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Find video protocols related to scientific articles indexed in Pubmed.
A ketone functionalized luminescent terbium metal-organic framework for sensing of small molecules.
Chem. Commun. (Camb.)
PUBLISHED: 11-20-2014
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A ketone functionalized luminescent terbium metal-organic framework has been realized for the highly selective and sensitive sensing of aniline.
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HIV risk among female sex workers with different patterns of drug use behaviors in Southwest China: a cross-sectional study.
AIDS Care
PUBLISHED: 11-20-2014
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Although many researchers found that drug use behaviors significantly increased HIV risk, few of them investigated the association between HIV risk and different drug use behaviors among female sex workers (FSWs) in China. The current study examines demographic and behavioral risk factors as well as the infections of HIV, syphilis, and among a subgroup of FSWs who are injection drug users (IDU) or noninjection drug users (NIDU) in comparison to Hepatitis C Virus (HCV) nondrug users (non-DU). We conducted secondary analysis of the 2010 National Sentinel Surveillance (NSS) data from Guangxi China. A self-administered, standard behavioral surveillance survey was completed by a total of 12,622 FSWs recruited from Guangxi, China. The Guangxi 2010 NSS sample included 2.6% NIDU and 0.5% IDU. Compared to non-DU, IDU were more likely to report no condom use in the last sex act (aOR = 3.25, 95%CI = 1.65, 6.40), inconsistent condom use in the past month (aOR = 4.88, 95%CI = 2.66, 8.96), having an HIV testing (aOR = 2.48, 95%CI = 1.34, 4.58), infections of HIV (aOR = 42.60, 95%CI = 9.45, 192.06), syphilis (aOR = 4.13, 95%CI = 1.86, 9.16), and HCV (aOR = 74.54, 95%CI = 30.26, 183.61). NIDU had 2.89 times higher than non-DU to report a history of sexually transmitted disease and 26% less likely to report inconsistent condom use in the past month (p < 0.05). We called for tailored, accessible, and nonjudgmental drug treatments coupled with effective sexual risk reduction interventions to help FSWs with various drug use problems to reduce their vulnerability and susceptibility of HIV risk in China as well as other cultural settings.
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Critical Roles of Clostridium difficile Toxin B Enzymatic Activities in Pathogenesis.
Infect. Immun.
PUBLISHED: 11-19-2014
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TcdB is one of the key virulence factors of Clostridium difficile that is responsible for causing serious and potentially fatal colitis. The toxin contains at least two enzymatic domains: an effector glucosyltransferase domain for inactivating host Rho GTPases and a cysteine protease domain for the delivery of the effector domain into host cytosol. Here we describe a novel intrabody approach to examine the role of these enzymes of TcdB in cellular intoxication. By screening a single-domain heavy chain (VHH) library raised against TcdB, we identified two VHH antibodies - 7F and E3 - that specifically inhibit TcdB cysteine protease and glucosyltransferase activity, respectively. Cytoplasmic expression of 7F intrabody in Vero cells inhibited TcdB autoprocessing and delayed cellular intoxication, whereas E3 intrabody completely blocked the cytopathic effects of TcdB holotoxin. These data also demonstrate for the first time that toxin autoprocessing occurs after cysteine protease and glucosyltransferase domains translocate into the cytosol of target cells. We further determined the role of the enzymatic activities of TcdB in in vivo toxicity using a sensitive systemic challenge model in mice. Consistent with these in vitro results, a cysteine protease non-cleavable mutant TcdB-L543A delayed toxicity in mice whereas glycosyltransferase-deficient TcdB demonstrated no toxicity up to 500-fold LD50 when they were injected systemically. Thus, glucosyltransferase but not cysteine protease activity is critical for TcdB-mediated cytopathic effects and its systemic toxicity, highlighting the importance of targeting toxin glucosyltransferase activity for future therapy.
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PARP1 Mediates LPS-Induced HMGB1 Release by Macrophages through Regulation of HMGB1 Acetylation.
J. Immunol.
PUBLISHED: 11-14-2014
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The high-mobility group box protein 1 (HMGB1) is increasingly recognized as an important inflammatory mediator. In some cases, the release of HMGB1 is regulated by poly(ADP-ribose) polymerase-1 (PARP-1), but the mechanism is still unclear. In this study, we report that PARP-1 activation contributes to LPS-induced PARylation of HMGB1, but the PARylation of HMGB1 is insufficient to direct its migration from the nucleus to the cytoplasm; PARP-1 regulates the translocation of HMGB1 to the cytoplasm through upregulating the acetylation of HMGB1. In mouse bone marrow-derived macrophages, genetic and pharmacological inhibition of PARP-1 suppressed LPS-induced translocation and release of HMGB1. Increased PARylation was accompanied with the nucleus-to-cytoplasm translocation and release of HMGB1 upon LPS exposure, but PARylated HMGB1 was located at the nucleus, unlike acetylated HMGB1 localized at the cytoplasm in an import assay. PARP inhibitor and PARP-1 depletion decreased the activity ratio of histone acetyltransferases to histone deacetylases that elevated after LPS stimulation and impaired LPS-induced acetylation of HMGB1. In addition, PARylation of HMGB1 facilitates its acetylation in an in vitro enzymatic reaction. Furthermore, reactive oxygen species scavenger (N-acetyl-l-cysteine) and the ERK inhibitor (FR180204) impaired LPS-induced PARP activation and HMGB1 release. Our findings suggest that PARP-1 regulates LPS-induced acetylation of HMGB1 in two ways: PARylating HMGB1 to facilitate the latter acetylation and increasing the activity ratio of histone acetyltransferases to histone deacetylases. These studies revealed a new mechanism of PARP-1 in regulating the inflammatory response to endotoxin.
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Pyrosequencing of mcrA and archaeal 16S rRNA genes reveals diversity and substrate preference of anaerobic digester methanogen communities.
Appl. Environ. Microbiol.
PUBLISHED: 11-09-2014
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Methanogenic archaea play a key role in biogas-producing anaerobic digestion yet remain poorly taxonomically characterised. This is in part due to the limitations of low-throughput Sanger sequencing of a single (16S rRNA) gene, which in the past may have under-sampled methanogen diversity. In this study, archaeal communities from three sludge digesters in Hong Kong and one wastewater digester in China were examined using high-throughput pyrosequencing of the methyl coenzyme M reductase (mcrA) and 16S rRNA genes. Methanobacteriales, Methanomicrobiales and Methanosarcinales were detected in each digester, indicating both hydrogenotrophic and acetoclastic methanogenesis were occurring. Two sludge digesters had similar community structures, likely due to their similar design and feedstock. Taxonomic classification of the mcrA genes suggested these digesters were dominated by acetoclastic methanogens, particularly Methanosarcinales, while the other digesters were dominated by hydrogenotrophic Methanomicrobiales. The proposed euryarchaeotal order Methanomassiliicoccales and the uncultured WSA2 group were detected with the 16S rRNA gene, and potential mcrA genes for these groups were identified. 16S rRNA gene sequencing also recovered several crenarchaeotal groups potentially involved in the initial anaerobic digestion processes. Overall, the two genes produced different taxonomic profiles for the digesters, while higher methanogen richness was detected using the mcrA gene, supporting the use of this functional gene as a complement to the 16S rRNA gene to better assess methanogen diversity. A significant positive correlation was detected between methane production and the abundance of mcrA transcripts in digesters treating sludge and wastewater samples, supporting the mcrA gene as a biomarker for methane yield.
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EGFR mutation testing practices within the Asia Pacific region: Results of a multicenter diagnostic survey.
J Thorac Oncol
PUBLISHED: 11-08-2014
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The efficacy of EGFR tyrosine kinase inhibitors in EGFR mutation-positive NSCLC patients necessitates accurate, timely testing. Although EGFR mutation testing has been adopted by many laboratories in Asia, data are lacking on the proportion of NSCLC patients tested in each country, and the most commonly used testing methods.
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Social Support and Condom Use Among Female Sex Workers in China.
Health Care Women Int
PUBLISHED: 11-04-2014
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While the relationship between social support and psychological well-being has been well established, limited studies have explored how social support might affect condom use among female sex workers (FSWs). Using cross-sectional data from 1,022 FSWs in Guangxi China, we examined how different forms of support from diverse sources may influence condom use among FSWs. Friends, co-workers, and stable partners were FSWs' main sources of social support. Social support from diverse sources differently impact FSWs' condom use. Policy-makers need to consider complicated profile of social support received by FSWs and create supportive environment for FSWs to protect them from HIV risks.
