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.
Fistula Output Microorganism-Susceptible Antimicrobial Prophylaxis Is Associated with a Lower Risk of Surgical Site Infection in Gastrointestinal Fistula Patients Undergoing One-Stage Definitive Surgery.
Surg Infect (Larchmt)
PUBLISHED: 11-18-2014
Show Abstract
Hide Abstract
Abstract Background: Empiric broad-spectrum antimicrobial prophylaxis (AMP) may not be sufficient to minimize the risk of surgical site infections (SSIs) after definitive surgical treatment of gastrointestinal (GI) fistula. This study investigates whether AMP targeted toward fistula microbiology is associated with a lower risk of SSIs in GI fistula patients undergoing one-stage definitive surgery. Methods: Fistula output was sampled from the abdominal fistula opening for microbial growth and drug sensitivity prior to surgery. The primary outcome measure was the overall incidence rate of SSIs. Results: A total of 191 patients were examined. Pre-operative microbial culture identified microbial growth in 149 patients (76.0%). Post-operative SSIs occurred in 51 patients (26.7%). Risk index category, abdominal incision length, and time of peritoneal drain removal had significantly negative impacts on SSIs frequency. Sensitive AMP agents were associated with a significantly lower risk of SSIs, compared with insensitive AMP agents, but with a similar risk to indefinite AMP agents (23.2% vs. 45.2% vs. 23.1%; odds ratio [95% confidence interval]: 2.724 [1.063, 6.979], p=0.034; 1.008 [0.467-2.177], p=0.984). Conclusions: Antimicrobial prophylaxis targeted toward fistula output AMP may minimize the occurrence of SSIs after one-stage definitive surgical treatment of GI fistula.
Related JoVE Video
Norcantharidin enhances TIMP?2 anti?vasculogenic mimicry activity for human gallbladder cancers through downregulating MMP?2 and MT1?MMP.
Int. J. Oncol.
PUBLISHED: 09-12-2014
Show Abstract
Hide Abstract
Vasculogenic mimicry (VM) is a tumor microcirculation pattern in highly aggressive gallbladder cancers (GBCs). We recently reported the anti?VM activity of norcantharidin (NCTD) in highly aggressive GBC?SD cells and xenografts. In this study, we further investigated that NCTD enhanced tissue inhibitor of matrix metalloproteinase?2 (TIMP?2) anti?VM activity for GBCs and the underlying mechanisms. In vivo and in vitro experiments were performed to determine the effects of NCTD in combination with TIMP?2 on tumor growth, host survival, VM formation, hemodynamic of GBC?SD xenografts, and VM?like networks and malignant phenotypes of GBC?SD cells. Expression of matrix metalloproteinase (MMP)?2 and membrane type 1?MMP (MT1?MMP) among human GBCs, GBC?SD cells and xenografts were determined, respectively. The results showed that expression of MMP?2 and MT1?MMP in human GBCs, GBC?SD cells and xenografts was significantly related to VM in GBCs; a shorter survival time of VM?positive patients with high expression of MMP?2 or MT1?MMP compared to that of the patients with low expression. After treatment with NCTD+TIMP?2, tumor growth, VM formation, VM hemodynamic of the xenografts in vivo were significantly inhibited as compared to control, NCTD or TIMP?2 group, with a prolonged survival time of the xenograft mice (log?rank test, P=0.0115); and these observations were confirmed by VM?like networks by 3?D matrices and showed that proliferation, apoptosis, invasion, migration of GBC?SD cells in vitro were markedly affected. Furthermore, expression of MMP?2 and MT1?MMP in VM formation of the xenografts in vivo and GBC?SD cells in vitro was downregulated as compared to control, NCTD or TIMP?2 group. Thus, we concluded that NCTD enhances TIMP?2 antitumor and anti?VM activities in GBCs through downregulating MMP?2 and MT1?MMP.
Related JoVE Video
[MiR-425 up-regulation induced by interleukin-1? promotes the proliferation of gastric cancer cell AGS].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 08-27-2014
Show Abstract
Hide Abstract
To evaluate the mechanism of interleukin-1 (IL-1) in tumorigenesis.
Related JoVE Video
Autonomous basin climbing method with sampling of multiple transition pathways: application to anisotropic diffusion of point defects in hcp Zr.
J Phys Condens Matter
PUBLISHED: 08-19-2014
Show Abstract
Hide Abstract
This paper presents an extension of the autonomous basin climbing (ABC) method, an atomistic activation-relaxation technique for sampling transition-state pathways. The extended algorithm (ABC-E) allows the sampling of multiple transition pathways from a given minimum, with the additional feature of identifying the pathways in the order of increasing activation barriers, thereby prioritizing them according to their importance in the kinetics. Combined with on-the-fly kinetic Monte Carlo calculations, the method is applied to simulate the anisotropic diffusion of point defects in hcp Zr. Multiple migration mechanisms are identified for both the interstitials and vacancies, and benchmarked against results from other methods in the literature. The self-interstitial atom (SIA) diffusion kinetics shows a maximum anisotropy at intermediate temperatures (400~700 K), a non-monotonic behavior that we explain to originate from the stabilities and migration mechanisms associated with different SIA sites. The accuracy of the ABC-E calculations is validated, in part, by the existing results in the literature for point defect diffusion in hcp Zr, and by benchmarking against analytical results on a hypothetical rough-energy landscape. Lastly, sampling prioritization and computational efficiency are demonstrated through a direct comparison between the ABC-E and the activation relaxation technique.
Related JoVE Video
Cullin1 regulates proliferation, migration and invasion of glioma cells.
Med. Oncol.
PUBLISHED: 08-08-2014
Show Abstract
Hide Abstract
This study was designed to explore the role of Cullin1 (Cul1) in the pathogenesis of human glioma and to investigate the role of Cul1 in the growth, migration and invasion of glioma cells. Expression of Cul1 in 191 glioma tissues, 8 normal brain tissues and 8 tumor adjacent normal brain tissues was analyzed by tissue microarray and immunohistochemistry. Cul1 expression in human glioblastoma cells was knocked down by specific siRNA to study the effect of down-regulation of Cul1 on proliferation, invasion and migration of glioma cells. Our results showed that Cul1 expression increased significantly in tissues from the benign tumor and malignant tumor in comparison with those from the tumor-adjacent normal brain (P<0.05 for both). We did not find any correlation between Cul1 expression and clinicopathological parameters. In addition, we found that knockdown of Cul1 by RNA interference markedly inhibited cell proliferation and caused cessation of cell cycle. This reduced cell proliferation was due to G1 phase arrest as cyclinA, cyclinD1 and cyclinE were diminished, whereas p21 and p27 were up-regulated. We further demonstrated that silencing of Cul1 in glioma cells inhibited the cell migration and invasion abilities, and down-regulation of MMP-2 and MMP-9 expression greatly contributed to the reduced cell invasion and migration abilities. Our data indicated that Cul1 expression significantly increased in human glioma, and it may be involved in proliferation, migration and invasion of glioma cells.
Related JoVE Video
Activation of the AT1R/HIF-1 ? /ACE Axis Mediates Angiotensin II-Induced VEGF Synthesis in Mesenchymal Stem Cells.
Biomed Res Int
PUBLISHED: 06-30-2014
Show Abstract
Hide Abstract
A local renin-angiotensin system (RAS) is expressed in mesenchymal stem cells (MSCs) and regulates stem cell function. The local RAS influences the survival and tissue repairing ability of transplanted stem cells. We have previously reported that angiotensin II (Ang II) pretreatment can significantly increase vascular endothelial growth factor (VEGF) synthesis in MSCs through the ERK1/2 and Akt pathways via the Ang II receptor type 1 (AT1R). However, the role of angiotensin-converting enzyme (ACE) has not been clarified. Furthermore, whether Ang II pretreatment activates hypoxia-inducible factor-1? (HIF-1?) in MSCs has not been elucidated. Our data show that both ACE and HIF-1? are involved in promoting VEGF expression in MSCs, and that both are upregulated by Ang II stimulation. The upregulation of ACE appeared after the rapid degradation of exogenous Ang II, and led to the formation of endogenous Ang II. On the other hand, the ACE inhibitor, captopril, attenuated Ang II-enhanced HIF-1? upregulation, while HIF-1? suppression markedly attenuated ACE expression. This interesting finding suggests an interaction between ACE and HIF-1?. We conclude that Ang II pretreatment, as a trigger, activated the AT1R/HIF-1?/ACE axis that then mediated Ang II-induced VEGF synthesis in MSCs.
Related JoVE Video
Evolution of elastic heterogeneity during aging in metallic glasses.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 06-25-2014
Show Abstract
Hide Abstract
The properties of glasses vary widely depending on the way they are prepared, even though their structures appear similar. We show that the local potential energy landscape (PEL) sensitively reflects the stability differences through simulation of local structural excitation in a model metallic glass. It is observed that the spectrum of local structural excitation develops a pseudogap at low energies as the glass becomes more stable. We also demonstrate that the spatial variation of the atomic level shear modulus, rather than the distribution of the magnitude of the single atom shear modulus, is more closely related to the nature of the PEL and the stabilities of glasses. In particular, local aggregation of atoms with low shear modulus greatly contributes to instability of the system.
Related JoVE Video
Sirt3 attenuates hydrogen peroxide-induced oxidative stress through the preservation of mitochondrial function in HT22 cells.
Int. J. Mol. Med.
