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Find video protocols related to scientific articles indexed in Pubmed.
An intermolecular C-H functionalization method for the synthesis of 3-hydroxy-2-oxindoles.
Org. Biomol. Chem.
PUBLISHED: 09-24-2014
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An intermolecular C-H functionalization method is developed for the synthesis of 3-hydroxy-2-oxindoles. Rh(iii)-catalyzed N-nitroso-directed C-H addition to ethyl 2-oxoacetate allows subsequent denitrosation-triggered cyclization construction of 3-hydroxy-2-oxindoles. The method features a broad substrate scope and its synthetic utility is demonstrated on the synthesis of target compounds bearing functional groups (hydroxyl, bromo) amenable to further elaboration.
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ESTs analysis of putative genes engaged in Polyporus umbellatus sclerotial development.
Int J Mol Sci
PUBLISHED: 07-27-2014
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Polyporus umbellatus is one of the most widely used and precious medicinal fungi and the underground sclerotia are known to be with great medicinal value. However, the molecular mechanisms involved in sclerotial development are poorly understood. In the present study, we constructed a forward suppression subtractive hybridization (SSH) cDNA library of Polyporus umbellatus to identify genes expressing differently between mycelium and sclerotia. In this library, a total of 1202 clones were sequenced, assembled into 222 contigs and 524 singletons which were further searched against the NCBI nonredundant (NR) protein database (E-value cutoff, 10-5). Based on sequence similarity with known proteins, 378 sequences between mycelium and sclerotial were identified and classified into different functional categories through Gene Ontology (GO), Clusters of orthologous Groups of proteins (COGs). We have finally identified a majority of differentially expressed genes (constituting 5.6% of the present library) between the two different periods. An expression level of 32 selected expressed sequence tags (ESTs) generated from the above SSH cDNA library was studied through RT-PCR. This study provides the first global overview of genes putatively involved in Polyporus umbellatus sclerotial development and provides a preliminary basis for further functional research in terms of regulated gene expression in sclerotial production.
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Rhodium(III)-Catalyzed N-Nitroso-Directed C?H Addition to Ethyl 2-Oxoacetate for Cycloaddition/Fragmentation Synthesis of Indazoles.
Chemistry
PUBLISHED: 07-22-2014
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Rh(III) -catalyzed N-nitroso-directed C?H addition to ethyl 2-oxoacetate allows subsequent construction of indazoles, a privileged heterocycle scaffold in synthetic chemistry, through the exploitation of reactivity between the directing group and installed group. The formal [2+2] cycloaddition/fragmentation reaction pathway identified herein, a unique reactivity pattern hitherto elusive for the N-nitroso group, emphasizes the importance of forward reactivity analysis in the development of useful C?H functionalization-based synthetic tools. The synthetic utility of the protocol is demonstrated with the synthesis of a tricyclic-fused ring system. The diversity of covalent linkages available for the nitroso group should enable the extension of the genre of reactivity reported herein to the synthesis of other types of heterocycles.
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[Epidemiological investigation of hand-foot-and-mouth disease in children and exposed population in Hangzhou city].
Zhejiang Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 05-01-2014
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To investigate the epidemic characteristics of hand-foot-and-mouth disease (HFMD) in children and exposed population in Hangzhou city.
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Ratiometric fluorescence detection of fluoride ion by indole-based receptor.
Talanta
PUBLISHED: 04-17-2014
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A novel artificial receptor 1 containing the indolocarbazole-NH moieties as the recognition sites exhibited high selectivity and sensitivity toward F(-) over other typical anionic species in DMSO solution. Upon addition of F(-) into the solution, receptor 1 showed a remarkable ratiometric shift of the fluorescence maximum from 535 to 590 nm, and also a prominent color change from light yellow to orange, which was observable by the naked eye. The recognition properties of receptor 1 were investigated by (1)H NMR, UV-vis, and fluorescence titration experiments, with the results suggesting a two-step strategy of binding with F(-). In addition, the theoretical calculations were carried out to reveal the role of intramolecular charge transfer in the ratiometric fluorescence recognition process.
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Complement 5a receptor mediates angiotensin II-induced cardiac inflammation and remodeling.
Arterioscler. Thromb. Vasc. Biol.
PUBLISHED: 04-17-2014
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Inflammation contributes to hypertension-induced cardiac damage and fibrotic remodeling. Complement activation produces anaphylatoxins, which are major inflammatory effectors. Here, we investigated the role of complement anaphylatoxins in angiotensin II (Ang II)-induced cardiac remodeling.
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A cresyl violet-based fluorescent off-on probe for the detection and imaging of hypoxia and nitroreductase in living organisms.
Chem Asian J
PUBLISHED: 04-14-2014
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A new cresyl violet-based fluorescent off-on probe has been developed through a one-step synthesis for the detection of nitroreductase (NTR) and hypoxia. The detection mechanism is based on the NTR-catalyzed reduction of the probe to cresyl violet, accompanied with a large fluorescence enhancement at a long wavelength of 625?nm. The probe can detect NTR in aqueous solution with high selectivity and sensitivity, and the detection limit is 1?ng?mL(-1) NTR. Most importantly, the probe has been successfully used to image not only NTR and hypoxia in living cells, but also the distribution of NTR in zebrafish in vivo.
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Using an autologistic regression model to identify spatial risk factors and spatial risk patterns of hand, foot and mouth disease (HFMD) in Mainland China.
BMC Public Health
PUBLISHED: 04-04-2014
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There have been large-scale outbreaks of hand, foot and mouth disease (HFMD) in Mainland China over the last decade. These events varied greatly across the country. It is necessary to identify the spatial risk factors and spatial distribution patterns of HFMD for public health control and prevention. Climate risk factors associated with HFMD occurrence have been recognized. However, few studies discussed the socio-economic determinants of HFMD risk at a space scale.
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CXCL12 in astrocytes contributes to bone cancer pain through CXCR4-mediated neuronal sensitization and glial activation in rat spinal cord.
J Neuroinflammation
PUBLISHED: 04-03-2014
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Previous studies have demonstrated that chemokine CXCL12 and its receptor CXCR4 are critical for pain sensitization, but the mechanisms involved are not clear. In this study, we investigated the specific cellular mechanisms of CXCL12/CXCR4 chemokine signaling in the development and maintenance of bone cancer pain after tumor cell implantation (TCI).
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Increased vulnerability with aging to MPTP: the mechanisms underlying mitochondrial dynamics.
Neurol. Res.
PUBLISHED: 03-14-2014
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The risk and vulnerability of Parkinson disease (PD) are especially high in the elderly. However, the underlying causes are unknown. 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mice are useful tools to some extent for investigating PD-related problems due to their PD-like symptoms. The study is aimed to determine whether and what mitochondrial-events during aging are related with the increased vulnerability of the elderly to MPTP.
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Activity levels and expression of antioxidant enzymes in the ascorbate-glutathione cycle in artificially aged rice seed.
Plant Physiol. Biochem.
PUBLISHED: 03-06-2014
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Reactive oxygen species are the main contributors to seed deterioration. In order to study scavenging systems for reactive oxygen species in aged seed, we performed analyses using western blotting, real-time quantitative reverse-transcription polymerase chain reaction, high-performance liquid chromatography, and antioxidant enzyme activity analyses in artificially aged rice seeds (Oryza sativa L. cv. wanhua no.11). Aging seeds by storing them at 50 °C for 1, 9, or 17 months increased the superoxide radical and hydrogen peroxide levels and reduced the germination percentage from 99% to 92%, 55%, and 2%, respectively. The activity levels of superoxide dismutase (SOD), glutathione reductase (GR), and dehydroascorbate reductase (DHAR) did not change in aged seeds. In contrast, the activity levels of catalase (CAT), ascorbate peroxidase (APX), and monodehydroascorbate reductase (MDHAR) were significantly decreased in aged seeds, as were the expression of catalase and cytosolic ascorbate peroxidase protein. Transcript accumulation analysis showed that specific expression patterns were complex for each of the antioxidant enzyme types in the rice embryos. Overall, the expression of most genes was down-regulated, along with their protein expression. In addition, the reduction in the amount of ascorbate and glutathione was associated with the reduction in scavenging enzymes activity in aged rice embryos. Our data suggest that the depression of the antioxidant system, especially the reduction in the expression of CAT1, APX1 and MDHAR1, may be responsible for the accumulation of reactive oxygen species in artificially aged seed embryos, leading to a loss of seed vigor.
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Taurine improves the spatial learning and memory ability impaired by sub-chronic manganese exposure.
J. Biomed. Sci.
PUBLISHED: 02-15-2014
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Excessive manganese exposure induced cognitive deficit. Several lines of evidence have demonstrated that taurine improves cognitive impairment induced by numerous neurotoxins. However, the role of taurine on manganese-induced damages in learning and memory is still elusive. This goal of this study was to investigate the beneficial effect of taurine on learning and memory capacity impairment by manganese exposure in an animal model.
