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Find video protocols related to scientific articles indexed in Pubmed.
Revealing Structural Changes of Prion Protein during Conversion from ?-Helical Monomer to ?-Oligomers by Means of ESR and Nanochannel Encapsulation.
ACS Chem. Biol.
PUBLISHED: 11-07-2014
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Under nondenaturing neutral pH conditions, full-length mouse recombinant prion protein lacking the only disulfide bridge can spontaneously convert from an ?-helical-dominant conformer (?-state) to a ?-sheet-rich conformer (?-state), which then associates into ?-oligomers, and the kinetics of this spontaneous conversion depends on the properties of the buffer used. The molecular details of this structural conversion have not been reported due to the difficulty of exploring big protein aggregates. We introduced spin probes into different structural segments (three helices and the loop between strand 1 and helix 1), and employed a combined approach of ESR spectroscopy and protein encapsulation in nanochannels to reveal local structural changes during the ?-to-? transition. Nanochannels provide an environment in which prion protein molecules are isolated from each other, but the ?-to-? transition can still occur. By measuring dipolar interactions between spin probes during the transition, we showed that helix 1 and helix 3 retained their helicity, while helix 2 unfolded to form an extended structure. Moreover, our pulsed ESR results allowed clear discrimination between the intra- and intermolecular distances between spin labeled residues in helix 2 in the ?-oligomers, making it possible to demonstrate that the unfolded helix 2 segment lies at the association interface of the ?-oligomers to form cross-? structure.
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The coagulation characteristics of humic acid by using acid-soluble chitosan, water-soluble chitosan, and chitosan coagulant mixtures.
Environ Technol
PUBLISHED: 11-04-2014
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Abstract Chitosan is a potential substitute for traditional aluminum salts in water treatment systems. This study compared the characteristics of humic acid (HA) removal by using acid-soluble chitosan, water-soluble chitosan, and coagulant mixtures of chitosan with aluminum sulfate (alum) or polyaluminum chloride (PACl). In addition, we evaluated their respective coagulation efficiencies at various coagulant concentrations, pH values, turbidities, and hardness levels. Furthermore, we determined the size and settling velocity of flocs formed by these coagulants to identify the major factors affecting HA coagulation. The coagulation efficiency of acid- and water-soluble chitosan for 15?mg/l of HA was 74.4% and 87.5%, respectively. The optimal coagulation range of water-soluble chitosan (9-20?mg/l) was broader than that of acid-soluble chitosan (4-8?mg/l). Notably, acid-soluble chitosan/PACl and water-soluble chitosan/alum coagulant mixtures exhibited a higher coagulation efficiency for HA than for PACl or alum alone. Furthermore, these coagulant mixtures yielded an acceptable floc settling velocity and savings in both installation and operational expenses. Based on these results, we confidently assert that coagulant mixtures with a 1:1 mass ratio of acid-soluble chitosan/PACl and water-soluble chitosan/alum provide a substantially more cost-effective alternative to using chitosan alone for removing HA from water. Supplementary material.
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Highly Efficient Visible Light Photocatalytic Reduction of CO2 to Hydrocarbon Fuels by Cu-Nanoparticle Decorated Graphene Oxide.
Nano Lett.
PUBLISHED: 11-03-2014
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The production of renewable solar fuel through CO2 photoreduction, namely artificial photosynthesis, has gained tremendous attention in recent times due to the limited availability of fossil-fuel resources and global climate change caused by rising anthropogenic CO2 in the atmosphere. In this study, graphene oxide (GO) decorated with copper nanoparticles (Cu-NPs), hereafter referred to as Cu/GO, has been used to enhance photocatalytic CO2 reduction under visible-light. A rapid one-pot microwave process was used to prepare the Cu/GO hybrids with various Cu contents. The attributes of metallic copper nanoparticles (?4-5 nm in size) in the GO hybrid are shown to significantly enhance the photocatalytic activity of GO, primarily through the suppression of electron-hole pair recombination, further reduction of GO's bandgap, and modification of its work function. X-ray photoemission spectroscopy studies indicate a charge transfer from GO to Cu. A strong interaction is observed between the metal content of the Cu/GO hybrids and the rates of formation and selectivity of the products. A factor of greater than 60 times enhancement in CO2 to fuel catalytic efficiency has been demonstrated using Cu/GO-2 (10 wt % Cu) compared with that using pristine GO.
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Laparoscopic Nissen fundoplication for gastro-oesophageal reflux disease in infants.
Pediatr. Surg. Int.
PUBLISHED: 10-14-2014
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Data on laparoscopic Nissen fundoplication for gastro-oesophageal reflux disease (GERD) in infants remain limited. We describe our experience with this operation in children and in particular, infants younger than 12 months old.
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Lactobacillus formosensis sp. nov., a novel lactic acid bacterium isolated from fermented soybean meal.
Int. J. Syst. Evol. Microbiol.
PUBLISHED: 10-05-2014
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A Gram-reaction-positive, catalase-negative, facultatively anaerobic, rod-shaped lactic acid bacterium, designated strain S215T, was isolated from fermented soybean meal. The organism produced D-lactic acid from glucose without gas formation. 16S rRNA gene sequencing results showed that strain S215T had 98.7-99.6% sequence similarity to that of the type strain of three Lactobacillus (L. farciminis BCRC 14043T, L. futsaii BCRC 80278T and L. crustorum JCM 15951T). A comparison of two housekeeping genes, rpoA and pheS, revealed that strain S215T was well separated from the reference strains of the genus Lactobacillus. DNA-DNA hybridization studies indicated that strain S15T had DNA related to the three types of Lactobacillus (33-66%). The DNA G+C content of strain S215T was 36.2 mol%. The cell walls contained peptidoglycan of the D-meso-diaminopimelic acid type and the major fatty acids were C18:1 ?9c (41.5%), C16:0 (23.4%) and C19:0 cyclo ?10c/19?6 (22.8%). Phenotypic and genotypic features demonstrated that these isolates represented a novel species of the genus Lactobacillus, for which the name Lactobacillus formosensis sp. nov. was proposed. The type strain was S215T = NBRC 109509T = BCRC 80582T).
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Structures, chemotaxonomic significance, cytotoxic and Na(+),K(+)-ATPase inhibitory activities of new cardenolides from Asclepias curassavica.
Org. Biomol. Chem.
PUBLISHED: 10-02-2014
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Five new cardenolide lactates () and one new dioxane double linked cardenolide glycoside () along with 15 known compounds ( and ) were isolated from the ornamental milkweed Asclepias curassavica. Their structures were elucidated by extensive spectroscopic methods (IR, UV, MS, 1D- and 2D-NMR). The molecular structures and absolute configurations of and were further confirmed by single-crystal X-ray diffraction analysis. Simultaneous isolation of dioxane double linked cardenolide glycosides () and cardenolide lactates () provided unique chemotaxonomic markers for this genus. Compounds were evaluated for the inhibitory activities against DU145 prostate cancer cells. The dioxane double linked cardenolide glycosides showed the most potent cytotoxic effect followed by normal cardenolides and cardenolide lactates, while the C21 steroids were non-cytotoxic. Enzymatic assay established a correlation between the cytotoxic effects in DU145 cancer cells and the Ki for the inhibition of Na(+),K(+)-ATPase. Molecular docking analysis revealed relatively strong H-bond interactions between the bottom of the binding cavity and compounds or , and explained why the dioxane double linked cardenolide glycosides possessed higher inhibitory potency on Na(+),K(+)-ATPase than the cardenolide lactate.
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Rhodiola crenulata- and Cordyceps sinensis-based supplement boosts aerobic exercise performance after short-term high altitude training.
High Alt. Med. Biol.
PUBLISHED: 09-25-2014
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High altitude training is a widely used strategy for improving aerobic exercise performance. Both Rhodiola crenulata (R) and Cordyceps sinensis (C) supplements have been reported to improve exercise performance. However, it is not clear whether the provision of R and C during high altitude training could further enhance aerobic endurance capacity. In this study, we examined the effect of R and C based supplementation on aerobic exercise capacity following 2-week high altitude training. Alterations to autonomic nervous system activity, circulatory hormonal, and hematological profiles were investigated. Eighteen male subjects were divided into two groups: Placebo (n=9) and R/C supplementation (RC, n=9). Both groups received either RC (R: 1400?mg+C: 600?mg per day) or the placebo during a 2-week training period at an altitude of 2200?m. After 2 weeks of altitude training, compared with Placebo group, the exhaustive run time was markedly longer (Placebo: +2.2% vs. RC: +5.7%; p<0.05) and the decline of parasympathetic (PNS) activity was significantly prevented in RC group (Placebo: -51% vs. RC: -41%; p<0.05). Red blood cell, hematocrit, and hemoglobin levels were elevated in both groups to a comparable extent after high altitude training (p<0.05), whereas the erythropoietin (EPO) level remained higher in the Placebo group (?48% above RC values; p<0.05). The provision of an RC supplement during altitude training provides greater training benefits in improving aerobic performance. This beneficial effect of RC treatment may result from better maintenance of PNS activity and accelerated physiological adaptations during high altitude training.
