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Find video protocols related to scientific articles indexed in Pubmed.
Lead Optimization and Modulation of hERG Activity in a Series of Aminooxazoline Xanthene ?-Site Amyloid Precursor Protein Cleaving Enzyme (BACE1) Inhibitors.
J. Med. Chem.
PUBLISHED: 11-13-2014
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The optimization of a series of aminooxazoline xanthene inhibitors of ?-site amyloid precursor protein cleaving enzyme 1 (BACE1) is described. An early lead compound showed robust A? lowering activity in a rat pharmacodynamic model, but advancement was precluded by a low therapeutic window to QTc prolongation in cardiovascular models consistent with in vitro activity on the hERG ion channel. While the introduction of polar groups was effective in reducing hERG binding affinity, this came at the expense of higher than desired Pgp-mediated efflux. A balance of low Pgp efflux and hERG activity was achieved by lowering the polar surface area of the P3 substituent while retaining polarity in the P2' side chain. The introduction of a fluorine in position 4 of the xanthene ring improved BACE1 potency (5-10-fold). The combination of these optimized fragments resulted in identification of compound 40, which showed robust A? reduction in a rat pharmacodynamic model (78% A? reduction in CSF at 10 mg/kg po) and also showed acceptable cardiovascular safety in vivo.
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Platinum(ii) clovers targeting G-quadruplexes and their anticancer activities.
Dalton Trans
PUBLISHED: 11-07-2014
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Two porphyrin-bridged tetranuclear platinum(ii) complexes are found to effectively stabilize various kinds of G-quadruplexes. Their clover-like shape endows them with the capability of targeting G-quadruplexes rather than the double-stranded structure. Their excellent anticancer activity is the result of a dual effect, inhibition of the telomerase activity and repression of oncogene expression.
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Days to heading 7, a major quantitative locus determining photoperiod sensitivity and regional adaptation in rice.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 11-05-2014
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Success of modern agriculture relies heavily on breeding of crops with maximal regional adaptability and yield potentials. A major limiting factor for crop cultivation is their flowering time, which is strongly regulated by day length (photoperiod) and temperature. Here we report identification and characterization of Days to heading 7 (DTH7), a major genetic locus underlying photoperiod sensitivity and grain yield in rice. Map-based cloning reveals that DTH7 encodes a pseudo-response regulator protein and its expression is regulated by photoperiod. We show that in long days DTH7 acts downstream of the photoreceptor phytochrome B to repress the expression of Ehd1, an up-regulator of the "florigen" genes (Hd3a and RFT1), leading to delayed flowering. Further, we find that haplotype combinations of DTH7 with Grain number, plant height, and heading date 7 (Ghd7) and DTH8 correlate well with the heading date and grain yield of rice under different photoperiod conditions. Our data provide not only a macroscopic view of the genetic control of photoperiod sensitivity in rice but also a foundation for breeding of rice cultivars better adapted to the target environments using rational design.
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Complex absorbing potential based Lorentzian fitting scheme and time dependent quantum transport.
J Chem Phys
PUBLISHED: 11-03-2014
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Based on the complex absorbing potential (CAP) method, a Lorentzian expansion scheme is developed to express the self-energy. The CAP-based Lorentzian expansion of self-energy is employed to solve efficiently the Liouville-von Neumann equation of one-electron density matrix. The resulting method is applicable for both tight-binding and first-principles models and is used to simulate the transient currents through graphene nanoribbons and a benzene molecule sandwiched between two carbon-atom chains.
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[Cloning of full-length cDNA of HMGR from Gobiocypris rarus and analysis of its expression profiles in male exposed to pentachlorophenol].
Huan Jing Ke Xue
PUBLISHED: 10-24-2014
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3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) is the first rate-limiting enzyme in the mevalonate (MVA) pathway. The full-length cDNA of HMGR was cloned from Gobiocypris rarus, and HMGR expression profiles in different tissues and in response to different treatments of pentachlorophenol (PCP) were analyzed by real-time PCR, to investigate the endocrine disruption mechanism of PCP, which altered steroid hormone precursors (cholesterol) levels by modulating gene transcription profiles of HMGR. Based on the homologous clone strategy and rapid-amplification of cDNA ends (RACE) technology, the full-length 3 101-base-pair (bp) cDNA of HMGR was isolated from the livers of rare minnow (Gobiocypris rarus) for the first time, and was designated as GrHMGR (GenBank accession number KF885724). GrHMGR encoded a protein of 884 amino acids and phylogenetic tree analysis indicated that the deduced protein GrHMGR had extensive sequence similarities to other fish HMGRs. Real-time PCR analyses indicated that GrHMGR mRNA expression was tightly controlled in a tissue-specific fashion, with the sites of expression being brain, gonads and liver, and the highest site of expression being gonads. After male rare minnows were exposed to different concentrations of PCP, significant decrease in GrHMGR gene expression with increased PCP concentration in the brain and gonads were observed, together with the differential gene expression trend in the liver. Furthermore, it was found that the decrease of HMGR could reduce the synthesis of cholesterol. This proved that PCP might disrupt the pathway of cholesterol synthesis and then influenced the endocrine system of rare minnow.
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Compliance with severe sepsis bundles and its effect on patient outcomes of severe community-acquired pneumonia in a limited resources country.
Arch Med Sci
PUBLISHED: 10-23-2014
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Validation of compliance with severe sepsis bundles is still needed. The purpose of this study was to determine compliance and its outcomes in severe community-acquired pneumonia (CAP) patients in a limited resources country.
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[Relationship between CD4+CD25+Treg cells, Th17 cells and IL-6 and the prognosis of hepatitis B virus-related acute-on-chronic liver failure: a meta-analysis].
Zhonghua Gan Zang Bing Za Zhi
PUBLISHED: 09-10-2014
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To investigate the role ofCD4+CD25+ T regulatory (Treg) cells, T helper (Th)17cells and interleukin (IL)-6 in the progression of hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF) and determine their value as prognostic markers.
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[Dan'e-fukang soft extract for dysmenorrhea: a meta-analysis].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 09-05-2014
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To assess the efficacy and safety of Dan'e-fukang soft extract for dysmenorrhea by meta-analysis.
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Understanding the Kondo resonance in the d-CoPc/Au(111) adsorption system.
J Chem Phys
PUBLISHED: 09-01-2014
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By combining the density functional theory (DFT) and a hierarchical equations of motion (HEOM) approach, we investigate the Kondo phenomena in a composite system consisting of a dehydrogenated cobalt phthalocyanine molecule (d-CoPc) adsorbed on an Au(111) surface. DFT calculations are performed to determine the ground-state geometric and electronic structures of the adsorption system. It is found that the singly occupied dz(2) orbital of Co forms a localized spin, which could be screened by the substrate conduction electrons. This screening leads to the prominent Kondo features as observed in the scanning tunneling microscopy experiments. We then employ the HEOM approach to characterize the Kondo correlations of the adsorption system. The calculated temperature-dependent differential conductance spectra and the predicted Kondo temperature agree well with the experiments, and the universal Kondo scaling behavior is correctly reproduced. This work thus provides important insights into the relevant experiments, and it also highlights the applicability of the combined DFT+HEOM approach to the studies of strongly correlated condensed matter systems.
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Preparation of poly(vinylphenylboronic acid)-chain-grafted poly(glycidylmethacrylate-co-ethylenedimethacrylate) beads for the selective enrichment of glycoprotein.
J Sep Sci
PUBLISHED: 08-19-2014
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Surface-initiated atom transfer radical polymerization was successfully used to prepare 4-vinylphenylboronic acid-functionalized poly(glycidylmethacrylate-co-ethylenedimethacrylate) beads for the selective enrichment of glycoprotein from complex biological samples in this study. The modified bead surfaces were characterized using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The sorption behaviors, including adsorption isotherms, incubation time and pH effect, were investigated. The results demonstrated that the boronated beads have a high affinity for glycoprotein, which is due to the well-defined boronic acid brushes on the beads surfaces. Furthermore, the polyvinylphenylboronic acid-grafted poly(glycidylmethacrylate-co-ethylenedimethacrylate) beads were used to efficiently enrich and purify glycoprotein from real egg white samples and ?-fetoprotein from human serum samples. The mass spectrometry results demonstrated that the polyvinylphenylboronic acid-grafted poly(glycidylmethacrylate-co-ethylenedimethacrylate) beads are a suitable material for the enrichment of glycosylated protein from complex biological samples. This article is protected by copyright. All rights reserved.
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Characterization of the microbial community in different types of Daqu samples as revealed by 16S rRNA and 26S rRNA gene clone libraries.
World J. Microbiol. Biotechnol.
PUBLISHED: 08-18-2014
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Daqu is a fermentative saccharification agent that is used to initiate fermentation in the production of Chinese liquor and vinegar. Different types of Daqu can be distinguished based on the maximum fermentation temperature, location of production, and raw materials used. We aimed to characterize and distinguish the different types of Daqu using a culture-independent cloning method. The lowest microbial diversity was found in Daqu produced at high-temperature. Principal component analysis (PCA) was used to compare the bacterial composition of Daqu from different regions (i.e., northern Daqu and southern Daqu). Staphylococcus gallinarum and Staphylococcus saprophyticus were found in southern Daqu, and were absent in northern Daqu. The fungi Saccharomycopsis fibuligera and Lichtheimia ramosa dominated in low/medium-temperature Daqu, whereas Thermomyces lanuginosus occurred in high-temperature Daqu. Our study identified potential biomarkers for the different types of Daqu, which can be useful for quality control and technology development of liquor or vinegar production.
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Evaluation of tumor response to cytokine-induced killer cells therapy in malignant solid tumors.
