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Find video protocols related to scientific articles indexed in Pubmed.
Impaired B Cell Inhibition by Lupus Bone Marrow Mesenchymal Stem Cells Is Caused by Reduced CCL2 Expression.
J. Immunol.
PUBLISHED: 10-22-2014
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Mesenchymal stem cells (MSC) from healthy human and normal mice can inhibit normal B cell proliferation, differentiation, and Ab secretion in vitro. However, it remains unknown whether MSC from lupus-like mice and patients with systemic lupus erythematosus (SLE) exhibit the same immunoregulatory activity as normal MSC for B cell inhibition and, if not, what the underlying molecular mechanism would be. In this study, we showed that bone marrow-derived MSCs from lupus-like mice and SLE patients had an impairment in suppressing normal B cell proliferation and differentiation, which was caused by the reduction of CCL2 levels. Knockdown of CCL2 in normal MSC damaged their suppressive capacity for B cells. Conversely, overexpression of CCL2 in lupus MSCs restored their immunoregulatory ability for B cells in vitro and ameliorated the pathology of lupus nephritis and serological changes in MRL/lpr mice in vivo. Mechanistically, MSC-mediated B cell inhibition was dependent on matrix metalloproteinase proteolytic processing of CCL2. These findings reveal a novel function of CCL2 in B cell regulation by MSCs and suggest that CCL2 manipulation on MSCs may serve as a potential pathway for developing the more effective MSC-based therapy in autoimmune diseases associated with B cell activation, such as SLE.
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Multicolored-Fluorescence Switching of ICT-Type Organic Solids with Clear Color Difference: Mechanically Controlled Excited State.
Chemistry
PUBLISHED: 09-23-2014
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A donor-acceptor-type fluorophore containing a twisted diphenylacrylonitrile and triphenylamine has been developed by using the Suzuki reaction. The system indicates typical intramolecular charge-transfer properties. Upon mechanical grinding or hydrostatic pressure, the fluorophore reveals a multicolored fluorescence switching. Interestingly, a fluorescence color transition from green to red was clearly observed, and the change of photoluminescent (PL) wavelength gets close to 111?nm. The mechanisms of high-contrast mechanochromic behavior are fully investigated by techniques including powder XRD, PL lifetime, high-pressure PL lifetime, and Raman spectra analysis. The tremendous PL wavelength shift is attributed to gradual transition of excited states from the local excited state to the charge-transfer state.
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Induction of Nur77-dependent apoptotic pathway by a coumarin derivative through activation of JNK and p38 MAPK.
Carcinogenesis
PUBLISHED: 09-03-2014
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Coumarins are plant-derived natural products with a broad range of known pharmacological activities including anticancer effects. However, the molecular mechanisms by which this class of promising compounds exerts their anticancer effects remain largely unknown. We report here that a furanocoumarin named apaensin could effectively induce apoptosis of cancer cells through its activation of Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). Apoptosis induction by apaensin in cancer cells was suppressed by chemical inhibitors of JNK and p38 MAPK. Inhibition of the expression of orphan nuclear receptor Nur77 by small interfering RNA (siRNA) approach also abrogated the death effect of apaensin. Molecular analysis demonstrated that JNK activation was required for the nuclear export of Nur77, a known apoptotic event in cancer cells. Although p38 MAPK activation was not involved in Nur77 nuclear export, it was essential for Nur77 mitochondrial targeting through induction of Nur77 interaction with Bcl-2, which is also known to convert Bcl-2 from an antiapoptotic to a proapoptotic molecule. Together, our results identify a new natural product that targets orphan nuclear receptor Nur77 through its unique activation of JNK and p38 MAPK and provide insight into the complex regulation of the Nur77-Bcl-2 apoptotic pathway.
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A functional biphasic biomaterial homing mesenchymal stem cells for in vivo cartilage regeneration.
Biomaterials
PUBLISHED: 08-28-2014
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Cartilage regeneration after trauma is still a great challenge for clinicians and researchers due to many reasons, such as joint load-bearing, synovial movement and the paucity of endogenous repair cells. To overcome these limitations, we constructed a functional biomaterial using a biphasic scaffold platform and a bone-derived mesenchymal stem cells (BMSCs)-specific affinity peptide. The biphasic scaffold platform retains more cells homogeneously within the sol-gel transition of chitosan and provides sufficient solid matrix strength. This biphasic scaffold platform is functionalized with an affinity peptide targeting a cell source of interest, BMSCs. The presence of conjugated peptide gives this system a biological functionality towards BMSC-specific homing both in vitro and in vivo. The functional biomaterial can stimulate stem cell proliferation and chondrogenic differentiation during in vitro culture. Six months after in vivo implantation, compared with routine surgery or control scaffolds, the functional biomaterials induced superior cartilage repair without complications, as indicated by histological observations, magnetic resonance imaging and biomechanical properties. Beyond cartilage repair, this functional biphasic scaffold may provide a biomaterial framework for one-step tissue engineering strategy by homing endogenous cells to stimulate tissue regeneration.
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[Clinical classification and selection of surgical approaches for cervical spinal dumbbell tumors].
Zhonghua Yi Xue Za Zhi
PUBLISHED: 08-22-2014
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To explore the clinical classification and selection of surgical approaches for cervical spinal dumbbell tumors.
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Restored immunosuppressive effect of mesenchymal stem cells on B cells after OAZ downregulation in patients with systemic lupus erythematosus.
PUBLISHED: 08-20-2014
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Objective: To explore whether Olf1/EBF associated zinc finger protein (OAZ), a candidate lupus susceptibility gene involved in antinuclear antibody production, plays a role in mesenchymal stem cells (MSCs) - B cells regulation. Methods: MSCs from bone marrow (BM) of SLE patients and healthy controls, were expanded and incubated with siRNAs specific for OAZ or non-targeting sequence. Knockdown of mRNA levels of OAZ and its downstream genes was measured using RT-PCR, and protein levels of chemokine/cytokine and immunoglobulins by ELISA or Western blots. Effects of modulating OAZ levels in MSCs, either by silencing or overexpression, on B-cell proliferation and terminal differentiation were assessed by coculturing with mouse splenic cells. Results: OAZ gene expression was highly enriched in MSCs compared to PBLs, and elevated in SLE patients compared to controls. After silencing OAZ expression, SLE MSCs could regain the ability to inhibit B-cell proliferation and terminal differentiation, indicated by decreased percentages of BrdU(+) cells and CD138(+) cells as well as levels of IgG, IgM and antinuclear antibodies (ANA). Chemokine (C-C motif) ligand 2 (CCL2) elevated after OAZ knock-down, while anti-CCL2 antibody completely counteracted the effect of OAZ silence. Umbilical cord derived normal MSCs that overexpressed OAZ had diminished ability to inhibit B-cell proliferation and terminal differentiation. Conclusion: OAZ downregulation could restore the impaired immunoregulation function of SLE MSCs to B cells, contributing to ANA reduction. OAZ might represent a new therapeutic target for SLE patients. © 2014 American College of Rheumatology.
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Selectivity Mechanism of ATP-competitive Inhibitors for PKB and PKA.
Chem Biol Drug Des
PUBLISHED: 07-22-2014
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Protein kinase B (PKB) acts as a central node on the PI3K kinase pathway. Constitutive activation and overexpression of PKB have been identified to involve in various cancers. However, protein kinase A (PKA) sharing high homology with PKB, is essential for metabolic regulation. Therefore, specific targeting on PKB is crucial strategy in drug design and development for anti-tumor. Here, we had revealed the selectivity mechanism for PKB inhibitors with molecular dynamics simulation and 3D-QSAR methods. Selective inhibitors of PKB could form more hydrogen bonds and hydrophobic contacts with PKB than those with PKA. This could explain that selective inhibitor M128 is more potent to PKB than to PKA. Then 3D-QSAR models were constructed for these selective inhibitors and evaluated by test set compounds. 3D-QSAR model comparison of PKB-inhibitors and PKA-inhibitors reveals possible methods to improve the selectivity of inhibitors. These models can be used to design new chemical entities and make quantitative prediction of the specific selective inhibitors before resorting to in vitro and in vivo experiment. This article is protected by copyright. All rights reserved.
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Structure elucidation and biological activity of two new trichothecenes from an endophyte, Myrothecium roridum.
