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.
The Transcription Factor GTF2IRD1 Regulates the Topology and Function of Photoreceptors by Modulating Photoreceptor Gene Expression across the Retina.
J. Neurosci.
PUBLISHED: 11-14-2014
Show Abstract
Hide Abstract
The mechanisms that specify photoreceptor cell-fate determination, especially as regards to short-wave-sensitive (S) versus medium-wave-sensitive (M) cone identity, and maintain their nature and function, are not fully understood. Here we report the importance of general transcription factor II-I repeat domain-containing protein 1 (GTF2IRD1) in maintaining M cone cell identity and function as well as rod function. In the mouse, GTF2IRD1 is expressed in cell-fate determined photoreceptors at postnatal day 10. GTF2IRD1 binds to enhancer and promoter regions in the mouse rhodopsin, M- and S-opsin genes, but regulates their expression differentially. Through interaction with the transcription factors CRX and thyroid hormone receptor ? 2, it enhances M-opsin expression, whereas it suppresses S-opsin expression; and with CRX and NRL, it enhances rhodopsin expression. In an apparent paradox, although GTF2IRD1 is widely expressed in multiple cell types across the retina, knock-out of GTF2IRD1 alters the retinal expression of only a limited number of annotated genes. Interestingly, however, the null mutation leads to altered topology of cone opsin expression in the retina, with aberrant S-opsin overexpression and M-opsin underexpression in M cones. Gtf2ird1-null mice also demonstrate abnormal M cone and rod electrophysiological responses. These findings suggest an important role for GTF2IRD1 in regulating the level and topology of rod and cone gene expression, and in maintaining normal retinal function.
Related JoVE Video
Transcallosal Connectivity Changes from Infancy to Late Adulthood: An Ex-vivo Diffusion Spectrum Imaging Study of Macaque Brains.
Brain Connect
PUBLISHED: 11-13-2014
Show Abstract
Hide Abstract
Interhemispheric communication plays a critical role to assure normal brain functions in cognition and behavior. As nonhuman primate (NHP) brain resembles most aspects of human brain, a thorough knowledge of interhemispheric cortical connectivity changes in NHP brains throughout the developmental and aging periods may provide valuable insight for translational and clinical researches. In the present study, formalin-fixed rhesus monkey brains aged from 1 to 24 years old were utilized to examine transcallosal connectivity changes using diffusion spectrum imaging (DSI). It was found that the transcallosal connectivity for most frontal cortical areas including dorso- and ventro-lateral prefrontal, premotor and motor cortices demonstrated pronounced alterations with age. However, such pattern was less obvious in temporal, posterior parietal and visual cortices. The DSI results revealed the age-related evolution pattern of transcallosal connectivity in various cortical areas of macaque brains from infancy to late adulthood, and may have implication for assessing the functional defects or alterations in the associated cortical areas during development and aging in human.
Related JoVE Video
A Longitudinal Magnetization Transfer Imaging Evaluation of Brain Injury in a Macaque Model of NeuroAIDS.
AIDS Res. Hum. Retroviruses
PUBLISHED: 11-07-2014
Show Abstract
Hide Abstract
Abstract Magnetization transfer (MT) imaging has been explored in prior studies of HIV patients and showed the potential capacity to assess brain injury after HIV infection. In the present study, adult pig-tailed macaques were infected with a highly neuropathogenic virus SIVsmmFGb. MT imaging was exploited to examine the monkey brains before simian immunodeficiency virus (SIV) inoculation and 2, 4, 8, 12, 16, and 20 weeks post-SIV inoculation. Blood samples were collected from each animal for monitoring CD4(+) and CD8(+) T cells before each MRI scan. The MT ratios (MTR) in several brain regions of interest were evaluated longitudinally. Significant reductions of MTR were observed in whole brain and selected regions of interest (genu, splenium, thalamus, caudate, centrum semiovale, frontal white matter, frontal gray matter, and putamen) in the SIV-infected monkeys, consistent with those reported previously in HIV patients. In particular, the longitudinal results indicate that abnormal MTR reduction can be detected as early as in 2 weeks and MTR may be more sensitive to the brain injury in cortical regions than in subcortical regions during acute SIV infection. In addition, MTR reduction in genu, centrum semiovale, and thalamus significantly correlated with the CD4(+) T cell percentage decrease. Also, the MTR reduction in thalamus correlated with the CD8(+) T cell percentage elevation. Taken together, this study reported the longitudinal evolution of MTR in different brain regions during SIV infection and further validates previous findings in HIV patients. The preliminary results suggest that MT imaging could be a robust and sensitive approach to characterize the neurodegeneration after SIV or HIV infection.
Related JoVE Video
Non-small cell lung cancer with EML4-ALK translocation in Chinese male never-smokers is characterized with early-onset.
BMC Cancer
PUBLISHED: 10-30-2014
Show Abstract
Hide Abstract
The translocations of the anaplastic lymphoma kinase (ALK) gene with the echinoderm microtubule-associated protein-like 4 (EML4) gene on chromosome 2p have been identified in non-small-cell lung cancers (NSCLCs) as oncogenic driver mutations. It has been suggested that EML4-ALK fusion is associated with the resistance in NSCLCs to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs), such as gefitinib and erlotinib. In contrast, ALK tyrosine kinase inhibitor (ALK TKI) crizotinib has shown superior effects in combating NSCLCs with EML4-ALK. Thus, characterization of EML4-ALK fusion genes and clinical features of resulting carcinomas would be a great benefit to disease diagnosis and designing customized treatment plans. Studies have suggested that EML4-ALK translocation occurs more frequently in never-smokers with NSCLC, especially in female patients. However, it is not clear whether this is the case in male patients, too. In this study, we have determined the frequency of EML4-ALK translocation in male never-smokers with NSCLC in a cohort of Chinese patients. The clinical features associated with EML4-ALK translocation were also investigated.
Related JoVE Video
The structural basis for enhancer-dependent assembly and activation of the AAA transcriptional activator NorR.
Mol. Microbiol.
PUBLISHED: 10-26-2014
Show Abstract
Hide Abstract
?(54) -dependent transcription controls a wide range of stress-related genes in bacteria and is tightly regulated. In contrast to ?(70) , the ?(54) - RNA polymerase holoenzyme forms a stable closed complex at the promoter site that rarely isomerizes into transcriptionally competent open complexes. The conversion into open complexes requires the ATPase activity of activator proteins that bind remotely upstream of the transcriptional start site. These activators belong to the large AAA protein family and the majority of them consist of an N-terminal regulatory domain, a central AAA domain and a C-terminal DNA binding domain. Here we use a functional variant of the NorR activator, a dedicated NO sensor, to provide the first structural and functional characterization of a full length AAA activator in complex with its enhancer DNA. Our data suggest an inter-dependent and synergistic relationship of all three functional domains and provide an explanation for the dependence of NorR on enhancer DNA. Our results show that NorR readily assembles into higher order oligomers upon enhancer binding, independent of activating signals. Upon inducing signals, the N-terminal regulatory domain relocates to the periphery of the AAA ring. Together our data provide an assembly and activation mechanism for NorR.
Related JoVE Video
[Synthesis reduction of central neurotransmitter 5-hydroxytryptamine by branched chain amino acid and associated antagonists improves postoperative fatigue syndrome].
Zhonghua Wei Chang Wai Ke Za Zhi
PUBLISHED: 10-25-2014
Show Abstract
Hide Abstract
To observe the change of postoperative fatigue in rats after the effect of branched chain amino acid(BCAA) and associated antagonists on central neurotransmitter 5-HT metabolic pathway, and to investigate the role of 5-HT in the development of postoperative fatigue syndrome(POFS).
Related JoVE Video
Mapping Cardiac Fiber Orientations from High-Resolution DTI to High-Frequency 3D Ultrasound.
Proc SPIE
PUBLISHED: 10-21-2014
Show Abstract
Hide Abstract
The orientation of cardiac fibers affects the anatomical, mechanical, and electrophysiological properties of the heart. Although echocardiography is the most common imaging modality in clinical cardiac examination, it can only provide the cardiac geometry or motion information without cardiac fiber orientations. If the patient's cardiac fiber orientations can be mapped to his/her echocardiography images in clinical examinations, it may provide quantitative measures for diagnosis, personalized modeling, and image-guided cardiac therapies. Therefore, this project addresses the feasibility of mapping personalized cardiac fiber orientations to three-dimensional (3D) ultrasound image volumes. First, the geometry of the heart extracted from the MRI is translated to 3D ultrasound by rigid and deformable registration. Deformation fields between both geometries from MRI and ultrasound are obtained after registration. Three different deformable registration methods were utilized for the MRI-ultrasound registration. Finally, the cardiac fiber orientations imaged by DTI are mapped to ultrasound volumes based on the extracted deformation fields. Moreover, this study also demonstrated the ability to simulate electricity activations during the cardiac resynchronization therapy (CRT) process. The proposed method has been validated in two rat hearts and three canine hearts. After MRI/ultrasound image registration, the Dice similarity scores were more than 90% and the corresponding target errors were less than 0.25 mm. This proposed approach can provide cardiac fiber orientations to ultrasound images and can have a variety of potential applications in cardiac imaging.
Related JoVE Video
Regulation of FSP27 protein stability by AMPK and HSC70.
Am. J. Physiol. Endocrinol. Metab.
PUBLISHED: 10-16-2014
Show Abstract
Hide Abstract
Fat specific protein 27 (FSP27) plays a pivotal role in controlling the formation of large lipid droplet and energy metabolism. The cellular levels of FSP27 are tightly regulated through the proteasomal ubiquitin-mediated degradation. However, the upstream signals that trigger FSP27 degradation and the underlying mechanism(s) have yet to be identified. Here we show that AMP-activated protein kinase (AMPK) activation by AICAR (5-amino-1-?-D-ribofuranosyl-imidazole-4-carboxamide) or phenformin induced the ubiquitination of FSP27 and promoted its degradation in 3T3-L1 adipocytes. The levels of FSP27 protein could be maintained by either knocking down AMPK?1 or blocking proteasomal pathway. Moreover, AICAR treatment induced multilocularization of LDs in 3T3-L1 adipocytes, reminiscent of the morphological changes in cells depleted of FSP27. Furthermore, mass spectrometry-based proteomic analysis identified heat shock cognate 70 (HSC70) as a novel binding protein of FSP27. The specific interaction was confirmed by co-immunoprecipitation of both ectopically expressed and endogenous proteins. Importantly, knockdown of HSC70 by small interference RNA resulted in increased half-life of FSP27 in cells treated with a protein synthesis inhibitor cycloheximide (CHX) or AICAR. However, silencing of the E3 ubiquitin ligase CHIP (C terminus of HSC70-Interacting Protein) failed to alter the stability of FSP27 protein under both conditions. Taken together, our data indicate that AMPK is a negative regulator of FSP27 stability through the proteasomal ubiquitin-dependent protein catabolic process. Promotion of FSP27 degradation may be an important factor responsible for the beneficial effect of AMPK activators on energy metabolism.
