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Find video protocols related to scientific articles indexed in Pubmed.
Pancreatic cell tracing, lineage tagging and targeted genetic manipulations in multiple cell types using pancreatic ductal infusion of adeno-associated viral vectors and/or cell-tagging dyes.
Nat Protoc
PUBLISHED: 10-30-2014
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Genetic manipulations, with or without lineage tracing for specific pancreatic cell types, are very powerful tools for studying diabetes, pancreatitis and pancreatic cancer. Nevertheless, the use of Cre/loxP systems to conditionally activate or inactivate the expression of genes in a cell type- and/or temporal-specific manner is not applicable to cell tracing and/or gene manipulations in more than one lineage at a time. Here we report a technique that allows efficient delivery of dyes for cell tagging into the mouse pancreas through the duct system, and that also delivers viruses carrying transgenes or siRNA under a specific promoter. When this technique is applied in genetically modified mice, it enables the investigator to perform either double lineage tracing or cell lineage tracing combined with gene manipulation in a second lineage. The technique requires <40 min.
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Self-Driven One-Step Oil Removal from Oil Spill on Water via Selective-Wettability Steel Mesh.
ACS Appl Mater Interfaces
PUBLISHED: 10-21-2014
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Marine oil spills seriously endanger sea ecosystems and coastal environments, resulting in a loss of energy resources. Environmental and economic demands emphasize the need for new methods of effectively separating oil-water mixtures, while collecting oil content at the same time. A new surface-tension-driven, gravity-assisted, one-step, oil-water separation method is presented for sustained filtration and collection of oil from a floating spill. A benchtop prototype oil collection device uses selective-wettability (superhydrophobic and superoleophilic) stainless steel mesh that attracts the floating oil, simultaneously separating it from water and collecting it in a container, requiring no preseparation pumping or pouring. The collection efficiencies for oils with wide ranging kinematic viscosities (0.32-70.4 cSt at 40 °C) are above 94%, including motor oil and heavy mineral oil. The prototype device showed high stability and functionality over repeated use, and can be easily scaled for efficient cleanup of large oil spills on seawater. In addition, a brief consolidation of separation requirements for oil-water mixtures of various oil densities is presented to demonstrate the versatility of the material system developed herein.
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A lithium anode protection guided highly-stable lithium-sulfur battery.
Chem. Commun. (Camb.)
PUBLISHED: 10-07-2014
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A Li3N protection layer is fabricated on the surface of a Li anode by an in situ method to suppress the shuttle effect on the basis of anode protection. The discharge capacity is retained at 773 mA h g(-1) after 500 cycles with an average coulombic efficiency of 92.3% in the electrolyte without LiNO3, while the sulfur loading of the simple sulfur cathode was 2.5-3 mg cm(-2).
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[Clinical application of primary tumor contralateral facial artery musculocutaneous flap to reconstruct oral and maxillofacial defects].
Hua Xi Kou Qiang Yi Xue Za Zhi
PUBLISHED: 09-23-2014
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This study aims to explore the method that uses primary tumor contralateral facial artery musculocutaneous (FAMM) flap to reconstruct defects of the tongue and floor of mouth.
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Effervescence-assisted dispersive liquid-liquid microextraction using a solid effervescent agent as a novel dispersion technique for the analysis of fungicides in apple juice.
J Sep Sci
PUBLISHED: 09-22-2014
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A novel effervescence-assisted dispersive liquid-liquid microextraction method has been developed for the determination of four fungicides in apple juice samples. In this method, a solid effervescent agent is added into samples to assist the dispersion of extraction solvent. The effervescent agent is environmentally friendly and only produces an increase in the ionic strength and a negligible variation in the pH value of the aqueous sample, which does not interfere with the extraction of the analytes. The parameters affecting the extraction efficiency were investigated including the composition of effervescent agent, effervescent agent amount, formulation of effervescent agent, adding mode of effervescent agent, type and volume of extraction solvent, and pH. Under optimized conditions, the method showed a good linearity within the range of 0.05-2 mg/L for pyrimethanil, fludioxonil, and cyprodinil, and 0.1-4 mg/L for kresoxim-methyl, with the correlation coefficients >0.998. The limits of detection for the method ranged between 0.005 and 0.01 mg/L. The recoveries of the target fungicides in apple juice samples were in the range of 72.4-110.8% with the relative standard deviations ranging from 1.2 to 6.8%.
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A shuttle effect free lithium sulfur battery based on a hybrid electrolyte.
Phys Chem Chem Phys
PUBLISHED: 09-08-2014
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A room temperature hybrid electrolyte based lithium-sulfur cell was successfully cycled with an excellent coulombic efficiency of 100%. The initial discharge specific capacities of up to 1528 mA h g(-1), 1386 mA h g(-1) and 1341 mA h g(-1), respectively, at C/20, C/5 and C/2 rates were realized and remained at 720 mA h g(-1) after 40 cycles at the C/5 rate.
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CRISPR/Cas9-mediated targeted mutagenesis in Nicotiana tabacum.
Plant Mol. Biol.
PUBLISHED: 09-07-2014
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Genome editing is one of the most powerful tools for revealing gene function and improving crop plants. Recently, RNA-guided genome editing using the type II clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein (Cas) system has been used as a powerful and efficient tool for genome editing in various organisms. Here, we report genome editing in tobacco (Nicotiana tabacum) mediated by the CRISPR/Cas9 system. Two genes, NtPDS and NtPDR6, were used for targeted mutagenesis. First, we examined the transient genome editing activity of this system in tobacco protoplasts, insertion and deletion (indel) mutations were observed with frequencies of 16.2-20.3 % after transfecting guide RNA (gRNA) and the nuclease Cas9 in tobacco protoplasts. The two genes were also mutated using multiplexing gRNA at a time. Additionally, targeted deletions and inversions of a 1.8-kb fragment between two target sites in the NtPDS locus were demonstrated, while indel mutations were also detected at both the sites. Second, we obtained transgenic tobacco plants with NtPDS and NtPDR6 mutations induced by Cas9/gRNA. The mutation percentage was 81.8 % for NtPDS gRNA4 and 87.5 % for NtPDR6 gRNA2. Obvious phenotypes were observed, etiolated leaves for the psd mutant and more branches for the pdr6 mutant, indicating that highly efficient biallelic mutations occurred in both transgenic lines. No significant off-target mutations were obtained. Our results show that the CRISPR/Cas9 system is a useful tool for targeted mutagenesis of the tobacco genome.
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Ionic-liquid-based, manual-shaking- and ultrasound-assisted, surfactant-enhanced emulsification microextraction for the determination of three fungicide residues in juice samples.
J Sep Sci
PUBLISHED: 09-02-2014
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A novel manual shaking and ultrasound-assisted surfactant-enhanced emulsification microextraction method was developed for the determination of three fungicides in juice samples. In this method, the ionic liquid, 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, instead of a volatile organic solvent was used as the extraction solvent. The surfactant, NP-10, was used as an emulsifier to enhance the dispersion of the water-immiscible ionic liquid into an aqueous phase, which accelerated the mass transfer of the analytes. Organic dispersive solvent typically required in common dispersive liquid-liquid microextraction methods was not necessary. In addition, manual shaking for 15 s before ultrasound to preliminarily mix the extraction solvent and the aqueous sample could greatly shorten the time for dispersing the ionic liquid into aqueous solution by ultrasound irradiation. Several experimental parameters affecting the extraction efficiency, including type and volume of extraction solvent, type and concentration surfactant, extraction time and pH, were optimized. Under the optimized conditions, good linearity with the correlation coefficients (?) higher than 0.9986 and high sensitivity with the limit of detection ranged from 0.4 to 1.6 ?g L(-1) were obtained. The average recoveries ranged from 61.4-86.0% for spiked juice, with relative standard deviations from 1.8 to 9.7%. The proposed method was demonstrated to be a simple, fast, and efficient method for the analysis of the target fungicides in juice samples. This article is protected by copyright. All rights reserved.
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Reduction of AUF1-mediated follistatin mRNA decay during glucose starvation protects cells from apoptosis.
Nucleic Acids Res.
PUBLISHED: 08-26-2014
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Follistatin (FST) performs several vital functions in the cells, including protection from apoptosis during stress. The expression of FST is up-regulated in response to glucose deprivation by an unknown mechanism. We herein showed that the induction of FST by glucose deprivation was due to an increase in the half-life of its mRNA. We further identified an AU-rich element (ARE) in the 3'UTR of FST mRNA that mediated its decay. The expression of FST was elevated after knocking down AUF1 and reduced when AUF1 was further expressed. In vitro binding assays and RNA pull-down assays revealed that AUF1 interacted with FST mRNA directly via its ARE. During glucose deprivation, a majority of AUF1 shuttled from cytoplasm to nucleus, resulting in dissociation of AUF1 from FST mRNA and thus stabilization of FST mRNA. Finally, knockdown of AUF1 decreased whereas overexpression of AUF1 increased glucose deprivation-induced apoptosis. The apoptosis promoting effect of AUF1 was eliminated in FST expressing cells. Collectively, this study provided evidence that AUF1 is a negative regulator of FST expression and participates in the regulation of cell survival under glucose deprivation.
