Demethylation of arsenic limits its volatilization in fungi

International Nuclear Information System (INIS)

Su, Shiming; Zeng, Xibai; Feng, Qiufen; Bai, Lingyu; Zhang, Lili; Jiang, Sheng; Li, Aiguo; Duan, Ran; Wang, Xiurong; Wu, Cuixia; Wang, Yanan

2015-01-01

Arsenic (As) biomethylation is increasingly being regarded as a promising method to volatize As from the environment; however, the As volatilization efficiency of most microorganisms is low. Here, the speciation transformation of dimethylarsinic acid (DMA) as an important methylation intermediate in the cells of Fusarium oxysporum CZ-8F1, Penicillium janthinellum SM-12F4, and Trichoderma asperellum SM-12F1 were investigated. These fungal strains have been certified to volatilize As from As-loaded environment. In situ X-ray absorption near edge structure (XANES) indicated that demethylation of DMA with methylarsonic acid (MMA), arsenate [As(V)], and arsenite [As(III)] as intermediates or products occurred in fungal cells after exposure to DMA for 15 days. 36.7–55.7% of the original DMA could lose one or two methyl groups and be changed into MMA or inorganic As. Chromatographic separation of the cell lysates also supported these findings. Thus it comes that demethylation might be a remarkable internal factor limiting As volatilization efficiency. - Highlights: • XAS and chromatographic separation were used to study the speciation change of DMA. • DMA demethylation with MMA, As(V), and As(III) as products occurred in fungal cells. • Demethylation might be responsible for the limited volatilization efficiency of As. - Demethylation might be responsible for the limited methylation efficiency of As

EG-13GENOME-WIDE METHYLATION ANALYSIS IDENTIFIES GENOMIC DNA DEMETHYLATION DURING MALIGNANT PROGRESSION OF GLIOMAS

Science.gov (United States)

Saito, Kuniaki; Mukasa, Akitake; Nagae, Genta; Aihara, Koki; Otani, Ryohei; Takayanagi, Shunsaku; Omata, Mayu; Tanaka, Shota; Shibahara, Junji; Takahashi, Miwako; Momose, Toshimitsu; Shimamura, Teppei; Miyano, Satoru; Narita, Yoshitaka; Ueki, Keisuke; Nishikawa, Ryo; Nagane, Motoo; Aburatani, Hiroyuki; Saito, Nobuhito

2014-01-01

Low-grade gliomas often undergo malignant progression, and these transformations are a leading cause of death in patients with low-grade gliomas. However, the molecular mechanisms underlying malignant tumor progression are still not well understood. Recent evidence indicates that epigenetic deregulation is an important cause of gliomagenesis; therefore, we examined the impact of epigenetic changes during malignant progression of low-grade gliomas. Specifically, we used the Illumina Infinium Human Methylation 450K BeadChip to perform genome-wide DNA methylation analysis of 120 gliomas and four normal brains. This study sample included 25 matched-pairs of initial low-grade gliomas and recurrent tumors (temporal heterogeneity) and 20 of the 25 recurring tumors recurred as malignant progressions, and one matched-pair of newly emerging malignant lesions and pre-existing lesions (spatial heterogeneity). Analyses of methylation profiles demonstrated that most low-grade gliomas in our sample (43/51; 84%) had a CpG island methylator phenotype (G-CIMP). Remarkably, approximately 50% of secondary glioblastomas that had progressed from low-grade tumors with the G-CIMP status exhibited a characteristic partial demethylation of genomic DNA during malignant progression, but other recurrent gliomas showed no apparent change in DNA methylation pattern. Interestingly, we found that most loci that were demethylated during malignant progression were located outside of CpG islands. The information of histone modifications patterns in normal human astrocytes and embryonal stem cells also showed that the ratio of active marks at the site corresponding to DNA demethylated loci in G-CIMP-demethylated tumors was significantly lower; this finding indicated that most demethylated loci in G-CIMP-demethylated tumors were likely transcriptionally inactive. A small number of the genes that were upregulated and had demethylated CpG islands were associated with cell cycle-related pathway. In

Methylmercury decomposition in sediments and bacterial cultures: Involvement of methanogens and sulfate reducers in oxidative demethylation

International Nuclear Information System (INIS)

Oremland, R.S.; Culbertson, C.W.; Winfrey, M.R.

1991-01-01

The biogeochemical cycling of mercury has received considerable attention because of the toxicity of methylmercury, its bioaccumulation in biota, and its biomagnification in aquatic food chains. The formation of methylmercury is mediated primarily by microorganisms. Demethylation of monomethylmercury in freshwater and estuarine sediments and in bacterial cultures was investigated with 14 CH 3 HgI. Under anaerobiosis, results with inhibitors indicated partial involvement of both sulfate reducers and methanogens, the former dominated estuarine sediments, while both were active in freshwaters. Aerobes were the most significant demethylators in estuarine sediments, but were unimportant in freshwater sediments. Products of anaerobic demthylation were mainly 14 CO 2 as well as lesser amounts of 14 CH 4 . Acetogenic activity resulted in fixation of some 14 CO 2 produced from 14 CH 3 HgI into acetate. Aerobic demethylation in estuarine sediments produced only 14 CH 4 , while aerobic demethylation in freshwater sediments produced small amounts of both 14 CH 4 and 14 CO 2 . Two species of Desulfovibrio produced only traces of 14 CH 4 from 14 CH 3 HgI, while a culture of a methylotrophic methanogen formed traces of 14 CO 2 and 14 CH 4 when grown on trimethylamine in the presence of the 14 CH 3 HgI. These results indicate that both aerobes and anaerobes demethylate mercury in sediments, but that either group may dominate in a particular sediment type. Aerobic demethylation in the estuarine sediments appeared to proceed by the previously characterized organomercurial-lyase pathway, because methane was the sole product. This indicates the presence of an oxidative pathway, possibly one in which methylmercury serves as an analog of one-carbon substrates

Global DNA hypermethylation-associated cancer chemotherapy resistance and its reversion with the demethylating agent hydralazine

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Benitez-Bribiesca Luis

2006-08-01

Full Text Available Abstract Background The development of resistance to cytotoxic chemotherapy continues to be a major obstacle for successful anticancer therapy. It has been shown that cells exposed to toxic concentrations of commonly used cancer chemotherapy agents develop DNA hypermetylation. Hence, demethylating agents could play a role in overcoming drug resistance. Methods MCF-7 cells were rendered adriamycin-resistant by weekly treatment with adriamycin. Wild-type and the resulting MCF-7/Adr cells were analyzed for global DNA methylation. DNA methyltransferase activity and DNA methyltransferase (dnmt gene expression were also determined. MCF-7/Adr cells were then subjected to antisense targeting of dnmt1, -3a, and -b genes and to treatment with the DNA methylation inhibitor hydralazine to investigate whether DNA demethylation restores sensitivity to adriamycin. Results MCF-7/Adr cells exhibited the multi-drug resistant phenotype as demonstrated by adriamycin resistance, mdr1 gene over-expression, decreased intracellular accumulation of adriamycin, and cross-resistance to paclitaxel. The mdr phenotype was accompanied by global DNA hypermetylation, over-expression of dnmt genes, and increased DNA methyltransferase activity as compared with wild-type MCF-7 cells. DNA demethylation through antisense targeting of dnmts or hydralazine restored adriamycin sensitivity of MCF-7/Adr cells to a greater extent than verapamil, a known inhibitor of mdr protein, suggesting that DNA demethylation interferes with the epigenetic reprogramming that participates in the drug-resistant phenotype. Conclusion We provide evidence that DNA hypermethylation is at least partly responsible for development of the multidrug-resistant phenotype in the MCF-7/Adr model and that hydralazine, a known DNA demethylating agent, can revert the resistant phenotype.

Theoretical study on the N-demethylation mechanism of theobromine catalyzed by P450 isoenzyme 1A2.

Science.gov (United States)

Tao, Jing; Kang, Yuan; Xue, Zhiyu; Wang, Yongting; Zhang, Yan; Chen, Qiu; Chen, Zeqin; Xue, Ying

2015-09-01

Theobromine, a widely consumed pharmacological active substance, can cause undesirable muscle stiffness, nausea and anorexia in high doses ingestion. The main N-demethylation metabolic mechanism of theobromine catalyzed by P450 isoenzyme 1A2 (CYP1A2) has been explored in this work using the unrestricted hybrid density functional method UB3LYP in conjunction with the LACVP(Fe)/6-31G (H, C, N, O, S, Cl) basis set. Single-point calculations including empirical dispersion corrections were carried out at the higher 6-311++G** basis set. Two N-demethylation pathways were characterized, i.e., 3-N and 7-N demethylations, which involve the initial N-methyl hydroxylation to form carbinolamines and the subsequent carbinolamines decomposition to yield monomethylxanthines and formaldehydes. Our results have shown that the rate-limiting N-methyl hydroxylation occurs via a hydrogen atom transfer (HAT) mechanism, which proceeds in a spin-selective mechanism (SSM) in the gas phase. The carbinolamines generated are prone to decomposition via the contiguous heteroatom-assisted proton-transfer. Strikingly, 3-N demethylation is more favorable than 7-N demethylation due to its lower free energy barrier and 7-methylxanthine therefore is the optimum product reported for the demethylation of theobromine catalyzed by CYP1A2, which are in good agreement with the experimental observation. This work has first revealed the detail N-demethylation mechanisms of theobromine at the theoretical level. It can offer more significant information for the metabolism of purine alkaloid. Copyright © 2015 Elsevier Inc. All rights reserved.

Fast Curing Bio-Based Phenolic Resins via Lignin Demethylated under Mild Reaction Condition

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Jiongjiong Li

2017-09-01

Full Text Available Demethylation technique has been used to enhance lignin reactivity for preparation of phenolic resins. However, the demethylation efficiency and the demethylated lignin (DL reactivity were still unsatisfactory. To improve the demethylation efficiency, alkali lignin was demethylated under different mild conditions using sodium sulfite as a catalyst. Lignin and DL were characterized by 1H-NMR (nuclear magnetic resonance and Fourier transform infrared (FT-IR spectroscopy to determine the demethylation mechanism. With the demethylation of lignin, the methoxyl group content decreased from 1.93 m mol/g to 1.09 m mol/g, and the phenolic hydroxyl group content increased from 0.56 m mol/g to 0.82 m mol/g. These results revealed that methoxyl groups were attacked by SO32−, and some methoxyl groups were converted to phenolic hydroxyl groups by a nucleophilic substitution reaction, generating DL with high reactivity. The chemical properties of lignin-based phenolic resins were studied by 13C-NMR and FT-IR spectroscopy, and their physical properties were also investigated. The results indicated that lignin-based phenolic resins exhibited faster curing rate and shorter gel time. In addition, the bonding strength increased from 0.92 MPa to 1.07 MPa, and the formaldehyde emission decreased from 0.58 mg/L to 0.22 mg/L after lignin demethylated at the optimum condition.

Arsenic Demethylation by a C·As Lyase in Cyanobacterium Nostoc sp. PCC 7120.

Science.gov (United States)

Yan, Yu; Ye, Jun; Xue, Xi-Mei; Zhu, Yong-Guan

2015-12-15

Arsenic, a ubiquitous toxic substance, exists mainly as inorganic forms in the environment. It is perceived that organoarsenicals can be demethylated and degraded into inorganic arsenic by microorganisms. Few studies have focused on the mechanism of arsenic demethylation in bacteria. Here, we investigated arsenic demethylation in a typical freshwater cyanobacterium Nostoc sp. PCC 7120. This bacterium was able to demethylate monomethylarsenite [MAs(III)] rapidly to arsenite [As(III)] and also had the ability to demethylate monomethylarsenate [MAs(V)] to As(III). The NsarsI encoding a C·As lyase responsible for MAs(III) demethylation was cloned from Nostoc sp. PCC 7120 and heterologously expressed in an As-hypersensitive strain Escherichia coli AW3110 (ΔarsRBC). Expression of NsarsI was shown to confer MAs(III) resistance through arsenic demethylation. The purified NsArsI was further identified and functionally characterized in vitro. NsArsI existed mainly as the trimeric state, and the kinetic data were well-fit to the Hill equation with K0.5 = 7.55 ± 0.33 μM for MAs(III), Vmax = 0.79 ± 0.02 μM min(-1), and h = 2.7. Both of the NsArsI truncated derivatives lacking the C-terminal 10 residues (ArsI10) or 23 residues (ArsI23) had a reduced ability of MAs(III) demethylation. These results provide new insights for understanding the important role of cyanobacteria in arsenic biogeochemical cycling in the environment.

Biochemistry and occurrence of O-demethylation in plant metabolism

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Jillian Hagel

2010-07-01

Full Text Available Demethylases play a pivitol role in numerous biological processes from covalent histone modification and DNA repair to specialized metabolism in plants and microorganisms. Enzymes that catalyze O- and N-demethylation include 2-oxoglutarate (2OG/Fe(II-dependent dioxygenases, cytochromes P450, Rieske-domain proteins and flavin adenine dinucleotide (FAD-dependent oxidases. Proposed mechanisms for demethylation by 2OG/Fe(II-dependent enzymes involve hydroxylation at the O- or N-linked methyl group followed by formaldehyde elimination. Members of this enzyme family catalyze a wide variety of reactions in diverse plant metabolic pathways. Recently, we showed that 2OG/Fe(II-dependent dioxygenases catalyze the unique O-demethylation steps of morphine biosynthesis in opium poppy, which provides a rational basis for the widespread occurrence of demethylases in benzylisoquinoline alkaloid metabolism.

Adoptive cancer immunotherapy using DNA-demethylated T helper cells as antigen-presenting cells

DEFF Research Database (Denmark)

Kirkin, Alexei F.; Dzhandzhugazyan, Karine N.; Guldberg, Per

2018-01-01

In cancer cells, cancer/testis (CT) antigens become epigenetically derepressed through DNA demethylation and constitute attractive targets for cancer immunotherapy. Here we report that activated CD4+ T helper cells treated with a DNA-demethylating agent express a broad repertoire of endogenous CT...... antigens and can be used as antigen-presenting cells to generate autologous cytotoxic T lymphocytes (CTLs) and natural killer cells. In vitro, activated CTLs induce HLA-restricted lysis of tumor cells of different histological types, as well as cells expressing single CT antigens. In a phase 1 trial of 25...... patients with recurrent glioblastoma multiforme, cytotoxic lymphocytes homed to the tumor, with tumor regression ongoing in three patients for 14, 22, and 27 months, respectively. No treatment-related adverse effects were observed. This proof-of-principle study shows that tumor-reactive effector cells can...

Oxidative demethylation of lanosterol in cholesterol biosynthesis: accumulation of sterol intermediates

International Nuclear Information System (INIS)

Shafiee, A.; Trzaskos, J.M.; Paik, Y.K.; Gaylor, J.L.

1986-01-01

With [ 3 H-24,25]-dihydrolanosterol as substrate, large-scale metabolic formation of intermediates of lanosterol demethylation was carried out to identify all compounds in the metabolic process. Utilizing knowledge of electron transport of lanosterol demethylation, we interrupted the demethylation reaction allowing accumulation and confirmation of the structure of the oxygenated intermediates lanost-8-en-3 beta,32-diol and 3 beta-hydroxylanost-8-en-32-al, as well as the demethylation product 4,4-dimethyl-cholesta-8,14-dien-3 beta-ol. Further metabolism of the delta 8.14-diene intermediate to a single product 4,4-dimethyl-cholest-8-en-3 beta-ol occurs under interruption conditions in the presence of 0.5 mM CN-1. With authentic compounds, each intermediate has been rigorously characterized by high performance liquid chromatography and gas-liquid chromatography plus mass spectral analysis of isolated and derivatized sterols. Intermediates that accumulated in greater abundance were further characterized by ultraviolet, 1 H-NMR, and infrared spectroscopy of the isolated sterols

JMJD1B Demethylates H4R3me2s and H3K9me2 to Facilitate Gene Expression for Development of Hematopoietic Stem and Progenitor Cells

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Sihui Li

2018-04-01

Full Text Available Summary: The arginine methylation status of histones dynamically changes during many cellular processes, including hematopoietic stem/progenitor cell (HSPC development. The arginine methyltransferases and the readers that transduce the histone codes have been defined. However, whether arginine demethylation actively occurs in cells and what enzyme demethylates the methylarginine residues during various cellular processes are unknown. We report that JMJD1B, previously identified as a lysine demethylase for H3K9me2, mediates arginine demethylation of H4R3me2s and its intermediate, H4R3me1. We show that demethylation of H4R3me2s and H3K9me2s in promoter regions is correlated with active gene expression. Furthermore, knockout of JMJD1B blocks demethylation of H4R3me2s and/or H3K9me2 at distinct clusters of genes and impairs the activation of genes important for HSPC differentiation and development. Consequently, JMJD1B−/− mice show defects in hematopoiesis. Altogether, our study demonstrates that demethylase-mediated active arginine demethylation process exists in eukaryotes and that JMJD1B demethylates both H4R3me2s and H3K9me2 for epigenetic programming during hematopoiesis. : Li et al. identify the arginine demethylase (RDM activity of JMJD1B, a known lysine demethylase (KDM. They reveal that JMJD1B actively mediates demethylation of histone markers H4R3me2s and H3K9me2 in hematopoietic stem/progenitor cells (HSPCs. Keywords: JMJD1B, KDM3B, PRMT5, arginine demethylase, histone, epigenetic programming, gene expression, hematopoiesis

Chemical groups and structural characterization of lignin via thiol-mediated demethylation

Science.gov (United States)

Lihong Hu; Hui Pan; Yonghong Zhou; Chung-Yun Hse; Chengguo Liu; Baofang Zhang; Bin Xu

2014-01-01

A new approach to increase the reactivity of lignin by thiol-mediated demethylation was investigated in this study. Demethylated lignin was characterized by the changes in its hydroxyl and methoxyl groups, molecular weight, and other properties using titration and spectroscopy methods including FT-IR, 1H NMR, UV,and GPC. The total...

Enhanced photo(geno)toxicity of demethylated chlorpromazine metabolites

Energy Technology Data Exchange (ETDEWEB)

Palumbo, Fabrizio [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Garcia-Lainez, Guillermo [Instituto de Investigación Sanitaria (IIS) La Fe, Hospital Universitari i Politècnic La Fe, Avenida de Fernando Abril Martorell 106, 46026 Valencia (Spain); Limones-Herrero, Daniel [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Coloma, M. Dolores; Escobar, Javier [Instituto de Investigación Sanitaria (IIS) La Fe, Hospital Universitari i Politècnic La Fe, Avenida de Fernando Abril Martorell 106, 46026 Valencia (Spain); Jiménez, M. Consuelo [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Miranda, Miguel A., E-mail: mmiranda@qim.upv.es [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); and others

2016-12-15

Chlorpromazine (CPZ) is an anti-psychotic drug widely used to treat disorders such as schizophrenia or manic-depression. Unfortunately, CPZ exhibits undesirable side effects such as phototoxic and photoallergic reactions in humans. In general, the influence of drug metabolism on this type of reactions has not been previously considered in photosafety testing. Thus, the present work aims to investigate the possible photo(geno)toxic potential of drug metabolites, using CPZ as an established reference compound. In this case, the metabolites selected for the study are demethylchlorpromazine (DMCPZ), didemethylchlorpromazine (DDMCPZ) and chlorpromazine sulfoxide (CPZSO). The demethylated CPZ metabolites DMCPZ and DDMCPZ maintain identical chromophore to the parent drug. In this work, it has been found that the nature of the aminoalkyl side chain modulates the hydrophobicity and the photochemical properties (for instance, the excited state lifetimes), but it does not change the photoreactivity pattern, which is characterized by reductive photodehalogenation, triggered by homolytic carbon-chlorine bond cleavage with formation of highly reactive aryl radical intermediates. Accordingly, these metabolites are phototoxic to cells, as revealed by the 3T3 NRU assay; their photo-irritation factors are even higher than that of CPZ. The same trend is observed in photogenotoxicity studies, both with isolated and with cellular DNA, where DMCPZ and DDMCPZ are more active than CPZ itself. In summary, side-chain demethylation of CPZ, as a consequence of Phase I biotransformation, does not result a photodetoxification. Instead, it leads to metabolites that exhibit in an even enhanced photo(geno)toxicity. - Highlights: • Demethylated CPZ metabolites are phototoxic to cells, as revealed by the NRU assay. • Single cell electrophoresis (Comet Assay) confirms the photodamage to cellular DNA. • DNA single strand breaks formation is observed on agarose gel electrophoresis. �

Enhanced photo(geno)toxicity of demethylated chlorpromazine metabolites

International Nuclear Information System (INIS)

Palumbo, Fabrizio; Garcia-Lainez, Guillermo; Limones-Herrero, Daniel; Coloma, M. Dolores; Escobar, Javier; Jiménez, M. Consuelo; Miranda, Miguel A.

2016-01-01

Chlorpromazine (CPZ) is an anti-psychotic drug widely used to treat disorders such as schizophrenia or manic-depression. Unfortunately, CPZ exhibits undesirable side effects such as phototoxic and photoallergic reactions in humans. In general, the influence of drug metabolism on this type of reactions has not been previously considered in photosafety testing. Thus, the present work aims to investigate the possible photo(geno)toxic potential of drug metabolites, using CPZ as an established reference compound. In this case, the metabolites selected for the study are demethylchlorpromazine (DMCPZ), didemethylchlorpromazine (DDMCPZ) and chlorpromazine sulfoxide (CPZSO). The demethylated CPZ metabolites DMCPZ and DDMCPZ maintain identical chromophore to the parent drug. In this work, it has been found that the nature of the aminoalkyl side chain modulates the hydrophobicity and the photochemical properties (for instance, the excited state lifetimes), but it does not change the photoreactivity pattern, which is characterized by reductive photodehalogenation, triggered by homolytic carbon-chlorine bond cleavage with formation of highly reactive aryl radical intermediates. Accordingly, these metabolites are phototoxic to cells, as revealed by the 3T3 NRU assay; their photo-irritation factors are even higher than that of CPZ. The same trend is observed in photogenotoxicity studies, both with isolated and with cellular DNA, where DMCPZ and DDMCPZ are more active than CPZ itself. In summary, side-chain demethylation of CPZ, as a consequence of Phase I biotransformation, does not result a photodetoxification. Instead, it leads to metabolites that exhibit in an even enhanced photo(geno)toxicity. - Highlights: • Demethylated CPZ metabolites are phototoxic to cells, as revealed by the NRU assay. • Single cell electrophoresis (Comet Assay) confirms the photodamage to cellular DNA. • DNA single strand breaks formation is observed on agarose gel electrophoresis. �

Targeted DNA demethylation of the Arabidopsis genome using the human TET1 catalytic domain

Science.gov (United States)

Gallego-Bartolomé, Javier; Gardiner, Jason; Liu, Wanlu; Papikian, Ashot; Ghoshal, Basudev; Kuo, Hsuan Yu; Zhao, Jenny Miao-Chi; Jacobsen, Steven E.

2018-01-01

DNA methylation is an important epigenetic modification involved in gene regulation and transposable element silencing. Changes in DNA methylation can be heritable and, thus, can lead to the formation of stable epialleles. A well-characterized example of a stable epiallele in plants is fwa, which consists of the loss of DNA cytosine methylation (5mC) in the promoter of the FLOWERING WAGENINGEN (FWA) gene, causing up-regulation of FWA and a heritable late-flowering phenotype. Here we demonstrate that a fusion between the catalytic domain of the human demethylase TEN-ELEVEN TRANSLOCATION1 (TET1cd) and an artificial zinc finger (ZF) designed to target the FWA promoter can cause highly efficient targeted demethylation, FWA up-regulation, and a heritable late-flowering phenotype. Additional ZF–TET1cd fusions designed to target methylated regions of the CACTA1 transposon also caused targeted demethylation and changes in expression. Finally, we have developed a CRISPR/dCas9-based targeted demethylation system using the TET1cd and a modified SunTag system. Similar to the ZF–TET1cd fusions, the SunTag–TET1cd system is able to target demethylation and activate gene expression when directed to the FWA or CACTA1 loci. Our study provides tools for targeted removal of 5mC at specific loci in the genome with high specificity and minimal off-target effects. These tools provide the opportunity to develop new epialleles for traits of interest, and to reactivate expression of previously silenced genes, transgenes, or transposons. PMID:29444862

Vitamin C induces specific demethylation of H3K9me2 in mouse embryonic stem cells via Kdm3a/b.

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Ebata, Kevin T; Mesh, Kathryn; Liu, Shichong; Bilenky, Misha; Fekete, Alexander; Acker, Michael G; Hirst, Martin; Garcia, Benjamin A; Ramalho-Santos, Miguel

2017-01-01

Histone methylation patterns regulate gene expression and are highly dynamic during development. The erasure of histone methylation is carried out by histone demethylase enzymes. We had previously shown that vitamin C enhances the activity of Tet enzymes in embryonic stem (ES) cells, leading to DNA demethylation and activation of germline genes. We report here that vitamin C induces a remarkably specific demethylation of histone H3 lysine 9 dimethylation (H3K9me2) in naïve ES cells. Vitamin C treatment reduces global levels of H3K9me2, but not other histone methylation marks analyzed, as measured by western blot, immunofluorescence and mass spectrometry. Vitamin C leads to widespread loss of H3K9me2 at large chromosomal domains as well as gene promoters and repeat elements. Vitamin C-induced loss of H3K9me2 occurs rapidly within 24 h and is reversible. Importantly, we found that the histone demethylases Kdm3a and Kdm3b are required for vitamin C-induced demethylation of H3K9me2. Moreover, we show that vitamin C-induced Kdm3a/b-mediated H3K9me2 demethylation and Tet-mediated DNA demethylation are independent processes at specific loci. Lastly, we document Kdm3a/b are partially required for the upregulation of germline genes by vitamin C. These results reveal a specific role for vitamin C in histone demethylation in ES cells and document that DNA methylation and H3K9me2 cooperate to silence germline genes in pluripotent cells.

Evidence that active demethylation mechanisms maintain the genome of carcinoma in situ cells hypomethylated in the adult testis

DEFF Research Database (Denmark)

Kristensen, D G; Nielsen, J E; Jørgensen, Anne

2014-01-01

cells were assessed by quantitative measurements. The expression of TET1, TET2, APOBEC1, MBD4, APEX1, PARP1, DNMT1, DNMT3A, DNMT3B and DNMT3L in adult testis specimens with CIS and in human fetal testis was investigated by immunohistochemistry and immunofluorescence.Results:DNA from micro-dissected CIS...... cells contained very low levels of 5hmC produced by ten eleven translocation (TET) enzymes. CIS cells and fetal germ cells expressed the suggested initiator of active demethylation, APOBEC1, and the base excision repair proteins MBD4, APEX1 and PARP1, whereas TETs - the alternative initiators were...

Demethylation of methylmercury in growing rice plants: An evidence of self-detoxification

International Nuclear Information System (INIS)

Xu, Xiaohan; Zhao, Jiating; Li, Yunyun; Fan, Yuqin; Zhu, Nali; Gao, Yuxi; Li, Bai; Liu, Hanyu; Li, Yu-Feng

2016-01-01

Mercury (Hg) is a global pollutant that poses a serious threat to human and the environment. Rice was found as an important source for human exposure to Hg in some areas. In this study, the transportation and transformation of IHg and MeHg in rice plants exposed to IHg or MeHg were investigated. The IHg and MeHg concentrations in rice roots and shoots collected every five days were analyzed by HPLC-ICP-MS and SR-XANES. When exposed to MeHg, the percent of IHg in rice roots and shoots increased while MeHg decreased significantly, suggesting prominent demethylation of MeHg occurred. However no notable MeHg was found in both roots and shoots of rice plant when exposed to IHg. SR-XANES analysis further confirmed the demethylation of MeHg with rice. This study provides a new finding that demethylation of MeHg could occur in growing rice, which may be a self-defense process of rice plant. - Graphical abstract: Inorganic mercury in Rice (Oryza sativa L.) plants exposed to methylmercury was detected: An evidence of rice plant against methylmercury phytotoxicity. Display Omitted - Highlights: • Demethylation of MeHg in rice plant was found in rice root. • Hg in rice roots mainly present as MeHg-SR or RS-Hg-SR form. • MeHg-SR in roots can be gradually transformed to RS-Hg-SR with rice growth. - Demethylation of MeHg in growing rice.

TET1 promotes cisplatin-resistance via demethylating the vimentin promoter in ovarian cancer.

Science.gov (United States)

Han, Xi; Zhou, Yuanyuan; You, Yuanyi; Lu, Jiaojiao; Wang, Lijie; Hou, Huilian; Li, Jing; Chen, Wei; Zhao, Le; Li, Xu

2017-04-01

The development of chemo-resistance impairs the outcome of the first line platinum-based chemotherapies for ovarian cancer. Deregulation of DNA methylation/demethylation provides a critical mechanism for the occurrence of chemo-resistance. The ten-eleven translocation (TET) family of dioxygenases including TET1/2/3 plays an important part in DNA demethylation, but their roles in cisplatin resistance have not been elucidated. Using cisplatin-sensitive and cisplatin-resistant ovarian cancer cell models, we found that TET1 was significantly upregulated in cisplatin-resistant CP70 cells compared with that in cisplatin-sensitive A2780 cells. Ectopic expression of TET1 in A2780 cells promoted cisplatin resistance and decreased cytotoxicity induced by cisplatin, while inhibition of TET1 by siRNA transfection in CP70 cells attenuated cisplatin resistance and enhanced cytotoxicity of cisplatin. Increased TET1 induced re-expression of vimentin through active DNA demethylation, and cause partial epithelial-to-mesenchymal (EMT) in A2780 cells. Contrarily, knocking down of TET1 in CP70 cells reduced vimentin expression and reversed EMT process. Immunohistochemical analysis of TET1 in human ovarian cancer tissues revealed that TET1 existed in nucleus and cytoplasm in ovarian cancer tissues. And the expression of nuclear TET1 was positively correlated with residual tumor and chemotherapeutic response. Thus, TET1 expression causes resistance to cisplatin and one of the targets of TET1 action is vimentin in ovarian cancer. © 2017 International Federation for Cell Biology.

DNA demethylation activates genes in seed maternal integument development in rice (Oryza sativa L.).

Science.gov (United States)

Wang, Yifeng; Lin, Haiyan; Tong, Xiaohong; Hou, Yuxuan; Chang, Yuxiao; Zhang, Jian

2017-11-01

DNA methylation is an important epigenetic modification that regulates various plant developmental processes. Rice seed integument determines the seed size. However, the role of DNA methylation in its development remains largely unknown. Here, we report the first dynamic DNA methylomic profiling of rice maternal integument before and after pollination by using a whole-genome bisulfite deep sequencing approach. Analysis of DNA methylation patterns identified 4238 differentially methylated regions underpin 4112 differentially methylated genes, including GW2, DEP1, RGB1 and numerous other regulators participated in maternal integument development. Bisulfite sanger sequencing and qRT-PCR of six differentially methylated genes revealed extensive occurrence of DNA hypomethylation triggered by double fertilization at IAP compared with IBP, suggesting that DNA demethylation might be a key mechanism to activate numerous maternal controlling genes. These results presented here not only greatly expanded the rice methylome dataset, but also shed novel insight into the regulatory roles of DNA methylation in rice seed maternal integument development. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A non-heme iron-mediated chemical demethylation in DNA and RNA.

Science.gov (United States)

Yi, Chengqi; Yang, Cai-Guang; He, Chuan

2009-04-21

DNA methylation is arguably one of the most important chemical signals in biology. However, aberrant DNA methylation can lead to cytotoxic or mutagenic consequences. A DNA repair protein in Escherichia coli, AlkB, corrects some of the unwanted methylations of DNA bases by a unique oxidative demethylation in which the methyl carbon is liberated as formaldehyde. The enzyme also repairs exocyclic DNA lesions--that is, derivatives in which the base is augmented with an additional heterocyclic subunit--by a similar mechanism. Two proteins in humans that are homologous to AlkB, ABH2 and ABH3, repair the same spectrum of lesions; another human homologue of AlkB, FTO, is linked to obesity. In this Account, we describe our studies of AlkB, ABH2, and ABH3, including our development of a general strategy to trap homogeneous protein-DNA complexes through active-site disulfide cross-linking. AlkB uses a non-heme mononuclear iron(II) and the cofactors 2-ketoglutarate (2KG) and dioxygen to effect oxidative demethylation of the DNA base lesions 1-methyladenine (1-meA), 3-methylcytosine (3-meC), 1-methylguanine (1-meG), and 3-methylthymine (3-meT). ABH3, like AlkB, works better on single-stranded DNA (ssDNA) and is capable of repairing damaged bases in RNA. Conversely, ABH2 primarily repairs lesions in double-stranded DNA (dsDNA); it is the main housekeeping enzyme that protects the mammalian genome from 1-meA base damage. The AlkB-family proteins have moderate affinities for their substrates and bind DNA in a non-sequence-specific manner. Knowing that these proteins flip the damaged base out from the duplex DNA and insert it into the active site for further processing, we first engineered a disulfide cross-link in the active site to stabilize the Michaelis complex. Based on the detailed structural information afforded by the active-site cross-linked structures, we can readily install a cross-link away from the active site to obtain the native-like structures of these complexes

ERRα induces H3K9 demethylation by LSD1 to promote cell invasion

OpenAIRE

Carnesecchi, Julie; Forcet, Christelle; Zhang, Ling; Tribollet, Violaine; Barenton, Bruno; Boudra, Rafik; Cerutti, Catherine; Billas, Isabelle M. L.; Sérandour, Aurélien A.; Carroll, Jason S.; Beaudoin, Claude; Vanacker, Jean-Marc

2017-01-01

Dynamic demethylation of histone residues plays a crucial role in the regulation of gene expression. Lysine Specific Demethylase 1 (LSD1) can remove both transcriptionally permissive and repressive histone marks. How these activities are controlled is not clearly understood. Here, we show that the estrogen-related receptor α (ERRα) induces LSD1 to erase repressive marks in vitro. Through such a mechanism, LSD1 and ERRα commonly activate a set of transcriptional targets that include genes invo...

FOXP3 Expression in GARP-Transduced Helper T Cells Is Not Associated with FOXP3 TSDR Demethylation.

Science.gov (United States)

Kehrmann, Jan; Zeschnigk, Michael; Buer, Jan; Probst-Kepper, Michael

2011-10-01

AIM: Glycoprotein A repetitions predominant (GARP or LRRC32) represents a human regulatory CD4+ CD25(hi) FOXP3+ T (T(reg)) cell-specific receptor that controls FOXP3. Ectopic expression of GARP in helper T (T(h)) cells has been shown to be sufficient for the induction of FOXP3 and generation of a stable regulatory phenotype. Since expression of FOXP3 in Treg cells is epigenetically controlled by a conserved motif, the so-called T(reg)-specific demethylated region (TSDR), we asked whether GARP-mediated upregulation of FOXP3 in Th cells is similarly accompanied by demethylation of the TSDR. METHODS: DNA methylation of the FOXP3 TSDR was analyzed by direct sequencing of polymerase chain reaction (PCR) products from bisulfite-treated genomic DNA. RESULTS: Although GARP-transduced T(h) cells exhibit constitutive FOXP3 expression and a regulatory phenotype, the FOXP3 TSDR is completely methylated as in naive T(h) cells. GARP-mediated FOXP3 upregulation in T(h) cells is not associated with T(reg)-specific demethylation of the FOXP3 TSDR. CONCLUSION: Although GARP-engineered T(h) cells exhibit stable FOXP3 expression and a phenotypic reprogramming towards T(reg) cells in vitro, these cells do not completely mimic the epigenotype of natural T(reg) cells. Thus, concepts based on the genetic modification of T(h) cells as cellular therapies to treat autoimmune diseases or to control transplantation tolerance should be critically tested before any clinical application.

Genistein promotes DNA demethylation of the steroidogenic factor 1 (SF-1) promoter in endometrial stromal cells

International Nuclear Information System (INIS)

Matsukura, Hiroshi; Aisaki, Ken-ichi; Igarashi, Katsuhide; Matsushima, Yuko; Kanno, Jun; Muramatsu, Masaaki; Sudo, Katsuko; Sato, Noriko

2011-01-01

Highlights: → Genistein (GEN) is a phytoestrogen found in soy products. → GEN demethylated/unsilenced the steroidogenic factor 1 gene in endometrial tissue. → GEN thus altered mRNA expression in uteri of ovariectomized (OVX) mice. → A high-resolution melting assay was used to screen for epigenetic change. → We isolated an endometrial cell clone that was epigenetically modulated by GEN. -- Abstract: It has recently been demonstrated that genistein (GEN), a phytoestrogen in soy products, is an epigenetic modulator in various types of cells; but its effect on endometrium has not yet been determined. We investigated the effects of GEN on mouse uterine cells, in vivo and in vitro. Oral administration of GEN for 1 week induced mild proliferation of the endometrium in ovariectomized (OVX) mice, which was accompanied by the induction of steroidogenic factor 1 (SF-1) gene expression. GEN administration induced demethylation of multiple CpG sites in the SF-1 promoter; these sites are extensively methylated and thus silenced in normal endometrium. The GEN-mediated promoter demethylation occurred predominantly on the luminal side, as opposed to myometrium side, indicating that the epigenetic change was mainly shown in regenerated cells. Primary cultures of endometrial stromal cell colonies were screened for GEN-mediated alterations of DNA methylation by a high-resolution melting (HRM) method. One out of 20 colony-forming cell clones showed GEN-induced demethylation of SF-1. This clone exhibited a high proliferation capacity with continuous colony formation activity through multiple serial clonings. We propose that only a portion of endometrial cells are capable of receiving epigenetic modulation by GEN.

Genistein promotes DNA demethylation of the steroidogenic factor 1 (SF-1) promoter in endometrial stromal cells

Energy Technology Data Exchange (ETDEWEB)

Matsukura, Hiroshi, E-mail: hmatsukura.epi@mri.tmd.ac.jp [Department of Molecular Epidemiology, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Aisaki, Ken-ichi; Igarashi, Katsuhide; Matsushima, Yuko; Kanno, Jun [Division of Cellular and Molecular Toxicology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan); Muramatsu, Masaaki [Department of Molecular Epidemiology, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Sudo, Katsuko [Department of Molecular Epidemiology, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan); Animal Research Center, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402 (Japan); Sato, Noriko, E-mail: nsato.epi@tmd.ac.jp [Department of Molecular Epidemiology, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062 (Japan)

2011-08-26

Highlights: {yields} Genistein (GEN) is a phytoestrogen found in soy products. {yields} GEN demethylated/unsilenced the steroidogenic factor 1 gene in endometrial tissue. {yields} GEN thus altered mRNA expression in uteri of ovariectomized (OVX) mice. {yields} A high-resolution melting assay was used to screen for epigenetic change. {yields} We isolated an endometrial cell clone that was epigenetically modulated by GEN. -- Abstract: It has recently been demonstrated that genistein (GEN), a phytoestrogen in soy products, is an epigenetic modulator in various types of cells; but its effect on endometrium has not yet been determined. We investigated the effects of GEN on mouse uterine cells, in vivo and in vitro. Oral administration of GEN for 1 week induced mild proliferation of the endometrium in ovariectomized (OVX) mice, which was accompanied by the induction of steroidogenic factor 1 (SF-1) gene expression. GEN administration induced demethylation of multiple CpG sites in the SF-1 promoter; these sites are extensively methylated and thus silenced in normal endometrium. The GEN-mediated promoter demethylation occurred predominantly on the luminal side, as opposed to myometrium side, indicating that the epigenetic change was mainly shown in regenerated cells. Primary cultures of endometrial stromal cell colonies were screened for GEN-mediated alterations of DNA methylation by a high-resolution melting (HRM) method. One out of 20 colony-forming cell clones showed GEN-induced demethylation of SF-1. This clone exhibited a high proliferation capacity with continuous colony formation activity through multiple serial clonings. We propose that only a portion of endometrial cells are capable of receiving epigenetic modulation by GEN.

Position of coordination of the lithium ion determines the regioselectivity of demethylations of 3,4-dimethoxymorphinans with L-selectride.

Science.gov (United States)

Wu, Huifang; Thatcher, Linn N; Bernard, Denzil; Parrish, Damon A; Deschamps, Jeffrey R; Rice, Kenner C; MacKerell, Alexander D; Coop, Andrew

2005-06-23

[reaction: see text] L-Selectride is an efficient agent for the 3-O-demethylation of opioids and is known to cleave the least hindered methoxyl group in a molecule. The treatment of a 3,4-dimethoxymorphinan containing a 6-ketal with L-Selectride gave selective 4-O-demethylation, rather than cleavage of the less hindered 3-methoxyl. In contrast, a 3,4-dimethoxymorphinan lacking a 6-ketal gave selective 3-O-demethylation, suggesting that the regiochemistry of L-Selectride-mediated O-demethylation can be manipulated through altering the position of coordination of the lithium ion.

Uptake and Metabolism of Antibiotics Roseoflavin and 8-Demethyl-8-Aminoriboflavin in Riboflavin-Auxotrophic Listeria monocytogenes.

Science.gov (United States)

Matern, Andreas; Pedrolli, Danielle; Großhennig, Stephanie; Johansson, Jörgen; Mack, Matthias

2016-12-01

The riboflavin analogs roseoflavin (RoF) and 8-demethyl-8-aminoriboflavin (AF) are produced by the bacteria Streptomyces davawensis and Streptomyces cinnabarinus Riboflavin analogs have the potential to be used as broad-spectrum antibiotics, and we therefore studied the metabolism of riboflavin (vitamin B 2 ), RoF, and AF in the human pathogen Listeria monocytogenes, a bacterium which is a riboflavin auxotroph. We show that the L. monocytogenes protein Lmo1945 is responsible for the uptake of riboflavin, RoF, and AF. Following import, these flavins are phosphorylated/adenylylated by the bifunctional flavokinase/flavin adenine dinucleotide (FAD) synthetase Lmo1329 and adenylylated by the unique FAD synthetase Lmo0728, the first monofunctional FAD synthetase to be described in bacteria. Lmo1329 generates the cofactors flavin mononucleotide (FMN) and FAD, whereas Lmo0728 produces FAD only. The combined activities of Lmo1329 and Lmo0728 are responsible for the intracellular formation of the toxic cofactor analogs roseoflavin mononucleotide (RoFMN), roseoflavin adenine dinucleotide (RoFAD), 8-demethyl-8-aminoriboflavin mononucleotide (AFMN), and 8-demethyl-8-aminoriboflavin adenine dinucleotide (AFAD). In vivo reporter gene assays and in vitro transcription/translation experiments show that the L. monocytogenes FMN riboswitch Rli96, which controls expression of the riboflavin transport gene lmo1945, is negatively affected by riboflavin/FMN and RoF/RoFMN but not by AF/AFMN. Treatment of L. monocytogenes with RoF or AF leads to drastically reduced FMN/FAD levels. We suggest that the reduced flavin cofactor levels in combination with concomitant synthesis of inactive cofactor analogs (RoFMN, RoFAD, AFMN, and AFAD) explain why RoF and AF contribute to antibiotic activity in L. monocytogenes IMPORTANCE: The riboflavin analogs roseoflavin (RoF) and 8-demethyl-8-aminoriboflavin (AF) are small molecules which are produced by Streptomyces davawensis and Streptomyces cinnabarinus

Early de novo DNA methylation and prolonged demethylation in the muscle lineage.

Science.gov (United States)

Tsumagari, Koji; Baribault, Carl; Terragni, Jolyon; Varley, Katherine E; Gertz, Jason; Pradhan, Sirharsa; Badoo, Melody; Crain, Charlene M; Song, Lingyun; Crawford, Gregory E; Myers, Richard M; Lacey, Michelle; Ehrlich, Melanie

2013-03-01

Myogenic cell cultures derived from muscle biopsies are excellent models for human cell differentiation. We report the first comprehensive analysis of myogenesis-specific DNA hyper- and hypo-methylation throughout the genome for human muscle progenitor cells (both myoblasts and myotubes) and skeletal muscle tissue vs. 30 non-muscle samples using reduced representation bisulfite sequencing. We also focused on four genes with extensive hyper- or hypo-methylation in the muscle lineage (PAX3, TBX1, MYH7B/MIR499 and OBSCN) to compare DNA methylation, DNaseI hypersensitivity, histone modification, and CTCF binding profiles. We found that myogenic hypermethylation was strongly associated with homeobox or T-box genes and muscle hypomethylation with contractile fiber genes. Nonetheless, there was no simple relationship between differential gene expression and myogenic differential methylation, rather only for subsets of these genes, such as contractile fiber genes. Skeletal muscle retained ~30% of the hypomethylated sites but only ~3% of hypermethylated sites seen in myogenic progenitor cells. By enzymatic assays, skeletal muscle was 2-fold enriched globally in genomic 5-hydroxymethylcytosine (5-hmC) vs. myoblasts or myotubes and was the only sample type enriched in 5-hmC at tested myogenic hypermethylated sites in PAX3/CCDC140 andTBX1. TET1 and TET2 RNAs, which are involved in generation of 5-hmC and DNA demethylation, were strongly upregulated in myoblasts and myotubes. Our findings implicate de novo methylation predominantly before the myoblast stage and demethylation before and after the myotube stage in control of transcription and co-transcriptional RNA processing. They also suggest that, in muscle, TET1 or TET2 are involved in active demethylation and in formation of stable 5-hmC residues.

Synthesis and characterization of N-demethylated metabolites of malachite green and leucomalachite green.

Science.gov (United States)

Cho, Bongsup P; Yang, Tianle; Blankenship, Lonnie R; Moody, Joanna D; Churchwell, Mona; Beland, Frederick A; Culp, Sandra J

2003-03-01

Malachite green (MG), a triphenylmethane dye used to treat fungal and protozoan infections in fish, undergoes sequential oxidation to produce various N-demethylated derivatives (monodes-, dides(sym)-, dides(unsym)-, trides-, and tetrades-) both before and after reduction to leucomalachite green (LMG). The close structure resemblance of the metabolites with aromatic amine carcinogens implicates a potential genotoxicity from exposure to MG. The availability of the synthetic standards is important for metabolic and DNA adduct studies of MG. This paper describes a simple and versatile method for the synthesis of MG, LMG, and their N-demethylated metabolites. The synthesis involves a coupling of 4-(dimethylamino)benzophenone or 4-nitrobenzophenone with the aryllithium reagents derived from appropriately substituted 4-bromoaniline derivatives, followed by treatment with HCl in methanol. The resulting cationic MG and their leuco analogues showed systematic UV/vis spectral and tandem mass fragmentation patterns consistent with sequential N-demethylation. The extensive (1)H and (13)C spectral assignments of the metabolites were aided by the availability of (13)C(7)-labeled MG and LMG. The results indicate the existence of a resonance structure with the cationic charge located in the central methane carbon (C(7)). The synthetic procedure is general in scope so that it can be extended to the preparation of N-demethylated metabolites of other structurally related N-methylated triphenylmethane dyes.

Green synthesis of low-toxicity graphene-fulvic acid with an open band gap enhances demethylation of methylmercury.

Science.gov (United States)

Hu, Xiangang; Mu, Li; Lu, Kaicheng; Kang, Jia; Zhou, Qixing

2014-06-25

The demethylation of methylmercury has received substantial attention. Here, a novel chemical method for the demethylation of methylmercury is proposed. The low-toxicity graphene-fulvic acid (FA, a ubiquitous material in the environment) was synthesized without the use of a chemical reagent. The hybridized graphene-FA presented an indirect open band gap of 2.25-2.87 eV as well as adequate aqueous dispersion. More importantly, the hybridized graphene-FA exhibited 6- and 10-fold higher photocatalytic efficiencies for the demethylation of methylmercury than FA and free FA with graphene, respectively. This result implies that immobilized, rather than free, FA accelerated the catalysis. Furthermore, inorganic mercuric ion, elemental mercury, and mercuric oxide were identified as the primary demethylation products. For free FA with graphene, graphene quenches the excited-state FA, inhibiting the demethylation by electron transfer. In contrast, the graphene of the self-assembled graphene-FA serves as an electron reservoir, causing electron-hole pair separation. Graphene-FA showed a negligible toxicity toward microalgae compared to graphene. The above results reveal that the green synthesis of graphene and organic molecules is a convenient strategy for obtaining effective cocatalysts.

A Convenient and Efficient Method for Demethylation of Aryl Methyl Ethers with Magnesium Iodide in Ionic Liquid

International Nuclear Information System (INIS)

Lee, Kwan Soo; Kim, Kee D.