PUBLISHED: 05-24-2014
Show Abstract
Hide Abstract
Sirtuins (Sirt) are a family of phylogenetically conserved nicotinamide adenine nucleotide (NAD(+))-dependent protein deacetylases, among which Sirt3 resides primarily in the mitochondria and serves as a stress responsive deacetylase, playing a role in protecting cells from damage under stress conditions. The present study aimed to investigate the role of Sirt3 in hydrogen peroxide (H(2)O(2))-induced oxidative neuronal injury in HT22 mouse hippocampal cells. Treatment with H(2)O(2) increased the expression of Sirt3 in a dose- and time-dependent manner, and the knockdown of Sirt3 using specific small interfering RNA (siRNA) exacerbated the H(2)O(2)-induced neuronal injury. The overexpression of Sirt3 induced by lentiviral transfection significantly reduced the generation of reactive oxygen species (ROS) and lipid peroxidation following injury, whereas the activities of endogenous antioxidant enzymes were not affected. Further experiments revealed that the H(2)O(2)-induced inhibition of mitochondrial complex activity and adenosine triphosphate (ATP) synthesis, the decrease in mitochondrial Ca(2+) buffering capacity and mitochondrial swelling were all partly reversed by Sirt3. Furthermore, the overexpression of Sirt3 attenuated the release of cytochrome c, the increase in the Bax/Bcl-2 ratio, as well as caspase-9/caspase-3 activity induced by H(2)O(2), and eventually inhibited apoptotic neuronal cell death. These results suggest that Sirt3 acts as a prosurvival factor, playing an essential role in protecting HT22 cells under H(2)O(2)-induced oxidative stress, possibly by inhibiting ROS accumulation and the activation of the mitochondrial apoptotic pathway.
Related JoVE Video
An integrated assessment for wind energy in Lake Michigan coastal counties.
Integr Environ Assess Manag
PUBLISHED: 05-15-2014
Show Abstract
Hide Abstract
The benefits and challenges of onshore and offshore wind energy development were assessed for a four-county area of coastal Michigan. Economic, social, environmental, and spatial dimensions were considered. The coastal counties have suitable wind resources for energy development which could contribute toward Michigan's ten percent renewable energy standard. Wind energy is cost-effective with contract prices less than the benchmark energy price of a new coal-fired power plant. Constructing a 100 MW wind farm could have a $54.7 million economic impact. A patchwork of township-level zoning ordinances regulates wind energy siting. Voluntary collaborations among adjacent townships standardizing the ordinances could reduce regulatory complexity. A Delphi Inquiry on offshore wind energy in Lake Michigan elicited considerable agreement on its challenges, but little agreement on the benefits to coastal communities. Offshore turbines could be acceptable to the participants if they reduced pollution; benefited coastal communities; involved substantial public participation; and had minimal impact on property values and tourism. The US Coast Guard will take a risk-based approach to evaluating individual offshore developments and has no plans to issue blanket restrictions around the wind farms. Models showed that using wind energy to reach the remainder of the ten percent renewable energy standard could reduce SO2 , NOx , and CO2 pollution by 4-7 percent. Turbines are highly likely to impact the area's navigational and defense radar systems but planning and technological upgrades can reduce the impact. The integrated assessment shows that responsible wind energy development can enhance the quality of life by reducing air pollution and associated health problems and enhancing economic development. Policies could reduce the negative impacts to local communities while preserving the benefits to the broader region. Integr Environ Assess Manag © 2014 SETAC.
Related JoVE Video
How thermally activated deformation starts in metallic glass.
Nat Commun
PUBLISHED: 05-13-2014
Show Abstract
Hide Abstract
The studies on dynamics and deformation in glassy materials are particularly challenging because of their strongly disordered atomic structure. Here, by probing the changes in the atomic displacements and stresses at saddle points of the potential energy landscape, we show that thermally activated deformation is triggered by subnano-scale rearrangements of a small number of atoms, typically less than 10 atoms. The individual triggers are invariant of the cooling history or elastic structure of the system. However, the organizations between different trigger centres can be varied and are related to the overall stability of the system. This finding allows a semi-quantitative construction of the potential energy landscape and brings a new perspective to the study of the mechanical properties of glasses.
Related JoVE Video
Sirt3 protects cortical neurons against oxidative stress via regulating mitochondrial Ca2+ and mitochondrial biogenesis.
Int J Mol Sci
PUBLISHED: 04-27-2014
Show Abstract
Hide Abstract
Oxidative stress is a well-established event in the pathology of several neurobiological diseases. Sirt3 is a nicotinamide adenine nucleotide (NAD+)-dependent protein deacetylase that regulates mitochondrial function and metabolism in response to caloric restriction and stress. This study aims to investigate the role of Sirt3 in H2O2 induced oxidative neuronal injury in primary cultured rat cortical neurons. We found that H2O2 treatment significantly increased the expression of Sirt3 in a time-dependent manner at both mRNA and protein levels. Knockdown of Sirt3 with a specific small interfering RNA (siRNA) exacerbated H2O2-induced neuronal injury, whereas overexpression of Sirt3 by lentivirus transfection inhibited H2O2-induced neuronal damage reduced the generation of reactive oxygen species (ROS), and increased the activities of endogenous antioxidant enzymes. In addition, the intra-mitochondrial Ca2+ overload, but not cytosolic Ca2+ increase after H2O2 treatment, was strongly attenuated after Sirt3 overexpression. Overexpression of Sirt3 also increased the content of mitochondrial DNA (mtDNA) and the expression of mitochondrial biogenesis related transcription factors. All these results suggest that Sirt3 acts as a prosurvival factor playing an essential role to protect cortical neurons under H2O2 induced oxidative stress, possibly through regulating mitochondrial Ca2+ homeostasis and mitochondrial biogenesis.
Related JoVE Video
[Efficacy of BAHA softband in young children with bilateral congenital aural atresia].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 04-24-2014
Show Abstract
Hide Abstract
To retrospectively analyze the auditory and speech development of young children with bilateral congenital aural atresia after using bone-anchored hearing aid (BAHA) softband.
Related JoVE Video
Activation of mGluR5 attenuates NMDA-induced neurotoxicity through disruption of the NMDAR-PSD-95 complex and preservation of mitochondrial function in differentiated PC12 cells.
Int J Mol Sci
PUBLISHED: 04-17-2014
Show Abstract
Hide Abstract
Glutamate-mediated toxicity is implicated in various neuropathologic conditions, and activation of ionotropic and metabotropic glutamate receptors is considered to be the most important mechanism. It has been reported that pharmacological saturation of metabotropic glutamate receptors (mGluRs) can facilitate N-methyl-D-aspartate receptor (NMDAR) related signaling cascades, but the mechanism leading to mGluR-NMDAR interactions in excitotoxic neuronal injury has remained unidentified. In the present study, we investigated the role of mGluR5 in the regulation of N-methyl-D-aspartate (NMDA)-induced excitotoxicity in differentiated PC12 cells. We found that activation of mGluR5 with the specific agonist R,S-2-chloro-5-hydroxyphenylglycine (CHPG) increased cell viability and inhibited lactate dehydrogenase (LDH) release in a dose-dependent manner. CHPG also inhibited an increase in the Bax/Bcl-2 ratio, attenuated cleavage of caspase-9 and caspase-3, and reduced apoptotic cell death after NMDA treatment. The NMDA-induced mitochondrial dysfunction, as indicated by mitochondrial reactive oxygen species (ROS) generation, collapse of mitochondrial membrane potential (MMP), and cytochrome c release, was also partly prevented by CHPG treatment. Furthermore, CHPG blocked the NMDA-induced interaction of NMDAR with postsynaptic density protein-95 (PSD-95), but had no effects on intracellular calcium concentrations. All these results indicated that activation of mGluR5 protects differentiated PC12 cells from NMDA-induced neuronal excitotoxicity by disrupting NMDAR-PSD-95 interaction, which might be an ideal target for investigating therapeutic strategies in various neurological diseases where excitotoxicity may contribute to their pathology.
Related JoVE Video
Role of toll-like receptors in lung cancer.
J. Recept. Signal Transduct. Res.
PUBLISHED: 03-18-2014
Show Abstract
Hide Abstract
Lung cancer is a leading cause of death world-wide and the long-term survival rate for patients with lung cancer is one of the lowest for any cancer. Toll-like receptors (TLRs), evolutionarily conserved innate, are expressed in a wide variety of tissues and cell types, and they play key role in the innate immune system. TLRs have been found to be expressed by some kinds of tumor cells. However, what is the biological function of TLRs on tumor cells and whether human lung cancer cells can express TLRs remain to be fully understood. This review was performed to sum up the role of TLRs in lung cancer.
Related JoVE Video
Clinical evaluation for batch consistency of an inactivated enterovirus 71 vaccine in a large-scale phase 3 clinical trial.
