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Find video protocols related to scientific articles indexed in Pubmed.
Generation of iPS Cells from Human Peripheral Blood Mononuclear Cells Using Episomal Vectors.
Methods Mol. Biol.
PUBLISHED: 11-19-2014
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Mononuclear Cells…?>Peripheral blood is the easy-to-access, minimally invasive, and the most abundant cell source to use for cell reprogramming. The episomal vector is among the best approaches for generating integration-free induced pluripotent stem (iPS) cells due to its simplicity and affordability. Here we describe the detailed protocol for the efficient generation of integration-free iPS cells from peripheral blood mononuclear cells. With this optimized protocol, one can readily generate hundreds of iPS cell colonies from 1 ml of peripheral blood.
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Enzymatic Saccharification of Cassava Residues and Glucose Inhibitory Kinetics on ?-Glucosidase from Hypocrea orientalis.
J. Agric. Food Chem.
PUBLISHED: 11-14-2014
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Cassava residues are byproducts of the starch industry containing abundant cellulose for bioproduction of green fuel. To obtain maximum sugar yields from cassava residues, the optimal conditions for hydrolyzing the residues were determined using cellulase prepared from a novel Hypocrea orientalis strain. The optimal pH value and optimal temperature for the cellulase hydrolysis were 5.0 and 50 °C, respectively. The concentration of NaOH was determined to be 1% for pretreatment of cassava residues to gain enough soluble sugars suitably. The yield of released sugars was 10 mg/mL in the optimal conditions after 24 h of reaction, which was similar to that of bagasse and wheat grass. Inhibition kinetics of H. orientalis ?-glucosidase (BG) by glucose was first studied using the progress-of-substrate-reaction method as described by Tsou (Tsou, C. L. Adv. Enzymol. Related Areas Mol. Biol. 1988, 61, 381-436), and the microscopic inhibition rate constants of glucose were determined. The results showed that glucose could inhibit BG reversibly and competitively. The rate constants of forward (k+0) and reverse (k-0) reaction were measured to be 4.88 × 10(-4) (mM·s)(-1) and 2.7 × 10(-4) s(-1), respectively. Meanwhile, the inhibition was more significant than that of l-glucose, d-mannose, d-galactose, d-aminoglucose, acetyl-d-glucose, and d-fructose. This work reveals how to increase sugar yields and reduce product inhibition during enzymatic saccharification of cellulose.
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RGC-32 deficiency protects against high fat diet-induced obesity and insulin resistance in mice.
J. Endocrinol.
PUBLISHED: 11-12-2014
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Obesity is an important independent risk factor for type 2 diabetes, cardiovascular diseases and many other chronic diseases. Adipose tissue inflammation is a critical link between obesity and insulin resistance and type 2 diabetes and a contributor to disease susceptibility and progression. The objective of this study was to determine the role of response gene to complement 32 (RGC-32) in the development of obesity and insulin resistance. Wild-type (WT) and RGC-32 knockout (RGC32-/-) mice were fed normal chow or high-fat diet (HFD) for 12 weeks. Metabolic, biochemical and histologic analyses were performed. 3T3-L1 preadipocytes were used to study the role of RGC-32 in adipocytes in vitro. RGC32-/- mice fed with HFD exhibited a lean phenotype with reduced epididymal fat weight compared to WT controls. Blood biochemical analysis and insulin tolerance test showed that RGC-32 deficiency improved HFD-induced dyslipidemia and insulin resistance. Although it had no effect on adipocyte differentiation, RGC-32 deficiency ameliorated adipose tissue and systemic inflammation. Moreover, RGC32-/- induced browning of adipose tissues and increased energy expenditure. Our data indicated that RGC-32 plays an important role in diet-induced obesity and insulin resistance, and thus it may serve as a potential novel drug target for developing therapeutics to treat obesity and metabolic disorders.
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[Autologous peripheral blood CD34+ stem cells transplanted into 100 patients with advanced cirrhosis].
Zhonghua Gan Zang Bing Za Zhi
PUBLISHED: 11-05-2014
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To investigate whether transplantation of autologous peripheral blood CD34+ stem cells is a viable approach for treating patients with advanced cirrhosis,which is currently hindered by a shortage in liver donors.
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Delitschiapyrone A, a Pyrone-Naphthalenone Adduct Bearing a New Pentacyclic Ring System from the Leaf-Associated Fungus Delitschia sp. FL1581.
Org. Lett.
PUBLISHED: 11-03-2014
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Delitschiapyrone A (1), an ?-pyrone-naphthalenone adduct with an unprecedented pentacyclic ring system, was isolated from a solid culture of the leaf-associated fungus Delitschia sp. FL1581. The structure of 1 was elucidated by spectroscopic analysis and X-ray crystallography, and its absolute configuration was defined by experimental and calculated ECD. Biosynthetically, the unique 6/6/5/7/6 pentacyclic core of 1 may be formed by an intermolecular Diels-Alder-type addition of the precursors derived from (1'R)-2',3'-dihydropyrenocine C (2) and 6-ethyl-2,7-dimethoxyjuglone (3) found to co-occur with 1 in this fungus.
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[Soil-transmitted nematode infection of children and its influencing factors in poverty-stricken areas in two provinces of southwest China].
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi
PUBLISHED: 10-28-2014
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To understand the infection status and the main risk factors of soil-transmitted nematodes in children in the poverty-stricken areas of Guizhou Province and Sichuan Province, so as to provide the evidences for making suitable control strategies in these areas.
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DNAzyme-based biosensors and nanodevices.
Chem. Commun. (Camb.)
PUBLISHED: 10-23-2014
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DNAzymes, screened through in vitro selection, have shown great promise as molecular tools in the design of biosensors and nanodevices. The catalytic activities of DNAzymes depend specifically on cofactors and show multiple enzymatic turnover properties, which make DNAzymes both versatile recognition elements and outstanding signal amplifiers. Combining nanomaterials with unique optical, magnetic and electronic properties, DNAzymes may yield novel fluorescent, colorimetric, surface-enhanced Raman scattering (SERS), electrochemical and chemiluminescent biosensors. Moreover, some DNAzymes have been utilized as functional components to perform arithmetic operations or as "walkers" to move along DNA tracks. DNAzymes can also function as promising therapeutics, when designed to complement target mRNAs or viral RNAs, and consequently lead to down-regulation of protein expression. This feature article focuses on the most significant achievements in using DNAzymes as recognition elements and signal amplifiers for biosensors, and highlights the applications of DNAzymes in logic gates, DNA walkers and nanotherapeutics.
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Bispyrene-Fluorescein Hybrid Based FRET Cassette: A Convenient Platform toward Ratiometric Time-Resolved Probe for Bioanalytical Applications.
Anal. Chem.
PUBLISHED: 10-01-2014
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Pyrene excimer possesses a large Stokes shift and long fluorescence lifetime and has been widely applied in developing time-resolved biosensing systems to solve the autofluorescence interference problems in biological samples. However, only a few of pyrene excimer-based small molecular probes have been reported so far. Ratiometric probes, on the other hand, can eliminate interferences from environmental factors such as instrumental efficiency and environmental conditions by a built-in correction of the dual emission bands but are ineffective for endogenous autofluorescence in biosystems. In this work, by combining the advantages of time-resolved fluorescence technique with ratiometric probe, we reported a bispyrene-fluorescein hybrid FRET cassette (PF) as a novel ratiometric time-resolved sensing platform for bioanalytical applications, with pH chosen as a biorelated target. The probe PF showed a fast, highly selective, and reversible ratiometric fluorescence response to pH in a wide range from 3.0 to 10.0 in buffered solution. By employing time-resolved fluorescence technique, the pH-induced fluorescence signal of probe PF can be well-discriminated from biological autofluorescence background, which enables us to detect pH in a range of 4.0-8.0 in cell media within a few seconds. It has also been preliminarily applied for ratiometric quantitative monitoring of pH changes in living cells with satisfying results. Since many fluorescein-based fluorescence probes have been developed, our strategy might find wide applications in design ratiometric time-resolved probes for detection of various biorelated targets.
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Alkyne-functionalized superstable graphitic silver nanoparticles for Raman imaging.
