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Find video protocols related to scientific articles indexed in Pubmed.
[The strategies of endosomal escape for intracellular gene delivery].
Yao Xue Xue Bao
PUBLISHED: 10-18-2014
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The intracellular trafficking and subcellular distribution of exogenous gene is very important for gene delivery. A successful gene vehicle should overcome various barriers including endosomal membrane barriers to delivery gene to the target organelle. Traditional nonviral vehicle is unable to avoid endosomal pathway efficiently, so the efficiency of gene delivery is low and the application of gene drugs is limited. In order to achieve efficient nonviral gene delivery, a lot of researches based on endosomal escape have been carried out and some agents with the function of endsomal escape have been found. These agents facilitate the endsomal escape via various mechanisms, such as fusion into the lipid bilayer of endosomes, pore formation in the endosomal membrane, proton sponge effect and photochemical methods to rupture the endosomal membrane. In this review, various reported strategies for endsomal escape are described according to the escape mechanisms, and their applications in intracellular gene delivery are also discussed.
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Amphiregulin promotes the immunosuppressive activity of intrahepatic CD4(+) regulatory T cells to impair CD8(+) T cell immunity against hepatitis B virus infection.
Immunology
PUBLISHED: 08-18-2014
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Hepatitis B virus (HBV) infection causes liver diseases and hepatocellular carcinoma. Immunotolerance in HBV-infected patients is one of the factors that incur failure of HBV clearance and persistent HBV amplification. However, the mechanisms underlying immunotolerance after HBV infection are yet to be thoroughly understood. Here using a novel HBV mouse model, we found for the first time that epidermal growth factor receptor (EGFR) is up-regulated on intrahepatic regulatory T cells (Treg cells) in HBV-infected mouse livers. The EGFR-positive Treg cells are more immunosuppressive than EGFR-negative Treg cells, demonstrated by higher expression of immunosuppressive cytokines and robust inhibition of CD8(+) T cell proliferation in vitro. Furthermore, EGFR-positive Treg cells potently restrain CD8(+) T cell-mediated anti-viral activity, leading to higher HBV burden in hepatocytes. Amphiregulin, a cytokine of EGF family, is significantly up-regulated in HBV-infected livers, while the cellular sources of Amphiregulin are still elusive. Amphiregulin promotes the immunosuppressive activity of EGFR-positive Treg cells in vitro, so as to profoundly inhibit production of anti-viral components in CD8(+) T cells. Taken together, our discovery elucidated a novel mechanism contributing to immunotolerance and viral amplification after HBV infection. Our study may provide new clues for developing therapeutic strategies against HBV infection. This article is protected by copyright. All rights reserved.
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Design, synthesis and biological evaluation of novel 1-hydroxyl-3-aminoalkoxy xanthone derivatives as potent anticancer agents.
Eur J Med Chem
PUBLISHED: 07-22-2014
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A series of novel 1-hydroxyl-3-aminoalkoxy xanthone derivatives were designed, synthesized and evaluated for in vitro anticancer activity against four selected human cancer cell lines (nasopharyngeal neoplasm CNE, liver cancer BEL-7402, gastric cancer MGC-803, lung adenocarcinoma A549). Most of the synthesized compounds exhibit effective cytotoxic activity against the four tested cancer cell lines with the IC50 values at micromolar concentration level. Some preliminary structure-activity relationships were also discussed. In this series of derivatives, compound 3g shows excellent broad spectrum anticancer activity with IC50 values ranging from 3.57 to 20.07 ?M. The in vitro anticancer activity effect and action mechanism of compound 3g on human gastric carcinoma MGC-803 cell were further investigated. The results showed that compound 3g exhibits dose- and time-dependent anticancer effects on MGC-803 cells through apoptosis, which might be associated with its decreasing intracellular calcium and the mitochondrial membrane potential.
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Eight-year survival of AIDS patients treated with Chinese herbal medicine.
Am. J. Chin. Med.
