JoVE Visualize What is visualize?
Stop Reading. Start Watching.
Advanced Search
Stop Reading. Start Watching.
Regular Search
Find video protocols related to scientific articles indexed in Pubmed.
Thermally Induced Percolational Transition and Thermal Stability of Silver Nanowire Networks Studied by THz Spectroscopy.
ACS Appl Mater Interfaces
PUBLISHED: 11-18-2014
Show Abstract
Hide Abstract
Great demand toward flexible optoelectronic devices finds metal nanowires (NWs) the most promising flexible transparent conducting material with superior mechanical property. However, ultrathin metal nanowires suffer from relatively poor thermal stability and sheet conductance, attributed to the poor adhesivity of the ohmic contact between nanowires. Thermal heating and annealing at 200 °C increase the conductivity of metal network, but prolonged annealing accelerates the breakage of NWs near NW junction and the formation of Ag droplets. In this study, thermal stability of silver NW (AgNW) films is investigated through the in-situ measurements of sheet resistance and terahertz (THz) conductivity. With the improved ohmic contact at the NW junctions by heating, a characteristic transition from subpercolative to percolative network is observed by in-situ THz spectroscopy. It is found that stamp-transferred graphene incorporated with near-percolative AgNW network can dramatically enhance the thermal stability of graphene-AgNW (GAgNW) hybrid film. In both in-situ measurements, little variation of physical parameters in GAgNW film is observed during up to 3 hours of annealing. The presented results offer the potential of graphene-incorporated metal nanowire film as highly conductive electrode that also has high thermal stability and excellent transparency for next-generation electronics and optoelectronics on flexible substrates.
Related JoVE Video
Diamagnetic Levitation Promotes Osteoclast Differentiation from RAW264.7 Cells.
IEEE Trans Biomed Eng
PUBLISHED: 11-15-2014
Show Abstract
Hide Abstract
The superconducting magnet with a high magnetic force field can levitate diamagnetic materials. In this study, a specially designed superconducting magnet with large gradient high magnetic field (LGHMF), which provides three apparent gravity levels (? g, 1 g and 2 g), was used to study its influence on receptor activator of nuclear factor-?B ligand (RANKL)-induced osteoclast differentiation from pre-osteoclast cell line RAW264.7. The effects of LGHMF on the viability, nitric oxide (NO) production, morphology in RAW264.7 cells were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method, Griess method and immunofluorescence staining, respectively. The changes induced by LGHMF in osteoclast formation, mRNA expression and bone resorption were determined by tartrate-resistant acid phosphatase staining, semi-quantity PCR and bone resorption test, respectively. The results showed that: 1) LGHMF had no lethal effect on osteoclast precursors but attenuated NO release in RAW264.7 cells. 2) Diamagnetic levitation (? g) enhanced both the formation and bone resorption capacity of osteoclast. Moreover, diamagnetic levitation up-regulated mRNA expression of RANK, Cathepsin K, MMP-9 and NFATc1 while down-regulated RunX2 in comparison with controls. Furthermore, diamagnetic levitation induced obvious morphological alterations in osteoclast, including active cytoplasmic peripheral pseudopodial expansion, formation of pedosome belt and aggregation of actin ring. 3) Magnetic field produced by LGHMF attenuated osteoclast resorption activity. Collectively, LGHMF with combined effects has multiple effects on osteoclast, which attenuated osteoclast resorption with magnetic field whereas promoted osteoclast differentiation with diamagnetic levitation. Therefore, these findings indicate that diamagnetic levitation could be used as a novel ground-based microgravity simulator which facilitates bone cell research of weightlessness condition.
Related JoVE Video
Granulocyte colony-stimulating factor ameliorates coronary artery elastin breakdown in a mouse model of Kawasaki disease.
Chin. Med. J.
PUBLISHED: 11-11-2014
Show Abstract
Hide Abstract
Coronary artery damage from Kawasaki disease (KD) is closely linked to the dysfunction of the endothelial progenitor cells (EPCs). The aim of the present study was to evaluate the modulatory effect of granulocyte colony-stimulating factor (G-CSF) on EPCs and elastin breakdown of coronary arteries in a KD mouse model.
Related JoVE Video
Phase imaging using shifted wavefront sensor images.
Opt Lett
PUBLISHED: 11-01-2014
Show Abstract
Hide Abstract
We propose a new approach to the complete retrieval of a coherent field (amplitude and phase) using the same hardware configuration as a Shack-Hartmann sensor but with two modifications: first, we add a transversally shifted measurement to resolve ambiguities in the measured phase; and second, we employ factored form descent (FFD), an inverse algorithm for coherence retrieval, with a hard rank constraint. We verified the proposed approach using both numerical simulations and experiments.
Related JoVE Video
High-speed and broadband terahertz wave modulators based on large-area graphene field-effect transistors.
Opt Lett
PUBLISHED: 11-01-2014
Show Abstract
Hide Abstract
We present a broadband terahertz wave modulator with improved modulation depth and switch speed by cautiously selecting the gate dielectric materials in a large-area graphene-based field-effect transistor (GFET). An ultrathin Al2O3 film (?60??nm) is deposited by an atomic-layer-deposition technique as a high-k gate dielectric layer, which reduces the Coulomb impurity scattering and cavity effect, and thus greatly improves the modulation performance. Our modulator has achieved a modulation depth of 22% and modulation speed of 170 kHz in a frequency range from 0.4 to 1.5 THz, which is a large improvement in comparison to its predecessor of SiO2-based GFET.
Related JoVE Video
High-Precision (143)Nd/(144)Nd Ratios from NdO(+) Data Corrected with in-Run Measured Oxygen Isotope Ratios.
Anal. Chem.
PUBLISHED: 10-27-2014
Show Abstract
Hide Abstract
The NdO(+) technique has been considerably refined in recent years for high-precision measurement of Nd isotope ratios in low-level samples (1-5 ng Nd). As oxygen isotopic compositions may vary significantly with experimental conditions such as filament material, ionization enhancer and the ambient oxygen in the ion source, great "care" should be taken for using correct oxygen isotopic compositions to do the isobaric oxide corrections for the "conventional" NdO(+) method. Our method presented here for NdO(+) data reduction and PrO(+) interference corrections uses the oxygen isotope composition determined in each cycle of the NdO(+) measurements. For that purpose, we measured the small ion signals of (150)Nd(17)O(+) and (150)Nd(18)O(+) with amplifiers equipped with 10(12) ? feedback resistors, and those of Nd(16)O(+) ion beams with 10(11) ? amplifiers. Using 10(12) ? amplifiers facilitates a precise measurement of the very small (150)Nd(17)O(+) and (150)Nd(18)O(+) ion signals and calculation of highly accurate and precise (143)Nd/(144)Nd isotope ratios. The (143)Nd/(144)Nd ratios for JNdi-1 standards and several whole-rock reference materials determined with the method on 4 ng of Nd loads are consistent with previously reported values within analytical error, with internal and external precision (2 RSE and 2 RSD) of better than 20 and 30 ppm, respectively.
Related JoVE Video
Delivery of an enzyme-IGFII fusion protein to the mouse brain is therapeutic for mucopolysaccharidosis type IIIB.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 09-29-2014
Show Abstract
Hide Abstract
Mucopolysaccharidosis type IIIB (MPS IIIB, Sanfilippo syndrome type B) is a lysosomal storage disease characterized by profound intellectual disability, dementia, and a lifespan of about two decades. The cause is mutation in the gene encoding ?-N-acetylglucosaminidase (NAGLU), deficiency of NAGLU, and accumulation of heparan sulfate. Impediments to enzyme replacement therapy are the absence of mannose 6-phosphate on recombinant human NAGLU and the blood-brain barrier. To overcome the first impediment, a fusion protein of recombinant NAGLU and a fragment of insulin-like growth factor II (IGFII) was prepared for endocytosis by the mannose 6-phosphate/IGFII receptor. To bypass the blood-brain barrier, the fusion protein ("enzyme") in artificial cerebrospinal fluid ("vehicle") was administered intracerebroventricularly to the brain of adult MPS IIIB mice, four times over 2 wk. The brains were analyzed 1-28 d later and compared with brains of MPS IIIB mice that received vehicle alone or control (heterozygous) mice that received vehicle. There was marked uptake of the administered enzyme in many parts of the brain, where it persisted with a half-life of approximately 10 d. Heparan sulfate, and especially disease-specific heparan sulfate, was reduced to control level. A number of secondary accumulations in neurons [?-hexosaminidase, LAMP1(lysosome-associated membrane protein 1), SCMAS (subunit c of mitochondrial ATP synthase), glypican 5, ?-amyloid, P-tau] were reduced almost to control level. CD68, a microglial protein, was reduced halfway. A large amount of enzyme also appeared in liver cells, where it reduced heparan sulfate and ?-hexosaminidase accumulation to control levels. These results suggest the feasibility of enzyme replacement therapy for MPS IIIB.
Related JoVE Video
Heterobimetallic dinuclear lanthanide alkoxide complexes as acid-base difunctional catalysts for transesterification.