Hum Vaccin Immunother
PUBLISHED: 03-14-2014
Show Abstract
Hide Abstract
The demonstration of batch-to-batch consistency to confirm the reliability of the manufacturing process has become a mandatory step in vaccine development. This is a post-hoc analysis aimed to provide more solid evidence on the immunogenicity and consistency of 3 consecutive batches of a novel inactivated enterovirus 71 (EV71) vaccine. In total 10?245 healthy Chinese children aged 6-35 months had been recruited and randomized to receive one of 3 batches of EV71 vaccine or placebo according to a two-dose immunization schedule in a phase 3 clinical trial. Blood samples were taken just before and 28 days after vaccinations for serological tests of EV71 neutralizing antibody (NTAb) titer from the subjects. Among them, 7263 (70.9%) subjects with seronegative EV71 NTAb at baseline and the data of serological tests post-vaccination available were included for the analysis. The results showed that EV71 vaccine elicited high geometric mean titers (GMTs) of 407.0 U/mL (95% CI, 373.5-443.6) for batch 1, 468.1 U/mL (95% CI, 432.2-507.0) for batch 2, and 520.6 U/mL (95% CI, 481.2-563.3) for batch 3. The two-sided 95% confidence intervals (CIs) for the GMT ratios between each pair of vaccine batches were all within an interval of [0.67, 1.5]. Subjects who received EV71 vaccines demonstrated significant higher GMTs than those received placebos did (P<0.001). In terms of incidence of both local and general adverse reactions, no differences were found among 3 vaccine batches and placebos. EV71 vaccine was highly immunogenic in children, and the 3 consecutive batches were well consistent.
Related JoVE Video
Norcantharidin inhibits tumor growth and vasculogenic mimicry of human gallbladder carcinomas by suppression of the PI3-K/MMPs/Ln-5?2 signaling pathway.
BMC Cancer
PUBLISHED: 03-10-2014
Show Abstract
Hide Abstract
Vasculogenic mimicry (VM) is a novel tumor blood supply in some highly aggressive malignant tumors. Recently, we reported VM existed in gallbladder carcinomas (GBCs) and the formation of the special passage through the activation of the PI3K/MMPs/Ln-5?2 signaling pathway. GBC is a highly aggressive malignant tumor with disappointing treatments and a poor prognosis. Norcantharidin (NCTD) has shown to have multiple antitumor activities against GBCs, etc; however the exact mechanism is not thoroughly elucidated. In this study, we firstly investigated the anti-VM activity of NCTD as a VM inhibitor for GBCs and its underlying mechanisms.
Related JoVE Video
NF-kappaB-dependent microRNA-425 upregulation promotes gastric cancer cell growth by targeting PTEN upon IL-1? induction.
Mol. Cancer
PUBLISHED: 02-20-2014
Show Abstract
Hide Abstract
Overexpression of the proinflammatory cytokine IL-1? is associated with diverse diseases, including cancer. Alteration of microRNAs has been observed in cancer cells exposed to proinflammatory cytokines, yet their function in inflammation stress remains elusive. Here, we show that IL-1? induces the upregulation of miR-425, which negatively regulates phosphatase and tensin homolog expression by targeting its 3' UTR. An increase in miR-425 depends on IL-1?-induced NF-kappaB activation, which enhances miR-425 gene transcription upon IL-1? induction. Consequently, repression of phosphatase and tensin homolog by miR-425 promotes gastric cancer cell proliferation, which is required to protect cells from cisplatin-induced apoptosis. Taken together, our data support a critical role for NF-kappaB-dependent upregulation of miR-425, which represents a new pathway for the repression of phosphatase and tensin homolog activation and the promotion of cell survival upon IL-1? induction.
Related JoVE Video
The efficacy of unilateral bone-anchored hearing devices in Chinese Mandarin-speaking patients with bilateral aural atresia.
JAMA Otolaryngol Head Neck Surg
PUBLISHED: 02-08-2014
Show Abstract
Hide Abstract
The bone-anchored hearing device (BAHD) was not introduced in China until 2010. To our knowledge, this is the first study to assess the efficacy of Chinese Mandarin-speaking patients with bilateral aural atresia.
Related JoVE Video
Upstream Transcription Factor 1 (USF1) allelic variants regulate lipoprotein metabolism in women and USF1 expression in atherosclerotic plaque.
Sci Rep
PUBLISHED: 01-20-2014
Show Abstract
Hide Abstract
Upstream transcription factor 1 (USF1) allelic variants significantly influence future risk of cardiovascular disease and overall mortality in females. We investigated sex-specific effects of USF1 gene allelic variants on serum indices of lipoprotein metabolism, early markers of asymptomatic atherosclerosis and their changes during six years of follow-up. In addition, we investigated the cis-regulatory role of these USF1 variants in artery wall tissues in Caucasians. In the Cardiovascular Risk in Young Finns Study, 1,608 participants (56% women, aged 31.9 ± 4.9) with lipids and cIMT data were included. For functional study, whole genome mRNA expression profiling was performed in 91 histologically classified atherosclerotic samples. In females, serum total, LDL cholesterol and apoB levels increased gradually according to USF1 rs2516839 genotypes TT < CT < CC and rs1556259 AA < AG < GG as well as according to USF1 H3 (GCCCGG) copy number 0 < 1 < 2. Furthermore, the carriers of minor alleles of rs2516839 (C) and rs1556259 (G) of USF1 gene had decreased USF1 expression in atherosclerotic plaques (P = 0.028 and 0.08, respectively) as compared to non-carriers. The genetic variation in USF1 influence USF1 transcript expression in advanced atherosclerosis and regulates levels and metabolism of circulating apoB and apoB-containing lipoprotein particles in sex-dependent manner, but is not a major determinant of early markers of atherosclerosis.
Related JoVE Video
Accumulation of androstadiene-dione by overexpression of heterologous 3-ketosteroid ?1-dehydrogenase in Mycobacterium neoaurum NwIB-01.
World J. Microbiol. Biotechnol.
PUBLISHED: 01-20-2014
Show Abstract
Hide Abstract
Mycobacterium neoaurum NwIB-01 exhibits powerful ability to cleave the side chain of soybean phytosterols to accumulate 4-androstene-3,17-dione (AD) and 1,4-androstadiene-3,17-dione (ADD). The difficulty in separation of AD from ADD is one of the key bottlenecks to the microbial transformation of phytosterols in the industry. To enhance ADD quantity in products, 3-ketosteroid ?(1)-dehydrogenase genes (kstD M and kstD(A)) were obtained from M. neoaurum NwIB-01 and Arthrobacter simplex respectively. Using replicating vector pMV261, kstD(M) and kstD(A) were overexpressed in M. neoaurum NwIB-01. For foreign gene stable expression, the integration vector pMV306 was used for kstD M/kstD(A) overexpression and the relevant sequences of promoter and kanamycin antibiotic resistance gene sequences were amplified by PCR to verify plasmid integrity. The resultant plasmid and mutant strain were verified and the kstD augmentation mutants were good ADD-producing strains. The ADD producing capacity of NwIB-04 and NwIB-05 was 0.1401 and 0.1740 g/l (cultured in shake bottles with 0.4 g/l phytosterols), and the molar ratio of ADD in products was 98.34 and 98.60%, respectively. This study on the manipulation of the main kstDM gene in Mycobacterium sp. provides a feasible way to achieve excellent phytosterol-transformation strains with high product purity.
Related JoVE Video
iNR-Drug: predicting the interaction of drugs with nuclear receptors in cellular networking.
Int J Mol Sci
PUBLISHED: 01-13-2014
Show Abstract
Hide Abstract
Nuclear receptors (NRs) are closely associated with various major diseases such as cancer, diabetes, inflammatory disease, and osteoporosis. Therefore, NRs have become a frequent target for drug development. During the process of developing drugs against these diseases by targeting NRs, we are often facing a problem: Given a NR and chemical compound, can we identify whether they are really in interaction with each other in a cell? To address this problem, a predictor called "iNR-Drug" was developed. In the predictor, the drug compound concerned was formulated by a 256-D (dimensional) vector derived from its molecular fingerprint, and the NR by a 500-D vector formed by incorporating its sequential evolution information and physicochemical features into the general form of pseudo amino acid composition, and the prediction engine was operated by the SVM (support vector machine) algorithm. Compared with the existing prediction methods in this area, iNR-Drug not only can yield a higher success rate, but is also featured by a user-friendly web-server established at http://www.jci-bioinfo.cn/iNR-Drug/, which is particularly useful for most experimental scientists to obtain their desired data in a timely manner. It is anticipated that the iNR-Drug server may become a useful high throughput tool for both basic research and drug development, and that the current approach may be easily extended to study the interactions of drug with other targets as well.
Related JoVE Video
MicroRNA-34a induces apoptosis in the human glioma cell line, A172, through enhanced ROS production and NOX2 expression.
Biochem. Biophys. Res. Commun.
PUBLISHED: 01-04-2014
Show Abstract
Hide Abstract
MicroRNA is a type of non-coding small RNA involved in regulating genes and signaling pathways through incomplete complementation with target genes. Recent research supports key roles of miRNA in the formation and development of human glioma.
Related JoVE Video
Inhibition of tumor vasculogenic mimicry and prolongation of host survival in highly aggressive gallbladder cancers by norcantharidin via blocking the ephrin type a receptor 2/focal adhesion kinase/paxillin signaling pathway.
PLoS ONE
PUBLISHED: 01-01-2014
Show Abstract
Hide Abstract
Vasculogenic mimicry (VM) is a newly-defined tumor microcirculation pattern in highly aggressive malignant tumors. We recently reported tumor growth and VM formation of gallbladder cancers through the contribution of the ephrin type a receptor 2 (EphA2)/focal adhesion kinase (FAK)/Paxillin signaling pathways. In this study, we further investigated the anti-VM activity of norcantharidin (NCTD) as a VM inhibitor for gallbladder cancers and the underlying mechanisms. In vivo and in vitro experiments to determine the effects of NCTD on tumor growth, host survival, VM formation of GBC-SD nude mouse xenografts, and vasculogenic-like networks, malignant phenotypes i.e., proliferation, apoptosis, invasion and migration of GBC-SD cells. Expression of VM signaling-related markers EphA2, FAK and Paxillin in vivo and in vitro were examined by immunofluorescence, western blotting and real-time polymerase chain reaction (RT-PCR), respectively. The results showed that after treatment with NCTD, GBC-SD cells were unable to form VM structures when injecting into nude mouse, growth of the xenograft was inhibited and these observations were confirmed by facts that VM formation by three-dimensional (3-D) matrix, proliferation, apoptosis, invasion, migration of GBC-SD cells were affected; and survival time of the xenograft mice was prolonged. Furthermore, expression of EphA2, FAK and Paxillin proteins/mRNAs of the xenografts was downregulated. Thus, we concluded that NCTD has potential anti-VM activity against human gallbladder cancers; one of the underlying mechanisms may be via blocking the EphA2/FAK/Paxillin signaling pathway.
