The objective of this study is to use high (49/s) and low (9/s) stimulation rates of the BAEP to investigate the possible mechanism responsible for BPPV. A total of 81 patients (55 women and 26 men, mean age ± SD = 54.6 ± 15.0) with idiopathic BPPV, as well as 106 control subjects (70 women and 36 men, mean age ± SD = 51.2 ± 16.3) participated in the study. The results of high (49/s) and low (9/s) stimulation rates of the BAEP test were compared and analyzed. The difference in BAEP wave I peak latencies between low and high stimulation rate (DPL I) and BAEP wave I peak latency in high stimulation (HPL I) of affected ears (0.24 ± 0.14 and 1.91 ± 0.21 ms) in BPPV patients were significantly prolonged when compared with the controls (0.10 ± 0.08 and 1.76 ± 0.18 ms) and unaffected ears (0.12 ± 0.10 and 1.82 ± 0.21 ms) (p < 0.001). The abnormal rate of DPL I in the affected ear (52/83, 62.65 %) was significantly higher than that in the unaffected ear (7/79, 8.86 %) and the normal left ear (4/106, 3.77 %). We suggest that ischemia of the inner ear might be one of the causes of BPPV and that DPL I may be used to assess the ischemic degree in subjects over 20 years old.
We report an aptamer discovery technology that reproducibly yields higher affinity aptamers in fewer rounds compared to conventional selection. Our method (termed particle display) transforms libraries of solution-phase aptamers into "aptamer particles", each displaying many copies of a single sequence on its surface. We then use fluorescence-activated cell sorting (FACS) to individually measure the relative affinities of >10(8) aptamer particles and sort them in a high-throughput manner. Through mathematical analysis, we identified experimental parameters that enable optimal screening, and demonstrate enrichment performance that exceeds the theoretical maximum achievable with conventional selection by many orders of magnitude. We used particle display to obtain high-affinity DNA aptamers for four different protein targets in three rounds, including proteins for which previous DNA aptamer selection efforts have been unsuccessful. We believe particle display offers an extraordinarily efficient mechanism for generating high-quality aptamers in a rapid and economic manner, towards accelerated exploration of the human proteome.
The purpose of this study was to evaluate the in vitro antibacterial effect of AH Plus (Dentsply, DeTrey, Konstanz, Germany) incorporated with quaternary ammonium epoxy silicate (QAES) against Enterococcus faecalis.
In order to demonstrate the variation of bioaccessibility of PAHIs in microbial degradation process, PAH contaminated coking plant soil was remediated using microbial agent, and the bioaccessibility of PAHs was assessed using solid phase micro extraction (SPME) and solid phase extraction (SPE), difference and correlation between PAH degradation and PAH bioaccessbility variation were also analyzed. Results showed that the dominant PAHs in the coking plant soil and its pore water were low molecular weight (LMW) PAHs, and 68.3% of total PAH was degraded by the microbial agent, which was mainly due to the LMW PAH degradation. Decrease of PAH concentration in soil pore water was also contributed by LMW PAHs, however, individual PAH reductions in soil pore water were lower than those PAH degradations. Fast desorption fraction was calculated from Tenax-TA extraction, and those fractions for LMW PAHs decreased, while those for high molecular weight (HMW) PAHs did not change significantly. Strong correlation between PAH degraded and PAH concentration in soil pore water or fast desorption fraction of Tenax-TA extraction was observed. The results above demonstrated that PAH concentration in soil pore water and fast desorption fraction of Tenax-TA extraction can be used to predict PAH degradation in soil, which provided some theoretical basis for the remediation of PAH contaminated soil from coking plant.
Studies of protein evolution have focused on amino acid substitutions with much less systematic analysis on insertion and deletions (indels) in protein coding genes. We hence surveyed 7,500 genes between Drosophila melanogaster and D. simulans, using D. yakuba as an outgroup for this purpose. The evolutionary rate of coding indels is indeed low, at only 3% of that of nonsynonymous substitutions. As coding indels follow a geometric distribution in size and tend to fall in low-complexity regions of proteins, it is unclear whether selection or mutation underlies this low rate. To resolve the issue, we collected genomic sequences from an isogenic African line of D. melanogaster (ZS30) at a high coverage of 70× and analyzed indel polymorphism between ZS30 and the reference genome. In comparing polymorphism and divergence, we found that the divergence to polymorphism ratio (i.e., fixation index) for smaller indels (size ?10 bp) is very similar to that for synonymous changes, suggesting that most of the within-species polymorphism and between-species divergence for indels are selectively neutral. Interestingly, deletions of larger sizes (size ?11 bp and ?30 bp) have a much higher fixation index than synonymous mutations and 44.4% of fixed middle-sized deletions are estimated to be adaptive. To our surprise, this pattern is not found for insertions. Protein indel evolution appear to be in a dynamic flux of neutrally driven expansion (insertions) together with adaptive-driven contraction (deletions), and these observations provide important insights for understanding the fitness of new mutations as well as the evolutionary driving forces for genomic evolution in Drosophila species.