2010-01-01

We have developed a new and efficient method for the demethylation of various types of aryl methyl ethers using readily available, stable, and easily handled magnesium iodide in [BMIM]BF 4 ionic liquid. Owing to its simplicity and mild reaction conditions the protocol reported herein may serve as a useful alternative to the existing methods for the deprotection of aryl methyl ethers to the corresponding phenolic derivatives. Demethylation of aryl methyl ethers to the corresponding phenols are very important reactions in organic synthesis. A number of methods have been reported for the cleavage of highly stable aryl methyl ethers utilizing strong acids or bases such as aluminum chloride, boron tribromide, cerium chloride, alkaline thiolate, methyl magnesium iodide, and L-Selectride. However, all of these methods invariably suffered from one or more drawbacks such as harsh reaction conditions, long reaction times, difficulty of manipulation, use of exotic reagents, and low reaction yields. Furthermore, in the most of known methods for demethylation of aryl methyl ethers, use of large excess amounts of demethylating agents have been generally required. Thus, it is highly desirable to develop an improved convenient and efficient procedure for demethylation reactions of aryl methyl ethers

A Convenient and Efficient Method for Demethylation of Aryl Methyl Ethers with Magnesium Iodide in Ionic Liquid

Energy Technology Data Exchange (ETDEWEB)

Lee, Kwan Soo [KAIST, Daejeon (Korea, Republic of); Kim, Kee D. [Sangji University, Wonju (Korea, Republic of)

2010-12-15

We have developed a new and efficient method for the demethylation of various types of aryl methyl ethers using readily available, stable, and easily handled magnesium iodide in [BMIM]BF{sub 4} ionic liquid. Owing to its simplicity and mild reaction conditions the protocol reported herein may serve as a useful alternative to the existing methods for the deprotection of aryl methyl ethers to the corresponding phenolic derivatives. Demethylation of aryl methyl ethers to the corresponding phenols are very important reactions in organic synthesis. A number of methods have been reported for the cleavage of highly stable aryl methyl ethers utilizing strong acids or bases such as aluminum chloride, boron tribromide, cerium chloride, alkaline thiolate, methyl magnesium iodide, and L-Selectride. However, all of these methods invariably suffered from one or more drawbacks such as harsh reaction conditions, long reaction times, difficulty of manipulation, use of exotic reagents, and low reaction yields. Furthermore, in the most of known methods for demethylation of aryl methyl ethers, use of large excess amounts of demethylating agents have been generally required. Thus, it is highly desirable to develop an improved convenient and efficient procedure for demethylation reactions of aryl methyl ethers.

Dynamic changes in DNA demethylation in the tree shrew (Tupaia belangeri chinensis) brain during postnatal development and aging.

Science.gov (United States)

Wei, Shu; Hua, Hai-Rong; Chen, Qian-Quan; Zhang, Ying; Chen, Fei; Li, Shu-Qing; Li, Fan; Li, Jia-Li

2017-03-18

Brain development and aging are associated with alterations in multiple epigenetic systems, including DNA methylation and demethylation patterns. Here, we observed that the levels of the 5-hydroxymethylcytosine (5hmC) ten-eleven translocation (TET) enzyme-mediated active DNA demethylation products were dynamically changed and involved in postnatal brain development and aging in tree shrews ( Tupaia belangeri chinensis ). The levels of 5hmC in multiple anatomic structures showed a gradual increase throughout postnatal development, whereas a significant decrease in 5hmC was found in several brain regions in aged tree shrews, including in the prefrontal cortex and hippocampus, but not the cerebellum. Active changes in Tet mRNA levels indicated that TET2 and TET3 predominantly contributed to the changes in 5hmC levels. Our findings provide new insight into the dynamic changes in 5hmC levels in tree shrew brains during postnatal development and aging processes.

Base-oxidant promoted metal-free N-demethylation of arylamines

Indian Academy of Sciences (India)

A metal-free oxidative N-demethylation of arylamines with triethylamine as a base and tert-butyl hydroperoxide (TBHP) as oxidant is reported in this paper. The reaction is general, practical, inexpensive, non-toxic, and the method followed is environmentally benign, with moderate to good yields.

A New Synthetic Route to Dihydrobenzopyran Via Tandem Demethylation Cyclisation

Directory of Open Access Journals (Sweden)

G. Shanmugam

2000-06-01

Full Text Available A tandem demethylation-cyclisation reaction resulting in the formation of pyran rings using AlCl3/EtSH reagent under mild reaction conditions is reported. X-ray diffraction studies on the intermediate support the suggested mechanism.

Inhibition of CYP2D6-mediated tramadol O-demethylation in methadone but not buprenorphine maintenance patients.

Science.gov (United States)

Coller, Janet K; Michalakas, Jennifer R; James, Heather M; Farquharson, Aaron L; Colvill, Joel; White, Jason M; Somogyi, Andrew A

2012-11-01

Management of pain in opioid dependent individuals is problematic due to numerous issues including cross-tolerance to opioids. Hence there is a need to find alternative analgesics to classical opioids and tramadol is potentially one such alternative. Methadone inhibits CYP2D6 in vivo and in vitro. We aimed to investigate the effect of methadone on the pathways of tramadol metabolism: O-demethylation (CYP2D6) to the opioid-active metabolite M1 and N-demethylation (CYP3A4) to M2 in subjects maintained on methadone or buprenorphine as a control. Compared with subjects on buprenorphine, methadone reduced the clearance of tramadol to active O-desmethyl-tramadol (M1) but had no effect on N-desmethyltramadol (M2) formation. Similar to other analgesics whose active metabolites are formed by CYP2D6 such as codeine, reduced formation of O-desmethyltramadol (M1) is likely to result in reduced analgesia for subjects maintained on methadone. Hence alternative analgesics whose metabolism is independent of CYP2D6 should be utilized in this patient population. To compare the O- (CYP2D6 mediated) and N- (CYP3A4 mediated) demethylation metabolism of tramadol between methadone and buprenorphine maintained CYP2D6 extensive metabolizer subjects. METHODS Nine methadone and seven buprenorphine maintained subjects received a single 100 mg dose of tramadol hydrochloride. Blood was collected at 4 h and assayed for tramadol, methadone, buprenorphine and norbuprenorphine (where appropriate) and all urine over 4 h was assayed for tramadol and its M1 and M2 metabolites. The urinary metabolic ratio [median (range)] for O-demethylation (M1) was significantly lower (P= 0.0002, probability score 1.0) in the subjects taking methadone [0.071 (0.012-0.103)] compared with those taking buprenorphine [0.192 (0.108-0.392)], but there was no significant difference (P= 0.21, probability score 0.69) in N-demethylation (M2). The percentage of dose [median (range)] recovered as M1 was significantly lower

(/sup 125/I) 7-iodo-6-demethyl-6-deoxytetracycline HCl: its use in the study of bone mineralization

Energy Technology Data Exchange (ETDEWEB)

Belbeck, L W; Bowen, B M; Garnett, E S [McMaster Univ., Hamilton, Ontario (Canada); Porter, J K; Teare, F W

1979-06-01

/sup 125/I 7-iodo-6-demethyl-6-deoxytetracycline can be used in a non-invasive method to indicate sites of active bone mineralization. Sequential doses of this agent have been used to follow bone repair in a fractured femur of a dog without resorting to bone biopsy. Metabolic problems that involve bone may also be studied with this potentially useful radiopharmaceutical.

Genome-wide CpG island methylation and intergenic demethylation propensities vary among different tumor sites.

Science.gov (United States)

Lee, Seung-Tae; Wiemels, Joseph L

2016-02-18

The epigenetic landscape of cancer includes both focal hypermethylation and broader hypomethylation in a genome-wide manner. By means of a comprehensive genomic analysis on 6637 tissues of 21 tumor types, we here show that the degrees of overall methylation in CpG island (CGI) and demethylation in intergenic regions, defined as 'backbone', largely vary among different tumors. Depending on tumor type, both CGI methylation and backbone demethylation are often associated with clinical, epidemiological and biological features such as age, sex, smoking history, anatomic location, histological type and grade, stage, molecular subtype and biological pathways. We found connections between CGI methylation and hypermutability, microsatellite instability, IDH1 mutation, 19p gain and polycomb features, and backbone demethylation with chromosomal instability, NSD1 and TP53 mutations, 5q and 19p loss and long repressive domains. These broad epigenetic patterns add a new dimension to our understanding of tumor biology and its clinical implications. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Sensory rhodopsins I and II modulate a methylation/demethylation system in Halobacterium halobium phototaxis

International Nuclear Information System (INIS)

Spudich, E.N.; Takahashi, T.; Spudich, J.L.

1989-01-01

This work demonstrates that phototaxis stimuli in the archaebacterium Halobacterium halobium control a methylation/demethylation system in vivo through photoactivation of sensory rhodopsin I (SR-I) in either its attractant or repellent signaling form as well as through the repellent receptor sensory rhodopsin II (SR-II, also called phoborhodopsin). The effects of positive stimuli that suppress swimming reversals (i.e., an increase in attractant or decrease in repellent light) and negative stimuli that induce swimming reversals (i.e., a decrease in attractant or increase in repellent light) through each photoreceptor were monitored by assaying release of volatile [3H]methyl groups. This assay has been used to measure [3H]methanol produced during the process of adaptation to chemotactic stimuli in eubacteria. In H. halobium positive photostimuli produce a transient increase in the rate of demethylation followed by a decrease below the unstimulated value, whereas negative photostimuli cause an increase followed by a rate similar to that of the unstimulated value. Photoactivation of the SR-I attractant and simultaneous photoactivation of the SR-II repellent receptors cancel in their effects on demethylation, demonstrating the methylation system is regulated by an integrated signal. Analysis of mutants indicates that the source for the volatile methyl groups is intrinsic membrane proteins distinct from the chromoproteins that share the membrane. A methyl-accepting protein (94 kDa) previously correlated in amount with the SR-I chromoprotein (25 kDa) is shown here to be missing in a recently isolated SR-I-SR-II+ mutant (Flx3b), thus confirming the association of this protein with SR-I. Photoactivated SR-II in mutant Flx3b controls demethylation, predicting the existence of a photomodulated methyl-accepting component distinct from the 94-kDa protein of SR-I

Demethylation of host-cell DNA at the site of avian retrovirus integration

Czech Academy of Sciences Publication Activity Database

Hejnar, Jiří; Elleder, Daniel; Hájková, P.; Walter, J.; Blažková, Jana; Svoboda, Jan

2003-01-01

Roč. 2003, č. 311 (2003), s. 641-648 ISSN 0006-291X Institutional research plan: CEZ:AV0Z5052915 Keywords : DNA methylation and demethylation * integration of retroviruses * gene silencing Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.836, year: 2003

ERRα protein is stabilized by LSD1 in a demethylation-independent manner.

Directory of Open Access Journals (Sweden)

Julie Carnesecchi

Full Text Available The LSD1 histone demethylase is highly expressed in breast tumors where it constitutes a factor of poor prognosis and promotes traits of cancer aggressiveness such as cell invasiveness. Recent work has shown that the Estrogen-Related Receptor α (ERRα induces LSD1 to demethylate the Lys 9 of histone H3. This results in the transcriptional activation of a number of common target genes, several of which being involved in cellular invasion. High expression of ERRα protein is also a factor of poor prognosis in breast tumors. Here we show that, independently of its demethylase activities, LSD1 protects ERRα from ubiquitination, resulting in overexpression of the latter protein. Our data also suggests that the elevation of LSD1 mRNA and protein in breast cancer (as compared to normal tissue may be a key event to increase ERRα protein, independently of its corresponding mRNA.

ERRα protein is stabilized by LSD1 in a demethylation-independent manner.

Science.gov (United States)

Carnesecchi, Julie; Cerutti, Catherine; Vanacker, Jean-Marc; Forcet, Christelle

2017-01-01

The LSD1 histone demethylase is highly expressed in breast tumors where it constitutes a factor of poor prognosis and promotes traits of cancer aggressiveness such as cell invasiveness. Recent work has shown that the Estrogen-Related Receptor α (ERRα) induces LSD1 to demethylate the Lys 9 of histone H3. This results in the transcriptional activation of a number of common target genes, several of which being involved in cellular invasion. High expression of ERRα protein is also a factor of poor prognosis in breast tumors. Here we show that, independently of its demethylase activities, LSD1 protects ERRα from ubiquitination, resulting in overexpression of the latter protein. Our data also suggests that the elevation of LSD1 mRNA and protein in breast cancer (as compared to normal tissue) may be a key event to increase ERRα protein, independently of its corresponding mRNA.

Tet1 and Tet2 maintain mesenchymal stem cell homeostasis via demethylation of the P2rX7 promoter.

Science.gov (United States)

Yang, Ruili; Yu, Tingting; Kou, Xiaoxing; Gao, Xiang; Chen, Chider; Liu, Dawei; Zhou, Yanheng; Shi, Songtao

2018-06-01

Ten-eleven translocation (Tet) family-mediated DNA oxidation represents an epigenetic modification capable of converting 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC), which regulates various biological processes. However, it is unknown whether Tet family affects mesenchymal stem cells (MSCs) or the skeletal system. Here we show that depletion of Tet1 and Tet2 results in impaired self-renewal and differentiation of bone marrow MSCs (BMMSCs) and a significant osteopenia phenotype. Tet1 and Tet2 deficiency reduces demethylation of the P2rX7 promoter and downregulates exosome release, leading to intracellular accumulation of miR-297a-5p, miR-297b-5p, and miR-297c-5p. These miRNAs inhibit Runx2 signaling to impair BMMSC function. We show that overexpression of P2rX7 rescues the impaired BMMSCs and osteoporotic phenotype in Tet1 and Tet2 double knockout mice. These results indicate that Tet1 and Tet2 play a critical role in maintaining BMMSC and bone homeostasis through demethylation of P2rX7 to control exosome and miRNA release. This Tet/P2rX7/Runx2 cascade may serve as a target for the development of novel therapies for osteopenia disorders.

Synergistic Cytotoxic Effect of L-Asparaginase Combined with Decitabine as a Demethylating Agent in Pediatric T-ALL, with Specific Epigenetic Signature

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Salvatore Serravalle

2016-01-01

Full Text Available T-Acute Lymphoblastic Leukemia (T-ALL remains a subgroup of pediatric ALL, with a lower response to standard chemotherapy. Some recent studies established the fundamental role of epigenetic aberrations such as DNA hypermethylation, to influence patients’ outcome and response to chemotherapy. Moreover, L-asparaginase is an important chemotherapeutic agent for treatment of ALL and resistance to this drug has been linked to ASNS expression, which can be silenced through methylation. Therefore, we tested whether the sensitivity of T-ALL cell lines towards L-asparaginase is correlated to the epigenetic status of ASNS gene and whether the sensitivity can be modified by concurrent demethylating treatment. Hence we treated different T-ALL cell lines with L-asparaginase and correlated different responses to the treatment with ASNS expression. Then we demonstrated that the ASNS expression was dependent on the methylation status of the promoter. Finally we showed that, despite the demethylating effect on the ASNS gene expression, the combined treatment with the demethylating agent Decitabine could synergistically improve the L-asparaginase sensitivity in those T-ALL cell lines characterized by hypermethylation of the ASNS gene. In conclusion, this preclinical study identified an unexpected synergistic activity of L-asparaginase and Decitabine in the subgroup of T-ALL with low ASNS expression due to hypermethylation of the ASNS promoter, while it did not restore sensitivity in the resistant cell lines characterized by higher ASNS expression.

DNA demethylation upregulated Nrf2 expression in Alzheimer's disease cellular model

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Huimin eCao

2016-01-01

Full Text Available Nuclear factor erythroid 2-related factor 2 (Nrf2 is an important transcription factor in the defense against oxidative stress. Cumulative evidence has shown that oxidative stress plays a key role in the pathogenesis of Alzheimer's disease (AD. Previous animal and clinical studies had observed decreased expression of Nrf2 in AD. However, the underlying regulation mechanisms of Nrf2 in AD remain unclear. Here, we used the DNA methyltransferases (Dnmts inhibitor 5-aza-2′-deoxycytidine (5-Aza to test whether Nrf2 expression was regulated by methylation in N2a cells characterizing by expressing human Swedish mutant amyloid precursor protein (N2a/APPswe. We found 5-Aza treatment increased Nrf2 at both mRNA and protein levels via down-regulating the expression of Dnmts and DNA demethylation. In addition, 5-Aza mediated upregulation of Nrf2 expression was concomitant with increased nuclear translocation of Nrf2 and higher expression of Nrf2 downstream target gene NAD(PH:quinone oxidoreductas (NQO1. Our study showed that DNA demethylation promoted the Nrf2 cell signaling pathway, which may enhance the antioxidant system against AD development.

Global identification of genes regulated by estrogen signaling and demethylation in MCF-7 breast cancer cells

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Putnik, Milica, E-mail: milica.putnik@ki.se [Department of Biosciences and Nutrition, Novum, Karolinska Institutet, Huddinge S-14183 (Sweden); Zhao, Chunyan, E-mail: chunyan.zhao@ki.se [Department of Biosciences and Nutrition, Novum, Karolinska Institutet, Huddinge S-14183 (Sweden); Gustafsson, Jan-Ake, E-mail: jan-ake.gustafsson@ki.se [Department of Biosciences and Nutrition, Novum, Karolinska Institutet, Huddinge S-14183 (Sweden); Department of Biology and Biochemistry, Science and Engineering Research Center Bldg, University of Houston, Houston, TX 77204-5056 (United States); Dahlman-Wright, Karin, E-mail: karin.dahlman-wright@ki.se [Department of Biosciences and Nutrition, Novum, Karolinska Institutet, Huddinge S-14183 (Sweden)

2012-09-14

Highlights: Black-Right-Pointing-Pointer Estrogen signaling and demethylation can both control gene expression in breast cancers. Black-Right-Pointing-Pointer Cross-talk between these mechanisms is investigated in human MCF-7 breast cancer cells. Black-Right-Pointing-Pointer 137 genes are influenced by both 17{beta}-estradiol and demethylating agent 5-aza-2 Prime -deoxycytidine. Black-Right-Pointing-Pointer A set of genes is identified as targets of both estrogen signaling and demethylation. Black-Right-Pointing-Pointer There is no direct molecular interplay of mediators of estrogen and epigenetic signaling. -- Abstract: Estrogen signaling and epigenetic modifications, in particular DNA methylation, are involved in regulation of gene expression in breast cancers. Here we investigated a potential regulatory cross-talk between these two pathways by identifying their common target genes and exploring underlying molecular mechanisms in human MCF-7 breast cancer cells. Gene expression profiling revealed that the expression of approximately 140 genes was influenced by both 17{beta}-estradiol (E2) and a demethylating agent 5-aza-2 Prime -deoxycytidine (DAC). Gene ontology (GO) analysis suggests that these genes are involved in intracellular signaling cascades, regulation of cell proliferation and apoptosis. Based on previously reported association with breast cancer, estrogen signaling and/or DNA methylation, CpG island prediction and GO analysis, we selected six genes (BTG3, FHL2, PMAIP1, BTG2, CDKN1A and TGFB2) for further analysis. Tamoxifen reverses the effect of E2 on the expression of all selected genes, suggesting that they are direct targets of estrogen receptor. Furthermore, DAC treatment reactivates the expression of all selected genes in a dose-dependent manner. Promoter CpG island methylation status analysis revealed that only the promoters of BTG3 and FHL2 genes are methylated, with DAC inducing demethylation, suggesting DNA methylation directs repression of

Global identification of genes regulated by estrogen signaling and demethylation in MCF-7 breast cancer cells

International Nuclear Information System (INIS)

Putnik, Milica; Zhao, Chunyan; Gustafsson, Jan-Åke; Dahlman-Wright, Karin

2012-01-01

Highlights: ► Estrogen signaling and demethylation can both control gene expression in breast cancers. ► Cross-talk between these mechanisms is investigated in human MCF-7 breast cancer cells. ► 137 genes are influenced by both 17β-estradiol and demethylating agent 5-aza-2′-deoxycytidine. ► A set of genes is identified as targets of both estrogen signaling and demethylation. ► There is no direct molecular interplay of mediators of estrogen and epigenetic signaling. -- Abstract: Estrogen signaling and epigenetic modifications, in particular DNA methylation, are involved in regulation of gene expression in breast cancers. Here we investigated a potential regulatory cross-talk between these two pathways by identifying their common target genes and exploring underlying molecular mechanisms in human MCF-7 breast cancer cells. Gene expression profiling revealed that the expression of approximately 140 genes was influenced by both 17β-estradiol (E2) and a demethylating agent 5-aza-2′-deoxycytidine (DAC). Gene ontology (GO) analysis suggests that these genes are involved in intracellular signaling cascades, regulation of cell proliferation and apoptosis. Based on previously reported association with breast cancer, estrogen signaling and/or DNA methylation, CpG island prediction and GO analysis, we selected six genes (BTG3, FHL2, PMAIP1, BTG2, CDKN1A and TGFB2) for further analysis. Tamoxifen reverses the effect of E2 on the expression of all selected genes, suggesting that they are direct targets of estrogen receptor. Furthermore, DAC treatment reactivates the expression of all selected genes in a dose-dependent manner. Promoter CpG island methylation status analysis revealed that only the promoters of BTG3 and FHL2 genes are methylated, with DAC inducing demethylation, suggesting DNA methylation directs repression of these genes in MCF-7 cells. In a further analysis of the potential interplay between estrogen signaling and DNA methylation, E2 treatment

Stable knockdown of PASG enhances DNA demethylation but does not accelerate cellular senescence in TIG-7 human fibroblasts.

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Suzuki, Toshikazu; Farrar, Jason E; Yegnasubramanian, Srinivasan; Zahed, Muhammed; Suzuki, Nobuo; Arceci, Robert J

2008-09-01

Demethylation of 5-methylcytosine in genomic DNA is believed to be one of the mechanisms underlying replicative life-span of mammalian cells. Both proliferation associated SNF2-like gene (PASG, also termed Lsh) and DNA methyltransferase 3B (Dnmt3b) knockout mice result in embryonic genomic hypomethylation and a replicative senescent phenotype. However, it is unclear whether gradual demethylation of DNA during somatic cell division is directly involved in senescence. In this study, we retrovirally transduced TIG-7 human fibroblasts with a shRNA against PASG and compared the rate of change in DNA methylation as well as the replicative life-span to control cells under low (3%) and ambient (20%) oxygen. Expression of PASG protein was decreased by approximately 80% compared to control cells following transduction of PASG shRNA gene. The rate of cell growth was the same in both control and PASG-suppressed cells. The rate of demethylation of DNA was significantly increased in PASG-suppressed cells as compared control cells. However, decreased PASG expression did not shorten the replicative life-span of TIG-7 cells. Culture under low oxygen extended the life-span of TIG-7 cells but did not alter the rate of DNA demethylation. While knockout of PASG during development results in genomic hypomethylation and premature senescence, our results show that while downregulation of PASG expression in a somatic cell also leads to DNA hypomethylation, there is no associated senescent phenotype. These results suggest differences in cellular consequences of hypomethylation mediated by PASG during development compared to that in somatic cells.

Epigenetic Changes during Hepatic Stellate Cell Activation.

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Silke Götze

Full Text Available Hepatic stellate cells (HSC, which can participate in liver regeneration and fibrogenesis, have recently been identified as liver-resident mesenchymal stem cells. During their activation HSC adopt a myofibroblast-like phenotype accompanied by profound changes in the gene expression profile. DNA methylation changes at single genes have been reported during HSC activation and may participate in the regulation of this process, but comprehensive DNA methylation analyses are still missing. The aim of the present study was to elucidate the role of DNA methylation during in vitro activation of HSC.The analysis of DNA methylation changes by antibody-based assays revealed a strong decrease in the global DNA methylation level during culture-induced activation of HSC. To identify genes which may be regulated by DNA methylation, we performed a genome-wide Methyl-MiniSeq EpiQuest sequencing comparing quiescent and early culture-activated HSC. Approximately 400 differentially methylated regions with a methylation change of at least 20% were identified, showing either hypo- or hypermethylation during activation. Further analysis of selected genes for DNA methylation and expression were performed revealing a good correlation between DNA methylation changes and gene expression. Furthermore, global DNA demethylation during HSC activation was investigated by 5-bromo-2-deoxyuridine assay and L-mimosine treatment showing that demethylation was independent of DNA synthesis and thereby excluding a passive DNA demethylation mechanism.In summary, in vitro activation of HSC initiated strong DNA methylation changes, which were associated with gene regulation. These results indicate that epigenetic mechanisms are important for the control of early HSC activation. Furthermore, the data show that global DNA demethylation during activation is based on an active DNA demethylation mechanism.

Quaternary ammonium oxidative demethylation: X-ray crystallographic, resonance Raman, and UV-visible spectroscopic analysis of a Rieske-type demethylase.

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Daughtry, Kelly D; Xiao, Youli; Stoner-Ma, Deborah; Cho, Eunsun; Orville, Allen M; Liu, Pinghua; Allen, Karen N

2012-02-08

Herein, the structure resulting from in situ turnover in a chemically challenging quaternary ammonium oxidative demethylation reaction was captured via crystallographic analysis and analyzed via single-crystal spectroscopy. Crystal structures were determined for the Rieske-type monooxygenase, stachydrine demethylase, in the unliganded state (at 1.6 Å resolution) and in the product complex (at 2.2 Å resolution). The ligand complex was obtained from enzyme aerobically cocrystallized with the substrate stachydrine (N,N-dimethylproline). The ligand electron density in the complex was interpreted as proline, generated within the active site at 100 K by the absorption of X-ray photon energy and two consecutive demethylation cycles. The oxidation state of the Rieske iron-sulfur cluster was characterized by UV-visible spectroscopy throughout X-ray data collection in conjunction with resonance Raman spectra collected before and after diffraction data. Shifts in the absorption band wavelength and intensity as a function of absorbed X-ray dose demonstrated that the Rieske center was reduced by solvated electrons generated by X-ray photons; the kinetics of the reduction process differed dramatically for the liganded complex compared to unliganded demethylase, which may correspond to the observed turnover in the crystal.

Nicotine demethylation in Nicotiana cell suspension cultures: N'-formylnornicotine is not involved.

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Bartholomeusz, Trixie Ann; Bhogal, Ramneek K; Molinié, Roland; Felpin, François-Xavier; Mathé-Allainmat, Monique; Meier, Anna-Carolin; Dräger, Birgit; Lebreton, Jacques; Roscher, Albrecht; Robins, Richard J; Mesnard, François

2005-10-01

Nicotine or nornicotine enriched with stable isotopes in either the N'-methyl group or the pyrrolidine-N were fed to Nicotiana plumbaginifolia suspension cell cultures that do not form endogenous nicotine. The metabolism of these compounds was investigated by analysing the incorporation of isotope into other alkaloids using gas chromatography-mass spectroscopy (GC-MS). Nicotine metabolism primarily resulted in the accumulation of nornicotine, the N'-demethylation product. In addition, six minor metabolites appeared during the course of nicotine metabolism, four of which were identified as cotinine, myosmine, N'-formylnornicotine and N'-carboethoxynornicotine. While cotinine was formed from [(13)C,(2)H(3)-methyl]nicotine without dilution of label, N'-formylnornicotine was labelled at only about 6% of the level of nicotine and N'-carboethoxynornicotine was unlabelled. Feeding with [1'-(15)N]nornicotine resulted in incorporation without dilution of label into both N'-formylnornicotine and N'-carboethoxynornicotine. This pattern strongly indicates that, while nornicotine and cotinine are derived directly from nicotine, N'-formylnornicotine and N'-carboethoxynornicotine are metabolites of nornicotine. Thus, it is directly demonstrated that N'-formylnornicotine is not an intermediate in nicotine demethylation.

Lidocaine and ropivacaine, but not bupivacaine, demethylate deoxyribonucleic acid in breast cancer cells in vitro

NARCIS (Netherlands)

Lirk, P.; Hollmann, M. W.; Fleischer, M.; Weber, N. C.; Fiegl, H.

2014-01-01

Lidocaine demethylates deoxyribonucleic acid (DNA) in breast cancer cells. This modification of epigenetic information may be of therapeutic relevance in the perioperative period, because a decrease in methylation can reactivate tumour suppressor genes and inhibit tumour growth. The objectives of

O2 -independent demethylation of trimethylamine N-oxide by Tdm of Methylocella silvestris.

Science.gov (United States)

Zhu, Yijun; Ksibe, Amira Z; Schäfer, Hendrik; Blindauer, Claudia A; Bugg, Timothy D H; Chen, Yin

2016-11-01

Bacterial trimethylamine N-oxide (TMAO) demethylase, Tdm, carries out an unusual oxygen-independent demethylation reaction, resulting in the formation of dimethylamine and formaldehyde. In this study, site-directed mutagenesis, homology modelling and metal analyses by inorganic mass spectrometry have been applied to gain insight into metal stoichiometry and underlying catalytic mechanism of Tdm of Methylocella silvestris BL2. Herein, we demonstrate that active Tdm has 1 molar equivalent of Zn 2+ and 1 molar equivalent of non-haem Fe 2+ . We further investigated Zn 2+ - and Fe 2+ -binding sites through homology modelling and site-directed mutagenesis and found that Zn 2+ is coordinated by a 3-sulfur-1-O motif. An aspartate residue (D198) likely bridges Fe 2+ and Zn 2+ centres, either directly or indirectly via H-bonding through a neighbouring H 2 O molecule. H276 contributes to Fe 2+ binding, mutation of which results in an inactive enzyme, and the loss of iron, but not zinc. Site-directed mutagenesis of Tdm also led to the identification of three hydrophobic aromatic residues likely involved in substrate coordination (F259, Y305, W321), potentially through a cation-π interaction. Furthermore, a crossover experiment using a substrate analogue gave direct evidence that a trimethylamine-alike intermediate was produced during the Tdm catalytic cycle, suggesting TMAO has a dual role of being both a substrate and an oxygen donor for formaldehyde formation. Together, our results provide novel insight into the role of Zn 2+ and Fe 2+ in the catalysis of TMAO demethylation by this unique oxygen-independent enzyme. © 2016 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

The autoradiolytic and the γ-induced demethylation of solid thymine-(methyl-14C)

International Nuclear Information System (INIS)

Merwitz, O.

1980-01-01

The autoradiolytic and the γ-induced demethylation of solid thymine were measured qualitatively and quantitatively for the first time with specially purified thymine-(methyl- 14 C). Analogous experiments with thymine-(methyl- 3 H) and radio-gaschromatographic analysis provided proof for the formation of molecular hydrogen and methane. Ethane was not detected. The results are discussed in connection with e.s.r.-spectroscopic studies. (author)

A probabilistic generative model for quantification of DNA modifications enables analysis of demethylation pathways.

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Äijö, Tarmo; Huang, Yun; Mannerström, Henrik; Chavez, Lukas; Tsagaratou, Ageliki; Rao, Anjana; Lähdesmäki, Harri

2016-03-14

We present a generative model, Lux, to quantify DNA methylation modifications from any combination of bisulfite sequencing approaches, including reduced, oxidative, TET-assisted, chemical-modification assisted, and methylase-assisted bisulfite sequencing data. Lux models all cytosine modifications (C, 5mC, 5hmC, 5fC, and 5caC) simultaneously together with experimental parameters, including bisulfite conversion and oxidation efficiencies, as well as various chemical labeling and protection steps. We show that Lux improves the quantification and comparison of cytosine modification levels and that Lux can process any oxidized methylcytosine sequencing data sets to quantify all cytosine modifications. Analysis of targeted data from Tet2-knockdown embryonic stem cells and T cells during development demonstrates DNA modification quantification at unprecedented detail, quantifies active demethylation pathways and reveals 5hmC localization in putative regulatory regions.

Demethylation of methylated arsenic species during generation of arsanes with tetrahydridoborate(1−) in acidic media

Czech Academy of Sciences Publication Activity Database

Marschner, Karel; Musil, Stanislav; Dědina, Jiří

2016-01-01

Roč. 88, č. 12 (2016), s. 6366-6373 ISSN 0003-2700 R&D Projects: GA ČR GA14-23532S Institutional support: RVO:68081715 Keywords : arsenic speciation analysis * hydride generation * demethylation Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 6.320, year: 2016

Raman spectroscopic characterisations and analytical discrimination between caffeine and demethylated analogues of pharmaceutical relevance

Science.gov (United States)

Edwards, H. G. M.; Munshi, T.; Anstis, M.

2005-05-01

The FT Raman spectrum of caffeine was analysed along with that of its demethylated analogues, theobromine and theophylline. The similar but not identical structures of these three compounds allowed a more detailed assignment of the Raman bands. Noticeable differences in the Raman spectra of these compounds were apparent and key marker bands have been identified for the spectroscopic identification of these three compounds.

KDM1A triggers androgen-induced miRNA transcription via H3K4me2 demethylation and DNA oxidation.

Science.gov (United States)

Yang, Shu; Zhang, Jiyuan; Zhang, Yalong; Wan, Xuechao; Zhang, Congzhe; Huang, Xiaohui; Huang, Wenhua; Pu, Honglei; Pei, Chaohan; Wu, Hai; Huang, Yan; Huang, Shengdong; Li, Yao

2015-06-15

Androgen receptor (AR) is a ligand dependent transcription factor that regulates the transcription of target genes. AR activity is closely involved in the maintenance and progression of prostate cancer. After the binding with androgen, AR moves into nucleus and binds to DNA sequence containing androgen response elements (ARE). Flavin-dependent monoamine oxidase KDM1A is necessary for AR driven transcription while the mechanism remains unclear. The association between androgen-dependent transcription and oxidation was tested through pharmaceutical inhibitions and siRNA knockdown of DNA oxidation repair components in prostate cancer cells. The recruitment of involved proteins and the histone methylation dynamics on ARE region was explored by chromatin immunoprecipitation (ChIP). Oxidation inhibition reduced AR dependent expression of KLK3, TMPRSS2, hsa-miR-125b2, and hsa-miR-133b. And such reduction could be restored by H2 O2 treatment. KDM1A recruitment and H3K4me2 demethylation on ARE regions, which produce H2 O2 , are associated with AR targets transcription. AR targets transcription and coupled oxidation recruit 8-oxoguanine-DNA glycosylase (OGG1) and the nuclease APEX1 to ARE regions. Such recruitment depends on KDM1A, and is necessary for AR targets transcription. Our work underlined the importance of histone demethylation and DNA oxidation/repairing machinery in androgen-dependent transcription. The present finds have implications for research into new druggable targets for prostate cancer relying on the cascade of AR activity regulation. © 2015 Wiley Periodicals, Inc.

TSA-induced DNMT1 down-regulation represses hTERT expression via recruiting CTCF into demethylated core promoter region of hTERT in HCT116.

Science.gov (United States)

Choi, Jee-Hye; Min, Na Young; Park, Jina; Kim, Jin Hong; Park, Soo Hyun; Ko, Young Jong; Kang, Yoonsung; Moon, Young Joon; Rhee, Sangmyung; Ham, Seung Wook; Park, Ae Ja; Lee, Kwang-Ho

2010-01-01

Trichostatin A (TSA), an inhibitor of histone deacetylase, is a well-known antitumor agent that effectively and selectively induces tumor growth arrest and apoptosis. Recently, it was reported that hTERT is one of the primary targets for TSA-induced apoptosis in cancer cells but the mechanism of which has not yet been elucidated. In the present study, to better understand the epigenetic regulation mechanism responsible for the repression of hTERT by TSA, we examined expression of hTERT in the HCT116 colon cancer cell line after treatment with TSA and performed site-specific CpG methylation analysis of the hTERT promoter. We found that TSA-induced the demethylation of site-specific CpGs on the promoter of hTERT, which was caused by down-regulation of DNA methyltransferase 1 (DNMT1). Among the demethylated region, the 31st-33rd CpGs contained a binding site for CTCF, an inhibitor of hTERT transcription. ChIP analysis revealed that TSA-induced demethylation of the 31st-33rd CpGs promoted CTCF binding on hTERT promoter, leading to repression of hTERT. Taken together, down-regulation of DNMT1 by TSA caused demethylation of a CTCF binding site on the hTERT promoter, the result of which was repression of hTERT via recruitment of CTCF to the promoter. Copyright 2009 Elsevier Inc. All rights reserved.

Global demethylation of rat chondrosarcoma cells after treatment with 5-aza-2'-deoxycytidine results in increased tumorigenicity.

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Christopher A Hamm

Full Text Available Abnormal patterns of DNA methylation are observed in several types of human cancer. While localized DNA methylation of CpG islands has been associated with gene silencing, the effect that genome-wide loss of methylation has on tumorigenesis is not completely known. To examine its effect on tumorigenesis, we induced DNA demethylation in a rat model of human chondrosarcoma using 5-aza-2-deoxycytidine. Rat specific pyrosequencing assays were utilized to assess the methylation levels in both LINEs and satellite DNA sequences following 5-aza-2-deoxycytidine treatment. Loss of DNA methylation was accompanied by an increase in invasiveness of the rat chondrosarcoma cells, in vitro, as well as by an increase in tumor growth in vivo. Subsequent microarray analysis provided insight into the gene expression changes that result from 5-aza-2-deoxycytidine induced DNA demethylation. In particular, two genes that may function in tumorigenesis, sox-2 and midkine, were expressed at low levels in control cells but upon 5-aza-2-deoxycytidine treatment these genes became overexpressed. Promoter region DNA analysis revealed that these genes were methylated in control cells but became demethylated following 5-aza-2-deoxycytidine treatment. Following withdrawal of 5-aza-2-deoxycytidine, the rat chondrosarcoma cells reestablished global DNA methylation levels that were comparable to that of control cells. Concurrently, invasiveness of the rat chondrosarcoma cells, in vitro, decreased to a level indistinguishable to that of control cells. Taken together these experiments demonstrate that global DNA hypomethylation induced by 5-aza-2-deoxycytidine may promote specific aspects of tumorigenesis in rat chondrosarcoma cells.

Active Learning by Querying Informative and Representative Examples.

Science.gov (United States)

Huang, Sheng-Jun; Jin, Rong; Zhou, Zhi-Hua

2014-10-01

Active learning reduces the labeling cost by iteratively selecting the most valuable data to query their labels. It has attracted a lot of interests given the abundance of unlabeled data and the high cost of labeling. Most active learning approaches select either informative or representative unlabeled instances to query their labels, which could significantly limit their performance. Although several active learning algorithms were proposed to combine the two query selection criteria, they are usually ad hoc in finding unlabeled instances that are both informative and representative. We address this limitation by developing a principled approach, termed QUIRE, based on the min-max view of active learning. The proposed approach provides a systematic way for measuring and combining the informativeness and representativeness of an unlabeled instance. Further, by incorporating the correlation among labels, we extend the QUIRE approach to multi-label learning by actively querying instance-label pairs. Extensive experimental results show that the proposed QUIRE approach outperforms several state-of-the-art active learning approaches in both single-label and multi-label learning.

A phase I study of hydralazine to demethylate and reactivate the expression of tumor suppressor genes

International Nuclear Information System (INIS)

Zambrano, Pilar; Sandoval, Karina; Trejo-Becerril, Catalina; Chanona-Vilchis, Jose; Duenas-González, Alfonso; Segura-Pacheco, Blanca; Perez-Cardenas, Enrique; Cetina, Lucely; Revilla-Vazquez, Alma; Taja-Chayeb, Lucía; Chavez-Blanco, Alma; Angeles, Enrique; Cabrera, Gustavo

2005-01-01

The antihypertensive compound hydralazine is a known demethylating agent. This phase I study evaluated the tolerability and its effects upon DNA methylation and gene reactivation in patients with untreated cervical cancer. Hydralazine was administered to cohorts of 4 patients at the following dose levels: I) 50 mg/day, II) 75 mg/day, III) 100 mg/day and IV) 150 mg/day. Tumor biopsies and peripheral blood samples were taken the day before and after treatment. The genes APC, MGMT; ER, GSTP1, DAPK, RARβ, FHIT and p16 were evaluated pre and post-treatment for DNA promoter methylation and gene expression by MSP (Methylation-Specific PCR) and RT-PCR respectively in each of the tumor samples. Methylation of the imprinted H19 gene and the 'normally methylated' sequence clone 1.2 was also analyzed. Global DNA methylation was analyzed by capillary electrophoresis and cytosine extension assay. Toxicity was evaluated using the NCI Common Toxicity Criteria. Hydralazine was well tolerated. Toxicities were mild being the most common nausea, dizziness, fatigue, headache and palpitations. Overall, 70% of the pretreatment samples and all the patients had at least one methylated gene. Rates of demethylation at the different dose levels were as follows: 50 mg/day, 40%; 75 mg/day, 52%, 100 mg/day, 43%, and 150 mg/day, 32%. Gene expression analysis showed only 12 informative cases, of these 9 (75%) re-expressed the gene. There was neither change in the methylation status of H19 and clone 1.2 nor changes in global DNA methylation. Hydralazine at doses between 50 and 150 mg/day is well tolerated and effective to demethylate and reactivate the expression of tumor suppressor genes without affecting global DNA methylation

Mercury methylation and demethylation by periphyton biofilms and their host in a fluvial wetland of the St. Lawrence River (QC, Canada)

International Nuclear Information System (INIS)

Hamelin, Stéphanie; Planas, Dolors; Amyot, Marc

2015-01-01

Wetlands in large rivers are important sites of production of the neurotoxin methylmercury (MeHg), and the periphyton growing on wetland macrophytes are increasingly recognized as key players in this production and transfer in food webs. Information is lacking about mercury methylation (K m ) and demethylation (K d ) rates in periphytic biofilms from the Northern Hemisphere, as well as about the drivers of net MeHg production, hampering ecosystem modeling of Hg cycling. Mercury methylation and demethylation rates were measured in periphytic biofilms growing on submerged plants in a shallow fluvial lake located in a temperate cold region (St. Lawrence River, Quebec, Canada). Incubations were performed in situ within macrophyte beds using low-level spikes of 199 HgO and Me 200 Hg stable isotopes as tracers. A direct relationship was observed between K m (0.002 to 0.137 d −1 ) and [MeHg] in periphyton. A similar relationship was found between K d (0.096 to 0.334 d −1 ) and [inorganic Hg]. Periphyton of Lake St. Pierre reached high levels of net MeHg production that were two orders of magnitude higher than those found in local sediment. This production varied through the plant growing season and was mainly driven by environmental variables such as depth of growth, available light, dissolved oxygen, temperature, plant community structure, and productivity of the habitat. - Highlights: • Periphyton Hg methylation and demethylation were studied in a large fluvial lake. • Addition of stable Hg isotopes was used to obtain in situ rates for these processes. • Net methylation was higher in periphyton than in local sediments. • Methylation and demethylation rates fluctuated during the summer. • Key drivers of rates were depth, light, temperature, and community structure

Mercury methylation and demethylation by periphyton biofilms and their host in a fluvial wetland of the St. Lawrence River (QC, Canada)

Energy Technology Data Exchange (ETDEWEB)

Hamelin, Stéphanie; Planas, Dolors [GRIL, Département de sciences biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montreal, Quebec H3C 3P8 (Canada); Amyot, Marc [GRIL, Département de sciences biologiques, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, Quebec H3C 3J7 (Canada)

2015-04-15

Wetlands in large rivers are important sites of production of the neurotoxin methylmercury (MeHg), and the periphyton growing on wetland macrophytes are increasingly recognized as key players in this production and transfer in food webs. Information is lacking about mercury methylation (K{sub m}) and demethylation (K{sub d}) rates in periphytic biofilms from the Northern Hemisphere, as well as about the drivers of net MeHg production, hampering ecosystem modeling of Hg cycling. Mercury methylation and demethylation rates were measured in periphytic biofilms growing on submerged plants in a shallow fluvial lake located in a temperate cold region (St. Lawrence River, Quebec, Canada). Incubations were performed in situ within macrophyte beds using low-level spikes of {sup 199}HgO and Me{sup 200}Hg stable isotopes as tracers. A direct relationship was observed between K{sub m} (0.002 to 0.137 d{sup −1}) and [MeHg] in periphyton. A similar relationship was found between K{sub d} (0.096 to 0.334 d{sup −1}) and [inorganic Hg]. Periphyton of Lake St. Pierre reached high levels of net MeHg production that were two orders of magnitude higher than those found in local sediment. This production varied through the plant growing season and was mainly driven by environmental variables such as depth of growth, available light, dissolved oxygen, temperature, plant community structure, and productivity of the habitat. - Highlights: • Periphyton Hg methylation and demethylation were studied in a large fluvial lake. • Addition of stable Hg isotopes was used to obtain in situ rates for these processes. • Net methylation was higher in periphyton than in local sediments. • Methylation and demethylation rates fluctuated during the summer. • Key drivers of rates were depth, light, temperature, and community structure.

Herbivore-Induced DNA Demethylation Changes Floral Signalling and Attractiveness to Pollinators in Brassica rapa.

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Roman T Kellenberger

Full Text Available Plants have to fine-tune their signals to optimise the trade-off between herbivore deterrence and pollinator attraction. An important mechanism in mediating plant-insect interactions is the regulation of gene expression via DNA methylation. However, the effect of herbivore-induced DNA methylation changes on pollinator-relevant plant signalling has not been systematically investigated. Here, we assessed the impact of foliar herbivory on DNA methylation and floral traits in the model crop plant Brassica rapa. Methylation-sensitive amplified fragment length polymorphism (MSAP analysis showed that leaf damage by the caterpillar Pieris brassicae was associated with genome-wide methylation changes in both leaves and flowers of B. rapa as well as a downturn in flower number, morphology and scent. A comparison to plants with jasmonic acid-induced defence showed similar demethylation patterns in leaves, but both the floral methylome and phenotype differed significantly from P. brassicae infested plants. Standardised genome-wide demethylation with 5-azacytidine in five different B. rapa full-sib groups further resulted in a genotype-specific downturn of floral morphology and scent, which significantly reduced the attractiveness of the plants to the pollinator bee Bombus terrestris. These results suggest that DNA methylation plays an important role in adjusting plant signalling in response to changing insect communities.

Recent activities of the Seismology Division Early Career Representative(s)

Science.gov (United States)

Agius, Matthew; Van Noten, Koen; Ermert, Laura; Mai, P. Martin; Krawczyk, CharLotte

2016-04-01

The European Geosciences Union is a bottom-up-organisation, in which its members are represented by their respective scientific divisions, committees and council. In recent years, EGU has embarked on a mission to reach out for its numerous 'younger' members by giving awards to outstanding young scientists and the setting up of Early Career Scientists (ECS) representatives. The division representative's role is to engage in discussions that concern students and early career scientists. Several meetings between all the division representatives are held throughout the year to discuss ideas and Union-wide issues. One important impact ECS representatives have had on EGU is the increased number of short courses and workshops run by ECS during the annual General Assembly. Another important contribution of ECS representatives was redefining 'Young Scientist' to 'Early Career Scientist', which avoids discrimination due to age. Since 2014, the Seismology Division has its own ECS representative. In an effort to more effectively reach out for young seismologists, a blog and a social media page dedicated to seismology have been set up online. With this dedicated blog, we'd like to give more depth to the average browsing experience by enabling young researchers to explore various seismology topics in one place while making the field more exciting and accessible to the broader community. These pages are used to promote the latest research especially of young seismologists and to share interesting seismo-news. Over the months the pages proved to be popular, with hundreds of views every week and an increased number of followers. An online survey was conducted to learn more about the activities and needs of early career seismologists. We present the results from this survey, and the work that has been carried out over the last two years, including detail of what has been achieved so far, and what we would like the ECS representation for Seismology to achieve. Young seismologists are

A new mechanism for reduced sensitivity to demethylation-inhibitor fungicides in the fungal banana black Sigatoka pathogen Pseudocercospora fijiensis

NARCIS (Netherlands)

Díaz-Trujillo, C.; Chong, P.; Stergiopoulos, I.; Meijer, H.J.G.; Wit, de P.J.G.M.; Kema, G.H.J.

2017-01-01

The Dothideomycete Pseudocercospora fijiensis, previously Mycosphaerella fijiensis, is the causal agent of black Sigatoka, one of the most destructive diseases of bananas and plantains. Disease management depends on fungicide applications with a major share for sterol demethylation-inhibitors

A new mechanism for reduced sensitivity to demethylation-inhibitor fungicides in the fungal banana black Sigatoka pathogen Pseudocercospora fijiensis

NARCIS (Netherlands)

Díaz-Trujillo, C.; Chong, P.; Stergiopoulos, I.; Meijer, H.J.G.; Wit, de P.J.G.M.; Kema, G.H.J.

2018-01-01

The Dothideomycete Pseudocercospora fijiensis, previously Mycosphaerella fijiensis, is the causal agent of black Sigatoka, one of the most destructive diseases of bananas and plantains. Disease management depends on fungicide applications with a major share for sterol demethylation-inhibitors

Mitochondrial control through nutritionally regulated global histone H3 lysine-4 demethylation.