Related JoVE Video
[Risk factors for chronic allograft failure in renal transplant recipients].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 10-15-2014
Show Abstract
Hide Abstract
To identify the potential risk factors for the development of chronic renal allograft failure in renal transplant recipients.
Related JoVE Video
Proton energy optimization and reduction for intensity-modulated proton therapy.
Phys Med Biol
PUBLISHED: 10-08-2014
Show Abstract
Hide Abstract
Intensity-modulated proton therapy (IMPT) is commonly delivered via the spot-scanning technique. To 'scan' the target volume, the proton beam is controlled by varying its energy to penetrate the patient's body at different depths. Although scanning the proton beamlets or spots with the same energy can be as fast as 10-20?m?s(-1), changing from one proton energy to another requires approximately two additional seconds. The total IMPT delivery time thus depends mainly on the number of proton energies used in a treatment. Current treatment planning systems typically use all proton energies that are required for the proton beam to penetrate in a range from the distal edge to the proximal edge of the target. The optimal selection of proton energies has not been well studied. In this study, we sought to determine the feasibility of optimizing and reducing the number of proton energies in IMPT planning. We proposed an iterative mixed-integer programming optimization method to select a subset of all available proton energies while satisfying dosimetric criteria. We applied our proposed method to six patient datasets: four cases of prostate cancer, one case of lung cancer, and one case of mesothelioma. The numbers of energies were reduced by 14.3%-18.9% for the prostate cancer cases, 11.0% for the lung cancer cases and 26.5% for the mesothelioma case. The results indicate that the number of proton energies used in conventionally designed IMPT plans can be reduced without degrading dosimetric performance. The IMPT delivery efficiency could be improved by energy layer optimization leading to increased throughput for a busy proton center in which a delivery system with slow energy switch is employed.
Related JoVE Video
A single-field integrated boost treatment planning technique for spot scanning proton therapy.
Radiat Oncol
PUBLISHED: 09-05-2014
Show Abstract
Hide Abstract
Intensity modulated proton therapy (IMPT) plans are normally generated utilizing multiple field optimization (MFO) techniques. Similar to photon based IMRT, MFO allows for the utilization of a simultaneous integrated boost in which multiple target volumes are treated to discrete doses simultaneously, potentially improving plan quality and streamlining quality assurance and treatment delivery. However, MFO may render plans more sensitive to the physical uncertainties inherent to particle therapy. Here we present clinical examples of a single-field integrated boost (SFIB) technique for spot scanning proton therapy based on single field optimization (SFO) treatment-planning techniques.
Related JoVE Video
[Clinicopathological characteristics and imaging features of primary spinal Ewing's/PNET].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 08-27-2014
Show Abstract
Hide Abstract
To explore the clinicopathological and imaging features of Ewing's sarcoma/peripheral primitive neuroectodermal tumors in vertebral column and to improve knowledge of the disease.
Related JoVE Video
Methyltransferase-Defective Avian Metapneumovirus Vaccines Provide Complete Protection against Challenge with the Homologous Colorado Strain and the Heterologous Minnesota Strain.
J. Virol.
PUBLISHED: 08-13-2014
Show Abstract
Hide Abstract
Avian metapneumovirus (aMPV), also known as avian pneumovirus or turkey rhinotracheitis virus, is the causative agent of turkey rhinotracheitis and is associated with swollen head syndrome in chickens. Since its discovery in the 1970s, aMPV has been recognized as an economically important pathogen in the poultry industry worldwide. The conserved region VI (CR VI) of the large (L) polymerase proteins of paramyxoviruses catalyzes methyltransferase (MTase) activities that typically methylate viral mRNAs at guanine N-7 (G-N-7) and ribose 2'-O positions. In this study, we generated a panel of recombinant aMPV (raMPV) Colorado strains carrying mutations in the S-adenosyl methionine (SAM) binding site in the CR VI of L protein. These recombinant viruses were specifically defective in ribose 2'-O, but not G-N-7 methylation and were genetically stable and highly attenuated in cell culture and viral replication in the upper and lower respiratory tracts of specific-pathogen-free (SPF) young turkeys. Importantly, turkeys vaccinated with these MTase-defective raMPVs triggered a high level of neutralizing antibody and were completely protected from challenge with homologous aMPV Colorado strain and heterologous aMPV Minnesota strain. Collectively, our results indicate (i) that aMPV lacking 2'-O methylation is highly attenuated in vitro and in vivo and (ii) that inhibition of mRNA cap MTase can serve as a novel target to rationally design live attenuated vaccines for aMPV and perhaps other paramyxoviruses.
Related JoVE Video
Enhanced Fluorescence of Gold Nanoclusters Composed of HAuCl4 and Histidine by Glutathione: Glutathione Detection and Selective Cancer Cell Imaging.
Small
PUBLISHED: 08-11-2014
Show Abstract
Hide Abstract
Glutathione (GSH) can significantly and selectively enhance the fluorescence intensity of Au nanoclusters (NCs) prepared by blending HAuCl4 and histidine in solution. The quantum yield of the Au NCs after adding GSH can reach above 10%. Besides, GSH capping shifts the excitation peak of Au NCs from ultraviolet (386 nm) to visible light (414 nm) and improves the stability of the Au NCs. The cytotoxicities of the Au NCs with and without GSH for normal lung cells (ATII) and cancerous lung cells (A549) are evaluated. The GSH-capped Au NCs have much less cytotoxicity to both normal and cancer cells, as compared to those without GSH. For Au NCs without GSH, less cytotoxicity is observed in cancer cells than in normal cells. In addtion, the Au NCs can selectively detect GSH over cysteine and homocysteine, the two biothiols which commonly exist in cells that can seriously affect GSH detection. Most importantly, Au NCs without GSH can selectively image the cancer cells, especially for the liver cancer cells whose GSH content is much higher than other cell types. This property makes the Au NCs a powerful probe to distinguish cancer cells from normal cells.
Related JoVE Video
Acute and subchronic toxicities of QX100626, a 5-HT4 receptor agonist, in rodents and Beagle dogs.
Regul. Toxicol. Pharmacol.
PUBLISHED: 08-07-2014
Show Abstract
Hide Abstract
Serotonin 5-hydroxytryptamine 4(5-HT4) receptor agonists have been widely prescribed as a prokinetics drug for patients with gastro-esophageal reflux disease and functional dyspepsia. QX100626, one of the 5-HT4 receptor agonists, has been studied as a promising agent for this clinical use. The objective of the present study was to identify possible target organs of toxicity and propose a non-toxic dose of QX100626 for clinical usage. After single lethal dose oral and intravenous testing in rodents, some signs indicative of adverse CNS effects were observed. The minimum toxic dose of QX100626 for a single oral administration for dogs was 90.0mg/kgb.w., and the severe toxic dose was more than 300mg/kgb.w. The No Observed Adverse Effect Level (NOAEL) of QX100626 by daily oral administration for rats and dogs was 20mg/kg and 10mg/kg, respectively, whereas the minimum toxic dosages were 67 and 30mg/kg, respectively. All of the adverse effects suggested that kidney, digestive tract, as well as nervous, hematological, and respiratory systems might be the target organs of toxicity for humans induced by QX100626. The compound could be a safe alternative to other existing prokinetic agents for the treatment of functional bowel disorders.
Related JoVE Video
Theoretical study on the initial stage of a magnesium battery based on a V2O5 cathode.
Phys Chem Chem Phys
PUBLISHED: 07-31-2014
Show Abstract
Hide Abstract
Several first-principles calculations based on density functional theory have been carried out looking at the key issues of a magnesium battery with a V2O5 cathode. This kind of magnesium battery was reported by D. Aurbach's group in 2013. Our theoretical studies provide explanations for the experimental findings such as higher voltage, slow ion diffusivity and the decrease of the crystallinity. The calculated open circuit voltage of a magnesium battery with a V2O5 cathode is 3.06 V, which is 0.22 V higher than a lithium battery with the same cathode. Electronic band structure calculations suggest that higher electronic conductivity must be expected in a magnesium battery. Elastic constants are obtained, which give information on the stability of the magnesiated cathode. Furthermore, we have also calculated the diffusion barriers of Li and Mg ions in the cathode using the nudged elastic band method. The hopping barrier of Mg ions is 1.26 eV, which is much higher than that of Li ions (0.35 eV). The obtained minimum energy paths show the different hopping processes in the lithium and magnesium batteries, which can explain the phenomenon of slow diffusion in experiments. The possible transition pathway between the ? and ? phases is analyzed for the first time, which gives an explanation for the reversibility of Mg ions in the V2O5 cathode.
Related JoVE Video
Longitudinal monitoring of stem cell grafts in vivo using magnetic resonance imaging with inducible maga as a genetic reporter.
Theranostics
PUBLISHED: 07-27-2014
Show Abstract
Hide Abstract
The ability to longitudinally monitor cell grafts and assess their condition is critical for the clinical translation of stem cell therapy in regenerative medicine. Developing an inducible genetic magnetic resonance imaging (MRI) reporter will enable non-invasive and longitudinal monitoring of stem cell grafts in vivo.
Related JoVE Video
Molecular basis of nucleotide-dependent substrate engagement and remodeling by an AAA+ activator.
Nucleic Acids Res.
PUBLISHED: 07-25-2014
Show Abstract
Hide Abstract
Binding and hydrolysis of ATP is universally required by AAA+ proteins to underpin their mechano-chemical work. Here we explore the roles of the ATPase site in an AAA+ transcriptional activator protein, the phage shock protein F (PspF), by specifically altering the Walker B motif sequence required in catalyzing ATP hydrolysis. One such mutant, the E108Q variant, is defective in ATP hydrolysis but fully remodels target transcription complexes, the RNAP-?(54) holoenzyme, in an ATP dependent manner. Structural analysis of the E108Q variant reveals that unlike wild-type protein, which has distinct conformations for E108 residue in the ATP and ADP bound forms, E108Q adapts the same conformation irrespective of nucleotide bound. Our data show that the remodeling activities of E108Q are strongly favored on pre-melted DNA and engagement with RNAP-?(54) using ATP binding can be sufficient to convert the inactive holoenzyme to an active form, while hydrolysis per se is required for nucleic acid remodeling that leads to transcription bubble formation. Furthermore, using linked dimer constructs, we show that RNAP-?(54) engagement by adjacent subunits within a hexamer are required for this protein remodeling activity while DNA remodeling activity can tolerate defective ATP hydrolysis of alternating subunits.