J. Am. Chem. Soc.
PUBLISHED: 09-23-2014
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Noble metals, especially gold, have been widely used in plasmon resonance applications. Although silver has a larger optical cross section and lower cost than gold, it has attracted much less attention because of its easy corrosion, thereby degrading plasmonic signals and limiting its applications. To circumvent this problem, we report the facile synthesis of superstable AgCu@graphene (ACG) nanoparticles (NPs). The growth of several layers of graphene onto the surface of AgCu alloy NPs effectively protects the Ag surface from contamination, even in the presence of hydrogen peroxide, hydrogen sulfide, and nitric acid. The ACG NPs have been utilized to enhance the unique Raman signals from the graphitic shell, making ACG an ideal candidate for cell labeling, rapid Raman imaging, and SERS detection. ACG is further functionalized with alkyne-polyethylene glycol, which has strong Raman vibrations in the Raman-silent region of the cell, leading to more accurate colocalization inside cells. In sum, this work provides a simple approach to fabricate corrosion-resistant, water-soluble, and graphene-protected AgCu NPs having a strong surface plasmon resonance effect suitable for sensing and imaging.
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High prevalence of headaches in patients with epilepsy.
J Headache Pain
PUBLISHED: 08-23-2014
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To examine the association between headaches and epilepsy.
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Bioactive metabolites from the endophytic fungus Alternariaalternata.
Fitoterapia
PUBLISHED: 08-16-2014
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Two altenuene derivatives (1-2) and one isocoumarin (3), together with six known compounds (4-9) were isolated from solid cultures of an endophytic fungus Alternaria alternata, obtained from the fresh branches of Camellia sinensis. Chiral analysis revealed the racemic nature of 1 and 2, which were subsequently resolved into two pairs of enantiomers [(+)-1 and (-)-1, (+)-2 and (-)-2]. Structures of all the isolates were identified through spectroscopic data. Absolute configurations of the two pairs of enantiomers were determined by electronic circular dichroism (ECD) calculation and the chiral center of C-10 in 3 was deduced via [Rh2(OCOCF3)4]-induced CD experiment. All the isolates were evaluated for their antimicrobial abilities against the pathogenic bacteria and fungi as well as cytotoxic activities against two human tumor cell lines. Compound 5 was the most active against Bacillus subtilis with MIC80 of 8.6?g/ml, and compounds 1-3, 6-7 and 9 exhibited moderate to weak inhibition towards the test pathogenic microorganism. Compound 4 showed mild cytotoxic activity against human osteosarcoma cells U2OS with IC50 of 28.3?M.
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The complete mitochondrial genome of Garrulax perspicillatus (Passeriformes, Timaliidae).
Mitochondrial DNA
PUBLISHED: 08-05-2014
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Abstract The complete sequences of the mitochondrial DNA genome from Garrulax perspicillatus was determined by 21 pairs of primers using the polymerase chain reaction method. The genome (17,873?bp in length) contained 37 genes (2 rRNA genes, 22 tRNA genes and 13 protein-coding genes) 2 control regions (CR) at two different locations of mitogenome. All the protein-coding genes in G. perspicillatus were distributed on the H-strand, except for the ND6 subunit gene and eight tRNA genes which were encoded on the L-strand.
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The complete mitochondrial genome of Elaphe bimaculata (Reptilia, Serpentes, Colubridae).
Mitochondrial DNA
PUBLISHED: 08-05-2014
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Abstract The Chinese leopard snake (Elaphe bimaculata) is an endemic species to China. The complete nucleotide sequence of the mitochondrial (mt) genome of E. bimaculata is determined in this study. The circle genome was 17,183?bp in length and consisted of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 2 duplicate control regions. Several peculiar features were observed in mitogenome of E. bimaculata, such as the translocation of tRNA(Leu(UUR)) gene and an incomplete copy for tRNA(Pro).
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Chemometric strategy for automatic chromatographic peak detection and background drift correction in chromatographic data.
J Chromatogr A
PUBLISHED: 07-29-2014
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Peak detection and background drift correction (BDC) are the key stages in using chemometric methods to analyze chromatographic fingerprints of complex samples. This study developed a novel chemometric strategy for simultaneous automatic chromatographic peak detection and BDC. A robust statistical method was used for intelligent estimation of instrumental noise level coupled with first-order derivative of chromatographic signal to automatically extract chromatographic peaks in the data. A local curve-fitting strategy was then employed for BDC. Simulated and real liquid chromatographic data were designed with various kinds of background drift and degree of overlapped chromatographic peaks to verify the performance of the proposed strategy. The underlying chromatographic peaks can be automatically detected and reasonably integrated by this strategy. Meanwhile, chromatograms with BDC can be precisely obtained. The proposed method was used to analyze a complex gas chromatography dataset that monitored quality changes in plant extracts during storage procedure.
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Nucleic Acid Aptamer-Mediated Drug Delivery for Targeted Cancer Therapy.
ChemMedChem
PUBLISHED: 07-25-2014
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Aptamers are emerging as promising therapeutic agents and recognition elements. In particular, cell-SELEX (systematic evolution of ligands by exponential enrichment) allows in vitro selection of aptamers selective to whole cells without prior knowledge of the molecular signatures on the cell surface. The advantage of aptamers is their high affinitiy and binding specificity towards the target. This Minireview focuses on single-stranded (ss) oligonucleotide (DNA or RNA)-based aptamers as cancer therapeutics/theranostics. Specifically, aptamer-nanomaterial conjugates, aptamer-drug conjugates, targeted phototherapy and targeted biotherapy are covered in detail. In reviewing the literature, the potential of aptamers as delivery systems for therapeutic and imaging applications in cancer is clear, however, major challenges remain to be resolved, such as the poorly understood pharmacokinetics, toxicity and off-target effects, before they can be fully exploited in a clinical setting.
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Rhodamine-based fluorescent probe for direct bio-imaging of lysosomal pH changes.
Talanta
PUBLISHED: 07-18-2014
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Intracellular pH plays a pivotal role in various biological processes. In eukaryotic cells, lysosomes contain numerous enzymes and proteins exhibiting a variety of activities and functions at acidic pH (4.5-5.5), and abnormal variation in the lysosomal pH causes defects in lysosomal function. Thus, it is important to investigate lysosomal pH in living cells to understand its physiological and pathological processes. In this work, we designed a one-step synthesized rhodamine derivative (RM) with morpholine as a lysosomes tracker, to detect lysosomal pH changes with high sensitivity, high selectivity, high photostability and low cytotoxicity. The probe RM shows a 140-fold fluorescence enhancement over a pH range from 7.4 to 4.5 with a pKa value of 5.23. Importantly, RM can detect the chloroquine-induced lysosomal pH increase and monitor the dexamethasone-induced lysosomal pH changes during apoptosis in live cells. All these features demonstrate its value of practical application in biological systems.
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Spatiotemporal Expression of Cdx4 in the Developing Anorectum of Rat Embryos with Ethylenethiourea-Induced Anorectal Malformations.
Cells Tissues Organs (Print)
PUBLISHED: 07-16-2014
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Purpose: The aim of this study was to determine the expression of Cdx4 (caudal-type homeobox gene-4) during anorectal development in normal and ethylenethiourea (ETU)-induced anorectal malformation (ARM) embryos with a view to establishing the possible role of Cdx4 in ARM pathogenesis. Materials and Methods: ARM was induced by ETU on the 10th gestational day (GD10) in rat embryos. Cesarean deliveries were then performed to harvest the embryos. Spatiotemporal expression of Cdx4 was evaluated in normal rat embryos (n = 354) and ARM embryos (n = 378) from GD13 to GD16. Results: Immunohistochemical staining and immunofluorescence revealed that, in normal embryos, Cdx4 expression was extensively detected on the epithelium of the cloaca on GD13. On GD14, the Cdx4-positive cells were intensively detected on the hindgut. On GD15, the anal membrane was constantly immunoreactive to Cdx4. On GD16, Cdx4-labeled cells were observed on the epithelium of the anus. In the ARM embryos, the epithelium of the cloaca, urorectal septum (URS) and anorectum was negative or faint for Cdx4. In the normal embryo group, Cdx4 protein and mRNA expression showed time-dependent changes in the developing hindgut from GD13 to GD16 on Western blot and real-time reverse transcription plus polymerase chain reaction. Once the URS divided the cloaca into the primitive rectum and urogenital sinus (UGS) on GD15, Cdx4 expression began to decrease. In addition, the expression level of Cdx4 in the ARM group from GD13 to GD15 was significantly lower than that in the normal group (p < 0.05). Conclusions: In ARM embryos, an imbalance in the spatiotemporal expression of Cdx4 was noted during anorectal morphogenesis from GD13 to GD16. This suggests that ETU may cause downregulation of Cdx4 expression. Downregulation of Cdx4 at the time of cloacal separation into the primitive rectum and UGS might thus be related to the development of ARM. © 2014 S. Karger AG, Basel.
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The complete mitochondrial genome of Glandirana tientaiensis (Ranidae, Anura).
