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Find video protocols related to scientific articles indexed in Pubmed.
Characterization and bacterial anti-adherent effect on modified PMMA denture acrylic resin containing platinum nanoparticles.
J Adv Prosthodont
PUBLISHED: 03-03-2014
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This study characterized the synthesis of a modified PMMA (Polymethyl methacrylate) denture acrylic loading platinum nanoparticles (PtN) and assessed its bacterial inhibitory efficacy to produce novel antimicrobial denture base material.
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Treatment of dental implant-related maxillary sinusitis with functional endoscopic sinus surgery in combination with an intra-oral approach.
J Korean Assoc Oral Maxillofac Surg
PUBLISHED: 02-28-2014
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The present report describes the case of a patient who underwent maxillary sinusitis right after dental implant installation with sinus lifting. Computed tomography scan revealed a dental implant (#16) was protruded inside the right maxillary sinus and confirmed the obstruction of ostium. A symptom remission was gained with the dual approaches combined by functional endoscopic sinus surgery and an intra-oral approach. Fully recovered function and healing of sinus were identified after 10 months follow-up. We report the case of sinusitis caused by protrusion of implants with sinus floor lift procedures and propose that practitioners should be aware of the possible its complications and management.
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Adenylyl cyclase-associated protein 1 is a receptor for human resistin and mediates inflammatory actions of human monocytes.
Cell Metab.
PUBLISHED: 01-03-2014
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Human resistin is a cytokine that induces low-grade inflammation by stimulating monocytes. Resistin-mediated chronic inflammation can lead to obesity, atherosclerosis, and other cardiometabolic diseases. Nevertheless, the receptor for human resistin has not been clarified. Here, we identified adenylyl cyclase-associated protein 1 (CAP1) as a functional receptor for human resistin and clarified its intracellular signaling pathway to modulate inflammatory action of monocytes. We found that human resistin directly binds to CAP1 in monocytes and upregulates cyclic AMP (cAMP) concentration, protein kinase A (PKA) activity, and NF-?B-related transcription of inflammatory cytokines. Overexpression of CAP1 in monocytes enhanced the resistin-induced increased activity of the cAMP-dependent signaling. Moreover, CAP1-overexpressed monocytes aggravated adipose tissue inflammation in transgenic mice that express human resistin from their monocytes. In contrast, suppression of CAP1 expression abrogated the resistin-mediated inflammatory activity both in vitro and in vivo. Therefore, CAP1 is the bona fide receptor for resistin leading to inflammation in humans.
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Design and synthesis of a cell-permeable, drug-like small molecule inhibitor targeting the polo-box domain of polo-like kinase 1.
PLoS ONE
PUBLISHED: 01-01-2014
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Polo-like kinase-1 (Plk1) plays a crucial role in cell proliferation and the inhibition of Plk1 has been considered as a potential target for specific inhibitory drugs in anti-cancer therapy. Several research groups have identified peptide-based inhibitors that target the polo-box domain (PBD) of Plk1 and bind to the protein with high affinity in in vitro assays. However, inadequate proteolytic resistance and cell permeability of the peptides hinder the development of these peptide-based inhibitors into novel therapeutic compounds.
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Structures of the Bacillus subtilis Glutamine Synthetase Dodecamer Reveal Large Intersubunit Catalytic Conformational Changes Linked to a Unique Feedback Inhibition Mechanism.
J. Biol. Chem.
PUBLISHED: 10-24-2013
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Glutamine synthetase (GS), which catalyzes the production of glutamine, plays essential roles in nitrogen metabolism. There are two main bacterial GS isoenzymes, GSI-? and GSI-?. GSI-? enzymes, which have not been structurally characterized, are uniquely feedback-inhibited by Gln. To gain insight into GSI-? function, we performed biochemical and cellular studies and obtained structures for all GSI-? catalytic and regulatory states. GSI-? forms a massive 600-kDa dodecameric machine. Unlike other characterized GS, the Bacillus subtilis enzyme undergoes dramatic intersubunit conformational alterations during formation of the transition state. Remarkably, these changes are required for active site construction. Feedback inhibition arises from a hydrogen bond network between Gln, the catalytic glutamate, and the GSI-?-specific residue, Arg(62), from an adjacent subunit. Notably, Arg(62) must be ejected for proper active site reorganization. Consistent with these findings, an R62A mutation abrogates Gln feedback inhibition but does not affect catalysis. Thus, these data reveal a heretofore unseen restructuring of an enzyme active site that is coupled with an isoenzyme-specific regulatory mechanism. This GSI-?-specific regulatory network could be exploited for inhibitor design against Gram-positive pathogens.
