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Find video protocols related to scientific articles indexed in Pubmed.
A pilot clinical study of Class III surgical patients facilitated by improved accelerated osteogenic orthodontic treatments.
Angle Orthod
PUBLISHED: 10-28-2014
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Objective: To evaluate if the improved accelerated osteogenic orthodontics (IAOO) procedure could speed Class III surgical patients' preoperative orthodontic treatment duration and, if yes, to what extent. This study was also designed to determine whether or not an IAOO procedure affects the tooth-moving pattern during extraction space closure. Materials and Methods: The samples in this study consisted of 24 Class III surgical patients. Twelve skeletal Class III surgery patients served as an experimental group (group 1) and the others as a control group (group 2). Before treatment, the maxillary first premolars were removed. For group 1, after the maxillary dental arch was aligned and leveled (T2), IAOO procedures were performed in the maxillary alveolar bone. Except for this IAOO procedure in group 1, all 24 patients experienced similar combined orthodontic and orthognathic treatment. Study casts of the maxillary dentitions were made before orthodontic treatment (T1) and after extraction space closure (T3). All of the casts were laser scanned, and the amount of movement of the maxillary central incisor, canine, and first molar, as well as arch widths, were digitally measured and analyzed by using the three-dimensional model superimposition method. Results: The time durations T3-T2 were significantly reduced in group 1 by 8.65 ± 2.67 months and for T3-T1 were reduced by 6.39 ± 2.00 months (P < .001). Meanwhile, the tooth movement rates were all higher in group 1 (P < .05). There were no significant differences in the amount of teeth movement in the sagittal, vertical, and transverse dimensions between the two groups (P > .05). Conclusion: The IAOO can reduce the surgical orthodontic treatment time for the skeletal Class III surgical patient by more than half a year on average. The IAOO procedures do not save anchorage.
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[The changes of p-Akt/MuRF1/FoxO1 proteins expressions in the conditions of training and immobilization in rats' gastrocnemius muscle].
Sheng Li Xue Bao
PUBLISHED: 10-22-2014
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This study was aimed to investigate the changes of muscle protein synthesis and degradation under different movement conditions, so as to provide theoretical basis for muscle atrophy mechanism. Sprague Dawley (SD) rats were randomly divided into control, endurance training (treadmill training), hind limb overhanging and eccentric training (treadmill training, angle -16º) groups. The gastrocnemius muscles of rats were taken and weighed. The muscle was sectioned, and HE staining was employed to determine the cell's cross-sectional area. Protein expression of p-Akt was measured by immunohistochemistry; and the expressions of MuRF1 and FoxO1 were determined by Western blot. The results showed that, compared with control group, hind limb overhanging and eccentric training groups exhibited decreased muscle weight and cross-sectional area, but endurance training group did not show any changes. The expressions of p-Akt in endurance and eccentric training groups, not in hind limb overhanging group, were significantly higher than that in control group. Compared with that of control, MuRF1 protein remained unchanged in endurance training groups, but was increased in eccentric training and hind limb overhanging groups; FoxO1 protein was decreased in endurance training group, but was increased in eccentric training and hind limb overhanging groups. These results indicate that movement (endurance and eccentric training) can activate Akt expression, but does not increase muscle weight, whereas eccentric training and hind limb overhanging can increase the expressions of MuRF1 and FoxO1, and induce amyotrophy, suggesting MuRF1 and FoxO1 are major determinant factors in muscle atrophy.
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Emergence of amplitude and oscillation death in identical coupled oscillators.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 09-08-2014
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We deduce rigorous conditions for the onset of amplitude death (AD) and oscillation death (OD) in a system of identical coupled paradigmatic Stuart-Landau oscillators. A nonscalar coupling and high frequency are beneficial for the onset of AD. In strong contrast, scalar diffusive coupling and low intrinsic frequency are in favor of the emergence of OD. Our finding contributes to clearly distinguish intrinsic geneses for AD and OD, and further substantially corroborates that AD and OD are indeed two dynamically distinct oscillation quenching phenomena due to distinctly different mechanisms.
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Compressed-sensing-based fluorescence molecular tomographic image reconstruction with grouped sources.
Biomed Eng Online
PUBLISHED: 08-20-2014
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Although the quality of reconstructed results can be improved with the increment of the number of measurements, the scale of the matrices involved in the reconstruction of fluorescence molecular tomography (FMT) will become larger, which leads to the poor efficiency of the process of tomographic image reconstruction. In this paper, we proposed a new method for image reconstruction of FMT based on compressed sensing, in which a scheme of grouped sources is incorporated.
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Manipulation of receptor oligomerization as a strategy to inhibit signaling by TNF superfamily members.
Sci Signal
PUBLISHED: 08-19-2014
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Signaling by receptor activator of nuclear factor ?B (RANK) in response to its ligand RANKL, which is a member of the tumor necrosis factor (TNF) superfamily of cytokines, stimulates osteoclast formation and bone resorption. Thus, this ligand-receptor pair is a therapeutic target for various disorders, such as osteoporosis and metastasis of cancer to bone. RANKL exists as a physiological homotrimer, with each monomer recognizing a single molecule of RANK or the decoy receptor osteoprotegerin (OPG), which inhibits osteoclastogenesis. We engineered a RANKL protein in which all three monomers of RANKL were encoded as a single polypeptide chain, which enabled us to independently control receptor binding at each binding interface. To generate an effective RANK inhibitor, we used an unbiased forward genetic approach to identify mutations in RANKL that had a 500-fold increased affinity for RANK but had decreased affinity for the decoy receptor OPG. Incorporating mutations that blocked receptor binding into this high-affinity RANKL variant generated a mutant RANKL that completely inhibited wild-type RANKL-induced osteoclastogenesis in vitro and bone resorption in mice. Our approach may be generalized to enable the inhibition of other TNF receptor signaling systems, which are implicated in a wide range of pathological conditions.
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Emodin inhibits breast cancer cell proliferation through the ER?-MAPK/Akt-cyclin D1/Bcl-2 signaling pathway.
Asian Pac. J. Cancer Prev.
PUBLISHED: 08-16-2014
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The aim of the present study was to investigate the involvement of emodin on the growth of human breast cancer MCF-7 and MDA-MB-231 cells and the estrogen (E2) signal pathway in vitro.
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PI3P phosphatase activity is required for autophagosome maturation and autolysosome formation.
EMBO Rep.
PUBLISHED: 08-14-2014
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Autophagosome formation is promoted by the PI3 kinase complex and negatively regulated by myotubularin phosphatases, indicating that regulation of local phosphatidylinositol 3-phosphate (PtdIns3P) levels is important for this early phase of autophagy. Here, we show that the Caenorhabditis elegans myotubularin phosphatase MTM-3 catalyzes PtdIns3P turnover late in autophagy. MTM-3 acts downstream of the ATG-2/EPG-6 complex and upstream of EPG-5 to promote autophagosome maturation into autolysosomes. MTM-3 is recruited to autophagosomes by PtdIns3P, and loss of MTM-3 causes increased autophagic association of ATG-18 in a PtdIns3P-dependent manner. Our data reveal critical roles of PtdIns3P turnover in autophagosome maturation and/or autolysosome formation.
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Dynamic simulation of motion effects in IMAT lung SBRT.
Radiat Oncol
PUBLISHED: 07-02-2014
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BackgroundIntensity modulated arc therapy (IMAT) has been widely adopted for Stereotactic Body Radiotherapy (SBRT) for lung cancer. While treatment dose is optimized and calculated on a static Computed Tomography (CT) image, the effect of the interplay between the target and linac multi-leaf collimator (MLC) motion is not well described and may result in deviations between delivered and planned dose. In this study, we investigated the dosimetric consequences of the inter-play effect on target and organs at risk (OAR) by simulating dynamic dose delivery using dynamic CT datasets.MethodsFifteen stage I non-small cell lung cancer (NSCLC) patients with greater than 10 mm tumor motion treated with SBRT in 4 fractions to a dose of 50 Gy were retrospectively analyzed for this study. Each IMAT plan was initially optimized using two arcs. Simulated dynamic delivery was performed by associating the MLC leaf position, gantry angle and delivered beam monitor units (MUs) for each control point with different respiratory phases of the 4D-CT using machine delivery log files containing time stamps of the control points. Dose maps associated with each phase of the 4D-CT dose were calculated in the treatment planning system and accumulated using deformable image registration onto the exhale phase of the 4D-CT. The original IMAT plans were recalculated on the exhale phase of the CT for comparison with the dynamic simulation.ResultsThe dose coverage of the PTV showed negligible variation between the static and dynamic simulation. There was less than 1.5% difference in PTV V95% and V90%. The average inter-fraction and cumulative dosimetric effects among all the patients were less than 0.5% for PTV V95% and V90% coverage and 0.8 Gy for the OARs. However, in patients where target is close to the organs, large variations were observed on great vessels and bronchus for as much as 4.9 Gy and 7.8 Gy.ConclusionsLimited variation in target dose coverage and OAR constraints were seen for each SBRT fraction as well as over all four fractions. Large dose variations were observed on critical organs in patients where these organs were closer to the target.
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High dose radiotherapy to automated implantable cardioverter-defibrillator: a case report and review of the literature.
Case Rep Oncol Med
PUBLISHED: 07-01-2014
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We report a case of successful full-dose chemoradiotherapy to stage IIIB nonsmall cell lung cancer (NSCLC) in a 59-year-old man with extensive cardiac history and an automated implantable cardioverter-defibrillator (AICD) located within the radiotherapeutic field. In this case, the AICD was a St. Jude Medical Fortify Assura VR 1257-40Q ICD, and it was implanted prophylactically during bypass grafting. Although we do not recommend routine radiotherapy dose to exceed recommended current guidelines due to the potential risks to the patient, this is a situation where relocation of the device was not possible. Fortunately, our patient was not AICD-dependent; so following much discussion and deliberation, the decision was made to treat the patient with AICD in place. The patient completed definitive chemoradiotherapy with concurrent cisplatin and etoposide and thoracic irradiation to 69.6?Gy. The minimum, maximum, and mean doses to the AICD directly were 13.5?Gy, 52.4?Gy, and 29.3?Gy, respectively. The device withstood full thoracic radiation dose, and the patient denied cardiac symptoms during the time before, during, and after completion of therapy. We sought to offer this case for both teaching and guidance in practice and to contribute to the published literature currently available in this area.