Mitochondrial DNA
PUBLISHED: 07-11-2014
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Abstract The Tiantai frog (Glandirana tientaiensis) is an endemic to China, which has been listed as an endangered species in IUCN Red List of Threatened Species. In this study, the complete nucleotide sequence of the mitochondrial genome of G. tientaiensis is determined. The circle genome is 17,681?bp and consists of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 1 control region. Comparing with the typical mtDNA of species in the family Ranidae, no distinctive rearrangement of mtDNA genes was found. Yet a obvious feature on the use of codon were observed, that 8 of 13 protein-conding genes ended with a single stop nucleotide T except for COI, ATPase 8, ND4L, ND6 and Cyt b.
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Design, synthesis and evaluation of novel tacrine-(?-carboline) hybrids as multifunctional agents for the treatment of Alzheimer's disease.
Bioorg. Med. Chem.
PUBLISHED: 07-09-2014
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A series of tacrine-(?-carboline) hybrids (11a-q) were designed, synthesized and evaluated as multifunctional cholinesterase inhibitors against Alzheimer's disease (AD). In vitro studies showed that most of them exhibited significant potency to inhibit acetylcholinesterase (eeAChE and hAChE), butyrylcholinesterase (BuChE) and self-induced ?-amyloid (A?) aggregation, Cu(2+)-induced A? (1-42) aggregation, and to chelate metal ions. Especially, 11l presented the greatest ability to inhibit cholinesterase (IC50, 21.6nM for eeAChE, 63.2nM for hAChE and 39.8nM for BuChE), good inhibition of A? aggregation (65.8% at 20?M) and good antioxidant activity (1.57 trolox equivalents). Kinetic and molecular modeling studies indicated that 11l was a mixed-type inhibitor, binding simultaneously to the catalytic anionic site (CAS) and the peripheral anionic site (PAS) of AChE. In addition, 11l could chelate metal ions, reduce PC12 cells death induced by oxidative stress and penetrate the blood-brain barrier (BBB). These results suggested that 11l might be an excellent multifunctional agent for AD treatment.
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Design, synthesis and evaluation of multifunctional salphen derivatives for the treatment of Alzheimer's disease.
Eur J Med Chem
PUBLISHED: 07-08-2014
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A series of salphen derivatives (1-26) have been designed, synthesized, and evaluated as chemical reagents that target and modulate multiple facets of Alzheimer's disease. Most of the compounds exhibit a significant ability to inhibit self-induced and Cu(2+)-induced ?-amyloid (A?1-42) aggregation, and to function as potential antioxidants and biometal chelators. In particular, the antioxidant activity of compound 2 is 2.6-fold of the trolox value by using the ABTS radical scavenging method, and it also shows a significant ability to inhibit self-induced and Cu(2+)-induced ?-amyloid (A?1-42) aggregation (70.3%, 20 ?M and 85.7%, 50 ?M, respectively). Moreover, it is capable of decreasing reactive oxygen species (ROS) induced by Cu(2+)-A?, shows a good neuroprotective effect in human SH-SY5Y neuroblastoma cells and can cross the blood-brain barrier. In addition, compound 2 retains the activities of antioxidant, anti A? aggregation and neuroprotection after capturing the metal ions Cu(2+), Fe(3+) and Zn(2+) (its metal complexes 18, 22 and 23). Taken together, these results suggest that compound 2 might be a promising lead compound for AD treatment.
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[An improved method for generating integration-free human induced pluripotent stem cells].
Zhongguo Shi Yan Xue Ye Xue Za Zhi
PUBLISHED: 07-04-2014
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The genome instability and tumorigenicity of induced pluripotent stem cells (iPSC) hinder their great potentials for clinical application. Using episomal vectors to generate iPSC is the best way to solve safety issues at present. This method is simple and the exogenous gene was not integrated into the host genome. However, the reprogramming efficiency for this method is very low and thus limits its usage. This study was purposed to improve episomal method for generating induced pluripotent stem cells from cord blood mononuclear cells (CB MNC), to establish integration-free iPSC technology system, and to lay the foundation for individualized iPSC for future clinical uses. To improve the reprogramming efficiency for iPSC, episomal method was used at various combinations of episomal vectors, pre-stimulating culture mediums and oxygen condition were tested to optimize the method. The results showed that using erythroid culture medium for culturing 8 days, transfecting with episomal vectors with SFFV (spleen focus forming virus) promoter under the hypoxic condition (3%), CB MNC could be mostly efficiently reprogrammed with the efficiency 0.12%. Furthermore, the results showed that erythroblasts (CD36(+)CD71(+)CD235a(low)) were the cells that are reprogrammed with high efficiency after culture for 8 days. It is concluded that a highly efficient and safe method for generation of integration-free iPSC is successfully established, which is useable in clinical study.
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Intelligent layered nanoflare: "lab-on-a-nanoparticle" for multiple DNA logic gate operations and efficient intracellular delivery.
Nanoscale
PUBLISHED: 06-28-2014
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DNA strand displacement cascades have been engineered to construct various fascinating DNA circuits. However, biological applications are limited by the insufficient cellular internalization of naked DNA structures, as well as the separated multicomponent feature. In this work, these problems are addressed by the development of a novel DNA nanodevice, termed intelligent layered nanoflare, which integrates DNA computing at the nanoscale, via the self-assembly of DNA flares on a single gold nanoparticle. As a "lab-on-a-nanoparticle", the intelligent layered nanoflare could be engineered to perform a variety of Boolean logic gate operations, including three basic logic gates, one three-input AND gate, and two complex logic operations, in a digital non-leaky way. In addition, the layered nanoflare can serve as a programmable strategy to sequentially tune the size of nanoparticles, as well as a new fingerprint spectrum technique for intelligent multiplex biosensing. More importantly, the nanoflare developed here can also act as a single entity for intracellular DNA logic gate delivery, without the need of commercial transfection agents or other auxiliary carriers. By incorporating DNA circuits on nanoparticles, the presented layered nanoflare will broaden the applications of DNA circuits in biological systems, and facilitate the development of DNA nanotechnology.
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Design and synthesis of new 7-(N-substituted-methyl)-camptothecin derivatives as potent cytotoxic agents.
Bioorg. Med. Chem. Lett.
PUBLISHED: 05-09-2014
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A series of novel 7-(N-substituted-methyl)-camptothecin derivatives was designed, synthesized, and evaluated for in vitro cytotoxicity against four human tumor cell lines, A-549, MDA-MB-231, KB, and KBvin. All of the derivatives showed promising in vitro cytotoxic activity against the tested tumor cell lines, with IC50 values ranging from 0.0023 to 1.11 ?M, and were as or more potent than topotecan. Compounds 9d, 9e, and 9r exhibited the highest antiproliferative activity among all prepared derivatives. Furthermore, all of the compounds were more potent than paclitaxel against the multidrug-resistant (MDR) KBvin subline. With a concise efficient synthesis and potent cytotoxic profiles, especially significant activity towards KBvin, compounds 9d, 9e, and 9r merit further development as a new generation of camptothecin-derived anticancer clinical trial candidates.
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Functional DNA-containing nanomaterials: cellular applications in biosensing, imaging, and targeted therapy.
Acc. Chem. Res.
PUBLISHED: 04-29-2014
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CONSPECTUS: DNA performs a vital function as a carrier of genetic code, but in the field of nanotechnology, DNA molecules can catalyze chemical reactions in the cell, that is, DNAzymes, or bind with target-specific ligands, that is, aptamers. These functional DNAs with different modifications have been developed for sensing, imaging, and therapeutic systems. Thus, functional DNAs hold great promise for future applications in nanotechnology and bioanalysis. However, these functional DNAs face challenges, especially in the field of biomedicine. For example, functional DNAs typically require the use of cationic transfection reagents to realize cellular uptake. Such reagents enter the cells, increasing the difficulty of performing bioassays in vivo and potentially damaging the cell's nucleus. To address this obstacle, nanomaterials, such as metallic, carbon, silica, or magnetic materials, have been utilized as DNA carriers or assistants. In this Account, we describe selected examples of functional DNA-containing nanomaterials and their applications from our recent research and those of others. As models, we have chosen to highlight DNA/nanomaterial complexes consisting of gold nanoparticles, graphene oxides, and aptamer-micelles, and we illustrate the potential of such complexes in biosensing, imaging, and medical diagnostics. Under proper conditions, multiple ligand-receptor interactions, decreased steric hindrance, and increased surface roughness can be achieved from a high density of DNA that is bound to the surface of nanomaterials, resulting in a higher affinity for complementary DNA and other targets. In addition, this high density of DNA causes a high local salt concentration and negative charge density, which can prevent DNA degradation. For example, DNAzymes assembled on gold nanoparticles can effectively catalyze chemical reactions even in living cells. And it has been confirmed that DNA-nanomaterial complexes can enter cells more easily than free single-stranded DNA. Nanomaterials can be designed and synthesized in needed sizes and shapes, and they possess unique chemical and physical properties, which make them useful as DNA carriers or assistants, excellent signal reporters, transducers, and amplifiers. When nanomaterials are combined with functional DNAs to create novel assay platforms, highly sensitive biosensing and high-resolution imaging result. For example, gold nanoparticles and graphene oxides can quench fluorescence efficiently to achieve low background and effectively increase the signal-to-background ratio. Meanwhile, gold nanoparticles themselves can be colorimetric reporters because of their different optical absorptions between monodispersion and aggregation. DNA self-assembled nanomaterials contain several properties of both DNA and nanomaterials. Compared with DNA-nanomaterial complexes, DNA self-assembled nanomaterials more closely resemble living beings, and therefore they have lower cytotoxicity at high concentrations. Functional DNA self-assemblies also have high density of DNA for multivalent reaction and three-dimensional nanostructures for cell uptake. Now and in the future, we envision the use of DNA bases in making designer molecules for many challenging applications confronting chemists. With the further development of artificial DNA bases using smart organic synthesis, DNA macromolecules based on elegant molecular assembly approaches are expected to achieve great diversity, additional versatility, and advanced functions.