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Increasing risks of ischemic stroke in oral cancer patients treated with radiotherapy or chemotherapy: a nationwide cohort study.
Int. J. Neurosci.
PUBLISHED: 09-19-2014
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Background: Several studies have identified correlations between cancer and increased risks of ischemic stroke (IS), particularly following radiotherapy (RT) or chemotherapy (CT). However, data regarding relative risks of IS in oral cancer are limited. The aim of this study was to compare hazard ratios (HR) of IS among oral cancer patients treated with and without RT, CT, or both (CCRT). Methods: We analyzed data collected by the Taiwan National Health Insurance Research Database (NHIRD) from 1996 to 2009, which covered approximately 99.5% of the medical claims submitted nationally. A total of 21,853 patients diagnosed with oral cancer from 2000 to 2008 were included. The Cox proportional hazard model was used to estimate the HRs of IS among different treatment modalities and a matched cohort. Results: The overall risk of IS was1.24-fold greater in patients treated with RT/CT/CCRT than those treated with surgery alone and 1.08-fold greater for surgery with adjuvant therapy (radiotherapy or chemotherapy after surgery) after adjusting for confounding factors. The incidence of IS was 0.23-fold lower in matched control group than in the oral cancer cohort. In subgroup analysis, patients who received RT/CT/CCRT and aged <40 years old were at a 2.77-fold greater risk for IS than age-matched patients who underwent surgery alone, although this difference decreased with patient age. Conclusions: Oral cancer patients, particularly those aged <40 years, who underwent RT or CT are at increased risks for IS. Other significant risk factors for IS included Charlson comorbidity index (CCI) >1, hypertension, coronary artery disease, and atrial fibrillation.
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Serum Concentrations of Anthraquinones after Intake of Folium Sennae and Potential Modulation on P-glycoprotein.
Planta Med.
PUBLISHED: 09-01-2014
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Folium Sennae (leaves of Cassia angustifolia or senna) is a laxative and a component in diets for weight control. It contains a variety of anthranoids such as sennosides, aloe-emodin, and rhein. In order to measure the serum concentrations of senna anthranoids, Sprague-Dawley rats were orally administered with single dose and multiple doses of Folium Sennae. The concentrations of anthranoids in serum were determined by HPLC method before and after hydrolysis with sulfatase and ?-glucuronidase. The results showed that in the serum, aloe-emodin glucuronides and rhein glucuronides were the major metabolites. Traces of rhein free form were present transiently during the early phase, whereas the free form of aloe-emodin was not detected. We also evaluated the modulation effect of Folium Sennae on P-glycoprotein by using the LS 180 cell model which showed that it significantly inhibited P-glycoprotein by 16-46?%. In conclusion, senna anthranoids were rapidly and extensively metabolized to rhein glucuronides and aloe-emodin glucuronides in rats. Folium Sennae ingestion inhibited the efflux function of P-glycoprotein in the intestine.
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Simultaneous determination of gonadotropin-inhibitory and gonadotropin-releasing hormones using ultra-high performance liquid chromatography electrospray ionization tandem mass spectrometry.
Anal Bioanal Chem
PUBLISHED: 08-23-2014
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Gonadotropin-inhibitory hormones (GnIH) and gonadotropin-releasing hormones (GnRH) are neuropeptides essential for the regulation of reproduction in all vertebrate animals examined. Determination of neuropeptides in the biological sample is highly challenging due to their complex matrix and weak stability. The wide variety of peptides or protein degradation products often interferes with the determination of the target peptide. This study aims to develop a specific ultra-high performance liquid chromatography-tandem mass spectrometry method for simultaneous determination of nine critical neuropeptides in biological samples. A separation method by ultra-performance liquid chromatography coupled to a multiple reaction monitoring (MRM) by tandem mass spectrometry allows the selective determination of the neuropeptides in brain and plasma matrices after solid-phase extraction. Specific MSMS transitions were optimized using MRM of multiple-charged peptides generated by electrospray ionization in positive mode. The resulting analytical method was fully validated with thorough evaluation of stability, recovery, matrix effect, and intra- and interday accuracy and precision in sea lamprey brain and plasma. The optimized method shows linearity in a wide range of concentrations with limit of quantification ranging from 0.1 to 0.75 ng/mL. With slight modification, this method can be applied to other biological samples.
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Novel Active Comb-shaped Dry Electrode for EEG Measurement in Hairy Site.
IEEE Trans Biomed Eng
PUBLISHED: 08-15-2014
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Electroencephalography (EEG) is an important bio-potential, and has been widely applied in clinical applications. The conventional EEG electrode with conductive gels is usually used for measuring EEG. However, the use of conductive gel also encounters with the issue of drying and hardening. Recently, many dry EEG electrode based on different conductive materials and techniques were proposed to solve the above issue. However, measuring EEG in the hairy site is still a difficult challenge. In this study, a novel active comb-shaped dry electrode was proposed to measure EEG in hairy site. Different form other comb-shaped or spike-shaped dry electrodes, it can provide more excellent performance of avoiding the signal attenuation, phase distortion, and the reduction of common mode rejection ratio. Even under walking motion, it can effectively acquire EEG in hairy site. Finally, the experiments for alpha rhythm and steady state visually evoked potential were also tested to validate the proposed electrode.
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Phase I and phase II reductive metabolism simulation of nitro aromatic xenobiotics with electrochemistry coupled with high resolution mass spectrometry.
Anal Bioanal Chem
PUBLISHED: 08-06-2014
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Electrochemistry combined with (liquid chromatography) high resolution mass spectrometry was used to simulate the general reductive metabolism of three biologically important nitro aromatic molecules: 3-trifluoromethyl-4-nitrophenol (TFM), niclosamide, and nilutamide. TFM is a pesticide used in the Laurential Great Lakes while niclosamide and nilutamide are used in cancer therapy. At first, a flow-through electrochemical cell was directly connected to a high resolution mass spectrometer to evaluate the ability of electrochemistry to produce the main reduction metabolites of nitro aromatic, nitroso, hydroxylamine, and amine functional groups. Electrochemical experiments were then carried out at a constant potential of -2.5 V before analysis of the reduction products by LC-HRMS, which confirmed the presence of the nitroso, hydroxylamine, and amine species as well as dimers. Dimer identification illustrates the reactivity of the nitroso species with amine and hydroxylamine species. To investigate xenobiotic metabolism, the reactivity of nitroso species to biomolecules was also examined. Binding of the nitroso metabolite to glutathione was demonstrated by the observation of adducts by LC-ESI(+)-HRMS and the characteristics of their MSMS fragmentation. In conclusion, electrochemistry produces the main reductive metabolites of nitro aromatics and supports the observation of nitroso reactivity through dimer or glutathione adduct formation.
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Randomized controlled trial comparing 7-day triple, 10-day sequential, and 7-day concomitant therapies for Helicobacter pylori infection.
Antimicrob. Agents Chemother.
PUBLISHED: 07-28-2014
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With the rising prevalence of antimicrobial resistance, the failure rate of the standard triple therapy for Helicobacter pylori infection is increasing. Sequential therapy and concomitant therapy have been recommended to replace standard triple therapy for H. pylori eradication in regions with high clarithromycin resistance. The aim of this prospective, randomized, and controlled study was to simultaneously assess the efficacies of 10-day sequential and 7-day concomitant therapies versus a 7-day standard triple therapy for treating H. pylori infection. Consecutive H. pylori-infected subjects were randomly assigned to a 7-day standard triple therapy (pantoprazole, clarithromycin, and amoxicillin for 7 days), a 10-day sequential therapy (pantoprazole and amoxicillin for 5 days, followed by pantoprazole, clarithromycin, and metronidazole for a further 5 days), or a 7-day quadruple therapy (pantoprazole, clarithromycin, amoxicillin, and metronidazole for 7 days). H. pylori status was confirmed 6 weeks after therapy. Three hundred seven H. pylori-infected participants were randomized to receive triple (n = 103), sequential (n = 102), or concomitant (n = 102) therapies. The eradication rates by an intention-to-treat analysis in the three treatment groups were 81.6% (95% confidence interval [CI], 74.1% to 89.0%), 89.2% (95% CI, 83.2% to 95.2%), and 94.1% (95% CI, 89.5% to 98.7%). The seven-day concomitant therapy had a higher eradication rate than did the 7-day triple therapy (difference, 12.5%; 95% CI, 3.7% to 21.3%). There were no significant differences in the eradication rates between the sequential and standard triple therapies. All three treatments exhibited similar frequencies of adverse events (8.7%, 8.8%, and 13.7%, respectively) and drug compliance (99.0%, 98.0%, and 100.0%, respectively). In conclusion, the seven-day concomitant therapy is superior to the 7-day standard triple therapy for H. pylori eradication. Additionally, it is less complex than the 10-day sequential therapy because the drugs are not changed halfway through the treatment course. (This study has been registered at ClinicalTrials.gov under registration no. NCT1769365.).