J Transl Med
PUBLISHED: 08-12-2014
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CIK cells therapy has been evaluated as an adoptive cell immunotherapy for cancer patients, but there still have not been any standardized systems for evaluating the antitumor efficacy yet. The WHO and RECIST criteria have already been established for a few years but not sufficient to fully characterize the activity of immunotherapy. Based on these two criteria, the irRC was proposed for evaluating the efficacy of immunotherapy. A variety of bioassays for immune monitoring including the specific and non-specific methods, have been established. We recommend detect levels of various immunocytes, immune molecules and soluble molecules to find the correlations among them and clinicopathological characteristics to establish criteria for immunological classification. We also recommend a paradigm shift for the oncologists in the evaluation of immune therapies to ensure assessment of activity based on clinically relevant criteria and time points.
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A new receptor tyrosine kinase inhibitor, icotinib, for patients with lung adenocarcinoma cancer without indication for chemotherapy.
Oncol Lett
PUBLISHED: 06-19-2014
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Epidermal growth factor receptor (EGFR) is an important therapeutic target in lung cancer. Gefitinib and erlotinib, two reversible EGFR receptor tyrosine kinases inhibitors (TKIs), have been approved for the treatment of patients with metastatic non small-cell lung cancer. Icotinib, which is a selective EGFR-TKI, provides a similar efficacy to gefitinib. The present study aimed to investigate the survival and safety of icotinib in patients with lung adenocarcinoma with a poor performance status (PS). A total of 42 cases of lung adenocarcinoma, including 35 females and 7 males, were enrolled. Icotinib was used as the first-line of treatment due to poor PS of the patient or a more advanced age. Icotinib (125 mg) was orally administered three times per day. The overall response rate and disease control rates were 33.3 and 85.7%, respectively. The median survival time was 13.0 months (95% CI, 5.6-20.4), The median progression-free survival time was 7.0 months, and the 1-year survival rate was 71.4%. A total of 79% of patients had an improved PS following icotinib treatment. Grade 1 to 2 rashes and diarrhea were the most frequent side effects. One patient succumbed during the study due to interstitial pneumonia. In conclusion, this is the first study indicating that patients with lung adenocarcinoma and poor PS may benefit from first-line icotinib therapy, but should be cautious of the occurrence of interstitial lung disease.
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Interfering with CXCR4 expression inhibits proliferation, adhesion and migration of breast cancer MDA-MB-231 cells.
Oncol Lett
PUBLISHED: 06-12-2014
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To investigate the effect and mechanism of the CXC chemokine receptor 4 (CXCR4) in the proliferation and migration of breast cancer, a short-hairpin RNA (shRNA) eukaryotic expression vector targeting CXCR4 was constructed, and the impact of such on the proliferation, adhesion and migration of human breast cancer MDA-MB-231 cells was observed. The fragments of CXCR4-shRNA were synthesized and cloned into a pGCsi-U6-Neo-green fluorescent protein vector. The recombinant plasmids were transfected into 293T cells and the most efficacious interfering vector was selected. MDA-MB-231 cells were transfected by liposome assay. The effects of silencing CXCR4 expression by shRNA on the growth, adhesion and migration of MDA-MB-231 cells were determined by Cell Counting Kit-8, cell-matrix adhesion and wound-healing assays. The shRNA eukaryotic expression vectors targeting CXCR4 (CXCR4-shRNA) were successfully constructed and transfected into 293T cells. Quantitative polymerase chain reaction and western blot analysis revealed that the maximum inhibitory rate of CXCR4 expression was 81.3%. CXCR4-shRNA transfection significantly inhibited the proliferation of MDA-MB-231 cells (P<0.05), as well as the adhesion between MDA-MB-231 cells and the extracellular matrix (P<0.05). Furthermore, wound-healing assays demonstrated that the migration distance of MDA-MB-231 cells in the CXCR4-shRNA transfection group was significantly smaller than that in the control plasmid and blank control groups (P<0.01). The CXCR4-shRNA interfering vector specifically inhibited CXCR4 expression, as well as the proliferation, adhesion and migration of MDA-MB-231 cells.
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Real-time separation of non-stationary sound fields with pressure and particle acceleration measurements.
J. Acoust. Soc. Am.
PUBLISHED: 06-09-2014
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To extract the desired non-stationary sound field generated by a target source in the presence of disturbing sources, a real-time sound field separation method with pressure and particle acceleration measurements is proposed. In this method, the pressure and particle acceleration signals at a time instant are first measured on one measurement plane, where the particle acceleration is obtained by the finite difference approximation with the aid of an auxiliary measurement plane; then, the desired pressure signal generated by the target source at the same time instant can be extracted in a timely manner, by a simple superposition of the measured pressure and the convolution between the measured particle acceleration and the derived impulse response function. Thereby, the proposed method possesses a significant feature of real-time separation of non-stationary sound fields, which provides the potential to in situ analyze the radiation characteristics of a non-stationary source. The proposed method was examined through numerical simulation and experiment. Results demonstrated that the proposed method can not only extract the desired time-evolving pressure signal generated by the target source at any space point, but can also obtain the desired spatial distribution of the pressure field generated by the target source at any time instant.
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Serum B7-H4 expression is a significant prognostic indicator for patients with gastric cancer.
World J Surg Oncol
PUBLISHED: 06-08-2014
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B7-H4 is a novel B7 ligand that plays an important role in the T cell-mediated immune response as a negative regulator. Previous studies have suggested the aberrant expression of membrane B7-H4 in tumor cells. The aim of this study is to determine the expression levels of preoperative soluble B7-H4 (sB7-H4) in circulation and to investigate the correlations between sB7-H4 levels and clinicopathological parameters as well as the survival rate of patients with gastric cancer.
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NBS1 Glu185Gln polymorphism and susceptibility to urinary system cancer: a meta-analysis.
Tumour Biol.
PUBLISHED: 06-04-2014
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A number of studies have investigated the association between the NBS1 Glu185Gln (rs1805794, 8360 G?>?C) polymorphism and risk for urinary system cancer including bladder cancer, prostate cancer, and renal cell cancer; however, the findings are conflicting. We conducted a meta-analysis focusing on eight published studies with 3,542 cases and 4,210 controls to derive a more precise evaluation of the relationship between the NBS1 Glu185Gln polymorphism and urinary system cancer susceptibility. Overall, the NBS1 Glu185Gln polymorphism was significantly related to increased risk for urinary system cancer (homozygous model: odds ratio (OR)?=?1.23, 95 % confidence interval (95 % CI)?=?1.05-1.44, p?=?0.011; heterozygous model: OR?=?1.14, 95 % CI?=?1.04-1.26, p?=?0.008; dominant model: OR?=?1.16, 95 % CI?=?1.05-1.27, p?=?0.002; and Gln vs. Glu: OR?=?1.12, 95 % CI?=?1.04-1.20, p?=?0.002) and further stratification analysis indicated an increased risk for bladder cancer (heterozygous model: OR?=?1.13, 95 % CI?=?1.02-1.26, p?=?0.022; dominant model: OR?=?1.14, 95 % CI?=?1.03-1.26, p?=?0.014; and Gln vs. Glu: OR?=?1.09, 95 % CI?=?1.01-1.18, p?=?0.023) and Caucasian populations (homozygous model: OR?=?1.33, 95 % CI?=?1.11-1.59, p?=?0.002; heterozygous model: OR?=?1.16, 95 % CI?=?1.04-1.30, p?=?0.009; dominant model: OR?=?1.19, 95 % CI?=?1.07-1.32, p?=?0.001; and Gln vs. Glu: OR?=?1.15, 95 % CI?=?1.06-1.25, p?
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Plasma microRNA profiling in nasopharyngeal carcinoma patients reveals miR-548q and miR-483-5p as potential biomarkers.
Chin J Cancer
PUBLISHED: 05-26-2014
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MicroRNAs (miRNAs), which play a role in tumorigenesis, may also serve as diagnostic or prognostic biomarkers. However, studies on human miRNA profiles in plasma from nasopharyngeal carcinoma (NPC) patients are in their infancy. Here, we used microarrays to perform systematic profiling of human miRNAs in plasma from NPC patients. We subsequently used real-time quantitative polymerase chain reaction (Q-PCR) to validate miRNAs with aberrant expression that could serve as potential biomarkers. By comparing the plasma miRNA profiles of 31 NPC patients and 19 controls, 39 of 887 human miRNAs were found to be aberrantly expressed. Considering the fold change and P value, miR-548q and miR-483-5p were validated in 132 samples from 82 NPC patients and 50 controls. Moreover, high expression of miR-548q and miR-483-5p was further found in 3 NPC cell lines and clinical biopsy tissues from 54 NPC patients and 22 controls. Our results revealed that miR-548q and miR-483-5p are potential biomarkers of NPC. Combining the receiver operating characteristic (ROC) analyses of these 2 miRNAs, an area under the ROC curve (AUC) of 0.737 with 67.1% sensitivity and 68.0% specificity were obtained, showing the preliminary diagnostic value of plasma miRNAs. Moreover, most NPC patients with a poor outcome exhibited high expression (> median) of miR-548q (70.6%) and miR-483-5p (64.7%) in tissue samples, indicating their prognostic value. The high expression levels of miR-548q and miR-483-5p in plasma, cell lines, and clinical tissues of NPC patients indicate that their roles in NPC should be explored in the future.
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The impact of intermittent and repetitive cold stress exposure on endoplasmic reticulum stress and instability of atherosclerotic plaques.
Cell. Physiol. Biochem.
PUBLISHED: 05-19-2014
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The incidence of acute coronary syndrome caused by the rupture of atherosclerotic plaque and subsequent arterial thrombosis increases as the weather gets colder. However, the association between cold stress and atherosclerotic plaque rupture is currently unknown.