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Multicolor fluorescent biosensor for multiplexed detection of DNA.
Anal. Chem.
PUBLISHED: 04-29-2014
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Development of efficient methods for highly sensitive and rapid screening of specific oligonucleotide sequences is essential to the early diagnosis of serious diseases. In this work, an aggregated cationic perylene diimide (PDI) derivative was found to efficiently quench the fluorescence emission of a variety of anionic oligonucleotide-labeled fluorophores that emit at wavelengths from the visible to NIR region. This broad-spectrum quencher was then adopted to develop a multicolor biosensor via a label-free approach for multiplexed fluorescent detection of DNA. The aggregated perylene derivative exhibits a very high quenching efficiency on all ssDNA-labeled dyes associated with biosensor detection, having efficiency values of 98.3 ± 0.9%, 97 ± 1.1%, and 98.2 ± 0.6% for FAM, TAMRA, and Cy5, respectively. An exonuclease-assisted autocatalytic target recycling amplification was also integrated into the sensing system. High quenching efficiency combined with autocatalytic target recycling amplification afforded the biosensor with high sensitivity toward target DNA, resulting in a detection limit of 20 pM, which is about 50-fold lower than that of traditional unamplified homogeneous fluorescent assay methods. The quencher did not interfere with the catalytic activity of nuclease, and the biosensor could be manipulated in either preaddition or postaddition manner with similar sensitivity. Moreover, the proposed sensing system allows for simultaneous and multicolor analysis of several oligonucleotides in homogeneous solution, demonstrating its potential application in the rapid screening of multiple biotargets.
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A highly sensitive and reductant-resistant fluorescent probe for nitroxyl in aqueous solution and serum.
Chem. Commun. (Camb.)
PUBLISHED: 04-23-2014
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A novel coumarin-based fluorescent probe, P-CM, for quantitative detection of nitroxyl (HNO) was developed. P-CM exhibits a selective response to HNO over other biological reductants and was also applied for quantitative detection of HNO in bovine serum with satisfactory results.
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The complete mitochondrial genome of Turdus hortulorum (Passeriformes, Turdidae).
Mitochondrial DNA
PUBLISHED: 04-09-2014
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Abstract The grey-backed thrush (Turdus hortulorum) is an endangered bird species, which is mainly distributed in northern China, Korean Peninsula and Vietnam. In this study, the complete nucleotide sequence of the mitochondrial genome of T. hortulorum is determined. The circle genome was 16,759?bp in length and consisted of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and 1 control region (D-loop). The mtDNA of T. hortulorum is similar to the typical mtDNA of birds and other vertebrates.
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Clinical outcome of autologous hematopoietic stem cell infusion via hepatic artery or portal vein in patients with end-stage liver diseases.
Chin. Med. Sci. J.
PUBLISHED: 04-05-2014
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To investigate the efficacy of hematopoietic stem cell (HSC) transplantation via the hepatic artery vs. the portal vein for end-stage liver disease (ESLD).
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Temporal and spatial expression of caudal-type homeobox gene-2 during hindgut development in rat embryos with ethylenethiourea-induced anorectal malformations.
Cell Tissue Res.
PUBLISHED: 02-27-2014
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The main aim of this study was to determine Cdx2 expression patterns during anorectal development in normal and anorectal malformation (ARM) embryos with a view to establishing the possible role of Cdx2 in ARM pathogenesis. ARM was induced with ethylenethiourea on the 10th gestational day (GD10) in rat embryos, and Cesarean deliveries were performed to harvest the embryos. The temporal and spatial expression of Cdx2 was evaluated in normal rat embryos (n?=?303) and ARM embryos (n?=?321) from GD13 to GD16. Immunohistochemical staining revealed that, in normal embryos, Cdx2 was mainly expressed on the epithelium of the urorectal septum (URS) and the hindgut on GD13. On GD14, Cdx2-immunopositive cells were extensively detected on the URS, hindgut, and cloacal membrane. On GD15, increased immunopositive tissue staining on the anal membrane was evident. In ARM embryos, the epithelium of the cloaca, URS, and anorectum were negative or faintly immunostaining for Cdx2. Analyses by Western blot and real-time reverse transcription plus the polymerase chain reaction revealed that, in the normal group, Cdx2 protein and mRNA expression showed time-dependent changes in the developing hindgut from GD13 to GD16. Upon the URS division of the cloaca into the primitive rectum and urogenital sinus (UGS) on GD15, Cdx2 expression began to decrease. Moreover, the Cdx2 expression level in the ARM group from GD13 to GD14 was significantly lower than that in the normal group (P?
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Ectopic expression of HOXC6 blocks myeloid differentiation and predisposes to malignant transformation.
Exp. Hematol.
PUBLISHED: 02-12-2014
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Insertional mutagenesis resulting from the integration of retroviral vectors has led to the discovery of many oncogenes associated with leukemia. We investigated the role of HOXC6, identified by proximal provirus integration in a large animal hematopoietic stem cell gene therapy study, for a potential involvement in hematopoietic stem cell activity and hematopoietic cell fate decision. HOXC6 was overexpressed in the murine bone marrow transplantation model and tested in a competitive repopulation assay in comparison to the known hematopoietic stem cell expansion factor, HOXB4. We have identified HOXC6 as a factor that enhances competitive repopulation capacity in vivo and colony formation in vitro. Ectopic HOXC6 expression also induced strong myeloid differentiation and expansion of granulocyte-macrophage progenitors/common myeloid progenitors (GMPs/CMPs) in vivo, resulting in myeloid malignancies with low penetrance (3 of 17 mice), likely in collaboration with Meis1 because of a provirus integration mapped to the 3' region in the malignant clone. We characterized the molecular basis of HOXC6-induced myeloid differentiation and malignant cell transformation with complementary DNA microarray analysis. Overexpression of HOXC6 induced a gene expression signature similar to several acute myeloid leukemia subtypes when compared with normal GMPs/CMPs. These results demonstrate that HOXC6 acts as a regulator in hematopoiesis and is involved in malignant transformation.
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An aggregated perylene-based broad-spectrum, efficient and label-free quencher for multiplexed fluorescent bioassays.
Biosens Bioelectron
PUBLISHED: 02-11-2014
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Fluorescent sensing systems based on the quenching of fluorophores have found wide applications in bioassays. An efficient quencher will endow the sensing system a high sensitivity. The frequently used quenchers are based on organic molecules or nanomaterials, which usually need tedious synthesizing and modifying steps, and exhibit different quenching efficiencies to different fluorophores. In this work, we for the first time report that aggregated perylene derivative can serve as a broad-spectrum and label-free quencher that is able to efficiently quench a variety of fluorophores, such as green, red and far red dyes labeled on DNA. By choosing nucleases as model biomolecules, such a broad-spectrum quencher was then employed to construct a multiplexed bioassay platform through a label-free manner. Due to the high quenching efficiency of the aggregated perylene, the proposed platform could detect nuclease with high sensitivity, with a detection limit of 0.03U/mL for EcoRV, and 0.05U/mL for EcoRI. The perylene quencher does not affect the activity of nuclease, which makes it possible to design post-addition type bioassay platform. Moreover, the proposed platform allows simultaneous and multicolor analysis of nucleases in homogeneous solution, demonstrating its value of potential application in rapid screening of multiple bio-targets.