Science.gov (United States)

Soloveychik, Maria; Xu, Mengshu; Zaslaver, Olga; Lee, Kwanyin; Narula, Ashrut; Jiang, River; Rosebrock, Adam P; Caudy, Amy A; Meneghini, Marc D

2016-11-29

Histone demethylation by Jumonji-family proteins is coupled with the decarboxylation of α-ketoglutarate (αKG) to yield succinate, prompting hypotheses that their activities are responsive to levels of these metabolites in the cell. Consistent with this paradigm we show here that the Saccharomyces cerevisiae Jumonji demethylase Jhd2 opposes the accumulation of H3K4me3 in fermenting cells only when they are nutritionally manipulated to contain an elevated αKG/succinate ratio. We also find that Jhd2 opposes H3K4me3 in respiratory cells that do not exhibit such an elevated αKG/succinate ratio. While jhd2∆ caused only limited gene expression defects in fermenting cells, transcript profiling and physiological measurements show that JHD2 restricts mitochondrial respiratory capacity in cells grown in non-fermentable carbon in an H3K4me-dependent manner. In association with these phenotypes, we find that JHD2 limits yeast proliferative capacity under physiologically challenging conditions as measured by both replicative lifespan and colony growth on non-fermentable carbon. JHD2's impact on nutrient response may reflect an ancestral role of its gene family in mediating mitochondrial regulation.

Mitochondrial control through nutritionally regulated global histone H3 lysine-4 demethylation

Science.gov (United States)

Soloveychik, Maria; Xu, Mengshu; Zaslaver, Olga; Lee, Kwanyin; Narula, Ashrut; Jiang, River; Rosebrock, Adam P.; Caudy, Amy A.; Meneghini, Marc D.

2016-01-01

Histone demethylation by Jumonji-family proteins is coupled with the decarboxylation of α-ketoglutarate (αKG) to yield succinate, prompting hypotheses that their activities are responsive to levels of these metabolites in the cell. Consistent with this paradigm we show here that the Saccharomyces cerevisiae Jumonji demethylase Jhd2 opposes the accumulation of H3K4me3 in fermenting cells only when they are nutritionally manipulated to contain an elevated αKG/succinate ratio. We also find that Jhd2 opposes H3K4me3 in respiratory cells that do not exhibit such an elevated αKG/succinate ratio. While jhd2∆ caused only limited gene expression defects in fermenting cells, transcript profiling and physiological measurements show that JHD2 restricts mitochondrial respiratory capacity in cells grown in non-fermentable carbon in an H3K4me-dependent manner. In association with these phenotypes, we find that JHD2 limits yeast proliferative capacity under physiologically challenging conditions as measured by both replicative lifespan and colony growth on non-fermentable carbon. JHD2’s impact on nutrient response may reflect an ancestral role of its gene family in mediating mitochondrial regulation. PMID:27897198

Representing cognitive activities and errors in HRA trees

International Nuclear Information System (INIS)

Gertman, D.I.

1992-01-01

A graphic representation method is presented herein for adapting an existing technology--human reliability analysis (HRA) event trees, used to support event sequence logic structures and calculations--to include a representation of the underlying cognitive activity and corresponding errors associated with human performance. The analyst is presented with three potential means of representing human activity: the NUREG/CR-1278 HRA event tree approach; the skill-, rule- and knowledge-based paradigm; and the slips, lapses, and mistakes paradigm. The above approaches for representing human activity are integrated in order to produce an enriched HRA event tree -- the cognitive event tree system (COGENT)-- which, in turn, can be used to increase the analyst's understanding of the basic behavioral mechanisms underlying human error and the representation of that error in probabilistic risk assessment. Issues pertaining to the implementation of COGENT are also discussed

Exploring Representativeness and Informativeness for Active Learning.

Science.gov (United States)

Du, Bo; Wang, Zengmao; Zhang, Lefei; Zhang, Liangpei; Liu, Wei; Shen, Jialie; Tao, Dacheng

2017-01-01

How can we find a general way to choose the most suitable samples for training a classifier? Even with very limited prior information? Active learning, which can be regarded as an iterative optimization procedure, plays a key role to construct a refined training set to improve the classification performance in a variety of applications, such as text analysis, image recognition, social network modeling, etc. Although combining representativeness and informativeness of samples has been proven promising for active sampling, state-of-the-art methods perform well under certain data structures. Then can we find a way to fuse the two active sampling criteria without any assumption on data? This paper proposes a general active learning framework that effectively fuses the two criteria. Inspired by a two-sample discrepancy problem, triple measures are elaborately designed to guarantee that the query samples not only possess the representativeness of the unlabeled data but also reveal the diversity of the labeled data. Any appropriate similarity measure can be employed to construct the triple measures. Meanwhile, an uncertain measure is leveraged to generate the informativeness criterion, which can be carried out in different ways. Rooted in this framework, a practical active learning algorithm is proposed, which exploits a radial basis function together with the estimated probabilities to construct the triple measures and a modified best-versus-second-best strategy to construct the uncertain measure, respectively. Experimental results on benchmark datasets demonstrate that our algorithm consistently achieves superior performance over the state-of-the-art active learning algorithms.

Relationship of the demethylation of the DNA with the induction of the sister chromatid exchanges (SCE) In vivo

International Nuclear Information System (INIS)

Toribio E, E.

2005-01-01

The methylation of the DNA is an epigenetic modification that has an important paper in the regulation of the functionality of the genome of the organisms. It can be altered by demethylation processes, either natural or experimentally induced. The 5-azacytidine (Aza) is a compound that causes the demethylation of the DNA (dm-DNA), inducing with it, expression genic and increase in the frequency of the Sister Chromatid Exchange (SCE). The SCE is a genotoxicity indicator, caused by diverse mutagens and carcinogen. Since the biological meaning and the formation mechanism of this phenomenon has not been totally illustrious, the exploration of the relation between the dm-DNA and the induction of SCE, it could offer new knowledge to explain those queries. The purpose of this work was to study in cells of the mouse bone marrow In vivo, the effect of the Aza on the induction of SCE, based on two aspects: 1) dose answer and 2) the effectiveness of multiple exhibition. To six groups of three to five animals, they are administered Aza to dose of 5, 10, 15 or 20 mg/Kg of weight; in sharp or multiple form, previously to the bromodeoxyuridine supply and 24 h was sacrificed after this; 2 h after an injection with colchicine. Preparations of those metaphases were made, those which were dyed by means of a technique of fluorescence more Giemsa. It was observed that to sharp low dose, the Aza produced an increment in the frequency of SCE that although small it was proportional and statistically significant. To sharp and multiple high doses, the Aza doesn't cause additional increments of SCE, but if toxicity at cellular level and of individuals. It is concluded that a relationship exists between the dm-DNA and the induction of SCE. It is suggested that the total demethylation of the DNA causes 2 SCE/Cell in cells of the mouse bone marrow, or that the cytotoxicity prevents to evidence a bigger induction. (Author)

Tet1 oxidase regulates neuronal gene transcription, active DNA hydroxymethylation, object location memory, and threat recognition memory

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Dinesh Kumar

2015-10-01

Full Text Available A dynamic equilibrium between DNA methylation and demethylation of neuronal activity-regulated genes is crucial for memory processes. However, the mechanisms underlying this equilibrium remain elusive. Tet1 oxidase has been shown to play a key role in the active DNA demethylation in the central nervous system. In this study, we used Tet1 gene knockout (Tet1KO mice to examine the involvement of Tet1 in memory consolidation and storage in the adult brain. We found that Tet1 ablation leads to altered expression of numerous neuronal activity-regulated genes, compensatory upregulation of active demethylation pathway genes, and upregulation of various epigenetic modifiers. Moreover, Tet1KO mice showed an enhancement in the consolidation and storage of threat recognition (cued and contextual fear conditioning and object location memories. We conclude that Tet1 plays a critical role in regulating neuronal transcription and in maintaining the epigenetic state of the brain associated with memory consolidation and storage.

Cell-based DNA demethylation detection system for screening of epigenetic drugs in 2D, 3D and xenograft models

Czech Academy of Sciences Publication Activity Database

Agrawal, K.; Das, V.; Otmar, Miroslav; Krečmerová, Marcela; Džubák, P.; Hajdúch, M.

2015-01-01

Roč. 14, Suppl 2 (2015), B72 ISSN 1535-7163. [AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics. 05.11.2015-09.11.2015, Boston] R&D Projects: GA MPO(CZ) FR-TI4/625; GA MŠk(CZ) LO1304 Institutional support: RVO:61388963 Keywords : demethylation * epigenetic drugs * fluorescence detection system Subject RIV: CC - Organic Chemistry

Tet1 Oxidase Regulates Neuronal Gene Transcription, Active DNA Hydroxy-methylation, Object Location Memory, and Threat Recognition Memory.

Science.gov (United States)

Kumar, Dinesh; Aggarwal, Milan; Kaas, Garrett A; Lewis, John; Wang, Jing; Ross, Daniel L; Zhong, Chun; Kennedy, Andrew; Song, Hongjun; Sweatt, J David

2015-10-01

A dynamic equilibrium between DNA methylation and demethylation of neuronal activity-regulated genes is crucial for memory processes. However, the mechanisms underlying this equilibrium remain elusive. Tet1 oxidase has been shown to play a key role in the active DNA demethylation in the CNS. In this study, we used Tet1 gene knockout (Tet1KO) mice to examine the involvement of Tet1 in memory consolidation and storage in the adult brain. We found that Tet1 ablation leads to: altered expression of numerous neuronal activity-regulated genes, compensatory upregulation of active demethylation pathway genes, and upregulation of various epigenetic modifiers. Moreover, Tet1KO mice showed an enhancement in the consolidation and storage of threat recognition (cued and contextual fear conditioning) and object location memories. We conclude that Tet1 plays a critical role in regulating neuronal transcription and in maintaining the epigenetic state of the brain associated with memory consolidation and storage.

SET oncoprotein accumulation regulates transcription through DNA demethylation and histone hypoacetylation.

Science.gov (United States)

Almeida, Luciana O; Neto, Marinaldo P C; Sousa, Lucas O; Tannous, Maryna A; Curti, Carlos; Leopoldino, Andreia M

2017-04-18

Epigenetic modifications are essential in the control of normal cellular processes and cancer development. DNA methylation and histone acetylation are major epigenetic modifications involved in gene transcription and abnormal events driving the oncogenic process. SET protein accumulates in many cancer types, including head and neck squamous cell carcinoma (HNSCC); SET is a member of the INHAT complex that inhibits gene transcription associating with histones and preventing their acetylation. We explored how SET protein accumulation impacts on the regulation of gene expression, focusing on DNA methylation and histone acetylation. DNA methylation profile of 24 tumour suppressors evidenced that SET accumulation decreased DNA methylation in association with loss of 5-methylcytidine, formation of 5-hydroxymethylcytosine and increased TET1 levels, indicating an active DNA demethylation mechanism. However, the expression of some suppressor genes was lowered in cells with high SET levels, suggesting that loss of methylation is not the main mechanism modulating gene expression. SET accumulation also downregulated the expression of 32 genes of a panel of 84 transcription factors, and SET directly interacted with chromatin at the promoter of the downregulated genes, decreasing histone acetylation. Gene expression analysis after cell treatment with 5-aza-2'-deoxycytidine (5-AZA) and Trichostatin A (TSA) revealed that histone acetylation reversed transcription repression promoted by SET. These results suggest a new function for SET in the regulation of chromatin dynamics. In addition, TSA diminished both SET protein levels and SET capability to bind to gene promoter, suggesting that administration of epigenetic modifier agents could be efficient to reverse SET phenotype in cancer.

Resolution, configurational assignment, and enantiopharmacology at glutamate receptors of 2-amino-3-(3-carboxy-5-methyl-4-isoxazolyl)propionic acid (ACPA) and demethyl-ACPA

DEFF Research Database (Denmark)

Johansen, T N; Stensbøl, T B; Nielsen, B

2001-01-01

We have previously described (RS)-2-amino-3-(3-carboxy-5-methyl-4-isoxazolyl)propionic acid (ACPA) as a potent agonist at the (RS)-2-amino-3-(3-hydroxy-5-methyl-4-isoxazolyl)propionic acid (AMPA) receptor subtype of (S)-glutamic acid (Glu) receptors. We now report the chromatographic resolution...... of ACPA and (RS)-2-amino-3-(3-carboxy-4-isoxazolyl)propionic acid (demethyl-ACPA) using a Sumichiral OA-5000 column. The configuration of the enantiomers of both compounds have been assigned based on X-ray crystallographic analyses, supported by circular dichroism spectra and elution orders on chiral HPLC...... columns. Furthermore, the enantiopharmacology of ACPA and demethyl-ACPA was investigated using radioligand binding and cortical wedge electrophysiological assay systems and cloned metabotropic Glu receptors. (S)-ACPA showed high affinity in AMPA binding (IC(50) = 0.025 microM), low affinity in kainic acid...

The Roles of a Flavone-6-Hydroxylase and 7-O-Demethylation in the Flavone Biosynthetic Network of Sweet Basil*

Science.gov (United States)

Berim, Anna; Gang, David R.

2013-01-01

Lipophilic flavonoids found in the Lamiaceae exhibit unusual 6- and 8-hydroxylations whose enzymatic basis is unknown. We show that crude protein extracts from peltate trichomes of sweet basil (Ocimum basilicum L.) cultivars readily hydroxylate position 6 of 7-O-methylated apigenin but not apigenin itself. The responsible protein was identified as a P450 monooxygenase from the CYP82 family, a family not previously reported to be involved in flavonoid metabolism. This enzyme prefers flavones but also accepts flavanones in vitro and requires a 5-hydroxyl in addition to a 7-methoxyl residue on the substrate. A peppermint (Mentha × piperita L.) homolog displayed identical substrate requirements, suggesting that early 7-O-methylation of flavones might be common in the Lamiaceae. This hypothesis is further substantiated by the pioneering discovery of 2-oxoglutarate-dependent flavone demethylase activity in basil, which explains the accumulation of 7-O-demethylated flavone nevadensin. PMID:23184958

[Clinical Significance of ID4 Gene Mehtylation in Demethylation-Treated MDS Cell Line and 2 MDS Patients].

Science.gov (United States)

Kang, Hui-Yuan; Wang, Xin-Rong; Gao, Li; Wang, Wei; Li, Mian-Yang; Wang, Li-Li; Wang, Cheng-Bin; Yu, Li

2015-04-01

To evaluate significance of ID4 gene mehtylation in demethylating myelodysplastic syndrome(MDS) cell Line MUTZ1 and 2 patients with MDS. The methylation-specific PCR (MS-PCR) and reverse transcription-PCR (RT-PCR) were applied to identify the methylation status and gene expression of ID4 gene in MDS cell line MUTZ1, a patient with aplastic anemia(AA) and a donor with normal bone marrow (NBM). RT-PCR was applied to detect the ID4 gene expression status in MUTZ1 cell line treated with decitabine at 3 different concentrations. Then bisulfite sequencing PCR (BSP) was applied to detect ID4 gene methylation status in 2 MDS parients treated with decitabine. The MDS cell line MUTZ-1 displayed a complete methylation of ID4 gene promoter with little mRNA expression. Inversely, bone marrow of an AA patient and NBM showed complete unmethylation of this gene with intensity mRNA expression. With the increase of decitabine concentration, ID4 gene mRNA expression was more and more increased. After decitabine treatment, ID4 gene methylation-positive frequencies of both the 2 MDS patients were much more decreased than that of the first treatment. So, ID4 gene mRNA expression inhibited by promoter hypemethylation could be recovered by using demethylation medicine. ID4 as a new potential anti-oncogene suggests that its methylation may become a marker for selection and assessment of therapeutic schedules in patients with MDS.

Cell-based DNA demethylation detection system for screening of epigenetic drugs in 2D, 3D, and xenograft models

Czech Academy of Sciences Publication Activity Database

Agrawal, K.; Das, V.; Otmar, Miroslav; Krečmerová, Marcela; Džubák, P.; Hajdúch, M.

91A, č. 2 (2017), s. 133-143 ISSN 1552-4922 R&D Projects: GA MZd(CZ) NV15-31984A; GA MŠk(CZ) LO1304; GA MŠk(CZ) LM2015064; GA TA ČR(CZ) TE01020028 Institutional support: RVO:61388963 Keywords : DNA methylation * DNA methylation inhibitors * demethylation detection system * epigenetic drugs * high content screening Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 3.222, year: 2016

DNA methylation in porcine preimplantation embryos developed in vivo and produced by in vitro fertilization, parthenogenetic activation and somatic cell nuclear transfer

DEFF Research Database (Denmark)

Deshmukh, Rahul Shahaji; Østrup, Olga; Østrup, Esben

2011-01-01

DNA demethylation and remethylation are crucial for reprogramming of the differentiated parental/somatic genome in the recipient ooplasm upon somatic cell nuclear transfer. Here, we analyzed the DNA methylation dynamics during porcine preimplantation development. Porcine in vivo developed (IV......), in vitro fertilized (IVF), somatic cell nuclear transfer (SCNT) and parthenogenetically activated (PA) embryos were evaluated for DNA methylation quantification at different developmental stages. Fertilized (IV and IVF) one-cell stages lacked a substantial active demethylation of the paternal genome...

DNA methylation in porcine preimplantation embryos developed in-vivo or produced by in-vitro fertilization, parthenogenetic activation and somatic cell nuclear transfer

DEFF Research Database (Denmark)

Deshmukh, Rahul Shahaji; Østrup, Olga; Østrup, Esben

2011-01-01

DNA demethylation and remethylation are crucial for reprogramming of the differentiated parental/somatic genome in the recipient ooplasm upon somatic cell nuclear transfer. Here, we analyzed the DNA methylation dynamics during porcine preimplantation development. Porcine in vivo developed (IV......), in vitro fertilized (IVF), somatic cell nuclear transfer (SCNT) and parthenogenetically activated (PA) embryos were evaluated for DNA methylation quantification at different developmental stages. Fertilized (IV and IVF) one-cell stages lacked a substantial active demethylation of the paternal genome...

Suppression of Wnt signaling by the miR-29 family is mediated by demethylation of WIF-1 in non-small-cell lung cancer

Energy Technology Data Exchange (ETDEWEB)

Tan, Min [Department of Respiratory Medicine, Shanghai Tenth People’s Hospital, Tongji University, Shanghai 200072 (China); Wu, Junjie, E-mail: wujunjiesh@126.com [Department of Pneumology, Changhai Hospital of Shanghai, Second Military Medical University, Shanghai 200433 (China); State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai 200433 (China); Cai, Yong, E-mail: dryongcai@126.com [Department of Radiation Oncology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai 200433 (China)

2013-09-06

Highlights: •Dnmt3A and Dnmt3B are involved in the down-regulation of WIF-1 expression in non-small-cell lung cancer. •MiR-29 family members could restore WIF-1 expression through demethylation. •MiR-29s suppress Wnt/β-catenin signaling pathway and inhibit tumor growth. •The expression of miR-29a and miR-29b could be regulated partially in a positive feedback loop. -- Abstract: Wnt inhibitory factor-1 (WIF-1) silencing induced by promoter hypermethylation is a common mechanism of aberrant activation of the Wnt signaling pathway in non-small-cell lung cancer (NSCLC). However, the activity of regulators associated with the methylation of the WIF-1 gene remains unclear. Here, we investigated the role of three DNA methyltransferases (DNMT1, DNMT3A and DNMT3B) in the expression of WIF-1. The three DNMTs were up-regulated in NSCLC tumor tissues and suppression of DNMT3A and DNMT3B restored the expression of WIF-1 in NSCLC cells. The miR-29 family (miR-29a, -29b, and -29c), which negatively regulates DNMT3A and DNMT3B, was examined in association with the Wnt/β-catenin signaling pathway. A positive correlation between the expression of WIF-1 and that of MiR-29s was observed in NSCLC tissues. Methylation-specific PCR and Western blotting indicated that miR-29s positively regulate WIF-1 expression by inhibiting the methylation of its promoter. Furthermore, miR-29 overexpression downregulated β-catenin expression, inhibited cell proliferation and induced apoptosis. The expression of miR-29a and miR-29b was partially regulated by DNMT3A and DNMT3B in a positive feedback loop. Taken together, our findings show that miR-29s suppress the Wnt signaling pathway through demethylation of WIF-1 in NSCLC.

Synthesis and antibacterial activity of insignin and its 8-methoxy- and 6-demethoxy derivatives

Directory of Open Access Journals (Sweden)

Aamer Saeed

2006-06-01

Full Text Available A short and efficient synthesis of insignin (8-hydroxy-6-methoxy-3-heptyl- isocoumarin (1, a metabolite of natural lichens, has been described. Reaction of 3,5-dimethoxyhomophthalic anhydride (2 with octanoyl chloride in the presence of 1,1,3,3-tetramethylguanidine (TMG and triethyl amine afforded the 6,8-dimethoxy-3-heptylisocoumarin (3 in high yield. Regioselective demethylation of the latter using anhydrous aluminum chloride furnished the 8-hydroxy-6-methoxy-3-heptylisocoumarin (1 whereas, the complete demethylation of (3 yielded 6,8-dihydroxy-3-heptylisocoumarin (4. The isocoumarins (1, 3, and 4 were examined in vitro for antibacterial activity and were shown to exhibit moderate activity.

Production of 17-O-demethyl-geldanamycin, a cytotoxic ansamycin polyketide, by Streptomyces hygroscopicus DEM20745.

Science.gov (United States)

Baksh, Aron; Kepplinger, Bernhard; Isah, Hadiza A; Probert, Michael R; Clegg, William; Wills, Corinne; Goodfellow, Michael; Errington, Jeff; Allenby, Nick; Hall, Michael J

2017-08-01

The actinomycete DEM20745, collected from non-rhizosphere soil adjacent to Paraserianthes falactaria trees (Cangkringan, Indonesia), is an efficient producer of the anticancer ansamycin polyketide 17-O-demethyl-geldanamycin (17-O-DMG), a biosynthetic precursor of the Hsp90 inhibitor geldanamycin (GDM). In DEM20745, 17-O-DMG is the major ansamycin product observed reaching a maximum titre of 17 mg/L in the fermentation broth. 17-O-DMG has the potential to be a key starting material for the semi-synthesis of GDM analogues for use in anticancer therapy. Thus, this preferential biosynthesis of 17-O-DMG facilitates easy access to this important molecule and provides further insight in the biosynthesis of the geldanamycins.

Demethylation by 5-aza-2'-deoxycytidine in colorectal cancer cells targets genomic DNA whilst promoter CpG island methylation persists

International Nuclear Information System (INIS)

Mossman, David; Kim, Kyu-Tae; Scott, Rodney J

2010-01-01

DNA methylation and histone acetylation are epigenetic modifications that act as regulators of gene expression. Aberrant epigenetic gene silencing in tumours is a frequent event, yet the factors which dictate which genes are targeted for inactivation are unknown. DNA methylation and histone acetylation can be modified with the chemical agents 5-aza-2'-deoxycytidine (5-aza-dC) and Trichostatin A (TSA) respectively. The aim of this study was to analyse de-methylation and re-methylation and its affect on gene expression in colorectal cancer cell lines treated with 5-aza-dC alone and in combination with TSA. We also sought to identify methylation patterns associated with long term reactivation of previously silenced genes. Colorectal cancer cell lines were treated with 5-aza-dC, with and without TSA, to analyse global methylation decreases by High Performance Liquid Chromatography (HPLC). Re-methylation was observed with removal of drug treatments. Expression arrays identified silenced genes with differing patterns of expression after treatment, such as short term reactivation or long term reactivation. Sodium bisulfite sequencing was performed on the CpG island associated with these genes and expression was verified with real time PCR. Treatment with 5-aza-dC was found to affect genomic methylation and to a lesser extent gene specific methylation. Reactivated genes which remained expressed 10 days post 5-aza-dC treatment featured hypomethylated CpG sites adjacent to the transcription start site (TSS). In contrast, genes with uniformly hypermethylated CpG islands were only temporarily reactivated. These results imply that 5-aza-dC induces strong de-methylation of the genome and initiates reactivation of transcriptionally inactive genes, but this does not require gene associated CpG island de-methylation to occur. In addition, for three of our selected genes, hypomethylation at the TSS of an epigenetically silenced gene is associated with the long term reversion of

Aerosol azacytidine inhibits orthotopic lung cancers in mice through Its DNA demethylation and gene reactivation effects.

Directory of Open Access Journals (Sweden)

Xuan Qiu

Full Text Available We devised an aerosol based demethylation therapy to achieve therapeutic efficacy in premalignant or in situ lesions of lung cancer, without systemic toxicity. Optimum regimens of aerosolized azacytidine (Aza were designed and used in orthotopic human non-small cell lung cancer xenograft models. The therapeutic efficacy and toxicity of aerosol Aza were compared with intravenously administered Aza. We observed that 80% of the droplets of the aerosol Aza measured ∼0.1-5 microns, which resulted in deposition in the lower bronchial airways. An animal model that phenocopies field carcinogeneisis in humans was developed by intratracheal inoculation of the human lung cancer cells in mice, thus resulting in their distribution throughout the entire airway space. Aerosolized Aza significantly prolonged the survival of mice bearing endo-bronchial lung tumors. The aerosol treatment did not cause any detectable lung toxicity or systemic toxicity. A pre-pharmacokinetic study in mice demonstrated that lung deposition of aerosolized Aza was significantly higher than the intravenous route. Lung tumors were resected after aerosol treatment and the methylation levels of 24 promoters of tumor-suppresser genes related to lung cancer were analyzed. Aerosol Aza significantly reduced the methylation level in 9 of these promoters and reexpressed several genes tested. In conclusion, aerosol Aza at non-cytotoxic doses appears to be effective and results in DNA demethylation and tumor suppressor gene re-expression. The therapeutic index of aerosol Aza is >100-fold higher than that of intravenous Aza. These results provide a preclinical rationale for a phase I clinical trial of aerosol Aza to be initiated at our Institution.

A 5-methylcytosine DNA glycosylase/lyase demethylates the retrotransposon Tos17 and promotes its transposition in rice

KAUST Repository

La, Honggui; Ding, Bo; Mishra, Gyan Prakash; Zhou, Bo; Yang, Hongmei; Bellizzi, Maria Del Rosario; Chen, Songbiao; Meyers, Blake C.; Peng, Zhaohua; Zhu, Jian-Kang; Wang, Guoliang

2011-01-01

DNA 5-methylcytosine (5-meC) is an important epigenetic mark for transcriptional gene silencing in many eukaryotes. In Arabidopsis, 5-meC DNA glycosylase/lyases actively remove 5-meC to counter-act transcriptional gene silencing in a locus-specific manner, and have been suggested to maintain the expression of transposons. However, it is unclear whether plant DNA demethylases can promote the transposition of transposons. Here we report the functional characterization of the DNA glycosylase/lyase DNG701 in rice. DNG701 encodes a large (1,812 amino acid residues) DNA glycosylase domain protein. Recombinant DNG701 protein showed 5-meC DNA glycosylase and lyase activities in vitro. Knockout or knockdown of DNG701 in rice plants led to DNA hypermethylation and reduced expression of the retrotransposon Tos17. Tos17 showed less transposition in calli derived from dng701 knockout mutant seeds compared with that in wild-type calli. Overexpression of DNG701 in both rice calli and transgenic plants substantially reduced DNA methylation levels of Tos17 and enhanced its expression. The overexpression also led to more frequent transposition of Tos17 in calli. Our results demonstrate that rice DNG701 is a 5-meC DNA glycosylase/lyase responsible for the demethylation of Tos17 and this DNA demethylase plays a critical role in promoting Tos17 transposition in rice calli.

A 5-methylcytosine DNA glycosylase/lyase demethylates the retrotransposon Tos17 and promotes its transposition in rice

KAUST Repository

La, Honggui

2011-09-06

DNA 5-methylcytosine (5-meC) is an important epigenetic mark for transcriptional gene silencing in many eukaryotes. In Arabidopsis, 5-meC DNA glycosylase/lyases actively remove 5-meC to counter-act transcriptional gene silencing in a locus-specific manner, and have been suggested to maintain the expression of transposons. However, it is unclear whether plant DNA demethylases can promote the transposition of transposons. Here we report the functional characterization of the DNA glycosylase/lyase DNG701 in rice. DNG701 encodes a large (1,812 amino acid residues) DNA glycosylase domain protein. Recombinant DNG701 protein showed 5-meC DNA glycosylase and lyase activities in vitro. Knockout or knockdown of DNG701 in rice plants led to DNA hypermethylation and reduced expression of the retrotransposon Tos17. Tos17 showed less transposition in calli derived from dng701 knockout mutant seeds compared with that in wild-type calli. Overexpression of DNG701 in both rice calli and transgenic plants substantially reduced DNA methylation levels of Tos17 and enhanced its expression. The overexpression also led to more frequent transposition of Tos17 in calli. Our results demonstrate that rice DNG701 is a 5-meC DNA glycosylase/lyase responsible for the demethylation of Tos17 and this DNA demethylase plays a critical role in promoting Tos17 transposition in rice calli.

Incidence of invasive macrophytes on methylmercury budget in temperate lakes: Central role of bacterial periphytic communities

International Nuclear Information System (INIS)

Gentès, Sophie; Monperrus, Mathilde; Legeay, Alexia; Maury-Brachet, Régine; Davail, Stephane; André, Jean-Marc; Guyoneaud, Rémy

2013-01-01

Several studies demonstrated high mercury (Hg) methylation and demethylation in the periphyton associated with floating roots in tropical ecosystems. The importance of aquatic plants on methylmercury production in three temperate ecosystems from south-western France was evaluated through Hg species concentrations, and Hg methylation/demethylation activities by using stable isotopic tracers ( 199 Hg(II), Me 201 Hg). Hg accumulation and high methylation and demethylation yields were detected in plant roots and periphyton, whereas results for sediment and water were low to insignificant. The presence of sulfate reducing prokaryotes was detected in all compartments (T-RFLP based on dsrAB amplified through nested PCR) and their main role in Hg methylation could be demonstrated. In turn, sulfate reduction inhibition did not affect demethylation activities. The estimation of net MeHg budgets in these ecosystems suggested that aquatic rhizosphere is the principal location for methylmercury production and may represent an important source for the contamination of the aquatic food chain. - Highlights: ► Both Hg methylation and demethylation occur in the periphyton of temperate ecosystems. ► Aquatic rhizosphere is the main compartment for net methylmercury production. ► Sulfate reducers are detected in all ecosystem compartments (water, sediment, periphyton). ► Sulfate reducers are responsible for methylmercury production in aquatic roots. - The incidence of periphytic microbial communities on net methylmercury production is highlighted in temperate aquatic ecosystems.

Agonists and partial agonists of rhodopsin: retinal polyene methylation affects receptor activation.

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Vogel, Reiner; Lüdeke, Steffen; Siebert, Friedrich; Sakmar, Thomas P; Hirshfeld, Amiram; Sheves, Mordechai

2006-02-14

Using Fourier transform infrared (FTIR) difference spectroscopy, we have studied the impact of sites and extent of methylation of the retinal polyene with respect to position and thermodynamic parameters of the conformational equilibrium between the Meta I and Meta II photoproducts of rhodopsin. Deletion of methyl groups to form 9-demethyl and 13-demethyl analogues, as well as addition of a methyl group at C10 or C12, shifted the Meta I/Meta II equilibrium toward Meta I, such that the retinal analogues behaved like partial agonists. This equilibrium shift resulted from an apparent reduction of the entropy gain of the transition of up to 65%, which was only partially offset by a concomitant reduction of the enthalpy increase. The analogues produced Meta II photoproducts with relatively small alterations, while their Meta I states were significantly altered, which accounted for the aberrant transitions to Meta II. Addition of a methyl group at C14 influenced the thermodynamic parameters but had little impact on the position of the Meta I/Meta II equilibrium. Neutralization of the residue 134 in the E134Q opsin mutant increased the Meta II content of the 13-demethyl analogue, but not of the 9-demethyl analogue, indicating a severe impairment of the allosteric coupling between the conserved cytoplasmic ERY motif involved in proton uptake and the Schiff base/Glu 113 microdomain in the 9-demethyl analogue. The 9-methyl group appears therefore essential for the correct positioning of retinal to link protonation of the cytoplasmic motif with protonation of Glu 113 during receptor activation.

Non-Relative Value Unit-Generating Activities Represent One-Fifth of Academic Neuroradiologist Productivity.

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Wintermark, M; Zeineh, M; Zaharchuk, G; Srivastava, A; Fischbein, N

2016-07-01

A neuroradiologist's activity includes many tasks beyond interpreting relative value unit-generating imaging studies. Our aim was to test a simple method to record and quantify the non-relative value unit-generating clinical activity represented by consults and clinical conferences, including tumor boards. Four full-time neuroradiologists, working an average of 50% clinical and 50% academic activity, systematically recorded all the non-relative value unit-generating consults and conferences in which they were involved during 3 months by using a simple, Web-based, computer-based application accessible from smartphones, tablets, or computers. The number and type of imaging studies they interpreted during the same period and the associated relative value units were extracted from our billing system. During 3 months, the 4 neuroradiologists working an average of 50% clinical activity interpreted 4241 relative value unit-generating imaging studies, representing 8152 work relative value units. During the same period, they recorded 792 non-relative value unit-generating study reviews as part of consults and conferences (not including reading room consults), representing 19% of the interpreted relative value unit-generating imaging studies. We propose a simple Web-based smartphone app to record and quantify non-relative value unit-generating activities including consults, clinical conferences, and tumor boards. The quantification of non-relative value unit-generating activities is paramount in this time of a paradigm shift from volume to value. It also represents an important tool for determining staffing levels, which cannot be performed on the basis of relative value unit only, considering the importance of time spent by radiologists on non-relative value unit-generating activities. It may also influence payment models from medical centers to radiology departments or practices. © 2016 by American Journal of Neuroradiology.

Automated extraction of lysergic acid diethylamide (LSD) and N-demethyl-LSD from blood, serum, plasma, and urine samples using the Zymark RapidTrace with LC/MS/MS confirmation.

Science.gov (United States)

de Kanel, J; Vickery, W E; Waldner, B; Monahan, R M; Diamond, F X

1998-05-01

A forensic procedure for the quantitative confirmation of lysergic acid diethylamide (LSD) and the qualitative confirmation of its metabolite, N-demethyl-LSD, in blood, serum, plasma, and urine samples is presented. The Zymark RapidTrace was used to perform fully automated solid-phase extractions of all specimen types. After extract evaporation, confirmations were performed using liquid chromatography (LC) followed by positive electrospray ionization (ESI+) mass spectrometry/mass spectrometry (MS/MS) without derivatization. Quantitation of LSD was accomplished using LSD-d3 as an internal standard. The limit of quantitation (LOQ) for LSD was 0.05 ng/mL. The limit of detection (LOD) for both LSD and N-demethyl-LSD was 0.025 ng/mL. The recovery of LSD was greater than 95% at levels of 0.1 ng/mL and 2.0 ng/mL. For LSD at 1.0 ng/mL, the within-run and between-run (different day) relative standard deviation (RSD) was 2.2% and 4.4%, respectively.

Analysis of acylcarnitines as their N-demethylated ester derivatives by gas chromatography-chemical ionization mass spectrometry.

Science.gov (United States)

Huang, Z H; Gage, D A; Bieber, L L; Sweeley, C C

1991-11-15

A novel approach to the analysis of acylcarnitines has been developed. It involves a direct esterification using propyl chloroformate in aqueous propanol followed by ion-pair extraction with potassium iodide into chloroform and subsequent on-column N-demethylation of the resulting acylcarnitine propyl ester iodides. The products, acyl N-demethylcarnitine propyl esters, are volatile and are easily analyzed by gas chromatography-chemical ionization mass spectrometry. For medium-chain-length (C4-C12) acylcarnitine standards, detection limits are demonstrated to be well below 1 ng starting material using selected ion monitoring. Well-separated gas chromatographic peaks and structure-specific mass spectra are obtained with samples of synthetic and biological origin. Seven acylcarnitines have been characterized in the urine of a patient suffering from medium-chain acyl-CoA dehydrogenase deficiency.

Escitalopram is a weak inhibitor of the CYP2D6 catalyzed O-demethylation of (+)-tramadol but does not reduce the hypoalgesic effect in experimental pain

DEFF Research Database (Denmark)

Noehr-Jensen, L; Zwisler, S T; Larsen, F

2009-01-01

Tramadol is O–demethylated to the active metabolite (+)–O–desmethyltramadol ((+)–M1) via CYP2D6, an enzyme that is weakly inhibited by escitalopram. We investigated the possibility of a pharmacokinetic (PK) and pharmacodynamic (PD) effect of escitalopram on tramadol metabolism. Fifteen healthy...... subjects completed this randomized, double–blind, three–phase, crossover trial. Combinations of escitalopram 20 mg/day or placebo together with tramadol 150 mg or placebo were used. Blood samples for pharmacokinetics were drawn at 0–24 h after medication. The analgesic effect of (+)–M was assessed...... AUEC1–12 of CPT were 4,140 and 4,388 cm·s after placebo and escitalopram, respectively (P = 0.71). Although escitalopram is a weak inhibitor of CYP2D6, it does not impair the analgesic effect of tramadol....

Participation of the Neighborhood Representatives (Mukhtars into Managerial Activities in Local Level: Burdur Case

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Mustafa LAMBA

2017-05-01

Full Text Available Neighborhood representatives (mukhtars are the nearest administrative units to citizens in local level. It is required to take advantage of that the neighborhood representatives know their districts and residents better than central and local government authorities. In addition, it will be appropriate to the principles of subsidiarity and the European Charter of Local Self Government to determine problems and demands of neighborhoods by their representatives. It is necessary to maintain communication channels and keep close relations with neighborhood representatives by local governments to use that advantage efficiently. It is aimed in this study to determine the participation level of neighborhood representatives into managerial activities in local level. For that purpose, the neighborhood representatives in the center of Burdur province are included in the research. According to the findings, it has been determined that the neighborhood representatives have participated into various activities without experiencing any difficulty, and they have been informed about the services regarding to their neighborhoods, and they have kept close relationship with central and local administrations, and most of them could communicate with local authorities directly. Therefore, it has been concluded that the neighborhood representatives have been influential enough in decision-making mechanisms in local level in Burdur.

Redistribution of cell cycle by arsenic trioxide is associated with demethylation and expression changes of cell cycle related genes in acute promyelocytic leukemia cell line (NB4).

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Hassani, Saeed; Khaleghian, Ali; Ahmadian, Shahin; Alizadeh, Shaban; Alimoghaddam, Kamran; Ghavamzadeh, Ardeshir; Ghaffari, Seyed H

2018-01-01

PML-RARα perturbs the normal epigenetic setting, which is essential to oncogenic transformation in acute promyelocytic leukemia (APL). Transcription induction and recruitment of DNA methyltransferases (DNMTs) by PML-RARα and subsequent hypermethylation are components of this perturbation. Arsenic trioxide (ATO), an important drug in APL therapy, concurrent with degradation of PML-RARα induces cell cycle change and apoptosis. How ATO causes cell cycle alteration has remained largely unexplained. Here, we investigated DNA methylation patterns of cell cycle regulatory genes promoters, the effects of ATO on the methylated genes and cell cycle distribution in an APL cell line, NB4. Analysis of promoter methylation status of 22 cell cycle related genes in NB4 revealed that CCND1, CCNE1, CCNF, CDKN1A, GADD45α, and RBL1 genes were methylated 60.7, 84.6, 58.6, 8.7, 33.4, and 73.7%, respectively, that after treatment with 2 μM ATO for 48 h, turn into 0.6, 13.8, 0.1, 6.6, 10.7, and 54.5% methylated. ATO significantly reduced the expression of DNMT1, 3A, and 3B. ATO induced the expression of CCND1, CCNE1, and GADD45α genes, suppressed the expression of CCNF and CDKN1A genes, which were consistent with decreased number of cells in G1 and S phases and increased number of cells in G2/M phase. In conclusion, demethylation and alteration in the expression level of the cell cycle related genes may be possible mechanisms in ATO-induced cell cycle arrest in APL cells. It may suggest that ATO by demethylation of CCND1 and CCNE1 and their transcriptional activation accelerates G1 and S transition into the G2/M cell cycle arrest.

Demethylation-mediated miR-129-5p up-regulation inhibits malignant phenotype of osteogenic osteosarcoma by targeting Homo sapiens valosin-containing protein (VCP).

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Long, Xin Hua; Zhou, Yun Fei; Peng, Ai Fen; Zhang, Zhi Hong; Chen, Xuan Yin; Chen, Wen Zhao; Liu, Jia Ming; Huang, Shan Hu; Liu, Zhi Li

2015-05-01

Previous studies demonstrated that increased Homo sapiens valosin-containing protein (VCP) may be involved in osteosarcoma (OS) metastasis. However, the underlying mechanism of VCP over-expression in OS remains unknown. In the present study, we found a significantly negative correlation between miR-129-5p and VCP protein expression in OS tissues with pulmonary metastasis (Spearman's rho, rs = -0.948). Bioinformatical prediction, Luciferase reporter assay, Western blot, and RT-PCR assays performed on OS cells indicated that VCP is a target of miR-129-5p. In addition, three CPG islands in the region of miR-129-5p promoter were detected by bioinformatical prediction, and significantly higher expression of miR-129-5p and lower methylation level of miR-129-2 gene in OS cells treated with 5-Aza-2'-deoxycytidine (a potent DNA demethylating agent) than in those untreated cells were observed. Furthermore, lower migratory and invasive ability was found in cells with elevated miR-129-5p than in those with decreased miR-129-5p. These findings indicated that increased miR-129-5p may be mediated by demethylation and inhibit OS cell migration and invasion by targeting VCP in OS, and targeting miR-129-5p/VCP signaling pathway may serve as a therapeutic strategy for OS management, although further studies will be necessary.

Meclofenamic acid selectively inhibits FTO demethylation of m6A over ALKBH5

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Huang, Yue; Yan, Jingli; Li, Qi; Li, Jiafei; Gong, Shouzhe; Zhou, Hu; Gan, Jianhua; Jiang, Hualiang; Jia, Gui-Fang; Luo, Cheng; Yang, Cai-Guang

2015-01-01

Two human demethylases, the fat mass and obesity-associated (FTO) enzyme and ALKBH5, oxidatively demethylate abundant N6-methyladenosine (m6A) residues in mRNA. Achieving a method for selective inhibition of FTO over ALKBH5 remains a challenge, however. Here, we have identified meclofenamic acid (MA) as a highly selective inhibitor of FTO. MA is a non-steroidal, anti-inflammatory drug that mechanistic studies indicate competes with FTO binding for the m6A-containing nucleic acid. The structure of FTO/MA has revealed much about the inhibitory function of FTO. Our newfound understanding, revealed herein, of the part of the nucleotide recognition lid (NRL) in FTO, for example, has helped elucidate the principles behind the selectivity of FTO over ALKBH5. Treatment of HeLa cells with the ethyl ester form of MA (MA2) has led to elevated levels of m6A modification in mRNA. Our collective results highlight the development of functional probes of the FTO enzyme that will (i) enable future biological studies and (ii) pave the way for the rational design of potent and specific inhibitors of FTO for use in medicine. PMID:25452335

MINA controls proliferation and tumorigenesis of glioblastoma by epigenetically regulating cyclins and CDKs via H3K9me3 demethylation.

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Huang, M-Y; Xuan, F; Liu, W; Cui, H-J

2017-01-19

It is generally known that histone demethylases regulate gene transcription by altering the methylate status on histones, but their roles in cancers and the underlying molecular mechanisms still remain unclear. MYC-induced nuclear antigen (MINA) is reported to be a histone demethylase and highly expressed in many cancers. Here, for the first time, we show that MINA is involved in glioblastoma carcinogenesis and reveal the probable mechanisms of it in cell-cycle control. Kaplan-Meier analysis of progression-free survival showed that high MINA expression was strongly correlated with poor outcome and advancing tumor stage. MINA knockdown significantly repressed the cell proliferation and tumorigenesis abilities of glioblastoma cells in vitro and in vivo that were rescued by overexpressing the full-length MINA afterwards. Microarray analysis after knockdown of MINA revealed that MINA probably regulated glioblastoma carcinogenesis through the predominant cell-cycle pathways. Further investigation showed that MINA deficiency led to a cell-cycle arrest in G1 and G2 phases. And among the downstream genes, we found that cyclins and cyclin-dependent kinases were directly activated by MINA via the demethylation of H3K9me3.

Synergism between demethylation inhibitor fungicides or gibberellin inhibitor plant growth regulators and bifenthrin in a pyrethroid-resistant population of Listronotus maculicollis (Coleoptera: Curculionidae).

Science.gov (United States)

Ramoutar, D; Cowles, R S; Requintina, E; Alm, S R

2010-10-01

In 2007-2008, the "annual bluegrass weevil," Listronotus maculicollis Kirby (Coleoptera: Curculionidae), a serious pest of Poa annua L. (Poales: Poaceae) on U.S. golf courses, was shown to be resistant to two pyrethroids, bifenthrin and lambda-cyhalothrin. In 2008, we showed that bifenthrin resistance was principally mediated by oxidase detoxification (cytochrome P450 [P450]). P450s can be inhibited by demethylation inhibitor fungicides and gibberellin inhibitor plant growth regulators, both of which are commonly used on golf courses. We tested these compounds for synergistic activity with bifenthin against a pyrethroid-resistant population of L. maculicollis. The LD50 value for bifenthrin was significantly reduced from 87 ng per insect (without synergists) to 9.6-40 ng per insect after exposure to the fungicides fenarimol, fenpropimorph, prochloraz, propiconazole, and pyrifenox and the plant growth regulators flurprimidol, paclobutrazol, and trinexapac-ethyl. Simulated field exposure with formulated products registered for use on turf revealed enhanced mortality when adult weevils were exposed to bifenthrin (25% mortality, presented alone) combined with field dosages of propiconizole, fenarimol, flurprimidol, or trinexapac-ethyl (range, 49-70% mortality).

Dioxygenases Catalyze O-Demethylation and O,O-Demethylenation with Widespread Roles in Benzylisoquinoline Alkaloid Metabolism in Opium Poppy*

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Farrow, Scott C.; Facchini, Peter J.

2013-01-01

In opium poppy, the antepenultimate and final steps in morphine biosynthesis are catalyzed by the 2-oxoglutarate/Fe(II)-dependent dioxygenases, thebaine 6-O-demethylase (T6ODM) and codeine O-demethylase (CODM). Further investigation into the biochemical functions of CODM and T6ODM revealed extensive and unexpected roles for such enzymes in the metabolism of protopine, benzo[c]phenanthridine, and rhoeadine alkaloids. When assayed with a wide range of benzylisoquinoline alkaloids, CODM, T6ODM, and the functionally unassigned paralog DIOX2, renamed protopine O-dealkylase, showed novel and efficient dealkylation activities, including regio- and substrate-specific O-demethylation and O,O-demethylenation. Enzymes catalyzing O,O-demethylenation, which cleave a methylenedioxy bridge leaving two hydroxyl groups, have previously not been reported in plants. Similar cleavage of methylenedioxy bridges on substituted amphetamines is catalyzed by heme-dependent cytochromes P450 in mammals. Preferred substrates for O,O-demethylenation by CODM and protopine O-dealkylase were protopine alkaloids that serve as intermediates in the biosynthesis of benzo[c]phenanthridine and rhoeadine derivatives. Virus-induced gene silencing used to suppress the abundance of CODM and/or T6ODM transcripts indicated a direct physiological role for these enzymes in the metabolism of protopine alkaloids, and they revealed their indirect involvement in the formation of the antimicrobial benzo[c]phenanthridine sanguinarine and certain rhoeadine alkaloids in opium poppy. PMID:23928311

Dioxygenases catalyze O-demethylation and O,O-demethylenation with widespread roles in benzylisoquinoline alkaloid metabolism in opium poppy.

Science.gov (United States)

Farrow, Scott C; Facchini, Peter J

2013-10-04

In opium poppy, the antepenultimate and final steps in morphine biosynthesis are catalyzed by the 2-oxoglutarate/Fe(II)-dependent dioxygenases, thebaine 6-O-demethylase (T6ODM) and codeine O-demethylase (CODM). Further investigation into the biochemical functions of CODM and T6ODM revealed extensive and unexpected roles for such enzymes in the metabolism of protopine, benzo[c]phenanthridine, and rhoeadine alkaloids. When assayed with a wide range of benzylisoquinoline alkaloids, CODM, T6ODM, and the functionally unassigned paralog DIOX2, renamed protopine O-dealkylase, showed novel and efficient dealkylation activities, including regio- and substrate-specific O-demethylation and O,O-demethylenation. Enzymes catalyzing O,O-demethylenation, which cleave a methylenedioxy bridge leaving two hydroxyl groups, have previously not been reported in plants. Similar cleavage of methylenedioxy bridges on substituted amphetamines is catalyzed by heme-dependent cytochromes P450 in mammals. Preferred substrates for O,O-demethylenation by CODM and protopine O-dealkylase were protopine alkaloids that serve as intermediates in the biosynthesis of benzo[c]phenanthridine and rhoeadine derivatives. Virus-induced gene silencing used to suppress the abundance of CODM and/or T6ODM transcripts indicated a direct physiological role for these enzymes in the metabolism of protopine alkaloids, and they revealed their indirect involvement in the formation of the antimicrobial benzo[c]phenanthridine sanguinarine and certain rhoeadine alkaloids in opium poppy.

Modulators of membrane drug transporters potentiate the activity of the DMI fungicide oxpoconazole against Botrytis cinerea

NARCIS (Netherlands)

Hayashi, K.; Schoonbeek, H.; Waard, de M.A.