Related JoVE Video
How to understand the efficacy measurements for enterovirus type 71 vaccine?
Hum Vaccin Immunother
PUBLISHED: 11-28-2013
Show Abstract
Hide Abstract
The choice of endpoint was most important for an efficacy vaccine trial. The objective of this paper is to gear toward answering questions about the rationality and scientificity of the primary endpoints choosing, case capturing and diagnosis strategy in our recently reported EV71 vaccine efficacy phase 3 trial. In order to obtain both high sensitivity and specificity in the case detecting, EV71-associated disease had been chosen as primary endpoint, a broad spectrum of clinical symptoms was surveyed, both the real-time RT-PCR and virus isolation were combined for the laboratory diagnosis, and serial specimens since disease onset were collected for assays. Though, the EV71 vaccine efficacy was well measured in the phase 3 trial, several potential factors could also have influences on the cases confirming. More evidence of EV71 vaccine efficacy will be demanded in post-marketing studies in the future.
Related JoVE Video
Mapping strain rate dependence of dislocation-defect interactions by atomistic simulations.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 10-10-2013
Show Abstract
Hide Abstract
Probing the mechanisms of defect-defect interactions at strain rates lower than 10(6) s(-1) is an unresolved challenge to date to molecular dynamics (MD) techniques. Here we propose an original atomistic approach based on transition state theory and the concept of a strain-dependent effective activation barrier that is capable of simulating the kinetics of dislocation-defect interactions at virtually any strain rate, exemplified within 10(-7) to 10(7) s(-1). We apply this approach to the problem of an edge dislocation colliding with a cluster of self-interstitial atoms (SIAs) under shear deformation. Using an activation-relaxation algorithm [Kushima A, et al. (2009) J Chem Phys 130:224504], we uncover a unique strain-rate-dependent trigger mechanism that allows the SIA cluster to be absorbed during the process, leading to dislocation climb. Guided by this finding, we determine the activation barrier of the trigger mechanism as a function of shear strain, and use that in a coarse-graining rate equation formulation for constructing a mechanism map in the phase space of strain rate and temperature. Our predictions of a crossover from a defect recovery at the low strain-rate regime to defect absorption behavior in the high strain-rate regime are validated against our own independent, direct MD simulations at 10(5) to 10(7) s(-1). Implications of the present approach for probing molecular-level mechanisms in strain-rate regimes previously considered inaccessible to atomistic simulations are discussed.
Related JoVE Video
Blockade of SOCE protects HT22 cells from hydrogen peroxide-induced apoptosis.
Biochem. Biophys. Res. Commun.
PUBLISHED: 10-09-2013
Show Abstract
Hide Abstract
Oxidative stress is an established event in the pathology of neurobiological diseases. Previous studies indicated that store-operated Ca(2+) entry (SOCE) has been involved in oxidative stress. The present study was carried out to investigate the effects of SOCE inhibition on neuronal oxidative stress injury induced by hydrogen peroxide (H2O2) in HT22 cells, a murine hippocampal neuronal model. H2O2 insult induced significant intracellular Ca(2+) overload, mitochondrial dysfunction and cell viability decrease. Inhibition of SOCE by pharmacological inhibitor and STIM1 RNAi significantly alleviated intracellular Ca(2+) overload, restored the mitochondrial membrane potential (MMP), decreased cytochrome C release and eventually inhibited H2O2-induced cell apoptosis. These findings suggest that SOCE inhibition exhibited neuroprotection against oxidative stress induced by H2O2 and SOCE might be a useful therapeutic target in neurobiological disorders.
Related JoVE Video
Radiation-Sensitising Effects of Antennapedia Proteins (ANTP)-SmacN7 on Tumour Cells.
Int J Mol Sci
PUBLISHED: 10-08-2013
Show Abstract
Hide Abstract
The objective of this study was to investigate the underlying mechanisms behind the radiation-sensitising effects of the antennapedia proteins (ANTP)-smacN7 fusion protein on tumour cells. ANTP-SmacN7 fusion proteins were synthesised, and the ability of this fusion protein to penetrate cells was observed. Effects of radiation on the expression of X-linked inhibitor of apoptosis protein (XIAP) were detected by western blotting. The radiation-sensitising effects of ANTP-SmacN7 fusion proteins were observed by a clonogenic assay. The effects of drugs and radiation on tumour cell apoptosis were determined using Annexin V/FITC double staining. Changes in caspase-8, caspase-9 and caspase-3 were detected by western blot before and after ANTP-SmacN7 inhibition of XIAP. The ANTP-SmacN7 fusion protein could enter and accumulate in cells; in vitro XIAP expression of radiation-induced tumour cells was negatively correlated with tumour radiosensitivity. The ANTP-SmacN7 fusion protein promoted tumour cell apoptosis through the activation of caspase3. ANTP-SmacN7 fusion protein may reduce tumour cell radioresistance by inducing caspase3 activation.
Related JoVE Video
[Prevention and treatment of common complications of ear reconstruction].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 10-01-2013
Show Abstract
Hide Abstract
To explore the prevention and treatment of common complications of ear reconstruction.
Related JoVE Video
Evaluation of the comet assay for assessing the dose-response relationship of DNA damage induced by ionizing radiation.
Int J Mol Sci
PUBLISHED: 09-04-2013
Show Abstract
Hide Abstract
Dose- and time-response curves were combined to assess the potential of the comet assay in radiation biodosimetry. The neutral comet assay was used to detect DNA double-strand breaks in lymphocytes caused by ?-ray irradiation. A clear dose-response relationship with DNA double-strand breaks using the comet assay was found at different times after irradiation (p < 0.001). A time-response relationship was also found within 72 h after irradiation (p < 0.001). The curves for DNA double-strand breaks and DNA repair in vitro of human lymphocytes presented a nice model, and a smooth, three-dimensional plane model was obtained when the two curves were combined.
Related JoVE Video
HIF1 contributes to hypoxia-induced pancreatic cancer cells invasion via promoting QSOX1 expression.
Cell. Physiol. Biochem.
PUBLISHED: 07-23-2013
Show Abstract
Hide Abstract
Quiescin sulfhydryl oxidase 1 (QSOX1), which oxidizes sulfhydryl groups to form disulfide bonds in proteins, is found to be over-expressed in various pancreatic cancer cell lines and patients. QSOX1 promotes invasion of pancreatic cancer cells by activating MMP-2 and MMP-9. However, its regulatory mechanism remains largely undefined.
Related JoVE Video
Auditory development after placement of bone-anchored hearing aids Softband among Chinese Mandarin-speaking children with bilateral aural atresia.
Int. J. Pediatr. Otorhinolaryngol.
PUBLISHED: 07-22-2013
Show Abstract
Hide Abstract
To evaluate auditory developments of Chinese Mandarin-speaking children with congenital bilateral aural atresia after using Bone-anchored hearing aids (Baha) Softband and to compare them with matched peers with normal hearing.
Related JoVE Video
Cytogenetic abnormalities in lymphocytes from victims exposed to cobalt-60 radiation.
Int J Mol Sci
PUBLISHED: 06-24-2013
Show Abstract
Hide Abstract
The present study investigates cytogenetic damage in lymphocytes, derived from three victims who were unfortunately exposed to cobalt-60 (60Co) radiation (the 1999 accident occurred in a village in Chinas Henan province). Case A of the three victims was exposed to a higher dose of 60Co radiation than Cases B and C. The chromosomal aberrations, cytokinesis-block micronucleus (CBMN, the CBMN assay), and DNA double-strand breaks (DSBs, the comet assay) examined in this study are biomarkers for cytogenetic abnormalities. After the lymphocytes collected from the victims were cultured, the frequencies of dicentric chromosomes and rings (dic + r) and CBMN in the first mitotic division detected in the lymphocytes of Case A were found to be substantially higher than in Cases B and C. Similarly, the DNA-DSB level found in the peripheral blood collected from Case A was much higher than those of Cases B and C. These results suggest that an acutely enhanced induction of the 60Co-induced cytogenetic abnormality frequency in humans depends on the dose of 60Co radiation. This finding is supported by the data obtained using practical techniques to evaluate early lymphoid-tissue abnormalities induced after exposure to acute radiation.
Related JoVE Video
Tumor suppressor PDCD4 modulates miR-184-mediated direct suppression of C-MYC and BCL2 blocking cell growth and survival in nasopharyngeal carcinoma.
