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Find video protocols related to scientific articles indexed in Pubmed.
Ribavirin enhances myeloid-derived suppressor cell differentiation through CXCL9/10 downregulation.
Immunopharmacol Immunotoxicol
PUBLISHED: 09-25-2014
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Abstract Elevation of myeloid-derived suppressor cells (MDSCs) was observed in some viral infectious diseases. In this study, we studied whether ribavirin, a widely used clinical antiviral drug, could impact the differentiation of human MDSCs in vitro. Flow cytometric analysis showed that ribavirin treatment (5-20?µg/ml) significantly enhanced the differentiation of monocytic MDSCs in a dose-dependent manner. The ribavirin-generated MDSCs were immune-suppressive toward autologous T cells. The mRNA expression of some cytokines was further examined by quantitative reverse transcription polymerase chain reaction. We observed a significant down-regulation of chemokine (C-X-C motif) ligand 9 (CXCL9) and CXCL10 mRNA in ribavirin-generated MDSCs, when compared with control. Peripheral blood mononuclear cells from clinical chronic hepatitis C patients subjected to ribavirin therapy also displayed a similar suppression in CXCL9/10 mRNA expression. Administration of recombinant CXCL9/10 proteins clearly counteracted the effect of ribavirin on MDSCs. In summary, this study showed that ribavirin enhanced human MDSCs differentiation in vitro, which may be attribute to the down-regulation of CXCL9/10 expression.
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Synthesis of monodisperse nanocolloidal microspheres with controlled size by vesicle bilayer templating.
Chem. Commun. (Camb.)
PUBLISHED: 05-30-2014
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This study describes a new method to prepare monodisperse polystyrene (PS) colloidal nanoparticles with controlled size ranging from 60 nm to 140 nm by the direct polymerization of styrene and divinylbenzene inside the bilayers of the polydisperse hyperbranched polymer vesicles.
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Efficacy and toxicity of cisplatin liposomes modified with polyethylenimine.
Pharmazie
PUBLISHED: 05-06-2014
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The polycation transfection agent, polyethylenimine (PEI) was introduced into cisplatin (CDDP)-encapsulated liposomes by modification with amphiphilic PEI-cholesterol (PEI-Chol) to evaluate its potential application in chemotherapeutic drug delivery. Compared with unmodified neutral liposomes (CDDP-NL), the remarkable features of PEI-modified cationic liposomes (CDDP-CL) increased cytotoxicity attributed to enhanced cellular uptake and extended cellular retention resulting from endosome escape in vitro. In a H22 hepatoma-bearing mouse model, CDDP-CL reduced the nephrotoxicity associated with CDDP and had an antitumor activity similar to free drug, without inducing obvious system toxicity. These results confirm that the cationic modification of liposomes with PEI is efficient and safe for antitumor drug delivery.
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Imprinted-like biopolymeric micelles as efficient nanovehicles for curcumin delivery.
Colloids Surf B Biointerfaces
PUBLISHED: 04-09-2014
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To enhance the solubility and improve the bioavailability of hydrophobic curcumin, a new kind of imprinted-like biopolymeric micelles (IBMs) was designed. The IBMs were prepared via co-assembly of gelatin-dextran conjugates with hydrophilic tea polyphenol, then crosslinking the assembled micelles and finally removing the template tea polyphenol by dialysis. The obtained IBMs show selective binding for polyphenol analogous drugs over other drugs. Furthermore, curcumin can be effectively encapsulated into the IBMs with 5×10(4)-fold enhancement of aqueous solubility. We observed the sustained drug release behavior from the curcumin-loaded IBMs (CUR@IBMs) in typical biological buffers. In addition, we found the cell uptake of CUR@IBMs is much higher than that of free curcumin. The cell cytotoxicity results illustrated that CUR@IBMs can improve the growth inhibition of HeLa cells compared with free curcumin, while the blank IBMs have little cytotoxicity. The in vivo animal study demonstrated that the IBMs could significantly improve the oral bioavailability of curcumin.