2003-01-01

Modulators known to reduce multidrug resistance in tumour cells were tested for their potency to synergize the fungitoxic activity of the fungicide oxpoconazole, a sterol demethylation inhibitor (DMI), against Botrytis cinerea Pers. Chlorpromazine, a phenothiazine compound known as a calmodulin

Induction of the mesenchymal to epithelial transition by demethylation-activated microRNA-125b is involved in the anti-migration/invasion effects of arsenic trioxide on human chondrosarcoma.

Science.gov (United States)

Bao, Xing; Ren, Tingting; Huang, Yi; Wang, Shidong; Zhang, Fan; Liu, Kuisheng; Zheng, Bingxin; Guo, Wei

2016-08-30

In addition to treating acute promyelocytic leukemia, arsenic trioxide (ATO) suppresses other solid tumors, including chondrosarcoma. However, the effects of ATO on metastasis in chondrosarcoma cells, and the underlying molecular mechanisms remain unclear. The effects of ATO on the migratory and invasive capacities of chondrosarcoma cells were investigated by Wound healing, Transwell and EMT assays. The expression of miR-125b in human chondrosarcoma tissues and cell lines was detected by real-time PCR analysis. Bisulfite sequencing analysis (BSP) was used to detect the effects of ATO on the expression of miR-125b. The gain-of-function and loss-of-function experiments were performed on chondrosarcoma cell lines to investigate the effects of miR-125b on chondrosarcoma invasion, and to determine whether signal transducer and activator of transcription 3(Stat3) mediates these effects. Dual-luciferase reporter assay was used to identify whether Stat3 is a direct target of miR-125b. MiR-125b was significantly downregulated in human metastatic chondrosarcoma tissues and cell lines but not in non-metastatic chondrosarcoma tissues. ATO up-regulates the expression of miR-125b by the demethylation of DNA. ATO induces MET and attenuates the invasive capacities of chondrosarcoma cells through miR-125b. Stat3 was verified as a direct target of miR-125b, which is involved in ATO regulating EMT-associated traits. These findings, for the first time, provides evidence that the miR-125b-mediated inhibition of Stat3 is involved in the ATO-induced attenuation of metastasis in chondrosarcoma cells.

Epigenetic regulations in the IFNγ signalling pathway: IFNγ-mediated MHC class I upregulation on tumour cells is associated with DNA demethylation of antigen-presenting machinery genes

Czech Academy of Sciences Publication Activity Database

Vlková, Veronika; Štěpánek, Ivan; Hrušková, Veronika; Šenigl, Filip; Mayerová, Veronika; Šrámek, Martin; Šímová, Jana; Bieblová, Jana; Indrová, Marie; Hejhal, Tomáš; Dérian, N.; Klatzmann, D.; Six, A.; Reiniš, Milan

2014-01-01

Roč. 5, č. 16 (2014), s. 6923-35 ISSN 1949-2553 R&D Projects: GA ČR GAP301/10/2174; GA MZd NT14461 EU Projects: European Commission(XE) 18933 - CLINIGENE Grant - others:French state funds within the Investissements d’Avenir program(FR) ANR-11-IDEX-0004-02 Institutional support: RVO:68378050 Keywords : IFNγ signalling pathway * DNA demethylation * tumour Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.359, year: 2014

Demethylation regulation of BDNF gene expression in dorsal root ganglion neurons is implicated in opioid-induced pain hypersensitivity in rats.

Science.gov (United States)

Chao, Yu-Chieh; Xie, Fang; Li, Xueyang; Guo, Ruijuan; Yang, Ning; Zhang, Chen; Shi, Rong; Guan, Yun; Yue, Yun; Wang, Yun

2016-07-01

Repeated administration of morphine may result in opioid-induced hypersensitivity (OIH), which involves altered expression of numerous genes, including brain-derived neurotrophic factor (BDNF) in dorsal root ganglion (DRG) neurons. Yet, it remains unclear how BDNF expression is increased in DRG neurons after repeated morphine treatment. DNA methylation is an important mechanism of epigenetic control of gene expression. In the current study, we hypothesized that the demethylation regulation of certain BDNF gene promoters in DRG neurons may contribute to the development of OIH. Real-time RT-PCR was used to assess changes in the mRNA transcription levels of major BDNF exons including exon I, II, IV, VI, as well as total BDNF mRNA in DRGs from rats after repeated morphine administration. The levels of exon IV and total BDNF mRNA were significantly upregulated by repeated morphine administration, as compared to that in saline control group. Further, ELISA array and immunocytochemistry study revealed a robust upregulation of BDNF protein expression in DRG neurons after repeated morphine exposure. Correspondingly, the methylation levels of BDNF exon IV promoter showed a significant downregulation by morphine treatment. Importantly, intrathecal administration of a BDNF antibody, but not control IgG, significantly inhibited mechanical hypersensitivity that developed in rats after repeated morphine treatment. Conversely, intrathecal administration of an inhibitor of DNA methylation, 5-aza-2'-deoxycytidine (5-aza-dC) markedly upregulated the BDNF protein expression in DRG neurons and enhanced the mechanical allodynia after repeated morphine exposure. Together, our findings suggest that demethylation regulation of BDNF gene promoter may be implicated in the development of OIH through epigenetic control of BDNF expression in DRG neurons. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of 5-azacytidine on natural killer cell activating receptor expression in patients with refractory anemia with excess of blasts

Directory of Open Access Journals (Sweden)

Régis T. Costello

2015-01-01

Full Text Available Epigenetic drugs modify DNA methylation and are used in refractory anemia with excess of blasts (RAEB. These drugs may reactivate anti-oncogene expression and restore a normal phenotype instead of inducing antitumor toxicity, although they also have immunosuppressive effects on T-lymphocytes [1] In RAEB and acute myeloid leukemia, a defect in natural killer (NK cell cytotoxicity has been shown, which relies on abnormal expression of activating receptors. Previous study has shown that 5-azacytidine impaired mRNA synthesis and induced apoptosis in NK cells [2]. In this study we investigated the effect of the demethylating drug 5-azacytidine (Vidaza® on NK receptors with the hypothesis that demethylation of the promoters of activating NK receptor genes induces gene reactivation and thus may increase their expression.

A Simple, Rapid and Mild One Pot Synthesis of Benzene Ring Acylated and Demethylated Analogues of Harmine under Solvent-free Conditions

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Bina S. Siddiqui

2008-08-01

Full Text Available A simple, rapid, solvent-free, room temperature one pot synthesis of benzene ring acylated and demethylated analogues of harmine using acyl halides/acid anhydrides and AlCl3 has been developed. Eight different acyl halides/acid anhydrides were used in the synthesis. The resulting mixture of products was separated by column chromatography to afford 10- and 12-monoacyl analogues, along with 10,12-diacyl-11-hydroxy products. In five cases the corresponding 10-acyl-11-hydroxy analogues were also obtained. Yields from the eight syntheses (29 products in total were in the 6-34% range and all compounds were fully characterized.

Hypomethylation of the Treg-Specific Demethylated Region in FOXP3 Is a Hallmark of the Regulatory T-cell Subtype in Adult T-cell Leukemia.

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Shimazu, Yayoi; Shimazu, Yutaka; Hishizawa, Masakatsu; Hamaguchi, Masahide; Nagai, Yuya; Sugino, Noriko; Fujii, Sumie; Kawahara, Masahiro; Kadowaki, Norimitsu; Nishikawa, Hiroyoshi; Sakaguchi, Shimon; Takaori-Kondo, Akifumi

2016-02-01

Adult T-cell leukemia (ATL) is an aggressive T-cell malignancy caused by human T-cell leukemia virus type 1. Because of its immunosuppressive property and resistance to treatment, patients with ATL have poor prognoses. ATL cells possess the regulatory T cell (Treg) phenotype, such as CD4 and CD25, and usually express forkhead box P3 (FOXP3). However, the mechanisms of FOXP3 expression and its association with Treg-like characteristics in ATL remain unclear. Selective demethylation of the Treg-specific demethylated region (TSDR) in the FOXP3 gene leads to stable FOXP3 expression and defines natural Tregs. Here, we focus on the functional and clinical relationship between the epigenetic pattern of the TSDR and ATL. Analysis of DNA methylation in specimens from 26 patients with ATL showed that 15 patients (58%) hypomethylated the TSDR. The FOXP3(+) cells were mainly observed in the TSDR-hypomethylated cases. The TSDR-hypomethylated ATL cells exerted more suppressive function than the TSDR-methylated ATL cells. Thus, the epigenetic analysis of the FOXP3 gene identified a distinct subtype with Treg properties in heterogeneous ATL. Furthermore, we observed that the hypomethylation of TSDR was associated with poor outcomes in ATL. These results suggest that the DNA methylation status of the TSDR is an important hallmark to define this heterogeneous disease and to predict ATL patient prognosis. ©2015 American Association for Cancer Research.

Screening and identification of metabolites of two kinds of main active ingredients and hepatotoxic pyrrolizidine alkaloids in rat after lavage Farfarae Flos extract by UHPLC-Q-TOF-MS mass spectrometry.

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Cheng, Xiaoye; Liao, Man; Diao, Xinpeng; Sun, Yupeng; Zhang, Lantong

2018-02-01

Farfarae Flos, the dried flower buds of Tussilago farfara L., is usually used to treat coughs, bronchitic and asthmatic conditions as an important traditional Chinese medicine. Tussilagone and methl butyric acid tussilagin ester are seen as representatives of two kinds of active substances. In addition, the pyrrolizidine alkaloids, mainly senkirkine and senecionine, present in the herb can be hepatoxic. In this study, a rapid and sensitive ultra-high-performance liquid chromatography coupled with hybrid triple quadrupole time-of-flight mass spectrometry method was successfully applied to identify the metabolites of tussilagone, methl butyric acid tussilagin ester, senkirkine and senecionine. A total of 35, 37, 18 and nine metabolites of tussilagone, methl butyric acid tussilagin ester, senkirkine and senecionine in rats were tentatively identified. Hydrolysis, oxidation, reduction and demethylation were the major metabolic reactions for tussilagone and methl butyric acid tussilagin ester. The main biotransformation routes of senkirkine and senecionine were identified as demethylation, N-methylation, oxidation and reduction. This study is the first reported analysis and characterization of the metabolites and the proposed metabolic pathways might provide further understanding of the metabolic fate of the chemical constituents after oral administration of Farfarae Flos extract in vivo. Copyright © 2017 John Wiley & Sons, Ltd.

Urease Activity Represents an Alternative Pathway for Mycobacterium tuberculosis Nitrogen Metabolism

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Lin, Wenwei; Mathys, Vanessa; Ang, Emily Lei Yin; Koh, Vanessa Hui Qi; Martínez Gómez, Julia María; Ang, Michelle Lay Teng; Zainul Rahim, Siti Zarina; Tan, Mai Ping; Pethe, Kevin

2012-01-01

Urease represents a critical virulence factor for some bacterial species through its alkalizing effect, which helps neutralize the acidic microenvironment of the pathogen. In addition, urease serves as a nitrogen source provider for bacterial growth. Pathogenic mycobacteria express a functional urease, but its role during infection has yet to be characterized. In this study, we constructed a urease-deficient Mycobacterium tuberculosis strain and confirmed the alkalizing effect of the urease activity within the mycobacterium-containing vacuole in resting macrophages but not in the more acidic phagolysosomal compartment of activated macrophages. However, the urease-mediated alkalizing effect did not confer any growth advantage on M. tuberculosis in macrophages, as evidenced by comparable growth profiles for the mutant, wild-type (WT), and complemented strains. In contrast, the urease-deficient mutant exhibited impaired in vitro growth compared to the WT and complemented strains when urea was the sole source of nitrogen. Substantial amounts of ammonia were produced by the WT and complemented strains, but not with the urease-deficient mutant, which represents the actual nitrogen source for mycobacterial growth. However, the urease-deficient mutant displayed parental colonization profiles in the lungs, spleen, and liver in mice. Together, our data demonstrate a role for the urease activity in M. tuberculosis nitrogen metabolism that could be crucial for the pathogen's survival in nutrient-limited microenvironments where urea is the sole nitrogen source. Our work supports the notion that M. tuberculosis virulence correlates with its unique metabolic versatility and ability to utilize virtually any carbon and nitrogen sources available in its environment. PMID:22645285

A DEMETER-like DNA demethylase governs tomato fruit ripening.

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Liu, Ruie; How-Kit, Alexandre; Stammitti, Linda; Teyssier, Emeline; Rolin, Dominique; Mortain-Bertrand, Anne; Halle, Stefanie; Liu, Mingchun; Kong, Junhua; Wu, Chaoqun; Degraeve-Guibault, Charlotte; Chapman, Natalie H; Maucourt, Mickael; Hodgman, T Charlie; Tost, Jörg; Bouzayen, Mondher; Hong, Yiguo; Seymour, Graham B; Giovannoni, James J; Gallusci, Philippe

2015-08-25

In plants, genomic DNA methylation which contributes to development and stress responses can be actively removed by DEMETER-like DNA demethylases (DMLs). Indeed, in Arabidopsis DMLs are important for maternal imprinting and endosperm demethylation, but only a few studies demonstrate the developmental roles of active DNA demethylation conclusively in this plant. Here, we show a direct cause and effect relationship between active DNA demethylation mainly mediated by the tomato DML, SlDML2, and fruit ripening- an important developmental process unique to plants. RNAi SlDML2 knockdown results in ripening inhibition via hypermethylation and repression of the expression of genes encoding ripening transcription factors and rate-limiting enzymes of key biochemical processes such as carotenoid synthesis. Our data demonstrate that active DNA demethylation is central to the control of ripening in tomato.

Molecular basis of the activity of the phytopathogen pectin methylesterase

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Fries, Markus; Ihrig, Jessica; Brocklehurst, Keith; Shevchik, Vladimir E; Pickersgill, Richard W

2007-01-01

We provide a mechanism for the activity of pectin methylesterase (PME), the enzyme that catalyses the essential first step in bacterial invasion of plant tissues. The complexes formed in the crystal using specifically methylated pectins, together with kinetic measurements of directed mutants, provide clear insights at atomic resolution into the specificity and the processive action of the Erwinia chrysanthemi enzyme. Product complexes provide additional snapshots along the reaction coordinate. We previously revealed that PME is a novel aspartic-esterase possessing parallel β-helix architecture and now show that the two conserved aspartates are the nucleophile and general acid-base in the mechanism, respectively. Other conserved residues at the catalytic centre are shown to be essential for substrate binding or transition state stabilisation. The preferential binding of methylated sugar residues upstream of the catalytic site, and demethylated residues downstream, drives the enzyme along the pectin molecule and accounts for the sequential pattern of demethylation produced by both bacterial and plant PMEs. PMID:17717531

Validation of 13CO2 breath analysis as a measurement of demethylation of stable isotope labeled aminopyrine in man

International Nuclear Information System (INIS)

Schneider, J.F.; Schoeller, D.A.; Nemchausky, B.; Bayer, J.L.; Klein, P.

1978-01-01

Interval sampling of expired breath as a simple, non-invasive assessment of the effect of liver disease upon hepatic microsomal drug metabolism, has been demonstrated with [ 14 C] dimethylaminoantipyrine (aminopyrine). In order to eliminate radiation risk the authors have validated the use of aminopyrine labeled with the stable, non-radioactive isotope 13 C. Simultaneous oral administration of both [ 14 C]- and [ 13 C] aminopyrine to five adult subjects without liver disease as well as five patients with known liver disease, resulted in the excretion of label at nearly identical rates in both individual time collections (r=0.94) as well as cumulative excretion for three hours (r=0.97). An oral dose of 2-mg/kg of [ 13 C) aminopyrine resulted in rates of production of 13 CO 2 significantly greater than baseline variations in 13 CO 2 production in the fasting, resting subject. Measurements of a single peak value at one half hour correlated closely with the determination of cumulative appearance over three hours (r=0.96). A consistent reproducible increase in the peak production of 13 CO 2 was observed when five patients received phenobarbital. Stable isotope labeled aminopyrine may be used to detect the effects of disease and treatment upon hepatic N-demethylation activity in human subjects without incurring any risk from radiation. Furthermore, the availability of another isotopic carbon label should make possible the study of direct drug-drug interaction utilizing CO 2 analysis. (Auth.)

Phlpp1 facilitates post-traumatic osteoarthritis and is induced by inflammation and promoter demethylation in human osteoarthritis

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Bradley, Elizabeth W.; Carpio, Lomeli R.; McGee-Lawrence, Meghan E.; Becerra, Clara Castillejo; Amanatullah, Derek F.; Ta, Lauren E.; Otero, Miguel; Goldring, Mary B.; Kakar, Sanjeev; Westendorf, Jennifer J.

2016-01-01

OBJECTIVE Osteoarthritis (OA) is the most common form of arthritis and a leading cause of disability. OA is characterized by articular chondrocyte deterioration, subchondral bone changes and debilitating pain. One strategy to promote cartilage regeneration and repair is to accelerate proliferation and matrix production of articular chondrocytes. We previously reported that the protein phosphatase Phlpp1 controls chondrocyte differentiation by regulating the activities of anabolic kinases. Here we examined the role of Phlpp1 in osteoarthritis progression in a murine model. We also assessed PHLPP1 expression and promoter methylation. DESIGN Knee joints of WT and Phlpp1−/− mice were surgically destabilized by transection of the medial meniscal ligament (DMM). Mice were assessed for signs of OA progression via radiographic and histological analyses, and pain assessment for mechanical hypersensitivity using the von Frey assay. Methylation of the PHLPP1 promoter and PHLPP1 expression was evaluated in human articular cartilage and chondrocyte cell lines. RESULTS Following DMM surgeries, Phlpp1 deficient mice showed fewer signs of OA and cartilage degeneration. Mechanical allodynia associated with DMM surgeries was also attenuated in Phlpp1−/− mice. PHLPP1 was highly expressed in human articular cartilage from OA patients, but was undetectable in cartilage specimens from femoral neck fractures. Higher PHLPP1 levels correlated with less PHLPP1 promoter CpG methylation in cartilage from OA patients. Blocking cytosine methylation or treatment with inflammatory mediators enhanced PHLPP1 expression in human chondrocyte cell lines. CONCLUSION Phlpp1 deficiency protects against OA progression while CpG demethylation and inflammatory responses promote PHLPP1 expression. PMID:26746148

[Fundamental role of the workers' representative in preventive safety activity].

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Ossicini, A; Bindi, L; Casale, M C

2003-01-01

With the arrival of Legislative Decree 626/94 which brought into Italian law the EU directives on workers' health and safety at the workplace, our country has also introduced rules that make a break with the past in this area, with the creation of new professional roles. The workers' safety representative takes on a fundamentally important role in the management of prevention, safety and health for workers in their place of employment in accordance with article 19. In fact, before the introduction of this Legislative Decree, the "protection" of workers' health was essentially based on rules and regulations the application of which was left to the exclusive and direct responsibility of the relationship between the employer and doctor, leaving out any participation by the worker. Whereas in the past workers could only be considered the final receivers of instructions about the security measures to apply, with Law 626 the workers themselves became active participants in the assessment of risks at work and consequently in the implementing of all the safety and hygiene measures contributing to the reduction of risk levels. The new regulations now in force assign important tasks to the workers' safety representative; all tasks and responsibilities associated with that role are examined and discussed, especially those relating to rights to information and training, consultation and participation in the process of designing and promoting safety measures. The job of workers' representative today takes on a fundamentally important meaning and role in a self-regulating system of work safety, where he or she has a proper area responsibility, so becoming a reference point for the workers generally.

Demethylation of Circulating Estrogen Receptor Alpha Gene in Cerebral Ischemic Stroke.

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Hsiu-Fen Lin

Full Text Available Estrogen is involved in neuron plasticity and can promote neuronal survival in stroke. Its actions are mostly exerted via estrogen receptor alpha (ERα. Previous animal studies have shown that ERα is upregulated by DNA demethylation following ischemic injury. This study investigated the methylation levels in the ERα promoter in the peripheral blood of ischemic stroke patients.The study included 201 ischemic stroke patients, and 217 age- and sex-comparable healthy controls. The quantitative methylation level in the 14 CpG sites of the ERα promoter was measured by pyrosequencing in each participant. Multivariate regression model was used to adjust for stroke traditional risk factors. Stroke subtypes and sex-specific analysis were also conducted.The results demonstrated that the stroke cases had a lower ERα methylation level than controls in all 14 CpG sites, and site 13 and site 14 had significant adjusted p-values of 0.035 and 0.026, respectively. Stroke subtypes analysis showed that large-artery atherosclerosis and cardio-embolic subtypes had significantly lower methylation levels than the healthy controls at CpG site 5, site 9, site 12, site 13 and site 14 with adjusted p = 0.039, 0.009, 0.025, 0.046 and 0.027 respectively. However, the methylation level for the patients with small vessel subtype was not significant. We combined the methylation data from the above five sites for further sex-specific analysis. The results showed that the significant association only existed in women (adjusted p = 0.011, but not in men (adjusted p = 0.300.Female stroke cases have lower ERα methylation levels than those in the controls, especially in large-artery and cardio-embolic stroke subtypes. The study implies that women suffering from ischemic stroke of specific subtype may undergo different protective mechanisms to reduce the brain injury.

Activity of two chlorinated lincomycin analogues against chloroquine-resistant falciparum malaria in owl monkeys.

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Powers, K G; Jacobs, R L

1972-01-01

The chloroquine-resistant Oak Knoll strain of Plasmodium falciparum, recently adapted to the owl monkey (Aotus trivirgatus), was insusceptible to chloroquine therapy. Two chlorinated lincomycin analogues tested in this host-parasite system cured blood-induced infections. Acute infections were treated orally for 7 consecutive days with either 15 or 75 mg of clindamycin hydrochloride (U-21) per kg per day, 10 or 50 mg of N-demethyl-4'-pentyl clindamycin hydrochloride (U-24) per kg per day, or 20 mg of chloroquine base per kg per day. These lincomycin analogues cleared trophozoites from the peripheral blood by the end of the 7-day treatment period. The speed of clearance of parasites was not dose-related, but curative activity appeared dependent upon the amount of drug given as well as the number of daily treatments. The efficacy of U-21 and U-24 is of particular interest since they represent major structural departures from compounds commonly used in the treatment of malaria.

Why eicosanoids could represent a new class of tocolytics on uterine activity in pregnant women.

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Corriveau, Stéphanie; Berthiaume, Maryse; Rousseau, Eric; Pasquier, Jean-Charles

2009-10-01

The purpose of this study was to assess the effects of exogenous eicosanoids on spontaneous uterine contractile activity. Eight uterine biopsies were performed from women who were undergoing elective cesarean delivery. Tension measurements were performed in vitro on myometrial strips. Contractile activities were quantified by the calculation of the area under the curve. The effects of eicosanoids and specific enzyme inhibitors were assessed. Fractions from various uterine tissues were analyzed by Western blot. Data demonstrate the presence, in some tested tissues, of cytochrome P-450 epoxygenase and soluble epoxide hydrolase, which respectively produce and degrade epoxyeicosatrienoic acid regioisomers. Inhibition of soluble epoxide hydrolase with 12-(3-adamantan-1-yl-ureido)-dodecanoic acid or omega-hydroxylase with N-methylsulfonyl-12,12-dibromododec-11-enamide resulted in a tocolytic effect; N-methylsulfonyl-6-[2-propargyloxyphenyl] hexanamide, which is an epoxygenase inhibitor, had no effect. Exogenous epoxyeicosatrienoic acids displayed significant tocolytic effects on spontaneous contractile activities. Epoxy- and hydroxyeicosanoids represent new bioactive, arachidonic acid by-products with in vitro tocolytic activities. These findings suggest that cytochrome P-450 isozymes may represent relevant pharmacologic targets under physiopathologic conditions.

Inhibition of H3K27me3 Histone Demethylase Activity Prevents the Proliferative Regeneration of Zebrafish Lateral Line Neuromasts

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Bao, Beier; He, Yingzi; Tang, Dongmei; Li, Wenyan; Li, Huawei

2017-01-01

The H3K27 demethylases are involved in a variety of biological processes, including cell differentiation, proliferation, and cell death by regulating transcriptional activity. However, the function of H3K27 demethylation in the field of hearing research is poorly understood. Here, we investigated the role of H3K27me3 histone demethylase activity in hair cell regeneration using an in vivo animal model. Our data showed that pharmacologic inhibition of H3K27 demethylase activity with the specific small-molecule inhibitor GSK-J4 decreased the number of regenerated hair cells in response to neomycin damage. Furthermore, inhibition of H3K27me3 histone demethylase activity dramatically suppressed cell proliferation and activated caspase-3 levels in the regenerating neuromasts of the zebrafish lateral line. GSK-J4 administration also increased the expression of p21 and p27 in neuromast cells and inhibited the ERK signaling pathway. Collectively, our findings indicate that H3K27me3 demethylation is a key epigenetic regulator in the process of hair cell regeneration in zebrafish and suggest that H3K27me3 histone demethylase activity might be a novel therapeutic target for the treatment of hearing loss. PMID:28348517

Fire activity and severity in the western US vary along proxy gradients representing fuel amount and fuel moisture.

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Sean A Parks

Full Text Available Numerous theoretical and empirical studies have shown that wildfire activity (e.g., area burned at regional to global scales may be limited at the extremes of environmental gradients such as productivity or moisture. Fire activity, however, represents only one component of the fire regime, and no studies to date have characterized fire severity along such gradients. Given the importance of fire severity in dictating ecological response to fire, this is a considerable knowledge gap. For the western US, we quantify relationships between climate and the fire regime by empirically describing both fire activity and severity along two climatic water balance gradients, actual evapotranspiration (AET and water deficit (WD, that can be considered proxies for fuel amount and fuel moisture, respectively. We also concurrently summarize fire activity and severity among ecoregions, providing an empirically based description of the geographic distribution of fire regimes. Our results show that fire activity in the western US increases with fuel amount (represented by AET but has a unimodal (i.e., humped relationship with fuel moisture (represented by WD; fire severity increases with fuel amount and fuel moisture. The explicit links between fire regime components and physical environmental gradients suggest that multivariable statistical models can be generated to produce an empirically based fire regime map for the western US. Such models will potentially enable researchers to anticipate climate-mediated changes in fire recurrence and its impacts based on gridded spatial data representing future climate scenarios.

Activity of Two Chlorinated Lincomycin Analogues Against Chloroquine-Resistant Falciparum Malaria in Owl Monkeys1

Science.gov (United States)

Powers, Kendall G.; Jacobs, Richard L.

1972-01-01

The chloroquine-resistant Oak Knoll strain of Plasmodium falciparum, recently adapted to the owl monkey (Aotus trivirgatus), was insusceptible to chloroquine therapy. Two chlorinated lincomycin analogues tested in this host-parasite system cured blood-induced infections. Acute infections were treated orally for 7 consecutive days with either 15 or 75 mg of clindamycin hydrochloride (U-21) per kg per day, 10 or 50 mg of N-demethyl-4′-pentyl clindamycin hydrochloride (U-24) per kg per day, or 20 mg of chloroquine base per kg per day. These lincomycin analogues cleared trophozoites from the peripheral blood by the end of the 7-day treatment period. The speed of clearance of parasites was not dose-related, but curative activity appeared dependent upon the amount of drug given as well as the number of daily treatments. The efficacy of U-21 and U-24 is of particular interest since they represent major structural departures from compounds commonly used in the treatment of malaria. PMID:4207758

The roles of co-chaperone CCRP/DNAJC7 in Cyp2b10 gene activation and steatosis development in mouse livers.

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Marumi Ohno

Full Text Available Cytoplasmic constitutive active/androstane receptor (CAR retention protein (CCRP and also known as DNAJC7 is a co-chaperone previously characterized to retain nuclear receptor CAR in the cytoplasm of HepG2 cells. Here we have produced CCRP knockout (KO mice and demonstrated that CCRP regulates CAR at multiple steps in activation of the cytochrome (Cyp 2b10 gene in liver: nuclear accumulation, RNA polymerase II recruitment and epigenetic modifications. Phenobarbital treatment greatly increased nuclear CAR accumulation in the livers of KO males as compared to those of wild type (WT males. Despite this accumulation, phenobarbital-induced activation of the Cyp2b10 gene was significantly attenuated. In ChIP assays, a CAR/retinoid X receptor-α (RXRα heterodimer binding to the Cyp2b10 promoter was already increased before phenobarbital treatment and further pronounced after treatment. However, RNA polymerase II was barely recruited to the promoter even after phenobarbital treatment. Histone H3K27 on the Cyp2b10 promoter was de-methylated only after phenobarbital treatment in WT but was fully de-methylated before treatment in KO males. Thus, CCRP confers phenobarbital-induced de-methylation capability to the promoter as well as the phenobarbital responsiveness of recruiting RNA polymerase II, but is not responsible for the binding between CAR and its cognate sequence, phenobarbital responsive element module. In addition, KO males developed steatotic livers and increased serum levels of total cholesterol and high density lipoprotein in response to fasting. CCRP appears to be involved in various hepatic regulations far beyond CAR-mediated drug metabolism.

Epigenetic identification of ZNF545 as a functional tumor suppressor in multiple myeloma via activation of p53 signaling pathway

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Fan, Yu [Chongqing Key Laboratory of Molecular Oncology and Epigenetics, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Zhan, Qian [The Center for Clinical Molecular Medical Detection, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Xu, Hongying [Chongqing Key Laboratory of Molecular Oncology and Epigenetics, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Li, Lili; Li, Chen [Cancer Epigenetics Laboratory, Department of Clinical Oncology, Sir YK Pao Center for Cancer and Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong and CUHK Shenzhen Research Institute (Hong Kong); Xiao, Qian; Xiang, Shili; Hui, Tianli [Chongqing Key Laboratory of Molecular Oncology and Epigenetics, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Xiang, Tingxiu, E-mail: larissaxiang@163.com [Chongqing Key Laboratory of Molecular Oncology and Epigenetics, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China); Ren, Guosheng, E-mail: rengs726@126.com [Chongqing Key Laboratory of Molecular Oncology and Epigenetics, The First Affiliated Hospital of Chongqing Medical University, Chongqing (China)

2016-06-10

The KRAB–zinc-finger protein ZNF545 was recently identified as a potential suppressor gene in several tumors. However, the regulatory mechanisms of ZNF545 in tumorigenesis remain unclear. In this study, we investigated the expression and roles of ZNF545 in multiple myeloma (MM). ZNF545 was frequently downregulated in MM tissues compared with non-tumor bone marrow tissues. ZNF545 expression was silenced by promoter methylation in MM cell lines, and could be restored by demethylation treatment. ZNF545 methylation was detected in 28.3% of MM tissues, compared with 4.3% of normal bone marrow tissues. ZNF545 transcriptionally activated the p53 signaling pathway but had no effect on Akt in MM, whereas ectopic expression of ZNF545 in silenced cells suppressed their proliferation and induced apoptosis. We therefore identified ZNF545 as a novel tumor suppressor inhibiting tumor growth through activation of the p53 pathway in MM. Moreover, tumor-specific methylation of ZNF545 may represent an epigenetic biomarker for MM diagnosis, and a potential target for specific therapy. -- Highlights: •Downregulated ZNF545 in MM tissues and cell lines and ectopic expression of ZNF545 suppresses tumor growth. •Tumor-specific methylation of ZNF545 represents an epigenetic biomarker for MM diagnosis, and a potential target for specific therapy. •ZNF545 exerts its tumor suppressive effects via transcriptional activating p53 pathway.

Epigenetic identification of ZNF545 as a functional tumor suppressor in multiple myeloma via activation of p53 signaling pathway

International Nuclear Information System (INIS)

Fan, Yu; Zhan, Qian; Xu, Hongying; Li, Lili; Li, Chen; Xiao, Qian; Xiang, Shili; Hui, Tianli; Xiang, Tingxiu; Ren, Guosheng

2016-01-01

The KRAB–zinc-finger protein ZNF545 was recently identified as a potential suppressor gene in several tumors. However, the regulatory mechanisms of ZNF545 in tumorigenesis remain unclear. In this study, we investigated the expression and roles of ZNF545 in multiple myeloma (MM). ZNF545 was frequently downregulated in MM tissues compared with non-tumor bone marrow tissues. ZNF545 expression was silenced by promoter methylation in MM cell lines, and could be restored by demethylation treatment. ZNF545 methylation was detected in 28.3% of MM tissues, compared with 4.3% of normal bone marrow tissues. ZNF545 transcriptionally activated the p53 signaling pathway but had no effect on Akt in MM, whereas ectopic expression of ZNF545 in silenced cells suppressed their proliferation and induced apoptosis. We therefore identified ZNF545 as a novel tumor suppressor inhibiting tumor growth through activation of the p53 pathway in MM. Moreover, tumor-specific methylation of ZNF545 may represent an epigenetic biomarker for MM diagnosis, and a potential target for specific therapy. -- Highlights: •Downregulated ZNF545 in MM tissues and cell lines and ectopic expression of ZNF545 suppresses tumor growth. •Tumor-specific methylation of ZNF545 represents an epigenetic biomarker for MM diagnosis, and a potential target for specific therapy. •ZNF545 exerts its tumor suppressive effects via transcriptional activating p53 pathway.

A High-Throughput Mass Spectrometry Assay Coupled with Redox Activity Testing Reduces Artifacts and False Positives in Lysine Demethylase Screening.

Science.gov (United States)

Wigle, Tim J; Swinger, Kerren K; Campbell, John E; Scholle, Michael D; Sherrill, John; Admirand, Elizabeth A; Boriack-Sjodin, P Ann; Kuntz, Kevin W; Chesworth, Richard; Moyer, Mikel P; Scott, Margaret Porter; Copeland, Robert A

2015-07-01

Demethylation of histones by lysine demethylases (KDMs) plays a critical role in controlling gene transcription. Aberrant demethylation may play a causal role in diseases such as cancer. Despite the biological significance of these enzymes, there are limited assay technologies for study of KDMs and few quality chemical probes available to interrogate their biology. In this report, we demonstrate the utility of self-assembled monolayer desorption/ionization (SAMDI) mass spectrometry for the investigation of quantitative KDM enzyme kinetics and for high-throughput screening for KDM inhibitors. SAMDI can be performed in 384-well format and rapidly allows reaction components to be purified prior to injection into a mass spectrometer, without a throughput-limiting liquid chromatography step. We developed sensitive and robust assays for KDM1A (LSD1, AOF2) and KDM4C (JMJD2C, GASC1) and screened 13,824 compounds against each enzyme. Hits were rapidly triaged using a redox assay to identify compounds that interfered with the catalytic oxidation chemistry used by the KDMs for the demethylation reaction. We find that overall this high-throughput mass spectrometry platform coupled with the elimination of redox active compounds leads to a hit rate that is manageable for follow-up work. © 2015 Society for Laboratory Automation and Screening.

Relative contribution of rat cytochrome P450 isoforms to the metabolism of caffeine: the pathway and concentration dependence.

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Kot, Marta; Daniel, Władysława A

2008-04-01

The aim of the present study was to estimate the relative contribution of rat P450 isoforms to the metabolism of caffeine and to assess the usefulness of caffeine as a marker substance for estimating the activity of P450 in rat liver and its potential for pharmacokinetic interactions in pharmacological experiments. The results obtained using rat cDNA-expressed P450s indicated that 8-hydroxylation was the main oxidation pathway of caffeine (70%) in the rat. CYP1A2 was found to be a key enzyme catalyzing 8-hydroxylation (72%) and substantially contributing to 3-N-demethylation (47%) and 1-N-demethylation (37.5%) at a caffeine concentration of 0.1mM (relevant to "the maximum therapeutic concentration in humans"). Furthermore, CYP2C11 considerably contributed to 3-N-demethylation (31%). The CYP2C subfamily (66%) - mainly CYP2C6 (27%) and CYP2C11 (29%) - played a major role in catalyzing 7-N-demethylation. At higher substrate concentrations, the contribution of CYP1A2 to the metabolism of caffeine decreased in favor of CYP2C11 (N-demethylations) and CYP3A2 (mainly 8-hydroxylation). The obtained results were confirmed with liver microsomes (inhibition and correlation studies). Therefore, caffeine may be used as a marker substance for assessing the activity of CYP1A2 in rats, using 8-hydroxylation (but not 3-N-demethylation-like in humans); moreover, caffeine may also be used to simultaneously, preliminarily estimate the activity of CYP2C using 7-N-demethylation as a marker reaction. Hence caffeine pharmacokinetics in rats may be changed by drugs affecting the activity of CYP1A2 and/or CYP2C, e.g. by some antidepressants.

Deferasirox and vitamin D improves overall survival in elderly patients with acute myeloid leukemia after demethylating agents failure.

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Etienne Paubelle

Full Text Available The prognosis of acute myeloid leukemia (AML in elderly (≥65 years patients is poor and treatment remains non-consensual especially for those who are not eligible for intensive therapies. Our group has shown that in vitro the iron chelator deferasirox (DFX synergizes with vitamin D (VD to promote monocyte differentiation in primary AML cells. Herein, we present results from a retrospective case-control study in which the association of DFX (1-2 g/d and 25-hydroxycholecalciferol (100,000 IU/week (DFX/VD was proposed to patients following demethylating agents failure. Median survival of patients treated with DFX/VD combination (n = 17 was significantly increased in comparison with matched patients receiving best supportive care (BSC alone (n = 13 (10.4 versus 4 months respectively. In addition, the only factor associated to an increased overall survival in DFX/VD-treated patients was serum VD levels. We conclude that DFX/VD treatment correlated with increased overall survival of AML patients in this retrospective cohort of elderly patients.

Determination of parameters influencing methylation and demethylation in tropical lakes in Brazil and Nicaragua

International Nuclear Information System (INIS)

Hylander, Lars D.; Ahlgren, Ingemar; Erikson, Rolf; Lantz, Peter; Toernblom, Erik; Forsberg, Bruce R.; Guimaraes, Jean R.D.; Meili, Markus; Montenegro Guillen, Salvador; Vammen, Katherine; Altamirano, Maximina; Zelaya, Argentina; Sarria Sacasa, Karla; Jimenez, Mario

2001-01-01

Increased awareness about the toxicity of mercury (Hg) has during the latest decades resulted in reduced Hg use in industrialised countries. Developing countries, on the contrary, have largely increased their anthropogenic Hg emissions caused by its use in gold mining, transfer of Hg emitting factories from developed countries, and increased burning of coal without appropriate flue gas cleaning. These increased emissions occur mainly in the tropics, where the fate of Hg is not well documented. The aim of the present study is to increase the knowledge about Hg levels and transformations in two tropical areas affected by anthropogenic Hg emissions - the Pantanal wetland in Brazil, housing gold miners using the amalgamation method, and Lake Xolotilan (Managua) in Nicaragua, where a chlor-alkali plant relocated from the USA has emitted much Hg. Actual Hg content in water, biota, and sediment will be determined by atomic fluorescence spectrophotometry and atomic absorption spectrophotometry. Mercury inethylation capacity in sediments and selected biota will be determined with in-situ incubations with 203 Hg and subsequent radiological measurements. Factors affecting the methylation and demethylation rates will be identified by varying environmental conditions such as pH, redox potential, conductivity, light, temperature, geochemical factors and population of bacteria. Sediment turnover will be studied by determining fallout cesium ( 137 Cs) in sediment profiles. The study is expected to increase the knowledge about Hg-transformations in the tropics and point out proper measures to reduce health hazards due to Hg-exposure. (author)

Effects of emodin on the demethylation of tumor-suppressor genes in pancreatic cancer PANC-1 cells.

Science.gov (United States)

Zhang, Hao; Chen, Liang; Bu, He-Qi; Yu, Qing-Jiang; Jiang, Dan-Dan; Pan, Feng-Ping; Wang, Yu; Liu, Dian-Lei; Lin, Sheng-Zhang

2015-06-01

Emodin, a natural anthraquinone derivative isolated from Rheum palmatum, has been reported to inhibit the growth of pancreatic cancer cells through different modes of action; yet, the detailed mechanism remains unclear. In the present study, we hypothesized that emodin exerts its antitumor effect by participating in the regulation of the DNA methylation level. Our research showed that emodin inhibited the growth of pancreatic cancer PANC-1 cells in a dose- and time-dependent manner. Dot-blot results showed that 40 µM emodin significantly inhibited genomic 5 mC expression in the PANC-1 cells, and mRNA-Seq showed that different concentrations of emodin could alter the gene expression profile in the PANC-1 cells. BSP confirmed that the methylation levels of P16, RASSF1A and ppENK were decreased, while concomitantly the unmethylated status was increased. RT-PCR and western blotting results confirmed that the low expression or absence of expression of mRNA and protein in the PANC-1 cells was re-expressed following treatment with emodin. In conclusion, our study for the first time suggests that emodin inhibits pancreatic cancer cell growth, which may be related to the demethylation of tumor-suppressor genes. The related mechanism may be through the inhibition of methyltransferase expression.

Chemical synthesis of high specific-activity [35S]adenosylhomocysteine

International Nuclear Information System (INIS)

Stern, P.H.; Hoffman, R.M.

1986-01-01

The study of the family of transmethylases, critical to normal cellular function and often altered in cancer, can be facilitated by the availability of a high specific-activity S-adenosylhomocysteine. The authors report the two-step preparation of [ 35 S]adenosylhomocysteine from [ 35 S]methionine at a specific activity of 1420 Ci/mmol in an overall yield of 24% by a procedure involving demethylation of the [ 35 S]methionine to [ 35 S]homocysteine followed by condensation with 5'-chloro-5'-deoxyadenosine. The ease of the reactions, ready availability and low cost of the reagents and high specific-activity and stability of the product make the procedure an attractive one with many uses, and superior to current methodology

Monozygotic twins discordant for common variable immunodeficiency reveal impaired DNA demethylation during naïve-to-memory B-cell transition

Science.gov (United States)

Rodríguez-Cortez, Virginia C.; del Pino-Molina, Lucia; Rodríguez-Ubreva, Javier; Ciudad, Laura; Gómez-Cabrero, David; Company, Carlos; Urquiza, José M.; Tegnér, Jesper; Rodríguez-Gallego, Carlos; López-Granados, Eduardo; Ballestar, Esteban

2015-01-01

Common variable immunodeficiency (CVID), the most frequent primary immunodeficiency characterized by loss of B-cell function, depends partly on genetic defects, and epigenetic changes are thought to contribute to its aetiology. Here we perform a high-throughput DNA methylation analysis of this disorder using a pair of CVID-discordant MZ twins and show predominant gain of DNA methylation in CVID B cells with respect to those from the healthy sibling in critical B lymphocyte genes, such as PIK3CD, BCL2L1, RPS6KB2, TCF3 and KCNN4. Individual analysis confirms hypermethylation of these genes. Analysis in naive, unswitched and switched memory B cells in a CVID patient cohort shows impaired ability to demethylate and upregulate these genes in transitioning from naive to memory cells in CVID. Our results not only indicate a role for epigenetic alterations in CVID but also identify relevant DNA methylation changes in B cells that could explain the clinical manifestations of CVID individuals. PMID:26081581

Caffeine demethylation measured by breath analysis in experimental liver injury in the rat

Energy Technology Data Exchange (ETDEWEB)

Schaad, H.J.; Renner, E.L.; Wietholtz, H.; Preisig, R. [University of Berne, Department of Clinical Pharmaceology, Berne (Switzerland); Arnaud, M.J. [Nestle Research Center, Nestec Ltd., Vevey (Switzerland)

1995-01-01

To assess the effect of experimental liver injury on caffeine metabolism, 1 {mu}{sup C}i/kg b.w. of [3-methyl{sup 14}C]-caffeine (together with 5 mg/kg b.w. of the cold compound) was injected i.p. to four different experimental groups and respective controls of unanesthetized male Sprague-Dawley rats. Exhaled {sup 14}CO{sub 2} was completely collected during 4 h and peak exhalation rate and fraction of dose recovered were calculated. 1/3 hepatectomy affected {sup 14}CO{sub 2} exhalation to a limited extent, decreasing solely peak exhalation rate (p<0.05 compared to sham-operated control). 2/3 hepatectomy, on the other hand, resulted in significant reduction (p<0.01) in both peak exhalation rate (by 59%) and fraction of dose recovered (by 47%), that were proportionate to the loss of liver mass (50%). End-to-side portocaval shunt led to the well-documented hepatic `atrophy`, liver weight being diminished on average to 50% within 2 weeks of surgery; however, reductions in peak exhalation rate (by 75%) and fraction of dose recovered (by 64%) were even more pronounced. Finally, 48 h bile duct ligation was equivalent to `functional 2/3 hepatectomy`, peak exhalation rate (by 65%) and fraction of dose recovered (by 56%) being markedly diminished despite increased liver weight. These results indicate that {sup 14}CO{sub 2} exhalation curves following administration of specifically labelled caffeine are quantitative indicators of acute or chronic loss of functioning liver mass. In addition, the 3-demethylation pathway appears to be particularly sensitive to the inhibitory effects of cholestasis on microsomal function. (au) (30 refs.).

Studies of H3K4me3 demethylation by KDM5B/Jarid1B/PLU1 reveals strong substrate recognition in vitro and identifies 2,4-pyridine-dicarboxylic acid as an in vitro and in cell inhibitor

DEFF Research Database (Denmark)

Kristensen, Line Hyltoft; Nielsen, Anders Laerke; Helgstrand, Charlotte

2012-01-01

Dynamic methylations and demethylations of histone lysine residues are important for gene regulation and are facilitated by histone methyltransferases and histone demethylases (HDMs). KDM5B/Jarid1B/PLU1 is an H3K4me3/me2 specific lysine demethylase belonging to the family of JmjC domain containing...... lysine specific HDMs (JHDMs). Several studies have linked KDM5B to breast, prostate and skin cancer, highlighting its potential as a drug target. However, most inhibitor studies have focused on other JHDMs, and inhibitors for KDM5B remain to be explored. Here, we report the expression, purification...... and characterization of the catalytic core of recombinant KDM5B (residues 1-769, ccKDM5B). We show that ccKDM5B, recombinantly expressed in insect cells, demethylates H3K4me3 and H3K4me2 in vitro. The kinetic characterization showed that ccKDM5B has a K(m) (app) value of 0.5 µM for its tri-methylated substrate H3...

Relationship of the demethylation of the DNA with the induction of the sister chromatid exchanges (SCE) In vivo; Relacion de la desmetilacion del ADN con la induccion de intercambios en las cromatidas hermanas (ICH) In vivo

Energy Technology Data Exchange (ETDEWEB)

Toribio E, E

2005-07-01

The methylation of the DNA is an epigenetic modification that has an important paper in the regulation of the functionality of the genome of the organisms. It can be altered by demethylation processes, either natural or experimentally induced. The 5-azacytidine (Aza) is a compound that causes the demethylation of the DNA (dm-DNA), inducing with it, expression genic and increase in the frequency of the Sister Chromatid Exchange (SCE). The SCE is a genotoxicity indicator, caused by diverse mutagens and carcinogen. Since the biological meaning and the formation mechanism of this phenomenon has not been totally illustrious, the exploration of the relation between the dm-DNA and the induction of SCE, it could offer new knowledge to explain those queries. The purpose of this work was to study in cells of the mouse bone marrow In vivo, the effect of the Aza on the induction of SCE, based on two aspects: 1) dose answer and 2) the effectiveness of multiple exhibition. To six groups of three to five animals, they are administered Aza to dose of 5, 10, 15 or 20 mg/Kg of weight; in sharp or multiple form, previously to the bromodeoxyuridine supply and 24 h was sacrificed after this; 2 h after an injection with colchicine. Preparations of those metaphases were made, those which were dyed by means of a technique of fluorescence more Giemsa. It was observed that to sharp low dose, the Aza produced an increment in the frequency of SCE that although small it was proportional and statistically significant. To sharp and multiple high doses, the Aza doesn't cause additional increments of SCE, but if toxicity at cellular level and of individuals. It is concluded that a relationship exists between the dm-DNA and the induction of SCE. It is suggested that the total demethylation of the DNA causes 2 SCE/Cell in cells of the mouse bone marrow, or that the cytotoxicity prevents to evidence a bigger induction. (Author)

Relationship of the demethylation of the DNA with the induction of the sister chromatid exchanges (SCE) In vivo; Relacion de la desmetilacion del ADN con la induccion de intercambios en las cromatidas hermanas (ICH) In vivo

Energy Technology Data Exchange (ETDEWEB)

Toribio E, E

2005-07-01

The methylation of the DNA is an epigenetic modification that has an important paper in the regulation of the functionality of the genome of the organisms. It can be altered by demethylation processes, either natural or experimentally induced. The 5-azacytidine (Aza) is a compound that causes the demethylation of the DNA (dm-DNA), inducing with it, expression genic and increase in the frequency of the Sister Chromatid Exchange (SCE). The SCE is a genotoxicity indicator, caused by diverse mutagens and carcinogen. Since the biological meaning and the formation mechanism of this phenomenon has not been totally illustrious, the exploration of the relation between the dm-DNA and the induction of SCE, it could offer new knowledge to explain those queries. The purpose of this work was to study in cells of the mouse bone marrow In vivo, the effect of the Aza on the induction of SCE, based on two aspects: 1) dose answer and 2) the effectiveness of multiple exhibition. To six groups of three to five animals, they are administered Aza to dose of 5, 10, 15 or 20 mg/Kg of weight; in sharp or multiple form, previously to the bromodeoxyuridine supply and 24 h was sacrificed after this; 2 h after an injection with colchicine. Preparations of those metaphases were made, those which were dyed by means of a technique of fluorescence more Giemsa. It was observed that to sharp low dose, the Aza produced an increment in the frequency of SCE that although small it was proportional and statistically significant. To sharp and multiple high doses, the Aza doesn't cause additional increments of SCE, but if toxicity at cellular level and of individuals. It is concluded that a relationship exists between the dm-DNA and the induction of SCE. It is suggested that the total demethylation of the DNA causes 2 SCE/Cell in cells of the mouse bone marrow, or that the cytotoxicity prevents to evidence a bigger induction. (Author)

Simultaneous determination of the novel tyrosine kinase inhibitor meditinib and its active metabolite demethylation meditinib in monkey plasma by liquid chromatography-tandem mass spectrometry and its application to pharmacokinetic studies.