PUBLISHED: 04-09-2014
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Treatment of acquired immunodeficiency syndrome (AIDS) currently relies on the use of antiretroviral drugs. Little is known about Chinese herbal medicine (CHM) outcomes in patients living with AIDS. We conducted a cohort study to investigate long-term survival among CHM-treated AIDS patients. Patients were poor farmers who contracted HIV-1 infection when selling blood in the 1990s. Symptoms of AIDS included recurring respiratory tract infections with a clinical diagnosis of pneumonia, swollen lymph nodes and weight loss. 385 patients with AIDS were included and 165 of them used a 16-herb formula for 14 days to 9 months. The eight-year survival rate was 87% for the CHM users and 34% for the non-users (increased survival probability for CHM user, 9.6; 95% CI = 6.0-15.4; p < 0.0001). Survival probability further increased 14.6-fold (95% CI = 8.2-26.1), when excluding the users who received CHM for less than three months. Zero deaths were found in patients who used CHM for six to nine months. All the survivors regained their body weight and none of them experienced a relapse of AIDS or any severe adverse events. After the CHM treatment for an average of 3.6 months, the plasma HIV load was 74.7% lower (paired t-test, p = 0.151) and the number of blood CD4+ lymphocytes increased from 253 to 314 (paired t-test, p = 0.021). Without life-long medication, CHM may be beneficial for long-term survival of AIDS patients.
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Sonication assisted preparation of graphene oxide/graphitic-C?N? nanosheet hybrid with reinforced photocurrent for photocatalyst applications.
Dalton Trans
PUBLISHED: 03-15-2014
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Graphitic C3N4 (g-C3N4), as an advanced metal free photocatalyst, is known to be poorly exfoliated and dispersed in water from its powder form which has a layered structure, the intrinsic plane structure is not destroyed, and this has largely limited its application. In this work, we report our progress on successful sonication exfoliation of g-C3N4 nanosheets in graphene oxide (GO) aqueous solution. By making use of the substrate character of GO, g-C3N4 nanosheets of unvaried intrinsic structure were exfoliated and anchored on the GO surface, resulting in a GO/g-C3N4 hybrid. Moreover, the photocurrent of the hybrid was largely reinforced at the optimal weight fraction of GO. As a result, the corresponding photocatalytic performance of the hybrid with optimized photocurrent character was largely improved.
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A link between the nuclear-localized srGAP3 and the SWI/SNF chromatin remodeler Brg1.
Mol. Cell. Neurosci.
PUBLISHED: 02-06-2014
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The Slit-Robo GTPase activating protein 3 (srGAP3) is an important modulator of actin cytoskeletal dynamics and has an important influence on a variety of neurodevelopmental processes. Mutations in the SRGAP3 gene on chromosome 3p25 have been found in patients with intellectual disability. Genome-wide association studies and behavioral assays of knockout mice had also revealed SRGAP3 as a risk gene for schizophrenia. We have recently shown that srGAP3 protein undergoes regulated shuttling between the cytoplasm and the nucleus during neuronal development. It is shown here that nuclear-localized srGAP3 interacts with the SWI/SNF remodeling factor Brg1. This interaction is mediated by the C-terminal of srGAP3 and the ATPase motif of Brg1. In the primary cultured rat cortical neurons, the levels of nuclear-localized srGAP3 and its interaction with Brg1 have a significant impact on dendrite complexity. Furthermore, the interaction between srGAP3 and Brg1 was also involved in valproic acid (VPA) -induced neuronal differentiation of Neuro2a cells. We then show that GTP-bound Rac1 and GAP-43 may be potential mediators of nuclear srGAP3 and Brg1. Our results not only indicate a novel signaling pathway that contributes to neuronal differentiation and dendrite morphology, but also implicate a novel molecular mechanism underlying srGAP3 regulation of gene expression.
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Facile synthesis of a surface plasmon resonance-enhanced Ag/AgBr heterostructure and its photocatalytic performance with 450 nm LED illumination.
Dalton Trans
PUBLISHED: 01-31-2013
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In this paper, a plasmonic Ag/AgBr heterostructure was reduced by AgBr, which was successfully synthesized by a facile hydrothermal process at a temperature as low as 90 °C. The morphological and structural observation, crystallinity and optical performance of the products grown were carried out by using scanning electron microscopy, X-ray diffraction, energy dispersive spectrometry and UV-vis diffuse reflectance spectroscopy. The photocatalytic activities of Ag/AgBr heterostructures were evaluated by the degradation of methylene blue under 450 nm LED arrays. The results revealed that the plasmonic Ag/AgBr heterostructures exhibited much higher photocatalytic activities than pure AgBr and commercial Degussa P25. The visible-light photocatalytic activity enhancement of Ag/AgBr heterostructures could be attributed to the surface plasmon resonance and its synergistic effect on the photosensitive AgBr. Furthermore, a mechanism of the plasmon synergistically enhanced photocatalytic process was proposed.
