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Find video protocols related to scientific articles indexed in Pubmed.
One Pot, Two Phases: Individual Orthorhombic and Face-Centered Cubic ZnSnO3 Obtained Synchronously in One Solution.
Inorg Chem
PUBLISHED: 11-14-2014
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Many modern technologies rely on the functional materials that are subject to their phase purity. The topic of obtaining pure crystals from the concomitant allotropes is ever before the eyes of numerous researchers. Here we adopt a template-inducing route and obtain the isolated allotropes located in the appointed regions in the same reaction system. As a typical example, well-defined individual face-centered cubic and orthorhombic ZnSnO3 crystals were successfully synthesized assisted by a ZnO inducing template or without it in an identical solution, respectively. And the different growing mechanisms of the ZnSnO3 allotropes were also proposed, which takes a pivotal step toward the realization of allotropes dividing. Moreover, the two individual pure-phased ZnSnO3 allotropes obtained in one reaction system exhibit porous microspherical morphologies constructed by the tiny nanograins, resulting in their high sensitivities to ethanol with fast response and recovery and good selectivity and stability.
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The Discovery and Optimization of 4,5-Diarylisoxazoles as Potent Dual Inhibitors of Pyruvate Dehydrogenase Kinase (PDHK) and Heat Shock Protein 90 (HSP90).
J. Med. Chem.
PUBLISHED: 11-11-2014
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Upregulation of pyruvate dehydrogenase kinase (PDHK) has been observed in a variety of cancers. Inhibition of PDHK offers an attractive opportunity for the development of novel cancer therapies. To obtain novel PDHK inhibitors, we took advantage of the homology of the ATP-binding pocket between HSP90 and PDHK, and utilized 4,5-diarylisoxazole based HSP90 inhibitor for structural design. Our efforts led to the identification of 5k that inhibited PDHK1 with an IC50 value of 17 nM, which however, showed marginal cellular activity. Further structural optimization resulted in compound 11a with improved cellular activity which could effectively modulate the metabolic profile of cancer cells and led to the inhibition of cancer cell proliferation, evidenced by the increased oxidative phosphorylation and decreased glycolysis and associated oxidative stress. Our results suggested 11a as an excellent lead compound and a favorable biological tool to further evaluate the therapeutic potential of PDHK and HSP90 dual inhibitors in the treatment of cancer.
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[Microsurgical resection of anterior clinoid meningiomas-- 46 cases report].
Zhonghua Wai Ke Za Zhi
PUBLISHED: 06-14-2014
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To investigate the microsurgical tchniques and effects for the resection of anterior clinoid meningioma (ACM).
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Two functional sequence variants of the GATA6 gene promoter in patients with indirect inguinal hernia.
Gene
PUBLISHED: 05-13-2014
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Inguinal hernia is a common surgical disease, majority of which are indirect inguinal hernia (IIH). A positive family history has indicated that genetic factors play important roles in the IIH development. To date, genetic causes and underlying mechanisms for inguinal hernia remain largely unknown. During the embryonic development, GATA transcription factor 6 (GATA6) plays an essential role. Mutations in GATA6 gene and changed GATA6 levels have been associated with human diseases. As GATA6 acts in a dosage-dependent manner, we speculated that changed GATA6 levels, resulting from DNA sequence variants (DSVs) within the gene regulatory regions, may mediate the IIH development. In this study, the GATA6 gene promoter was genetically and functionally analyzed in IIH patients and ethnic-matched controls. Eleven DNA sequence variants (DSVs), including four SNPs and seven new variants, within the GATA6 gene promoter were identified. Two heterozygous DSVs, g.22168361C>A and g.22169106C>T, were identified in two IIH patients, but in none of controls. In cultured human fibroblast, these DSVs significantly reduced the GATA6 gene promoter activities. In addition, three heterozygous DSVs were only found in three controls. Five DSVs, including four SNPs and one new variant, were found in both IIH patients and controls with similar frequencies. Therefore, the DSVs within the GATA6 gene promoter may contribute to the IIH development as a risk factor by changing the GATA6 levels.
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Novel and functional DNA sequence variants within the GATA6 gene promoter in ventricular septal defects.
Int J Mol Sci
PUBLISHED: 04-29-2014
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Congenital heart disease (CHD) is the most common birth defect in humans. Genetic causes and underlying molecular mechanisms for isolated CHD remain largely unknown. Studies have demonstrated that GATA transcription factor 6 (GATA6) plays an essential role in the heart development. Mutations in GATA6 gene have been associated with diverse types of CHD. As GATA6 functions in a dosage-dependent manner, we speculated that changed GATA6 levels, resulting from DNA sequence variants (DSVs) within the gene regulatory regions, may mediate the CHD development. In the present study, GATA6 gene promoter was genetically and functionally analyzed in large groups of patients with ventricular septal defect (VSD) (n=359) and ethnic-matched healthy controls (n=365). In total, 11 DSVs, including four SNPs, were identified in VSD patients and controls. Two novel and heterozygous DSVs, g.22169190A>T and g.22169311C>G, were identified in two VSD patients, but in none of controls. In cultured cardiomyocytes, the activities of the GATA6 gene promoter were significantly reduced by the DSVs g.22169190A>T and g.22169311C>G. Therefore, our findings suggested that the DSVs within the GATA6 gene promoter identified in VSD patients may change GATA6 levels, contributing to the VSD development as a risk factor.
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Functional sequence variants within the SIRT1 gene promoter in indirect inguinal hernia.
Gene
PUBLISHED: 03-30-2014
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Inguinal hernia is a common surgical disease, for which genetic factors have been suggested to play a role. Sirtuin 1 (SIRT1), a highly conserved NAD-dependent class III deacetylase, has been implicated in human diseases. Since SIRT1 regulates differentiation and proliferation of human skeletal muscles and fibroblasts, we speculated that misregulation of SIRT1 gene, caused by DNA sequence variants (DSVs) within its regulatory regions, may contribute to inguinal hernia development. In this study, SIRT1 gene promoter was genetically and functionally analyzed in patients with indirect inguinal hernia (IIH) (n=139) and ethnic-matched healthy controls (n=148). Two heterozygous DSVs, g.69644213G>A and g.69644268T>A, and one single nucleotide polymorphism (SNP), g.69643707A>C (rs35706870), were found in IIH patients, but not in controls. Two closely-linked SNPs, g.69644217A>C (rs932658) and g.69644341G>C (rs2394443), were found in IIH patients with significantly higher frequency, compared to controls (P=0.006). The C alleles of the SNPs g.69644217A>C (rs932658) and g.69644341G>C (rs2394443) were associated with IIH (P=0.028, OR 1.600, 95%CI 1.049-2.439). These DSVs significantly altered the transcriptional activities of the SIRT1 gene promoter in cultured cells. Therefore, our data suggested that these DSVs may alter the transcriptional activities of SIRT1 gene promoter and change SIRT1 levels, contributing to IIH development as risk factors.
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Bi2MoO6 nanobelts for crystal facet-enhanced photocatalysis.
Small
PUBLISHED: 03-25-2014
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?-Bi2MoO6 single-crystal nanobelts with dominant {010} facets exhibit facet-enhanced photocatalytic property for the photodegradation of dye pollutants under visible light irradiation. The charge carriers are more efficiently separated on the low-index facets due to the exposure of more photoactive sites to the reacting substrates.