Science.gov (United States)

Liang, Feng; Kong, Qi; Guo, Yongqi; Wang, Yu; Sun, Dejie; Liu, Shi; Cai, Jinling; Guan, Yongbiao; Ding, Rigao

2015-08-01

Meditinib (ME) is a novel tyrosine kinase inhibitor used as an antichronic myeloid leukemia drug. A simple, sensitive and specific LC/MS/MS method was developed and validated for the analysis of ME and its metabolite demethylation meditinib (PI) in monkey plasma using naltrexone as the internal standard. Sample preparation involved protein precipitation with methanol. The analysis was carried out on an Agilent C8 column (3.5 µm, 2.1 × 50 mm). Elution was achieved with a mobile phase gradient varying the proportion of a water solution containing 0.1% formic acid (solvent A) and a 0.1% formic acid in methanol solution (solvent B) at a flow rate of 300 μL/min. The method had a linear calibration curve over the concentration range of 2-1000 ng/mL for ME and 2-1000 ng/mL for PI. The lower limits of quantification of ME and PI were 2 and 2 ng/mL, respectively. The intra- and inter-day precision values were 85%. The assay has been successfully used for pharmacokinetic evaluation of ME and PI using the monkey as an animal model, and those data are reported for the first time. Copyright © 2015 John Wiley & Sons, Ltd.

Novel, Highly Specific N-Demethylases Enable Bacteria To Live on Caffeine and Related Purine Alkaloids

Science.gov (United States)

Summers, Ryan M.; Louie, Tai Man; Yu, Chi-Li; Gakhar, Lokesh; Louie, Kailin C.

2012-01-01

The molecular basis for the ability of bacteria to live on caffeine as a sole carbon and nitrogen source is unknown. Pseudomonas putida CBB5, which grows on several purine alkaloids, metabolizes caffeine and related methylxanthines via sequential N-demethylation to xanthine. Metabolism of caffeine by CBB5 was previously attributed to one broad-specificity methylxanthine N-demethylase composed of two subunits, NdmA and NdmB. Here, we report that NdmA and NdmB are actually two independent Rieske nonheme iron monooxygenases with N1- and N3-specific N-demethylation activity, respectively. Activity for both enzymes is dependent on electron transfer from NADH via a redox-center-dense Rieske reductase, NdmD. NdmD itself is a novel protein with one Rieske [2Fe-2S] cluster, one plant-type [2Fe-2S] cluster, and one flavin mononucleotide (FMN) per enzyme. All ndm genes are located in a 13.2-kb genomic DNA fragment which also contained a formaldehyde dehydrogenase. ndmA, ndmB, and ndmD were cloned as His6 fusion genes, expressed in Escherichia coli, and purified using a Ni-NTA column. NdmA-His6 plus His6-NdmD catalyzed N1-demethylation of caffeine, theophylline, paraxanthine, and 1-methylxanthine to theobromine, 3-methylxanthine, 7-methylxanthine, and xanthine, respectively. NdmB-His6 plus His6-NdmD catalyzed N3-demethylation of theobromine, 3-methylxanthine, caffeine, and theophylline to 7-methylxanthine, xanthine, paraxanthine, and 1-methylxanthine, respectively. One formaldehyde was produced from each methyl group removed. Activity of an N7-specific N-demethylase, NdmC, has been confirmed biochemically. This is the first report of bacterial N-demethylase genes that enable bacteria to live on caffeine. These genes represent a new class of Rieske oxygenases and have the potential to produce biofuels, animal feed, and pharmaceuticals from coffee and tea waste. PMID:22328667

Consideration of statistical uncertainties for the determination of representative values of the specific activity of wastes

International Nuclear Information System (INIS)

Barthel, R.

2008-01-01

The German Radiation Protection Commission has recommended 'Principles and Methods for the Consideration of Statistical Uncertainties for the Determination of Representative Values of the Specific Activity of NORM wastes' concerning the proof of compliance with supervision limits or dose standards according to paragraph 97 and paragraph 98 of the Radiation Protection Ordinance, respectively. The recommendation comprises a method ensuring the representativeness of estimates for the specific activity of NORM wastes, which also assures the required evidence for conformity with respect to supervision limits or dose standards, respectively. On the basis of a sampling survey, confidence limits for expectation values of specific activities are determined, which will be used to show that the supervision limit or the dose standard is met or exceeded with certainty, or that the performed sampling is not sufficient for the intended assessment. The sampling effort depends on the type and the width of the distribution of specific activities and is determined by the position of the confidence interval with respect to the supervision limit or of the resulting doses with respect to the dose standard. The statistical uncertainties that are described by confidence limits may be reduced by an optimised extension of the sample number, as far as necessary. (orig.)

Spatiotemporally Representative and Cost-Efficient Sampling Design for Validation Activities in Wanglang Experimental Site

Directory of Open Access Journals (Sweden)

Gaofei Yin

2017-11-01

Full Text Available Spatiotemporally representative Elementary Sampling Units (ESUs are required for capturing the temporal variations in surface spatial heterogeneity through field measurements. Since inaccessibility often coexists with heterogeneity, a cost-efficient sampling design is mandatory. We proposed a sampling strategy to generate spatiotemporally representative and cost-efficient ESUs based on the conditioned Latin hypercube sampling scheme. The proposed strategy was constrained by multi-temporal Normalized Difference Vegetation Index (NDVI imagery, and the ESUs were limited within a sampling feasible region established based on accessibility criteria. A novel criterion based on the Overlapping Area (OA between the NDVI frequency distribution histogram from the sampled ESUs and that from the entire study area was used to assess the sampling efficiency. A case study in Wanglang National Nature Reserve in China showed that the proposed strategy improves the spatiotemporally representativeness of sampling (mean annual OA = 74.7% compared to the single-temporally constrained (OA = 68.7% and the random sampling (OA = 63.1% strategies. The introduction of the feasible region constraint significantly reduces in-situ labour-intensive characterization necessities at expenses of about 9% loss in the spatiotemporal representativeness of the sampling. Our study will support the validation activities in Wanglang experimental site providing a benchmark for locating the nodes of automatic observation systems (e.g., LAINet which need a spatially distributed and temporally fixed sampling design.

Determination of parameters influencing methylation and demethylation in tropical lakes in Brazil and Nicaragua

International Nuclear Information System (INIS)

Hylander, Lars D.; Ahlgren, Ingemar; Broberg, Anders; Lantz, Peter; Tornblom, Erik; Forsberg, Bruce R.; Guimaraes, Jean R.D.; Mauro, Jane; Markus, Meili; Guillen Montenegro, Salvador; Vammen, Katherine; Sacasa, Sarria Karla; Regnell, Olof

2002-01-01

Increased awareness about the toxicity of mercury (Hg) has during the latest decades resulted in reduced use of Hg in industrialised countries. Developing countries, on the contrary, have largely increased their anthropogenic Hg emissions caused by its use in gold mining, transfer of Hg emitting factories from developed countries, and increased burning of coal without appropriate flue gas cleaning. The contribution of global Hg sources and the importance of other parameters to increased Hg levels encountered in hydroelectric reservoirs and other areas after flooding is not well understood, especially not in the tropics. The aim of the present study is to increase the knowledge about Hg transformations in tropical areas. Total Hg content in water, biota, and sediment will be determined by atomic absorption and fluorescence spectrophotometry and methyl Hg content in biota by gaschromatography after extraction with acids, hydroxides, and organic solvents. Mercury methylation capacity in sediments, water, and selected biota will be determined with 203 Hg and subsequent radiological measurements of insitu incubations. Factors affecting the methylation and demethylation rates will be identified with laboratory incubations with 203 Hg at varying environmental conditions such as organic matter, pH, redox potential, conductivity, light, temperature, geochemical factors and populations of bacteria. The populations of bacteria will be determined to quantity by isotope techniques. The first experiments indicate markedly larger methylation capacity as well as bacterial production of incubated samples of Eichhornia crassipes, originating from Brazil, compared to Myriophyllum spicatum from Sweden. The results are the first step to better understand the importance of environmental parameters and bacterial production for methylation of Hg. (author)

The overmethylated genes in Helicobacter pylori-infected gastric mucosa are demethylated in gastric cancers

Directory of Open Access Journals (Sweden)

Choi Sang-Wook

2010-11-01

Full Text Available Abstract Background The transitional-CpG sites between weakly methylated genes and densely methylated retroelements are overmethylated in the gastric mucosa infected with Helicobacter pylori (H. pylori and they are undermethylated in the gastric cancers depending on the level of loss of heterozygosity (LOH events. This study delineated the transitional-CpG methylation patterns of CpG-island-containing and -lacking genes in view of the retroelements. Methods The transitional-CpG sites of eight CpG-island-containing genes and six CpG-island-lacking genes were semi-quantitatively examined by performing radioisotope-labelling methylation-specific PCR under stringent conditions. The level of LOH in the gastric cancers was estimated using the 40 microsatellite markers on eight cancer-associated chromosomes. Each gene was scored as overmethylated or undermethylated based on an intermediate level of transitional-CpG methylation common in the H. pylori-negative gastric mucosa. Results The eight CpG-island genes examined were overmethylated depending on the proximity to the nearest retroelement in the H. pylori-positive gastric mucosa. The six CpG-island-lacking genes were similarly methylated in the H. pylori-positive and -negative gastric mucosa. In the gastric cancers, long transitional-CpG segments of the CpG-island genes distant from the retroelements remained overmethylated, whereas the overmethylation of short transitional-CpG segments close to the retroelements was not significant. Both the CpG-island-containing and -lacking genes tended to be decreasingly methylated in a LOH-level-dependent manner. Conclusions The overmethylated genes under the influence of retroelement methylation in the H. pylori-infected stomach are demethylated in the gastric cancers influenced by LOH.

Control of DEMETER DNA demethylase gene transcription in male and female gamete companion cells in Arabidopsis thaliana.

Science.gov (United States)

Park, Jin-Sup; Frost, Jennifer M; Park, Kyunghyuk; Ohr, Hyonhwa; Park, Guen Tae; Kim, Seohyun; Eom, Hyunjoo; Lee, Ilha; Brooks, Janie S; Fischer, Robert L; Choi, Yeonhee

2017-02-21

The DEMETER (DME) DNA glycosylase initiates active DNA demethylation via the base-excision repair pathway and is vital for reproduction in Arabidopsis thaliana DME-mediated DNA demethylation is preferentially targeted to small, AT-rich, and nucleosome-depleted euchromatic transposable elements, influencing expression of adjacent genes and leading to imprinting in the endosperm. In the female gametophyte, DME expression and subsequent genome-wide DNA demethylation are confined to the companion cell of the egg, the central cell. Here, we show that, in the male gametophyte, DME expression is limited to the companion cell of sperm, the vegetative cell, and to a narrow window of time: immediately after separation of the companion cell lineage from the germline. We define transcriptional regulatory elements of DME using reporter genes, showing that a small region, which surprisingly lies within the DME gene, controls its expression in male and female companion cells. DME expression from this minimal promoter is sufficient to rescue seed abortion and the aberrant DNA methylome associated with the null dme-2 mutation. Within this minimal promoter, we found short, conserved enhancer sequences necessary for the transcriptional activities of DME and combined predicted binding motifs with published transcription factor binding coordinates to produce a list of candidate upstream pathway members in the genetic circuitry controlling DNA demethylation in gamete companion cells. These data show how DNA demethylation is regulated to facilitate endosperm gene imprinting and potential transgenerational epigenetic regulation, without subjecting the germline to potentially deleterious transposable element demethylation.

Demethylation of induced pluripotent stem cells from type 1 diabetic patients enhances differentiation into functional pancreatic β cells.

Science.gov (United States)

Manzar, Gohar S; Kim, Eun-Mi; Zavazava, Nicholas

2017-08-25

Type 1 diabetes (T1D) can be managed by transplanting either the whole pancreas or isolated pancreatic islets. However, cadaveric pancreas is scarcely available for clinical use, limiting this approach. As such, there is a great need to identify alternative sources of clinically usable pancreatic tissues. Here, we used induced pluripotent stem (iPS) cells derived from patients with T1D to generate glucose-responsive, insulin-producing cells (IPCs) via 3D culture. Initially, T1D iPS cells were resistant to differentiation, but transient demethylation treatment significantly enhanced IPC yield. The cells responded to high-glucose stimulation by secreting insulin in vitro The shape, size, and number of their granules, as observed by transmission electron microscopy, were identical to those found in cadaveric β cells. When the IPCs were transplanted into immunodeficient mice that had developed streptozotocin-induced diabetes, they promoted a dramatic decrease in hyperglycemia, causing the mice to become normoglycemic within 28 days. None of the mice died or developed teratomas. Because the cells are derived from "self," immunosuppression is not required, providing a much safer and reliable treatment option for T1D patients. Moreover, these cells can be used for drug screening, thereby accelerating drug discovery. In conclusion, our approach eliminates the need for cadaveric pancreatic tissue.

Chemoprevention of colorectal cancer by black raspberry anthocyanins involved the modulation of gut microbiota and SFRP2 demethylation.

Science.gov (United States)

Chen, Lili; Jiang, Bowen; Zhong, Chunge; Guo, Jun; Zhang, Lihao; Mu, Teng; Zhang, Qiuhua; Bi, Xiuli

2018-03-08

Freeze-dried black raspberry (BRB) powder is considered as a potential cancer chemopreventive agent. In this study, we fed azoxymethane (AOM)/dextran sodium sulfate (DSS)-treated C57BL/6J mice with a diet containing BRB anthocyanins for 12 weeks, and this led to a reduction in colon carcinogenesis. These animals had consistently lower tumor multiplicity compared with AOM/DSS-treated mice not receiving BRB anthocyanins. In AOM/DSS-treated mice, the number of pathogenic bacteria, including Desulfovibrio sp. and Enterococcus spp., was increased significantly, whereas probiotics such as Eubacterium rectale, Faecalibacterium prausnitzii and Lactobacillus were dramatically decreased, but BRB anthocyanins supplement could reverse this imbalance in gut microbiota. BRB anthocyanins also caused the demethylation of the SFRP2 gene promoter, resulting in increased expression of SFRP2, both at the mRNA and protein levels. Furthermore, the expression levels of DNMT31 and DNMT3B, as well as of p-STAT3 were downregulated by BRB anthocyanins in these animals. Taken together, these results suggested that BRB anthocyanins could modulate the composition of gut commensal microbiota, and changes in inflammation and the methylation status of the SFRP2 gene may play a central role in the chemoprevention of CRC.

The Cell Cycle: An Activity Using Paper Plates to Represent Time Spent in Phases of the Cell Cycle

Science.gov (United States)

Scherer, Yvette D.

2014-01-01

In this activity, students are given the opportunity to combine skills in math and geometry for a biology lesson in the cell cycle. Students utilize the data they collect and analyze from an online onion-root-tip activity to create a paper-plate time clock representing a 24-hour cell cycle. By dividing the paper plate into appropriate phases of…

Intramolecular Oxidative O-Demethylation of an Oxoferryl Porphyrin Complexed with a Per-O-methylated β-Cyclodextrin Dimer.

Science.gov (United States)

Kitagishi, Hiroaki; Kurosawa, Shun; Kano, Koji

2016-11-22

The intramolecular oxidation of ROCH 3 to ROCH 2 OH, where the latter compound spontaneously decomposed to ROH and HCHO, was observed during the reaction of the supramolecular complex (met-hemoCD3) with cumene hydroperoxide in aqueous solution. Met-hemoCD3 is composed of meso-tetrakis(4-sulfonatophenyl)porphinatoiron(III) (Fe III TPPS) and a per-O-methylated β-cyclodextrin dimer having an -OCH 2 PyCH 2 O- linker (Py=pyridine-3,5-diyl). The O=Fe IV TPPS complex was formed by the reaction of met-hemoCD3 with cumene hydroperoxide, and isolated by gel-filtration chromatography. Although the isolated O=Fe IV TPPS complex in the cyclodextrin cage was stable in aqueous solution at 25 °C, it was gradually converted to Fe II TPPS (t 1/2 =7.6 h). This conversion was accompanied by oxidative O-demethylation of an OCH 3 group in the cyclodextrin dimer. The results indicated that hydrogen abstraction by O=Fe IV TPPS from ROCH 3 yields HO-Fe III TPPS and ROCH 2 . . This was followed by radical coupling to afford Fe II TPPS and ROCH 2 OH. The hemiacetal (ROCH 2 OH) immediately decomposed to ROH and HCHO. This study revealed the ability of oxoferryl porphyrin to induce two-electron oxidation. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Yucca Mountain Climate Technical Support Representative

International Nuclear Information System (INIS)

Sharpe, Saxon E

2007-01-01

The primary objective of Project Activity ORD-FY04-012, 'Yucca Mountain Climate Technical Support Representative', was to provide the Office of Civilian Radioactive Waste Management (OCRWM) with expertise on past, present, and future climate scenarios and to support the technical elements of the Yucca Mountain Project (YMP) climate program. The Climate Technical Support Representative was to explain, defend, and interpret the YMP climate program to the various audiences during Site Recommendation and License Application. This technical support representative was to support DOE management in the preparation and review of documents, and to participate in comment response for the Final Environmental Impact Statement, the Site Recommendation Hearings, the NRC Sufficiency Comments, and other forums as designated by DOE management. Because the activity was terminated 12 months early and experience a 27% reduction in budget, it was not possible to complete all components of the tasks as originally envisioned. Activities not completed include the qualification of climate datasets and the production of a qualified technical report. The following final report is an unqualified summary of the activities that were completed given the reduced time and funding

Epigenetic switch involved in activation of pioneer factor FOXA1-dependent enhancers

Science.gov (United States)

Sérandour, Aurélien A.; Avner, Stéphane; Percevault, Frédéric; Demay, Florence; Bizot, Maud; Lucchetti-Miganeh, Céline; Barloy-Hubler, Frédérique; Brown, Myles; Lupien, Mathieu; Métivier, Raphaël; Salbert, Gilles; Eeckhoute, Jérôme

2011-01-01

Transcription factors (TFs) bind specifically to discrete regions of mammalian genomes called cis-regulatory elements. Among those are enhancers, which play key roles in regulation of gene expression during development and differentiation. Despite the recognized central regulatory role exerted by chromatin in control of TF functions, much remains to be learned regarding the chromatin structure of enhancers and how it is established. Here, we have analyzed on a genomic-scale enhancers that recruit FOXA1, a pioneer transcription factor that triggers transcriptional competency of these cis-regulatory sites. Importantly, we found that FOXA1 binds to genomic regions showing local DNA hypomethylation and that its cell-type-specific recruitment to chromatin is linked to differential DNA methylation levels of its binding sites. Using neural differentiation as a model, we showed that induction of FOXA1 expression and its subsequent recruitment to enhancers is associated with DNA demethylation. Concomitantly, histone H3 lysine 4 methylation is induced at these enhancers. These epigenetic changes may both stabilize FOXA1 binding and allow for subsequent recruitment of transcriptional regulatory effectors. Interestingly, when cloned into reporter constructs, FOXA1-dependent enhancers were able to recapitulate their cell type specificity. However, their activities were inhibited by DNA methylation. Hence, these enhancers are intrinsic cell-type-specific regulatory regions of which activities have to be potentiated by FOXA1 through induction of an epigenetic switch that includes notably DNA demethylation. PMID:21233399

Physical activity, sedentary behavior, and body mass index in the Czech Republic: a nationally representative survey.

Science.gov (United States)

Mitáš, Josef; Ding, Ding; Frömel, Karel; Kerr, Jacqueline

2014-07-01

Post-communist countries have experienced rapid economic development and social changes, which have been accompanied by changes in health-related lifestyle behaviors, such as physical activity. The purpose of this study was to examine the associations of domain-specific physical activity and total sedentary time with BMI among adults in the Czech Republic. We surveyed a nationally representative sample (n = 4097) of the Czech Republic in fall 2007 using the International Physical Activity Questionnaire (long form). Multiple linear regression analyses were used to examine associations of physical activity, sedentary time and sociodemographic characteristics with BMI. Older age, lower educational attainment, and lower levels of leisure-time physical activity were associated with higher BMI. Compared with those living in large cities, men living in small towns and women living in small villages had higher BMI. This study has identified correlates of BMI in the Czech Republic. Although more evidence from longitudinal studies is needed, findings from the current study can inform interventions to prevent the rising obesity epidemic.

Discovery of gemfibrozil analogues that activate PPARα and enhance the expression of gene CPT1A involved in fatty acids catabolism.

Science.gov (United States)

De Filippis, Barbara; Giancristofaro, Antonella; Ammazzalorso, Alessandra; D'Angelo, Alessandra; Fantacuzzi, Marialuigia; Giampietro, Letizia; Maccallini, Cristina; Petruzzelli, Michele; Amoroso, Rosa

2011-10-01

A new series of gemfibrozil analogues conjugated with α-asarone, trans-stilbene, chalcone, and their bioisosteric modifications were synthesized and evaluated to develop PPARα agonists. In this attempt, we have removed the methyls on the phenyl ring of gemfibrozil and introduced the above scaffolds in para position synthesizing two series of derivatives, keeping the dimethylpentanoic skeleton of gemfibrozil unaltered or demethylated. Four compounds exhibited good activation of the PPARα receptor and were also screened for their activity on PPARα-regulated gene CPT1A. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Enhancement of protocatechuate decarboxylase activity for the effective production of muconate from lignin-related aromatic compounds.

Science.gov (United States)

Sonoki, Tomonori; Morooka, Miyuki; Sakamoto, Kimitoshi; Otsuka, Yuichiro; Nakamura, Masaya; Jellison, Jody; Goodell, Barry

2014-12-20

The decarboxylation reaction of protocatechuate has been described as a bottleneck and a rate-limiting step in cis,cis-muconate (ccMA) bioproduction from renewable feedstocks such as sugar. Because sugars are already in high demand in the development of many bio-based products, our work focuses on improving protocatechuate decarboxylase (Pdc) activity and ccMA production in particular, from lignin-related aromatic compounds. We previously had transformed an Escherichia coli strain using aroY, which had been used as a protocatechuate decarboxylase encoding gene from Klebsiella pneumoniae subsp. pneumoniae A170-40, and inserted other required genes from Pseudomonas putida KT2440, to allow the production of ccMA from vanillin. This recombinant strain produced ccMA from vanillin, however the Pdc reaction step remained a bottleneck during incubation. In the current study, we identify a way to increase protocatechuate decarboxylase activity in E. coli through enzyme production involving both aroY and kpdB; the latter which encodes for the B subunit of 4-hydroxybenzoate decarboxylase. This permits expression of Pdc activity at a level approximately 14-fold greater than the strain with aroY only. The expression level of AroY increased, apparently as a function of the co-expression of AroY and KpdB. Our results also imply that ccMA may inhibit vanillate demethylation, a reaction step that is rate limiting for efficient ccMA production from lignin-related aromatic compounds, so even though ccMA production may be enhanced, other challenges to overcome vanilate demethylation inhibition still remain.

Selective inhibition of the demethylation at C-14 in ergosterol biosynthesis by the fungicide, Denmert (S-1358)

International Nuclear Information System (INIS)

Kato, Toshiro; Kawase, Yasuo

1976-01-01

A direct evidence of the inhibitory effect in a cell-free system of S. cerevisiae was experimentally studied, and the site of action of Denmert (S-n-butyl S'-p-tert-butylbenzyl N-3-pyridyldithiocarbon-imidate) in sterol biosynthesis was examined. 14 C-labeled lanosterol and 14-desmethyl-lanosterol were biosynthetically prepared. DL-mevalonate-2- 14 C was incubated with yeast cell-free homogenates for 3 hr at 28 deg C while being shaked vigorously in atmospheric oxygen. The resultant 14 C-labeled sterol was extracted and chromatographed on a silicic acid-Hyflo Super Cel column. 4,4-dimethyl sterol thus obtained was acetylated with acetic anhydride and pyridine. The separation of lanosteryl acetate and 14-desmethyl lanosteryl acetate was accomplished on alumina thin-layer plates. After the saponification of each steryl acetate, the quantity of the sterol was assessed by gas chromatography with cholesterol as an internal standard. The incubation of the 14 C-labeled sterol was achieved under the same conditions as those for the DL-mevalonate-2- 14 C except the addition of the substrate which was dispersed in 0.1M phosphate buffer. Denmert inhibited the conversion of 14 C-labeled lanosterol to 4-desmethyl sterol, while the conversion of 14 C-labeled 14-desmethyl lanosterol to 4-desmethyl sterol was hardly affected by the fungicide. Therefore, Denmert is a potent selective inhibitor of the demethylation at the C-14 position in ergosterol biosynthesis. The fungicide, triarimol, exhibited the same effect on sterol biosynthesis as that of Denmert. (Iwakiri, K.)

Symmetric dimeric bisbenzimidazoles DBP(n reduce methylation of RARB and PTEN while significantly increase methylation of rRNA genes in MCF-7 cancer cells.

Directory of Open Access Journals (Sweden)

Svetlana V Kostyuk

Full Text Available Hypermethylation is observed in the promoter regions of suppressor genes in the tumor cancer cells. Reactivation of these genes by demethylation of their promoters is a prospective strategy of the anticancer therapy. Previous experiments have shown that symmetric dimeric bisbenzimidazoles DBP(n are able to block DNA methyltransferase activities. It was also found that DBP(n produces a moderate effect on the activation of total gene expression in HeLa-TI population containing epigenetically repressed avian sarcoma genome.It is shown that DBP(n are able to penetrate the cellular membranes and accumulate in breast carcinoma cell MCF-7, mainly in the mitochondria and in the nucleus, excluding the nucleolus. The DBP(n are non-toxic to the cells and have a weak overall demethylation effect on genomic DNA. DBP(n demethylate the promoter regions of the tumor suppressor genes PTEN and RARB. DBP(n promotes expression of the genes RARB, PTEN, CDKN2A, RUNX3, Apaf-1 and APC "silent" in the MCF-7 because of the hypermethylation of their promoter regions. Simultaneously with the demethylation of the DNA in the nucleus a significant increase in the methylation level of rRNA genes in the nucleolus was detected. Increased rDNA methylation correlated with a reduction of the rRNA amount in the cells by 20-30%. It is assumed that during DNA methyltransferase activity inhibition by the DBP(n in the nucleus, the enzyme is sequestered in the nucleolus and provides additional methylation of the rDNA that are not shielded by DBP(n.It is concluded that DBP (n are able to accumulate in the nucleus (excluding the nucleolus area and in the mitochondria of cancer cells, reducing mitochondrial potential. The DBP (n induce the demethylation of a cancer cell's genome, including the demethylation of the promoters of tumor suppressor genes. DBP (n significantly increase the methylation of ribosomal RNA genes in the nucleoli. Therefore the further study of these compounds is needed

Activity Profiles and Physiological Responses of Representative Tag Football Players in Relation to Playing Position and Physical Fitness

Science.gov (United States)

2015-01-01

This study determined the physical fitness, match-activity profiles and physiological responses of representative tag football players and examined the relationship between physical fitness and the match-activity profile. Microtechnology devices and heart rate (HR) chest straps were used to determine the match-activity profiles of sixteen tag football players for five matches during the 2014 Australian National Championships. The relationships between lower body muscular power, straight line running speed and Yo-Yo intermittent recovery test level 2 (Yo-Yo IR2) and the match-activity profile were examined using Pearson’s correlation coefficients. Outside players had greater lower body muscular power (ES = 0.98) and straight line running speed (ES = 1.03–1.18) than inside players, and also covered greater very high-speed running (VHSR) distance/min (ES = 0.67) and reached higher peak running speeds (ES = 0.95) during matches. Inside and outside players performed a similar number of repeated high-intensity effort (RHIE) bouts and reported similar mean and maximum efforts per RHIE bout. However, there were differences between playing positions for mean and maximal RHIE effort durations (ES = 0.69–1.15) and mean RHIE bout recovery (ES = 0.56). Inside and outside players also reported small to moderate differences (ES = 0.43–0.80) for times spent in each HR zone. There were a number of moderate to very large correlations between physical fitness measures and match-activity profile variables. This study found lower body muscular power, straight line running speed and Yo-Yo IR2 to be related to the match-activities of representative tag football players, although differences between inside and outside players suggest that athlete testing and training practices should be modified for different playing positions. PMID:26642320

Statins augment the chemosensitivity of colorectal cancer cells inducing epigenetic reprogramming and reducing colorectal cancer cell 'stemness' via the bone morphogenetic protein pathway

NARCIS (Netherlands)

Kodach, L.L.; Jacobs, R.J.; Voorneveld, P.W.; Wildenberg, M.E.; Verspaget, H.W.; van Wezel, T.; Morreau, H.; Hommes, D.W.; Peppelenbosch, M.P.; van den Brink, G.R.; Hardwick, J.C.H.

2011-01-01

Promoter hypermethylation is an important and potentially reversible mechanism of tumour suppressor gene silencing in cancer. Compounds that demethylate tumour suppressor genes and induce differentiation of cancer cells, but do not have toxic side effects, would represent an exciting option in

Methylation of the chicken vitellogenin gene: influence of estradiol administration.

Science.gov (United States)

Meijlink, F C; Philipsen, J N; Gruber, M; Ab, G

1983-01-01

The degree of methylation of the chicken vitellogenin gene has been investigated. Upon induction by administration of estradiol to a rooster, methyl groups at specific sites near the 5'-end of the gene are eliminated. The process of demethylation is slower than the activation of the gene. Demethylation is therefore probably not a prerequisite to gene transcription. At least two other sites in the coding region of the gene are methylated in the liver of estrogenized roosters, but not in the liver of a laying hen, where the gene is naturally active. Images PMID:6298743

May 2013 Council of Chapter Representatives Notes

Directory of Open Access Journals (Sweden)

Robbins RA

2013-05-01

Full Text Available No abstract available. Article truncated at 150 words. The Council of Chapter Representatives met in conjunction with the ATS meeting in Philadelphia on May 18, 2012.Roll Call. The meeting was called to order at 11 AM. Representatives from Arizona, California, DC Metro, Louisiana, Michigan, New Mexico, New York, Oregon, and Rhode Island were in attendance, and by telephone from Washington.Chapter Updates. Information on chapter activities and a chapter brochure. There are currently 19 active chapters. Most are having annual meetings. Advocacy. Gary Ewart from ATS Government Relations gave a presentation on Washington activities. Highlights included activities on the SGR, a number of air pollution regulations and a letter campaign advocating regulation of cigars. ATS President 2013-14-vision for the coming year. Patrician Finn gave a summary of what she hopes to accomplish over the next year. The theme of her presidency will be health equality. ATS Executive Director-update. Steve Crane gave a positive presentation on the …

Effect of diethyldithiocarbamate (DDC) and ticlopidine on CYP1A2 activity and caffeine metabolism: an in vitro comparative study with human cDNA-expressed CYP1A2 and liver microsomes.

Science.gov (United States)

Kot, Marta; Daniel, Władysława A

2009-01-01

The aim of the present study was to test the effect of diethyldithiocarbamate (DDC), which is regarded as a cytochrome P450 (CYP) CYP2A6 and CYP2E1 inhibitor, and ticlopidine, an efficient CYP2B6, CYP2C19 and CYP2D6 inhibitor, on the activity of human CYP1A2 and the metabolism of caffeine (1-N-, 3-N- and 7-N-demethylation, and C-8-hydroxylation). The experiment was carried out in vitro using human cDNA-expressed CYP1A2 (Supersomes) and human pooled liver microsomes. The effects of DDC and ticlopidine were compared to those of furafylline (a strong CYP1A2 inhibitor). A comparative in vitro study provides clear evidence that ticlopidine and DDC, applied at concentrations that inhibit the above-mentioned CYP isoforms, potently (as compared to furafylline) inhibit human CYP1A2 and caffeine metabolism, in particular 1-N- and 3-N-demethylation.

Learning in later life: participation in formal, non-formal and informal activities in a nationally representative Spanish sample.

Science.gov (United States)

Villar, Feliciano; Celdrán, Montserrat

2013-06-01

This article examines the participation of Spanish older people in formal, non-formal and informal learning activities and presents a profile of participants in each kind of learning activity. We used data from a nationally representative sample of Spanish people between 60 and 75 years old ( n  = 4,703). The data were extracted from the 2007 Encuesta sobre la Participación de la Población Adulta en Actividades de Aprendizaje (EADA, Survey on Adult Population Involvement in Learning Activities). Overall, only 22.8 % of the sample participated in a learning activity. However, there was wide variation in the participation rates for the different types of activity. Informal activities were far more common than formal ones. Multivariate logistic regression indicated that education level and involvement in social and cultural activities were associated with likelihood of participating, regardless of the type of learning activity. When these variables were taken into account, age did not predict decreasing participation, at least in non-formal and informal activities. Implications for further research, future trends and policies to promote older adult education are discussed.

Effects of Conazole Fungicides on Spontaneous Activity in Neural Networks

Science.gov (United States)

Hexaconazole (HEX), Tetraconazole (TET), Fluconazole (FLU), and Triadimefon (TRI) are conazole fungicides, used to control powdery mildews on crops, and as veterinary and clinical treatments. TRI, a demethylation inhibitor, is neurotoxic in vivo, and previous in vitro experiments...

Enantiomeric separation of some demethylated analogues of clofibric acid by capillary zone electrophoresis and nano-liquid chromatography.

Science.gov (United States)

Fantacuzzi, Marialuigia; Bettoni, Giancarlo; D'Orazio, Giovanni; Fanali, Salvatore

2006-03-01

The enantiomeric separation of some demethylated analogues of clofibric acid, namely 2-(6-chloro-benzothiazol-2-ylsulfanyl)-, 2-(6-methoxy-benzothiazol-2-ylsulfanyl)-, 2-(quinolin-2-yloxy)-, 2-(6-chloro-quinolin-2-yloxy)-, 2-(7-chloro-quinolin-4-yloxy)-propionic acid (compounds A-E, respectively), has been studied by CZE and nano-LC using for the first technique two beta-CD derivatives and vancomycin added to the BGE and vancomycin-modified silica particles for the second one, with the aim to find the optimum experimental conditions for the baseline resolution. The type and the concentration of the chiral selector added to the BGE, the buffer pH, the type of organic modifier and its concentration, the capillary temperature and the applied voltage played a very important role in the enantioresolution of the analysed compounds. The use of 6-monodeoxy-6-monoamino-beta-CD allowed to achieve baseline resolution of four of five clofibric acid derivatives in less than 10 min while heptakis-(2,3,6-tri-O-methyl)-beta-CD partially resolved the same compounds in their enantiomers. Employing vancomycin as the chiral selector in CZE, the counter-current partial filling method was chosen achieving baseline resolution of four analytes. All the studied compounds were enantioresolved employing a capillary column packed with vancomycin stationary phase by nano-LC, and the resolution was strongly influenced by the concentration of the organic modifier and by the pH of the mobile phase. The best results were achieved at pH 4.5 in presence of 60% of methanol (MeOH). However, longer analysis times were observed in the experiments carried out by nano-LC.

[Experimental rationale for the parameters of a rapid method for oxidase activity determination].

Science.gov (United States)

Butorina, N N

2010-01-01

Experimental rationale is provided for the parameters of a rapid (1-2-min) test to concurrently determine the oxidase activity of all bacteria grown on the membrane filter after water filtration. Oxidase reagents that are the aqueous solutions of tetramethyl-p-phenylenediamine dihydrochloride and demethyl-p-phenylenediamine dihydrochloride have been first ascertained to exert no effect on the viability and enzymatic activity of bacteria after one-hour contact. An algorithm has been improved for the rapid oxidase activity test: the allowable time for bacteria to contact oxidase reagents and procedures for minimizing the effect on bacterial biochemical activity following the contact. An accelerated method based on lactose medium with tergitol 7 and Endo agar has been devised to determine coliform bacteria, by applying the rapid oxidase test: the time of a final response is 18-24 hours. The method has been included into GOST 52426-2005.

Effect of Garden Cress Seeds Powder and Its Alcoholic Extract on the Metabolic Activity of CYP2D6 and CYP3A4

Directory of Open Access Journals (Sweden)

Fahad I. Al-Jenoobi

2014-01-01

Full Text Available The powder and alcoholic extract of dried seeds of garden cress were investigated for their effect on metabolic activity of CYP2D6 and CYP3A4 enzymes. In vitro and clinical studies were conducted on human liver microsomes and healthy human subjects, respectively. Dextromethorphan was used as a common marker for measuring metabolic activity of CYP2D6 and CYP3A4 enzymes. In in vitro studies, microsomes were incubated with NADPH in presence and absence of different concentrations of seeds extract. Clinical investigations were performed in two phases. In phase I, six healthy female volunteers were administered a single dose of dextromethorphan and in phase II volunteers were treated with seeds powder for seven days and dextromethorphan was administered with last dose. The O-demethylated and N-demethylated metabolites of dextromethorphan were measured as dextrorphan (DOR and 3-methoxymorphinan (3-MM, respectively. Observations suggested that garden cress inhibits the formation of DOR and 3-MM metabolites. This inhibition of metabolite level was attributed to the inhibition of CYP2D6 and CYP3A4 activity. Garden cress decreases the level of DOR and 3-MM in urine and significantly increases the urinary metabolic ratio of DEX/DOR and DEX/3-MM. The findings suggested that garden cress seeds powder and ethanolic extract have the potential to interact with CYP2D6 and CYP3A4 substrates.

Quantification of citalopram or escitalopram and their demethylated metabolites in neonatal hair samples by liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Frison, Giampietro; Favretto, Donata; Vogliardi, Susanna; Terranova, Claudio; Ferrara, Santo Davide

2008-08-01

Citalopram and escitalopram are highly selective serotonin reuptake inhibitors widely used in the treatment of depression. They exhibit adverse drug reactions and side effects, however, and the development of specific methods for their determination is of great interest in clinical and forensic toxicology. A liquid chromatography-tandem mass spectrometry method has been developed and validated for the assay of citalopram, escitalopram, and their demethylated metabolites in 10-mg hair samples. The analytes were extracted by incubation in methanol and liquid/liquid extraction with diethyl ether/dichloromethane. Gradient elution on a narrow bore C18 column was realized using clomipramine-d3 as an internal standard. Positive ion electrospray ionization and tandem mass spectrometry determination by collision-induced dissociation were performed in an ion trap mass spectrometer. The method exhibited a linear range of 25 to 2000 pg/mg, a quantification limit of 25 pg/mg for all analytes, relative standard deviations in the range of 12.10 to 9.80 (intraassay), and 13.80 to 11.78 (interassay), and accuracies (as percent recovery of the spiked standards) in the range of 90% to 110%; it was applied to the determination of citalopram and escitalopram and their metabolites in hair samples of two newborns to document their in utero exposure to the drugs. The method proved suitable for neonatal hair analysis of citalopram or escitalopram and was applied to two real cases of gestational exposure.

Association Between Objectively Measured Physical Activity and Erectile Dysfunction among a Nationally Representative Sample of American Men.

Science.gov (United States)

Loprinzi, Paul D; Edwards, Meghan

2015-09-01

Emerging work suggests an inverse association between physical activity and erectile dysfunction (ED). The majority of this cross-sectional research comes from convenience samples and all studies on this topic have employed self-report physical activity methodology. Therefore, the purpose of this brief-report, confirmatory research study was to examine the association between objectively measured physical activity and ED in a national sample of Americans. Data from the 2003-2004 National Health and Nutrition Examination Survey were used. Six hundred ninety-two adults between the ages of 50 and 85 years (representing 33.2 million adults) constituted the analytic sample. Participants wore an ActiGraph 7164 accelerometer (ActiGraph, Pensacola, FL, USA) for up to 7 days with ED assessed via self-report. The main outcome measure used was ED assessed via self-report. After adjustments, for every 30 min/day increase in moderate-to-vigorous physical activity, participants had a 43% reduced odds of having ED (odds ratioadjusted  = 0.57; 95% confidence interval: 0.40-0.81; P = 0.004). This confirmatory study employing an objective measure of physical activity in a national sample suggests an inverse association between physical activity and ED. © 2015 International Society for Sexual Medicine.

Identification, replication and characterization of epigenetic remodelling in the aging genome

DEFF Research Database (Denmark)

Li, Shuxia; Christiansen, Lene; Christensen, Kaare

Background: Aging is a complex biological process that involves numerous changes at various levels through remodelling of multiple biological processes and regulatory mechanisms including epigenetics. Recent analysis of the DNA methylome has reported large numbers of epigenetic markers associated......, and by overwhelming age-related methylation in CpG island and demethylation at shore/shelf and open sea. Biological pathway analysis showed that age-dependent methylations were especially involved in cellular signalling activities while demethylations were particularly related to functions of the extracellular matrix....... Conclusion: Extensive epigenetic remodelling in the DNA methylome could be involved in the aging process. The identified age-methylated and demethylated sites displayed differential distribution patterns over genomic regions and were involved in biological pathways closely related to aging phenotypes and age...

Evaluation of Packed-Bed Reactor and Continuous Stirred Tank Reactor for the Production of Colchicine Derivatives

OpenAIRE

Dubey, Kashyap Kumar; Kumar, Dhirendra; Kumar, Punit; Haque, Shafiul; Jawed, Arshad

2013-01-01

Bioconversion of colchicine into its pharmacologically active derivative 3-demethylated colchicine (3-DMC) mediated by P450BM3 enzyme is an economic and promising strategy for the production of this inexpensive and potent anticancer drug. Continuous stirred tank reactor (CSTR) and packed-bed reactor (PBR) of 3 L and 2 L total volumes were compared for the production of 3-demethylated colchicine (3-DMC) a colchicine derivative using Bacillus megaterium MTCC*420 under aerobic conditions. Statis...

Early postoperative erythromycin breath test correlates with hepatic cytochrome P4503A activity in liver transplant recipients

DEFF Research Database (Denmark)

Schmidt, L E; Olsen, A K; Stentoft, K

2001-01-01

BACKGROUND: Interindividual variation in the pharmacokinetics of the immunosuppressive agents cyclosporine (INN, ciclosporin) and tacrolimus may result from differences in the activity of cytochrome P4503A (CYP3A). The erythromycin breath test is an in vivo assay of hepatic CYP3A activity......, but the method has never been directly validated. The aim of the study was to investigate whether an early postoperative erythromycin breath test correlated with the hepatic CYP3A protein level and catalytic activity in liver transplant recipients. METHODS: In 18 liver transplant recipients, the erythromycin...... breath test was performed within 2 hours after transplantation. A graft biopsy was obtained during surgery and analyzed for the CYP3A protein level by Western blotting and for CYP3A activity with erythromycin demethylation and testosterone 6beta- hydroxylation assays. RESULTS: The erythromycin breath...

Abundance, genetic diversity and sensitivity to demethylation inhibitor fungicides of Aspergillus fumigatus isolates from organic substrates with special emphasis on compost.

Science.gov (United States)

Santoro, Karin; Matić, Slavica; Gisi, Ulrich; Spadaro, Davide; Pugliese, Massimo; Gullino, Maria L

2017-12-01

Aspergillus fumigatus is a widespread fungus that colonizes dead organic substrates but it can also cause fatal human diseases. Aspergilloses are treated with demethylation inhibitor (DMI) fungicides; however, resistant isolates appeared recently in the medical and also environmental area. The present study aims at molecular characterizing and quantifying A. fumigatus in major environmental habitats and determining its sensitivity to medical and agricultural DMI fungicides. A. fumigatus was isolated only rarely from soil and meadow/forest organic matter but high concentrations (10 3 to 10 7  cfu/g) were detected in substrates subjected to elevated temperatures, such as compost and silage. High genetic diversity of A. fumigatus from compost was found based on SSR markers, distinguishing among fungal isolates even when coming from the same substrate sample, while subclustering was observed based on mutations in cyp51A gene. Several cyp51A amino acid substitutions were found in 15 isolates, although all isolates were fully sensitive to the tested DMI fungicides, with exception of one isolate in combination with one fungicide. This study suggests that the tested A. fumigatus isolates collected in Italy, Spain and Hungary from the fungus' major living habitats (compost) and commercial growing substrates are not potential carriers for DMI resistance in the environment. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Changes in cytochrome P4501A activity during development in common tern chicks fed polychlorinated biphenyls, as measured by the caffeine breath test

Energy Technology Data Exchange (ETDEWEB)

Feyk, L.A.; Giesy, J.P.; Bosveld, A.T.C.; Van den Berg, M.

2000-03-01

Cytochrome P4501A (CYPIA) activity is often used as a biomarker of exposure of wildlife to polyhalogenated diaromatic hydrocarbons and is usually measured ex vivo in liver tissue. A caffeine breath test (CBT) with radiolabeled substrate ({sup 14}C-caffeine) was used to measure in vivo CYP1A activity twice during development in 14 common tern (Sterna hirundo) chicks treated with polyhalogenated diaromatic hydrocarbons. Tern hatchlings were fed fish spiked with 3,3{prime}, 4,4{prime},5-pentachlorobiphenyl (PCB 126) and 2,2{prime},4,4{prime},5,5{prime}-hexachlorobiphenyl (PCB 153) such that the diet contained an average of 23, 99, or 561 pg of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents per gram of fish for 21 d. Sixteen additional common tern chicks were similarly dosed with polyhalogenated diaromatic hydrocarbons but were not subjected to the CBT procedure. In weeks 1 and 2, caffeine N-demethylation and ethoxyresorufin-O-deethylation activity on day 21 were elevated in birds that received the greatest PCB dose. There was less constitutive and greater induction of ethoxyresorufin-O-deethylation activity than caffeine N-demethylation. The {sup 14}C-CBT was less invasive than the ethoxyresorufin-O-deethylase assay. Only one morphological parameter differed significantly between CBT subjects and no-CBT subjects fed the same level of PCBs. Bursa weight was significantly less in control CBT subjects than in control no-CBT subjects, but bursa weights did not differ among CBT and no-CBT birds from the two PCB treatment groups. No alterations of survival or growth occurred in CBT subjects compared with no-CBT subjects.

Engineering activities on the ITER representative diagnostic equatorial port plug

International Nuclear Information System (INIS)

Meunier, L.; Doceul, L.; Salasca, S.; Martins, J.-P.; Jullien, F.; Dechelle, Christian; Bidaud, Pierre; Pilard, Vincent; Terra, Alexis; Ogea, Mathieu; Ciattaglia, Emanuela; Walker, Christopher

2009-01-01

Most of ITER diagnostic systems are integrated in port plugs, which are water cooled stainless steel structures inserted into the vacuum vessel ports. The port plug must provide basic functions such as neutron and gamma shielding, supporting the first wall armour (BSM), closing the vacuum vessel ports, while supporting the diagnostic equipments. ITER diagnostic port plug must resist a severe environment like high temperature due to neutron interaction with the structures and high electromechanical loading during disruptions events. CEA has contributed to the design and integration tasks in the frame of the representative equatorial port plug EQ no. 01, in particular on the engineering, structural and thermal finite element analysis. These detailed analyses have highlighted some design issues which were worked out through different solutions. This paper contains a description of the engineering activities performed such as: -The static mechanical calculations of the top plate closure system under disruption load. -The static mechanical calculations of the BSM attachment to the port plug. These two first studies led to design changes proposals which significantly improved the behaviour of the structures but also showed that the safety margin with respect to design limits is quite low. -The design of a Diagnostic Shield Module (DSM) integrated inside the port plug and a proposition of attachment scheme, with respect to disruption loads. The manufacturing of the DSM has been taken into account, as well as diagnostic integration inside the structure and maintenance aspects. -The thermal assessment of the port plug under neutronic load during normal operation, with the optimization of the cooling system. The maximum temperature calculated in normal operation has been reduced from 900 deg. C to less than 400 deg. C in the front plate; and the cooling arrangement at the back of the port plug has been simplified without important temperature increase.

