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.
Interleukin-33 promotes disease progression in patients with primary biliary cirrhosis.
Tohoku J. Exp. Med.
PUBLISHED: 11-18-2014
Show Abstract
Hide Abstract
Primary biliary cirrhosis (PBC) is a progressive autoimmune liver disease that can cause a series of complications, including cirrhosis, liver failure and hepatocellular carcinoma. Interleukin-33 (IL-33) is expressed in various non-hematopoietic cells and a certain population of immune cells, and exerts its biological effects by binding to the specific receptor, suppression of tumorigenicity 2 (ST2). A soluble form of ST2 (sST2) has been postulated to act as a decoy receptor for IL-33. In this study, we aimed to investigate the role of IL-33 in the pathogenesis of PBC. The study included 20 healthy controls and 68 patients with PBC. We thus found the increased serum IL-33 levels in PBC patients. Its elevated levels were positively correlated with serum alkaline phosphatase levels (a key parameter for the definition of PBC) and with Child-Pugh scores, which were used to determine the prognosis of liver cirrhosis. Moreover, the serum concentrations of sST2 were significantly higher in PBC patients compared with healthy subjects, irrespective of the disease severity. Importantly, the cells that express IL-33 and/or myeloperoxidase (a marker for neutrophils) were accumulated in the livers of PBC patients, and their number increased with the severity of liver lesions. Lastly, in vitro chemotaxis assays revealed that IL-33 enhanced the migration of neutrophils. These data suggest that IL-33 may affect the progress of PBC by recruiting neutrophils to the liver. This expanded knowledge of IL-33 in PBC patients is important for developing therapeutic strategies (e.g., neutralization of IL-33), selecting optimal clinical management, and predicting prognosis.
Related JoVE Video
Rapid, Selective, and Ultrasensitive Fluorimetric Analysis of Mercury and Copper Levels in Blood Using Bimetallic Gold-Silver Nanoclusters with "Silver Effect"-Enhanced Red Fluorescence.
Anal. Chem.
PUBLISHED: 10-29-2014
Show Abstract
Hide Abstract
Bimetallic alloying gold-silver nanoclusters (Au-AgNCs) have been synthesized by a one-pot biomineralization synthesis route at a vital molar ratio of Au/Ag precursors in the protein matrix. Unexpectedly, the prepared Au-AgNCs could exhibit dramatically enhanced red fluorescence, which is about 6.5-fold and 4.7-fold higher than that of common AuNCs and core-shell Au@AgNCs, respectively. A rapid, selective, and ultrasensitive fluorimetric method has thereby been developed using Au-AgNCs as fluorescent probes toward the separate detections of Hg(2+) and Cu(2+) ions in blood. The interactions of Au-AgNCs with Hg(2+) and Cu(2+) ions were systematically characterized by microscopy imaging, UV-vis, and fluorescence measurements. It is demonstrated that the "silver effect" gives the Au-AgNCs probes not only greatly enhanced red fluorescence but also the strong capacity to specifically sense Cu(2+) ions in addition to improved response to Hg(2+) ions. Moreover, aided by a Cu(2+) chelating agent, exclusive detection of Hg(2+) ions could also be expected with the coexistence of a high level of Cu(2+) ions, as well as reversible Cu(2+) analysis by restoring the fluorescence of Au-AgNCs. Additionally, Au-AgNCs with strong red fluorescence could facilitate fluorimetric analysis with minimal interference from blood backgrounds. Such an Au-AgNCs-based fluorimetric method can allow for the selective analysis of Hg(2+) and Cu(2+) ions down to 0.30 nM and 0.60 nM in blood, respectively, promising a novel detection method to be applied in the clinical laboratory.
Related JoVE Video
[Regulative effect of bakuchiol on ESF-1 cells anti-aging gene].
Zhong Yao Cai
PUBLISHED: 10-28-2014
Show Abstract
Hide Abstract
To explore the mechanism of bakuchiol on anti-aging gene mRNA expression level of human skin fibroblasts (ESF-1).
Related JoVE Video
Core-Shell Nanoparticles Based on Pullulan and Poly(?-amino) Ester for Hepatoma-Targeted Codelivery of Gene and Chemotherapy Agent.
ACS Appl Mater Interfaces
PUBLISHED: 10-27-2014
Show Abstract
Hide Abstract
This study designs a novel nanoparticle system with core-shell structure based on pullulan and poly(?-amino) ester (PBAE) for the hepatoma-targeted codelivery of gene and chemotherapy agent. Plasmid DNA expressing green fluorescent protein (pEGFP), as a model gene, was fully condensed with cationic PBAE to form the inner core of PBAE/pEGFP polycomplex. Methotrexate (MTX), as a model chemotherapy agent, was conjugated to pullulan by ester bond to synthesize polymeric prodrug of MTX-PL. MTX-PL was then adsorbed on the surface of PBAE/pEGFP polycomplex to form MTX-PL/PBAE/pEGFP nanoparticles with a classic core-shell structure. MTX-PL was also used as a hepatoma targeting moiety, because of its specific binding affinity for asialoglycoprotein receptor (ASGPR) overexpressed by human hepatoma HepG2 cells. MTX-PL/PBAE/pEGFP nanoparticles realized the efficient transfection of pEGFP in HepG2 cells and exhibited significant inhibitory effect on the cell proliferation. In HepG2 tumor-bearing nude mice, MTX-PL/PBAE/pEGFP nanoparticles were mainly distributed in the tumor after 24 h postintravenous injection. Altogether, this novel codelivery system with a strong hepatoma-targeting property achieved simultaneous delivery of gene and chemotherapy agent into tumor at both cellular and animal levels.
Related JoVE Video
Peroxisome proliferator activated receptor alpha inhibits hepatocarcinogenesis through mediating NF-?B signaling pathway.
Oncotarget
PUBLISHED: 10-21-2014
Show Abstract
Hide Abstract
Peroxisome proliferator-activated receptor alpha (PPAR?) ligands have been reported to suppress cancer growth. However, the role of PPAR? in hepatocarcinogenesis remains unclear. We investigated the functional significance of PPAR? in HCC. PPAR?-knockout (PPAR?-/-) mice were more susceptible to diethylnitrosamine (DEN)-induced HCC at 6 months compared with wild-type (WT) littermates (80% versus 43%, P < 0.05). In resected HCCs, TUNEL-positive apoptotic cells were significantly less in PPAR?-/- mice than in WT mice (P < 0.01), commensurate with a reduction in cleaved caspase-3 and caspase-7 protein expression. Ki-67 staining showed increased cell proliferation in PPAR?-/- mice (P < 0.01), with concomitant up-regulation of cyclin-D1 and down-regulation of p15. Moreover, ectopic expression of PPAR? in HCC cells significantly suppressed cell proliferation and induced apoptosis. The anti-tumorigenic function of PPAR? was mediated via NF-?B as evidenced by inhibition of NF-?B promoter activity, diminution of phosphor-p65, phosphor-p50 and BCL2 levels, and enhancing IkB? protein. Chromatin immunoprecipitation analysis confirmed PPAR?directly binds to the IkB? promoter. In conclusion, PPAR? deficiency enhances susceptibility to DEN-initiated HCC. PPAR? suppresses tumor cell growth by inhibiting cell proliferation and inducing cell apoptosis via direct targeting I?B? and NF-?B signaling pathway.
Related JoVE Video
The heterogeneity of non-motor symptoms of Parkinson's disease.
Neurol. Sci.
PUBLISHED: 10-19-2014
Show Abstract
Hide Abstract
In addition to motor symptoms, patients with Parkinson's disease (PD) may experience non-motor symptoms (NMS), more often with more advanced disease stage. However, the clinical feature of the NMS and potential risk factors that affect NMS in idiopathic PD patients remain unclear. 493 PD patients diagnosed with PD via the UK. Parkinson's Disease Society Brain Bank Clinical Diagnostic Criteria and 93 healthy control subjects (CN) were recruited in the current study. Questionnaires were used to assess the NMS, motor symptoms, cognitive function, and disease severity in both groups. Levodopa daily dose was calculated in PD patients. Multivariate linear regression analysis was used to identify the risk factors that potentially affect NMS in PD patients. The results showed that, the NMS occurrence and positive endorsement rate of PD patients were significantly higher compared to CN subjects. Multiple stepwise regression analysis found the motor symptom was the only factor that affected NMS in PD patients within five years of the disease course, whereas motor symptoms, cognitive function, disease severity and Levodopa daily dose significantly affected NMS if the disease course was more than five years. These findings demonstrated that NMS are affected by several risk factors at different stages of PD. The distribution of difference NMS is associated with the severity of motor symptoms and the dosage of anti-PD medications in Chinese PD patients.
Related JoVE Video
1,5-diaminonaphthalene hydrochloride assisted laser desorption/ionization mass spectrometry imaging of small molecules in tissues following focal cerebral ischemia.
Anal. Chem.
PUBLISHED: 10-03-2014
Show Abstract
Hide Abstract
A sensitive analytical technique for visualizing small endogenous molecules simultaneously is of great significance for clearly elucidating metabolic mechanisms during pathological progression. In the present study, 1,5-naphthalenediamine (1,5-DAN) hydrochloride was prepared for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) of small molecules in liver, brain, and kidneys from mice. Furthermore, 1,5-DAN hydrochloride assisted LDI MSI of small molecules in brain tissue of rats subjected to middle cerebral artery occlusion (MCAO) was carried out to investigate the altered metabolic pathways and mechanisms underlying the development of ischemic brain damage. Our results suggested that the newly prepared matrix possessed brilliant features including low cost, strong ultraviolet absorption, high salt tolerance capacity, and fewer background signals especially in the low mass range (typically m/z < 500), which permitted us to visualize the spatial distribution of a broad range of small molecule metabolites including metal ions, amino acids, carboxylic acids, nucleotide derivatives, peptide, and lipids simultaneously. Nineteen endogenous metabolites involved in metabolic networks such as ATP metabolism, tricarboxylic acid (TCA) cycle, glutamate-glutamine cycle, and malate-aspartate shuttle, together with metal ions and phospholipids as well as antioxidants underwent relatively obvious changes after 24 h of MCAO. The results were highly consistent with the data obtained by MRM MS analysis. These findings highlighted the promising potential of the organic salt matrix for application in the field of biomedical research.