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DNA-based hybridization chain reaction for an ultrasensitive cancer marker EBNA-1 electrochemical immunosensor.
Biosens Bioelectron
PUBLISHED: 02-10-2014
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An ultrasensitive and selective electrochemical immunosensor was developed for the detection of Epstein Barr virus nuclear antigen 1 (EBNA-1). Firstly, a suspension of graphene sheets (GS) and multi-walled carbon nanotubes (MWCNTs) was prepared with the aid of chitosan (CS) solution and then modified on a glassy carbon electrode (GCE). Gold nanoparticles (AuNPs) were then electrodeposited onto the surface of the GS-MWCNTs film by cyclic voltammetry (CV) to immobilize the captured antibodies. After that, specific sandwich immunoreactions were formed among the captured antibody, EBNA-1, and secondary antibody, DNA-coated carboxyl multi-wall carbon nanotubes (DNA-MWCNTs-Ab2). DNA initiator strands (S0) and secondary antibodies linked to the MWCNTs and double-helix DNA polymers were obtained by hybridization chain reaction (HCR), and here S0 on the MWCNTs propagates a chain reaction of hybridization events between two alternating hairpins to form a nicked double-helix. Finally, electroactive indicator doxorubicin hydrochloride was intercalated into the CG-GC steps between the HCR products and could produce an electrochemical signal, which was monitored by differential pulse voltammetry (DPV). Under optimum conditions, the amperometric signal increased linearly with the target concentrations (0.05-6.4ngmL(-1)), and the immunosensor exhibited a detection limit as low as 0.7pgmL(-1) (S/N=3). The proposed method showed acceptable stability and reproducibility, as well as favorable recovery for EBNA-1 in human serum. The proposed immunosensor provides a novel avenue for signal amplification and potential applications in bioanalysis and clinical diagnostics.
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Hepatic antioxidant enzymes SOD and CAT of Nile tilapia (Oreochromis niloticus) in response to pesticide methomyl and recovery pattern.
Bull Environ Contam Toxicol
PUBLISHED: 02-07-2014
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Hepatic antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) of Nile tilapia in response to pesticide methomyl and recovery pattern were researched by exposing tilapia to sub-lethal methomyl concentrations of 0, 0.2, 2, 20 and 200 ?g/L for 30 days, and then transferred to methomyl-free water for 18 days. Hepatic SOD and CAT were measured at 10 min (day 0), 6, 12, 18, 24 and 30 days after starting the experiment and at 18 days after transferring to methomyl-free water. The results showed hepatic SOD and CAT activities in 2, 20 and 200 ?g/L groups were affected significantly, however, that in 0.2 ?g/L group didn't change significantly compared to control during 30-day exposure period. Thus it would appear the 0.2 ?g/L methomyl might be considered the no observed adverse effect level. Recovery data showed that, for SOD, the effects produced by lower concentration of methomyl 2 ?g/L were reversible but not at concentrations higher than 20 ?g/L, however, for CAT, the effects produced by all the concentrations were reversible.
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Tissue-specific deletion of Crry from mouse proximal tubular epithelial cells increases susceptibility to renal ischemia-reperfusion injury.
Kidney Int.
PUBLISHED: 02-05-2014
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The murine cell surface protein Crry (complement receptor 1-related protein/gene y) is a key complement regulator with similar activities to human membrane cofactor protein (MCP) and decay-accelerating factor. MCP has a critical role in preventing complement-mediated tissue injury and its mutation has been implicated in several human kidney diseases. The study of Crry in mice has relevance to understanding MCP activity in human diseases; however, such efforts have been hampered by the embryonic lethality phenotype of Crry gene knockout. Here we used a conditional gene-targeting approach and deleted Crry from the mouse proximal tubular epithelial cells where Crry is prominently expressed. Absence of Crry from proximal tubular epithelial cells resulted in spontaneous C3 deposition on the basolateral surface but no apparent renal disease in unchallenged mice. However, mice deficient in Crry on proximal tubular epithelial cells developed exacerbated renal injury when subjected to renal ischemia-reperfusion, showing increased blood urea nitrogen levels, higher tubular injury scores, more tubular epithelial cell apoptosis, and inflammatory infiltrates. Renal ischemia-reperfusion injury in the Crry conditional knockout mice was prevented by blocking C3 and C5 activation using an anti-properdin or anti-C5 monoclonal antibody (mAb), respectively. Thus, Crry has a critical role in protecting proximal tubular epithelial cells during ischemia-reperfusion challenge. Our results highlight the latent risk for inflammatory kidney injury associated with defects in membrane complement regulators.
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Reconstructing full-length ureteral defects using a spiral bladder muscle flap with vascular pedicles.
Urology
PUBLISHED: 01-27-2014
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This study investigates the efficacy of ureteral reconstruction using a spiral bladder muscle flap with vascular pedicles (ie, the superior vesical arteries) to repair full-length ureteral defects and explores a surgical approach for repairing long ureteral defects (>20 cm) using a bladder muscle flap.
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Effects of chronic exposure of methomyl on the antioxidant system in liver of Nile tilapia (Oreochromis niloticus).
Ecotoxicol. Environ. Saf.
PUBLISHED: 01-07-2014
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The chronic effect of methomyl on the antioxidant system in tilapia (Oreochromis niloticus) was investigated. Fish were exposed to sub-lethal concentrations of 0.2, 2, 20 and 200?gL(-1) for 30 days, and then transferred to methomyl-free water for 18 days. Hepatic antioxidant parameters, including Glutathione-S-transferase (GST), Glutathione peroxidase (GPx), Glutathione reductase (GR), Reduced glutathione (GSH) and oxidized glutathione (GSSG), were measured at 10min (day 0), 6, 12, 18, 24 and 30 days after starting the experiment and at 18 days after transferring to methomyl-free water. There were no significant changes in enzymatic activity and content of antioxidants in liver of tilapia exposed to 0.2?gL(-1) methomyl compared to controls. However, the results showed significant increases in activities of GST, GR, GPx and levels of GSSG accompanied by a decrease in GSH levels following methomyl exposure in tilapia to 2, 20 or 200?gL(-1) over the 30-day exposure period and the highest induction rates in GST, GR, GPx and GSSG were 150.87%, 163.21%, 189.76%, and 179.56% of the control respectively, and the highest inhibition rate in GSH was 50.67% of the control, suggesting the presence of oxidative stress. Thus it would appear that the 0.2?gL(-1) methomyl might be considered as the no observed adverse effect level (NOAEL). Recovery data showed that the effects produced by lower concentration of methomyl 20?gL(-1) were reversible but not at the higher 200?gL(-1) concentration.
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Decay-accelerating factor 1 deficiency exacerbates leptospiral-induced murine chronic nephritis and renal fibrosis.
PLoS ONE
PUBLISHED: 01-01-2014
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Leptospirosis is a global zoonosis caused by pathogenic Leptospira, which can colonize the proximal renal tubules and persist for long periods in the kidneys of infected hosts. Here, we characterized the infection of C57BL/6J wild-type and Daf1-/- mice, which have an enhanced host response, with a virulent Leptospira interrogans strain at 14 days post-infection, its persistence in the kidney, and its link to kidney fibrosis at 90 days post-infection. We found that Leptospira interrogans can induce acute moderate nephritis in wild-type mice and is able to persist in some animals, inducing fibrosis in the absence of mortality. In contrast, Daf1-/- mice showed acute mortality, with a higher bacterial burden. At the chronic stage, Daf1-/- mice showed greater inflammation and fibrosis than at 14 days post-infection and higher levels at all times than the wild-type counterpart. Compared with uninfected mice, infected wild-type mice showed higher levels of IL-4, IL-10 and IL-13, with similar levels of ?-smooth muscle actin, galectin-3, TGF-?1, IL-17, IFN-?, and lower IL-12 levels at 90 days post-infection. In contrast, fibrosis in Daf1-/- mice was accompanied by high expression of ?-smooth muscle actin, galectin-3, IL-10, IL-13, and IFN-?, similar levels of TGF-?1, IL-12, and IL-17 and lower IL-4 levels. This study demonstrates the link between Leptospira-induced murine chronic nephritis with renal fibrosis and shows a protective role of Daf1.
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Increased constituent ratios of Klebsiella sp., Acinetobacter sp., and Streptococcus sp. and a decrease in microflora diversity may be indicators of ventilator-associated pneumonia: a prospective study in the respiratory tracts of neonates.