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A case of acute retinal toxicity caused by an intraocular foreign body composed of cobalt alloy.
Cutan Ocul Toxicol
PUBLISHED: 07-05-2013
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Abstract Context: We describe a case of acute retinal toxicity caused by an intraocular foreign body composed of a cobalt alloy. Case presentation: A 36-year-old man presented to an outside clinic with a traumatic cataract and corneal laceration of his left eye, which had occurred while grinding a shelf. The lacerated cornea was closed primarily and the traumatic cataract was phacoemulsified. He was transferred to our hospital due to identification of a metallic intraocular foreign body in the vitreous. On arrival at our institution, the intraocular foreign body was removed as soon as possible after vitrectomy. On the first postoperative day, vasculitis and serous retinal detachment were observed on the retina at the previous site of the foreign body. Two months after surgery, atrophy of nearly half of the inferior retina was noted on funduscopy, and visual acuity was such that the patient could only count fingers at 30?cm. Analysis of the foreign body revealed that it was composed of 84.99% tungsten carbide, 15% cobalt and had traces of titanium and alumina. Discussion: Cobalt containing metallic foreign bodies should be immediately removed, as they have the potential to cause permanent visual disturbance.
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Therapeutic effect of whole body vibration on chronic knee osteoarthritis.
Ann Rehabil Med
PUBLISHED: 06-10-2013
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To investigate the effect on pain reduction and strengthening of the whole body vibration (WBV) in chronic knee osteoarthritis (OA).
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The effect of intravitreal bevacizumab injection before Ahmed valve implantation in patients with neovascular glaucoma.
Int Ophthalmol
PUBLISHED: 05-30-2013
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To evaluate the effect of intravitreal bevacizumab (IVB) before Ahmed valve implantation for treatment of neovascular glaucoma (NVG). This study is a retrospective, comparative, consecutive case series. The study group consisted of 27 eyes of 26 patients with NVG who underwent an Ahmed valve implantation. Thirteen eyes were treated with Ahmed valve implantation alone (control group), and 14 eyes were treated with a combination of preoperative IVB injection and Ahmed valve implantation (IVB group). Visual acuity, intraocular pressure (IOP), number of anti-glaucoma medications, surgical complications, and success rate were compared between the two groups. There were no significant differences in preoperative characteristics between the two groups. Visual acuity at 1, 2 weeks, and 1 month after surgery were significantly better in the IVB group (p = 0.038, 0.034, and 0.032, respectively). Hyphema associated with Ahmed valve implantation occurred significantly less in the IVB group (p = 0.016). On the other hand, the mean IOP and number of anti-glaucoma medications at all follow-up periods were similar between the two groups. Kaplan-Meier survival analysis showed the probability of success 6 months after surgery as 71.4 % in the IVB group and 84.6 % in the control group. No significant difference in success rate was found between the groups (p = 0.422). IVB before Ahmed valve implantation for treatment of NVG reduced the incidence of hyphema. In this retrospective study, IVB provided better visual outcome in the early postoperative periods but did not significantly improve mean IOP, number of anti-glaucoma medications, or success rate.
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Protective effect of ginsenoside-Rb2 from Korean red ginseng on the lethal infection of haemagglutinating virus of Japan in mice.
J Ginseng Res
PUBLISHED: 05-30-2013
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Korean red ginseng has been shown to possess a variety of biological activities. However, little is known about antiviral activity of ginsenosides of Korean red ginseng. Here, we investigated the protective effect by oral administration of various ginsenosides on the lethal infection of haemagglutinating virus of Japan (HVJ) in mice. In a lethal infection model in which almost all mice infected with HVJ died within 15 days, the mice were administered orally (per os) with 1 mg/mouse of dammarane-type (ginsenoside-Rb1, -Rb2, -Rd, -Re, and -Rg2) or oleanolic acid-type (ginsenoside-Ro) ginsenosides 3, 2, and 1 d before virus infection. Ginsenoside-Rb2 showed the highest protective activity, although other dammarane-type and oleanolic acid-type ginsenosides also induced a significant protection against HVJ. However, neither the consecutive administration with a lower dosage (300 ?g/mouse) nor the single administration of ginsenoside-Rb2 (1 mg/mouse) was active. In comparison of the protective activity between ginsenoside-Rb2 and its two hydrolytic products [20(S)- and 20(R)-ginsenoside-Rg3], 20(S)-ginsenoside-Rg3, but not 20(R)-ginsenoside-Rg3, elicited a partial protection against HVJ. The protective effect of ginsenoside-Rb2 and 20(S)-ginsenoside-Rg3 on HVJ infection was confirmed by the reduction of virus titers in the lungs of HVJ-infected mice. These results suggest that ginsenoside-Rb2 is the most effective among ginsenosides from red ginseng to prevent the lethal infection of HVJ, so that this ginsenoside is a promising candidate as a mucosal immunoadjuvant to enhance antiviral activity.