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Latent tuberculosis infection and occupational protection among health care workers in two types of public hospitals in China.
PLoS ONE
PUBLISHED: 08-26-2014
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To determine the impact factors of latent tuberculosis infection (LTBI) and the knowledge of TB prevention and treatment policy among health care workers (HCWs) in different types of hospitals and explore the strategies for improving TB prevention and control in medical institutions in China.
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Transplantation of endothelial progenitor cells for improving placental perfusion in preeclamptic rats.
Arch. Gynecol. Obstet.
PUBLISHED: 07-21-2014
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Effective treatments for preeclampsia are currently unavailable. As endothelial progenitor cell-transplantation may improve ischemia, it is an important undertaking to study the role of endothelial progenitor cells for improving the symptom of preeclampsia.
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Evaluation of pars plana sclera fixation of posterior chamber intraocular lens.
Indian J Ophthalmol
PUBLISHED: 07-10-2014
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The purpose of this study was to evaluate the clinical efficacy and safety of modified posterior chamber intraocular lens (PCIOL) implantation with transscleral fixation.
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Total retroperitoneal laparoscopic nephroureterectomy with bladder-cuff resection for upper urinary tract transitional cell carcinoma.
J Invest Surg
PUBLISHED: 07-02-2014
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ABSTRACT Background: Open nephroureterectomy (ONU) and bladder cuff resection (ONU-BCR) has been the gold standard of surgical treatment for upper urinary tract transitional cell carcinoma (UUT-TCC). The aim of this study is to introduce a modified total retroperitoneal laparoscopic nephroureterectomy (LNU) with bladder-cuff resection (LNU-BCR) method for treating UUT-TCC and compare its clinical efficacy with ONU-BCR.
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First finding of subgroup-E avian leukosis virus from wild ducks in China.
Vet. Microbiol.
PUBLISHED: 06-26-2014
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To analyze the status of avian leukosis virus subgroup E (ALV-E) in wild ducks in China, we collected 276 wild ducks, including 12 species, from four provinces of China. The PCR detection for ALV-E identified four samples as positive samples and the detection rate was 1.45%. The env sequences of ALV-E were cloned and sequenced. In gp85, genes of the four ALV-E strains showed a high homology (98.1-99.5%) with ev-1, ev-3, and SD0501 and more than 90% homology with other subgroup-A and subgroup-B avian leukosis viruses. However, they showed a slightly lower identity with subgroup-J (NX0101 and HPRS103), from 47.5 to 48.1%. Simultaneously, a further comparison with ALV-E representative isolates indicated that the amino acid substitutions of the four wild duck strains were distributed throughout the gp85. In total, these results suggested that the subgroup-E avian leukosis virus has been found in wild ducks in China.
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Image decoding of photonic crystal beads array in the microfluidic chip for multiplex assays.
Sci Rep
PUBLISHED: 06-18-2014
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Along with the miniaturization and intellectualization of biomedical instruments, the increasing demand of health monitoring at anywhere and anytime elevates the need for the development of point of care testing (POCT). Photonic crystal beads (PCBs) as one kind of good encoded microcarriers can be integrated with microfluidic chips in order to realize cost-effective and high sensitive multiplex bioassays. However, there are difficulties in analyzing them towards automated analysis due to the characters of the PCBs and the unique detection manner. In this paper, we propose a strategy to take advantage of automated image processing for the color decoding of the PCBs array in the microfluidic chip for multiplex assays. By processing and alignment of two modal images of epi-fluorescence and epi-white light, every intact bead in the image is accurately extracted and decoded by PC colors, which stand for the target species. This method, which shows high robustness and accuracy under various configurations, eliminates the high hardware requirement of spectroscopy analysis and user-interaction software, and provides adequate supports for the general automated analysis of POCT based on PCBs array.
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On-demand intracellular amplification of chemoradiation with cancer-specific plasmonic nanobubbles.
Nat. Med.
PUBLISHED: 06-01-2014
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Chemoradiation-resistant cancers limit treatment efficacy and safety. We show here the cancer cell-specific, on-demand intracellular amplification of chemotherapy and chemoradiation therapy via gold nanoparticle- and laser pulse-induced mechanical intracellular impact. Cancer aggressiveness promotes the clustering of drug nanocarriers and gold nanoparticles in cancer cells. This cluster, upon exposure to a laser pulse, generates a plasmonic nanobubble, the mechanical explosion that destroys the host cancer cell or ejects the drug into its cytoplasm by disrupting the liposome and endosome. The same cluster locally amplifies external X-rays. Intracellular synergy of the mechanical impact of plasmonic nanobubble, ejected drug and amplified X-rays improves the efficacy of standard chemoradiation in resistant and aggressive head and neck cancer by 100-fold in vitro and 17-fold in vivo, reduces the effective entry doses of drugs and X-rays to 2-6% of their clinical doses and efficiently spares normal cells. The developed quadrapeutics technology combines four clinically validated components and transforms a standard macrotherapy into an intracellular on-demand theranostic microtreatment with radically amplified therapeutic efficacy and specificity.
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Engineered Hair Follicle Mesenchymal Stem Cells Overexpressing Controlled-Release Insulin Reverse Hyperglycemia in Mice with Type l Diabetes.
Cell Transplant
PUBLISHED: 05-20-2014
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Genetically engineered stem cells that overexpress genes encoding therapeutic products can be exploited to correct metabolic disorders by repairing and regenerating diseased organs or restoring their function. Hair follicles are readily accessible and serve as a rich source of autologous stem cells for cell-based gene therapy. Here, we isolated mesenchymal stem cells from human hair follicles (HF-MSCs) and engineered them to overexpress the human insulin gene and release human insulin in a time and dose-dependent manner in response to rapamycin. The engineered HF-MSCs retained their characteristic cell-surface markers and retained their potential to differentiate into adipocytes and osteoblasts. When mice with streptozotocin-induced type 1 diabetes were engrafted with these engineered HF-MSCs, these cells expressed and released a dose of human insulin, dramatically reversed hyperglycemia, and significantly reduced death rate. Moreover, the engineered HF-MSCs did not form detectable tumors throughout the 120 days animal tests in our experiment. Our results show that HF-MSCs can be used to safely and efficiently express therapeutic transgenes and therefore show promise for cell-based gene therapy of human disease.
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Epinephrine promotes development potential of vitrified mouse oocytes.
Pak. J. Biol. Sci.
PUBLISHED: 05-03-2014
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Cryopreserved oocytes show low developmental ability. To understand the mechanism underlying their development impairment, study was designed to determine the effect of epinephrine on the in vitro developmental competence of vitrified mouse oocytes. Mature oocytes were vitrified using Open Pulled Straw (OPS) method. The vitrified oocytes were warmed and introduced into M2 medium which contains epinephrine at different concentrations (10(-2), 10(-4), 10(-6), 10(-8) mol L(-1) in an incubator for 1 h. Then the survival rate of the oocytes was evaluated and the subsequent development of oocytes was assessed through in vitro Fertilization (IVF). Furthermore, the levels of intracellular ROS, GSH and the concentration of ATP were determined among 10(-4) mol L(-1) epinephrine-treated group, vitrification group and fresh group. Results showed that vitrified oocytes treated with 10(-4)) mol L(-1) epinephrine had significant higher rates of cleavage (66.4 vs.45.2%) and blastocyst (47.2 vs. 34.7%) than no epinephrine treated group, as well as more blastocyst cells (54.5 vs. 36.8) and lower ratio of apoptotic cells (5.9 vs. 21.5%; p < 0.05). Further experiment found that 10(-4) mol L(-1) epinephrine treatment could significantly reduce intracellular ROS level and enhance cytoplasmic ATP concentration (p < 0.05), but there was no different in GSH level compared to vitrification group. In conclusion, epinephrine could promote vitrified oocytes cryosurvival and their subsequent development ability, which maybe related with the changes of intracellular ROS level and ATP content.
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Acetaldehyde dehydrogenase 2 (ALDH2) deficiency exacerbates pressure overload-induced cardiac dysfunction by inhibiting Beclin-1 dependent autophagy pathway.