PLoS ONE
PUBLISHED: 01-01-2014
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Ventilator-associated pneumonia (VAP) is a common complication and cause of death in neonates on mechanical ventilation. However, it is difficult to define the causes of VAP. To understand the causes of VAP, we undertook a prospective study based on the diversity of the microflora in VAP. The experimental group consisted of newborns who suffered from respiratory distress syndrome (RDS) and VAP, while the control group suffered from RDS without VAP. Sputa were collected within 1, 3, and 5 days of ventilation and were divided into six groups. DNA was extracted from the samples, and the 16S rDNA was PCR amplified, separated using denaturing gradient gel electrophoresis (DGGE), cloned and sequenced. The resulting sequences were compared using BLAST. The DGGE pictures were measured, and the richness, Shannon-Wiener index, and cluster maps were analyzed. No differences were found regarding the constituent ratio of any genus between the Non-VAP and VAP group within 1 day after intubation. After 1 to 3 days, the constituent ratios of Klebsiella sp., Acinetobacter sp., and Streptococcus sp. in the VAP group were higher than those in the Non-VAP group, and the ratios of Serratia sp. and Achromobacter sp. were lower. After 3 to 5 days, the ratios of Klebsiella sp., Acinetobacter sp., Serratia sp., and Achromobacter sp. were lower than those in the Non-VAP group. The richness and Shannon-Wiener index of the Non-VAP group were higher than those of the VAP group from 1 to 3 days after intubation, while no differences were found within 1 day and from 3 to 5 days. We conclude that during the first three days of intubation, the microflora diversity in the lower respiratory tract was reduced due to VAP, and the greater constituent ratios of Klebsiella sp., Acinetobacter sp., and Streptococcus sp. in the sputum may be indicators of VAP.
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Synthesis of three OSW-1 analogs with maltose side chains bearing different protection groups.
J Asian Nat Prod Res
PUBLISHED: 12-06-2013
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In order to simplify the synthesis of OSW-1s disaccharide side chain and explore the structure-activity relationship of OSW-1, three 16?-O-maltose OSW-1 analogs carrying three maltose side chains bearing different protections were designed and synthesized.
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[Diversity analysis of biofilm bacteria on tracheal tubes removed from intubated neonates].
Zhonghua Er Ke Za Zhi
PUBLISHED: 11-15-2013
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The catheter-related infections caused by mechanical ventilation have become a intractable clinical problem, and it is related to the formation of bacterial biofilm (BF) on the surface of the implanted material. The majority of natural biofilms are formed by multiple bacterial species. However, there always only one or limited species were detected on tracheal tubes removed from intubated neonates by using traditional methods including bacterium culture and antigen detection. The aims of this study were to observe the bacterial communities diversity of BF on endotracheal tube (ETT), and discuss the difference between traditional bacterium culture methods and the use of molecular biology techniques on the basis of denatured gradient gel electrophoresis (DGGE), to provide new ideas for clinical prevention, diagnosis and treatment of bacterial infections.
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Nox gene expression and cytochemical localization of hydrogen peroxide in Polyporus umbellatus sclerotial formation.
Int J Mol Sci
PUBLISHED: 11-01-2013
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The effect of temperature shift on Polyporus umbellatus sclerotial development was investigated. Micromorphology of the sclerotia was observed by using scanning electron microscopy (SEM). The cytochemical localization of H2O2 expressed as CeCl3 deposition at the subcellular level was observed by using transmission electron microscopy (TEM). Nox gene expression in sclerotia and mycelia was detected by quantitative real-time PCR (qRT-PCR) analysis. In addition, superoxide dismutase (SOD) and catalase (CAT) specific activities increased during sclerotial development and decreased after the antioxidant diphenyleneiodonium (DPI) was used. Results indicated that the temperature shift treatment induced P. umbellatus sclerotial formation. Compared with the mycelia, the Nox gene was respectively upregulated by 10.577-, 30.984- and 25.469-fold in the sclerotia of SI, SD and SM stages respectively. During the sclerotial formation, H2O2 accumulation was observed in the cell walls or around the organelle membranes of the mycelial cells. The antioxidant DPI decreased the generation of H2O2 in mycelial cells. The specific activity of SOD and CAT levels was decreased significantly by DPI. The activity of the two antioxidant enzymes in the mycelia increased much more during sclerotial formation (p < 0.05). Oxidative stress was closely associated with sclerotial development in P. umbellatus induced by temperature shift treatment.
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Effects of chronic exposure of methomyl on the antioxidant system in kidney of Nile tilapia (Oreochromis niloticus) and recovery pattern.
J. Toxicol. Environ. Health Part A
PUBLISHED: 10-26-2013
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Tilapia were exposed to sublethal methomyl concentrations of 0, 0.2, 2, 20, or 200 ?g/L for 30 d, and then were transferred to methomyl-free water for 18 d. Renal antioxidant parameters, including catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione peroxidase (GPx) , glutathione reductase (GR), total glutathione (GSH), and reduced glutathione (GSSG), were examined in tilapia at d 0, 6, 12, 18, 24, and 30 after starting the experiment and at 18 d after transferring to methomyl-free water. There were no significant changes in enzymatic activity and content of antioxidants in kidney of tilapia exposed to 0.2 ?g/L methomyl compared to controls. The results showed significant increases in SOD, CAT, GST, GR, GPx, and level of GSSG accompanied by a decrease in GSH levels following methomyl exposure in tilapia to 2, 20, or 200 ?g/L over the 30-d exposure period, suggesting the presence of oxidative stress. Thus, it would appear the 0.2 ?g/L methomyl might be considered the no-observed-adverse-effect level (NOAEL). Recovery data showed that the effects produced by lower concentration of methomyl at 20 ?g/L were reversible but not at the higher 200 ?g/L concentration.
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Rhodium(III)-catalyzed indole synthesis using N-N bond as an internal oxidant.
J. Am. Chem. Soc.
PUBLISHED: 10-24-2013
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We report herein a Rh(III)-catalyzed cyclization of N-nitrosoanilines with alkynes for streamlined synthesis of indoles. The synthetic protocol features a distinct internal oxidant, N-N bond, as a reactive handle for catalyst turnover, as well as a hitherto tantalizingly elusive intermolecular redox-neutral manifold, predicated upon C-H activation, for the formation of a five-membered azaheterocycle. The compatibility of seemingly dichotomous acidic and basic conditions ensures reaction versatility for multifarious synthetic contexts. The tolerance of an array of auxiliary functional groups potentially permits predefined, programmable substitution patterns to be incorporated into the indole scaffold. Comprehensive mechanistic studies, under acidic condition, support [RhCp*](2+) as generally the catalyst resting state (switchable to [RhCp*(OOC(t)Bu)](+) under certain circumstance) and C-H activation as the turnover-limiting step. Given the variety of covalent linkages available for the nitroso group, this labile functionality is likely to be harnessed as a generic handle for strikingly diverse coupling reactions.
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Influences of d-tyrosine on the stability of activated sludge flocs.
Bioresour. Technol.
PUBLISHED: 08-29-2013
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The sludge floc stability is essential for the solid/liquid separation in biological wastewater treatment. In this study, the effect of an exogenous d-tyrosine on the shear stability and surface characteristics of activated sludge flocs was investigated. Sludge flocs were found to be less stable in the addition of d-tyrosine. d-Tyrosine inhibited the production of extracellular polymeric substances (EPS) especially for the proteins. A high correlation coefficient was observed between the composition of EPS fraction and d-tyrosine content. In addition, the hydrophobicity of sludge flocs was reduced and the zeta potential was more negative with the content of d-tyrosine increased. A linear relationship between the extracellular polymeric substances and surface characteristics for sludge flocs indicated that the inhibited EPS production may be responsible for the instability of sludge upon the addition of d-tyrosine.
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Transcriptional environment and chromatin architecture interplay dictates globin expression patterns of heterospecific hybrids derived from undifferentiated human embryonic stem cells or from their erythroid progeny.
Exp. Hematol.
PUBLISHED: 08-16-2013
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To explore the response of ? globin locus with established chromatin domains upon their exposure to new transcriptional environments, we transferred the chromatin-packaged ? globin locus of undifferentiated human embryonic stem cells (hESCs) or hESC-derived erythroblasts into an adult transcriptional environment. Distinct globin expression patterns were observed. In hESC-derived erythroblasts where both ? and ? globin were active and marked by similar chromatin modifications, ? globin was immediately silenced upon transfer, whereas ? globin continued to be expressed for months, implying that different transcriptional environments were required for their continuing expression. Whereas ? globin was silent both in hESCs and in hESC-derived erythroblasts, ? globin was only activated upon transfer from hESCs, but not in the presence of dominant ? globin transferred from hESC-derived erythroblasts, confirming the competing nature of ? versus ? globin expression. With time, however, silencing of ? globin occurred in the adult transcriptional environment with concurrent activation of ?-globin, accompanied by a drastic change in the epigenetic landscape of ? and ? globin gene regions without apparent changes in the transcriptional environment. This switching process could be manipulated by overexpression or downregulation of certain transcription factors. Our studies provide important insights into the interplay between the transcription environment and existing chromatin domains, and we offer an experimental system to study the time-dependent human globin switching.