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Role of aldehyde dehydrogenase 2 in 1-methy-4-phenylpyridinium ion-induced aldehyde stress and cytotoxicity in PC12 cells.
Neurochem. Res.
PUBLISHED: 06-27-2014
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Aldehyde stress contributes to molecular mechanisms of cell death and the pathogenesis of Parkinson's disease (PD). The neurotoxin 1-Methy-4-Phenylpyridinium Ion (MPP(+)) is commonly used to model PD. Aldehyde dehydrogenase 2 (ALDH2) is an important enzyme detoxifying aldehydes. The aim of this study is to evaluate whether MPP(+)-induced neurotoxicity is involved in aldehyde stress by modulation of ALDH2. Our results demonstrated that treatment of PC12 cells with MPP(+) leads to aldehyde stress by increasing in loads of malondialdehyde and 4-hydroxynonenal, which indicated that MPP(+)-induced aldehyde stress contributes to its cytotoxicity in PC12 cells. We also showed that MPP(+) up-regulates the expression and activity of ALDH2 in PC12 cells and that inhibition of ALDH2 by its specific inhibitor daidzin prevents MPP(+)-induced decrease in cell viability and increases in apoptosis, oxidative stress and aldehyde stress in PC12 cells. These findings suggest that aldehyde stress contributes to MPP(+)-induced toxicity in PC12 cells by upregulation of ALDH2. This study provides a novel insight into the role of ALDH2 in the neurotoxicity of MPP(+).
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An insulin-sensitizing thiazolidinedione, which minimally activates PPAR?, does not cause bone loss.
J. Bone Miner. Res.
PUBLISHED: 06-12-2014
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Rosiglitazone is an insulin-sensitizing thiazolidinedione (TZD) which activates the transcription factor, peroxisome proliferator-activated receptor gamma (PPAR?). While rosiglitazone effectively treats type II diabetes mellitus (T2DM), it carries substantial complications including increased fracture risk. This predisposition to fracture is consistent with the fact that PPAR? preferentially promotes formation of adipocytes at the cost of osteoblasts. Rosiglitazone-activated PPAR?, however, also stimulates osteoclast formation. A new TZD analog with low affinity for binding and activation of PPAR? but whose insulin-sensitizing properties mirror those of rosiglitazone, has been recently developed. Because of its therapeutic implications, we investigated the effects of this new TZD analog (MSDC-0602) on skeletal homeostasis, in vitro and in vivo. Confirming it activates the nuclear receptor in osteoclasts, rosiglitazone enhances expression of the PPAR? target gene, CD36. MSDC-0602, in contrast, minimally activates PPAR? and does not alter CD36 expression in the bone resorptive cells. Consistent with this finding, rosiglitazone increases RANKL-induced osteoclast differentiation and number whereas MSDC-0602 fails to do. To determine if this new TZD analog is bone sparing, in vivo, we fed adult male C57BL/6 mice MSDC-0602 or rosiglitazone. 6-months of a rosiglitazone diet results in a 35% decrease in bone mass with increased number of osteoclasts whereas that of MSDC-0602 fed mice is indistinguishable from control. Thus PPAR?-sparing eliminates the skeletal side effects of TZDs while maintaining their insulin-sensitizing properties. © 2014 American Society for Bone and Mineral Research.
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Benefits of exenatide on obesity and non-alcoholic fatty liver disease with elevated liver enzymes in patients with type 2 diabetes.
Diabetes Metab. Res. Rev.
PUBLISHED: 04-27-2014
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The purpose of this study was to evaluate the advantages of exenatide treatment on obesity and non-alcoholic fatty liver disease (NAFLD) with elevated liver enzymes in patients with type 2 diabetes (T2D).
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Hydrogen sulfide inhibits homocysteine-induced endoplasmic reticulum stress and neuronal apoptosis in rat hippocampus via upregulation of the BDNF-TrkB pathway.
Acta Pharmacol. Sin.
PUBLISHED: 04-21-2014
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Homocysteine (Hcy) can elicit neuronal cell death, and hyperhomocysteinemia is a strong independent risk factor for Alzheimer's disease. The aim of this study was to examine the effects of hydrogen sulfide (H2S) on Hcy-induced endoplasmic reticulum (ER) stress and neuronal apoptosis in rat hippocampus.
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Vinculin regulates osteoclast function.
J. Biol. Chem.
PUBLISHED: 03-27-2014
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Osteoclastic bone resorption depends upon the cell's ability to organize its cytoskeleton. Because vinculin (VCL) is an actin-binding protein, we asked whether it participates in skeletal degradation. Thus, we mated VCL(fl/fl) mice with those expressing cathepsin K-Cre (CtsK-VCL) to delete the gene in mature osteoclasts or lysozyme M-Cre (LysM-VCL) to target all osteoclast lineage cells. VCL-deficient osteoclasts differentiate normally but, reflecting cytoskeletal disorganization, form small actin rings and fail to effectively resorb bone. In keeping with inhibited resorptive function, CtsK-VCL and LysM-VCL mice exhibit a doubling of bone mass. Despite cytoskeletal disorganization, the capacity of VCL(-/-) osteoclastic cells to normally phosphorylate c-Src in response to ?v?3 integrin ligand is intact. Thus, integrin-activated signals are unrelated to the means by which VCL organizes the osteoclast cytoskeleton. WT VCL completely rescues actin ring formation and bone resorption, as does VCL(P878A), which is incapable of interacting with Arp2/3. As expected, deletion of the VCL tail domain (VCL(1-880)), which binds actin, does not normalize VCL(-/-) osteoclasts. The same is true regarding VCL(I997A), which also prevents VCL/actin binding, and VCL(A50I) and VCL(811-1066), both of which arrest talin association. Thus, VCL binding talin, but not Arp2/3, is critical for osteoclast function, and its selective inhibition retards physiological bone loss.
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Human intestinal microbial metabolism of naringin.
Eur J Drug Metab Pharmacokinet
PUBLISHED: 03-24-2014
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Naringin, a major flavonoid in citrus fruits, has been proved to be a promising antitussive candidate. It undertakes complicated metabolism. In this study, human intestinal microbial metabolism of naringin was studied in vitro. Six persons' fecal water, which have intestinal microbial enzyme, were used in the first experiment. Naringin was metabolized by fecal water into naringenin. Subsequently, 3-(4-hydroxyphenyl)propionic acid (4-HPPA) was produced with naringenin degradation by a person's fecal water. However, 4-HPPA was not detected after naringenin degradation by the other 5 subjects' fecal water and the reason might be that the degrading velocity of 4-HPPA exceeded the producing velocity. To confirm the difference in degrading 4-HPPA among human feces, 22 healthy persons' feces were used for incubation. In this second experiment, 15 persons' feces could degrade 4-HPPA, but the other 7 subjects' could not. Human feces showed different ability of degrading 4-HPPA, and there are no gender differences. These results may be helpful for explaining findings in pharmacological and toxicological studies and are groundwork for clinical studies.
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Gap junction blockade induces apoptosis in human endometrial stromal cells.
Mol. Reprod. Dev.
PUBLISHED: 03-19-2014
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One of the most dynamic adult human tissues is the endometrium. Through coordinated, cyclical proliferation, differentiation, leukocyte recruitment, apoptosis, and desquamation, the uterine lining is expanded and shed monthly, unless pregnancy is established. Errors in these steps potentially cause endometrial dysfunction, abnormal uterine bleeding, failed embryonic implantation, infertility, or endometrial carcinoma. Our prior studies showed that gap junctions comprised of Gap junction alpha-1 (GJA1) protein, also known as connexin 43 (CX43), subunits are critical to endometrial stromal cell differentiation. The current studies were undertaken to explore the mechanism of endometrial dysfunction when gap junction intercellular communication (GJIC) is disrupted. Gap junction blockade by two distinct GJIC inhibitors, 18?-glycyrrhetinic acid (AGA) and octanol (OcOH), suppressed proliferation and induced apoptosis in endometrial stromal cells, as manifested by reduced biomarkers of cell viability, increased TUNEL staining, caspase-3 activation, sub-G1 chromosomal DNA complement, as well as shortened telomere length. Unexpectedly, we also observed that the chemical inhibitors blocked CX43 gene expression. Moreover, when endometrial stromal cells were induced to undergo hormonal decidualization, following a 7-day exposure to 10?nM 17?-estradiol?+?100?nM progesterone?+?0.5?mM dibutyryl cAMP, characteristic epithelioid changes in cell shape and secretion of prolactin were blunted in the presence of AGA or OcOH, recapitulating effects of RNA interference of CX43. Our findings indicate that endometrial stromal cell proliferation and maintenance of decidualized endometrial function are GJIC-dependent, and that disruption of gap junctions induces endometrial stromal cell apoptosis. These observations may have important implications for several common clinical endometrial pathologies.
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Metabolic model reconstruction and analysis of an artificial microbial ecosystem for vitamin C production.
J. Biotechnol.
PUBLISHED: 03-13-2014
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An artificial microbial ecosystem (AME) consisting of Ketogulonicigenium vulgare and Bacillus megaterium is currently used in a two-step fermentation process for vitamin C production. In order to obtain a comprehensive understanding of the metabolic interactions between the two bacteria, a two-species stoichiometric metabolic model (iWZ-KV-663-BM-1055) consisting of 1718 genes, 1573 metabolites, and 1891 reactions (excluding exchange reactions) was constructed based on separate genome-scale metabolic models (GSMMs) of K. vulgare and B. megaterium. These two compartments (k and b) of iWZ-KV-663-BM-1055 shared 453 reactions and 548 metabolites. Compartment b was richer in subsystems than compartment k. In minimal media with glucose (MG), metabolite exchange between compartments was assessed by constraint-based analysis. Compartment b secreted essential amino acids, nucleic acids, vitamins and cofactors important for K. vulgare growth and biosynthesis of 2-keto-l-gulonic acid (2-KLG). Further research showed that when co-cultured with B. megaterium in l-sorbose-CSLP medium, the growth rate of K. vulgare and 2-KLG production were increased by 111.9% and 29.42%, respectively, under the constraints employed. Our study demonstrated that GSMMs and constraint-based methods can be used to decode the physiological features and inter-species interactions of AMEs used in industrial biotechnology, which will be of benefit for improving regulation and refinement in future industrial processes.