J. Org. Chem.
PUBLISHED: 09-23-2014
Show Abstract
Hide Abstract
A practical lanthanide(III)-catalyzed transesterification of carboxylic esters, weakly reactive carbonates, and much less-reactive ethyl silicate with primary and secondary alcohols was developed. Heterobimetallic dinuclear lanthanide alkoxide complexes [Ln2Na8{(OCH2CH2NMe2)}12(OH)2] (Ln = Nd (I), Sm (II), and Yb (III)) were used as highly active catalysts for this reaction. The mild reaction conditions enabled the transesterification of various substrates to proceed in good to high yield. Efficient activation of transesterification may be endowed by the above complexes as cooperative acid-base difunctional catalysts, which is proposed to be responsible for the higher reactivity in comparison with simple acid/base catalysts.
Related JoVE Video
CUL4B promotes proliferation and inhibits apoptosis of human osteosarcoma cells.
Oncol. Rep.
PUBLISHED: 09-05-2014
Show Abstract
Hide Abstract
Cullin 4B (CUL4B) is a component of the Cullin4B-Ring E3 ligase complex (CRL4B) that functions in proteolysis and is implicated in tumorigenesis. Here, we report that CUL4B is associated with tumorigenesis by promoting proliferation and inhibiting apoptosis of human osteosarcoma cells. We performed RNA interference (RNAi) with a lentiviral vector system to silence the CUL4B gene using osteosarcoma SAOS-2 cells. The negative control included the normal target cells infected with the negative control virus whereas the knockdown cells included the normal target cells transfected with the RNAi target virus. We assessed the inhibition resulting from the decreased expression of the CUL4B gene on the proliferation rate of SAOS-2 cells, and also evaluated the cell cycle distribution, apoptosis and clonability. Compared with the negative control, the CUL4B gene expression was significantly inhibited in the SAOS-2 cells at the mRNA and protein levels in the knockdown group (P<0.01). Furthermore, in the knockdown group, the cell proliferation rate and clonability were also significantly inhibited (P<0.01). The apoptosis rate increased significantly (P<0.05). A significant decrease in the number of cells in the G1 phase (P<0.01) and significant increases in the S (P<0.01) and G2 phases (P<0.05) were observed. The silencing of CUL4B gene expression can effectively inhibit osteosarcoma cell proliferation and induce apoptosis. These findings may provide a novel biomarker for the treatment of osteosarcoma.
Related JoVE Video
Retroperitoneoscopic dismembered pyeloplasty for ureteropelvic junction obstruction: modification of the procedure and our experience.
Urol J
PUBLISHED: 09-02-2014
Show Abstract
Hide Abstract
To report a modified retroperitoneoscopic dismembered pyeloplasty technique and its application in the treatment of ureteropelvic junction obstruction (UPJO).
Related JoVE Video
Chronic Hydrocephalus and Perihematomal Tissue Injury Developed in a Rat Model of Intracerebral Hemorrhage with Ventricular Extension.
Transl Stroke Res
PUBLISHED: 08-30-2014
Show Abstract
Hide Abstract
Primary spontaneous intracerebral hemorrhage (ICH) with secondary intraventricular hemorrhage (IVH) is an important clinical problem of which little is known. IVH and hydrocephalus are independent predictors of poor outcome in ICH. The aims of this study were, therefore, to establish a rat model of ICH with ventricular extension and investigate the occurrence of post-hemorrhagic chronic hydrocephalus and perihematomal tissue injury. Based on our previous rat model of IVH, we adjusted the injection coordinates and 200 ?l autologous blood was stereotaxically infused into the right striatum (coordinates: 0.2 mm posterior, 2.2 mm lateral, and 5.0 mm depth to the bregma). At 24 h post-infusion, the rats produced reproducible hematoma and ventricle expansion, which closely mimics the ICH with ventricular extension in humans. Hematoma consequences and perihematomal tissue injury were evaluated on the acute phase. At 4 weeks, ventricular dilatation, brain tissue loss, hippocampus volume, and cortical thickness were measured with magnetic resonance imaging and neurocognitive function was assessed using the Morris water maze test. With blood infusion, the animals demonstrated brain edema, blood-brain barrier breakdown, and marked perihematomal tissue injury on the acute phase. At 4 weeks, the T2 images showed remarkable hydrocephalus and tissue loss, and the Morris water maze test revealed neurocognitive deficits. The present ICH with the ventricular extension rat model features characteristics of both ICH and IVH rat models, which could be used for extending our pathophysiological understanding of post-hemorrhagic chronic hydrocephalus and perihematomal tissue damage.
Related JoVE Video
Calcium intake and ion transporter genetic polymorphisms interact in human colorectal neoplasia risk in a 2-phase study.
J. Nutr.
PUBLISHED: 08-27-2014
Show Abstract
Hide Abstract
The kidney-specific sodium-potassium-chloride cotransporter (NKCC2) protein encoded by solute carrier family 12 member 1 (SLC12A1) is the direct downstream effector of the inward-rectifier potassium channel (ROMK) encoded by potassium inwardly-rectifying channel, subfamily J, member 1 (KCNJ1), both of which are critical for calcium reabsorption in the kidney.
Related JoVE Video
Urinary CD80 levels as a diagnostic biomarker of minimal change disease.
Pediatr. Nephrol.
PUBLISHED: 08-21-2014
Show Abstract
Hide Abstract
Early diagnosis of minimal change disease (MCD) in nephrotic syndrome (NS) patients remains challenging. Doctors often make a diagnosis of MCD using invasive renal biopsy. CD80, a transmembrane protein, is present on podocytes in a number of experimental models of NS. Urinary CD80 levels are significantly elevated in MCD but not in focal segmental glomerulosclerosis (FSGS) or other glomerulopathies. The purpose of this study was to investigate the feasibility of using urinary CD80 levels as a biomarker for the diagnosis of MCD.
Related JoVE Video
Memetic algorithm-based multi-objective coverage optimization for wireless sensor networks.
Sensors (Basel)
PUBLISHED: 08-09-2014
Show Abstract
Hide Abstract
Maintaining effective coverage and extending the network lifetime as much as possible has become one of the most critical issues in the coverage of WSNs. In this paper, we propose a multi-objective coverage optimization algorithm for WSNs, namely MOCADMA, which models the coverage control of WSNs as the multi-objective optimization problem. MOCADMA uses a memetic algorithm with a dynamic local search strategy to optimize the coverage of WSNs and achieve the objectives such as high network coverage, effective node utilization and more residual energy. In MOCADMA, the alternative solutions are represented as the chromosomes in matrix form, and the optimal solutions are selected through numerous iterations of the evolution process, including selection, crossover, mutation, local enhancement, and fitness evaluation. The experiment and evaluation results show MOCADMA can have good capabilities in maintaining the sensing coverage, achieve higher network coverage while improving the energy efficiency and effectively prolonging the network lifetime, and have a significant improvement over some existing algorithms.
Related JoVE Video
[Therapeutic effect of regular urethral dilatation on patients with postoperative urethral stricture].
Zhong Nan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 08-02-2014
Show Abstract
Hide Abstract
To determine the therapeutic effect of regular urethral dilatation on patients with postoperative urethral stricture.
Related JoVE Video
Reactive oxygen species deficiency induces autoimmunity with type 1 interferon signature.
Antioxid. Redox Signal.
PUBLISHED: 07-29-2014
Show Abstract
Hide Abstract
Abstract Aims: Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by mutations in the phagocyte reactive oxygen species (ROS)-producing NOX2 enzyme complex and characterized by recurrent infections associated with hyperinflammatory and autoimmune manifestations. A translational, comparative analysis of CGD patients and the corresponding ROS-deficient Ncf1(m1J) mutated mouse model was performed to reveal the molecular pathways operating in NOX2 complex deficient inflammation.
Related JoVE Video
LPS-induced dental pulp inflammation increases expression of ionotropic purinergic receptors in rat trigeminal ganglion.
Neuroreport
PUBLISHED: 07-24-2014
Show Abstract
Hide Abstract
Severe toothache can be caused by dental pulp inflammation. The ionotropic purinergic receptor family (P2X) is reported to mediate nociception in primary afferent neurons. This study aims to investigate the involvement of P2X receptors in the sensitization of the trigeminal ganglion (TG) caused by dental pulp inflammation. Lipopolysaccharides were unilaterally applied to the pulp of the upper molar of the rat to induce dental pulp inflammation. Increased expression of c-fos, a marker of neuronal activity, was induced in V1-V2 division, indicating the activation of TG neurons. The expressions of P2X2, P2X3, and P2X5 were also increased in the V1-V2 division of TG, primarily in small-sized and medium-sized neurons. Markers of glutamatergic afferents, VGluT1, and GABAergic afferents, GAD67, were induced by lipopolysaccharides and coexpressed with P2X in small-sized TG neurons. The present findings suggest that the P2X2, P2X3, and P2X5 receptors are upregulated as part of the sensitization produced by dental pulp inflammation.
Related JoVE Video
Preserved function of late-outgrowth endothelial cells in medically treated hypertensive patients under well-controlled conditions.