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Characteristics of TCM constitutions of adult Chinese women in Hong Kong and identification of related influencing factors: a cross-sectional survey.
J Transl Med
PUBLISHED: 04-29-2014
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Traditional Chinese Medicine Constitution (TCMC) refers to an integrated, metastable and natural specialty of individual in morphosis, physiological functions and psychological conditions. It is formed on the basis of innate and acquired endowments in the human life process, which can be divided into normal constitution and unbalanced ones. The aim of this study was to investigate the distribution of TCMCs of Chinese women in Hong Kong and its acquired influencing factors.
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Thinking outside the brain for cognitive improvement: Is peripheral immunomodulation on the way?
Neuropharmacology
PUBLISHED: 04-27-2014
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Cognitive impairment is a devastating condition commonly observed with normal aging and neurodegenerative disorders such as Alzheimer's Disease (AD). Although major efforts to prevent or slow down cognitive decline are largely focused within the central nervous system (CNS), it has become clear that signals from the systemic milieu are closely associated with the dysfunctional brain. In particular, the bidirectional crosstalk between the CNS and peripheral immune system plays a decisive role in shaping neuronal survival and function via neuroimmune, neuroendocrinal and bioenergetic mechanisms. Importantly, it is emerging that some neuroprotective and cognition-strengthening drugs may work by targeting the brain-periphery interactions, which could be intriguingly achieved without entering the CNS. We describe here how recent advances in dissecting cognitive deficits from a systems-perspective have contributed to a non-neurocentric understanding of its pathogenesis and treatment strategy. We also discuss the therapeutic and diagnostic implications of these exciting progresses and consider some key issues in the clinical translation. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'.
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Upregulated dynamin 1 in an acute seizure model and in epileptic patients.
Synapse
PUBLISHED: 04-26-2014
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Dynamin 1 is a neuron-specific guanosine triphosphatase (GTPase) that is an essential component of membrane fission during synaptic vesicle recycling and endocytosis. This study evaluated the dynamin 1 expression pattern in the acute lithium-pilocarpine rat model and in patients with temporal lobe epilepsy (TLE) and investigated whether altering the dynamin 1 expression pattern affects epileptic seizures in vivo and in vitro. The immunofluorescence, western blot analysis, and reverse transcription-PCR results show that the dynamin 1 expression level increased significantly in experimental rats from day 1 to day 7 after the onset of seizures and was significantly higher in TLE patients. The behavioral study revealed that inhibiting dynamin 1 increased the latency time of the first seizure and decreased the frequency and severity of the seizures. In addition, electrophysiological recordings from brain slices showed that inhibiting dynamin 1 reduces the frequency of Mg-free induced seizure-like activity. The anticonvulsant effect of dynasore was more effective at 10 µM than at 1 µM or 160 µM. These results indicate that the altered level of dynamin 1 may contribute to the development of epileptic seizures and that the targeted regulation of dynamin 1 activity may control epileptic seizures. Synapse, 2014. © 2014 Wiley Periodicals, Inc.
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Association between FABP2 Ala54Thr polymorphisms and type 2 diabetes mellitus risk: a HuGE Review and Meta-Analysis.
J. Cell. Mol. Med.
PUBLISHED: 04-25-2014
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Many studies have examined the association between the FABP2 (rs1799883) Ala54Thr gene polymorphism and type 2 diabetes mellitus risk (T2DM) in various populations, but their results have been inconsistent. To assess this relationship more precisely, A HuGE review and meta-analysis were performed. The PubMed and CNKI database was searched for case-control studies published up to April 2014. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 13 studies, comprising 2020 T2DM cases and 2910 controls were included. Overall, for the Thr carriers (Ala/Thr and Thr/Thr) versus the wild-type homozygotes (Ala/Ala), the pooled OR was 1.18 (95% CI = 1.04-1.34, P = 0.062 for heterogeneity), for Thr/Thr versus Ala/Ala the pooled OR was 1.17 (95% CI = 1.05-1.41 P = 0.087 for heterogeneity). In the stratified analysis by ethnicity, the significantly risks were found among Asians but not Caucasians. This meta-analysis suggests that the FABP2 (rs1799883) Ala54Thr polymorphisms are associated with increased susceptibility to T2DM risk among Asians but not Caucasians.
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[Effects of liraglutide on the expression of local renin-angiotensin system, transforming growth factor-?1 and collagen type III in pulmonary tissue of diabetic rats].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 04-24-2014
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To explore the effects of GLP-1 receptor analog liraglutide on the expression of local renin-angiotensin system (RAS), TGF-?1 and collagen type III in pulmonary tissue of diabetic rats.
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5-HT6 Receptor Recruitment of mTOR Modulates Seizure Activity in Epilepsy.
Mol. Neurobiol.
PUBLISHED: 04-22-2014
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Approximately 30 % of epilepsy cases are refractory to current pharmacological treatments. Thus, novel therapeutic approaches that prevent or reverse the molecular and cellular mechanisms of epilepsy are required. 5-HT6 receptor (HTR6) blockade can modulate multiple neurotransmitter systems, and HTR6 may be a potential therapeutic treatment for neurological diseases, including epilepsy. Here, we investigated the role of HTR6 in epilepsy. We detected HTR6 expression both in human epileptic tissues and the pilocarpine rat model by western blotting. We observed behavioral changes after administration of pilocarpine in rats pretreated with a selective HTR6 antagonist, SB-399885, and recorded the electrophysiological index in the pilocarpine rat model pre- or posttreated with SB-399885 by electroencephalogram (EEG) and whole-cell clamp. We measured the activity of mammalian target of rapamycin (mTOR) in the pilocarpine rat model pretreated with the mTOR-specific inhibitor, rapamycin, and SB-399885 using western blotting. We found that HTR6 expression was upregulated in both human tissues and the pilocarpine rat model, and that SB-399885 could suppress epileptic seizures and mTOR activity in epileptic seizures. These results suggest that HTR6 plays an important role in modulating seizure activity and that the blockade of the HTR6/mTOR pathway could be a potential therapeutic target for epilepsy treatment.
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Cerebellar, brainstem and spinal cord metastases from esophageal cancer following radiotherapy: A case report and literature review.
Oncol Lett
PUBLISHED: 04-16-2014
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Cerebellar, brainstem and spinal cord metastases from esophageal cancer following radiotherapy are extremely rare. The current study presents the case of a 74-year-old male who was admitted to the Zhejiang Cancer Hospital (Hangzhou, China) with a poorly-differentiated neuroendocrine carcinoma of the esophagus. Following radiotherapy, multiple abnormal signals in the brainstem and spinal cord were found on magnetic resonance imaging (MRI). Following palliative radiochemotherapy, the clinical symptoms and abnormal MRI signals in the brainstem and spinal cord were found to improve. This case revealed that brain metastasis from esophageal carcinoma may occur simultaneously with brainstem and spinal cord metastases.
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Loss of p27 upregulates MnSOD in a STAT3-dependent manner, disrupts intracellular redox activity and enhances cell migration.
J. Cell. Sci.
PUBLISHED: 04-11-2014
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Cell migration is a dynamic process that is central to a variety of physiological functions as well as disease pathogenesis. The modulation of cell migration by p27 (officially known as CDKN1B) has been reported, but the exact mechanism(s) whereby p27 interacts with downstream effectors that control cell migration have not been elucidated. By systematically comparing p27(+/+) mouse embryonic fibroblasts (MEFs) with genetically ablated p27(-/-) MEFs using wound-healing, transwell and time-lapse microscopic analyses, we provide direct evidence that p27 inhibits both directional and random cell migration. Identical results were obtained with normal and cancer epithelial cells using complementary knockdown and overexpression approaches. Additional studies revealed that overexpression of manganese superoxide dismutase (MnSOD, officially known as SOD2) and reduced intracellular oxidation played a key role in increased cell migration in p27-deficient cells. Furthermore, we identified signal transducer and activator of transcription 3 (STAT3) as the transcription factor responsible for p27-regulated MnSOD expression, which was further mediated by ERK- and ATF1-dependent transactivation of the cAMP response element (CRE) within the Stat3 promoter. Collectively, our data strongly indicate that p27 plays a crucial negative role in cell migration by inhibiting MnSOD expression in a STAT3-dependent manner.
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Association of Ureaplasma urealyticum colonization with development of bronchopulmonary dysplasia: a systemic review and meta-analysis.
J. Huazhong Univ. Sci. Technol. Med. Sci.
PUBLISHED: 04-08-2014
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There is controversy regarding the roles of Ureaplasma urealyticum (U. urealyticum) colonization in the development of bronchopulmonary dysplasia (BPD). This study explored the association between U. urealyticum and bronchopulmonary dysplasia at 36 weeks post-menstrual age (BPD36). Studies published before December 31, 2013 were searched from Medline, Embase, Ovid, Web of Science, and Cochrane databases, with the terms "Ureaplasma urealyticum", "chronic lung disease", or "BPD36" used, and English language as a limit. The association between U. urealyticum colonization and BPD36 was analyzed with RevMan 4.2.10 software, using the odds ratio (OR) and relative risk (RR) for dichotomous variables. Out of the enrolled 81 studies, 11 investigated the BPD36 in total 1193 infants. Pooled studies showed no association between U. urealyticum colonization and subsequent development of BPD36, with the OR and RR being 1.03 (95% CI=0.78-1.37; P=0.84) and 1.01 (95% CI= 0.88-1.16, P=0.84), respectively. These findings indicated no association between U. urealyticum colonization and the development of BPD36.
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(4S,5R)-4-Benz-yloxy-5-[4-(cyclo-hexa-ne-carbon-yl)phen-yl]-1-(4-meth-oxy-benz-yl)pyrrolidin-2-one.
