abstract
Polycyclic hydrocarbon compounds with a singlet biradical ground state show unique physical properties and promising material applications; therefore, it is important to understand the fundamental structure/biradical character/physical properties relationships. In this study, para-quinodimethane (p-QDM)-bridged quinoidal perylene dimers 4 and 5 with different fusion modes and their corresponding aromatic counterparts, the pericondensed quaterrylenes 6 and 7, were synthesized. Their ground-state electronic structures and physical properties were studied by using various experiments assisted with DFT calculations. The proaromatic p-QDM-bridged perylene monoimide dimer 4 has a singlet biradical ground state with a small singlet/triplet energy gap (-2.97?kcal?mol(-1)), whereas the antiaromatic s-indacene-bridged N-annulated perylene dimer 5 exists as a closed-shell quinoid with an obvious intramolecular charge-transfer character. Both of these dimers showed shorter singlet excited-state lifetimes, larger two-photon-absorption cross sections, and smaller energy gaps than the corresponding aromatic quaterrylene derivatives 6 and 7, respectively. Our studies revealed how the fusion mode and aromaticity affect the ground state and, consequently, the photophysical properties and electronic properties of a series of extended polycyclic hydrocarbon compounds.
Related JoVE Video
Surgical team composition differs between laparoscopic and open procedures.
Surg Endosc
PUBLISHED: 03-27-2014
Show Abstract
Hide Abstract
Performing laparoscopic procedures requires different skill sets and team dynamics compared with open procedures. We evaluated team composition and procedure time between these two surgical approaches using data collected from hospitals in the United State and Canada.
Related JoVE Video
Association between computed tissue density asymmetry in bilateral mammograms and near-term breast cancer risk.
Breast J
PUBLISHED: 03-27-2014
Show Abstract
Hide Abstract
This study investigated association between bilateral mammographic density asymmetry and near-term breast cancer risk. A data base of digital mammograms acquired from 690 women was retrospectively collected. All images were originally interpreted as negative by radiologists. During the next subsequent screening examinations (between 12 and 36 months later), 230 women were diagnosed positive for cancer, 230 were recalled for additional diagnostic workups and proved to be benign, and 230 remained negative (not recalled). We applied a computerized scheme to compute the differences of five image features between the left and right mammograms, and trained an artificial neural network (ANN) to compute a bilateral mammographic density asymmetry score. Odds ratios (ORs) were used to assess associations between the ANN-generated scores and risk of women having detectable cancers during the next screening examinations. A logistic regression method was applied to test for trend as a function of the increase in ANN-generated scores. The results were also compared with ORs computed using other existing cancer risk factors. The ORs showed an increasing risk trend with the increase in ANN-generated scores (from 1.00 to 9.07 between positive and negative case groups). The regression analysis also showed a significant increase trend in slope (p < 0.05). No significant increase trends of the ORs were found when using woman's age, subjectively rated breast density, or family history of breast cancer. This study demonstrated that the computed bilateral mammographic density asymmetry had potential to be used as a new risk factor to improve discriminatory power in predicting near-term risk of women developing breast cancer.
Related JoVE Video
Docosahexaenoic acid prevents palmitate-induced activation of proteolytic systems in C2C12 myotubes.
J. Nutr. Biochem.
PUBLISHED: 03-26-2014
Show Abstract
Hide Abstract
Saturated fatty acids like palmitate contribute to muscle atrophy in a number of conditions (e.g., type II diabetes) by altering insulin signaling. Akt is a key modulator of protein balance that inhibits the FoxO transcription factors (e.g., FoxO3) which selectively induce the expression of atrophy-inducing genes (atrogenes) in the ubiquitin-proteasome and autophagy-lysosome systems. Conversely, omega-3 polyunsaturated fatty acids have beneficial effects on insulin signaling and may preserve muscle mass. In an earlier report, the omega-3 fatty acid docosahexaenoic acid (DHA) protected myotubes from palmitate-induced atrophy; the mechanisms underlying the alterations in protein metabolism were not identified. This study investigated whether DHA prevents a palmitate-induced increase in proteolysis by restoring Akt/FoxO signaling. Palmitate increased the rate of protein degradation, while cotreatment with DHA prevented the response. Palmitate reduced the activation state of Akt and increased nuclear FoxO3 protein while decreasing its cytosolic level. Palmitate also increased the messenger RNAs (mRNAs) of two FoxO3 atrogene targets, the E3 ubiquitin ligase atrogin-1/MAFbx and the autophagy mediator Bnip3. DHA attenuated the effects of palmitate on Akt activation, FoxO3 localization and atrogene mRNAs. DHA, alone or in combination with palmitate and decreased the ratio of LC3B-II:LC3B-I protein as well as the rate of autophagosome formation, as indicated by reduced LC3B-II protein in the presence of 10 mmol/L methylamine, suggesting an independent effect of DHA on the macroautophagy pathway. These data indicate that palmitate induces myotube atrophy, at least in part, by activating multiple proteolytic systems and that DHA counters the catabolic effects of palmitate by restoring Akt/FoxO signaling.
Related JoVE Video
Controlled charged amino acids of Ti-binding peptide for surfactant-free selective adsorption.