Biochim. Biophys. Acta
PUBLISHED: 05-01-2014
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Mitochondrial aldehyde dehydrogenase 2 (ALDH2) was demonstrated to play cardioprotective roles in cardiovascular diseases. Nonetheless, little is known about the roles and mechanisms of ALDH2 in pressure overload-induced cardiac damages. In this study, we revealed that ALDH2 deficiency overtly exacerbated transverse aortic constriction (TAC)-induced cardiac dysfunction. Cardiomyocyte enlargement was observed in both WT and ALDH2-/- mice in HE-stained myocardial tissue samples at 8weeks post TAC surgery. Mitochondrial morphology and structure were also significantly damaged post TAC surgery and the changes were aggravated in ALDH2-/- TAC hearts. ALDH2 deficiency also depressed myocardial autophagy in hearts at 8weeks post TAC surgery with a potential mechanism of repressing the expression of Beclin-1 and promoting the interaction between Bcl-2 and Beclin-1. These data indicate that ALDH2 deficiency exacerbates the pressure overload induced cardiac dysfunction partly by inhibiting Beclin-1 dependent autophagy pathway. This article is part of a Special Issue entitled: Autophagy and protein quality control in cardiometabolic diseases.
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Endothelial progenitor cells as a possible component of stem cell niche to promote self-renewal of mesenchymal stem cells.
Mol. Cell. Biochem.
PUBLISHED: 04-28-2014
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Stem cells dwell at the "stem cell niche" to accomplish a series of biological processes. The composition of the niche should be determined because the insufficient understanding of this feature limits the development in the study of stem cells. We showed in our study on mesenchymal stem cells (MSCs) that the MSCs first neighbored to CD31(+) cells, which proved to be endothelial progenitor cells (EPCs), and formed a group of cell colony before they exerted their biological functions. It was further proved that EPCs have close interactions with MSCs and promoted the self-renewal of the MSCs in vitro and in vivo. Together with these achievements, we hypothesized that EPCs may be a possible biological component of the MSC stem cell niche and affect the biological processes of MSCs.
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Molecular cloning, characterization, and expression analysis of a heat shock protein (HSP) 70 gene from Paphia undulata.
Gene
PUBLISHED: 04-12-2014
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In this study, a full-length HSP70 cDNA from Paphia undulata was cloned using reverse transcriptase polymerase chain reaction (RT-PCR) coupled with rapid amplification of cDNA ends (RACE). The full-length cDNA is 2,351 bp, consisting of a 5'-untranslated region (UTR) of 83 bp, a 3'-UTR of 315 bp, and an open reading frame (ORF) of 1,953 bp. This cDNA encodes 650 amino acids with an estimated molecular weight of 71.3 kDa and an isoelectric point of 5.51. Based on the amino acid sequence analysis and phylogenetic analysis, this HSP70 gene was identified as a member of the cytoplasmic HSP70 family, being the constitutive expression, and it was designated as PuHSC70. The distribution of PuHSC70 mRNA in the mantle, digestive gland, adductor muscle, gonad, gill, heart, and hemocytes suggested that PuHSC70 is ubiquitously expressed. The mRNA levels of PuHSC70 under high temperature and high salinity stresses were analyzed by real-time PCR. Under high temperature stress of 32°C, PuHSC70 mRNA in the mantle, digestive gland, gill, and heart was significantly up-regulated at 1h and 2h, and it was then progressively down-regulated. In the adductor muscle, the level of PuHSC70 mRNA gradually increased throughout the study period; the mRNA levels in the gonad and hemocytes increased significantly at 4h and 8h (P<0.05) and then decreased at 8h and 14 h, respectively, however they increased again afterwards, reaching the highest levels at 50h. Under high salinity (32 ‰) stress, the mRNA levels of PuHSC70 in the mantle and gonad were increased significantly only at 24h and 48 h (P<0.05), and at the rest of the study period they were slightly elevated. Compared with the pretreatment level, the levels of expression in the digestive gland and gill were unchanged or reduced throughout the study period. The levels of PuHSC70 mRNA in the adductor muscle, hemocytes, and heart were significantly increased, reaching a maximum at 24h, and then they gradually decreased; moreover, in the heart, the mRNA expression recovered to the pretreatment level at 50h; while in the adductor muscle and hemocytes, the expression level remained higher than that of the control. The cloning and expression analyses of PuHSC70 provide theoretical basis to further study the mechanism of physiological response to thermal and high salinity stresses.
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[Effects of exogenous suppressor of cytokine signaling on cell apoptosis in ectopic endometrial stromal cells].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 04-12-2014
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To explore the effects of exogenous suppressor of cytokine signaling 3 (SOCS3) in Janus Kinase/Signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathways and examine the relationship between exogenous SOCS3 and cell proliferation and apoptosis in ectopic endometrial stromal cells.
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Autophagy eliminates cytoplasmic ?-catenin and NICD to promote the cardiac differentiation of P19CL6 cells.
Cell. Signal.
PUBLISHED: 04-10-2014
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Autophagy plays important roles in adipogenesis and neuron development. However, how autophagy contributes to cardiac development is not well understood. The main aim of our study was to determine the association between autophagy and myocardial differentiation and its roles in this process. Using a well-established in vitro cardiomyocyte differentiation system, P19CL6 cells, we found that autophagy occurred from the early stage of cardiac differentiation. Blocking autophagy by knocking-down of autophagy-related gene Atg7 or Atg5 inhibited the cardiac differentiation of P19CL6 cells. Further investigation demonstrated that LC3 and P62 could form a complex with ?-catenin and NICD, respectively, and promoted the degradation of ?-catenin and NICD. Enhancing autophagy promoted the formation of complex, whereas blocking autophagy attenuated the degradation of ?-catenin and NICD. Taken together, autophagy could facilitate P19CL6 cells to complete the cardiac differentiation process through blocking Wnt and Notch signaling pathways.
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Sparse representation based SAR vehicle recognition along with aspect angle.
ScientificWorldJournal
PUBLISHED: 04-09-2014
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As a method of representing the test sample with few training samples from an overcomplete dictionary, sparse representation classification (SRC) has attracted much attention in synthetic aperture radar (SAR) automatic target recognition (ATR) recently. In this paper, we develop a novel SAR vehicle recognition method based on sparse representation classification along with aspect information (SRCA), in which the correlation between the vehicle's aspect angle and the sparse representation vector is exploited. The detailed procedure presented in this paper can be summarized as follows. Initially, the sparse representation vector of a test sample is solved by sparse representation algorithm with a principle component analysis (PCA) feature-based dictionary. Then, the coefficient vector is projected onto a sparser one within a certain range of the vehicle's aspect angle. Finally, the vehicle is classified into a certain category that minimizes the reconstruction error with the novel sparse representation vector. Extensive experiments are conducted on the moving and stationary target acquisition and recognition (MSTAR) dataset and the results demonstrate that the proposed method performs robustly under the variations of depression angle and target configurations, as well as incomplete observation.
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The transcription factor CUTL1 is associated with proliferation and prognosis in malignant melanoma.
Melanoma Res.
PUBLISHED: 04-02-2014
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The transcription factor CUTL1 (CCAAT displacement protein 1) has been reported to participate in the proliferation of diverse types of cancer. In the present study, we investigated the potential involvement of CUTL1 in the proliferation of malignant melanoma. We found that CUTL1 expression was upregulated in malignant melanoma tissues and cell lines, and CUTL1 expression was selected as a prognostic predictor for malignant melanoma patients by both univariate and multivariate analysis. Knockdown of CUTL1 by short hairpin RNA significantly reduced the colony-forming ability of malignant melanoma cells in vitro and reduced tumor growth in vivo, whereas forced overexpression of CUTL1 produced the opposite results. Consistently, cell cycle progression was impaired upon downregulation of CUTL1 and enhanced when CUTL1 was upregulated. Additional experiments suggested that CUTL1 may regulate the proliferation of malignant melanoma by modulating the expression of cell cycle-related proteins.
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Hierarchical mesoporous iron-based fluoride with partially hollow structure: facile preparation and high performance as cathode material for rechargeable lithium ion batteries.
Phys Chem Chem Phys
PUBLISHED: 03-28-2014
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Hierarchical mesoporous structured iron based fluorides (abbreviated as HMIFs) are successfully synthesized for the first time by a solvothermal method through self-assembly. The fluorides are built from a large amount of nanorods with a size more than a dozen nanometers and exhibit dual phases consisting of Fe1.9F4.75·0.95H2O and FeF3·H2O. A possible formation mechanism is proposed by systematically investigating the synthesis conditions including temperature, reaction time and the amount of the fluorides source. The electrochemical performance of HMIFs as cathodes for rechargeable lithium batteries is investigated. A large reversible capacity exceeding 200 mA h g(-1) without any conducting agent coating and excellent cyclic performance with a residual capacity of 148 mA h g(-1) after 100 cycles are obtained at 0.1 C. In addition, an outstanding rate performance exceeding 100 mA h g(-1) at 5 C highlights the advantages of HMIFs materials for energy storage applications in high-performance LIBs.