Schistosomiasis is an endemic parasite disease and praziquantel is the only drug currently in use to control this disease. Experimental and epidemiological evidence strongly suggests that Microtus fortis ( Mf ) is a naturally resistant vertebrate host of Schistosoma japonicum . In the present study, we found that Mf serum albumin ( Mf -albumin) and the conditioned medium of pcDNA3.1- Mf -albumin caused 46.2% and 38.7% schistosomula death rates in 96 h, respectively, which were significantly higher than that of the negative control (p < 0.05). We also found that mice injected with Mf -albumin had a 43.5% reduction in worm burden and a 48.1% reduction in liver eggs per gram (p < 0.05) in comparison to the control animals. To characterise the mechanisms involved in clearance, schistosomula were incubated with fluorescein isothiocyanate-labelled Mf -albumin and fluorescent enrichment effects were found in the gut lumen of schistosomula after 48 h of incubation. Next, digestive tract excretions from schistosomula were collected and the sensitivity of Mf -albumin to digestive tract excretions was evaluated. The results indicated that schistosomula digestive tract excretions showed indigestibility of Mf -albumin. The death of schistosomula could be partially attributed to the lack of digestion of Mf -albumin by digestive tract excretions during the development of the schistosomula stage. Therefore, these data indicate the potential of Mf -albumin as one of the major selective forces for schistosomiasis.
Usually, next generation sequencing (NGS) technology has the property of ultra-high throughput but the read length is remarkably short compared to conventional Sanger sequencing. Paired-end NGS could computationally extend the read length but with a lot of practical inconvenience because of the inherent gaps. Now that Illumina paired-end sequencing has the ability of read both ends from 600 bp or even 800 bp DNA fragments, how to fill in the gaps between paired ends to produce accurate long reads is intriguing but challenging.
A method for the determination of fluorescent whitening agents in plastic food contact materials by high performance liquid chromatography (HPLC) with fluorescence detector was developed. The samples were extracted with trichloromethane by sonication for 30 min at 40 degrees C. The HPLC method was performed on a column of Eclipse XDB-C18 (250 mm x 4.6 mm, 5 microm) by gradient elution using 5 mmol/L ammonium acetate and acetonitrile as the mobile phases, and detected by the fluorescence detector at an excitation wavelength of 350 nm and an emission wavelength of 430 nm. The experimental results indicated that the four fluorescent whitening agents were separated well. The limits of detection (LOD) (S/N = 3) were 0.3, 0.1, 0.05, 0.14 mg/L, and the limits of quantification (LOQ) (S/N = 10) were 1.0, 0.4, 0.2, 0.5 mg/L for 1,4-bis (4-cyanostyryl) benzene (C. I. 199), 1,4-bis (2-benzoxazolyl) naphthalene (C. I. 367), 4,4-bis(2-methoxystyryl) biphenyl (C. I. 378) and 2,5-thiophenediylbis (5-tert-butyl-1,3-benzoxazole) (C. I. 184), respectively. Good linearities with correlation coefficients (r2) not less than 0.991 were obtained. The proposed method is simple, accurate, sensitive and can meet the requirements of the routine determination of fluorescent whitening agents in entry-exit products.
Herein we disclose an organocatalytic aryl-aryl bond-forming process for the regio- and atroposelective synthesis of 2,2-diamino-1,1-binaphthalenes (BINAMs). In the presence of catalytic amounts of axially chiral phosphoric acids, achiral N,N-binaphthyl hydrazines undergo a facile [3,3]-sigmatropic rearrangement to afford enantiomerically enriched BINAM derivatives in good to excellent yield. This transformation represents the first example of a metal-free, catalytic C(sp(2))-C(sp(2)) bond formation between two aromatic rings with concomitant de novo atroposelective installation of an axis of chirality. Density functional calculations reveal that, in the transition state for C-C bond formation, the phosphoric acid proton of the catalyst is fully transferred to one of the N-atoms of the substrate, and the resulting phosphate acts as a chiral counterion.
Genomic deletions are known to be widespread in many species. Variant sequencing-based approaches for identifying deletions have been developed, but their powers to detect those deletions that affect medium-sized regions are limited when the sequencing coverage is low.
Quaternary ammonium methacryloxy silicate (QAMS), an organically modified silicate (ORMOSIL) functionalized with polymerizable methacrylate groups and an antimicrobial agent with a long lipophilic alkyl chain quaternary ammonium group, was synthesized through a silane-based sol-gel route. By dissolving QAMS in methyl methacrylate monomer, this ORMOSIL molecule was incorporated into an auto-polymerizing, powder/liquid orthodontic acrylic resin system, yielding QAMS-containing poly(methyl methacrylate). The QAMS-containing acrylic resin showed a predominant contact-killing effect on Streptococcus mutans (ATCC 35668) and Actinomyces naeslundii (ATCC 12104) biofilms, while inhibiting adhesion of Candida albicans (ATCC 90028) on the acrylic surface. The antimicrobial activities of QAMS-containing acrylic resin were maintained after a 3month water-aging period. Bromophenol blue assay showed minimal leaching of quaternary ammonium species when an appropriate amount of QAMS (<4wt.%) was incorporated into the acrylic resin. The results suggest that QAMS is predominantly co-polymerized with the poly(methyl methacrylate) network, and only a minuscule amount of free QAMS molecules is present within the polymer network after water-aging. Acrylic resin with persistent antimicrobial activities represents a promising method for preventing bacteria- and fungus-induced stomatitis, an infectious disease commonly associated with the wearing of removable orthodontic appliances.