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A mannosylated cell-penetrating peptide-graft-polyethylenimine as a gene delivery vector.
Biomaterials
PUBLISHED: 01-27-2014
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Polyethylenimine (PEI) is widely applied in non-viral gene delivery vectors. PEI with high molecular weight is highly effective in gene transfection but is high cytotoxic. Conversely, PEI with low molecular weight displays lower cytotoxicity but less delivering efficiency. To overcome this issue, a novel copolymer with mannosylated, a cell-penetrating peptide (CPP), grafting into PEI with molecular weight of 1800 (Man-PEI1800-CPP) were prepared in this study to target antigen-presenting cells (APCs) with mannose receptors and enhance transfection efficiency with grafting CPP. The copolymer was characterized by (1)H NMR and FTIR. Spherical nanoparticles were formed with diameters of about 80-250 nm by mixing the copolymer and DNA at various charge ratios of copolymer/DNA(N/P). Gel retardation assays indicated that Man-PEI1800-CPP polymers efficiently condensed DNA at low N/P ratios. Cytotoxicity studies showed that Man-PEI1800-CPP/DNA complexes maintained in a high percentage of cell viability compared to the PEI with molecular weight of 25 k (PEI25k). Laser scan confocal microscopy and flow cytometry confirmed that Man-PEI1800-CPP/DNA complexes resulted in higher cell uptake efficiency on DC2.4 cells than on Hela cells line. The transfection efficiency of Man-PEI1800-CPP was significantly higher than that of PEI25k on DC2.4 cells. More importantly, the complexes were mainly distributed in the epidermis and dermis of skin and targeted on splenocytes after percutaneous coating based on microneedles in vivo. These results indicated that Man-PEI1800-CPP was a potential APCs targeted of non-virus vector for gene therapy.
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NOTES for Surgical Treatment of Long-Segment Hirschsprungs Disease: Report of Three Cases.
J Laparoendosc Adv Surg Tech A
PUBLISHED: 10-24-2013
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Abstract Purpose: The aim of this study was to evaluate the feasibility of natural orifice translumenal endoscopic surgery (NOTES(®); American Society for Gastrointestinal Endoscopy [Oak Brook, IL] and Society of American Gastrointestinal and Endoscopic Surgeons [Los Angeles, CA]) for the surgical management of long-segment Hirschsprungs disease. Patients and Methods: Three children with long-segment Hirschsprungs disease were enrolled in this study. In all three cases the transition zone was proximal to the splenic flexure, with too long a segment of distal aganglionic colon to perform an isolated transanal pull-through. Our procedure was as follows. A rectal mucosectomy was performed starting 0.5?cm proximal to the dentate line and extending proximally to the level of the intraperitoneal rectum. Three cannulas were inserted through the muscular sleeve into the abdominal cavity. The mesocolon, lateral peritoneum, and greater omentum were ligated and divided in order to mobilize the colon. After mobilization, the aganglionic distal bowel segment was pulled through the anus and resected. Finally the colo-anal anastomosis was created. Results: All three operations were successfully performed without intraoperative complications. No additional ports or conversion to an open procedure was required. The operative times were 242, 195, and 174 minutes, respectively. All three children were discharged without complication with follow-up for at least 1 year. One year after the procedure the 3 patients were stooling one to three times per day, with no fecal soiling or constipation. Conclusions: This NOTES procedure may be a safe and feasible option for the surgical treatment of long-segment Hirschsprungs disease.
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Ghrelin increases hippocampal recombination activating gene 1 expression and spatial memory performance in mice.