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Fabrication of interfacial functionalized porous polymer monolith and its adsorption properties of copper ions.
J. Hazard. Mater.
PUBLISHED: 03-03-2014
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The interfacial functionalized poly (glycidyl methacrylate) (PGMA) porous monolith was fabricated and applied as a novel porous adsorbent for copper ions (Cu(2+)). PGMA porous material with highly interconnected pore network was prepared by concentrated emulsion polymerization template. Then polyacrylic acid (PAA) was grafted onto the interface of the porous monolith by the reaction between the epoxy group on PGMA and a carboxyl group on PAA. Finally, the porous monolith was interfacial functionalized by rich amount of carboxyl groups and could adsorb copper ions effectively. The chemical structure and porous morphology of the porous monolith were measured by Fourier transform infrared spectroscopy and scanning electron microscopy. Moreover, the effects of pore size distribution, pH value, co-existing ions, contacting time, and initial concentrations of copper ions on the adsorption capacity of the porous adsorbents were studied.
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Stereospecific [3+2] cycloaddition of 1,2-cyclopropanated sugars and ketones catalyzed by SnCl4: an efficient synthesis of multi-substituted perhydrofuro[2,3-b]furans and perhydrofuro[2,3-b]pyrans.
Chem. Commun. (Camb.)
PUBLISHED: 02-21-2014
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Stereospecific [3+2] cycloaddition of 1,2-cyclopropanated sugars and ketones catalyzed by SnCl4 is described. The method offers multi-substituted perhydrofuro[2,3-b]furans (bis-THFs) and perhydrofuro[2,3-b]pyrans containing a quaternary carbon chiral center in good to excellent yields.
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Gain and loss of function of P2X7 receptors: mechanisms, pharmacology and relevance to diabetic neuropathic pain.
Mol Pain
PUBLISHED: 02-18-2014
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Genetic causes of exaggerated or reduced pain sensitivity in humans are well known. Recently, single nucleotide polymorphisms (SNPs) in the gene P2RX7, coding for the ATP-gated ion channel P2X7, have been described that cause gain-of-function (GOF) and loss-of-function (LOF), respectively of this channel. Importantly, P2RX7 SNPs have been associated with more or less severe pain scores in patient suffering of post-mastectomy pain and osteoarthritis.
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Rat cortex and hippocampus-derived soluble factors for the induction of adipose-derived mesenchymal stem cells into neuron-like cells.
Cell Biol. Int.
PUBLISHED: 01-27-2014
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To simulate brain microenvironment, adipose-derived mesenchymal stem cells (AMSC) were induced to differentiate to neuronal-like cells in rat cortex and hippocampus medium (Cox?+?Hip). First, isolated AMSC were characterized by flow cytometer and the capacity of adipogenesis and osteogenesis. After induction in rat cortex and hippocampus conditioned medium, the cell morphological change was examined and neural marker proteins (?-?-Tubulin, NSE, Nissl body) expression was detected by immunofluorescence staining. A variety of synaptic marker proteins, including GAP43, SHANK2, SHANK3 and Bassoon body, were detected. ELISA was used to measure brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF) secretion at different time-points. AMSCs positively expressed CD13, CD44 and CD90 and could differentiate into osteoblasts or adipocytes. After induction in Cox?+?Hip medium for 14 days, cells had a typical neuronal perikaryal appearance, which was suggestive of neuronal differentiation. After 14 days of Cox?+?Hip treatment, the percentage of cells expressing ?-?-Tubulin, NSE and Nissl was 53.9?±?0.8%, 51.3?±?1.7% and 16.4?±?2.1%, respectively. Expression of GAP43, SHANK2, SHANK3 and Bassoon body was detected, indicating synapse formation after treatment in Cox?+?Hip medium. Differentiated AMSCs secreted neurotrophic factors NGF and BDNF. Thus rat cortex and hippocampus-derived soluble factors can induce AMSCs to a neuronal-like phenotype, suggesting that AMSCs have a dual role in supplementing newborn neurons and secreting neurotrophic factors, and therefore could be help as a potential treatment for nervous system diseases.
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Human adipose-derived mesenchymal stem cells: a better cell source for nervous system regeneration.
Chin. Med. J.
PUBLISHED: 01-21-2014
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In order to suggest an ideal source of adult stem cells for the treatment of nervous system diseases, MSCs from human adipose tissue and bone marrow were isolated and studied to explore the differences with regard to cell morphology, surface markers, neuronal differentiation capacity, especially the synapse structure formation and the secretion of neurotrophic factors.
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Identification of functional cooperative mutations of SETD2 in human acute leukemia.
Nat. Genet.
PUBLISHED: 01-15-2014
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Acute leukemia characterized by chromosomal rearrangements requires additional molecular disruptions to develop into full-blown malignancy, yet the cooperative mechanisms remain elusive. Using whole-genome sequencing of a pair of monozygotic twins discordant for MLL (also called KMT2A) gene-rearranged leukemia, we identified a transforming MLL-NRIP3 fusion gene and biallelic mutations in SETD2 (encoding a histone H3K36 methyltransferase). Moreover, loss-of-function point mutations in SETD2 were recurrent (6.2%) in 241 patients with acute leukemia and were associated with multiple major chromosomal aberrations. We observed a global loss of H3K36 trimethylation (H3K36me3) in leukemic blasts with mutations in SETD2. In the presence of a genetic lesion, downregulation of SETD2 contributed to both initiation and progression during leukemia development by promoting the self-renewal potential of leukemia stem cells. Therefore, our study provides compelling evidence for SETD2 as a new tumor suppressor. Disruption of the SETD2-H3K36me3 pathway is a distinct epigenetic mechanism for leukemia development.
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Disturbance of endogenous hydrogen sulfide generation and endoplasmic reticulum stress in hippocampus are involved in homocysteine-induced defect in learning and memory of rats.
Behav. Brain Res.
PUBLISHED: 01-02-2014
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Homocysteine (Hcy) is a risk factor for Alzheimer's disease (AD). Hydrogen sulfide (H2S) acts as an endogenous neuromodulator and neuroprotectant. It has been shown that endoplasmic reticulum (ER) stress is involved in the pathological mechanisms of the learning and memory dysfunctions and that H2S exerts its neuroprotective role via suppressing ER stress. In the present work, we explored the effects of intracerebroventricular injection of Hcy on the formation of learning and memory, the generation of endogenous H2S, and the expression of ER stress in the hippocampus of rats. We found that intracerebroventricular injection of Hcy in rats leads to learning and memory dysfunctions in the Morris water maze and novel of object recognition test and decreases in the expression of cystathionine-?-synthase, the major enzyme responsible for endogenous H2S generation, and the generation of endogenous H2S in the hippocampus of rats. We also showed that exposure of Hcy could up-regulate the expressions of glucose-regulated protein 78 (GRP78), CHOP, and cleaved caspase-12, which are the major mark proteins of ER stress, in the hippocampus of rats. Taken together, these results suggest that the disturbance of hippocampal endogenous H2S generation and the increase in ER stress in the hippocampus are related to Hcy-induced defect in learning and memory.
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Archform comparisons between skeletal class II and III malocclusions.
PLoS ONE
PUBLISHED: 01-01-2014
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The purpose of this cross-sectional research was to explore the relationship of the mandibular dental and basal bone archforms between severe Skeletal Class II (SC2) and Skeletal Class III (SC3) malocclusions. We also compared intercanine and intermolar widths in these two malocclusion types. Thirty-three virtual pretreatment mandibular models (Skeletal Class III group) and Thirty-five Skeletal Class II group pretreatment models were created with a laser scanning system. FA (the midpoint of the facial axis of the clinical crown)and WALA points (the most prominent point on the soft-tissue ridge)were employed to produce dental and basal bone archforms, respectively. Gained scatter diagrams of the samples were processed by nonlinear regression analysis via SPSS 17.0. The mandibular dental and basal bone intercanine and intermolar widths were significantly greater in the Skeletal Class III group compared to the Skeletal Class II group. In both groups, a moderate correlation existed between dental and basal bone arch widths in the canine region, and a high correlation existed between dental and basal bone arch widths in the molar region. The coefficient of correlation of the Skeletal Class III group was greater than the Skeletal Class II group. Fourth degree, even order power functions were used as best-fit functions to fit the scatter plots. The radius of curvature was larger in Skeletal Class III malocclusions compared to Skeletal Class II malocclusions (rWALA3>rWALA2>rFA3>rFA2). In conclusion, mandibular dental and basal intercanine and intermolar widths were significantly different between the two groups. Compared with Skeletal Class II subjects, the mandibular archform was more flat for Skeletal Class III subjects.
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PB2 588I enhances the 2009 H1N1 pandemic influenza virus virulence by increasing viral replication and exacerbating PB2 inhibition of interferon-beta expression.