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A controllable gate effect in cobalt(II) organic frameworks by reversible structure transformations.
Angew. Chem. Int. Ed. Engl.
PUBLISHED: 07-19-2013
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With H2 O or NH3 stimuli, the blue cobalt-based metal-organic framework (MOF) BP can reversibly transform to red RP. The removal/recovery of terephthalate ligands accompanied by the transformation leads to a gate effect, which allows the encapsulation and release of small solvent molecules under certain conditions. This is the first example of topology transformation from a self-penetrating to interpenetrating net in 3D MOFs.
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Synthesis and ferrimagnetic properties of an unprecedented polynuclear cobalt complex composed of [Co24] macrocycles.
Chem. Commun. (Camb.)
PUBLISHED: 07-05-2013
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An unprecedented polynuclear cobalt complex with a [Co(24)] macrocycle in the presence of [Co(H(2)O)(6)](2+) has been prepared and characterized. In this complex, [Co(H(2)O)(6)](2+) not only acts as a counterion to balance the negative charge of the 2D layer, but may also serve as a template in the assembly of the [Co(24)] macrocyclic complex through hydrogen-bond interactions. Magnetic analyses indicate that the title compound shows homometallic ferrimagnetic behavior.
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Characterization of the interactions between tetracycline antibiotics and microbial extracellular polymeric substances with spectroscopic approaches.
Environ Sci Pollut Res Int
PUBLISHED: 06-03-2013
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The antibiotics have attracted global attentions for their impact on aquatic ecosystem. The knowledge about the fate of antibiotics encountering extracellular polymeric substances (EPS) is, however, limited. In this study, we investigated the interacting mechanisms of tetracycline (TC) to EPS extracted from aerobic activated sludge. The contributions of the main components of EPS, extracellular proteins, and polysaccharides were evaluated using bovine serum albumin and alginate sodium, respectively. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and nuclear magnetic resonance indicated that hydroxyl, carboxyl, and amino groups were the domain chemical groups involved in the interaction between TC and EPS, and the binding of TC onto EPS changed the structure of these chemical groups, thus causing shifts in their UV-visible absorption spectra. In addition, we found that extracellular proteins, rather than polysaccharides, were the major active contents involved in the interaction. Three-dimensional excitation-emission matrix fluorescence spectroscopy showed that the fluorophores in EPS were clearly quenched by TC and the static quenching process was observed, implying the complex formation of TC and EPS. Furthermore, thermodynamic analysis indicated that the binding of TC with EPS is spontaneous and dominated by electrostatic forces.
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Properdin in complement activation and tissue injury.
Mol. Immunol.
PUBLISHED: 05-15-2013
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The plasma protein properdin is the only known positive regulator of complement activation. Although regarded as an initiator of the alternative pathway of complement activation at the time of its discovery more than a half century ago, the role and mechanism of action of properdin in the complement cascade has undergone significant conceptual evolution since then. Despite the long history of research on properdin, however, new insight and unexpected findings on the role of properdin in complement activation, pathogen infection and host tissue injury are still being revealed by ongoing investigations. In this article, we provide a brief review on recent studies that shed new light on properdin biology, focusing on the following three topics: (1) its role as a pattern recognition molecule to direct and trigger complement activation, (2) its context-dependent requirement in complement activation on foreign and host cell surfaces, and (3) its involvement in alternative pathway complement-mediated immune disorders and considerations of properdin as a potential therapeutic target in human diseases.
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A novel lactoferrin-modified ?-cyclodextrin nanocarrier for brain-targeting drug delivery.
Int J Pharm
PUBLISHED: 05-10-2013
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The blood-brain barrier (BBB) restricts the transfer and delivery of most drug substances to brain. In this study, a novel nano-drug delivery system for brain-targeting was developed and investigated in vitro and in vivo. Lactoferrin (Lf) was selected as a brain-targeting ligand and conjugated to ?-cyclodextrin (?-CD) via the heterobifunctional polyethyleneglycol (PEG) linker NHS-PEG-MAL, yielding Lf conjugated ?-cyclodextrin (Lf-CD). UV-vis, FTIR, NMR and transmission electron microscopy (TEM) techniques clearly demonstrated the successful synthesis of Lf-CD nanoparticles with the average diameter of 92.9 ± 16.5 nm. Using near-infrared fluorescent dye IR-775 chloride (IR) as a model compound of poorly water-soluble drugs, IR-loaded Lf-CD nanoparticles (Lf-CD/IR) were successfully prepared with a high entrapment efficiency of 98.1 ± 4.8%. Biodistribution and pharmacokinetics of Lf-CD/IR were evaluated in KM mice after intravenous administration. The results of tissue distribution studies revealed that Lf-CD/IR treatment showed greatly improved BBB transport efficiency. In addition, AUC0-2h of IR in brain after Lf-CD/IR treatment was seven fold higher compared with that of IR treatment without Lf-CD nano-carriers, demonstrating that the introduction of Lf-CD drug-delivery system positively resulted in a higher AUC located in brain tissue. These results provide evidence that Lf-CD nanoparticles could be exploited as a potential brain-targeting drug delivery system for hydrophobic drugs and diagnostic reagents which normally fail to pass through the BBB.
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[NVP-BEZ235 inhibits proliferation and colony-forming capability of CD34(+)CD38(-) human acute myeloid leukemia stem cells].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 05-01-2013
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This study was aimed to explore the effect of NVP-BEZ235, a dual phosphatidylinositol 3-kinase/mammalian target of rapamycin inhibitor, on proliferation, cell cycle and colony forming capability of CD34(+)CD38(-) human acute myeloid leukemia (AML) KG1a cells. Flow cytometry was used to detect expression of CD34 and CD38 on the surface of human AML KG1a cells; Trypan blue assay was used to analyze the effect of NVP-BEZ235 at various concentrations on proliferation of KG1a cells; flow cytometry was performed to examine the cell cycle of KG1a cells after NVP-BEZ235 treatment; Soft agar colony-forming experiment was used to detect the colony forming ability of KG1a cells treated with NVP-BEZ235 at various concentrations. The results indicated that the percentage of CD34(+)CD38(-) AML KG1a cells was (98.02 ± 0.72)%. NVP-BEZ235 (0.125 - 1 µmol/L) inhibited the proliferation of KG1a cells in a time-and dose-dependent manner (P < 0.05) and the 50% inhibition concentrations (IC50) at 24 h and 48 h were 0.597 µmol/L and 0.102 µmol/L, respectively. KG1a cells were arrested at G0/G1 phase after treating with 0.5 µmol/L NVP-BEZ235 for 24 h, it was significantly higher than that of control group (83.2 ± 3.80)% vs (43.47 ± 9.60)% (P < 0.05). KG1a cells treated with NVP-BEZ235 (0 - 1 µmol/L) for 14 d and 21 d, the number of colony decreased respectively from (375.67 ± 21.46) per 2500 KG1a cells and (706.33 ± 87.31) per 2500 KG1a cells to 0, with statistical significance (P < 0.05). It is concluded that NVP-BEZ235 can inhibit proliferation and colony-forming capability of CD34(+)CD38(-) human AML KG1a cells.
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TGF-?1 -509C/T (or +869T/C) polymorphism might be not associated with hepatocellular carcinoma risk.
Tumour Biol.
PUBLISHED: 03-21-2013
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Many studies have reported the role of transforming growth factor-?1 (TGF-?1) -509C/T or +869T/C polymorphism with hepatocellular carcinoma (HCC) risk. However, these studies have yielded conflicting results. Hence, we performed this meta-analysis to investigate the association between TGF-?1 -509C/T or +869T/C polymorphism and HCC. A total of 11 studies including 2,577 HCC cases and 4,107 controls were included in the meta-analysis. Overall, TGF-?1 -509C/T (or +869T/C) polymorphism was not associated with HCC risk (homogeneous co-dominant model: OR = 1.29, 95 % CI = 0.88-1.89; heterogeneous co-dominant model: OR = 1.15, 95 % CI = 0.91-1.45; dominant model: OR = 1.14, 95 % CI = 0.87-1.48; recessive model: OR = 1.15, 95 % CI = 0.89-1.49). In the subgroup analysis, TGF-?1 -509C/T (or +869T/C) polymorphism was significantly associated with HCC risk in Caucasians under the recessive model (OR = 1.65, 95 % CI = 1.07-2.55) but not in other genetic models. In addition, we did not observe significant association in Asians under all genetic models. In conclusion, our meta-analysis indicates that TGF-?1 -509C/T (or +869T/C) polymorphism was not associated with risk of HCC, although a marginal association was found for Caucasians. However, a study with the larger sample size is needed to further evaluate gene-environment interaction on the association.
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C3 glomerulopathy: consensus report.
Kidney Int.