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Long-range traveling waves of activity triggered by local dichoptic stimulation in V1 of behaving monkeys.
J. Neurophysiol.
PUBLISHED: 10-25-2014
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Traveling waves of cortical activity, in which local stimulation triggers lateral spread of activity to distal locations, have been hypothesized to play an important role in cortical function. However, there is conflicting physiological evidence for the existence of spreading traveling waves of neural activity triggered locally. Dichoptic stimulation, in which the two eyes view dissimilar monocular patterns, can lead to dynamic wave-like fluctuations in visual perception and therefore provides a promising means for identifying and studying cortical traveling waves. Here we used voltage-sensitive dye imaging to test for the existence of traveling waves of activity in V1 of awake, fixating monkeys viewing dichoptic stimuli. We find clear traveling waves that are initiated by brief localized contrast increments in one of the monocular patterns and, then, propagate at speeds of about 30 mm/s. These results demonstrate that under an appropriate visual context, circuitry in visual cortex in alert animals is capable of supporting long-range traveling waves triggered by local stimulation.
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[Multislice spiral CT diagnosis error analysis of children's airway foreign bodies].
Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi
PUBLISHED: 10-18-2014
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Analysis of multislice CT (MSCT) on the misdiagnosis reasons of children bronchial foreign body, avoid missed diagnosis, to achieve reasonable application.
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Nanotube Li2MoO4: a novel and high-capacity material as a lithium-ion battery anode.
Nanoscale
PUBLISHED: 10-03-2014
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Carbon-coated Li2MoO4 hexagonal hollow nanotubes were fabricated via a facile sol-gel method involving the solution synthesis of Li2MoO4 with subsequent annealing under an inert atmosphere to decompose the organic carbon source. To the best of our knowledge, this is the first report on the synthesis of Li2MoO4 nanotubes. More significantly, we have found that Li2MoO4 can be used as an anode material for lithium-ion batteries (LIBs). When evaluated as an anode material, the carbon-coated Li2MoO4 hollow nanotubes show an excellent electrochemical performance with a high reversible capacity (?550 mA h g(-1)) after 23 cycles, good rate capability and cycling stability. Meanwhile, carbon-free Li2MoO4 sample, fabricated via a solid state reaction, was also prepared for comparison. The Li storage mechanism has been investigated in-detail by advanced XPS, in situ XRD and HRTEM.
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Predictors of poor sleep quality and excessive daytime sleepiness in peritoneal dialysis patients.
Ren Fail
PUBLISHED: 09-17-2014
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Abstract To explore the possible impact factors on daytime sleepiness among peritoneal patients from a single center in China. A cross-sectional study was conducted in 98 prevalent peritoneal dialysis (PD) patients using both the Pittsburgh Sleep Quality Index (PSQI) questionnaire of sleep quality and the Epworth Sleepiness Scale (ESS) questionnaire of excessive daytime sleepiness (EDS). Biochemical differences between daytime sleepiness and non-daytime sleepiness population were evaluated, following univariate and multivariable analysis to find the risk factors on sleep disturbance. The prevalence of "poor sleep quality" (PSQI?>?5) was 74.49%, while daytime sleepiness (ESS???9) occurred in 22.45%. Mean PSQI was 9.06?±?4.60 and EES was 6.31?±?4.98. Compared to non-EDS cases, patients with ESS???9 had worse residual renal function (RRF), higher serum creatinine, higher serum magnesium and elevated serum ferritin. In univariate analysis, ESS correlated with serum albumin (r?=?0.346, p?=?0.015), phosphate (r?=?0.313, p?=?0.029), magnesium (r?=?0.376, p?=?0.008) and urinary Kt/V (r?=?-0.341, p?=?0.029). Finally, multivariable linear regression indicated that urinary Kt/V, PSQI and magnesium were independent predictors of ESS score. EDS does exist in PD patients and is associated both with poor nighttime sleep quality and lower RRF. Hypermagnesemia may be a treatable risk factor to improve daytime tiredness.
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In Situ X-ray Absorption Spectroscopy Studies of Kinetic Interaction between Platinum(II) Ions and UiO-66 Series Metal-Organic Frameworks.
J Phys Chem B
PUBLISHED: 09-07-2014
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The interaction of guest Pt(II) ions with UiO-66-X (X = NH2, H, NO2, OMe, F) series metal-organic frameworks (MOFs) in aqueous solution was investigated using in situ X-ray absorption spectroscopy. All of these MOFs were found to be able to coordinate with Pt(II) ions. The Pt(II) ions in UiO-66-X MOFs generally coordinate with 1.6-2.4 Cl and 1.4-2.4 N or O atoms. We also studied the time evolution of the coordination structure and found that Pt(II) maintained a coordination number of 4 throughout the whole process. Furthermore, the kinetic parameters of the interaction of Pt(II) ions with UiO-66-X series MOFs (X = NH2, H, NO2, OMe, F) were determined by combinational linear fitting of extended X-ray absorption fine structure (EXAFS) spectra of the samples. The Pt(II) adsorption rate constants were found to be 0.063 h(-1) for UiO-66-NH2 and 0.011-0.017 h(-1) for other UiO-66-X (X = H, NO2, OMe, F) MOFs, which means that Pt(II) adsorption in UiO-66-NH2 is 4-6 times faster than that in other UiO-66 series MOFs. FTIR studies suggested that the carboxyl groups could be the major host ligands binding with Pt(II) ions in UiO-66 series MOFs, except for UiO-66-NH2, in which amino groups coordinate with Pt(II) ions.
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Effects of P-glycoprotein and its inhibitors on apoptosis in K562 cells.
Molecules
PUBLISHED: 08-25-2014
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P-glycoprotein (P-gp) is a major factor in multidrug resistance (MDR) which is a serious obstacle in chemotherapy. P-gp has also been implicated in causing apoptosis of tumor cells, which was shown to be another important mechanism of MDR recently. To study the influence of P-gp in tumor cell apoptosis, K562/A cells (P-gp+) and K562/S cells (P-gp-) were subjected to doxorubicin (Dox), serum withdrawal, or independent co-incubation with multiple P-gp inhibitors, including valspodar (PSC833), verapamil (Ver) and H108 to induce apoptosis. Apoptosis was simultaneously detected by apoptotic rate, cell cycle by flow cytometry and cysteine aspartic acid-specific protease 3 (caspase 3) activity by immunoassay. Cytotoxicity and apoptosis induced by PSC833 were evaluated through an MTT method and apoptosis rate, and cell cycle combined with caspase 3 activity, respectively. The results show that K562/A cells are more resistant to apoptosis and cell cycle arrest than K562/S cells after treatment with Dox or serum deprivation. The apoptosis of K562/A cells increased after co-incubation with each of the inhibitors of P-gp. P-gp inhibitors also enhanced cell cycle arrest in K562/A cell. PSC833 most strikingly decreased viability and led to apoptosis and S phase arrest of cell cycle in K562/A cells. Our study demonstrates that P-gp inhibits the apoptosis of tumor cells in addition to participating in the efflux of intracellular chemotherapy drugs. The results of the caspase 3 activity assay also suggest that the role of P-gp in apoptosis avoidance is caspase-related.
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Relationship between Ganglion Cell Layer Thickness and Estimated Retinal Ganglion Cell Counts in the Glaucomatous Macula.
Ophthalmology
PUBLISHED: 08-19-2014
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To investigate the relationship between macular ganglion cell-inner plexiform layer (mGCIPL) thickness and estimated macular retinal ganglion cell (RGC) counts in glaucoma.
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Experimental study of needle-tissue interaction forces: effect of needle geometries, insertion methods and tissue characteristics.
J Biomech
PUBLISHED: 08-15-2014
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A thorough understanding of needle-tissue interaction mechanics is necessary to optimize needle design, achieve robotically needle steering, and establish surgical simulation system. It is obvious that the interaction is influenced by numerous variable parameters, which are divided into three categories: needle geometries, insertion methods, and tissue characteristics. A series of experiments are performed to explore the effect of influence factors (material samples n=5 for each factor) on the insertion force. Data were collected from different biological tissues and a special tissue-equivalent phantom with similar mechanical properties, using a 1-DOF mechanical testing system instrumented with a 6-DOF force/torque (F/T) sensor. The experimental results indicate that three basic phases (deformation, insertion, and extraction phase) are existent during needle penetration. Needle diameter (0.7-3.2mm), needle tip (blunt, diamond, conical, and beveled) and bevel angle (10-85°) are turned out to have a great influence on insertion force, so do the insertion velocity (0.5-10mm/s), drive mode (robot-assisted and hand-held), and the insertion process (interrupted and continuous). Different tissues such as skin, muscle, fat, liver capsule and vessel are proved to generate various force cures, which can contribute to the judgement of the needle position and provide efficient insertion strategy.