J. Agric. Food Chem.
PUBLISHED: 06-17-2014
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Worldwide, many different grains are infected by various fungi that may produce trichothecene mycotoxins. Fungi that produce trichothecenes, as well as the trichothecenes themselves, are potential problems for public health. On the other hand, trichothecenes possess multiple biological activities. Reduced toxicity may result in their applications in the pharmaceutical field. Two new trichothecenes along with seven known trichothecenes were isolated from an endophyte of the herb plant Ajuga decumbens. Their structures were deduced from 1D and 2D NMR data. The results of MTT assays revealed that new trichothecene 2',3'-epoxymyrothecine A, 1, and myrothecine A, 3, exhibited much lower toxicity compared to other trichothecenes. New trichothecene 2',3'-epoxymyrothecine A, 1, could induce phosphorylation of JNK (c-Jun N-terminal protein kinase) protein and the PARP (poly ADP-ribose polymerase) cleavage, and eventually induce apoptosis in cancer cells. These results point out the possibility for application of trichothecenes as chemotherapeutic agent.
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Different clinical characteristics between perimesencephalic subarachnoid hemorrhage and diffuse subarachnoid hemorrhage with negative initial angiography.
Turk Neurosurg
PUBLISHED: 05-23-2014
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The purpose of this study was to compare the different clinical features, outcome and treatment strategies in patients with perimesencephalic SAH (p-SAH) and diffuse SAH (d-SAH).
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Directing chondrogenic differentiation of mesenchymal stem cells with a solid-supported chitosan thermogel for cartilage tissue engineering.
Biomed Mater
PUBLISHED: 04-25-2014
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Hydrogels are attractive for cartilage tissue engineering because of their high plasticity and similarity with the native cartilage matrix. However, one critical drawback of hydrogels for osteochondral repair is their inadequate mechanical strength. To address this limitation, we constructed a solid-supported thermogel comprising a chitosan hydrogel system and demineralized bone matrix. Scanning electron microscopy, the equilibrium scanning ratio, the biodegradation rate, biomechanical tests, biochemical assays, metabolic activity tests, immunostaining and cartilage-specific gene expression analysis were used to evaluate the solid-supported thermogel. Compared with pure hydrogel or demineralized matrix, the hybrid biomaterial showed superior porosity, equilibrium swelling and degradation rate. The hybrid scaffolds exhibited an increased mechanical strength: 75% and 30% higher compared with pure hydrogels and demineralized matrix, respectively. After three days culture, bone-derived mesenchymal stem cells (BMSCs) maintained viability above 90% in all three materials; however, the cell retention of the hybrid scaffolds was more efficient and uniform than the other materials. Matrix production and chondrogenic differentiation of BMSCs in the hybrid scaffolds were superior to its precursors, based on glycosaminoglycan quantification and hyaline cartilage marker expression after three weeks in culture. Its easy preparation, favourable biophysical properties and chondrogenic capacity indicated that this solid-supported thermogel could be an attractive biomaterial framework for cartilage tissue engineering.
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Role of integrin ?2 ?1 in mediating osteoblastic differentiation on three-dimensional titanium scaffolds with submicron-scale texture.
J Biomed Mater Res A
PUBLISHED: 04-09-2014
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Hierarchical surface roughness of titanium and titanium alloy implants plays an important role in osseointegration. In vitro and in vivo studies show greater osteoblast differentiation and bone formation when implants have submicron-scale textured surfaces. In this study, we tested the potential benefit of combining a submicron-scale textured surface with three-dimensional (3D) structure on osteoblast differentiation and the involvement of an integrin-driven mechanism. 3D titanium scaffolds were made using orderly oriented titanium meshes and microroughness was added to the wire surface by acid-etching. MG63 and human osteoblasts were seeded on 3D scaffolds and 2D surfaces with or without acid etching. At confluence, increased osteocalcin, vascular endothelial growth factor, osteoprotegerin (OPG), and alkaline phosphatase (ALP) activity were observed in MG63 and human osteoblasts on 3D scaffolds in comparison to 2D surfaces at the protein level, indicating enhanced osteoblast differentiation. To further investigate the mechanism of osteoblast-3D scaffold interaction, the role of integrin ?2?1 was examined. The results showed ?1 and ?2?1 integrin silencing abolished the increase in osteoblastic differentiation markers on 3D scaffolds. Time course studies showed osteoblasts matured faster in the 3D environment in the early stage of culture, while as cells proliferated, the maturation slowed down to a comparative level as 2D surfaces. After 12 days of postconfluent culture, osteoblasts on 3D scaffolds showed a second-phase increase in ALP activity. This study shows that osteoblastic differentiation is improved on 3D scaffolds with submicron-scale texture and is mediated by integrin ?2?1. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2014.
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Synthesis and Biological Evaluation of 2-oxo-pyrazine-3-carboxamide-yl Nucleoside Analogues and Their Epimers as Inhibitors of Influenza A Viruses.
Chem Biol Drug Des
PUBLISHED: 04-01-2014
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Novel 2-oxo-pyrazine-3-carboxamide-yl nucleoside analogues and their epimers were designed, synthesized and evaluated for their activities against influenza A viruses H1N1 and H3N2 in Madin-Darby canine kidney cells. All the compounds showed low cytotoxicities in these anti-influenza tests. One of the epimers, 4-[(1S, 3R, 4R, 7R)-7-hydroxy-1-(hydroxymethyl)-2,5-dioxabicyclo[2.2.1]heptan-3-yl]-3-oxo-3,4-dihydropyrazine-2-carboxamide 8a, with high antiviral activities (IC50  = 7.41, 5.63 ?m for H3N2 and H1N1, respectively) and remarkable low cytotoxicity (TC50  > 200 ?m), has great potential for further development as a novel anti-influenza A agent. Molecular docking of compound 8a with RNA-dependent RNA polymerase was performed to understand the binding mode between these inhibitors and the active site of RdRp and to rationalize some SARs.
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Myrotheciumones: bicyclic cytotoxic lactones isolated from an endophytic fungus of Ajuga decumbens.
Bioorg. Med. Chem. Lett.
PUBLISHED: 03-17-2014
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Two new bicyclic lactones, myrotheciumones A (1) and B (2) which possessed a rare ring-fusion system were isolated from Myrothecium roridum (M. roridum), an endophytic fungus of the medicinal herb plant Ajuga decumbens (A. decumbens) via an in vitro cytotoxicity assay. Structures were deduced from 1D and 2D NMR (Nuclear magnetic resonance) data. Myrotheciumone A's in vitro cytotoxicity and apoptotic activity were evaluated and myrotheciumone A was shown to exert cytotoxicity via inducing apoptosis in cancer cell line.
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Total synthesis and RXR?-mediated transcription studies of neriifolone B and related compounds.
Bioorg. Med. Chem.
PUBLISHED: 03-13-2014
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Neriifolone B (1), a natural product containing a novel 4',4'-dimethyl-4',5'-dihydropyran-6-one[2',3':3,4]xanthone skeleton, was found to be a potent inhibitor of transcription mediated by retinoid X receptor ? (RXR?). The first total synthesis of neriifolone B (1) was achieved in 14 steps with an overall yield of 7.1%. A Claisen rearrangement was employed as the key step in the sequence. The activity of six natural xanthones and eight compounds related to neriifolone B (1) against RXR?-mediated transcription was evaluated. Two neriifolone B analogs, 17 and 11?, were potent inhibitors of RXR? transcriptional activity. Preliminary structure-activity relationship studies are discussed briefly.
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Surface modification on polycaprolactone electrospun mesh and human decalcified bone scaffold with synovium-derived mesenchymal stem cells-affinity peptide for tissue engineering.
J Biomed Mater Res A
PUBLISHED: 01-26-2014
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Synovium-derived mesenchymal stem cells (SMSC) have been studied for over a decade since first being successfully isolated in 2001. These cells demonstrate the most promising therapeutic efficacy for musculoskeletal regeneration of the MSC family, particularly for cartilage regeneration. However, the mobilization and transfer of MSCs to defective or damaged tissues and organs in vivo with high accuracy and efficiency has been a major problem in tissue engineering (TE). In the present study, we identified a seven amino acid peptide sequence [SMSCs-affinity peptide (LTHPRWP; L7)] through phage display technology that has a high specific affinity to SMSCs. Our analysis suggested that L7 efficiently and specifically interacted with SMSCs without any species specificity. Thereafter, L7 was covalently conjugated onto both polycaprolactone (PCL) electrospun meshes and human decalcified bone scaffolds (hDBSc) to investigate its TE applications. After 24 h coculture with human SMSCs (hSMSCs), L7-conjugated PCL electrospun meshes had significantly more adherent hSMSCs than the control group, and the cells expanded well. Similar results were obtained using hDBSs. These results suggest that the novel L7 peptide sequence has a high specific affinity to SMSCs. Covalently conjugating this peptide to either artificial polymer material (PCL mesh) or natural material (hDBS) significantly enhances the adhesion of SMSCs. This method is applicable to a wide range of potential SMSC-based TE applications, particularly to cartilage regeneration, via surface modification on various type of materials. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2014.