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High-throughput sequencing to identify miRNA biomarkers in colorectal cancer patients.
Oncol Lett
PUBLISHED: 01-30-2014
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The altered expression of microRNAs (miRNAs) is associated with a number of cancer types. The study of the association between the miRNA profile and cancer may be useful to identify potential biomarkers of certain types of cancer. In the present study, 19 miRNAs were identified by high-throughput sequencing in the serum of colorectal cancer (CRC) patients. A network analysis was performed based on a computational approach to identify associations between CRC and miRNAs. The present study may be useful to identify cancer-specific signatures and potentially useful biomarkers for the diagnosis of CRC. The network analysis of miRNA-target genes may aid in identifying altered miRNA regulatory networks that are involved in tumor pathogenesis.
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The complete mitochondrial genome of Garrulax cineraceus (Aves, Passeriformes, Timaliidae).
Mitochondrial DNA
PUBLISHED: 01-24-2014
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Abstract The complete sequence of the mitochondrial DNA genome from Garrulax cineraceus was determined using the polymerase chain reaction method. The genome (17,800?bp in length) contained 37 genes (13 protein-coding genes, 2 rRNA genes and 22 tRNA genes) and 2 control regions (D-loop) at two different locations of mitogenome, which is similar to the typical mtDNA of vertebrates. All the protein-coding genes in G. cineraceus were distributed on the H-strand, except for the ND6 subunit gene and eight tRNA genes which were encoded on the L-strand.
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Comorbidity between headache and epilepsy in a Chinese epileptic center.
Epilepsy Res.
PUBLISHED: 01-21-2014
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Here we investigated the characteristics and prevalence of headaches in patients with epilepsy in a Chinese epileptic center based on the International Classification of Headache Disorders, 2nd edition. We found that 60.14% (667/1109) of patients reported headaches. Headache was less prevalent in males (57.17%) than in females (63.75%). Interictal headaches were present in 34.62% of patients, and 139/1109 (12.53%) patients had interictal migraine, which was a higher percentage than reported in a large population-based study from the same area (9.3%) using the same screening question. In addition, 469 (70.31%) patients had postictal headache, migraine characteristics were present in 73.35% of these patients, and 15.35% also suffered from interictal migraine. Lastly, 8.85% patients had preictal headache. These results confirm that headache is very common in patients with epilepsy. Seizures often trigger postictal headaches with migraine features. The comorbidity of migraines and epilepsy should receive clinical attention, as it may influence antiepileptic drug choice, and the headache may require specific treatment.
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The complete mitochondrial genome of Microhyla pulchra (Amphidia, Anura, Microhylidae).
Mitochondrial DNA
PUBLISHED: 01-21-2014
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Abstract The complete mitochondrial genome of Microhyl pulchra was determined in this work. This mitogenome was 16,744?bp in length, containing 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and a control region (CR). The following four distinctive features were observed: a protein-coding gene (ND1) began with GTG as start codon; eight protein-coding genes (ND1, COII, ATP6, COIII, ND3, ND4, ND5 and Cytb) ended with incomplete stop codon T; four tRNA genes positions (tRNA-Leu (CUN)/tRNA-Thr/Trna-Pro/tRNA-Phe) located between CR and 12S rRNA genes, which was a novel mtDNA gene rearrangement in amphibians; there was no significant repeat regions in the CR.
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A rhodamine-appended water-soluble conjugated polymer: an efficient ratiometric fluorescence sensing platform for intracellular metal-ion probing.
Chem. Commun. (Camb.)
PUBLISHED: 01-15-2014
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Thewater-soluble CP was conjugatedwith a rhodamine spirolactam for the first time to develop a new FRET-based ratiometric fluorescence sensing platform(CP 1) for intracellular metal-ion probing. CP 1 exhibits excellent water-solubility with twowell-resolved emission peaks, which benefit ratiometric intracellular imaging applications.
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The complete mitochondrial genome of Paradoxornis webbianus (Passeriformes, Muscicapidae).
Mitochondrial DNA
PUBLISHED: 01-14-2014
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Abstract The complete sequences of the mitochondrial DNA genome from Paradoxornis webbianus was determined using the polymerase chain reaction method. The genome (16,960?bp in length) contained 37 genes (13 protein-coding genes, 2 rRNA genes and 22 tRNA genes), a control region (D-loop) and a non-coding region at two different locations of mitogenome, which is similar to the typical mtDNA of vertebrates. All the protein-coding genes in P. webbianus were distributed on the H-strand, except for the ND6 subunit gene and eight tRNA genes which were encoded on the L-strand.
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Radiation dose in the thyroid and the thyroid cancer risk attributable to CT scans for pediatric patients in one general hospital of China.
Int J Environ Res Public Health
PUBLISHED: 01-09-2014
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To quantify the radiation dose in the thyroid attributable to different CT scans and to estimate the thyroid cancer risk in pediatric patients.
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Identification of miRNAs differentially expressed in clinical stages of human colorectal carcinoma-an investigation in Guangzhou, China.
PLoS ONE
PUBLISHED: 01-01-2014
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Aberrant expression of microRNAs (miRNAs) has been implicated in human cancer, including colorectal cancer (CRC). Such dysregulated miRNAs may have potential as diagnostic markers or therapeutic targets. However, the nature of an association between these miRNAs and clinical stages of CRC is still not clear. To this end, we performed a miRNA profiling of 1547 distinct human miRNAs using 31 samples of tumor and paired normal mucosa obtained from 31 CRC patients. Based on statistical analyses of profiling data, we identified 569 miRNAs that were significantly dysregulated in CRC relative to normal tissues (P<0.05). Among the 569 dysregulated miRNAs, downregulation of 17 was associated with stages II, III, and IV colon and rectal cancers (separate or combined), according to our criteria. We also assessed the potential of these dysregulated miRNAs as diagnostic biomarkers for CRC patients who were without metastasis, and the value of the dysregulated miRNAs for predicting metastasis, lymph node and distant. Their distinct expression patterns in colon and rectal cancers were also examined. Although our findings cannot be immediately applied toward clinical diagnosis, our new study model for determining and assessing the biomarker potential of dysregulated miRNAs should be useful in further research in detection of human CRC.
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Absolute configuration study of a new dimeric indole alkaloid from the leaves and twigs of Psychotria henryi.
J Asian Nat Prod Res
PUBLISHED: 12-20-2013
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From the leaves and twigs of Psychotria henryi, a new dimeric indole alkaloid, named psychohenin, was isolated, whose structure was elucidated on the basis of extensive spectroscopic analysis. The absolute configuration of psychohenin was determined by a single-crystal X-ray diffraction study using a mirror Cu K? radiation.
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Chemical Constituents from Trichilia connaroides and Their Nitric Oxide Production and ?-Glucosidase Inhibitory Activities.
Planta Med.
PUBLISHED: 12-19-2013
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Phytochemical investigation of the stem and bark of Trichilia connaroides led to the isolation of eight new nortriterpenoids (1-8), along with fifteen known compounds (9-23). Their structures were established based on extensive spectroscopic analysis. The absolute configuration of 2 was confirmed by X-ray crystallographic study. The nitric oxide production and ?-glucosidase inhibitory effects for these isolates were evaluated: moderate to strong nitric oxide production inhibitory activities were found for 5, 6, and 11-15, with IC50 values ranging from 7.5 to 26.3?µM; marked ?-glucosidase inhibitory effects were observed for 22 and 23, with IC50 values of 2.3 and 0.4?µM, respectively.
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Design, synthesis and evaluation of novel tacrine-rhein hybrids as multifunctional agents for the treatment of Alzheimers disease.
Org. Biomol. Chem.
PUBLISHED: 12-06-2013
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A series of tacrine-rhein hybrid compounds have been designed and synthesized as novel multifunctional potent ChE inhibitors. Most of the compounds inhibited ChEs in the nanomolar range in vitro effectively. Compound was one of the most potent inhibitors and was 5-fold more active than tacrine toward AChE, and it also showed a moderate BuChE inhibition with an IC50 value of 200 nM. Kinetic and molecular modeling studies of also indicated that it was a mixed-type inhibitor binding simultaneously to the active and peripheral sites of AChE. In inhibition of the AChE-induced A? aggregation assay, compound (70.2% at 100 ?M) showed the greatest inhibitory activity. In addition, showed metal-chelating property and low hepatotoxicity. These results suggested that might be an excellent multifunctional agent for AD treatment.
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Target-Triggered Cyclic Assembly of DNA-Protein Hybrid Nanowires for Dual-Amplified Fluorescence Anisotropy Assay of Small Molecules.