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Differential role for p120-catenin in regulation of TLR4 signaling in macrophages.
J. Immunol.
PUBLISHED: 07-11-2014
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Activation of TLR signaling through recognition of pathogen-associated molecular patterns is essential for the innate immune response against bacterial and viral infections. We have shown that p120-catenin (p120) suppresses TLR4-mediated NF-?B signaling in LPS-challenged endothelial cells. In this article, we report that p120 differentially regulates LPS/TLR4 signaling in mouse bone marrow-derived macrophages. We observed that p120 inhibited MyD88-dependent NF-?B activation and release of TNF-? and IL-6, but enhanced TIR domain-containing adapter-inducing IFN-?-dependent IFN regulatory factor 3 activation and release of IFN-? upon LPS exposure. p120 silencing diminished LPS-induced TLR4 internalization, whereas genetic and pharmacological inhibition of RhoA GTPase rescued the decrease in endocytosis of TLR4 and TLR4-MyD88 signaling, and reversed the increase in TLR4-TIR domain-containing adapter-inducing IFN-? signaling induced by p120 depletion. Furthermore, we demonstrated that altered p120 expression in macrophages regulates the inflammatory phenotype of LPS-induced acute lung injury. These results indicate that p120 functions as a differential regulator of TLR4 signaling pathways by facilitating TLR4 endocytic trafficking in macrophages, and support a novel role for p120 in influencing the macrophages in the lung inflammatory response to endotoxin.
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Robust multimaterial tellurium-based chalcogenide glass fibers for mid-wave and long-wave infrared transmission.
Opt Lett
PUBLISHED: 07-01-2014
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We describe an approach for producing robust multimaterial chalcogenide glass fibers for mid-wave and long-wave mid-infrared transmission. By combining the traditional rod-in-tube process with multimaterial coextrusion, we prepare a hybrid glass-polymer preform that is drawn continuously into a robust step-index fiber with a built-in, thermally compatible polymer jacket. Using tellurium-based chalcogenides, the fibers have a transparency window covering the 3-12 ?m spectral range, making them particularly attractive for delivering quantum cascade laser light and in space applications.
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Primary diffuse large B-cell lymphoma of the ovary is of a germinal centre B-cell-like phenotype.
Virchows Arch.
PUBLISHED: 06-14-2014
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Primary ovarian lymphoma is rare. To better understand the clinicopathological and molecular features of these tumours, we studied 14 patients (age range 13 to 74 years, mean 46.9 years) with non-Hodgkin's lymphoma who initially presented with an ovarian tumour. The clinicopathological features were reviewed and tissue samples were studied by immunohistochemistry and for immunoglobulin gene rearrangement, presence of Epstein Barr virus and for MYC and BCL-2 rearrangements by fluorescence in situ hybridisation. The most common symptoms were abdominal pain and abdominal distension. Ten patients had a unilateral (7 left, 3 right) ovarian mass and 4 had bilateral ovarian masses, size range 4 to 13 cm (mean, 7.9 cm). Of the 14 lymphomas, 12 were classified as diffuse large B-cell lymphoma (DLBCL) and 2 as Burkitt lymphoma. The Burkitt lymphomas had a MYC rearrangement. The DLBCLs were of the germinal centre B-cell-like subtype. One DLBCL patient had MYC and BCL2 rearrangements. The treatment consisted of various combinations of surgery, chemotherapy and radiotherapy. The follow-up period ranged from 3 to 56 months. During the follow-up period, 8 patients died of disease, 4 were alive with disease, and 2 were alive without disease. Most primary ovarian lymphomas are of germinal centre B-cell-like subtype DLBCL, which have high proliferative activity and poor prognosis.
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Selective Host-Guest Interaction between Metal Ions and Metal-Organic Frameworks using Dynamic Nuclear Polarization Enhanced Solid-State NMR Spectroscopy.
Chemistry
PUBLISHED: 06-09-2014
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The host-guest interaction between metal ions (Pt(2+) and Cu(2+) ) and a zirconium metal-organic framework (UiO-66-NH2 ) was explored using dynamic nuclear polarization-enhanced (15) N{(1) H} CPMAS NMR spectroscopy supported by X-ray absorption spectroscopy and density functional calculations. The combined experimental results conclude that each Pt(2+) coordinates with two NH2 groups from the MOF and two Cl(-) from the metal precursor, whereas Cu(2+) do not form chemical bonds with the NH2 groups of the MOF framework. Density functional calculations reveal that Pt(2+) prefers a square-planar structure with the four ligands and resides in the octahedral cage of the MOF in either cis or trans configurations.
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Anti-tumor activity of oridonin on SNU-5 subcutaneous xenograft model via regulation of c-Met pathway.
Tumour Biol.
PUBLISHED: 06-02-2014
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Gastric cancer is the leading cause of cancer death worldwide. Oridonin, a diterpenoid isolated from Rabdosia rubescens, has attracted considerable attention as a potential treatment for gastric cancer based on its anti-tumor effects in many tumor cell lines. However, detailed anti-tumor mechanisms of oridonin remain a matter of speculation. In the present study, a gastric carcinoma cell line harboring c-Met gene amplification SNU-5 was used to investigate the underlying mechanisms. The results showed that in vitro, oridonin potently inhibited c-Met phosphorylation and c-Met-dependent cell proliferation (IC50 value, 36.8 ?M), meanwhile down-regulated the expression of the downstream signaling molecules including phospho-c-Raf, phospho-Erk, and phospho-Akt. In vivo, oridonin showed efficacy at well-tolerated doses, including marked cytoreductive anti-tumor activity in SNU-5 subcutaneous xenograft model. The anti-tumor efficacy of oridonin was dose-dependent and showed strong inhibition of c-Met phosphorylation. Additional mechanism of action studies showed dose-dependent inhibition of c-Met-dependent signal transduction, tumor cell proliferation (Ki67), and reduction of microvessel density (CD31). These results suggested that the anti-tumor activity of oridonin may be mediated by direct effects on tumor cell growth or survival as well as anti-angiogenic mechanisms. In summary, the results indicated that oridonin exerted anti-tumor growth on human gastric cancer SNU-5 in vitro and in vivo by direct regulation of c-Met signaling pathway and the anti-tumor effects was mainly based on its anti-proliferation and anti-angiogenesis.
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Adjuvant chemotherapy for patients with primary hepatocellular carcinoma: A meta-analysis.
Int. J. Cancer
PUBLISHED: 05-18-2014
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Numerous studies have investigated the effects of adjuvant chemotherapy for primary hepatocellular carcinoma (HCC) patients. We conducted this analysis to evaluate the efficacy of adjuvant chemotherapy in HCC patients after hepatectomy. PubMed/MEDLINE, EMBASE, Cochrane, and other databases were searched for eligible studies. The major endpoints were overall survival (OS) and disease-free survival (DFS). The pooled odds ratio (OR) was calculated using a random-effects model to summarize the results. In the meta-analysis of 13 randomized control trials (RCTs) and 35 observational studies with 4747 patients, hepatectomy plus adjuvant chemotherapy showed superiority over hepatectomy alone in 1-year DFS (OR?=?1.86, 1.38-2.51, p?
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[The role of RNA pooling technique in the diagnosis of acute HIV infection and the estimation on HIV incidence among low-grade-venues female sex workers].
Zhonghua Liu Xing Bing Xue Za Zhi
PUBLISHED: 05-17-2014
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To examine the feasibility of RNA pooling technique in the diagnosis on acute HIV infection among female sex workers (FSWs) working at the low-grade venues.
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HIV-related behavioral risk factors among older female sex workers in Guangxi, China.