Colloids Surf B Biointerfaces
PUBLISHED: 03-15-2014
Show Abstract
Hide Abstract
The adsorption mechanism of titanium-binding peptide (TBP) on metal oxide substrates was investigated by evaluating the adsorption behavior of ferritins with various alanine-substituted TBPs. Results revealed that (a) a positively charged amino acid, lysine (K) or arginine (R), in TBP can anchor ferritin to negative zeta-potential substrates, (b) the adsorption force of K is stronger than R, and (c) local electrostatic interactions and flexibility of TBP directly affect adsorption. Based on these findings, selective ferritin adsorption on SiO2 with TiOX patterned surfaces in a surfactant-free condition was demonstrated. Alanine-substituted TBP with one positively charged amino acid (K) and one negatively charged amino acid (D), achieved ferritin-selective adsorption without a surfactant. The importance of controlled electrostatic forces between TBP and a substrate for selective adsorption without a surfactant was clearly demonstrated.
Related JoVE Video
Angiotensin-converting enzyme gene polymorphisms and risk for sporadic Alzheimer's disease: a meta-analysis.
J Neural Transm
PUBLISHED: 03-08-2014
Show Abstract
Hide Abstract
Numerous studies have tested for associations between common polymorphisms of the angiotensin-converting enzyme gene and sporadic Alzheimer disease (SAD), but results have been inconclusive. Using meta-analysis, our study aimed to clarify the nature of the genetic risks contributed by the three polymorphisms (rs4291, rs4343, rs1800764) for developing SAD. Through searching of Pubmed, Embase, Alzgene and manually searching relevant references, a total of 14 articles with 26 independent studies were included. Odds ratios (ORs) with 95 % confidence intervals (CIs) were used to assess the strength of the association studies. The heterogeneity across the studies was tested, as was publication bias. We observed significant association between SNP rs4291 and SAD using allelic comparison (OR = 1.08, 95 % CI 1.03-1.14), homozygote comparison (OR = 1.16, 95 % CI 1.04-1.30) and the recessive model (OR = 1.10, 95 % CI 1.02-1.18). Association with SNP rs1800764 was revealed but it was not sufficiently robust to withstand the Benjamini-Hochberg method and stepdown Bonferroni correction. Significant association was not identified in the analysis for SNP rs4343. In subgroup analyses, the risk of SAD associated with SNP rs4291 appeared to be significant among Caucasians and in older cases (mean age ?75 years). Our results confirmed a significant but modest association between SNP rs4291 and SAD susceptibility. Further study of the pathogenetic characteristics of this polymorphism and independent confirmation of the association in larger studies are warranted.
Related JoVE Video
Optimization of breast mass classification using sequential forward floating selection (SFFS) and a support vector machine (SVM) model.
Int J Comput Assist Radiol Surg
PUBLISHED: 03-06-2014
Show Abstract
Hide Abstract
Improving radiologists' performance in classification between malignant and benign breast lesions is important to increase cancer detection sensitivity and reduce false-positive recalls. For this purpose, developing computer-aided diagnosis schemes has been attracting research interest in recent years. In this study, we investigated a new feature selection method for the task of breast mass classification.
Related JoVE Video
Prediction of near-term risk of developing breast cancer using computerized features from bilateral mammograms.
Comput Med Imaging Graph
PUBLISHED: 03-03-2014
Show Abstract
Hide Abstract
Asymmetry of bilateral mammographic tissue density and patterns is a potentially strong indicator of having or developing breast abnormalities or early cancers. The purpose of this study is to design and test the global asymmetry features from bilateral mammograms to predict the near-term risk of women developing detectable high risk breast lesions or cancer in the next sequential screening mammography examination. The image dataset includes mammograms acquired from 90 women who underwent routine screening examinations, all interpreted as negative and not recalled by the radiologists during the original screening procedures. A computerized breast cancer risk analysis scheme using four image processing modules, including image preprocessing, suspicious region segmentation, image feature extraction, and classification was designed to detect and compute image feature asymmetry between the left and right breasts imaged on the mammograms. The highest computed area under curve (AUC) is 0.754±0.024 when applying the new computerized aided diagnosis (CAD) scheme to our testing dataset. The positive predictive value and the negative predictive value were 0.58 and 0.80, respectively.
Related JoVE Video
A computerized global MR image feature analysis scheme to assist diagnosis of breast cancer: a preliminary assessment.
Eur J Radiol
PUBLISHED: 03-02-2014
Show Abstract
Hide Abstract
To develop a new computer-aided detection scheme to compute a global kinetic image feature from the dynamic contrast enhanced breast magnetic resonance imaging (DCE-MRI) and test the feasibility of using the computerized results for assisting classification between the DCE-MRI examinations associated with malignant and benign tumors.
Related JoVE Video
SMN1 duplications contribute to sporadic amyotrophic lateral sclerosis susceptibility: evidence from a meta-analysis.
J. Neurol. Sci.
PUBLISHED: 02-19-2014
Show Abstract
Hide Abstract
To investigate the association between SMN1 and SMN2 copy number variations (CNVs) and sporadic amyotrophic lateral sclerosis (SALS) by a meta-analysis.
Related JoVE Video
The negative ion photoelectron spectrum of meta-benzoquinone radical anion (MBQ??): a joint experimental and computational study.