Related JoVE Video
Ultrasensitive Electroanalysis of Low-Level Free MicroRNAs in Blood by Maximum Signal Amplification of Catalytic Silver Deposition Using Alkaline Phosphatase-Incorporated Gold Nanoclusters.
Anal. Chem.
PUBLISHED: 10-02-2014
Show Abstract
Hide Abstract
An ultrasensitive sandwich-type analysis method has been initially developed for probing low-level free microRNAs (miRNAs) in blood by a maximal signal amplification protocol of catalytic silver deposition. Gold nanoclusters (AuNCs) were first synthesized and in-site incorporated into alkaline phosphatase (ALP) to form the ALP-AuNCs. Unexpectedly, the so incorporated AuNCs could dramatically enhance the catalysis activities of ALP-AuNCs versus native ALP. A sandwiched hybridization protocol was then proposed using ALP-AuNCs as the catalytic labels of the DNA detection probes for targeting miRNAs that were magnetically caught from blood samples by DNA capture probes, followed by the catalytic ligation of two DNA probes complementary to the targets. Herein, the ALP-AuNC labels could act as the bicatalysts separately in the ALP-catalyzed substrate dephosphorylation reaction and the AuNCs-accelerated silver deposition reaction. The signal amplification of ALP-AuNCs-catalyzed silver deposition was thereby maximized to be measured by the electrochemical outputs. The developed electroanalysis strategy could allow for the ultrasensitive detection of free miRNAs in blood with the detection limit as low as 21.5 aM, including the accurate identification of single-base mutant levels in miRNAs. Such a sandwich-type analysis method may circumvent the bottlenecks of the current detection techniques in probing short-chain miRNAs. It would be tailored as an ultrasensitive detection candidate for low-level free miRNAs in blood toward the diagnosis of cancer and the warning or monitoring of cancer metastasis in the clinical laboratory.
Related JoVE Video
Polymorphism Ala54Thr of fatty acid-binding protein 2 gene is not associated with stroke risk in Han population of Hunan China.
Med. Sci. Monit.
PUBLISHED: 09-30-2014
Show Abstract
Hide Abstract
The aim of this study is to make sure whether polymorphism Ala54Thr of gene Fatty Acid-Binding Protein 2 (FABP2) is associated with stroke risk in Hunan Han population of China.
Related JoVE Video
[Development of researches on acupuncture-assisted fertilization outside of China].
Zhen Ci Yan Jiu
PUBLISHED: 09-16-2014
Show Abstract
Hide Abstract
Increasing evidence shows that acupuncture therapy may have a role in promoting fertilization. Authors of the present paper collected the related articles in English published from January 2003 to May 2013 in databases of Ovid Medline, Maternity and Infant Care and Medline (Pubmed), and made an analysis. Results of many randomized controlled clinical trials (RCT) indicated that acupuncture intervention had a positive role in raising pregnancy rate, fetus surviving rate of the transplanted embryo, and increasing the neuropeptide Y content in the ollicular fluid in patients experiencing embryo transplantation, and in raising survival rate of zygote, conception rate of embryo transplantation, and in improving azoospermia in patients undergoing in vitro fertilization. But many systematic reviews and Meta-analysis did not support the above-mentioned conclusion of acupuncture therapy about promoting fertilization. The authors hold that despite of dominated positive outcomes of RCT for acupuncture-assisted fertilization, further well designed RCT are still warranted for providing further definite and convincing evidence.
Related JoVE Video
Glycated hemoglobin independently or in combination with fasting plasma glucose versus oral glucose tolerance test to detect abnormal glycometabolism in acute ischemic stroke: a Chinese cross-sectional study.
BMC Neurol
PUBLISHED: 09-12-2014
Show Abstract
Hide Abstract
BackgroundThe investigation of glycated hemoglobin (HbA1c) as a diagnostic tool for abnormal glycometabolism is lack in acute ischemic stroke patients in China and worldwide. This paper was aimed to determine whether HbA1c, fasting plasma glucose (FPG), or HbA1c combined with FPG, could be used to screen for diabetes mellitus (DM) or prediabetes in acute ischemic stroke patients without previous DM.MethodsAcute ischemic stroke patients without previous DM (n¿=¿1,316) were selected from the Abnormal gluCose Regulation in Patients with Acute StrOke acrosS China Study (ACROSS-China). Oral glucose tolerance test (OGTT), HbA1c, FPG, and HbA1c combined with FPG were used as the screening methods to categorize the glycometabolic status. OGTT was taken as the golden method. Venn diagrams and the overlap index were used to determine the associations among the three methods of identifying abnormal glycometabolism. The area under the receiver operating characteristic curve (AUROC) and Youden index were used to assess and compare the accuracy in detecting abnormal glycometabolism. Youden analyses were performed to determine the ideal cutoff values of HbA1c in diagnosing abnormal glycometabolism.ResultsIn acute ischemic stroke patients without previous DM, the overlaps of HbA1c versus OGTT, HbA1c versus FPG, and all the three methods independently, were low for detecting abnormal glycometabolism (all <50%). HbA1c can significantly detect more cases of prediabetes than OGTT (P¿<¿0.001). The combination of HbA1c and FPG significantly raised the sensitivity to over 60.0%, specificity to over 80.0%, and the diagnostic accuracy (Youden index from under 40.0% to 42.4%)for DM. HbA1c of 5.7%-6.4% had a low to moderate concordance with OGTT for identifying prediabetes (AUROC¿=¿0.557, P¿=¿0.001). HbA1c values of 6.3% and 5.9% were found to be the ideal cutoff values for detecting DM and abnormal glycometabolism in our data, respectively.ConclusionsThe combination of HbA1c and FPG increased the diagnostic rate of DM when compared with OGTT, and increased the diagnostic accuracy for DM compared with HbA1c or FPG alone. Our results advocate the use of HbA1c as screening tool for the diagnosis of pre-diabetes.
Related JoVE Video
[Role of PI3K/Akt signaling in hydrogen sulfide-induced alteration in expression of collagen I and III in hepatic stellate cells].
Zhonghua Gan Zang Bing Za Zhi
PUBLISHED: 09-10-2014
Show Abstract
Hide Abstract
To investigate the role of the PI3K/Akt signaling pathway in hydrogen sulfide-induced alterations in expression of collagen I and collagen III in hepatic stellate cells.
Related JoVE Video
Protein apparent dielectric constant and its temperature dependence from remote chemical shift effects.
J. Am. Chem. Soc.
PUBLISHED: 09-05-2014
Show Abstract
Hide Abstract
A NMR protocol is introduced that permits accurate measurement of minute, remote chemical shift perturbations (CSPs), caused by a mutation-induced change in the electric field. Using protein GB3 as a model system, (1)H(N) CSPs in K19A and K19E mutants can be fitted to small changes in the electric field at distal sites in the protein using the Buckingham equation, yielding an apparent dielectric constant ?a of 8.6 ± 0.8 at 298 K. These CSPs, and their derived ?a value, scale strongly with temperature. For example, CSPs at 313 K are about ?30% smaller than those at 278 K, corresponding to an effective ?a value of about 7.3 at 278 K and 10.5 at 313 K. Molecular dynamics simulations in explicit solvent indicate that solvent water makes a significant contribution to ?a.
Related JoVE Video
Nonlinear effects in paul traps operated in the second stability region: analytical analysis and numerical verification.
J. Am. Soc. Mass Spectrom.
PUBLISHED: 09-03-2014
Show Abstract
Hide Abstract
Paul trap working in the second stability region has long been recognized as a possible approach for achieving high-resolution mass spectrometry (MS), which however is still far away from the experimental implementations because of the narrow working area and inefficient ion trapping. Full understanding of the ion motional behavior is helpful for solving the problem. In this article, the ion motion in a superimposed octopole field, which was characterized by the nonlinear Mathieu equation, was solved analytically using Poincare-Lighthill-Kuo (PLK) method. This method equivalently described the nonlinear disturbance by an effective quadrupole field with perturbed Mathieu parameters, a u (') and q u (') , which would bring huge convenience in the studies of nonlinear ion dynamics and was, therefore, used for rapid evaluation of the nonlinear effects of ion motion. Fourth-order Runge-Kutta method (4th R-K) indicated the error of PLK for characterizing the frequency shift of ion motion was within 15%.
Related JoVE Video
A phosphorylation-sensitive tyrosine-tailored magnetic particle for electrochemically probing free organophosphates in blood.
Analyst
PUBLISHED: 09-02-2014
Show Abstract
Hide Abstract
A simple, rapid, sensitive, selective, and field-deployable detection protocol has been initially proposed for the early warning and diagnosis of exposure to organophosphates (OPs) by electrochemically monitoring the direct biomarkers of free OPs in blood. Phosphorylation-sensitive tyrosine (Tyr), which was tested with unique electroactivity, was bound onto Fe3O4 particles mediated by the mussel-inspired dopamine to form Fe3O4@Tyr particles with well-defined shape and well-retained Tyr electroactivities, as characterized separately by electron microscopy and electrochemical measurements. A "lab-on-a-particle"-based detection procedure combined with a magnetic electrode was thus developed by employing Fe3O4@Tyr particles as capturing probes for detecting free OPs in blood, dimethyl-dichloro-vinyl phosphate (DDVP) as an example. A significant difference in electrochemical responses could be obtained for Fe3O4@Tyr particles before and after DDVP exposure, based on the phosphorylation-induced inhibition of electroactivities of loaded Tyr. Investigation results indicate that highly specific and sensitive phosphorylation for the inhibition of Tyr electroactivities by sensitive electrochemical outputs could endow the OP detection with high selectivity and sensitivity (i.e., down to about 0.16 nM DDVP in blood). Moreover, strong and stable Tyr-OP bindings especially irreversible electrochemical oxidization of the Tyr probe could facilitate the OP evaluation with high reproducibility and stability over time. In particular, the simple "lab-on-a-particle"-based detection procedure equipped with a portable electrochemical transducer can be tailored for the field-deployable or on-site monitoring of the exposure to various nerve agents and pesticides.