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Oral intake of curcumin markedly activated CYP 3A4: in vivo and ex-vivo studies.
Sci Rep
PUBLISHED: 07-22-2014
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Curcumin, a specific secondary metabolite of Curcuma species, has potentials for a variety of beneficial health effects. It is nowadays used as a dietary supplement. Everolimus (EVL) is an immunosuppressant indicated for allograft rejection and cancer therapy, but with narrow therapeutic window. EVL is a substrate of P-glycoprotein (P-gp) and cytochrome P450 3A4 (CYP3A4). This study investigated the effect of coadministration of curcumin on the pharmacokinetics of EVL in rats and the underlying mechanisms. EVL (0.5?mg/kg) was orally administered without and with 50 and 100?mg/kg of curcumin, respectively, in rats. Blood samples were collected at specific time points and EVL concentrations in blood were determined by QMS® immunoassay. The underlying mechanisms were evaluated using cell model and recombinant CYP 3A4 isozyme. The results indicated that 50 and 100?mg/kg of curcumin significantly decreased the AUC0-540 of EVL by 70.6% and 71.5%, respectively, and both dosages reduced the Cmax of EVL by 76.7%. Mechanism studies revealed that CYP3A4 was markedly activated by curcumin metabolites, which apparently overrode the inhibition effects of curcumin on P-gp. In conclusion, oral intake of curcumin significantly decreased the bioavailability of EVL, a probe substrate of P-gp/CYP 3A4, mainly through marked activation on CYP 3A4.
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A polystyrene-based microfluidic device with three-dimensional interconnected microporous walls for perfusion cell culture.
Biomicrofluidics
PUBLISHED: 07-01-2014
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In this article, we present a simple, rapid prototyped polystyrene-based microfluidic device with three-dimensional (3D) interconnected microporous walls for long term perfusion cell culture. Patterned 3D interconnected microporous structures were created by a chemical treatment together with a protective mask and the native hydrophobic nature of the microporous structures were selectively made hydrophilic using oxygen plasma treatment together with a protective mask. Using this polystyrene-based cell culture microfluidic device, we successfully demonstrated the support of four days perfusion cell culture of hepatocytes (C3A cells).
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A new clarification method to visualize biliary degeneration during liver metamorphosis in Sea Lamprey (Petromyzon marinus).
J Vis Exp
PUBLISHED: 06-26-2014
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Biliary atresia is a rare disease of infancy, with an estimated 1 in 15,000 frequency in the southeast United States, but more common in East Asian countries, with a reported frequency of 1 in 5,000 in Taiwan. Although much is known about the management of biliary atresia, its pathogenesis is still elusive. The sea lamprey (Petromyzon marinus) provides a unique opportunity to examine the mechanism and progression of biliary degeneration. Sea lamprey develop through three distinct life stages: larval, parasitic, and adult. During the transition from larvae to parasitic juvenile, sea lamprey undergo metamorphosis with dramatic reorganization and remodeling in external morphology and internal organs. In the liver, the entire biliary system is lost, including the gall bladder and the biliary tree. A newly-developed method called "CLARITY" was modified to clarify the entire liver and the junction with the intestine in metamorphic sea lamprey. The process of biliary degeneration was visualized and discerned during sea lamprey metamorphosis by using laser scanning confocal microscopy. This method provides a powerful tool to study biliary atresia in a unique animal model.
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Randomized controlled trial of monthly versus biweekly endoscopic variceal ligation for the prevention of esophageal variceal rebleeding.
J. Gastroenterol. Hepatol.
PUBLISHED: 06-24-2014
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Endoscopic variceal ligation (EVL) is effective in preventing esophageal variceal rebleeding. However, the optimal EVL interval remains unclear.
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Demonstration of a broad band spectral head-mounted display with freeform mirrors.
Opt Express
PUBLISHED: 06-13-2014
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It has been demonstrated that electrical stimulation of the retina can produce visual perception for blind patients suffering from macular degeneration and retinitis pigmentosa. In order to let the retinal chip generate enough electrical stimulation, the near infrared ray source is added to enhance the stimulation current. However, it is a challenge to design a head-mounted display (HMD) that covers both visible and infrared rays. Since the HMD system covers such a broad spectral band, large color aberrations will be induced. In order to eliminate these large aberrations, a mirror system is adopted that will create a no color aberration system. We also use two freeform mirrors (FFMs) to reduce residual aberrations such as spherical aberrations and coma. The FFMs serve as the near-eye viewing optics that magnifies the image which is displayed through a microdisplay. Based on a 0.61 in. microdisplay, the HMD system demonstrates a diagonal field of view (FOV) of 30 degree and an f/# of 3.75, with an exit pupil diameter of 8 mm and eye clearance of 15mm.
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Pheromone 3kPZS evokes context-dependent serotonin sexual dimorphism in the brain of the sea lamprey, Petromyzon marinus (L).
Integr Zool
PUBLISHED: 06-13-2014
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Mature male sea lamprey (Petromyzon marinus Linnaeus, 1758) release a sex pheromone, 3-keto-petromyzonol sulfate (3kPZS), that has been shown to induce sexually dimorphic behavioral responses in conspecifics. However, the neural mechanism of such responses is mostly unknown. We examined the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) and the expression of 5-HT1A receptors in the forebrain and brainstem of sea lamprey exposed to the vehicle (0.91 ppm methanol) or 10(-10) M 3kPZS for 2h using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (LC-MS/MS), immunohistochemistry, and real-time quantitative PCR. Exposure to 3kPZS for 2h increased 5-HT concentration in the forebrain of adult females (F test, p < 0.05), whereas 5-HT was not detected in the forebrain of adult males. On the contrary, 3kPZS exposure decreased 5-HT concentration in the brainstem of adult females (F test, p < 0.0005) and had no effect in adult males. Pheromone exposure evoked context-dependent sexual dimorphism in brain 5-HT1A receptor immunoreactivity, but had no effect on 5-HT1A mRNA concentrations in the brain with 2h exposure time. It appears that in sea lamprey pheromone 3kPZS affects the 5-HT system in the brain in a context-dependent, sexually dimorphic manner. This article is protected by copyright. All rights reserved.
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Comparison of hemostatic efficacy of argon plasma coagulation with and without distilled water injection in treating high-risk bleeding ulcers.
Biomed Res Int
PUBLISHED: 05-30-2014
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Argon plasma coagulation (APC) is useful to treat upper gastrointestinal bleeding, but its hemostatic efficacy has received little attention. Aims. This investigation attempted to determine whether additional endoscopic injection before APC could improve hemostatic efficacy in treating high-risk bleeding ulcers.
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Characteristics of nonylphenol and bisphenol A accumulation by fish and implications for ecological and human health.
Sci. Total Environ.
PUBLISHED: 05-28-2014
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Fish populations constitute an important part of aquatic ecosystems. Thus, their accumulation of nonylphenol (NP) and bisphenol A (BPA) may pose risks to ecosystems and human health. This study analyzed the concentrations of NP and BPA in four types of fishes (i.e., wild/farmed freshwater fishes and wild/farmed marine fishes). Wild freshwater fishes contained higher concentrations of NP and BPA than the other three types of fishes. The concentrations of NP in the wild freshwater fishes ranged from 1.01 to 277?g/kg ww, with bioconcentration factors (BCFs) and biota-sediment accumulation factors (BSAFs) ranging from 74.0 to 2.60×10(4)L/kg and from 0.003 to 18.3, respectively. The wild freshwater fishes contained relatively low amounts of BPA, varying from ND to 25.2?g/kg ww, with the BCFs and BSAFs ranging from 1.00 to 274L/kg and from 0.003 to 3.40, respectively. Five fish species particularly showed high BCFs and BSAFs, indicating that they could be an important source of NP for higher trophic levels, most likely resulting in ecological risks. The demersal fishes showed a greater ability to accumulate NP than the pelagic ones. The fact that the 95th percentile values of the risk quotient (RQ) for NP and BPA were higher than the acceptable threshold indicated that these two compounds would have adverse effects on aquatic organisms in Taiwanese rivers. The consumption of wild marine fishes had the highest 95th percentile values of hazard quotient (HQ) for NP and BPA among the four types of fishes, particularly for the population aged 0-3years. However, the 95th percentile values of HQ for NP and BPA were all less than 1, suggesting that exposure to NP and BPA through fish consumption posed no remarkable risk to human health in Taiwan.