Anal. Chem.
PUBLISHED: 11-14-2013
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Aptamer-based fluorescence anisotropy (FA) assays have attracted great interest in recent years. However, a key factor that determines FA value is molar mass, thus limiting the utility of this assay for the detection of small molecules. To solve this problem, streptavidin, as a molar mass amplifier, was used in a hybridization chain reaction (HCR) to construct a target-triggered cyclic assembly of DNA-protein hybrid nanowires for highly sensitive detection of small molecules by fluorescence anisotropy. In this assay, one blocking DNA strand is released by target-aptamer recognition. The DNA then serves as an initiator to trigger enzyme-free autonomous cross-opening of hairpin probes via HCR to form a DNA nanowire for further assembly of streptavidin. Using adenosine triphosphate (ATP) as the small molecule target, this novel dual-amplified, aptamer-based FA assay affords high sensitivity with a detection limit of 100 nM. This limit of detection (LOD) is much lower than that of the disassembly approach without HCR amplification or the assembly strategy without streptavidin. In contrast to the previous turn-off disassembly approaches based on nonspecific interactions between the aptamer probe and amplification moieties, the proposed aptamer-based FA assay method exhibits a turn-on response to ATP, which can increase sensing reliability and reduce the risk of false hits. Moreover, because of its resistance to environmental interferences, this FA assay has been successfully applied for direct detection of 0.5 ?M ATP in complex biological samples, including cell media, human urine, and human serum, demonstrating its practicality in real complex biological systems.
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Honokiol trimers and dimers via biotransformation catalyzed by Momordica charantia peroxidase: Novel and potent ?-glucosidase inhibitors.
Bioorg. Med. Chem.
PUBLISHED: 10-23-2013
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Ten honokiol oligomers (1-10), including four novel trimers (1-4) and four novel dimers (5-8), were obtained by means of biotransformation of honokiol catalyzed by Momordica charantia peroxidase (MCP) for the first time. Their structures were established on the basis of spectroscopic methods. The biological results demonstrated that most of the oligomers were capable of inhibiting ?-glucosidase with significant abilities, which were one to two orders of magnitude more potent than the substrate, honokiol. In particular, compound 2, the honokiol trimer, displayed the greatest inhibitory activity against ?-glucosidase with an IC50 value of 1.38?M. Kinetic and CD studies indicated that 2 inhibited ?-glucosidase in a reversible, mixed-type manner and caused conformational changes in the secondary structure of the enzyme protein. These findings suggested that 2 might be exploited as a promising drug candidate for the treatment of diabetes.
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Aphanamenes A and B, two new acyclic diterpene [4 + 2]-cycloaddition adducts from Aphanamixis grandifolia.
Org. Lett.
PUBLISHED: 10-18-2013
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Aphanamenes A (1) and B (2), two unprecedented acyclic diterpene dimers formed via a [4 + 2]-cycloaddition, were isolated from the root bark of Aphanamixis grandifolia. Their structures were elucidated by spectroscopic analyses, and the absolute configuration of 1 was determined by ECD calculations. Both 1 and 2 showed significant inhibition on NO production on lipopolysaccharide-induced RAW264.7 macrophages.
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Optimization of extraction of phenolics from leaves of Ficus virens.
J Zhejiang Univ Sci B
PUBLISHED: 10-09-2013
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In this research, the conditions for extraction of phenolics from leaves of Ficus virens were optimized using response surface methodology (RSM). The extraction abilities of phenolics (EAP) and flavonoids (EAF), the 2,2-diphenyl-1-pierylhydrazyl (DPPH) free-radical scavenging potential, and the ferric reducing/antioxidant power (FRAP) were used as quality indicators. The results of single-factor experiments showed that temperature, ethanol concentration, extraction time, and the number of extraction cycles were the main influencing variables, and these provided key information for the central composite design. The results of RSM fitted well to a second degree polynomial model and more than 98% of the variability was explained. The ideal extraction conditions for EAP, EAF, DPPH free-radical scavenging potential, and FRAP were obtained. Considering the four quality indicators overall, the ideal extraction conditions were 58% ethanol at 57 °C for 37 min with three extraction cycles. At the ideal extraction conditions, the values of EAP, EAF, DPPH free-radical scavenging potential, and FRAP were 5.72%, 3.09%, 58.88 mg ascorbic acid equivalent (AAE)/g dry weight (DW), and 15.86 mg AAE/g DW, respectively. In addition, linear correlations were observed between EAP, EAF, and antioxidant potential.
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Inhibitory effect of four triterpenoids from trichilia connaroides on nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells.
Chem. Pharm. Bull.
PUBLISHED: 10-04-2013
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Two new highly rearranged trichiliton-type limonoids (trichilitons G-H, 1-2), and two new cycloartane-type triterpenoids, 21-(E)-coumaroyloxy-5?-cycloart-24-ene-3,23-dione (3) and 21-(E)-feruloyloxy-5?-cycloart-24-ene-3,23-dione (4), were isolated from the stem and bark of Trichilia connaroides. These isolates were elucidated on the basis of detailed spectroscopic analysis, and inhibitory effect of these compounds on lipopolysaccharide-induced nitric oxide production in mouse macrophage RAW264.7 cells was evaluated.
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A label-free electrochemical biosensor for highly sensitive and selective detection of DNA via a dual-amplified strategy.
Biosens Bioelectron
PUBLISHED: 09-28-2013
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In this work, by combining the enzymatic recycling reaction with the DNA functionalized gold nanoparticles (AuNPs)-based signal amplification, we have developed an electrochemical biosensor for label-free detection of DNA with high sensitivity and selectivity. In the new designed biosensor, a hairpin-structured probe HP was designed to hybridize with target DNA first, and an exonuclease ExoIII was chosen for the homogeneous enzymatic cleaving amplification. The hybridization of target DNA with the probe HP induced the partial cleavage of the probe HP by ExoIII to release the enzymatic products. The enzymatic products could then hybridize with the hairpin-structured capture probe CP modified on the electrode surface. Finally, DNA functionalized AuNPs was further employed to amplify the detection signal. Due to the capture of abundant methylene blue (MB) molecules by both the multiple DNAs modified on AuNPs surface and the hybridization product of capture DNA and enzymatic products, the designed biosensor achieved a high sensitivity for target DNA, and a detection limit of 0.6pM was obtained. Due to the employment of two hairpin-structured probes, HP and CP, the proposed biosensor also exhibited high selectivity to target DNA. Moreover, since ExoIII does not require specific recognition sequences, the proposed biosensor might provide a universal design strategy to construct DNA biosensor which can be applied in various biological and medical samples.
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[UFLC/Q-TOF-MS based analysis on material base of atractylodis macrocephalae rhizoma stir-fried with wheat bran].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 09-27-2013
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To establish a fingerprint spectrum for Atractylodis Macrocephalae Rhizoma stir-fried with wheat bran based on UFLC/Q-TOF-MS, and make a principal component analysis (PCA) with Markview software, in order to compare the changes of components between raw and processed Atractylodis Macrocephalae Rhizoma with raw wheat bran as the blank. The results showed that the changed in components raw Atractylodis Macrocephalae Rhizoma and Atractylodis Macrocephalae Rhizoma stir-fried with wheat bran were apparently observed by PCA. Six compounds were identified to have significant changes in mass fraction before and after being stir-fried, namely atractylenolide-I, atractylenolide-II, atractylenolide-III, atractylentrid, atractylon and an unknown compound. Among them, atractylenolide-I and atractylenolide-II generated from dehydration and dehydrogenation of atractylenolide-III may be the material base of Atractylodis Macrocephalae Rhizoma stir-fried with wheat bran for strengthening spleen.
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In vivo delivery of Atoh1 gene to rat cochlea using a dendrimer-based nanocarrier.
J Biomed Nanotechnol
PUBLISHED: 09-11-2013
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Gene therapy is a promising clinical solution to hearing loss. However suitable gene carriers for the auditory system are currently unavailable. Given the unique structure of the inner ear, the route of delivery and gene transfer efficiency are still not optimal at present. This study presented a non-viral delivery system of in vivo delivery of Atoh1 gene (a potentially therapeutic gene for hearing loss) to rat cochlea. We treated polyamidoamine (PAMAM) dendrimers by activating and modifying with Na-carboxymethyl-beta-cyclodextrins (CM-beta-CD) in sequence. A novel gene carrier (CM-beta-CD modified activated PAMAM dendrimers, CMAP) was then constructed. CMAP nanoparticles could bind pRK5-Atoh1-EGFP plasmids to form vector-DNA complexes (dendriplexes) with a mean particle size of 132 +/- 20 nm and zeta potential of 31 +/- 3 mV. These dendriplexes were locally applied on the round window membrane and delivered to the inner ear by passive gradient permeation. Results showed that the Atoh1 gene was successfully transferred into the cells as indicated by the green fluorescence detected in the inner ear. A relatively selective gene transfer with high efficiency was achieved in the auditory hair cells but not much in other cell types in the cochlea. Auditory brainstem response was determined seven days after inoculation, indicating good tolerance. This approach may provide a novel tool for inner ear gene therapy and initiate the applications of biomaterials to treat auditory disorders.