Avian Pasteurella multocida is a causative agent of fowl cholera. Two proteins OmpH and OmpA are the major immunogenic antigens of avian P. multocida, which play an important role in inducing immune responses that confer resistance against infections. In the present study, we used pcDNA3.1(+) as a vector and constructed DNA vaccines with the genes encoding the two antigens mentioned above. These DNA vaccines include monovalent (pcDNA-OMPH, pOMPH and pcDNA-OMPA, pOMPA), divalent combination (pcDNA-OMPH+pcDNA-OMPA, pOMPH+pOMPA) and fusion of two gene vaccines (pcDNA-OMPH/OMPA, pOMPHA). The immune responses to these DNA vaccines were evaluated by serum antibody titers, lymphocyte proliferation assay and titers of a cytokines, IFN-?. The protective efficacy after challenging with a virulent avian P. multocida strain, CVCC474, was evaluated by survival rate. A significant increase in serum antibody levels was observed in chickens vaccinated with divalent combination and fusion DNA vaccines. Additionally, the lymphocyte proliferation (SI value) and the levels of IFN-? were both higher in chickens immunized with divalent combination and fusion DNA vaccines than in those vaccinated with monovalent DNA vaccines (P<0.05). Furthermore, the protection provided by divalent combination and fusion DNA vaccines was superior to that provided by monovalent DNA vaccines after challenging with the avian P. multocida strain CVCC474. And the protective efficacy in chickens immunized three times with the fusion DNA vaccine was equivalent to the protective efficacy in chickens vaccinated once with the attenuated live vaccine. This suggests that divalent combination and fusion DNA vaccines represent a promising approach for the prevention of fowl cholera.
A method based on solid phase extraction (SPE) with magnetic multi-walled carbon nanotubes (MWCNTs) as adsorbent was developed for the determination of 13 phthalate acid esters (PAEs) in water samples by gas chromatography-mass spectrometry (GC-MS). The factors affecting the extraction efficiency, such as extraction time, pH of water sample, desorption solvent, and desorption time, were carefully investigated. The optimized conditions were as follows: extraction time, 10 min; pH of water samples, 5 - 7; desorption solvent, 2 mL acetone; desorption time, 5 min. The extraction efficiencies were 89.7% - 100.5% under the optimized conditions. The method was sensitive with the detection limits (S/N = 3) between 0.08 -0.47 microg/L for the 13 PAEs. The developed method was successfully applied for the analysis of tap water, bottle drinking water and lake water, and none of the 13 PAEs was detected. The recoveries ranged from 84.5% to 107.5% for the 3 real spiked samples, and the relative standard deviations were between 1.9% and 12.8%. The developed method has proved convenient, time-saving, accurate, sensitive, and environmental-friendly, and can be used for the determination of PAEs in water samples.
Concentrations and variations of fine particulate matter (PM2.5) and carbon monoxide (CO) within tents from the Nam Co and Ando regions were observed at summer 2009, in order to understand the concentrations and variations of PM2.5 and CO in these tents (or in rooms) and their main affect factors, as well as the exposure of different residents. The result indicates that the twenty-four hour average concentrations of PM2.5 and CO (V/V) in the tents without chimney are 1.272 mg x m(-3) and 5.035 x 10(-6), which are significantly higher than those of tents installed chimneys (0.097 mg x m(-3) and 0.089 x 10(-6)). Diurnal variations of PM2.5 and CO are similar and show multiple peaks, which is different with those in the eastern rural areas of China and closely connected with the behaviors of the residents within the tents. Generally, women and children spend three or four hours longer in tents than other family members every day. Children have the highest exposure of 0.972 mg x m(-3) and 0.132 x 10(-6) for PM2.5 and CO, respectively. Therefore, although the outdoor air in the Tibetan Plateau is very clean, the air of the Tibetan tents are seriously polluted and mainly caused by yak dung combustion.
We present the analysis of the evolution of tumors in a case of hepatocellular carcinoma. This case is particularly informative about cancer growth dynamics and the underlying driving mutations. We sampled nine different sections from three tumors and seven more sections from the adjacent nontumor tissues. Selected sections were subjected to exon as well as whole-genome sequencing. Putative somatic mutations were then individually validated across all 9 tumor and 7 nontumor sections. Among the mutations validated, 24 were amino acid changes; in addition, 22 large indels/copy number variants (>1 Mb) were detected. These somatic mutations define four evolutionary lineages among tumor cells. Separate evolution and expansion of these lineages were recent and rapid, each apparently having only one lineage-specific protein-coding mutation. Hence, by using a cell-population genetic definition, this approach identified three coding changes (CCNG1, P62, and an indel/fusion gene) as tumor driver mutations. These three mutations, affecting cell cycle control and apoptosis, are functionally distinct from mutations that accumulated earlier, many of which are involved in inflammation/immunity or cell anchoring. These distinct functions of mutations at different stages may reflect the genetic interactions underlying tumor growth.