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A QoS aware resource allocation strategy for 3D A/V streaming in OFDMA based wireless systems.
ScientificWorldJournal
PUBLISHED: 05-26-2014
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Three-dimensional (3D) video is expected to be a "killer app" for OFDMA-based broadband wireless systems. The main limitation of 3D video streaming over a wireless system is the shortage of radio resources due to the large size of the 3D traffic. This paper presents a novel resource allocation strategy to address this problem. In the paper, the video-plus-depth 3D traffic type is considered. The proposed resource allocation strategy focuses on the relationship between 2D video and the depth map, handling them with different priorities. It is formulated as an optimization problem and is solved using a suboptimal heuristic algorithm. Numerical results show that the proposed scheme provides a better quality of service compared to conventional schemes.
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Teaghrelins, unique acylated flavonoid tetraglycosides in Chin-shin oolong tea, are putative oral agonists of the ghrelin receptor.
J. Agric. Food Chem.
PUBLISHED: 05-22-2014
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Chin-shin oolong tea, a popular tea in Taiwan, was empirically perceived to induce hunger and accelerate gastric emptying in a manner similar to the physiological effects of ghrelin, an endogenous acylated peptide known as the hunger hormone. Two unique acylated flavonoid tetraglycosides previously identified in Chin-shin oolong tea were demonstrated to induce hunger of rats in a food intake assay and, thus, named teaghrelin-1 and teaghrelin-2. Similar to GHRP-6, a synthetic analogue of ghrelin, teaghrelin-1 stimulated growth hormone secretion of rat primary anterior pituitary cells in a dose-dependent manner, and the stimulation was inhibited by [D-Arg(1),D-Phe(5),D-Trp(7,9),Leu(11)]-substance P, an antagonist of the ghrelin receptor. While teaghrelin-2 remained unmodified, a meta-O-methylated metabolite of teaghrelin-1 was detected in bile of rats after intravenous injection. Presumably, teaghrelins are promising oral agonists of the ghrelin receptor.
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Identification of caleosin and two oleosin isoforms in oil bodies of pine megagametophytes.
Plant Physiol. Biochem.
PUBLISHED: 04-25-2014
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Numerous oil bodies of 0.2-2 ?m occupied approximately 80% of intracellular space in mature pine (Pinus massoniana) megagametophytes. They were stably isolated and found to comprise mostly triacylglycerols as examined by thin layer chromatography analysis and confirmed by both Nile red and BODIPY stainings. Fatty acids released from the triacylglycerols of pine oil bodies were mainly unsaturated, including linoleic acid (60%), adrenic acid (12.3%) and vaccenic acid (9.7%). Proteins extracted from pine oil bodies were subjected to immunological cross-recognition, and the results showed that three proteins of 28, 16 and 14 kDa were detected by antibodies against sesame seed caleosin, sesame oleosin-L and lily pollen oleosin-P, respectively. Complete cDNA fragments encoding these three pine oil-body proteins, tentatively named caleosin, oleosin-L and oleosin-G, were obtained by PCR cloning and further confirmed by mass spectrometric analysis. Consistently, phylogenetic tree analyses showed that pine caleosin was closely-related to the caleosin of cycad megagametophyte among known caleosin sequences. While pine oleosin-L was found clustered with seed oleosin isoforms of angiosperm species, oleosin-G was distinctively grouped with the oleosin-P of lily pollen. The oleosin-G identified in pine megagametophytes seems to represent a new class of seed oleosin isoform evolutionarily close to the pollen oleosin-P.
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Role of the BaeSR two-component system in the regulation of Acinetobacter baumannii adeAB genes and its correlation with tigecycline susceptibility.
BMC Microbiol.
PUBLISHED: 04-25-2014
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Tigecycline resistance in Acinetobacter baumannii is primarily acquired through overexpression of the AdeABC efflux pump. Besides AdeRS, other two-component regulatory systems (TCSs) involving the regulation of this transporter have not been clarified.
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Relationship between TG/HDL-C ratio and metabolic syndrome risk factors with chronic kidney disease in healthy adult population.
Clin Nutr
PUBLISHED: 04-20-2014
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The triglycerides-to-high-density lipoprotein-cholesterol (TG/HDL-C) ratio has been identified as a biomarker of insulin resistance and a predictor for atherosclerosis. The objectives of this study were to investigate which the TG/HDL-C ratio is useful to detect metabolic syndrome (MS) risk factors and subclinical chronic kidney disease (CKD) in general population without known CKD or renal impairment and to compare predictive accuracy of MS risk factors.
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The role of TGF-? signaling and apoptosis in innate and adaptive immunity in zebrafish: a systems biology approach.
BMC Syst Biol
PUBLISHED: 04-15-2014
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The immune system is a key biological system present in vertebrates. Exposure to pathogens elicits various defensive immune mechanisms that protect the host from potential threats and harmful substances derived from pathogens such as parasites, bacteria, and viruses. The complex immune system of humans and many other vertebrates can be divided into two major categories: the innate and the adaptive immune systems. At present, analysis of the complex interactions between the two subsystems that regulate host defense and inflammatory responses remains challenging.
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Evaluation of subcortical grey matter abnormalities in patients with MRI-negative cortical epilepsy determined through structural and tensor magnetic resonance imaging.
BMC Neurol
PUBLISHED: 04-15-2014
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Although many studies have found abnormalities in subcortical grey matter (GM) in patients with temporal lobe epilepsy or generalised epilepsies, few studies have examined subcortical GM in focal neocortical seizures. Using structural and tensor magnetic resonance imaging (MRI), we evaluated subcortical GM from patients with extratemporal lobe epilepsy without visible lesion on MRI. Our aims were to determine whether there are structural abnormalities in these patients and to correlate the extent of any observed structural changes with clinical characteristics of disease in these patients.
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Adaptive divergence with gene flow in incipient speciation of Miscanthus floridulus/sinensis complex (Poaceae).
Plant J.
PUBLISHED: 04-14-2014
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Young incipient species provide ideal materials for untangling the process of ecological speciation in the presence of gene flow. The Miscanthus floridulus/sinensis complex exhibits diverse phenotypic and ecological differences despite recent divergence (approximately 1.59 million years ago). To elucidate the process of genetic differentiation during early stages of ecological speciation, we analyzed genomic divergence in the Miscanthus complex using 72 randomly selected genes from a newly assembled transcriptome. In this study, rampant gene flow was detected between species, estimated as M = 3.36 × 10(-9) to 1.20 × 10(-6) , resulting in contradicting phylogenies across loci. Nevertheless, beast analyses revealed the species identity and the effects of extrinsic cohesive forces that counteracted the non-stop introgression. As expected, early in speciation with gene flow, only 3-13 loci were highly diverged; two to five outliers (approximately 2.78-6.94% of the genome) were characterized by strong linkage disequilibrium, and asymmetrically distributed among ecotypes, indicating footprints of diversifying selection. In conclusion, ecological speciation of incipient species of Miscanthus probably followed the parapatric model, whereas allopatric speciation cannot be completely ruled out, especially between the geographically isolated northern and southern M. sinensis, for which no significant gene flow across oceanic barriers was detected. Divergence between local ecotypes in early-stage speciation began at a few genomic regions under the influence of natural selection and divergence hitchhiking that overcame gene flow.
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Comparing the efficacy and clinical outcome of telbivudine and entecavir naïve patients with hepatitis B virus-related compensated cirrhosis.
J. Gastroenterol. Hepatol.
PUBLISHED: 04-10-2014
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There is limited data on the efficacy and outcome of telbivudine (LdT) therapy in patients with chronic hepatitis B and compensated cirrhosis. We evaluated LdT as first-line therapy in these patients and compared with those treated with entecavir (ETV).
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Through diffusion tensor magnetic resonance imaging to evaluate the original properties of neural pathways of patients with partial seizures and secondary generalization by individual anatomic reference atlas.
Biomed Res Int
PUBLISHED: 04-04-2014
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To investigate white matter (WM) abnormalities in neocortical epilepsy, we extract supratentorial WM parameters from raw tensor magnetic resonance images (MRI) with automated region-of-interest (ROI) registrations. Sixteen patients having neocortical seizures with secondarily generalised convulsions and 16 age-matched normal subjects were imaged with high-resolution and diffusion tensor MRIs. Automated demarcation of supratentorial fibers was accomplished with personalized fiber-labeled atlases. From the individual atlases, we observed significant elevation of mean diffusivity (MD) in fornix (cres)/stria terminalis (FX/ST) and sagittal stratum (SS) and a significant difference in fractional anisotropy (FA) among FX/ST, SS, posterior limb of the internal capsule (PLIC), and posterior thalamic radiation (PTR). For patients with early-onset epilepsy, the diffusivities of the SS and the retrolenticular part of the internal capsule were significantly elevated, and the anisotropies of the FX/ST and SS were significantly decreased. In the drug-resistant subgroup, the MDs of SS and PTR and the FAs of SS and PLIC were significantly different. Onset age was positively correlated with increases in FAs of the genu of the corpus callosum. Patients with neocortical seizures and secondary generalisation had microstructural anomalies in WM. The changes in WM are relevant to early onset, progression, and severity of epilepsy.