J. Virol.
PUBLISHED: 12-11-2013
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The 2009 pandemic H1N1 influenza virus (pdm/09) is typically mildly virulent in mice. In a previous study, we identified four novel swine isolates of pdm/09 viruses that exhibited high lethality in mice. Comparing the consensus sequences of the PB2 subunit of human isolates of pdm/09 viruses with those of the four swine isolate viruses exhibited one consensus mutation: T588I. In this study, we determined that 588T is an amino acid mutation conserved in pdm/09 viruses that was exceedingly rare in previous human influenza isolates. To investigate whether the PB2-T558I mutation has an effect on the increased pathogenicity, we rescued a variant containing PB2-588I (Mex_PB2-588I) in the pdm/09 virus, A/Mexico/4486/2009(H1N1), referred to Mex_WT, and characterized the variant in vitro and in vivo. The results indicated that the mutation significantly enhanced polymerase activity in mammalian cells, and the variant exhibited increased growth properties and induced significant weight loss in a mouse model compared to the wild type (WT). We determined that the mutation exacerbated PB2 inhibition of MAVS-mediated IFN-? expression, and PB2-588I was observed to bind to MAVS more efficiently than PB2-588T. The variant induced lower levels of host IFN-? expression than the WT strain during infection. These findings indicate that the pdm/09 influenza virus has increased pathogenicity upon the acquisition of the PB2-T588I mutation and highlight the need for the continued surveillance of the genetic variation of molecular markers in influenza viruses, because of their potential effects on pathogenicity and threats to human health.
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Image reconstruction of fluorescent molecular tomography based on the simplified matrix system.
J Opt Soc Am A Opt Image Sci Vis
PUBLISHED: 12-11-2013
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Fluorescent molecular tomographic image reconstruction usually involves repeatedly solving large-scale matrix equations, which are computationally expensive. In this paper, a method is proposed to reduce the scale of the matrix system. The Jacobian matrix is simplified by deleting the columns or the rows whose values are smaller than a threshold. Furthermore, the measurement data are divided into two groups and are used for iteration of image reconstruction in turn. The simplified system is then solved in the wavelet domain to further accelerate the process of solving the inverse problem. Simulation results demonstrate that the proposed method can significantly speed up the reconstruction process.
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Apurinic/apyrimidinic endonuclease 1 polymorphisms are associated with ovarian cancer susceptibility in a Chinese population.
Int. J. Gynecol. Cancer
PUBLISHED: 11-22-2013
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Apurinic/apyrimidinic endonuclease 1 (APE1) plays an essential role in the base excision repair pathway. Recent studies have shown that APE1 polymorphisms are associated with an increased risk for many types of cancers. This study investigated the association between APE1 polymorphisms and the susceptibility of ovarian cancer.
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Cbl-b and PI3K/Akt pathway are differently involved in oxygen-glucose deprivation preconditioning in PC12 cells.
Chin. Med. J.
PUBLISHED: 11-16-2013
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Transient sublethal ischemia is known as ischemic preconditioning, which enables cells and tissues to survive subsequent prolonged lethal ischemic injury. Ischemic preconditioning exerts neuroprotection through phosphatidylinositol 3-kinase (PI3K)/Akt pathway. Cbl-b belongs to the Casitas B-lineage lymphoma (Cbl) family, and it can regulate the cell signal transduction.The roles of ubiquitin ligase Cbl-b and PI3K/Akt pathway and the relationship between them in oxygen-glucose deprivation preconditioning (OGDPC) in PC12 cells were investigated in the present study.
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[Inhibitory effect of luteolin on the angiogenesis of chick chorioallantoic membrane and invasion of breast cancer cells via downregulation of AEG-1 and MMP-2].
Sheng Li Xue Bao
PUBLISHED: 10-17-2013
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The purpose of the present study was to investigate the effect of luteolin on the angiogenesis and invasion of breast cancer cells. MTT assay was used to examine breast cancer proliferation. The chick chorioallantoic membrane model was used to assess the angiogenesis effect. Wound healing assay was used to assess cell invasion ability. Western blot was used to analyze Bcl-2, AEG-1 and MMP-2 expression levels. The results showed luteolin inhibited MCF-7 cells proliferation in a dose- and time-dependent manner, and the expression of Bcl-2 protein was decreased. Luteolin had a strong anti-angiogenesis of chick chorioallantoic membrane. After treatment of MCF-7 cells with luteolin at 60 ?mol/L for 48 h, migration rate was reduced by 71.07% compared with control (P < 0.01). After treatment of MCF-7 cells with luteolin at 60 ?mol/L for 48 h, the expression of AEG-1 and MMP-2 was reduced by 82.34% (P < 0.05) and 85.70% (P < 0.05) respectively, compared with control. In conclusion, the results suggest that luteolin can inhibit the proliferation of breast cancer cells, and suppress the expression of Bcl-2. Furthermore, luteolin has strong anti-angiogenesis of chick chorioallantoic membrane and anti-invasive activity on breast cancer cells, and down-regulates the expression of AEG-1 and MMP-2.
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Generalizing the transition from amplitude to oscillation death in coupled oscillators.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 09-29-2013
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Amplitude death (AD) and oscillation death (OD) are two structurally different oscillation quenching types in coupled nonlinear oscillators. The transition from AD to OD has been recently realized due to the interplay between heterogeneity and coupling strength [A. Koseska et al., Phys. Rev. Lett. 111, 024103 (2013)]. We identify here the transition from AD to OD in nonlinear oscillators with couplings of distinct natures. It is demonstrated that the presence of time delay in the coupling cannot induce such a transition in identical oscillators, but it can indeed facilitate its occurrence with a low degree of heterogeneity. Moreover, it is further shown that the AD to OD transition is reliably observed in identical oscillators with dynamic and conjugate couplings. The coexistence of AD and OD and rich stable OD configurations after the transition are revealed, which are of great significance for potential applications in physics, biology, and control studies.
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Antidepressant-like and anxiolytic-like effects of hydrogen sulfide in behavioral models of depression and anxiety.
Behav Pharmacol
PUBLISHED: 08-27-2013
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Depression is a common and debilitating mental illness and is often comorbid with anxiety disorders. Altered synaptic plasticity is considered to be an important mechanism underlying antidepressant drug action. It has been reported that hydrogen sulfide (H2S), the third gaseous transmitter, facilitates the induction of hippocampal long-term potentiation and augments synaptic neurotransmission, involved in the regulation of synaptic plasticity. The aim of this study was to clarify the antidepressant-like and anxiolytic-like effects of H2S. H2S (NaHS, 1.68 or 5.6 mg/kg, intraperitoneally, for 7 days) exerts a specific antidepressant-like effect in the forced swimming test of mice and rats and the tail suspension test of mice, and reduces the anxiety-like behaviors of both mice and rats in the elevated plus-maze test. These results reveal a unique antagonistic action of H2S in depressive-like and anxiety-like behaviors and suggest that elevating H2S signaling in the brain may represent a novel approach for the treatment of depressive and anxiety disorders.
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[Relationship between ER-?36 and Akt in PC12 cells exposed to glucose deprivation].
Sheng Li Xue Bao
PUBLISHED: 08-22-2013
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ER-?36 is a novel 36-kDa variant of ER-?. A large of evidence demonstrated that ER-?36 responded to membrane-initiated estrogen signaling pathways which were involved in the physiological and pathological process in many kinds of cells. In this study, knock-down of ER-?36 expression in pheochromocytoma (PC12) cells (named as PC12-36L cells) by using the shRNA method was used to evaluate the relationship between ER-?36 and Akt in neurons under glucose deprivation. The effect of ER-?36 on outgrowth of PC12 cells, as well as the neuroprotective effect of ER-?36 on injured PC12 cells exposed to glucose deprivation was observed by using MTT assay, Western blot and Annexin V/PI staining et al. The results showed that, (1) Glucose deprivation induced by MEM treatment for 6 h reduced survival rate and increased apoptotic rate in PC12 cells significantly compared to control group (P < 0.01); and it produced a decrease in the expression of Glut-4 protein (P < 0.01); (2) The expression level of ER-?36 was decreased significantly at 3 h of glucose deprivation, and then increased, while phosphorylation of Akt participated in the glucose deprivation was increased at first and then reduced; LY294002 (PI3K inhibitor) contributed to decreased expression of ER-?36, and suppressed the activation of Akt; (3) The rate of apoptosis was significantly increased in PC12-36L cells after glucose deprivation compared with that in wild type PC12 cells (P < 0.01). Furthermore, phosphorylation of Akt was decreased and Caspase-3 was increased by glucose deprivation in PC12-36L cells compared with those in wild type PC12 cells. The study reveals that phosphorylation of Akt is associated with ER-?36 in PC12 cells exposed to glucose deprivation, and both are involved in the regulation of stress responses.
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In vivo analysis of highly conserved Nef activities in HIV-1 replication and pathogenesis.
Retrovirology
PUBLISHED: 08-16-2013
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The HIV-1 accessory protein, Nef, is decisive for progression to AIDS. In vitro characterization of the protein has described many Nef activities of unknown in vivo significance including CD4 downregulation and a number of activities that depend on Nef interacting with host SH3 domain proteins. Here, we use the BLT humanized mouse model of HIV-1 infection to assess their impact on viral replication and pathogenesis and the selection pressure to restore these activities using enforced in vivo evolution.
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Simultaneous generation of gradients with gradually changed slope in a microfluidic device for quantifying axon response.
Anal. Chem.
PUBLISHED: 08-07-2013
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Over the past decades, various microfluidic devices have been developed to investigate the role of the molecular gradient in axonal development; however, there are very few devices providing quantitative information about the response of axons to molecular gradients with different slopes. Here, we propose a novel laminar-based microfluidic device enabling simultaneous generation of multiple gradients with gradually changed slope on a single chip. This device, with two asymmetrically designed peripheral channels and opposite flow direction, could generate gradients with gradually changed slope in the center channel, enabling us to investigate simultaneously the response of axons to multiple slope gradients with the same batch of neurons. We quantitatively investigated the response of axon growth rate and growth direction to substrate-bound laminin gradients with different slopes using this single-layer chip. Furthermore, we compartmented this gradient generation chip and a cell culture chip by a porous membrane to investigate quantitatively the response of axon growth rate to the gradient of soluble factor netrin-1. The results suggested that contacting with a molecular gradient would effectively accelerate neurites growth and enhance axonal formation, and the axon guidance ratio obviously increased with the increase of gradient slope in a proper range. The capability of generating a molecular gradient with continuously variable slopes on a single chip would open up opportunities for obtaining quantitative information about the sensitivity of axons and other types of cells in response to gradients of various proteins.