J. Am. Chem. Soc.
PUBLISHED: 02-19-2014
Show Abstract
Hide Abstract
Negative ion photoelectron (NIPE) spectra of the radical anion of meta-benzoquinone (MBQ, m-OC6H4O) have been obtained at 20 K, using both 355 and 266 nm lasers for electron photodetachment. The spectra show well-resolved peaks and complex spectral patterns. The electron affinity of MBQ is determined from the first resolved peak to be 2.875 ± 0.010 eV. Single-point, CASPT2/aug-cc-pVTZ//CASPT2/aug-cc-pVDZ calculations predict accurately the positions of the 0-0 bands in the NIPE spectrum for formation of the four lowest electronic states of neutral MBQ from the (2)A2 state of MBQ(•-). In addition, the Franck-Condon factors that are computed from the CASPT2/aug-cc-pVDZ optimized geometries, vibrational frequencies, and normal mode vectors, successfully simulate the intensities and frequencies of the vibrational peaks in the NIPE spectrum that are associated with each of these electronic states. The successful simulation of the NIPE spectrum of MBQ(•-) allows the assignment of (3)B2 as the ground state of MBQ, followed by the (1)B2 and (1)A1 electronic states, respectively 9.0 ± 0.2 and 16.6 ± 0.2 kcal/mol higher in energy than the triplet. These experimental energy differences are in good agreement with the calculated values of 9.7 and 15.7 kcal/mol. The relative energies of these two singlet states in MBQ confirm the previous prediction that their relative energies would be reversed from those in meta-benzoquinodimethane (MBQDM, m-CH2C6H4CH2).
Related JoVE Video
Extract of okra lowers blood glucose and serum lipids in high-fat diet-induced obese C57BL/6 mice.
J. Nutr. Biochem.
PUBLISHED: 02-05-2014
Show Abstract
Hide Abstract
Okra is an important tropical vegetable and source of dietary medicine. Here, we assayed the effects of an ethanol extract of okra (EO) and its major flavonoids isoquercitrin and quercetin 3-O-gentiobioside on metabolic disorders in high-fat diet-induced obese mouse. We found that treatment with EO, isoquercitrin and quercetin 3-O-gentiobioside reduced blood glucose and serum insulin levels and improved glucose tolerance in obese mice. Meanwhile, serum triglyceride levels and liver morphology in the mice were significantly ameliorated by EO and isoquercitrin treatment. Total cholesterol levels in isoquercitrin and quercetin 3-O-gentiobioside treated mice were also reduced. We also found that EO inhibited the expression of nuclear receptor transcription factor PPAR?, which is an important regulator of lipid and glucose homeostasis. Furthermore, we determined that EO and quercetin 3-O-gentiobioside have antioxidant activity in vitro. Our results indicate that okra may serve as a dietary therapy for hyperglycemia and hypertriglyceridemia.
Related JoVE Video
Negative association of R-Ras activation and breast cancer development.
Oncol. Rep.
PUBLISHED: 01-03-2014
Show Abstract
Hide Abstract
R-Ras, a member of the Ras superfamily, is expressed in a wide variety of tissues and regulates cell adhesion, migration, differentiation and apoptosis. Research has raised the possibility that R-Ras may function as a positive regulator of cell proliferation and transformation in the breast. To understand the possible role of R-Ras in breast epithelial carcinogenesis, the expression and activation of R-Ras were detected in each of 69 pairs of breast cancer tissues and normal tumor-adjacent tissue samples by qRT-PCR, western blot analysis and GST pull down assay; 12 available cell lines were also subjected to western blot analysis and GST pull down assay. To further address the role of R-Ras in transformation-related phenotype formation of breast cancer cell line MCF-7 in vitro, R-Ras38V, a constitutively activated mutant of R-Ras, was transfected into MCF-7 cells, and the cell proliferation, migration and cell cycle distribution were analyzed. The results showed that although there was slight difference in the protein expression of R-Ras between the breast cancer tissues and normal tissues, the activation of R-Ras was reduced in 63.8% of the cancer tissues when compared to the normal tissue samples. In addition, the results also showed that R-Ras38V inhibited cell proliferation, migration and cell cycle progression in the presence of serum. Contradicting the positive association reported in previous studies, our results indicate that R-Ras activation may negatively regulate the transformation of breast epithelial cells, and the loss of activation of R-Ras may be involved in the carcinogenesis of breast cancer. To solve this controversy, further independent studies are needed to validate our study results.
Related JoVE Video
Impact of Emphysema Heterogeneity on Pulmonary Function.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
To investigate the association between emphysema heterogeneity in spatial distribution, pulmonary function and disease severity.
Related JoVE Video
Optimization of Network Topology in Computer-Aided Detection Schemes Using Phased Searching with NEAT in a Time-Scaled Framework.
Cancer Inform
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
In the field of computer-aided mammographic mass detection, many different features and classifiers have been tested. Frequently, the relevant features and optimal topology for the artificial neural network (ANN)-based approaches at the classification stage are unknown, and thus determined by trial-and-error experiments. In this study, we analyzed a classifier that evolves ANNs using genetic algorithms (GAs), which combines feature selection with the learning task. The classifier named "Phased Searching with NEAT in a Time-Scaled Framework" was analyzed using a dataset with 800 malignant and 800 normal tissue regions in a 10-fold cross-validation framework. The classification performance measured by the area under a receiver operating characteristic (ROC) curve was 0.856 ± 0.029. The result was also compared with four other well-established classifiers that include fixed-topology ANNs, support vector machines (SVMs), linear discriminant analysis (LDA), and bagged decision trees. The results show that Phased Searching outperformed the LDA and bagged decision tree classifiers, and was only significantly outperformed by SVM. Furthermore, the Phased Searching method required fewer features and discarded superfluous structure or topology, thus incurring a lower feature computational and training and validation time requirement. Analyses performed on the network complexities evolved by Phased Searching indicate that it can evolve optimal network topologies based on its complexification and simplification parameter selection process. From the results, the study also concluded that the three classifiers - SVM, fixed-topology ANN, and Phased Searching with NeuroEvolution of Augmenting Topologies (NEAT) in a Time-Scaled Framework - are performing comparably well in our mammographic mass detection scheme.