Affinity reagents that bind to specific molecular targets are an essential tool for both diagnostics and targeted therapeutics. There is a particular need for advanced technologies for the generation of reagents that specifically target cell-surface markers, because transmembrane proteins are notoriously difficult to express in recombinant form. We have previously shown that microfluidics offers many advantages for generating affinity reagents against purified protein targets, and we have now significantly extended this approach to achieve successful in vitro selection of T7 phage-displayed peptides that recognize markers expressed on live, adherent cells within a microfluidic channel. As a model, we have targeted neuropilin-1 (NRP-1), a membrane-bound receptor expressed at the surface of human prostate carcinoma cells that plays central roles in angiogenesis, cell migration, and invasion. We show that, compared to conventional biopanning methods, microfluidic selection enables more efficient discovery of peptides with higher affinity and specificity by providing controllable and reproducible means for applying stringent selection conditions against minimal amounts of target cells without loss. Using our microfluidic system, we isolate peptide sequences with superior binding affinity and specificity relative to the well known NRP-1-binding RPARPAR peptide. As such microfluidic systems can be used with a wide range of biocombinatorial libraries and tissue types, we believe that our method represents an effective approach toward efficient biomarker discovery from patient samples.
Microtus fortis is a naturally vertebrate host resistant to Schistosoma japonicum infection. In order to understand the molecular mechanism and identify the molecules related to the natural resistance to S. japanicum infection of M. fortis, we screened a gene pool named gE76 by expression cloning and proved it to have high anti-schistosomula effects in our previous work. In this study we identified a clone named gE76.44. We found that the conditioned medium of pcDNA1.1-gE76.44 caused 14.0% schistosomula death rate in 96 h, which was significantly higher than that of negative control (P<0.05). The gE76.44 was sequenced and the full-length cDNA was 2008 bp with ORF of 1590bp encoding a polypeptide of 529 amino acid residues. Bioinformatics analysis indicated it was the homologue of karyopherin alpha 2 (KPNA2). To further confirm its anti-schistosome activity, we inserted full length of Mf-KPNA2 (KPNA2 of M. fortis) gene into a retroviral expression vector pLXSN and packaged the recombinant virus with PA317 cells. Mice infected with S. japanicum cercariae were administrated by intravenous injection through tail vein and treated with pLXSN-KPNA2. Adult worms and egg reduction were counted after heart perfusion of mice 42 d after infection. We found that compared with the control, mice injected with Mf-KPNA2 had 39.42% worm burden reduction and 76.50% reduction in LEPG (liver eggs per gram) (P<0.01), indicating its anti-schistosome effect of Mf-KPNA2 in vivo. Taken together, the results suggested Mf-KPNA2 as a novel anti-schistosome molecule in vitro and in vivo.
A tandem NHC-catalyzed aza-benzoin/Michael reaction has been developed as a method to efficiently produce dihydroindenones and pyrrolidinone-containing tricycles. The novel reaction pattern involves tert-butyl aryl(tosyl)methylcarbamates reacting as both electrophile and nucleophile on the same carbon.
Four new triterpenoid saponins (1-4) were isolated from the rhizome of Ardisia gigantifolia STAPF. The structures of new saponins were established as 3beta-o-alpha-L-rhamnopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->2)]-beta-D-glucopyranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl-16alpha-hydroxy-13,28-epoxy-oleanane (1), 3beta-o-alpha-L-rhamnopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->2)]-beta-D-glucopyranosyl-(1-->4)-[beta-D-glucopyrano-syl-(1-->2)]-alpha-L-arabinopyranosyl-16alpha-hydroxy-13,28-epoxy-30-acetoxy-oleanane (2), 3beta-o-alpha-L-rhamnopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->4)-beta-D-xylopyranosyl-(1-->2)]-beta-D-glucopyranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl-16alpha-hydroxy-13,28-epoxy-oleanane (3) and 3beta-o-alpha-L-rhamnopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->2)]-beta-D-glucopyranosyl-(1-->4)-[beta-D-6-O-acetylglucopranosyl-(1-->2)]-alpha-L-arabinopyranosyl-16alpha-hydroxy-13,28-epoxy-oleanane (4) were isolated from Ardisia gigantifolia STAPF. Their structures were elucidated by means of (1)H- and (13)C-NMR spectroscopic studies, including 2D-NMR technique. The cytotoxic activities of saponins 1-4 are reported against three human cancer cell lines, namely, Hela human cervical carcinoma cells, EJ human bladder tumor cells, and BCG-823 human gastric carcinoma cells.
To explore the relationship between tumor necrosis factor (TNF) gene polymorphisms in donors and recipients and the incidence and severity of acute graft-versus-host diseases (aGVHD) after unrelated allogeneic hematopoietic stem cell transplantation (allo-HSCT).