AIDS Care
PUBLISHED: 04-28-2014
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Previous literature suggests a high rate of HIV infections among older female sex workers (FSWs) in China. However, limited data are available regarding HIV- related behavioral risk factors among this population. In the current study, we aim to examine the demographic and behavioral factors that place older FSWs at a high risk of HIV infection. We conducted secondary analysis of the 2010 National Sentinel Surveillance (NSS) data from Guangxi, China. A self-administered, standard behavioral surveillance survey was completed by a total of 12,622 FSWs in Guangxi, China. The Guangxi 2010 NSS sample included 19.4% FSWs aged 35 years or older ("older FSWs"). The overall HIV prevalence was 1.0% for the entire sample with 2.0% among older FSWs and 0.8% among younger ones. Older age was an independent predictor of unprotected sex, injection drug use, and a self-reported history of syphilis infection. Future HIV prevention interventions targeting FSWs should consider older FSWs' vulnerable status. Efforts are needed to address their financial needs and invest in skills for socio-economic empowerment.
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Synthesis of N-alkyl isatins via oxidative cyclization of N-alkyl 2-bromo(chloro)acetanilides.
Org. Biomol. Chem.
PUBLISHED: 04-17-2014
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A highly efficient method for the synthesis of N-alkyl isatins starting from N-alkyl 2-bromo or 2-chloro acetanilides is described. The starting materials are easy to prepare and the yields of isatins are generally high. Operationally the reaction is very simple to run. Even though best results were obtained with a catalytic amount of CuI, the reactions of N-alkyl 2-bromo acetanilides actually performed well even in the absence of any metal catalyst.
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Violence Against Chinese Female Sex Workers From Their Stable Partners: A Hierarchical Multiple Regression Analysis.
Health Care Women Int
PUBLISHED: 04-16-2014
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Limited data are available regarding risk factors that are related to intimate partner violence (IPV) against female sex workers (FSWs) in the context of stable partnerships. Out of the 1,022 FSWs, 743 reported ever having a stable partnership and 430 (more than half) of those reported experiencing IPV. Hierarchical multivariate regression revealed that some characteristics of stable partners (e.g., low education, alcohol use) and relationship stressors (e.g., frequent friction, concurrent partnerships) were independently predictive of IPV against FSWs. Public health professionals who design future violence prevention interventions targeting FSWs need to consider the influence of their stable partners.
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Androgen receptor splice variants activating the full-length receptor in mediating resistance to androgen-directed therapy.
Oncotarget
PUBLISHED: 04-12-2014
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Upregulation of constitutively-active androgen receptor splice variants (AR-Vs) has been implicated in AR-driven tumor progression in castration-resistant prostate cancer. To date, functional studies of AR-Vs have been focused mainly on their ability to regulate gene expression independent of the full-length AR (AR-FL). Here, we showed that AR-V7 and ARv567es, two major AR-Vs, both facilitated AR-FL nuclear localization in the absence of androgen and mitigated the ability of the antiandrogen enzalutamide to inhibit AR-FL nuclear trafficking. AR-V bound to the promoter of its specific target without AR-FL, but co-occupied the promoter of canonical AR target with AR-FL in a mutually-dependent manner. AR-V expression attenuated both androgen and enzalutamide modulation of AR-FL activity/cell growth, and mitigated the in vivo antitumor efficacy of enzalutamide. Furthermore, ARv567es levels were upregulated in xenograft tumors that had acquired enzalutamide resistance. Collectively, this study highlights a dual function of AR-Vs in mediating castration resistance. In addition to trans-activating target genes independent of AR-FL, AR-Vs can serve as a "rheostat" to control the degree of response of AR-FL to androgen-directed therapy via activating AR-FL in an androgen-independent manner. The findings shed new insights into the mechanisms of AR-V-mediated castration resistance and have significant therapeutic implications.
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Bioactivities of Compounds from Elephantopus scaber, an Ethnomedicinal Plant from Southwest China.
Evid Based Complement Alternat Med
PUBLISHED: 04-02-2014
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Elephantopus scaber is an ethnomedicinal plant used by the Zhuang people in Southwest China to treat headaches, colds, diarrhea, hepatitis, and bronchitis. A new ? -truxinate derivative, ethyl, methyl 3,4,3',4'-tetrahydroxy- ? -truxinate (1), was isolated from the ethyl acetate extract of the entire plant, along with 4 known compounds. The antioxidant activity of these 5 compounds was determined by ABTS radical scavenging assay. Compound 1 was also tested for its cytotoxicity effect against HepG2 by MTT assay (IC50 = 60? ? M), and its potential anti-inflammatory, antibiotic, and antitumor bioactivities were predicted using target fishing method software.
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HIV and syphilis prevalence trends among men who have sex with men in Guangxi, China: yearly cross-sectional surveys, 2008-2012.
BMC Infect. Dis.
PUBLISHED: 03-28-2014
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Men who have sex with men (MSM) represent the fastest growing key population for incident HIV cases in China. We examined five consecutive years of HIV and syphilis prevalence and risk factors data among MSM in Guangxi Province with the second highest estimated number of people living with HIV/AIDS (PLWHAs) in China in 2011.
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A novel multivalent, single-domain antibody targeting TcdA and TcdB prevents fulminant Clostridium difficile infection in mice.
J. Infect. Dis.
PUBLISHED: 03-27-2014
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The incidence of Clostridium difficile infection (CDI) and associated mortality have increased rapidly worldwide in recent years. Therefore, it is critical to develop new therapies for CDI. In this study, we generated a novel, potently neutralizing, tetravalent, and bispecific antibody composed of 2 heavy-chain-only VH (VHH) binding domains against both TcdA and TcdB (designated "ABA") that reverses fulminant CDI in mice infected with an epidemic 027 strain after a single injection of the antibody. We demonstrated that ABA bound to both toxins simultaneously and displayed a significantly enhanced neutralizing activity both in vitro and in vivo. Additionally, ABA was able to broadly neutralize toxins from clinical C. difficile isolates that express both TcdA and TcdB but failed to neutralize the toxin from TcdA(-)TcdB(+) C. difficile strains. This study thus provides a rationale for the development of multivalent VHHs that target both toxins and are broadly neutralizing for treating severe CDI.
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Prevalence of transmitted HIV-1 drug resistance remains low in Guangxi, China, eight years after scale-up of highly-active antiretroviral therapy.
Intervirology
PUBLISHED: 03-19-2014
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Highly-active antiretroviral therapy (HAART) was scaled up in Guangxi, China in 2005. The number of individuals receiving free HAART increased dramatically from June 2010 under the Guangxi Government's anti-HIV programme. We aimed to determine the prevalence of HIV-transmitted drug resistance (TDR) of Guangxi.
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MicroRNA-27b targets gremlin 1 to modulate fibrotic responses in pulmonary cells.
J. Cell. Biochem.
PUBLISHED: 03-12-2014
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Fibrosis is a chronic disease characterized by an excessive deposition of scar tissue in the affected organs. A central mediator of this process is transforming growth factor-? (TGF-?), which stimulates the production of extracellular matrix proteins such as collagens. MicroRNAs (miRNAs) have been implicated in both fibrosis as well as in TGF-? signaling, but the extent of their regulation has not been fully defined. A functional screen was conducted using a library of miRNA inhibitors to identify miRNAs that affect TGF-?-induced type I collagen expression, a key event in the development of fibrosis. The inhibition of one miRNA in particular, miR-27b, caused a significant increase in type I collagen expression. We found that miR-27b directly targets Gremlin 1 by binding to its 3'-UTR, reducing its mRNA levels. TGF-? signaling decreased miR-27b expression and caused a corresponding increase in Gremlin 1 levels, suggesting that TGF-? regulates Gremlin 1 expression in part by modulating miR-27b expression. Reducing Gremlin 1 levels by either siRNA-mediated gene silencing or by using the miR-27b mimic inhibited the expression of several genes known to be involved in fibrosis, while increasing Gremlin 1 levels by the addition of either recombinant protein or the miR-27b inhibitor enhanced the expression of these genes. In summary, we have demonstrated that miR-27b targets Gremlin 1, and that this regulation likely represents an important control point in fibrotic pathways.
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Use of probiotics in the treatment of severe acute pancreatitis: a systematic review and meta-analysis of randomized controlled trials.
Crit Care
PUBLISHED: 03-04-2014
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Necrotic tissue infection can worsen the prognosis of severe acute pancreatitis (SAP), and probiotics have been shown to be beneficial in reducing the infection rate in animal experiments and primary clinical trials. However, the results of multicenter randomized clinical trials have been contradictory. Our aim in this study was to systematically review and quantitatively analyze all randomized controlled trials with regard to important outcomes in patients with predicted SAP who received probiotics.
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Increased expression of Notch1 in temporal lobe epilepsy: animal models and clinical evidence.