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Emergence of Enterococcus species in the infectious microorganisms cultured from patients with endophthalmitis in South Korea.
Infection
PUBLISHED: 04-24-2013
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To investigate the microorganisms in culture-proven endophthalmitis and their susceptibilities to antimicrobial agents commonly used in South Korea.
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Hesperidin Suppresses Melanosome Transport by Blocking the Interaction of Rab27A-Melanophilin.
Biomol Ther (Seoul)
PUBLISHED: 04-17-2013
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We investigated the inhibitory effects of hesperidin on melanogenesis. To find melanosome transport inhibitor from natural products, we collected the structural information of natural products from Korea Food and Drug Administration (KFDA) and performed pharmacophore-based in silico screening for Rab27A and melanophilin (MLPH). Hesperidin did not inhibit melanin production in B16F10 murine melanoma cells stimulated with ?-melanocyte stimulating hormone (?-MSH), and also did not affect the catalytic activity of tyrosinase. But, hesperidin inhibited melanosome transport in melanocyte and showed skin lightening effect in pigmented reconstructed epidermis model. Therefore, we suggest that hesperidin is a useful inhibitor of melanosome transport and it might be applied to whitening agent.
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Identification of Novel Rab27a/Melanophilin Blockers by Pharmacophore-Based Virtual Screening.
Appl. Biochem. Biotechnol.
PUBLISHED: 03-19-2013
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Melanocytes are unique cells that produce specific melanin-containing intracellular organelles called melanosomes. Melanosomes are transported from the perinuclear area of melanocytes toward the plasma membrane as they become more melanized in order to increase skin pigmentation. In this vesicular trafficking of melanosomes, Rab27a, melanophilin, and myosin Va play crucial roles in linking melanosomes to actin-based motors. To identify novel compounds to inhibit binding interface between Rab27a and melanophilin, a pharmacophore model was built based on a modeled 3D structure of the protein complex that describes the essential binding residues in the intermolecular interaction. A pharmacophore model was employed to screen a chemical library database. Finally, 25 virtual hits were selected for biological evaluations. The biological activities of 11 analogues were evaluated in a second assay. Two compounds were identified as having concentration-dependent inhibitory activity. By analyzing structure-activity relationships of derivatives of BMD-20, two hydroxyl functional groups were found to be critical for blocking the intermolecular binding between Rab27a and melanophilin.
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p34 is a novel regulator of the oncogenic behavior of NEDD4-1 and PTEN.
Cell Death Differ.
PUBLISHED: 03-05-2013
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PTEN is one of the most frequently mutated or deleted tumor suppressors in human cancers. NEDD4-1 was recently identified as the E3 ubiquitin ligase for PTEN; however, a number of important questions remain regarding the role of ubiquitination in regulating PTEN function and the mechanisms by which PTEN ubiquitination is regulated. In the present study, we demonstrated that p34, which was identified as a binding partner of NEDD4-1, controls PTEN ubiquitination by regulating NEDD4-1 protein stability. p34 interacts with the WW1 domain of NEDD4-1, an interaction that enhances NEDD4-1 stability. Expression of p34 promotes PTEN poly-ubiquitination, leading to PTEN protein degradation, whereas p34 knockdown results in PTEN mono-ubiquitination. Notably, an inverse correlation between PTEN and p34/NEDD4-1 levels was confirmed in tumor samples from colon cancer patients. Thus, p34 acts as a key regulator of the oncogenic behavior of NEDD4-1 and PTEN.
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Recombinant expression of soluble murine prion protein for C-terminal modification.
FEBS Lett.
PUBLISHED: 01-18-2013
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Membrane attachment of prion protein (PrP) via its glycosylphosphatidylinositol (GPI) anchor plays a key role during conversion of cellular PrP(C) into its pathogenic isoform PrP(Sc). Strategies to access homogenous lipidated PrP via expressed protein ligation (EPL) are required to fully decipher the effect of membrane attachment. Such strategies suffer from insoluble expression of PrP-intein fusion constructs and low folding efficiencies that severely limit the available amount of homogeneous lipidated PrP. Here, we describe an alternative method for expression of soluble PrP-intein fusion proteins in Escherichia coli that provides access to natively folded PrP ready to use in EPL.