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M2 macrophages promote beta-cell proliferation by up-regulation of SMAD7.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 03-17-2014
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Determination of signaling pathways that regulate beta-cell replication is critical for beta-cell therapy. Here, we show that blocking pancreatic macrophage infiltration after pancreatic duct ligation (PDL) completely inhibits beta-cell proliferation. The TGF? superfamily signaling inhibitor SMAD7 was significantly up-regulated in beta cells after PDL. Beta cells failed to proliferate in response to PDL in beta-cell-specific SMAD7 mutant mice. Forced expression of SMAD7 in beta cells by itself was sufficient to promote beta-cell proliferation in vivo. M2, rather than M1 macrophages, seem to be the inducers of SMAD7-mediated beta-cell proliferation. M2 macrophages not only release TGF?1 to directly induce up-regulation of SMAD7 in beta cells but also release EGF to activate EGF receptor signaling that inhibits TGF?1-activated SMAD2 nuclear translocation, resulting in TGF? signaling inhibition. SMAD7 promotes beta-cell proliferation by increasing CyclinD1 and CyclinD2, and by inducing nuclear exclusion of p27. Our study thus reveals a molecular pathway to potentially increase beta-cell mass through enhanced SMAD7 activity induced by extracellular stimuli.
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Barrier function of the coelomic epithelium in the developing pancreas.
Mech. Dev.
PUBLISHED: 02-26-2014
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Tight spatial regulation of extracellular morphogen signaling within the close confines of a developing embryo is critical for proper organogenesis. Given the complexity of extracellular signaling in developing organs, together with the proximity of adjacent organs that use disparate signaling pathways, we postulated that a physical barrier to signaling may exist between organs in the embryo. Here we describe a previously unrecognized role for the embryonic coelomic epithelium in providing a physical barrier to contain morphogenic signaling in the developing mouse pancreas. This layer of cells appears to function both to contain key factors required for pancreatic epithelial differentiation, and to prevent fusion of adjacent organs during critical developmental windows. During early foregut development, this barrier appears to play a role in preventing splenic anlage-derived activin signaling from inducing intestinalization of the pancreas-specified epithelium.
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Angiogenin stimulates ribosomal RNA transcription by epigenetic activation of the ribosomal DNA promoter.
J. Cell. Physiol.
PUBLISHED: 02-22-2014
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Angiogenin (ANG) undergoes nuclear translocation and promotes ribosomal RNA (rRNA) transcription thereby enhancing cell growth and proliferation. However, the mode of action of ANG in stimulating rRNA transcription is unclear. Here, we show that ANG enhances the formation of RNA polymerase I (Pol I) pre-initiation complex at the ribosomal DNA (rDNA) promoter. ANG binds at the upstream control element (UCE) of the promoter and enhances promoter occupancy of RNA Pol I as well as the selectivity factor SL1 components TAFI 48 and TAFI 110. We also show that ANG increases the number of actively transcribing rDNA by epigenetic activation through promoter methylation and histone modification. ANG binds to histone H3, inhibits H3K9 methylation, and activates H3K4 methylation as well as H4 acetylation at the rDNA promoter. These data suggest that one of the mechanisms by which ANG stimulates rRNA transcription is through an epigenetic activation of rDNA promoter.
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Ribosome profiling reveals sequence-independent post-initiation pausing as a signature of translation.
Cell Res.
PUBLISHED: 02-12-2014
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The journey of a newly synthesized polypeptide starts in the peptidyltransferase center of the ribosome, from where it traverses the exit tunnel. The interior of the ribosome exit tunnel is neither straight nor smooth. How the ribosome dynamics in vivo is influenced by the exit tunnel is poorly understood. Genome-wide ribosome profiling in mammalian cells reveals elevated ribosome density at the start codon and surprisingly the downstream 5th codon position as well. We found that the highly focused ribosomal pausing shortly after initiation is attributed to the geometry of the exit tunnel, as deletion of the loop region from ribosome protein L4 diminishes translational pausing at the 5th codon position. Unexpectedly, the ribosome variant undergoes translational abandonment shortly after initiation, suggesting that there exists an obligatory step between initiation and elongation commitment. We propose that the post-initiation pausing of ribosomes represents an inherent signature of the translation machinery to ensure productive translation.
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Molecular characteristics of the complete genome of a J-subgroup avian leukosis virus strain isolated from Eurasian teal in China.
Virus Genes
PUBLISHED: 02-06-2014
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The J-subgroup avian leukosis virus (ALV-J) strain WB11098J was isolated from a wild Eurasian teal, and its proviral genomic sequences were determined. The complete proviral sequence of WB11098J was 7868 nt long. WB11098J was 95.3.9 % identical to the prototype strain HPRS-103, 94.2 % identical to the American strain ADOL-7501, 94.5-94.7 % identical to Chinese broiler isolates, 94.8-97.5 % identical to layer chicken isolates, and 94.4-95.0 % identical to Chinese local chicken isolates at the nucleotide level. Phylogenetic analysis showed that the WB11098J isolate shared the greatest homology with the layer strain SD09DP03 and was included in the same cluster. Interestingly, two 19-bp insertions in the U3 regions of the 5'LTR and 5'UTR that were most likely derived from other retroviruses were found in the WB11098J isolate. These insertions separately introduced one E2BP-binding site in the U3 region of the 5'LTR and a RNA polymerase II transcription factor IIB and core promoter motif of ten elements in the 5'UTR. A 5-bp deletion was identified in the U3 region of the 5'LTR. No nucleotides were deleted in the rTM or DR-1 regions in the 3'UTR. A 1-bp deletion was detected in the E element and introduced a specific and distinct binding site for c-Ets-1. Our study is the first to report the molecular characteristics of the complete genome of an ALV-J that was isolated from a wild bird and will provide necessary information for further understanding of the evolution of ALV-J.
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Structure-dependent activities of polybrominated diphenyl ethers and hydroxylated metabolites on zebrafish retinoic acid receptor.
Environ Sci Pollut Res Int
PUBLISHED: 01-30-2014
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Polybrominated diphenyl ethers (PBDEs), a group of potential endocrine-disrupting chemicals (EDCs) have been shown to disrupt retinoid homeostasis in different species in both laboratory and field studies. However, the molecular mechanisms of interactions with the retinoic acid receptor (RAR) are not fully understood. Zebrafish have proven useful for investigating mechanisms of chemical toxicity. In the present study, a reporter gene assay was used to investigate the activities of 11 PBDEs and six OH-PBDEs with different degrees of bromination on zebrafish RAR. All tested OH-PBDEs induced RAR transcriptional activity; however, of the 11 PBDEs examined, only BDE28 and BDE154 affected the RAR transcriptional activity. Homology modeling and molecular docking were employed to simulate the interactions of PBDEs/OH-PBDEs with zebrafish RARs and to identify binding affinities to analyze the specialization of the interaction between RARs and PBDEs/OH-PBDEs. The results showed that although these compounds could bind with RARs, the effects of PBDEs/OH-PBDEs on RAR transcriptional activity did not depend on their RAR-binding abilities. The present study is the first attempt to demonstrate that OH-PBDEs could induce RAR transcriptional activity by binding directly with RAR; these effects are possibly related to the structure of the compounds, especially their hydroxylation and bromination. Most of the PBDEs could not directly interact with the RAR.
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Subadventitial cystectomy in the management of biliary fistula with liver hydatid disease.
Acta Trop.
PUBLISHED: 01-27-2014
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Biliary fistulas are the most common morbidity (8.2-26%) following hydatid liver surgery. The aim of this study was to evaluate the results of subadventitial cystectomy in the treatment of liver hydatid cyst associated with a biliocystic fistula. The medical records of 153 patients who underwent subadventitial cystectomy for a liver hydatid cyst between January 2006 and December 2010 were retrospectively reviewed. Cysts were located in the right lobe anterior segment 37 (24.2%) patients, right lobe posterior segment 59 (38.6%) patients, the left lobe in 26 (17.0%) patients, and both lobes in 6 (3.9%) patients. The surgical procedures performed were closed (non-incised) subadventitial total cystectomy in 74 patients (48.4%), open (incised) subadventitial total cystectomy in 30 patients (19.6%), and subadventitial subtotal cystectomy in 49 patients (32.0%). Biliocystic communication was found in 52 patients (34.0%), and 21 patients (13.7%) were treated with T-tube drainage. Two patients had performed biliodigestive anastomosis. Biliary fistula was detected in 9 patients after subtotal subadventitial cystectomy. Biliary fistulas closed spontaneously within 10 days and 61 days respectively and the amount of drainage varying between 50 and 400ml after the procedure. Postoperative complication and recurrence rates were 19.0% and 0.7%, respectively. The mortality rate was 0%. Subadventitial cystectomy should be the surgical treatment of choice for this disease because of its feasibility and low rates of recurrence, complications of the residual cavity, and incidence of associated biliary fistula.