Cell Death Dis
PUBLISHED: 06-21-2013
Show Abstract
Hide Abstract
Programmed cell death 4 (PDCD4), a novel tumor suppressor, inhibits cell proliferation, migration and invasion as well as promotes cell apoptosis in tumors. However, the molecular mechanism of its tumor-suppressive function remains largely unknown in tumors including nasopharyngeal carcinoma (NPC). In this study, downregulated PDCD4 expression was significantly associated with the status of NPC progression and poor prognosis. PDCD4 markedly suppressed the ability of cell proliferation and cell survival by modulating C-MYC-controlled cell cycle and BCL-2-mediated mitochondrion apoptosis resistance signals, and oncogenic transcription factor C-JUN in NPC. Furthermore, miR-184, a tumor-suppressive miRNA modulated by PDCD4 directly targeting BCL2 and C-MYC, participated in PDCD4-mediated suppression of cell proliferation and survival in NPC. Further, we found that PDCD4 decreased the binding of C-Jun to the AP-1 element on the miR-184 promoter regions by PI3K/AKT/JNK/C-Jun pathway and stimulated miR-184 expression. In clinical fresh specimens, reduced PDCD4 mRNA level was positively correlated with miR-184 expression in NPC. Our studies are the first to demonstrate that PDCD4 as tumor suppressor regulated miR-184-mediated direct targeting of BCL2 and C-MYC via PI3K/AKT and JNK/C-Jun pathway attenuating cell proliferation and survival in NPC.
Related JoVE Video
Investigation of molecular alterations of AKT-3 in triple-negative breast cancer.
Histopathology
PUBLISHED: 06-16-2013
Show Abstract
Hide Abstract
Triple-negative breast cancer (TNBC) is responsible for a disproportionate number of breast cancer (BC) deaths, owing to its intrinsic aggressiveness and a lack of treatment options, especially targeted therapies. Thus, there is an urgent need for the development of better targeted treatments for TNBC. Molecular alteration of AKT-3 was previously reported in oestrogen receptor (ER)-positive BC. AKT-3 has also been suggested to play a role in hormone-unresponsive BC. The aim of this study was to investigate molecular alterations of AKT-3 in TNBC, to perform associated survival analysis, and to compare these findings with the incidence of AKT-3 molecular alterations in ER-positive BC.
Related JoVE Video
MetSizeR: selecting the optimal sample size for metabolomic studies using an analysis based approach.
BMC Bioinformatics
PUBLISHED: 06-07-2013
Show Abstract
Hide Abstract
Determining sample sizes for metabolomic experiments is important but due to the complexity of these experiments, there are currently no standard methods for sample size estimation in metabolomics. Since pilot studies are rarely done in metabolomics, currently existing sample size estimation approaches which rely on pilot data can not be applied.
Related JoVE Video
Efficacy, safety, and immunology of an inactivated alum-adjuvant enterovirus 71 vaccine in children in China: a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.
Lancet
PUBLISHED: 05-29-2013
Show Abstract
Hide Abstract
A vaccine for enterovirus 71 (EV71) is needed to address the high burden of disease associated with infection. We assessed the efficacy, safety, immunogenicity, antibody persistence, and immunological correlates of an inactivated alum-adjuvant EV71 vaccine.
Related JoVE Video
Homer1 knockdown protects dopamine neurons through regulating calcium homeostasis in an in vitro model of Parkinsons disease.
Cell. Signal.
PUBLISHED: 05-13-2013
Show Abstract
Hide Abstract
Homer1 protein is an important scaffold protein at postsynaptic density and has been demonstrated to play a central role in calcium signaling in the central nervous system. The aim of this study was to investigate the effects of Homer1 knockdown on MPP(+) induced neuronal injury in cultured dopamine (DA) neurons. We found that down-regulating Homer1 expression with specific small interfering RNA (siRNA) significantly suppressed LDH release, reduced Propidium iodide (PI) or Hoechst staining, increased the number of tyrosine hydroxylase (TH) positive cells and DA uptake, and attenuated apoptotic and necrotic cell death after MPP(+) injury. Homer1 knockdown decreased intracellular reactive oxygen species (ROS) generation through inhibition of intracellular calcium overload, but did not affect the endogenous antioxidant enzyme activities. Calcium imaging was used to examine the changes of intracellular Ca(2+) concentration ([Ca(2+)]cyt) and Ca(2+) in endoplasmic reticulum (ER) ([Ca(2+)]ER), and the results showed that Homer1 siRNA transfection attenuated ER Ca(2+) release up to 120min after MPP(+) injury. Furthermore, decrease of [Ca(2+)]cyt induced by Homer1 knockdown in MPP(+) treated neurons was further enhanced by NMDA receptor antagonists MK-801 and AP-5, but not canonical transient receptor potential (TRPC) channel antagonist SKF-96365. l-type calcium antagonist isradipine but not nimodipine further inhibited intracellular calcium overload after MPP(+) insult in Homer1 down-regulated neurons. These results suggest that Homer1 knockdown has protective effects against neuronal injury in in vitro PD model by reducing calcium overload mediated ROS generation, and this protection may be dependent at least in part on the regulatory effects on the function of calcium channels in both plasma membrane and ER.
Related JoVE Video
MiR-29c inhibits glioma cell proliferation, migration, invasion and angiogenesis.
J. Neurooncol.
PUBLISHED: 05-10-2013
Show Abstract
Hide Abstract
Previous studies reported that miR-29c is significantly downregulated in several tumors. However, little is known about the effect and molecular mechanisms of action of miR-29c in human glioma. Using quantitative RT-PCR, we demonstrated that miR-29c was significantly downregulated in glioma cell lines and human primary glioma tissues, compared to normal human astrocytes and matched non-tumor associated tissues (P < 0.05, ?(2) test). Overexpression of miR-29c dramatically reduced the proliferation and caused cessation of cell cycle. The reduced cell proliferation is due to G1 phase arrest as cyclin D1 and cyclin E are diminished whereas p27 and p21 are upregulated. We further demonstrated that miR-29c overexpression suppressed the glioma cell migration and invasion abilities by targeting MMP-2. In addition, we also found that overexpression of miR-29c sharply inhibited angiogenesis, which correlated with down-regulation of VEGF. The data indicate that miR-29c may be a tumor suppressor involved in the progression of glioma.
Related JoVE Video
Development and validation of a liquid chromatography-tandem mass spectrometry method for simultaneous determination of amlodipine, atorvastatin and its metabolites ortho-hydroxy atorvastatin and para-hydroxy atorvastatin in human plasma and its applicati
J Pharm Biomed Anal
PUBLISHED: 03-09-2013
Show Abstract
Hide Abstract
A sensitive, simple and rapid high-performance liquid chromatography coupled with positive ion electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method was developed for the simultaneous determination of amlodipine, atorvastatin and its metabolites ortho-hydroxy atorvastatin and para-hydroxy atorvastatin in human plasma. The analytes were extracted from human plasma through liquid-liquid extraction method. A mixture of methyl tert-butyl ether and ethyl acetate (50:50, v/v) was used as the extractant. The chromatographic separation was achieved on a CAPCELLPAK CR 1:4 (5 ?m, 150 mm × 2.0 mm i.d.) column within 6.0 min with the mobile phase consisted of acetonitrile and ammonium acetate buffer (20mM) containing 0.3% formic acid (50:50, v/v). Data acquisition was carried out in multiple reaction monitoring (MRM) mode. The method was validated and was successfully applied to the bioequivalence study of combination tablets containing AM and AT with coadministered individual drugs in 50 healthy Chinese male volunteers.
Related JoVE Video
A novel mutation in the TCOF1 gene found in two Chinese cases of Treacher Collins syndrome.
Int. J. Pediatr. Otorhinolaryngol.
PUBLISHED: 02-16-2013
Show Abstract
Hide Abstract
To analyze the clinical features, hearing rehabilitation and family related gene mutations in the Chinese cases of Treacher Collins syndrome (TCS). The purpose of this study is to emphasize the genetic research result correlating with the clinical assessment of TCS in Chinese families.
Related JoVE Video
Contribution of the PI3K/MMPs/Ln-5?2 and EphA2/FAK/Paxillin signaling pathways to tumor growth and vasculogenic mimicry of gallbladder carcinomas.
Int. J. Oncol.
PUBLISHED: 02-01-2013
Show Abstract
Hide Abstract
Vasculogenic mimicry (VM) is a new tumor blood supply in some highly aggressive malignant tumors. We previously reported VM in human gallbladder carcinomas, 3-D matrices in vitro and nude mouse xenografts in vivo of highly aggressive GBC-SD cells and its clinical significance. In this study, we further studied the underlying mechanisms of VM in gallbladder carcinomas via the 3-D matrix in vitro, the nude mouse xenografts in vivo of GBC-SD or SGC-996 cells, immunohistochemistry (H&E staining and CD31-PAS double staining), electron microscopy, expression of MMP-2, MT1-MMP, PI3K, Ln-5?2, EphA2, FAK and Paxillin-P proteins/mRNAs determined by SABC, ELISA, immunofluorescence, western blotting and qRT-PCR, respectively. It was shown that all of untreated highly aggressive GBC-SD cells and xenografts formed vasculogenic-like structures within 2 weeks of seeding and injecting, and facilitated the growth of tumor cells or xenografts; whereas poorly aggressive SGC-996 cells or GBC-SD cells treated by TIMP-2 were unable to form the vasculogenic-like structures with the same conditions; and tumor xenograft growth was inhibited. Expression of MMP-2, MT1-MMP proteins/mRNAs from sections and supernates of 3-D matrix in vitro, expression of PI3K, MMP-2, MT1-MMP, Ln-5?2, EphA2, FAK and Paxillin-P proteins/mRNAs from sections of xenografts in vivo in untreated GBC-SD group was upregulated significantly (all P<0.001); however, expression of these VM signal-related proteins/mRNAs in the SGC-996 group and GBC-SD treated by the TIMP-2 group was significantly downregulated (all P<0.001). Thus, we identified for the first time that highly aggressive GBC-SD cells formed VM in vitro and in vivo through the upregulation of PI3K/MMPs/Ln-5?2 and/or EphA2/FAK/Paxillin signaling. PI3K/MMPs/Ln-5?2 and EphA2/FAK/Paxillin as key signaling pathways in a coordinated manner contributed to tumor growth and VM of gallbladder carcinomas and provided novel targets that could be potentially exploited for therapeutic intervention of human gallbladder carcinomas.