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CTP synthase 1, a smooth muscle-sensitive therapeutic target for effective vascular repair.
Arterioscler. Thromb. Vasc. Biol.
PUBLISHED: 09-05-2013
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Vascular remodeling as a result of smooth muscle cell (SMC) proliferation and neointima formation is a major medical challenge in cardiovascular intervention. However, antineointima drugs often indistinguishably block re-endothelialization, an essential step toward successful vascular repair, because of their nonspecific effect on endothelial cells (ECs). The objective of this study is to identify a therapeutic target that differentially regulates SMC and EC proliferation.
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Clinical factors associated with postictal headache in Chinese patients with partial epilepsy.
Seizure
PUBLISHED: 08-24-2013
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To investigate the incidence of postictal headache (PIH) and the factors potentially related to the occurrence of PIH in a Chinese epileptic center.
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Design, synthesis and biological evaluation of imine resveratrol derivatives as multi-targeted agents against Alzheimers disease.
Eur J Med Chem
PUBLISHED: 08-16-2013
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A series of imine resveratrol derivatives (1-20) have been designed, synthesized, and evaluated as multi-targeted compounds for the treatment of Alzheimers disease (AD). In vitro studies show that most of the molecules exhibit a significant ability to inhibit self-induced and Cu(2+)-induced ?-amyloid (A?1-42) aggregation, and to function as potential antioxidants and biometal chelators. In particular, compound 9 is a potential lead compound for AD treatment (for compound 9, IC50 = 14.1 ?M for the antioxidant activity using DPPH free radical method; 64.6% at 20 ?M for self-induced A? aggregation). Moreover, it is capable of decreasing reactive oxygen species (ROS) induced by Cu-A? and shows good neuroprotective effects in human SH-SY5Y neuroblastoma cells. Taken together, these results suggest that 9 might be a promising lead compound for AD treatment.
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High-sensitivity naphthalene-based two-photon fluorescent probe suitable for direct bioimaging of H2S in living cells.
Anal. Chem.
PUBLISHED: 08-02-2013
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H2S is the third endogenously generated gaseous signaling compound and has also been known to involve a variety of physiological processes. To better understand its physiological and pathological functions, efficient methods for monitoring of H2S in living systems are desired. Although quite a few one photon fluorescence probes have been reported for H2S, two-photon (TP) probes are more favorable for intracellular imaging. In this work, by employing a donor-?-acceptor-structured naphthalene derivative as the two-photon fluorophore and an azide group as the recognition unit, we reported a new two-photon bioimaging probe 6-(benzo[d]thiazol-2-yl)-2-azidonaphthalene (NHS1) for H2S with improved sensitivity. The probe shows very low background fluorescence in the absence of H2S. In the presence of H2S, however, a significant enhancement for both one photon and TP excited fluorescence were observed, resulting in a high sensitivity to H2S in aqueous solutions with a detection limit of 20 nM observed, much lower than the previously reported TP probe. The probe also exhibits a wide linear response concentration range (0-5 ?M) to H2S with high selectivity. All these features are favorable for direct monitoring of H2S in complex biological samples. It was then applied for direct TP imaging of H2S in living cells with satisfactory sensitivity, demonstrating its value of practical application in biological systems.
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The complete mitochondrial genome of Oocatochus rufodorsatus (Reptilia, Serpentes, Colubridae).
Mitochondrial DNA
PUBLISHED: 07-31-2013
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Abstract The complete mitochondrial genome from the red-backed ratsnake Oocatochus rufodorsatus was determined. The following four distinctive features are observed: duplicate control regions that have nearly identical sequences at two different locations of mitogenome, translocation of tRNA-Leu (UUR), a pseudogene for tRNA-Pro and truncations of T?C arm for most tRNA genes.
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Hollow graphitic nanocapsules as efficient electrode materials for sensitive hydrogen peroxide detection.
Biosens Bioelectron
PUBLISHED: 07-18-2013
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Carbon nanomaterials are typically used in electrochemical biosensing applications for their unique properties. We report a hollow graphitic nanocapsule (HGN) utilized as an efficient electrode material for sensitive hydrogen peroxide detection. Methylene blue (MB) molecules could be efficiently adsorbed on the HGN surfaces, and this adsorption capability remained very stable under different pH regimes. HGNs were used as three-dimensional matrices for coimmobilization of MB electron mediators and horseradish peroxidase (HRP) to build an HGN-HRP-MB reagentless amperometric sensing platform to detect hydrogen peroxide. This simple HGN-HRP-MB complex demonstrated very sensitive and selective hydrogen peroxide detection capability, as well as high reproducibility and stability. The HGNs could also be utilized as matrices for immobilization of other enzymes, proteins or small molecules and for different biomedical applications.
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A simple and pH-independent and ultrasensitive fluorescent probe for the rapid detection of Hg2+.
Talanta
PUBLISHED: 07-13-2013
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Development of fluorescent probes for Hg(2+) has become a hot topic in modern chemical research due to its high toxicity. In this paper, we for the first time report the synthesis and application of a thioether spirocyclic rhodamine B derivative (TR) as an efficient fluorescent probe for Hg(2+). TR was synthesized using a simple procedure under mild condition. By employing a thioether spirocycle instead of classic spirolactam as recognition unit, our proposed probe TR is acidity-insensitive, and exhibits a pH-independent and ultrasensitive response to Hg(2+). The probe works well within a wide pH range from 3.5 to 11.5, and exhibits a 350-fold fluorescence enhancement upon 0.5 equiv of Hg(2+) triggered, with a detection limit of 2.5 nM estimated for Hg(2+). In virtue of the strong thiophilic characteristic of Hg(2+), the response of the probe to Hg(2+) is instantaneous and highly selective, which make it favorable for cellular Hg(2+) imaging applications. It has been preliminarily used for highly sensitive monitoring of Hg(2+) level in living cells with satisfying resolution, demonstrating its value of the practical applications in biological systems.
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Cellular reprogramming of human peripheral blood cells.
Genomics Proteomics Bioinformatics
PUBLISHED: 06-25-2013
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Breakthroughs in cell fate conversion have made it possible to generate large quantities of patient-specific cells for regenerative medicine. Due to multiple advantages of peripheral blood cells over fibroblasts from skin biopsy, the use of blood mononuclear cells (MNCs) instead of skin fibroblasts will expedite reprogramming research and broaden the application of reprogramming technology. This review discusses current progress and challenges of generating induced pluripotent stem cells (iPSCs) from peripheral blood MNCs and of in vitro and in vivo conversion of blood cells into cells of therapeutic value, such as mesenchymal stem cells, neural cells and hepatocytes. An optimized design of lentiviral vectors is necessary to achieve high reprogramming efficiency of peripheral blood cells. More recently, non-integrating vectors such as Sendai virus and episomal vectors have been successfully employed in generating integration-free iPSCs and somatic stem cells.
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A superquenched DNAzyme-perylene complex: a convenient, universal and low-background strategy for fluorescence catalytic biosensors.
Chem. Commun. (Camb.)
PUBLISHED: 06-17-2013
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Taking advantage of the super-quenching effect of the cationic perylene derivative on adjacent fluorophores, we for the first time reported a DNAzyme-perylene complex-based strategy for constructing fluorescence catalytic biosensors with improved sensitivity.
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Response gene to complement 32 deficiency causes impaired placental angiogenesis in mice.
Cardiovasc. Res.
PUBLISHED: 05-21-2013
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The objectives of this study are to determine the role of response gene to complement 32 (RGC-32) in the placental angiogenesis during pregnancy and explore the underlying mechanisms.
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Pyrophosphate-regulated Zn(2+)-dependent DNAzyme activity: an amplified fluorescence sensing strategy for alkaline phosphatase.