Neural Regen Res
PUBLISHED: 02-25-2014
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Temporal lobe epilepsy is associated with astrogliosis. Notch1 signaling can induce astrogliosis in glioma. However, it remains unknown whether Notch1 signaling is involved in the pathogenesis of epilepsy. This study investigated the presence of Notch1, hairy and enhancer of split-1, and glial fibrillary acidic protein in the temporal neocortex and hippocampus of lithium-pilocarpine-treated rats. The presence of Notch1 and hairy and enhancer of split-1 was also explored in brain tissues of patients with intractable temporal lobe epilepsy. Quantitative electroencephalogram analysis and behavioral observations were used as auxiliary measures. Results revealed that the presence of Notch1, hairy and enhancer of split-1, and glial fibrillary acidic protein were enhanced in status epilepticus and vehicle-treated spontaneous recurrent seizures rats, but remain unchanged in the following groups: control, absence of either status epilepticus or spontaneous recurrent seizures, and zileuton-treated spontaneous recurrent seizures. Compared with patient control cases, the presences of Notch1 and hairy and enhancer of split-1 were upregulated in the temporal neocortex of patients with intractable temporal lobe epilepsy. Therefore, these results suggest that Notch1 signaling may play an important role in the onset of temporal lobe epilepsy via astrogliosis. Furthermore, zileuton may be a potential therapeutic strategy for temporal lobe epilepsy by blocking Notch1 signaling.
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Application of capillary electrophoresis for the early diagnosis of cancer.
Anal Bioanal Chem
PUBLISHED: 02-21-2014
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Early diagnosis is the key to the effective treatment of cancer. The detection of cancer biomarkers plays a critical role not only in cancer early diagnosis, but also in classification and staging tumor progression, or assessment prognosis and treatment response. Currently, various molecular diagnostic techniques have been developed for cancer biomarker studies, with many of the more effective approaches requiring a separation step before detection. Capillary electrophoresis (CE) can perform rapid and efficient separation with small samples, which is well-suited for analysis of both small- and macro- molecule biomarkers in complex samples. CE has different separation modes and can couple to different detectors into a variety of platforms, such as conducting studies on DNA/ RNA point mutation, protein misexpression, and metabolite abnormality. Similarly, microchip capillary electrophoresis (MCE) appears as a very important biomarker screening platform with the merits of high throughput, integration, and miniaturization, which makes it a promising clinical tool. By hyphenated different detectors, or integrated with immunoassay, PCR/LDR and related technologies, MCE can be constructed into diverse platforms used in genomics, proteomics, and metabolomics study for biomarkers discovery. The multiplex biomarker screening approach via CE- or MCE-based platforms is becoming a trend. This paper focuses on studies of cancer biomarkers via CE/MCE platforms, based on the studies published over the past 3 years. Some recent CE applications in the field of cancer study, such as cancer theranostics, are introduced.
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Quantitative analysis of glycerol levels in human urine by liquid chromatography-tandem mass spectrometry.
J. Chromatogr. B Analyt. Technol. Biomed. Life Sci.
PUBLISHED: 02-12-2014
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Glycerol has the latent capacity to act as a plasma volume expander and disguise blood doping practices. Therefore, it has been prohibited in sports as a masking agent by the World Anti-Doping Agency (WADA) since January 2010 and a urinary threshold (1mg/mL) was recommended recently [1]. The purpose of this study was to establish and validate a novel quantitative method for the determination of urinary glycerol concentrations using a liquid chromatography-tandem mass spectrometry approach. This simple yet highly specific method made use of the derivatization of glycerol by benzoyl chloride in aqueous solution at 40°C followed by analysis via LC-ESI-MS/MS without sample pre-concentration or cleanup. The assay was linear over the concentration range of 1.0-1000?g/mL for glycerol in human urine. The lower limit of detection (LLOD) and lower limit of quantitation (LLOQ) were 0.3?g/mL and 1.0?g/mL, respectively. The intra- and inter-day precision of the method at three concentration levels (3, 500 and 900?g/mL) was less than 12.2%. The method also afforded satisfactory results in terms of accuracy, derivatization yield, extraction recovery, matrix effect and specificity. The method has been successfully applied to the detection of glycerol in "Quality Assurance Program" samples provided by the World Association of Anti-Doping Scientists (WAADS) and routine doping-control samples in our laboratory.
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Regulatory constraints in the generation and differentiation of IgE-expressing B cells.
Curr. Opin. Immunol.
PUBLISHED: 02-01-2014
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B cells expressing antibodies of the immunoglobulin E (IgE) isotype are rare, yet are heavily implicated in the pathogenesis of allergies and asthma. This review discusses recent methodological advances that permit sensitive probing of IgE-expressing (IgE(+)) B cells in vivo and have accordingly clarified the basic behavior and fate of IgE(+) B cells during immune responses in mouse models. IgE antibody secreting plasma cells can arise from extrafollicular foci, germinal centers, and memory B cells. However, compared to B cells expressing other isotypes, IgE(+) B cells are susceptible to multiple additional regulatory constraints that restrict the size of the IgE(+) B cell pool at each stage, coordinately limiting the overall magnitude, affinity, and duration of the IgE antibody response.
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Prevalence of HIV, syphilis, and HCV infection and associated risk factors among male clients of low-paying female sex workers in a rural county of Guangxi, China: a cross-sectional study.
Sex Transm Infect
PUBLISHED: 01-30-2014
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The purpose of this study was to examine prevalence of HIV, syphilis and hepatitis C virus (HCV) infection as well as related risk factors among a group of male clients of low-paying female sex workers (FSW) (eg, women who usually encounter their clients on the street or small establishments in rural or less developed areas, or who charge low fees for each sexual service) in a rural county of China.
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Relative contribution of stoichiometry and mean coordination to the fragility of Ge-As-Se glass forming liquids.
J Phys Chem B
PUBLISHED: 01-28-2014
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The structural relaxation properties of 34 compositions of Ge-As-Se glass forming liquids are investigated by differential scanning calorimetry (DSC). The fragility index (m) and activation energies for enthalpy relaxation (Ea) exhibit universal trends with respect to stoichiometry and mean coordination (?r?), respectively. The liquid fragility which defines the full temperature dependence of the relaxation processes shows no well defined trend with respect to ?r? but instead is found to be closely determined by the excess or deficiency in selenium with respect to stoichiometry. The mean coordination on the other hand appears to be an accurate predictor of the activation energy near the glass transition where most constraints are still intact. No intermediate phase is observed in either case. These results emphasize that chemical effects rather than topological effects appear to control the wide ranging structural mobility of these glass forming liquids. The consequences of these findings in terms of the thermal stability of the corresponding glasses are discussed. It is similarly found that sub-Tg relaxation is controlled by stoichiometry rather than topology.
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Facilitated brain delivery of poly (ethylene glycol)-poly (lactic acid) nanoparticles by microbubble-enhanced unfocused ultrasound.
Biomaterials
PUBLISHED: 01-18-2014
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Nanotechnology plays a unique instrumental role in the revolutionary development of brain-specific drug delivery, imaging, and diagnosis, but is highly limited by the existence of blood-brain barrier (BBB). In this study, microbubble-enhanced unfocused ultrasound (MEUUS) was developed as an approach to mediate an extensive brain delivery of poly (ethylene glycol) - poly (lactic acid) (PEG-PLA) nanoparticles. Following the MEUUS treatment, the nanoparticles signals were found to penetrate through the vascular walls and distributed deeply into the parenchyma at a significantly higher level (more than 250%) than those of the non-MEUUS treated control. Such effect was reversible and dependent on nanoparticles injection timing, sonication mode and mechanical index. Together with the transmission electron microscopy analysis, the increased brain accumulation of nanoparticles was claimed to be largely mediated by an ultrasound-induced stable cavitation of the microbubble which resulted in mechanical stretching of the vessel wall and consequently induced cellular transcytosis of the nanoparticles. The MEUUS technique was also used to facilitate the brain delivery of PEG-PLA nanoparticles functionalized with amyloid beta-specific antibody 6E10 for enabling the recognition of the hallmarks of Alzheimer's disease that widely distributed in the brain. No erythrocytes extravasation and other visible damages in the brain were detected following the MEUUS treatment. These findings together indicated that unfocused ultrasound with the aid of microbubble could effectively improve the brain delivery of nanoparticles, and this approach might serve as a safe and flexible platform for the potential application of nanoparticles in the diagnosis and therapy of brain diseases.
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The function of BAFF on T helper cells in autoimmunity.
Cytokine Growth Factor Rev.