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The effects of co-delivery of BMSC-affinity peptide and rhTGF-?1 from coaxial electrospun scaffolds on chondrogenic differentiation.
Biomaterials
PUBLISHED: 01-19-2014
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Electrospinning is a promising technology for the fabrication of scaffolds in cartilage tissue engineering. Two other important elements for tissue engineering are seed cells and bioactive factors. Bone marrow-derived stem cells (BMSCs) and rhTGF-?1 are extensively studied for cartilage regeneration. However, little is known about scaffolds that can both specifically enrich BMSCs and release rhTGF-?1 to promote chondrogenic differentiation of the incorporated BMSCs. In this study, we first fabricated coaxial electrospun fibers using a polyvinyl pyrrolidone/bovine serum albumin/rhTGF-?1 composite solution as the core fluid and poly(?-caprolactone) solution as the sheath fluid. Structural analysis revealed that scaffold fibers were relatively uniform with a diameter of 674.4 ± 159.6 nm; the core-shell structure of coaxial fibers was homogeneous and proteins were evenly distributed in the core. Subsequently, the BMSC-specific affinity peptide E7 was conjugated to the coaxial electrospun fibers to develop a co-delivery system of rhTGF-?1 and E7. The results of (1)H nuclear magnetic resonance indicate that the conjugation between the E7 and scaffolds was covalent. The rhTGF-?1 incorporated in E7-modified scaffolds could maintain sustained release and bioactivity. Cell adhesion, spreading, and DNA content analyses indicate that the E7 promoted BMSC initial adhesion, and that the scaffolds containing both E7 and rhTGF-?1 (CBrhTE) were the most favorable for BMSC survival. Meanwhile, CBrhTE scaffolds could promote the chondrogenic differentiation ability of BMSCs. Overall, the CBrhTE scaffold could synchronously improve all three of the basic components required for cartilage tissue engineering in vitro, which paves the road for designing and building more efficient tissue scaffolds for cartilage repair.
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Investigation on the structure and upconversion fluorescence of Yb³?/Ho³? co-doped fluorapatite crystals for potential biomedical applications.
Sci Rep
PUBLISHED: 01-17-2014
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Rare-earth Yb(3+) and Ho(3+) co-doped fluorapatite (FA:Yb(3+)/Ho(3+)) crystals were prepared by hydrothermal synthesis, and their structure, upconversion properties, cell proliferation and imaging were investigated. The synthesized crystals, with a size of 16 by 286?nm, have a hexagonal crystal structure of classic FA and a Ca/Yb/Ho molar ratio of 100/16/2.1. Several reasonable Yb(3+)/Ho(3+) -embedding lattice models along the fluorine channel of the FA crystal cell are proposed for the first time, such as models for (Ca7YbHo©)(PO4)6F2 and (Ca6YbHoNa2)(PO4)6F2. The activated FA:Yb(3+)/Ho(3+) crystals were found to exhibit distinct upconversion fluorescence. The 543- and 654-nm signals in the emission spectra could be assigned, respectively, to the (5)F4 ((5)S2) - (5)I8 and (5)F5 - (5)I8 transitions of holmium via 980-nm near-infrared excitation and the energy transfer of ytterbium. After the surfaces were grafted with hydrophilic dextran, the crystals displayed clear fluorescent cell imaging. Thus, the prepared novel FA:Yb(3+)/Ho(3+) upconversion fluorescent crystals have potential applications in the biomedical field.
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Preparation and characterization of polylactide/poly(?-caprolactone)-poly(ethylene glycol)-poly(?-caprolactone) hybrid fibers for potential application in bone tissue engineering.
Int J Nanomedicine
PUBLISHED: 01-01-2014
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The aim of this study was to develop a kind of osteogenic biodegradable composite graft consisting of human placenta-derived mesenchymal stem cell (hPMSC) material for site-specific repair of bone defects and attenuation of clinical symptoms. The novel nano- to micro-structured biodegradable hybrid fibers were prepared by electrospinning. The characteristics of the hybrid membranes were investigated by a range of methods, including Fourier transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry. Morphological study with scanning electron microscopy showed that the average fiber diameter and the number of nanoscale pores on each individual fiber surface decreased with increasing concentration of poly(?-caprolactone)-poly(ethylene glycol)-poly(?-caprolactone) (PCEC). The prepared polylactide (PLA)/PCEC fibrous membranes favored hPMSC attachment and proliferation by providing an interconnected, porous, three-dimensional mimicked extracellular environment. What is more, hPMSCs cultured on the electrospun hybrid PLA/PCEC fibrous scaffolds could be effectively differentiated into bone-associated cells by positive alizarin red staining. Given the good cellular response and excellent osteogenic potential in vitro, the electrospun PLA/PCEC fibrous scaffolds could be one of the most promising candidates for bone tissue engineering.
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Structure-based design and synthesis of novel dual-target inhibitors against cyanobacterial fructose-1,6-bisphosphate aldolase and fructose-1,6-bisphosphatase.
J. Agric. Food Chem.
PUBLISHED: 07-26-2013
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Cyanobacteria class II fructose-1,6-bisphoshate aldolase (Cy-FBA-II) and cyanobacteria fructose-1,6-bisphosphatase (Cy-FBPase) are two neighboring key regulatory enzymes in the Calvin cycle of the cyanobacteria photosynthesis system. Each of them might be taken as a potential target for designing novel inhibitors to chemically control harmful algal blooms (HABs). In the present paper, a series of novel inhibitors were rationally designed, synthesized, and optimized based upon the structural and interactional information of both Cy-FBA-II and Cy-FBPase, and their inhibitory activities were examined in vitro and in vivo. The experimental results showed that compounds L19e-L19g exhibited moderate inhibitory activities (IC50 = 28.1-103.2 ?M) against both Cy-FBA-II and Cy-FBPase; compounds L19a-L19d, L19h, L20a-L20d exhibited high Cy-FBA-II inhibitory activities (IC50 = 2.3-16.9 ?M) and moderate Cy-FBPase inhibitory activities (IC50 = 31.5-141.2 ?M); however, compounds L20e-L20h could potently inhibit both Cy-FBA-II and Cy-FBPase with IC50 values less than 30 ?M, which demonstrated more or less dual-target inhibitors feature. Moreover, most of them exhibited potent algicide activity (EC50 = 0.8-22.3 ppm) against cyanobacteria Synechocystis sp. PCC 6803.
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Giant cranionasal and cystic-solid craniopharyngioma associated with extensive bone erosion and ossification.
J Craniofac Surg
PUBLISHED: 07-16-2013
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Craniopharyngioma (CP), a rare benign and slow-growing epithelial tumor, is mainly located within the sellar/parasellar region. Primary CP involving the nasal cavity and the sellar region with extensive erosion of the skull base and ossification simultaneity has not been described previously. The authors report a 23-year-old man who presented to our institute with complaints of repeated nasal cavity bloodshed, liquid flow, and progressive visual loss. A neuroimaging examination showed a giant cranionasal and cystic-solid CP extending from the suprasellar region to the nasopharynx with inhomogeneous enhancement, which is associated with extensive erosion of the skull base and ossification. The patient underwent a transsphenoidal surgery to resect the nasopharyngeal component of CP and a subfrontal craniotomy with a total removal of intracranial component by grinding 3 months later. A histopathologic examination revealed characteristic features of adamantinomatous CP associated with ossification. The current study demonstrates that CP can exhibit cranionasal growth pattern and arise from residue of craniopharyngeal duct. Extensive erosion of the skull base, calcification, and ossification can present in tumor simultaneity. A 2-stage stratagem is important for its total removal because of the peculiar hardness. Postsurgical course is unevenly and should be dealt with carefully.
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Cu-doped zinc oxide and its polythiophene composites: Preparation and antibacterial properties.