Related JoVE Video
Angiotensin-converting enzyme insertion/deletion polymorphism is not a major determining factor in the development of sporadic Alzheimer disease: evidence from an updated meta-analysis.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Angiotensin-converting enzyme gene (ACE) insertion/deletion (I/D) polymorphism have long been linked to sporadic Alzheimer disease (SAD), but the established data remained controversial. To clarify this inconsistency, a comprehensive meta-analysis was conducted. Through searching of Pubmed, Embase, Alzgene, China National Knowledge Infrastructure (CNKI) and manually searching relevant references, 53 independent studies from 48 articles were included, involving a total of 8153 cases and 14932 controls. The strength of association was assessed by using odds ratios (ORs) with 95% confidence intervals (CIs). Further stratified analyses and heterogeneity analyses were tested, as was publication bias. Overall, significant associations were revealed between I/D polymorphism and SAD risk using allelic comparison (OR?=?1.09, 95%CI?=?1.01-1.17, p?=?0.030), homozygote comparison (OR?=?1.17, 95%CI?=?1.01-1.34, p?=?0.030) and the dominant model (OR?=?1.16, 95%CI?=?1.04-1.29, p?=?0.008), but they were not sufficiently robust to withstand the false-positive report probability (FPRP) analyses. Otherwise, in subgroup analyses restricted to the high quality studies, the large sample size studies and studies with population-based controls, no significant association was observed in any genetic models. In summary, the current meta-analysis suggested that the ACE I/D polymorphism is unlikely to be a major determining factor in the development of SAD.
Related JoVE Video
MicroRNA-365 inhibits vascular smooth muscle cell proliferation through targeting cyclin D1.
Int J Med Sci
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
MicroRNA-365 (miR-365) plays crucial roles in regulating cell proliferation, apoptosis and differentiation in various cell types. However, its function in vascular smooth muscle cells (VSMCs) is largely unknown. In our study, we found miR-365 was highly expressed in adult rat carotid arteries, but was significantly decreased in rat carotid arteries after balloon injury, a process involving neointima formation and VSMC proliferation. In vitro, the miR-365 significantly inhibited cell proliferation of isolated primary rat aortic VSMCs. Furthermore, we identified that cyclin D1 was a direct target of miR-365 in VSMCs. The miR-365 suppressed cyclin D1 expression on both mRNA and protein level. Luciferase reporter assay demonstrated that miR-365 inhibited cyclin D1 through targeting its 3'UTR. Importantly, cyclin D1 overexpression rescued the inhibitory effect of miR-365 on VSMCs proliferation. Taken together, by our studies, we identified a new MicroRNA, miR-365, involving in the pathological process of vascular injury, which inhibits VSMC proliferation through targeting cyclinD1.
Related JoVE Video
Bifidobacterium breve attenuates murine dextran sodium sulfate-induced colitis and increases regulatory T cell responses.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
While some probiotics have shown beneficial effects on preventing or treating colitis development, others have shown no effects. In this study, we have assessed the immunomodulating effects of two probiotic strains, Lactobacillus rhamnosus (L. rhamnosus) and Bifidobacterium breve (B. breve) on T cell polarization in vitro, using human peripheral blood mononuclear cells (PBMC), and in vivo, using murine dextran sodium sulfate (DSS) colitis model. With respect to the latter, the mRNA expression of T cell subset-associated transcription factors and cytokines in the colon was measured and the T helper type (Th) 17 and regulatory T cell (Treg) subsets were determined in the Peyer's patches. Both L. rhamnosus and B. breve incubations in vitro reduced Th17 and increased Th2 cell subsets in human PBMCs. In addition, B. breve incubation was also able to reduce Th1 and increase Treg cell subsets in contrast to L. rhamnosus. In vivo intervention with B. breve, but not L. rhamnosus, significantly attenuated the severity of DSS-induced colitis. In DSS-treated C57BL/6 mice, intervention with B. breve increased the expression of mRNA encoding for Th2- and Treg-associated cytokines in the distal colon. In addition, intervention with B. breve led to increases of Treg and decreases of Th17 cell subsets in Peyer's patches of DSS-treated mice. B. breve modulates T cell polarization towards Th2 and Treg cell-associated responses in vitro and in vivo. In vivo B. breve intervention ameliorates DSS-induced colitis symptoms and this protective effect may mediated by its effects on the T-cell composition.
Related JoVE Video
miR-23a is decreased during muscle atrophy by a mechanism that includes calcineurin signaling and exosome-mediated export.
Am. J. Physiol., Cell Physiol.
PUBLISHED: 12-11-2013
Show Abstract
Hide Abstract
Skeletal muscle atrophy is prevalent in chronic diseases and microRNAs (miRs) may play a key role in the wasting process. miR-23a was previously shown to inhibit the expression of atrogin-1 and MuRF1 in muscle. It also was reported to be regulated by NFATc3 in cardiomyocytes. The objective of this study was to determine if miR-23a is regulated during muscle atrophy and to evaluate the relationship between calcineurin (Cn)/nuclear factor of activated T-cells (NFAT) signaling and miR-23a expression in skeletal muscle cells during atrophy. miR-23a was decreased in the gastrocnemius of rats with acute streptozotocin (STZ)-induced diabetes, a condition known to increase atrogin-1 and MuRF1 expression and cause atrophy. Treatment of C2C12 myotubes with Dexamethasone (Dex) for 48 hours also reduced miR-23a as well as RCAN1.4 mRNA, which is transcriptionally regulated by NFAT. Both NFATc3 nuclear localization and the amount of miR-23a decreased rapidly within 1 hour of Dex administration suggesting a link between Cn signaling and miR-23a. Compared to primary myotubes from wild type mice, myotubes from CnA?-/- or CnA?-/- mice had a lower level of miR-23a. Dex did not further suppress miR-23a in the Cn-deficient myotubes. Overexpression of CnA? in C2C12 myotubes prevented Dex-induced suppression of miR-23a. Finally, miR-23a was present in exosomes isolated from the media of C2C12 myotubes and Dex increased its exosomal abundance. Dex did not alter the number of exosomes released into the media. We conclude that atrophy-inducing conditions down regulate miR-23a in muscle by mechanisms involving attenuated Cn/NFAT signaling and selective packaging into exosomes.