Hypertension
PUBLISHED: 07-21-2014
Show Abstract
Hide Abstract
Endothelial progenitor cells (EPCs) participate in renal repair, but their number and function may be impaired by exposure to cardiovascular risk factors. The number of circulating EPCs is decreased in essential and renovascular hypertensive patients, but the effects of hypertension on EPC function are incompletely understood. We hypothesized that EPC function was preserved under well-controlled conditions in treated hypertensive patients. Patients with atherosclerotic renal artery stenosis (ARAS; n=22) or essential hypertension (n=24) were studied during controlled sodium intake and antihypertensive regimen. Late-outgrowth EPCs were isolated from the inferior vena cava (IVC) and renal vein blood of ARAS and essential hypertension patients and a peripheral vein of matched normotensive controls (n=18). The angiogenic function of EPCs was assessed in vitro, and multidetector computed tomography was used to measure single-kidney hemodynamics and function in ARAS and essential hypertension patients. Inflammatory biomarkers and EPC homing signal levels and renal release were calculated. Inferior vena cava and renal vein-obtained EPC function were similar in ARAS and essential hypertension patients and comparable to that in normal controls (tube length, 171.86±16.846, 191.09±14.222, 174.925±19.774 ?m, respectively). Function of renal vein-obtained EPCs directly correlated with stenotic kidney glomerular filtration rate, EPC homing factors, and anti-inflammatory mediator levels in ARAS patients. Therefore, EPC function was relatively preserved in ARAS patients, although it directly correlated with renal function. Adequate EPC function supports the feasibility of using autologous EPCs as a therapeutic option in essential and renovascular hypertensive patients. Homing signals and inflammatory mediators may potentially regulate EPC angiogenic function.
Related JoVE Video
The biomechanical role of periodontal ligament in bonded and replanted vertically fractured teeth under cyclic biting forces.
Int J Oral Sci
PUBLISHED: 07-07-2014
Show Abstract
Hide Abstract
After teeth are replanted, there are two possible healing responses: periodontal ligament healing or ankylosis with subsequent replacement resorption. The purpose of this study was to compare the fatigue resistance of vertically fractured teeth after bonding the fragments under conditions simulating both healing modes. Thirty-two human premolars were vertically fractured and the fragments were bonded together with Super-Bond C&B. They were then randomly distributed into four groups (BP, CP, CA, BA). The BP and CP groups were used to investigate the periodontal ligament healing mode whilst the BA and CA groups simulated ankylosis. All teeth had root canal treatment performed. Metal crowns were constructed for the CP and CA groups. The BP and BA groups only had composite resin restorations in the access cavities. All specimens were subjected to a 260?N load at 4?Hz until failure of the bond or until 2×10(6) cycles had been reached if no fracture occurred. Cracks were detected by stereomicroscope imaging and also assessed via dye penetration tests. Finally, interfaces of the resin luting agent were examined by scanning electron microscope. The results confirmed that the fatigue resistance was higher in the groups with simulated periodontal ligament healing. Periodontal reattachment showed important biomechanical role in bonded and replanted vertically fractured teeth.International Journal of Oral Science advance online publication, 12 September 2014; doi:10.1038/ijos.2014.51.
Related JoVE Video
Whole bone marrow cell culture: A convenient protocol for the in vitro expansion of endothelial progenitor cells.
Exp Ther Med
PUBLISHED: 07-04-2014
Show Abstract
Hide Abstract
The number and function of endothelial progenitor cells (EPCs) may be a predictive factor for the severity and outcome of cardiovascular disease. However, the manipulation of bone marrow mononuclear cell (BMMC) cultures for EPCs is an elaborate and difficult procedure in small experimental animals. The present study aimed to assess the feasibility of whole bone marrow cell (WBMC) culture for expanding EPCs in small experimental animals. C57BL/6 mice (age, 3-4 weeks; weight, 9.47±0.76 g) were used as the experimental animals, and WBMCs were isolated from the femora and tibiae and cultured in endothelial cell growth medium-2. A BMMC culture for EPCs was used as a control. EPC growth, phenotype and functions were assessed in vitro and in vivo. The results demonstrated that EPCs were easily obtained from a WBMC culture in vitro. The cells exhibited similar growth and biological characteristics when compared with the EPCs derived from the traditional BMMC culture system. Thus, the cells were able to simultaneously bind to lectin and cause phagocytosis of acetylated-low density lipoproteins. In addition, the cells exhibited high expression levels of cluster of differentiation 34 and fetal liver kinase 1, and possessed similar functional properties to BMMC-derived EPCs, including vascular network formation, proliferation, adhesion and migration abilities in vitro. Thus, WBMC-derived EPCs can improve the outcome of pulmonary vascular disease when transplanted into a monocrotaline-induced pulmonary hypertension mouse model. The results of the present study indicated that the WBMC culture system is a more convenient and effective method of obtaining and expanding EPCs compared with BMMC culture, with the advantage of a simplified procedure.
Related JoVE Video
Real-time 3D particle manipulation visualized using volume holographic gratings.
Opt Lett
PUBLISHED: 07-01-2014
Show Abstract
Hide Abstract
Holographic optical tweezers (HOTs) extend optical trapping into three dimensions. Volume imaging then becomes a concern as trapped objects are easily moved out of focus of the imaging objective lens. Here we demonstrate a three-dimensional real-time interactive optical trapping, manipulating, and imaging system based on HOTs incorporated with volume holographic microscope. Intensity information about the trapped objects at multiple depths can be captured in a single measurement. This method is compatible with most imaging modes such as bright-field and fluorescence.
Related JoVE Video
Age-related changes of the diffusion tensor imaging parameters of the normal cervical spinal cord.
Eur J Radiol
PUBLISHED: 06-27-2014
Show Abstract
Hide Abstract
The diffusion tensor imaging (DTI) parameters of the cervical spinal cord (CSC) changes with age. However, previous studies only examined specific CSC areas.
Related JoVE Video
Methods for time series analysis of RNA-seq data with application to human Th17 cell differentiation.
Bioinformatics
PUBLISHED: 06-17-2014
Show Abstract
Hide Abstract
Gene expression profiling using RNA-seq is a powerful technique for screening RNA species' landscapes and their dynamics in an unbiased way. While several advanced methods exist for differential expression analysis of RNA-seq data, proper tools to anal.yze RNA-seq time-course have not been proposed.
Related JoVE Video
Constitutive nuclear expression of dentin matrix protein 1 fails to rescue the Dmp1-null phenotype.
J. Biol. Chem.
PUBLISHED: 06-10-2014
Show Abstract
Hide Abstract
Dentin matrix protein 1 (DMP1) plays multiple roles in bone, tooth, phosphate homeostasis, kidney, salivary gland, reproductive cycles, and the development of cancer. In vitro studies have indicated two different biological mechanisms: 1) as a matrix protein, DMP1 interacts with ?v?3 integrin and activates MAP kinase signaling; and 2) DMP1 serves as a transcription co-factor. In vivo studies have demonstrated its key role in osteocytes. This study attempted to determine whether DMP1 functions as a transcription co-factor and regulates osteoblast functions. For gene expression comparisons using adenovirus constructs, we targeted the expression of DMP1 either to the nucleus only by replacing the endogenous signal peptide with a nuclear localization signal (NLS) sequence (referred to as (NLS)DMP1) or to the extracellular matrix as the WT type (referred to as (SP)DMP1) in MC3T3 osteoblasts. High levels of DMP1 in either form greatly increased osteogenic gene expression in an identical manner. However, the targeted (NLS)DMP1 transgene driven by a 3.6-kb rat Col 1?1 promoter in the nucleus of osteoblasts and osteocytes failed to rescue the phenotyope of Dmp1-null mice, whereas the (SP)DMP1 transgene rescued the rickets defect. These studies support the notion that DMP1 functions as an extracellular matrix protein, rather than as a transcription co-factor in vivo. We also show that DMP1 continues its expression in osteoblasts during postnatal development and that the deletion of Dmp1 leads to an increase in osteoblast proliferation. However, poor mineralization in the metaphysis indicates a critical role for DMP1 in both osteoblasts and osteocytes.
Related JoVE Video
Comparison of corneal deformation parameters after SMILE, LASEK, and femtosecond laser-assisted LASIK.
J Refract Surg
PUBLISHED: 06-07-2014
Show Abstract
Hide Abstract
To investigate the differences in corneal deformation parameters after femtosecond laser small incision lenticule extraction (SMILE), laser-assisted subepithelial keratomileusis (LASEK), and femtosecond laser-assisted LASIK (FS-LASIK).
Related JoVE Video
Chain-network anatase/TiO2 (B) thin film with improved photocatalytic efficiency.
Nanotechnology
PUBLISHED: 05-21-2014
Show Abstract
Hide Abstract
A 3-dimensional chain-network anatase/TiO2 (B) was obtained via the basic hydrothermal treatment of a sandwich Ti/TiO2/Ti film on a glass substrate that was prepared from 16 nm anatase TiO2 nanoparticles. The Ti film was converted to the TiO2 (B) phase in a Teflon vessel containing a 10 M NaOH aqueous solution that was encapsulated in a stainless-steel autoclave and heated at 130 °C for 2 h. The TiO2 (B) then served as a binder layer that enabled the formation of pearl-necklace chains made of anatase TiO2 nanoparticles, and these chain-like structures thoroughly interpenetrated into the textured layer. Decomposition tests using methylene blue indicated that the chain-network anatase/TiO2 (B) mixed-phase film had a photocatalytic half-life that was 0.84 and 0.69 times shorter than those of as-prepared anatase TiO2 and P25, respectively. In addition, the intensity of the room temperature photoluminescence spectra of anatase TiO2 was 2.55-fold higher than that of the chain-network anatase/TiO2 (B). We thus conclude that the remarkable photocatalytic activity of the chain-network anatase/TiO2 (B) is attributed to the chain-network structural characteristics and a synergistic effect of the matching band gap potentials, which increases the transfer of photogenerated electrons and reduces electron-hole recombination.