Acta Crystallogr Sect E Struct Rep Online
PUBLISHED: 04-01-2014
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The title compound, C32H35NO4, is an unexpected product obtained in the SmI2-mediated radical cross-coupling of a lactam 2-pyridyl sulfone with an arone. The asymmetric unit contains two mol-ecules. In both mol-ecules, the core pyrrolidinone ring adopts an approximate envelope conformation (with the C atom bearling the benzyloxy substituent as the flap) and the cyclo-hexyl ring has a chair conformation. The relative orientation of the two substitutent groups at the 4- and 5-positions of the pyrrolidinone ring is anti in both mol-ecules, with O(benz-yloxy)-C-C-C(benzene) torsion angles of 150.8?(3) and 154.2?(2)°. In the crystal, C-H?O inter-actions involving carbonyl groups as acceptors lead to the formation of a tape motif propagating parallel to the a-axis direction.
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All-trans retinoic acid enhances the effect of 5-aza-2'-deoxycytidine on p16INK4a demethylation, and the two drugs synergistically activate retinoic acid receptor ? gene expression in the human erythroleukemia K562 cell line.
Oncol Lett
PUBLISHED: 03-20-2014
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The aim of the current study was to investigate the antineoplastic activities of 5-aza-2'-deoxycytidine (also known as decitabine; DAC) and all-trans retinoic acid (ATRA), administered alone or in combination, in K562 cells in vitro, as well as the effects on the expression of the tumor suppressor genes, p16INK4a (p16) and retinoic acid receptor ? (RAR-?). Cell growth inhibition, differentiation and apoptosis in K562 cells treated with DAC and/or ATRA were detected. The methylation of the p16 and RAR-? genes in the K562 cells was detected using the methylation-specific polymerase chain reaction (PCR) method. Quantitative PCR was used for the detection of the mRNA expression of the p16 and RAR-? genes, and western blot analysis was used to detect protein expression. DAC and ATRA, alone or in combination, had no effect on the growth inhibition, differentiation and apoptosis of the K562 cells. DAC alone induced the demethylation of the p16 gene, and combination of DAC and ATRA demonstrated more evident demethylation of the p16 gene, however, ATRA alone had no effect on methylation. The RAR-? promoter region was not methylated in the K562 cells. DAC in combination with ATRA appeared to produce a greater activation of the RAR-? gene, which led to the upregulation of the RAR-? expression level. ATRA enhanced the effect of DAC on p16 demethylation, and the combination of the two drugs was found to activate RAR-? expression, which indicated that DAC used in combination with ATRA has clinical potential in the treatment of human erythroleukemia.
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Microbiota dynamics related to environmental conditions during the fermentative production of Fen-Daqu, a Chinese industrial fermentation starter.
Int. J. Food Microbiol.
PUBLISHED: 03-06-2014
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Chinese Daqu is used as a starter for liquor and vinegar fermentations. It is produced by solid state fermentation of cereal-pulse mixtures. A succession of fungi, lactic acid bacteria and Bacillus spp. was observed during the production of Daqu. Mesophilic bacteria followed by fungi, dominated the first phase of fermentation. Next, lactic acid bacteria increased in relative abundance, resulting in an increase of the acidity of Daqu. At the final stages of fermentation, Bacillus spp. and thermophilic fungi became the dominant groups, possibly due to their tolerance to low water activity and high temperature. Both culture-dependent and culture-independent analyses confirmed that Bacillus spp. were ubiquitous throughout the process. Yeast species such as Wickerhamomyces anomalus, Saccharomycopsis fibuligera and Pichia kudriavzevii were present throughout almost the entire fermentation process, but the zygomycetous fungus Lichtheimia corymbifera proliferated only during the final stages of fermentation. Canonical correspondence analysis (CCA) revealed the significance of acidity, moisture content and temperature in correlation with the composition of the microbial communities at different stages.
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A Monte Carlo simulation based two-stage adaptive resonance theory mapping approach for offshore oil spill vulnerability index classification.
Mar. Pollut. Bull.
PUBLISHED: 02-27-2014
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In this paper, a Monte Carlo simulation based two-stage adaptive resonance theory mapping (MC-TSAM) model was developed to classify a given site into distinguished zones representing different levels of offshore Oil Spill Vulnerability Index (OSVI). It consisted of an adaptive resonance theory (ART) module, an ART Mapping module, and a centroid determination module. Monte Carlo simulation was integrated with the TSAM approach to address uncertainties that widely exist in site conditions. The applicability of the proposed model was validated by classifying a large coastal area, which was surrounded by potential oil spill sources, based on 12 features. Statistical analysis of the results indicated that the classification process was affected by multiple features instead of one single feature. The classification results also provided the least or desired number of zones which can sufficiently represent the levels of offshore OSVI in an area under uncertainty and complexity, saving time and budget in spill monitoring and response.
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Rice LTG1 is involved in adaptive growth and fitness under low ambient temperature.
Plant J.
PUBLISHED: 02-05-2014
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Low temperature (LT) is one of the most prevalent factors limiting the productivity and geographical distribution of rice (Oryza sativa L.). Although significant progress has been made in elucidating the effect of LT on seed germination and reproductive development in rice, the genetic component affecting vegetative growth under LT remains poorly understood. Here, we report that rice cultivars harboring the dominant LTG1 (Low Temperature Growth 1) allele are more tolerant to LT (15-25°C, a temperature range prevalent in high-altitude, temperate zones and high-latitude areas), than those with the ltg1 allele. Using a map-based cloning strategy, we show that LTG1 encodes a casein kinase I. A functional nucleotide polymorphism was identified in the coding region of LTG1, causing a single amino acid substitution (I357K) that is associated with the growth rate, heading date and yield of rice plants grown at LT. We present evidence that LTG1 affects rice growth at LT via an auxin-dependent process(es). Furthermore, phylogenetic analysis of this locus suggests that the ltg1 haplotype arose before the domestication of rice in tropical climates. Together, our data demonstrate that LTG1 plays an important role in the adaptive growth and fitness of rice cultivars under conditions of low ambient temperature.
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Glutamine downregulates TLR-2 and TLR-4 expression and protects intestinal tract in preterm neonatal rats with necrotizing enterocolitis.
J. Pediatr. Surg.
PUBLISHED: 01-31-2014
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Toll-like receptor (TLR)-4 and TLR-2 play an essential role in the pathogenesis of necrotizing enterocolitis (NEC). In this study, we investigated the protective effect of glutamine (Gln) in an NEC neonatal rat model, and the potential association with TLR-4 and TLR-2 expression in local intestinal tissues.
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Limonoids from the fruits of Khaya ivorensis.
Molecules
PUBLISHED: 01-22-2014
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Two new limonoids, namely 14,15-didehydroruageanin A (1) and 3-O-methyl- butyrylseneganolide A (2), were isolated from the fruits of Khaya ivorensis along with six known limonoids: seneganolide A (3), 1,3-dideacetylkhivorin (4), 7-deacetylkhivorin (5), 3-deacetylkhivorin (6), 1-deacetylkhivorin (7), and 3-deacetyl-7-oxokhivorin (8). All the compounds were evaluated for their cytotoxicity against five tumor cell lines.
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Insights into drug discovery from natural medicines using reverse pharmacokinetics.
Trends Pharmacol. Sci.
PUBLISHED: 01-21-2014
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Natural medicines (NMs) are indispensable sources for the development of modern drugs. However, the targets for most natural compounds are unknown and the current pharmacokinetic evaluation systems developed for target-defined drugs may not be directly applicable to NM-based drug discovery, which is a major hindrance in bringing natural compounds to the clinic. Here, we propose the concept of 'reverse pharmacokinetics' and discuss how a 'reverse pharmacokinetics' perspective could help clarify key questions in modern drug discovery from NMs with validated clinical benefits, thereby strengthening the translational potential. Reverse pharmacokinetics can provide physiologically relevant clues to the target identification and mechanistic study of NMs, which may also innovate drug discovery for complex diseases. We anticipate that an evolving deep understanding of the novel mode of action of natural compounds with a reverse pharmacokinetic insight may improve discovery of both single ingredient and multiple-component modern drugs from NMs.
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Incidence of deep venous thrombosis in Chinese patients undergoing arthroscopic knee surgery for cruciate ligament reconstruction.
Knee Surg Sports Traumatol Arthrosc
PUBLISHED: 01-17-2014
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This study investigated the incidence of deep venous thrombosis (DVT) in patients undergoing arthroscopic cruciate ligament surgery.
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New bone formation enhanced by ADSCs overexpressing hRunx2 during mandibular distraction osteogenesis in osteoporotic rabbits.
J. Orthop. Res.
PUBLISHED: 01-14-2014
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Promoting new bone formation during distraction osteogenesis (DO) in elderly patients with osteoporosis is still a challenge. In this study, we investigated the effect of gene therapy using local Runt-related gene 2 on new bone formation during osteoporotic mandibular DO in rabbits. First, we successfully established a mandibular osteoporotic animal model by ovariectomizing rabbits. Second, the right mandibles of the osteoporotic rabbits were distracted after corticotomy. The distraction gap of the rabbits in Group A2 and B2 were injected with Adv-hRunx2-GFP-transfected adipose-derived stromal cells (ADSCs) and Adv-GFP-transfected ADSCs, respectively. Rabbits in Groups C2 (ovariectomized control) and D2 (sham surgery control) were injected with physiologic saline. New-generation bone tissue in the distraction gap was analyzed via plain radiographic examinations, micro-computed tomography, histological examinations, and biomechanical testing at weeks 3, 6, and 9 of the consolidation period. Results of above examinations showed that no ideal new bone formation was observed in Groups B2 and C2, but obvious ideal new bone formation was observed in Group A2 and D2. The results suggested that gene therapy using rhRunx2-modified ADSCs promoted new bone formation during osteoporotic mandibular DO and effectively compensated for the detrimental effects of systemic osteoporosis on new bone formation.