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Neurobiological and pharmacological validity of curcumin in ameliorating memory performance of senescence-accelerated mice.
Pharmacol. Biochem. Behav.
PUBLISHED: 01-28-2013
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The senescence-accelerated mouse prone 8 (SAMP8 mice) is known as a neurodegenerative model and may show age-related deficits of cognition. Curcumin, a major active component of spic turmeric, could increase the capacity of learning and memory in the aged rat. However, it is not known whether curcumin could improve cognitive deficits in SAMP8 mice. The present study was undertaken to evaluate the effect of curcumin on the learning and memory of SAMP8 mice and its possible mechanisms. Subjects were randomly divided into four groups: SAMR1 mice, SAMP8 mice and two SAMP8 mice groups treated, intragastrically, with curcumin at the dose of 20 and 50mg/kg per day, respectively. After 25days, spatial memory, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, p-calcium/calmodulin-dependent kinase II (p-CaMKII) and p-N-methyl-d-aspartate receptor subunit 1 (p-NMDAR1) expression in the hippocampus of mice were examined by using the Morris water maze, biochemical analysis, immunohistochemistry and Western blot. Compared with SAMR1 mice, SAMP8 mice had longer escape latency, higher MDA content, lower SOD activity in the hippocampus, and lower intensity of p-CaMKII in the stratum lucidum of hippocampal CA3 and p-NMDAR1 expression in the hippocampal membrane fraction. Both 20 and 50mg/kg curcumin administration significantly shortened the escape latencies and decreased the hippocampal MDA content in the SAMP8 mice. 50mg/kg curcumin administration significantly ameliorated the hippocampal SOD activity, and increased the intensity of p-CaMKII in the stratum lucidum of hippocampal CA3 and p-NMDAR1 expression in the hippocampal membrane fraction of the SAMP8 mice. The present study demonstrated that curcumin treatment could attenuate cognitive deficits of SAMP8 mice in a dose-dependent manner by decreasing the oxidative stress and improving the expression of p-CaMKII and p-NMDAR1 in the hippocampus. Thus treatment with curcumin may have a potential therapeutic agent for aging-related cognitive dysfunctions.
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The inverse F-BAR domain protein srGAP2 acts through srGAP3 to modulate neuronal differentiation and neurite outgrowth of mouse neuroblastoma cells.
PLoS ONE
PUBLISHED: 01-27-2013
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The inverse F-BAR (IF-BAR) domain proteins srGAP1, srGAP2 and srGAP3 are implicated in neuronal development and may be linked to mental retardation, schizophrenia and seizure. A partially overlapping expression pattern and highly similar protein structures indicate a functional redundancy of srGAPs in neuronal development. Our previous study suggests that srGAP3 negatively regulates neuronal differentiation in a Rac1-dependent manner in mouse Neuro2a cells. Here we show that exogenously expressed srGAP1 and srGAP2 are sufficient to inhibit valporic acid (VPA)-induced neurite initiation and growth in the mouse Neuro2a cells. While ectopic- or over-expression of RhoGAP-defective mutants, srGAP1(R542A) and srGAP2(R527A) exert a visible inhibitory effect on neuronal differentiation. Unexpectedly, knockdown of endogenous srGAP2 fails to facilitate the neuronal differentiation induced by VPA, but promotes neurite outgrowth of differentiated cells. All three IF-BAR domains from srGAP1-3 can induce filopodia formation in Neuro2a, but the isolated IF-BAR domain from srGAP2, not from srGAP1 and srGAP3, can promote VPA-induced neurite initiation and neuronal differentiation. We identify biochemical and functional interactions of the three srGAPs family members. We propose that srGAP3-Rac1 signaling may be required for the effect of srGAP1 and srGAP2 on attenuating neuronal differentiation. Furthermore, inhibition of Slit-Robo interaction can phenocopy a loss-of-function of srGAP3, indicating that srGAP3 may be dedicated to the Slit-Robo pathway. Our results demonstrate the interplay between srGAP1, srGAP2 and srGAP3 regulates neuronal differentiation and neurite outgrowth. These findings may provide us new insights into the possible roles of srGAPs in neuronal development and a potential mechanism for neurodevelopmental diseases.
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The role of stream water carbon dynamics and export in the carbon balance of a tropical seasonal rainforest, southwest China.