DNA variants in a 31-kb region of the human major histocompatibility complex, encompassing the tumor necrosis factor (TNF) gene cluster, were surveyed by direct sequencing of 283 unrelated individuals from six Chinese populations. A total of 273 polymorphic sites were identified, with nearly half of them novel. We observed an excess of rare variants and negative values of selection tests of the region, implying either that these populations experienced a historical expansion or that the surveyed region was subjected to natural selection. Different characteristics of the sequence variation in the six populations outline the genetic differentiation between Northern and Southern Chinese populations. The distributions of recombination rates are similar among all the populations, with variation in the magnitude and/or in the fine location of hot spots. Tag single-nucleotide polymorphisms (SNPs) selected from HapMap (Phase II) CHB data accounted for an average of 64% of common SNPs from the six Chinese populations. We also observed a limited transferability of tag SNPs between Chinese populations on the 31-kb region with an excess of untaggable SNPs and ragged linkage disequilibrium blocks. It suggested that the design and interpretation of future association studies should be more cautious, and that a resequencing approach may refine tag SNP selection on Chinese-specific disease mapping.
Microtus fortis is a naturally resistant vertebrate host of Schistosoma japonicum by preventing completion of parasites life cycle. Sera of M. fortis were found to have anti-schistosome effect in vitro and in vivo. In order to identify genes associated with the anti-schistosome effect of M. fortis, we screened a M. fortis marrow cDNA expression library by expression cloning and identified a 331-bp clone gC14.75. It was the homologue of heat shock protein 90alpha (HSP90alpha). Full-length of M. fortis HSP90alpha gene, Mf-HSP90alpha, was amplified according to gC14.75 and Cricetulus griseus HSP90alpha. To test the potential anti-schistosome function of Mf-HSP90alpha, we prepared conditioned medium of Mf-HSP90alpha and added it to schistosomula cultured in vitro. It caused 27.0% schistosomula death rate in 96h, which was considerably higher than that of negative control. We transferred Mf-HSP90alpha by retroviral expression vector pLXSN into mice to investigate its anti-schistosome effect in vivo. Compared with those of DMEM injection control, mice injected with Mf-HSP90alpha recombinant retrovirus had 40.8% worm burden reduction and 57.9% reduction in liver eggs per gram (LEPG) indicating its anti-schistosome effect in vivo. Taken together, our results suggested Mf-HSP90alpha as a novel anti-schistosome molecule in vitro and in vivo.
Our study provides a promising alternative of biomimetic coating which functionalizes the dental implant with adhesion peptides and may be useful for enhancing the bone remodeling around Ti implants. A chimeric peptide consisting of an Arg-Gly-Asp (RGD) sequence (mediating cell adhesion) and a RKLPDA (minTBP-1) sequence (specifically recognizing and binding to Ti substrate) was designed and synthesized. The chimeric peptide affinity to Ti disks, as well as its role in mediating MC3T3-E1 cell attachment and afterwards spreading on pre-coated Ti disks, was investigated. The chimeric peptide not only showed favorable affinity to Ti surfaces but also facilitated the adhesion of MC3T3-E1 cells.
Activator of G protein Signaling 3 (AGS3) is a receptor-independent G protein activator that has been implicated in multiple biological events such as brain development, neuroplasticity and addiction, cardiac function, Golgi structure/function, macroautophagy and metabolism. However, how AGS3 is regulated is little known. We demonstrate here that AGS3 interacts with a ubiquitin specific protease USP9x, and this interaction is at least partially mediated through the C-terminal G protein regulatory domain of AGS3. Knockdown of USP9x causes a moderate reduction in the level of AGS3. In contrast, overexpression of either USP9x or its deubiquitinating domain UCH increases the amount of AGS3, whereas expression of the mutant UCH domain that lacks deubiquitinating activity does not have the same effect. As previously observed in AGS3 knockdown cells, the localization of several marker proteins of the late Golgi compartments is disturbed in cells depleted of USP9x. Taken together, our study suggests that USP9x can modulate the level of a subpopulation of AGS3, and this modulation plays a role in regulating the structure of the late Golgi compartments. Finally, we have found that levels of AGS3 and USP9x are co-regulated in the prefrontal cortex of rats withdrawn from repeated cocaine treatment. In conjunction with the above data, this observation indicates a potential role of USP9X in the regulation of the AGS3 level during cocaine-induced neuroplasticity.
Histone lysine methyltransferase complexes are essential for chromatin organization and gene regulation. Whether any of this machinery functions in membrane traffic is unknown. In this study, we report that mammal Dpy-30 (mDpy-30), a subunit of several histone H3 lysine 4 (H3K4) methyltransferase (H3K4MT) complexes, resides in the nucleus and at the trans-Golgi network (TGN). The TGN targeting of mDpy-30 is mediated by BIG1, a TGN-localized guanine nucleotide exchange factor for adenosine diphosphate ribosylation factor GTPases. Altering mDpy-30 levels changes the distribution of cation-independent mannose 6-phosphate receptor (CIMPR) without affecting that of TGN46 or transferrin receptor. Our experiments also indicate that mDpy-30 functions in the endosome to TGN transport of CIMPR and that its knockdown results in the enrichment of internalized CIMPR and recycling endosomes near cell protrusions. Much like mDpy-30 depletion, the knockdown of Ash2L or RbBP5, two other H3K4MT subunits, leads to a similar redistribution of CIMPR. Collectively, these results suggest that mDpy-30 and probably H3K4MT play a role in the endosomal transport of specific cargo proteins.