Related JoVE Video
Covalently Bound Tetracoordinated Organoborons as Superhalogens: A Combined Negative Ion Photoelectron Spectroscopy and Theoretical Study.
J Phys Chem A
PUBLISHED: 11-21-2013
Show Abstract
Hide Abstract
Molecular species with electron affinities (EAs) larger than that of the chlorine atom (3.6131 eV) are superhalogens. The corresponding negative ions, namely, superhalogen anions, are intrinsically very stable with high electron binding energies (EBEs) and widely exist as building blocks of bulk materials and ionic liquids. The most common superhalogen anions proposed and experimentally confirmed to date are either ionic salts or compact inorganic species. Herein, we report a new class of superhalogen species, a series of tetracoordinated organoboron anions [BL4](-) (L = phenyl (1), 4-fluorophenyl (2), 1-imidazolyl (3), L4 = H(pyrazolyl)3 (4)) with bulky organic ligands covalently bound to the central B atom. Negative ion photoelectron spectroscopy (NIPES) reveals that all of these anions possess EBEs higher than that of Cl(-) with the adiabatic/vertical detachment energy (ADE/VDE) of 4.44/4.8 (1), 4.78/5.2 (2), 5.08/5.4 (3), and 4.59/4.9 eV (4), respectively. First-principles calculations confirmed high EBEs of [BL4](-) and predicted that these anions are thermodynamically stable against fragmentation. The unraveled superhalogen nature of these species provides a molecular basis to explain the wide-ranging applications of tetraphenylborate (TPB) (1) and trispyrazolylborate (Tp) (4) in many areas spanning from industrial waste treatment to soft material synthesis and organometallic chemistry.
Related JoVE Video
Dibenzoheptazethrene Isomers with Different Biradical Characters: An Exercise of Clars Aromatic Sextet Rule in Singlet Biradicaloids.
J. Am. Chem. Soc.
PUBLISHED: 11-20-2013
Show Abstract
Hide Abstract
Clars aromatic sextet rule has been widely used for the prediction of the reactivity and stability of polycyclic aromatic hydrocarbons with a closed-shell electronic configuration. Recent advances in open-shell biradicaloids have shown that the number of aromatic sextet rings plays an important role in determination of their ground states. In order to test the validity of this rule in singlet biradicaloids, the two soluble and stable dibenzoheptazethrene isomers DBHZ1 and DBHZ2 were prepared by different synthetic approaches and isolated in crystalline form. These two molecules have different numbers of aromatic sextet rings in their respective biradical resonance forms and thus are expected to exhibit varied singlet biradical character. This assumption was verified by different experimental methods, including nuclear magnetic resonance (NMR), electron spin resonance (ESR), superconducting quantum interference device (SQUID), steady-state and transient absorption spectroscopy (TA), and X-ray crystallographic analysis, assisted by unrestricted symmetry-broken density functional theory (DFT) calculations. DBHZ2, with more aromatic sextet rings in the biradical form, was demonstrated to possess greater biradical character than DBHZ1; as a result, DBHZ2 exhibited an intense one-photon absorption (OPA) in the near-infrared region (?abs(max) = 804 nm) and a large two-photon absorption (TPA) cross-section (?((2))max = 2800 GM at 1600 nm). This investigation together with previous studies indicates that Clars aromatic sextet rule can be further extended to the singlet biradicaloids to predict their ground states and singlet biradical characters.
Related JoVE Video
Hydrogen-bond networks: strengths of different types of hydrogen bonds and an alternative to the low barrier hydrogen-bond proposal.
J. Am. Chem. Soc.
PUBLISHED: 11-19-2013
Show Abstract
Hide Abstract
We report quantifying the strengths of different types of hydrogen bonds in hydrogen-bond networks (HBNs) via measurement of the adiabatic electron detachment energy of the conjugate base of a small covalent polyol model compound (i.e., (HOCH2CH2CH(OH)CH2)2CHOH) in the gas phase and the pKa of the corresponding acid in DMSO. The latter result reveals that the hydrogen bonds to the charged center and those that are one solvation shell further away (i.e., primary and secondary) provide 5.3 and 2.5 pKa units of stabilization per hydrogen bond in DMSO. Computations indicate that these energies increase to 8.4 and 3.9 pKa units in benzene and that the total stabilizations are 16 (DMSO) and 25 (benzene) pKa units. Calculations on a larger linear heptaol (i.e., (HOCH2CH2CH(OH)CH2CH(OH)CH2)2CHOH) reveal that the terminal hydroxyl groups each contribute 0.6 pKa units of stabilization in DMSO and 1.1 pKa units in benzene. All of these results taken together indicate that the presence of a charged center can provide a powerful energetic driving force for enzyme catalysis and conformational changes such as in protein folding due to multiple hydrogen bonds in a HBN.