PUBLISHED: 03-20-2013
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C3 glomerulopathy is a recently introduced pathological entity whose original definition was glomerular pathology characterized by C3 accumulation with absent or scanty immunoglobulin deposition. In August 2012, an invited group of experts (comprising the authors of this document) in renal pathology, nephrology, complement biology, and complement therapeutics met to discuss C3 glomerulopathy in the first C3 Glomerulopathy Meeting. The objectives were to reach a consensus on: the definition of C3 glomerulopathy, appropriate complement investigations that should be performed in these patients, and how complement therapeutics should be explored in the condition. This meeting report represents the current consensus view of the group.
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Luminescence enhancement of ZnO-core/a-SiN(x):H-shell nanorod arrays.
Opt Express
PUBLISHED: 03-14-2013
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We report a remarkable improvement of photoluminescence from ZnO-core/a-SiN(x):H-shell nanorod arrays by modulating the bandgap of a-SiN(x):H shell. The a-SiN(x):H shell with a large bandgap can significantly enhance UV emission by more than 8 times compared with the uncoated ZnO nanorods. Moreover, it is found that the deep-level defect emission can be almost completely suppressed for all the core-shell nanostructures, which is independent of the bandgaps of a-SiN(x):H shells. Combining with the analysis of infrared absorption spectrum and luminescence characteristics of NH(x)-plasma treated ZnO nanorods, the improved photoluminescence is attributed to the decrease of nonradiative recombination probability and the reduction of surface band bending of ZnO cores due to the H and N passivation and the screening effect from the a-SiN(x):H shells. Our findings open up new possibilities for fabricating stable and efficient UV-only emitting devices.
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Genetic diversity and population structure of yellow catfish Pelteobagrus fulvidraco from five lakes in the middle and lower reaches of the Yangtze River, China, based on mitochondrial DNA control region.
Mitochondrial DNA
PUBLISHED: 03-06-2013
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Genetic diversity and population structure of yellow catfish Pelteobagrus fulvidraco were examined by using mitochondrial DNA control region sequences in 143 specimens sampled from five lakes in the middle and lower reaches of the Yangtze River, China; 151 polymorphic sites defined 72 distinct haplotypes. Haplotype diversity indices (0.903-0.953) and nucleotide diversity indices (0.00378-0.00970) demonstrated low genetic diversity of the yellow catfish populations in the five lakes. The analysis of molecular variance and the fixation index (F(st) = 0.0896) revealed insignificant genetic difference between samples from different lakes. In addition, neutral tests and analysis of mismatch distribution suggested that yellow catfish might have undergone a population expansion. Neighbor-joining tree indicated a correlation between these population genetic differences and geographic distance. This study revealed the extant population genetic diversity and structure of the yellow catfish and was in favor of the related fishery management issues including fishery stock identification, conservation, and artificial breeding.
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Overexpression of YKL-40 predicts plaque instability in carotid atherosclerosis with CagA-positive Helicobacter pylori infection.
PLoS ONE
PUBLISHED: 02-21-2013
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YKL-40 has been demonstrated to be related to atherosclerosis, but its role in predicting plaque status and the outcome of carotid atherosclerosis (CAS) caused by CagA-positive Helicobacter pylori remains unclear. This study was aimed to investigate the role of YKL-40 in predicting the outcome of carotid atherosclerosis with CagA-positive Helicobacter pylori infection.
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Blocking properdin, the alternative pathway, and anaphylatoxin receptors ameliorates renal ischemia-reperfusion injury in decay-accelerating factor and CD59 double-knockout mice.
J. Immunol.
PUBLISHED: 02-20-2013
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Complement is implicated in the pathogenesis of ischemia-reperfusion injury (IRI). The activation pathway(s) and effector(s) of complement in IRI may be organ specific and remain to be fully characterized. We previously developed a renal IRI model in decay-accelerating factor (DAF) and CD59 double-knockout (DAF(-/-)CD59(-/-)) mice. In this study, we used this model to dissect the pathway(s) by which complement is activated in renal IRI and to evaluate whether C3aR- or C5aR-mediated inflammation or the membrane attack complex was pathogenic. We crossed DAF(-/-)CD59(-/-) mice with mice deficient in various complement components or receptors including C3, C4, factor B (fB), factor properdin (fP), mannose-binding lectin, C3aR, C5aR, or Ig and assessed renal IRI in the resulting mutant strains. We found that deletion of C3, fB, fP, C3aR, or C5aR significantly ameliorated renal IRI in DAF(-/-)CD59(-/-) mice, whereas deficiency of C4, Ig, or mannose-binding lectin had no effect. Treatment of DAF(-/-)CD59(-/-) mice with an anti-C5 mAb reduced renal IRI to a greater degree than did C5aR deficiency. We also generated and tested a function-blocking anti-mouse fP mAb and showed it to ameliorate renal IRI when given to DAF(-/-)CD59(-/-) mice 24 h before, but not 4 or 8 h after, ischemia/reperfusion. These results suggest that complement is activated via the alternative pathway during the early phase of reperfusion, and both anaphylatoxin-mediated inflammation and the membrane attack complex contribute to tissue injury. Further, they demonstrate a critical role for properdin and support its therapeutic targeting in renal IRI.
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KLF11 mediates PPAR? cerebrovascular protection in ischaemic stroke.
Brain
PUBLISHED: 02-12-2013
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Peroxisome proliferator-activated receptor gamma (PPAR?) is emerging as a major regulator in neurological diseases. However, the role of (PPAR?) and its co-regulators in cerebrovascular endothelial dysfunction after stroke is unclear. Here, we have demonstrated that (PPAR?) activation by pioglitazone significantly inhibited both oxygen-glucose deprivation-induced cerebral vascular endothelial cell death and middle cerebral artery occlusion-triggered cerebrovascular damage. Consistent with this finding, selective (PPAR?) genetic deletion in vascular endothelial cells resulted in increased cerebrovascular permeability and brain infarction in mice after focal ischaemia. Moreover, we screened for (PPAR?) co-regulators using a genome-wide and high-throughput co-activation system and revealed KLF11 as a novel (PPAR?) co-regulator, which interacted with (PPAR?) and regulated its function in mouse cerebral vascular endothelial cell cultures. Interestingly, KLF11 was also found as a direct transcriptional target of (PPAR?). Furthermore, KLF11 genetic deficiency effectively abolished pioglitazone cytoprotection in mouse cerebral vascular endothelial cell cultures after oxygen-glucose deprivation, as well as pioglitazone-mediated cerebrovascular protection in a mouse middle cerebral artery occlusion model. Mechanistically, we demonstrated that KLF11 enhanced (PPAR?) transcriptional suppression of the pro-apoptotic microRNA-15a (miR-15a) gene, resulting in endothelial protection in cerebral vascular endothelial cell cultures and cerebral microvasculature after ischaemic stimuli. Taken together, our data demonstrate that recruitment of KLF11 as a novel (PPAR?) co-regulator plays a critical role in the cerebrovascular protection after ischaemic insults. It is anticipated that elucidating the coordinated actions of KLF11 and (PPAR?) will provide new insights into understanding the molecular mechanisms underlying (PPAR?) function in the cerebral vasculature and help to develop a novel therapeutic strategy for the treatment of stroke.
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Down regulation of TRAIL and FasL on NK cells by Cyclosporin A in renal transplantation patients.
Immunol. Lett.
PUBLISHED: 02-11-2013
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TNF-related apoptosis-inducing ligand (TRAIL) and FasL can participate in cell mediated cytotoxicity via their death domain-mediated apoptotic signaling in the host-versus-graft disease occurred after renal transplantation. However, the effect of Cyclosporin A (CsA) commonly used as a drug to prevent and to treat renal transplant rejection, on these molecules have not been fully determined. In the present study, we found that with CsA administration, the expression of TRAIL and FasL predominantly on NK cells from renal transplantation patients was increased at day 5 after operation and went down to normal level on day 13. While, the levels of soluble TRAIL (sTRAIL) and sFasL in the serum increased within 25 days and went down to normal level three month later. In addition, we showed that a remarkable increase of TRAIL and FasL expression both on the surface of activated lymphocytes especially on NK cells and in the supernatants generated from mixed lymphocytes culture (MLC). Furthermore, the enhancement of these two molecules was greatly decreased by adding 500 ng/mL CsA at the beginning of MLC. We conclude that CsA may inhibit the transplant rejection partially by down-regulating the expression of TRAIL and FasL on NK cells.
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Deletion of Crry and DAF on murine platelets stimulates thrombopoiesis and increases factor H-dependent resistance of peripheral platelets to complement attack.