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Effects of vitrification for germinal vesicle and metaphase II oocytes on subsequent centromere cohesion and chromosome aneuploidy in mice.
Theriogenology
PUBLISHED: 01-22-2014
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The present study examined the effect of vitrification on oocyte aneuploidy and centromere cohesion. Firstly, germinal vesicle (GV) and in vitro matured oocytes (metaphase II, MII) were vitrified by open-pulled straw method. Secondly, thawed GV oocytes were matured in vitro to detect the aneuploidy rate and the sister inter-kinetochore (iKT) distance (in situ spreading and immunofluorescent staining). The results revealed that the sister iKT distance and the aneuploidy rate in eggs matured from vitrified-thawed GV oocytes were higher than that from in vivo matured, in vitro matured, and in vitro matured frozen oocytes (0.47 ± 0.03 vs. 0.33 ± 0.01 vs. 0.33 ± 0.02 vs. 0.34 ± 0.01 ?m; P < 0.01 and 22.9% vs. 6.5% vs. 5.8% vs. 11.8%; P < 0.05, respectively). Furthermore, the percentage of sister chromosome pairs whose sister iKT distances were higher than 0.9 ?m in eggs matured from vitrified-thawed GV oocytes (8.7%) was higher than that from in vivo matured (1.6%), in vitro matured (1.6%), and in vitro matured frozen oocytes (2.3%) (P < 0.05). The sister iKT distance was associated with centromere cohesion. To investigate whether vitrification of GV oocytes deteriorated centromere cohesion by affecting cohesin complex formation, thawed and fresh GV oocytes were used to detect the cohesin subunits (SMC1?, STAG3, SMC3, and REC8) mRNA expression (quantitative real-time polymerase chain reaction). The relative expression of three cohesin subunits (SMC1?, STAG3, and SMC3) was significantly decreased in GV oocytes after vitrification. In conclusion, vitrification of GV oocytes may result in the subsequent deterioration of centromere cohesion and an increase in the aneuploidy rate. MII oocytes may be the ideal candidate to avoid aneuploidy for fertility cryopreservation.
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Genetic diversity and phylogenetic analysis of glycoprotein gp85 of avian leukosis virus subgroup J wild-bird isolates from Northeast China.
Arch. Virol.
PUBLISHED: 01-22-2014
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Avian leukosis virus subgroup J (ALV-J), first isolated in 1989, preferentially infects meat-type birds. Chinese layer flocks have experienced outbreaks of this virus since 2008. To analyze the status of ALV-J infection in wild birds in China, 585 wild birds collected from three provinces of Northeast China from 2010 to 2012 were tested, and six ALV-J strains were isolated for the first time. Furthermore, the gp85 genes of the six strains were amplified, cloned, and sequenced. The results indicated that two different ALV-J strains coexisted in Chinese wild birds from 2010 to 2012. These results not only expand the epidemiological data available for ALV-J and provide necessary information for the further understanding of the evolution of ALV-J, but they also highlight the potential role of wild-bird migration in the spread of ALV-J.
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Pancreatic duct cells as a source of VEGF in mice.
Diabetologia
PUBLISHED: 01-16-2014
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Vascular endothelial growth factor (VEGF) is essential for proper pancreatic development, islet vascularisation and insulin secretion. In the adult pancreas, VEGF is thought to be predominantly secreted by beta cells. Although human duct cells have previously been shown to secrete VEGF at angiogenic levels in culture, an analysis of the kinetics of VEGF synthesis and secretion, as well as elucidation of an in vivo role for this ductal VEGF in affecting islet function and physiology, has been lacking.
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Immunoglobulin Fc domain fusion to TRAIL significantly prolongs its plasma half-life and enhances its antitumor activity.
Mol. Cancer Ther.
PUBLISHED: 01-15-2014
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TRAIL (Apo2L) is a potent inducer of cell death. Interest in TRAIL has increased, following the observation that TRAIL can selectively kill a wide variety of human cancer cells without killing normal cells both in vitro and when grown as xenografts. Therefore, TRAIL has been proposed as a promising anticancer agent and currently is being tested in clinical trials. However, recombinant TRAIL has a very short plasma half-life, which limits its therapeutic potential. To overcome this limitation, we investigated the ability of the human IgG1 fragment crystallizable region (Fc) to enhance TRAIL stability. In this report, we show that Fc-TRAIL chimeric protein displays higher specific activity in vitro and a significantly longer half-life in mice than recombinant human TRAIL (rh-TRAIL). No short-term toxicity, especially liver toxicity, was observed. More importantly, Fc-TRAIL was much more effective in inhibiting tumor growth in a xenograft tumor model compared with rh-TRAIL. Our data suggest that fusion of Fc to TRAIL is able to improve the bioavailability and activity of TRAIL both in vitro and in vivo, and Fc-TRAIL may be explored for future clinical applications in cancer treatment and prevention.
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Morphology and morphogenesis of Epistylis plicatilis ehrenberg, 1831 (Ciliophora, Peritrichia) from Wuhan, China.
J. Morphol.
PUBLISHED: 01-04-2014
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A limnetic peritrichous ciliate, Epistylis plicatilis Ehrenberg, 1831, was collected from a freshwater ditch beside Moshan Hill, Wuhan, China. Its morphology, infraciliature, and morphogenesis were investigated based on specimens examined in vivo, following staining with protargol and by scanning electron microscopy. The characteristics of the Wuhan population of E. plicatilis are as follows: 1) colonial, each colony typically comprising 30-50 individuals, with a dichotomously branched, noncontractile stalk; 2) fully expanded zooids measure 90-155 × 30-50 µm in vivo; 3) a series of 6 or 7 conspicuous folds appear in the posterior region of the zooid when it contracts; 4) single horseshoe-shaped macronucleus oriented transversely; 5) single contractile vacuole located in peristomial region on dorsal wall of infundibulum; 6) myoneme system comprises 20-24 longitudinal fibers, peristomial disk fibers as a wreath-like net and peristomial ring fibers; 7) narrowly spaced transverse striations on the surface of the body; 8) infundibular polykineties 1 and 2 are three-rowed, infundibular polykinety 3 is two-rowed; and 9) stomatogenesis is of the buccokinetal type; in the new oral apparatus, infundibular polykineties 2 and 3, the haplokinety, and the germinal kinety all originate from the germinal kinety of the parental oral apparatus whereas the polykinety and infundibular polykinety 1 originate from the parental haplokinety. An improved diagnosis of E. plicatilis is supplied.
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Associations between Cox-2 rs20417 and rs5275 polymorphisms and the risk of hepatocellular carcinoma: a meta analysis.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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Genetic polymorphisms of cyclooxygenase-2 (Cox-2) gene have been implicated in the susceptibility to hepatocellular carcinoma (HCC), but the findings from published studies are conflicting and inconclusive. To obtain a more precise estimate of the association of Cox-2 polymorphisms with HCC risk, we performed a meta-analysis of eight eligible case-control studies identified through an extensive online database search of PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Wanfang and Chinese Biomedicine Database; after exclusion, 2324 cases and 2604 controls were included. The pooled odds ratios with corresponding 95% confidence intervals were calculated to assess associations, using fixed- or random-effect models. In addition, subgroup analysis by ethnicity and sensitivity analysis were performed. Our results showed that the Cox-2 rs20417 (-765 G/C) polymorphism was not associated with HCC risk in the studied genetic contrast modes (C vs. G, GC vs. GG, and CC + GC vs. GG). No significant association was found with ethnic groups examined (P > 0.05). Similarly, no significant association of the Cox-2 rs5275 (+ 8473 T/C) polymorphism and HCC risk was found under any of the studied contrasts (C vs. T, TC vs. TT, CC vs. TT, CC + TC vs. TT, CC vs. TC + TT). The present meta-analysis, combining all currently available data, suggests no significant associations of either Cox-2 polymorphism with HCC risk. Further studies with a larger sample size are needed to determine the association in different ethnicities.
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Burst strength of tubing and casing based on twin shear unified strength theory.
PLoS ONE
PUBLISHED: 01-01-2014
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The internal pressure strength of tubing and casing often cannot satisfy the design requirements in high pressure, high temperature and high H2S gas wells. Also, the practical safety coefficient of some wells is lower than the design standard according to the current API 5C3 standard, which brings some perplexity to the design. The ISO 10400: 2007 provides the model which can calculate the burst strength of tubing and casing better than API 5C3 standard, but the calculation accuracy is not desirable because about 50 percent predictive values are remarkably higher than real burst values. So, for the sake of improving strength design of tubing and casing, this paper deduces the plastic limit pressure of tubing and casing under internal pressure by applying the twin shear unified strength theory. According to the research of the influence rule of yield-to-tensile strength ratio and mechanical properties on the burst strength of tubing and casing, the more precise calculation model of tubing-casing's burst strength has been established with material hardening and intermediate principal stress. Numerical and experimental comparisons show that the new burst strength model is much closer to the real burst values than that of other models. The research results provide an important reference to optimize the tubing and casing design of deep and ultra-deep wells.