Related JoVE Video
PPAR-? agonist stabilizes KLF4 protein via activating Akt signaling and reducing KLF4 ubiquitination.
Biochem. Biophys. Res. Commun.
PUBLISHED: 11-17-2013
Show Abstract
Hide Abstract
Peroxisome proliferator activated receptor ? (PPAR-?) plays important roles in cell cycle regulation, differentiation and apoptosis. Krüppel-like factor 4 (KLF4) modulates vascular smooth muscle cell (VSMC) phenotype. Both KLF4 and PPAR-? are involved in VSMC proliferation and differentiation. However, the actual relationship between KLF4 and PPAR-? in VSMCs is not clear. In this study, we found that PPAR-? agonist pioglitazone increases KLF4 protein levels but does not influence KLF4 gene transcription. PPAR-? overexpression increases, while PPAR-? knockdown reduces KLF4 expression, suggesting that the increase in KLF4 protein levels induced by pioglitazone is PPAR-?-dependent. Further study showed that pioglitazone enhances KLF4 protein stability through reducing KLF4 ubiquitination. Furthermore, we demonstrated that stabilization of KLF4 by pioglitazone was related to the activation of Akt signaling pathway. Taken together, we revealed that PPAR-? agonist pioglitazone stabilizes KLF4 protein via activating Akt signaling and reducing KLF4 ubiquitination, providing further insights into PPAR-? and KLF4 in regulating each others expression in VSMCs.
Related JoVE Video
Phenformin enhances the therapeutic benefit of BRAF(V600E) inhibition in melanoma.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 10-21-2013
Show Abstract
Hide Abstract
Biguanides, such as the diabetes therapeutics metformin and phenformin, have demonstrated antitumor activity both in vitro and in vivo. The energy-sensing AMP-activated protein kinase (AMPK) is known to be a major cellular target of biguanides. Based on our discovery of cross-talk between the AMPK and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) signaling pathways, we investigated the antitumor effects of combining phenformin with a BRAF inhibitor PLX4720 on the proliferation of BRAF-mutated melanoma cells in vitro and on BRAF-driven tumor growth in vivo. Cotreatment of BRAF-mutated melanoma cell lines with phenformin and PLX4720 resulted in synergistic inhibition of cell viability, compared with the effects of the single agent alone. Moreover, treatment with phenformin significantly delayed the development of resistance to PLX4720 in cultured melanoma cells. Biochemical analyses showed that phenformin and PLX4720 exerted cooperative effects on inhibiting mTOR signaling and inducing apoptosis. Noticeably, phenformin selectively targeted subpopulations of cells expressing JARID1B, a marker for slow cycling melanoma cells, whereas PLX4720 selectively targeted JARID1B-negative cells. Finally, in contrast to their use as single agents, the combination of phenformin and PLX4720 induced tumor regression in both nude mice bearing melanoma xenografts and in a genetically engineered BRAF(V600E)/PTEN(null)-driven mouse model of melanoma. These results strongly suggest that significant therapeutic advantage may be achieved by combining AMPK activators such as phenformin with BRAF inhbitors for the treatment of melanoma.
Related JoVE Video
Synthetic retinoid Am80 up-regulates apelin expression by promoting interaction of RAR? with KLF5 and Sp1 in vascular smooth muscle cells.
Biochem. J.
PUBLISHED: 09-03-2013
Show Abstract
Hide Abstract
Previous studies have demonstrated that both retinoids and apelin possess potent cardiovascular properties and that retinoids can mediate the expression of many genes in the cardiovascular system. However, it is not clear whether and how retinoids regulate apelin expression in rat VSMCs (vascular smooth muscle cells). In the present study, we investigated the molecular mechanism of apelin expression regulation by the synthetic retinoid Am80 in VSMCs. The results showed that Am80 markedly up-regulated apelin mRNA and protein levels in VSMCs. Furthermore, KLF5 (Krüppel-like factor 5) and Sp1 (stimulating protein-1) co-operatively mediated Am80-induced apelin expression through their direct binding to the TCE (transforming growth factor-? control element) on the apelin promoter. Interestingly, upon Am80 stimulation, the RAR? (retinoic acid receptor ?) was recruited to the apelin promoter by interacting with KLF5 and Sp1 prebound to the TCE site of the apelin promoter to form a transcriptional activation complex, subsequently leading to the up-regulation of apelin expression in VSMCs. An in vivo study indicated that Am80 increased apelin expression in balloon-injured arteries of rats, consistent with the results from the cultured VSMCs. Thus the results of the present study describe a novel mechanism of apelin regulation by Am80 and further expand the network of RAR? in the retinoid pathway.
Related JoVE Video
The unfolding of G-quadruplexes and its adverse effect on DNA-gold nanoparticles-based sensing system.