J. Immunol.
PUBLISHED: 02-06-2013
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Complement receptor 1-related gene/protein y (Crry) and decay-accelerating factor (DAF) are two murine membrane C3 complement regulators with overlapping functions. Crry deletion is embryonically lethal whereas DAF-deficient mice are generally healthy. Crry(-/-)DAF(-/-) mice were viable on a C3(-/-) background, but platelets from such mice were rapidly destroyed when transfused into C3-sufficient mice. In this study, we used the cre-lox system to delete platelet Crry in DAF(-/-) mice and studied Crry/DAF-deficient platelet development in vivo. Rather than displaying thrombocytopenia, Pf4-Cre(+)-Crry(flox/flox) mice had normal platelet counts and their peripheral platelets were resistant to complement attack. However, chimera mice generated with Pf4-Cre(+)-Crry(flox/flox) bone marrows showed platelets from C3(-/-) but not C3(+/+) recipients to be sensitive to complement activation, suggesting that circulating platelets in Pf4-Cre(+)-Crry(flox/flox) mice were naturally selected in a complement-sufficient environment. Notably, Pf4-Cre(+)-Crry(flox/flox) mouse platelets became complement susceptible when factor H function was blocked. Examination of Pf4-Cre(+)-Crry(flox/flox) mouse bone marrows revealed exceedingly active thrombopoiesis. Thus, under in vivo conditions, Crry/DAF deficiency on platelets led to abnormal platelet turnover, but peripheral platelet count was compensated for by increased thrombopoiesis. Selective survival of Crry/DAF-deficient platelets aided by factor H protection and compensatory thrombopoiesis demonstrates the cooperation between membrane and fluid phase complement inhibitors and the bodys ability to adaptively respond to complement regulator deficiencies.
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Slow magnetic relaxation in two new 1D/0D Dy(III) complexes with a sterically hindered carboxylate ligand.
Inorg Chem
PUBLISHED: 02-04-2013
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Two carboxylate-bridged Dy(III) complexes, [Dy(2)(piv)(5)(?(3)-OH)(H(2)O)](n) (1) and [Dy(2)(piv)(6)(phen)(2)] (2) (pivH = pivalic acid; phen = 1,10-phenanthroline), have been synthesized and structurally characterized. Complex 1 takes a one-dimensional (1D) chain structure based on [Dy(4)(?(3)-OH)(2)(piv)(8)(H(2)O)(2)](2+) units, while complex 2 is a dinuclear structure bridged by syn,syn-carboxylates. Magnetic investigation indicates weak ferromagnetic interaction between adjacent Dy(III) ions of the Dy(4) unit in 1 and weak intramolecular antiferromagnetic interaction between Dy(III) ions and/or depopulation of the Dy(III) excited-state Stark sublevels in 2. Alternating-current susceptibility measurements revealed frequency- and temperature-dependent out-of-phase signals under a zero direct-current field in 1, with typical slow magnetic relaxation behavior with an anisotropic barrier U ? 4.5 K, while 2 exhibits field-induced single-molecule-magnet behavior with ?E/k(B) = 28.43 K under a 2 kOe external field.
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Physicochemical properties and antioxidant activity of chitosan from the blowfly Chrysomya megacephala larvae.
Int. J. Biol. Macromol.
PUBLISHED: 01-31-2013
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In the present study, we extracted the chitosan from the larvae of blowfly Chrysomya megacephala, a new source of insect chitosan, using chemical methods. We evaluated the physical properties of the blowfly chitosan using a variety of approaches, including preliminary color-change identification, molecular weight determination, elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR), solid-state (13)C cross-polarization and magic-angle-spinning nuclear magnetic resonance spectroscopy ((13)C CP/MAS NMR) and scanning electron microscopy (SEM). Its antioxidant property was examined through 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assays. The results showed that the molecular weight of the blowfly chitosan (501 kDa) was lower than that of the commercial chitosan (989 kDa), and its degree of deacetylation (DDA) (87.9-89.6%) was also higher than that of the commercial chitosan (83.8-85.8%). Furthermore, the blowfly chitosan exhibited excellent antioxidant activity and its IC50 value was 1.2 mg/ml. Therefore, the blowfly larvae could be a novel alternative source of chitosan and might be used as a natural antioxidant.
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Preparation and characterization of a novel dual-retention mechanism mixed-mode stationary phase with PEG 400 and succinic anhydride as ligand for protein separation in WCX and HIC modes.
Biomed. Chromatogr.
PUBLISHED: 01-29-2013
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A novel dual-retention mechanism mixed-mode stationary phase based on silica gel functionalized with PEG 400 and succinic anhydride as the ligand was prepared and characterized by infrared spectra and elemental analysis. Because of the ligand containing PEG 400 and carboxyl function groups, it displayed hydrophobic interaction chromatography (HIC) characteristic in a high-salt-concentration mobile phase, and weak cation exchange chromatography (WCX) characteristic in a low-salt-concentration mobile phase. As a result, it can be employed to separate proteins with both WCX and HIC modes. The resolution and selectivity of the stationary phase was evaluated under both HIC and WCX modes with protein standards, and its performance was comparable to that of conventional ion-exchange chromatography and HIC columns. The results indicated that the novel dual-retention mechanism column, in many cases, could replace two individual WCX and HIC columns as a 2D column. In addition, the mixed retention mechanism of proteins on this 2D column was investigated with stoichiometric displacement theory for retention of solute in liquid chromatography in detail in order to understand why the dual-retention mechanism column has high resolution and selectivity for protein separation under WCX and HIC modes, respectively. Based on this 2D column, a new 2DLC technology with a single column was developed. It is very important in proteome research and recombinant protein drug production to save column expense and simplify the processes in biotechnology. Copyright © 2013 John Wiley & Sons, Ltd.
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Tissue-engineered conduit using bladder acellular matrix and bladder epithelial cells for urinary diversion in rabbits.
Chin. Med. J.
PUBLISHED: 01-18-2013
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For muscle invasive bladder cancer, radical cystectomy is the most effective treatment now and urinary diversion is often necessary. The use of intestinal tissue for urinary diversion is frequently associated with complications. In this study, we aimed to make a tissue-engineered conduit (TEC) using bladder epithelial cells and bladder acellular matrix (BAM) for urinary diversion in rabbits.
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Exposure to heat-inactivated Trichophyton rubrum resulting in a limited immune response of human keratinocytes.
Chin. Med. J.
PUBLISHED: 01-18-2013
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Trichophyton rubrum (T. rubrum) represents the most important agent of dermatophytosis in humans. T. rubrum infection causes slight inflammation, and tends to be chronic and recurrent. It is suggested that it may result from the failure of epithelial cells to recognize T. rubrum effectively and initiate effective immune responses. The C-type lectin receptors (CLR) and toll-like receptors (TLR) are the two major pattern recognition receptors (PRRs) that recognize fungal components. Therefore, the purpose of the study was to analyze the expression of those PRRs and the cytokines in HaCaT cells stimulated with heat-inactivated T. rubrum conidia and hyphae, respectively.
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Sclerotial formation of Polyporus umbellatus by low temperature treatment under artificial conditions.
PLoS ONE
PUBLISHED: 01-07-2013
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Polyporus umbellatus sclerotia have been used as a diuretic agent in China for over two thousand years. A shortage of the natural P. umbellatus has prompted researchers to induce sclerotial formation in the laboratory.
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Analysis of the transcriptome of blowfly Chrysomya megacephala (Fabricius) larvae in responses to different edible oils.
PLoS ONE
PUBLISHED: 01-01-2013
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Chrysomya megacephala (Fabricius), a prevalent necrophagous blowfly that is easily mass reared, is noted for being a mechanical vector of pathogenic microorganisms, a pollinator of numerous crops, and a resource insect in forensic investigation in the postmortem interval. In the present study, in order to comprehensively understand the physiological and biochemical functions of C. megacephala, we performed RNA-sequencing and digital gene expression (DGE) profiling using Solexa/Illumina sequencing technology.
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Characteristics of patients with fluid extravasation during retrograde ureteroscopic holmium laser lithotripsy for renal calculi.
Saudi Med J
PUBLISHED: 12-14-2011
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To explore the risk factors of fluid extravasation during retrograde ureteroscopic holmium laser lithotripsy for renal calculi.
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Crosstalk between complement and toll-like receptors.
Toxicol Pathol
PUBLISHED: 11-22-2011
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The complement system and toll-like receptors (TLRs) are two components of innate immunity that are critical for first-line host defense. Many pathogen-associated molecular patterns activate both complement and TLRs, and recent studies in animal models have revealed a marked synergistic interaction between the two systems. In mice deficient in a membrane complement regulator, prototypical TLR ligands such as LPS, zymosan, and polyI:C caused increased systemic complement activation, which in turn led to a profound elevation of proinflammatory cytokine biosynthesis. This phenotype required interaction between complement and TLRs because complement activation alone by cobra venom factor without TLR engagement did not lead to appreciable cytokine production. The regulatory effect of complement on TLR signaling was mediated by the anaphylatoxins C5a and C3a through a receptor-dependent mechanism and involved increased mitogen-activated protein kinase and nuclear factor ?B activation. The crosstalk between complement and TLRs may also impact adaptive immunity, for example, the differentiation of T helper 17 (Th-17) cells. Given that excessive activation of either TLR or complement has been associated with inflammatory tissue injury as occurs in sepsis and autoimmune diseases, the new insight on complement and TLR crosstalk may have therapeutic implications.