Related JoVE Video
Structure and mechanism of action of the BRCA2 breast cancer tumor suppressor.
Nat. Struct. Mol. Biol.
PUBLISHED: 07-24-2014
Show Abstract
Hide Abstract
Mutations in BRCA2 increase susceptibility to breast, ovarian and prostate cancers. The product of human BRCA2, BRCA2 protein, has a key role in the repair of DNA double-strand breaks and interstrand cross-links by RAD51-mediated homologous recombination. Here, we present a biochemical and structural characterization of full-length (3,418 amino acid) BRCA2, alone and in complex with RAD51. We show that BRCA2 facilitates nucleation of RAD51 filaments at multiple sites on single-stranded DNA. Three-dimensional EM reconstructions revealed that BRCA2 exists as a dimer and that two oppositely oriented sets of RAD51 molecules bind the dimer. Single-stranded DNA binds along the long axis of BRCA2, such that only one set of RAD51 monomers can form a productive complex with DNA and establish filament formation. Our data define the molecular mechanism by which this tumor suppressor facilitates RAD51-mediated homologous-recombinational repair.
Related JoVE Video
Rational design of human metapneumovirus live attenuated vaccine candidates by inhibiting viral mRNA cap methyltransferase.
J. Virol.
PUBLISHED: 07-23-2014
Show Abstract
Hide Abstract
The paramyxoviruses human respiratory syncytial virus (hRSV), human metapneumovirus (hMPV), and human parainfluenza virus type 3 (hPIV3) are responsible for the majority of pediatric respiratory diseases and inflict significant economic loss, health care costs, and emotional burdens. Despite major efforts, there are no vaccines available for these viruses. The conserved region VI (CR VI) of the large (L) polymerase proteins of paramyxoviruses catalyzes methyltransferase (MTase) activities that typically methylate viral mRNAs at positions guanine N-7 (G-N-7) and ribose 2'-O. In this study, we generated a panel of recombinant hMPVs carrying mutations in the S-adenosylmethionine (SAM) binding site in CR VI of L protein. These recombinant viruses were specifically defective in ribose 2'-O methylation but not G-N-7 methylation and were genetically stable and highly attenuated in cell culture and viral replication in the upper and lower respiratory tracts of cotton rats. Importantly, vaccination of cotton rats with these recombinant hMPVs (rhMPVs) with defective MTases triggered a high level of neutralizing antibody, and the rats were completely protected from challenge with wild-type rhMPV. Collectively, our results indicate that (i) amino acid residues in the SAM binding site in the hMPV L protein are essential for 2'-O methylation and (ii) inhibition of mRNA cap MTase can serve as a novel target to rationally design live attenuated vaccines for hMPV and perhaps other paramyxoviruses, such as hRSV and hPIV3.
Related JoVE Video
The oncoprotein HBXIP enhances migration of breast cancer cells through increasing filopodia formation involving MEKK2/ERK1/2/Capn4 signaling.
Cancer Lett.
PUBLISHED: 07-16-2014
Show Abstract
Hide Abstract
We have reported that the oncoprotein hepatitis B X-interacting protein (HBXIP) plays a crucial role in the promotion of migration of breast cancer cells. Lamellipodia and filopodia protrusions play fundamental roles, involving dynamic cytoskeleton reorganization in the metastasis of cancer. Here, we observed that the expression levels of both HBXIP and Calpain small subunit 1 (Capn4) were very high in clinical metastatic lymph nodes of breast tumor. Then, we found that HBXIP was able to up-regulate Capn4 at the levels of promoter, mRNA and protein in breast cancer cells through activation of ERK1/2. Moreover, we showed that HBXIP activated ERK1/2 through up-regulating MEKK2. In function, we revealed that HBXIP increased the filopodia formation through Capn4, resulting in cell migration. Thus, we conclude that the oncoprotein HBXIP enhances the migration of breast cancer through increasing filopodia formation involving MEKK2/ERK1/2/Capn4 signaling. Therapeutically, HBXIP may serve as a novel target in breast cancer.
Related JoVE Video
Dissecting the signaling mechanisms underlying recognition and preference of food odors.
J. Neurosci.
PUBLISHED: 07-11-2014
Show Abstract
Hide Abstract
Food is critical for survival. Many animals, including the nematode Caenorhabditis elegans, use sensorimotor systems to detect and locate preferred food sources. However, the signaling mechanisms underlying food-choice behaviors are poorly understood. Here, we characterize the molecular signaling that regulates recognition and preference between different food odors in C. elegans. We show that the major olfactory sensory neurons, AWB and AWC, play essential roles in this behavior. A canonical G?-protein, together with guanylate cyclases and cGMP-gated channels, is needed for the recognition of food odors. The food-odor-evoked signal is transmitted via glutamatergic neurotransmission from AWC and through AMPA and kainate-like glutamate receptor subunits. In contrast, peptidergic signaling is required to generate preference between different food odors while being dispensable for the recognition of the odors. We show that this regulation is achieved by the neuropeptide NLP-9 produced in AWB, which acts with its putative receptor NPR-18, and by the neuropeptide NLP-1 produced in AWC. In addition, another set of sensory neurons inhibits food-odor preference. These mechanistic logics, together with a previously mapped neural circuit underlying food-odor preference, provide a functional network linking sensory response, transduction, and downstream receptors to process complex olfactory information and generate the appropriate behavioral decision essential for survival.
Related JoVE Video
[Metapneumovirus expands the understanding of Paramyxovirus cell fusion--a review].
Wei Sheng Wu Xue Bao
PUBLISHED: 07-11-2014
Show Abstract
Hide Abstract
For most viruses in Paramyxoviridae, cell fusion requires both attachment protein and fusion protein. The attachment protein is responsible for the binding to its cognate receptors, while the interaction between fusion protein and attachment protein triggers the fusion protein which is responsible for the fusion. However, the Metapneumovirus fusion in Pneumovirinae subfamily displayed different mechanism where the attachment protein is not required. The cell fusion is accomplished by fusion protein alone without the help of the attachment protein. Recent studies indicate that low pH is required for cell fusion promoted by some hMPV strains. The fusion protein of aMPV type A is highly fusogenic, whereas that of type B is low. The original fusion models for Paramyxovirus cannot explain the phenomenon above. The mechanism to regulate the cell fusion of Metapneumovirus is poorly understood. It is becoming a hot spot for the study of cell fusion triggered by Paramyxovirus where it enlarged the traditional scope of Paramyxovirus fusion. In this review, we discuss the new achievements and advances in the understanding of cell fusion triggered by Metapneumovirus.
Related JoVE Video
Elevated circulating levels of CTRP1, a novel adipokine, in diabetic patients.
Endocr. J.
PUBLISHED: 06-24-2014
Show Abstract
Hide Abstract
Complement C1q tumor necrosis factor-related protein 1 (CTRP1), an adipose tissue-derived adipokine has been shown to decrease blood glucose levels and to improve metabolism of glucose in mice. In addition, CTRP1 has exhibited significant association with BMI, adiponectin and TNF-? in diabetic animal models. However, there are no published studies addressing CTRP1 levels in type 2 diabetic patients. Therefore, it was of interest to evaluate plasma CTRP1 levels and associated clinical parameters and biomarkers in patients with type 2 diabetes. 135 subjects were recruited to this study, including 62 type 2 diabetic patients (DM group) and 73 healthy subjects (control group). We measured biochemical parameters, CTRP1, TNF-? and adiponectin using enzyme-linked immunosorbent assay (ELISA). Plasma CTRP1 levels showed a significant difference between the DM group and the control group (646.3 ± 154.4 ng/mL vs. 442.6 ± 165.4 ng/mL, p < 0.01). In addition, CTRP1 was strongly positively associated with BMI, glucose levels, HbA1c, HOMA-IR and TNF-? in diabetic patients. CTRP1 showed negative correlation with adiponectin. In Multivariate regression analysis, CTRP1 was strongly independently associated with diabetes when CTRP1 levels were analyzed by both as a continuous variable and quartile (OR: 1.009, 95% CI: 1.004-1.015, p < 0.05; OR: 2.443, 95% CI: 1.379-4.182, p < 0.01, respectively). Increased plasma CTRP1 was independently associated with type 2 diabetes. Profiling of plasma adipokines such as CTRP1 is particularly important to obtain a greater understanding of their contribution to the type 2 diabetic state.
Related JoVE Video
Extensive vascular mineralization in the brain of a chimpanzee (Pan troglodytes).
Comp. Med.
PUBLISHED: 06-24-2014
Show Abstract
Hide Abstract
Spontaneous vascular mineralization (deposition of iron or calcium salts) has been observed in marble brain syndrome, mineralizing microangiopathy, hypothyroidism, Fahr syndrome, Sturge-Weber syndrome, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, and calciphylaxis in humans and as an aging or idiopathic lesion in the brains of horses, cats, nonhuman primates, mice, rats, cattle, white-tailed deer, and dogs. Here we present a 27-y-old, adult male chimpanzee (Pan troglodytes) with spontaneous, extensive vascular mineralization localized solely to the brain. The chimpanzee exhibited tremors and weakness of the limbs, which progressed to paralysis before euthanasia. Magnetic resonance brain imaging in 2002 and 2010 (immediately before euthanasia) revealed multiple hypointense foci, suggestive of iron- and calcium-rich deposits. At necropsy, the brain parenchyma had occasional petechial hemorrhage, and microscopically, the cerebral, cerebellar and brain stem, gray and white matter had moderate to severe mural aggregates of a granular, basophilic material (mineral) in the blood vessels. In addition, these regions often had moderate to severe medial to transmural deposition of mature collagen in the blood vessels. We ruled out common causes of brain mineralization in humans and animals, but an etiology for the mineralization could not be determined. To our knowledge, mineralization in brain has been reported only once to occur in a chimpanzee, but its chronicity in our case makes it particularly interesting.