PUBLISHED: 01-14-2014
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B cell-activating factor belonging to the TNF family (BAFF) exerts its pathogenic role in supporting the survival and proliferation of B cells, regulating class switch recombination as well as the selection of autoreactive B cells. Overexpression of BAFF induces a dramatic expansion of activated B cells, particularly marginal zone B cells, as well as hypergammaglobulinemia, autoantibody production and immune complex deposition. However, in addition to its effect on B cells, recent work has also demonstrated that BAFF can promote T cell activation, proliferation and differentiation. In this review, we have discussed the recent progress on the function and role of BAFF on T cells and T cell-mediated diseases.
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Global regulation of mRNA translation and stability in the early Drosophila embryo by the Smaug RNA-binding protein.
Genome Biol.
PUBLISHED: 01-07-2014
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Smaug is an RNA-binding protein that induces the degradation and represses the translation of mRNAs in the early Drosophila embryo. Smaug has two identified direct target mRNAs that it differentially regulates: nanos and Hsp83. Smaug represses the translation of nanos mRNA but has only a modest effect on its stability, whereas it destabilizes Hsp83 mRNA but has no detectable effect on Hsp83 translation. Smaug is required to destabilize more than one thousand mRNAs in the early embryo, but whether these transcripts represent direct targets of Smaug is unclear and the extent of Smaug-mediated translational repression is unknown.
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Pestalafuranones F-J, five new furanone analogues from the endophytic fungus Nigrospora sp. BM-2.
Molecules
PUBLISHED: 01-03-2014
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Five new 2(5H)-furanone-type derivatives, pestalafuranones F-J (compounds 3-7), together with two known compounds, pestalafuranones A (1) and B (2), were isolated from the ethyl acetate extract from the fermentation broth of the endophytic fungus Nigrospora sp. BM-2 in a hypersaline medium. The structures of these metabolites were elucidated by EIMS, HREIMS and NMR spectroscopic data. Compounds 1-7 exhibited no cytotoxic activities against the MDA-MB-231 and Caski cancer cell lines.
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Ethnobotany of dye plants in Dong communities of China.
J Ethnobiol Ethnomed
PUBLISHED: 01-02-2014
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Dyes derived from plants have an extensive history of use for coloring food and clothing in Dong communities and other indigenous areas in the uplands of China. In addition to use as coloring agents, Dong communities have historically utilized dye plants for their value for enhancing the nutritive, medicinal and preservative properties of foods. However, the persistence of plant-derived dyes and associated cultural practices and traditional knowledge is threatened with rapid socio-economic change in China. Research is needed to document the ethnobotany of dye plants in indigenous communities towards their conservation and potential commercialization as a sustainable means of supporting local development initiatives.
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Primary gliosarcoma with long-survival: report of two cases and review of literature.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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Gliosarcoma (GS) is a rare high-grade malignant tumor with poor prognosis. The survival period of GS ranges from 4 to 18.5 months. Rarely would it be over 40 months. Survival of intraventricular GS is less than 8 months.
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Psychological Fears among Low-Paid Female Sex Workers in Southwest China and Their Implications for HIV Prevention.
PLoS ONE
PUBLISHED: 01-01-2014
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Commercial sex plays a critical role in rapidly increasing heterosexual transmission of HIV in China. Low-paid female sex workers (FSWs) are especially vulnerable to HIV/AIDS. Because of the illegality and stigma associated with sex work, FSWs may constantly live with fears in their daily life. Based on cross-sectional study of 794 low-paid FSWs in China we described their psychological fears related to commercial sex and examined the associations between fears and HIV-related behaviors. Fear of HIV infection was significantly associated with consistent use of condoms with clients. However, fear of breaching sex worker identity significantly prevented the FSWs from consistently using condoms with clients and taking HIV tests. Fear of being arrested by the police was positively associated with consistent use of condoms but negatively associated with accessing HIV prevention services. Our findings underlined the importance of examining the triadic interaction of behavioral, psychological and environmental factors in HIV prevention interventions among low-paid FSWs.
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Assessment of choroidal thickness in healthy and glaucomatous eyes using swept source optical coherence tomography.
PLoS ONE
PUBLISHED: 01-01-2014
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To evaluate choroidal thickness (CT) in healthy and glaucomatous eyes using Swept Source Optical Coherence Tomography (SS-OCT).
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Aphrodisiac Use Associated with HIV Infection in Elderly Male Clients of Low-Cost Commercial Sex Venues in Guangxi, China: A Matched Case-Control Study.
PLoS ONE
PUBLISHED: 01-01-2014
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Rising HIV infection rates have been observed among elderly people in Guangxi, China. Inexpensive aphrodisiacs are available for purchase in suburban and rural areas. This study aims to investigate the association between aphrodisiac use and increased HIV risk for middle-aged and elderly men in Guangxi.
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Transplantation of bone marrow stromal cells enhances infiltration and survival of CNP and Schwann cells to promote axonal sprouting following complete transection of spinal cord in adult rats.
Am J Transl Res
PUBLISHED: 01-01-2014
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This study aimed to investigate the roles of bone marrow stromal cells (BMSCs) in promoting axonal regeneration after complete transection of spinal cord in adult rats. Transplantation was done 9 days after injury. Only a few BMSCs were detected at the injury site 8 weeks after transplantation, yet there was robust growth of axons. The scarcity of surviving BMSCs may attribute to the adverse conditions in their ambient environment. In this connection, the immediate accumulation of a large number of macrophages/reactive microglia following BMSCs transplantation and subsequent cavitation of tissues may be detrimental to their survival. An unexpected finding following BMSCs transplantation was the marked increase in the nestin, GFAP, NF200, olig 3 and CNP positive cells at the injury site. Immunoelectron microscopy showed CNP cells were oval or fibroblast-like and had multiple perineurial-like compartments with long extending filopodia. The spatial relationship between regenerating axons and CNP-positive cells was also confirmed by double immunofluorescence staining. Our results suggest that transplantation of BMSCs elicits the influx and survival of local cells including CNP positive cells and Schwann cells into injury site, which provide structural support for the axon regeneration and remyelination after spinal cord injury.
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Screening for acute HIV infections and estimating HIV incidence among female sex workers from low-grade venues in Guangxi, China.
PLoS ONE
PUBLISHED: 01-01-2014
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Guangxi has become one of the provinces with the most severe HIV-1 epidemic in China, where heterosexual contact is the dominant transmission route. However, data of acute HIV infections and HIV incidence among female sex workers (FSWs) from low-grade venues are scant.
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Androgen receptor splice variant AR3 promotes prostate cancer via modulating expression of autocrine/paracrine factors.
J. Biol. Chem.
PUBLISHED: 12-02-2013
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Deregulation of androgen receptor (AR) splice variants have been implicated to play a role in prostate cancer development and progression. To understand their functions in prostate, we established a transgenic mouse model (AR3Tg) with targeted expression of the constitutively active and androgen-independent AR splice variant AR3 (a.k.a. AR-V7) in prostate epithelium. We found that over-expression of AR3 modulates expression of a number of tumor-promoting autocrine/ paracrine growth factors (including Tgf?2 and Igf1) and expands prostatic progenitor cell population, leading to development of prostatic intraepithelial neoplasia. In addition, we showed that some epithelial-mesenchymal-transition (EMT) associated genes are upregulated in AR3Tg prostates, suggesting that AR3 may antagonize AR activity and halt differentiation process driven by AR and androgen. This notion is supported by our observations that the number of ck5+/ck8+ intermediate cells is increased in AR3Tg prostates after castration, and expression of AR3 transgene in these intermediate cells compromises prostate epithelium regeneration upon androgen replacement. Our results demonstrate that AR3 is a driver of prostate cancer, at least in part, through modulating multiple tumor-promoting autocrine/paracrine factors.
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Dual leucine zipper kinase as a therapeutic target for neurodegenerative conditions.
Future Med Chem
PUBLISHED: 11-02-2013
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Dual leucine zipper kinase (DLK) is a serine/threonine protein kinase that is a member of the mixed lineage kinase subfamily. Mixed lineage kinases are upstream MAP3Ks that activate the JNK pathway. DLK is primarily responsible for activating JNK and mediating the apoptotic stress response in various cell types, specifically neurons. Inhibition and knockdown of DLK has been demonstrated to have neuroprotective effects in cellular and animal models of Alzheimers disease, glaucoma, Parkinsons disease and other neurodegenerative conditions. Several series of ATP-binding site inhibitors have been identified through profiling efforts providing launch points for future medicinal chemistry programs.