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Development of cyclic peptomer inhibitors targeting the polo-box domain of polo-like kinase 1.
Bioorg. Med. Chem.
PUBLISHED: 01-11-2013
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The polo-box domain (PBD) of polo-like kinase 1 (Plk1) is essentially required for the function of Plk1 in cell proliferation. The availability of the phosphopeptide-binding pocket on PBD provides a unique opportunity to develop novel protein-protein interaction inhibitors. Recent identification of a minimal 5-residue-long phosphopeptide, PLHSpT, as a Plk1 PBD-specific ligand has led to the development of several peptide-based inhibitors, but none of them is cyclic peptide. Through the combination of single-peptoid mimics and thio-ether bridged cyclization, we successfully demonstrated for the first time two cyclic peptomers, PL-116 and PL-120, dramatically improved the binding affinity without losing mono-specificity against Plk1 PBD in comparison with the linear parental peptide, PLHSpT. These cyclic peptomers could serve as promising templates for future drug designs to inhibit Plk1 PBD.
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De novo design and synthesis of ultra-short peptidomimetic antibiotics having dual antimicrobial and anti-inflammatory activities.
PLoS ONE
PUBLISHED: 01-01-2013
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Much attention has been focused on the design and synthesis of potent, cationic antimicrobial peptides (AMPs) that possess both antimicrobial and anti-inflammatory activities. However, their development into therapeutic agents has been limited mainly due to their large size (12 to 50 residues in length) and poor protease stability.
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Arthroscopic management of stiff elbow.
Orthopedics
PUBLISHED: 06-15-2011
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Elbow stiffness is a common problem encountered by orthopedic surgeons. Various management options have been described in the literature, including conservative measures and open and arthroscopic surgery. Arthroscopic management of stiff elbow remains controversial. The purpose of this study was to evaluate the functional results of arthroscopic management of stiff elbow.Thirty patients with stiff elbow underwent arthroscopic release surgery and were followed up for an average of 27.3 months. Surgery included anterior and posterior capsular release, coronoid process debridement, bony spur excision, and loose body removal. Postoperative outcome was assessed using the Mayo Elbow Performance Score and range of motion at the elbow. Mayo Elbow Performance Score increased from a mean 64.5 preoperatively to a mean 83.17 postoperatively. Range of motion also improved, from a mean preoperative extension and flexion of 22.83° and 96.83°, respectively, vs a mean 10.83° and 120.84°, respectively, at final follow-up. No intra- or postoperative complication was seen in any case. Underlying etiology and timing of surgery influenced the end result, with better results seen in patients with traumatic etiology and those with a shorter duration of symptoms.Arthroscopic release allows good visualization and rectification of intra-articular pathology and is a safe and effective tool for the management of stiff elbow.
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Caspase-3 cleavage links delta-catenin to the novel nuclear protein ZIFCAT.
J. Biol. Chem.
PUBLISHED: 05-11-2011
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?-Catenin is an Armadillo protein of the p120-catenin subfamily capable of modulating cadherin stability, small GTPase activity, and nuclear transcription. From yeast two-hybrid screening of a human embryonic stem cell cDNA library, we identified ?-catenin as a potential interacting partner of the caspase-3 protease, which plays essential roles in apoptotic as well as non-apoptotic processes. Interaction of ?-catenin with caspase-3 was confirmed using cleavage assays conducted in vitro, in Xenopus apoptotic extracts, and in cell line chemically induced contexts. The cleavage site, a highly conserved caspase consensus motif (DELD) within Armadillo repeat 6 of ?-catenin, was identified through peptide sequencing. Cleavage thus generates an amino-terminal (residues 1-816) and carboxyl-terminal (residues 817-1314) fragment, each containing about half of the central Armadillo domain. We found that cleavage of ?-catenin both abolishes its association with cadherins and impairs its ability to modulate small GTPases. Interestingly, 817-1314 possesses a conserved putative nuclear localization signal that may facilitate the nuclear targeting of ?-catenin in defined contexts. To probe for novel nuclear roles of ?-catenin, we performed yeast two-hybrid screening of a mouse brain cDNA library, resolving and then validating interaction with an uncharacterized KRAB family zinc finger protein, ZIFCAT. Our results indicate that ZIFCAT is nuclear and suggest that it may associate with DNA as a transcriptional repressor. We further determined that other p120 subfamily catenins are similarly cleaved by caspase-3 and likewise bind ZIFCAT. Our findings potentially reveal a simple yet novel signaling pathway based upon caspase-3 cleavage of p120-catenin subfamily members, facilitating the coordinate modulation of cadherins, small GTPases, and nuclear functions.