Related JoVE Video
Immunogenicity and safety of an enterovirus 71 vaccine in healthy Chinese children and infants: a randomised, double-blind, placebo-controlled phase 2 clinical trial.
Lancet
PUBLISHED: 01-29-2013
Show Abstract
Hide Abstract
Enterovirus 71 (EV71) outbreaks are a socioeconomic burden, especially in the western Pacific region. Results of phase 1 clinical trials suggest an EV71 vaccine has a clinically acceptable safety profile and immunogenicity. We aimed to assess the best possible dose and formulation, immunogenicity, and safety profile of this EV71 vaccine in healthy Chinese children.
Related JoVE Video
Vascularised greater trochanter bone graft, combined free iliac flap and impaction bone grafting for osteonecrosis of the femoral head.
Int Orthop
PUBLISHED: 01-23-2013
Show Abstract
Hide Abstract
To investigate the curative efficacy of osteonecrosis of the femoral head (ONFH) in a hip-preserving operative approach, by grafting a vascularized greater trochanter flap combined with a free iliac flap, in an attempt to seek an innovative approach for patients who suffered middle to late stage ONFH without total hip arthroplasty (THA) surgery.
Related JoVE Video
Effect of radiation on the Notch signaling pathway in osteoblasts.
Int. J. Mol. Med.
PUBLISHED: 01-22-2013
Show Abstract
Hide Abstract
Notch signaling has been shown to be important in osteoblast differentiation. Therapeutic radiation has been shown to alter the skeletal system, yet little information is available on the changes in Notch signaling in irradiated osteoblasts. The purpose of this study was to analyze the effect of radiation therapy with 2 and 4 Gy on Notch signaling in osteoblasts. In order to assess the radiation damage on osteoblast differentiation, total RNA and protein were collected three days after exposure to radiation. The effects of radiation on Notch signaling at the early and terminal stages of osteoblastic MC3T3-E1 cell differentiation was analyzed by qRT-PCR and western blot analysis. Our study applied a previously established method to induce MC3T3-E1 cell differentiation into osteoblasts and osteoblast precursors. Our results showed that the expression of Notch receptors (Notch1-4), ligands (Jagged1, Jagged2 and Delta1), target of Notch signaling (Hes1) and markers (ALP, M-CSF, RANKL and OPG) were altered following 2 and 4 Gy of irradiation. The present research did not indicate a strong relationship between Notch1 regulation and suppression of osteoblast differentiation. We found Hes1 may play a role in the radiation effect on osteoblast differentiation. Our results indicate that radiated osteoblast precursors and osteoblasts promoted osteoclast differentiation and proliferation.
Related JoVE Video
Evaluation of prediction models for the staging of prostate cancer.
BMC Med Inform Decis Mak
PUBLISHED: 01-08-2013
Show Abstract
Hide Abstract
There are dilemmas associated with the diagnosis and prognosis of prostate cancer which has lead to over diagnosis and over treatment. Prediction tools have been developed to assist the treatment of the disease.
Related JoVE Video
Simultaneous determination of iloperidone and its two active metabolites in human plasma by liquid chromatography-tandem mass spectrometry: application to a pharmacokinetic study.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 01-04-2013
Show Abstract
Hide Abstract
A selective, sensitive and accurate high-performance liquid chromatographic- tandem mass spectrometry (HPLC-MS/MS) method for simultaneous determination of iloperidone and its two active metabolites, P88 and P95, in human plasma has been first developed and validated. The analytes and internal standard (IS), pioglitazone hydrochloride, were extracted from human plasma via liquid-liquid extraction with ethyl acetate and separated on a CAPCELL PAK C18 MG IIIcolumn (150mm×2.0mm, 5?m) set at 40°C. The mobile phase was acetonitrile: 5mM ammonium formate containing 0.3% formic acid (pH 4.8) (25:75, v/v), with a flow rate of 0.35mL/min. The mass spectrometer was operated in multiple reaction monitoring (MRM) mode using the transitions m/z 427.2?261.2 for iloperidone, m/z 429.1?261.1 for P88 and P95, and m/z 357.1?133.7 for the I.S. (pioglitazone hydrochloride). The method was validated to be linear over the concentration range of 10-10,000pg/mL for iloperidone and P88, 50-15,000pg/mL for P95. The mean recoveries were more than 78.88%, and the intra- and inter-day precisions were less than 10.24% and accuracy was -5.78 to 5.40%, which indicated that the quantitative method was reliable and accurate. The validated method has been successfully applied to a human pharmacokinetic study of iloperidone and two active metabolites, P88 and P95, after oral administration of 4mg iloperidone tablets in 12 healthy Chinese volunteers.
Related JoVE Video
Norcantharidin: a potential antiangiogenic agent for gallbladder cancers in vitro and in vivo.
Int. J. Oncol.
PUBLISHED: 10-11-2011
Show Abstract
Hide Abstract
Our objective was to explore the antiangiogenic activity of norcantharidin (NCTD) as an angiogenic inhibitor for gallbladder cancers. In vitro and in vivo experiments to determine the effects of NCTD on HUVECs, chicken CAM capillaries and gallbladder cancer xenograft angiogenesis in nude mice were respectively done. The MTT method was used to assay the cytotoxicity of NCTD on HUVECs. Immunofluorescence was used to evaluate HUVEC apoptosis. The scraping line method, matrigel invasion assay and tube formation assay were used to detect the migration, invasion and tube formation of HUVECs. A digital camera was used to observe chicken CAM capillaries. Experiments with NCTD in a xenograft model were used to observe the effect of NCTD on xenograft growth and survival of mice with xenografts. CD?? immunohistochemistry, flow cytometry and micro-MRA were used, respectively, to determine MVD, cell apoptosis and hemodynamic analysis of the xenografts. Immunohistochemistry and RT-PCR were used, respectively, to detect the expression of VEGF, Ang-2, TSP, TIMP-2 proteins/mRNAs of the xenografts. The xenograft MVD associated with tumor volume, the PCNA/apoptosis ratio and related-protein expression was evaluated simultaneously. We found that NCTD effectively inhibited the proliferation, migration, invasion and capillary-like tube formation of HUVECs in vitro; it reduced angiogenesis and directly destroyed the formed CAM capillaries in vivo. In the experiments in mice, NCTD not only inhibited significantly xenograft proliferation and growth, prolonged survival time of mice with xenografts, decreased the xenograft MVD and vascular perfusion, but also, similarly to ES, decreased significantly the expression of VEGF or Ang-2 protein/mRNA, increased the expression of TSP or TIMP-2 protein/mRNA. Moreover, the xenograft MVD was positively related with tumor volume, PCNA/apoptosis ratio, and VEGF or Ang-2 expression, respectively (all P<0.05), but negatively correlated with TSP or TIMP-2 expression (both P<0.05). These data showed that NCTD could serve as a potential antiangiogenic agent for gallbladder cancers.
Related JoVE Video
[Temperature-controlled radiofrequency-assisted endoscopic tonsillectomy and adenoidectomy in children].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 09-29-2011
Show Abstract
Hide Abstract
To compare the outcomes of temperature-controlled radiofrequency-assisted endoscopic tonsillectomy and adenoidectomy (rT + A) and conventional tonsillectomy and adenoidectomy (cT + A) in children.
Related JoVE Video
Size-dependent in vivo toxicity of PEG-coated gold nanoparticles.
Int J Nanomedicine
PUBLISHED: 09-20-2011
Show Abstract
Hide Abstract
Gold nanoparticle toxicity research is currently leading towards the in vivo experiment. Most toxicology data show that the surface chemistry and physical dimensions of gold nanoparticles play an important role in toxicity. Here, we present the in vivo toxicity of 5, 10, 30, and 60 nm PEG-coated gold nanoparticles in mice.
Related JoVE Video
[Characteristics of soil respiration in Phyllostachys edulis forest in Wanmulin Natural Reserve and related affecting factors].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 08-05-2011
Show Abstract
Hide Abstract
By using Li-Cor 8100 open soil carbon flux system, the dynamic changes of soil respiration rate in Phyllostachys edulis forest in Wanmulin Natural Reserve in Fujian Province of China were measured from January 2009 to December 2009, with the relationships between the dynamic changes and related affecting factors analyzed. The monthly variation of soil respiration rate in the forest presented a double peak curve, with the peaks appeared in June 2009 (6. 83 micromol x m(-2) x s(-1)) and September 2009 (5.59 micromol x m(-2) x s(-1)), and the seasonal variation of the soil respiration rate was significant, with the maximum in summer and the minimum in winter. The soil respiration rate had significant correlation with the soil temperature at depth 5 cm (P < 0.05), but no significant correlation with soil moisture (P > 0.05). The monthly variation of litter fall mass in the forest was in single peak shape, and there was a significantly positive correlation between the monthly litter fall mass and soil respiration rate (P < 0.05). Two-factor model of soil temperature and litter fall mass could explain 93.2% variation of the soil respiration rate.