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Molecular characterization of three ferret badger (Melogale moschata) rabies virus isolates from Jiangxi province, China.
Arch. Virol.
PUBLISHED: 02-28-2014
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Ferret badger (FB) rabies viruses JX09-17(fb), JX09-18 and JX10-37 were isolated from three different regions in Jiangxi province, China, in 2009 and 2010. The complete nucleotide sequence identity between these three isolates was 87-93 %. Compared with the other Chinese rabies virus isolates and vaccine strains, 101 substitutions (53 in JX10-37, 23 in JX09-17(fb) and 25 in JX09-18) in the five structural proteins were observed, and 47 of these substitutions (27 in JX10-37, 14 in JX09-17(fb) and 6 in JX09-18) were unique among lyssaviruses. Amino acid substitutions of S231 and Q333 were noted respectively in the G protein antigenic site I of JX10-37 and site III in JX09-17(fb). Phylogenetic analysis showed that JX09-17(fb) is rooted within the China I lineage, JX09-18 is in China II, and JX10-37 is independent. Evolutionary analysis and comparative sequence data indicate that isolate JX10-37 is a variant virus that diverged from canine rabies viruses around 1933 (range 1886-1963).
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Mechanical ball-milling preparation of fullerene/cobalt core/shell nanocomposites with high electrochemical hydrogen storage ability.
ACS Appl Mater Interfaces
PUBLISHED: 02-14-2014
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The design and synthesis of new hydrogen storage nanomaterials with high capacity at low cost is extremely desirable but remains challenging for today's development of hydrogen economy. Because of the special honeycomb structures and excellent physical and chemical characters, fullerenes have been extensively considered as ideal materials for hydrogen storage materials. To take the most advantage of its distinctive symmetrical carbon cage structure, we have uniformly coated C60's surface with metal cobalt in nanoscale to form a core/shell structure through a simple ball-milling process in this work. The X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectra, high-solution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectrometry (EDX) elemental mappings, and X-ray photoelectron spectroscopy (XPS) measurements have been conducted to evaluate the size and the composition of the composites. In addition, the blue shift of C60 pentagonal pinch mode demonstrates the formation of Co-C chemical bond, and which enhances the stability of the as-obtained nanocomposites. And their electrochemical experimental results demonstrate that the as-obtained C60/Co composites have excellent electrochemical hydrogen storage cycle reversibility and considerably high hydrogen storage capacities of 907 mAh/g (3.32 wt % hydrogen) under room temperature and ambient pressure, which is very close to the theoretical hydrogen storage capacities of individual metal Co (3.33 wt % hydrogen). Furthermore, their hydrogen storage processes and the mechanism have also been investigated, in which the quasi-reversible C60/Co?C60/Co-Hx reaction is the dominant cycle process.
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Novel and functional ABCB1 gene variant in sporadic Parkinson's disease.
Neurosci. Lett.
PUBLISHED: 01-15-2014
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Parkinson's disease (PD) is a common progressive neurodegenerative disease. Most cases of PD are sporadic, which is caused by interaction of genetic and environmental factors. To date, genetic causes for sporadic PD remain largely unknown. ATP-binding cassette sub-family B member 1 (ABCB1) is a membrane-associated protein that acts as an efflux transporter for many substrates, including chemotherapeutic agents, anti-epilepsy medicine, antibiotics and drugs for PD. ABCB1 gene is widely expressed in human tissues, including endothelial cells of capillary blood vessels at blood-brain barrier sites. In PD patients, decreased ABCB1 levels have been reported. We speculated that misregulation of ABCB1 gene expression, caused by DNA sequence variants (DSVs) within its regulatory regions, may be involved in PD development. In this study, we genetically and functionally analyzed the proximal promoter of the human ABCB1 gene, which is required for constitutive expression, in sporadic PD patients and healthy controls. The results showed that a novel and heterozygous DSV g.117077G>A was identified in one PD patient, but in none of the controls. This DSV significantly altered the transcriptional activity of the ABCB1 gene promoter in transiently transfected HEK-293 cells. A heterozygous DSV g.116347T>C was only found in one control. Four single-nucleotide polymorphisms, g.116154T>C (rs28746504), g.117130A>G (rs2188524), g.117356C>G (rs34976462) and g.117372T>C (rs3213619), and one heterozygous deletion DSV g.116039del were found in PD patients and controls with similar frequencies. Therefore, our findings suggest that ABCB1 gene promoter DSVs may contribute to PD development as a rare risk factor.
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Recombinant adenovirus-mediated overexpression of 3?-hydroxysteroid-?24 reductase.
Neural Regen Res
PUBLISHED: 01-10-2014
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3?-Hydroxysteroid-?24 reductase (DHCR24) is a multifunctional enzyme that localizes to the endoplasmic reticulum and has neuroprotective and cholesterol-synthesizing activities. DHCR24 overexpression confers neuroprotection against apoptosis caused by amyloid ? deposition. The present study aimed to construct two recombinant adenoviruses driving DHCR24 expression specifically in neurons. Two SYN1 promoter DNA fragments were obtained from human (h) and rat (r). Recombinant Ad-r(h)SYN1-DHCR24 was transfected into AD-293, N2A (mouse neuroblastoma), and MIN6 (mouse pancreatic carcinoma) cells. Western blot analysis showed DHCR24 was specially expressed in 293 and N2A cells, but no specific band was found in MIN6 cells. This demonstrates that the recombinant adenoviruses successfully express DHCR24, and no expression is observed in non-neuronal cells. TUNEL assay results showed apoptosis was inhibited in adenovirus-transfected neurons. Detecting reactive oxygen species by immunofluorescence, we found that adenovirus transfection inhibits apoptosis through scavenging excess reactive oxygen species. Our findings show that the recombinant DHCR24 adenoviruses induce neuron-specific DHCR24 expression, and thereby lay the foundation for further studies on DHCR24 gene therapy for Alzheimer's disease.
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3 ?-hydroxysteroid-? 24 reductase (DHCR24) protects neuronal cells from apoptotic cell death induced by endoplasmic reticulum (ER) stress.
PLoS ONE
PUBLISHED: 01-01-2014
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3?-Hydroxysteroid-?24 reductase (DHCR24) is an endoplasmic reticulum (ER)-localized multifunctional enzyme that possesses anti-apoptotic and cholesterol-synthesizing activities. Accumulating evidence suggests that ER stress is involved in the pathogenesis of neurodegenerative disease. In this study, we investigated whether DHCR24 may function as a neuroprotective protein under ER stress. Neuroblastoma N2A cells were infected with adenovirus expressing myc-tagged DHCR24 (Ad-DHCR24) or lacZ (Ad-lacZ, serving as a control) and subjected to ER-stress, induced with Tunicamycin (TM). Cells infected with Ad-DHCR24-myc were resistant to TM-induced apoptosis, and showed weaker level of caspase-12 activity. These cells also exhibited lower levels of Bip and CHOP proteins than Ad-LacZ-infected cells. Moreover, a stronger and rapid activation of PERK, and a prolonged activation of JNK and p38 were observed in Ad-LacZ-infected cells. The generation of intracellular reactive oxygen species from ER stress was also diminished by the overexpression of DHCR24. Additionally, intracellular cholesterol level was also elevated in the Ad-DHCR24-infected cells, accompanied by a well-organized formation of caveolae (cholesterol-rich microdomain) on the plasma membrane, and improved colocalization of caveolin-1 and insulin-like growth factor 1 receptor. These results demonstrated for the first time that DHCR24 could protect neuronal cells from apoptosis induced by ER stress.