Engineering activities on the ITER representative diagnostic equatorial port plug

Energy Technology Data Exchange (ETDEWEB)

Meunier, L. [Association Euratom CEA, CEA/DSM/IRFM (France)], E-mail: lmeunier@cea.fr; Doceul, L.; Salasca, S.; Martins, J.-P.; Jullien, F.; Dechelle, Christian; Bidaud, Pierre; Pilard, Vincent; Terra, Alexis; Ogea, Mathieu [Association Euratom CEA, CEA/DSM/IRFM (France); Ciattaglia, Emanuela [EFDA CSU, Garching (Germany); Walker, Christopher [ITER International Organisation (France)

2009-06-15

Most of ITER diagnostic systems are integrated in port plugs, which are water cooled stainless steel structures inserted into the vacuum vessel ports. The port plug must provide basic functions such as neutron and gamma shielding, supporting the first wall armour (BSM), closing the vacuum vessel ports, while supporting the diagnostic equipments. ITER diagnostic port plug must resist a severe environment like high temperature due to neutron interaction with the structures and high electromechanical loading during disruptions events. CEA has contributed to the design and integration tasks in the frame of the representative equatorial port plug EQ no. 01, in particular on the engineering, structural and thermal finite element analysis. These detailed analyses have highlighted some design issues which were worked out through different solutions. This paper contains a description of the engineering activities performed such as: -The static mechanical calculations of the top plate closure system under disruption load. -The static mechanical calculations of the BSM attachment to the port plug. These two first studies led to design changes proposals which significantly improved the behaviour of the structures but also showed that the safety margin with respect to design limits is quite low. -The design of a Diagnostic Shield Module (DSM) integrated inside the port plug and a proposition of attachment scheme, with respect to disruption loads. The manufacturing of the DSM has been taken into account, as well as diagnostic integration inside the structure and maintenance aspects. -The thermal assessment of the port plug under neutronic load during normal operation, with the optimization of the cooling system. The maximum temperature calculated in normal operation has been reduced from 900 deg. C to less than 400 deg. C in the front plate; and the cooling arrangement at the back of the port plug has been simplified without important temperature increase.

[Antiviral activity of representatives of the family Crassulaceae].

Science.gov (United States)

Shirobokov, V P; Evtushenko, A I; Lapchik, V F; Shirobokova, D N; Suptel', E A

1981-12-01

The antiviral properties of the juice of 11 species of the orpine family were studied. 8 of them belonged to the genera Kalanchoe, i. e. Kalanchoe diagremontiona R. Hamet, K. pinnata (Zam.) Persoon, K. Peteri Werd., K. prolifera (Bovie) R. Hamet, K. marnierriana (Mann. et Boit) Jacobs; K. blossfeldiana v. Poelln, K. beharensis Drake del Gastillo, K. waldheimii R. Hamet et Perr and 3 belonged to the Sedum genera, i. e. Sedum telephium L., S. spectabile Boreau, S. acre L. A high virus neutralizing activity of the juice from 4 species of Kalanchoe, i. e. K. blossfeldiana, K. waldheimii, K. pinnata and K. beharensis was shown. Inhibition of the virus infecting activity was observed at the juice dilutions from 1-2 to 1-8000 and higher. The viricidal factor of Kalanchoe is stable. It is not destroyed by ether, alcohol and potassium periodate. It is not absorbed by bentonite at the acid pH values. Addition of cattle serum or purified proteins to the juice resulted in their precipitation which suppressed the viricidal activity of the juice.

Anti-bacterial compounds from the sponge Haliclona sp.

Digital Repository Service at National Institute of Oceanography (India)

Parameswaran, P.S.; Kamat, S.Y.; Chandramohan, D.; Nair, S.; Das, B.

located the active principles in petroleum ether and ethyl acetate fractions Further purification of these active fractions on silica gel columns and subsequently on HPLC yielded several active compounds two of which have been identified as demethyl...

Association of Physical Activity with Alcohol Abuse and Dependence in a Nationally-Representative U.S. Sample.

Science.gov (United States)

Damian, April Joy; Mendelson, Tamar

2017-11-10

Alcohol use is a pervasive and costly public health problem in the United States. Relapse rates from alcohol use disorders are high. Although exercise has been proposed as a strategy to prevent relapse, lifestyle modification is the least studied aspect of relapse prevention programs, especially among racial/ethnic minority populations. The current study assessed whether being physically active was associated with remission from alcohol abuse or dependence among Black (African American and Afro Caribbean) adults in the U.S. We utilized data on Black adult participants (n = 4,828) from the nationally representative National Survey of American Life (NSAL) conducted in 2001-2003. Logistic regression models were estimated to assess the odds of being in 12-month remission or currently meeting DSM-IV criteria for alcohol abuse or dependence based on level of physical activity, adjusting for socio-demographic and neighborhood characteristics. People who endorsed being physically active had higher odds of being in 12-month remission from alcohol use problems (OR: 1.67, 95% CI: 1.28, 2.17) than people who were physically inactive, adjusting for individual- and neighborhood-level characteristics. People who were physically active did not differ significantly from those who were inactive with respect to odds of currently meeting DSM-IV criteria for alcohol abuse or dependence. Conclusions/Importance: Physical activity was positively associated with being in 12-month remission from alcohol use problems. Longitudinal studies are needed to establish temporal ordering and to explore exercise as a potential relapse prevention strategy for alcohol use problems.

Biochemical background of toxic interaction between tiamulin and monensin.

Science.gov (United States)

Szucs, Gyula; Tamási, Viola; Laczay, Péter; Monostory, Katalin

2004-03-15

Tiamulin, a diterpene antibiotic, is used for treatment of pulmonary and gastrointestinal infections in swine and poultry. Combined administration of tiamulin and ionophores (e.g. monensin) to farm animals may lead to intoxication manifested in severe clinical symptoms. Tiamulin metabolite complex with cytochrome P450 has been suggested to be the basis of drug-interactions. However, the formation of metabolic intermediate complex is questionable. The effect of tiamulin-treatment on cytochrome P450 activities was investigated in rats. Ethylmorphine and aminopyrine N-demethylation activities as well as monensin metabolism (O-demethylation) increased in liver microsomes of tiamulin-treated (200 mg/kg) animals. CYP3A1 induction caused by tiamulin was confirmed by the results of Western blot analysis. To test metabolic intermediate complex formation as a result of tiamulin treatment, cytochrome P450 activities were also determined in the presence of potassium ferricyanide. The findings together with those of in vitro complex formation suggested that formation of metabolic intermediate complexes of tiamulin with cytochrome P450 could be excluded. On the other hand, the results of inhibition studies showed significant decrease of ethylmorphine or aminopyrine as well as monensin demethylation in the presence of tiamulin. Our results proved that tiamulin has dual effect on cytochromes P450. It is able to induce and directly inhibit CYP3A enzymes, which are predominantly responsible for monensin O-demethylation. The direct effect of tiamulin as an inhibitor might play a more important role in toxicity than its putative effect as a chemical inducer of CYP3A enzymes.

[Physical movement - is it good for the back? Nationwide representative study on different effects of physical activity at the workplace and in leisure time].

Science.gov (United States)

Schneider, S; Zoller, S

2009-10-01

Physical activity is an important component of primary and secondary prevention of orthopedic complaints such as back pain as well as for many other syndromes. This epidemiologic research project investigated the multifactorial interaction between physical leisure activities and back pain and also the question whether regular physical activity at the workplace can be equated with the effect of regular leisure activity. From a patients point of view this could be construed as an"excuse" to refrain from leisure and fitness sports. Within the framework of a cooperative project between the Orthopedic University Clinic in Heidelberg and the Robert-Koch Institute in Berlin, representative data were gathered for the first time in Germany on physical activity at the workplace and in leisure time as well as the prevalence of back pain. Within the first national health survey a random sample of 3,488 employed German citizens aged 18-69 years old was investigated with multiple logistic regression analyses.The prevalence of 7-day back pain in Germany was 34% and the prevalence for 1-year was 60%. Physical activity at the workplace was associated with a significantly higher risk for back pain whilst leisure sport activity was accompanied by a lower prevalence of back pain. Although 39% of all persons who were inactive in sport and physical activities claimed to have felt back pain at least once in a retrospective 7-day period, the corresponding values for persons active in sport were 33% (1-2 h sport/week), 27% (2-4 h sport/week) and 30% (>4 h sport/week).This study provides population-based epidemiologic data on the prevalence of back pain among employed German citizens for the first time since the reunification. Although causal conclusions cannot principally be derived from cross-sectional data, the results of this analysis allow the multifactorial conditional structure to be unraveled. Our data demonstrate that manual physical employment does not represent a substitute for

Representing and estimating interactions between activities in a need-based model of activity generation

NARCIS (Netherlands)

Nijland, L.; Arentze, T.; Timmermans, H.

2013-01-01

Although several activity-based models made the transition to practice in recent years, modeling dynamic activity generation and especially, the mechanisms underlying activity generation are not well incorporated in the current activity-based models. For instance, current models assume that

Representing and estimating interactions between activities in a need-based model of activity generation

NARCIS (Netherlands)

Nijland, E.W.L.; Arentze, T.A.; Timmermans, H.J.P.

2011-01-01

Although several activity-based models made the transition to practice in recent years, modelling dynamic activity generation and especially, the mechanisms underlying activity generation are not well incorporated in the current activity-based models. For example, current models assume that

Enantiomeric metabolic interactions and stereoselective human methadone metabolism.

Science.gov (United States)

Totah, Rheem A; Allen, Kyle E; Sheffels, Pamela; Whittington, Dale; Kharasch, Evan D

2007-04-01

Methadone is administered as a racemate, although opioid activity resides in the R-enantiomer. Methadone disposition is stereoselective, with considerable unexplained variability in clearance and plasma R/S ratios. N-Demethylation of methadone in vitro is predominantly mediated by cytochrome P450 CYP3A4 and CYP2B6 and somewhat by CYP2C19. This investigation evaluated stereoselectivity, models, and kinetic parameters for methadone N-demethylation by recombinant CYP2B6, CYP3A4, and CYP2C19, and the potential for interactions between enantiomers during racemate metabolism. CYP2B6 metabolism was stereoselective. CYP2C19 was less active, and stereoselectivity was opposite that for CYP2B6. CYP3A4 was not stereoselective. With all three isoforms, enantiomer N-dealkylation rates in the racemate were lower than those of (R)-(6-dimethyamino-4,4-diphenyl-heptan-3-one) hydrochloride (R-methadone) or (S)-(6-dimethyamino-4,4-diphenyl-heptan-3-one) hydrochloride (S-methadone) alone, suggesting an enantiomeric interaction and mutual metabolic inhibition. For CYP2B6, the interaction between enantiomers was stereoselective, with S-methadone as a more potent inhibitor of R-methadone N-demethylation than R-of S-methadone. In contrast, enantiomer interactions were not stereoselective with CYP2C19 or CYP3A4. For all three cytochromes P450, methadone N-demethylation was best described by two-site enzyme models with competitive inhibition. There were minor model differences between cytochromes P450 to account for stereoselectivity of metabolism and enantiomeric interactions. Changes in plasma R/S methadone ratios observed after rifampin or troleandomycin pretreatment in humans in vivo were successfully predicted by CYP2B6- but not CYP3A4-catalyzed methadone N-demethylation. CYP2B6 is a predominant catalyst of stereoselective methadone metabolism in vitro. In vivo, CYP2B6 may be a major determinant of methadone metabolism and disposition, and CYP2B6 activity and stereoselective metabolic

Potential Mechanism of Action of 3'-Demethoxy-6-O-demethyl-isoguaiacin on Methicillin Resistant Staphylococcus aureus.

Science.gov (United States)

Favela-Hernández, Juan Manuel J; Clemente-Soto, Aldo F; Balderas-Rentería, Isaías; Garza-González, Elvira; Camacho-Corona, María del Rayo

2015-07-08

Bacterial infections represent one of the main threats to global public health. One of the major causative agents associated with high morbidity and mortality infections in hospitals worldwide is methicillin-resistant Staphylococcus aureus. Therefore, there is a need to develop new antibacterial agents to treat these infections, and natural products are a rich source of them. In previous studies, we reported that lignan 3'-demethoxy-6-O-demethylisoguaiacin, isolated and characterized from Larrea tridentate, showed the best activity towards methicillin-resistant S. aureus. Thus, the aim of this study was to determine the potential molecular mechanism of the antibacterial activity of 3'-demethoxy-6-O-demethylisoguaiacin against methicillin-resistant S. aureus using microarray technology. Results of microarray genome expression were validated by real-time polymerase chain reaction (RT-PCR). The genetic profile expression results showed that lignan 3'-demethoxy-6-O-demethylisoguaiacin had activity on cell membrane affecting proteins of the ATP-binding cassette (ABC) transport system causing bacteria death. This molecular mechanism is not present in any antibacterial commercial drug and could be a new target for the development of novel antibacterial agents.

Mining and representing recommendations in actively evolving recommender systems

DEFF Research Database (Denmark)

Assent, Ira

2010-01-01

Recommender systems provide an automatic means of filtering out interesting items, usually based on past similarity of user ratings. In previous work, we have suggested a model that allows users to actively build a recommender network. Users express trust, obtain transparency, and grow (anonymous......) recommender connections. In this work, we propose mining such active systems to generate easily understandable representations of the recommender network. Users may review these representations to provide active feedback. This approach further enhances the quality of recommendations, especially as topics...... of interest change over time. Most notably, it extends the amount of control users have over the model that the recommender network builds of their interests....

A new mechanism for reduced sensitivity to demethylation-inhibitor fungicides in the fungal banana black Sigatoka pathogen Pseudocercospora fijiensis.

Science.gov (United States)

Diaz-Trujillo, Caucasella; Chong, Pablo; Stergiopoulos, Ioannis; Cordovez, Viviane; Guzman, Mauricio; De Wit, Pierre J G M; Meijer, Harold J G; Scalliet, Gabriel; Sierotzki, Helge; Lilia Peralta, Esther; Arango Isaza, Rafael E; Kema, Gerrit H J

2017-11-04

The Dothideomycete Pseudocercospora fijiensis, previously Mycosphaerella fijiensis, is the causal agent of black Sigatoka, one of the most destructive diseases of bananas and plantains. Disease management depends on fungicide applications, with a major contribution from sterol demethylation-inhibitors (DMIs). The continued use of DMIs places considerable selection pressure on natural P. fijiensis populations, enabling the selection of novel genotypes with reduced sensitivity. The hitherto explanatory mechanism for this reduced sensitivity was the presence of non-synonymous point mutations in the target gene Pfcyp51, encoding the sterol 14α-demethylase enzyme. Here, we demonstrate a second mechanism involved in DMI sensitivity of P. fijiensis. We identified a 19-bp element in the wild-type (wt) Pfcyp51 promoter that concatenates in strains with reduced DMI sensitivity. A polymerase chain reaction (PCR) assay identified up to six Pfcyp51 promoter repeats in four field populations of P. fijiensis in Costa Rica. We used transformation experiments to swap the wt promoter of a sensitive field isolate with a promoter from a strain with reduced DMI sensitivity that comprised multiple insertions. Comparative in vivo phenotyping showed a functional and proportional up-regulation of Pfcyp51, which consequently decreased DMI sensitivity. Our data demonstrate that point mutations in the Pfcyp51 coding domain, as well as promoter inserts, contribute to the reduced DMI sensitivity of P. fijiensis. These results provide new insights into the importance of the appropriate use of DMIs and the need for the discovery of new molecules for black Sigatoka management. © 2017 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.

Representative parameter of immunostimulatory ginseng polysaccharide to predict radioprotection

Energy Technology Data Exchange (ETDEWEB)

Son, Hyeog Jin; Shim, Ji Young; Ahn, Ji Yeon; Yun, Yeon Sook; Song, Jie Young [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

2008-09-15

According to the increase in the use of radiotherapy to cancer patients, many approaches have been tried to develop new agents for the protection of surrounding normal tissues. However, it is still few applied in the clinic as a radioprotector. We aim to find a representative parameter for radioprotection to easily predict the activity of in vivo experiment from the results of in vitro screening. The polysaccharide extracted from Panax ginseng was used in this study because the immunostimulator has been regarded as one of the radioprotective agent category and was already reported having a promising radioprotective activity through the increase of hematopoietic cells and the production of several cytokines. Mitogenic activity, AK cells activity and nitric oxide production were monitored for the in vitro immunological assay, and endogenous Colony-Forming Unit (e-CFU) was measured as in vivo radioprotective parameter. The immunological activity was increased by the galactose contents of ginseng polysaccharide dependently. The result of this study suggests that mitogenic activity of splenocytes demonstrated a good correlation with in vivo radioprotective effect, and may be used as a representative parameter to screen the candidates for radioprotector.

"Are Thai children and youth sufficiently active? prevalence and correlates of physical activity from a nationally representative cross-sectional study".

Science.gov (United States)

Amornsriwatanakul, Areekul; Lester, Leanne; Bull, Fiona C; Rosenberg, Michael

2017-05-30

Children and youth gain multiple health benefits from regular participation in physical activity (PA). However, in Thailand there is limited national data on children and youth's PA behaviors and recent reports suggest that Thai children and youth have low levels of PA. Furthermore, there is almost no data on the factors associated with inactivity to support the development of a Thai National PA Plan. The purpose of this paper is to investigate Thai children and youth's participation in PA and its correlates across sociodemographic characteristics and different PA domains. This study applied a cross-sectional study design with a multi-stage stratified cluster sampling. A national representative sample of 13,255 children and youth aged 6-17 years were used for data analysis. A previously validated questionnaire was used to assess PA prevalence. Logistic regression was conducted to examine the relationships of socio-demographic factors, and participation in different PA domains with overall PA. Only 23.4% of Thai children and youth met recommended levels of PA and there were large gender and regional differences. PA levels generally declined with age, although the level observed in the 10-13 year group was slightly higher than other year groups. A majority of children and youth engaged in a large number of different activities across PA domains. Sex, age, BMI, geographical regions, organized sports, participation in sport and recreational activities were significant predictors of meeting the global PA guidelines, whereas participation in physical education, active transport, and the number of screen time activities had no association. Girls were less likely to achieve sufficient PA levels (OR = 0.49, 95%CI; 0.45-0.54, p Thai children and youth is low, despite the high levels of engagement in a large number of PA. The results indicate that policy and interventions aimed at increasing PA are needed with special attention required to address specific groups less

Mineralization of phenmedipham and derivates by Trichoderma viride. Immobilization of 14C residues. Effects on biological activity and germ number

International Nuclear Information System (INIS)

Bellinck, C.; Mayaudon, J.

1979-01-01

The degradation of phenmedipham and derivates by T. viride was investigated. This microorganisms is unable to cleave the aromatic ring but demethylates the three herbicides. The half-life periods of the phenylcarbamates vary from 11 to 38 days; those of their residues from 250 to 900 days. The most part of residual 14 C is found as soluble material. Adsorption varies in the following order: humin > humic acids > fulvic acids. No intact herbicide can be detected forty days after soil treatment. 14 C phenylcarbamates or 14 C residues are found by autoradiography in mycelial fragments and spores of T. viride. The period of most active degradation of herbicides is characterized by a numerical increase of germs and a fall of biological activity [fr

Metabolite Profiling of Eastern Teaberry (Gaultheria procumbens L. Lipophilic Leaf Extracts with Hyaluronidase and Lipoxygenase Inhibitory Activity

Directory of Open Access Journals (Sweden)

Piotr Michel

2017-03-01

Full Text Available The phytochemical profile and anti-inflammatory activity of Gaultheria procumbens dry lipophilic leaf extracts were evaluated. Forty compounds were identified by GC-MS, representing 86.36% and 81.97% of the petroleum ether (PE and chloroform (CHE extracts, respectively, with ursolic acid (28.82%, oleanolic acid (10.11%, methyl benzoate (10.03%, and methyl salicylate (6.88% dominating in CHE, and methyl benzoate (21.59%, docosane (18.86%, and octacosane (11.72% prevailing in PE. Three components of CHE were fully identified after flash chromatography isolation and spectroscopic studies as (6S,9R-vomifoliol (4.35%, 8-demethyl-latifolin (1.13%, and 8-demethylsideroxylin (2.25%. Hyaluronidase and lipoxygenase inhibitory activity was tested for CHE (IC50 = 282.15 ± 10.38 μg/mL and 899.97 ± 31.17 μg/mL, respectively, PE (IC50 = 401.82 ± 16.12 μg/mL and 738.49 ± 15.92 μg/mL, and nine of the main constituents versus heparin (IC50 = 366.24 ± 14.72 μg/mL and indomethacin (IC50 = 92.60 ± 3.71 μg/mL as positive controls. With the best activity/concentration relationships, ursolic and oleanolic acids were recommended as analytical markers for the extracts and plant material. Seasonal variation of both markers following foliar development was investigated by UHPLC-PDA. The highest levels of ursolic (5.36–5.87 mg/g DW of the leaves and oleanolic (1.14–1.26 mg/g DW acids were observed between August and October, indicating the optimal season for harvesting.

UTX and UTY demonstrate histone demethylase-independent function in mouse embryonic development.

Directory of Open Access Journals (Sweden)

Karl B Shpargel

2012-09-01

Full Text Available UTX (KDM6A and UTY are homologous X and Y chromosome members of the Histone H3 Lysine 27 (H3K27 demethylase gene family. UTX can demethylate H3K27; however, in vitro assays suggest that human UTY has lost enzymatic activity due to sequence divergence. We produced mouse mutations in both Utx and Uty. Homozygous Utx mutant female embryos are mid-gestational lethal with defects in neural tube, yolk sac, and cardiac development. We demonstrate that mouse UTY is devoid of in vivo demethylase activity, so hemizygous X(Utx- Y(+ mutant male embryos should phenocopy homozygous X(Utx- X(Utx- females. However, X(Utx- Y(+ mutant male embryos develop to term; although runted, approximately 25% survive postnatally reaching adulthood. Hemizygous X(+ Y(Uty- mutant males are viable. In contrast, compound hemizygous X(Utx- Y(Uty- males phenocopy homozygous X(Utx- X(Utx- females. Therefore, despite divergence of UTX and UTY in catalyzing H3K27 demethylation, they maintain functional redundancy during embryonic development. Our data suggest that UTX and UTY are able to regulate gene activity through demethylase independent mechanisms. We conclude that UTX H3K27 demethylation is non-essential for embryonic viability.

14 CFR 1274.906 - Designation of New Technology Representative and Patent Representative.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Designation of New Technology... Conditions § 1274.906 Designation of New Technology Representative and Patent Representative. Designation of New Technology Representative and Patent Representative July 2002 (a) For purposes of administration...

The position of imidazopyridine and metabolic activation are pivotal factors in the antimutagenic activity of novel imidazo[1,2-a]pyridine derivatives.

Science.gov (United States)

El-Sayed, Wael M; Hussin, Warda A; Al-Faiyz, Yasair S; Ismail, Mohamed A

2013-09-05

The antimutagenic activity of eight novel imidazo[1,2-a]pyridine derivatives (I-VIII) against sodium azide (NaN3) and benzo[a]pyrene (B[a]P) was evaluated using the Salmonella reverse mutation assay. At non-toxic concentrations (12.5-50 µM), imidazopyridines I, II, III, and V with a terminal imidazopyridine group were mutagenic, while derivatives VII and VIII with a central imidazopyridine group were not mutagenic. Compounds IV, VII, and VIII exerted a moderate antimutagenic activity against NaN3 under pre-exposure conditions, and a strong activity (>40%) against B[a]P in the presence of S9 under both pre- and co-exposure conditions and mostly independent on the dose. Imidazopyridines possibly inhibited the microsomal-dependent activation of B[a]P. The demethylated derivative VII was the most active antimutagen. All imidazopyridines had a low to moderate antioxidant activity. The antibacterial activity of imidazopyridines was sporadic and moderate probably due to the failure of bacteria to convert imidazopyridines into active metabolites. The position of imidazopyridine was a pivotal factor in the mutagenic/antimutagenic activity. The strong antimutagenic compounds were dicationic planar compounds with a centered imidazo[1,2-a]pyridine spacer. With LD50 of 60 mg/kg in mice for both derivatives VII and VIII, it is safe to investigate the anticancer activity of these derivatives in animal models. © 2013 Elsevier B.V. All rights reserved.

Potential Mechanism of Action of 3′-Demethoxy-6-O-demethyl-isoguaiacin on Methicillin Resistant Staphylococcus aureus

Directory of Open Access Journals (Sweden)

Juan Manuel J. Favela-Hernández

2015-07-01

Full Text Available Bacterial infections represent one of the main threats to global public health. One of the major causative agents associated with high morbidity and mortality infections in hospitals worldwide is methicillin-resistant Staphylococcus aureus. Therefore, there is a need to develop new antibacterial agents to treat these infections, and natural products are a rich source of them. In previous studies, we reported that lignan 3′-demethoxy-6-O-demethylisoguaiacin, isolated and characterized from Larrea tridentate, showed the best activity towards methicillin-resistant S. aureus. Thus, the aim of this study was to determine the potential molecular mechanism of the antibacterial activity of 3′-demethoxy-6-O-demethylisoguaiacin against methicillin-resistant S. aureus using microarray technology. Results of microarray genome expression were validated by real-time polymerase chain reaction (RT-PCR. The genetic profile expression results showed that lignan 3′-demethoxy-6-O-demethylisoguaiacin had activity on cell membrane affecting proteins of the ATP-binding cassette (ABC transport system causing bacteria death. This molecular mechanism is not present in any antibacterial commercial drug and could be a new target for the development of novel antibacterial agents.

An active learning representative subset selection method using net analyte signal

Science.gov (United States)

He, Zhonghai; Ma, Zhenhe; Luan, Jingmin; Cai, Xi

2018-05-01

To guarantee accurate predictions, representative samples are needed when building a calibration model for spectroscopic measurements. However, in general, it is not known whether a sample is representative prior to measuring its concentration, which is both time-consuming and expensive. In this paper, a method to determine whether a sample should be selected into a calibration set is presented. The selection is based on the difference of Euclidean norm of net analyte signal (NAS) vector between the candidate and existing samples. First, the concentrations and spectra of a group of samples are used to compute the projection matrix, NAS vector, and scalar values. Next, the NAS vectors of candidate samples are computed by multiplying projection matrix with spectra of samples. Scalar value of NAS is obtained by norm computation. The distance between the candidate set and the selected set is computed, and samples with the largest distance are added to selected set sequentially. Last, the concentration of the analyte is measured such that the sample can be used as a calibration sample. Using a validation test, it is shown that the presented method is more efficient than random selection. As a result, the amount of time and money spent on reference measurements is greatly reduced.

Identification of three new phase II metabolites of a designer drug methylone formed in rats by N-demethylation followed by conjugation with dicarboxylic acids.

Science.gov (United States)

Židková, Monika; Linhart, Igor; Balíková, Marie; Himl, Michal; Dvořáčková, Veronika; Lhotková, Eva; Páleníček, Tomáš

2018-06-01

1. Methylone (3,4-methylenedioxy-N-methylcathinone, MDMC), which appeared on the illicit drug market in 2004, is a frequently abused synthetic cathinone derivative. Known metabolic pathways of MDMC include N-demethylation to normethylone (3,4-methylenedioxycathinone, MDC), aliphatic chain hydroxylation and oxidative demethylenation followed by monomethylation and conjugation with glucuronic acid and/or sulphate. 2. Three new phase II metabolites, amidic conjugates of MDC with succinic, glutaric and adipic acid, were identified in the urine of rats dosed subcutaneously with MDMC.HCl (20 mg/kg body weight) by LC-ESI-HRMS using synthetic reference standards to support identification. 3. The main portion of administered MDMC was excreted unchanged. Normethylone, was a major urinary metabolite, of which a minor part was conjugated with dicarboxylic acids. 4. Previously identified ring-opened metabolites 4-hydroxy-3-methoxymethcathinone (4-OH-3-MeO-MC), 3-hydroxy-4-methoxymeth-cathinone (3-OH-4-MeO-MC) and 3,4-dihydroxymethcathinone (3,4-di-OH-MC) mostly in conjugated form with glucuronic and/or sulphuric acids were also detected. 5. Also, ring-opened metabolites derived from MDC, namely, 4-hydroxy-3-methoxycathinone (4-OH-3-MeO-C), 3-hydroxy-4-methoxycathinone (3-OH-4-MeO-C) and 3,4-dihydroxycathinone (3,4-di-OH-C) were identified for the first time in vivo.

Biogeochemistry of mercury in contaminated environment in the wider Idrija region and the Gulf of Trieste. Highlights and achievements

International Nuclear Information System (INIS)

Horvat, Milena

2002-01-01

Activities at mercury (Hg) mines can lead to the mobilization of large quantities of Hg that enter the environment and are transported downstream. Although much of this Hg is deposited near the source, over time much of this Hg can be carried hundreds of kilometers where it can potentially enter and bioaccumulate in distant food webs. Mining activities in the ldrija, Slovenia mining district occurred for 500 years and the legacy of that mining can be seen in high concentrations of Hg throughout the watershed and into the Gulf of Trieste. Mercury concentrations are high in the sediments near the mouth of the Soca/Isonzo, River in the Gulf, and the Soca River continues to deliver ∼1.5 tons of Hg to the marine environment ∼100 km from the mine. Much of the Hg carried to the sea is probably as fine cinnabar particles, and the potential remobilization and further transformation of this Hg is of concern with regard to local environmental and the accumulation of methylmercury (MeHg in seafood. Mercury sulfide minerals are subject to dissolution and increased bioavailability when they contact sulfidic environments such as what occurs in coastal marine sediments. This 'newly' available Hg can potentially undergo methylation to supply the environment with newly formed MeHg. Indeed, Gulf sediments contain significant concentrations of MeHg and effluxes of MeHg from Gulf sediments have been observed in recent studies. However, sediments can also support active demethylation by aerobic and anaerobic bacteria. This demethylation can be due to either oxidative or reductive pathways. The present study was conducted to determine the potential of sediments from the Gulf of Trieste to methylate and demethylate Hg including an assessment of which demethylation pathway is most prevalent

Hypoxia, Epithelial-Mesenchymal Transition, and TET-Mediated Epigenetic Changes

Directory of Open Access Journals (Sweden)

Shih-Han Kao

2016-02-01

Full Text Available Tumor hypoxia is a pathophysiologic outcome of disrupted microcirculation with inadequate supply of oxygen, leading to enhanced proliferation, epithelial-mesenchymal transition (EMT, metastasis, and chemo-resistance. Epigenetic changes induced by hypoxia are well documented, and they lead to tumor progression. Recent advances show that DNA demethylation mediated by the Ten-eleven translocation (TET proteins induces major epigenetic changes and controls key steps of cancer development. TET enzymes serve as 5mC (5-methylcytosine-specific dioxygenases and cause DNA demethylation. Hypoxia activates the expression of TET1, which also serves as a co-activator of HIF-1α transcriptional regulation to modulate HIF-1α downstream target genes and promote epithelial-mesenchymal transition. As HIF is a negative prognostic factor for tumor progression, hypoxia-activated prodrugs (HAPs may provide a favorable therapeutic approach to lessen hypoxia-induced malignancy.

14 CFR 1260.58 - Designation of new technology representative and patent representative.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Designation of new technology... of new technology representative and patent representative. Designation of New Technology... of this grant entitled “New Technology,” the following named representatives are hereby designated by...

The role of CYP2D6 in primary and secondary oxidative metabolism of dextromethorphan: in vitro studies using human liver microsomes.

Science.gov (United States)

Kerry, N L; Somogyi, A A; Bochner, F; Mikus, G

1994-01-01

1. The enzyme kinetics of dextromethorphan O-demethylation in liver microsomes from three extensive metabolisers (EM) with respect to CYP2D6 indicated high (Km1 2.2-9.4 microM) and low (Km2 55.5-307.3 microM) affinity sites whereas microsomes from two poor metabolisers (PM) indicated a single site (Km 560 and 157 microM). Similar differences were shown for 3-methoxymorphinan O-demethylation to 3-hydroxymorphinan (Km 6.9-9.6 microM in EM subjects; Km 307 and 213 microM in PM subjects). 2. Dextromethorphan O-demethylation was inhibited competitively by quinidine (Ki 0.1 microM), rac-perhexiline (Ki 0.4 microM), dextropropoxyphene (Ki 6 microM), rac-methadone (Ki 8 microM), and 3-methoxymorphinan (Ki 15 microM). These compounds were also potent inhibitors of 3-methoxymorphinan O-demethylation with IC50 values ranging from 0.02-12 microM. Anti-LKM1 serum inhibited both dextromethorphan and 3-methoxymorphinan O-demethylations in a titre-dependent manner. 3. The Michaelis-Menten constant for dextromethorphan N-demethylation to 3-methoxymorphinan (Km 632-977 microM) and dextrorphan N-demethylation to 3-hydroxymorphinan (Km 1571-4286 microM) did not differ between EM and PM microsomes. These N-demethylation reactions were not inhibited by quinidine and rac-methadone or LKM1 antibodies. 4. Dextromethorphan and 3-methoxymorphinan are metabolised by the same P450 isoform, CYP2D6, whereas the N-demethylation reactions are not carried out by CYP2D6. PMID:7826826

Regulation and function of DNA methylation in plants and animals

KAUST Repository

He, Xinjian; Chen, Taiping; Zhu, Jian-Kang

2011-01-01

) pathway. In animals, multiple mechanisms of active DNA demethylation have been proposed, including a deaminase- and DNA glycosylase-initiated BER pathway. New information concerning the effects of various histone modifications on the establishment

MTHFR methylation moderates the impact of smoking on DNA methylation at AHRR for African American young adults.

Science.gov (United States)

Beach, Steven R H; Lei, Man Kit; Ong, Mei Ling; Brody, Gene H; Dogan, Meeshanthini V; Philibert, Robert A

2017-09-01

Smoking has been shown to have a large, reliable, and rapid effect on demethylation of AHRR, particularly at cg05575921, suggesting that methylation may be used as an index of cigarette consumption. Because the availability of methyl donors may also influence the degree of demethylation in response to smoking, factors that affect the activity of methylene tetrahydrofolate reductase (MTHFR), a key regulator of methyl group availability, may be of interest. In the current investigation, we examined the extent to which individual differences in methylation of MTHFR moderated the association between smoking and demethylation at cg05575921 as well as at other loci on AHRR associated with a main effect of smoking. Using a discovery sample (AIM, N = 293), and a confirmatory sample (SHAPE, N = 368) of young adult African Americans, degree of methylation of loci in the first exon of MTHFR was associated with amplification of the association between smoking and AHRR demethylation at cg05575921. However, genetic variation at a commonly studied MTHFR variant, C677T, did not influence cg05575921 methylation. The significant interaction between MTHFR methylation and the smoking-induced response at cg05575921 suggests a role for individual differences in methyl cycle regulation in understanding the effects of cigarette consumption on genome wide DNA methylation. © 2017 Wiley Periodicals, Inc.

Enzyme induction in neonates after fetal exposure to antiepileptic drugs

International Nuclear Information System (INIS)

Rating, D.; Jaeger-Roman, E.; Nau, H.; Kuhnz, W.; Helge, H.

1983-01-01

The 13 C-AP breath test is shown to be a convenient, noninvasive method to monitor velocity and capacity of P450-dependent AP N-demethylation in infancy and childhood. According to 13 C-AP breath tests, neonates have a very low capacity to eliminate 13 CO 2 , which is only 15 to 21% of the activity in adults. During the first year of life AP N-demethylation increases to reach its maximum at about 2 years; afterwards a slight decrease occurs. In 25 neonates exposed prenatally to different antiepileptic drugs 13 C-AP breath test was efficiently used to prove that cytochrome AP N-demethylation was considerably stimulated. After primidone/phenobarbitone, especially in combination with phenytoin, 13 C elimination reaches and even surpasses the range for older children. Valproate exposure during fetal life is not consistently followed by a significant increase in AP N-demethylation. The enzyme induction demonstrated by 13 C-AP breath test was often accompanied by accelerated metabolic clearance and shortened half-life times of transplacentally acquired antiepileptic drugs. There was good agreement between 13 C-AP breath tests and pharmacokinetic data for primidone/phenobarbitone but not for phenytoin. In contrast, in the case of phenytoin exposure during pregnancy the pharmacokinetic parameters and the 13 C breath test data will transport very different informations about enzyme induction in these neonates

Testing Theory of Planned Behavior and Neo-Socioanalytic Theory models of trait activity, industriousness, exercise social cognitions, exercise intentions, and physical activity in a representative U.S. sample.

Science.gov (United States)

Vo, Phuong T; Bogg, Tim

2015-01-01

Prior research identified assorted relations between trait and social cognition models of personality and engagement in physical activity. Using a representative U.S. sample (N = 957), the goal of the present study was to test two alternative structural models of the relationships among the extraversion-related facet of activity, the conscientiousness-related facet of industriousness, social cognitions from the Theory of Planned Behavior (perceived behavioral control, affective attitudes, subjective norms, intentions), Social Cognitive Theory (self-efficacy, outcome expectancies), and the Transtheoretical Model (behavioral processes of change), and engagement in physical activity. Path analyses with bootstrapping procedures were used to model direct and indirect effects of trait and social cognition constructs on physical activity through two distinct frameworks - the Theory of Planned Behavior and Neo-Socioanalytic Theory. While both models showed good internal fit, comparative model information criteria showed the Theory-of-Planned-Behavior-informed model provided a better fit. In the model, social cognitions fully mediated the relationships from the activity facet and industriousness to intentions for and engagement in physical activity, such that the relationships were primarily maintained by positive affective evaluations, positive expected outcomes, and confidence in overcoming barriers related to physical activity engagement. The resultant model - termed the Disposition-Belief-Motivation model- is proposed as a useful framework for organizing and integrating personality trait facets and social cognitions from various theoretical perspectives to investigate the expression of health-related behaviors, such as physical activity. Moreover, the results are discussed in terms of extending the application of the Disposition-Belief-Motivation model to longitudinal and intervention designs for physical activity engagement.

Dormancy activation mechanism of oral cavity cancer stem cells.

Science.gov (United States)

Chen, Xiang; Li, Xin; Zhao, Baohong; Shang, Dehao; Zhong, Ming; Deng, Chunfu; Jia, Xinshan

2015-07-01

Radiotherapy and chemotherapy are targeted primarily at rapidly proliferating cancer cells and are unable to eliminate cancer stem cells in the G0 phase. Thus, these treatments cannot prevent the recurrence and metastasis of cancer. Understanding the mechanisms by which cancer stem cells are maintained in the dormant G0 phase, and how they become active is key to developing new cancer therapies. The current study found that the anti-cancer drug 5-fluorouracil, acting on the oral squamous cell carcinoma KB cell line, selectively killed proliferating cells while sparing cells in the G0 phase. Bisulfite sequencing PCR showed that demethylation of the Sox2 promoter led to the expression of Sox2. This then resulted in the transformation of cancer stem cells from the G0 phase to the division stage and suggested that the transformation of cancer stem cells from the G0 phase to the division stage is closely related to an epigenetic modification of the cell.

Survey by senior NRC management to obtain veiwpoints on the safety impact of regulatory activities from representative utilities operating and constructing nuclear power plants

International Nuclear Information System (INIS)

1981-08-01

A survey of licensee staff members representing the several organizational elements in different licensee corporate and plant staffs was conducted by senior NRC management to obtain licensee views on the potential safety consequences and impact of NRC regulatory activities. The comments received addressed the full scope of NRC activities and the negative impact of agency actions on licensee resources, staff performance, planning and scheduling, and organizational effectiveness. The findings of the survey is that the pace and nature of regulatory actions have created a potential safety problem which deserves further evaluation by the agency

Determination of total and organic mercury and evaluation of methylation and demethylation processes in sediments of the Rio Grande Reservoir, State of Sao Paulo, Brazil

International Nuclear Information System (INIS)

Franklin, Robson Leocadio

2010-01-01

The Rio Grande reservoir is located in the metropolitan area of Sao Paulo and it is a very important water supply for this region. In the present study bottom waters and sediment samples collected in this reservoir, in four sampling points, in four campaigns, from September 2008 to January 2010, were analyzed. Firstly total Hg was determined in sediment and bottom waters by cold vapor atomic absorption technique (CV AAS). Following, the analytical methodology for organic Hg was adapted from literature, where the organomercurial compounds were extracted with dichloromethane in acid medium and subsequent destruction of organic compounds by bromine chloride. The validation of this methodology, in terms of precision and accuracy, was performed by means of IAEA 405 and BCR-CRM 580 reference materials analyses. For methylation and demethylation processes evaluation in this environment, the following physical and chemical parameters were assessed, in situ: pH, water temperature, redox potential (EH), transparency and depth. For the sediment samples, granulometry, total organic carbon, sulphate-reducing bacteria, total N and P, besides the metals Co, Cu, Fe and Mn were evaluated. The selection of these parameters was related to the factors that influence the behavior of MeHg in the sediments and its transition zone. Total Hg ranging from 1.0 to 71.0 mg kg'- 1 and organic mercury from -1 in sediments and methylation rates from 0.06 to 1.4% were found, along the reservoir. Different methylation conditions along the reservoir and its influences were also discussed. As supplementary study the concentration of some metals and trace elements in the sediments by neutron activation analysis technique was determined. As, Ba, Br, Co, Cr, Cs, Hf, Fe, Na, Rb, Sb, Sc and Zn and rare earth elements Ce, Eu, La, Lu, Nd, Sm and Yb were determined. The enrichment factor in relation to earth crust values using Sc as normalizer element reached values higher than 2.0 for the elements As, Br

Synthesis and trypanocidal activity of 7, 2'-dioxygenated isoflavones and oxypropanolamine derivatives

International Nuclear Information System (INIS)

Faria, Terezinha de J.; Silva, Luiz G. Fonseca e; Souza Filho, Jose D. de; Chiari, Egler; Oliveira, Alaide B. de

2005-01-01

7, 2'-Dihydroxyisoflavone was shown to be active against the bloodstream trypomastigote form of Trypanosoma cruzi, the etiologic agent of Chagas' disease. Amphiphilic derivatives of this isoflavone were synthesized aiming to obtain hydrosoluble compounds of potential use as prophylactic agents to be added to blood for transfusion. This isoflavone was obtained by demethylation of 7-hydroxy-2'-methoxyisoflavone that was synthesized via the intermediate deoxybenzoin. Its reaction with epichlorohydrin, followed by aminolysis with diethylamine, afforded the 7-oxypropanolamine which on treatment with methyl iodide gave the corresponding ammonium salt. The 7-hydroxy-2'-methoxyisoflavone was inactive in the in vitro assays, the 7-oxypropanolamine was more active than 7, 2'-dihydroxyisoflavone while the ammonium salt has not eliminated the parasite from the blood besides causing total lysis of the erythrocytes. The simple synthetic procedures described in the present paper can be used to provide gram quantities of 7, 2'-dihydroxyisoflavone and its 7-oxypropanolamine derivative that should be further investigated in in vivo murine models as potential chemotherapeutic agents for treatment of Chagas' disease. (author)

48 CFR 1852.227-72 - Designation of new technology representative and patent representative.

Science.gov (United States)

2010-10-01

... CONTRACT CLAUSES Texts of Provisions and Clauses 1852.227-72 Designation of new technology representative... of New Technology Representative and Patent Representative (JUL 1997) (a) For purposes of administration of the clause of this contract entitled “New Technology” or “Patent Rights—Retention by the...

Testing Theory of Planned Behavior and Neo-Socioanalytic Theory models of trait activity, industriousness, exercise social cognitions, exercise intentions, and physical activity in a representative U.S. sample

Directory of Open Access Journals (Sweden)

Phuong Thi Vo

2015-08-01

Full Text Available Prior research identified assorted relations between trait and social cognition models of personality and engagement in physical activity. Using a representative U.S. sample (N = 957, the goal of the present study was to test two alternative structural models of the relationships among the extraversion-related facet of activity, the conscientiousness-related facet of industriousness, social cognitions from the Theory of Planned Behavior (perceived behavioral control, affective attitudes, subjective norms, intentions, Social Cognitive Theory (self-efficacy, outcome expectancies, and the Transtheoretical Model (behavioral processes of change, and engagement in physical activity. Path analyses with bootstrapping procedures were used to model direct and indirect effects of trait and social cognition constructs on physical activity through two distinct frameworks – the Theory of Planned Behavior and Neo-Socioanalytic Theory. While both models showed good internal fit, comparative model information criteria showed the Theory-of-Planned-Behavior-informed model provided a better fit. In the model, social cognitions fully mediated the relationships from the activity facet and industriousness to intentions for and engagement in physical activity, such that the relationships were primarily maintained by positive affective evaluations, positive expected outcomes, and confidence in overcoming barriers related to physical activity engagement. The resultant model – termed the Disposition-Belief-Motivation model – is proposed as a useful framework for organizing and integrating personality trait facets and social cognitions from various theoretical perspectives to investigate the expression of health-related behaviors, such as physical activity. Moreover, the results are discussed in terms of extending the application of the Disposition-Belief-Motivation model to longitudinal and intervention designs for physical activity engagement.

Testing Theory of Planned Behavior and Neo-Socioanalytic Theory models of trait activity, industriousness, exercise social cognitions, exercise intentions, and physical activity in a representative U.S. sample

Science.gov (United States)

Vo, Phuong T.; Bogg, Tim

2015-01-01

Prior research identified assorted relations between trait and social cognition models of personality and engagement in physical activity. Using a representative U.S. sample (N = 957), the goal of the present study was to test two alternative structural models of the relationships among the extraversion-related facet of activity, the conscientiousness-related facet of industriousness, social cognitions from the Theory of Planned Behavior (perceived behavioral control, affective attitudes, subjective norms, intentions), Social Cognitive Theory (self-efficacy, outcome expectancies), and the Transtheoretical Model (behavioral processes of change), and engagement in physical activity. Path analyses with bootstrapping procedures were used to model direct and indirect effects of trait and social cognition constructs on physical activity through two distinct frameworks – the Theory of Planned Behavior and Neo-Socioanalytic Theory. While both models showed good internal fit, comparative model information criteria showed the Theory-of-Planned-Behavior-informed model provided a better fit. In the model, social cognitions fully mediated the relationships from the activity facet and industriousness to intentions for and engagement in physical activity, such that the relationships were primarily maintained by positive affective evaluations, positive expected outcomes, and confidence in overcoming barriers related to physical activity engagement. The resultant model – termed the Disposition-Belief-Motivation model– is proposed as a useful framework for organizing and integrating personality trait facets and social cognitions from various theoretical perspectives to investigate the expression of health-related behaviors, such as physical activity. Moreover, the results are discussed in terms of extending the application of the Disposition-Belief-Motivation model to longitudinal and intervention designs for physical activity engagement. PMID:26300811

Importance of phytoalexin tolerance and detoxification for pathogenicity. Progress report, June 1983-June 1985

International Nuclear Information System (INIS)

VanEtten, H.; Matthews, D.

1985-01-01

This study focuses on the biochemistry of phytoalexin detoxifying enzymes. Progress is reported on purification, substrate specificity, and mechanism of several enzymes involved. Some aspects of the regulation of pisatin demethylase were studied since parallel genetic studies suggest its regulation is an important factor in the pathogenicity of Nectria haematococca. We have established that the detoxification of pisatin requires two components: NADPH-cytochrome c reductase and cytochrome P-450. The ability to separate and reconstitute these two components has allowed us to demonstrate that the reductase from a non-demethylating isolate of N. haematococca will support demethylating activity when combined with the cytochrome P-450 from a demethylating isolate. The finding that the critical genetic factor here is the cytochrome P-450 fraction reinforces the hypothesis that the multiple pda genes of this fungus encode different cytochrome P-450 isozymes. The evidence for monooxygenase catalyzed metabolism of maackiain suggests the existence of additional members of a phytoalexin detoxifying cytochrome P-450 family. 4 refs., 1 fig., 1 tab

Administrative Circular No. 13 (Rev. 3) - Guarantees for representatives of the personnel

CERN Multimedia

2014-01-01

Administrative Circular No. 13 (Rev. 3) entitled “Guarantees for representatives of the personnel”, approved by the Director-General following discussion at the Standing Concertation Committee meeting of 5 December 2013 and entering into force on 1 January 2014, is available on the intranet site of the Human Resources Department (see here).   This circular is applicable to all members of the personnel. It cancels and replaces Administrative Circular No. 13 (Rev. 2) entitled “Guarantees for members of the personnel holding representative office” of November 1992. The circular was revised in order to adapt the time given to the representatives of the personnel to perform their elective mandate and to ensure more transparency in their activities, by indicating, inter alia, the percentage of time worked in the framework of their mandate, as well as the training, activities and ensuing results. Department Head Office HR Department

Investigations into the post-natal development of demethylating enzyme systems by determination of carbon dioxide 14 in the air exhaled by mice after applications of carbon 14 dimethyl amino-antipyrine

International Nuclear Information System (INIS)

Schmidt, H.