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Metastable interwoven mesoporous metal-organic frameworks.
Inorg Chem
PUBLISHED: 09-25-2013
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Three isostructural interwoven 3,4-connected mesoporous metal-organic frameworks of pto-a topology (UTSA-28-Cu, UTSA-28-Zn, and UTSA-28-Mn) were synthesized and structurally characterized. Because of their metastable nature, their gas sorption properties are highly dependent on the metal ions and activation profiles. The most stable, UTSA-28a-Cu, exhibits promising gas storage and separation capacities.
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Prohibitin-2 binding modulates insulin-like growth factor-binding protein-6 (IGFBP-6)-induced rhabdomyosarcoma cell migration.
J. Biol. Chem.
PUBLISHED: 09-03-2013
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Insulin-like growth factor (IGF)-binding protein (IGFBP)-6 decreases cancer cell proliferation and survival by inhibiting the effects of IGF-II. More recently, IGFBP-6 was found to promote the migration of rhabdomyosarcoma (RMS) cells in an IGF-independent manner, and MAPK pathways were involved in this process. However, the precise molecular mechanisms of these IGF-independent migratory actions of IGFBP-6 are largely unknown. Here, we report that prohibitin-2 (PHB2), a single-span membrane protein, is a key regulator of IGFBP-6-induced RMS cell migration. PHB2 and IGFBP-6 co-localize on the RMS cell surface, and they specifically interact, as demonstrated by affinity chromatography, co-immunoprecipitation, biosensor analysis, and confocal microscopy. Binding affinities for PHB2 are 9.0 ± 1.0 nM for IGFBP-6 and 10.2 ± 0.5 nM for mIGFBP-6, a non-IGF-binding mutant of IGFBP-6. The C-domain but not the N-domain of IGFBP-6 is involved in PHB2 binding. In addition, IGFBP-6 indirectly increases PHB2 tyrosine phosphorylation on RMS membranes. Importantly, PHB2 knockdown completely abolished IGFBP-6-mediated RMS cell migration. In contrast, IGFBP-6-induced MAPK pathway activation was not affected, suggesting that PHB2 may act as a downstream effector of these pathways. These results indicate that PHB2 plays a key role in this IGF-independent action of IGFBP-6 and suggest a possible therapeutic target for RMS.
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Mechanisms of Antibacterial Activity of MgO: Non-ROS Mediated Toxicity of MgO Nanoparticles Towards Escherichia coli.
Small
PUBLISHED: 08-08-2013
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The toxicity of metal oxide nanomaterials and their antimicrobial activity is attracting increasing attention. Among these materials, MgO is particularly interesting as a low cost, environmentally-friendly material. The toxicity of MgO, similar to other metal oxide nanomaterials, is commonly attributed to the production of reactive oxygen species (ROS). We investigated the toxicity of three different MgO nanoparticle samples, and clearly demonstrated robust toxicity towards Escherichia coli bacterial cells in the absence of ROS production for two MgO nanoparticle samples. Proteomics data also clearly demonstrate the absence of oxidative stress and indicate that the primary mechanism of cell death is related to the cell membrane damage, which does not appear to be due to lipid peroxidation.
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Substrate induced emergence of different active bacterial and archaeal assemblages during biomethane production.
Bioresour. Technol.
PUBLISHED: 07-27-2013
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This study analyzed the composition of a methane-generating microbial community and the corresponding active members during the transformation of three target substrates (food waste, cellulose or xylan) by barcoded 454 pyrosequencing of the bacterial and archaeal 16S rRNA genes in the DNA and RNA. The number of operational taxonomic units at 97% similarity for bacteria and archaea ranged from 162-261 and 31-166, respectively. Principal coordinates analysis and Venn diagram revealed that there were significant differences in the microbial community structure between the active members transforming each substrate and the inoculum. The active bacterial populations detected were those required for the hydrolysis of the amended substrate. The active archaeal populations were methanogens but the ratio of Methanosarcinales and Methanomicrobiales varied between the cultures. Overall, results of this study showed that a subset of the populations became active and altered in relative abundance during methane production according to the amended substrate.
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Electrochemiluminescence immunosensor for tumor markers based on biological barcode mode with conductive nanospheres.
Biosens Bioelectron
PUBLISHED: 07-22-2013
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A novel sandwich-type electrochemiluminescence (ECL) immunosensor was developed for highly sensitive and selective determination of tumor markers based on biological barcode mode. N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and the second antibody (Ab2) were simultaneously immobilized on conductive nanospheres to construct ABEI/Ab2-CNSs probes, which could form sandwich immunocomplex by Ab2 and emit ECL signals by ABEI. The gold layer coated on the surface of the conductive nanospheres could extend the outer Helmholtz plane (OHP) of the ECL immunosensor effectively. Benefited from it, all ABEI molecules immobilized on conductive nanospheres would act as biological barcode to give in-situ ECL signals without interfering with the activity of the second antibody. In such a case, the sensitivity of the ECL immunosensor would be greatly improved because an antigen molecule would correspond to ECL signals of thousands of ABEI molecules. Using prostate specific antigen (PSA) as a model tumor marker, the ECL intensity was found to increase with the logarithm of PSA concentration with a wide linear range from 0.04 to 10fg/mL. In addition, specificity, stability, reproducibility, regeneration and application were satisfactory. Therefore, this developed ECL immunosensor has a potential for practical detection of disease-related proteins besides tumor markers in the clinical diagnostics.
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Modelling and control of a five-degrees-of-freedom pneumatically actuated magnetic resonance-compatible robot.
Int J Med Robot
PUBLISHED: 06-21-2013
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Magnetic resonance imaging (MRI) combined with robotic assistance has the potential to improve on clinical outcomes of biopsy and local treatment of prostate cancer. This paper introduces a pneumatically actuated surgical robotic system for prostatic interventions under MRI guidance.
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Biotemplated syntheses of macroporous materials for bone tissue engineering scaffolds and experiments in vitro and vivo.
ACS Appl Mater Interfaces
PUBLISHED: 06-17-2013
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The macroporous materials were prepared from the transformation of cuttlebone as biotemplates under hydrothermal reactions and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric/differential thermal analyses (TG-DTA), and scanning electron microscopy (SEM). Cell experimental results showed that the prepared materials as bone tissue engineering scaffolds or fillers had fine biocompatibility suitable for adhesion and proliferation of the hMSCs (human marrow mesenchymal stem cells). Histological analyses were carried out by implanting the scaffolds into a rabbit femur, where the bioresorption, degradation, and biological activity of the scaffolds were observed in the animal body. The prepared scaffolds kept the original three-dimensional frameworks with the ordered porous structures, which made for blood circulation, nutrition supply, and the cells implantation. The biotemplated syntheses could provide a new effective approach to prepare the bone tissue engineering scaffold materials.
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High-temperature-stable and regenerable catalysts: platinum nanoparticles in aligned mesoporous silica wells.
ChemSusChem
PUBLISHED: 05-29-2013
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We report the synthesis, structural characterization, thermal stability study, and regeneration of nanostructured catalysts made of 2.9 nm Pt nanoparticles sandwiched between a 180 nm SiO2 core and a mesoporous SiO2 shell. The SiO2 shell consists of 2.5 nm channels that are aligned perpendicular to the surface of the SiO2 core. The nanostructure mimics Pt nanoparticles that sit in mesoporous SiO2 wells (Pt@MSWs). By using synchrotron-based small-angle X-ray scattering, we were able to prove the ordered structure of the aligned mesoporous shell. By using high-temperature cyclohexane dehydrogenation as a model reaction, we found that the Pt@MSWs of different well depths showed stable activity at 500 °C after the induction period. Conversely, a control catalyst, SiO2 -sphere-supported Pt nanoparticles without a mesoporous SiO2 shell (Pt/SiO2 ), was deactivated. We deliberately deactivated the Pt@MSWs catalyst with a 50 nm deep well by using carbon deposition induced by a low H2 /cyclohexane ratio. The deactivated Pt@MSWs catalyst was regenerated by calcination at 500 °C with 20 % O2 balanced with He. After the regeneration treatments, the activity of the Pt@MSWs catalyst was fully restored. Our results suggest that the nanostructured catalysts-Pt nanoparticles confined inside mesoporous SiO2 wells-are stable and regenerable for treatments and reactions that require high temperatures.
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Alcohol and sexual risk: an event-level analysis in commercial sex setting.