Nearly monodisperse YVO(4) architectures with persimmon-like, cube-like and nanoparticle shapes have been synthesised on a large scale by means of a complexing-agent-assisted solution route. The shape and size of these as-prepared architectures can be tuned effectively by controlling the reaction conditions, such as reaction time, the molar ratio of complexing agent/Y(3+) and different complexing agents. As a typical morphology, the growth process of monodisperse nanopersimmons has been examined. To extend this method, other LnVO(4) (Ln=Ce, Gd, Dy, Er) complexes with well-defined shape and dimensionality can also be achieved by adjusting different rare earth precursors. Further studies reveal that the morphology of the as-synthesised lanthanide orthovanadate is determined mainly by the interaction between rare earth ion and the complexing agent. Ultraviolet (UV) absorption and photoluminescence spectra show that the optical properties of YVO(4) nanopersimmons are relevant to their size and shape. This work sheds some light on the design of well-defined complex nanostructures, and explores the potential applications of the as-synthesised architectures.
N-Heterocyclic carbene catalyzed ring expansion of readily accessible 2-acyl-1-formylcyclopropanes was developed. With 5 mol % of triazolium salt 5 and 30 mol % of DBU, ring expansion of various 2-acyl-1-formylcyclopropanes led to 3,4-dihydro-alpha-pyrones in good to excellent yields.
Slowly does it! By adding the substrate by a syringe pump, a highly efficient Friedel-Crafts reaction of 4,7-dihydroindoles with nitroolefins was realized with 0.5 mol % of a chiral phosphoric acid. The Friedel-Crafts alkylation, together with a subsequent oxidation of the product, led to 2-substituted indoles in excellent enantiomeric excesses, which can be easily transformed to enantioenriched tetrahydro-gamma-carbolines.
A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/ MS) analytical method was developed for the simultaneous determination of ten aminoglycoside residues (streptomycin, dihydrostrepmycin, neomycin, kanamycin, tobramycin, gentamycin, apramycin, hygromycin B, paromomycin, and amkacin) in milk and dairy products. The sample was extracted with 5% trichloroacetic acid aqueous solution, then the extract was purified by a hydrophilic-lipophilic balance (HLB) cartridge. The ten aminoglycoside residues were separated by ion-pair reversed phase high performance liquid chromatography. Heptafluorobutyric acid was used as ion pair agent due to its volatility. Then the analytes were detected by electrospray ionization tandem mass spectrometry. The pretreatment condition of the sample, the HPLC condition and the MS operation parameters were optimized. The results showed that the linearities of the ten aminoglycoside residues in 20-1000 microg/L had the correlation coefficient between 0.9946-0.9997. The recoveries ranged from 71.2% and 101.7% with the relative standard deviations of 3.4%-13.8%. The proposed method was successfully applied to the determination of the mass concentrations of the analytes in related samples, which provides a simple, and convenient method for the quality control of milk and dairy products. Furthermore, this method is effective for the safety monitoring of aminoglycoside residues in milk and dairy products.
OBJECTIVE: To investigate the effects of T-2 toxin on testosterone biosynthesis in mouse Leydig cells. METHODS: Leydig cells isolated from clean and healthy Kunming male mice, whose concentration was adjusted to 5 × 10(5)/mL and the purity identified by the modified 3?-hydroxysteroid dehydrogenase staining method, were used to establish a primary Leydig cell culture model. Blank control group (treated with 0 ng/mL human chorionic gonadotropin (hCG) and 0 mol/L T-2 toxin), inductive control group (treated with 10 ng/mL hCG and 0 mol/L T-2 toxin), low-dose T-2-toxin-exposure group (treated with 10 ng/mL hCG and 10(-9) mol/L T-2 toxin), middle-dose T-2 toxin-exposure group (treated with 10 ng/mL hCG and 10(-8) mol/L T-2 toxin) and high-dose T-2-toxin-exposure group (treated with 10 ng/mL hCG and 10(-7) mol/L T-2 toxin) were designed. The testosterone level was measured after 24 h incubation. RESULTS: After 24 h culture in liquid medium containing serum, the fresh isolated Leydig cells grew well and the purity exceeded 90%. By inducing 10 ng/mL hCG, the testosterone level of Leydig cells increased significantly and the difference compared with the blank control was of statistical sense. Compared with the inductive control group, the testosterone level of Leydig cells decreased, and the difference was of statistical sense in all T-2-toxin-exposure groups. Furthermore, the decrease was due to the increase in the dosage of T-2 toxin. CONCLUSIONS: T-2 toxin can directly decrease the testosterone biosynthesis in the primary Leydig cells derived from the mouse testis.