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Small cell type neuroendocrine carcinoma colliding with squamous cell carcinoma at esophagus.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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Collision tumor is an extremely rare tumor which defined as the concrescence of two distinct primaries neoplasms. We report here a case of collision tumor at lower third esophagus composed of small cell type neuroendocrine carcinoma (NEC), which is an very rare, highly aggressive and poorly prognostic carcinoma and squamous cell carcinoma (SqCC). In our case, pathologically, the small cell carcinoma display the characteristic of small, round, ovoid or spindle-shaped tumor cells with scant cytoplasm, which colliding with a moderately differentiated squamous cell carcinoma. Immunohistochemical staining demonstrated positive activities for CD56, synaptophysin, 34?E12, CK 5/6, ki-67 (70%-80%), but negative for CD99, chromogranin A, and TTF-1. Accurate diagnosis was made base on these findings.
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Detection and molecular characterization of J subgroup avian leukosis virus in wild ducks in China.
PLoS ONE
PUBLISHED: 01-01-2014
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To assess the status of avian leukosis virus subgroup J (ALV-J) in wild ducks in China, we examined samples from 528 wild ducks, representing 17 species, which were collected in China over the past 3 years. Virus isolation and PCR showed that 7 ALV-J strains were isolated from wild ducks. The env genes and the 3'UTRs from these isolates were cloned and sequenced. The env genes of all 7 wild duck isolates were significantly different from those in the prototype strain HPRS-103, American strains, broiler ALV-J isolates and Chinese local chicken isolates, but showed close homology with those found in some layer chicken ALV-J isolates and belonged to the same group. The 3'UTRs of 7 ALV-J wild ducks isolates showed close homology with the prototype strain HPRS-103 and no obvious deletion was found in the 3'UTR except for a 1 bp deletion in the E element that introduced a binding site for c-Ets-1. Our study demonstrated the presence of ALV-J in wild ducks and investigated the molecular characterization of ALV-J in wild ducks isolates.
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An efficient method for the sanitary vitrification of bovine oocytes in straws.
J Anim Sci Biotechnol
PUBLISHED: 01-01-2014
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At present, vitrification has been widely applied to humans, mice and farm animals. To improve the efficiency of vitrification in straw, bovine oocytes were used to test a new two-step vitrification method in this study.
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Suppression of graft regeneration, not ischemia/reperfusion injury, is the primary cause of small-for-size syndrome after partial liver transplantation in mice.
PLoS ONE
PUBLISHED: 01-01-2014
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Ischemia/reperfusion injury (IRI) is commonly considered to play a crucial role in the pathogenesis of small-for-size syndrome (SFSS) after liver transplantation. Rapid regeneration is also considered essential for the survival of SFS grafts.
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The association between the oocyte pool and aneuploidy: a comparative study of the reproductive potential of young and aged mice.
J. Assist. Reprod. Genet.
PUBLISHED: 11-06-2013
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The present study examined the effect of aging on female reproductive potential.
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High expression of CXCR-2 correlates with lymph node metastasis and predicts unfavorable prognosis in resected esophageal carcinoma.
Med. Oncol.
PUBLISHED: 10-31-2013
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CXC chemokines have been reported to play critical roles in tumor growth, angiogenesis, invasion and metastasis of various human cancers. However, expression of CXC chemokines type 2 (CXCR2) and its association with clinicopathological characters and patients prognosis in esophageal cancer are scarcely reported. We retrospectively collected clinicopathologic characteristics of 95 esophageal cancer patients undergoing esophagectomies. Immunohistochemistry was used to detect the expression of CXCR2. The survival was analyzed by the Kaplan-Meier method. Univariate and multivariate analyses were then performed to determine the relationship between CXCR2 and the clinical characteristics and to analyze whether CXCR2 expression was a significant independent prognostic factor for esophageal cancer patients. CXCR2 was highly expressed in 57.9 % of the randomly selected specimens. The expression of CXCR2 was significantly related to lymph node metastasis (P = 0.044) and predicted poor overall status in operable esophageal cancer patients (P = 0.012). Cox proportional hazard analysis regression analysis indicated that CXCR2 expression (P = 0.030) and lymphatic metastasis (P < 0.001) may serve as independent prognostic markers for esophageal cancer patients. Our results demonstrate that CXCR2 significantly correlates with lymph node metastasis and is a poor prognostic factor in resected esophageal squamous cell carcinoma.
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Potential association of pulmonary tuberculosis with genetic polymorphisms of toll-like receptor 9 and interferon-gamma in a Chinese population.
BMC Infect. Dis.
PUBLISHED: 10-28-2013
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Association studies have been employed to investigate the relationships between host single nucleotide polymorphisms (SNPs) and susceptibility to pulmonary Tuberculosis (PTB). However, such candidate genetic markers have not been widely studied in Chinese population, especially with respect to the disease development from latent M. tuberculosis infection (LTBI).
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A smad signaling network regulates islet cell proliferation.
Diabetes
PUBLISHED: 10-02-2013
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Pancreatic ?-cell loss and dysfunction are critical components of all types of diabetes. Human and rodent ?-cells are able to proliferate, and this proliferation is an important defense against the evolution and progression of diabetes. Transforming growth factor-? (TGF-?) signaling has been shown to affect ?-cell development, proliferation, and function, but ?-cell proliferation is thought to be the only source of new ?-cells in the adult. Recently, ?-cell dedifferentiation has been shown to be an important contributory mechanism to ?-cell failure. In this study, we tie together these two pathways by showing that a network of intracellular TGF-? regulators, smads 7, 2, and 3, control ?-cell proliferation after ?-cell loss, and specifically, smad7 is necessary for that ?-cell proliferation. Importantly, this smad7-mediated proliferation appears to entail passing through a transient, nonpathologic dedifferentiation of ?-cells to a pancreatic polypeptide-fold hormone-positive state. TGF-? receptor II appears to be a receptor important for controlling the status of the smad network in ?-cells. These studies should help our understanding of properly regulated ?-cell replication.
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Enhancement of osteoinduction by continual simvastatin release from poly(lactic-co-glycolic acid)-hydroxyapatite-simvastatin nano-fibrous scaffold.
J Biomed Nanotechnol
PUBLISHED: 09-25-2013
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Simvastatin is considered as a stimulator for bone formation. However, the half-life for simvastatin is generally 2 hours, which means, it is difficult to maintain biologically active simvastatin in vivo. To overcome this limitation, we created a system to slowly release simvastatin in vitro and in vivo. We constructed a poly(lactic-co-glycolic acid)/hydroxyapatite nano-fibrous scaffold to carry simvastatin. Releasing assays showed that simvastatin was released from poly(lactic-co-glycolic acid)/hydroxyapatite/simvastatin quickly within - 15 days, and small amounts continued to be released through day 56 (experiments terminated). MTT assays demonstrated that both poly(lactic-co-glycolic acid)/hydroxyapatite and poly(lactic-co-glycolic acid)/hydroxyapatite/simvastatin promoted MC3T3-E1 cell proliferation. However, Alkaline phosphatase assays showed that only poly(lactic-co-glycolic acid)/hydroxyapatite/simvastatin scaffold significantly promoted the osteogenic differentiation of MC3T3-E1 cells in vitro on day 14. To further test in vivo, we created calvaria bone defect models and implanted either poly(lactic-co-glycolic acid)/hydroxyapatite or poly(lactic-co-glycolic acid)/hydroxyapatite/simvastatin. After 4 or 8 weeks post-implantation, the results indicated that poly(lactic-co-glycolic acid)/hydroxyapatite/simvastatin scaffold induced bone formation more efficiently than poly(lactic-co-glycolic acid)/hydroxyapatite alone. Our data demonstrates that poly(lactic-co-glycolic acid)/hydroxyapatite/simvastatin has the potential to aid in healing bone defects and promoting bone regeneration in the future although we still need to optimize this complex to efficiently promote bone regeneration.
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?-Cells are dispensable in postnatal morphogenesis and maturation of mouse pancreatic islets.
Am. J. Physiol. Endocrinol. Metab.