Related JoVE Video
Preparation and characterization of monoclonal antibody against human B7-H4 molecule.
Monoclon Antib Immunodiagn Immunother
PUBLISHED: 08-30-2014
Show Abstract
Hide Abstract
B7-H4, a member of B7 family, is widely expressed in tumor tissues and plays an important role in the negative regulation of T cell immunity. In this study, we report on the establishment and characterization of a functional anti-human B7-H4 monoclonal antibody (MAb) 5G3 through hybridoma method. Flow cytometry analysis showed that MAb 5G3 specifically bound to B7-H4 molecule. Functional experiments indicated that MAb 5G3 could block the inhibitory role of B7-H4 molecule on A549 cells in and reduce the apoptosis of Jurkat cells, suggesting that MAb 5G3 is an antagonistic antibody and a useful tool for further studies of B7-H4 functions in cancers.
Related JoVE Video
Clinical efficacy of endoscopic pancreatic drainage for pain relief with malignant pancreatic duct obstruction.
Asian Pac. J. Cancer Prev.
PUBLISHED: 08-30-2014
Show Abstract
Hide Abstract
This study was conducted to investigate the efficacy of pancreatic drainage for pain relief in advanced pancreatic cancer.
Related JoVE Video
[MiR-425 up-regulation induced by interleukin-1? promotes the proliferation of gastric cancer cell AGS].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 08-27-2014
Show Abstract
Hide Abstract
To evaluate the mechanism of interleukin-1 (IL-1) in tumorigenesis.
Related JoVE Video
Percutaneous transhepatic and endoscopic biliary drainage for malignant biliary tract obstruction: a meta-analysis.
World J Surg Oncol
PUBLISHED: 08-23-2014
Show Abstract
Hide Abstract
Various malignant tumors can obstruct the extrahepatic biliary tract. Two major techniques for restoring bile flow in this circumstance are endoscopic biliary drainage (EBD) and percutaneous transhepatic biliary drainage (PTBD).We conducted a meta-analysis to compare the effectiveness and safety of the two techniques.
Related JoVE Video
Plasma-based ambient sampling/ionization/transmission integrated source for mass spectrometry.
Analyst
PUBLISHED: 08-23-2014
Show Abstract
Hide Abstract
Better sensitivity and interface of ambient sampling/ionization mass spectrometry remain a challenge. Herein, a novel, plasma-based, ambient sampling/ionization/transmission (PASIT) integrated source in a pin-to-funnel configuration was developed for the sensitive analysis of complex samples. With the funnel sleeve directly affected by direct-current discharge plasma, PASIT combines the ability to sample/ionize analyte molecules and then efficiently collect/transport charged mass species under atmospheric pressure and consequently shows an improved sensitivity. The integrated source enhances the signal intensity by more than 2 orders of magnitude compared with the previous pin-to-plate plasma source without significant background addition. A surface limit of detection (LOD) of 130 fmol mm-(2) (S/N = 3) has been achieved for clenbuterol on filter paper with an argon carrier gas. Demonstrated applications include the direct determination of active ingredients from drugs and symbolic compounds from natural plants and cholesterol from mouse brain tissue sections.
Related JoVE Video
The interaction of nonstructural protein 9 with retinoblastoma protein benefits the replication of genotype 2 porcine reproductive and respiratory syndrome virus in vitro.
Virology
PUBLISHED: 08-21-2014
Show Abstract
Hide Abstract
The nonstructural protein 9 (Nsp9) of porcine reproductive and respiratory syndrome virus (PRRSV) is a RNA-dependent RNA polymerase (RdRp) that plays a vital role in viral replication. This study first demonstrated that the Nsp9 of genotype 2 PRRSV interacted with cellular retinoblastoma protein (pRb), and Nsp9 co-localized with pRb in the cytoplasm of PRRSV-infected MARC-145 cells and pulmonary alveolar macrophages (PAMs). Next, the overexpression of truncated pRb was shown to inhibit the PRRSV replication and silencing the pRb gene could facilitate the PRRSV replication in MARC-145 cells. Finally, the pRb level was confirmed to be down-regulated in PRRSV-infected MARC-145 cells, and Nsp9 was shown to promote the pRb degradation by proteasome pathway. These findings indicate that the interaction of Nsp 9 with pRb benefits the replication of genotype 2 PRRSV in vitro, helping to understand the roles of Nsp9 in the replication and pathogenesis of PRRSV.
Related JoVE Video
Separation of Cis- and Trans-Cypermethrin by Reversed-Phase High-Performance Liquid Chromatography.
J Chromatogr Sci
PUBLISHED: 08-16-2014
Show Abstract
Hide Abstract
As a pyrethroid insecticide, cypermethrin (CP) possesses three chiral centers and thus consists of eight optical isomers. High-performance liquid chromatography (HPLC) methods have been established for the separation and determination of pyrethroid insecticides. In this article, we report a new reversed-phase high-performance liquid chromatography (RP-HPLC) method of separating the diastereomers of CP. Our method was performed on a C18 column with the following specifications: mobile phase, methanol/acetonitrile/water (58:18:24, v/v/v); flow rate, 1.0 mL/min; column temperature, 20°C and UV-detection wavelength, 235 nm. The results showed that the applied procedure was linear based on calibration curves with equation (y = 16.595x + 1.7892) within the CP concentration range of 5-100 mg/L. The limit of detection and limit of quantification of CP were 0.2 and 0.7 mg/L, respectively. CP or ?-CP extracted from the microbial degradation system was determined, and the method was proved to be accurate and applicable. Therefore, the proposed RP-HPLC method was simple, inexpensive and can be used to study stability and determine CP residues in pharmaceutical preparations or in the environment.
Related JoVE Video
NR2B overexpression leads to the enhancement of specific protein phosphorylation in the brain.
Brain Res.
PUBLISHED: 08-13-2014
Show Abstract
Hide Abstract
n-methyl-d-aspartate receptors (NMDARs) are highly expressed in the central nervous system (CNS) including the cerebral cortex, and it has been found that they contribute significantly to the processes of learning and memory. Dysfunctions of NMDARs are implicated in many neurological disorders. To further investigate the specific role of the NR2B subunit of NMDARs in brain functions, we have examined differences in gene expression in the cerebral cortex between NR2B transgenic mice and their wild-type littermates using the DNA microarray. Total of 179 differentially expressed genes were identified, including genes involved in ion channel activity and/or neurotransmission, signal transduction, structure/cytoskeleton, transcription, and hormone/growth factor activity. Signal pathway analysis has indicated that multiple pathways were involved in this process, especially the Mitogen-activated protein kinases/Extracellular signal-regulated kinases (MAPK/ERK) pathway. The phosphorylation levels of ERK and cAMP response element-binding protein (CREB), and the mRNA levels of CREB target genes (C-Fos and Nr4a1) were significantly upregulated in the cerebral cortices of NR2B transgenic mice compared to their wild-type littermates. Our study suggested that a chronic increase of NMDARs activation by NR2B overexpression in the forebrain may enhance the protein serine/threonine phosphorylation levels of MAPK/ERK-CREB and thereby regulated their signaling pathway.
Related JoVE Video
Prediction of S-nitrosylation modification sites based on kernel sparse representation classification and mRMR algorithm.
Biomed Res Int
PUBLISHED: 08-12-2014
Show Abstract
Hide Abstract
Protein S-nitrosylation plays a very important role in a wide variety of cellular biological activities. Hitherto, accurate prediction of S-nitrosylation sites is still of great challenge. In this paper, we presented a framework to computationally predict S-nitrosylation sites based on kernel sparse representation classification and minimum Redundancy Maximum Relevance algorithm. As much as 666 features derived from five categories of amino acid properties and one protein structure feature are used for numerical representation of proteins. A total of 529 protein sequences collected from the open-access databases and published literatures are used to train and test our predictor. Computational results show that our predictor achieves Matthews' correlation coefficients of 0.1634 and 0.2919 for the training set and the testing set, respectively, which are better than those of k-nearest neighbor algorithm, random forest algorithm, and sparse representation classification algorithm. The experimental results also indicate that 134 optimal features can better represent the peptides of protein S-nitrosylation than the original 666 redundant features. Furthermore, we constructed an independent testing set of 113 protein sequences to evaluate the robustness of our predictor. Experimental result showed that our predictor also yielded good performance on the independent testing set with Matthews' correlation coefficients of 0.2239.
Related JoVE Video
Two coordination polymers constructed from a multidentate carboxylic acid ligand with a tertiary amine serve as acid-base catalysts for the synthesis of chloropropene carbonate from CO2 under atmospheric pressure.
Dalton Trans
PUBLISHED: 08-12-2014
Show Abstract
Hide Abstract
Two new coordination polymers, [Ni(H2O)(Hpdcd)(H2O)2]·DMF (1) and [Co(H2O)(Hpdcd)(H2O)2]·DMF (2) (H3pdcd = 1-(4-carboxyphenyl)-2,5-dimethyl, 1H-pyrrole-3,4-dicarboxylic acid), which were designed based on a tertiary amine ligand, were synthesized and characterized using multiple spectroscopy techniques, including single-crystal X-ray diffraction. These two 1D linear chains possess the properties of both a Lewis acid and organic base, which was confirmed by temperature programmed desorption of ammonia and on-line mass spectrometry (NH3-TPD-MS), and selective sorption for carbon dioxide. Due to their acid-base properties, the compounds exhibited high catalytic activity, in the absence of co-catalysts, for solvent-free synthesis of chloropropene carbonate from CO2 and epichlorohydrin under atmospheric CO2 pressure. The yields of chloropropene carbonate were 88% and 87% for 1 and 2, respectively, under the optimized conditions.