Chemosphere
PUBLISHED: 05-24-2013
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Cu-doped zinc oxide and its polythiophene nanocomposites were prepared by the Sol-Gel and in situ polymerization methods, respectively. The structures, morphologies and compositions of the samples were characterized. The antibacterial properties of the samples on three kinds of strains were determined by using powder inhibition zones, minimum inhibitory concentrations and minimal bactericidal concentrations. The study confirmed that the antibacterial activities of the composites were better than those of their each component. The antibacterial mechanisms of the samples were discussed further.
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Molecular dynamics simulations of amyloid fibrils: an in silico approach.
Acta Biochim. Biophys. Sin. (Shanghai)
PUBLISHED: 03-26-2013
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Amyloid fibrils play causal roles in the pathogenesis of amyloid-related degenerative diseases such as Alzheimers disease, type II diabetes mellitus, and the prion-related transmissible spongiform encephalopathies. The mechanism of fibril formation and protein aggregation is still hotly debated and remains an important open question in order to develop therapeutic method of these diseases. However, traditional molecular biological and crystallographic experiments could hardly observe atomic details and aggregation process. Molecular dynamics (MD) simulations could provide explanations for experimental results and detailed pathway of protein aggregation. In this review, we focus on the applications of MD simulations on several amyloidogenic protein systems. Furthermore, MD simulations could help us to understand the mechanism of amyloid aggregation and how to design the inhibitors.
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High-dose methylprednisolone pulse therapy upregulated Fc?RIIb expression on B cells in primary Sjögrens syndrome patients with thrombocytopenia.
Clin. Rheumatol.
PUBLISHED: 01-31-2013
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Abnormalities in B cell are characteristic feature of primary Sjögrens syndrome (pSS). As Fc?RIIb is a key regulator of B cells, the objective of this study is to investigate the role of the inhibitory receptor Fc?RIIb in B cells from pSS patients, and whether glucocorticoid can affect B cell subpopulations or Fc?RIIb expression. Thirty pSS patients and 15 healthy controls were enrolled in this study. The results showed that the percentage of memory CD19(+)CD27(+) B cells was significantly lower in pSS patients compared to in healthy controls. Fc?RIIb expression on memory CD19(+)CD27(+) B cells from active pSS patients was significantly reduced compared with those from inactive or healthy controls. The level of Fc?RIIb on memory CD19(+)CD27(+) B cells from active pSS patients was negatively correlated with anti-SSA antibody titers and Sjögrens syndrome disease activity index. After a high-dose methylprednisolone pulse therapy for 3 days, Fc?RIIb expression on memory B cells was upregulated, with the raised level of platelets. In vitro, dexamethasone could elevate Fc?RIIb expression on B cells of pSS patients in a dose-dependent manner. Taken together, our data suggest that the upregulation of Fc?RIIb may be expected to be a new therapeutic strategy in pSS patients.
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Reproducibility, fidelity, and discriminant validity of linear RNA amplification for microarray-based identification of major human enteric viruses.
Appl. Microbiol. Biotechnol.
PUBLISHED: 01-04-2013
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Human enteric viruses are inherently a group of viruses that confer similar or overlapping clinical symptoms and pose a challenge for correct etiological diagnosis. DNA microarray technology has emerged to be of major interest to detect broad range of viral pathogens including enteric viruses. However, this approach requires a relative large amount of target nucleic acid for hybridization analysis. This feature limits its further applicability. To address this challenge, we evaluated a novel single primer linear isothermal amplification (Ribo-SPIA) procedure for preparation of single-stranded cDNA (sscDNA) from minute amount of starting RNA for microarray-based simultaneous detection and identification of three major human enteric viruses including hepatitis A virus, norovirus, and coxsachievirus B2. We performed a series of tests using different amounts of input RNA ranging from 30 ng to 55 pg to assess amplification yield, reproducibility, analytical sensitivity, and fidelity. We demonstrated that as little as 55 pg of viral RNA could produce adequate material by Ribo-SPIA to enable successful identification by microarray analysis without compromising detection specificity. Pairwise comparison of technical replicates hybridized to the microarrays by regression analysis showed excellent reproducibility in the appropriate sensitivity range. We also showed that the use of sscDNA as labeled targets offered increased microarray detection accuracy over complementary RNA generated by traditional T7 in vitro transcription amplification method.
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Effects of structural properties of electrospun TiO2 nanofiber meshes on their osteogenic potential.
Acta Biomater
PUBLISHED: 07-20-2011
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Ideal outcomes in the field of tissue engineering and regenerative medicine involve biomaterials that can enhance cell differentiation and production of local factors for natural tissue regeneration without the use of systemic drugs. Biomaterials typically used in tissue engineering applications include polymeric scaffolds that mimic the three-dimensional structural environment of the native tissue, but these are often functionalized with proteins or small peptides to improve their biological performance. For bone applications, titanium implants, or more appropriately the TiO2 passive oxide layer formed on their surface, have been shown to enhance osteoblast differentiation in vitro and to promote osseointegration in vivo. In this study we evaluated the effect on osteoblast differentiation of pure TiO2 nanofiber meshes with different surface microroughness and nanofiber diameters, prepared by the electrospinning method. MG63 cells were seeded on TiO2 meshes, and cell number, differentiation markers and local factor production were analyzed. The results showed that cells grew throughout the entire surfaces and with similar morphology in all groups. Cell number was sensitive to surface microroughness, whereas cell differentiation and local factor production was regulated by both surface roughness and nanofiber diameter. These results indicate that scaffold structural cues alone can be used to drive cell differentiation and create an osteogenic environment without the use of exogenous factors.
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Manufacturing of adeno-associated viruses, for example: AAV2.
Methods Mol. Biol.
PUBLISHED: 05-19-2011
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Adeno-associated virus (AAV) is one of the most promising vectors for gene therapy. There are several ways of producing AAV vectors but large-scale production of this vector remains a major challenge. Virovek developed a novel method of expressing the AAV Rep and Cap genes in insect cells mediated by intron-splicing mechanism and producing AAV vectors with these Rep and Cap sequences containing the artificial intron. The recombinant baculoviruses harboring these artificial intron-containing Rep and Cap sequences are very stable and the AAV vectors produced in insect cells with these recombinant baculoviruses are very infectious.
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Male germ cell apoptosis and epigenetic histone modification induced by Tripterygium wilfordii Hook F.
PLoS ONE
PUBLISHED: 05-12-2011
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Multiglycosides of Tripterygium wilfordii Hook f (GTW), a Chinese herb-derived medicine used as a remedy for rheumatoid arthritis, are considered to be a reversible anti-fertility drug affecting the mammalian spermatids. However, the mechanism behind this effect is still unknown. To study the possible mechanism behind the impact of GTW on spermatogenesis, we administered 4 groups of 4-week-old male mice with different doses of GTW. We found a dose-dependent decrease in the number of germ cells after 40 days of GTW treatment, and an increase in apoptotic cells from the low-dose to the high-dose group. During this same period the dimethylated level of histone H3 lysine 9 (H3K9me2) in GTW-treated testes germ cells declined. Additionally, spermatogonial stem cells (SSCs) from 6-day-old mice were isolated to evaluate the possible effect of GTW or triptolide on development of SSCs. We found a significantly higher incidence of apoptosis and lower dimethylation level of H3K9me2 in the SSCs of GTW or triptolide treatment than in controls. Thus, these data suggest that the GTW-induced apoptosis might be responsible for the fertility impairment in mice. This damage could be traced back to the early stages of spermatogenesis. GTW also affected the epigenetic modification of H3K9 in spermatogenesis. Molecular dynamics simulation suggested that triptolide and dimethylated or trimethylated H3K9 might have similar interaction mechanisms with EED (embryonic ectoderm development). These candidate activation mechanisms provide the first glimpse into the pathway of GTW-induced gonad toxicity, which is crucial for further research and clinical application.
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Fatty acids as natural specific inhibitors of the proto-oncogenic protein Shp2.
Bioorg. Med. Chem. Lett.