PUBLISHED: 08-27-2013
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Glucagon-producing ?-cells are the second-most abundant cell type in the islet. Whereas ?-cells make up less than 20% of the cells in a mature mouse islet, they occupy a much larger proportion of the pancreatic endocrine cell population during the early postnatal period, the time when morphological and functional maturation occurs to form adult islets. To determine whether ?-cells have a role in postnatal islet development, a diphtheria toxin-mediated ?-cell ablation mouse model was established. Rapid and persistent depletion of ?-cells was achieved by daily injection of the toxin for 2 wk starting at postnatal day 1 (P1). Total pancreatic glucagon content in the ?-cell-ablated mice was undetectable at P14 and still less than 0.3% of that of the control mice at 4 mo of age. Histological analyses revealed that formation of spherical islets occurred normally, and the islet size distribution was not changed despite the near-total lack of ?-cells. Furthermore, there were no differences in expression of ?-cell maturation marker proteins, including urocortin 3 and glucose transporter 2, in the ?-cell-ablated islets at P14. Mice lacking ?-cells grew normally and appeared healthy. Both glucose and insulin tolerance tests demonstrated that the ?-cell-ablated mice had normal glucose homeostasis. These results indicate that ?-cells do not play a critical role in postnatal islet morphogenesis or functional maturation of ?-cells.
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Prevalence and related risk behaviors of HIV, syphilis, and anal HPV infection among men who have sex with men from Beijing, China.
AIDS Behav
PUBLISHED: 08-24-2013
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Specific risk behaviors related to different sexually transmitted infections have not been widely evaluated among men who have sex with men in China. In the present study, a total of 302 MSM were recruited from Beijing with a prevalence of HIV, syphilis, and anal HPV infection as 9.9, 19.2 and 71.4%, respectively. Lower education level was observed to be related to higher infection rate of HIV and syphilis. "Ever found sexual partners in gay venues" was significantly associated with HIV infection as well. "Taking anilinction as regular sexual behavior" was observed to be a significant predictor for anal HPV infection.
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Accumulation of chlorothalonil and its metabolite, 4-hydroxychlorothalonil, in soil after repeated applications and its effects on soil microbial activities under greenhouse conditions.
Environ Sci Pollut Res Int
PUBLISHED: 08-12-2013
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The effect of repeated chlorothalonil applications on its persistence and soil microbial activities were investigated in planted soil under greenhouse conditions. The results revealed that suppressed dissipation of chlorothalonil and the consequent accumulation of chlorothalonil and its toxic metabolite, 4-hydroxychlorothalonil, resulted from four successive applications at rates of 2, 4, and 10 kg a.i./ha. Soil respiration for 7 h (SR7) was slightly affected by chlorothalonil applications at all three levels, whereas soil respiration for 24 h (SR24) at 10 kg a.i./ha was reduced by 17.6-59.1 %, depending upon the frequency. This harmful effect of chlorothalonil on SR24 persisted throughout the experiment although it gradually weakened with time. A persistent inhibitory effect on soil dehydrogenase activity was also observed with repeated applications of chlorothalonil at 10 kg a.i./ha. This study indicated that repeated chlorothalonil applications may lead to the accumulation of chlorothalonil and its metabolite in soil under greenhouse conditions and thereby alter soil microbial activity.
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Process for the fabrication of complex three-dimensional microcoils in fused silica.
Opt Lett
PUBLISHED: 08-02-2013
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The creation of complex three-dimensional (3D) microcoils has attracted significant attention from both scientific and applied research communities. However, it still remains challenging to build 3D microcoils with arbitrary configurations using conventional planar lithographic fabrication methods. This Letter presents a new facile method based on an improved femtosecond laser wet etch technology and metal microsolidifying process for the fabrication of on-chip complex 3D microcoils inside fused silica. The diameter of the microcoils is about 30 ?m, and the effective length of the microchannel is about 13 mm. The aspect ratio of the microcoils can be larger than 400:1, and the microchannel exhibiting good uniformity and smoothness also has good flowability for high-viscosity conductive gallium metal. Based on this approach, we fabricated complex microcoils such as U-shaped and O-shaped microcoils that can be easily integrated into a "lab on a chip" platform or microelectric system inside fused-silica substrate.
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Soliton self-frequency shift controlled by a weak seed laser in tellurite photonic crystal fibers.
Opt Lett
PUBLISHED: 08-02-2013
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We report the first demonstration of soliton self-frequency shift (SSFS) controlled by a weak continuous-wave (CW) laser, from a tellurite photonic crystal fiber pumped by a 1560 nm femtosecond fiber laser. The control of SSFS is performed by the cross-gain modulation of the 1560 nm femtosecond laser. By varying the input power of the weak CW laser (1560 nm) from 0 to 1.17 mW, the soliton generated in the tellurite photonic crystal fiber blue shifts from 1935 to 1591 nm. The dependence of the soliton wavelength on the operation wavelength of the weak CW laser is also measured. The results show the CW laser with a wavelength tunable range of 1530-1592 nm can be used to control the SSFS generation.
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HOXC9 directly regulates distinct sets of genes to coordinate diverse cellular processes during neuronal differentiation.
BMC Genomics
PUBLISHED: 07-26-2013
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Cellular differentiation is characterized by the acquisition of specialized structures and functions, cell cycle exit, and global attenuation of the DNA damage response. It is largely unknown how these diverse cellular events are coordinated at the molecular level during differentiation. We addressed this question in a model system of neuroblastoma cell differentiation induced by HOXC9.
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A novel adaptive-weighted-average framework for blood glucose prediction.
Diabetes Technol. Ther.
PUBLISHED: 07-24-2013
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Blood glucose (BG) prediction plays a very important role in daily BG management of patients with diabetes mellitus. Several algorithms, such as autoregressive (AR) models and artificial neural networks, have been proposed for BG prediction. However, every algorithm has its own subject range (i.e., one algorithm might work well for one diabetes patient but poorly for another patient). Even for one individual patient, this algorithm might perform well during the preprandial period but poorly during the postprandial period.
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Neurogenin3 activation is not sufficient to direct duct-to-beta cell transdifferentiation in the adult pancreas.
J. Biol. Chem.
PUBLISHED: 07-18-2013
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It remains controversial whether adult pancreatic ducts harbor facultative beta cell progenitors. Because neurogenin3 (Ngn3) is a key determinant of pancreatic endocrine cell neogenesis during embryogenesis, many studies have also relied upon Ngn3 expression as evidence of beta cell neogenesis in adults. Recently, however, Ngn3 as a marker of adult beta cell neogenesis has been called into question by reports of Ngn3 expression in fully-developed beta cells. Nevertheless, direct evidence as to whether Ngn3 activation in adult pancreatic duct cells may lead to duct-to-beta cell transdifferentiation is lacking. Here we studied two models of Ngn3 activation in adult pancreatic duct cells (low-dose alloxan treatment and pancreatic duct ligation) and lineage-traced Ngn3-activated duct cells by labeling them through intraductal infusion with a cell-tagging dye, CFDA-SE No dye-labeled beta cells were found during the follow-up in either model, suggesting that activation of Ngn3 in duct cells is not sufficient to direct their transdifferentiation into beta cells. Therefore, Ngn3 activation in duct cells is not a signature for adult beta cell neogenesis.
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trans-10, cis-12 conjugated linoleic acid enhances in vitro maturation of porcine oocytes.
Mol. Reprod. Dev.
PUBLISHED: 07-17-2013
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The aim of this study was to determine the effects of trans-10, cis-12 conjugated linoleic acid (t10c12 CLA) supplementation on oocyte maturation and embryo development in pigs. Compared with the control, supplementation of 50?µM t10c12 CLA to in vitro maturation (IVM) medium significantly increased the proportion of oocytes at the metaphase-II (MII) stage and subsequent parthenogenetic embryo development in terms of cleavage rate, blastocyst formation rate, and cell numbers in blastocysts. The t10c12 CLA-treated oocytes resumed meiotic maturation and progressed to the MII stage significantly faster than those of control. The expression of phosphorylated mitogen-activated protein kinase 3/1 (p-MAPK3/1) and cyclooxygenase-2 (COX2) in cumulus oocyte complexes (COCs) at 5, 10, and 22?hr of IVM were significantly increased in the t10c12 CLA-treatment group. The level of p-MAPK3/1 in t10c12 CLA-treated MII oocytes was also higher (P?
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Cohesin loading factor Nipbl localizes to chromosome axes during mammalian meiotic prophase.
Cell Div
PUBLISHED: 06-17-2013
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Sister chromatid cohesion mediated by the cohesin complex is essential for accurate chromosome segregation during mitosis and meiosis. Loading of cohesin onto chromosomes is dependent on another protein complex called kollerin, containing Nipbl/Scc2 and Mau2/Scc4. Nipbl is an evolutionarily conserved large protein whose haploinsufficiency in humans causes a developmental disorder called Cornelia de Lange syndrome. Although the function of Nipbl homologues for chromosome cohesion in meiotic cells of non-vertebrate models has been elucidated, Nipbl has not been characterized so far in mammalian spermatocytes or oocytes.
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A sphere-cut-splice crossover for the evolution of cluster structures.