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Reference values for healthy human myocardium using a T1 mapping methodology: results from the International T1 Multicenter cardiovascular magnetic resonance study.
J Cardiovasc Magn Reson
PUBLISHED: 03-26-2014
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T1 mapping is a robust and highly reproducible application to quantify myocardial relaxation of longitudinal magnetisation. Available T1 mapping methods are presently site and vendor specific, with variable accuracy and precision of T1 values between the systems and sequences. We assessed the transferability of a T1 mapping method and determined the reference values of healthy human myocardium in a multicenter setting.
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The role of Mss11 in Candida albicans biofilm formation.
Mol. Genet. Genomics
PUBLISHED: 03-22-2014
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Candida albicans is an opportunistic human pathogen that can form a biofilm on biotic or inert surfaces such as epithelia and clinical devices. In this study, we examine the formation of C. albicans biofilm by establishing a key gene-centered network based on protein-protein interaction (PPI) and gene expression datasets. Starting from C. albicans Cph1 and Efg1, transcription factors associated with morphogenesis of biofilm formation, a network elucidates the complex cellular process and predicts potential unknown components related to biofilm formation. Subsequently, we analyzed the functions of Mss11 among these identified proteins to test the efficiency of the proposed computational approach. MSS11-deleted mutants were compared with a wild-type strain, indicating that the mutant is defective in forming a mature biofilm and partially attenuates the virulence of C. albicans in an infected mouse model. Finally, a DNA microarray analysis was conducted to identify the potential target genes of C. albicans Mss11. The findings of this study clarify complex gene or protein interaction during the biofilm formation process of C. albicans, supporting the application of a systems biology approach to study fungal pathogenesis.
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Responses of Candida albicans to the human antimicrobial peptide LL-37.
J. Microbiol.
PUBLISHED: 03-07-2014
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Candida albicans is amajor fungal pathogen in humans. Antimicrobial peptides (AMPs) are critical components of the innate immune response in vertebrates and represent the first line of defense against microbial infection. LL-37 is the only member of the human family of cathelicidin AMPs and is commonly expressed by various tissues and cells, including surfaces of epithelia. The candidacidal effects of LL-37 have been well documented, but the mechanisms by which LL-37 kills C. albicans are not completely understood. In this study, we examined the effects of LL-37 on cell wall and cellular responses in C. albicans. Using transmission electron microscopy, carbohydrate analyses, and staining for ?-1,3-glucan, changing of C. albicans cell wall integrity was detected upon LL-37 treatment. In addition, LL-37 also affected cell wall architecture of the pathogen. Finally, DNA microarray analysis and quantitative PCR demonstrated that sub-lethal concentrations of LL-37 modulated the expression of genes with a variety of functions, including transporters, regulators for biological processes, response to stress or chemical stimulus, and pathogenesis. Together, LL-37 induces complex responses in C. albicans, making LL-37 a promising candidate for use as a therapeutic agent against fungal infections.
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Effectiveness and safety of antiplatelet in stroke patients with end-stage renal disease undergoing dialysis.
Int J Stroke
PUBLISHED: 03-05-2014
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Antiplatelet therapy is known to decrease the risk of secondary ischemic stroke. However, the effectiveness and safety of antiplatelet therapy in patients with end-stage renal disease are uncertain, especially in dialysis.
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Hostility modifies the association between TV viewing and cardiometabolic risk.
J Obes
PUBLISHED: 02-26-2014
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It was hypothesized that television viewing is predictive of cardiometabolic risk. Moreover, people with hostile personality type may be more susceptible to TV-induced negative emotions and harmful health habits which increase occurrence of cardiometabolic risk.
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Role of endoscopic papillary balloon dilation in patients with recurrent bile duct stones after endoscopic sphincterotomy.
J Chin Med Assoc
PUBLISHED: 02-12-2014
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Endoscopic sphincterotomy (ES) is an established treatment for patients with choledocholithiasis or common bile duct stones (CBDS), but further management of patients after ES with recurrent CBDS remains controversial. Endoscopic papillary large balloon dilation (EPLBD) has been used safely and effectively for stone removal in patients after ES with recurrent CBDS. The aim of this study was to evaluate the clinical efficacy of EPLBD in patients after complete ES with recurrent CBDS.
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Identification and quantification of sea lamprey gonadotropin-releasing hormones by electrospray ionization tandem mass spectrometry.
J Chromatogr A
PUBLISHED: 02-12-2014
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Gonadotropin-releasing hormones (GnRH) are neuropeptide hormones that regulate reproduction in vertebrates. Twenty-five unique chordate GnRH isoforms have been identified, all with very similar molecular architecture. Identification and quantification of endogenous GnRH in biological samples is extremely challenging due to the high levels of sequence similarity among these GnRH peptides and complexity of the biological matrices laden with large numbers of other peptides and protein degradation fragments, and due to low levels of GnRH abundance. In this study, three lamprey GnRH (lGnRH-I, -II, and -III) were extracted from sea lamprey brain tissue and plasma samples by solid-phase extraction (SPE) and identified by a high resolution Q-TOF mass spectrometry (MS). A rapid quantitation method was developed and validated to determine the concentrations of these three lGnRHs by using a UPLC coupled tandem MS in positive ESI multiple reaction monitoring (MRM) mode. Luteinizing hormone-release hormone (LHRH, one of the mammalian GnRHs) was used as the internal standard. The developed quantitation method was fully validated for its recovery, matrix effect, linearity, repeatability, precision and accuracy, and storage stability. This method exhibited excellent linearity in a broad concentration range for all three lGnRHs (R(2)>0.99) and limits of detection (LOD; as low as 0.007 ng/mL). Brain and plasma samples from a total of 280 sea lampreys were analyzed with the developed method to investigate the biological relevance of the lGnRH levels. The concentrations of these three lGnRHs were detected at levels of pictogram per microgram brain tissue and milliliter of plasma. The obtained analytical performance parameters and collected data from real biological samples have proven that this is a robust, sensitive, and fully validated LC-MS/MS method to simultaneously quantify three neuropeptide hormones in complex biological matrices.
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Essential functional modules for pathogenic and defensive mechanisms in Candida albicans infections.
Biomed Res Int
PUBLISHED: 02-10-2014
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The clinical and biological significance of the study of fungal pathogen Candida albicans (C. albicans) has markedly increased. However, the explicit pathogenic and invasive mechanisms of such host-pathogen interactions have not yet been fully elucidated. Therefore, the essential functional modules involved in C. albicans-zebrafish interactions were investigated in this study. Adopting a systems biology approach, the early-stage and late-stage protein-protein interaction (PPI) networks for both C. albicans and zebrafish were constructed. By comparing PPI networks at the early and late stages of the infection process, several critical functional modules were identified in both pathogenic and defensive mechanisms. Functional modules in C. albicans, like those involved in hyphal morphogenesis, ion and small molecule transport, protein secretion, and shifts in carbon utilization, were seen to play important roles in pathogen invasion and damage caused to host cells. Moreover, the functional modules in zebrafish, such as those involved in immune response, apoptosis mechanisms, ion transport, protein secretion, and hemostasis-related processes, were found to be significant as defensive mechanisms during C. albicans infection. The essential functional modules thus determined could provide insights into the molecular mechanisms of host-pathogen interactions during the infection process and thereby devise potential therapeutic strategies to treat C. albicans infection.
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Early Austronesians: into and out of Taiwan.
Am. J. Hum. Genet.
PUBLISHED: 02-10-2014
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A Taiwan origin for the expansion of the Austronesian languages and their speakers is well supported by linguistic and archaeological evidence. However, human genetic evidence is more controversial. Until now, there had been no ancient skeletal evidence of a potential Austronesian-speaking ancestor prior to the Taiwan Neolithic ~6,000 years ago, and genetic studies have largely ignored the role of genetic diversity within Taiwan as well as the origins of Formosans. We address these issues via analysis of a complete mitochondrial DNA genome sequence of an ~8,000-year-old skeleton from Liang Island (located between China and Taiwan) and 550 mtDNA genome sequences from 8 aboriginal (highland) Formosan and 4 other Taiwanese groups. We show that the Liangdao Man mtDNA sequence is closest to Formosans, provides a link to southern China, and has the most ancestral haplogroup E sequence found among extant Austronesian speakers. Bayesian phylogenetic analysis allows us to reconstruct a history of early Austronesians arriving in Taiwan in the north ~6,000 years ago, spreading rapidly to the south, and leaving Taiwan ~4,000 years ago to spread throughout Island Southeast Asia, Madagascar, and Oceania.