PUBLISHED: 05-11-2011
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Src homology-2 domain-containing protein tyrosine phosphatase (Shp2), a novel proto-oncogenic protein, is an important target in cancer therapy research. Approximately 2000 plant extracts were screened to find its natural specific inhibitors, with the ethyl acetate (EtOAc) active extract of the root of Angelica dahurica showing considerable inhibitory effects (IC(50)=21.6 mg/L). Bioguided isolation of EtOAc extract led to 13 compounds, including 10 fatty acids and derivatives. All these compounds were isolated from the plant for the first time. The inhibitory effects of these compounds on the enzyme activities of Shp2, VH1-related human protein (VHR), and hematopoietic protein tyrosine phosphatase (HePTP) were investigated. 8Z,11Z-Feptadecadienoic acid (4), 14Z,17Z-tricosadienoic acid (5), caffeic acid (9), and 2-hydroxy-3-[(1-oxododecyl) oxy]propyl-?-d-glucopyranoside (11) showed considerable selective inhibition of Shp2 activity. After treatment of HepG2 cells with the compounds, only compound 5, a polyunsaturated fatty acid, strongly induced poly (ADP-ribose) polymerase (PARP) cleavage in a dose- and time-dependent manner and increased the activities of caspase-3, caspase-8, and caspase-9 at 100 ?M. Compound 5 also inhibited colony formation of HepG2 cells in a dose-dependent manner. Thus, this study reported fatty acids as specific Shp2 inhibitors and provided the molecular basis of one active compound as novel potential anticancer drug.
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Detection and identification of common food-borne viruses with a tiling microarray.
Open Virol J
PUBLISHED: 02-24-2011
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Microarray hybridization based identification of viral genotypes is increasingly assuming importance due to outbreaks of multiple pathogenic viruses affecting humans causing wide-spread morbidity and mortality. Surprisingly, microarray based identification of food-borne viruses, one of the largest groups of pathogenic viruses, causing more than 1.5 billion infections world-wide every year, has lagged behind. Cell-culture techniques are either unavailable or time consuming for routine application. Consequently, current detection methods for these pathogens largely depend on polymerase chain reaction (PCR) based techniques, generally requiring an investigator to preselect the target virus of interest. Here we describe the first attempt to use the microarray as an identification tool for these viruses. We have developed methodology to synthesize targets for virus identification without using PCR, making the process genuinely sequence independent. We show here that a tiling microarray can simultaneously detect and identify the genotype and strain of common food-borne viruses in a single experiment.
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Spontaneous spinal epidural hematoma.
J Clin Neurosci
PUBLISHED: 02-11-2011
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Spontaneous spinal epidural hematoma (SSEH) is a rare emergent condition. It may result in paraplegia, quadriplegia and even death. Prompt diagnosis and emergent decompressive surgical management have been recommended to prevent mortality and morbidity. Although several factors have been associated with prognosis, controversy remains, partly due to its rarity. Thus, the history, clinical presentation, physical examination findings, radiological images, and surgical and pathological records of 30 patients with SSEH (21 male, nine female [sex ratio of 2.3:1], average age of 35 years) treated between January 2002 and September 2010 have been reviewed. The association of age, sex, hypertension, vascular malformation, vertebral level, position and extension of the hematoma, progression interval, operative interval, spinal cord edema, and preoperative neurological condition with the prognosis is discussed. The outcome was better for patients with incomplete neurological deficit (p = 0.001), lesions extending <4 vertebral segments (p = 0.026), and lesions in the thoracolumbar and lumbar region. A shorter progression interval often led to a less favorable prognosis (p = 0.017). Patients with spinal cord edema experienced a worse preoperative neurological deficit (p = 0.005) and a worse outcome (p = 0.000). Patients with a progression interval ?12hours presented with a worse preoperative neurological deficit (p = 0.026). Early surgical intervention to evacuate the hematoma remains the main treatment for most symptomatic patients. Conservative treatment may be used only for those in a good preoperative neurological condition. Prognosis is associated with the preoperative neurological condition, progression internal, spinal cord edema, and extension and vertebral level of the SSEH. Patients with SSEH in the cervical or cervicothoracic region with a complete preoperative motor deficit have a higher mortality rate.
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A viscoelastic chitosan-modified three-dimensional porous poly(L-lactide-co-?-caprolactone) scaffold for cartilage tissue engineering.
J Biomater Sci Polym Ed
PUBLISHED: 02-07-2011
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Biomaterials have been playing important roles in cartilage regeneration. Although many scaffolds have been reported to enhance cartilage regeneration, none of the scaffolds available are optimal regarding mechanical properties, integration with host cartilage and providing proper micro-environment for chondrocyte attachment, proliferation and differentiation. In the current study, chitosan-modified poly(L-lactide-co-?-caprolactone) (PLCL) scaffolds were fabricated to simulate the main biochemical components of cartilage, as well as their interaction with the aim to endow them with viscoelasticity similar to native cartilage. Porous PLCL scaffolds were fabricated with porogen-leaching, freeze-extraction and freeze-gelation before chitosan was cross-linked. The acquired porous scaffolds had pore sizes ranging from 200 to 500 ?m and about 85% porosity with good interconnection between individual pores. Chitosan was successfully cross-linked to PLCL scaffolds, as validated by ninhydrin staining and X-ray photoelectron spectroscopy (XPS). The viscoelasticity of the scaffolds was similar to that of bovine cartilage and they had a relatively good recovery ratio from compression deformation, while the Youngs modulus was one order of magnitude less than cartilage. Not only could the chitosan-modified PLCL scaffolds promote cell adhesion and proliferation, but also they could significantly enhance excretion of aggrecan and type-II collagen, as testified by both histology and quantitative PCR, compared with PLCL scaffolds. With the fabrication of biomimetic scaffolds, it is possible to make scaffolds for cartilage tissue engineering, which are not only biocompatible, but also have mechanical properties similar to native cartilage.
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[Chemical constituents of bear bile].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 12-15-2010
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To study the chemical constituents of bear bile.
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ASD: a comprehensive database of allosteric proteins and modulators.
Nucleic Acids Res.
PUBLISHED: 11-04-2010
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Allostery is the most direct, rapid and efficient way of regulating protein function, ranging from the control of metabolic mechanisms to signal-transduction pathways. However, an enormous amount of unsystematic allostery information has deterred scientists who could benefit from this field. Here, we present the AlloSteric Database (ASD), the first online database that provides a central resource for the display, search and analysis of structure, function and related annotation for allosteric molecules. Currently, ASD contains 336 allosteric proteins from 101 species and 8095 modulators in three categories (activators, inhibitors and regulators). Proteins are annotated with a detailed description of allostery, biological process and related diseases, and modulators with binding affinity, physicochemical properties and therapeutic area. Integrating the information of allosteric proteins in ASD should allow for the identification of specific allosteric sites of a given subtype among proteins of the same family that can potentially serve as ideal targets for experimental validation. In addition, modulators curated in ASD can be used to investigate potent allosteric targets for the query compound, and also help chemists to implement structure modifications for novel allosteric drug design. Therefore, ASD could be a platform and a starting point for biologists and medicinal chemists for furthering allosteric research. ASD is freely available at http://mdl.shsmu.edu.cn/ASD/.
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A novel screening model for the molecular drug for diabetes and obesity based on tyrosine phosphatase Shp2.
Bioorg. Med. Chem. Lett.
PUBLISHED: 07-28-2010
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Tyrosine phosphatase Src-homology phosphotyrosyl phosphatase 2 (Shp2) was identified as a potential molecular target for therapeutic treatment of diabetes and obesity. However, there is still no systematic research on the enhancers for the Shp2 enzyme. The present study established a novel powerful model for the high-throughput screening of Shp2 enhancers and successfully identified a new specific Shp2 enhancer, oleanolic acid, from Chinese herbs.
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The effect of NF-?B pathway on proliferation and apoptosis of human umbilical vein endothelial cells induced by intermittent high glucose.
Mol. Cell. Biochem.
PUBLISHED: 06-30-2010
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Our previous study found that blocking nuclear factor (NF)-?B signaling could protect human umbilical vein endothelial cells (HUVECs) from apoptosis and proliferation inhibition due to high glucose (HG). Intermittent HG makes glucose toxicity more significant. In this study, we aimed to investigate the effect of NF-?B pathway on HUVECs induced by intermittent HG (a daily alternating 5.5 or 30.5 mmol/l glucose). A recombinant adenovirus containing a RNAi cassette targeting the NF-?B/p65 gene was produced, and its silencing effect on p65 gene was detected by Western blot analysis in HUVECs cultured with intermittent HG. The subsequent effect on proliferation of HUVECs in the indicated conditions was measured by the AlamarBlue assay. The Bcl-2 expression was also detected by Western blot. The results showed that the expression of p65 protein could be inhibited efficiently by the RNAi adenovirus. Intermittent HG also induced the translocation of NF-?B in HUVECs. Inhibition of NF-?B with the RNAi adenovirus could prevent the effects. At the 6th day after HUVECs were exposed to intermittent HG, the proliferation of HUVECs with Ad-1566 was significantly higher than that of HUVECs with Ad-DEST (P < 0.01). Knockdown of NF-?B/p65 up-regulated the Bcl-2 expression of HUVECs under intermittent HG conditions (P < 0.01). These findings concluded that the NF-?B/p65-targeting RNAi adenovirus is an important tool, which can efficiently inhibit the expression of p65 gene in HUVECs. Intermittent HG reduces HUVECs proliferation with a concomitant increase in apoptosis. Knockdown of NF-?B/p65 partly protected HUVECs from proliferation inhibition and may reduce apoptosis.