Related JoVE Video
Effects of tacrolimus and cyclosporine treatment on metabolic syndrome and cardiovascular risk factors after renal transplantation: a meta-analysis.
Chin. Med. J.
PUBLISHED: 06-17-2014
Show Abstract
Hide Abstract
The therapeutic success of renal transplantation has been largely attributable to the development of effective and balanced immunosuppressive treatment regimens. This study provides a meta-analysis of a series of randomized controlled trials that compared the effects of tacrolimus and cyclosporine on metabolic syndrome (MetS) and cardiovascular risk factors after renal transplantation.
Related JoVE Video
Preparation of oxidized agar and characterization of its properties.
Carbohydr Polym
PUBLISHED: 06-10-2014
Show Abstract
Hide Abstract
A series of oxidized agars with different carboxyl content were prepared, and their properties were determined and analyzed. The results showed that the gelling temperature, the optical rotation and the apparent viscosity of the agar solution, and the melting temperature, the strength, the hardness, the fracturability, the springiness, the chewiness and the gumminess of agar gel all decreased except that the cohesiveness increased after oxidation. The gel skeleton structures of agar before and after oxidation were all of the porous network structures, but the pores of gel skeleton structure became smaller and denser after oxidation.
Related JoVE Video
Mutational analysis of dimeric linkers in peri- and cytoplasmic domains of histidine kinase DctB reveals their functional roles in signal transduction.
Open Biol
PUBLISHED: 06-06-2014
Show Abstract
Hide Abstract
Membrane-associated histidine kinases (HKs) in two-component systems respond to environmental stimuli by autophosphorylation and phospho-transfer. HK typically contains a periplasmic sensor domain that regulates the cytoplasmic kinase domain through a conserved cytoplasmic linker. How signal is transduced from the ligand-binding site across the membrane barrier remains unclear. Here, we analyse two linker regions of a typical HK, DctB. One region connects the first transmembrane helix with the periplasmic Per-ARNT-Sim domains, while the other one connects the second transmembrane helix with the cytoplasmic kinase domains. We identify a leucine residue in the first linker region to be essential for the signal transduction and for maintaining the delicate balance of the dimeric interface, which is key to its activities. We also show that the other linker, belonging to the S-helix coiled-coil family, plays essential roles in signal transduction inside the cell. Furthermore, by combining mutations with opposing activities in the two regions, we show that these two signalling transduction elements are integrated to produce a combined effect on the final activity of DctB.
Related JoVE Video
miR-27 inhibits adipocyte differentiation via suppressing CREB expression.
Acta Biochim. Biophys. Sin. (Shanghai)
PUBLISHED: 06-05-2014
Show Abstract
Hide Abstract
miR-27 plays a negative role in the regulation of adipogenesis. However, the molecular mechanism still remains to be clarified. In the present study, we found that miR-27 inhibits adipogenesis partially by repressing the early adipogenic transcription factor cAMP response element-binding protein by directly targeting its 3' untranslated region. In addition, we demonstrated that tumor necrosis factor-? (TNF-?) treatment up-regulates miR-27 through the NF-?B pathway. Furthermore, anti-miR-27 reduces the TNF-?-induced inhibition of adipogenesis. Simultaneously, the levels of miR-27 expression were decreased in mature adipocytes of obese mice when compared with lean mice. Our data revealed a novel mechanism of miR-27 in the regulation of adipogenesis.
Related JoVE Video
Peak-specific phase correction for automated spectrum processing of in vivo magnetic resonance spectroscopic imaging by using the multiscale approach.
Bo Pu Xue Za Zhi
PUBLISHED: 05-27-2014
Show Abstract
Hide Abstract
Automatic metabolite quantification with curve fitting is essential in analyzing large amount of in vivo magnetic resonance spectroscopic imaging (MRSI) data. However, such data analysis is usually hindered by distorted metabolite peaks and baselines normally seen in in vivo MRS. In the present study, a multiscale approach was utilized for peak-specific automatic phase correction in multi-slice MRSI data of human brain. The results suggest that this novel approach can improve the robustness and efficiency of metabolite quantification and facilitate automatic analysis of multi-slice in vivo MRSI data in human brain.
Related JoVE Video
The ?-SiC nanowires (~100 nm) induce apoptosis via oxidative stress in mouse osteoblastic cell line MC3T3-E1.
Biomed Res Int
PUBLISHED: 05-21-2014
Show Abstract
Hide Abstract
Silicon carbide (SiC), a compound of silicon and carbon, with chemical formula SiC, the beta modification ( ?-SiC), with a zinc blende crystal structure (similar to diamond), is formed at temperature below 1700°C. ?-SiC will be the most suitable ceramic material for the future hard tissue replacement, such as bone and tooth. The in vitro cytotoxicity of ?-SiC nanowires was investigated for the first time. Our results indicated that 100 nm long SiC nanowires could significantly induce the apoptosis in MC3T3-E1 cells, compared with 100 ?m long SiC nanowires. And 100 nm long SiC nanowires increased oxidative stress in MC3T3-E1 cells, as determined by the concentrations of MDA (as a marker of lipid peroxidation) and 8-OHdG (indicator of oxidative DNA damage). Moreover, transmission electron microscopy (TEM) was performed to evaluate the morphological changes of MC3T3-E1 cells. After treatment with 100 nm long SiC nanowires, the mitochondria were swelled and disintegrated, and the production of ATP and the total oxygen uptake were also decreased significantly. Therefore, ?-SiC nanowires may have limitations as medical material.
Related JoVE Video
[Research on integrated application of tumor magnetic induction hyperthermia treatment planning system and modern medical information systems].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 05-09-2014
Show Abstract
Hide Abstract
Magnetic induction hyperthermia becomes a very important tumor treatment method at present. In order to ensure a successful operation, doctors should make hyperthermia treatment planning before surgery. Based on Integration Healthcare Enterprise (IHE) framework and Digital Imaging and Communications in Medcine (DICOM) standard, we proposed and carried out a network workflow integrated with modern medical information systems for the dissemination of information in magnetic induction hyperthermia like accurate accessing patient information and radiology image data, storing processed images, sharing and verifying hyperthermia reports. The results proved that our system could not only improve the efficiency of magnetic induction hyperthermia treatment planning, but also save medical resources and reduce labor costs.
Related JoVE Video
Identification of a novel phosphorylation site in adipose triglyceride lipase as a regulator of lipid droplet localization.
Am. J. Physiol. Endocrinol. Metab.
PUBLISHED: 05-06-2014
Show Abstract
Hide Abstract
Adipose triglyceride lipase (ATGL), the rate-limiting enzyme for triacylglycerol (TG) hydrolysis, has long been known to be a phosphoprotein. However, the potential phosphorylation events that are involved in the regulation of ATGL function remain incompletely defined. Here, using a combinatorial proteomics approach, we obtained evidence that at least eight different sites of ATGL can be phosphorylated in adipocytes. Among them, Thr³?² resides within the hydrophobic region known to mediate lipid droplet (LD) targeting. Although it had no impact on the TG hydrolase activity, substitution of phosphorylation-mimic Asp for Thr³?² eliminated LD localization and LD-degrading capacity of ATGL expressed in HeLa cells. In contrast, mutation of Thr³?² to Ala gave a protein that bound LDs and functioned the same as the wild-type protein. In nonstimulated adipocytes, the Asp mutation led to decreased LD association and basal lipolytic activity of ATGL, whereas the Ala mutation produced opposite effects. Moreover, the LD translocation of ATGL upon ?-adrenergic stimulation was also compromised by the Asp mutation. In accord with these findings, the Ala mutation promoted and the Asp mutation attenuated the capacity of ATGL to mediate lipolysis in adipocytes under both basal and stimulated conditions. Collectively, these studies identified Thr³?² as a novel phosphorylation site that may play a critical role in determining subcellular distribution as well as lipolytic action of ATGL.
Related JoVE Video
Clinical Implementation of Intensity Modulated Proton Therapy for Thoracic Malignancies.
Int. J. Radiat. Oncol. Biol. Phys.
PUBLISHED: 05-01-2014
Show Abstract
Hide Abstract
Intensity modulated proton therapy (IMPT) can improve dose conformality and better spare normal tissue over passive scattering techniques, but range uncertainties complicate its use, particularly for moving targets. We report our early experience with IMPT for thoracic malignancies in terms of motion analysis and management, plan optimization and robustness, and quality assurance.
Related JoVE Video
The oncoprotein hepatitis B X-interacting protein promotes the migration of ovarian cancer cells through the upregulation of S-phase kinase-associated protein 2 by Sp1.
Int. J. Oncol.
PUBLISHED: 04-29-2014
Show Abstract
Hide Abstract
Hepatitis B X-interacting protein (HBXIP) is a novel oncoprotein. We have previously reported that HBXIP promotes the proliferation and migration of breast cancer cells. S-phase kinase-associated protein 2 (Skp2) is another oncoprotein which is important for migration. In this study, we investigated whether Skp2 is involved in the migration enhanced by HBXIP in ovarian cancer. The expression of HBXIP and Skp2 in ovarian cancer tissues was examined by immunohistochemistry using tissue microarrays. The role of HBXIP and Skp2 in the migration of ovarian cancer cells was investigated by wound-healing assay and Transwell migration assay. The effect of HBXIP on Skp2 was assessed by reverse transcription polymerase chain reaction (RT-PCR), western blot analysis, luciferase reporter gene assays and chromatin immunoprecipitation in ovarian cancer cells (SKOV3 and CAOV3). We found that both HBXIP and Skp2 were highly expressed in ovarian cancer tissues. We observed that the overexpression of HBXIP enhanced the migration of ovarian cancer cells, while Skp2 siRNAs decreased the cell migration enhanced by HBXIP. The HBXIP siRNAs inhibited ovarian cancer cell migration and Skp2 rescued the migration inhibition induced by HBXIP siRNA. HBXIP could upregulate Skp2 at the levels of mRNA and protein in ovarian cancer cells. Moreover, HBXIP increased the activity of Skp2 promoter via binding to the transcription factor Sp1. HBXIP is highly expressed in ovarian cancer tissues. HBXIP enhances the migration of ovarian cancer cells. HBXIP was able to stimulate the activity of Skp2 promoter via transcription factor Sp1 thus promoting the migration of ovarian cancer cells.
Related JoVE Video
[The incidence of aspirin resistance and relevant influencing factors in patients on maintenance hemodialysis].