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Epithelial-to-mesenchymal transition in human esophageal cancer associates with tumor progression and patient's survival.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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The epithelial-mesenchymal transition (EMT) is an essential step in invasion and metastasis of human cancers. Identification of EMT status would help us to properly understand the mechanism of cancer metastasis and progression. In the present study, tissue microarray and immunohistochemical staining of two important markers, E-cadherin and Vimentin, were used to characterize the EMT status in human esophageal cancer. We selected the appropriate cut-off values of expression levels of E-cadherin and Vimentin, and found 63 out of 105 cases of esophageal cancers underwent EMT. And we also found that in the subgroup with (T3 + T4), the ratio of patients undergoing EMT was significantly higher than that in the subgroup with (T1 + T2) (P = 0.0097), and in the subgroup with metastasis, the ratio of patients undergoing EMT was significantly higher than that in the subgroup with no metastasis (P = 0.0253). The log-rank survival analysis showed that the overall survival rate of the patients undergoing EMT was significantly poorer than that of the patients with wide type status (P = 0.0278, HR = 2.470, 95% CI: 1.971~2.970). In the COX model analysis, we also found that the EMT status of the esophageal cancer patients could be used as an independent risk factor for the prediction of prognosis of this malignancy (P = 0.026, HR = 2.306, 95% CI: 1.103~4.824). Thus, our present study successfully established a method by using tissue microarray and the markers, E-cadherin and Vimentin, to conveniently and properly identify the EMT status in human esophageal cancer, and revealed that the EMT status significantly associated with invasion, metastasis and prognosis in this malignancy.
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Myeloid mineralocorticoid receptor deficiency inhibits aortic constriction-induced cardiac hypertrophy in mice.
PLoS ONE
PUBLISHED: 01-01-2014
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Mineralocorticoid receptor (MR) blockade has been shown to suppress cardiac hypertrophy and remodeling in animal models of pressure overload (POL). This study aims to determine whether MR deficiency in myeloid cells modulates aortic constriction-induced cardiovascular injuries. Myeloid MR knockout (MMRKO) mice and littermate control mice were subjected to abdominal aortic constriction (AAC) or sham operation. We found that AAC-induced cardiac hypertrophy and fibrosis were significantly attenuated in MMRKO mice. Expression of genes important in generating reactive oxygen species was decreased in MMRKO mice, while that of manganese superoxide dismutase increased. Furthermore, expression of genes important in cardiac metabolism was increased in MMRKO hearts. Macrophage infiltration in the heart was inhibited and expression of inflammatory genes was decreased in MMRKO mice. In addition, aortic fibrosis and inflammation were attenuated in MMRKO mice. Taken together, our data indicated that MR deficiency in myeloid cells effectively attenuated aortic constriction-induced cardiac hypertrophy and fibrosis, as well as aortic fibrosis and inflammation.
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Aberrant phenotypes in Kikuchi's disease.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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Initial reports emphasized the immunophenotypic similarities between benign and malignant T cell populations, while some previous studies indicating that aberrant T-cell antigen loss is a good marker for detecting malignant T-cell proliferation. Recently, we found a very interesting and thought-provoking phenomenon: In benign disease-28 of 38 (73.7%) cases of Kikuchi's disease also showed aberrant phenotypes with loss of pan-T cell antigens, which makes the differential diagnosis between Kikuchi's disease and T cell lymphoma more challenging. In our study, 38 cases of Kikuchi's disease and 30 cases of reactive lymphoid hyperplasia (RLH) were studied by EliVision immunohistochemical staining. As well as TCR gene rearrangement using PCR was negative in 10 tested cases of the Kikuchi's disease. Among these cases, the most common antigen deficiency was CD5 (22 cases), then CD7 (11 cases), CD2 (8 cases) and CD3 (2 cases). Compared with proliferative and xanthomatous types of Kikuchi's disease, antigens tended to be lost in necrotizing type. Based on follow-up data, a correlation was not found between the occurrence of aberrant phenotypes and prognosis. In RLH, obvious pan-T cell antigen loss was also not found. In conclusion, this is the first study to demonstrate distinct patterns of antigen loss in Kikuchi's disease, suggesting that T cell antigen loss is not reliable as an auxiliary diagnostic standard for T cell lymphoma.
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Lemur tyrosine kinase-3 is a significant prognostic marker for patients with colorectal cancer.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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Lemur tyrosine kinase-3 (LMTK3) belongs to the family of serine-threonine-tyrosine kinases and the aberrant expression of LMTK3 was observed in several human malignancies. However, the association of LMTK3 with clinical outcomes in colorectal cancer patients is unclear. Thus, this present study was to evaluate the association of LMTK3 expression level with clinicopathologic factors and prognosis of patients with colorectal cancer (CRC). The expression level of LMTK3 in 69 archival paraffin-embedded colorectal tumor tissue specimens was examined by immunohistochemistry (IHC). As a result, we found that the LMTK3 expression level was significantly elevated in CRC tissues as compared with Crohn's disease or colorectal polyp tissues (P<0.0001, P<0.0001, respectively). Positive LMTK3 signals in the colorectal cancer cells were observed in about 89.9% (62 of 69) CRC tissue specimens. Additionally, LMTK3 expression was significantly correlated with lymph node metastasis and tumor-node-metastasis (TNM) classification (P=0.003, and P=0.008, respectively), but not with sex, age, tumor location, histological differentiation, tumor size, or depth of tumor invasion (all P>0.05). Kaplan-Meier survival curves showed that the overall survival rate was significantly higher in the patients with low expression of LMTK3 when compared with those patients with high LMTK3 (P=0.010). Moreover, multivariate analysis revealed that LMTK3 expression was an independent prognostic factor for CRC patients (P=0.047). These results suggest that LMTK3 protein could serve as a prognostic marker for CRC patients.
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Comparative genomic hybridization identifies virulence differences in Streptococcus suis.
PLoS ONE
PUBLISHED: 01-01-2014
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Streptococcus suis is an important zoonotic pathogen. However, identification of virulent S. suis strains is complicated because of the high diversity of the species. Here we evaluated the genetic difference among S. suis strains using comparative genomic hybridization (CGH) and virulence variation in vivo and in vitro. We showed that different clades differed in their ability to activate TLR2/6 in vitro and their capacity to induce cytokine production in vivo as well as their resistance to phagocytosis and survival in vivo. Our data showed the S. suis strains tested can be classified into three groups having differing levels of virulence: epidemic and highly virulent strains were clustered into clade Ia (epidemic and highly virulent group, E/HV group), virulent strains were clustered into clade Ib (virulent group, V group), and intermediately or weakly virulent strains were clustered into other clades (intermediately or weakly virulent group, I/WV group). Our study provided further insight into the genomic and virulence variation of S. suis.
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[Estimation of shelter forest area in Three-North Shelter Forest Program region based on multi-sensor remote sensing data].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 12-31-2013
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The Three-North Shelter Forest Program is a key forestry ecological project in China. The quantity and spatial distribution of the shelter forest in the program affect the ecological environment of the entire Three-North region. In this paper, multi-sensor remote sensing data were used to scientifically, objectively and comprehensively estimate the quantity and spatial distribution pattern of the shelter forest in this region in 1978-2008. Firstly, the Landsat TM images (30 m in resolution) were adopted to extract the shelter forest data in this region in 2008. Then, based on random sampling techniques, the calibration formulae for the shelter forest area in different precipitation climate regions estimated by the SPOT5 (2.5 m in resolution) and Landsat TM were constructed. By using the above-mentioned results, the shelter forest area in the Three-North region in 2008 was estimated. In 2008, the total area of the shelter forest (canopy density of arbor shelter forest was >0.3, coverage of shrub shelter forest was > 40%, and accuracy was about 85%) in this region was 328360.03 km2, with 116244.55 km2 in Northeast China, 42981.32 km2 in North China, 76767.05 km2 in Loess Plateau, and 92367.11 km2 in Mongolia-Xinjiang Region. According to the classification of shelter forest types, the areas of coniferous forest, broadleaved forest, mixed broadleaf-conifer forest and shrubland were 62614.74, 121628.51, 22144.09 and 121972.69 km2, respectively.
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Time-dependent density functional theory quantum transport simulation in non-orthogonal basis.
J Chem Phys
PUBLISHED: 12-17-2013
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Basing on the earlier works on the hierarchical equations of motion for quantum transport, we present in this paper a first principles scheme for time-dependent quantum transport by combining time-dependent density functional theory (TDDFT) and Keldyshs non-equilibrium Greens function formalism. This scheme is beyond the wide band limit approximation and is directly applicable to the case of non-orthogonal basis without the need of basis transformation. The overlap between the basis in the lead and the device region is treated properly by including it in the self-energy and it can be shown that this approach is equivalent to a lead-device orthogonalization. This scheme has been implemented at both TDDFT and density functional tight-binding level. Simulation results are presented to demonstrate our method and comparison with wide band limit approximation is made. Finally, the sparsity of the matrices and computational complexity of this method are analyzed.