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Effect of prophylactic topical brimonidine (0.15%) administration on the development of subconjunctival hemorrhage after intravitreal injection.
Retina (Philadelphia, Pa.)
PUBLISHED: 03-26-2011
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Brimonidine (0.15%), which is used to lower intraocular pressure, is an ?-2-adrenergic agonist that has vasoconstrictive effects. This study examined whether the administration of brimonidine (0.15%) before intravitreal injection prevents subconjunctival hemorrhage.
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Anti-cancer properties of glucosamine-hydrochloride in YD-8 human oral cancer cells: Induction of the caspase-dependent apoptosis and down-regulation of HIF-1?.
Toxicol In Vitro
PUBLISHED: 02-23-2011
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Evidence suggests anti-tumor activities of glucosamine-hydrochloride (GS-HCl). In the present study, we investigated anti-proliferative, growth suppressive and/or pro-apoptotic effects of GS-HCl on YD-8 human oral squamous cell carcinoma (OSCC) cells. Fundamentally, treatment with GS-HCl strongly inhibited proliferation and induced apoptosis in YD-8 cells, as determined by MTS and DNA fragmentation analyses. Of further note, as measured by Western analyses, GS-HCl treatment led to activation of caspase-3, cytosolic accumulation of cytochrome c, down-regulation of Mcl-1 and HIF-1?, up-regulation of GRP78, an indicator of ER stress, and generation of ROS in YD-8 cells. Importantly, results of pharmacological inhibition studies showed that treatment with z-VAD-fmk, a pan-caspase inhibitor, but not with vitamin E, an anti-oxidant strongly blocked the GS-HCl-induced apoptosis in YD-8 cells. Analyses of additional cell culture works further revealed that GS-HCl had a strong growth suppressive effect on not only YD-8 but also YD-10B and YD-38, two other human OSCC cell lines. These findings collectively demonstrate that GS-HCl has anti-proliferative, anti-survival, and pro-apoptotic effects on YD-8 cells and the effects appear to be mediated via mechanisms associated with the mitochondrial-dependent activation of caspases, down-regulation of Mcl-1, and induction of ER stress. Considering HIF-1? as a tumor angiogenic transcription factor, the ability of GS-HCl to down-regulate HIF-1? in YD-8 cells may further support its anti-cancer property. It is thus suggested that GS-HCl may be used as a potential anti-cancer drug against human OSCC.
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In vitro antimicrobial effect of the tissue conditioner containing silver nanoparticles.
J Adv Prosthodont
PUBLISHED: 01-27-2011
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The aim of this study was to identify in vitro antimicrobial activity of the tissue conditioner containing silver nanoparticles on microbial strains, Staphylococcus aureus, Streptococcus mutans and Candida albicans.
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Protein immobilization on liposomes and lipid-coated nanoparticles by protein trans-splicing.
J. Pept. Sci.
PUBLISHED: 09-24-2010
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A plethora of methods exist to link proteins to surfaces in order to generate functionalized materials. However, general tools that lead to functional immobilization of recombinantly expressed proteins on membranes such as liposomes or lipid-coated nanoparticles are rare. Here we present an approach that takes advantage of a double-palmitoylated peptide that mediates stable membrane anchoring in combination with protein trans-splicing for efficient immobilization of recombinant proteins fused to split intein segments. Two different DnaE split inteins from Synechocystis and Nostoc punctiforme are tested and compared to immobilization via direct native chemical ligation using a protein thioester. Protein trans-splicing proceeds at low protein concentrations and leads to functionalized vesicles and membrane-coated silica nanoparticles.
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Molecular mechanism by which the nucleoid occlusion factor, SlmA, keeps cytokinesis in check.
EMBO J.