Related JoVE Video
Characterisation and manipulation of docetaxel resistant prostate cancer cell lines.
Mol. Cancer
PUBLISHED: 07-18-2011
Show Abstract
Hide Abstract
There is no effective treatment strategy for advanced castration-resistant prostate cancer. Although Docetaxel (Taxotere®) represents the most active chemotherapeutic agent it only gives a modest survival advantage with most patients eventually progressing because of inherent or acquired drug resistance. The aims of this study were to further investigate the mechanisms of resistance to Docetaxel. Three Docetaxel resistant sub-lines were generated and confirmed to be resistant to the apoptotic and anti-proliferative effects of increasing concentrations of Docetaxel.
Related JoVE Video
The impact of high-dose statin therapy on transendothelial neutrophil migration and serum cholesterol levels in healthy male volunteers.
Eur. J. Clin. Pharmacol.
PUBLISHED: 05-06-2011
Show Abstract
Hide Abstract
Cardiac surgery presents a risk to all major organs due to activation of the systemic inflammatory response. Patients referred for cardiac surgery are typically older, usually have comorbid conditions, and are thus at higher risk of postoperative multiorgan dysfunction. Patients demonstrating evidence of organ dysfunction require intensive postoperative management. Any means to predict and reduce the inflammatory response mounted postcardiac surgery could translate into a clinical benefit for the patient and reduce the length of stay in intensive care.
Related JoVE Video
Astrocyte elevated gene-1 overexpression in human primary gallbladder carcinomas: an unfavorable and independent prognostic factor.
Oncol. Rep.
PUBLISHED: 04-27-2011
Show Abstract
Hide Abstract
Astrocyte elevated gene-1 (AEG-1), as an HIV-1 or TNF-?-inducible transcript, is correlated with various aspects of tumor malignancy. However, the status of AEG-1 expression and its clinical significance in human gallbladder carcinoma (GBC) remains unknown. In the present study, we investigated AEG-1 expression in two GBC cell lines (GBC-SD and SGC-996) and GBC tissues by immunohistochemical, Western blot and real-time PCR analysis. We found that AEG-1 was highly expressed in GBC samples (63.4%, 26 of 41) compared with normal gallbladder mucosa (p=0.0003) and highly invasive GBC-SD cell lines at both the protein (p=0.0043) and mRNA levels (p=0.0001), and strongly correlated with differentiation degree (p=0.006), Nevin stage (p=0.0344), Ki-67 expression (p=0.0024) and liver infiltration (p=0.0332) in these patients. Multivariate analysis indicated that AEG-1 overexpression was an independent prognostic marker for GBC patients. Moreover, patients with high AEG-1 levels had shorter survival time (p=0.008). Our results suggest that the AEG-1 protein is a valuable marker of GBC progression and could be a potential therapeutic target.
Related JoVE Video
First-principles investigation of ag-doped gold nanoclusters.
Int J Mol Sci
PUBLISHED: 02-18-2011
Show Abstract
Hide Abstract
Gold nanoclusters have the tunable optical absorption property, and are promising for cancer cell imaging, photothermal therapy and radiotherapy. First-principle is a very powerful tool for design of novel materials. In the present work, structural properties, band gap engineering and tunable optical properties of Ag-doped gold clusters have been calculated using density functional theory. The electronic structure of a stable Au(20) cluster can be modulated by incorporating Ag, and the HOMO-LUMO gap of Au(20-) (n)Ag(n) clusters is modulated due to the incorporation of Ag electronic states in the HOMO and LUMO. Furthermore, the results of the imaginary part of the dielectric function indicate that the optical transition of gold clusters is concentration-dependent and the optical transition between HOMO and LUMO shifts to the low energy range as the Ag atom increases. These calculated results are helpful for the design of gold cluster-based biomaterials, and will be of interest in the fields of radiation medicine, biophysics and nanoscience.
Related JoVE Video
Isolated pancreatic granulocytic sarcoma: a case report and review of the literature.
World J. Gastroenterol.
PUBLISHED: 01-29-2011
Show Abstract
Hide Abstract
Granulocytic sarcoma (GS) is an extramedullary tumor mass consisting of immature myeloid cells. Isolated pancreatic granulocyte sarcoma is extremely rare. We report a very unusual pancreatic granulocytic sarcoma in a patient without acute myeloid leukemia. The patient presented with acute epigastric pain because of splenic infarction due to a mass consisting of myeloblasts in the pancreatic tail. The patients underwent splenectomy and distal pancreatectomy. Pathology and immunohistochemistry suggested a GS. Despite local surgery, an isolated tumor recurred 2 mo after operation and the patient died 3 mo after removal of the tumor. Only 7 reported cases of pancreatic GS were identified in the literature and the mass was located in the pancreatic head. This is the first report of GS in the pancreatic tail with splenic infarction.
Related JoVE Video
Applying random forests to identify biomarker panels in serum 2D-DIGE data for the detection and staging of prostate cancer.
J. Proteome Res.
PUBLISHED: 01-27-2011
Show Abstract
Hide Abstract
In recent years, Prostate Specific Antigen (PSA) testing is widespread and has been associated with deceased mortality rates; however, this testing has raised concerns of overdiagnosis and overtreatment. It is clear that additional biomarkers are required. To identify these biomarkers, we have undertaken proteomics and metabolomics expression profiles of serum samples from BPH, Gleason score 5 and 7 using two-dimensional difference in gel electrophoresis (2D-DIGE) and nuclear magnetic resonance spectroscopy (NMR). Panels of serum protein biomarkers were identified by applying Random Forests to the 2D-DIGE data. The evaluation of selected biomarker panels has shown that they can provide higher prediction accuracy than the current diagnostic standard. With careful validation of these serum biomarker panels, these panels may potentially help to reduce unnecessary invasive diagnostic procedures and more accurately direct the urologist to curative surgery.
Related JoVE Video
Cellular localization of debromohymenialdisine and hymenialdisine in the marine sponge Axinella sp. using a newly developed cell purification protocol.
Mar. Biotechnol.
PUBLISHED: 01-19-2011
Show Abstract
Hide Abstract
Sponges (Porifera), as the best known source of bioactive marine natural products in metazoans, play a significant role in marine drug discovery and development. As sessile filter-feeding animals, a considerable portion of the sponge biomass can be made of endosymbiotic and associated microorganisms. Understanding the cellular origin of targeted bioactive compounds from sponges is therefore important not only for providing chemotaxonomic information but also for defining the bioactive production strategy in terms of sponge aquaculture, cell culture, or fermentation of associated bacteria. The two alkaloids debromohymenialdisine (DBH) and hymenialdisine (HD), which are cyclin-dependent kinase inhibitors with pharmacological activities for treating osteoarthritis and Alzheimers disease, have been isolated from the sponge Axinella sp. In this study, the cellular localization of these two alkaloids was determined through the quantification of these alkaloids in different cell fractions by high-performance liquid chromatography (HPLC). First, using a differential centrifugation method, the dissociated cells were separated into different groups according to their sizes. The two bioactive alkaloids were mainly found in sponge cells obtained from low-speed centrifugation. Further cell purifications were accomplished by a newly developed multi-step protocol. Four enriched cell fractions (C1, C2, C3, and C4) were obtained and subjected to light and transmission electron microscopy, cytochemical staining, and HPLC quantification. Compared to the low concentrations in other cell fractions, DBH and HD accounted for 10.9% and 6.1%, respectively, of dry weight in the C1 fraction. Using the morphological characteristics and cytochemical staining results, cells in the C1 fraction were speculated to be spherulous cells. This result shows that DBH and HD in Axinella sp. are located in sponge cells and mostly stored in spherulous cells.
Related JoVE Video
A pilot histomorphology and hemodynamic of vasculogenic mimicry in gallbladder carcinomas in vivo and in vitro.
J. Exp. Clin. Cancer Res.
PUBLISHED: 01-18-2011
Show Abstract
Hide Abstract
Vasculogenic mimicry (VM), as a new blood supply for tumor growth and hematogenous metastases, has been recently described in highly aggressive human melanoma cells, etc. We previously reported VM in human gallbladder carcinomas and its clinical significance. In this study, we further studied histomorphology and hemodynamic of VM in gallbladder carcinomas in vivo and in vitro.
Related JoVE Video
Mechanism of void nucleation and growth in bcc Fe: atomistic simulations at experimental time scales.
Phys. Rev. Lett.
PUBLISHED: 01-03-2011
Show Abstract
Hide Abstract
Evolution of small-vacancy clusters in bcc Fe is simulated using a multiscale approach coupling an atomistic activation-relaxation method for sampling transition-state pathways with environment-dependent reaction coordinate calculations and a kinetic Monte Carlo simulation to reach time scales on the order of ~10? s. Under vacancy-supersaturated condition, di- and trivacancy clusters form and grow by coalescence (Ostwald ripening). For cluster size greater than four we find a transition temperature of 150 °C for accelerated cluster growth, as observed in positron annihilation spectroscopy experiments. Implications for the mechanism of stage-IV radiation-damage-recovery kinetics are discussed.
Related JoVE Video
[Protein loss in critically ill patients during continuous veno-venous hemofiltration].
Zhonghua Wai Ke Za Zhi
PUBLISHED: 12-18-2010
Show Abstract
Hide Abstract
To evaluate protein loss in critically ill patients with acute renal failure during continuous veno-venous hemofiltration (CVVH) and analysis the major factor impacting protein clearance.
Related JoVE Video
[Three cases of eosinophilichyperplastic lymphogranuloma in childrens parotid area].