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Molecular characterization of a rabies virus isolate from a rabid dog in Hanzhong District, Shaanxi Province, China.
Arch. Virol.
PUBLISHED: 10-06-2013
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A canine rabies virus, Shaanxi-HZ-6, was isolated in Shaanxi Province, China, in 2009. Its genome has been completely sequenced and found to be closely related to the China I rabies virus strains widely circulating in China. The genomic length was 11,923 base pairs, and the overall organization of the genome was similar to that of other rabies virus isolates. Compared with isolates CQ92 and J, 84 amino acid substitutions (7 in the N gene, 15 in P, 6 in M, 25 in G, 31 in L) were observed in strain Shaanxi-HZ-6. Amino acid substitutions of R264H and V332I were noted in the G protein antigenic site I and site III, respectively. Residue 333 of the G protein, which is considered to be associated with pathogenicity, was Arg in Shaanxi-HZ-6. These and other substitutions may help provide an explanation why the China I lineage strain maintains its prevalence in China.
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A novel long non-coding RNA-ARA: Adriamycin Resistance Associated.
Biochem. Pharmacol.
PUBLISHED: 08-26-2013
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Long non-coding RNAs (lncRNAs) are emerging as an integral functional component of human genome and have been investigated as critical regulators in molecular biology of cancer. A recent study reported that lncRNA-UCA1 induced drug resistance in adriamycin chemotherapy. However, the contributions of lncRNAs to adriamycin resistance in cancers remain largely unknown. To address this issue, we performed a genome-wide lncRNA microarray analysis in adriamycin resistant MCF-7/ADR and parental MCF-7 cells, and revealed differential expression of lncRNAs in distinct category and chromosome distribution patterns. A specific differentially expressed lncRNA (Adriamycin Resistance Associated, termed ARA) was validated in MCF-7/ADR and HepG2/ADR cells. ARA is derived from an intron of PAK3 gene, predicted to contain several stable hairpins in secondary structure and has conservative sequences in primates. ARA expression is significantly associated with adriamycin sensitivity in a panel of breast and liver cancer cell lines and is markedly up-regulated in parental sensitive MCF-7 and HepG2 cell lines after receiving adriamycin treatment. The functions of ARA were assessed by silencing this lncRNA in vitro, and we found that ARA knockdown reduced the proliferation, induced cell death, G2/M arrest and migration defects. Furthermore, microarray transcriptomic analysis was carried out to comprehensively depict the ARA-regulated genes. We showed that ARA can modulate multiple signalling pathways, including MAPK signalling pathway, metabolism pathways, cell cycle and cell adhesion-related biological pathways, and regulate cellular processes, including transcriptional processes and protein binding function. Overall, our results indicate novel insights of adriamycin resistance in lncRNA level.
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[Localization and function of CD59 and Cbp in T lymphocytes].
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
PUBLISHED: 06-11-2013
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To investigate the distributions of GPI-anchored protein CD59 and C-terminal Src kinase-binding protein (Cbp) in cell membrane of T lymphocytes and the roles in cell activation and proliferation.
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Novel and functional variants within the TBX18 gene promoter in ventricular septal defects.
Mol. Cell. Biochem.
PUBLISHED: 04-08-2013
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Congenital heart disease (CHD) is the most common birth defect in humans. Genetic causes for CHD remain largely unknown. T-box transcription factor 18 (TBX18) gene is expressed in the developing heart, including myocardium of the left ventricle and interventricular septum. Epicardial cells expressing TBX18 gene contribute to the cardiac fibroblast and smooth muscle cells. We speculated that the DNA sequence variants (DSVs) within TBX18 gene promoter may mediate CHD development by affecting TBX18 levels and the cardiac gene regulatory network. In this study, we genetically and functionally analyzed the TBX18 gene promoter in patients with ventricular septal defects (VSD) (n = 326) and ethnic-matched healthy controls (n = 327). Three novel heterozygous DSVs (g.85474435del, g.85474418C>T, and g.85473965C>G) and one single nucleotide polymorphism (g.85474871C>T, rs77693245) were identified in VSD patients, but none in the controls. Functional analysis revealed that the DSVs (g.85474871C>T, g.85474435del, and g.85473965C>G) significantly decreased the transcriptional activities of the TBX18 gene promoter. The effect of DSV (g.85474418C>T) on the TBX18 gene promoter was marginal, but not significant. Therefore, the DSVs within the TBX18 gene promoter identified in VSD patients may be involved in the VSD etiology.
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Novel and functional sequence variants within the TBX2 gene promoter in ventricular septal defects.
Biochimie
PUBLISHED: 03-21-2013
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Congenital heart disease (CHD) is the most common birth defects in humans. To date, genetic causes for CHD remain largely unknown. T-box transcription factor 2 (TBX2) gene is expressed in the myocardium of atrioventricular canal, outflow tract and inflow tract and plays a critical role in heart chamber formation. Genomic deletion and duplication of TBX2 gene have been associated with cardiac defects. As TBX2 acts in a dose-dependent manner, we hypothesized that DNA sequence variants (DSVs) within TBX2 gene promoter may mediate CHD development by changing TBX2 levels. In this study, TBX2 gene promoter was genetically analyzed in large cohorts of patients with ventricular septal defect (VSD) (n = 324) and ethnic-matched healthy controls (n = 328). Four novel and heterozygous DSVs, g.59477201C > T, g.59477347G > A, g.59477353delG and g.59477371G > A were identified in VSD patients, but in none of controls. Functional analyses revealed that all of the four DSVs significantly decreased transcriptional activities of TBX2 gene promoter. Therefore, our data suggested that the DSVs within TBX2 gene promoter identified in VSD patients may contribute to VSD etiology.
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Two novel and functional DNA sequence variants within an upstream enhancer of the human NKX2-5 gene in ventricular septal defects.
Gene
PUBLISHED: 02-26-2013
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Mortality in patients with congenital heart disease (CHD) is significantly increased even with successful surgeries. The main causes are late cardiac complications, such as heart failure and arrhythmia, probably due to genetic defects. To date, genetic causes for CHD remain largely unknown. NKX2-5 gene encodes a highly conserved homeobox transcription factor, which is essential to the heart development in embryos and cardiac function in adults. Mutations in NKX2-5 gene have been implicated in diverse types of CHD, including ventricular septal defect (VSD). As NKX2-5 is a dosage-sensitive regulator, we have speculated that changed NKX2-5 levels may mediate CHD development by influencing cardiac gene regulatory network. In previous studies, we have analyzed the NKX2-5 gene promoter and a proximal enhancer in VSD patients. In the present study, we further genetically and functionally analyzed an upstream enhancer of the NKX2-5 gene in large cohorts of VSD patients (n=340) and controls (n=347). Two novel heterozygous DNA sequence variants (DSVs), g.17483576C>G and g.17483564C>T, were identified in three VSD patients, but none in controls. Functionally, these two DSVs significantly decreased the activity of the enhancer (P<0.01). Another novel heterozygous DSV, g.17483557Ins, was found in both VSD patients and controls with similar frequencies (P>0.05). Taken together, our data suggested that the DSVs within the upstream enhancer of the NKX2-5 gene may contribute to a small number of VSD. Therefore, genetic studies of CHD may provide insight into designing novel therapies for adult CHD patients.