1982-01-01

Albino mice were subcutaneously injected with carbon 14 dimethyl aminopyrines, the methyl group of which can be metabolised in the organism into carbon dioxide 14. The following results were obtained: In the carbon dioxide 14 exhalation of neonate, young and adult animals after administration of carbon 14 aminopyrine, distinct differences were noted. The maximum of elimination via the lungs occurs after 20-30 minutes in grown-up mice, in neonates or young animals distinctly later (60-90 min). The carbon dioxide 14 exhalation was also measured after additional subcutaneous application of methrotrexate. In mice aged 8 and 10 days a distinct decrease in carbon dioxide 14 exhalation was found. By contrast, a rise in carbon dioxide 14 exhaled was found in mice aged 2 days. The orientating experiments with folic acid and carbon 14 dimethyl aminopyrine show that leucovorin leads to a distinct increase in carbon dioxide 14 exhalation during the first 30 minutes. As a cause of the different degrees of stimulation respectively inhibition of demethylation, different biochemical ways of formaldehyde formation are pointed out. One of these probably includes the folate-dependent reaction. (orig./MG) [de

Representing time

Directory of Open Access Journals (Sweden)

Luca Poncellini

2010-06-01

Full Text Available The analysis of natural phenomena applied to architectural planning and design is facing the most fascinating and elusive of the four dimensions through which man attempts to define life within the universe: time. We all know what time is, said St. Augustine, but nobody knows how to describe it. Within architectural projects and representations, time rarely appears in explicit form. This paper presents the results of a research conducted by students of NABA and of the Polytechnic of Milan with the purpose of representing time considered as a key element within architectural projects. Student investigated new approaches and methodologies to represent time using the two-dimensional support of a sheet of paper.

Synthesis and trypanocidal activity of 7, 2'-dioxygenated isoflavones and oxypropanolamine derivatives

Energy Technology Data Exchange (ETDEWEB)

Faria, Terezinha de J. [Universidade Estadual de Londrina, PR (Brazil). Dept. de Quimica]. E-mail: tjfaria@uel.br; Silva, Luiz G. Fonseca e; Souza Filho, Jose D. de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica; Chiari, Egler [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Parasitologia; Oliveira, Alaide B. de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Farmacia. Dept. de Produtos Farmaceuticos

2005-11-15

'-Dihydroxyisoflavone was shown to be active against the bloodstream trypomastigote form of Trypanosoma cruzi, the etiologic agent of Chagas' disease. Amphiphilic derivatives of this isoflavone were synthesized aiming to obtain hydrosoluble compounds of potential use as prophylactic agents to be added to blood for transfusion. This isoflavone was obtained by demethylation of 7-hydroxy-2'-methoxyisoflavone that was synthesized via the intermediate deoxybenzoin. Its reaction with epichlorohydrin, followed by aminolysis with diethylamine, afforded the 7-oxypropanolamine which on treatment with methyl iodide gave the corresponding ammonium salt. The 7-hydroxy-2'-methoxyisoflavone was inactive in the in vitro assays, the 7-oxypropanolamine was more active than 7, 2'-dihydroxyisoflavone while the ammonium salt has not eliminated the parasite from the blood besides causing total lysis of the erythrocytes. The simple synthetic procedures described in the present paper can be used to provide gram quantities of 7, 2'-dihydroxyisoflavone and its 7-oxypropanolamine derivative that should be further investigated in in vivo murine models as potential chemotherapeutic agents for treatment of Chagas' disease. (author)

Understanding and Representing Changing Work Structures and Practices through Art

Science.gov (United States)

Wieland, Stacey M. B.

2018-01-01

Courses: Organizational Communication, Advanced Organizational Communication, Organizing Work, Management/Organizational History. Objectives: This activity will help students to understand major shifts in the organization of work and creatively represent changing work structures and practices. An optional follow-up assignment is included. A…

Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria

Directory of Open Access Journals (Sweden)

Nelson L. Brock

2013-05-01

Full Text Available Members of the marine Roseobacter clade can degrade dimethylsulfoniopropionate (DMSP via competing pathways releasing either methanethiol (MeSH or dimethyl sulfide (DMS. Deuterium-labeled [2H6]DMSP and the synthetic DMSP analogue dimethyltelluriopropionate (DMTeP were used in feeding experiments with the Roseobacter clade members Phaeobacter gallaeciensis DSM 17395 and Ruegeria pomeroyi DSS-3, and their volatile metabolites were analyzed by closed-loop stripping and solid-phase microextraction coupled to GC–MS. Feeding experiments with [2H6]DMSP resulted in the incorporation of a deuterium label into MeSH and DMS. Knockout of relevant genes from the known DMSP demethylation pathway to MeSH showed in both species a residual production of [2H3]MeSH, suggesting that a second demethylation pathway is active. The role of DMSP degradation pathways for MeSH and DMS formation was further investigated by using the synthetic analogue DMTeP as a probe in feeding experiments with the wild-type strain and knockout mutants. Feeding of DMTeP to the R. pomeroyi knockout mutant resulted in a diminished, but not abolished production of demethylation pathway products. These results further corroborated the proposed second demethylation activity in R. pomeroyi. Isotopically labeled [2H3]methionine and 34SO42−, synthesized from elemental 34S8, were tested to identify alternative sulfur sources besides DMSP for the MeSH production in P. gallaeciensis. Methionine proved to be a viable sulfur source for the MeSH volatiles, whereas incorporation of labeling from sulfate was not observed. Moreover, the utilization of selenite and selenate salts by marine alphaproteobacteria for the production of methylated selenium volatiles was explored and resulted in the production of numerous methaneselenol-derived volatiles via reduction and methylation. The pathway of selenate/selenite reduction, however, proved to be strictly separated from sulfate reduction.

Fiscal years 2007 and 2008 : representative examples of completed RD&T projects and activities

Science.gov (United States)

2009-06-01

The tables in this document correspond to major offices and initiatives at the Federal Highway Administration's Office of Research, Development, and Technology (RD&T), located at the Turner-Fairbank Highway Research Center. The tables provide represe...

Isolation and structure elucidation of a new indole alkaloid from Rauvolfia serpentina hairy root culture: the first naturally occurring alkaloid of the raumacline group.

Science.gov (United States)

Sheludko, Yuri; Gerasimenko, Irina; Kolshorn, Heinz; Stöckigt, Joachim

2002-05-01

A new monoterpenoid indole alkaloid, 10-hydroxy- N(alpha)-demethyl-19,20-dehydroraumacline ( 1), was isolated as a mixture of E- and Z-isomers from hairy root culture of Rauvolfia serpentina Benth. ex Kurz (Apocynaceae) and the structure was determined by 1D and 2D NMR analyses. The new indole alkaloid represents the first naturally occurring alkaloid of the raumacline group and its putative biosynthetical pathway is discussed.

The Aorta-Gonad-Mesonephros Organ Culture Recapitulates 5hmC Reorganization and Replication-Dependent and Independent Loss of DNA Methylation in the Germline.

Science.gov (United States)

Calvopina, Joseph Hargan; Cook, Helene; Vincent, John J; Nee, Kevin; Clark, Amander T

2015-07-01

Removal of cytosine methylation from the genome is critical for reprogramming and transdifferentiation and plays a central role in our understanding of the fundamental principles of embryo lineage development. One of the major models for studying cytosine demethylation is the mammalian germ line during the primordial germ cell (PGC) stage of embryo development. It is now understood that oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) is required to remove cytosine methylation in a locus-specific manner in PGCs; however, the mechanisms downstream of 5hmC are controversial and hypothesized to involve either active demethylation or replication-coupled loss. In the current study, we used the aorta-gonad-mesonephros (AGM) organ culture model to show that this model recapitulates germ line reprogramming, including 5hmC reorganization and loss of cytosine methylation from Snrpn and H19 imprinting control centers (ICCs). To directly address the hypothesis that cell proliferation is required for cytosine demethylation, we blocked PI3-kinase-dependent PGC proliferation and show that this leads to a G1 and G2/M cell cycle arrest in PGCs, together with retained levels of cytosine methylation at the Snrpn ICC, but not at the H19 ICC. Taken together, the AGM organ culture model is an important tool to evaluate mechanisms of locus-specific demethylation and the role of PI3-kinase-dependent PGC proliferation in the locus-specific removal of cytosine methylation from the genome.

USING CHIRALITY TO INFORM THE METABOLISM OF TRIADIMEFON TO TRIADIMENOL: A CROSS-SPECIES EXAMINATION

Science.gov (United States)

Triadimefon is a systemic agricultural fungicide of the conazole class whose metabolite, triadimenol, provides the majority of the actual fungicidal activity; i.e. inhibition of steroid demethylation. Triadimenol is also registered and used as a fungicide. Both chemicals are ch...

Methods for measuring specific rates of mercury methylation and degradation and their use in determining factors controlling net rates of mercury methylation

International Nuclear Information System (INIS)

Ramlal, P.S.; Rudd, J.W.M.; Hecky, R.E.

1986-01-01

A method was developed to estimate specific rates of demethylation of methyl mercury in aquatic samples by measuring the volatile 14 C end products of 14 CH 3 HgI demethylation. This method was used in conjuction with a 203 Hg 2+ radiochemical method which determines specific rates of mercury methylation. Together, these methods enabled us to examine some factors controlling the net rate of mercury methylation. The methodologies were field tested, using lake sediment samples from a recently flooded reservoir in the Southern Indian Lake system which had developed a mercury contamination problem in fish. Ratios of the specific rates of methylation/demethylation were calculated. The highest ratios of methylation/demethylation were calculated. The highest ratios of methylation/demethylation occurred in the flooded shorelines of Southern Indian Lake. These results provide an explanation for the observed increases in the methyl mercury concentrations in fish after flooding

Twenty-sixth general conference meeting of representatives of RCA member states. Report

International Nuclear Information System (INIS)

1997-10-01

The meeting discussed the following issues: RCA Annual Report 1996; Report of the 19th RCA Working Group Meeting, Yangon Myanmar, 10-14 March 1997; RCA in the next 25 years; Development finance and the RCA; locating a senior RCA representative in the region; RCA guidelines and operating rules; TCDC activities; terminal tripartite review meeting on UNDP/RCA/IAEA project; status of new joint UNDP/RCA/IAEA project; options for the new joint project; RCA activities and budget in 1997 and 1998; reformulation and health care project; RCA proposed programme for 1999-2000; country statements; extension of RCA agreement; RCA 25th anniversary; venue and date of the 20th regular meeting of national RCA representatives

Twenty-sixth general conference meeting of representatives of RCA member states. Report

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-10-01

The meeting discussed the following issues: RCA Annual Report 1996; Report of the 19th RCA Working Group Meeting, Yangon Myanmar, 10-14 March 1997; RCA in the next 25 years; Development finance and the RCA; locating a senior RCA representative in the region; RCA guidelines and operating rules; TCDC activities; terminal tripartite review meeting on UNDP/RCA/IAEA project; status of new joint UNDP/RCA/IAEA project; options for the new joint project; RCA activities and budget in 1997 and 1998; reformulation and health care project; RCA proposed programme for 1999-2000; country statements; extension of RCA agreement; RCA 25th anniversary; venue and date of the 20th regular meeting of national RCA representatives.

Regulation and function of DNA methylation in plants and animals

KAUST Repository

He, Xinjian

2011-02-15

DNA methylation is an important epigenetic mark involved in diverse biological processes. In plants, DNA methylation can be established through the RNA-directed DNA methylation pathway, an RNA interference pathway for transcriptional gene silencing (TGS), which requires 24-nt small interfering RNAs. In mammals, de novo DNA methylation occurs primarily at two developmental stages: during early embryogenesis and during gametogenesis. While it is not clear whether establishment of DNA methylation patterns in mammals involves RNA interference in general, de novo DNA methylation and suppression of transposons in germ cells require 24-32-nt piwi-interacting small RNAs. DNA methylation status is dynamically regulated by DNA methylation and demethylation reactions. In plants, active DNA demethylation relies on the repressor of silencing 1 family of bifunctional DNA glycosylases, which remove the 5-methylcytosine base and then cleave the DNA backbone at the abasic site, initiating a base excision repair (BER) pathway. In animals, multiple mechanisms of active DNA demethylation have been proposed, including a deaminase- and DNA glycosylase-initiated BER pathway. New information concerning the effects of various histone modifications on the establishment and maintenance of DNA methylation has broadened our understanding of the regulation of DNA methylation. The function of DNA methylation in plants and animals is also discussed in this review. © 2011 IBCB, SIBS, CAS All rights reserved.

Molecular mechanisms and potential functions of histone demethylases

DEFF Research Database (Denmark)

Kooistra, Susanne Marije; Helin, Kristian

2012-01-01

of two families of enzymes that can demethylate histones has changed this notion. The biochemical activities of these histone demethylases towards specific Lys residues on histones, and in some cases non-histone substrates, have highlighted their importance in developmental control, cell-fate decisions...

Differential Activity of Voltage- and Ca2+-Dependent Potassium Channels in Leukemic T Cell Lines: Jurkat Cells Represent an Exceptional Case

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Salvador Valle-Reyes

2018-05-01

Full Text Available Activation of resting T cells relies on sustained Ca2+ influx across the plasma membrane, which in turn depends on the functional expression of potassium channels, whose activity repolarizes the membrane potential. Depending on the T-cells subset, upon activation the expression of Ca2+- or voltage-activated K+ channels, KCa or Kv, is up-regulated. In this study, by means of patch-clamp technique in the whole cell mode, we have studied in detail the characteristics of Kv and KCa currents in resting and activated human T cells, the only well explored human T-leukemic cell line Jurkat, and two additional human leukemic T cell lines, CEM and MOLT-3. Voltage dependence of activation and inactivation of Kv1.3 current were shifted up to by 15 mV to more negative potentials upon a prolonged incubation in the whole cell mode and displayed little difference at a stable state in all cell lines but CEM, where the activation curve was biphasic, with a high and low potential components. In Jurkat, KCa currents were dominated by apamine-sensitive KCa2.2 channels, whereas only KCa3.1 current was detected in healthy T and leukemic CEM and MOLT-3 cells. Despite a high proliferation potential of Jurkat cells, Kv and KCa currents were unexpectedly small, more than 10-fold lesser as compared to activated healthy human T cells, CEM and MOLT-3, which displayed characteristic Kv1.3high:KCa3.1high phenotype. Our results suggest that Jurkat cells represent perhaps a singular case and call for more extensive studies on primary leukemic T cell lines as well as a verification of the therapeutic potential of specific KCa3.1 blockers to combat acute lymphoblastic T leukemias.

TCUP: A novel hAT transposon active in maize tissue culture

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Alan eSmith

2012-01-01

Full Text Available Transposable elements are capable of inducing heritable de novo genetic variation. The sequences capable of reactivation, and environmental factors that induce mobilization, remain poorly defined even in well-studied genomes such as maize. We treated maize tissue culture with the demethylating agent 5-aza-2-deoxcytidine and examined long-term tissue culture lines to discover silenced transposable elements that have the potential to induce heritable genetic variation. Through these screens we have identified a novel low copy number hAT transposon, Tissue Culture Up-Regulated (TCUP, which is transcribed at high levels in long-term maize Black Mexican Sweet (BMS tissue culture and up-regulated in response to treatment with 5-aza-2-deoxycytidine. Analysis of the TIGR Maize Gene Index revealed that this element is the most frequently represented EST from the BMS cell culture library and is not represented in other tissue libraries, which is the basis for its name. A full-length sequence was assembled in inbred B73 that contains the putative functional motifs required for autonomous movement of a hAT transposon. Transposon display detected movement of TCUP in two long-term tissue cultured cell lines of the genotype Hi-II AxB and BMS. This research implicates TCUP as a transposon that is capable of reactivation and which may also be particularly sensitive to the stress of the tissue culture environment. Our findings are consistent with the hypothesis that epigenetic alterations potentiate genomic responses to stress during clonal propagation of plants.

Antecedents and Consequences of Sales Representatives' Relationship Termination Competence

DEFF Research Database (Denmark)

Geersbro, Jens; Ritter, Thomas

2013-01-01

. In addition, termination competence significantly affects the value of customer portfolios. Practical implications: The findings suggest that managers should more actively consider relationship termination as a legitimate option in customer relationship management. In order to increase the value of a firm......'s customer portfolio, managers must not only provide a clear definition of the types of customers the organization does not want to serve, but must also implement termination routines within the organization. Managers also need to establish incentives for sales representatives to terminate relationships......Purpose: Most firms have a number of unprofitable customer relationships that drain the firms' resources. However, firms in general and sales representatives in particular hesitate to address this problem and, ultimately, to terminate business relationships. This paper therefore aims to investigate...

Representing Development

DEFF Research Database (Denmark)

Representing Development presents the different social representations that have formed the idea of development in Western thinking over the past three centuries. Offering an acute perspective on the current state of developmental science and providing constructive insights into future pathways, ...

Efeito da variação do ph e da temperatura de síntese no desempenho de adesivos à base de creosoto vegetal desmetilado-formaldeído Effect ph variation and synthesis temperature on the performance of thermosetting adhesive formulations based on demethylated wood creosote-formaldehyde

Directory of Open Access Journals (Sweden)

Crístian Bacelar Santos

2003-08-01

Full Text Available O objetivo deste trabalho foi a produção de adesivos para madeira a partir de creosoto desmetilado. Para isto, foram sintetizadas diferentes formulações de adesivos para madeira a partir de creosoto desmetilado e paraformaldeído, variando-se o pH inicial da formulação (12,00, 12,25, 12,50, 12,75, 13,00, 13,25 e 13,50 e a temperatura de síntese (60 e 70 °C, para possibilitar a verificação dos melhores pHs e da melhor temperatura para elaboração do adesivo. Foi verificado, por meio da avaliação do gel time, que a melhor temperatura de síntese foi 70 °C. Foram realizadas, então, análises por DSC (calorimetria diferencial exploratória, para obtenção dos parâmetros cinéticos e caracterização das formulações adesivas de creosoto desmetilado sintetizadas a 70 °C. Os adesivos foram utilizados para colagem, a quente (160 °C e sob pressão (12 kgf/cm², de lâminas de Araucaria angustifolia. Após a colagem, foram realizados os ensaios de resistência mecânica ao cisalhamento por tração, para condição seca e úmida. Verificou-se que a resistência da linha de cola e a porcentagem de falha na madeira para os adesivos de creosoto desmetilado sintetizados a 70 °C foram inferiores às do adesivo de fenol-formaldeído sintetizado em laboratório, que foi utilizado como padrão.The objective of this work was the production of adhesives based on demethylated creosote for bonding of wood. Different formulations of demethylated wood bcreosote/formaldehyde were evaluated aiming at improving their bonding properties. The initial pH value and the synthesis temperature were varied in order to obtain the best values for producing the adhesives. Thus, seven pH values (12.00, 12.25, 12.50, 12.75, 13.00, 13.25, and 13.50 and two different temperatures (60 °C and 70 °C were applied. It was observed by gel time evaluation that the best synthesis temperature was 70 °C. The kinetic parameters were obtained through DSC analysis

Representing dispositions

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Röhl Johannes

2011-08-01

Full Text Available Abstract Dispositions and tendencies feature significantly in the biomedical domain and therefore in representations of knowledge of that domain. They are not only important for specific applications like an infectious disease ontology, but also as part of a general strategy for modelling knowledge about molecular interactions. But the task of representing dispositions in some formal ontological systems is fraught with several problems, which are partly due to the fact that Description Logics can only deal well with binary relations. The paper will discuss some of the results of the philosophical debate about dispositions, in order to see whether the formal relations needed to represent dispositions can be broken down to binary relations. Finally, we will discuss problems arising from the possibility of the absence of realizations, of multi-track or multi-trigger dispositions and offer suggestions on how to deal with them.

Zebra Mussel Antifouling Activity of the Marine Natural Product Aaptamine and Analogs

Science.gov (United States)

Diers, Jeffrey A.; Bowling, John J.; Duke, Stephen O.; Wahyuono, Subagus; Kelly, Michelle; Hamann, Mark T.

2016-01-01

Several aaptamine derivatives were selected as potential zebra mussel (Dreissena polymorpha) antifoulants because of the noteworthy absence of fouling observed on Aaptos sponges. Sponges of the genus Aaptos collected in Manado, Indonesia consistently produce aaptamine-type alkaloids. To date, aaptamine and its derivatives have not been carefully evaluated for their antifoulant properties. Structure–activity relationship studies were conducted using several aaptamine derivatives in a zebra mussel antifouling assay. From these data, three analogs have shown significant antifouling activity against zebra mussel attachment. Aaptamine, isoaaptamine, and the demethylated aaptamine compounds used in the zebra mussel assay produced EC50 values of 24.2, 11.6, and 18.6 μM, respectively. In addition, neither aaptamine nor isoaaptamine produced a phytotoxic response (as high as 300 μM) toward a nontarget organism, Lemna pausicostata, in a 7-day exposure. The use of these aaptamine derivatives from Aaptos sp. as potential environmentally benign antifouling alternatives to metal-based paints and preservatives is significant, not only as a possible control of fouling organisms, but also to highlight the ecological importance of these and similar biochemical defenses. PMID:16718618

Decreased electrophysiological activity represents the conscious state of emptiness in meditation

Science.gov (United States)

Hinterberger, Thilo; Schmidt, Stephanie; Kamei, Tsutomu; Walach, Harald

2014-01-01

Many neuroscientific theories explain consciousness with higher order information processing corresponding to an activation of specific brain areas and processes. In contrast, most forms of meditation ask for a down-regulation of certain mental processing activities while remaining fully conscious. To identify the physiological properties of conscious states with decreased mental and cognitive processing, the electrical brain activity (64 channels of EEG) of 50 participants of various meditation proficiencies was measured during distinct and idiosyncratic meditative tasks. The tasks comprised a wakeful “thoughtless emptiness (TE),” a “focused attention,” and an “open monitoring” task asking for mindful presence in the moment and in the environment without attachment to distracting thoughts. Our analysis mainly focused on 30 highly experienced meditators with at least 5 years and 1000 h of meditation experience. Spectral EEG power comparisons of the TE state with the resting state or other forms of meditation showed decreased activities in specific frequency bands. In contrast to a focused attention task the TE task showed significant central and parietal gamma decreases (p meditation practice did not present those differences significantly. Our findings indicate that a conscious state of TE reached by experienced meditators is characterized by reduced high-frequency brain processing with simultaneous reduction of the low frequencies. This suggests that such a state of meditative conscious awareness might be different from higher cognitive and mentally focused states but also from states of sleep and drowsiness. PMID:24596562

Physical activity and coronary artery calcification in two cohorts of women representing early and late postmenopause.

Science.gov (United States)

Storti, Kristi L; Pettee Gabriel, Kelley K; Underwood, Darcy A; Kuller, Lewis H; Kriska, Andrea M

2010-01-01

The aim of this study was to examine the association between physical activity (PA) and coronary artery calcification (CAC) among two cohorts of postmenopausal (PM) women representing early and late postmenopause. The cross-sectional relationship between PA and CAC was examined in 173 younger PM women (mean age ± SD, 56.8 ± 2.9 y) from the Women on the Move Through Activity and Nutrition (WOMAN) study and 121 older PM women (mean age ± SD, 73.9 ± 3.8 y) from the Walking Women Follow-up (WWF) study who had complete PA and CAC data. PA was measured objectively using a pedometer over a 7-day period in both cohorts. CAC was assessed using electron beam tomography. Descriptive statistics were used to describe median levels of PA and CAC, as well as proportions of detectable CAC (0 vs > 0). Fifty-seven percent of WOMAN study participants and 74% of WWF study participants had detectable CAC. The median (interquartile range) CAC score was 1.4 (0-23.3) for participants in the WOMAN study and 38.8 (0-264.4) among WWF study participants. Median (interquartile range) step counts were 6,447 (4,823-8,722) steps per day in the WOMAN study and 5,466 (3,610-7,576) steps per day for WWF study participants. Among WWF study participants, there was a statistically significant inverse association between pedometer steps and CAC (P for trend = 0.002); no association was found among WOMAN study participants. Among older PM women, higher levels of PA were associated with lower CAC. However, the relationship was not observed in PM women, likely due to the lower prevalence of CAC in this age group.

5-Hydroxymethylcytosine Remodeling Precedes Lineage Specification during Differentiation of Human CD4+ T Cells

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Colm E. Nestor

2016-07-01

Full Text Available 5-methylcytosine (5mC is converted to 5-hydroxymethylcytosine (5hmC by the TET family of enzymes as part of a recently discovered active DNA de-methylation pathway. 5hmC plays important roles in regulation of gene expression and differentiation and has been implicated in T cell malignancies and autoimmunity. Here, we report early and widespread 5mC/5hmC remodeling during human CD4+ T cell differentiation ex vivo at genes and cell-specific enhancers with known T cell function. We observe similar DNA de-methylation in CD4+ memory T cells in vivo, indicating that early remodeling events persist long term in differentiated cells. Underscoring their important function, 5hmC loci were highly enriched for genetic variants associated with T cell diseases and T-cell-specific chromosomal interactions. Extensive functional validation of 22 risk variants revealed potentially pathogenic mechanisms in diabetes and multiple sclerosis. Our results support 5hmC-mediated DNA de-methylation as a key component of CD4+ T cell biology in humans, with important implications for gene regulation and lineage commitment.

Representative of the municipality

International Nuclear Information System (INIS)

Castellnou Barcelo, J.

2007-01-01

Full text of publication follows. The decommissioning of the Vandellos-I nuclear power plant was a big challenge for the host community of Vandellos i l'Hospitalet de l'Infant and the close-by region. Closing down of the facility resulted in a rise of unemployment and a decrease of municipal income. The public was concerned with three issues: safety, transparency and information about the decommissioning, and economic future. Therefore, from the very beginning, municipal governments entered into negotiations with ENRESA on socio-economic benefits, including local employment in dismantling activities, and other types of financial and non-financial compensation. The ADE business association, i.e. a network of business organisations was created that guided the allotment of work to local firms. To satisfy public demand, local municipalities focused on the triad of safety, dialogue and local development, considered the three 'pillars of trust'. A Municipal Monitoring Commission was created, made up of representatives of affected municipalities, the regional government, the ADE business association, trade unions, the local university, the NPP management and ENRESA to monitor the dismantling process and regularly inform the local public. Items that were handled by this Commission included: - Work process monitoring. - Workers. - Materials Control. - Conventional and radioactive or contaminated waste management. - Emanation waste management (liquid and gas) - Safety (training and accidents). - Surveillance (radiological and environmental: dust, noise). - Effects. - Fulfillment of agreed conditions. A number of communication tools and channels were used, e.g., public information meetings, an information centre, the municipal magazine, the municipal radio station, and meetings with representatives of the local press. Particularly innovative was the idea to ask academics from the University of Tarragona to help with 'translating' technical information into language that could

40 CFR 60.4112 - Changing Hg designated representative and alternate Hg designated representative; changes in...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Changing Hg designated representative and alternate Hg designated representative; changes in owners and operators. 60.4112 Section 60.4112... Generating Units Hg Designated Representative for Hg Budget Sources § 60.4112 Changing Hg designated...

/sup 14/C-D-galactose breath test for evaluation of liver function in patients with chronic liver disease

Energy Technology Data Exchange (ETDEWEB)

Caspary, W F; Schaffer, J

1978-01-01

D-galactose metabolism and demethylation of aminopyrine by healthy controls and patients with chronic active hepatitis (CAH) and cirrhosis (Ci), were assessed by a breath analysis technique measuring /sup 14/CO2 exhalation after oral ingestion of /sup 14/C-D-galactose or /sup 14/C-aminopyrine. Patients with CAH and Ci exhibited decreased /sup 14/CO2-exhalation rates following /sup 14/-D-galactose or /sup 14/C-aminopyrine. D-galactose oxidation capacity of the liver can be assessed by a breath analysis technique in analogy to the demethylating function for aminopyrine. The ordinary oral D-galactose tolerance test seems, however, superior in comparison to the /sup 14/C-D-galactose tolerance test, in discriminating between healthy controls and patients with chronic liver disease.

Selection of appropriate Chinese terms to represent intensity and types of physical activity terms for use in the Taiwan version of IPAQ.

Science.gov (United States)

Liou, Yiing Mei; Jwo, Clark J C; Yao, Kaiping Grace; Chiang, Li-Chi; Huang, Lian-Hua

2008-12-01

In order to analyze the health risks of insufficient activity by international comparisons, the first author obtained the permission to translate and develop a Taiwan version of the International Physical Activity Questionnaire (IPAQ). The objective was to determine culturally sensitive Chinese translations for the terms "moderate", "vigorous" and "physical activity" as well as to identify representative types of physical activity for Taiwanese. This study used discussions by 12 expert focus groups, 6 expert audits, a scale survey, field study, Cognitive Aspect Survey Methodology (CASM), dual independent translation and back-translation to establish a consensus on physical activity-related concepts, terminologies and types that define the intensity of common activities of Taiwanese by integrating both local and foreign studies. The Chinese terms "fei li", "zhong deng fei li" and "shen ti huo dong", respectively, were identified as suitable and adequate translations for the English terms "vigorous", "moderate" and "physical activity". The common Taiwanese activities were accurately categorized and listed in questionnaires, forming culturally sensitive scales. Taiwan versions of IPAQ's self-administered long version (SL), self-administered short version (SS), and telephone interview short version (TS) were developed. Their content validity indices were .992, .994, and .980, as well as .994, .992, and .994 for language equivalence and meaning similarity between the English and Chinese versions of the IPAQ-LS, IPAQ-SS, and IPAQ-TS, respectively. Consistency values for the English and Chinese versions in terms of intraclass correlation coefficients were .945, .704, and .894, respectively. The IPAQ-Taiwan is not only a sensitive and precise tool, but also shows the effectiveness of the methodology (CASM) used in tool development. Subjects who did not regularly exercise and had an education less than a junior high school level underestimated the moderate

Characterizing the context of sedentary lifestyles in a representative sample of adults: a cross-sectional study from the physical activity measurement study project.

Science.gov (United States)

Kim, Youngwon; Welk, Gregory J

2015-12-09

Research has clearly demonstrated that excess time spent on sedentary behavior (SB) increases health risks in the population. However, the lack of information on the context of SB in the population prevents a detailed understanding of sedentary lifestyles. The purpose of this study was to characterize the context of SB in a representative sample of adults and to examine differences across various socio-demographic indicators. A diverse sample of 1442 adults (ages 20-71 year) completed an interviewer-administered 24-h activity recall to provide detailed information about the time, type and location of the previous day's activities. All reported activities were matched with MET scores from the Compendium of Physical Activity but only SB (i.e., METS Work: 27.5%, Community: 24.8%, Home/Indoor: 20.5%, Home/Outdoor: 15.8%, and Transportation: 11.3%). Patterns of SB allocations varied considerably across different socio-demographic indicators indicating the extreme variability in SB in the population. The findings provide unique insights about the context of SB at the population level, and can serve as a guide for developing intervention/policy studies to reduce sedentary time and minimize disparities in SB.

Grip strength, postural control, and functional leg power in a representative cohort of British men and women: associations with physical activity, health status, and socioeconomic conditions.

Science.gov (United States)

Kuh, Diana; Bassey, E Joan; Butterworth, Suzanne; Hardy, Rebecca; Wadsworth, Michael E J

2005-02-01

Understanding the health, behavioral, and social factors that influence physical performance in midlife may provide clues to the origins of frailty in old age and the future health of elderly populations. The authors evaluated muscle strength, postural control, and chair rise performance in a large representative prospective cohort of 53-year-old British men and women in relation to functional limitations, body size, health and activity, and socioeconomic conditions. Nurses interviewed 2984 men and women in their own homes in England, Scotland, and Wales and conducted physical examinations in 2956 of them. Objective measures were height, weight, and three physical performance tests: handgrip strength, one-legged standing balance time, and time to complete 10 chair rises. Functional limitations (difficulties walking, stair climbing, gripping, and falls), health status, physical activity, and social class were obtained using a structured questionnaire. Those with the worst scores on the physical performance tests had higher rates of functional limitations for both upper and lower limbs. Women had much weaker handgrip strength, somewhat poorer balance time, and only slightly poorer chair rise time compared with men. In women, health problems and low levels of physical activity contributed to poor physical performance on all three measures. In men, physical activity was the predominant influence. Heavier weight and poorer socioeconomic conditions contributed to poorer balance and chair rise times. In this representative middle-aged group, physical performance levels varied widely, and women were seriously disadvantaged compared with men. In general, physical performance was worse for men and women living in poorer socioeconomic conditions with greater body weight, poorer health status, and inactive lifestyles. These findings support recommendations for controlling excess body weight, effective health interventions, and the maintenance of active lifestyles during aging.

Sidestepping questions of legitimacy: how community representatives manoeuvre to effect change in a health service.

Science.gov (United States)

Nathan, Sally; Stephenson, Niamh; Braithwaite, Jeffrey

2014-01-01

Empirical studies of community participation in health services commonly tie effectiveness to the perceived legitimacy of community representatives among health staff. This article examines the underlying assumption that legitimacy is the major pathway to influence for community representatives. It takes a different vantage point from previous research in its examination of data (primarily through 34 in-depth interviews, observation and recording of 26 meetings and other interactions documented in field notes) from a 3-year study of community representatives' action in a large health region in Australia. The analysis primarily deploys Michel de Certeau's ideas of Strategy and Tactic to understand the action and effects of the generally 'weaker players' in the spaces and places dominated by powerful institutions. Through this lens, we can see the points where community representatives are active participants following their own agenda, tactically capitalising on cracks in the armour of the health service to seize opportunities that present themselves in time to effect change. Being able to see community representatives as active producers of change, not simply passengers following the path of the health service, challenges how we view the success of community participation in health.

Experience with the 14C-aminopyrine breath test in hepatic cirrhosis and under the influence of diclofenac-sodium (Voltaren/sup R/)

International Nuclear Information System (INIS)

Reinicke, C.; Hippius, M.

1983-01-01

The 14 C-aminopyrine breath test is a simple procedure for the non-invasive determination of the microsomal function of the liver. After oral administration of 74 kBq 14 C-aminopyrine the 14 CO 2 activity of the expired breath air is determined in hourly intervals. There is a close correlation between its decrease and the elimination of aminopyrine from the plasma. Both the elimination constant of 14 CO 2 and the maximal specific 14 CO 2 activity are useful quantitative parameters of the test. They allow conclusions as to the hepatic demethylation capacity. Both parameters were significantly lower in 15 patients with liver cirrhosis than in 12 control patients. The non-steroidal anti-inflammatory drug diclofenac-sodium did not significantly influence the demethylation of 14 C-aminopyrine in 5 patients with rheumatic diseases and in 2 healthy probands. Further experience with the breath test is necessary, especially with respect to its suitability for prospective investigation. (author)

/sup 14/CO/sub 2/ breath test: Facilities and limitations of a rapid and noninvasive method for in vivo evaluation of modified hepatic cytochrome P-450 - a critique

Energy Technology Data Exchange (ETDEWEB)

Bruech, M.; Kling, L.; Legrum, W.; Maser, E.

1986-05-01

By means of the breath test technique the cascade from O-demethylations to CO/sub 2/ was investigated after pretreatment of mice with warfarin, phenobarbital, cobaltous chloride, sodium vanadate and metyrapone. It was the intention to examine the validity of the technique with respect to cytochrome P-450 activity. Therefore three different radioactive labeled substrates, i.e., hydrogen carbonate, formate and xenobiotics, were applied at three different levels of the one-carbon pathway and were utilized to demonstrate possible interference of the modifiers with the sequence from O-demethylation to CO/sub 2/. Real in vivo information about a modified cytochrome P-450 system can be obtained using model substrates carefully selected with regard to the type of expected modification of the monooxygenase system. In addition, a parallel monitoring of the consecutive reaction sequence by measuring the conversion of formate to CO/sub 2/ is necessary in order to guarantee the validity of the in vivo technique in visualizing the activity of the hepatic monooxygenase system.

The 14CO2 breath test: Facilities and limitations of a rapid and noninvasive method for in vivo evaluation of modified hepatic cytochrome P-450 - a critique

International Nuclear Information System (INIS)

Bruech, M.; Kling, L.; Legrum, W.; Maser, E.

1986-01-01

By means of the breath test technique the cascade from O-demethylations to CO 2 was investigated after pretreatment of mice with warfarin, phenobarbital, cobaltous chloride, sodium vanadate and metyrapone. It was the intention to examine the validity of the technique with respect to cytochrome P-450 activity. Therefore three different radioactive labeled substrates, i.e., hydrogen carbonate, formate and xenobiotics, were applied at three different levels of the one-carbon pathway and were utilized to demonstrate possible interference of the modifiers with the sequence from O-demethylation to CO 2 . Real in vivo information about a modified cytochrome P-450 system can be obtained using model substrates carefully selected with regard to the type of expected modification of the monooxygenase system. In addition, a parallel monitoring of the consecutive reaction sequence by measuring the conversion of formate to CO 2 is necessary in order to guarantee the validity of the in vivo technique in visualizing the activity of the hepatic monooxygenase system. (orig.)

Social Modulation or Hormonal Causation? Linkages of Testosterone with Sexual Activity and Relationship Quality in a Nationally Representative Longitudinal Sample of Older Adults.

Science.gov (United States)

Das, Aniruddha; Sawin, Nicole

2016-11-01

This study used population-representative longitudinal data from the 2005-2006 and 2010-2011 waves of the National Social Life, Health and Aging Project-a probability sample of US adults aged 57-85 at baseline (N = 650 women and 620 men)-to examine the causal direction in linkages of endogenous testosterone (T) with sexual activity and relationship quality. For both genders, our autoregressive effects indicated a large amount of temporal stability, not just in individual-level attributes (T, masturbation) but also dyadic ones (partnered sex, relationship quality)-indicating that a need for more nuanced theories of relational processes. Cross-lagged results suggested gender-specific effects-generally more consistent with sexual or relational modulation of T than with hormonal causation. Specifically, men's findings indicated their T might be elevated by their sexual (masturbatory) activity but not vice versa, although androgen levels did lower men's subsequent relationship quality. Women's T, in contrast, was negatively influenced not just by their higher relationship quality but also by their more frequent partnered sex-perhaps reflecting a changing function of sexual activity in late life.

Representing vision and blindness.

Science.gov (United States)

Ray, Patrick L; Cox, Alexander P; Jensen, Mark; Allen, Travis; Duncan, William; Diehl, Alexander D

2016-01-01

There have been relatively few attempts to represent vision or blindness ontologically. This is unsurprising as the related phenomena of sight and blindness are difficult to represent ontologically for a variety of reasons. Blindness has escaped ontological capture at least in part because: blindness or the employment of the term 'blindness' seems to vary from context to context, blindness can present in a myriad of types and degrees, and there is no precedent for representing complex phenomena such as blindness. We explore current attempts to represent vision or blindness, and show how these attempts fail at representing subtypes of blindness (viz., color blindness, flash blindness, and inattentional blindness). We examine the results found through a review of current attempts and identify where they have failed. By analyzing our test cases of different types of blindness along with the strengths and weaknesses of previous attempts, we have identified the general features of blindness and vision. We propose an ontological solution to represent vision and blindness, which capitalizes on resources afforded to one who utilizes the Basic Formal Ontology as an upper-level ontology. The solution we propose here involves specifying the trigger conditions of a disposition as well as the processes that realize that disposition. Once these are specified we can characterize vision as a function that is realized by certain (in this case) biological processes under a range of triggering conditions. When the range of conditions under which the processes can be realized are reduced beyond a certain threshold, we are able to say that blindness is present. We characterize vision as a function that is realized as a seeing process and blindness as a reduction in the conditions under which the sight function is realized. This solution is desirable because it leverages current features of a major upper-level ontology, accurately captures the phenomenon of blindness, and can be

Targeting CXCR4 reverts the suppressive activity of T-regulatory cells in renal cancer.

Science.gov (United States)

Santagata, Sara; Napolitano, Maria; D'Alterio, Crescenzo; Desicato, Sonia; Maro, Salvatore Di; Marinelli, Luciana; Fragale, Alessandra; Buoncervello, Maria; Persico, Francesco; Gabriele, Lucia; Novellino, Ettore; Longo, Nicola; Pignata, Sandro; Perdonà, Sisto; Scala, Stefania

2017-09-29

With the intent to identify biomarkers in renal cell carcinoma (RCC) the functional status of T-regulatory cells (Tregs) was investigated in primary RCC. Tregs were isolated from tumoral-(TT), peritumoral tissue-(PT) and peripheral blood-(PB) of 42 primary RCC patients and function evaluated through effector T cells (Teff) proliferation, cytokines release and demethylation of Treg Specific Region (TSDR). The highest value of Tregs was detected in TT with the uppermost amount of effector-Tregs-(CD4 + CD25 hi FOXP3 hi CD45RA - ). PB-RCC Tregs efficiently suppress Teff proliferation compared to healthy donor (HD)-Tregs and, at the intrapatient evaluation, TT-derived Tregs were the most suppressive. Higher demethylation TSDR was detected in TT- and PB-RCC Tregs vs HD-Tregs ( P <0,001). CXCR4 is highly expressed on Tregs, thus we wished to modulate Tregs function through CXCR4 inhibition. CXCR4 antagonism, elicited by a new peptidic antagonist, Peptide-R29, efficiently reversed Tregs suppression of Teff proliferation. Thus Tregs functional evaluation precisely reflects Tregs status and may be a reliable biomarker of tumoral immune response. In addition, treatment with CXCR4 antagonist, impairing Tregs function, could improve the anticancer immune response, in combination with conventional therapy and/or immunotherapy such as checkpoints inhibitors.

Representing cognitive activities and errors in HRA trees

International Nuclear Information System (INIS)

Gertman, D.I.

1992-01-01

This paper discusses development of a means by which to present cognitive information in human reliability assessment (HRA) event trees. The descriptions found in probabilistic risk assessments (PRAs) regarding the demands on, and the resulting performance of, nuclear power plant (NPP) crews often make use of the technique for human error rate prediction (THERP), which provides a mechanism, the HRA event tree, for presenting the analyst's conceptualization of the activities underlying performance and the errors associated with that performance. When using THERP, analysts have often omitted the more complex elements of human cognition from these trees. There has yet to be a concerted effort to take theory, principles, and data from cognitive psychology and wed it to the logic structure of the HRA event tree. This paper attempts to do so. The COGENT modeling scheme (cognitively based HRA event trees) adds two taxonomies to the HRA event tree proposed by Swain and Guttman. The first taxonomy, the one proposed by Norman and Reason, describes the type of error committed and implies something about the underlying cognition as well. The second of these, the Rasmussen taxonomy, provides description regarding the skill-based, rule-based, or knowledge-based behavior underlying the execution of tasks. It is not apparent and must be deduced from the pattern of errors exhibited by personnel

Comparatives of Expressive Activities of Junior High School Students with Different Types of Representative Systems

Directory of Open Access Journals (Sweden)

Geydebrekht N.A.

2017-08-01

Full Text Available The article presents data from a study of drawings of children of primary school age to identify the сcomparative diagnostic parameters that allow to define the leading representative system in the child. 164 drawings of 51 persons under test of the two grades of primary school were analyzed. The observation and modified in relation to primary school age version of the method «Representational systems bias test» (Lewis A., Puselik R., 2012 were used as elements of the diagnostic unit. Based on these results it is concluded that the drawings of children of primary school age with different types of representative systems have differences, sufficient to justify their diagnostic informative value. The results of the study make comparative profiles of children of primary school age with different types of representational systems to facilitate the diagnostic part of the work with children's drawings.

Severe tremor after cotrimoxazole-induced elevation of venlafaxine serum concentrations in a patient with major depressive disorder.

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Geber, Christian; Ostad Haji, Elnaz; Schlicht, Konrad; Hiemke, Christoph; Tadić, André

2013-06-01

: We describe a female patient who was an extensive metabolizer of cytochrome P450 isoenzyme (CYP) 2D6 and an intermediate metabolizer of CYP2C19 (genotype: CYP2C19 *1/*2). She exhibited high serum concentrations of venlafaxine and O-desmethylvenlafaxine and developed severe tremor after comedication with cotrimoxazole (sulfamethazole/trimethoprim). Venlafaxine is mainly metabolized by O- and N-demethylation. O-demethylation is catalyzed by the highly polymorphic CYP2D6 and N-demethylation by several enzymes, CYP2C19, CYP2C9, and CYP3A4. The observed overall pharmacokinetic effect was most probably the result of decreased N-demethylation of venlafaxine by (1) reduced expression of CYP2C19 due to a genetic deficit and (2) inhibition of CYP2C9 by cotrimoxazole.

Muscle Contraction Induces Acute Hydroxymethylation of the Exercise-Responsive Gene Nr4a3

DEFF Research Database (Denmark)

Pattamaprapanont, Pattarawan; Garde, Christian; Fabre, Odile

2016-01-01

stimulated over time is required to determine whether contraction-induced demethylation is preceded by changes in the hydroxymethylcytosine level. Here, we established an acute skeletal muscle contraction model to mimic the effects of acute exercise on gene expression. We used this model to investigate...... promoters. Exercise induces dynamic DNA demethylation at gene promoters; however, the contribution of the demethylation precursor hydroxymethylcytosine is unknown. Given the evanescent nature of hydroxymethylcytosine, a muscle contraction model that allows for the collection of samples that are repeatedly...... the effect of muscle contraction on DNA demethylation and hydroxymethylation. First, we performed an acute exercise study in healthy humans to identify an exercise-responsive gene that we could study in culture. We identified the nuclear receptor subfamily 4 group A member 3 (Nr4a3) gene with the highest...

Represented Speech in Qualitative Health Research

DEFF Research Database (Denmark)

Musaeus, Peter

2017-01-01

Represented speech refers to speech where we reference somebody. Represented speech is an important phenomenon in everyday conversation, health care communication, and qualitative research. This case will draw first from a case study on physicians’ workplace learning and second from a case study...... on nurses’ apprenticeship learning. The aim of the case is to guide the qualitative researcher to use own and others’ voices in the interview and to be sensitive to represented speech in everyday conversation. Moreover, reported speech matters to health professionals who aim to represent the voice...... of their patients. Qualitative researchers and students might learn to encourage interviewees to elaborate different voices or perspectives. Qualitative researchers working with natural speech might pay attention to how people talk and use represented speech. Finally, represented speech might be relevant...

Seasonal mercury transformation and surficial sediment detoxification by bacteria of Marano and Grado lagoons

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Baldi, Franco; Gallo, Michele; Marchetto, Davide; Fani, Renato; Maida, Isabel; Horvat, Milena; Fajon, Vesna; Zizek, Suzana; Hines, Mark

2012-11-01

Marano and Grado lagoons are polluted by mercury from the Isonzo River and a chlor-alkali plant, yet despite this contamination, clam cultivation is one of the main activities in the region. Four stations (MA, MB, MC and GD) were chosen for clam seeding and surficial sediments were monitored in autumn, winter and summer to determine the Hg detoxifying role of bacteria. Biotransformation of Hg species in surficial sediments of Marano and Grado lagoons was investigated while taking into consideration the speciation of organic matter in the biochemical classes of PRT (proteins), CHO (carbohydrates) and LIP (lipids), water-washed cations and anions, bacterial biomass, Hg-resistant bacteria, some specific microbial activities such as sulfate reduction rates, Hg methylation rates, Hg-demethylation rates, and enzymatic ionic Hg reduction. MeHg in sediments was well correlated with PRT content, whereas total Hg in sediments correlated with numbers of Hg-resistant bacteria. Correlations of the latter with Hg-demethylation rates in autumn and winter suggested a direct role Hg-resistant bacteria in Hg detoxification by producing elemental Hg (Hg0) from ionic Hg and probably also from MeHg. MeHg-demethylation rates were ˜10 times higher than Hg methylation rates, were highest in summer and correlated with high sulfate reduction rates indicating that MeHg was probably degraded in summer by sulfate-reducing bacteria via an oxidative pathway. During the summer period, aerobic heterotrophic Hg-resistant bacteria decreased to <2% compared to 53% in winter. Four Hg-resistant bacterial strains were isolated, two Gram-positive (Staphylococcus and Bacillus) and two Gram-negative (Stenotrophomonas and Pseudomonas). Two were able to produce Hg0, but just one contained a merA gene; while other two strains did not produce Hg0 even though they were able to grow at 5 μg ml of HgCl2. Lagoon sediments support a strong sulfur cycle in summer that controls Hg methylation and demethylation

Do Public Involvement Activities in Biomedical Research and Innovation Recruit Representatively? A Systematic Qualitative Review.