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Development of a minimal chemically defined medium for Ketogulonicigenium vulgare WSH001 based on its genome-scale metabolic model.
J. Biotechnol.
PUBLISHED: 07-25-2013
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Commercial production of 2-keto-l-gulonic acid (2-KLG), the immediate precursor of l-ascorbic acid, is by Ketogulonicigenium vulgare in co-culture with Bacillus megaterium. We used flux balance analysis (FBA) to study a genome-scale metabolic model (GSMM) of K. vulgare, iWZ663, and found that K. vulgare is deficient in nutrient biosynthetic pathways. Individually omitting l-glycine, l-cysteine, l-methionine, l-tryptophan, adenine, thymine, thiamine and pantothenate from complete chemically defined medium (CDM), caused biomass formation of K. vulgare to decrease to 1%, 21%, 16%, 1%, 26%, 57%, 73% and 24%, respectively. Based on these results and FBA, a minimal chemically defined medium (MCDM) was developed that supported monoculture of K. vulgare (0.28OD600) and 2-KLG production (3.59g/L), which were similar to those in complete CDM or corn steep liquor powder (CSLP) medium. This study demonstrated the potential of using GSMM and FBA to characterize nutrient requirements, optimize CDM, and study interactions in co-culture.
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Targetable fluorescent probe for monitoring exogenous and endogenous NO in mitochondria of living cells.
Anal. Chem.
PUBLISHED: 07-18-2013
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Nitric oxide (NO) is a ubiquitous cellular messenger molecule in the cardiovascular, nervous, and immune systems. Mitochondrion is the main area where endogenous NO is synthesized by inducible NOS enzymes in mammalian cells. Thus, real-time monitoring NO in mitochondria is very meaningful for NO chemical biology. Although a variety of fluorescent probes for NO have been successfully developed, they are not suited for detecting mitochondrial NO because none of them can specifically localize in mitochondria. Herein, Mito-Rh-NO, the first mitochondria-targetable "turn-on" fluorescent probe for NO, has been developed through attaching a triphenylphosphonium to a rhodamine spirolactam. The characteristics of this probe are as following: (1) Mito-Rh-NO exhibits high sensitivity toward NO. In solution, Mito-Rh-NO responds to NO by significant fluorescence enhancement up to 60-fold, and its NO detection limit is as low as 4.0 nM. (2) The NO sensing of Mito-Rh-NO is highly selective, which will not interfere with the other reactive oxygen and nitrogen species. (3) Mito-Rh-NO has a low cytotoxic effect: after being treated with 10 ?M Mito-Rh-NO for 24 h, the survival rate is higher than 90%. (4) Mito-Rh-NO specifically localizing in mitochondria: colocalization experiment of Mito-Rh-NO and Rh 123, a typical mitotracker, shows the merged fluorescent microcopy image with a high Pearsons colocalization coefficient 0.92 and overlap coefficient 0.99. (5) Mito-Rh-NO demonstrates high applicability for real-time monitoring of mitochondrial NO in live cells. Both the exogenous NO released by the donor NOC13 and endogenous NO generated in cells under stimulation have been visualized under confocal microscopy.
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[Relationship between the inhibitory effect of fraxetin on breast cancer and estrogen signaling pathway].
Sheng Li Xue Bao
PUBLISHED: 06-22-2013
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Estrogen signaling pathways play an important role in the regulation of the physiological function of breast cancer cell proliferation and apoptosis. The article used MTT assay, flow cytometer analysis and Western blot to detect the inhibition of fraxetin on MCF-7 cell cycle distribution and apoptosis, ER?, cyclin D1 and Bcl-2 expression levels, MAPK and PI3K signaling pathway to investigate the mechanism of anti-breast cancer of fraxetin. The results showed fraxetin inhibited E2?-stimulated MCF-7 cell proliferation in a dose- and time-dependent manner, reversed E2?-induced anti-apoptosis and promoted G0/G1 phase arrest. After treatment with fraxetin, the expression of ER? in MCF-7 cell was decreased, and estrogen genomic signaling pathway was inhibited by down-regulating the expression of cyclin D1 and Bcl-2 proteins. After MCF-7 cells were treated with fraxetin, the expressions of MAPK/Erk1/2 protein were reduced, which affected estrogen non-genomic signaling pathway. The results suggest fraxetin plays a part in anti-breast cancer function through E2?-mediated genomic and non-genomic signaling pathways.
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[Diverse expression of ER-?36, a novel variant of ER-?, in hippocampus and cortex of neonatal and adult rats].
Sheng Li Xue Bao
PUBLISHED: 06-22-2013
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ER-?36, a novel variant of ER-?, is expressed in breast, uterus, digestive tract, respiratory tract etc. The aim of the present study was to investigate the distribution and expression of ER-?36 in the central nervous system (CNS). Here, we comparatively analyzed the expression pattern of ER-?36 in the hippocampus and cortex of neonatal (1-day-old) and adult (12-week-old) Sprague-Dawley (SD) rats by using immunohistochemistry/immunocytochemistry analysis and Western blot. The results showed that ER-?36 was expressed both in hippocampus and cortex of adult rats, but mainly distributed in pyramidal neurons. ER-?36 was mainly located on the cytomembrane of hippocampal and cortical neurons from neonatal rats. Compared with the cortical neurons, the hippocampal neurons showed lower ER-?36 protein expression in the neonatal rats, but exhibited higher level of ER-?36 in the adult rats. Furthermore, the adult rats showed higher levels of ER-?36 expression in both hippocampus and cortex compared with the neonatal rats. These results suggest that ER-?36 might be involved in the regulation of membrane-initiated estrogen signaling throughout the postnatal development of diverse brain regions, and thus will be a potential target for the treatment of degenerative diseases in nervous system.
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Apelin protects sarcoplasmic reticulum function and cardiac performance in ischaemia-reperfusion by attenuating oxidation of sarcoplasmic reticulum Ca2+-ATPase and ryanodine receptor.
Cardiovasc. Res.
PUBLISHED: 06-13-2013
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Apelin, an endogenous cytokine, has a number of biological effects on the cardiovascular system, including a cardioprotective effect and calcium modulation. Because the intracellular calcium abnormality is considered to play an important role in cardiac dysfunction induced by ischaemia-reperfusion (I/R), the aim of this study was to examine the effects of apelin-13 on I/R-induced changes in cardiac performance and sarcoplasmic reticulum (SR) function.
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Melitidin: a flavanone glycoside from Citrus grandis Tomentosa.
Nat Prod Commun
PUBLISHED: 06-07-2013
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Citrus grandis Tomentosa is a traditional Chinese medicine, used as an antitussive. In this research, melitidin, a flavanone glycoside, was isolated from this species for the first time by using chromatographic methods. The structure was confirmed through comprehensive analyses of its ultraviolet, infrared, 1H and 13C NMR, HMBC and HMQC spectroscopic and high-resolution mass spectrometric data. Meliditin showed a good antitussive effect on cough induced by citric acid in Guinea pig, suggesting that it was a contributor to the antitussive effect of C. grandis Tomentosa.
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Caveolin-1, through its ability to negatively regulate TLR4, is a crucial determinant of MAPK activation in LPS-challenged mammary epithelial cells.
Asian Pac. J. Cancer Prev.
PUBLISHED: 06-04-2013
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To explore the role of caveolin-1(CAV-1) gene silencing on MAPK activation in lipopolysaccharide (LPS)-challenged human mammary epithelial cells.
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Carbon dioxide adsorbent based on rich amines loaded nano-silica.
J Colloid Interface Sci
PUBLISHED: 05-17-2013
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An easy strategy to obtain an effective carbon dioxide adsorbent based on rich amines functionalized nano-silica was proposed. Polyacrylic acid (PAA), acted as a multi-functional bridge, was firstly immobilized onto the surface of silica nanoparticles. Each carboxylic acid group was subsequently reacted with an amine group of alkylamines, and plenty of remained amines groups could be coated onto silica nanoparticles. As a result, the rich amines loaded nano-silica was fabricated and applied as CO2 adsorbent. The structures and morphologies of amines modified nano-silica were characterized by FTIR, TGA, TEM, and CHNS elemental analysis. Moreover, the effect of molecular weight of PAA and that of alkylamine on CO2 absorption capacity was discussed. As expected, SiO2-PAA(3000)-PEI(10000) adsorbent possessed remarkably high CO2 uptake of approximately 3.8 mmol/g-adsorbent at 100 KPa CO2, 40°C. Moreover, it was found that the adsorbent exhibited a high CO2 adsorption rate, a good selectivity for CO2-N2 separation, and could be easily regenerated.
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The 2009 pandemic (H1N1) viruses isolated from pigs show enhanced pathogenicity in mice.
Vet. Res.
PUBLISHED: 05-14-2013
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Since the emergence of the 2009 pandemic (H1N1) virus (2009/H1N1) in April 2009, cases of transmission from humans to pigs have been reported frequently. In our previous studies, four 2009/H1N1 variants were isolated from pigs. To better understand the phenotypic differences of the pig isolates compared with the human isolate, in this study mice were inoculated intranasally with different 2009/H1N1 viruses, and monitored for morbidity, mortality, and viral replication, cytokine production and pathological changes in the lungs. The results show that all isolates show effective replication in lungs, but varying in their ability to cause morbidity. In particular, the strains of A/swine/Nanchang/3/2010 (H1N1) and A/swine/Nanchang/F9/2010 (H1N1) show the greatest virulence with a persisting replication in lungs and high lethality for mice, compared with the human isolate A/Liaoning /14/2009 (H1N1), which shows low virulence in mice. Furthermore, the lethal strains could induce more severe lung pathological changes and higher production of cytokines than that of other strains at an early stage. Amino acid sequence analysis illustrates prominent differences in viral surface glycoproteins and polymerase subunits between pig isolates and human strains that might correlate with their phenotypic differences. These studies demonstrate that the 2009/H1N1 pig isolates exhibit heterogeneous infectivity and pathogencity in mice, and some strains possess an enhanced pathogenicity compared with the human isolate.