PLoS ONE
PUBLISHED: 01-11-2013
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A two-year study (2009 ~ 2010) was carried out to investigate the dynamics of different carbon (C) forms, and the role of stream export in the C balance of a 23.4-ha headwater catchment in a tropical seasonal rainforest at Xishuangbanna (XSBN), southwest China. The seasonal volumetric weighted mean (VWM) concentrations of total inorganic C (TIC) and dissolved inorganic C (DIC) were higher, and particulate inorganic C (PIC) and organic C (POC) were lower, in the dry season than the rainy season, while the VWM concentrations of total organic C (TOC) and dissolved organic C (DOC) were similar between seasons. With increased monthly stream discharge and stream water temperature (SWT), only TIC and DIC concentrations decreased significantly. The most important C form in stream export was DIC, accounting for 51.8% of the total C (TC) export; DOC, POC, and PIC accounted for 21.8%, 14.9%, and 11.5% of the TC export, respectively. Dynamics of C flux were closely related to stream discharge, with the greatest export during the rainy season. C export in the headwater stream was 47.1 kg C ha(-1) yr(-1), about 2.85% of the annual net ecosystem exchange. This finding indicates that stream export represented a minor contribution to the C balance in this tropical seasonal rainforest.
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Characterization of diethylnitrosamine-induced liver carcinogenesis in Syrian golden hamsters.
Exp Ther Med
PUBLISHED: 10-08-2011
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The aim of this study was to characterize hepatocarcinogenesis in diethylnitrosamine (DEN)-treated hamsters. Syrian golden hamsters (n=36) were administered DEN by hypodermic injection and addition to drinking water. Morphological analyses, including light microscopy and immunohistochemistry of ?-fetal protein (AFP), were performed on liver and lung tissues. Primary cell culture and tumor transplantation were carried out to evaluate the potential application in hepatocellular carcinoma (HCC) research. From 25 to 50 weeks of treatment, liver tumors, including macronodular HCC and ascites, were found in one-third (4/12) of the animals treated with DEN. HCC was characterized by poor differentiation, frequent mitosis, AFP reaction, vessel invasion and potential application in primary cell culture and xenotransplantation. Pre-neoplastic lesions were hyperplastic nodules comprised of clear cells, bile duct proliferation, fatty metamorphosis and multilocular cysts. The DEN-treated hamsters also showed lung tumors consisting of AFP-negative, well-differentiated neoplastic cells. Characterization of DEN-induced HCC in hamsters provides insights into human hepatocarcinogenesis. This animal model has potential applications in HCC research.
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[Anticancer effect of 5-fluorouracil combined with extract of Rosa roxburghii Tratt on human endometrial adenocarcinoma].
Zhongguo Zhong Xi Yi Jie He Za Zhi
PUBLISHED: 09-14-2011
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To investigate anticancer effects of 5-fluorouracil (5-FU) combined with CL, extract of Rosa roxburghii Tratt on human endometrial adenocarcinoma cell line (JEC).
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[Effect of electroacupuncture on nitric oxide synthase in rats with cerebral ischemia-reperfusion injury].
Zhongguo Zhong Xi Yi Jie He Za Zhi
PUBLISHED: 08-10-2011
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To study the effect of electroacupuncture on nitric oxide synthase (NOS) in rats with cerebral ischemia-reperfusion injury.
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Tanshinone IIA activates calcium-dependent apoptosis signaling pathway in human hepatoma cells.
J Nat Med
PUBLISHED: 05-26-2011
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Tanshinone IIA (Tan IIA), a natural product from herb Salvia miltiorrhiza Bunge, has potential anti-tumor activity. The aim of this study was to pinpoint the molecular mechanisms underlying Tan IIA-induced cancer cell apoptosis. Human hepatoma BEL-7402 cells treated with Tan IIA underwent assessment with MTT assay for cell viability, 10-day culture for colony formation, flow cytometry and fluorescence microscopy for apoptosis and cell cycle analysis. Changes in intracellular [Ca(2+)] and mitochondrial membrane potential (??) reflected the calcium-dependent apoptosis pathway. RT-PCR was used to detect gene expression of Bad and metallothionein 1A (MT 1A). Cytotoxicity of Tan IIA was tested in human amniotic mesenchymal stem cells (HAMCs). Tan IIA exhibited dose-dependent and time-dependent anticancer effects on BEL-7402 cells through apoptosis and G(0)/G(1) arrest. Cells treated with Tan IIA increased their intracellular calcium, decreased their mitochondrial membrane potential and induced Bad and MT 1A mRNA expression. No adverse effects of Tan IIA were found in HAMCs. In conclusion, these results indicate that Tan IIA-induced cancer cell apoptosis acts via activation of calcium-dependent apoptosis signaling pathways and upregulation of MT 1A expression.