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Detecting metabolites of different transition metal-lithospermate B complexes after intravenous injection in rats.
Acta Pharmacol. Sin.
PUBLISHED: 01-24-2014
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Lithospermate B (LSB) isolated from the traditional Chinese medicine danshen (Salvia miltiorrhiza) is an effective Na(+)/K(+)-ATPase inhibitor and used to treat congestive heart failure. The inhibition of LSB on Na(+)/K(+)-ATPase is potentiated by forming complexes with transition metal ions. Here we investigated the safety and metabolites of different transition metal-LSB complexes in rats.
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Early entecavir treatment for chronic hepatitis B with severe acute exacerbation.
Antimicrob. Agents Chemother.
PUBLISHED: 01-13-2014
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A previous study found that lamivudine, if started early enough, may improve the chance of survival in chronic hepatitis B virus (HBV) with severe acute exacerbation (SAE). The aim of this study was to investigate the effect of early entecavir treatment before the bilirubin level exceeds 20 mg/dl for chronic HBV with SAE. Consecutive patients with chronic HBV with SAE and a serum bilirubin level of <20 mg/dl who received lamivudine or entecavir were enrolled. Short-term (4 months) survival was evaluated. One hundred fourteen patients received lamivudine, and 53 patients received entecavir. The baseline characteristics were similar for the two groups except that the entecavir group was older and had a lower alanine aminotransferase (ALT) level. Three patients (8.0%) in the entecavir group and 9 patients (7.9%) in the lamivudine group died (P=1.000). If only patients who started antiviral treatment before serum bilirubin level rose to more than 15 mg/dl were included, 3 patients (8.3%) in the entecavir group and 3 patients (3.0%) in the lamivudine group died (P=0.189). If only patients with an HBV DNA level higher than 10(5) copies/ml and a bilirubin level lower than 15 mg/dl were included, 5 out of 40 patients (12.5%) in the entecavir group died and 1 out of 59 patients (1.7%) in the lamivudine group died. Multivariate analysis found that entecavir treatment was associated with more mortality than lamivudine (P=0.035). Early entecavir treatment in patients with high viral load is associated with more short-term mortality than lamivudine for chronic HBV with severe acute exacerbation.
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Comparative performance of PET tracers in biochemical recurrence of prostate cancer: a critical analysis of literature.
Am J Nucl Med Mol Imaging
PUBLISHED: 01-01-2014
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Positron emission tomography (PET) with a number of tracers targeted to particular biological features of cancer has been explored for the imaging evaluation of patients with biochemical recurrence of prostate cancer after curative primary treatment. However, these reports are often heterogeneous in study design, patient cohorts, standards of reference for the imaging findings, data analysis, and data reporting. The aim of our study was to address these limitations by extracting and re-analyzing the PET detection data only from studies that satisfied pre-defined sets of patient selection criteria and verification standards. Our investigation analyzed the effects of 5 tracers ((18)F-fluorodeoxyglucose (FDG), (11)C-acetate (ACET), (11)C- or (18)F-choline (CHOL), anti-1-amino-3-(18)F-fluorocyclobutane-1-carboxylic acid (FACBC), and radiolabeled ligand targeted to prostate-specific membrane antigen (PSMA)), 2 treatment types (radical prostatectomy and radiation therapy), and whether the detected disease was local or metastatic, including lesion type (bone, lymph node, soft tissue). FDG exhibited the lowest detection rate for any suspected disease. ACET tended to be advantageous over CHOL in detecting local recurrence and lymph node lesions, even though the difference was not statistically significant. FACBC had greater likelihood of detecting local recurrence, when compared to CHOL, though this difference was not statistically significant. PSMA tended to show a higher proportion of patients with suspected disease compared to the other four tracers. Patients treated with radiation therapy had greater odds of displaying local recurrence on PET than those treated with radical prostatectomy. We also provide suggestions for future investigations that facilitate communication and the impact of the findings.
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Impact of EGFR mutation detection methods on the efficacy of erlotinib in patients with advanced EGFR-wild type lung adenocarcinoma.
PLoS ONE
PUBLISHED: 01-01-2014
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Methods used for epidermal growth factor receptor (EGFR) mutation testing vary widely. The impact of detection methods on the rates of response to EGFR-tyrosine kinase inhibitors (TKIs) in EGFR-wild type (wt) lung adenocarcinoma patients is unknown.
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Hepatic arterial infusion chemotherapy for patients with huge unresectable hepatocellular carcinoma.
PLoS ONE
PUBLISHED: 01-01-2014
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The optimal treatment for huge unresectable hepatocellular carcinoma (HCC) remains controversial. The outcome of transcatheter arterial chemoembolization (TACE) for patients huge unresectable HCC is generally poor and the survival benefit of TACE in these patients is unclear. The aim of the study is to compare the effect of hepatic arterial infusion chemotherapy (HAIC) versus symptomatic treatment in patients with huge unresectable HCC.
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Not only hysterectomy but also cesarean section can predict incomplete flexible sigmoidoscopy among patients with prior abdominal or pelvic surgery.
J Chin Med Assoc
PUBLISHED: 01-01-2014
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Flexible sigmoidoscopy (FS) is a safe and effective method for colorectal cancer (CRC) screening. Several studies have demonstrated that individuals who have undergone surgery are at a greater risk of having incomplete FS. This study explored predictors of incomplete FS and reduced polyp detection rates for participants who had undergone abdominal or pelvic surgery.
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The structure of Rap1 in complex with RIAM reveals specificity determinants and recruitment mechanism.
J Mol Cell Biol
PUBLISHED: 11-28-2013
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The small GTPase Rap1 induces integrin activation via an inside-out signaling pathway mediated by the Rap1-interacting adaptor molecule (RIAM). Blocking this pathway may suppress tumour metastasis and other diseases that are related to hyperactive integrins. However, the molecular basis for the specific recognition of RIAM by Rap1 remains largely unknown. Herein we present the crystal structure of an active, GTP-bound GTPase domain of Rap1 in complex with the Ras association (RA)-pleckstrin homology (PH) structural module of RIAM at 1.65 Å. The structure reveals that the recognition of RIAM by Rap1 is governed by side-chain interactions. Several side chains are critical in determining specificity of this recognition, particularly the Lys31 residue in Rap1 that is oppositely charged compared with the Glu31/Asp31 residue in other Ras GTPases. Lys31 forms a salt bridge with RIAM residue Glu212, making it the key specificity determinant of the interaction. We also show that disruption of these interactions results in reduction of Rap1:RIAM association, leading to a loss of co-clustering and cell adhesion. Our findings elucidate the molecular mechanism by which RIAM mediates Rap1-induced integrin activation. The crystal structure also offers new insight into the structural basis for the specific recruitment of RA-PH module-containing effector proteins by their small GTPase partners.
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Metal-Free, Acid-Promoted Synthesis of Imidazole Derivatives via a Multicomponent Reaction.
Org. Lett.
PUBLISHED: 11-26-2013
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An expedient and metal-free synthetic route has been developed for the construction of tri- and tetrasubstituted imidazole derivatives via acid promoted multicomponent reaction methodology. The reaction proceeded smoothly with a range of functionalities to produce the imidazole scaffolds in good to excellent yields.
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Gold nanosponges: green synthesis, characterization, and cytotoxicity.
J Nanosci Nanotechnol
PUBLISHED: 11-20-2013
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A simply approach for the synthesis of Au nanostructures in tea infusions at room temperature is developed. By controlling the concentrations of tea infusions, Au nanostructures in various shapes and sizes have been prepared. From 1 x (original concentration) and 0.01 x (100 times diluted) tea infusions, 52.2 +/- 8.1 nm Au nanosponges (T-Au NSs) and 23 +/- 2 nm spherical Au nanoparticles (T-Au NPs) were prepared. The phytochemicals present on the surface of T-Au NSs were proved by surface-assisted laser desorption/ionization mass spectrometry, Fourier transform infrared spectrometry and capillary electrophoresis coupled with UV detection. The energy-dispersive X-ray spectroscopy and powder X-ray diffraction data reveal pure crystalline structures of the T-Au NSs. The dark field scattering images observe that the T-Au NSs have significant affinity toward HeLa cells. The cytotoxicity of T-Au NSs on HeLa cells is through caspase-3 activation.
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Accelerating drug discovery via organs-on-chips.