The 4kD scorpion defensin (SD) is a potent disulfide-linked peptide. In this study, we expressed it in methylotrophic yeast Pichia pastoris and purified it using Ni-NTA His Bind Resin. We investigated its in vitro antibacterial activity and effect in combination with several conventional antibiotics. We first examined its antibacterial activity towards several Gram-positive and Gram-negative bacteria. Then we used the broth microdilution method to test drugs alone and in combination and used the fractional inhibitory concentration (FIC index) to classify the drug interactions. Our study showed the expressed SD peptide has antibacterial activity against Salmonella typhimurium, E. coli and S. aureus etc. Synergy or additive interaction was observed between SD and Norfloxacin, Polymyxin B and Ampicillin. Cell growth tests showed that combination of SD and Norfloxacin can improve their activity against bacteria. This result maybe permit lower using of the conventional antibiotic agents more effectively and safely.
In order to investigate the temporal and spatial variations, sources, and major controlling factors of the major ions in Nam Co Lake water, inshore surface water samples were collected at a fixed site (30 degrees 47.27N, 90 degrees 58.53E, 4718 m a. s. l.) from 2006 to 2010, at the vertical profiles in the center of the lake in August 2009, and at both the vertical profiles in the center of the lake and at the surface layers of different sites in the Nam Co Lake in October 2010. The results indicated that Na+ was the dominant cation and HCO3- was the dominant anion in the lake water. The concentrations of most ions were higher in monsoon seasons (June - September) and lower in non-monsoon seasons, especially when the lake was frozen (January -April). However, the Ca2+ concentration showed a reverse trend of seasonal variations, namely, higher values in the frozen period and lower in monsoon seasons. Analysis of water samples collected from the vertical profiles indicated that the concentrations of all ions except Ca2+ increased with the depth in nonmonsoon seasons (e. g. October). The major ions in Nam Co Lake were mainly contributed by river input. There were a variety of factors that influenced the temporal and spatial variations of the major ions in the Nam Co Lake, such as evaporation, precipitation, pH values, etc., among which, evaporation was the most important controlling factor, causing the increasing Na+ concentration and decreasing Ca2+ concentration in the lake water.
To investigate the tempo-spatial distribution of total mercury (T-Hg) concentration in water bodies in the Nam Co basin on the Tibetan Plateau, inflowing river water and surface lake water samples were collected from 2007 to 2010. The T-Hg concentration and its relationship with precipitation and river runoff were analyzed. The results showed that the average T-Hg concentration was (1.09 +/- 0.73) ng x L(-1) and (2.87 +/- 2.59) ng x L(-1) for surface lake water and river water, respectively, both of which were significantly lower than those of Hg contaminated waters. T-Hg concentration in off-shore lake water was much higher during the monsoon season than in the non-monsoon season, and its level and spatial variation were significantly greater than those in central lake water. T-Hg concentration in river water showed significant seasonal variations with the highest values during the monsoon season and the lowest during the post-monsoon season, which were in accordance with the variations of precipitation. A fixed point observation at Niyaqu River indicated that the temporal changes of the T-Hg concentrations in river water were in accordance with those of the runoff. The spatial distribution features of T-Hg concentrations in inflowing river water varied in different periods, possibly resulting from the differences in drainage areas, background mercury levels in soils, and water supplies for rivers at different locations of the Nam Co basin.
Nucleic acid-based aptamers possess many useful features that make them a promising alternative to antibodies and other affinity reagents, including well-established chemical synthesis, reversible folding, thermal stability and low cost. However, the selection process typically used to generate aptamers (SELEX) often requires significant resources and can fail to yield aptamers with sufficient affinity and specificity. A number of seminal theoretical models and numerical simulations have been reported in the literature offering insights into experimental factors that govern the effectiveness of the selection process. Though useful, these previous models have not considered the full spectrum of experimental factors or the potential impact of tuning these parameters at each round over the course of a multi-round selection process. We have developed an improved mathematical model to address this important question, and report that both target concentration and the degree of non-specific background binding are critical determinants of SELEX efficiency. Although smaller target concentrations should theoretically offer superior selection outcome, we show that the level of background binding dramatically affect the target concentration that will yield maximum enrichment at each round of selection. Thus, our model enables experimentalists to determine appropriate target concentrations as a means for protocol optimization. Finally, we perform a comparative analysis of two different selection methods over multiple rounds of selection, and show that methods with inherently lower background binding offer dramatic advantages in selection efficiency.
To evaluate the possibility of generation 4 polyamidoamine (G4PAMAM) dendrimers acting as the delivery system of vascular endothelial growth factor (VEGF) antisense oligodeoxynucleotides (VEGFASODN), and to investigate the anti-tumor effect of G4PAMAM/VEGFASODN complex on the cultured cells and the mouse tumor xenograft model.