Related JoVE Video
Laparoendoscopic single-site ureteroureterostomy with intraoperative retrograde ureteroscopy-assisted technique for benign proximal and middle ureteral strictures: a single-center experience.
J Laparoendosc Adv Surg Tech A
PUBLISHED: 05-20-2014
Show Abstract
Hide Abstract
To report a minimally invasive and reproducible technique that greatly facilitates the identification of the stricture during laparoendoscopic single-site ureteroureterostomy (LESS-UU) for benign proximal and middle ureteral strictures, using the intraoperative retrograde ureteroscopy-assisted technique.
Related JoVE Video
[The influence of positive end-expiratory pressure on cerebral blood flow and cerebrovascular autoregulation in patients with acute respiratory distress syndrome].
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue
PUBLISHED: 05-10-2014
Show Abstract
Hide Abstract
To explore the influence of different positive end-expiratory pressure (PEEP) levels on cerebral blood flow (CBF) and cerebrovascular autoregulation in patients with acute respiratory distress syndrome(ARDS).
Related JoVE Video
MicroRNA expression profiles related to early stage murine concanavalin A-induced hepatitis.
Cell. Physiol. Biochem.
PUBLISHED: 05-09-2014
Show Abstract
Hide Abstract
Fulminant hepatitis is a severe liver disease characterized by massive hepatocyte necrosis and clinical signs of liver failure. This study explores the expression profile of microRNAs, which are regulators of a number of pathophysiological processes, during the early stage of concanavalin A (Con A)-induced hepatitis.
Related JoVE Video
Deferoxamine attenuates acute hydrocephalus after traumatic brain injury in rats.
Transl Stroke Res
PUBLISHED: 04-29-2014
Show Abstract
Hide Abstract
Acute post-traumatic ventricular dilation and hydrocephalus are relatively frequent consequences of traumatic brain injury (TBI). Several recent studies have indicated that high iron levels in brain may relate to hydrocephalus development after intracranial hemorrhage. However, the role of iron in the development of post-traumatic hydrocephalus is still unclear. This study was to determine whether or not iron has a role in hydrocephalus development after TBI. TBI was induced by lateral fluid-percussion in male Sprague-Dawley rats. Some rats had intraventricular injection of iron. Acute hydrocephalus was measured by magnetic resonance T2-weighted imaging and brain hemorrhage was determined by T2* gradient-echo sequence imaging and brain hemoglobin levels. The effect of deferoxamine on TBI-induced hydrocephalus was examined. TBI resulted in acute hydrocephalus at 24 h (lateral ventricle volume: 24.1?±?3.0 vs. 9.9?±?0.2 mm(3) in sham group). Intraventricular injection of iron also caused hydrocephalus (25.7?±?3.4 vs. 9.0?±?0.6 mm(3) in saline group). Deferoxamine treatment attenuated TBI-induced hydrocephalus and heme oxygenase-1 upregulation. In conclusion, iron may contribute to acute hydrocephalus after TBI.
Related JoVE Video
Resveratrol reduces the proinflammatory effects and lipopolysaccharide- induced expression of HMGB1 and TLR4 in RAW264.7 cells.
Cell. Physiol. Biochem.
PUBLISHED: 03-21-2014
Show Abstract
Hide Abstract
Resveratrol (Res) is a polyphenol anti-inflammatory agent. We have studied the link between the anti-inflammatory effects of Res and the high mobility group box 1(HMGB1) signaling pathway.
Related JoVE Video
Enhancement of femtosecond lenticule extraction for visual symptomatic eye after myopia correction.
BMC Ophthalmol
PUBLISHED: 03-15-2014
Show Abstract
Hide Abstract
The novel Femtosecond lenticule extraction (FLEx) procedure has been considered safe, predictable, and effective in treating myopia and myopic astigmatism, with few complications. However, an enhancement procedure after FLEx may be required in some cases, but has not been reported in detail.
Related JoVE Video
BIIB021, an Hsp90 inhibitor, effectively kills a myelodysplastic syndrome cell line via the activation of caspases and inhibition of PI3K/Akt and NF-?B pathway proteins.
Exp Ther Med
PUBLISHED: 03-12-2014
Show Abstract
Hide Abstract
The novel orally available inhibitor of the molecular chaperone heat shock protein 90 (Hsp90), BIIB021, induces the apoptosis of various types of tumor cell in vitro and in vivo. However, the effects and mechanisms of this agent on myelodysplastic syndrome (MDS) cell lines remain unknown. The aim of this study was to investigate the effects of BIIB021 on SKM-1 cells (a MDS cell line) and examine its mechanisms of action. The results showed that BIIB021 inhibited the growth of SKM-1 cells effectively in vitro. The treatment of SKM-1 cells with BIIB021 resulted in the inhibition of cell growth through G0/G1-phase cell cycle arrest and induced apoptosis by activating caspase-3, -8 and -9. Furthermore, this study also demonstrated that the mechanisms of apoptosis in SKM-1 cells were associated with the suppression of the phosphatidylinositide 3-kinase/Akt and nuclear factor-?B signaling pathways. Therefore, the findings indicate a novel approach for the treatment of high-risk MDS.
Related JoVE Video
Enhanced p62 expression triggers concomitant autophagy and apoptosis in a rat chronic spinal cord compression model.
Mol Med Rep
PUBLISHED: 03-10-2014
Show Abstract
Hide Abstract
Chronic spinal cord compression is the result of mechanical pressure on the spinal cord, which in contrast to traumatic spinal cord injury, leads to slowly progressing nerve degeneration. These two types of spinal cord injuries may trigger similar mechanisms, including motoric nerve cell apoptosis and autophagy, however, depending on differences in the underlying injury severity, nerve reactions may predominantly involve the conservation of function or the initiation of functions for the removal of irreversibly damaged cells. p62 is a multidomain adapter protein, which is involved in apoptosis and cell survival as well as autophagy, and is a common component of protein aggregations in neurodegenerative diseases. In the present study, a rat chronic spinal cord compression model was used, in which the spinal cord was progressively compressed for six weeks and then constantly compressed for another 10 weeks. As a result Basso, Beattie and Bresnahan locomotor scaling revealed a gradual score decrease until the 6th week followed by constant recovery until the 16th week after spinal cord compression was initiated. During the first eight weeks of the experiment, p62 and nuclear factor-?B (NF-?B) were increasingly expressed up to a constant plateau at 12-16 weeks, whereas caspase 3 exhibited a marginally enhanced expression at 8 weeks, however, reached a constant maximum peak 12-16 weeks after the beginning of spinal cord compression. It was hypothesized that, in the initial phase of spinal cord compression, enhanced p62 expression triggered NF-?B activity, directing the cell responses mainly to cell survival and autophagy, whereas following eight weeks of spinal cord compression, caspase 3 was additionally activated indicating cumulative elimination of irreversibly damaged nerve cells with highly activated autophagy.
Related JoVE Video
The amino acid at residue 155 in nonstructural protein 4 of porcine reproductive and respiratory syndrome virus contributes to its inhibitory effect for interferon-? transcription in vitro.
Virus Res.
PUBLISHED: 02-25-2014
Show Abstract
Hide Abstract
Type I interferons (IFNs), predominantly IFN-? and ?, play important roles in both innate and adaptive immune responses against viral infections. Porcine reproductive and respiratory syndrome virus (PRRSV) has been recognized to be able to down-regulate the IFN response during in vivo and in vitro infection. In this study, we first analyzed inhibitory effect of each NSP of low pathogenic PRRSV HB-1/3.9 on IFN-? transcription in MARC-145 cells, and the results showed that the IFN-? promoter activation could be suppressed by NSP1?, NSP2, NSP1?, NSP3, NSP4, NSP5 and NSP11. We next confirmed that the inhibitory effect of NSP4 was mainly mediated through suppressing NF-?B activation, whereas not hindering NF-?B phosphorylation and nuclear translocation, and nuclear-localized NSP4 was responsible for inhibiting IFN-? activation. We further found that the NSP4 of different pathogenic PRRSV strains exhibited differential inhibitory effect on IFN-?, NF-?B, and IRF3 transcription, and the NSP4 of highly pathogenic (HP)-PRRSV could display more strong inhibitory effect. Finally, we determined that the amino acid at residue 155 in NSP4 contributed to its inhibitory effect for IFN-? transcription in vitro by altering its subcellular distribution. Our findings suggest that the nucleus-localized NSP4 of PRRSV participates in the modulation of the host type I IFNs system, and also provide novel insight for understanding the pathogenesis of the Chinese HP-PRRSV.