Lab Chip
PUBLISHED: 11-07-2013
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Considerable advances have been made in the development of micro-physiological systems that seek to faithfully replicate the complexity and functionality of animal and human physiology in research laboratories. Sometimes referred to as "organs-on-chips", these systems provide key insights into physiological or pathological processes associated with health maintenance and disease control, and serve as powerful platforms for new drug development and toxicity screening. In this Focus article, we review the state-of-the-art designs and examples for developing multiple "organs-on-chips", and discuss the potential of this emerging technology to enhance our understanding of human physiology, and to transform and accelerate the drug discovery and preclinical testing process. This Focus article highlights some of the recent technological advances in this field, along with the challenges that must be addressed for these technologies to fully realize their potential.
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Biosynthesis and release of pheromonal bile salts in mature male sea lamprey.
BMC Biochem.
PUBLISHED: 10-28-2013
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In vertebrates, bile salts are primarily synthesized in the liver and secreted into the intestine where they aid in absorption of dietary fats. Small amounts of bile salts that are not reabsorbed into enterohepatic circulation are excreted with waste. In sexually mature male sea lamprey (Petromyzon marinus L.) a bile salt is released in large amounts across gill epithelia into water where it functions as a pheromone. We postulate that the release of this pheromone is associated with a dramatic increase in its biosynthesis and transport to the gills upon sexual maturation.
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A MedRadio-band low-energy-per-bit 4-Mbps CMOS OOK receiver for implantable medical devices.
Conf Proc IEEE Eng Med Biol Soc
PUBLISHED: 10-11-2013
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A 4-Mbps 400-MHz On-Off Keying (OOK) receiver implemented in 0.18-um CMOS technology for implantable epilepsy sense-and-stimulation devices is presented. The proposed receiver is composed of a new current-mode full-wave envelope detector and differential cascaded gain amplifiers which is operated at MedRadio band. The fabricated receiver has power consumption of 0.27 mW and energy consumption of 0.07 nJ per bit at 4-Mbps. The sensitivity of receiver is -45.67 dBm.
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Baseline high viral load and unfavorable patterns of alanine aminotransferase change predict virological relapse in patients with chronic hepatitis C genotype 1 or 2 obtaining rapid virological response during antiviral therapy.
Hepat Mon
PUBLISHED: 10-01-2013
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Rapid virological response (RVR) strongly predicts sustained virological response (SVR) in patients with chronic hepatitis C (CHC), and abbreviates antiviral therapy in some patients.
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Lactococcus formosensis sp. nov., a novel lactic acid bacterium isolated from yan-tsai-shin (fermented broccoli stems).
Int. J. Syst. Evol. Microbiol.
PUBLISHED: 09-25-2013
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A coccal-shaped organism, designated 516T, was isolated from yan-tsai-shin (fermented broccoli stems), which is a traditional fermented food in Taiwan. 16S rRNA gene sequencing results showed that strain 516T had 98.9% sequence similarity to that of the type strain Lactococcus garvieae NBRC 100943T. Comparison of three housekeeping genes, rpoA, rpoB and pheS, revealed that strain 516T was well separated from L. garvieae NBRC 100943T. DNA-DNA hybridization studies indicated that strain 516T had low DNA relatedness with L. garvieae NBRC 100943T (46.1%). The DNA G+C content of strain 516T was 38.1 mol% and the major fatty acids were C16:0 (22.7%) and cyclo-C19:0 ?8c (17.9%) and summed feature 7 (29.0%). Based on the evidence, strain 516T represents a novel species of the genus Lactococcus, for which the name L. formosensis sp. nov. is proposed. The type strain is 516T = NBRC 109475T = BCRC 80576T.
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Ten-Day Quadruple Therapy Comprising Proton-Pump Inhibitor, Bismuth, Tetracycline, and Levofloxacin Achieves a High Eradication Rate for Helicobacter pylori Infection after Failure of Sequential Therapy.
Helicobacter
PUBLISHED: 09-06-2013
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Sequential therapy has been recommended in the Maastricht IV/Florence Consensus Report as the first-line treatment for Helicobacter pylori eradication in regions with high clarithromycin resistance. However, it fails in 5-24% of infected subjects, and the recommended levofloxacin-containing triple rescue therapy only achieves a 77% eradication rate after failure of sequential therapy.
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Real time in vivo investigation of superoxide dynamics in zebrafish liver using a single-fiber fluorescent probe.
Biomed Opt Express
PUBLISHED: 09-01-2013
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Superoxide anion is the key radical that causes intracellular oxidative stress. The lack of a method to directly monitor superoxide concentration in vivo in real time has severely hindered our understanding on its pathophysiology. We made transgenic zebrafish to specifically express yellow fluorescent proteins, a reversible superoxide-specific indicator, in the liver and used a fiber-optic fluorescent probe to noninvasively monitor the superoxide concentration in real time. Several superoxide-inducing and scavenging reagents were administrated onto the fish to alter superoxide concentrations. The distinct biochemical pathways of the reagents can be discerned from the transient behaviors of fluorescence time courses. These results demonstrate the feasibility of this method for analyzing superoxide dynamics and its potential as an in vivo pharmaceutical screening platform.
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Enterococcus saccharolyticus subsp. taiwanensis subsp. nov., isolated from broccoli.
Int. J. Syst. Evol. Microbiol.
PUBLISHED: 08-19-2013
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A coccal strain isolated from fresh broccoli was initially identified as Enterococcus saccharolyticus; however, molecular identification and phenotypic traits did not support this identification. DNA-DNA hybridization with the type strain of E. saccharolyticus (76.4?% relatedness), DNA G+C content (35.7 mol%), phylogenetic analysis based on 16S rRNA, pheS and rpoA gene sequences, rep-PCR fingerprinting and profiles of cellular fatty acids, whole-cell proteins and enzyme activities, together with carbohydrate metabolism characteristics, indicated that this strain is distinct and represents a novel subspecies, for which the name Enterococcus saccharolyticus subsp. taiwanensis subsp. nov. is proposed. The type strain is 812(T) (?=?NBRC 109476(T)?=?BCRC 80575(T)). Furthermore, we present an emended description of Enterococcus saccharolyticus and proposal of Enterococcus saccharolyticus subsp. saccharolyticus subsp. nov. (type strain ATCC 43076(T)?=?CCUG 27643(T)?=?CCUG 33311(T)?=?CIP 103246(T)?=?DSM 20726(T)?=?JCM 8734(T)?=?LMG 11427(T)?=?NBRC 100493(T)?=?NCIMB 702594(T)).
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Phthalates may promote female puberty by increasing kisspeptin activity.
Hum. Reprod.
PUBLISHED: 08-14-2013
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Is there an association between exposure to phthalates and the timing of female puberty?
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Diversity of Lactic Acid Bacteria Associated with Fresh Coffee Cherries in Taiwan.
Curr. Microbiol.
PUBLISHED: 08-06-2013
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A total of 102 lactic acid bacteria (LAB) were isolated from three different coffee farms in Taiwan. These isolates were classified and identified by the restriction fragment length polymorphism analysis and sequencing of 16S ribosomal DNA. Heterofermentative Leuconostoc, and Weissella species were the most common LAB found in two farms located at an approximate altitude of 800 m. Lactococcus lactis subsp. lactis was the most common LAB found in the remaining farm was located at an approximate altitude of 1,200 m. It is therefore suggested that the altitude and climate may affect the distribution of LAB. On the basis of phylogenetic analysis, two strains included in the genera Enterococcus were considered as two potential novel species or subspecies. In addition, a total of 34 isolates showed the antifungal activity against Aspergillus flavus. Moreover, seven Lactococcus lactis subsp. lactis strains and one Enterococcus faecalis strain were found to have bacteriocin-like inhibitory substance-producing capability. These results suggest that various LAB are associated with fresh coffee cherries in Taiwan. Some of the isolates found in this study showed potential as antifungal agents.
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The sea lamprey has a primordial accessory olfactory system.
BMC Evol. Biol.
PUBLISHED: 08-01-2013
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A dual olfactory system, represented by two anatomically distinct but spatially proximate chemosensory epithelia that project to separate areas of the forebrain, is known in several classes of tetrapods. Lungfish are the earliest evolving vertebrates known to have this dual system, comprising a main olfactory and a vomeronasal system (VNO). Lampreys, a group of jawless vertebrates, have a single nasal capsule containing two anatomically distinct epithelia, the main (MOE) and the accessory olfactory epithelia (AOE). We speculated that lamprey AOE projects to specific telencephalic regions as a precursor to the tetrapod vomeronasal system.
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An acoustofluidic micromixer based on oscillating sidewall sharp-edges.
Lab Chip
PUBLISHED: 07-31-2013
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Rapid and homogeneous mixing inside a microfluidic channel is demonstrated via the acoustic streaming phenomenon induced by the oscillation of sidewall sharp-edges. By optimizing the design of the sharp-edges, excellent mixing performance and fast mixing speed can be achieved in a simple device, making our sharp-edge-based acoustic micromixer a promising candidate for a wide variety of applications.