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Neurogenesis of retinal ganglion cells is not essential to visual functional recovery after optic nerve injury in adult zebrafish.
PLoS ONE
PUBLISHED: 01-18-2013
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Zebrafish central nervous system (CNS) possesses a strong neural regeneration ability to restore visual function completely after optic nerve injury (ONI). However, whether neurogenesis of retinal ganglion cell (RGC) contributes to functional recovery remains controversial. Our quantitative analysis of RGCs in different ONI models showed that almost all RGCs survived in optic nerve crush (ONC) model; while over 90% of RGCs survived in the first 2 weeks with 75% remaining after 7 weeks in optic nerve transection (ONT) model. Retrograde labeling from tectum revealed a surprising regeneration rate, with over 90% and over 50% of RGCs regrowing axons to tectum at the first week in ONC and ONT model respectively. In the latter one, the number of regenerative RGCs after 4 weeks had no significant difference from the control group. As for neurogenesis, newborn RGCs were rarely detected either by double retrograde labeling or BrdU marker. Since few RGCs died, microglia number showed a temporary increase at 3 days post injury (dpi) and a decrease at 14 dpi. Finally, myelin structure within retina kept integrity and optomotor response (OMR) test demonstrated visual functional restoration at 5 weeks post injury (wpi). In conclusion, our results have directly shown that RGC survival and axon regrowth are responsible for functional recovery after ONI in adult zebrafish.
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Determination of methotrexate and folic acid by ion chromatography with electrochemical detection on a functionalized multi-wall carbon nanotube modified electrode.
J Chromatogr A
PUBLISHED: 01-16-2013
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A simple and sensitive method was developed for simultaneous determination of methotrexate (MTX) and folic acid (FA) by ion chromatography with electrochemical detection (IC-ECD). Quaternary amine functionalized multi-wall carbon nanotubes (q-MWNTs) modified glassy carbon electrode (GCE) was used as an amperometric sensor to determine MTX and FA. The electrochemical behaviors of MTX and FA at the q-MWNTs/GCE were studied by cyclic voltammetry (CV). Results indicated that this modified electrode exhibited electrocatalytic oxidation toward MTX and FA with high sensitivity, stability and long life. Good separation of MTX and FA was demonstrated by IC on an anion-exchange column with phosphate buffer solution (PBS) as eluent. Under the optimal conditions, the linear ranges were from 0.01 to 20mg/L for both MTX and FA with correlation coefficients r ? 0.9994. The obtained detection limits (LODs) for MTX and FA were 0.2 and 0.4 ?g/L (S/N=3), respectively. The method has been successfully applied to the determination of MTX and FA in plasma and urine of patients of rheumatoid arthritis.
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A novel and functional variant within the ATG5 gene promoter in sporadic Parkinsons disease.
Neurosci. Lett.
PUBLISHED: 01-15-2013
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Parkinsons disease (PD) is one of the most common neurodegenerative diseases. Majority of PD are sporadic, for which genetic causes remain largely unknown. Alpha-synuclein, the main component of Lewy bodies, plays a central role in the PD pathogenesis. Macroautophagy is a highly conserved cellular process that digests dysfunctional macromolecules and damaged organelles. Accumulating evidence indicates that macroautophagy (hereafter referred to as autophagy) is involved in alpha-synuclein degradation. Dysregulation of autophagy has been observed in the brain tissues from PD patients and animal models. We hypothesized that change expression levels of autophagy-related genes (ATG), including ATG5, may contribute to PD. In this study, we genetically and functionally analyzed the ATG5 gene promoter in groups of sporadic PD patients and ethnic-matched healthy controls. A novel heterozygous variant, 106774459T>A, was identified in one female patient, but in none of controls, which significantly enhanced transcriptional activities of the ATG5 gene promoter. Furthermore, ATG5 gene expression level in the PD patient was significantly elevated than that in controls. Four novel heterozygous variants, 106774423C>A, 106774418C>A, 106774382C>A and 106774206G>A, were only found in controls. The variant, 106774464C>T, and SNP-106774030A>G (rs510432) were found in PD patients and controls with similar frequencies. Collectively, the variant identified in PD patient may change ATG5 protein levels and alter autophagy activities, contributing to PD onset as a risk factor.
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Genetic analysis of the ATG7 gene promoter in sporadic Parkinsons disease.
Neurosci. Lett.
PUBLISHED: 01-04-2013
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Parkinsons disease (PD) is the second most common neurodegenerative disease. The majority of PD cases are sporadic, for which genetic causes and underlying molecular mechanisms remain largely unclear. Autophagy, a highly conserved cellular process that governs the breakdown of long-lived proteins and organelles, has been involved in the degradation of ?-synuclein (?-Syn), the main component of Lewy bodies. Accumulating evidence implicates deregulation of autophagy in the development and progression of sporadic PD. Altered autophagic gene expression has been observed in the brain tissues from PD patients and animal models. We hypothesized that changes in expression levels of autophagy-related genes (ATGs), rather than mutations associated with amino acid changes, may contribute to PD onset. In this study, the ATG7 gene promoter was sequenced bi-directionally in groups of sporadic PD patients and ethnic-matched healthy controls. As predicted, four novel heterozygous variants, 11313449G>A, 11313811T>C, 11313913G>A and 11314041G>A, were identified in five PD patients, but in none of the controls, which significantly decreased transcriptional activities of the ATG7 gene promoter. Two novel heterozygous variants, 11312947G>A and 11313006C>G, were only found in controls, which did not affect transcriptional activities of the ATG7 gene promoter. The other five novel variants were found in PD patients and controls with similar frequencies. Taken together, the sequence variants within the ATG7 gene promoter identified in PD patients may change ATG7 protein levels, which in turn would influence autophagic activity, contributing to PD onset as a risk factor.
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Decreased expression of lysosomal alpha-galactosiase A gene in sporadic Parkinsons disease.
Neurochem. Res.
PUBLISHED: 05-19-2011
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Parkinsons disease (PD) is a progressive neurodegenerative disease. To date, the causal genes and variants associated with sporadic PD are largely unknown. Accumulating evidence demonstrates that autophagy delivers alpha-syncuclein proteins to lysosome for degradation and dysfunctional autophagy is involved in the PD pathogenesis. We have previously screened a group of lysosomal hydrolases and found that alpha-galactosidase A (GLA) activity is significantly decreased in the peripheral leukocytes of sporadic PD patients. In this study, GLA transcript and protein levels were semi-quantitatively examined. The GLA transcript (P = 0.020) and protein (P = 0.027) levels in the peripheral leukocytes of sporadic PD patients were significantly decreased, compared to age- and sex-matched healthy controls. Furthermore, decreased GLA gene expression levels were strongly associated with sporadic PD (OR 3.33, 95%CI 1.17-9.52, P = 0.024). Therefore, our data suggest that insufficient GLA activity may contribute to the pathogenesis of sporadic PD. The underlying molecular mechanisms remain to be determined.