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A WBAN-based real-time electroencephalogram monitoring system: design and implementation.
J Med Syst
PUBLISHED: 05-28-2010
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In this study, a flexible wireless body area network (WBAN) node platform has been designed and implemented based on the Zigbee technology. In order to provide wide range WBAN for health monitoring, a Zigbee/Internet Gateway (ZiGW) has also been developed rather than using a PDA or a host PC to connect different WBANs by using the Internet as the communication infrastructure. The proposed body sensor node platform promises a cost-effective, flexible platform for developing physical sensor node in real-time health monitoring. The ZiGW can provide an effective method to connect WBAN with the Internet. In this work, we present the implementation of an Electroencephalogram (EEG) monitoring system using the proposed methods. In this proposed system, real-time EEG signals can be remotely monitored by physicians via Internet, and the collected EEG data is stored in the online EEG database which can be shared with physicians or researchers for further analysis.
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New steroidal glycosides isolated as CDL inhibitors of activated platelets.
Molecules
PUBLISHED: 04-24-2010
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Three new compounds were isolated from the dried bulbs of Allium macrostemon Bunge. Their structures were elucidated from their spectral data as (25R)-26-O-beta-D-glucopyranosyl-5alpha-furostane-3beta,12beta,22,26-tetraol-3-O-beta-D-glucopyranos-yl (1-->2) [beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-beta-D-galactopyranoside (1), (25R)-26-O-beta-D-glucopyranosyl-5alpha-furostane-3beta,12alpha,22,26-tetraol-3-O-beta-D-glucopyranosyl (1-->2) [beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl (1-->4)-beta-D-galacto- pyranoside (2) and (25R)-26-O-beta-D-glucopyranosyl-5beta-furostane-3beta,12alpha,22,26-tetraol-3-O-beta-D-glucopyranosyl (1-->2)-beta-D-galactopyranoside (3), respectively. The inhibition effect of all compounds on CD40 ligand (CD40L) expression on the membrane of activated platelets stimulated by ADP was tested. Compounds 1 and 2 exhibited significant inhibitory activities in a dose dependent manner (P < 0.05), suggesting their potential application as CD40L inhibitors.
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Successful treatment of sellar aspergillus abscess.
J Clin Neurosci
PUBLISHED: 03-07-2010
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A sellar aspergillus abscess is a rare fungal infection of the central nervous system (CNS). A retrospective analysis of three patients with sellar aspergillus abscess was conducted from 2006 to 2008. Data were retrieved from patient records at our hospital. Clinical findings, pathological data and final outcomes were reviewed and analysed. All patients underwent transsphenoidal surgery with the operating microscope and histopathologic examination revealed aspergillosis in all cases. Postoperatively, all patients received medical treatment with voriconazole and caspofungin. During the 3-6-month follow-up period, the patients were symptom free with no recurrences. Therefore, sellar aspergillus abscess should be included in the differential diagnosis of a sellar mass. Early and correct diagnosis via surgery can improve the prognosis. A combination of surgical resection and antifungal therapy has a good outcome. The importance of early treatment for sellar aspergillus abscesses is emphasised.
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Chemical regeneration of human tooth enamel under near-physiological conditions.
Chem. Commun. (Camb.)
PUBLISHED: 08-19-2009
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Regenerating the microstructure of human tooth enamel under near-physiological conditions (pH 6.0, 37 degrees C, 1 atm) using a simple chemical approach demonstrates a potential application to repair enamel damage in dental clinics.
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Direct growth of human enamel-like calcium phosphate microstructures on human tooth.
J Nanosci Nanotechnol
PUBLISHED: 05-16-2009
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Dental Enamel is the hardest mineralized tissue in the human body which is comprised of nanorod-like hydroxyapatite crystals arranged into a highly organized micro-architectural unit called an enamel prism. In this paper the direct growth of human enamel-like structures on human tooth using fluorapatite/phosphoric acid pastes is explored. SEM images show that the newly formed calcium phosphate crystals can be self-assembled into a similar ordered microstructure as those seen in human enamel. The mechanism of how these structures form is discussed. This work demonstrates the potential of applying nanotechnology to regenerate dental enamel clinically without cells.
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[Flavonoid constituents from herbs of Sarcopyramis bodinieri var. delicata].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 04-24-2009
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Phytochemical studies of the the herb Sarcopyramis bodinieri var. delicate (Melastomataceae) have been carried out. The compounds were separated by repeated D101 macroporous adsorption resin column combined with Sephadex LH-20, ODS, and silica gel chromatgrophy. The structures were identified on the basis of extensive spectroscopic data analysis, and by comparison of their spectral data with those reported. Eight flavonoid compounds isolated from the ethyl acetate extract was identified as isorhamnetin (1), quercetin (2), isorhamnetin-3-O-beta-D-glucopyranoside (3), quercetin-3-O-beta-D-glucopyranoside (4), isorhamnetin-3-O-(6"-acetyl)-beta-D-glucopyranoside (5), isorhamnetin-3-O-(2"-acetyl)-beta-D-glucopyranoside (6), quercetin-3-O-(6"-acetyl)-beta-D-glucopyranoside (7), and quercetin- 3-O-(6"-O-E-p-coumaroyl)-beta-D-glucopyranoside (8). All of the compounds were separated from the genus of Sarcopyramis for the first time.
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[Mechanism study of protobioside on tumor cell proliferation].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 03-02-2009
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To investigate the anti-proliferative effect of Protobioside on the HepG2 cells and its mechanism.
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pNovo+: de novo peptide sequencing using complementary HCD and ETD tandem mass spectra.
J. Proteome Res.
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De novo peptide sequencing is the only tool for extracting peptide sequences directly from tandem mass spectrometry (MS) data without any protein database. However, neither the accuracy nor the efficiency of de novo sequencing has been satisfactory, mainly due to incomplete fragmentation information in experimental spectra. Recent advancement in MS technology has enabled acquisition of higher energy collisional dissociation (HCD) and electron transfer dissociation (ETD) spectra of the same precursor. These spectra contain complementary fragmentation information and can be collected with high resolution and high mass accuracy. Taking these advantages, we have developed a new algorithm called pNovo+, which greatly improves the accuracy and speed of de novo sequencing. On tryptic peptides, 86% of the topmost candidate sequences deduced by pNovo+ from HCD + ETD spectral pairs matched the database search results, and the success rate reached 95% if the top three candidates were included, which was much higher than using only HCD (87%) or only ETD spectra (57%). On Asp-N, Glu-C, or Elastase digested peptides, 69-87% of the HCD + ETD spectral pairs were correctly identified by pNovo+ among the topmost candidates, or 84-95% among the top three. On average, it takes pNovo+ only 0.018 s to extract the sequence from a spectrum or spectral pair on a common personal computer. This is more than three times as fast as other de novo sequencing programs. The increase of speed is mainly due to pDAG, a component algorithm of pNovo+. pDAG finds the k longest paths in a directed acyclic graph without the antisymmetry restriction. We have verified that the antisymmetry restriction is unnecessary for high resolution, high mass accuracy data. The extensive use of HCD and ETD spectral information and the pDAG algorithm make pNovo+ an excellent de novo sequencing tool.
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Exploiting the Intron-splicing Mechanism of Insect Cells to Produce Viral Vectors Harboring Toxic Genes for Suicide Gene Therapy.