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A CMOS power-efficient low-noise current-mode front-end amplifier for neural signal recording.
IEEE Trans Biomed Circuits Syst
PUBLISHED: 07-16-2013
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In this paper, a new current-mode front-end amplifier (CMFEA) for neural signal recording systems is proposed. In the proposed CMFEA, a current-mode preamplifier with an active feedback loop operated at very low frequency is designed as the first gain stage to bypass any dc offset current generated by the electrode-tissue interface and to achieve a low high-pass cutoff frequency below 0.5 Hz. No reset signal or ultra-large pseudo resistor is required. The current-mode preamplifier has low dc operation current to enhance low-noise performance and decrease power consumption. A programmable current gain stage is adopted to provide adjustable gain for adaptive signal scaling. A following current-mode filter is designed to adjust the low-pass cutoff frequency for different neural signals. The proposed CMFEA is designed and fabricated in 0.18-?m CMOS technology and the area of the core circuit is 0.076 mm(2). The measured high-pass cutoff frequency is as low as 0.3 Hz and the low-pass cutoff frequency is adjustable from 1 kHz to 10 kHz. The measured maximum current gain is 55.9 dB. The measured input-referred current noise density is 153 fA /?Hz , and the power consumption is 13 ?W at 1-V power supply. The fabricated CMFEA has been successfully applied to the animal test for recording the seizure ECoG of Long-Evan rats.
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Probing cell-cell communication with microfluidic devices.
Lab Chip
PUBLISHED: 07-10-2013
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Intercellular communication is a mechanism that regulates critical events during embryogenesis and coordinates signalling within differentiated tissues, such as the nervous and cardiovascular systems. To perform specialized activities, these tissues utilize the rapid exchange of signals among networks that, while are composed of different cell types, are nevertheless functionally coupled. Errors in cellular communication can lead to varied deleterious effects such as degenerative and autoimmune diseases. However, the intercellular communication network is extremely complex in multicellular organisms making isolation of the functional unit and study of basic mechanisms technically challenging. New experimental methods to examine mechanisms of intercellular communication among cultured cells could provide insight into physiological and pathological processes alike. Recent developments in microfluidic technology allow miniaturized and integrated devices to perform intercellular communication experiments on-chip. Microfluidics have many advantages, including the ability to replicate in vitro the chemical, mechanical, and physical cellular microenvironment of tissues with precise spatial and temporal control combined with dynamic characterization, high throughput, scalability and reproducibility. In this Focus article, we highlight some of the recent work and advances in the application of microfluidics to the study of mammalian intercellular communication with particular emphasis on cell contact and soluble factor mediated communication. In addition, we provide some insights into likely direction of the future developments in this field.
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Long-term Outcomes of Carotid Artery Stenting for Radiation-Associated Stenosis.
Biomed J
PUBLISHED: 06-29-2013
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In Taiwan, the prevalence of head and neck cancer is relatively high. Because radiation-associated carotid stenosis is a significant risk factor for stroke, carotid artery stenting (CAS), instead of carotid endarterectomy, is indicated in patients with radiation-associated carotid stenosis. We sought to evaluate the effect of neck radiotherapy (XRT) on the long-term outcome of patients undergoing CAS.
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A thermogenic secondary sexual character in male sea lamprey.
J. Exp. Biol.
PUBLISHED: 06-28-2013
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Secondary sexual characters in animals are exaggerated ornaments or weapons for intrasexual competition. Unexpectedly, we found that a male secondary sexual character in sea lamprey (Petromyzon marinus) is a thermogenic adipose tissue that instantly increases its heat production during sexual encounters. This secondary sexual character, developed in front of the anterior dorsal fin of mature males, is a swollen dorsal ridge known as the rope tissue. It contains nerve bundles, multivacuolar adipocytes and interstitial cells packed with small lipid droplets and mitochondria with dense and highly organized cristae. The fatty acid composition of the rope tissue is rich in unsaturated fatty acids. The cytochrome c oxidase activity is high but the ATP concentration is very low in the mitochondria of the rope tissue compared with those of the gill and muscle tissues. The rope tissue temperature immediately rose up to 0.3°C when the male encountered a conspecific. Mature males generated more heat in the rope and muscle tissues when presented with a mature female than when presented with a male (paired t-test, P<0.05). On average, the rope generated 0.027±0.013 W cm(-3) more heat than the muscle in 10 min. Transcriptome analyses revealed that genes involved in fat cell differentiation are upregulated whereas those involved in oxidative-phosphorylation-coupled ATP synthesis are downregulated in the rope tissue compared with the gill and muscle tissues. Sexually mature male sea lamprey possess the only known thermogenic secondary sexual character that shows differential heat generation toward individual conspecifics.
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Discovery, Synthetic Methodology, and Biological Evaluation for Antiphotoaging Activity of Bicyclic[1,2,3]triazoles: In Vitro and in Vivo Studies.
J. Med. Chem.
PUBLISHED: 06-28-2013
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Novel bicyclic[1,2,3]triazoles (4, 7, 11, 15) have been synthesized using a one-pot metal free strategy with high structural diversity as photoprotective agents, and their effect on UVA-induced senescence in human dermal fibroblast cells (FB) and the associated mechanism are delineated. 11d plus UVA can induce a decrease in reactive oxygen species (ROS) production and senescence-associated ?-galactosidase (SA-?-gal) activity but an increase in adenosine triphosphate (ATP) synthesis and mitochondrial membrane potential (??mt). The mRNA levels of six senescence-associated genes, matrix metalloproteinase-1 (MMP-1), was decreased, while elastin, procollagen I type I, fibronectin, COL1?1, and tissue inhibitor of metalloproteinase-1 (TIMP-1) were increased. 11d plus UVA also decreased MMP-1 and increased TIMP-1 protein levels. Additionally, the thickness of the murine dorsal skin and epidermis, by UVA, was decreased by topical 11d treatment. Our results indicate that bicyclic[1,2,3]triazoles protect UVA-induced senescence-like characteristics in FB cells, which may provide potential prevention against photoaging.
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Tunable, pulsatile chemical gradient generation via acoustically driven oscillating bubbles.
Lab Chip
PUBLISHED: 06-19-2013
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We present a novel concept of generating both static and pulsatile chemical gradients using acoustically activated bubbles designed in a ladder-like arrangement. Furthermore, by regulating the amplitude of the bubble oscillation, we demonstrate that the chemical gradient profiles can be effectively tuned.
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Estimation of tea catechin levels using micellar electrokinetic chromatography: A quantitative approach.
Food Chem
PUBLISHED: 06-12-2013
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A simple, inexpensive micellar electrokinetic chromatography (MEKC) method with UV detection was used to determine seven catechins and one xanthine (caffeine) in tea. All the compounds were successfully separated (15kV) within a 15-min migration period with a high number of theoretical plates (>8.0×10(4)) in a running buffer (pH 7) containing 10mmoll(-1) sodium tetraborate, 4mmoll(-1) sodium phosphate, and 25mmoll(-1) SDS. The regression lines of all standard catechins were linear within the range of 0.03-4?gml(-1). Green tea infused at 95°C for 10min showed higher levels of catechins (especially epigallocatechin galate, epicatechin gallate, and epicatechin) than tea infused at 80°C. In addition, major differences were observed in the levels of catechins in the first and second infusions (both brewed at 95°C for 10min). Finally, green tea leaves were infused separately with tap water, deionised water, spring water, reverse osmosis water, and distilled water at 95°C, and the catechin content of the infusions was investigated by the proposed method. In the infusion brewed with tap water, catechins appeared to be epimerisation from the epistructure to the nonepistructure. This epimerisation may take place more readily in tap water than in distilled water owing to the complexity of the ions present in tap water.
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Synthesis, DNA-binding abilities and anticancer activities of triazole-pyrrolo[2,1-c][1,4]benzodiazepines hybrid scaffolds.
Bioorg. Med. Chem. Lett.
PUBLISHED: 05-28-2013
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We synthesized a new series of PBD-hybrid derivatives having tethered triazoles and investigated for their cytotoxicity. The studies indicated that cis-olefin compounds induce higher cytotoxicity with increase in the G1 cell cycle phase compared with the trans-compounds. Quantitative RT-PCR assay indicated that compounds (16a-d) induced G1 phase arrest through down-regulation of cyclin D1 and up-regulation of p21, p27, and p53 mRNA expressions. Compounds 16a-d induced A375 early apoptosis as detected by flow cytometry after double-staining with annexin V and propidium iodide. Moreover, the Western blot analysis showed that A375 treated by compounds (16a-d) resulted in decreased levels of Bcl-2 and Bcl-xL, increased levels of Bax and Bad, and caspase/PARP degradation to identify apoptotic cells.
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What is Visualize?

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

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

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