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Genetic analysis of the promoter region of the GATA4 gene in patients with ventricular septal defects.
Transl Res
PUBLISHED: 05-11-2011
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Ventricular septal defects (VSDs) are the most common type of congenital heart diseases (CHDs). To date, the genetic causes for sporadic VSDs remain largely unknown. GATA transcription factor 4 (GATA4) is a zinc-finger transcription factor that is expressed in developing heart and adult cardiomyocytes. Mutations in the coding region of the GATA4 gene have been identified in CHD patients, including VSD. As the GATA4 factor is a dosage-sensitive regulator, we hypothesized that the promoter region variants of the GATA4 gene may be genetic causes of VSD. In this study, we analyzed the promoter region of the GATA4 gene by bidirectional sequencing in 172 VSD patients and 171 healthy controls. The results showed that 5 heterozygous sequence variants (NG_008177:g.4071T>C, NG_008177:g.4148C>A, NG_008177:g.4566C>T, NG_008177:g.4653G>T, and NG_008177:g.4690G>deletion) within the promoter region of the GATA gene were identified in 5 VSD patients, but in none of controls. One heterozygous sequence variant (g.4762C>A) was found only in one control, which may have no functional significance. A functional analysis revealed that the transcriptional activity of variant NG_008177:g.4566C>T was reduced significantly, whereas the transcriptional activities of the variants (NG_008177:g.4071T>C, NG_008177:g.4148C>A, NG_008177:g.4653G>T, and NG_008177:g.4690G>deletion) were increased significantly compared with the wild-type GATA4 gene promoter. As GATA4 is a dosage-sensitive regulator during development, our data suggest that these sequence variants within the promoter region of the GATA4 gene may contribute to the VSD etiology by altering its gene expression. Additional studies in experimental animals will deepen our understanding of the genetic basis of VSD and shed light on designing novel molecular therapies for adult VSD patients carrying these variants.
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Genetic analysis of lysosomal alpha-galactosidase A gene in sporadic Parkinsons disease.
Neurosci. Lett.
PUBLISHED: 05-05-2011
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Parkinsons disease (PD) is a progressive neurodegenerative disease. Majority of PD cases are sporadic, resulting from interaction of genetic and environmental factors. Accumulating evidence indicates that autophagy, which delivers alpha-synuclein to lysosomes for degradation, is involved in the PD pathogenesis. Some lysosomal hydrolases, such as glucocerebrosidase gene and ATP13A2, a lysosomal ATPase gene, have been implicated in PD. We have previously screened the activities of a group of lysosomal hydrolases in sporadic PD patients and found that alpha-galactosidase A (GLA) activities are significantly decreased. In this study, we analyzed GLA gene in sporadic PD patients by sequencing its promoter and exon regions. One single-nucleotide polymorphism (SNP) in the promoter region, rs3027580 (NG_007119.1:g.4292G>C), and two SNPs in the GLA 5-untranslated region, rs2071225 (NM_000169.2:c.-10C>T) and rs3027585 (NM_000169.2:c.-12G>A), were identified with similar frequencies in sporadic PD patients and healthy controls. A novel variant (NG_007119.1:g.4488C>G) within the promoter region, at the -573 site upstream of the translation start codon (ATG), was found in one male PD patient, but not in female PD patients or healthy controls. Our data suggest that the sequence variant may affect GLA gene expression by altering transcription factor binding sites, contributing to the pathogenesis of sporadic PD.
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LAMP-2 gene expression in peripheral leukocytes is increased in patients with coronary artery disease.
Clin Cardiol
PUBLISHED: 04-05-2011
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Coronary artery disease (CAD) is a common complex disease that is caused by interaction between genetic and environmental factors. Accumulating evidence indicates that foam cells in the atherosclerotic plaques exhibit the characteristics of lysosomal storage diseases, namely lysosomal accumulation of indigested materials. In patients with lysosomal storage diseases, lysosomal accumulation of lipids and cholesterols in atherosclerotic plaque cells has been observed. However, the roles of lysosomal hydrolases and proteins in the pathogenesis of atherosclerosis and CAD remain unclear.
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Alterations of autophagic-lysosomal system in the peripheral leukocytes of patients with myocardial infarction.
Clin. Chim. Acta
PUBLISHED: 04-01-2011
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Myocardial infarction (MI) is a common and multifactorial disease. To date, causal genes and underlying mechanisms remain largely unknown. Autophagic-lysosomal system, a highly conserved degradative process in cells, has been implicated in lipid metabolism. In this study, we explored the alterations of the autophagic-lysosomal system in patients with acute MI.
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Decreased gene expression of LC3 in peripheral leucocytes of patients with coronary artery disease.
Eur. J. Clin. Invest.
PUBLISHED: 02-25-2011
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Coronary artery disease (CAD) is a common and multifactorial arterial disease that is mainly caused by atherosclerosis. Macrophages, lymphocytes and neutrophils have been implicated in atherosclerotic plaque development. Autophagy, a highly conserved cellular process for the removal of long-lived protein and organelles, plays a variety of pathophysiological roles. However, the roles of autophagy in peripheral leucocytes in atherosclerosis and CAD have not been explored.
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Altered expression of autophagic genes in the peripheral leukocytes of patients with sporadic Parkinsons disease.
Brain Res.
PUBLISHED: 01-12-2011
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Parkinsons disease (PD) is a progressive neurodegenerative disease caused by interaction of genetic and environmental factors. To date, genetic genes and variants causing PD remain largely unknown. Autophagy is a conserved cellular process including three subtypes, macroautophagy (hereafter referred to as autophagy), microautophagy and chaperone-mediated autophagy (CMA). Although reduced CMA and induced autophagy are observed in human PD brain samples, cell and animal PD models, CMA and autophagy have not been systemically studied in sporadic PD patients. In the peripheral leukocytes of sporadic PD patients, we examined gene expression levels of lysosome-associated membrane 2 (LAMP-2), a CMA receptor and a limiting step, and microtubule-associated protein 1 light chain 3 (LC3), product of which is sequentially cleaved and lipidated to form LC3-II as an autophagosome marker. Compared to age- and sex-matched healthy controls, LAMP-2 gene expression and protein levels in sporadic PD patients were significantly decreased, which may lead to reduced CMA activity and impaired fusion of autophagosome and lysosome. LC3 gene expression and LC3-II protein levels were significantly increased in sporadic PD patients, suggesting that autophagosomes are accumulated. Our findings, decreased LAMP-2 gene expression and increased LC3 gene expression, are consistent to the previous studies with dopaminergic neuronal cells in vitro and in vivo, which may contribute to the pathogenesis of sporadic PD by altering CMA and autophagy activities. The genetic causes leading to decreased LAMP-2 gene expression need further investigation and genetic or pharmacological restoration of LAMP-2 might be a novel strategy for treating PD patients.
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Ion chromatography combined with online electrochemical derivatization and fluorescence detection for the determination of carbamazepine in human plasma.