Related JoVE Video
Fabrication of nickel-foam-supported layered zinc-cobalt hydroxide nanoflakes for high electrochemical performance in supercapacitors.
Chem. Commun. (Camb.)
PUBLISHED: 08-12-2014
Show Abstract
Hide Abstract
Nickel foam supported Zn-Co hydroxide nanoflakes were fabricated by a facile solvothermal method. Benefited from the unique structure of Zn-Co hydroxide nanoflakes on a nickel foam substrate, the as prepared materials exhibited an excellent specific capacitance of 901 F g(-1) at 5 A g(-1) and remarkable cycling stability as electrode materials in supercapacitors.
Related JoVE Video
[Metabonomic study on protective effect of xiaoyao powder for acute hepatic injury in rats].
Zhong Yao Cai
PUBLISHED: 08-07-2014
Show Abstract
Hide Abstract
To study the metabonomic for acute hepatic injury in rats and the hepato-protective effect of Xiaoyao Powder in rats.
Related JoVE Video
Porcine reproductive and respiratory syndrome virus counteracts the porcine intrinsic virus restriction factors-IFITM1 and Tetherin in MARC-145 cells.
Virus Res.
PUBLISHED: 08-04-2014
Show Abstract
Hide Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) has been recognized to modulate the innate immune response of host. However, little is known about the effects of PRRSV infection on porcine intrinsic virus-restriction factors. This study presents the first demonstration that the nonstructural protein 3 (Nsp3) or envelope (E) protein of PRRSV interacted with porcine intrinsic virus-restriction factor IFITM1 or Tetherin. Next, in PRRSV-infected MARC-145 cells and the transfected cells with the IFITM1- or Tetherin-expressing plasmid, IFITM1 was shown to be mainly distributed perinuclear, and Tetherin was proposed to be partially removed away from cell surface. Moreover, the overexpression of IFITM1 and Tetherin were shown to have no obvious effects on the replication of PRRSV in MARC-145 cells. The Nsp3 of PRRSV was demonstrated to induce the proteasome-dependent degradation of IFITM1 upon PRRSV infection. These findings suggest that PRRSV might counteract the antiviral functions of IFITM1 and Tetherin by the interaction of the Nsp3 with IFITM1 and the E protein with Tetherin, providing a novel clue for exploring possible mechanisms associated with the evasion of PRRSV from immune recognition of host.
Related JoVE Video
Similarly up-regulated microRNA-106a in matched formalin-fixed paraffin-embedded and fresh frozen samples and the dynamic changes during gastric carcinogenesis and development.
Pathol. Res. Pract.
PUBLISHED: 07-30-2014
Show Abstract
Hide Abstract
Evidence increasingly suggests that miR-106a is always elevated in gastric cancer; however, little is known about the expression trend and clinical significance in the whole process of gastric carcinogenesis and development. To investigate the dynamic changes of miR-106a in each stage during gastric carcinogenesis, we used formalin-fixed, paraffin-embedded (FFPE) tissues which had been reported to have valuable information for miRNA research in our previous studies. Here, we compared the expression of miR-106a in FFPE and fresh frozen tissues using real-time polymerase chain reaction. On the basis of the high correlation of miR-106a quantitative data from the two resources, FFPE samples were subsequently performed to elucidate the location and expression of miR-106a using in situ hybridization in sequential tissues, including normal gastric mucosa, chronic atrophic gastritis combined with various degrees of dysplasia, early and advanced gastric cancer. Finally, we found that miR-106a was similarly up-regulated in gastric cancer regardless of sample types although fragmentation existed inevitably in FFPE tissues. Notably, the frequency and extent of miR-106a expression gradually increased during the transition from atypical hyperplasia to advanced carcinoma and had already had positive signals in early precancerous lesions but negative signals in normal gastric mucosal epithelial cells. Our research, according to these results, indicated that FFPE samples can serve as an important research tool for miRNA field, and the early changes of miR-106a detected in such samples may have clinical application as a potential biomarker for the discovery and diagnosis of gastric cancer.
Related JoVE Video
Adiponectin promotes pancreatic cancer progression by inhibiting apoptosis via the activation of AMPK/Sirt1/PGC-1? signaling.
Oncotarget
PUBLISHED: 07-23-2014
Show Abstract
Hide Abstract
Adiponectin is an adipocyte-secreted adipokine with pleiotropic actions. Clinical evidence has shown that serum adiponectin levels are increased and that adiponectin can protect pancreatic beta cells against apoptosis, which suggests that adiponectin may play an anti-apoptotic role in pancreatic cancer (PC). Here, we investigated the effects of adiponectin on PC development and elucidated the underlying molecular mechanisms. Adiponectin deficiency markedly attenuated pancreatic tumorigenesis in vivo. We found that adiponectin significantly inhibited the apoptosis of both human and mouse pancreatic cancer cells via adipoR1, but not adipoR2. Furthermore, adiponectin can increase AMP-activated protein kinase (AMPK) phosphorylation and NAD-dependent deacetylase sirtuin-1 (Sirt1) of PC cells. Knockdown of AMPK or Sirt1 can increase the apoptosis in PC cells. AMPK up-regulated Sirt1, and Sirt1 can inversely phosphorylate AMPK. Further studies have shown that Sirt1 can deacetylate peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1?), which can increase the expression levels of mitochondrial genes. Thus, adiponectin exerts potent anti-apoptotic effects on PC cells via the activation of AMPK/Sirt1/PGC1? signaling. Finally, adiponectin can elevate ?-catenin levels. Taken together, these novel findings reveal an unconventional role of adiponectin in promoting pancreatic cancers, and suggest that the effects of adiponectin on tumorigenesis are highly tissue-dependent.
Related JoVE Video
Lab-on-a-drop: biocompatible fluorescent nanoprobes of gold nanoclusters for label-free evaluation of phosphorylation-induced inhibition of acetylcholinesterase activity towards the ultrasensitive detection of pesticide residues.
Analyst
PUBLISHED: 07-23-2014
Show Abstract
Hide Abstract
A simple, sensitive, selective, and "lab-on-a-drop"-based fluorimetric protocol has been proposed using biocompatible fluorescent nanoprobes of gold nanoclusters (AuNCs) for the label-free evaluation of the catalytic activity and phosphorylation of acetylcholinesterase (AChE) under physiologically simulated environments. Protein-stabilized AuNCs were prepared and mixed with acetylthiocholine (ATC) serving as "a drop" of fluorimetric reaction substrate. The AChE-catalyzed hydrolysis of ATC releases thiocholine to cause the aggregation of the AuNCs towards a dramatic decrease in fluorescence intensities, which could be curbed by the phosphorylation-induced inhibition of AChE activity when exposed to organophosphorus compounds (OPs). The reaction procedures and conditions of AChE catalysis and phosphorylation were monitored by fluorimetric measurements and electron microscopy imaging. Moreover, a selective and ultrasensitive fluorimetric assay has been tailored for the detection of pesticide residues using dimethyl-dichloro-vinyl phosphate (DDVP) as an example. Investigation results indicate that the specific catalysis and irreversible OP-induced phosphorylation of AChE, in combination with sensitive fluorimetric outputs could facilitate the detection of total free OPs with high selectivity and sensitivity. A linear concentration of DDVP ranging from 0.032 nM to 20 nM could be obtained with a detection limit of 13.67 pM. Particularly, pesticide residues of DDVP in vegetable samples were quantified down to ~36 pM. Such a label-free "lab-on-a drop"-based fluorimetry may promise wide applications for the evaluation of the physiological catalytic activity of various enzymes (i.e., cholinesterase), and especially for monitoring the direct phosphorylation biomarkers of free OPs towards rapid and early warning, and accurate diagnosis of OP exposure.
Related JoVE Video
An improved multidimensional MPA procedure for bidirectional earthquake excitations.
ScientificWorldJournal
PUBLISHED: 07-20-2014
Show Abstract
Hide Abstract
Presently, the modal pushover analysis procedure is extended to multidimensional analysis of structures subjected to multidimensional earthquake excitations. an improved multidimensional modal pushover analysis (IMMPA) method is presented in the paper in order to estimate the response demands of structures subjected to bidirectional earthquake excitations, in which the unidirectional earthquake excitation applied on equivalent SDOF system is replaced by the direct superposition of two components earthquake excitations, and independent analysis in each direction is not required and the application of simplified superposition formulas is avoided. The strength reduction factor spectra based on superposition of earthquake excitations are discussed and compared with the traditional strength reduction factor spectra. The step-by-step procedure is proposed to estimate seismic demands of structures. Two examples are implemented to verify the accuracy of the method, and the results of the examples show that (1) the IMMPA method can be used to estimate the responses of structure subjected to bidirectional earthquake excitations. (2) Along with increase of peak of earthquake acceleration, structural response deviation estimated with the IMMPA method may also increase. (3) Along with increase of the number of total floors of structures, structural response deviation estimated with the IMMPA method may also increase.
Related JoVE Video
High efficiency photocatalysis for pollutant degradation with MoS2/C3N4 heterostructures.
Langmuir
PUBLISHED: 07-18-2014
Show Abstract
Hide Abstract
Porous graphitic carbon nitride was synthesized by controllable thermal polymerization of urea in air. Their textural, electrical, and optical properties were tuned by varying the heating rate. The presence of proper residual oxygen in carbon nitride matrix had enhanced light absorption and inhibited the recombination of charge carriers. Furthermore, the MoS2 nanosheets were coupled into the carbon nitride to form MoS2/C3N4 heterostructures via a facile ultrasonic chemical method. The optimized MoS2/C3N4 heterostructure with 0.05 wt % MoS2 showed a reaction rate constant as high as 0.301 min(-1), which was 3.6 times that of bare carbon nitride. As analyzed by SEM, TEM, UV-vis absorption, PL and photoelectrochemical measurements, intimate contact interface, extended light response range, enhanced separation speed of charge carriers, and high photocurrent density upon MoS2 coupling led to the photocatalytic promotion of the MoS2/C3N4 heterostructures. In this architecture, MoS2 served as electron trapper to extend the lifetime of separated electron-hole pairs. Meanwhile, the accumulated holes on the surface of carbon nitride oxidized the organic dye directly, which was a predominant process in the photodegradation of organic pollutants in water treatment. The promotional mechanisms and principles reported here would have great significance in heterogeneous photocatalysis.