Neuroreport
PUBLISHED: 07-11-2013
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Ghrelin, which has been shown to improve memory retention, is an endogenous ligand for the growth hormone secretagogue receptor. Recombination activating gene 1 (Rag1), which plays a critical role in the development and maturation of lymphocytes in the immune system, is also expressed in the central nervous system, particularly in the hippocampus, and has been implicated in memory formation. In the current study, the effects of ghrelin on Rag1 expression in the hippocampus and spatial memory performance in wild-type and Rag1 knockout (KO) mice were examined. The Morris water maze test was used to compare the spatial memory performance of wild-type and Rag1-KO mice. Transmission electron microscopy was used to assess morphological changes in synaptic shape and numbers in hippocampal areas after peripheral administration of ghrelin to wild-type and Rag1-KO mice. In wild-type mice, ghrelin increased synaptic vesicles and postsynaptic membrane deposits in the hippocampal CA3 region, shortened water maze escape latencies, and increased platform spans. In Rag1-KO mice, the escape latencies were significantly increased compared with the group of normal mice. Compared with wild-type mice, Rag1-KO mice showed decreasing platform spans. A tendency toward a shortening of the escape latency times and an increase in the platform spans in Rag1-KO mice was observed after ghrelin injection, but this difference was not statistically significant compared with control mice. After the administration of ghrelin, the expression of Rag1 in the hippocampus was significantly increased compared with control mice. Our results suggest that ghrelin potentiates learning and memory in mice, which may be, at least partly, through the regulation of hippocampal Rag1.
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Synthesis of Ag nanoclusters by a pH-dependent etching method in aqueous solution.
Nanoscale
PUBLISHED: 06-05-2013
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We developed a pH-dependent etching method for the synthesis of stable fluorescent silver nanoclusters (AgNCs) in aqueous solution. The AgNCs emit at 530 nm when excited at 380 nm and can be used for Hg(2+) detection with a low detection limit and high selectivity.
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Influence of lipid components on gene delivery by polycation liposomes: Transfection efficiency, intracellular kinetics and in vivo tumor inhibition.
Int J Pharm
PUBLISHED: 09-13-2011
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Transfection efficiency of non-viral gene vectors is influenced by many factors, including chemical makeup, cellular uptake pathway and intracellular delivery. To investigate the effect of lipid saturation on transfection efficiency of polycation liposomes (PCLs), a soybean phospholipids (SPL), egg phospholipids (EPL) and hydrogenated soybean phosphatidylcholine (HSPC) series was used to prepare PCLs. Testing these PCLs in a luciferase assay indicated that with increasing saturation (SPL
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Cellular uptake and elimination of lipophilic drug delivered by nanocarriers.
Pharmazie
PUBLISHED: 11-26-2010
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To investigate the cellular uptake and elimination process of a lipophilic drug loaded in different nanocarriers, emulsions, liposomes and poly (DL-lactide-co-glycolide) (PLGA) nanoparticles loaded with a model drug, coumarin 6, were prepared and their transportation in HeLa cells compared. After 4 h incubation, liposomes and nanoparticles mediated significantly higher intracellular drug levels, which were 3 or 2.5 times that of the emulsion group, into cells. A novel kinetic model was established to analyze the cellular elimination process. Emulsions had the longest intracellular mean residence time (MRT), which was about 1-2 times longer than other nanocarriers. The endocytosis inhibition experiment suggested that the coumarin 6 in liposomes and nanoparticles entered cells directly via diffusion, while part of the intracellular coumarin 6 was taken up through clathrin-mediated endocytosis in emulsions. Combined with the results on uptake pathway and kinetic parameters, it can be concluded that different nanocarriers bring about diverse mechanisms of cellular uptake and elimination.
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Facile fabrication of narrowly-distributed polymeric micelles via host-guest inclusion complexation of hyperbranched polymers and cyclodextrin and its two-dimensional self-assembly.