Biosens Bioelectron
PUBLISHED: 08-17-2013
Show Abstract
Hide Abstract
The adsorption of DNAs in G-quadruplex solution onto 13nm gold nanoparticles (AuNPs) was studied through monitoring of the localized surface plasmon resonance (LSPR) absorbance of 13nm AuNPs at 520 and 650nm (A650/A520) in the solutions of three widely studied guanine-rich sequences, TBA(5-GGTTGGTGTGGTTGG-3), PW17(5-GGGTAGGGCGGGTTGGG-3), and PSO (5-GGGTTAGGGTTAGGGTTAGGG-3). It was found that the degree of adsorption of DNAs in Pb(2+) stabilized G-quadruplex (G-Pb(2+)) solutions is up to 93% after more than 5h of incubation. Furthermore, the lead concentrations in the solutions containing G-quadruplex and AuNP were analyzed by an inductively coupled plasma atomic emission spectrometer. The results showed that Pb(2+) had been released from the G-quadruplexes, which means the G-quadruplexes may be unfolded in the presence of AuNP. This interaction between G-quadruplexes and AuNP demonstrated that long time incubation between DNAs and AuNPs would possibly make it unable to distinguish G-quadruplex from ssDNA. Thus, a biosensing system consisting of PW17 and AuNPs was developed to detect Pb(2+). It was found that the LSPR responses at A650/A520 were sensitive to [Pb(2+)]. However, the sensitivity of the system was interfered by the potential unfolding of PW17-Pb(2+) in the presence of AuNPs. This unexpected adverse effect of AuNPs on DNA-based biosensors should be taken into consideration in the future development of biosensing systems that are based on ssDNA aptamers and unmodified AuNPs.
Related JoVE Video
Evaluation of computer-aided detection and diagnosis systems.
Med Phys
PUBLISHED: 08-10-2013
Show Abstract
Hide Abstract
Computer-aided detection and diagnosis (CAD) systems are increasingly being used as an aid by clinicians for detection and interpretation of diseases. Computer-aided detection systems mark regions of an image that may reveal specific abnormalities and are used to alert clinicians to these regions during image interpretation. Computer-aided diagnosis systems provide an assessment of a disease using image-based information alone or in combination with other relevant diagnostic data and are used by clinicians as a decision support in developing their diagnoses. While CAD systems are commercially available, standardized approaches for evaluating and reporting their performance have not yet been fully formalized in the literature or in a standardization effort. This deficiency has led to difficulty in the comparison of CAD devices and in understanding how the reported performance might translate into clinical practice. To address these important issues, the American Association of Physicists in Medicine (AAPM) formed the Computer Aided Detection in Diagnostic Imaging Subcommittee (CADSC), in part, to develop recommendations on approaches for assessing CAD system performance. The purpose of this paper is to convey the opinions of the AAPM CADSC members and to stimulate the development of consensus approaches and "best practices" for evaluating CAD systems. Both the assessment of a standalone CAD system and the evaluation of the impact of CAD on end-users are discussed. It is hoped that awareness of these important evaluation elements and the CADSC recommendations will lead to further development of structured guidelines for CAD performance assessment. Proper assessment of CAD system performance is expected to increase the understanding of a CAD systems effectiveness and limitations, which is expected to stimulate further research and development efforts on CAD technologies, reduce problems due to improper use, and eventually improve the utility and efficacy of CAD in clinical practice.
Related JoVE Video
The ground state of (CS)4 is different from that of (CO)4: an experimental test of a computational prediction by negative ion photoelectron spectroscopy.
J Phys Chem A
PUBLISHED: 08-09-2013
Show Abstract
Hide Abstract
Cyclobutane-1,2,3,4-tetrathione, (CS)4, has recently been calculated to have a singlet ground state, (1)A1g, in which the highest b2g ? MO is doubly occupied and the lowest a2u ? MO is empty. Thus, (CS)4 is predicted to have a different ground state than its lighter congener, (CO)4, which has a triplet ground state, (3)B1u, in which these two MOs are each singly occupied. Here, we report the results of a negative ion photoelectron spectroscopy (NIPES) study of the radical anion (CS)4(•-), designed to test the prediction that (CS)4 has a singlet ground state. The NIPE spectrum reveals that (CS)4 does, indeed, have a singlet ground state with electron affinity (EA) = 3.75 eV. The lowest triplet state is found to lie 0.31 eV higher in energy than the ground state, and the open-shell singlet is 0.14 eV higher in energy than the triplet state. Calculations at the (U)CCSD(T)/aug-cc-pVTZ//(U)B3LYP/6-311+G(2df) level support the spectral assignments, giving EA = 3.71 eV and ?EST = 0.44 eV. These calculated values are, respectively, 0.04 eV (0.9 kcal/mol) smaller and 0.13 eV (3.0 kcal/mol) larger than the corresponding experimental values. In addition, RASPT2 calculations with various active spaces and basis sets converge on a (1)B1u-(3)B1u energy gap of 0.137 eV, in excellent agreement with the 0.14 eV energy difference obtained from the NIPE spectrum. Finally, calculations of the Franck-Condon factors for transitions from the ground state of (CS)4(•-) to the ground ((1)A1g) and two excited states ((3)B1u, (1)B1u) of (CS)4 account for all of the major spectral peaks and nicely reproduce the vibrational structure observed in each electronic transition. The close correspondence between the calculated and the observed features in the NIPE spectrum of (CS)4(•-) provides unequivocal proof that (CS)4, unlike (CO)4, has a singlet ground state.
Related JoVE Video
Prediction of near-term breast cancer risk based on bilateral mammographic feature asymmetry.
Acad Radiol
PUBLISHED: 08-05-2013
Show Abstract
Hide Abstract
The objective of this study is to investigate the feasibility of predicting near-term risk of breast cancer development in women after a negative mammography screening examination. It is based on a statistical learning model that combines computerized image features related to bilateral mammographic tissue asymmetry and other clinical factors.
Related JoVE Video
Photoelectron spectroscopy and theoretical study of M(IO3)2(-) (M = H, Li, Na, K): structural evolution, optical isomers, and hyperhalogen behavior.