Talanta
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This paper describes the determination of carbamazepine (CBZ) in human plasma using ion chromatography combined with online electrochemical derivatization and fluorescence detection. Separation of CBZ with anion exchange column was demonstrated to be feasible using either basic (10 mM NaOH) or acidic (0.1 M H(3)PO(4)) reagent with a small amount of acetonitrile (ACN) added as eluent. Electrochemical derivatization of CBZ into a strongly fluorescent product, which could be carried out only under the acidic condition, was investigated via the previously reported electrolytic cell (EC), as well as two modes of acidification. The linear range of CBZ for human plasma was between 10-2000 ?g L(-1) under the optimized experimental conditions. The limit of detection (LOD, S/N=3) was 1.3 ?g L(-1) and the relative standard deviation (RSD, n=7) was 2.6%. Better sensitivity and selectivity of the present method were demonstrated in comparison with ion chromatography with ultraviolet detection (IC-UV). The spiked recoveries of CBZ in 2 human plasma samples were 78.5 and 114%, respectively.
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Genetic analysis of the TBX3 gene promoter in ventricular septal defects.
Gene
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Congenital heart disease (CHD) is the most common birth defect in humans. Genetic causes and underlying molecular mechanisms for CHD remain largely unknown. T-box transcription factor 3 (TBX3) plays a critical role in the developing heart in a dose-dependent manner. TBX3 represses chamber myocardial gene expression. Mutations in TBX3 gene have been associated to ulnar-mammary syndrome with multiple developmental defects, including cardiac defects. We hypothesized that the sequence variants within TBX3 gene promoter that change TBX3 levels may mediate CHD development. In this study, TBX3 gene promoter was genetically analyzed in large cohorts of patients with ventricular septal defect (VSD) (n=325) and ethnic-matched healthy controls (n=359). Seven sequence variants, including two single-nucleotide polymorphisms (g.3863 C>T and g.4095G>T), three novel deletions (g.4433_4435del, g.4672_4675del and g.4820_4821del) and two novel insertions (g.3913_3914ins and g.4735_4736ins), were identified. Five of the seven variants were identified in VSD patients and controls with similar frequencies. Two other variants were found only in controls. These variants, which were observed in high frequencies, did not modify or interrupt the critical binding site for basic transcription factors. Taken together, these results suggested that the sequence variants within the TBX3 gene promoter did not contribute to VSD etiology.
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Amine-functionalized zirconium metal-organic framework as efficient visible-light photocatalyst for aerobic organic transformations.
Chem. Commun. (Camb.)
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An amine-functionalized zirconium metal-organic framework (MOF) was used as a visible-light photocatalyst for selective aerobic oxygenation of various organic compounds including alcohols, olefins and cyclic alkanes, at high efficiency and high selectivity. This study shows the great potential for design and application of MOF-based photocatalysts.
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Genetic analysis of the SIRT1 gene promoter in myocardial infarction.
Biochem. Biophys. Res. Commun.
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Myocardial infarction (MI) is a restrictive phenotype of coronary artery disease. To date, a group of genes and genetic loci have been associated to MI. However, the genetic causes and underlying molecular mechanisms for MI remain largely unknown. SIRT1, one of highly conserved NAD-dependent class III deacetylases, has been involved in several cellular processes and implicated in human diseases. Autophagy is one of major cellular degradative pathways, which plays important roles in lipid metabolism. Recent studies have shown that SIRT1 deacetylates autophagy-related genes, and the expressions of autophagic genes are altered in MI patients. Accordingly, we hypothesized that SIRT1 may be linked to the MI pathogenesis. In this study, the SIRT1 gene promoter were genetically analyzed in large cohorts of MI patients (n = 327) and controls (n = 358). The results showed that six single-nucleotide polymorphisms and 14 sequence variants were identified. Among these, five novel heterozygous variants (g.69643743Ins, g.69643840Ins, g.69643903G > C, g.69644235G > C and g.69644353G > T) and one single-nucleotide polymorphism (rs35706870) were identified in MI patients, but in none of controls. Moreover, five novel heterozygous variants (g.69643672G > A, g.69644226C > T, g.69644278A > G, g.69644408G > A and g.69644408G > T) were only found in controls. The rest variants were found in MI patients and controls with similar frequencies. Taken together, the variants identified in MI patients may alter the transcriptional activities of SIRT1 gene promoter, which may change SIRT1 levels, contributing to the MI pathogenesis as a risk factor.
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Genetic analysis of the SIRT1 gene promoter in ventricular septal defects.
Biochem. Biophys. Res. Commun.
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Mutations in cardiac transcription factor genes, such as GATA-4, NKX2-5 and TBX5 genes, have been associated to the patients with familial and isolated congenital heart disease (CHD). Little work has been done on the epigenetic causes for CHD. Sirtuis are highly conserved NAD-dependent class III deacetylases. In mammals, there are seven members of surtuin family, SIRT1-SIRT7. SIRT1, the closest to yeast Sir2, has deacetylase activity and ADP-ribosyltransferase activity. SIRT1 has been involved in many cellular processes and implicated in human diseases, such as obesity, type 2 diabetes, cancer and neurodegenerative diseases. We hypothesized that altered levels of SIRT1 gene expression, rather than mutations in SIRT1 gene, may contribute to the human diseases. In this study, we genetically analyze the SIRT1 gene promoter in patients with ventricular septal defects (VSD) (n=333) and ethic-matched healthy controls (n=348). In all, six single-nucleotide polymorphisms (SNPs) and twelve heterozygous sequence variants were identified. Four novel heterozygous variants, g.69643693A>G, g.69643963A>T, g.69643971G>A and g.69644366Ins, were found in six VSD patients, but in none of controls. Six SNPs and variants, g.69643707A>C (rs35706870), g.69643874C>A, g.69644209C>G, g.69644213G>A, g.69644268T>A and g.69644441G>A, were only identified in controls. The other SNPs and variants were found in both groups with similar frequencies. Therefore, the variants within the SIRT1 gene promoter identified in VSD patients may alter the transcriptional activities of SIRT1 gene promoter. Changed SIRT1 protein levels may contribute to the VSD etiology by affecting the activities of its substrates.
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Genetic analysis of the LAMP-2 gene promoter in patients with sporadic Parkinsons disease.
Neurosci. Lett.
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Parkinsons disease (PD) is a common neurodegenerative disease in the people of over 65. Majority of PD is sporadic, which is caused by interaction of genetic and environmental factors. To date, genetic causes and underlying molecular mechanisms for sporadic PD remain largely unknown. Autophagy is a conserved cellular degradative process, consisting of macroautophagy, microautophagy and chaperone-mediated autophagy (CMA). Macroautophagy (hereafter referred to as autophagy) and CMA are involved in the degradation of alpha-synuclein, a critical protein in the PD pathogenesis. Previous studies with brain tissues and leukocytes have shown that the expression levels of lysosome-associated membrane-2 (LAMP-2) gene are significantly decreased in PD patients. In this study, we genetically and functionally analyze the promoter region of LAMP-2 gene in sporadic PD patients. Two novel sequence variants and two single nucleotide polymorphisms (SNPs) were identified. The heterozygous variant, g.4127A>C, which was only found in one female PD patient, significantly reduced the transcriptional activities of LAMP-2 gene promoter. The hemizygous variant, g.5038G>A, which was only found in one male control, enhanced the transcriptional activities of LAMP-2 gene promoter. No significant difference in frequencies of the SNPs, rs42900 (g.4569A>C) and rs28603270 (g.4760T>G), was observed between PD patients and controls. Collectively, the sequence variants within the LAMP-2 gene promoter may be linked to the PD onset by changing LAMP-2 protein levels and impairing autophagy and CMA activities.