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Photoluminescence of CaxSr(1-x) (NbO3)2:Pr3+ (0 < or = x < or = 1) nanophosphors.
J Nanosci Nanotechnol
PUBLISHED: 11-15-2011
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Nanoparticles of CaxSr(1-x) (NbO3)2 doped with Pr3+ have been synthesized by sol-gel method. Particles have sizes in the range of 50-70 nm. The CaxSr(1-x) (NbO3)2:Pr3+ phosphors showed a white emission under the near-ultraviolet excitation (254 nm). There is a large photoluminescence enhancement of the CaxSr(1-x) (NbO3)2:Pr3+ phosphor samples when added with 0.5% KCl. X-ray diffraction (XRD), transmission electron microscope (TEM), photo luminescent (PL) analysis were utilized to characterize the CaxSr(1-x) (NbO3)2:Pr+ particles. The concentration quenching of the samples was discussed as well. The optical concentration and the calcination temperature were 0.8 mol% of Ca2+ and 900 degrees C for these phosphors, respectively, the possible mechanism was discussed. CaxSr(1-x) (NbO3)2:Pr3+ is a promising white phosphor under near-ultraviolet excitation for various applications.
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Rice DUR3 mediates high-affinity urea transport and plays an effective role in improvement of urea acquisition and utilization when expressed in Arabidopsis.
New Phytol.
PUBLISHED: 10-19-2011
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• Despite the great agricultural and ecological importance of efficient use of urea-containing nitrogen fertilizers by crops, molecular and physiological identities of urea transport in higher plants have been investigated only in Arabidopsis. • We performed short-time urea-influx assays which have identified a low-affinity and high-affinity (K(m) of 7.55 ?M) transport system for urea-uptake by rice roots (Oryza sativa). • A high-affinity urea transporter OsDUR3 from rice was functionally characterized here for the first time among crops. OsDUR3 encodes an integral membrane-protein with 721 amino acid residues and 15 predicted transmembrane domains. Heterologous expression demonstrated that OsDUR3 restored yeast dur3-mutant growth on urea and facilitated urea import with a K(m) of c. 10 ?M in Xenopus oocytes. • Quantitative reverse-transcription polymerase chain reaction (qPCR) analysis revealed upregulation of OsDUR3 in rice roots under nitrogen-deficiency and urea-resupply after nitrogen-starvation. Importantly, overexpression of OsDUR3 complemented the Arabidopsis atdur3-1 mutant, improving growth on low urea and increasing root urea-uptake markedly. Together with its plasma membrane localization detected by green fluorescent protein (GFP)-tagging and with findings that disruption of OsDUR3 by T-DNA reduces rice growth on urea and urea uptake, we suggest that OsDUR3 is an active urea transporter that plays a significant role in effective urea acquisition and utilisation in rice.
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Isomorphous tetrazolate MnII and CoII compounds built on ?-chain showing different magnetic behaviors.
Dalton Trans
PUBLISHED: 10-06-2011
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As a continuation of the study on using the tetrazolate ligands to construct coordination polymers, two isomorphous 3D coordination polymers built on ?-chain topological rod-shaped SBUs have been synthesized with formulae [M(2)(?(3)-OH)L(1)L(2)](n) (5-amino-1H-tetrazole (HL(1)), 2,3-pyrazinedicarboxylic acid (H(2)L(2)) and different 3d spin carriers (M = Mn(II), 1 and Co(II), 2)). The SBU consists of corner-sharing [M(3)(?(3)-OH)] isosceles triangle motifs with mixed multiple (?(4)-tetrazolyl, ?(3)-OH, syn-syn carboxylate) bridges. The SBUs were further linked by syn-anti carboxylates to form the sra net. Spin-competing was observed in the Mn(II) compound, whereas the Co(II) compound exhibits spin-canting.
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[Establishment of a cyanotic congenital heart defect porcine model with decreased pulmonary blood flow].
Zhonghua Xin Xue Guan Bing Za Zhi
PUBLISHED: 09-09-2011
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To establish a porcine model of congenital heart disease with decreased pulmonary blood to explore the morphological changes of immature pulmonary vascular vessels.
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[Pulmonary pathology in fatal human influenza A (H1N1) infection].
Zhonghua Bing Li Xue Za Zhi
PUBLISHED: 09-03-2011
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To study the pulmonary pathology in patients died of fatal human influenza A(H1N1) infection.
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Photodegradation of perfluorooctanoic acid by synthesized TiO2-MWCNT composites under 365nm UV irradiation.
Chemosphere
PUBLISHED: 08-16-2011
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Degradation of perfluorooctanoic acid (PFOA) is of great importance due to its global distribution, persistence and toxicity to bioorganisms. In present study, a composite TiO(2) with multiple wall carbon nanotubes (MWCNTs) was synthesized using sol-gel method and it was used as photocatalyst to degrade PFOA in water. The prepared composite catalyst displayed significant absorption in UV to visible light region. The loading content of TiO(2) on MWCNTs could be adjusted by changing the ratio of precursor to MWCNTs. Due to the combined effect of the adsorption ability and e(-) transport capacity of MWCNT, the composites displayed much higher photocatalytic ability to PFOA as compared to pure TiO(2) under UV irradiation. The photocatalyst prepared with 10:1 of tetrabutyl titanate/MWCNT was the most effective. With the optimal dosage at 1.6 g L(-1), almost 100% of PFOA was degraded in acid medium after irradiation for 8h. It was proposed that PFOA were mainly degraded by stepwise losing a moiety of CF(2).
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Cis-regulatory functions of overlapping HIF-1alpha/E-box/AP-1-like sequences of CD164.
BMC Mol. Biol.
PUBLISHED: 08-09-2011
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CD164 (also known as MGC-24v or endolyn) is a sialomucin which has been suggested to participate in regulating the proliferation, cell adhesion and differentiation of hematopoietic stem and progenitor cells. CD164 is also involved in the development of cancer. The functions of cis-regulatory elements of CD164 remain relatively unknown.
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Molecular determinants of disease in coxsackievirus B1 murine infection.
J. Med. Virol.
PUBLISHED: 07-09-2011
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To understand better how different genomic regions may confer pathogenicity for the coxsackievirus B (CVB), two intratypic CVB1 variants, and a number of recombinant viruses were studied. Sequencing analysis showed 23 nucleotide changes between the parental non-pathogenic CVB1N and the pathogenic CVB1Nm. Mutations present in CVB1Nm were more conserved than those in CVB1N when compared to other CVB sequences. Inoculation in C3H/HeJ mice showed that the P1 region is critical for pathogenicity in murine pancreas and heart. The molecular determinants of disease for these organs partially overlap. Several P1 region amino acid differences appear to be located in the decay-accelerating factor (DAF) footprint CVBs. CVB1N and CVB1Nm interacted with human CAR, but only CVB1N seemed to interact with human DAF, as determined using soluble receptors in a plaque-reduction assay. However, the murine homolog Daf-1 did not interact with any virus assessed by hemagglutination. The results of this study suggest that an unknown receptor interaction with the virus play an important role in the pathogenicity of CVB1Nm. Further in vivo studies may clarify this issue.
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Characterization of reference genes for quantitative real-time PCR analysis in various tissues of Anoectochilus roxburghii.
Mol. Biol. Rep.
PUBLISHED: 07-03-2011
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Accurate quantification of transcript profiling with quantitative real time polymerase chain reaction (qRT-PCR) relies on the reliable normalization of an appropriate reference gene. This study reported the identification and validation of nine reference genes, including ?-tubulin (?-TUB), elongation factor 1 alpha (EF-1?), elongation factor 1 beta (EF-1?), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ubiquitin (UBQ), actin 1/2(ACT-1 and ACT-2), 18S rRNA, and 26S rRNA, from Anoectochilus roxburghii (Wall.) Lindl., a valuable herb remedy widely used for various diseases treatment in traditional Chinese medicine. Transcriptional levels of the candidate reference genes were examined using qRT-PCR analysis and revealed differential expression of the genes in the leaf, stem, root, flower, and peduncle tissues. The relative quantities data were subjected to geNorm software for ranking the expression stability of the reference genes and the results showed that EF-1? and ACT-2 were the two best stable genes whereas GAPDH and 26S rRNA did not favor normalization of qRT-PCR in these tissues. The expression pattern of a squalene synthase encoding gene (SS) was also determined in parallel. The analyses were in great consistency when the qRT-PCR data was normalized to the expression of each or both of EF-1? and ACT-2 as the internal control, further confirming the reliability of EF-1? and ACT-2 as the best internal control. The present study provided the first important clues for accurate data normalization in transcript profiling in A. roxburghii, which will be essential to further functional genomics study in the valuable medicinal plant.