Zhonghua Nei Ke Za Zhi
PUBLISHED: 04-29-2014
Show Abstract
Hide Abstract
To explore aspirin resistance (AR) and its relevant influencing factors in patients on maintenance hemodialysis (MHD).
Related JoVE Video
Evaluation of the systematic error in using 3D dose calculation in scanning beam proton therapy for lung cancer.
J Appl Clin Med Phys
PUBLISHED: 04-28-2014
Show Abstract
Hide Abstract
The objective of this study was to evaluate and understand the systematic error between the planned three-dimensional (3D) dose and the delivered dose to patient in scanning beam proton therapy for lung tumors. Single-field and multifield optimized scanning beam proton therapy plans were generated for ten patients with stage II-III lung cancer with a mix of tumor motion and size. 3D doses in CT datasets for different respiratory phases and the time-weighted average CT, as well as the four-dimensional (4D) doses were computed for both plans. The 3D and 4D dose differences for the targets and different organs at risk were compared using dose-volume histogram (DVH) and voxel-based techniques, and correlated with the extent of tumor motion. The gross tumor volume (GTV) dose was maintained in all 3D and 4D doses, using the internal GTV override technique. The DVH and voxel-based techniques are highly correlated. The mean dose error and the standard deviation of dose error for all target volumes were both less than 1.5% for all but one patient. However, the point dose difference between the 3D and 4D doses was up to 6% for the GTV and greater than 10% for the clinical and planning target volumes. Changes in the 4D and 3D doses were not correlated with tumor motion. The planning technique (single-field or multifield optimized) did not affect the observed systematic error. In conclusion, the dose error in 3D dose calculation varies from patient to patient and does not correlate with lung tumor motion. Therefore, patient-specific evaluation of the 4D dose is important for scanning beam proton therapy for lung tumors.
Related JoVE Video
Alterations of hippocampal projections in adult macaques with neonatal hippocampal lesions: A Diffusion Tensor Imaging study.
Neuroimage
PUBLISHED: 04-23-2014
Show Abstract
Hide Abstract
Neuropsychological and brain imaging studies have demonstrated persistent deficits in memory functions and structural changes after neonatal neurotoxic hippocampal lesion in monkeys. However, the relevant microstructural changes in the white matter of affected brain regions following this early insult remain unknown. This study assessed white matter integrity in the main hippocampal projections of adult macaque monkeys with neonatal hippocampal lesions, using diffusion tensor imaging (DTI). Data analysis was performed using tract-based spatial statistics (TBSS) and compared with volume of interest statistics. Alterations of fractional anisotropy (FA) and diffusivity indices were observed in fornix, temporal stem, ventromedial prefrontal cortex and optical radiations. To further validate the lesion effects on the prefrontal cortex, probabilistic diffusion tractography was used to examine the integrity of the fiber connections between hippocampus and ventromedial prefrontal cortex, and alterations were found in these connections. In addition, increased radial diffusivity in the left ventromedial prefrontal cortex correlated negatively with the severity of deficits in working memory in the same monkeys. The findings revealed microstructural changes due to neonatal hippocampal lesion, and confirmed that neonatal neurotoxic hippocampal lesions resulted in significant and enduring functional alterations in the hippocampal projection system.
Related JoVE Video
The interaction of escitalopram and R-citalopram at the human serotonin transporter investigated in the mouse.
Psychopharmacology (Berl.)
PUBLISHED: 04-18-2014
Show Abstract
Hide Abstract
Escitalopram appears to be a superior antidepressant to racemic citalopram. It has been hypothesized that binding of R-citalopram to the serotonin transporter (SERT) antagonizes escitalopram binding to and inhibition of the SERT, thereby curtailing the elevation of extracellular 5-hydroxytryptamine (5-HTExt), and hence antidepressant efficacy. Further, it has been suggested that a putative allosteric binding site is important for binding of escitalopram to the primary, orthosteric, site, and for R-citalopram's inhibition hereof.
Related JoVE Video
Essential role for TrpC5-containing extracellular vesicles in breast cancer with chemotherapeutic resistance.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 04-14-2014
Show Abstract
Hide Abstract
A critical challenge for chemotherapy is the development of chemoresistance in breast cancer. However, the underlying mechanisms and validated predictors remain unclear. Extracellular vesicles (EVs) have gained attention as potential means for cancer cells to share intracellular contents. In adriamycin-resistant human breast cancer cells (MCF-7/ADM), we analyzed the role of transient receptor potential channel 5 (TrpC5) in EV formation and transfer as well as the diagnostic implications. Up-regulated TrpC5, accumulated in EVs, is responsible for EV formation and trapping of adriamycin (ADM) in EVs. EV-mediated intercellular transfer of TrpC5 allowed recipient cells to acquire TrpC5, consequently stimulating multidrug efflux transporter P-glycoprotein production through a Ca(2+)- and activated T-cells isoform c3-mediated mechanism and thus, conferring chemoresistance on nonresistant cells. TrpC5-containing circulating EVs were detected in nude mice bearing MCF-7/ADM tumor xenografts, and the level was lower after TrpC5-siRNA treatment. In breast cancer patients who underwent chemotherapy, TrpC5 expression in the tumor was significantly higher in patients with progressive or stable disease than in patients with a partial or complete response. TrpC5-containing circulating EVs were found in peripheral blood from patients who underwent chemotherapy but not patients without chemotherapy. Taken together, we found that TrpC5-containing circulating EVs may transfer chemoresistance property to nonchemoresistant recipient cells. It may be worthwhile to further explore the potential of using TrpC5-containing EVs as a diagnostic biomarker for chemoresistant breast cancer.
Related JoVE Video
HSCARG, a novel regulator of H2A ubiquitination by downregulating PRC1 ubiquitin E3 ligase activity, is essential for cell proliferation.
Nucleic Acids Res.
PUBLISHED: 04-07-2014
Show Abstract
Hide Abstract
Histone H2A ubiquitination plays critical roles in transcriptional repression and deoxyribonucleic acid (DNA) damage response. More attention has been focused on ubiquitin E3 ligases of H2A, however, less is known about the negative regulators of H2A ubiquitination. Here we identified HSCARG as a new negative regulatory protein for H2A ubiquitination and found a possible link between regulator of H2A ubiquitination and cell cycle. Mechanistically, HSCARG interacts with polycomb repressive complex 1 (PRC1) and deubiquitinase USP7 and inhibits PRC1 ubiquitination in a USP7-dependent manner. As ubiquitination of PRC1 is critical for its E3 ligase activity toward H2A, HSCARG and USP7 are further shown to decrease the level of H2A ubiquitination. Moreover, we demonstrated that HSCARG is involved in DNA damage response through affecting the level of H2A ubiquitination and localization of RAP80 at lesion points. Knockout of HSCARG results in persistent activation of checkpoint signaling and leads to cell cycle arrest. This study unravels a novel mechanism for the regulation of H2A ubiquitination and elucidates how regulators of H2A ubiquitination affect cell cycle.
Related JoVE Video
Longitudinal cerebral metabolic changes in pig-tailed macaques infected with the neurovirulent virus SIVsmmFGb.
J. Neurovirol.
PUBLISHED: 03-31-2014
Show Abstract
Hide Abstract
Longitudinal cerebral metabolite changes in pig-tailed macaques inoculated with the simian immunodeficiency virus SIVsmmFGb were evaluated with in vivo proton MRS at 3 T. Blood sample collection, and MRS were carried out before and 2, 4, 8, 12, 16, 20, and 24 weeks after SIV inoculation. Significant reduction of N-acetylaspartate (NAA)/creatine (Cr) and choline (Cho)/Cr ratios in prefrontal gray matter (PGM) and glutamate/glutamine(Glx)/Cr ratio in striatum, and increase of myo-inositol (mI)/Cr in striatum were observed during acute SIV infection. The metabolite alterations during the SIVsmmFGb infection are largely in agreement with previous findings in other non-human primate models and HIV patients. Also, NAA/Cr in PGM and striatum and Glx/Cr in striatum are negatively correlated with the percentage of CD8+ T cells after the SIV infection, suggesting the interaction between brain metabolite and immune dysfunction. The present study complements previous studies by describing the time course of alterations of brain metabolites during SIVsmmFGb infection. The findings further demonstrate the efficacy of the SIVsmmFGb-infected macaque as a model to characterize central nervous system infection using novel neuroimaging approaches and also as a tool for exploration of novel and advanced neuroimaging techniques in HIV/AIDS studies.
Related JoVE Video
Structural, phenotypic and functional maturation of bone marrow dendritic cells (BMDCs) induced by Chitosan (CTS).
Biologicals
PUBLISHED: 03-27-2014
Show Abstract
Hide Abstract
The objective of the present work was to explore the effect of CTS on structural, phenotypic and functional maturation of murine bone marrow derived dendritic cells (BMDCs). The maturity of BMDCs post treatment with CTS was evaluated using transmission electron microscopy (TEM) for structure changes, flow cytometry (FCM) for changes of key surface molecules, FITC-dextran bio-assay for phagocytosis, test of acid phosphatase activity (ACP) for biochemical changes and enzyme linked immunosorbent assay (ELISA) for cytokine level. We found that CTS downregulated the numbers of phagosomes inside the BMDCs, up-regulated the expression of MHC II, CD40, CD83, CD80 and CD86 molecules on BMDCs, decreased activity of ACP and phagocytosis by BMDCs, and induced production of higher levels of IL-12 and TNF-?. It was therefore confirmed that CTS could effectively promote the maturation of BMDCs. Our study provided more detailed evidence and rationale to support the application of CTS as an immune stimulator for enhancing host immunity and as an adjuvant in the design of DC-based vaccines.
Related JoVE Video
Effect of high dose isoflurane on cerebral blood flow in macaque monkeys.
Magn Reson Imaging
PUBLISHED: 03-27-2014
Show Abstract
Hide Abstract
The effect of high dose isoflurane on cerebral blood flow (CBF) was investigated in adult macaque monkeys receiving 1% to 2% isoflurane with the pseudo continuous arterial-spin-labeling (pCASL) MRI technique. High concentration (2%) of isoflurane resulted in significant increase in the mean CBF of the global, cortical, subcortical regions and the regional CBF in all subcortical structures and most cortical structures (such as motor cortex, anterior cingulate cortex, but not media prefrontal cortex). In addition, the changes of regional CBF in the affected regions correlated linearly with increasing isoflurane concentrations. The study demonstrates region-specific CBF abnormal increase in adult macaque monkeys under high dose (2%) isoflurane and suggests that the brain functionality in the corresponding structures may be affected and need to be taken consideration in either human or non-human primate neuroimaging studies.