Related JoVE Video
Cytotoxicity comparison of quercetin and its metabolites from in vitro fermentation of several gut bacteria.
Food Funct
PUBLISHED: 07-13-2014
Show Abstract
Hide Abstract
Part of quercetin is coerced into the colon after ingestion and interacts with the gut microbiota. The interaction between quercetin and gut microbiota will influence human health. The cytotoxicity of quercetin and its metabolites from human gut bacteria in vitro fermentation was investigated in this study. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide) (MTT) and agar diffusion disc methods were individually applied in vitro to examine their inhibitory effect on three cultured human cancer cells and five pathogenic bacteria species. The results showed that the metabolites from Clostridium perfringens and Bacteroides fragilis exerted a strong inhibitory effect (P < 0.05) on HCT-116 cells and that of Weissella confusa was stronger (P < 0.01) on both A549 cells and HeLa cells than on the others. Most metabolites have similar or decreased inhibitory ability on human cancer cells compared to quercetin itself. This inhibitory effect had not been detected in quercetin and its metabolites in five common pathogenic bacteria species. Quercetin is a potential chemopreventive agent. However, this study reported that some gut bacteria can improve their function of inhibiting cancer cells after fermenting quercetin.
Related JoVE Video
Influence of casein phosphopeptide-amorphous calcium phosphate application, smear layer removal, and storage time on resin-dentin bonding.
J Zhejiang Univ Sci B
PUBLISHED: 07-09-2014
Show Abstract
Hide Abstract
The aim of this study is to evaluate the influence of Tooth Mousse (TM) application, smear layer removal, and storage time on resin-dentin microtensile bond strength (µTBS). Dentin specimens were divided into two groups: (1) smear layer covered; (2) smear layer removed using 15% EDTA for 90 s. In each group, half the specimens were treated once with TM for 60 min. After bonding procedures using a two-step self-etching adhesive (Clearfil SE Bond (CSE); Kuraray Medical, Tokyo, Japan), an all-in-one adhesive (G-Bond (GB); GC Corp, Tokyo, Japan), and a total-etch adhesive (Adper Single Bond 2 (SB); 3M ESPE, St. Paul, MN, USA), the specimens were stored for 3 d or 6 months in deionized water at 37 °C, and µTBS was tested and analyzed. With the exception of SB (no TM application) and GB, the ?TBS was significantly increased for CSE and SB using EDTA pre-conditioning and 3 d of storage (P?0.001). Bond strength of GB decreased significantly when using EDTA (3 d storage, P<0.05). TM application only increased the ?TBS of GB (no EDTA) and SB (with EDTA) after 3 d (P?0.02). Comparing the adhesives after 3 d of storage, CSE exhibited the greatest ?TBS values followed by GB and SB (P?0.02). The factors of adhesive, EDTA, and TM did not show any significant impact on ?TBS when specimens were stored for 6 months (P>0.05). The additional application of TM and EDTA for cavity preparation seems only to have a short-term effect, and no influence on µTBS of dentin bonds after a period of 6 months.
Related JoVE Video
Expression of peptidylarginine deiminase 4 and protein tyrosine phosphatase nonreceptor type 22 in the synovium of collagen-induced arthritis rats.
Chin. Med. Sci. J.
PUBLISHED: 07-08-2014
Show Abstract
Hide Abstract
To study the expression level of peptidylarginine deiminase 4 (PADI4) and protein tyrosine phosphatase nonreceptor type 22 (PTPN22) in the synovium of rat model of collagen-induced arthritis, and to explore their possible therapeutic role in rheumatoid arthritis.
Related JoVE Video
High-throughput colorimetric assays for mercury(II) in blood and wastewater based on the mercury-stimulated catalytic activity of small silver nanoparticles in a temperature-switchable gelatin matrix.
Chem. Commun. (Camb.)
PUBLISHED: 07-05-2014
Show Abstract
Hide Abstract
A catalysis-based, label-free, and high-throughput colorimetric protocol has been initially proposed for detecting mercury(II) in blood and wastewater with 96-cell plates, based on the mercury-enhanced catalytic activity of small silver nanoparticles synthesized in a gelatin matrix with unique temperature switchable sol-gel transition.
Related JoVE Video
A quantitative method for measurement of HL-60 cell apoptosis based on diffraction imaging flow cytometry technique.
Biomed Opt Express
PUBLISHED: 07-01-2014
Show Abstract
Hide Abstract
A quantitative method for measurement of apoptosis in HL-60 cells based on polarization diffraction imaging flow cytometry technique is presented in this paper. Through comparative study with existing methods and the analysis of diffraction images by a gray level co-occurrence matrix algorithm (GLCM), we found 4 GLCM parameters of contrast (CON), cluster shade (CLS), correlation (COR) and dissimilarity (DIS) exhibit high sensitivities as the apoptotic rates. It was further demonstrated that the CLS parameter correlates significantly (R(2) = 0.899) with the degree of nuclear fragmentation and other three parameters showed a very good correlations (R(2) ranges from 0.69 to 0.90). These results demonstrated that the new method has the capability for rapid and accurate extraction of morphological features to quantify cellular apoptosis without the need for cell staining.
Related JoVE Video
IL-1? mediates MCP-1 induction by Wnt5a in gastric cancer cells.
BMC Cancer
PUBLISHED: 06-30-2014
Show Abstract
Hide Abstract
Both Wnt5a overexpression and macrophage infiltration have been implicated in inflammation and cancer. The aim of this study is to reveal the involvement of Wnt5a in macrophage recruitment in gastric cancer.
Related JoVE Video
Peroxisome proliferator?activated receptor ? polymorphisms as risk factors for dyslipidemia.
Mol Med Rep
PUBLISHED: 06-26-2014
Show Abstract
Hide Abstract
Peroxisome proliferator?activated receptor ? (PPAR?) may play an important role in lipid metabolism directly or by inducing the transcription of target genes. The aim of the present study was to investigate the association between common variants at the PPAR? locus (C1431T and Pro12Ala polymorphisms) and lipid serum levels. The studied population consisted of 820 subjects randomly selected from the Prevention of Multiple Metabolic Disorders and Metabolic Syndrome in Jiangsu Province cohort population. All subjects were interviewed and blood samples were obtained for laboratory analysis and DNA extraction. The TaqMan single nucleotide polymorphism genotyping assay was used for polymorphism genotyping. Individual polymorphisms and haplotype data were available for analysis. The 12Ala allele was found to be associated with significantly increased levels of triglyceride (TG) (P<0.01), whilst the 1431T allele was found to be associated with significantly increased levels of TG, total cholesterol (TC) and non?high?density lipoprotein (non?HDL) (P<0.01). When P?C, the most common haplotype, was used as the reference group, the P?T, A?C and A?T haplotypes were found to be associated with significantly increased levels of TG (P<0.01). In addition, the A?T haplotype was shown to be associated with significantly increased levels of TC and non?HDL (P<0.01). In conclusion these results suggest that PPAR? gene variability may increase the risk of dyslipidemia.
Related JoVE Video
Escherichia coli isolates from sick chickens in China: Changes in antimicrobial resistance between 1993 and 2013.
Vet. J.
PUBLISHED: 06-24-2014
Show Abstract
Hide Abstract
The use of antimicrobials for the control of infectious disease has increased in recent decades. Understanding trends in antimicrobial resistance provides clues about the relationship between antimicrobial use and the emergence of resistance. We examined the resistance of 540 Escherichia coli isolates to 19 antimicrobials that represent 11 classes of antimicrobial agents. The isolates were collected from chickens between 1993 and 2013 in China. Overall, >96.7% of the isolates were resistant to at least one of the tested compounds, and 87.2% of them displayed multidrug resistance (MDR) representing five to six antimicrobial classes. A high proportion of E. coli isolates were resistant to tetracycline (90.6%), nalidixic acid (80.6%), ampicillin (77.2%), trimethoprim-sulfamethoxazole (76.9%), and streptomycin (72.8%). Only 3.0% of the isolates were resistant to nitrofurantoin, and none was resistant to meropenem. Resistance to amikacin, ampicillin, aztreonam, ceftazidime, cefotaxime, cephalothin, chloramphenicol, ciprofloxacin, fosfomycin, levofloxacin, norfloxacin, nalidixic acid, piperacillin, and trimethoprim-sulfamethoxazole significantly increased from 1993 to 2013 (P?<0.01). There was an increasing trend in MDR over the 20?year period.
Related JoVE Video
Novel protein-repellent dental adhesive containing 2-methacryloyloxyethyl phosphorylcholine.
J Dent
PUBLISHED: 06-22-2014
Show Abstract
Hide Abstract
Biofilms at tooth-restoration margins can produce acids and cause secondary caries. A protein-repellent adhesive resin can potentially inhibit bacteria attachment and biofilm growth. However, there has been no report on protein-repellent dental resins. The objectives of this study were to develop a protein-repellent bonding agent incorporating 2-methacryloyloxyethyl phosphorylcholine (MPC), and to investigate its resistance to protein adsorption and biofilm growth for the first time.
Related JoVE Video
Delay in Diagnosis and Treatment of Symptomatic Breast Cancer in China.
Ann. Surg. Oncol.
PUBLISHED: 06-07-2014
Show Abstract
Hide Abstract
Delay in diagnosis and treatment of cancer may lead to advanced tumor characteristics and poor prognosis. Research and investigation from economically developing countries such as China are warranted to support these conclusions, so we studied the impact on prognosis of delays and factors predicting delay in symptomatic breast cancer patients in China.