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Evaluation of indices in differentiation between iron deficiency anemia and beta-thalassemia trait for Chinese children.
J. Pediatr. Hematol. Oncol.
PUBLISHED: 07-15-2010
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Iron deficiency anemia (IDA) and beta-thalassemia trait (beta-TT) are the most common microcytic anemia. Kinds of discrimination indices have been established as simple, fast, and inexpensive means since 1970s. This study evaluates the validity of 12 indices in differentiation between IDA and beta-TT for Chinese children. The 12 discrimination indices were red blood cell (RBC) count, RBC distribution width, Mentzer Index, Green and King Index, RBC distribution width Index, England and Fraser Index, Shine and Lal Index, Srivastava Index, Ricerca Index, Ehsani Index, Sirdah Index, and Huber-Herklotz-Index. A total of 300 children (beta-TT, n=127 and IDA, n=173) were enrolled in the study. We calculated the sensitivity and specificity, positive and negative predictive values, and Youdens index for each index. We also established new cut-off values by receiver operating characteristic curves. Green and King Index showed the highest reliability, as it had the largest area under the curve (AUC=0.947), whereas Srivastava Index and Shine and Lal Index showed the lowest reliability (AUC=0.679 and 0.532, respectively). We concluded Green and King Index, Ricerca Index, and England and Fraser Index could be used in discrimination between IDA and beta-TT in Chinese children.
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[Study on the constituents of petroleum ether fraction of Buxus microphylla].
Zhong Yao Cai
PUBLISHED: 10-31-2009
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To study the chemical constituents from the petroleum ether fraction of Buxus microphylla.
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[Study on the chemical constituents of Sarcandra glabra by HPLC-ESI-MS/MS].
Zhong Yao Cai
PUBLISHED: 08-04-2009
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To study and compare the main chemical constituents of Sarcandra glabra and qingrexiaoyanning capsules which were extracted by acetic ether.
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[Quantitative determination of 1-deoxynojirimycin in mulberry leaves by high-performance liquid chromatographic-tandem mass/mass spectrometry].
Zhong Yao Cai
PUBLISHED: 07-02-2009
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To develop a high-performance liquid chromatographic-tandem mass/mass spectrometric method to determine the concentration of 1-deoxynojirimycin (1-DNJ) in mulberry leaves.
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[Expression of serum sICAM-1 in patients with primary hepatocellular carcinoma and its relationship with liver fibrosis].
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
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To explore the clinical value of serum soluble intercellular adhesion molecule-1 (sICAM-1) in patients with primary hepatocellular carcinoma (PHC) and its relationship with liver fibrosis.
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Graphene oxide capturing surface-fluorinated TiO2 nanosheets for advanced photocatalysis and the reveal of synergism reinforce mechanism.
Dalton Trans
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Surface-fluorinated TiO2 (F-TiO2) nanosheets with exposed (001) facets were synthesized from a scalable hydrothermal treatment assisted by a specific stabilization effect of fluorine ions on the (001) facets. Assembly of F-TiO2 on graphene oxide (GO) sheets into GO/F-TiO2 hybrid in aqueous solution was further achieved by making use of the surfactant role of GO. Photocatalytic properties of GO/F-TiO2 hybrid were evaluated under 365 nm UV light irradiation for photodegradation of methylene blue (MB). An optimal GO content has been determined to be 3 wt%, and the corresponding apparent pseudo-first-order rate constant Kapp is 0.0493 min(-1), 3 times and 4 times more than that of pure TiO2 nanosheets and commercial P25 photocatalyst, respectively. To reveal the synergism reinforce mechanism of GO/F-TiO2 hybrid, photo absorption, surface absorption, and the photoelectrochemical current properties have been intensively studied. We found that enhanced electron-hole separation has been the key issue for the reinforcement of photocatalytic performance. F-TiO2 with exposed (001) facet has stronger electron-hole separation resulting in a higher photoelectrochemical current than that of P25 photocatalyst. Moreover, hybridization of F-TiO2 with GO could further increase the photoelectrochemical current and the largest current for the optimal weight fraction of GO is in good accordance with the photocatalysis performance. The GO/F-TiO2 interface junction that favors the electron-hole separation was attributed to the photoelectrochemical current enhancement.
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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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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.