Related JoVE Video
From orientation disordered to ordered-An ab initio simulation on ammonia borane phase transition within Van Der Waals corrections.
J Comput Chem
PUBLISHED: 03-19-2014
Show Abstract
Hide Abstract
In this work, we report a detailed theoretical investigation of the phase transition of ammonia borane (NH3 BH3 ; AB), from a tetragonal I4mm ( C4v9) phase with disordered orientation of hydrogen to an orthorhombic phase with Pmn21 ( C2v7) symmetry, as a function of temperature based on Density Functional Theory calculations with semiempirical dispersion potential correction. We define a series of substructures with the NH3 BH3 moiety always in C3 v symmetry and the partially occupied high temperature state can be described as a continuous transformation between these substructures. To understand the role of the van de Waals corrections to the physical properties, we use the empirical Grimme's dispersion potential correction (PBE-D2). Both Perdew-Burke-Emzerhof (PBE) and PBE-D2 functional yield almost the same energy sequence along the transition path. However, PBE-D2 functional shows obvious advantage in describing the lattice parameters of AB. The rigid rotor harmonic oscillator approximation is used to compute the free energy and the entropies contribution along the transition pathway. With knowledge of free energy surfaces along rotations of the ?[NH3 ] and ?[BH3 ] groups, complete transformation paths are mapped out. The phase transition is found to follow the sequence of partially occupied tetragonal system (I4mm) of a mixture of states with monoclinic (Cc), (CM) and orthorhombic (Pmn21 ) symmetries to fully occupied quasitetragonal system (the intermediate phase, Pmn21 ) to fully occupied orthorhombic system (Pmn21 ). © 2014 Wiley Periodicals, Inc.
Related JoVE Video
In vivo diffusion spectrum imaging of non-human primate brain: initial experience in transcallosal fiber examination.
Quant Imaging Med Surg
PUBLISHED: 03-18-2014
Show Abstract
Hide Abstract
In comparison with conventional diffusion tensor imaging (DTI) technique, diffusion spectrum imaging (DSI) allows for delineating crossing and touching fibers in the brain and has been explored in clinical and preclinical studies. Non-human primates (NHPs) resemble most aspects of human and are widely employed in various neuroscience researches and pharmaceutical development. In the present study, a parallel imaging-based DSI protocol was implemented for in vivo fiber tracking of macaque monkey brains on a 3.0 T clinical scanner. Transcallosal fiber tracts of adult macaque brains were examined with DSI and compared with those from a a conventional DTI protocol. The results demonstrate that DSI can reveal the transcallosal fiber bundles much more extensively than the conventional DTI. The preliminary results suggest that DSI may provide a feasible and robust approach for characterizing the fiber pathways in various disease models of NHPs.
Related JoVE Video
An optimal current observer for predictive current controlled buck DC-DC converters.
Sensors (Basel)
PUBLISHED: 03-16-2014
Show Abstract
Hide Abstract
In digital current mode controlled DC-DC converters, conventional current sensors might not provide isolation at a minimized price, power loss and size. Therefore, a current observer which can be realized based on the digital circuit itself, is a possible substitute. However, the observed current may diverge due to the parasitic resistors and the forward conduction voltage of the diode. Moreover, the divergence of the observed current will cause steady state errors in the output voltage. In this paper, an optimal current observer is proposed. It achieves the highest observation accuracy by compensating for all the known parasitic parameters. By employing the optimal current observer-based predictive current controller, a buck converter is implemented. The converter has a convergently and accurately observed inductor current, and shows preferable transient response than the conventional voltage mode controlled converter. Besides, costs, power loss and size are minimized since the strategy requires no additional hardware for current sensing. The effectiveness of the proposed optimal current observer is demonstrated experimentally.
Related JoVE Video
Bitterness intensity prediction of berberine hydrochloride using an electronic tongue and a GA-BP neural network.
Exp Ther Med
PUBLISHED: 03-11-2014
Show Abstract
Hide Abstract
The aim of this study was to predict the bitterness intensity of a drug using an electronic tongue (e-tongue). The model drug of berberine hydrochloride was used to establish a bitterness prediction model (BPM), based on the taste evaluation of bitterness intensity by a taste panel, the data provided by the e-tongue and a genetic algorithm-back-propagation neural network (GA-BP) modeling method. The modeling characteristics of the GA-BP were compared with those of multiple linear regression, partial least square regression and BP methods. The determination coefficient of the BPM was 0.99965±0.00004, the root mean square error of cross-validation was 0.1398±0.0488 and the correlation coefficient of the cross-validation between the true and predicted values was 0.9959±0.0027. The model is superior to the other three models based on these indicators. In conclusion, the model established in this study has a high fitting degree and may be used for the bitterness prediction modeling of berberine hydrochloride of different concentrations. The model also provides a reference for the generation of BPMs of other drugs. Additionally, the algorithm of the study is able to conduct a rapid and accurate quantitative analysis of the data provided by the e-tongue.
Related JoVE Video
Xanthogranulomatous prostatitis: multiparametric MRI appearances.
Clin Imaging
PUBLISHED: 03-11-2014
Show Abstract
Hide Abstract
Granulomatous prostatitis is an unusual form of prostatitis, and xanthogranulomatous prostatitis (XGP) is an even rarer granulomatous inflammation. Very few XGP cases have been reported in the literature. The reports concerning MRI features of XGP are even less. The present two cases of XGP in our report have different appearances from previous reports and are accompanied by abscess. We also exhibit the magnetic resonance spectroscopy and dynamic contrast-enhanced MRI characteristics, which have never been reported.
Related JoVE Video
Mfsd2a is a transporter for the essential omega-3 fatty acid docosahexaenoic acid.
Nature
PUBLISHED: 03-10-2014
Show Abstract
Hide Abstract
Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is essential for normal brain growth and cognitive function. Consistent with its importance in the brain, DHA is highly enriched in brain phospholipids. Despite being an abundant fatty acid in brain phospholipids, DHA cannot be de novo synthesized in brain and must be imported across the blood-brain barrier, but mechanisms for DHA uptake in brain have remained enigmatic. Here we identify a member of the major facilitator superfamily--Mfsd2a (previously an orphan transporter)--as the major transporter for DHA uptake into brain. Mfsd2a is found to be expressed exclusively in endothelium of the blood-brain barrier of micro-vessels. Lipidomic analysis indicates that Mfsd2a-deficient (Mfsd2a-knockout) mice show markedly reduced levels of DHA in brain accompanied by neuronal cell loss in hippocampus and cerebellum, as well as cognitive deficits and severe anxiety, and microcephaly. Unexpectedly, cell-based studies indicate that Mfsd2a transports DHA in the form of lysophosphatidylcholine (LPC), but not unesterified fatty acid, in a sodium-dependent manner. Notably, Mfsd2a transports common plasma LPCs carrying long-chain fatty acids such LPC oleate and LPC palmitate, but not LPCs with less than a 14-carbon acyl chain. Moreover, we determine that the phosphor-zwitterionic headgroup of LPC is critical for transport. Importantly, Mfsd2a-knockout mice have markedly reduced uptake of labelled LPC DHA, and other LPCs, from plasma into brain, demonstrating that Mfsd2a is required for brain uptake of DHA. Our findings reveal an unexpected essential physiological role of plasma-derived LPCs in brain growth and function.
Related JoVE Video
ncRuPAR inhibits gastric cancer progression by down-regulating protease-activated receptor-1.
Tumour Biol.
PUBLISHED: 03-07-2014
Show Abstract
Hide Abstract
ncRuPAR is a newly discovered long noncoding RNA molecule that can upregulate protease-activated receptor-1 (PAR-1) during embryonic growth; however, its role in cancer has not been elucidated. Here, we conducted a study to investigate the role of ncRuPAR in gastric cancer. Significant downregulation of ncRuPAR was detected in gastric cancer tissues compared with paired adjacent nontumor tissues; however, both PAR-1 and vascular endothelial growth factor (VEGF) messenger RNA (mRNA) levels were significantly higher in cancerous tissues compared with adjacent normal tissues. Additionally, the expression level of ncRuPAR was found to be significantly correlated with tumor invasion depth, lymph node metastasis, distant metastasis, tumor size, and tumor-nodes-metastasis (TNM) stage and inversely associated with the mRNA levels and extent (E) × intensity (I) scores of PAR-1 and VEGF. The protein level of PAR-1 was significantly correlated with tumor size only, while the VEGF protein level was significantly correlated with invasion depth and tumor size. The area under the receiver operating characteristic (ROC) curve of ncRuPAR was 0.84 (95 % CI 0.79-0.88) at a cutoff value of 4.97; ncRuPAR had a sensitivity of 88.41 %, a specificity of 73.91 %, and an accuracy of 81.16 % for the prediction of gastric cancer. These results suggest that ncRuPAR inhibits gastric cancer development, and its underlying mechanism involves the inhibition of PAR-1. In addition, ncRuPAR could be regarded as a marker for gastric cancer in the future.
Related JoVE Video
Multifield optimization intensity modulated proton therapy for head and neck tumors: a translation to practice.
Int. J. Radiat. Oncol. Biol. Phys.
PUBLISHED: 03-06-2014
Show Abstract
Hide Abstract
We report the first clinical experience and toxicity of multifield optimization (MFO) intensity modulated proton therapy (IMPT) for patients with head and neck tumors.
Related JoVE Video
Evaluation and mitigation of the interplay effects of intensity modulated proton therapy for lung cancer in a clinical setting.
Pract Radiat Oncol
PUBLISHED: 02-19-2014
Show Abstract
Hide Abstract
The primary aim of this study was to evaluate the impact of the interplay effects of intensity modulated proton therapy (IMPT) plans for lung cancer in the clinical setting. The secondary aim was to explore the technique of isolayered rescanning to mitigate these interplay effects.
Related JoVE Video
The oncoprotein HBXIP up-regulates SCG3 through modulating E2F1 and miR-509-3p in hepatoma cells.
Cancer Lett.