Addict Behav
PUBLISHED: 04-24-2013
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To assess the episodic relationship between alcohol and sexual risk in multiple-client occasions among female sex workers (FSWs).
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A fluorescence-switchable luminogen in the solid state: a sensitive and selective sensor for the fast "turn-on" detection of primary amine gas.
Chem. Commun. (Camb.)
PUBLISHED: 04-20-2013
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The emission of pyrrole-substituted benzoic acid can be repeatedly switched between the dark and bright states in the solid state by chemical fuming and heating processes, enabling it to work as a rapid sensitive fluorescent sensor for primary amine detection.
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Pd-catalyzed C3-selective arylation of pyridines with phenyl tosylates.
Chem. Commun. (Camb.)
PUBLISHED: 04-11-2013
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We have discovered that phenyl tosylates can be used to arylate pyridines at the C3-position using a Pd(OAc)2-1,10-phenanthroline catalyst system. We also discovered that the reaction of 4-methylpyridine with naphthyl tosylates occurred on the methyl group instead of at the C3-position.
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Performance of polymerase chain reaction techniques detecting granzyme B in the diagnosis of acute renal rejection: a meta-analysis.
Transplantation
PUBLISHED: 04-09-2013
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Studies have shown that granzyme B expression was up-regulated during acute renal rejection, which provides hopes for a noninvasive and reliable diagnostic method. However, the diagnostic performance has not been assessed systematically so far.
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The genome of Mesobuthus martensii reveals a unique adaptation model of arthropods.
Nat Commun
PUBLISHED: 03-18-2013
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Representing a basal branch of arachnids, scorpions are known as living fossils that maintain an ancient anatomy and are adapted to have survived extreme climate changes. Here we report the genome sequence of Mesobuthus martensii, containing 32,016 protein-coding genes, the most among sequenced arthropods. Although M. martensii appears to evolve conservatively, it has a greater gene family turnover than the insects that have undergone diverse morphological and physiological changes, suggesting the decoupling of the molecular and morphological evolution in scorpions. Underlying the long-term adaptation of scorpions is the expansion of the gene families enriched in basic metabolic pathways, signalling pathways, neurotoxins and cytochrome P450, and the different dynamics of expansion between the shared and the scorpion lineage-specific gene families. Genomic and transcriptomic analyses further illustrate the important genetic features associated with prey, nocturnal behaviour, feeding and detoxification. The M. martensii genome reveals a unique adaptation model of arthropods, offering new insights into the genetic bases of the living fossils.
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Fusaodavinvin, a novel metabolite containing sulfur from the endophytic fungus Fusarium sp. (CTGU-ZL-34).
Nat Prod Commun
PUBLISHED: 03-12-2013
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A novel metabolite containing sulfur, fusaodavinvin (1), was isolated from an endophytic fungus Fusarium sp.(CTGU-ZL-34), together with seven known compounds 2-8, and their structures were elucidated by NMR spectroscopy and MS. This is the first record of 3-(2R-hydroxyl-1-one-propane)-indole (compound 2) from nature. The isolated compounds were evaluated using the A549, Hep G2, Caski and MCF-7 cell lines by the MTT method, and compound 1 displayed significant inhibiting activity of four cancer cell lines with IC50 values of 11.5, 15.3, 15.2 and 60.5 microg/mL, respectively. However, compound 2 displayed no significant anticancer activity to the above four cancer cell lines.
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A dynamic dual role of IL-2 signaling in the two-step differentiation process of adaptive regulatory T cells.
J. Immunol.
PUBLISHED: 02-20-2013
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The molecular mechanism of the extrathymic generation of adaptive, or inducible, CD4(+)Foxp3(+) regulatory T cells (iTregs) remains incompletely defined. We show that exposure of splenic CD4(+)CD25(+)Foxp3(-) cells to IL-2, but not other common ?-chain cytokines, resulted in Stat5 phosphorylation and induced Foxp3 expression in ?10% of the cells. Thus, IL-2/Stat5 signaling may be critical for Foxp3 induction in peripheral CD4(+)CD25(+)Foxp3(-) iTreg precursors. In this study, to further define the role of IL-2 in the formation of iTreg precursors as well as their subsequent Foxp3 expression, we designed a two-step iTreg differentiation model. During the initial "conditioning" step, CD4(+)CD25(-)Foxp3(-) naive T cells were activated by TCR stimulation. Inhibition of IL-2 signaling via Jak3-Stat5 was required during this step to generate CD4(+)CD25(+)Foxp3(-) cells containing iTreg precursors. During the subsequent Foxp3-induction step driven by cytokines, IL-2 was the most potent cytokine to induce Foxp3 expression in these iTreg precursors. This two-step method generated a large number of iTregs with relatively stable expression of Foxp3, which were able to prevent CD4(+)CD45RB(high) cell-mediated colitis in Rag1(-/-) mice. In consideration of this information, whereas initial inhibition of IL-2 signaling upon T cell priming generates iTreg precursors, subsequent activation of IL-2 signaling in these precursors induces the expression of Foxp3. These findings advance the understanding of iTreg differentiation and may facilitate the therapeutic use of iTregs in immune disorders.
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Functional genomic screening identifies dual leucine zipper kinase as a key mediator of retinal ganglion cell death.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 02-19-2013
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Glaucoma, a major cause of blindness worldwide, is a neurodegenerative optic neuropathy in which vision loss is caused by loss of retinal ganglion cells (RGCs). To better define the pathways mediating RGC death and identify targets for the development of neuroprotective drugs, we developed a high-throughput RNA interference screen with primary RGCs and used it to screen the full mouse kinome. The screen identified dual leucine zipper kinase (DLK) as a key neuroprotective target in RGCs. In cultured RGCs, DLK signaling is both necessary and sufficient for cell death. DLK undergoes robust posttranscriptional up-regulation in response to axonal injury in vitro and in vivo. Using a conditional knockout approach, we confirmed that DLK is required for RGC JNK activation and cell death in a rodent model of optic neuropathy. In addition, tozasertib, a small molecule protein kinase inhibitor with activity against DLK, protects RGCs from cell death in rodent glaucoma and traumatic optic neuropathy models. Together, our results establish a previously undescribed drug/drug target combination in glaucoma, identify an early marker of RGC injury, and provide a starting point for the development of more specific neuroprotective DLK inhibitors for the treatment of glaucoma, nonglaucomatous forms of optic neuropathy, and perhaps other CNS neurodegenerations.
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Clinical observation and nursing care on the prevention of abdominal organ cluster transplantation rejection.
J Clin Nurs
PUBLISHED: 02-07-2013
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To investigate the clinical characteristics of rejection after upper abdominal cluster transplantation.
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A segment of 97 amino acids within the translocation domain of Clostridium difficile toxin B is essential for toxicity.
PLoS ONE
PUBLISHED: 02-05-2013
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Clostridium difficile toxin B (TcdB) intoxicates target cells by glucosylating Rho GTPases. TcdB (269 kDa) consists of at least 4 functional domains including a glucosyltransferase domain (GTD), a cysteine protease domain (CPD), a translocation domain (TD), and a receptor binding domain (RBD). The function and molecular mode of action of the TD, which is the largest segment of TcdB and comprises nearly 50% of the protein, remain largely unknown. Here we show that a 97-amino-acid segment (AA1756 - 1852, designated as ?97 or D97), located in the C-terminus of the TD and adjacent to the RBD, is essential for the cellular activity of TcdB. Deletion of this segment in TcdB (designated as TxB-D97), did not adversely alter toxin enzymatic activities or its cellular binding and uptake capacity. TxB-D97 bound to and entered cells in a manner similar to TcdB holotoxin. Both wild type and mutant toxins released their GTDs similarly in the presence of inositol hexakisphosphate (InsP6), and showed a similar glucosyltransferase activity in a cell-free glucosylating assay. Despite these similarities, the cytotoxic activity of TxB-D97 was reduced by more than 5 logs compared to wild type toxin, supported by the inability of TxB-D97 to glucosylate Rac1 of target cells. Moreover, the mutant toxin failed to elicit tumor necrosis factor alpha (TNF-?) in macrophages, a process dependent on the glucosyltransferase activity of the toxin. Cellular fractionation of toxin-exposed cells revealed that TxB-D97 was unable to efficiently release the GTD into cytosol. Thereby, we conclude the 97-amino-acid region of the TD C-terminus of TcdB adjacent to the RBD, is essential for the toxicity of TcdB.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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