J Chem Phys
PUBLISHED: 06-14-2013
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A new crossover operator is proposed to evolve the structures of the atomic clusters. It uses a sphere rather than a plane to cut and splice the parent structures. The child cluster is constructed by the atoms of one parent which lie inside the sphere, and the atoms of the other parent which lie outside the sphere. It can reliably produce reasonable offspring and preserve the good schemata in parent structures, avoiding the drawbacks of the classical plane-cut-splice crossover in the global searching ability and the local optimization speed. Results of Lennard-Jones clusters (30 ? N ? 500) show that at the same settings the genetic algorithm with the sphere-cut-splice crossover exhibits better performance than the one with the plane-cut-splice crossover. The average number of local minimizations needed to find the global minima and the average number of energy evaluation of each local minimization in the sphere scheme is 0.8075 and 0.8386 of that in the plane scheme, respectively. The mean speed-up ratio for the entire testing clusters reaches 1.8207. Moreover, the sphere scheme is particularly suitable for large clusters and the mean speed-up ratio reaches 2.3520 for the clusters with 110 ? N ? 500. The comparison with other successful methods in previous studies also demonstrates its good performance. Finally, a further analysis is presented on the statistical features of the cutting sphere and a modified strategy that reduces the probability of using tiny and large spheres exhibits better global search.
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The Histone H3 Methyltransferase G9A Epigenetically Activates the Serine-Glycine Synthesis Pathway to Sustain Cancer Cell Survival and Proliferation.
Cell Metab.
PUBLISHED: 06-07-2013
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Increased activation of the serine-glycine biosynthetic pathway is an integral part of cancer metabolism that drives macromolecule synthesis needed for cell proliferation. Whether this pathway is under epigenetic control is unknown. Here we show that the histone H3 lysine 9 (H3K9) methyltransferase G9A is required for maintaining the pathway enzyme genes in an active state marked by H3K9 monomethylation and for the transcriptional activation of this pathway in response to serine deprivation. G9A inactivation depletes serine and its downstream metabolites, triggering cell death with autophagy in cancer cell lines of different tissue origins. Higher G9A expression, which is observed in various cancers and is associated with greater mortality in cancer patients, increases serine production and enhances the proliferation and tumorigenicity of cancer cells. These findings identify a G9A-dependent epigenetic program in the control of cancer metabolism, providing a rationale for G9A inhibition as a therapeutic strategy for cancer.
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Monitoring the clearance of apoptotic and necrotic cells in the nematode Caenorhabditis elegans.
Methods Mol. Biol.
PUBLISHED: 06-05-2013
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The nematode Caenorhabditis elegans is an excellent model organism for studying the mechanisms -controlling cell death, including apoptosis, a cell suicide event, and necrosis, pathological cell deaths caused by environmental insults or genetic alterations. C. elegans has also been established as a model for understanding how dying cells are cleared from animal bodies. In particular, the transparent nature of worm bodies and eggshells make C. elegans particularly amenable for live-cell microscopy. Here we describe methods for identifying apoptotic and necrotic cells in living C. elegans embryos, larvae, and adults and for monitoring their clearance during development. We further discuss specific methods to distinguish engulfed from unengulfed apoptotic cells, and methods to monitor cellular and molecular events occurring during phagosome maturation. These methods are based on Differential Interference Contrast (DIC) microscopy or fluorescence microscopy using GFP-based reporters.
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Anal human papillomavirus infection among HIV-infected and uninfected men who have sex with men in Beijing, China.
J. Acquir. Immune Defic. Syndr.
PUBLISHED: 06-05-2013
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In light of Chinas unique ethnic and sociocultural context, and a marked rise in HIV prevalence among MSM, it is important to determine prevalence, genotypes and predictors of anal human papillomavirus (HPV) among HIV-infected and uninfected men who have sex with men (MSM) in Beijing, China.
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Plasticity and epigenetic inheritance of centromere-specific histone H3 (CENP-A)-containing nucleosome positioning in the fission yeast.
J. Biol. Chem.
PUBLISHED: 05-09-2013
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Nucleosomes containing the specific histone H3 variant CENP-A mark the centromere locus on each chromatin and initiate kinetochore assembly. For the common type of regional centromeres, little is known in molecular detail of centromeric chromatin organization, its propagation through cell division, and how distinct organization patterns may facilitate kinetochore assembly. Here, we show that in the fission yeast S. pombe, a relatively small number of CENP-A/Cnp1 nucleosomes are found within the centromeric core and that their positioning relative to underlying DNA varies among genetically homogenous cells. Consistent with the flexible positioning of Cnp1 nucleosomes, a large portion of the endogenous centromere is dispensable for its essential activity in mediating chromosome segregation. We present biochemical evidence that Cnp1 occupancy directly correlates with silencing of the underlying reporter genes. Furthermore, using a newly developed pedigree analysis assay, we demonstrated the epigenetic inheritance of Cnp1 positioning and quantified the rate of occasional repositioning of Cnp1 nucleosomes throughout cell generations. Together, our results reveal the plasticity and the epigenetically inheritable nature of centromeric chromatin organization.
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Dissipation and residues of clethodim and its oxidation metabolites in a rape-field ecosystem using QuEChERS and liquid chromatography/tandem mass spectrometry.
Food Chem
PUBLISHED: 05-06-2013
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A rapid, sensitive and selective method using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedure for simultaneous determination of clethodim and its oxidation metabolites (clethodim sulfoxide and clethodim sulphone) in soil, rape plant and rape seed was developed using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The limits of detection (LODs) of the proposed method ranged from 0.002mg/kg to 0.01mg/kg, and average recoveries were 78.7-104.2%. The trial results showed that clethodim dissipated so rapidly that few clethodim residues were detectable. Clethodim sulfoxide dissipated quickly in rape plant and soil with half-lives of 4.3 and 4.0days, respectively. Clethodim sulphone showed a tendency of rapid increase initially followed by a decrease in rape plant but could not be detected in soil. The terminal residues of clethodim in rape seedsat harvest time were below the maximum residue limit (MRL, 0.5mg/kg).
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Air-assisted liquid-liquid microextraction used for the rapid determination of organophosphorus pesticides in juice samples.
J Chromatogr A
PUBLISHED: 05-06-2013
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A novel and simple air-assisted liquid-liquid microextraction (AALLME) is introduced to analyze the organophosphorus pesticide (OPP) residues in fruit juice samples, using the gas chromatography-flame photometric detection (GC-FPD). In this method, fine extraction solvent drops are rapidly formed and dispersed into the aqueous samples, by using a syringe to withdraw and push-out the mixture of aqueous sample solution and extraction solvent several times. The parameters affecting the extraction efficiency were investigated including the type and volume of the extraction solvent, salt addition, extraction times, and pH. Under optimized conditions, the method showed good linearities with the correlation coefficients (?) higher than 0.9988, and the sensitivity with the limits of detection (LODs) between 0.02?gL(-1) and 0.6?gL(-1). The method was applied to determine the OPP residues in juice samples and the recoveries were ranged from 79% to 113% with relative standard deviations (RSDs) of 0.4-9.9%. The feasibility of the method in real samples was proved.
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Seroprevalence of Entamoeba histolytica infection among Chinese men who have sex with men.
PLoS Negl Trop Dis
PUBLISHED: 05-01-2013
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Men who have sex with men (MSM) were found to be one of the high-risk populations for Entamoeba histolytica (E. histolytica) infection. Accompanied by the prevalence of human immunodeficiency virus (HIV) among MSM, invasive amebiasis caused by E. histolytica has been paid attention to as an opportunistic parasitic infection. However, the status of E. histolytica infection among MSM has been barely studied in mainland China.
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Echinococcus of the liver treated with laparoscopic subadventitial pericystectomy.
Surg Laparosc Endosc Percutan Tech
PUBLISHED: 04-13-2013
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Because of the new radical procedure, subadventitial pericystectomy, has succeed in treatment for the liver hydatid cysts. The aim of this report is to describe the technical details of our laparoscopic method and report the initial results.
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Broadband amplification and highly efficient lasing in erbium-doped tellurite microstructured fibers.
Opt Lett
PUBLISHED: 04-03-2013
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We report broadband amplification and highly efficient lasing in erbium-doped tellurite microstructured fibers. A broad positive net gain bandwidth of 113 nm (1524-1637 nm) is obtained in a 17 cm long erbium-doped tellurite microstructured fiber upon a pump power of 94 mW at 1480 nm. An all-fiber lasing at 1561 nm with maximum unsaturated power of 140 mW and slope efficiency of 53.7% is achieved from the fiber by employing a linear cavity. In addition, the influence of the fiber length on amplification and lasing is investigated and laser oscillation at 1535 nm is realized in a 4.3 cm long fiber.
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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.

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

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