PUBLISHED: 02-18-2014
Show Abstract
Hide Abstract
Hepatitis B X-interacting protein (HBXIP) is an important oncoprotein in hepatocarcinogenesis. Here, we found that the expression levels of HBXIP were positively associated with those of Secretogranin III (SCG3) in clinical hepatocellular carcinoma tissues. We identified that HBXIP up-regulated the expression of SCG3 through modulating both E2F transcription factor 1 (E2F1) and miR-509-3p. HBXIP suppressed miR-509-3p through activating NF-?B. In function, we showed that SCG3 increased the proliferation of hepatoma cells and HBXIP enhanced the proliferation of the cells via SCG3 in vitro and in vivo. Thus, we conclude that HBXIP facilitates the proliferation of hepatoma cells through up-regulating SCG3.
Related JoVE Video
A fast multiparameter MRI approach for acute stroke assessment on a 3T clinical scanner: preliminary results in a non-human primate model with transient ischemic occlusion.
Quant Imaging Med Surg
PUBLISHED: 02-03-2014
Show Abstract
Hide Abstract
Many MRI parameters have been explored and demonstrated the capability or potential to evaluate acute stroke injury, providing anatomical, microstructural, functional, or neurochemical information for diagnostic purposes and therapeutic development. However, the application of multiparameter MRI approach is hindered in clinic due to the very limited time window after stroke insult. Parallel imaging technique can accelerate MRI data acquisition dramatically and has been incorporated in modern clinical scanners and increasingly applied for various diagnostic purposes. In the present study, a fast multiparameter MRI approach including structural T1-weighted imaging (T1W), T2-weighted imaging (T2W), diffusion tensor imaging (DTI), T2-mapping, proton magnetic resonance spectroscopy, cerebral blood flow (CBF), and magnetization transfer (MT) imaging, was implemented and optimized for assessing acute stroke injury on a 3T clinical scanner. A macaque model of transient ischemic stroke induced by a minimal interventional approach was utilized for evaluating the multiparameter MRI approach. The preliminary results indicate the surgical procedure successfully induced ischemic occlusion in the cortex and/or subcortex in adult macaque monkeys (n=4). Application of parallel imaging technique substantially reduced the scanning duration of most MRI data acquisitions, allowing for fast and repeated evaluation of acute stroke injury. Hence, the use of the multiparameter MRI approach with up to five quantitative measures can provide significant advantages in preclinical or clinical studies of stroke disease.
Related JoVE Video
Characterization of physicochemical properties of carboxymethyl agar.
Carbohydr Polym
PUBLISHED: 01-23-2014
Show Abstract
Hide Abstract
A series of carboxymethyl agars (CMAs) with different degree of substitution (DS) were prepared, and their properties were determined and analyzed. The results showed that with the increase of DS, the dissolving temperature, the gelling temperature, the gel melting temperature, the gel strength, the gel hardness, the gel fracturability, and the solution apparent viscosity of CMA all decreased, except that its gel cohesiveness and gel springiness increased. The variation process of agar molecules in solution from coil to helix could be observed by measuring the optical rotation of the solution at such a low concentration, at which even the solution could not form a gel. The gel skeleton microstructures of both agar and CMA were of porous network structure, and the pore size of CMA became smaller and denser with the increase of its DS. After carboxymethylation, the agar hygroscopicity was improved, but its thermal stability was lowered.
Related JoVE Video
Hepatitis B virus X protein accelerates hepatocarcinogenesis with partner survivin through modulating miR-520b and HBXIP.
Mol. Cancer
PUBLISHED: 01-23-2014
Show Abstract
Hide Abstract
Hepatitis B virus X protein (HBx) plays crucial roles in hepatocarcinogenesis. However, the underlying mechanism remains elusive. We have reported that HBx is able to up-regulate survivin in hepatocellular carcinoma tissues. The oncopreotein hepatitis B X-interacting protein (HBXIP), a target of miR-520b, is involved in the development of cancer. In this study, we focus on the investigation of hepatocarcinogenesis mediated by HBx.
Related JoVE Video
Magnetocaloric effects in a freestanding and flexible graphene-based superlattice synthesized with a spatially confined reaction.
Nat Commun
PUBLISHED: 01-22-2014
Show Abstract
Hide Abstract
Superlattices have attracted great interest because of their tailorable electronic properties at the interface. However, the lack of an efficient and low-cost synthetic method represents a huge challenge to implement superlattices into practical applications. Herein, we report a space-confined nanoreactor strategy to synthesize flexible freestanding graphene-based superlattice nanosheets, which consist of alternately intercalated monolayered metal-oxide frameworks and graphene. Taking vanadium oxide as an example, clear-cut evidences in extended X-ray absorption fine structure, high-resolution transmission electron microscopy and infrared spectra have confirmed that the vanadium oxide frameworks in the superlattice nanosheets show high symmetry derived from the space-confinement and electron-donor effect of graphene layers, which enable the superlattice nanosheets to show emerging magnetocaloric effect. Undoubtedly, this freestanding and flexible superlattice synthesized from a low-cost and scalable method avoids complex transferring processes from growth substrates for final applications and thus should be beneficial to a wide variety of functionalized devices.
Related JoVE Video
Polymorphism, Expression of Natural Resistance-associated Macrophage Protein 1 Encoding Gene (NRAMP1) and Its Association with Immune Traits in Pigs.
Asian-australas. J. Anim. Sci.
PUBLISHED: 01-08-2014
Show Abstract
Hide Abstract
Natural resistance-associated macrophage protein 1 encoding gene (NRAMP1) plays an important role in immune response against intracellular pathogens. To evaluate the effects of NRAMP1 gene on immune capacity in pigs, tissue expression of NRAMP1 mRNA was observed by real time quantitative polymerase chain reaction (PCR), and the results revealed NRAMP1 expressed widely in nine tissues. One single nucleotide polymorphism (SNP) (ENSSSCG00000025058: g.130 C>T) in exon1 and one SNP (ENSSSCG00000025058: g.657 A>G) in intron1 region of porcine NRAMP1 gene were demonstrated by DNA sequencing and PCR-RFLP analysis. A further analysis of SNP genotypes associated with immune traits including contain of white blood cell (WBC), granulocyte, lymphocyte, monocyte (MO), rate of cytotoxin in monocyte (MC) and CD4/CD8 T lymphocyte subpopulations in blood was carried out in four pig populations including Large White and three Chinese indigenous breeds (Wannan Black, Huai pig and Wei pig). The results showed that the SNP (ENSSSCG00000025058: g.130 C>T) was significantly associated with level of WBC % (p = 0.031), MO% (p = 0.024), MC% (p = 0.013) and CD4(-)CD8(+) T lymphocyte (p = 0.023). The other SNP (ENSSSCG00000025058: g.657 A>G) was significantly associated with the level of MO% (p = 0.012), MC% (p = 0.019) and CD4(-)CD8(+) T lymphocyte (p = 0.037). These results indicate that the NRAMP1 gene can be regarded as a molecular marker for genetic selection of disease susceptibility in pig breeding.
Related JoVE Video
Single-layered graphitic-C(3)N(4) quantum dots for two-photon fluorescence imaging of cellular nucleus.
Adv. Mater. Weinheim
PUBLISHED: 01-08-2014
Show Abstract
Hide Abstract
A promising, safe, and economic fluorescent probe, g-C3 N4 single-layered QDs, is introduced for two-photon fluorescence imaging of the cellular nucleus for the first time. The large two-photon absorption cross section, the high photostability, good biocompatibility and non-toxicity, negligible photothermal effect, and specific interaction with DNA render the single-layered g-C3 N4 QDs as a promising candidate for in vivo and in vitro two-photon fluorescence imaging and further biomedical applications.
Related JoVE Video
Ultrafast fluorescence imaging in vivo with conjugated polymer fluorophores in the second near-infrared window.
Nat Commun
PUBLISHED: 01-05-2014
Show Abstract
Hide Abstract
In vivo fluorescence imaging in the second near-infrared window (1.0-1.7??m) can afford deep tissue penetration and high spatial resolution, owing to the reduced scattering of long-wavelength photons. Here we synthesize a series of low-bandgap donor/acceptor copolymers with tunable emission wavelengths of 1,050-1,350?nm in this window. Non-covalent functionalization with phospholipid-polyethylene glycol results in water-soluble and biocompatible polymeric nanoparticles, allowing for live cell molecular imaging at >1,000?nm with polymer fluorophores for the first time. Importantly, the high quantum yield of the polymer allows for in vivo, deep-tissue and ultrafast imaging of mouse arterial blood flow with an unprecedented frame rate of >25 frames per second. The high time-resolution results in spatially and time resolved imaging of the blood flow pattern in cardiogram waveform over a single cardiac cycle (~200?ms) of a mouse, which has not been observed with fluorescence imaging in this window before.
Related JoVE Video
Baicalein ameliorates inflammatory-related apoptotic and catabolic phenotypes in human chondrocytes.
Int. Immunopharmacol.
PUBLISHED: 01-04-2014
Show Abstract
Hide Abstract
Osteoarthritis (OA), characterized by progressive destruction of articular cartilage, is the most common form of human arthritis and a major concern for aging societies worldwide. In OA, pro-inflammatory cytokines such as interleukin (IL)-1? and tumor necrosis factor (TNF)-? can trigger the caspase cascade to promote apoptosis and activate NF-?B to induce catabolic factors in chondrocytes. Here, the anti-apoptotic and anti-catabolic effects of baicalein on human OA chondrocytes treated by a mixture of IL-1? and TNF-? (IT) were investigated in vitro. In cultured chondrocytes, baicalein pretreatment attenuated apoptosis in a concentration-dependent manner in response to IT stimulation. Mechanistically, the anti-apoptotic effects of baicalein result from inhibition of nitric oxide production and downstream caspase signaling pathway. Moreover, administration of baicalein significantly reduced matrix metalloproteinase (MMP) 3 and MMP13 secretion in chondrocytes stimulated with IT. The anti-catabolic effects of baicalein were further demonstrated by the recovery of the glycosaminoglycan and type II collagen (COLII) deposition by histological analysis in IT-treated mouse articular cartilage explants. These findings suggest that baicalein might be a promising novel therapeutic agent for OA by virtue of its suppression of apoptosis and MMP secretion in OA chondrocytes.
Related JoVE Video
The physicochemical property characterization of agar acetate.
Carbohydr Polym
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
A series of agar acetates with different degree of substitution (DS) were prepared, and their properties were determined and analyzed. The results showed that the gelling temperature, the gel melting temperature, the gel strength, the gel hardness, the gel fracturability, the gel springiness and the solution apparent viscosity of agar acetates all decreased except that their gel cohesiveness increased with the increase of DS. The variation process of agar molecules in solution from coil to helix could be also observed by measuring solution optical rotation in a lower concentration at which even the solution could not form a gel. The gel skeleton structures of agar acetates were of porous network structures, and the pores became smaller and denser with the increase of DS. After acetylation, the water holding capacity of the agar was improved, but its thermal stability was lowered.