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Metabolic engineering of Torulopsis glabrata for malate production.
Metab. Eng.
PUBLISHED: 05-12-2013
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The yeast Torulopsis glabrata CCTCC M202019, which is used for industrial pyruvate production, was chosen to explore the suitability of engineering this multi-vitamin auxotrophic yeast for increased malate production. Various metabolic engineering strategies were used to manipulate carbon flux from pyruvate to malate: (i) overexpression of pyruvate carboxylase and malate dehydrogenase; (ii) identification of the bottleneck in malate production by model iNX804; (iii) simultaneous overexpression of genes RoPYC, RoMDH and SpMAE1. Using these strategies, 8.5gL(-1) malate was accumulated in the engineered strain T.G-PMS, which was about 10-fold greater than that of the control strain T.G-26. The results presented here suggest that T. glabrata CCTCC M202019 is a promising candidate for industrial malate production.
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Abdominal and pancreatic motion correlation using 4D CT, 4D transponders, and a gating belt.
J Appl Clin Med Phys
PUBLISHED: 05-09-2013
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The correlation between the pancreatic and external abdominal motion due to respiration was investigated on two patients. These studies utilized four dimensional computer tomography (4D CT), a four dimensional (4D) electromagnetic transponder system, and a gating belt system. One 4D CT study was performed during simulation to quantify the pancreatic motion using computer tomography images at eight breathing phases. The motion under free breathing and breath-hold were analyzed for the 4D electromagnetic transponder system and the gating belt system during treatment. A linear curve was fitted for all data sets and correlation factors were evaluated between the 4D electromagnetic transponder system and the gating belt system data. The 4D CT study demonstrated a modest correlation between the external marker and the pancreatic motion with R-square values larger than 0.8 for the inferior-superior (inf-sup). Then, the relative pressure from the belt gating system correlated well with the 4D electromagnetic transponder systems motion in the anterior-posterior (ant-post) and the inf-post directions. These directions have a correlation value of -0.93 and 0.76, while the lateral only had a 0.03 correlation coefficient. Based on our limited study, external surrogates can be used as predictors of the pancreatic motion in the inf-sup and the ant-post directions. Although there is a low correlation on the lateral direction, its motion is significantly shorter. In conclusion, an appropriate treatment delivery can be used for pancreatic cancer when an internal tracking system, such as the 4D electromagnetic transponder system, is unavailable.
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Prediction value of intercellular adhesion molecule-1 gene polymorphisms for epithelial ovarian cancer risk, clinical features, and prognosis.
Gene
PUBLISHED: 05-01-2013
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Intercellular adhesion molecule-1 (ICAM-1, encoded by ICAM-1) is implicated in tumorigenesis and tumor progression. ICAM-1 modulates the susceptibility to several types of cancer and the disease prognosis; however, its role in epithelial ovarian cancer (EOC) is unclear. Here, we evaluate single nucleotide polymorphisms (SNPs) in ICAM-1 as predictors of EOC risk and prognosis. Six ICAM-1 polymorphisms were genotyped in 408 patients with EOC and 520 controls using the MassARRAY system. The ICAM-1 mRNA levels in 89 EOC tissues and 35 normal ovarian tissues were examined using quantitative PCR. The ICAM-1 rs5498 G allele was associated with increased tumor grade (OR=2.650) and EOC risk (OR=1.405). This risk was more evident in females who had first-degree relatives (FDRs) with a tumor (OR=3.475) or who experienced early menarche (OR=2.774). The ICAM-1 expression in the cancerous tissue was elevated compared with that of normal ovarian tissues (p<0.0001), and it was associated with an rs5498 genotype (p=0.0002). ICAM-1 SNPs did not significantly predict the overall EOC survival (p>0.05). However, the rs5498 G allele correlated with EOC survival time in patients whose FDRs suffered from a tumor (p=0.001). ICAM-1 rs5498 likely confers a high risk for EOC in G allele carriers accompanied by up-regulation of ICAM-1 expression during carcinogenesis. The combination of ICAM-1 rs5498 and tumor history predicts the EOC prognosis.
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Clathrin and AP2 are required for phagocytic receptor-mediated apoptotic cell clearance in Caenorhabditis elegans.
PLoS Genet.
PUBLISHED: 05-01-2013
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Clathrin and the multi-subunit adaptor protein complex AP2 are central players in clathrin-mediated endocytosis by which the cell selectively internalizes surface materials. Here, we report the essential role of clathrin and AP2 in phagocytosis of apoptotic cells. In Caenorhabditis elegans, depletion of the clathrin heavy chain CHC-1 and individual components of AP2 led to a significant accumulation of germ cell corpses, which resulted from defects in both cell corpse engulfment and phagosome maturation required for corpse removal. CHC-1 and AP2 components associate with phagosomes in an inter-dependent manner. Importantly, we found that the phagocytic receptor CED-1 interacts with the ? subunit of AP2, while the CED-6/Gulp adaptor forms a complex with both CHC-1 and the AP2 complex, which likely mediates the rearrangement of the actin cytoskeleton required for cell corpse engulfment triggered by the CED-1 signaling pathway. In addition, CHC-1 and AP2 promote the phagosomal association of LST-4/Snx9/18/33 and DYN-1/dynamin by forming a complex with them, thereby facilitating the maturation of phagosomes necessary for corpse degradation. These findings reveal a non-classical role of clathrin and AP2 and establish them as indispensable regulators in phagocytic receptor-mediated apoptotic cell clearance.
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Overexpression of CD147 in ovarian cancer is initiated by the hypoxic microenvironment.
Cell Biol. Int.
PUBLISHED: 04-24-2013
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Ovarian cancer is a lethal malignant tumour characterised by activated invasion, distant metastasis, anti-cancer drug resistance, angiogenesis and metabolism. CD147, an extracellular matrix metalloproteinase inducer, is overexpressed in most ovarian tumours and plays an important role in the progression of ovarian cancer and other malignant tumours. However, the factor(s) initiating this overexpression is unknown. Because of rapid reproduction and their hypoxic microenvironment, malignant tumours use glycolysis for energy, and lactic acid produced is harmful to the cells. For survival, excessive lactate needs to be transported by monocarboxylate transporters (MCTs). Functioning of MCT1 and MCT4 require the ancillary of CD147. The gene for CD147 possesses two hypoxia-inducible factors binding sites in its 3-flank. It is logical to postulate that the hypoxic microenvironment is a major initiator of the overexpression of CD147, thus conferring on ovarian cancers their malignant properties. A model that can represent spontaneous ovarian cancer is necessary to verify this hypothesis.
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Reviving oscillations in coupled nonlinear oscillators.
Phys. Rev. Lett.
PUBLISHED: 04-18-2013
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By introducing a processing delay in the coupling, we find that it can effectively annihilate the quenching of oscillation, amplitude death (AD), in a network of coupled oscillators by switching the stability of AD. It revives the oscillation in the AD regime to retain sustained rhythmic functioning of the networks, which is in sharp contrast to the propagation delay with the tendency to induce AD. This processing delay-induced phenomenon occurs both with and without the propagation delay. Further this effect is rather general from two coupled to networks of oscillators in all known scenarios that can exhibit AD, and it has a wide range of applications where sustained oscillations should be retained for proper functioning of the systems.
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Insights into the increasing virulence of the swine-origin pandemic H1N1/2009 influenza virus.
Sci Rep
PUBLISHED: 03-19-2013
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Pandemic H1N1/2009 viruses have been stabilized in swine herds, and some strains display higher pathogenicity than the human-origin isolates. In this study, high-throughput RNA sequencing (RNA-seq) is applied to explore the systemic transcriptome responses of the mouse lungs infected by swine (Jia6/10) and human (LN/09) H1N1/2009 viruses. The transcriptome data show that Jia6/10 activates stronger virus-sensing signals, such as the toll-like receptor, RIG-I like receptor and NOD-like receptor signalings, as well as a stronger NF-?B and JAK-STAT signals, which play significant roles in inducing innate immunity. Most cytokines and interferon-stimulated genes show higher expression lever in Jia/06 infected groups. Meanwhile, virus Jia6/10 activates stronger production of reactive oxygen species, which might further promote higher mutation rate of the virus genome. Collectively, our data reveal that the swine-origin pandemic H1N1/2009 virus elicits a stronger innate immune reaction and pro-oxidation stimulation, which might relate closely to the increasing pathogenicity.
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Relationship between Oxidant/Antioxidant Markers and Severity of Microalbuminuria in the Early Stage of Nephropathy in Type 2 Diabetic Patients.
J Diabetes Res
PUBLISHED: 02-26-2013
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A wide range of microalbuminuria cutoff values are currently used for diagnosing the early stage of nephropathy in type 2 diabetes (T2D). This study analyzed the relationships between oxidant and antioxidant markers of nephropathy and the severity of microalbuminuria. The study included 50 healthy controls (Group 1), 50 diabetic patients with no nephropathy (Group 2), 50 diabetic patients with nephropathy and a urinary albumin excretion (UAE) of 30-200?mg/24?h (Group 3), and 50 diabetic patients with UAE 200-300?mg/24?h (Group 4). Serum nitrotyrosine, conjugated dienes, 8-hydroxy-2-deoxyguanosine (8-OHdG), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC) levels were determined. Oxidative stress is increased in the early stage of nephropathy in patients with T2D. There was a significant correlation between the extent of microalbuminuria and markers of oxidative stress. Multiple linear regression analysis identified lipid oxidative stress as a possible independent marker for evaluating the degree of renal damage in diabetic nephropathy. Stratifying microalbuminuria values during the early stage of nephropathy might be an important factor in facilitating earlier and more specific interventions.
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Amplitude death in nonlinear oscillators with mixed time-delayed coupling.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 02-25-2013
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Amplitude death (AD) is an emergent phenomenon whereby two or more autonomously oscillating systems completely lose their oscillations due to coupling. In this work, we study AD in nonlinear oscillators with mixed time-delayed coupling, which is a combination of instantaneous and time-delayed couplings. We find that the mixed time-delayed coupling favors the onset of AD for a larger set of parameters than in the limiting cases of purely instantaneous or completely time-delayed coupling. Coupled identical oscillators experience AD under instantaneous coupling mixed with a small proportion of time-delayed coupling. Our work gives a deeper understanding of delay-induced AD in coupled nonlinear oscillators.