Biosens Bioelectron
PUBLISHED: 05-19-2013
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In this work, based on the fact that pyrophosphate (PPi) could regulate the activity of Zn(2+)-dependent DNAzyme, we for the first time report a fluorescence turn-on sensing system for alkaline phosphatase (ALP) with improved sensitivity via nonprotein-enzymatic signal amplification. A catalytic and molecular beacon (CAMB) design was employed to further improve its sensitivity. Taking advantage of the strong interactions between PPi and the Zn(2+), the cofactor Zn(2+) was caged, and the DNAzyme activity was effectively inhibited. The introduction of ALP, however, could catalyze the hydrolysis of PPi and release free Zn(2+), resulting in the activation of DNAzyme to catalyze the cleavage of the molecular beacon substrate with a remarkable increase of fluorescent signal. These optimized designs together allow a high sensitivity for ALP, with a detection limit of 20 pM observed, much lower than previously reported methods. It has also been used for detection of ALP in human serum with satisfactory results, demonstrating its potential applications in clinical diagnosis.
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Detection of carbapenemase-encoding genes among clinical isolates of Pseudomonas aeruginosa in a Chinese burn unit.
J Burn Care Res
PUBLISHED: 05-14-2013
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The carbapenemases have recently emerged as molecules implicated in one of the most feared bacterial resistance mechanisms because of their ability to hydrolyze virtually all lactamase agents and their highly mobile genes. This study aimed to investigate the prevalence of carbapenemase and antimicrobial susceptibilities of Pseudomonas aeruginosa isolated from burn patients in Chongqing, China. Antimicrobial susceptibility of 111 isolates was determined by the disc agar diffusion test and the agar dilution method. Random Amplification of Polymorphic DNA polymerase chain reaction analysis revealed 111 P. aeruginosa 42 genotypes. Carbapenemase genes were amplified by polymerase chain reaction and the sequence verified by blast. Ninety-three of 111 (83.8%) isolates were resistant to imipenem; all of them had developed multidrug resistance and exhibited higher resistant rates compared with the imipenem-susceptible Pseudomonas. Ciprofloxacin was the most effective antipseudomonal agent. Thirty-three of the isolates were identified to contain the metallo-?-lactamase blaIMP-4 gene and belong to different Random Amplification of Polymorphic DNA polymerase chain reactiongenotypes. In conclusion, the high prevalence of multidrug resistance (94.6%) and the production of blaIMP-4 genes in P. aeruginosa isolates in burn patients highlight the necessity of considering these issues in burn hospitals.
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Multifunctional tacrine-flavonoid hybrids with cholinergic, ?-amyloid-reducing, and metal chelating properties for the treatment of Alzheimers disease.
Eur J Med Chem
PUBLISHED: 04-26-2013
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A new series of tacrine-flavonoid hybrids (13a-u) had been designed, synthesized, and evaluated as multifunctional cholinesterase (ChE) inhibitors against Alzheimers disease (AD). In vitro studies showed that most of the molecules exhibited a significant ability to inhibit ChE and self-induced amyloid-? (A?????) aggregation. Kinetic and molecular modeling studies also indicated compounds were mixed-type inhibitors, binding simultaneously to active, peripheral and mid-gorge sites of AChE. Particularly, compound 13k was found to be highly potent and showed a balanced inhibitory profile against ChE and self-induced A????? aggregation. Moreover, it also showed excellent metal chelating property and low cell toxicity. These results suggested that 13k might be an excellent multifunctional agent for AD treatment.
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Spatiotemporal expression of fibroblast growth factor 10 in human hindgut and anorectal development.
Cells Tissues Organs (Print)
PUBLISHED: 03-17-2013
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As fibroblast growth factor 10 (FGF-10) gene expression may have a role in anorectal duct formation, this study aimed to assess the spatiotemporal expression pattern of FGF-10 during development of the rectum and hindgut in human embryos. FGF-10 expression was evaluated in human embryos (n = 85) at 3-8 weeks of gestation after immunohistochemical evaluation using antibodies specific for FGF-10. From weeks 4 to 7 of gestation, FGF-10 expression was observed primarily in the apical epithelium of the dorsal urorectal septum, the cloacal membrane (CM) and the hindgut. Following CM rupture (week 7), the epithelium of the anal canal was negative for FGF-10; however, it was present within the urothelium through week 7. FGF-10 expression during the development of the human hindgut and anorectum suggests that it may play a role in hindgut and anorectal morphogenesis.
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Rapid and efficient reprogramming of human fetal and adult blood CD34+ cells into mesenchymal stem cells with a single factor.
Cell Res.
PUBLISHED: 03-12-2013
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The direct conversion of skin cells into somatic stem cells has opened new therapeutic possibilities in regenerative medicine. Here, we show that human induced mesenchymal stem cells (iMSCs) can be efficiently generated from cord blood (CB)- or adult peripheral blood (PB)-CD34(+) cells by direct reprogramming with a single factor, OCT4. In the presence of a GSK3 inhibitor, 16% of the OCT4-transduced CD34(+) cells are converted into iMSCs within 2 weeks. Efficient direct reprogramming is achieved with both episomal vector-mediated transient OCT4 expression and lentiviral vector-mediated OCT4 transduction. The iMSCs express MSC markers, resemble bone marrow (BM)-MSCs in morphology, and possess in vitro multilineage differentiation capacity, yet have a greater proliferative capacity compared with BM-MSCs. Similar to BM-MSCs, the implanted iMSCs form bone and connective tissues, and are non-tumorigenic in mice. However, BM-MSCs do not, whereas iMSCs do form muscle fibers, indicating a potential functional advantage of iMSCs. In addition, we observed that a high level of OCT4 expression is required for the initial reprogramming and the optimal iMSC self-renewal, while a reduction of OCT4 expression is required for multilineage differentiation. Our method will contribute to the generation of patient-specific iMSCs, which could have applications in regenerative medicine. This discovery may also facilitate the development of strategies for direct conversion of blood cells into other types of cells of clinical importance.
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Versatile DNAzyme-based amplified biosensing platforms for nucleic acid, protein, and enzyme activity detection.
Anal. Chem.
PUBLISHED: 03-12-2013
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DNAzymes have been widely applied as signal amplifiers for enzyme-free and highly sensitive detection of DNA. A few of them have also been employed for amplified detection of other biomolecules via a target-triggered assembly of split or mutated DNAzyme strategy. However, most of these designs adopt Mg(2+)-dependent DNAzyme as the catalytic unit, which suffered from low catalytic cleavage activity. Meanwhile, some DNAzymes with high catalytic activity are not suitable for these designs because the slight modification of the catalytic core might results in remarkably decreased or even no catalytic activity of these DNAzymes. On the basis of DNAzyme topological effect or the terminal protection of small-molecule-linked DNA, we developed two versatile sensing platforms for amplified detection of different biotargets. Since no modification is necessary for the catalytic core of the DNAzyme in these designs, they can employ any DNAzyme with high catalytic activity as amplified unit, which affords a high amplified efficiency for the sensing platform. A catalytic and molecular beacon design was further employed to realize the true enzymatic multiple turnover of DNAzyme. These designs together allow a high sensitivity for the biotargets, resulting in a detection limit of 20 pM, 0.2 U/mL, and 1 ng/mL for target DNA, DNA adenine methylation methyltransferase (Dam MTase), and streptavidin, respectively, much lower than previously reported biosensors. In addition, the proposed sensing strategy is versatile. By conjugating with various recognition units, it can be employed to detect a wide range of biotargets, varying from nucleic acids to proteins with high sensitivity.
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Synthesis and characterizations of the first [V16O39Cl]6- (V16O39) polyanion.
Dalton Trans
PUBLISHED: 03-07-2013
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A compound containing the first [V16O39Cl](6-) (V16O39) polyanion has been hydrothermally synthesized and characterized.
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The complete mitochondrial genome of the Alpine black swallowtail, Papilio Maackii (Insecta: Lepidoptera: Papilionidae).
Mitochondrial DNA
PUBLISHED: 03-06-2013
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The complete mitochondrial genome (mitogenome) of the swallowtail butterfly Papilio maackii has been completed. It is 15,357 bp in length, and contains the typical complement of 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA), and 2 ribosomal RNA (rRNA) genes. Two A + T-rich regions are included in this mitogenome. Gene order in P. maackii mitogenome is basically identical to that of the inferred ancestral insect genome, with the exception of translocations of trnM, which is shared by some Papilios.
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Gay saunas and the risks of HIV and syphilis transmissions in China--results of a meta-analysis.
J Sex Med
PUBLISHED: 03-06-2013
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Previous studies suggest the risk of human immunodeficiency virus (HIV) transmission among men who have sex with men (MSM) is associated with characteristics of venues. However, very few studies have systematically compared HIV/sexually transmitted disease (STD) prevalence among MSM according to key venue type for sourcing sex partners.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

How does it work?

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

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

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