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Genetic analysis of an enhancer of the NKX2-5 gene in ventricular septal defects.
Gene
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Congenital heart disease (CHD) is one of the most common birth defects in humans. Mutations in cardiac transcription factor genes, such as GATA4, NKX2-5 and TBX5 genes, have been associated to a small portion of familial and isolated CHD cases. NKX2-5, a highly conserved homeobox gene, is expressed in the developing heart. During embryonic development, NKX2-5 plays pivotal roles in specifying cardiac progenitors, cardiac morphogenesis, cardiomyocyte differentiation and conduction system development. Numerous mutations in NKX2-5 gene have been reported in CHD patients, including atrial septal defect, ventricular septal defect (VSD) and tetrology of Fallot. We have previously identified the sequence variants within the NKX2-5 gene promoter in VSD patients. As several studies have revealed that the NKX2-5 gene is regulated by a complex module involving promoter and multiple independent cardiac enhancers, one of which is located between -3500 bp and -2500 bp upstream to the transcription start site, we hypothesized that the variants within the cardiac enhancer may contribute to CHD. In this study, we genetically analyzed the enhancer of NKX2-5 gene in large cohorts of VSD patients (n=322) and controls (n=336). The results showed that three novel variants, g.1467G>A, g.1487 Ins with a 13 bp insertion and g.1515 Ins with a 6 bp insertion, were identified within the enhancer element in both VSD patients and controls with similar frequencies (P>0.05). Therefore, our data suggested that the enhancer of NKX2-5 gene may not be a contributor to the VSD etiology. Other regulatory elements of the NKX2-5 gene will be further analyzed in CHD patients.
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Genetic analysis of the TBX1 gene promoter in ventricular septal defects.
Mol. Cell. Biochem.
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Congenital heart disease (CHD) is the most common birth defects in humans. The genetic causes for CHD remain largely unknown. T-box transcription factor 1 (TBX1), a dosage-sensitive regulator, plays a critical role in the heart development. Mutations in the coding regions of TBX1 gene have been associated to 22q11 deletion syndrome with cardiac defects and isolated CHD cases, including ventricular septal defect (VSD). To date, TBX1 gene promoter region has not been analyzed and reported in CHD patients. We hypothesized that the sequence variants within TBX1 gene promoter region may change TBX1 levels and mediate CHD development. In this study, the promoter regions of TBX1 gene were genetically and functionally analyzed in 280 VSD patients and 267 healthy controls. Two novel heterozygous variants, g.4353C>T and g.4510A>C, were found in two VSD patients, but in none of controls. The single-nucleotide polymorphism-rs41260844, g.4199T>C, was found more frequent in VSD patients than controls (P < 0.01). Functional analyses revealed that these sequence variants significantly enhanced transcriptional activities of TBX1 gene promoter. Therefore, the sequence variants within TBX1 gene promoter may contribute to the VSD etiology by altering the expression levels of TBX1 gene. Pharmaceutical or genetic manipulation of TBX1 gene expression may provide a novel personalized therapy to prevent and treat late cardiac complications for the adult CHD patients carrying these variants.
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[Determination of cations in wines and beverages based on capillary ion chromatography].
Se Pu
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A new method for the determination of five cations (sodium, ammonium, potassium, magnesium and calcium) in wines and beverages was developed and validated based on capillary ion chromatography. With a capillary ion exchange column (IonPac CS12A, 250 mm x 0.4 mm, 8 microm) and 18 mmol/L methanesulfonic acid (MSA) elution, the five cations can be well separated in 15 min. After suppression with a capillary suppressor (CCES 300), the background was much decreased, and the sensitivities of the cations were greatly improved. For the milky tea, acetonitrile was added into the sample solution to deposit the proteins. With the pretreatment of an OnGuard RP cartridge to remove hydrophobic substances in the sample, the developed method can be applied to the determination of the cations in wines and beverages. The calibration curves of peak area versus concentration gave correlation coefficients more than 0.9997 for these cations. Average recoveries were between 95.2% - 103.3%. The method is suitable for the determination of alkali metals and alkaline-earth metals in wines and beverages. The capillary ion chromatography provides analysis with less solvent consumption and better column efficiency, also possesses the advantages of high sensitivity, good selectivity and environmental friendly.
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Age-related decrease of the LAMP-2 gene expression in human leukocytes.
Clin. Biochem.
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Autophagy is a highly conserved degradation pathway in cells, which has been involved in many physiological processes and implicated in human age-related diseases. However, autophagy activities have not been systemically investigated with human tissues and cells.
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Studies on the binding behavior of prodigiosin with bovine hemoglobin by multi-spectroscopic techniques.
Spectrochim Acta A Mol Biomol Spectrosc
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In this article, the interaction mechanism of prodigiosin (PG) with bovine hemoglobin (BHb) is studied in detail using various spectroscopic technologies. UV-vis absorption and fluorescence spectra demonstrate the interaction process. The Stern-Volmer plot and the time-resolved fluorescence study suggest the quenching mechanism of fluorescence of BHb by PG is a static quenching procedure, and the hydrophobic interactions play a major role in binding of PG to BHb. Furthermore, synchronous fluorescence studies, Fourier transform infrared (FTIR) and circular dichroism (CD) spectra reveal that the conformation of BHb is changed after conjugation with PG.
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Fabrication of electrolytic cell for online post-column electrochemical derivatization in ion chromatography.
Anal. Chim. Acta
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An electrolytic cell (EC), composed of two ruthenium-plated titanium electrodes separated by cation-exchange membranes, was fabricated and evaluated for online postcolumn derivatization in ion chromatography (IC). Folic acid (FA) and methotrexate (MTX) were preliminarily used as prototype analytes to test the performance of EC. After separation by an anion exchange column, FA and MTX, which emit very weak fluorescence when excited, were electrochemically oxidized online in the anode chamber of the EC. The compounds with strong fluorescence, which are oxidation products, were detected by the fluorescence detector. The phosphate buffer solution (100 mM KH(2)PO(4)) served as an optimal eluent for anion exchange chromatographic separation and a suitable supporting electrolyte for electro-oxidation, leading to ideal compatibility between IC separation and the postcolumn electrochemical derivatization. For the presently proposed method, the linear ranges were from 0.01 mg L(-1) to 5 mg L(-1) for both FA and MTX. The detection limits of FA and MTX were 1.8 and 2.1 ?g L(-1), and the relative standard deviations (RSD, n=7) were 2.9% and 3.6%, respectively. The method was applied for the simultaneous determination of FA and MTX in the plasma of patients being treated for rheumatoid arthritis. The determination of MTX in the urine of the patients of diffuse large B cell lymphoma was also demonstrated.
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Genetic analysis of SIRT1 gene promoter in sporadic Parkinsons disease.
Biochem. Biophys. Res. Commun.