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Zap70 inhibits Syk-mediated osteoclast function.
J. Cell. Biochem.
PUBLISHED: 02-21-2013
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The ?v?3 integrin stimulates the resorptive capacity of the differentiated osteoclast (OC) by organizing its cytoskeleton via the tyrosine kinase, Syk. Thus, Syk-deficient OCs fails to spread or form actin rings, in vitro and in vivo. The Syk family of tyrosine kinases consists of Syk itself and Zap70 which are expressed by different cell types. Because of their structural similarity, and its compensatory properties in other cells, we asked if Zap70 can substitute for absence of Syk in OCs. While expression of Syk, as expected, normalizes the cytoskeletal abnormalities of Syk(-/-) OCs, Zap70 fails do so. In keeping with this observation, Syk, but not Zap70, rescues ?v?3 integrin-induced SLP76 phosphorylation in Syk(-/-) OCs. Furthermore the kinase sequence of Syk partially rescues the Syk(-/-) phenotype but full normalization also requires its SH2 domains. Surprisingly, expression of Zap70 inhibits WT OC spreading, actin ring formation and bone resorptive activity, but not differentiation. In keeping with arrested cytoskeletal organization, Zap70 blocks integrin-activated endogenous Syk and Vav3, SLP76 phosphorylation. Such inhibition requires Zap70 kinase activity, as it is abolished by mutation of the Zap70 kinase domain. Thus, while the kinase domain of Syk is uniquely required for OC function that of Zap70 inhibits it.
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Synthesis of 7-oxabicyclo[2.2.1]heptanes and 8-oxabicyclo[3.2.1]octanes from C-glycosides via an intramolecular cyclization.
J. Org. Chem.
PUBLISHED: 02-19-2013
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A simple and effective method for the synthesis of 7-oxabicyclo[2.2.1]heptanes and 8-oxabicyclo[3.2.1]octanes from acetonyl C-glycoside substrates is described, which involves an intramolecular cyclization reaction through a nucleophilic substitution at C-5 or C-6 of C-glycosides by a 2-enamine intermediate formed in the presence of pyrrolidine. Because anomeric epimerization occurs under these conditions, C-glycoside substrates with either anomeric configuration were converted to the same product(s) in same stereoselectivity and similar chemical yield.
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Transcriptional engineering of Escherichia coli K4 for fructosylated chondroitin production.
Biotechnol. Prog.
PUBLISHED: 02-15-2013
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The capsule polysaccharide (CPS) of Escherichia coli K4 (K4CPS) is identical to fructosylated chondroitin, which can be modified to chondroitin sulfate, a commercially valuable biopolymer commonly used in pharmaceutical applications. In this study, we homologously overexpressed the transcriptional regulator SlyA to enhance the expression of K4 capsule gene cluster and production of CPS. The iTRAQ quantificaton of proteomics revealed 77 up-regulated proteins and 143 down-regulated proteins in E. coli THslyA. Most enzymes of glycolysis and citrate cycle pathway were weakened, while proteins associated with K4CPS synthesis were up-regulated, showing a shift of carbon flux from cell growth to K4CPS production. Further, the production of K4CPS by the recombinant strain was 1 and 2.6 g/L in a shake flask and 7-L batch bioreactor, which was 1.85- and 1.53-fold higher than that of the wild-type strain, respectively. Thus, this study provides a viable strategy for improving the production of K4CPS through a transcriptional-level manipulation. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 2013.
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A novel synthetic receptor-based immunoassay for influenza vaccine quantification.
PLoS ONE
PUBLISHED: 02-12-2013
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Vaccination is the most effective prophylactic method for preventing influenza. Quantification of influenza vaccine antigens is critically important before the vaccine is used for human immunization. Currently the vaccine antigen quantification relies on hemagglutinin content quantification, the key antigenic component, by single radial immunodiffusion (SRID) assay. Due to the inherent disadvantages associated with the traditional SRID; i.e. low sensitivity, low throughput and need for annual reagents, several approaches have been proposed and investigated as alternatives. Yet, most alternative methods cannot distinguish native hemagglutinin from denatured form, making them less relevant to antigenic analyses. Here, we developed a quantitative immunoassay based on the sialic acid binding property of influenza vaccine antigens. Specifically, we chemically synthesized human and avian influenza virus receptors analogues, N-acetylneuraminic acid-2,6-lactose and N-acetylneuraminic acid-2,3-lactose derivatives with an azidopropyl aglycon, using ?-2,6- and ?-2,3-sialyltransferases, respectively. The azido group of the two sialyllactose-derivatives was reduced and conjugated to mouse serum albumin through a squarate linkage. We showed that the synthetic ?-2,6- and ?-2,3-receptors selectively bound to human and avian-derived hemagglutinins, respectively, forming the basis of a new, and robust assay for hemagglutinin quantification. Hemagglutinin treated at high temperature or low pH was measured differentially to untreated samples suggesting native conformation is dependent for optimal binding. Importantly, this receptor-based immunoassay showed excellent specificity and reproducibility, high precision, less turnaround time and significantly higher sensitivity and throughput compared with SRID in analyzing multiple influenza vaccines.
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Protective Effect of Phosphatidylcholine on Restoration of Ethanol-Injured Hepatocytes Related with Caveolin-1.
J. Membr. Biol.
PUBLISHED: 01-30-2013
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The absorption of phospholipid may improve the fluidity of membrane and enzyme activities. Phospholipids also play a role in promoting Caveolae formation and membrane synthesis. Caveolin-1 has a significant effect on signaling pathways involved in regulating cell proliferation and stress responsiveness. Thus, we can speculate that Caveolin-1 could affect the sense of environmental stress. We use Chang liver cell line to investigate the ability of Caveolin-1 to modulate the cellular response to ethanol injury. Caveolin-1 downregulate cells (Cav-1(-/-)) were established by stable transfecting with psiRNA-CAV1 plasmids, which were more sensitive to toxic effects of ethanol than the untransfected parental cells (WT). Releasing of ALT and electric conductivity were changed significantly in Cav-1(-/-) cells compared with WT. Caveolin-1 gene silencing could obviously down-regulate the activities of protein kinase C-? (PKC-?) and phospho-p42/44 MAP kinase, indicating cell proliferation and self-repairing abilities were inhibited. However, the levels of Caveolin-1 and PKC-? were increased by phosphatidylcholine administration. The results indicated that the inhibition of lipid peroxidation by phosphatidylcholine could lead to the prevention of membrane disruption, which closely correlated with the level of Caveolin-1. Since the protective effects of phosphatidylcholine against ethanol-induced lipid peroxidation might be regulated by phospholipid-PKC-? signaling pathway, related with Caveolin-1, the potential effects of phosphatidylcholine on membranes need to be verified.
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A novel approach to facilitate dopaminergic neuron generation from stem-cells: the combination of genetic modification and signaling factors within a three-dimensional perfusion microbioreactor.
Med. Hypotheses
PUBLISHED: 01-29-2013
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Recent evidence suggests that cell replacement therapy holds great promise for the treatment of Parkinsons disease. Many efforts have been made to improve current methods for differentiating stem or somatic cells into functional dopaminergic (DA) neurons. Previous studies have demonstrated that lineage-specific factors, extrinsic signaling factors and the cellular microenvironment are important considerations for generating functional DA neurons. We hypothesize that a combination of genetic modification, neurotrophic or extrinsic signaling factors and the construction of dynamic neural networks within a three-dimensional perfusion microbioreactor will produce greater efficiency and effectiveness in DA neuron generation from stem-cells.
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Pinning noise-induced stochastic resonance.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 01-15-2013
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This paper proposes the concept of pinning noise and then investigates the phenomenon of stochastic resonance of coupled complex systems driven by pinning noise, where the noise has an ?-stable distribution. Two kinds of pinning noise are taken into account: partial noise and switching noise. In particular, we establish a connection between switching noise and global noise when Gaussian noise is considered. It is shown that switching noise can not only achieve a stronger resonance effect, but it is also more robust to induce the resonance effect than partial noise.
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Sialyltransferase inhibitors: consideration of molecular shape and charge/hydrophobic interactions.
Carbohydr. Res.
PUBLISHED: 01-10-2013
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In order to evaluate the importance of molecular shape of inhibitor molecules and the charge/H-bond and hydrophobic interactions, we synthesized three types of molecules and tested them against a sialyltransferase. The first type of compounds were designed as substrate mimics in which the phosphate in CMP-Neu5NAc was replaced by a non-hydrolysable, uncharged 1,2,3-triazole moiety. The second type of compound contained a 2-deoxy-2,3-dehydro-acetylneuraminic moiety which was linked to cytidine through its carboxylic acid and amide linkers. In the third type of compound the sialyl phosphate was substituted by an aryl sulfonamide which was then linked to cytidine. Inhibition study of these cytidine conjugates against Campylobacter jejuni sialyltransferase Cst 06 showed that the first type of molecules are competitive inhibitors, whereas the other two could only inhibit the enzyme non-competitively. The results indicate that although the binding specificity may be guided by molecular shape and H-bond interaction, the charge and hydrophobic interactions contributed most to the binding affinity.
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Glutathione enhances 2-keto-l-gulonic acid production based on Ketogulonicigenium vulgare model iWZ663.