Related JoVE Video
An extracytoplasmic function sigma factor, ?(25), differentially regulates avermectin and oligomycin biosynthesis in Streptomyces avermitilis.
Appl. Microbiol. Biotechnol.
PUBLISHED: 02-18-2014
Show Abstract
Hide Abstract
?(25) is an extracytoplasmic function (ECF) ? factor in the bacterium Streptomyces avermitilis that plays a differential regulatory role in avermectin and oligomycin biosynthesis. Gene deletion, complementation, and overexpression experiments showed that ?(25) inhibited avermectin production but promoted oligomycin production. ?(25) indirectly inhibited avermectin production by affecting the transcription of the pathway-specific activator gene aveR, whereas it directly activated oligomycin production by initiating transcription of the pathway-specific activator gene olmRI. The divergently transcribed genes smrAB are located upstream of sig25 and encode a putative two-component system (TCS). ?(25) was found to initiate its own transcription, and its expression was directly activated by SmrA. The precise SmrA-binding sites in the region upstream of sig25 were determined by DNase I footprinting assays and identified two direct repeat sequences CTGTGA-n5-CTGTGA, suggesting that SmrA regulates sig25 transcription by binding to these direct repeats. The deletion of smrAB had the similar effect on avermectin and oligomycin A production to the deletion of sig25, indicating that ?(25) and SmrAB function similarly in the regulation of antibiotic production. These findings helpfully clarify the regulation of antibiotic biosynthesis by an ECF ? factor-TCS signal transduction system in S. avermitilis.
Related JoVE Video
Interferon-associated retinopathy risk in patients with diabetes and hypertensive hepatitis C.
World J. Gastroenterol.
PUBLISHED: 02-11-2014
Show Abstract
Hide Abstract
To investigate the association of hypertension and diabetes mellitus (DM) with interferon-associated retinopathy (IAR) risk in chronic hepatitis C (CHC).
Related JoVE Video
Hepatitis B virus X protein inhibits autophagic degradation by impairing lysosomal maturation.
Autophagy
PUBLISHED: 01-10-2014
Show Abstract
Hide Abstract
Deficiency in autophagy, a lysosome-dependent cell degradation pathway, has been associated with a variety of diseases especially cancer. Recently, the activation of autophagy by hepatitis B virus X (HBx) protein, which is implicated in hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC), has been identified in hepatic cells. However, the underlying mechanism and the relevance of HBx-activated autophagy to the carcinogenesis caused by HBV remain elusive. Here, by transfection of HBV genomic DNA and HBx in hepatic and hepatoma cells, we showed that HBV- or HBx-induced autophagosome formation was accompanied by unchanged MTOR (mechanistic target of rapamycin) activity and decreased degradation of LC3 and SQSTM1/p62, the typical autophagic cargo proteins. Further functional and morphological analysis indicated that HBx dramatically impaired lysosomal acidification leading to a drop in lysosomal degradative capacity and the accumulation of immature lysosomes possibly through interaction with V-ATPase affecting its lysosome targeting. Moreover, clinical specimen test showed increased SQSTM1 and immature lysosomal hydrolase CTSD (cathepsin D) in human liver tissues with chronic HBV infection and HBV-associated liver cancer. These data suggest that a repressive effect of HBx on lysosomal function is responsible for the inhibition of autophagic degradation, and this may be critical to the development of HBV-associated HCC.
Related JoVE Video
MMP9 deficiency increased the size of experimentally induced apical periodontitis.
J Endod
PUBLISHED: 01-02-2014
Show Abstract
Hide Abstract
Apical periodontitis is an inflammation and destruction of periapical tissues. Matrix metalloproteinase-9 (MMP-9) is thought to be involved in periapical lesion formation and progression. The aim of this study was to evaluate the lesion progression in MMP-9 knockout (KO) mice compared with that in control mice (wild type [WT]).
Related JoVE Video
Near-infrared optical absorption enhanced in black silicon via Ag nanoparticle-induced localized surface plasmon.
Nanoscale Res Lett
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Due to the localized surface plasmon (LSP) effect induced by Ag nanoparticles inside black silicon, the optical absorption of black silicon is enhanced dramatically in near-infrared range (1,100 to 2,500 nm). The black silicon with Ag nanoparticles shows much higher absorption than black silicon fabricated by chemical etching or reactive ion etching over ultraviolet to near-infrared (UV-VIS-NIR, 250 to 2,500 nm). The maximum absorption even increased up to 93.6% in the NIR range (820 to 2,500 nm). The high absorption in NIR range makes LSP-enhanced black silicon a potential material used for NIR-sensitive optoelectronic device.
Related JoVE Video
Two adjacent and similar TetR family transcriptional regulator genes, SAV577 and SAV576, co-regulate avermectin production in Streptomyces avermitilis.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Streptomyces avermitilis is an important bacterial species used for industrial production of avermectins, a family of broad-spectrum anthelmintic agents. We previously identified the protein SAV576, a TetR family transcriptional regulator (TFR), as a downregulator of avermectin biosynthesis that acts by controlling transcription of its major target gene SAV575 (which encodes cytochrome P450/NADPH-ferrihemoprotein reductase) and ave genes. SAV577, another TFR gene, encodes a SAV577 protein that displays high amino acid homology with SAV576. In this study, we examined the effect of SAV577 on avermectin production and the relationships between SAV576 and SAV577. SAV577 downregulated avermectin biosynthesis indirectly, similarly to SAV576. SAV576 and SAV577 both directly repressed SAV575 transcription, and reciprocally repressed each other's expression. SAV575 transcription levels in various S. avermitilis strains were correlated with avermectin production levels. DNase I footprinting and electrophoretic mobility shift assays indicated that SAV576 and SAV577 compete for the same binding regions, and that DNA-binding affinity of SAV576 is much stronger than that of SAV577. GST pull-down assays revealed no direct interaction between the two proteins. Taken together, these findings suggest that SAV577 regulates avermectin production in S. avermitilis by a mechanism similar to that of SAV576, and that the role of SAV576 is dominant over that of SAV577. This is the first report of two adjacent and similar TFR genes that co-regulate antibiotic production in Streptomyces.
Related JoVE Video
Hydrochemistry of the hot springs in western Sichuan province related to the Wenchuan MS 8.0 earthquake.
ScientificWorldJournal
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Hydrogeochemistry of 32 hot springs in the western Sichuan Province after the Wenchuan MS 8.0 earthquake was investigated by analyzing the concentrations of cation and anion and the isotopic compositions of hydrogen and oxygen. The water samples of the hot springs were collected four times from June 2008 to April 2010. Hydrogeochemical data indicated the water samples can be classified into 9 chemical types. Values of ? D and ?(18)O indicated that the spring waters were mainly derived from meteoric precipitation and affected by water-rock interaction and mixture of deep fluids. Concentrations of K(+)and SO4(-) of the samples from the Kangding district exhibited evident increases before the Wenchuan earthquake, indicating more supplement of deep fluids under the increase of tectonic stress. The chemical and isotopic variations of the water samples from the area closer to the epicenter area can be attributed to variation of regional stress field when the aftershock activities became weak.
Related JoVE Video
A study on the effect of resveratrol on lipid metabolism in hyperlipidemic mice.
Afr J Tradit Complement Altern Med
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
The content of resveratrol is relatively high in Polygonum cuspidatum Sieb. et Zucc., and the resveratrol has the effect of blood vessel dilating, microcirculation improving, platelet aggregation inhibiting and anti-cancer. The objective of this paper was to study the effect of resveratrol on lipid metabolism in hyperlipidemia mice.
Related JoVE Video
EGCG attenuates pro-inflammatory cytokines and chemokines production in LPS-stimulated L02 hepatocyte.
Acta Biochim. Biophys. Sin. (Shanghai)
PUBLISHED: 11-21-2013
Show Abstract
Hide Abstract
Endotoxin lipopolysaccharide (LPS) plays an important role in the acceleration of inflammatory reaction of hepatitis as the second attack. Compounds that can prevent inflammation by targeting LPS have potential therapeutic clinical application. Epigallocatechin-3-gallate (EGCG) has potent hepatocyte-protective effect and mild anti-hepatitis virus function. Here, we investigated whether EGCG attenuated the severity of inflammatory response in LPS-stimulated L02 hepatocytes. L02 hepatocytes were pretreated with EGCG for 2 h, then stimulated by LPS at 250 ng/ml. The expression levels of chemokine regulated upon activation normal T-cell expressed and secreted (Rantes) and monocyte chemotactic protein-1 (MCP-1), pro-inflammatory cytokines tumor necrosis factor-? (TNF-?) and interferon-?, adhesion molecule intercellular adhesion molecule-1 (ICAM-1), oxidant stress molecules nitric oxide (NO), vascular endothelial growth factor (VEGF), and matrix metalloproteinase-2 (MMP-2) were tested by enzyme-linked immunosorbent assay. The expression of total extracellular signal-regulated kinase 1/2 (ERK1/2), phospho-ERK1/2 (p-ERK1/2), p-AKT, total p38, phospho-p38 (p-p38), total p65 and phospho-p65 (p-p65), I?B?, phospho-I?B? (p-I?B?) and TNF receptor associated factor 2 were tested by western blot analysis. Our results showed that pre-treatment with EGCG could significantly reduce the production of TNF-?, Rantes, MCP-1, ICAM-1, NO, VEGF, and MMP-2 in LPS-stimulated L02 hepatocytes in a dose-dependent manner. The effect of EGCG may be related to the inhibition of nuclear factor-?B (NF-?B) and mitogen-activated protein kinase (MAPK) signaling pathways by down-regulation of p-I?B?, p65, p-p65, p-p38, p-ERK1/2, and p-AKT. These results indicate that EGCG suppresses LPS-induced inflammatory response and oxidant stress and exerts its hepatocyte-protective activity partially by inhibiting NF-?B and MAPK pathways.