Related JoVE Video
Overexpression of Wilms tumor 1 gene as a negative prognostic indicator in acute myeloid leukemia.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Chromosomal aberrations are useful in assessing treatment options and clinical outcomes of acute myeloid leukemia (AML) patients. However, 40 ? 50% of the AML patients showed no chromosomal abnormalities, i.e., with normal cytogenetics aka the CN-AML patients. Testing of molecular aberrations such as FLT3 or NPM1 can help to define clinical outcomes in the CN-AML patients but with various successes. Goal of this study was to test the possibility of Wilms' tumor 1 (WT1) gene overexpression as an additional molecular biomarker. A total of 103 CN-AML patients, among which 28% had overexpressed WT1, were studied over a period of 38 months. Patient's response to induction chemotherapy as measured by the complete remission (CR) rate, disease-free survival (DFS) and overall survival (OS) were measured. Our data suggested that WT1 overexpression correlated negatively with the CR rate, DFS and OS. Consistent with previous reports, CN-AML patients can be divided into three different risk subgroups based on the status of known molecular abnormalities, i.e., the favorable (NPM1(mt)/no FLT3(ITD)), the unfavorable (FLT3(ITD)) and the intermediate risk subgroups. The WT1 overexpression significantly reduced the CR, DFS and OS in both the favorable and unfavorable groups. As the results, patients with normal WT1 gene expression in the favorable risk group showed the best clinical outcomes and all survived with complete remission and disease-free survival over the 37 month study period; in contrast, patients with WT1 overexpression in the unfavorable risk group displayed the worst clinical outcomes. WT1 overexpression by itself is an independent and negative indicator for predicting CR rate, DFS and OS of the CN-AML patients; moreover, it increases the statistical power of predicting the same clinical outcomes when it is combined with the NPM1(mt) or the FLT3(ITD) genotypes that are the good or poor prognostic markers of CN-AML.
Related JoVE Video
Messenger RNA cap methylation influences pathogenesis of vesicular stomatitis virus in vivo.
J. Virol.
PUBLISHED: 12-26-2013
Show Abstract
Hide Abstract
One role of mRNA cap guanine-N-7 (G-N-7) methylation is to facilitate the efficient translation of mRNA. The role of mRNA cap ribose 2-O (2-O) methylation is enigmatic, although recent work has implicated this as a signature to avoid detection of RNA by the innate immune system (Daffis et al, 2010). Working with vesicular stomatitis virus (VSV), we previously showed that a panel of VSVs carrying mutations to a predicted methyltransferase catalytic site (rVSV-K1651A, D1762A, and E1833Q) or S-adenosylmethionine (SAM) binding site (rVSV-G1670A, G1672A, and G4A) were defective in cap methylation and were also attenuated for growth in cell culture. Here, we analyzed the virulence of these recombinants in mice. We found that recombinants rVSV-K1651A, D1762A, and E1833Q, which are defective in both G-N-7 and 2-O methylation, were highly attenuated in mice. All three viruses elicited a high level of neutralizing antibody, and provided full protection against a challenge with the virulent VSV. In contrast, mice inoculated with recombinants rVSV-G1670A and G1672A that are defective only in G-N-7 methylation, were attenuated in vivo yet retained a low level of virulence. Recombinant rVSV-G4A which is completely defective in both G-N-7 and 2-O methylation also exhibited low virulence in mice despite the fact that productive viral replication was not detected in lung and brain. Taken together, our results suggest that abrogation of viral mRNA cap methylation can serve as an approach to attenuate VSV, and perhaps other nonsegmented negative-strand RNA viruses for potential application as vaccines and viral vectors.
Related JoVE Video
Patient-specific quantification of respiratory motion-induced dose uncertainty for step-and-shoot IMRT of lung cancer.
Med Phys
PUBLISHED: 12-11-2013
Show Abstract
Hide Abstract
Purpose: The objective of this study was to quantify respiratory motion-induced dose uncertainty at the planning stage for step-and-shoot intensity-modulated radiation therapy (IMRT) using an analytical technique.Methods: Ten patients with stage II?III lung cancer who had undergone a planning four-dimensional (4D) computed tomographic scan and step-and-shoot IMRT planning were selected with a mix of motion and tumor size for this retrospective study. A step-and-shoot IMRT plan was generated for each patient. The maximum and minimum doses with respiratory motion were calculated for each plan, and the mean deviation from the 4D dose was calculated, taking delivery time, fractionation, and patient breathing cycle into consideration.Results: For all patients evaluated in this study, the mean deviation from the 4D dose in the planning target volume (PTV) was <2.5%, with a standard deviation <1.2%, and maximum point dose variation from the 4D dose was <6.2% in the PTV assuming delivery dose rate of 200 MU?min and patient breathing cycle of 8 s. The motion-induced dose uncertainty is a function of motion, fractionation, MU (plan modulation), dose rate, and patient breathing cycle.Conclusions: Respiratory motion-induced dose uncertainty varies from patient to patient. Therefore, it is important to evaluate the dose uncertainty on a patient-specific basis, which could be useful for plan evaluation and treatment strategy determination for selected patients.
Related JoVE Video
Improving spot-scanning proton therapy patient specific quality assurance with HPlusQA, a second-check dose calculation engine.
Med Phys
PUBLISHED: 12-11-2013
Show Abstract
Hide Abstract
Purpose: The purpose of this study was to validate the use of HPlusQA, spot-scanning proton therapy (SSPT) dose calculation software developed at The University of Texas MD Anderson Cancer Center, as second-check dose calculation software for patient-specific quality assurance (PSQA). The authors also showed how HPlusQA can be used within the current PSQA framework.Methods: The authors compared the dose calculations of HPlusQA and the Eclipse treatment planning system with 106 planar dose measurements made as part of PSQA. To determine the relative performance and the degree of correlation between HPlusQA and Eclipse, the authors compared calculated with measured point doses. Then, to determine how well HPlusQA can predict when the comparisons between Eclipse calculations and the measured dose will exceed tolerance levels, the authors compared gamma index scores for HPlusQA versus Eclipse with those of measured doses versus Eclipse. The authors introduce the ??? transformation as a way to more easily compare gamma scores.Results: The authors compared measured and calculated dose planes using the relative depth, z?R × 100%, where z is the depth of the measurement and R is the proton beam range. For relative depths than less than 80%, both Eclipse and HPlusQA calculations were within 2 cGy of dose measurements on average. When the relative depth was greater than 80%, the agreement between the calculations and measurements fell to 4 cGy. For relative depths less than 10%, the Eclipse and HPlusQA dose discrepancies showed a negative correlation, -0.21. Otherwise, the correlation between the dose discrepancies was positive and as large as 0.6. For the dose planes in this study, HPlusQA correctly predicted when Eclipse had and had not calculated the dose to within tolerance 92% and 79% of the time, respectively. In 4 of 106 cases, HPlusQA failed to predict when the comparison between measurement and Eclipses calculation had exceeded the tolerance levels of 3% for dose and 3 mm for distance-to-agreement.Conclusions: The authors found HPlusQA to be reasonably effective (79% ± 10%) in determining when the comparison between measured dose planes and the dose planes calculated by the Eclipse treatment planning system had exceeded the acceptable tolerance levels. When used as described in this study, HPlusQA can reduce the need for patient specific quality assurance measurements by 64%. The authors believe that the use of HPlusQA as a dose calculation second check can increase the efficiency and effectiveness of the QA process.
Related JoVE Video
Short co-incubation of gametes combined with early rescue ICSI: An optimal strategy for complete fertilization failure after IVF.
Hum Fertil (Camb)
PUBLISHED: 12-06-2013
Show Abstract
Hide Abstract
Failed fertilization after conventional IVF is one of the most frustrating experiences in assisted reproductive technology. "Late" rescue ICSI may be not an optimal strategy for treating unfertilized oocytes. Short co-incubation of gametes combined with early rescue ICSI has some advantages for complete fertilization failure after IVF. We evaluate the strategy and the optimal time for early rescue ICSI. A total of 180 patients underwent short co-incubation of gametes combined with early rescue ICSI treatment for complete fertilization failure after IVF (study group). A total of 494 ICSI patients with male factor infertility served as a control group. Clinical pregnancy rate, implantation rate, and live birth rate in the two groups were compared. The study group was divided into three different rescue time intervals (?6 h, 6-8 h, and ?8 h). Clinical pregnancy rate, implantation rate, and live birth rate were comparable between the study group and the control group. There was a negative correlation between clinical outcomes and rescue time interval.
Related JoVE Video
Defective adipose lipolysis and altered global energy metabolism in mice with adipose overexpression of the lipolytic inhibitor G0/G1 Switch Gene 2.
J. Biol. Chem.
PUBLISHED: 12-03-2013
Show Abstract
Hide Abstract
Biochemical and cell-based studies have identified the G0/G1 Switch Gene 2 (G0S2) as a selective inhibitor of the key intracellular triacylglycerol hydrolase, adipose triglyceride lipase (ATGL). To better understand the physiological role of G0S2, we constructed an adipose tissue-specific G0S2 transgenic mouse model. In comparison to wild type animals, the transgenic mice exhibited a significant increase in overall fat mass and a decrease in peripheral TG accumulation. Basal and adrenergically stimulated lipolysis was attenuated in adipose explants isolated from the transgenic mice. Following fasting or injection of a ?3-adrenergic agonist, in vivo lipolysis and ketogenesis were decreased in G0S2 transgenic mice when compared to wild type animals. Consequently, adipose overexpression of G0S2 prevented the switch of energy substrate from carbohydrates to fatty acids (FAs) during fasting. Moreover, G0S2 overexpression promoted accumulation of more and larger lipid droplets in brown adipocytes without impacting either mitochondrial morphology or expression of oxidative genes. This phenotypic change was accompanied by defective cold adaptation. Furthermore, feeding with a high fat diet (HFD) caused a greater gain of both body weight and adiposity in aP2-G0S2 mice. aP2-G0S2 mice also displayed a decrease in fasting plasma levels of FFA, TG and insulin as well as improved glucose and insulin tolerance. Cumulatively, these results indicate that fat-specific G0S2 overexpression uncouples adiposity from insulin sensitivity and overall metabolic health through inhibiting adipose lipolysis and decreasing circulating FAs.
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.