Mol Ther Nucleic Acids
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Two mammalian introns, the human growth hormone intron and the Simian virus 40 large T antigen intron, were inserted into the coding sequences of diphtheria toxin fragment A (DT-A) and barnase (Bar), respectively, to disrupt their open-reading frames (ORFs). Expression of these two toxic proteins were totally abolished, which enabled the production of normal levels of recombinant baculoviral and adeno-associated viral (AAV) vectors in insect cells. When these viral vectors were introduced into mammalian cells, the introns were spliced out and the toxic proteins were expressed, which resulted in apoptosis in mammalian cells. This is the first report to show that viral vectors harboring toxin genes can be produced at normal levels by exploiting the intron-splicing mechanism of insect cells. Furthermore, viral vectors carrying the DT-A gene under control of tumor-specific promoters were able to exert tumor-specific cell killing. This novel method to produce viral vectors harboring toxic genes under control of tumor-specific promoter offers a powerful tool for further research, as well as for the development of toxin-based suicide gene therapy drugs.Molecular Therapy - Nucleic Acids (2012) 1, e57; doi:10.1038/mtna.2012.48; published online 27 November 2012.
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A regulatory effect of IL-21 on T follicular helper-like cell and B cell in rheumatoid arthritis.
Arthritis Res. Ther.
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ABSTRACT: INTRODUCTION: Interleukin (IL)-21 is a member of type I cytokine family. Recent studies indicate that IL-21 can promote T follicular helper (Tfh) cell differentiation and survival, a specialized T cell subset which provides help for B cell. It can also regulate the activation, proliferation and differentiation of human B cell and immunoglobulin (Ig) production as well as isotype switching of plasma cell. Rheumatoid arthritis (RA) is characterized by auto-antibodies overproduction such as rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibody, suggesting a pivotal role of Tfh cell and B cell in the pathogenesis of RA. This study aimed to investigate whether IL-21 had a regulatory effect on Tfh cell and B cell in RA. METHODS: Serum IL-21 concentrations were measured by ELISA. The correlations between serum IL-21 levels and clinical features of RA patients were analyzed by Spearmans rank test. The percentages of Tfh-like cells, IL-21 receptor (R) expression on Tfh-like cells and B cells in peripheral blood (PB) were analyzed by flow cytometry. Peripheral blood mononuclear cells (PBMC) were stimulated by rIL-21 (100 ng/ml) in the presence or absence of anti-CD40 and/or anti-IgM, and changes of IL-21R, activation-associated surface markers (CD25, CD69 and CD40), the proliferation, apoptosis and differentiation of B cells were analyzed by flow cytometry. Production of IgG and IgM in the culture supernatants was determined by ELISA. RESULTS: The results showed that the serum IL-21 levels in RA patients were significantly higher than that of healthy controls (HC). IL-21 concentrations were positively correlated with 28-joint count disease activity score (DAS28) and anti-CCP antibody in RA patients with high IL-21 levels. Furthermore, the frequencies of peripheral CXCR5+PD-1+CD4+ Tfh-like cells markedly increased in RA patients and the percentages of Tfh-like cells were positively correlated with DAS28 and anti-CCP antibody levels. Moreover, elevated IL-21 levels were also correlated with the frequencies of Tfh-like cells. IL-21R expression on both Tfh-like cells and B cells were significantly enhanced in RA patients. In cultures vitro, exogenous IL-21 upregulated IL-21R expression and activation-associated surface markers on B cells and promoted more B cell proliferation in RA than in HC. This IL-21-mediated effect could be reversed by IL-21R-specific neutralizing antibody. Importantly, IL-21 promoted more differentiation of B cell into plasmablast and higher levels of IgG and IgM production in RA than in HC. CONCLUSIONS: Increased serum IL-21 levels in RA patients correlate with DAS28, anti-CCP antibody and frequencies of Tfh-like cells. IL-21 supports B cell activation, proliferation and antibody secretion via IL-21R pathway. Thus, IL-21 may be involved in the pathogenesis of RA and antagonizing IL-21 could be a novel strategy for the therapy of RA.
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Integrin-targeted trifunctional probe for cancer cells: a "seeing and counting" approach.
Anal. Chem.
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We report the design and synthesis of a trifunctional probe for seeing and counting cancer cells using both fluorescence imaging (FI) and inductively coupled plasma mass spectrometry (ICPMS) for the first time. It consisted of a guiding cyclic RGD peptide unit to catch cancer cells via targeting the ?(v)?(3) integrin overexpressed on their surface, a 5-amino-fluorescein moiety for FI using confocal laser scanning microscopy (CLSM) as well as a 2-aminoethyl-monoamide-DOTA group for loading stable europium ion and subsequent ICPMS quantification of the cancer cells without the use of radioactive isotopes. In addition to FI, the LOD (3?) of the ?(v)?(3) integrin was down to 69.2-309.4 amol per cell depending on the type of the ?(v)?(3)-positive cancer cells when using ICPMS and those of the cancer cell number reached 17-75. This probe developed enables us not only to see but also to count the ?(v)?(3)-positive cancer cells ultrasensitively, paving a new way for early diagnosis of cancer.
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[Chemical constituents contained in Desmodium caudatum].
Zhongguo Zhong Yao Za Zhi
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To study chemical constituents contained in Desmodium caudatum.
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Titanate nanotubes as a promising absorbent for high effective radioactive uranium ions uptake.
J Nanosci Nanotechnol
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In this study, titanate nanotubes with a layered structure were investigated for the uptake of radioactive uranium ions for the first time. The nanotubes have been successfully prepared with a reaction of Ti metal nanopowders and NaOH mixed solution by a novel and effective ultrasonic-assisted hydrothermal method. As the absorbent of radioactive ions, they have the ability to selectively adsorb radioactive U ions from water via ion exchange process and subsequently immobilize these ions in the nanotube sorbents without the need of further treatment after absorption. Sorption induces considerable deformation of the layer structures, resulting in the structures changing from the nanotubes to sheets and having the ability of permanent entrapment of the radioactive cations in these as-grown sheets. Our results have proved that titanate nanotubes can be used as a promising absorbent for the removal of nuclear leaking water at the first time.
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Activated NF-?B in bone marrow mesenchymal stem cells from systemic lupus erythematosus patients inhibits osteogenic differentiation through downregulating Smad signaling.
Stem Cells Dev.
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Osteoporosis in patients with systemic lupus erythematosus (SLE) is thought to be the result of accelerated osteoclastogenesis induced by pro-inflammatory cytokines such as tumor necrosis factor (TNF). However, the molecular mechanisms involved in the osteoblastogenesis in SLE patients are not fully understood. We investigated the bone morphogenetic protein-2 (BMP-2)-induced osteoblastic capacity of bone marrow-derived mesenchymal stem cells (BMMSCs) from SLE patients and the TNF signaling system in determining BMP-2-induced regulatory pathways. It showed that the capacity of osteogenic differentiation of BMMSCs from SLE patients was reduced compared with that from healthy controls. The nuclear factor ?B (NF-?B) signaling was activated while the BMP/Smad pathway was repressed in BMMSCs from SLE patients. TNF activated NF-?B pathway and inhibited the phosphorylation of Smad 1/5/8 and BMP-2-induced osteoblastic differentiation in BMMSCs from normal controls, while addition of pyrollidine dithiocarbamate (PDTC), an NF-?B inhibitor, to SLE-BMMSCs could partially reverse these effects. Thus, our findings have shown that the activated NF-?B pathway in SLE-BMMSCs inhibits the BMP-2-induced osteoblastic differentiation through BMP/Smad signaling pathway, suggesting that the impaired osteoblastic differentiation may participate in the pathology of osteoporosis in SLE patients.
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Transcript profile of the response of two soybean genotypes to potassium deficiency.
PLoS ONE
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The macronutrient potassium (K) is essential to plant growth and development. Crop yield potential is often affected by lack of soluble K. The molecular regulation mechanism of physiological and biochemical responses to K starvation in soybean roots and shoots is not fully understood. In the present study, two soybean varieties were subjected to low-K stress conditions: a low-K-tolerant variety (You06-71) and a low-K-sensitive variety (HengChun04-11). Eight libraries were generated for analysis: 2 genotypes ×2 tissues (roots and shoots) ×2 time periods [short term (0.5 to 12 h) and long term (3 to 12 d)]. RNA derived from the roots and shoots of these two varieties across two periods (short term and long term) were sequenced and the transcriptomes were compared using high-throughput tag-sequencing. To this end, a large number of clean tags (tags used for analysis after removal of dirty tags) corresponding to distinct tags (all types of clean tags) were identified in eight libraries (L1, You06-71-root short term; L2, HengChun04-11-root short term; L3, You06-71-shoot short term; L4, HengChun04-11-shoot short term; L5, You06-71-root long term; L6, HengChun04-11-root long term; L7, You06-71-shoot long term; L8, HengChun04-11-shoot long term). All clean tags were mapped to the available soybean (Glycine max) transcript database (http://www.soybase.org). Many genes showed substantial differences in expression across the libraries. In total, 5,440 transcripts involved in 118 KEGG pathways were either up- or down-regulated. Fifteen genes were randomly selected and their expression levels were confirmed using quantitative RT-PCR. Our results provide preliminary information on the molecular mechanism of potassium absorption and transport under low-K stress conditions in different soybean tissues.