Phys Chem Chem Phys
PUBLISHED: 08-16-2010
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A novel narrowly-distributed (ND) polymeric micelle obtained in combination with host-guest recognition and self-assembly is reported. First, the adamantyl-terminated hyperbranched poly[3-ethyl-3-(hydroxymethyl)oxetane] (HBPO-AD) was synthesized by esterification of hyperbranched poly[3-ethyl-3-(hydroxymethyl)oxetane] (HBPO) with 1-adamantanecarbonyl chloride. Then the ND polymeric core-shell micelles, with the hydrophobic HBPO-AD cores and hydrophilic beta-cyclodextrin (?-CD) shells, were prepared via host-guest inclusion complexation of HBPO-AD and ?-CD. The resultant polymer micelles were well characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Interestingly, after annealing at a temperature above the glass transition temperature (T(g)) for a certain time, the polymeric micelles can further self-assemble and fuse into two-dimensional (2D) sheets. The TEM, SEM and atomic force microscopy (AFM) characterization validate that the sheets are formed through stacking and fusion of tightly packed nanoparticles. In addition, the formation mechanism of polymeric complex micelles and 2D sheets has also been discussed.
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Comparison of clinical outcomes and anorectal manometry in patients with congenital anorectal malformations treated with posterior sagittal anorectoplasty and laparoscopically assisted anorectal pull through.
J. Pediatr. Surg.
PUBLISHED: 07-29-2009
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The objective of this study is to analyze the clinical outcomes and anorectal manometry (AM) in infants with congenital high anorectal malformations treated with posterior sagittal anorectoplasty (PSARP) and laparoscopically assisted anorectal pull through (LAARP).
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Enteral versus parenteral nutrition: effect on intestinal barrier function.
Ann. N. Y. Acad. Sci.
PUBLISHED: 06-23-2009
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Total parenteral nutrition (TPN), or the complete absence of enteral nutrients, is commonly used in a clinical setting. However, a major consequence of TPN administration is the development of mucosal atrophy and a loss of epithelial barrier function (EBF); and this loss may lead to an increase in clinical infections and septicemia. Our laboratory has investigated the mechanism of this TPN-associated loss of EBF using a mouse model. We have demonstrated that the mucosal lymphoid population significantly changes with TPN, and leads to a rise in interferon gamma (IFN-gamma) and decline in interleukin-10 (IL-10) expression-both of which contribute to the loss of EBF. Associated with these cytokine changes is a dramatic decline in the expression of tight junction and adherens junction proteins. This article discusses the potential mechanisms responsible for these changes, and potential strategies to alleviate this loss in EBF.
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Dissociation of E-cadherin and beta-catenin in a mouse model of total parenteral nutrition: a mechanism for the loss of epithelial cell proliferation and villus atrophy.
J. Physiol. (Lond.)
PUBLISHED: 05-07-2009
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Total parenteral nutrition (TPN) leads a loss of epithelial barrier function, decline in epithelial cell (EC) proliferation, and decreased expression of E-cadherin. As a large portion of intracellular beta-catenin is tightly associated with E-cadherin, we hypothesized that the loss of E-cadherin would result in a redistribution of intracellular beta-catenin, and could be a contributing mechanism for this TPN-associated loss of EC proliferation. An assessment of small bowel epithelium was performed in mice given either enteral nutrition (Control) or intravenous nutrition (TPN). TPN significantly down-regulated E-cadherin and beta-catenin expression, and resulted in a loss of a colocalization of these factors. TPN also up-regulated phosphorylated (p)-beta-catenin (Ser31/33,Thr41) and down-regulated (p)-beta-catenin(Ser552) expression. To further address mechanisms driving this, we observed a significant decrease in the abundance of p-AKT and p-GSK3beta expression, and an associated decline in tcf-4 transcription factors (cyclin D1, c-myc and Axin2), as well as a loss of EC proliferation by 7 days. To address whether the mechanism driving these changes was the absence of nutritional factors, glutamine was added to the TPN solution. This resulted in a partial restoration of beta-catenin expression and EC proliferation, suggesting that an alteration in nutrient delivery may affect many of these changes. Based on these findings, the loss of EC proliferation with TPN may well be due to a loss of total beta-catenin, as well as a concomitant change in the differential expression of beta-catenin phosphorylation sites, and a reduction in beta-catenin mediated tcf-4 transcription. This potential pathway may well explain many of the findings of mucosal atrophy associated with TPN.