Related JoVE Video
Huaier aqueous extract inhibits stem-like characteristics of MCF7 breast cancer cells via inactivation of hedgehog pathway.
Tumour Biol.
PUBLISHED: 05-25-2014
Show Abstract
Hide Abstract
The theory of targeting cancer stem-like cells (CSCs) provides novel strategy for cancer treatment. In the present study, we examined the inhibitory effect of Huaier aqueous extract on eradicating breast cancer stem cells and explored the underlying mechanisms. Our data demonstrated that various concentrations of Huaier extract significantly decreased the viabilities, numbers, and sizes of mammospheres. After incubation with Huaier extract for 24 h, the clonogenicity of MCF7 cell line was obviously impaired, along with less holoclones. In addition, Huaier extract reduced the number of cells expressing CD44+/CD24- and decreased the level of stem cell markers (OCT-4, NESTIN, and NANOG). The hedgehog (Hh), notch, and Wnt/?-catenin pathways were essential stem cell signaling pathways involved in regulating CSC renewal and maintenance. We reported that the inhibitory effect of Huaier extract was partly depended on the inactivation of Hh pathway. These findings provided experimental evidence that Huaier extract was a promising therapeutic drug for eliminating the breast cancer stem cells.
Related JoVE Video
Discriminating between deleterious and neutral non-frameshifting indels based on protein interaction networks and hybrid properties.
Mol. Genet. Genomics
PUBLISHED: 05-20-2014
Show Abstract
Hide Abstract
More than ten thousand coding variants are contained in each human genome; however, our knowledge of the way genetic variants underlie phenotypic differences is far from complete. Small insertions and deletions (indels) are one of the most common types of human genetic variants, and indels play a significant role in human inherited disease. To date, we still lack a comprehensive understanding of how indels cause diseases. Therefore, identification and analysis of such deleterious variants is a key challenge and has been of great interest in the current research in genome biology. Increasing numbers of computational methods have been developed for discriminating between deleterious indels and neutral indels. However, most of the existing methods are based on traditional sequential or structural features, which cannot completely explain the association between indels and the resulting induced inherited disease. In this study, we establish a novel method to predict deleterious non-frameshifting indels based on features extracted from both protein interaction networks and traditional hybrid properties. Each indel was coded by 1,246 features. Using the maximum relevance minimum redundancy method and the incremental feature selection method, we obtained an optimal feature set containing 42 features, of which 21 features were derived from protein interaction networks. Based on the optimal feature set, an 88 % accuracy and a 0.76 MCC value were achieved by a Random Forest as evaluated by the Jackknife cross-validation test. This method outperformed existing methods of predicting deleterious indels, and can be applied in practice for deleterious non-frameshifting indel predictions in genome research. The analysis of the optimal features selected in the model revealed that network interactions play more important roles and could be informative for better illustrating an indel's function and disease associations than traditional sequential or structural features. These results could shed some light on the genetic basis of human genetic variations and human inherited diseases.
Related JoVE Video
Long-term follow-up of sigmoid bladder augmentation for low-compliance neurogenic bladder.
Urology
PUBLISHED: 04-17-2014
Show Abstract
Hide Abstract
To assess the clinical and urodynamic outcomes of patients with low-compliance neurogenic bladder who were treated with sigmoid bladder augmentation (SBA) over a long-term follow-up.
Related JoVE Video
pH-sensitive pullulan-based nanoparticle carrier for adriamycin to overcome drug-resistance of cancer cells.
Carbohydr Polym
PUBLISHED: 04-13-2014
Show Abstract
Hide Abstract
Urocanic acid was conjugated to pullulan to synthesize O-urocanyl pullulan (URPA) with degree of substitution (DS) of 8.2%. URPA nanoparticles prepared by dialysis method had spherical shapes and a mean diameter of 156.8 ± 16.8 nm. Adriamycin (ADR) was successfully loaded into URPA nanoparticles and exhibited pH-sensitive in vitro release property. MTT assay showed that ADR-loaded URPA (ADR/URPA) nanoparticles had a significant higher toxicity against drug resistant MCF-7/ADR cells than free ADR, and the reversal index reached up to 9.6. The results of flow cytometry and confocal microscopy showed that URPA nanoparticles efficiently enhanced accumulation and retention of ADR in MCF-7/ADR cells and successfully delivered ADR into cell nucleus. The reversal effect of ADR/URPA nanoparticles on the drug resistance of MCF-7/ADR cells was perhaps related with their cell entry and intracellular drug release mechanisms.
Related JoVE Video
Nitidine chloride induces apoptosis, cell cycle arrest, and synergistic cytotoxicity with doxorubicin in breast cancer cells.
Tumour Biol.
PUBLISHED: 04-08-2014
Show Abstract
Hide Abstract
Medicinal plant extracts have been widely used for cancer treatment. Nitidine chloride (NC) is a natural bioactive alkaloid that has recently been reported to have diverse anticancer properties. We aimed to investigate the cytotoxic effects of NC and the effectiveness of combinatorial treatment including NC and doxorubicin in breast cancer cells. Using MTT and flowcytometry assays, we found that NC induced cell growth inhibition and G2/M cell cycle arrest in a time- and dose-dependent manner both in MCF-7 and MDA-MB-231 breast cancer cell lines. Cancer cell growth inhibition was associated with increased levels of the p53 and p21 proteins. Apoptosis induction by NC treatment was confirmed by JC-1 mitochondrial membrane potential, annexin V-positive cell, and TUNEL staining. Using western blot analysis, we found that NC upregulated the pro-apoptotic proteins Bax, cleaved caspase-9 and -3 and cleaved PARP and that it downregulated the anti-apoptotic proteins Bcl-2 and PARP. By using the PI3K/Akt inhibitor LY294002, we further demonstrated that NC-induced apoptosis might be Akt-specific or dependent. In addition, NC exhibited a synergistic effect with doxorubicin on the growth inhibition of the human breast cancer cell lines MCF-7 and MDA-MB-231. Our study demonstrated the anticancer effect of NC on breast cancer and highlighted the potential clinical application of NC.
Related JoVE Video
Compound specific isotope analysis of organophosphorus pesticides.
Chemosphere
PUBLISHED: 03-26-2014
Show Abstract
Hide Abstract
Compound-specific isotope analysis (CSIA) has been established as a tool to study the environmental fate of a wide range of contaminants. In this study, CSIA was developed to analyse the stable carbon isotope signatures of the widely used organophosphorus pesticides: dichlorvos, omethoate and dimethoate. The linearity of the GC-C-IRMS system was tested for target pesticides and led to an acceptable isotope composition within the uncertainty of the instrument. In order to assess the accuracy of the developed method, the effect of the evaporation procedure on measured carbon isotope composition (?(13)C) values was studied and showed that concentration by evaporation of solvents had no significant isotope effect. The CSIA was then applied to investigate isotope fractionation of the hydrolysis and photolysis of selected pesticides. The carbon isotope fractionation of tested pesticides was quantified by the Rayleigh model, which revealed a bulk enrichment factor (?) of -0.2±0.1‰ for hydrolysis of dichlorvos, -1.0±0.1‰ and -3.7±1.1‰ for hydrolysis and photolysis of dimethoate respectively. This study is a first step towards the application of CSIA to trace the transport and degradation of organophosphorus pesticides in the environment.
Related JoVE Video
Resolution of deep angiosperm phylogeny using conserved nuclear genes and estimates of early divergence times.
Nat Commun
PUBLISHED: 03-24-2014
Show Abstract
Hide Abstract
Angiosperms are the most successful plants and support human livelihood and ecosystems. Angiosperm phylogeny is the foundation of studies of gene function and phenotypic evolution, divergence time estimation and biogeography. The relationship of the five divergent groups of the Mesangiospermae (~99.95% of extant angiosperms) remains uncertain, with multiple hypotheses reported in the literature. Here transcriptome data sets are obtained from 26 species lacking sequenced genomes, representing each of the five groups: eudicots, monocots, magnoliids, Chloranthaceae and Ceratophyllaceae. Phylogenetic analyses using 59 carefully selected low-copy nuclear genes resulted in highly supported relationships: sisterhood of eudicots and a clade containing Chloranthaceae and Ceratophyllaceae, with magnoliids being the next sister group, followed by monocots. Our topology allows a re-examination of the evolutionary patterns of 110 morphological characters. The molecular clock estimates of Mesangiospermae diversification during the late to middle Jurassic correspond well to the origins of some insects, which may have been a factor facilitating early angiosperm radiation.
Related JoVE Video
Polarization imaging and classification of Jurkat T and Ramos B cells using a flow cytometer.
Cytometry A
PUBLISHED: 03-21-2014
Show Abstract
Hide Abstract
Label-free and rapid classification of cells can have awide range of applications in biology. We report a robust method of polarization diffraction imaging flow cytometry (p-DIFC) for achieving this goal. Coherently scattered light signals are acquired from single cells excited by a polarized laser beam in the form of two cross-polarized diffraction images. Image texture and intensity parameters are extracted with a gray level co-occurrence matrix (GLCM) algorithm to obtain an optimized set of feature parameters as the morphological "fingerprints" for automated cell classification. We selected the Jurkat T cells and Ramos B cells to test the p-DIFC method's capacity for cell classification. After detailed statistical analysis, we found that the optimized feature vectors yield accuracies of classification between the Jurkat and Ramos ranging from 97.8% to 100% among different cell data sets. Confocal imaging and three-dimensional reconstruction were applied to gain insights on the ability of p-DIFC method for classifying the two cell lines of highly similar morphology. Based on these results we conclude that the p-DIFC method has the capacity to discriminate cells of high similarity in their morphology with "fingerprints" features extracted from the diffraction images, which may be attributed to subtle but statistically significant differences in the nucleus-to-cell volume ratio in the case of Jurkat and Ramos cells.
Related JoVE Video
Cry1 and Tef gene polymorphisms are associated with major depressive disorder in the Chinese population.