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[Low carbon number fatty acid content prediction based on near-infrared spectroscopy].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 10-29-2013
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The rapid prediction of the low-carbon fatty acids (C < or = 14) content in grease samples was achieved by a mathematical model established by near infrared spectroscopy combined with support vector machine regression (SVR). In the present project, near-infrared spectrometer SupNIR-5700 was used to collect near-infrared spectra of 58 samples; partial least square (PLS) was applied to remove the strange samples, and principal component analysis (PCA) was conducted on the measurements; radial basis function (RBF) kernel function was selected to establish a regression model supporting vector machine, and then detailed analysis and discussions were conducted concerning their spectral preprocessing and parameters optimization methods. Experimental results showed that by applying particle swarm optimization (PSO) the model demonstrated improved performance, stronger generalization ability, better prediction accuracy and robustness. In the second pretreatment method after PSO, when the optimization parameters are: C = 2.085, gamma = 22.20, the prediction set and calibration set correlation coefficient (gamma) reached 0.998 0 and 0.925 8, respectively; and root mean square errors (MSE) were 0.000 4 and 0.014 3, respectively. Research results proved that the method based on near infrared spectroscopy and PSO-SVR for accurate and fast prediction of the low-carbon fatty acid content in vegetable oil is feasible.
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Serum lemur tyrosine kinase 3 expression in colorectal cancer patients predicts cancer progression and prognosis.
Med. Oncol.
PUBLISHED: 09-26-2013
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Lemur tyrosine kinase-3 (LMTK3) is a member of the families of serine-threonine-tyrosine kinases, which has been suggested to be a possible target and marker of breast cancer. However, its definitive physiopathological function in colorectal cancer (CRC) is poorly understood at present. The aim of this study was to determine the expression levels of preoperative-soluble LMTK3 (sLMTK3) in patients blood with CRC and to subsequently evaluate whether or not its level in serum can be used to predict cancer progression and prognosis. The expression levels of sLMTK3 were measured by sandwich enzyme-linked immunosorbent assay in blood specimens from 60 patients with CRC and 53 healthy volunteers. As a result, we found that the mean concentration of sKMTK3 in CRC patients was significantly higher than that in healthy volunteers (P = 0.012). The expression levels of sLMTK3 were significantly correlated with histological subtype, depth of tumor invasion, and tumor-node-metastasis (TNM) classification (P = 0.038, 0.021, and 0.049, respectively), but not with sex, age, tumor location, tumor size, or lymph node metastasis. Additionally, Kaplan-Meier survival curves showed that patients with high levels of sLMTK3 had a poorer overall survival rate when compared with those of patients with low levels of sLMTK3 (P = 0.041). Moreover, multivariate analysis demonstrated that sLMTK3 expression and TNM stage were independent prognostic factors for CRC patients (P = 0.047 and 0.008, respectively). These results suggest that serum LMTK3 could be a valuable biomarker for predicting the progression and prognosis of patients with CRC.
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[Study on saponins in shengmai injection].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 09-10-2013
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To investigate the saponin in Shengmai injection.
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Bornyl caffeate induces apoptosis in human breast cancer MCF-7 cells via the ROS- and JNK-mediated pathways.
Acta Pharmacol. Sin.
PUBLISHED: 08-13-2013
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Aim:To investigate the effects of bornyl caffeate discovered in several species of plant on human breast cancer cells in vitro and the underlying mechanisms.Methods:Human breast cancer cell line MCF-7 and other tumor cell lines (T47D, HepG2, HeLa, and PC12) were tested. Cell viability was determined using MTT assay, and apoptosis was defined by monitoring the morphology of the nuclei and staining with Annexin V-FITC. Mitochondrial membrane potential (MMP) was measured using JC-1 under fluorescence microscopy. Intracellular reactive oxygen species (ROS) were assessed by flow cytometry. The expression of apoptosis-associated proteins was determined by Western blotting analysis.Results:Bornyl caffeate (10, 25, and 50 ?mol/L) suppressed the viability of MCF-7 cells in dose- and time-dependent manners, but neither caffeic acid nor borneol showed cytotoxicity at a concentration of 50 ?mol/L. Bornyl caffeate also exerted cytotoxicity to HepG2, Hela, T47D, and PC12 cells. Bornyl caffeate dose-dependently induced apoptosis of MCF-7 cells, increased the expression of Bax and decreased the expression of Bcl-xl, resulting in the disruption of MMP and subsequent activation of caspase-3. Moreover, bornyl caffeate triggered the formation of ROS and activated p38 and c-Jun JNK. In MCF-7 cells, the cytotoxicity of bornyl caffeate was significantly attenuated by SB203580 (p38 inhibitor), SP600125 (JNK inhibitor), z-VAD (pan-caspase inhibitor) or the thiol antioxidant L-NAC.Conclusion:Bornyl caffeate exerts non-selective cytotoxicity against cancer cells of different origin in vitro. The compound induces apoptosis in human breast cancer MCF-7 cells via the ROS- and JNK-mediated pathways.
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Global detection and identification of components from Yunnan Baiyao based on liquid chromatography hybrid ion trap time-of-flight mass spectrometry.
J Sep Sci
PUBLISHED: 08-13-2013
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Yunnan Baiyao is a widely used herbal prescription in traditional medicine for the treatment of bleeding and hematological diseases, while its chemical profile remains elusive. In this work, a novel methodology combining polarity-directed extraction technique with a diagnostic ion filtering strategy based on LC hybrid ion trap TOF-MS analysis was developed for global, efficient, and rapid characterization of components in Yunnan Baiyao. Di-ethyl ether, n-butanol, and ethanol/water (70:30, v/v) covering low-to-high polarity ranges were chosen as the extraction solvent, respectively. The results clearly showed that, compared with conventional single extraction solvent, collaboratively using extraction solvents with different polarities can effectively increase the number of detected peaks and enrich the product ions information in multistage mass spectra analysis. By further matching diagnostic ions and fragmental pathways, a total of 34 components were successfully identified. Our work clearly demonstrates that integrating polarity-directed extraction and diagnostic ion filtering techniques is a powerful and reliable strategy for global detection and identification of complex chemicalome from herbal prescriptions, and may open new avenues for chemical analysis in other complex mixtures.
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[Forest resources in Qungyuan County of Liaoning, Northeast China: the structure and optimal spatial allocation].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 08-01-2013
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By using RS/GIS techniques and the method of multiple objective grey situation decision, and in considering the forest economic benefits (biomass and stand productivity) and ecological benefits (water and soil conservation) , an optimal spatial allocation of the present forest types in Qingyuan County of Liaoning, Northeast China was approached in this study. After the optimization of spatial allocation, the structural proportions of different forest types in Qingyuan County changed obviously, with the area of coniferous forests reduced from 43% to 23% , the area of broadleaved forests reduced from 51% to 31% , the area of mixed coniferous-broadleaf forests increased from 3% to 43% , and the area of shrubs remained unchanged. As compared with the results before optimization, the biomass, stand productivity, and water conservation function of the forest ecosystem in Qingyuan County after optimization increased by 0.6%, 2.1% , and 31.7%, respectively, and the soil conservation function remained unchanged. It could be concluded that after the optimization of spatial allocation, the forest ecosystem of Qingyuan County could maintain its soil conservation function, and, at the time of keeping higher timber production, fully exert waler conservation function, realizing the maximization of the economic and ecological benefits of the forest ecosystem.
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Study on the plasma protein binding rate of Schisandra lignans based on the LC-IT-TOF/MS technique with relative quantitative analysis.
Chin J Nat Med
PUBLISHED: 07-13-2013
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The main objective of the current study was to develop a universal method for a protein binding assay of complicated herbal components, and to investigate the possible relationship between compound polarity and protein binding using Schisadra lignans as an example. Firstly, the rat, dog and human plasma were spiked with three different concentrations of Schisandra chinensis extract (SLE), and ultramicrofiltration was used to obtain the unbound ingredients. Secondly, thirty-one Schisandra lignans in total plasma and ultrafiltered fluid were measured by LC-IT-TOFMS. Lastly, a relative exposure approach, which entailed calculating the relative concentrations of each Schisandra lignan from the corresponding calibration equation created from the calibration samples spiked with the stock solution of SLE, was applied in order to overcome the absence of authentic standards. The results showed that Schisandra lignans exhibited a high capability to bind with plasma protein, furthermore, the protein binding ratio of the lignan components increased proportionally with their individual chromatographic retention time, which indicated that the ratio of protein binding of lignans might increase accordingly with decreasing polarity. This study suggested that the compound polarity might be an important factor affecting the plasma protein binding of herbal components.
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Novel diagnosis and treatment of esophageal granular cell tumor: report of 14 cases and review of the literature.
Ann. Thorac. Surg.
PUBLISHED: 06-18-2013
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Granular cell tumors (GCT), especially in the esophagus, are rare neoplasms originating from the nervous system. There is still some controversy regarding the diagnosis and treatment of esophageal GCT.
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HOTAIR, a prognostic factor in esophageal squamous cell carcinoma, inhibits WIF-1 expression and activates Wnt pathway.
Cancer Sci.
PUBLISHED: 06-07-2013
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Long non-coding RNAs (LncRNAs) have been recently found to be pervasively transcribed in the genome and critical regulators of the epigenome. HOTAIR, as a well-known LncRNA, has been found to play important roles in several tumors. Herein, the clinical application value and biological functions of HOTAIR were focused and explored in esophageal squamous cell carcinoma (ESCC). It was found that there was a great upregulation of HOTAIR in ESCC compared to their adjacent normal esophageal tissues. Meanwhile, patients with high HOTAIR expression have a significantly poorer prognosis than those with low expression. Moreover, HOTAIR was further validated to promote migration and invasion of ESCC cells in vitro. Then some specific molecules with great significance were investigated after HOTAIR overexpression using microarray and quantitative real time-polymerase chain reaction (qPCR). WIF-1 playing an important role in Wnt/?-catenin signaling pathway was selected and further tested by immunehistochemistry. Generally, inverse correlation between HOTAIR and WIF-1 expression was demonstrated both in ESCC cells and tissues. Mechanistically, HOTAIR directly decreased WIF-1 expression by promoting its histone H3K27 methylation in the promoter region and then activated the Wnt/?-catenin signaling pathway. This newly identified HOTAIR/WIF-1 axis clarified the molecular mechanism of ESCC cell metastasis and represented a novel therapeutic target in patients with ESCC.