Global increase in patients seeking orthodontic treatment creates a demand for the use of acrylic resins in removable appliances and retainers. Orthodontic removable appliance wearers have a higher risk of oral infections that are caused by the formation of bacterial and fungal biofilms on the appliance surface. Here, we present the synthetic route for an antibacterial and antifungal organically-modified silicate (ORMOSIL) that has multiple methacryloloxy functionalities attached to a siloxane backbone (quaternary ammonium methacryloxy silicate, or QAMS). By dissolving the water-insoluble, rubbery ORMOSIL in methyl methacrylate, QAMS may be copolymerized with polymethyl methacrylate, and covalently incorporated in the pressure-processed acrylic resin. The latter demonstrated a predominantly contact-killing effect on Streptococcus mutans ATCC 36558 and Actinomyces naselundii ATCC 12104 biofilms, while inhibiting adhesion of Candida albicans ATCC 90028 on the acrylic surface. Apart from its favorable antimicrobial activities, QAMS-containing acrylic resins exhibited decreased water wettability and improved toughness, without adversely affecting the flexural strength and modulus, water sorption and solubility, when compared with QAMS-free acrylic resin. The covalently bound, antimicrobial orthodontic acrylic resin with improved toughness represents advancement over other experimental antimicrobial acrylic resin formulations, in its potential to simultaneously prevent oral infections during appliance wear, and improve the fracture resistance of those appliances.
Traditional bone regeneration strategies relied on supplementation of biomaterials constructs with stem or progenitor cells or growth factors. By contrast, cell homing strategies employ chemokines to mobilize stem or progenitor cells from host bone marrow and tissue niches to injured sites. Although silica-based biomaterials exhibit osteogenic and angiogenic potentials, they lack cell homing capability. Stromal cell-derived factor-1 (SDF-1) plays a pivotal role in mobilization and homing of stem cells to injured tissues. In this work, we demonstrated that 3-dimensional collagen scaffolds infiltrated with intrafibrillar silica are biodegradable and highly biocompatible. They exhibit improved compressive stress-strain responses and toughness over nonsilicified collagen scaffolds. They are osteoconductive and up-regulate expressions of osteogenesis- and angiogenesis-related genes more significantly than nonsilicified collagen scaffolds. In addition, these scaffolds reversibly bind SDF-1? for sustained release of this chemokine, which exhibits in vitro cell homing characteristics. When implanted subcutaneously in an in vivo mouse model, SDF-1?-loaded silicified collagen scaffolds stimulate the formation of ectopic bone and blood capillaries within the scaffold and abrogate the need for cell seeding or supplementation of osteogenic and angiogenic growth factors. Intrafibrillar-silicified collagen scaffolds with sustained SDF-1? release represent a less costly and complex alternative to contemporary cell seeding approaches and provide new therapeutic options for in situ hard tissue regeneration.
The design of antimicrobial polymers to address healthcare issues and minimize environmental problems is an important endeavor with both fundamental and practical implications. Quaternary ammonium silane-functionalized methacrylate (QAMS) represents an example of antimicrobial macromonomers synthesized by a sol-gel chemical route; these compounds possess flexible Si-O-Si bonds. In present work, a partially hydrolyzed QAMS co-polymerized with 2,2-[4(2-hydroxy 3-methacryloxypropoxy)-phenyl]propane is introduced. This methacrylate resin was shown to possess desirable mechanical properties with both a high degree of conversion and minimal polymerization shrinkage. The kill-on-contact microbiocidal activities of this resin were demonstrated using single-species biofilms of Streptococcus mutans (ATCC 36558), Actinomyces naeslundii (ATCC 12104) and Candida albicans (ATCC 90028). Improved mechanical properties after hydration provided the proof-of-concept that QAMS-incorporated resin exhibits self-repair potential via water-induced condensation of organic modified silicate (ormosil) phases within the polymerized resin matrix.
Many analytical techniques benefit greatly from the use of affinity reagent pairs, wherein each reagent recognizes a discrete binding site on a target. For example, antibody pairs have been widely used to dramatically increase the specificity of enzyme linked immunosorbent assays (ELISA). Nucleic acid-based aptamers offer many advantageous features relative to protein-based affinity reagents, including well-established chemical synthesis, thermostability, and low production cost. However, the generation of suitable aptamer pairs has posed a significant challenge, and few such pairs have been reported to date. To address this important challenge, we present multivalent aptamer isolation systematic evolution of ligands by exponential enrichment (MAI-SELEX), a technique designed for the efficient selection of aptamer pairs. In contrast to conventional selection methods, our method utilizes two selection modules to generate separate aptamer pools that recognize distinct binding sites on a single target. Using MAI-SELEX, we have isolated two groups of 2-fluoro-modified RNA aptamers that specifically recognize the ?V or ?3 subunits of integrin ?V?3. These aptamers exhibit low nanomolar affinities for their targets, with minimal cross-reactivity to other closely related integrin homologues. Moreover, we show that these aptamer pairs do not interfere with each others binding and effectively detect the target even in complex mixtures such as undiluted serum.
Literatures on knee osteoarthritis treated by acupuncture both in China and abroad published in the mainstay periodicals in recent 10 years were selected, and analyses were done in the following aspects: (1) Randomization, (2) Control group, (3) Sample size, (4) Intervention measurements, (5) Intervention periods, (6) Evaluation on therapeutic effects, (7) Follow-up assessment, (8) Adverse effects, (9) Ratio of the lost case. The result indicates that differences can still be found on the trial designation in China and abroad. The domestic research design should be more comprehensively and strictly.
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