J Affect Disord
PUBLISHED: 03-04-2014
Show Abstract
Hide Abstract
Accumulating evidences indicate that circadian abnormalities lead to sleep disorder, neurodegenerative diseases and depression. We have reported that the polymorphisms of a clock-related gene, Tef, contributed to the risk of sleep disturbances and depression in the Parkinson disease. The objective of the present study was to examine whether the three clock genes we previously studied are associated with major depressive disorder (MDD) in the Chinese population.
Related JoVE Video
Compound specific stable isotope analysis (CSIA) to characterize transformation mechanisms of ?-hexachlorocyclohexane.
J. Hazard. Mater.
PUBLISHED: 02-24-2014
Show Abstract
Hide Abstract
A systematic investigation of environmentally relevant transformation processes of alpha-hexachlorocyclohexane (?-HCH) was performed in order to explore the potential of compound specific stable isotope analysis (CSIA) to characterize reaction mechanisms. The carbon isotope enrichment factors (?C) for the chemical transformations of ?-HCH via direct photolysis, indirect photolysis (UV/H2O2), hydrolysis, electro-reduction or reduction by Fe(0) were quantified and compared to those previously published for biodegradation. Hydrogen abstraction by hydroxyl radicals generated by UV/H2O2 led to ?C of -1.9 ± 0.2 ‰ with an apparent kinetic carbon isotope effect (AKIEC) of 1.012 ± 0.001. Dehydrochlorination by alkaline hydrolysis yielded ?C of -7.6 ± 0.4 ‰ with AKIEC of 1.048 ± 0.003. Dechlorination either by homolytic bond cleavage in direct photolysis (?C=-2.8 ± 0.2 ‰) or single-electron transfer in electro-reduction (?C=-3.8 ± 0.4 ‰) corresponded to AKIEC of 1.017 ± 0.001 and 1.023 ± 0.003, respectively. Dichloroelimination catalyzed by Fe(0) via two-electron transfers resulted in ?C of -4.9 ± 0.1 ‰. AKIEC values assuming either a concerted or a stepwise mechanism were 1.030 ± 0.0006 and 1.015 ± 0.0003, respectively. Contrary to biodegradation, no enantioselectivity of ?-HCH was observed in chemical reactions, which might be used to discriminate chemical and biological in situ transformations.
Related JoVE Video
Effects of epidural neostigmine and clonidine in labor analgesia: A systematic review and meta-analysis.
J. Obstet. Gynaecol. Res.
PUBLISHED: 02-11-2014
Show Abstract
Hide Abstract
To evaluate the effect and quality of epidural neostigmine and clonidine added to initial spinal analgesia in labor analgesia.
Related JoVE Video
A new free-hand pedicle screw placement technique with reference to the supraspinal ligament.
J Biomed Res
PUBLISHED: 01-30-2014
Show Abstract
Hide Abstract
We sought to compare the safety and accuracy of a new free-hand pedicle screw placement technique to that of the conventional technique. One hundred fifty-three consecutive adult patients with simple fracture in the thoracic or/and lumbar spine were alternately assigned to either the new free-hand or the conventional group. In the new free-hand technique group, preoperative computerized tomography (CT) images were used to calculate the targeted medial-lateral angle of each pedicle trajectory and the pedicle screw was inserted perpendicular to the correspond-ing supraspinal ligament. In the conventional technique group, the medial-lateral and cranial-caudal angle of each pedicle trajectory was determined by intraoperatively under fluoroscopic guidance. The accuracy rate of pedicle screw placement, the time of intraoperative fluoroscopy, the operating time and the amount of blood loss during operation were respectively compared. All screws were analyzed by using intraoperative radiographs, intraoperative triggered electromyography (EMG) monitoring data, postoperative CT data and clinical outcomes. The accuracy rate of pedicle screw placement in the new free-hand technique group and the conventional technique group was 96.3% and 94.2% (P < 0.05), respectively. The intraoperative fluoroscopy time of the new technique group was less than that of the conventional technique group (5.37 seconds vs. 8.79 seconds, P < 0.05). However, there was no statistical difference in the operating time and the amount of blood loss during operation (P > 0.05). Pedicle screw placement with the free-hand technique which keeps the screw perpendicular to the supraspinal ligament is an accurate, reliable and safe technique to treat simple fracture in the thoracic or lumbar spine.
Related JoVE Video
Molecular characterization and functional divergence of two Gadd45g homologs in sex determination in half-smooth tongue sole (Cynoglossus semilaevis).
Comp. Biochem. Physiol. B, Biochem. Mol. Biol.
PUBLISHED: 01-26-2014
Show Abstract
Hide Abstract
The growth arrest and DNA-damage-inducible protein 45 gamma (Gadd45g) is known to play a major role in embryonic development and sex determination. In this study, two Gadd45g genes were isolated from half-smooth tongue sole (Cynoglossus semilaevis). Using chromosomal fluorescence in situ hybridization (FISH), Gadd45g1 and Gadd45g2 were located on the W and Z chromosomes, respectively. The full-length cDNA sequences of Gadd45g1 (1270bp) and Gadd45g2 (1181bp) were predicted to contain a 480-bp coding sequence that could encode a protein of 159 amino acids residues. A phylogenetic tree showed that the predicted Gadd45g1 and Gadd45g2 amino acid sequences clustered closely in one branch. It is proposed that Gadd45g1 and Gadd45g2 are paralogous genes derived from the divergence of the sex chromosome. Ka/Ks ratios indicated that Gadd45g1 and Gadd45g2 may have undergone a high number of mutations and have a divergence time of only about 68,000years, although Gadd45g homologs are highly conserved. The qRT-PCR demonstrated that Gadd45g1 and Gadd45g2 were highly expressed in ovary, and negligibly expressed in testis of male and neo-male. During development of the ovary (from 80 to 150days), the expression levels of both genes reached high levels. Gadd45g1 was also highly expressed at 50days, the stage just before gonad differentiation in C. semilaevis. All these findings imply functional divergence of the two Gadd45g homologs; Gadd45g1 may be necessary for sex differentiation in the early stage of gonad development, and then Gadd45g1 and Gadd45g2 maintain ovary development and the female character of half-smooth tongue sole.
Related JoVE Video
The Positive Regulatory Roles of the TIFY10 Proteins in Plant Responses to Alkaline Stress.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
The TIFY family is a novel plant-specific protein family, and is characterized by a conserved TIFY motif (TIFF/YXG). Our previous studies indicated the potential roles of TIFY10/11 proteins in plant responses to alkaline stress. In the current study, we focused on the regulatory roles and possible physiological and molecular basis of the TIFY10 proteins in plant responses to alkaline stress. We demonstrated the positive function of TIFY10s in alkaline responses by using the AtTIFY10a and AtTIFY10b knockout Arabidopsis, as evidenced by the relatively lower germination rates of attify10a and attify10b mutant seeds under alkaline stress. We also revealed that ectopic expression of GsTIFY10a in Medicago sativa promoted plant growth, and increased the NADP-ME activity, citric acid content and free proline content but decreased the MDA content of transgenic plants under alkaline stress. Furthermore, expression levels of the stress responsive genes including NADP-ME, CS, H+-ppase and P5CS were also up-regulated in GsTIFY10a transgenic plants under alkaline stress. Interestingly, GsTIFY10a overexpression increased the jasmonate content of the transgenic alfalfa. In addition, we showed that neither GsTIFY10a nor GsTIFY10e exhibited transcriptional activity in yeast cells. However, through Y2H and BiFc assays, we demonstrated that GsTIFY10a, not GsTIFY10e, could form homodimers in yeast cells and in living plant cells. As expected, we also demonstrated that GsTIFY10a and GsTIFY10e could heterodimerize with each other in both yeast and plant cells. Taken together, our results provided direct evidence supporting the positive regulatory roles of the TIFY10 proteins in plant responses to alkaline stress.
Related JoVE Video
ROCK Inhibitor Is Not Required for Embryoid Body Formation from Singularized Human Embryonic Stem Cells.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
We report a technology to form human embryoid bodies (hEBs) from singularized human embryonic stem cells (hESCs) without the use of the p160 rho-associated coiled-coil kinase inhibitor (ROCKi) or centrifugation (spin). hEB formation was tested under four conditions: +ROCKi/+spin, +ROCKi/-spin, -ROCKi/+spin, and -ROCKi/-spin. Cell suspensions of BG01V/hOG and H9 hESC lines were pipetted into non-adherent hydrogel substrates containing defined microwell arrays. hEBs of consistent size and spherical geometry can be formed in each of the four conditions, including the -ROCKi/-spin condition. The hEBs formed under the -ROCKi/-spin condition differentiated to develop the three embryonic germ layers and tissues derived from each of the germ layers. This simplified hEB production technique offers homogeneity in hEB size and shape to support synchronous differentiation, elimination of the ROCKi xeno-factor and rate-limiting centrifugation treatment, and low-cost scalability, which will directly support automated, large-scale production of hEBs and hESC-derived cells needed for clinical, research, or therapeutic applications.
Related JoVE Video
Predicting A-to-I RNA Editing by Feature Selection and Random Forest.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
RNA editing is a post-transcriptional RNA process that provides RNA and protein complexity for regulating gene expression in eukaryotes. It is challenging to predict RNA editing by computational methods. In this study, we developed a novel method to predict RNA editing based on a random forest method. A careful feature selection procedure was performed based on the Maximum Relevance Minimum Redundancy (mRMR) and Incremental Feature Selection (IFS) algorithms. Eighteen optimal features were selected from the 77 features in our dataset and used to construct a final predictor. The accuracy and MCC (Matthews correlation coefficient) values for the training dataset were 0.866 and 0.742, respectively; for the testing dataset, the accuracy and MCC were 0.876 and 0.576, respectively. The performance was higher using 18 features than all 77, suggesting that a small feature set was sufficient to achieve accurate prediction. Analysis of the 18 features was performed and may shed light on the mechanism and dominant factors of RNA editing, providing a basis for future experimental validation.
Related JoVE Video
Study of the mechanism of sonodynamic therapy in a rat glioma model.