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Decay-accelerating factor regulates T-cell immunity in the context of inflammation by influencing costimulatory molecule expression on antigen-presenting cells.
Blood
PUBLISHED: 06-07-2011
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Recent studies have indicated a role of complement in regulating T-cell immunity but the mechanism of action of complement in this process remains to be clarified. Here we studied mice deficient in decay-accelerating factor (DAF), a key membrane complement regulator whose deficiency led to increased complement-dependent T-cell immune responses in vivo. By crossing OT-II and OT-I T-cell receptor transgenic mice with DAF-knockout mice, we found that lack of DAF on T cells did not affect their responses to antigen stimulation. Similarly, lack of DAF on antigen-presenting cells (APCs) of naive mice did not alter their T-cell stimulating activity. In contrast, APCs from DAF-knockout mice treated with inflammatory stimuli were found to be more potent T-cell stimulators than cells from similarly treated wild-type mice. Acquisition of higher T-cell stimulating activity by APCs in challenged DAF-knockout mice required C3 and C5aR and was correlated with decreased surface PD-L1 and/or increased CD40 expression. These findings implied that DAF suppressed T-cell immunity as a complement regulator in the context of inflammation but did not play an intrinsic role on T cells or APCs. Collectively, our data suggest a systemic and indirect role of complement in T-cell immunity.
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Transmembrane transport of microcystin to Danio rerio zygotes: insights into the developmental toxicity of environmental contaminants.
Toxicol. Sci.
PUBLISHED: 05-20-2011
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Microcystins (MCs) produced by cyanobacteria and their continuing "blooms" are a worldwide problem owing to the toxicity of microcystin-LR (MC-LR) to plants and animals. In the present study, we investigated membrane transport of MC-LR and its toxic effects on zebrafish embryos using fragmentation of embryos, scanning electron microscope (SEM), fluorescence microscopy, and toxic exposure tests. At a concentration < 0.04 mmol/l, MC-LR was predominantly adsorbed on outer membrane surface of embryos according to Langmuir isotherm. The absorption characteristics of MC-LR within the range from 0.05 to 0.4 mmol/l conformed to Freundlich isotherm model. At concentrations > 0.50 mmol/l MC-LR directly entered the cytoplasm via partition. Thinning and disruption of membranes was confirmed using SEM and fluorescence morphological observations. Exposure to different concentrations of MC-LR resulted in differences in membrane transport and toxicity characteristics. At low concentrations, more than 75% of the adsorbed MC-LR accumulated on the outer membrane surface and resulted in axial malformation, tail curving, and tail twisting. Increasing the concentration of MC-LR to between 0.05 and 0.4 mmol/l improved membrane transport and it was evident in cytoplasm of embryos, resulting in serious pericardial edema, hatching gland edema, hemagglutination, hemorrhage, and vacuolization. At > 0.50 mmol/l, more than 70% of the adsorbed MC-LR entered the cytoplasm and this was lethal to the embryos. The current research outlines a new method and mechanism for the transmembrane transport of large molecular weight organic compounds and could be important for studies concerning molecular toxicology.
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Energy-efficient algorithm for sensor networks with non-uniform maximum transmission range.
Sensors (Basel)
PUBLISHED: 04-15-2011
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In wireless sensor networks (WSNs), the energy hole problem is a key factor affecting the network lifetime. In a circular multi-hop sensor network (modeled as concentric coronas), the optimal transmission ranges of all coronas can effectively improve network lifetime. In this paper, we investigate WSNs with non-uniform maximum transmission ranges, where sensor nodes deployed in different regions may differ in their maximum transmission range. Then, we propose an Energy-efficient algorithm for Non-uniform Maximum Transmission range (ENMT), which can search approximate optimal transmission ranges of all coronas in order to prolong network lifetime. Furthermore, the simulation results indicate that ENMT performs better than other algorithms.
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Genetic analysis of the O-antigen gene clusters of Yersinia pseudotuberculosis O:6 and O:7.
Glycobiology
PUBLISHED: 02-16-2011
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Among the 21 O-polysaccharide (OPS) O-antigen-based serotypes described for Yersinia pseudotuberculosis, those of O:6 and O:7 are unusual in that both contain colitose (4-keto-3,6-dideoxy-d-mannose or 4-keto-3,6-dideoxy-l-xylo-hexose), which has not otherwise been reported for this species, and the O:6 OPS also contains yersiniose A (4-C[(R)-1-hydroxyethyl]-3,6-dideoxy-d-xylo-hexose), another unusual dideoxyhexose sugar. In Y. pseudotuberculosis, the genes for OPS synthesis generally cluster together between the hemH and gsk loci. Here, we present the sequences of the OPS gene clusters of Y. pseudotuberculosis O:6 and O:7, and the location of the genes required for synthesis of these OPSs, except that there is still ambiguity regarding allocation of some of the glycosyltransferase functions. The O:6 and O:7 gene clusters have much in common with each other, but differ substantially from the group of 13 gene clusters already sequenced, which share several features and sequence similarities. We also present a possible sequence of events for the derivation of the O:6 and O:7 gene clusters from the most closely related set of 13 sequenced previously.
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Thymidine kinase gene modified bone marrow mesenchymal stem cells as vehicles for antitumor therapy.
Hum. Gene Ther.
PUBLISHED: 02-02-2011
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Bone marrow mesenchymal stem cells (BMSCs) represent an important source of cells for tissue repair. The tropism of these cells to the sites of injury and tumors has been well established. Their tumor-homing properties make BMSCs good candidates as antitumor agent delivery vehicles. In this study, we showed that BMSCs have the ability to migrate toward various cancer cells, including prostate cancer cells in vitro and in vivo and incorporating into the tumor mass. When infected with herpes simplex virus thymidine kinase (TK) gene by lentiviral transduction, TK-BMSCs maintained their tumor tropism capabilities and significantly inhibited the growth of subcutaneous PC3 prostate cancer xenografts in nude mice, in the presence of prodrug ganciclovir (GCV). Xenogenic TK-BMSCs also survived and exerted a significant antitumor effect in an animal model bearing metastastic RIF-1 (fibrosarcoma) tumor in the presence of prodrug GCV. The present study demonstrated that overexpression of TK in BMSCs did not affect their multidifferentiation potentials and their specific homing capacities toward the tumor mass, and the TK-BMSCs alone did not cause any harmful side effects in vivo. The use of TK-BMSCs as tumor-specific delivery vehicles together with controlled prodrug treatment may be a safe and novel anticancer therapy approach.
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Periostin identified as a potential biomarker of prostate cancer by iTRAQ-proteomics analysis of prostate biopsy.
Proteome Sci
PUBLISHED: 01-12-2011
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Proteomics may help us better understand the changes of multiple proteins involved in oncogenesis and progression of prostate cancer(PCa) and identify more diagnostic and prognostic biomarkers. The aim of this study was to screen biomarkers of PCa by the proteomics analysis using isobaric tags for relative and absolute quantification(iTRAQ).
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CXCR4 and matrix metalloproteinase-2 are involved in mesenchymal stromal cell homing and engraftment to tumors.
Cytotherapy
PUBLISHED: 12-20-2010
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Bone marrow-derived mesenchymal stromal cells (BMSC) have been shown to migrate to injury, ischemia and tumor microenvironments. The mechanisms by which mesenchymal stromal cells (MSC) migrate across endothelium and home to the target tissues are not yet fully understood.
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[Phloroglucinol: safe and effective for the prevention of bladder spasm after TURP].
Zhonghua Nan Ke Xue
PUBLISHED: 12-07-2010
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To evaluate the efficacy of phloroglucinol in preventing bladder spasm after transurethral resection of the prostate (TURP).
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[Preliminary interpretation on the relationship between the phenotype of CD133+ cells and niche in transplanted human glioma in mice].
Zhonghua Zhong Liu Za Zhi
PUBLISHED: 12-03-2010
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CD133(+) tumor cells are regarded as cancer stem cells (CSCs), responsible for tumor initiation, development, and relevant with chemo- and radio-resistance of tumors. However, how the destiny of CD133(+) cells is regulated by their niche remains largely unknown. In this study the interpretation of the relationship between CD133(+) cells and their niche were performed through investigating the distribution characteristics of CD133(+) cells in transplanted human glioma xenograft.
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[The application of quantitative detection of cystatin C in evaluation of renal function after renal transplantation].
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
PUBLISHED: 11-09-2010
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To establish ELISA method for quantitate the concentration of cystatin C (cys C) and to monitor the renal function of patients before and after renal transplantation.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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