PUBLISHED: 08-12-2010
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In Escherichia coli, cytokinesis is orchestrated by FtsZ, which forms a Z-ring to drive septation. Spatial and temporal control of Z-ring formation is achieved by the Min and nucleoid occlusion (NO) systems. Unlike the well-studied Min system, less is known about the anti-DNA guillotining NO process. Here, we describe studies addressing the molecular mechanism of SlmA (synthetic lethal with a defective Min system)-mediated NO. SlmA contains a TetR-like DNA-binding fold, and chromatin immunoprecipitation analyses show that SlmA-binding sites are dispersed on the chromosome except the Ter region, which segregates immediately before septation. SlmA binds DNA and FtsZ simultaneously, and the SlmA-FtsZ structure reveals that two FtsZ molecules sandwich a SlmA dimer. In this complex, FtsZ can still bind GTP and form protofilaments, but the separated protofilaments are forced into an anti-parallel arrangement. This suggests that SlmA may alter FtsZ polymer assembly. Indeed, electron microscopy data, showing that SlmA-DNA disrupts the formation of normal FtsZ polymers and induces distinct spiral structures, supports this. Thus, the combined data reveal how SlmA derails Z-ring formation at the correct place and time to effect NO.
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Mutually opposite effects of dopamine.HCl and chlorpromazine. HCl on the thickness of liposomal lipid bilayers.
Arch. Pharm. Res.
PUBLISHED: 03-02-2010
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The aim of this study was to provide a basis for examining the molecular mechanism for the pharmacological action of dopamine.HCl (DA) and chlorpromazin.HCl (CPZ). Radiationless energy transfer from the surface fluorescent probe, 1-anilinonaphthalene-8-sulfonic acid, to the hydrophobic fluorescent probe, bispyrenylpropane (Py-Py), was used to examine the effects of DA and CPZ on the thickness (D) of the liposomal lipid bilayers prepared with total lipids (SPMVTL) and phospholipids (SPMVPL) extracted from neuronal membranes. The thickness (D) of intact SPMVTL and SPMVPL (37 degrees C, pH 7.4) were 0.914 +/- 0.010 and 0.886 +/- 0.009 (arbitrary units, n = 5), respectively. DA decreased the thickness of both SPMVTL and SPMVPL in a dose-dependent manner with a significant decrease in thickness observed even at 40 x 10(-9) M and 40 x 10(-9) M, respectively. On the other hand, CPZ increased the thickness of both SPMVTL and SPMVPL in a dose-dependent manner with a significant increase in thickness observed even at 35 x 10(-5) M and 35 x 10(-5) M, respectively. The sensitivities to the decreasing and increasing effect of the membrane lipid bilayers thickness by DA and CPZ, respectively, differed according to the liposomes in descending order of SPMVPL and SPMVTL. The decreasing and increasing action of DA and CPZ, respectively, on the membrane thickness had many effects that may be responsible for the dopaminergic receptor-DA and -CPZ interaction as well as the protein-lipid interaction.
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Aspirin induces apoptosis in YD-8 human oral squamous carcinoma cells through activation of caspases, down-regulation of Mcl-1, and inactivation of ERK-1/2 and AKT.
Toxicol In Vitro
PUBLISHED: 01-25-2010
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NSAIDs and COX-2 inhibitors show anti-cancer activities in many cancer cells. In this study, we investigated the effects of NSAIDs (aspirin or indomethacin) and COX-2 inhibitor (NS-398) on growth of YD-8 human oral squamous carcinoma cells. Interestingly, among drugs tested, aspirin showed strongest inhibitory effects on viability and survival of YD-8 cells. Profoundly, aspirin treatment resulted in severe cell shrinkage and nuclear DNA fragmentation in YD-8 cells, suggesting the aspirin-induced apoptosis in YD-8 cells. Data of Western blot further demonstrated that aspirin treatment caused activation of caspases, down-regulation of Mcl-1 protein, dephosphorylation of ERK-1/2 and AKT, and also IkappaB-alpha proteolysis-dependent NF-kappaB activation in YD-8 cells. Aspirin, however, had no effect on expressions of Bcl-2, XIAP, and HIAP-1 in YD-8 cells. Importantly, pretreatment with z-VAD-fmk, a pan-caspase inhibitor blocked the aspirin-induced apoptosis and Mcl-1 down-regulation in YD-8 cells. These findings collectively suggest that aspirin induces apoptosis in YD-8 cells and the induction may be correlated to activation of caspases, caspase-dependent Mcl-1 proteolysis, inactivation of ERK-1/2 and AKT, and activation of NF-kappaB. It is suggested that aspirin may be applied a potential anti-cancer drug against human oral squamous carcinoma.
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Manganese-mediated up-regulation of HIF-1alpha protein in Hep2 human laryngeal epithelial cells via activation of the family of MAPKs.