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Impacts of You Gui Wan on the expression of estrogen receptors and angiogenic factors in OVX?rat vagina: a possible mechanism for the trophic effect of the formula on OVX?induced vaginal atrophy.
Mol Med Rep
PUBLISHED: 05-23-2013
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The administration of You Gui Wan (YGW) decoction has been observed to improve vaginal atrophy induced by ovariectomy (OVX) in rats. The aim of the current study was to explore the possible mechanisms underlying this effect. Following OVX, 37 Sprague Dawley female rats were randomly divided into three groups which were orally administered with YGW decoction, saline or estrogen for 11 weeks. In parallel with this, 19 normal and 17 rats with sham-surgery were used as controls. The effects of these treatments on estrogen receptors (ER) and various angiogenic factors, including vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor-1 (VEGFR-1), angiopoietin (Ang)1 and 2 and basic fibroblast growth factor (bFGF) in the vagina were compared using immunohistochemistry or quantitative polymerase chain reaction (qPCR). OVX was found to induce significant vaginal atrophy and decrease the expression of ER and various angiogenic factors when compared with the normal and sham-surgery animals (all P<0.05). Estrogen replacement and the administration of YGW decoction reversed the vaginal atrophic process. The hormonal replacement and YGW treatment recovered the protein expression of ER-? and -?, VEGF and VEGFR-1 and the mRNA levels of ER-?, VEGF, VEGFR-1, Ang1 and 2, and bFGF when compared with OVX-rats with saline, normal and sham-surgery treatments (all P<0.05). Thus, it may be concluded that a possible mechanism underlying the effect of YGW on OVX-induced vaginal atrophy may be the upregulated expression of ER and various angiogenic factors in the vaginal tissue.
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Synthesis of the bismuth oxyhalide solid solutions with tunable band gap and photocatalytic activities.
Dalton Trans
PUBLISHED: 05-17-2013
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Three series of BiOM(x)R(1-x) (M, R = Cl, Br, I) solid solutions were systematically synthesized through a low-temperature precipitation. These solid solutions were characterized by XRD, FESEM, TEM, EDS, UV-vis spectra, nitrogen sorption/desorption, and PL. The tunable band gaps of the as-prepared solid solutions were realized via only changing the molar ratio of two halide ions. Meanwhile, the influence of citric acid in the formations of controllable morphological structures was discussed to study the growth mechanism of solid solutions. The photocatalytic activities of the bismuth oxyhalide solid solutions have also been investigated by the degradation of Rhodamine-B (RhB) under visible light irradiation. The optimized solid solutions possess higher photocatalytic activity than pure ones [BiOM (M = Cl, Br, I)] due to the broadened range of visible light response and the reduced recombination rate of electron-holes pairs. The results show that the synthesis of BiOM(x)R(1-x) (M, R = Cl, Br, I) solid solutions have profound significance for the design of the novel photocatalyst materials.
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[Pharmacokinetic effect of sappan lignum on hydroxysafflor yellow A in carthami flos].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 05-16-2013
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To investigate the pharmacokinetic effect of Sappan Lignum on hydroxysafflor yellow A (HSYA) in Carthami Flos.
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A nonempirical scaling correction approach for density functional methods involving substantial amount of Hartree-Fock exchange.
J Chem Phys
PUBLISHED: 05-10-2013
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A nonempirical scaling correction (SC) approach has been developed for improving bandgap prediction in density functional theory [X. Zheng, A. J. Cohen, P. Mori-Sánchez, X. Hu, and W. Yang, Phys. Rev. Lett. 107, 026403 (2011)]. For finite systems such as atoms and molecules, the SC approach restores the Perdew-Parr-Levy-Balduz condition [Phys. Rev. Lett. 49, 1691 (1982)] that the total electronic energy should scale linearly with number of electrons between integers. Although the original SC approach is applicable to a variety of mainstream density functional approximations, it gives zero correction to the Hartree-Fock method. This is because the relaxation of orbitals with the change in electron number is completely neglected. In this work, with an iterative scheme for the evaluation of Fukui function, the orbital relaxation effects are accounted for explicitly via a perturbative treatment. In doing so, the SC approach is extended to density functionals involving substantial amount of Hartree-Fock exchange. Our new SC approach is demonstrated to improve systematically the predicted Kohn-Sham frontier orbital energies, and alleviate significantly the mismatch between fundamental and derivative gaps.
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Monitoring the ecology of Bacillus during Daqu incubation, a fermentation starter, using culture-dependent and culture-independent methods.
J. Microbiol. Biotechnol.
PUBLISHED: 05-08-2013
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Daqu, a traditional fermentation starter, has been used to produce attractively flavored foods such as vinegar and Chinese liquor for thousands of years. Although Bacillus spp. are one of the dominant microorganisms in Daqu, more precise information is needed to reveal why and how Bacillus became dominant in Daqu, and next, to assess the impact of Bacillus sp. on Daqu and its derived products. We combined culture-dependent and culture-independent methods to study the ecology of Bacillus during Daqu incubation. Throughout the incubation, 67 presumptive Bacillus spp. isolates were obtained, 52 of which were confirmed by 16S rDNA sequencing. The identified organisms belonged to 8 Bacillus species: B. licheniformis, B. subtilis, B. amyloliquefaciens, B. cereus, B. circulans, B. megaterium, B. pumilus, and B. anthracis. A primer set specific for Bacillus and related genera was used in a selective PCR study, followed by a nested DGGE PCR targeting the V9 region of the 16S rDNA. Species identified from the PCR-DGGE fingerprints were related to B. licheniformis, B. subtilis, B. amyloliquefaciens, B. pumilus, B. benzoevorans, and B. foraminis. The predominant species was found to be B. licheniformis. Certain B. licheniformis strains exhibited potent antimicrobial activities. The greatest species diversity occurred at the Liangmei stage of Daqu incubation. To date, we lack sufficient knowledge of Bacillus distribution in Daqu. Elucidating the ecology of Bacillus during Daqu incubation would enable the impact of Bacillus on Daqu to be accessed, and the quality and stabilization of Daqu-derived products to be optimized.
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Centrifugation: an important pre-analytic procedure that influences plasma microRNA quantification during blood processing.
Chin J Cancer
PUBLISHED: 04-19-2013
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Circulating microRNAs are robustly present in plasma or serum and have become a research focus as biomarkers for tumor diagnosis and prognosis. Centrifugation is a necessary procedure for obtaining high-quality blood supernatant. Herein, we investigated one-step and two-step centrifugations, two centrifugal methods routinely used in microRNA study, to explore their effects on plasma microRNA quantification. The microRNAs obtained from one-step and two-step centrifugations were quantified by microarray and TaqMan-based real-time quantitative polymerase chain reaction (Q-PCR). Dynamic light scattering was performed to explore the difference underlying the two centrifugal methods. The results from the microarray containing 1,347 microRNAs showed that the signal detection rate was greatly decreased in the plasma sample prepared by two-step centrifugation. More importantly, the microRNAs missing in this plasma sample could be recovered and detected in the precipitate generated from the second centrifugation. Consistent with the results from microarray, a marked decrease of three representative microRNAs in two-step centrifugal plasma was validated by Q-PCR. According to the size distribution of all nanoparticles in plasma, there were fewer nanoparticles with size >1,000 nm in two-step centrifugal plasma. Our experiments directly demonstrated that different centrifugation methods produced distinct quantities of plasma microRNAs. Thus, exosomes or protein complexes containing microRNAs may be involved in large nanoparticle formation and may be precipitated after two-step centrifugation. Our results remind us that sample processing methods should be first considered in conducting research.
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Kondo memory in driven strongly correlated quantum dots.
Phys. Rev. Lett.
PUBLISHED: 04-07-2013
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We investigate the real-time current response of strongly correlated quantum dot systems under sinusoidal driving voltages. By means of an accurate hierarchical equations of motion approach, we demonstrate the presence of prominent memory effects induced by the Kondo resonance on the real-time current response. These memory effects appear as distinctive hysteresis line shapes and self-crossing features in the dynamic current-voltage characteristics, with concomitant excitation of odd-number overtones. They emerge as a cooperative effect of quantum coherence-due to inductive behavior-and electron correlations-due to the Kondo resonance. We also show the suppression of memory effects and the transition to classical behavior as a function of temperature. All these phenomena can be observed in experiments and may lead to novel quantum memory applications.
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Electrochemical and density functional theory investigation on high selectivity and sensitivity of exfoliated nano-zirconium phosphate toward lead(II).
Anal. Chem.
PUBLISHED: 04-03-2013
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A new strategy on the understanding of selective and sensitive identification of Pb(II) using combined experimental and theoretical efforts is described. Amorphous phase formation of exfoliated nano-zirconium phosphate (ZrP) has been prepared via a hydrothermal process and subsequent intercalation reaction. Exfoliated ZrP was used as coating on the electrode surface, and it was found to be selective and sensitive for Pb(II) detection due to its selective adsorption ability. To better and scientifically understand the microscopic adsorption mechanism, density functional theory (DFT) calculations about the details of chemical interactions between heavy metal ions and exfoliated ZrP were carried out at an atomistic level. It is verified that the exfoliated ZrP shows the strongest adsorption capability toward Pb(II) among all heavy metal ions, thereby resulting in selective detection consequently. With our combined experimental and theoretical efforts, we are able to provide a new route to realize the improved selectivity in electrochemical sensing of toxic metal ions.