Related JoVE Video
Laparoendoscopic single-site retroperitoneoscopic adrenalectomy for pheochromocytoma: case selection, surgical technique, and short-term outcome.
J. Endourol.
PUBLISHED: 10-23-2013
Show Abstract
Hide Abstract
Abstract Purpose: To present our experience with case selection and operative skills of laparoendoscopic single-site (LESS) retroperitoneoscopic adrenalectomy for pheochromocytoma and evaluate its feasibility. Patients and Methods: Between June 2011 and December 2012, we performed LESS retroperitoneoscopic adrenalectomy for 16 patients with pheochromocytoma. In all patients, the diameter of the pheochromocytoma was less than 4.0?cm. During the operation, a single-port access was inserted through a 2.5-3.0?cm transverse incision below the tip of the 12th rib. Internally, the operative procedure duplicates the conventional retroperitoneoscopic adrenalectomy for pheochromocytoma. Results: No conversions to open surgery or standard laparoscopy with additional trocars were necessary. The mean operative duration was 68.1 minutes (range 41-125?min). The mean blood loss was negligible (<50?mL), and no patient needed blood transfusion. Intraoperative hypertension (SBP>180?mmHg) occurred in 12.5% (2/16) of the patients. No patient had sustained hypertension, and none experienced intraoperative hypotension (systolic blood pressure <80?mm Hg). The only postoperative complication was one case of pneumonia successfully treated with antibiotics. The average postoperative hospital stay was 3.1 days (range 2-5 days). All patients left the hospital with a good cosmetic appearance. Conclusions: In properly selected patients, LESS retroperitoneoscopic adrenalectomy is a feasible and safe procedure for pheochromocytoma.
Related JoVE Video
Use of high-pressure CO2 for concentrating CrVI from electroplating wastewater by Mg-Al layered double hydroxide.
ACS Appl Mater Interfaces
PUBLISHED: 10-18-2013
Show Abstract
Hide Abstract
The desorption of Cr(VI) from Cr(VI)-adsorbed layered double hydroxide (Cr(VI)-LDH) and the recycling of LDH adsorbent are the bottlenecks that limit the practical application of LDH in treating Cr(VI)-containing industrial wastewater. Given the strong affinity of LDH for CO2, we studied desorption and enrichment of Cr(VI) from Cr(VI)-LDH as well as recycling of LDH in the presence of high-pressure CO2. Results showed that Cr(VI) solution with concentration of 500 mg/L could be enriched more than 20 times in each adsorption-desorption cycle. The regenerated LDH maintained the layer structure and the sheets as revealed by XRD and TEM patterns. FT-IR data showed CO2 formed HCO3(-) at high pressure. The transformation from CO2 to HCO3(-) followed by the anion-exchange with CrO4(2-) was the critical factor for Cr(VI) desorption and LDH regeneration. A pilot-scale experiment was carried out with 20 L Cr(VI)-containing electroplating wastewater. The concentration of the desorbed Cr(VI) solution could reach up to 10000 mg/L, which could be used in electroplating after appropriate adjustment. The main advantages of this method are high concentration of Cr(VI), direct reuse of enriched Cr(VI), and efficient regeneration of LDH adsorbent. This method showed promises in recycling Cr(VI) and regenerating LDH in treating industrial wastewater.
Related JoVE Video
Hydrocephalus after intraventricular hemorrhage: the role of thrombin.
J. Cereb. Blood Flow Metab.
PUBLISHED: 10-17-2013
Show Abstract
Hide Abstract
Previous studies demonstrated that thrombin is an important factor in brain injury after intracerebral hemorrhage. This study investigated the effect of thrombin on hydrocephalus development in a rat intraventricular hemorrhage (IVH) model. There were three parts in this study. First, male Sprague-Dawley rats had an injection of 200??L saline, autologous blood or heparinized blood, into the right lateral ventricle. Second, rats had an injection of 50??L saline or 3U thrombin into the right lateral ventricle. Third, rats had an injection of thrombin (3U) with a protease-activated receptor-1 (PAR-1) antagonist, SCH79797 (0.15?nmol), or vehicle into the right lateral ventricle. Lateral ventricle volumes were measured by magnetic resonance imaging and the brains were used for immunohistochemistry and western blot analyses. Intraventricular injection of autologous blood induced hydrocephalus from day 1 to 28. Heparinized blood injection resulted in less hydrocephalus at all time points compared with blood injection alone (P<0.05). Intraventricular injection of thrombin caused significant hydrocephalus, ventricular wall damage, and periventricular blood-brain barrier disruption. Thrombin-induced hydrocephalus was reduced by co-injection of the PAR-1 antagonist SCH79797 (P<0.05). In conclusion, thrombin contributes to hydrocephalus development after IVH and thrombin-induced hydrocephalus is through PAR-1.Journal of Cerebral Blood Flow & Metabolism advance online publication, 11 December 2013; doi:10.1038/jcbfm.2013.225.
Related JoVE Video
From a gene-centric to whole-proteome view of differentiation of T helper cell subsets.
Brief Funct Genomics
PUBLISHED: 10-07-2013
Show Abstract
Hide Abstract
Proper differentiation of naïve T helper cells into functionally distinct subsets is of critical importance to human health. Consequently, the process is tightly controlled by a complex intracellular signalling network. To dissect the regulatory principles of this network, immunologists have early on embraced system-wide transcriptomics tools, leading to identification of large panels of potential regulatory factors. In contrast, the use of proteomics approaches in T helper cell research has been notably rare, and to this date relatively few high-throughput datasets have been reported. Here, we discuss the importance of such research and envision the possibilities afforded by mass spectrometry-based proteomics in the near future.
Related JoVE Video
Engineering of the TetR family transcriptional regulator SAV151 and its target genes increases avermectin production in Streptomyces avermitilis.
Appl. Microbiol. Biotechnol.
PUBLISHED: 09-18-2013
Show Abstract
Hide Abstract
Avermectins produced by Streptomyces avermitilis are used commercially for broad-spectrum parasite control in medical, veterinary, and agricultural fields. Our previous comparative transcriptome analysis of wild-type strain ATCC31267 vs. avermectin-overproducing strain 76-02-e revealed that the gene SAV151, which encodes a TetR family transcriptional regulator, was downregulated in 76-02-e. In the present study, we investigated the role of SAV151 in avermectin production. Deletion of SAV151 increased avermectin yield ~1-fold in ATCC31267, and this phenotype was complemented by a single copy of SAV151. Overexpression of SAV151 in ATCC31267 reduced avermectin yield by ~70 %. RT-PCR analysis showed that the promoting effect of SAV151 deletion on avermectin production was not due to alteration of ave genes at the transcriptional level. SAV151 negatively regulated the transcription of itself and of the adjacent transcriptional unit SAV152-SAV153-SAV154. In chromatin immunoprecipitation and gel shift assays, purified His6-tagged SAV151 protein bound to the bidirectional SAV151-SAV152 promoter region. SAV151 bound to two palindromic sequences in this region and thereby repressed transcription from both directions. Two of the SAV151 target genes, SAV152 (which encodes a putative dehydrogenase) and SAV154 (which encodes a putative hydrolase), had promoting effects on avermectin production. Our findings provide the basis for a strategy to increase avermectin production by controlling SAV151 and its target genes.
Related JoVE Video
Pyrido[2,3-d]pyrimidines: Discovery and preliminary SAR of a novel series of DYRK1B and DYRK1A inhibitors.
Bioorg. Med. Chem. Lett.
PUBLISHED: 09-17-2013
Show Abstract
Hide Abstract
DYRK1B is a kinase over-expressed in certain cancer cells (including colon, ovarian, pancreatic, etc.). Recent publications have demonstrated inhibition of DYRK1B could be an attractive target for cancer therapy. From a data-mining effort, the team has discovered analogues of pyrido[2,3-d]pyrimidines as potent enantio-selective inhibitors of DYRK1B. Cells treated with a tool compound from this series showed the same cellular effects as down regulation of DYRK1B with siRNA. Such effects are consistent with the proposed mechanism of action. Progress of the SAR study is presented.
Related JoVE Video
[The clinical research of nystatin in prevention of invasive fungal infections in patients on mechanical ventilation in intensive care unit].
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue
PUBLISHED: 09-12-2013
Show Abstract
Hide Abstract
To observe the effect of nystatin on incidence of invasive fungal infections (IFI) and the prognosis of mechanically ventilated critically ill patients.
Related JoVE Video
Multiple tracts percutaneous nephrolithotomy assisted by LithoClast master in one session for staghorn calculi: report of 117 cases.