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Parkinsons disease (PD) is one of the most common neurodegenerative diseases. To date, genetic causes and underlying molecular mechanisms for sporadic PD remain largely unknown. Sirtuis are highly conserved NAD-dependent class III deacetylases. SIRT1, the closest to yeast Sir2, has deacetylase activity and ADP-ribosyltransferase activity. SIRT1 gene has been connected to many cellular processes and implicated in human diseases, such as obesity, type 2 diabetes, cancer and neurodegenerative diseases. Studies in animal model have also associated SIRT1 with aggregation of alpha-synuclein, a critical protein in the PD pathogenesis. We hypothesized that the genetic variants within the regulatory regions of SIRT1 gene that repress its gene expression, rather than mutations in its coding region that abolish SIRT1 function, may contribute to PD as a risk factor. In this study, we genetically analyzed the promoter region of SIRT1 gene in sporadic PD patients and ethic-matched healthy controls. Three novel heterozygous sequence variants, g.69644133C>G, g.69644213G>A and g.69644351G>A, were identified in PD patients, but in none of controls, which may alter the transcriptional activities of SIRT1 gene promoter, resulting in reduced SIRT1 levels. One novel heterozygous variant, g.69644219G>A, linked with single-nucleotide polymorphism - g.69644217A>C (rs932658), was only found in one control, which may have no functional activity. Therefore, our results suggested that genetic variants within the SIRT1 gene promoter may repress SIRT1 gene expression, contributing to PD as a risk factor.
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Genetic and functional analysis of the NKX2-5 gene promoter in patients with ventricular septal defects.
Pediatr Cardiol
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The ventricular septal defect (VSD) is the most common type of congenital heart disease (CHD). The morbidity and mortality of CHD patients are significantly higher due to late cardiac complications, likely caused by genetic defects. Mutations in cardiac transcription factor genes such as GATA-4, TBX5, and NKX2-5 have been implicated in CHD cases. The NKX2-5 gene, a homeobox gene, is expressed in the developing heart and the adult heart. Because NKX2-5 is a dosage-sensitive regulator during embryonic development, the authors hypothesized that the expression levels of the NKX2-5 gene rather than the mutant protein may play important roles in CHD. In this study, the promoter regions and exon regions of the NKX2-5 gene were bidirectionally sequenced in large cohorts of VSD patients and healthy control subjects. The results showed that a novel sequence variant (g.4574c>deletion), found only in one VSD patient, and a single nucleotide polymorphism (rs118026695), the frequency of which was significantly higher in VSD patients, were identified within the promoter region. Functional analysis confirmed that these sequence variants significantly enhanced the transcriptional activities of the NKX2-5 gene promoter, altering the expression of the NKX2-5 gene and the cardiac gene regulatory network. In addition, a synonymous mutation in the second exon of the NKX2-5 gene was identified in one VSD patient, which may affect the translation process. Therefore, the authors data provide supportive evidence that mutations in the coding region of the NKX2-5 gene and sequence variants within its promoter region may be among the contributors to the CHD etiology.
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Lanthanide-doped Na(x)ScF(3+x) nanocrystals: crystal structure evolution and multicolor tuning.
J. Am. Chem. Soc.
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Rare-earth-based nanomaterials have recently drawn considerable attention because of their unique energy upconversion (UC) capabilities. However, studies of Sc(3+)-based nanomaterials are still absent. Herein we report the synthesis and fine control of Na(x)ScF(3+x) nanocrystals by tuning of the ratio of oleic acid (OA, polar surfactant) to 1-octadecene (OD, nonpolar solvent). When the OA:OD ratio was increased from low (3:17) to high (3:7), the nanocrystals changed from pure monoclinic phase (Na(3)ScF(6)) to pure hexagonal phase (NaScF(4)) via a transition stage at an intermediate OA:OD ratio (3:9) where a mixture of nanocrystals in monoclinic and hexagonal phases was obtained and the coexistence of the two phases inside individual nanocrystals was also observed. More significantly, because of the small radius of Sc(3+), Na(x)ScF(3+x):Yb/Er nanocrystals show different UC emission from that of NaYF(4):Yb/Er nanocrystals, which broadens the applications of rare-earth-based nanomaterials ranging from optical communications to disease diagnosis.
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Genetic analysis of the TBX20 gene promoter region in patients with ventricular septal defects.
Gene
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Congenital heart disease (CHD) is the most common human birth defect. The morbidity and mortality of CHD patients are significantly higher than normal population even after surgical correction of cardiac defects, which is likely caused by genetic defects. To date, genetic causes for CHD remain largely unknown. TBX20 gene encodes a T-box transcription factor that plays pivotal roles in cardiac morphogenesis and is required for maintaining adult heart function and maturation. Mutations in TBX20 gene have been reported in familiar and sporadic CHD patients. However, the promoter region of TBX20 gene has not been genetically analyzed in CHD patients. As TBX20 functions as a dosage-dependent regulator during the heart development, we hypothesized that the sequence variants within the promoter region of the TBX20 gene may contribute to CHD. In this study, we bi-directionally sequenced the promoter region of the TBX20 gene in 265 patients with ventricular septal defects (VSD) and 242 controls. Within the promoter region of the TBX20 gene, one single-nucleotide polymorphism (SNP), rs336284 (g.4740T>C), and one novel heterozygous variant g.4741 G>A, which was linked with rs336284 (g.4740 T>C), were found in both VSD patients and controls with similar frequencies. A novel heterozygous variant, g.4932 G>A, was found in one VSD patient, but in none of controls, which significantly inhibited the transcriptional activities of TBX20 gene promoter, suggesting that the variant may contribute to the VSD etiology. Therefore, our data provides new information with respect to TBX20 gene mutations in CHD patients.
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Determination of phenols with ion chromatography-online electrochemical derivatization based on porous electrode-fluorescence detection.
J Chromatogr A
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The current study describes the determination of phenols using ion chromatography-online electrochemical derivatization-fluorescence detection (IC/ED/FD). Six model phenols including 4-methylphenol (pMP), 2, 4-dimethylphenol (DMP), 4-tert-butylphenol (TBP), 4-hydroxylphenolacetic acid (pHPA), 4-acetamidophenol (pAAP), and phenol (P) were well separated on an anion-exchange column under ion exchange mode using NaOH with small amount of acetonitrile added as eluent. Online electrochemical derivatization performed via a laboratory-made electrolytic cell (EC), consisting of porous titanium electrode and cation-exchange membrane (CEM), allows the oxidation products that are strongly fluorescent to be detected by the fluorescence detector. NaOH eluent used in the present method matches well with the maximal fluorescence intensity obtained at alkaline condition for oxidized phenols, thus the addition of specific buffer solution after oxidation encountered in previous report could be eliminated. This process leads to a simplified procedure. The proposed method was sensitive to the limits of detection in the range of 0.4 ?g/L and 3.8 ?g/L and the limits of quantification between 1.2 ?g/L and 13 ?g/L due to the strong electro-oxidation capacity of porous titanium electrode, as well as the implementation of time-programmed potential over EC. The linear ranges were 2.0-1.0 × 10(4) ?g/L for pAAP and DMP, and 10-1.0 × 10(4) ?g/L for P, pMP, pHPA, and TBP, respectively. The relative standard deviations range from 0.9% to 4.8%. The utilization of the method was demonstrated by the analysis of real samples. The average spiked recoveries of target analytes in pool water were 81.0-118%.
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