Hua Xi Kou Qiang Yi Xue Za Zhi
PUBLISHED: 12-10-2010
Show Abstract
Hide Abstract
From March 2009 to October 2009, three pediatric patients with parotid tumor were cured. Preoperative physical examination showed regional swelling in parotid area, the surface skin was in moderate reddish purple, the border was vague, and the swelling was inactive. The patients IgE were significantly increased. B ultrasound examination demonstrated the focus was an isoecho with ringlike dark band around, which was concluded as bulls-eye sign. Magnetic resonance imaging (MRI) examination indicated a cystic mass between the skin and parotid. Preoperative diagnosis was eosinophilichyperplastic lymphogranuloma (Kimuras disease) and the granuloma was excised by operation. Pathological examination revealed the capillary vessel hyperplasia in local tissue with a plenty of eosinophils and lymphocytes infiltrating. The disease was confirmed. Although the disease is rare, the diagnosis still could be made by preoperative physical examination, laboratory and imaging examinations.
Related JoVE Video
Toxicologic effects of gold nanoparticles in vivo by different administration routes.
Int J Nanomedicine
PUBLISHED: 10-05-2010
Show Abstract
Hide Abstract
Gold nanoparticles have potential applications in biomedicine, but one of the important concerns is about their safety. Most toxicology data are derived from in vitro studies and may not reflect in vivo responses. Here, an animal toxicity study of 13.5 nm gold nanoparticles in mice is presented. Animal survival, weight, hematology, morphology, and organ index are characterized at different concentrations (137.5-2200 ?g/kg) over 14-28 days. The results show that low concentrations of gold nanoparticles do not cause an obvious decrease in body weight or appreciable toxicity, even after their breakdown in vivo. High concentrations of gold nanoparticles induced decreases in body weight, red blood cells, and hematocrit. It was also found that gold nanoparticles administered orally caused significant decreases in body weight, spleen index, and red blood cells. Of the three administration routes, the oral and intraperitoneal routes showed the highest toxicity, and the tail vein injection showed the lowest toxicity. Combining the results of all of these studies, we suggest that targeted gold nanopartices by tail vein injection may be suitable for enhancement of radiotherapy, photothermal therapy, and related medical diagnostic procedures.
Related JoVE Video
[Experimental study of directional differentiation of bone mesenchymal stem cells (BMSCs) to osteoblasts guided by serum containing cistanche deserticola].
Zhongguo Gu Shang
PUBLISHED: 09-24-2010
Show Abstract
Hide Abstract
To study directional differentiation of BMSCs guided by Desert living Cistanche (Herba Cistanches) which invigorates the kidney.
Related JoVE Video
Core fucosylation and alpha2-3 sialylation in serum N-glycome is significantly increased in prostate cancer comparing to benign prostate hyperplasia.
Glycobiology
PUBLISHED: 09-22-2010
Show Abstract
Hide Abstract
One of the most urgent requirements in prostate cancer diagnosis is the development of a blood-based test which would be able to distinguish prostate cancer from benign prostate hyperplasia (BPH). Previously published results found a significant difference between specific glycan levels in patients with advanced prostate cancer and healthy controls. N-Glycans from the whole serum glycoproteins were measured using our fully quantitative high-throughput N-glycan analysis in combination with exoglycosidase digestions in sera from 13 BPH and 34 prostate cancer samples (17 Gleason score 5 and 17 Gleason score 7). The levels of core-fucosylated biantennary glycans and ?2-3-linked sialic acids were significantly increased in prostate cancer patients compared with patients with BPH. Triantennary trigalactosylated glycans and tetraantennary tetrasialylated glycans with outer arm fucose were significantly decreased, and tetraantennary tetrasialylated glycans increased in Gleason 7 compared with Gleason 5. All these glycans can distinguish prostate cancer patients from BPH or Gleason 7 from Gleason 5 prostate cancer patients better than the current clinical test, prostate-specific antigen; therefore, their measurement may provide a new noninvasive approach to diagnose prostate cancer. However, additional validation studies would need to be carried out to further support this finding. Decreases in triantennary trigalactosylated glycans and/or bisected core-fucosylated biantennary monosialylated glycans and increases in tetraantennary tetrasialylated glycans correlate with perineural invasion, which could further help to diagnose tumor spread and predict patients survival.
Related JoVE Video
Genetic variants and their interactions in the prediction of increased pre-clinical carotid atherosclerosis: the cardiovascular risk in young Finns study.
PLoS Genet.
PUBLISHED: 09-01-2010
Show Abstract
Hide Abstract
The relative contribution of genetic risk factors to the progression of subclinical atherosclerosis is poorly understood. It is likely that multiple variants are implicated in the development of atherosclerosis, but the subtle genotypic and phenotypic differences are beyond the reach of the conventional case-control designs and the statistical significance testing procedures being used in most association studies. Our objective here was to investigate whether an alternative approach--in which common disorders are treated as quantitative phenotypes that are continuously distributed over a population--can reveal predictive insights into the early atherosclerosis, as assessed using ultrasound imaging-based quantitative measurement of carotid artery intima-media thickness (IMT). Using our population-based follow-up study of atherosclerosis precursors as a basis for sampling subjects with gradually increasing IMT levels, we searched for such subsets of genetic variants and their interactions that are the most predictive of the various risk classes, rather than using exclusively those variants meeting a stringent level of statistical significance. The area under the receiver operating characteristic curve (AUC) was used to evaluate the predictive value of the variants, and cross-validation was used to assess how well the predictive models will generalize to other subsets of subjects. By means of our predictive modeling framework with machine learning-based SNP selection, we could improve the prediction of the extreme classes of atherosclerosis risk and progression over a 6-year period (average AUC 0.844 and 0.761), compared to that of using conventional cardiovascular risk factors alone (average AUC 0.741 and 0.629), or when combined with the statistically significant variants (average AUC 0.762 and 0.651). The predictive accuracy remained relatively high in an independent validation set of subjects (average decrease of 0.043). These results demonstrate that the modeling framework can utilize the "gray zone" of genetic variation in the classification of subjects with different degrees of risk of developing atherosclerosis.
Related JoVE Video
Norcantharidin inhibits growth of human gallbladder carcinoma xenografted tumors in nude mice by inducing apoptosis and blocking the cell cycle in vivo.
HBPD INT
PUBLISHED: 08-07-2010
Show Abstract
Hide Abstract
Gallbladder carcinoma, a lethal malignant neoplasm with poor prognosis, has dismal results of surgical resection and chemoradiotherapy. We previously reported that norcantharidin (NCTD) is useful against growth, proliferation, and invasion of human gallbladder carcinoma GBC-SD cells in vitro. In this study, we further studied the inhibitory effect of NCTD on the growth of xenografted tumors of human gallbladder carcinoma in nude mice in vivo and the underlying mechanisms.
Related JoVE Video
Expression of miRNA-130a in nonsmall cell lung cancer.
Am. J. Med. Sci.
PUBLISHED: 07-14-2010
Show Abstract
Hide Abstract
MicroRNAs are short regulatory RNAs that negatively modulate gene expression at the posttranscriptional level and are deeply involved in the pathogenesis of several types of cancer. The miRNA-130a has been shown to play a role in antagonizing the inhibitory effects of GAX on endothelial cell proliferation, migration and tube formation, and antagonizing the inhibitory effects of HoxA5 on tube formation in vitro. Here the authors show, for the first time, that miRNA-130a expression is increased in nonsmall cell lung cancer (NSCLC) tissues. Statistical analysis showed that overexpression of miRNA-130a was strongly associated with lymph node metastasis, stage of tumor node metastasis classification and poor prognosis. Moreover, there was a significant difference in miRNA-130a expression levels between smoking and nonsmoking patients. Multivariate Cox regression analysis showed that miRNA-130a was an independent prognostic factor for patients with NSCLC. Together, these data suggest that miRNA-130a may comprise a potential novel prognostic marker for this disease.
Related JoVE Video
[Human osteoblast-like cells OS-732 intervened with alcohol and treated with liuweidihuang pill medicated serum].
Zhong Yao Cai
PUBLISHED: 06-26-2010
Show Abstract
Hide Abstract
To investigate the mechanism of osteonecrosis of the femoral head caused by alcohol and the therapeutic effects of the method of invigorating the kidney.
Related JoVE Video
Knockdown of Rad51 expression induces radiation- and chemo-sensitivity in osteosarcoma cells.
Med. Oncol.
PUBLISHED: 06-14-2010
Show Abstract
Hide Abstract
Osteosarcoma is the common primary bone malignancy in children and young adults in Eastern countries. Resistance to ionizing radiation (IR) or drugs is an underlying mechanism contributing to the failure of therapy in these patients. Rad51 is the key protein of DNA homologous recombination repair. Although high expression of Rad51 is associated with enhanced resistance to DNA damage induced by chemicals and/or ionizing radiation, the relevance of Rad51 expression in osteosarcoma and its relationship with IR sensitivity and chemo-resistance is not well understood. In this study, we elucidated the possibility of using Rad51 in the treatment of human osteosarcoma in vitro. Changes in chemo- and radiation sensitivity in cultured osteosarcoma cells occurred after suppression of Rad51 expression, using a plasmid vector-mediated short hairpin RNA (shRNA) expression system. The suppression of Rad51 correlated with cell cycle arrest in the G2 phase and inhibited tumor cell proliferation. Our results suggest that Rad51 expression levels might play an important role in radiation- and chemo-sensitivity of human osteosarcoma.
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.