J Chem Phys
PUBLISHED: 08-02-2013
Show Abstract
Hide Abstract
H(IO3)2(-) and M(IO3)2(-) (M = Li, Na, K) anions were successfully produced via electrospray ionization of their corresponding bulk salt solutions, and were characterized by combining negative ion photoelectron spectroscopy and quantum chemical calculations. The experimental vertical detachment energies (VDEs) of M(IO3)2(-) (M = H, Li, Na, K) are 6.25, 6.57, 6.60, and 6.51 eV, respectively, and they are much higher than that of IO3(-) (4.77 eV). The theoretical calculations show that each of these anions has two energetically degenerate optical isomers. It is found that the structure of H(IO3)2(-) can be written as IO3(-)(HIO3), in which the H atom is tightly bound to one of the IO3(-) groups and forms an iodic acid (HIO3) molecule; while the structures of M(IO3)2(-) can be written as (IO3(-))M(+)(IO3(-)), in which the alkali metal atoms interact with the two IO3(-) groups almost equally and bridge the two IO3(-) groups via two O atoms of each IO3(-) with the two MOOI planes nearly perpendicular to each other. In addition, the high VDEs of M(IO3)2(-) (M = Li, Na, K) can be explained by the hyperhalogen behavior of their neutral counterparts.
Related JoVE Video
[Changes of pyrethroid resistance and P450 monooxygenase activity with age in Anopheles sinensis in Huainan City, Anhui Province, China].
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
PUBLISHED: 07-31-2013
Show Abstract
Hide Abstract
To study the effect of mosquito age on the pyrethroid resistance and P450 monooxygenase activity in Anopheles sinensis in Huainan City, Anhui Province, China, as well as the molecular mechanism of pyrethroid resistance.
Related JoVE Video
The virulence-related rhoptry protein 5 (ROP5) of Toxoplasma Gondii is a novel vaccine candidate against toxoplasmosis in mice.
Vaccine
PUBLISHED: 06-29-2013
Show Abstract
Hide Abstract
Infections with the intracellular protozoan parasite Toxoplasma gondii pose a serious public health problem and are of great economic importance worldwide. The parasite rhoptry protein 5 (ROP5) has been implicated as a major virulence factor that reduces the accumulation of immunity-related GTPases (IRG) in parasitophorous vacuole membrane (PVM), which maintains PVM integrity and evades IFN?-mediated killing by intracellular parasites. To study the immunoprotective value of ROP5, BALB/c mice were immunized with a recombinant form of the protein administered alone or in combination with another promising vaccine antigen, rSAG1. All mice vaccinated with the recombinant antigens developed a high level of specific antibody responses against soluble tachyzoite antigens (STAg), a statistically significant increase of the splenocyte proliferation response, and significant levels of IFN-? and IL-2 production. In contrast to rSAG1, which only stimulated the release of IFN-? and IL-2, rROP5 induced the specific production of IL-10, the Th2-type cytokine, in addition to IFN-? and IL-2. These results demonstrated that rROP5 could induce significant cellular and humoral (Th1/Th2) immune responses. Moreover, mice immunized with rROP5 displayed a prolonged survival time against a lethal challenge with the T. gondii RH strain. Additionally, vaccination with the mixture of rROP5+rSAG1 resulted in higher levels of T. gondii-specific IgG antibodies and lymphocyte proliferative responses and conferred more efficient protection against T. gondii challenge compared to immunization with rROP5 or rSAG1 alone. Our studies show that recombinant ROP5 antigen may be a promising vaccine candidate against toxoplasmosis. To our knowledge, this is the first report to evaluate the immunoprotective value of ROP5.
Related JoVE Video
Molecular dynamics simulations on gate opening in ZIF-8: identification of factors for ethane and propane separation.
Langmuir
PUBLISHED: 06-28-2013
Show Abstract
Hide Abstract
Gate opening of zeolitic imidazolate frameworks (ZIFs) is an important microscopic phenomenon in explaining the adsorption, diffusion, and separation processes for large guest molecules. We present a force field, with input from density functional theory (DFT) calculations, for the molecular dynamics simulation on the gate opening in ZIF-8. The computed self-diffusivities for sorbed C1 to C3 hydrocarbons were in good agreement with the experimental values. The observed sharp diffusion separation from C2H6 to C3H8 was elucidated by investigating the conformations of the guest molecules integrated with the flexibility of the host framework.
Related JoVE Video
The origin of enantioselectivity in the L-threonine-derived phosphine-sulfonamide catalyzed aza-Morita-Baylis-Hillman reaction: effects of the intramolecular hydrogen bonding.
Org. Biomol. Chem.
PUBLISHED: 06-17-2013
Show Abstract
Hide Abstract
L-Threonine-derived phosphine-sulfonamide 4 was identified as the most efficient catalyst to promote enantioselective aza-Morita-Baylis-Hillman (MBH) reactions, affording the desired aza-MBH adducts with excellent enantioselectivities. Density functional theory (DFT) studies were carried out to elucidate the origin of the observed enantioselectivity. The importance of the intramolecular N-H···O hydrogen-bonding interaction between the sulfonamide and enolate groups was identified to be crucial in inducing a high degree of stereochemical control in both the enolate addition to imine and the subsequent proton transfer step, affording aza-MBH reactions with excellent enantioselectivity.
Related JoVE Video
The composition of surgical teams in the operating room and its impact on surgical team performance in China.
Surg Endosc
PUBLISHED: 06-13-2013
Show Abstract
Hide Abstract
Previous studies on surgical team composition have shown that surgical team size had an independent impact on surgical performance in US and Canadian hospitals. We aimed to investigate the impact of team composition on surgical performance in two Chinese hospitals.
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.