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Fabrication of biopolymeric complex coacervation core micelles for efficient tea polyphenol delivery via a green process.
Langmuir
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Nanoencapsulation is a promising method to improve the bioavailability of tea polyphenol (TPP). In this work, we adopted a green process to develop a new kind of complex coacervation core micelles (C3Ms) based on biopolymers for efficient tea polyphenol delivery. First, gelatin-dextran conjugate was synthesized using Maillard reaction. Then the C3Ms were produced by mixing gelatin-dextran conjugate with TPP. Variable factors on the self-assembly of the C3Ms were investigated. Under optimal conditions, the obtained C3Ms are of nanosize (average 86 nm in diameter) with narrow distribution. The formation of the C3Ms is attributed to hydrophobic interaction and hydrogen bonding instead of electrostatic interaction. Transmission electron microscope (TEM) and scanning electron microscope (SEM) results showed that C3Ms have a spherical shape with core-shell structure. ?-Potential measurement suggested that the core is composed of gelatin with TPP, whereas the shell is composed of dextran segments. The encapsulation efficiency of the C3Ms is pH-independent, but the loading capacity is controllable and as high as 360 wt % (weight/weight of protein). In addition, the C3Ms show sustained release of TPP in vitro. MTT assay revealed that the C3Ms have comparable or even stronger cytotoxicity against MCF-7 cells than free TPP.
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Polyethylenimine modified liposomes as potential carriers for antitumor drug delivery in vitro.
Pharmazie
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The transfection agent polycation polyethylenimine (PEI) has been rarely used to construct liposomes for chemical antitumor drugs. In this study, it was introduced into cisplatin (CDDP) encapsulated neutral liposomes (CDDP-NL) by amphiphilic PEI-cholesterol (PEI-Chol) to investigate its effect on the antitumor activity in A549 cells. The IC50 was 0.65 +/- 0.02, 2.94 +/- 0.21 and 2.03 +/- 0.15 microg/ml for CDDP-cationic liposomes (CDDP-CL), CDDP-NL and free CDDP, respectively. The enhanced anticancer activity was attributed to the addition of PEI-Chol which influenced cellular processing of CDDP. With the help of inhibitors, we found that besides clathrin dependent and actin dependent uptake pathways, caveolae-mediated endocytosis was involved in the internalization of CDDP-CL. Improved internalization of CDDP was observed. Intracellular Pt accumulations were 6.5 times and 3 times of those in CDDP-NL and free CDDP groups, respectively. The differences of intracellular location caused by endocytosis routes and lysosomes escape capacity of PEL-Chol was observed by fluorescence colocalization studies. PEI-Chol also decreased the Pt fraction exported out of cells and extended the cellular Pt retention of CDDP liposomes. In conclusion, cationic modification of liposomes with PEI is a potential and promising way for antitumor drug delivery.
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A POSS-based supramolecular amphiphile and its hierarchical self-assembly behaviors.
Macromol Rapid Commun
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A polyhedral oligomeric silsesquioxane (POSS)-based supramolecular amphiphile is prepared from the host-guest inclusion complexation between a mono adamantane-functionalized POSS (AD-POSS) and a ?-cyclodextrin oligomer (P(?-CD)). Assisted by the interface of H(2)O/toluene, the obtained supramolecular hybrids self-assemble into stable hollow nanospheres with thick walls. These hollow nanospheres aggregate together into a sphere layer through a spin coating technique, which then further transforms into a thin porous film containing nanometer-scale holes. The hollow nanospheres have a low cytotoxicity. The in vitro cell culture indicates the nanoporous films promote adhesion and proliferation of cells. The self-assembly morphologies and structures have been carefully characterized by SEM, TEM, AFM, DLS, XPS and water-contact angle measurements, and the self-assembly mechanism has also been discussed.
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What is Visualize?

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

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

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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.