Urolithiasis
PUBLISHED: 08-19-2013
Show Abstract
Hide Abstract
The objective of the study is to evaluate the safety, efficacy and outcome of multiple tracts percutaneous nephrolithotomy (PCNL) assisted by LithoClast master (the third-generation Electro Medical System) in one session for the treatment of staghorn calculi. From October 2011 to March 2013, 117 patients with staghorn calculi underwent multiple tracts PCNL in our hospital. The combined pneumatic and ultrasonic powered lithotripter (EMS LithoClast master) was used to fragment and remove the calculi. The data were retrospectively analyzed with regard to stone burden, number of tracts, operation time, total operative blood loss, postoperative hospital stay, complications rate, and stone clearance rate. A total of 142 renal units in 117 patients (63 men and 54 women) were treated. Of the 142 renal units, 77 (54.2 %) had complete staghorn calculi, and 65 (45.8 %) had partial staghorn calculi. A total of 416 tracts were established in the 142 renal units. The mean number of tracts used in a single renal unit was 2.8 (range 2-4), most required three tracts. The mean (range) operating time is 72 (55-130) min. The mean (range) duration of postoperative hospital stay is 5.5 (3-9) days. Mean estimated operative blood loss is 150 (60-350) mL. The complications included blood transfusion in 9 (7.7 %) patients, high fever in 12 (10.3 %), sepsis in 5 (4.3 %), hydrothorax in 4 (3.4 %), and pseudoaneurysm in 3 (2.6 %). A complete stone clearance rate of 87.2 % (102/117) was achieved after one session of PCNL. This rate increased to 94.0 % after a secondlook procedure. In conclusion, multiple tracts PCNL assisted by EMS LithoClast master in one session is safe and effective in achieving a great stone clearance rate with acceptable morbidity for the treatment of staghorn calculi.
Related JoVE Video
Acute visual loss in an orbital arteriovenous malformation.
Neurosciences (Riyadh)
PUBLISHED: 07-27-2013
Show Abstract
Hide Abstract
Arteriovenous malformations (AVMs) of the orbit are rare and are thought to be congenital. They can grow slowly or in a delayed fashion after a prolonged period of quiescence if there is a hemodynamic balance between the in-flow and the out-flow vessels. However, once the balance is destroyed, orbital AVMs may cause acute visual deterioration. We report a 17-year-old male with orbital AVM, and discuss the mechanism and the management of acute visual deterioration in this setting. Angiography revealed an orbital AVM with obvious drainage obstruction and serious orbital congestion, due to the disruption of the balance. He had no vision improvement although treated successfully with radical transarterial embolization. The worsening of drainage obstruction could alter the hemodynamic flow and lead to acute visual deterioration. Early and exact diagnosis and complete transarterial embolization therapy are important before the hemodynamic imbalance.
Related JoVE Video
Characterization of SAV7471, a TetR-family transcriptional regulator involved in the regulation of coenzyme A metabolism in Streptomyces avermitilis.
J. Bacteriol.
PUBLISHED: 07-26-2013
Show Abstract
Hide Abstract
The role of a tetR transcriptional regulatory gene (SAV7471) in avermectin production in the Gram-positive soil bacterium Streptomyces avermitilis was investigated by gene deletion, complementation, and overexpression experiments. Gene deletion of the SAV7471 open reading frame resulted in avermectin overproduction. The deletion also resulted in overexpression of SAV7472-SAV7473 transcripts, which encode a protein of unknown function and a flavoprotein possibly involved in pantothenate and coenzyme A (CoA) metabolism. EMSAs and footprinting assays showed that SAV7471 can bind to two palindromic sequences with high similarity in the intergenic region between SAV7471 and SAV7472, a region that contains the apparent transcription start sites for each gene detected by rapid amplification of 5 cDNA ends (5-RACE). In addition to SAV7472-SAV7473, at least two genes (SAV1104 and SAV1258) involved in CoA metabolism are negatively controlled by SAV7471. By negatively regulating the transcription of the target genes SAV7472-SAV7473 and other genes involved in CoA metabolism, SAV7471 may affect cellular metabolic flux and may thereby indirectly regulate avermectin biosynthesis.
Related JoVE Video
Large-scale preparation of shape controlled SnO and improved capacitance for supercapacitors: from nanoclusters to square microplates.
Nanoscale
PUBLISHED: 07-11-2013
Show Abstract
Hide Abstract
Here, we first provide a facile ultrasonic-assisted synthesis of SnO using SnCl2 and the organic solvent of ethanolamine (ETA). The moderate alkalinity of ETA and ultrasound play very important roles in the synthesis of SnO. After the hydrolysis of the intermediate of ETA-Sn(II), the as-synthesized SnO nanoclusters undergo assembly, amalgamation, and preferential growth to microplates in hydrothermal treatment. The as-synthesized SnO was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), ultraviolet-visible absorption spectroscopy (UV-vis) and X-ray diffraction (XRD). To explore its potential applications in energy storage, SnO was fabricated into a supercapacitor electrode and characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge measurements. The as-synthesized SnO exhibits remarkable pseudocapacitive activity including high specific capacitance (208.9 F g(-1) at 0.1 A g(-1)), good rate capability (65.8 F g(-1) at 40 A g(-1)), and excellent cycling stability (retention 119.3% after 10,000 cycles) for application in supercapacitors. The capacitive behavior of SnO with various crystal morphologies was observed by fitted EIS using an equivalent circuit. The novel synthetic route for SnO is a convenient and potential way to large-scale production of microplates which is expected to be applicable in the synthesis of other metal oxide nanoparticles.
Related JoVE Video
Interaction of lobed kudzuvine root, rhizoma chuanxiong with both acetylcholinesterase and beta-amyloid (A?1-42).
Pharmacogn Mag
PUBLISHED: 06-11-2013
Show Abstract
Hide Abstract
Lobed kudzuvine root and rhizoma chuanxiong are effective drugs in traditional Chinese medicine.
Related JoVE Video
Granulocyte colony-stimulating factor attenuates monocrotaline-induced pulmonary hypertension by upregulating endothelial progenitor cells via the nitric oxide system.
Exp Ther Med
PUBLISHED: 05-27-2013
Show Abstract
Hide Abstract
Granulocyte colony-stimulating factor (G-CSF) has exhibited efficacy at preventing the progression of pulmonary hypertension (PH); however, the exact mechanism is not completely clear. The aim of the present study was to assess whether this protective effect was mediated by the upregulation of circulating endothelial progenitor cells (EPCs) via the nitric oxide (NO) system. PH was induced in male Sprague-Dawley (SD) rats by the administration of a single subcutaneous injection of monocrotaline (MCT). The rats were treated with recombinant human G-CSF (rhG-CSF, 50 ?g/kg/day) by subcutaneous injection from day five to day seven subsequent to the injection of MCT. N?-nitro-L-arginine methyl ester (L-NAME, 4 mg/kg/day) was intragastrically administered in addition to rhG-CSF as a negative intervention. The changes in hemodynamics and histology, the number and function of circulating EPCs and the concentration of plasma NO were evaluated. With the occurrence of PH in the rat model, the number and function of circulating EPCs were demonstrated to be markedly downregulated. Moreover, a reduced plasma concentration of NO was observed, which was positively correlated with the number of circulating EPCs. Administration of rhG-CSF elevated the plasma level of NO, upregulated the number and function of circulating EPCs and effectively improved pulmonary hemodynamics and vascular reconstruction. Furthermore, the positive correlation between the levels of plasma NO and circulating EPCs was also observed in the rhG-CSF treatment group. However, the protective effect of rhG-CSF in PH was attenuated by L-NAME, which mediated the downregulation of NO and the EPCs. Thus, the present study suggests that G-CSF may attenuate the progression of MCT-induced PH by improving vascular injury repair mechanisms via the NO-mediated upregulation of EPCs.
Related JoVE Video
Three-dimensional finite element modeling of a maxillary premolar tooth based on the micro-CT scanning: A detailed description.
J. Huazhong Univ. Sci. Technol. Med. Sci.
PUBLISHED: 03-19-2013
Show Abstract
Hide Abstract
This study describes the details of how to construct a three-dimensional (3D) finite element model of a maxillary first premolar tooth based on micro-CT data acquisition technique, MIMICS software and ANSYS software. The tooth was scanned by micro-CT, in which 1295 slices were obtained and then 648 slices were selected for modeling. The 3D surface mesh models of enamel and dentin were created by MIMICS (STL file). The solid mesh model was constructed by ANSYS. After the material properties and boundary conditions were set, a loading analysis was performed to demonstrate the applicableness of the resulting model. The first and third principal stresses were then evaluated. The results showed that the number of nodes and elements of the finite element model were 56 618 and 311801, respectively. The geometric form of the model was highly consistent with that of the true tooth, and the deviation between them was -0.28%. The loading analysis revealed the typical stress patterns in the contour map. The maximum compressive stress existed in the contact points and the maximum tensile stress existed in the deep fissure between the two cusps. It is concluded that by using the micro-CT and highly integrated software, construction of the 3D finite element model with high quality will not be difficult for clinical researchers.