Onco Targets Ther
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
The study reported here examined the effect of hematoporphyrin monomethyl ether (HMME)-mediated sonodynamic therapy (SDT) on C6 gliomas implanted in rat brains.
Related JoVE Video
Cloning and Characterization of tesk1, a Novel Spermatogenesis-Related Gene, in the Tongue Sole (Cynoglossus semilaevis).
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Testis-specific protein kinase 1 (Tesk1) is a serine/threonine kinase with unique structural features. In the present study, we cloned and characterized the tesk1 gene of tongue sole, Cynoglossus semilaevis. The full-length tesk1 cDNA consists of 1,672 nucleotides, encoding a 331 amino acid polypeptide with a characteristic structure composed of an N-terminal kinase domain and a C-terminal proline-rich domain. The tesk1 genomic sequence contains eight exons and seven introns. Real-time quantitative PCR revealed that tesk1 mRNA is expressed predominantly in the testis, though the level of expression varied throughout development. We used in situ hybridization to show that tesk1 mRNA is expressed in the spermatids of males and pseudo-males, but not in triploid males. Our results suggest that tongue sole Tesk1 may play a role in spermatogenesis.
Related JoVE Video
Discriminating between lysine sumoylation and lysine acetylation using mRMR feature selection and analysis.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Post-translational modifications (PTMs) are crucial steps in protein synthesis and are important factors contributing to protein diversity. PTMs play important roles in the regulation of gene expression, protein stability and metabolism. Lysine residues in protein sequences have been found to be targeted for both types of PTMs: sumoylations and acetylations; however, each PTM has a different cellular role. As experimental approaches are often laborious and time consuming, it is challenging to distinguish the two types of PTMs on lysine residues using computational methods. In this study, we developed a method to discriminate between sumoylated lysine residues and acetylated residues. The method incorporated several features: PSSM conservation scores, amino acid factors, secondary structures, solvent accessibilities and disorder scores. By using the mRMR (Maximum Relevance Minimum Redundancy) method and the IFS (Incremental Feature Selection) method, an optimal feature set was selected from all of the incorporated features, with which the classifier achieved 92.14% accuracy with an MCC value of 0.7322. Analysis of the optimal feature set revealed some differences between acetylation and sumoylation. The results from our study also supported the previous finding that there exist different consensus motifs for the two types of PTMs. The results could suggest possible dominant factors governing the acetylation and sumoylation of lysine residues, shedding some light on the modification dynamics and molecular mechanisms of the two types of PTMs, and provide guidelines for experimental validations.
Related JoVE Video
Temperate pine barrens and tropical rain forests are both rich in undescribed fungi.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Most of fungal biodiversity on Earth remains unknown especially in the unexplored habitats. In this study, we compared fungi associated with grass (Poaceae) roots from two ecosystems: the temperate pine barrens in New Jersey, USA and tropical rain forests in Yunnan, China, using the same sampling, isolation and species identification methods. A total of 426 fungal isolates were obtained from 1600 root segments from 80 grass samples. Based on the internal transcribed spacer (ITS) sequences and morphological characteristics, a total of 85 fungal species (OTUs) belonging in 45 genera, 23 families, 16 orders, and 6 classes were identified, among which the pine barrens had 38 and Yunnan had 56 species, with only 9 species in common. The finding that grass roots in the tropical forests harbor higher fungal species diversity supports that tropical forests are fungal biodiversity hotspots. Sordariomycetes was dominant in both places but more Leotiomycetes were found in the pine barrens than Yunnan, which may play a role in the acidic and oligotrophic pine barrens ecosystem. Equal number of undescribed fungal species were discovered from the two sampled ecosystems, although the tropical Yunnan had more known fungal species. Pine barrens is a unique, unexplored ecosystem. Our finding suggests that sampling plants in such unexplored habitats will uncover novel fungi and that grass roots in pine barrens are one of the major reservoirs of novel fungi with about 47% being undescribed species.
Related JoVE Video
The relationship between frontal lobe lesions, course of post-stroke depression, and 1-year prognosis in patients with first-ever ischemic stroke.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Most studies on post-stroke depression (PSD) have focused on a certain time point after stroke instead of the time course of PSD. The aim of this study was to determine the relationship between frontal lobe lesions, course of PSD over a year following the stroke onset, and the 1-year prognosis in patients with first-ever ischemic stroke.
Related JoVE Video
Synthesis and Evaluation of a Nanoglobular Dendrimer 5-Aminosalicylic Acid Conjugate with a Hydrolyzable Schiff Base Spacer for Treating Retinal Degeneration.
ACS Nano
PUBLISHED: 12-20-2013
Show Abstract
Hide Abstract
Biocompatible dendrimers with well-defined nanosizes are increasingly being used as carriers for drug delivery. 5-Aminosalicylic acid (5-ASA) is an FDA-approved therapeutic agent recently found effective in treating retinal degeneration of animal models. Here, a water-soluble dendrimer conjugate of 5-ASA (AGFB-ASA) was designed to treat such retinal degeneration. The drug was conjugated to a generation 2 (G2) lysine dendrimer with a silsesquioxane core (nanoglobule) by using a hydrolyzable Schiff base spacer. Incubation of nanoglobular G2 dendrimer conjugates containing a 4-formylbenzoate (FB) Schiff base spacer in pH 7.4 phosphate buffers at 37 °C gradually released 5-ASA. Drug release from the dendrimer conjugate was significantly slower than from the low molecular weight free Schiff base of 5-ASA (FB-ASA). 5-ASA release from the dendrimer conjugate was dependent on steric hindrance around the spacer. After intraperitoneal injection, the nanoglobular 5-ASA conjugate provided more effective 7-day protection against light-induced retinal degeneration at a reduced dose than free 5-ASA in Abca4(-/-)Rdh8(-/-) mice. The dendrimer 5-ASA conjugate with a degradable spacer could be a good candidate for controlled delivery of 5-ASA to the eye for treatment of retinal degeneration.
Related JoVE Video
[Posterior C1-C2 transarticular screw fixation for atlantoaxial instability assisted by intraoperative 3-dimensional fluoroscopy-based navigation].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 12-05-2013
Show Abstract
Hide Abstract
To assess the feasibility, efficacy and indication of posterior C1-C2 transarticular screw fixation for atlantoaxial instability assisted by intraoperative 3-dimensional fluoroscopy-based navigation.
Related JoVE Video
Suppression of WC-independent frequency transcription by RCO-1 is essential for Neurospora circadian clock.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 11-25-2013
Show Abstract
Hide Abstract
Rhythmic activation and repression of clock gene transcription is essential for the functions of eukaryotic circadian clocks. In the Neurospora circadian oscillator, frequency (frq) transcription requires the WHITE COLLAR (WC) complex. Here, we show that the transcriptional corepressor regulation of conidiation-1 (RCO-1) is essential for clock function by regulating frq transcription. In rco-1 mutants, both overt and molecular rhythms are abolished, frq mRNA levels are constantly high, and WC binding to the frq promoter is dramatically reduced. Surprisingly, frq mRNA levels were constantly high in the rco-1 wc double mutants, indicating that RCO-1 suppresses WC-independent transcription and promotes WC complex binding to the frq promoter. Furthermore, RCO-1 is required for maintaining normal chromatin structure at the frq locus. Deletion of H3K36 methyltransferase su(var)3-9-enhancer-of-zeste-trithorax-2 (SET-2) or the chromatin remodeling factor CHD-1 leads to WC-independent frq transcription and loss of overt rhythms. Together, our results uncover a previously unexpected regulatory mechanism for clock gene transcription.
Related JoVE Video
P3DB 3.0: From plant phosphorylation sites to protein networks.
Nucleic Acids Res.
PUBLISHED: 11-15-2013
Show Abstract
Hide Abstract
In the past few years, the Plant Protein Phosphorylation Database (P(3)DB, http://p3db.org) has become one of the most significant in vivo data resources for studying plant phosphoproteomics. We have substantially updated P(3)DB with respect to format, new datasets and analytic tools. In the P(3)DB 3.0, there are altogether 47 923 phosphosites in 16 477 phosphoproteins curated across nine plant organisms from 32 studies, which have met our multiple quality standards for acquisition of in vivo phosphorylation site data. Centralized by these phosphorylation data, multiple related data and annotations are provided, including protein-protein interaction (PPI), gene ontology, protein tertiary structures, orthologous sequences, kinase/phosphatase classification and Kinase Client Assay (KiC Assay) data-all of which provides context for the phosphorylation event. In addition, P(3)DB 3.0 incorporates multiple network viewers for the above features, such as PPI network, kinase-substrate network, phosphatase-substrate network, and domain co-occurrence network to help study phosphorylation from a systems point of view. Furthermore, the new P(3)DB reflects a community-based design through which users can share datasets and automate data depository processes for publication purposes. Each of these new features supports the goal of making P(3)DB a comprehensive, systematic and interactive platform for phosphoproteomics research.
Related JoVE Video
Dynamic stress relaxation of orthodontic thermoplastic materials in a simulated oral environment.
Dent Mater J
PUBLISHED: 11-15-2013
Show Abstract
Hide Abstract
Mechanical properties are crucial for screening orthodontic thermoplastic materials for invisible aligners. However, most of previous studies were carried out within laboratory conditions which limit our understanding of the mechanical behaviors of aligners within oral environment. In this study, we studied the dynamic stress relaxation of thermoplastic materials by combination of Bose ElectroForce and a homemade temperature-controlled water bath. The 3-h stress relaxation curves of five orthodontic thermoplastic materials were measured within 37°C water bath as well as comparatively in ambient atmospheric environment (~20°C). The percentage residual stress at 0, 30, 60, 90, 120, 150, and 180 min was selected for statistical analyses. As expected, the experimental results showed that the residual stress within all five materials decreased with time, and that this process was significantly accelerated in the 37°C water bath (p<0.05). Compared with other materials, Erkodur and Masel exhibited slower relaxing rates in the 37°C water bath (p<0.05).
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.