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Dysregulations of intestinal and colonic UDP-glucuronosyltransferases in rats with type 2 diabetes.
Drug Metab. Pharmacokinet.
PUBLISHED: 04-02-2013
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Diabetes mellitus is a chronic disease of complex metabolic disorder associated with various types of complications. UDP-glucuronosyltransferases (UGTs), the major phase II conjugation enzymes, mediate the metabolism of both drugs and endogenous metabolites that may raise great concerns in the condition of diabetes. The aim of this study was to determine whether diabetes could affect UGTs in the intestinal and colonic tract. A high-fat diet combined with low-dose streptozotocin was used to induce a type 2 diabetic model in rats. The mRNA levels and enzymatic activities of UGT1A1, -1A6, and -1A7 in the diabetic intestine and colon were higher than those in nondiabetic rats. In contrast, both the activity and mRNA level of UGT2B1 in diabetic rats were lower than those in nondiabetic rats. Notably, the diabetic intestine and colon exhibited an inflammatory state with increased pro-inflammatory cytokines. Various transcriptional factors involved in UGT regulation were unanimously upregulated in the diabetic intestine and colon. These findings strongly suggest that the regulating pathways of the UGT1 family are adaptively upregulated in the diabetic gastrointestinal tract. Given the essential regulatory role of the gastrointestinal site in drug disposition, such changes in UGTs may have a dynamic and complex impact on therapeutic drugs and endogenous metabolomes.
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Effect of mobile phase additives on qualitative and quantitative analysis of ginsenosides by liquid chromatography hybrid quadrupole-time of flight mass spectrometry.
J Chromatogr A
PUBLISHED: 03-29-2013
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This study was to systematically investigate the effect of mobile phase additives, including ammonia water, formic acid, acetic acid, ammonium chloride and water (as a control), on qualitative and quantitative analysis of fifteen representative ginsenosides based on liquid chromatography hybrid quadrupole-time of flight mass spectrometry (LC-Q-TOF/MS). To evaluate the influence of mobile phase additives on qualitative performance, the quality of the negative mode MS/MS spectra of ginsenosides produced by online LC-Q-TOF/MS analyses, particularly the numbers and intensities of fragment ions, were compared under different adduct ion states, and found to be strongly affected by the mobile phase additives. When 0.02% acetic acid was added in the mobile phase, the deprotonated ginsenosides ions produced the most abundant product ions, while almost no product ion was observed for the chlorinated ginsenoside ions when 0.1mM ammonium chloride was used as the mobile phase additive. On the other hand, sensitivity, linear range and precision were adopted to investigate the quantitative performance affected by different mobile phase additives. Validation results of the LC-Q-TOF/MS-based quantitative performance for ginsenosides showed that ammonium chloride not only provided the highest sensitivity for all the target analytes, but also dramatically improved the linear ranges, the intra-day and inter-day precisions comparing to the results obtained using other mobile phase additives. Importantly, the validated method, using 0.1mM ammonium chloride as the mobile phase additive, was successfully applied to the quantitative analysis of ginsenosides in rat plasma after intragastric administration of Ginsenoside Extract at 200mg/kg. In conclusion, 0.02% acetic acid was deemed to be the most suitable mobile phase additive for qualitative analysis of ginsenosides, and 0.1mM ammonium chloride in mobile phase could lead to the best quantitative performance. Our results reveal that choosing the appropriate mobile phase additive is an important step in optimizing the analytical conditions, and the best quantitative method may not be suitable for the qualitative analysis.
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Synthesis of organic nitrates of luteolin as a novel class of potent aldose reductase inhibitors.
Bioorg. Med. Chem.
PUBLISHED: 03-19-2013
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Aldose reductase (AR) plays an important role in the design of drugs that prevent and treat diabetic complications. Aldose reductase inhibitors (ARIs) have received significant attentions as potent therapeutic drugs. Based on combination principles, three series of luteolin derivatives were synthesised and evaluated for their AR inhibitory activity and nitric oxide (NO)-releasing capacity in vitro. Eighteen compounds were found to be potent ARIs with IC50 values ranging from (0.099±0.008) ?M to (2.833±0.102) ?M. O(7)-Nitrooxyethyl-O(3),O(4)-ethylidene luteolin (La1) showed the most potent AR inhibitory activity [IC50=(0.099±0.008) ?M]. All organic nitrate derivatives released low concentrations of NO in the presence of l-cysteine. Structure-activity relationship studies suggested that introduction of an NO donor, protection of the catechol structure, and the ether chain of a 2-carbon spacer as a coupling chain on the luteolin scaffold all help increase the AR inhibitory activity of the resulting compound. This class of NO-donor luteolin derivatives as efficient ARIs offer a new concept for the development and design of new drug for preventive and therapeutic drugs for diabetic complications.
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Sequence polymorphisms of rfbT among the Vibrio cholerae O1 strains in the Ogawa and Inaba serotype shifts.
BMC Microbiol.
PUBLISHED: 03-07-2013
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Vibrio cholerae serogroup O1 has two major serotypes, Ogawa and Inaba, which may alternate among cholera epidemics. The rfbT gene is responsible for the conversion between the two serotypes. In this study, we surveyed the sequence variance of rfbT in the Ogawa and Inaba strains in China over a 48-year (1961-2008) period in which serotype shifts occurred among epidemic years.
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V-shaped dinuclear Pt(II) complexes: selective interaction with human telomeric G-quadruplex and significant inhibition towards telomerase.
Sci Rep
PUBLISHED: 02-25-2013
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A quaternized trigeminal ligand, 4-[4,6-di(4-pyridyl)-1,3,5-(2-triazinyl)]-1-methylpyridine-1-ium hexafluorophosphate (dptmp·PF6), and two derivative V-shaped dinuclear Pt(II) complexes, {[Pt(dien)]?(dptmp)}(PF?)? (1) and {[Pt(dpa)]?(dptmp)}(PF?)? (2), were synthesized, characterized and applied to a series of biochemical studies. FRET and SPR analyses showed these compounds, especially Pt(II) complexes, bound more strongly to human telomeric (hTel) G-quadruplex than to promoters (such as c-myc and bcl2) or to the duplex DNA. PCR-stop assays revealed that the Pt(II) complexes could bind to and stabilize G-quadruplex far more effectively than corresponding ligand. CD analyses further indicated the three compounds likely stabilized the formation of mixed-type parallel/antiparallel G-quadruplex structures. Their efficacy as telomerase inhibitors and potential anticancer drugs was explored via TRAP. The IC?? value was determined to be 0.113 ± 0.019??M for 1, indicating that it is one of the strongest known telomerase inhibitors. These results confirm that both V-shaped dinuclear Pt(II) complexes act as selective G-quadruplex binders and significant telomerase inhibitors.
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Ehd4 encodes a novel and Oryza-genus-specific regulator of photoperiodic flowering in rice.
PLoS Genet.
PUBLISHED: 02-21-2013
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Land plants have evolved increasingly complex regulatory modes of their flowering time (or heading date in crops). Rice (Oryza sativa L.) is a short-day plant that flowers more rapidly in short-day but delays under long-day conditions. Previous studies have shown that the CO-FT module initially identified in long-day plants (Arabidopsis) is evolutionary conserved in short-day plants (Hd1-Hd3a in rice). However, in rice, there is a unique Ehd1-dependent flowering pathway that is Hd1-independent. Here, we report isolation and characterization of a positive regulator of Ehd1, Early heading date 4 (Ehd4). ehd4 mutants showed a never flowering phenotype under natural long-day conditions. Map-based cloning revealed that Ehd4 encodes a novel CCCH-type zinc finger protein, which is localized to the nucleus and is able to bind to nucleic acids in vitro and transactivate transcription in yeast, suggesting that it likely functions as a transcriptional regulator. Ehd4 expression is most active in young leaves with a diurnal expression pattern similar to that of Ehd1 under both short-day and long-day conditions. We show that Ehd4 up-regulates the expression of the "florigen" genes Hd3a and RFT1 through Ehd1, but it acts independently of other known Ehd1 regulators. Strikingly, Ehd4 is highly conserved in the Oryza genus including wild and cultivated rice, but has no homologs in other species, suggesting that Ehd4 is originated along with the diversification of the Oryza genus from the grass family during evolution. We conclude that Ehd4 is a novel Oryza-genus-specific regulator of Ehd1, and it plays an essential role in photoperiodic control of flowering time in rice.
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Association of functional nucleotide polymorphisms at DTH2 with the northward expansion of rice cultivation in Asia.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 02-06-2013
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Flowering time (i.e., heading date in crops) is an important ecological trait that determines growing seasons and regional adaptability of plants to specific natural environments. Rice (Oryza sativa L.) is a short-day plant that originated in the tropics. Increasing evidence suggests that the northward expansion of cultivated rice was accompanied by human selection of the heading date under noninductive long-day (LD) conditions. We report here the molecular cloning and characterization of DTH2 (for Days to heading on chromosome 2), a minor-effect quantitative trait locus that promotes heading under LD conditions. We show that DTH2 encodes a CONSTANS-like protein that promotes heading by inducing the florigen genes Heading date 3a and RICE FLOWERING LOCUS T 1, and it acts independently of the known floral integrators Heading date 1 and Early heading date 1. Moreover, association analysis and transgenic experiments identified two functional nucleotide polymorphisms in DTH2 that correlated with early heading and increased reproductive fitness under natural LD conditions in northern Asia. Our combined population genetics and network analyses suggest that DTH2 likely represents a target of human selection for adaptation to LD conditions during rice domestication and/or improvement, demonstrating an important role of minor-effect quantitative trait loci in crop adaptation and breeding.
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