Related JoVE Video
Dual specific antitumor effects of Semliki Forest virus-based DNA vector carrying suicide Escherichia coli purine nucleoside phosphorylase gene via Salmonella.
Int. J. Oncol.
PUBLISHED: 02-10-2013
Show Abstract
Hide Abstract
The Escherichia coli purine nucleoside phospho-rylase/2-fluoro-2-deoxyadenosine (ePNP/F-dAdo) suicide system has demonstrated a powerful killing and bystander effects on tumor cells. However, several drawbacks to this approach remain to be resolved, such as the side-effects and the low efficiency of ePNP-targeted expression. A human telo-merase reverse transcriptase promoter-driven Semliki Forest virus-based DNA vector (pShT-ePNP) with high expression of the ePNP gene was constructed. Live attenuated Salmonella typhimurium 7207 (SL7207) was used initially as a vehicle to targetly transfer the large alphavirus vector into tumor cells. The in vitro quantitative analysis showed ~2-fold higher green fluorescent protein (GFP) expression for pShT-GFP than for conventional cytomegalovirus (CMV) promoter-mediated eukaryotic expression plasmids such as pIRES-GFP and the targeted expression of the ePNP gene in tumor cells was also detected by RT-PCR. After F-dAdo addition, the enzymatic conversion of F-Ado into 2-fluoroadmine (F-Ade) was tested by HPLC. Cell cytotoxicity assays showed that the significant inhibitory effect of the SL/pShT-ePNP system on tumor cells was dose- and time-dependent. Following oral administration, recombinant bacteria targetly allocated within the solid tumor and the expression of ePNP and GFP genes in vivo were detected by RT-PCR or observed by fluorescence microscopy. SL/pShT-ePNP and F-dAdo were also found to exert powerful therapeutic effects in combination against tumor growth and for prolonging the lifespan of tumor-bearing mice. These findings suggest that the SL/pShT-ePNP system may serve as a powerful strategy for tumor therapy.
Related JoVE Video
An intercomparison of satellite-derived ground-level NO? concentrations with GMSMB modeling results and in-situ measurements - a North American study.
Environ. Pollut.
PUBLISHED: 01-07-2013
Show Abstract
Hide Abstract
This paper investigates the biases associated with the ground-level nitrogen dioxide (NO2) concentrations derived from the satellite Ozone Monitoring Instrument (OMI) NO2 data through comparisons with the modeling and the monitoring results for the state of California in 2008. The seasonal and annual average ground-level NO2 concentrations are both analyzed from the OMI using the local NO2 profile obtained from the GEOS-Chem simulation. The OMI-derived ground-level NO2 concentrations are then compared with the NO2 concentrations predicted by a GIS-Based Multi-Source and Multi-Box model (GMSMB) and the in-situ measurements, correlation coefficients among the three sets of results are all above 0.84 with an average slope of 0.81 ± 0.04. Particularly, various biases associated with the three data sets have been analyzed, and the OMI-derived NO2 concentrations and the GMSMB modeling results have been proven to be essential for assessing regional air pollutant exposure risks with the aid of the extensive remote sensing database.
Related JoVE Video
Association between Mannose-binding lectin gene polymorphisms and hepatitis B virus infection: a meta-analysis.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
The results of studies on the relation between Mannose-binding lectin gene (mbl2) polymorphism and HBV infection were contradictory and inconclusive. In order to shed a light on these inconsistent findings and to clarify the role of mbl2 polymorphisms in susceptibility or progression of chronic hepatitis B (CHB), a meta-analysis was performed.
Related JoVE Video
A novel TetR family transcriptional regulator, SAV576, negatively controls avermectin biosynthesis in Streptomyces avermitilis.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
Avermectins produced by Streptomyces avermitilis are potent anti-parasitic agents that are useful in animal health care, agriculture, and the treatment of human infections. In a search for novel regulators that affect avermectin biosynthesis, comparative transcriptome analysis was performed between wild-type strain ATCC31267 and avermectin overproducing strain 76-02-e, revealing some differentially expressed genes. SAV576, which is downregulated in 76-02-e and encodes a TetR family transcriptional regulator (TFR), was shown to inhibit avermectin production by indirectly affecting the expression of ave genes. SAV576 directly repressed the transcription of its gene SAV576 and of adjacent genes SAV575 (encodes cytochrome P450/NADPH-ferrihemoprotein reductase) and SAV574. The SAV576-binding sites within the bidirectional SAV575-SAV576 promoter region were determined by DNase I footprinting assays. A consensus 15-bp palindromic sequence CCRTACRVYGTATGS was found in these binding sites and shown to be important for SAV576-binding activity. SAV575, an important target gene of SAV576, was shown to exert a positive effect on avermectin production. The study findings extend our limited knowledge of the complex regulation of avermectin biosynthesis and provide a basis for rational genetic manipulation of S. avermitilis to improve avermectin production through control of SAV576 and its target gene.
Related JoVE Video
The morphology of corneal cap and its relation to refractive outcomes in femtosecond laser small incision lenticule extraction (SMILE) with anterior segment optical coherence tomography observation.
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
To investigate the morphology of corneal caps in femtosecond laser small incision lenticule extraction (SMILE) and its relation to the refractive outcomes.
Related JoVE Video
Integrated fossil and molecular data reveal the biogeographic diversification of the eastern Asian-eastern North American disjunct hickory genus (Carya Nutt.).
PLoS ONE
PUBLISHED: 01-01-2013
Show Abstract
Hide Abstract
The hickory genus (Carya) contains ca. 17 species distributed in subtropical and tropical regions of eastern Asia and subtropical to temperate regions of eastern North America. Previously, the phylogenetic relationships between eastern Asian and eastern North American species of Carya were not fully confirmed even with an extensive sampling, biogeographic and diversification patterns had thus never been investigated in a phylogenetic context. We sampled 17 species of Carya and 15 species representing all other genera of the Juglandaceae as outgroups, with eight nuclear and plastid loci to reconstruct the phylogeny of Carya. The phylogenetic positions of seven extinct genera of the Juglandaceae were inferred using morphological characters and the molecular phylogeny as a backbone constraint. Divergence times within Carya were estimated with relaxed Bayesian dating. Biogeographic analyses were performed in DIVA and LAGRANGE. Diversification rates were inferred by LASER and APE packages. Our results support two major clades within Carya, corresponding to the lineages of eastern Asia and eastern North America. The split between the two disjunct clades is estimated to be 21.58 (95% HPD 11.07-35.51) Ma. Genus-level DIVA and LAGRANGE analyses incorporating both extant and extinct genera of the Juglandaceae suggested that Carya originated in North America, and migrated to Eurasia during the early Tertiary via the North Atlantic land bridge. Fragmentation of the distribution caused by global cooling in the late Tertiary resulted in the current disjunction. The diversification rate of hickories in eastern North America appeared to be higher than that in eastern Asia, which is ascribed to greater ecological opportunities, key morphological innovations, and polyploidy.
Related JoVE Video
[Research advances on treatment of hepatitis C infection based on RNA interference and microRNA modulation].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 12-23-2011
Show Abstract
Hide Abstract
Infection with hepatitis C virus (HCV) is one of the major global health problems, approximately 170 million people are infected worldwide. The chronic HCV infection is associated with a high risk of developing liver cirrhosis, hepatocellular carcinoma (HCC) and liver failure. Unfortunately, there is still no effective vaccine or antibodies available for the prevention of infection. RNA interference (RNAi) represents a promising new approach to combat viral infections, and recent developments in the field of gene therapy have increased the feasibility of clinical applications. RNAi techniques have made rapid progress in the basic understanding of HCV biology and revealed numerous new viral and host-cell factors as potential targets for therapy. Together with the improvement of gene delivery technique and the discovery of the critical role of microRNA (miRNA) in HCV infection, RNAi and miRNA-based antiviral strategies hold great promise for the future. In this article, we provide a comprehensive overview of current developments of therapeutic targets of RNAi, liver-targeted delivery systems and the potential applications of miRNAs in treatment of hepatitis C infection.
Related JoVE Video
[Alteration of mi-RNA expression profile after interferon treatment in HCV-infected Huh7.5.1 cells].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 12-23-2011
Show Abstract
Hide Abstract
To screen the mi-RNA expression profile after interferon treatment in cells infected with hepatitis C virus (HCV).
Related JoVE Video
[Effects of miR-122 on expression of hepatitis B virus proteins].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 12-23-2011
Show Abstract
Hide Abstract
To investigate the effect of miR-122 on the expression of hepatitis B virus (HBV) proteins.
Related JoVE Video
[Influence of miR-122 on IFN-? treatment for HCV infection].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 12-23-2011
Show Abstract
Hide Abstract
To investigate the influence of miR-122 on IFN-? treatment for HCV infection.
Related JoVE Video
[Inhibition of hepatitis C virus replication by small interfering RNA in cells infected by HCV].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 12-23-2011
Show Abstract
Hide Abstract
To investigate the inhibitive effects of small interfering RNA (siRNA) on hepatitis C virus (HCV) replication in cells infected by HCV in vitro.
Related JoVE Video

What is Visualize?

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

How does it work?

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

Video X seems to be unrelated to Abstract Y...

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