Toxicol In Vitro
PUBLISHED: 01-05-2010
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High exposure of manganese is believed to be a risk factor for respiratory diseases. Evidence suggests that overexpression of HIF-1alpha transcription factor is linked to pulmonary inflammation and vascular change. In this study, we investigated the effect of manganese-chloride (manganese) on expression and activity of HIF-1alpha in various human airway cells, including Hep2 (laryngeal), H292 (bronchial), and A549 (lung). Profoundly, while manganese treatment led to low or little effect on induction of HIF-1alpha protein in H292 or A549 cells, it strongly induced HIF-1alpha protein expression in Hep2 cells. Mn treatment, however, did not induce HIF-1alpha mRNA expression in Hep2 cells. Luciferase experiments further demonstrated that manganese treatment increased the HRE-driven luciferase activity, suggesting that the induced HIF-1 is functional. Interestingly, manganese treatment also caused activation of p38 MAPK, JNK-1/2, ERK-1/2, and ATF-2, but not of PKB or NF-kappaB in Hep2 cells. Importantly, the manganese-mediated expression and activity of HIF-1alpha protein were largely blocked by treatment with the inhibitor of p38 MAPK (SB203580), JNK-1/2 (SP600125), or ERK-1/2 (PD98059), suggesting roles of these MAPKs in the manganese-induced HIF-1alpha protein expression and activity. Moreover, treatment with SP600125 or SB203580, but not PD98059, had partial inhibitory effects on the stability of HIF-1alpha protein induced by manganese, suggesting that p38 MAPK and JNK-1/2 also contribute to the Mn-mediated HIF-1alpha protein stability. These results suggest that manganese is able to up-regulate HIF-1alpha at the protein level in Hep2 cells and the up-regulation is largely dependent of activities of the family of MAPKs.
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The Staphylococcus aureus pSK41 plasmid-encoded ArtA protein is a master regulator of plasmid transmission genes and contains a RHH motif used in alternate DNA-binding modes.
Nucleic Acids Res.
PUBLISHED: 09-16-2009
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Plasmids harbored by Staphylococcus aureus are a major contributor to the spread of bacterial multi-drug resistance. Plasmid conjugation and partition are critical to the dissemination and inheritance of such plasmids. Here, we demonstrate that the ArtA protein encoded by the S. aureus multi-resistance plasmid pSK41 is a global transcriptional regulator of pSK41 genes, including those involved in conjugation and segregation. ArtA shows no sequence homology to any structurally characterized DNA-binding protein. To elucidate the mechanism by which it specifically recognizes its DNA site, we obtained the structure of ArtA bound to its cognate operator, ACATGACATG. The structure reveals that ArtA is representative of a new family of ribbon-helix-helix (RHH) DNA-binding proteins that contain extended, N-terminal basic motifs. Strikingly, unlike most well-studied RHH proteins ArtA binds its cognate operators as a dimer. However, we demonstrate that it is also able to recognize an atypical operator site by binding as a dimer-of-dimers and the extended N-terminal regions of ArtA were shown to be essential for this dimer-of-dimer binding mode. Thus, these data indicate that ArtA is a master regulator of genes critical for both horizontal and vertical transmission of pSK41 and that it can recognize DNA utilizing alternate binding modes.
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Semisynthesis of membrane-attached prion proteins.
Meth. Enzymol.
PUBLISHED: 07-28-2009
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Conversion of cellular prion protein (PrP(C)) into the pathological conformer (PrP(Sc)) is the hallmark of prion diseases and has been studied extensively by using recombinantly expressed PrP (rPrP). Because of the inherent difficulties of expressing and purifying posttranslationally modified rPrP variants only a limited amount of data is available for membrane-associated PrP and its behavior in vitro and in vivo. Protein semisynthesis provides two alternative routes to access multimilligram amounts of membrane-attached rPrP, which are described in detail here. In both cases, rPrP fused to a C-terminal extension comprising either the Mycobacterium xenopi GyrA mini-intein or the Synechocystis sp. DnaE N-terminal split intein is expressed in E. coli. Protein purification was followed by reaction with chemically synthesized palmitoylated membrane anchor peptides to yield rPrP(Palm) or with a chemically synthesized glycosylphosphatidylinositol (GPI) anchor to give rPrP(GPI). Solubility problems encountered with synthetic membrane anchors were overcome by either incorporating a polyethylene glycol-based C-terminal tag (removable by specific proteolysis) or by direct incorporation into liposomes. The new rPrP(Palm) variants studied by a variety of in vitro methods exhibited a high affinity to liposomes and an increased lag phase during aggregation when compared to rPrP. Similar results were obtained for rPrP(GPI), in which only one alkyl chain is sufficient for quantitative membrane attachment. In vivo studies demonstrated that double lipidated rPrP(Palm) is efficiently taken up into the membranes of mouse neuronal and human epithelial kidney cells.