J. Biotechnol.
PUBLISHED: 01-09-2013
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Ketogulonicigenium vulgare is used widely during the industrial production of 2-keto-l-gulonic acid (2-KLG), the precursor of vitamin C, in a coculture with Bacillus megaterium. We analyzed the sulfate and coenzyme A metabolic module in the genome-scale metabolic model (GSMM) iWZ663 and found that the poor growth of K. vulgare was due to a deficiency in key reductases in the sulfate metabolic pathway. To carefully investigate the metabolism of sulfate, we developed a chemically defined medium (CDM) to produce pure cultures of K. vulgare. The addition of glutathione and l-cysteine to a flask culture of K. vulgare increased the cell growth, 2-KLG titer, and the intracellular coenzyme A level by 38.7%, 45.5%, and 85.3%, respectively, with glutathione, and by 25.6%, 35.8%, and 44.7%, respectively, with l-cysteine. The addition of glutathione to a 7-L fermenter culture of K. vulgare and B. megaterium increased the 2-KLG productivity by 20.9%. This study shows that the analysis of a specific metabolic module in GSMM can provide a potential strategy for optimizing microbial physiological functions.
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Effects on the photon beam from an electromagnetic array used for patient localization and tumor tracking.
J Appl Clin Med Phys
PUBLISHED: 01-08-2013
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One of the main components in a Calypso 4D localization and tracking system is an electromagnetic array placed above patients that is used for target monitoring during radiation treatment. The beam attenuation and beam spoiling properties of the Calypso electromagnetic array at various beam angles were investigated. Measurements were performed on a Varian Clinac iX linear accelerator with 6 MV and 15 MV photon beams. The narrow beam attenuation properties were measured under a field size of 1 cm × 1 cm, with a photon diode placed in a cylindrical graphite buildup cap. The broad beam attenuation properties were measured under a field size of 10 cm × 10 cm, with a 0.6 cc cylindrical Farmer chamber placed in a polystyrene buildup cap. Beam spoiling properties of the array were studied by measuring depth-dose change from the array under a field size of 10 cm × 10 cm in a water-equivalent plastic phantom with an embedded Markus parallel plate chamber. Change in depth doses were measured with the array placed at distances of 2, 5, and 10 cm from the phantom surface. Narrow beam attenuation and broad beam attenuation from the array were found to be less than 2%-3% for both 6 MV and 15 MV beams at angles less than 40°, and were more pronounced at more oblique angles. Spoiling effects are appreciable at beam buildup region, but are insignificant at depths beyond dmax. Dose measurements in a QA phantom using patient IMRT and VMAT treatment plans were shown to have less than 2.5% dose difference with the Calypso array. The results indicate that the dose difference due to the placement of Calypso array is clinically insignificant.
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Type I phosphotidylinosotol 4-phosphate 5-kinase ? regulates osteoclasts in a bifunctional manner.
J. Biol. Chem.
PUBLISHED: 01-07-2013
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Type 1 phosphotidylinosotol-4 phosphate 5 kinase ? (PIP5KI?) is central to generation of phosphotidylinosotol (4,5)P(2) (PI(4,5)P(2)). PIP5KI? also participates in cytoskeletal organization by delivering talin to integrins, thereby enhancing their ligand binding capacity. As the cytoskeleton is pivotal to osteoclast function, we hypothesized that absence of PIP5KI? would compromise their resorptive capacity. Absence of the kinase diminishes PI(4,5) abundance and desensitizes precursors to RANK ligand-stimulated differentiation. Thus, PIP5KI?(-/-) osteoclasts are reduced in number in vitro and confirm physiological relevance in vivo. Despite reduced numbers, PIP5KI?(-/-) osteoclasts surprisingly have normal cytoskeletons and effectively resorb bone. PIP5KI? overexpression, which increases PI(4,5)P(2), also delays osteoclast differentiation and reduces cell number but in contrast to cells lacking the kinase, its excess disrupts the cytoskeleton. The cytoskeleton-disruptive effects of excess PIP5KI? reflect its kinase activity and are independent of talin recognition. The combined arrested differentiation and disorganized cytoskeleton of PIP5KI?-transduced osteoclasts compromises bone resorption. Thus, optimal PIP5KI? and PI(4,5)P(2) expression, by osteoclasts, are essential for skeletal homeostasis.
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Reconstruction and analysis of the industrial strain Bacillus megaterium WSH002 genome-scale in silico metabolic model.
J. Biotechnol.
PUBLISHED: 01-03-2013
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A genome-scale metabolic model of Bacillus megaterium WSH002, an industrial bacterium widely used in the vitamin C industry, was reconstructed on the basis of the genome annotation and data from the literature and biochemical databases. It comprises 1112 reactions, 993 metabolites, and 1055 genes, including 43 new annotated genes. This model was able to predict qualitatively and quantitatively the growth of B. megaterium on a range of carbon and nitrogen sources, and the results agreed well with experimental data. A gene essentiality analysis predicted a core metabolic essential gene set of 57 genes on three different media. Furthermore, constraint-based analysis revealed that B. megaterium WSH002 is capable of producing and exporting several key metabolites, which could promote the growth of Ketogulonicigenium vulgare and 2-keto-l-gulonic acid (2-KLG) production. Here, the model represents a helpful tool for understanding and exploring this important industrial organism.
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Choline plasmalogens isolated from swine liver inhibit hepatoma cell proliferation associated with caveolin-1/Akt signaling.
PLoS ONE
PUBLISHED: 01-01-2013
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Plasmalogens play multiple roles in the structures of biological membranes, cell membrane lipid homeostasis and human diseases. We report the isolation and identification of choline plasmalogens (ChoPlas) from swine liver by high performance thin layer chromatography (HPTLC) and high performance liquid chromatography (HPLC)/MS. The growth and viability of hepatoma cells (CBRH7919, HepG2 and SMMC7721) was determined following ChoPlas treatment comparing with that of human normal immortal cell lines (HL7702). Result indicated that ChoPlas inhibited hepatoma cell proliferation with an optimal concentration and time of 25 ?mol/L and 24 h. To better understand the mechanism of the ChoPlas-induced inhibition of hepatoma cell proliferation, Caveolin-1 and PI3K/Akt pathway signals, including total Akt, phospho-Akt(pAkt) and Bcl-2 expression in CBRH7919 cells, were determined by western blot. ChoPlas treatment increased Caveolin-1 expression and reduced the expression of phospho-Akt (pAkt) and Bcl-2, downstream targets of the PI3K/Akt pathway. Further cell cycle analysis showed that ChoPlas treatment induced G1 and G1/S phase transition cell cycle arrest. The expression of essential cell cycle regulatory proteins involved in the G1 and G1/S phase transitions, cyclin D, CDK4, cyclin E and CDK2, were also analyzed by western blot. ChoPlas reduced CDK4, cyclin E and CDK2 expression. Taken together, the results indicate that swine liver-derived natural ChoPlas inhibits hepatoma cell proliferation associated with Caveolin-1 and PI3K/Akt signals.
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[Clinical features of severe intestinal graft-versus-host disease in 34 cases following allogeneic hematopoietic stem cell transplantation].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 12-16-2011
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This study was purposed to investigate the clinical features and related factors influencing prognosis of patients with severe intestinal graft-versus-host disease (siGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). 710 patients received allo-HSCT in Beijing Dao-Pei hospital from Jan 2007 to Jan 2011 were enrolled in this study. A total of 34 patients with siGVHD out of 710 patients were analyzed retrospectively, and the univariate analysis for related factors influencing prognosis were carried out by using SPSS 19.0 software. The results showed that the incidence of siGVHD was 4.79%, its medium occurrence time was 29 (18 - 210) days after allo-HSCT. 18 out of 34 patients with siGVHD received colonoscopy, among them 6 patients were complicated with viral enteritis. The deep ulcers could be found under colonoscope. Histopathologic examination revealed the viral inclusion bodies or positive viral antigen. Methylprednisolone (MP), cyclosporine A (CsA) or tacrolimus combined CD25 monoclonal antibody and oral budesonide were used for treatment of siGVHD. 29 out of 34 cases achieved complete response (CR) with CR rate of 85.29%, overall survival rate was 58.82% (20/34). 9 out of 29 cases achieving CR died of other complications. The univariate analysis of the related factor indicated the hyperacute GVHD is the adverse factor influencing overall survival of patients with siGVHD. It is concluded that early colonoscopy is an effective way for definitive diagnosis of siGVHD. The combined treatment including MP, CsA or tacrolimus, CD25 monoclonal antibody and oral budesonide shows a significant curative effects. Intensive treatment of complications in late period of GVHD can enhance the overall survival rate.
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Rac deletion in osteoclasts causes severe osteopetrosis.
J. Cell. Sci.
PUBLISHED: 11-23-2011
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Cdc42 mediates bone resorption principally by stimulating osteoclastogenesis. Whether its sister GTPase, Rac, meaningfully impacts upon the osteoclast and, if so, by what means, is unclear. We find that whereas deletion of Rac1 or Rac2 alone has no effect, variable reduction of Rac1 in osteoclastic cells of Rac2(-/-) mice causes severe osteopetrosis. Osteoclasts lacking Rac1 and Rac2 in combination (Rac double-knockout, RacDKO), fail to effectively resorb bone. By contrast, osteoclasts are abundant in RacDKO osteopetrotic mice and, unlike those deficient in Cdc42, express the maturation markers of the cells normally. Hence, the osteopetrotic lesion of RacDKO mice largely reflects impaired function, and not arrested differentiation, of the resorptive polykaryon. The dysfunction of RacDKO osteoclasts represents failed cytoskeleton organization as evidenced by reduced motility of the cells and their inability to spread or generate the key resorptive organelles (i.e. actin rings and ruffled borders), which is accompanied by abnormal Arp3 distribution. The cytoskeleton-organizing capacity of Rac1 is mediated through its 20-amino-acid effector domain. Thus, Rac1 and Rac2 are mutually compensatory. Unlike Cdc42 deficiency, their combined absence does not impact upon differentiation but promotes severe osteopetrosis by dysregulating the osteoclast cytoskeleton.
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Complete genome sequence of the industrial strain Bacillus megaterium WSH-002.
J. Bacteriol.
PUBLISHED: 11-01-2011
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Bacillus megaterium, an industrial strain, has been widely used in protein production and the vitamin C industry. Here we reported a finished, annotated, and compared 4.14-Mbp high-quality genome sequence of B. megaterium WSH-002, which is the companion strain for Ketogulonicigenium vulgare in the vitamin C industry and is stocked in our laboratory.
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