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Fabrication of electrospun silica-titania nanofibers with different silica content and evaluation of the morphology and osteoinductive properties.
J Biomed Mater Res A
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Ceramic-derived materials have shown enhanced osteogenic potential for bone tissue engineering applications. Silica is the major component of bioglass, and titania, the oxide complex of titanium, has been found to enhance osteoblast differentiation. In this study, three groups of sol-gel-derived silica-titania fibrous meshes with precursor ratios of Ti:Si = 7:3, 1:1, 3:7 were fabricated by electrospinning. The effects of silica content on the crystal phase and morphology of silica-titania hybrid nanofiber meshes were also analyzed by scanning electron microscopy, X-ray diffraction, and laser confocal microscopy. The osteogenic potential of the silica-titania meshes was evaluated by seeding mesenchymal stem cells (MSCs) on each mesh and determining cell number, osteodifferentiation markers, and osteopontin production over time. Our results show that cells proliferated throughout the mesh surfaces with similar morphology in all groups. Decreased cell proliferation was observed with the fiber meshes compared with glass controls, whereas cell differentiation toward osteoblast was enhanced on the mesh groups, especially on the Ti:Si = 7:3 group. These findings suggest that higher fiber diameter, degree of crystallization, and titania content of nanofibers can enhance osteodifferentiation of MSCs.
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Intradiploic hemangioma with repeated hemorrhage in a child with hemophilia.
J Neurosurg Pediatr
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Intraosseous hemangioma is an uncommon benign vascular tumor, which is most frequently found in middle-aged female patients. The clinical course is usually insidious and the outcome excellent after total resection. The authors report a case of a calvarial hemangioma in a child with hemophilia who experienced a catastrophic postoperative hematoma and discuss the mechanism, clinical features, and treatment of this condition.
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Cerebellar tonsillectomy with suboccipital decompression and duraplasty by small incision for Chiari I malformation (with syringomyelia): long term follow-up of 76 surgically treated cases.
Turk Neurosurg
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To explore the surgical effect of cerebellar tonsillectomy with suboccipital decompression and duraplasty by small surgical incision (3~4cm around the foramina magnum) on treating Chiari I Malformation (CM I) patients.
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Pure spinal epidural cavernous hemangioma.
Acta Neurochir (Wien)
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Pure epidural cavernous hemangiomas without bony involvement are rare, representing 4% of all spinal epidural tumors. Most of these are case reports and are easily misdiagnosed.
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Europium-labeled activity-based probe through click chemistry: absolute serine protease quantification using (153)Eu isotope dilution ICP/MS.
Angew. Chem. Int. Ed. Engl.
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Click and analyze: the titled probe was synthesized by conjugating a sulfonyl fluoride and azido unit using click chemistry to give SF-Eu, which can react specifically with serine (Ser) in the active site of serine protease (SP). Combination of the method with (153)Eu-isotope dilution ICP/MS enables absolute protein quantification of active SPs in biological samples using only one (153)Eu(NO(3))(3) isotopic standard.
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Symptomatic Rathke cleft cyst.
J Clin Neurosci
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Rathke cleft cysts (RCC) are uncommon intrasellar lesions. Although their clinical manifestations, radiological features and treatment are frequently reported, controversy remains as a result of their rarity. We reviewed the preoperative clinical manifestations, neurological examination findings, visual acuity and fields, endocrinological function, radiographic study findings, surgical and pathological records, and prognosis of 45 patients with RCC (21 males, 24 females, average age: 47 years) admitted to our department between January 2002 and January 2011. The most common clinical manifestations included headaches, and visual and hormonal disturbances. Most RCC were intrasellar with a suprasellar extension. The most common MRI patterns were hypointense on T1-weighted and hyperintense on T2-weighted images, isointense on T1-weighted and hyperintense on T2-weighted images, and hyperintense on T1-weighted and hyperintense on T2-weighted images. Aspiration and biopsy of the cyst wall were performed in most patients. Most patients experienced improved headaches and visual disturbance, but the hormonal disturbance rarely returned to normal, especially in those patients with a serious preoperative hormonal disturbance. The recurrence rate was 14%, which was associated with the extent of cyst removal, inflammation and rim enhancement, as well as the surgical approach. Aspiration and biopsy of the cyst wall still seems to be an effective treatment for most RCC for its low morbidity and good prognosis. Conservative treatment and close follow-up may be suitable for small cysts with subtle clinical manifestations.
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A resveratrol analog, phoyunbene B, induces G2/M cell cycle arrest and apoptosis in HepG2 liver cancer cells.
Bioorg. Med. Chem. Lett.
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Among the seven natural resveratrol analogs separated and identified from Pholidota yunnanensis R(OLFE), we found phoyunbene B (PYB, trans-3,4-dihydroxy-2,3,5-trimethoxystilbene) was more effective in inhibiting the growth of HepG2 hepatocellular carcinoma cells than resveratrol. The inhibitory effect of PYB in HepG2 cells was due to its induction of G2/M cell cycle arrest and apoptosis. Induction of G2/M phase cell cycle arrest by PYB was associated with its up-regulation of Cyclin B1, while its induction of apoptosis was accompanied with its down-regulation of Bcl-2 and up-regulation of Bax. Our in vitro invasion/migration assays also showed that PYB could inhibit the invasion of hepatocellular carcinoma cells.
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A spinal epidural dumbbell cellular schwannoma in an infant.
J Clin Neurosci
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Intraspinal schwannoma is a rare neoplasm in pediatric patients; cellular schwannoma is an unusual histological subtype of schwannoma. A six-month-old infant with an epidural dumbbell cellular schwannoma presented with progressive weakness of his arms and legs. A spinal MRI revealed an epidural mass from C5 to T4, and a complete surgical resection was achieved after laminotomy and facetectomy. The patient experienced a gradual neurological improvement and was still healthy without recurrence at the latest follow-up. The diagnosis of cellular schwannoma was confirmed on immunohistological examination.
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Polycaprolactone electrospun mesh conjugated with an MSC affinity peptide for MSC homing in vivo.
Biomaterials
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Mesenchymal stem cell (MSC) is a promising cell source candidate in tissue engineering (TE) and regenerative medicine. However, the inability to target MSCs in tissues of interest with high efficiency and engraftment has become a significant barrier for MSC-based therapies. The mobilization and transfer of MSCs to defective/damaged sites in tissues or organs in vivo with high efficacy and efficiency has been a major concern. In the present study, we identified a peptide sequence (E7) with seven amino acids through phage display technology, which has a high specific affinity to bone marrow-derived MSCs. Subsequent analysis suggested that the peptide could ef?ciently interact speci?cally with MSCs without any species specificity. Thereafter, E7 was covalently conjugated onto polycaprolactone (PCL) electrospun meshes to construct an "MSC-homing device" for the recruitment of MSCs both in vitro and in vivo. The E7-conjugated PCL electrospun meshes were implanted into a cartilage defect site of rat knee joints, combined with a microfracture procedure to mobilize the endogenous MSCs. After 7 d of implantation, immunofluorescence staining showed that the cells grown into the E7-conjugated PCL electrospun meshes yielded a high positive rate for specific MSC surface markers (CD44, CD90, and CD105) compared with those in arginine-glycine-aspartic acid (RGD)-conjugated PCL electrospun meshes (63.67% vs. 3.03%; 59.37% vs. 2.98%; and 61.45% vs. 3.82%, respectively). Furthermore, the percentage of CD68 positive cells in the E7-conjugated PCL electrospun meshes was much lower than that in the RGD-conjugated PCL electrospun meshes (5.57% vs. 53.43%). This result indicates that E7-conjugated PCL electrospun meshes absorb much less inflammatory cells in vivo than RGD-conjugated PCL electrospun meshes. The results of the present study suggest that the identified E7 peptide sequence has a high specific affinity to MSCs. Covalently conjugating this peptide on the synthetic PCL mesh significantly enhanced the MSC recruitment of PCL in vivo. This method provides a wide range of potential applications in TE.
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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.