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Defect study on polyaniline by positron annihilation spectrometry.
Appl Radiat Isot
PUBLISHED: 02-26-2009
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Fast coincidence system was constructed and applied to positron annihilation spectrometry (PAS). We studied on the factors that affected the time resolution of the system. Time resolutions were obtained and mutually compared with respect to several factors such as sizes, kinds of scintillators, length dependence of delay lines on the CFD583, and width variations of the windows for 511keV and 1.27MeV. Monoenergetic positron acceleration system was used to measure the lifetime components for the polyaniline, which have variable electric conductivity. We obtained 360-380ps as bulk lifetime for polyaniline, which intended to show that the higher the conductivity, the longer the bulk lifetime. The reasons were discussed in the context of the protonate H(+). The defect in the sample was discussed in the relation of positron lifetime corresponding to the variation of conductivity.
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Differential down-regulation of COX-2 and MMP-13 in human skin fibroblasts by glucosamine-hydrochloride.
J. Dermatol. Sci.
PUBLISHED: 01-14-2009
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Evidence suggests anti-inflammatory effects of glucosamine (GS) on inflammatory diseases. COX-2 is an enzyme to produce prostaglandins. MMPs are the family of matrix metalloproteinases degradable of ECM. Excess expression of COX-2 or MMPs involves in skin inflammation.
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Synthesis of C-4-modified zanamivir analogs as neuraminidase inhibitors and their anti-AIV activities.
Eur J Med Chem
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With the introduction of bioisosteres of the guanidinium group together with scaffold hopping, 35 zanamivir analogs with C-4-modification were synthesized, and their inhibitory activities against both group-1 and group-2 neuraminidase (H5N1 and H3N2) were determined. Compound D26 exerts the most potency, with IC(50) values of 0.58 and 2.72 ?M against N2 and N1, respectively. Further preliminary anti-avian influenza virus (AIV, H5N1) activities against infected MDCK cells were evaluated, and D5 exerts ?58% protective against AIV infection, which was comparable to zanamivir (?67%). In a rat pharmacokinetic study, compound D5 showed an increased plasma half-life (t(1/2)) compared to zanamivir following either intravenous or oral administration. This study may represent a new start point for the future development of improved anti-AIV agents.
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Antifungal and physical characteristics of modified denture base acrylic incorporated with silver nanoparticles.
Gerodontology
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This study evaluated the antifungal and physical characteristics of denture base acrylic combined with silver nanoparticles.
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Identification of chalcones as potent and selective PDE5A1 inhibitors.
Bioorg. Med. Chem. Lett.
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Chalcones have an affinity for many receptors, enzymes, and transcription factors as flavonoid analogues. Their most studied pharmacological action is that of vasodilatation due to inhibition of phosphodiesterase 5A1 (PDE5A1). To this end, we have established a recursive partitioning model with 3 chemical descriptors for the prediction of compounds that can inhibit PDE5A1. This model was able to predict active compounds with an accuracy of 82.8%. Compound 4 was found to be a potent and selective inhibitor, with a relatively low IC(50) value. The binding mechanism of this compound was also investigated through molecular docking studies.
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Ligand aligning method for molecular docking: alignment of property-weighted vectors.
J Chem Inf Model
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To reduce searching effort in conformational space of ligand docking positions, we propose an algorithm that generates initial binding positions of the ligand in a target protein, based on the property-weighted vector (P-weiV), the three-dimensional orthogonal vector determined by the molecular property of hydration-free energy density. The alignment of individual P-weiVs calculated separately for the ligand and the protein gives the initial orientation of a given ligand conformation relative to an active site; these initial orientations are then ranked by simple energy functions, including solvation. Because we are using three-dimensional orthogonal vectors to be aligned, only four orientations of ligand positions are possible for each ligand conformation, which reduces the search space dramatically. We found that the performance of P-weiV compared favorably to the use of principle moment of inertia (PMI) as implemented in LigandFit when we tested the abilities of the two approaches to correctly predict 205 protein-ligand complex data sets from the PDBBind database. P-weiV correctly predicted the alignment of ligands (within rmsd of 2.5 Å) with 57.6% reliability (118/205) for the top 10 ranked conformations and with 74.1% reliability (152/205) for the top 50 ranked conformations of Catalyst-generated conformers, as compared to 22.9% (47/205) and 31.2% (64/205), respectively, in the case of PMI with the same conformer set.
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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.

How does it work?

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

Video X seems to be unrelated to Abstract Y...

In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.