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Lander, Jonas; Hainz, Tobias; Hirschberg, Irene; Bossert, Sabine; Strech, Daniel

2016-01-01

Public involvement activities (PIAs) may contribute to the governance of ethically challenging biomedical research and innovation by informing, consulting with and engaging the public in developments and decision-making processes. For PIAs to capture a population's preferences (e.g. on issues in whole genome sequencing, biobanks or genome editing), a central methodological requirement is to involve a sufficiently representative subgroup of the general public. While the existing literature focusses on theoretical and normative aspects of 'representation', this study assesses empirically how such considerations are implemented in practice. It evaluates how PIA reports describe representation objectives, the recruitment process and levels of representation achieved. PIA reports were included from a systematic literature search if they directly reported a PIA conducted in a relevant discipline such as genomics, biobanks, biotechnology or others. PIA reports were analyzed with thematic text analysis. The text analysis was guided by an assessment matrix based on PIA-specific guidelines and frameworks. We included 46 relevant reports, most focusing on issues in genomics. 27 reports (59%) explicitly described representation objectives, though mostly without adjusting eligibility criteria and recruiting methods to the specific objective. 11 reports (24%) explicitly reported to have achieved the intended representation; the rest either reported failure or were silent on this issue. Representation of study samples in PIAs in biomedical research and innovation is currently not reported systematically. Improved reporting on representation would not only improve the validity and value of PIAs, but could also contribute to PIA results being used more often in relevant policy and decision-making processes. © 2016 S. Karger AG, Basel.

Experiment list: SRX186705 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available t play a role a chromatin remodeling and histone demethylation. PHF8 also bears a...a chromatin remodeling and histone demethylation. PHF8 also bears a PHD (plant homeodomain)- type zinc-finge

Distance to green space and physical activity: a danish national representative survey

DEFF Research Database (Denmark)

Toftager, Mette; Ekholm, Ola; Schipperijn, Jasper

2011-01-01

This study examines the relationship between distance to green space and the level of physical activity among the population of Denmark. In addition, the relationship between distance to green space and obesity is investigated.......This study examines the relationship between distance to green space and the level of physical activity among the population of Denmark. In addition, the relationship between distance to green space and obesity is investigated....

Vitamin C - A new player in regulation of the cancer epigenome

DEFF Research Database (Denmark)

Gillberg, Linn; Ørskov, Andreas D.; Liu, Minmin

2017-01-01

of pharmacological doses of vitamin C injected intravenously to selectively kill tumor cells. This review will focus on the potential of vitamin C to optimize the outcome of epigenetic therapy in cancer patients and alternatively to act as a therapeutic at high doses.......Over the past few years it has become clear that vitamin C, as a provider of reduced iron, is an essential factor for the function of epigenetic regulators that initiate the demethylation of DNA and histones. Vitamin C deficiency is rare in the general population, but is frequently observed...... of care. Recent in vitro studies suggest that vitamin C at physiological concentrations, combined with hypomethylating agents may act synergistically to cause DNA demethylation through active and passive mechanisms, respectively. Additionally, several recent studies have renewed interest in the use...

Experiment list: SRX186646 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available metalloenzymes that play a role a chromatin remodeling and histone demethylation. PHF8 also bears...mes that play a role a chromatin remodeling and histone demethylation. PHF8 also bears a PHD (plant homeodom

Neurophysiological correlates of artistic image creation by representatives of artistic professions

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Dikaya L. A.

2016-12-01

Full Text Available The steadily increasing demand for artistic professions brings to the fore the task of studying the phenomenon of art by researching the unique capacity of the human brain to create works of art in different spheres of creative activity. So far, only a few studies have investigated creativity-related brain activity in representatives of the creative professions. The aim of the empirical research was to study the neurophysiological correlates of artistic image creation by representatives of the artistic professions. The participants were 60 right-handed females aged 23-27, divided into three groups— artists (23 people, actors (17 people, and specialists who do not work in an artistic field (20 people. The mono-typing technique was used to model the creative artistic process. EEG signals were recorded in a resting state, and during four stages of the creation of an artistic image (viewing of monotypes, frustration, image creation, and thinking over the details from 21 electrodes set on the scalp according to the International 10-20 System. We analyzed EEG coherence for each functional trial at theta (4.00–8.00 Hz, alpha1 (8.00–10.5 Hz, alpha2 (10.5–13.00 Hz, and beta (13.00– 35.00 Hz frequency bands. For statistical analysis, we used MANOVA and post hoc analysis. We found that the neurophysiological correlates of creating an artistic image are different at different stages of the creative process, and have different features for artists and actors. The actors primarily show dominance of right hemisphere activity, while close interaction of the hemispheres distinguishes the brains of the artists. The differences revealed in brain cortex functioning when artists or actors create an artistic image reflect different strategies of imaginative creative work by representatives of these professions.

[Dangerous liaisons--physicians and pharmaceutical sales representatives].

Science.gov (United States)

Granja, Mónica

2005-01-01

Interactions between physicians and detailers (even when legitimate ones) raise scientific and ethical questions. In Portugal little thinking and discussion has been done on the subject and the blames for bribery have monopolized the media. This work intended to review what has been said in medical literature about these interactions. How do physicians see themselves when interacting with pharmaceutical companies and their representatives? Do these companies in fact change their prescriptive behaviour, and, if so, how do they change it? How can physicians interact with detailers and still keep their best practice? A Medline research, from 1966 till 2002, was performed using the key-words as follows. A database similar to Medline but concerning medical journals published in Portugal, Index das Revistas Médicas Portuguesas, was also researched from 1992 to 2002. Pharmaceutical companies are profit bound and they allot promoting activities, and detailing in particular, huge amounts of money. Most physicians hold firmly to the belief that they are able to resist and not be influenced by drug companies promotion activities. Nevertheless, all previous works on literature tell us the opposite. Market research also indicates that detailers effectively promote drug sales. Various works also suggest that the information detailers provide to physicians may be largely incorrect, even comparing it to the written information provided by the pharmaceutical companies they work for. The frequency at which portuguese physicians (especially family physicians) contact with pharmaceutical sales representatives is higher than the frequency reported in countries where the available studies come from (namely, Canada and the United States of America). This may put portuguese physicians at a higher risk, making it imperative that work and wide debate are initiated among the class.

Characterization of the human cytochrome P450 enzymes involved in the metabolism of dihydrocodeine

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Kirkwood, L. C.; Nation, R. L.; Somogyi, A. A.

1997-01-01

Aims Using human liver microsomes from donors of the CYP2D6 poor and extensive metabolizer genotypes, the role of individual cytochromes P-450 in the oxidative metabolism of dihydrocodeine was investigated. Methods The kinetics of formation of N- and O-demethylated metabolites, nordihydrocodeine and dihydromorphine, were determined using microsomes from six extensive and one poor metabolizer and the effects of chemical inhibitors selective for individual P-450 enzymes of the 1A, 2A, 2C, 2D, 2E and 3A families and of LKM1 (anti-CYP2D6) antibodies were studied. Results Nordihydrocodeine was the major metabolite in both poor and extensive metabolizers. Kinetic constants for N-demethylation derived from the single enzyme Michaelis-Menten model did not differ between the two groups. Troleandomycin and erythromycin selectively inhibited N-demethylation in both extensive and poor metabolizers. The CYP3A inducer, α-naphthoflavone, increased N-demethylation rates. The kinetics of formation of dihydromorphine in both groups were best described by a single enzyme Michaelis-Menten model although inhibition studies in extensive metabolizers suggested involvement of two enzymes with similar Km values. The kinetic constants for O-demethylation were significantly different in extensive and poor metabolizers. The extensive metabolizers had a mean intrinsic clearance to dihydromorphine more than ten times greater than the poor metabolizer. The CYP2D6 chemical inhibitors, quinidine and quinine, and LKM1 antibodies inhibited O-demethylation in extensive metabolizers; no effect was observed in microsomes from a poor metabolizer. Conclusions CYP2D6 is the major enzyme mediating O-demethylation of dihydrocodeine to dihydromorphine. In contrast, nordihydrocodeine formation is predominantly catalysed by CYP3A. PMID:9431830

The histone demethylase Jhdm1a regulates hepatic gluconeogenesis.

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Dongning Pan

Full Text Available Hepatic gluconeogenesis is required for maintaining blood glucose homeostasis; yet, in diabetes mellitus, this process is unrestrained and is a major contributor to fasting hyperglycemia. To date, the impacts of chromatin modifying enzymes and chromatin landscape on gluconeogenesis are poorly understood. Through catalyzing the removal of methyl groups from specific lysine residues in the histone tail, histone demethylases modulate chromatin structure and, hence, gene expression. Here we perform an RNA interference screen against the known histone demethylases and identify a histone H3 lysine 36 (H3K36 demethylase, Jhdm1a, as a key negative regulator of gluconeogenic gene expression. In vivo, silencing of Jhdm1a promotes liver glucose synthesis, while its exogenous expression reduces blood glucose level. Importantly, the regulation of gluconeogenesis by Jhdm1a requires its demethylation activity. Mechanistically, we find that Jhdm1a regulates the expression of a major gluconeogenic regulator, C/EBPα. This is achieved, at least in part, by its USF1-dependent association with the C/EBPα promoter and its subsequent demethylation of dimethylated H3K36 on the C/EBPα locus. Our work provides compelling evidence that links histone demethylation to transcriptional regulation of gluconeogenesis and has important implications for the treatment of diabetes.

The Histone Demethylase Jhdm1a Regulates Hepatic Gluconeogenesis

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Zou, Tie; Yao, Annie Y.; Cooper, Marcus P.; Boyartchuk, Victor; Wang, Yong-Xu

2012-01-01

Hepatic gluconeogenesis is required for maintaining blood glucose homeostasis; yet, in diabetes mellitus, this process is unrestrained and is a major contributor to fasting hyperglycemia. To date, the impacts of chromatin modifying enzymes and chromatin landscape on gluconeogenesis are poorly understood. Through catalyzing the removal of methyl groups from specific lysine residues in the histone tail, histone demethylases modulate chromatin structure and, hence, gene expression. Here we perform an RNA interference screen against the known histone demethylases and identify a histone H3 lysine 36 (H3K36) demethylase, Jhdm1a, as a key negative regulator of gluconeogenic gene expression. In vivo, silencing of Jhdm1a promotes liver glucose synthesis, while its exogenous expression reduces blood glucose level. Importantly, the regulation of gluconeogenesis by Jhdm1a requires its demethylation activity. Mechanistically, we find that Jhdm1a regulates the expression of a major gluconeogenic regulator, C/EBPα. This is achieved, at least in part, by its USF1-dependent association with the C/EBPα promoter and its subsequent demethylation of dimethylated H3K36 on the C/EBPα locus. Our work provides compelling evidence that links histone demethylation to transcriptional regulation of gluconeogenesis and has important implications for the treatment of diabetes. PMID:22719268

Alteration of runt-related transcription factor 3 gene expression and biologic behavior of esophageal carcinoma TE-1 cells after 5-azacytidine intervention.

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Wang, Shuai; Liu, Hong; Akhtar, Javed; Chen, Hua-Xia; Wang, Zhou

2013-01-01

5-Azacytidine (5-azaC) was originally identified as an anticancer drug (NSC102876) which can cause hypomethylation of tumor suppressor genes. To assess its effects on runt-related transcription factor 3 (RUNX3), expression levels and the promoter methylation status of the RUNX3 gene were assessed. We also investigated alteration of biologic behavior of esophageal carcinoma TE-1 cells. MTT assays showed 5-azaC inhibited the proliferation of TE-1 cells in a time and dose-dependent way. Although other genes could be demethylated after 5-azaC intervention, we focused on RUNX3 gene in this study. The expression level of RUNX3 mRNA increased significantly in TE-1 cells after treatment with 5-azaC at hypotoxic levels. RT-PCR showed 5-azaC at 50 μM had the highest RUNX3-induction activity. Methylation-specific PCR indicated that 5-azaC induced RUNX3 expression through demethylation. Migration and invasion of TE-1 cells were inhibited by 5-azaC, along with growth of Eca109 xenografts in nude mice. In conclusion, we demonstrate that the RUNX3 gene can be reactivated by the demethylation reagent 5-azaC, which inhibits the proliferation, migration and invasion of esophageal carcinoma TE-1 cells.

Methadone inhibits CYP2D6 and UGT2B7/2B4 in vivo: a study using codeine in methadone- and buprenorphine-maintained subjects

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Gelston, Eloise A; Coller, Janet K; Lopatko, Olga V; James, Heather M; Schmidt, Helmut; White, Jason M; Somogyi, Andrew A

2012-01-01

AIMS To compare the O-demethylation (CYP2D6-mediated), N-demethylation (CYP3A4-mediated) and 6-glucuronidation (UGT2B4/7-mediated) metabolism of codeine between methadone- and buprenorphine-maintained CYP2D6 extensive metabolizer subjects. METHODS Ten methadone- and eight buprenorphine-maintained subjects received a single 60 mg dose of codeine phosphate. Blood was collected at 3 h and urine over 6 h and assayed for codeine, norcodeine, morphine, morphine-3- and -6-glucuronides and codeine-6-glucuronide. RESULTS The urinary metabolic ratio for O-demethylation was significantly higher (P = 0.0044) in the subjects taking methadone (mean ± SD, 2.8 ± 3.1) compared with those taking buprenorphine (0.60 ± 0.43), likewise for 6-glucuronide formation (0.31 ± 0.24 vs. 0.053 ± 0.027; P D6 and UGTs 2B4 and 2B7 reactions in vivo, even though it is not a substrate for these enzymes. Plasma morphine was not altered, owing to the opposing effects of inhibition of both formation and elimination; however, morphine-6-glucuronide (analgesically active) concentrations were substantially reduced. Drug interactions with methadone are likely to include drugs metabolized by various UGTs and CYP2D6. PMID:22092298

Representing Color Ensembles.

Science.gov (United States)

Chetverikov, Andrey; Campana, Gianluca; Kristjánsson, Árni

2017-10-01

Colors are rarely uniform, yet little is known about how people represent color distributions. We introduce a new method for studying color ensembles based on intertrial learning in visual search. Participants looked for an oddly colored diamond among diamonds with colors taken from either uniform or Gaussian color distributions. On test trials, the targets had various distances in feature space from the mean of the preceding distractor color distribution. Targets on test trials therefore served as probes into probabilistic representations of distractor colors. Test-trial response times revealed a striking similarity between the physical distribution of colors and their internal representations. The results demonstrate that the visual system represents color ensembles in a more detailed way than previously thought, coding not only mean and variance but, most surprisingly, the actual shape (uniform or Gaussian) of the distribution of colors in the environment.

An equivalent body surface charge model representing three-dimensional bioelectrical activity

Science.gov (United States)

He, B.; Chernyak, Y. B.; Cohen, R. J.

1995-01-01

A new surface-source model has been developed to account for the bioelectrical potential on the body surface. A single-layer surface-charge model on the body surface has been developed to equivalently represent bioelectrical sources inside the body. The boundary conditions on the body surface are discussed in relation to the surface-charge in a half-space conductive medium. The equivalent body surface-charge is shown to be proportional to the normal component of the electric field on the body surface just outside the body. The spatial resolution of the equivalent surface-charge distribution appears intermediate between those of the body surface potential distribution and the body surface Laplacian distribution. An analytic relationship between the equivalent surface-charge and the surface Laplacian of the potential was found for a half-space conductive medium. The effects of finite spatial sampling and noise on the reconstruction of the equivalent surface-charge were evaluated by computer simulations. It was found through computer simulations that the reconstruction of the equivalent body surface-charge from the body surface Laplacian distribution is very stable against noise and finite spatial sampling. The present results suggest that the equivalent body surface-charge model may provide an additional insight to our understanding of bioelectric phenomena.

Characterization of Lignanamides from Hemp (Cannabis sativa L.) Seed and Their Antioxidant and Acetylcholinesterase Inhibitory Activities.

Science.gov (United States)

Yan, Xiaoli; Tang, Jiajing; dos Santos Passos, Carolina; Nurisso, Alessandra; Simões-Pires, Claudia Avello; Ji, Mei; Lou, Hongxiang; Fan, Peihong

2015-12-16

Hemp seed is known for its content of fatty acids, proteins, and fiber, which contribute to its nutritional value. Here we studied the secondary metabolites of hemp seed aiming at identifying bioactive compounds that could contribute to its health benefits. This investigation led to the isolation of 4 new lignanamides, cannabisin M (2), cannabisin N (5), cannabisin O (8), and 3,3'-demethyl-heliotropamide (10), together with 10 known lignanamides, among which 4 was identified for the first time from hemp seed. Structures were established on the basis of NMR, HR-MS, UV, and IR as well as by comparison with the literature data. Lignanamides 2, 7, and 9-14 showed good antioxidant activity, among which 7, 10, and 13 also inhibited acetylcholinesterase in vitro. The newly identified compounds in this study add to the diversity of hemp seed composition, and the bioassays implied that hemp seed, with lignanamides as nutrients, may be a good source of bioactive and protective compounds.

Knowledge Activation versus Sentence Mapping When Representing Fictional Characters' Emotional States.

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Gernsbacher, Morton Ann; Robertson, Rachel R. W.

1992-01-01

In a study of knowledge activation and sentence mapping, subjects read stories that described concrete actions, and then the content of the stories was manipulated (i.e. stories were written that implied different emotional states). It is suggested that the more emotionally evoking situations one encounters the more memory traces are stored and…

Application of the relative activity factor approach in scaling from heterologously expressed cytochromes p450 to human liver microsomes: studies on amitriptyline as a model substrate.

Science.gov (United States)

Venkatakrishnan, K; von Moltke, L L; Greenblatt, D J

2001-04-01

The relative activity factor (RAF) approach is being increasingly used in the quantitative phenotyping of multienzyme drug biotransformations. Using lymphoblast-expressed cytochromes P450 (CYPs) and the tricyclic antidepressant amitriptyline as a model substrate, we have tested the hypothesis that the human liver microsomal rates of a biotransformation mediated by multiple CYP isoforms can be mathematically reconstructed from the rates of the biotransformation catalyzed by individual recombinant CYPs using the RAF approach, and that the RAF approach can be used for the in vitro-in vivo scaling of pharmacokinetic clearance from in vitro intrinsic clearance measurements in heterologous expression systems. In addition, we have compared the results of two widely used methods of quantitative reaction phenotyping, namely, chemical inhibition studies and the prediction of relative contributions of individual CYP isoforms using the RAF approach. For the pathways of N-demethylation (mediated by CYPs 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4) and E-10 hydroxylation (mediated by CYPs 2B6, 2D6, and 3A4), the model-predicted biotransformation rates in microsomes from a panel of 12 human livers determined from enzyme kinetic parameters of the recombinant CYPs were similar to, and correlated with the observed rates. The model-predicted clearance via N-demethylation was 53% lower than the previously reported in vivo pharmacokinetic estimates. Model-predicted relative contributions of individual CYP isoforms to the net biotransformation rate were similar to, and correlated with the fractional decrement in human liver microsomal reaction rates by chemical inhibitors of the respective CYPs, provided the chemical inhibitors used were specific to their target CYP isoforms.

Anti-austeric activity of phenolic constituents of seeds of Arctium lappa.

Science.gov (United States)

Tezuka, Yasuhiro; Yamamoto, Keiichi; Awale, Suresh; Lia, Feng; Yomoda, Satoshi; Kadota, Shigetoshi

2013-04-01

From seeds of Arctium lappa L. (Asteraceae) we obtained arctigenin (1), arctiin (2), chlorogenic acid (3), 4,5-dicaffeoylquinic acid (4), 3,5-dicaffeoylquinic acid (5), 3,4-dicaffeoylquinic acid (6), matairesinol (11), isolappaol A (12), lappaol F (14), and lappaol B (15), together with 1:1 mixtures of isolappaol C (7) and lappaol C (8), arctignan E (9) and arctignan D (10), and 12 and lappaol A (13), while 3,3',4'-tri-O-demethylarctigenin (16), 3,3'-di-O-demethyl-4'-dehydroxyarctigenin (17), and 3-O-demethylarctigenin (18) were obtained by anaerobic microbiological metabolism of 1. Then, we evaluated the in vitro preferential cytotoxic activity of these pure compounds and 1:1 mixtures, together with enterodiol (19) and enterolactone (20), against human pancreatic cancer PANC-1 cells in nutrient-deprived medium (NDM). Among them, 1 and 18 showed potent activity, with PC50 values of 1.75 and 4.38 microM, respectively, while 11, 15, and 17 showed mild activity with PC50 values of 31.1, 30.9, and 38.7 microM, respectively. By comparing their structures and PC50 values, the following structural moieties could be concluded to be important for the preferential cytotoxicity of 1: 1) the 3-hydroxy-4-methoxyphenyl group at the 2-position on the gamma-butyrolactone ring, 2) the less polar substituent at the 3-position on the gamma-butyrolactone ring, and 3) the gamma-butyrolactone ring.

Synthesis of radioactively methyl-labelled (1)-carnitine

International Nuclear Information System (INIS)

Ingalls, S.T.; Hoppel, C.L.; Turkaly, J.S.

1982-01-01

Commercial (l)-carnitine chloride was N-demethylated by the action of sodium benzenemercaptide in warm N,N-dimethylformamide. The product 4-(N,N-dimethylammonio)-3-hydroxybutanoic acid chloride salt was isolated in good yield by ion exchange chromatography. Methylation of the product by 14 C -iodomethane in dry methanol produced biologically active 4-N-Me- 14 C -(l)-carnitine chloride of high specific activity in excellent yield. (author)

Three New Malyngamides from the Marine Cyanobacterium Moorea producens

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Kosuke Sueyoshi

2017-11-01

Full Text Available Three new compounds of the malyngamide series, 6,8-di-O-acetylmalyngamide 2 (1, 6-O-acetylmalyngamide 2 (2, and N-demethyl-isomalyngamide I (3, were isolated from the marine cyanobacterium Moorea producens. Their structures were determined by spectroscopic analysis and chemical derivatization and degradation. These compounds stimulated glucose uptake in cultured L6 myotubes. In particular, 6,8-di-O-acetylmalyngamide 2 (1 showed potent activity and activated adenosine monophosphate-activated protein kinase (AMPK.

Restricted mobility of Dnmt1 in preimplantation embryos: implications for epigenetic reprogramming

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Grohmann, Maik; Spada, Fabio; Schermelleh, Lothar; Alenina, Natalia; Bader, Michael; Cardoso, M Cristina; Leonhardt, Heinrich

2005-01-01

Background Mouse preimplantation development is characterized by both active and passive genomic demethylation. A short isoform of the prevalent maintenance DNA methyltransferase (Dnmt1S) is found in the cytoplasm of preimplantation embryos and transiently enters the nucleus only at the 8-cell stage. Results Using GFP fusions we show that both the long and short isoforms of Dnmt1 localize to the nucleus of somatic cells and the cytoplasm of preimplantation embryos and that these subcellular localization properties are independent of phosphorylation. Importantly, photobleaching techniques and salt extraction revealed that Dnmt1S has a very restricted mobility in the cytoplasm, while it is highly mobile in the nucleus of preimplantation embryos. Conclusion The restricted mobility of Dnmt1S limits its access to DNA and likely contributes to passive demethylation and epigenetic reprogramming during preimplantationdevelopment. PMID:16120212

DNA unwinding by ASCC3 helicase is coupled to ALKBH3 dependent DNA alkylation repair and cancer cell proliferation

Science.gov (United States)

Dango, Sebastian; Mosammaparast, Nima; Sowa, Mathew E.; Xiong, Li-Jun; Wu, Feizhen; Park, Keyjung; Rubin, Mark; Gygi, Steve; Harper, J. Wade; Shi, Yang

2011-01-01

Summary Demethylation by the AlkB dioxygenases represents an important mechanism for repair of N-alkylated nucleotides. However, little is known about their functions in mammalian cells. We report the purification of the ALKBH3 complex and demonstrate its association with the Activating Signal Co-integrator Complex (ASCC). ALKBH3 is overexpressed in various cancers, and both ALKBH3 and ASCC are important for alkylation damage resistance in these tumor cell lines. ASCC3, the largest subunit of ASCC, encodes a 3′-5′ DNA helicase, whose activity is crucial for the generation of single-stranded DNA upon which ALKBH3 preferentially functions for dealkylation. In cell lines that are dependent on ALKBH3 and ASCC3 for alkylation damage resistance, loss of ALKBH3 or ASCC3 leads to increased 3-methylcytosine and reduced cell proliferation, which correlates with pH2A.X and 53BP1 foci formation. Our data provide a molecular mechanism by which ALKBH3 collaborates with ASCC to maintain genomic integrity in a cell type specific manner. PMID:22055184

Stereoselective biodegradation of tricyclic terpanes in heavy oils from the Bolivar Coastal Fields, Venezuela

Energy Technology Data Exchange (ETDEWEB)

Alberdi, M. [Stanford University (United States). Dept. of Geological and Environmental Sciences; PDVSA-Intevep, Caracas (Venezuela); Moldowan, J.M.; Dahl, J.E. [Stanford University (United States). Dept. of Geological and Environmental Sciences; Peters, K.E. [Mobil Technology Co., Dallas, TX (United States)

2001-07-01

Gas chromatography-mass spectrometry (GC-MS) and GC-MS-MS analyses of heavy oils from Bolivar Coastal Fields (Lagunillas Field) show a complete set of demethylated tricyclic terpanes. As is the case for the 25-norhopanes, the demethylated tricyclics are probably formed in reservoirs by microbially-mediated removal of the methyl group from the C-10 position, generating putative 17-nor-tricyclic terpanes. Diastereomeric pairs of tricyclic terpanes are resolved above C{sub 24} due to resolution of 22S and 22R epimers, but the elution order of the 22S and 22R epimers is unknown. Early-eluting diastereomers (EE) predominate over late-eluting diastereomers (LE) (C{sub 25}-C{sub 29}) in the heavily degraded oils, indicating a stereoselective preference for the LE stereoisomers during biodegradation. Conversely, the LE diastereomers predominate over the EE diastereomers in the 17-nor tricyclic series (C{sub 24}-C{sub 28}), indicating that tricyclic terpanes and 17-nor-tricyclic terpanes are directly linked as precursors and products, respectively. A good correlation exists between the destruction of steranes and the demethylation of hopanes and tricyclic terpanes. This suggests that terpane demethylation occurs during sterane destruction and hopane demethylation, although the rate is slower, indicating that tricyclic terpanes are more resistant to biodegradation. (Author)

A plasmaless, photochemical etch process for porous organosilicate glass films

Science.gov (United States)

Ryan, E. Todd; Molis, Steven E.

2017-12-01

A plasmaless, photochemical etch process using ultraviolet (UV) light in the presence of NH3 or O2 etched porous organosilicate glass films, also called pSiCOH films, in a two-step process. First, a UV/NH3 or UV/O2 treatment removed carbon (mostly methyl groups bonded to silicon) from a pSiCOH film by demethylation to a depth determined by the treatment exposure time. Second, aqueous HF was used to selectively remove the demethylated layer of the pSiCOH film leaving the methylated layer below. UV in the presence of inert gas or H2 did not demethylate the pSiCOH film. The depth of UV/NH3 demethylation followed diffusion limited kinetics and possible mechanisms of demethylation are presented. Unlike reactive plasma processes, which contain ions that can damage surrounding structures during nanofabrication, the photochemical etch contains no damaging ions. Feasibility of the photochemical etching was shown by comparing it to a plasma-based process to remove the pSiCOH dielectric from between Cu interconnect lines, which is a critical step during air gap fabrication. The findings also expand our understanding of UV photon interactions in pSiCOH films that may contribute to plasma-induced damage to pSiCOH films.

Determinants of orofacial clefting II: Effects of 5-Aza-2'-deoxycytidine on gene methylation during development of the first branchial arch.

Science.gov (United States)

Seelan, Ratnam S; Mukhopadhyay, Partha; Warner, Dennis R; Smolenkova, Irina A; Pisano, M Michele; Greene, Robert M

2017-01-01

Defects in development of the secondary palate, which arise from the embryonic first branchial arch (1-BA), can cause cleft palate (CP). Administration of 5-Aza-2'-deoxycytidine (AzaD), a demethylating agent, to pregnant mice on gestational day 9.5 resulted in complete penetrance of CP in fetuses. Several genes critical for normal palatogenesis were found to be upregulated in 1-BA, 12h after AzaD exposure. MethylCap-Seq (MCS) analysis identified several differentially methylated regions (DMRs) in DNA extracted from AzaD-exposed 1-BAs. Hypomethylated DMRs did not correlate with the upregulation of genes in AzaD-exposed 1-BAs. However, most DMRs were associated with endogenous retroviral elements. Expression analyses suggested that interferon signaling was activated in AzaD-exposed 1-BAs. Our data, thus, suggest that a 12-h in utero AzaD exposure demethylates and activates endogenous retroviral elements in the 1-BA, thereby triggering an interferon-mediated response. This may result in the dysregulation of key signaling pathways during palatogenesis, causing CP. Copyright © 2016 Elsevier Inc. All rights reserved.

Representativeness of the IAGOS airborne measurements in the lower troposphere

OpenAIRE

Petetin, H.; Jeoffrion, M.; Sauvage, B.; Athier, G.; Blot, R.; Boulanger, D.; Clark, H.; Cousin, J.-M.; Gheusi, F.; Nedelec, P.; Steinbacher, M.; Thouret, V.

2018-01-01

In the framework of the In Service Aircraft for Global Observing System (IAGOS) program, airborne in-situ O3 and CO measurements are performed routinely using in-service aircraft, providing vertical profiles from the surface to about 10–12 km. Due to the specificity of IAGOS measurements (measurements around busy international airports), uncertainties exist on their representativeness in the lower troposphere as they may be impacted by emissions related to airport activities and/or other air...

Perceived and Objective Measures of Neighborhood Walkability and Physical Activity among Adults in Japan: A Multilevel Analysis of a Nationally Representative Sample.

Science.gov (United States)

Hanibuchi, Tomoya; Nakaya, Tomoki; Yonejima, Mayuko; Honjo, Kaori

2015-10-23

Although associations between a person's neighborhood and their health have been studied internationally, most studies have been limited to a few cities or towns. Therefore, we used a nationally representative sample to explore whether perceived and objective neighborhood walkability was associated with the physical activity of residents. Data were analyzed from the Japanese General Social Surveys of 2010 (n = 2395; 1114 men and 1281 women). Perceived walkability was scored using factor analysis for the respondents' perceptions of neighborhood conditions, while objective walkability was measured using the geographic information system approach. Finally, multilevel logistic regression analysis was performed to examine whether neighborhood walkability was associated with the frequency of leisure-time physical activity (LTPA) among respondents. We found that perceived walkability was positively associated with the frequency of LTPA (odds ratio of the highest quartile was 1.53 (1.14-2.05) compared with the lowest quartile); however, objective walkability showed no association. When stratified by gender, an association between perceived walkability and LTPA was observed among women, but only a marginally significant association was present between objective walkability and LTPA among men. We conclude that the association between neighborhood walkability and LTPA can be partially generalized across Japan.

Recruitment of representative samples for low incidence cancer populations: Do registries deliver?

Directory of Open Access Journals (Sweden)

Sanson-Fisher Rob

2011-01-01

Full Text Available Abstract Background Recruiting large and representative samples of adolescent and young adult (AYA cancer survivors is important for gaining accurate data regarding the prevalence of unmet needs in this population. This study aimed to describe recruitment rates for AYAs recruited through a cancer registry with particular focus on: active clinician consent protocols, reasons for clinicians not providing consent and the representativeness of the final sample. Methods Adolescents and young adults aged 14 to19 years inclusive and listed on the cancer registry from January 1 2002 to December 31 2007 were identified. An active clinician consent protocol was used whereby the registry sent a letter to AYAs primary treating clinicians requesting permission to contact the survivors. The registry then sent survivors who received their clinician's consent a letter seeking permission to forward their contact details to the research team. Consenting AYAs were sent a questionnaire which assessed their unmet needs. Results The overall consent rate for AYAs identified as eligible by the registry was 7.8%. Of the 411 potentially eligible survivors identified, just over half (n = 232, 56% received their clinician's consent to be contacted. Of those 232 AYAs, 65% were unable to be contacted. Only 18 AYAs (7.8% refused permission for their contact details to be passed on to the research team. Of the 64 young people who agreed to be contacted, 50% (n = 32 completed the questionnaire. Conclusions Cancer registries which employ active clinician consent protocols may not be appropriate for recruiting large, representative samples of AYAs diagnosed with cancer. Given that AYA cancer survivors are highly mobile, alternative methods such as treatment centre and clinic based recruitment may need to be considered.

Representative Model of the Learning Process in Virtual Spaces Supported by ICT

Science.gov (United States)

Capacho, José

2014-01-01

This paper shows the results of research activities for building the representative model of the learning process in virtual spaces (e-Learning). The formal basis of the model are supported in the analysis of models of learning assessment in virtual spaces and specifically in Dembo´s teaching learning model, the systemic approach to evaluating…

Nodulation of legumes, nitrogenase activity of roots and occurrence of nitrogen-fixing Azospirillum spp. In representative soils of central Amazonia

Energy Technology Data Exchange (ETDEWEB)

Sylvester-Bradley, R; De Oliverira, L A; De Podesta Filho, J A; John, T V

1980-12-01

Leguminosae do not predominate in the Brazilian Amazon rain forest, although they are among the five best represented families. Plant roots from various soils were examined for the presence of nodules, acetylene-reducing activity and N/sub 2/-fixing Azospirillum spp. Abundant nodulation was found in black earth (''terra preta dos indios'') and in one case on sandy soil under campinarana vegetation along a tributary of the upper Rio Negro. In sandy latosol some nodules occurred in secondary forest and fewer in primary forest. Legumes in disturbed clayey or sandy latosol showed more frequent nodulation. Primary forest on alluvial (''varzea'') soil, and in Bahia coastal rain forest on sandy latosol and Erythrina glauca used for shading cacao plantations were abundantly nodulated. Acetylene reduction assays showed no, or very little, nitrogenase activity of roots from primary or secondary forest on clayey latosol near Manaus. Nodulated roots from secondary forest on sandy latosol showed acetylene-reducing activity. High rates of acetylene reduction were observed in nodulated roots of primary forest on alluvial ''varzea'' soil. Root samples showed ethylene absorption in controls without acetylene which might interfere with the results of acetylene reduction tests. The incidence of Azospirillum was also higher in black earth than the other soils examined, and in soils with higher pH. The hypothesis that Azospirillum is associated with Trema micantha roots was refuted. Roots and soils collected under cultivated grasses showed a higher incidence of Azospirillum when fertilized with phosphorus and lime. Results indicate that nitrogen fixation did occur in association with roots in some soils, but not with roots of primary or secondary forest on clayey latosol in the vicinity of Manaus, which is the most common soil in Central Amazonia. The possible reasons for this are discussed.

OSMOSE experiment representativity studies.

Energy Technology Data Exchange (ETDEWEB)

Aliberti, G.; Klann, R.; Nuclear Engineering Division

2007-10-10

The OSMOSE program aims at improving the neutronic predictions of advanced nuclear fuels through measurements in the MINERVE facility at the CEA-Cadarache (France) on samples containing the following separated actinides: Th-232, U-233, U-234, U-235, U-236, U-238, Np-237, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, Am-243, Cm-244 and Cm-245. The goal of the experimental measurements is to produce a database of reactivity-worth measurements in different neutron spectra for the separated heavy nuclides. This database can then be used as a benchmark for integral reactivity-worth measurements to verify and validate reactor analysis codes and integral cross-section values for the isotopes tested. In particular, the OSMOSE experimental program will produce very accurate sample reactivity-worth measurements for a series of actinides in various spectra, from very thermalized to very fast. The objective of the analytical program is to make use of the experimental data to establish deficiencies in the basic nuclear data libraries, identify their origins, and provide guidelines for nuclear data improvements in coordination with international programs. To achieve the proposed goals, seven different neutron spectra can be created in the MINERVE facility: UO2 dissolved in water (representative of over-moderated LWR systems), UO2 matrix in water (representative of LWRs), a mixed oxide fuel matrix, two thermal spectra containing large epithermal components (representative of under-moderated reactors), a moderated fast spectrum (representative of fast reactors which have some slowing down in moderators such as lead-bismuth or sodium), and a very hard spectrum (representative of fast reactors with little moderation from reactor coolant). The different spectra are achieved by changing the experimental lattice within the MINERVE reactor. The experimental lattice is the replaceable central part of MINERVE, which establishes the spectrum at the sample location. This configuration

Chiral analyses of dextromethorphan/levomethorphan and their metabolites in rat and human samples using LC-MS/MS.

Science.gov (United States)

Kikura-Hanajiri, Ruri; Kawamura, Maiko; Miyajima, Atsuko; Sunouchi, Momoko; Goda, Yukihiro

2011-04-01

In order to develop an analytical method for the discrimination of dextromethorphan (an antitussive medicine) from its enantiomer, levomethorphan (a narcotic) in biological samples, chiral analyses of these drugs and their O-demethyl and/or N-demethyl metabolites in rat plasma, urine, and hair were carried out using LC-MS/MS. After the i.p. administration of dextromethorphan or levomethorphan to pigmented hairy male DA rats (5 mg/kg/day, 10 days), the parent compounds and their three metabolites in plasma, urine and hair were determined using LC-MS/MS. Complete chiral separation was achieved in 12 min on a Chiral CD-Ph column in 0.1% formic acid-acetonitrile by a linear gradient program. Most of the metabolites were detected as being the corresponding O-demethyl and N, O-didemethyl metabolites in the rat plasma and urine after the hydrolysis of O-glucuronides, although obvious differences in the amounts of these metabolites were found between the dextro and levo forms. No racemation was observed through O- and/or N-demethylation. In the rat hair samples collected 4 weeks after the first administration, those differences were more clearly detected and the concentrations of the parent compounds, their O-demethyl, N-demethyl, and N, O-didemethyl metabolites were 63.4, 2.7, 25.1, and 0.7 ng/mg for the dextro forms and 24.5, 24.6, 2.6, and 0.5 ng/mg for the levo forms, respectively. In order to fully investigate the differences of their metabolic properties between dextromethorphan and levomethorphan, DA rat and human liver microsomes were studied. The results suggested that there might be an enantioselective metabolism of levomethorphan, especially with regard to the O-demethylation, not only in DA rat but human liver microsomes as well. The proposed chiral analyses might be applied to human samples and could be useful for discriminating dextromethorphan use from levomethorphan use in the field of forensic toxicology, although further studies should be carried out

Representing Uncertainty by Probability and Possibility

DEFF Research Database (Denmark)

of uncertain parameters. Monte Carlo simulation is readily used for practical calculations. However, an alternative approach is offered by possibility theory making use of possibility distributions such as intervals and fuzzy intervals. This approach is well suited to represent lack of knowledge or imprecision......Uncertain parameters in modeling are usually represented by probability distributions reflecting either the objective uncertainty of the parameters or the subjective belief held by the model builder. This approach is particularly suited for representing the statistical nature or variance...

Synthesis and Antiproliferative Activity of Minor Hops Prenylflavonoids and New Insights on Prenyl Group Cyclization

Directory of Open Access Journals (Sweden)

Jarosław Popłoński

2018-03-01

Full Text Available Synthesis of minor prenylflavonoids found in hops and their non-natural derivatives were performed. The antiproliferative activity of the obtained compounds against some human cancer cell lines was investigated. Using xanthohumol isolated from spent hops as a lead compound, a series of minor hop prenylflavonoids and synthetic derivatives were obtained by isomerization, cyclisation, oxidative-cyclisation, oxidation, reduction and demethylation reactions. Three human cancer cell lines—breast (MCF-7, prostate (PC-3 and colon (HT-29—were used in antiproliferative assays, with cisplatin as a control compound. Five minor hop prenyl flavonoids and nine non-natural derivatives of xanthohumol have been synthetized. Syntheses of xanthohumol K, its dihydro- and tetrahydro-derivatives and 1″,2″,α,β-tetrahydroxanthohumol C were described for the first time. All of the minor hops prenyl flavonoids exhibited strong to moderate antiproliferative activity in vitro. The minor hops flavonoids xanthohumol C and 1″,2″-dihydroxanthohumol K and non-natural 2,3-dehydroisoxanthohumol exhibited the activity comparable to cisplatin. Results described in the article suggest that flavonoids containing chromane- and chromene-like moieties, especially chalcones, are potent antiproliferative agents. The developed new efficient, regioselective cyclisation reaction of the xanthohumol prenyl group to 1″,2″-dihydroxantohumol K may be used in the synthesis of other compounds with the chromane moiety.

Metabolism of femoxetine

International Nuclear Information System (INIS)

Larsson, H.; Lund, J.

1981-01-01

The metabolism of femoxetine, a serotonin uptake inhibitor, has been investigated in rats, dogs, monkeys, and human subjects using two 14 C-femoxetine compounds with labelling in different positions. The metabolic pathways were oxidations (and glucuronidation) and demethylation, both reactions most probably taking place in the liver. Nearly all femoxetine was metabolised, and the same metabolites were found in urine from all four species. Only a small percentage of the radioactivity excreted in the urine was not identified. Rat and dog excreted more N-oxide than monkey and man, while most of the radioactivity (60-100%) in these two species was excreted as two hydroxy metabolites. The metabolic pattern in monkey and man was very similar. About 50% was excreted in these two species as one metabolite, formed by demethylation of a methoxy group. A demethylation of a N-CH 3 group formed an active metabolite, norfemoxetine. The excretion of this metabolite in urine from man varied from 0 to 18% of the dose between individuals. Most of the radioactivity was excreted with the faeces in rat and dog, while monkey and man excreted most of the radioactivity in urine. This difference in excretion route might be explained by the difference in the metabolic pattern. No dose dependency was observed in any of the three animal species investigated. (author)

Circulating Differentially Methylated Amylin DNA as a Biomarker of β-Cell Loss in Type 1 Diabetes.

Directory of Open Access Journals (Sweden)

John A Olsen

Full Text Available In type 1 diabetes (T1D, β-cell loss is silent during disease progression. Methylation-sensitive quantitative real-time PCR (qPCR of β-cell-derived DNA in the blood can serve as a biomarker of β-cell death in T1D. Amylin is highly expressed by β-cells in the islet. Here we examined whether demethylated circulating free amylin DNA (cfDNA may serve as a biomarker of β-cell death in T1D. β cells showed unique methylation patterns within the amylin coding region that were not observed with other tissues. The design and use of methylation-specific primers yielded a strong signal for demethylated amylin in purified DNA from murine islets when compared with other tissues. Similarly, methylation-specific primers detected high levels of demethylated amylin DNA in human islets and enriched human β-cells. In vivo testing of the primers revealed an increase in demethylated amylin cfDNA in sera of non-obese diabetic (NOD mice during T1D progression and following the development of hyperglycemia. This increase in amylin cfDNA did not mirror the increase in insulin cfDNA, suggesting that amylin cfDNA may detect β-cell loss in serum samples where insulin cfDNA is undetected. Finally, purified cfDNA from recent onset T1D patients yielded a high signal for demethylated amylin cfDNA when compared with matched healthy controls. These findings support the use of demethylated amylin cfDNA for detection of β-cell-derived DNA. When utilized in conjunction with insulin, this latest assay provides a comprehensive multi-gene approach for the detection of β-cell loss.

40 CFR 72.22 - Alternate designated representative.

Science.gov (United States)

2010-07-01

... designated representative is selected shall include a procedure for the owners and operators of the source and affected units at the source to authorize the alternate designated representative to act in lieu...) In the event of a conflict, any action taken by the designated representative shall take precedence...

Representativeness and seasonality of major ion records derived from NEEM firn cores

Directory of Open Access Journals (Sweden)

G. Gfeller

2014-10-01

Full Text Available The seasonal and annual representativeness of ionic aerosol proxies (among others, calcium, sodium, ammonium and nitrate in various firn cores in the vicinity of the NEEM drill site in northwest Greenland have been assessed. Seasonal representativeness is very high as one core explains more than 60% of the variability within the area. The inter-annual representativeness, however, can be substantially lower (depending on the species making replicate coring indispensable to derive the atmospheric variability of aerosol species. A single core at the NEEM site records only 30% of the inter-annual atmospheric variability in some species, while five replicate cores are already needed to cover approximately 70% of the inter-annual atmospheric variability in all species. The spatial representativeness is very high within 60 cm, rapidly decorrelates within 10 m but does not diminish further within 3 km. We attribute this to wind reworking of the snow pack leading to sastrugi formation. Due to the high resolution and seasonal representativeness of the records we can derive accurate seasonalities of the measured species for modern (AD 1990–2010 times as well as for pre-industrial (AD 1623–1750 times. Sodium and calcium show similar seasonality (peaking in February and March respectively for modern and pre-industrial times, whereas ammonium and nitrate are influenced by anthropogenic activities. Nitrate and ammonium both peak in May during modern times, whereas during pre-industrial times ammonium peaked during July–August and nitrate during June–July.

Representative Sampling for reliable data analysis

DEFF Research Database (Denmark)

Petersen, Lars; Esbensen, Kim Harry

2005-01-01

regime in order to secure the necessary reliability of: samples (which must be representative, from the primary sampling onwards), analysis (which will not mean anything outside the miniscule analytical volume without representativity ruling all mass reductions involved, also in the laboratory) and data...

OAS :: Authorities : Permanent Representatives to the OAS

Science.gov (United States)

Rights Actions against Corruption C Children Civil Registry Civil Society Contact Us Culture Cyber Representative of Belize Diego Pary Rodríguez Bolivia Diego Pary Rodríguez Ambassador, Permanent Representative of Bolivia José Luiz Machado Brazil José Luiz Machado e Costa Ambassador, Permanent Representative

List of Accredited Representatives

Data.gov (United States)

Department of Veterans Affairs — VA accreditation is for the sole purpose of providing representation services to claimants before VA and does not imply that a representative is qualified to provide...

Understanding the determinants of selectivity in drug metabolism through modeling of dextromethorphan oxidation by cytochrome P450

Science.gov (United States)

Oláh, Julianna; Mulholland, Adrian J.; Harvey, Jeremy N.

2011-01-01

Cytochrome P450 enzymes play key roles in the metabolism of the majority of drugs. Improved models for prediction of likely metabolites will contribute to drug development. In this work, two possible metabolic routes (aromatic carbon oxidation and O-demethylation) of dextromethorphan are compared using molecular dynamics (MD) simulations and density functional theory (DFT). The DFT results on a small active site model suggest that both reactions might occur competitively. Docking and MD studies of dextromethorphan in the active site of P450 2D6 show that the dextromethorphan is located close to heme oxygen in a geometry apparently consistent with competitive metabolism. In contrast, calculations of the reaction path in a large protein model [using a hybrid quantum mechanical–molecular mechanics (QM/MM) method] show a very strong preference for O-demethylation, in accordance with experimental results. The aromatic carbon oxidation reaction is predicted to have a high activation energy, due to the active site preventing formation of a favorable transition-state structure. Hence, the QM/MM calculations demonstrate a crucial role of many active site residues in determining reactivity of dextromethorphan in P450 2D6. Beyond substrate binding orientation and reactivity of Compound I, successful metabolite predictions must take into account the detailed mechanism of oxidation in the protein. These results demonstrate the potential of QM/MM methods to investigate specificity in drug metabolism. PMID:21444768

Verification of Representative Sampling in RI waste

International Nuclear Information System (INIS)

Ahn, Hong Joo; Song, Byung Cheul; Sohn, Se Cheul; Song, Kyu Seok; Jee, Kwang Yong; Choi, Kwang Seop

2009-01-01

For evaluating the radionuclide inventories for RI wastes, representative sampling is one of the most important parts in the process of radiochemical assay. Sampling to characterized RI waste conditions typically has been based on judgment or convenience sampling of individual or groups. However, it is difficult to get a sample representatively among the numerous drums. In addition, RI waste drums might be classified into heterogeneous wastes because they have a content of cotton, glass, vinyl, gloves, etc. In order to get the representative samples, the sample to be analyzed must be collected from selected every drum. Considering the expense and time of analysis, however, the number of sample has to be minimized. In this study, RI waste drums were classified by the various conditions of the half-life, surface dose, acceptance date, waste form, generator, etc. A sample for radiochemical assay was obtained through mixing samples of each drum. The sample has to be prepared for radiochemical assay and although the sample should be reasonably uniform, it is rare that a completely homogeneous material is received. Every sample is shredded by a 1 ∼ 2 cm 2 diameter and a representative aliquot taken for the required analysis. For verification of representative sampling, classified every group is tested for evaluation of 'selection of representative drum in a group' and 'representative sampling in a drum'

Design and evaluation of representative indoor radon surveys

International Nuclear Information System (INIS)

Csige, I.; Csegzi, S.

2004-01-01

We have developed a procedure to design and evaluate representative indoor radon surveys. The procedure is based on random sampling of a population of houses and careful statistical analysis of measured indoor radon concentrations. The method is designed to estimate the fraction of houses in which annual average 222 Rn activity concentration may exceed a certain reference level. Measurements of annual average indoor 222 Rn activity concentration were done in sleeping rooms at pillow level using etched track type radon detectors. We applied the above procedure in an old fashioned village and in a fast developing small city in Transylvania, Romania. In the village almost all houses were single floor wooden made houses without cellar built with traditional technology on a geologically uniform area. The distribution of indoor 222 Rn activity concentration in a sample of 115 houses can almost perfectly be fitted with log-normal probability density function. The correlation coefficient of linear fitting on linearized scales was k = -0.9980. The percentages of houses expected to have annual average 222 Rn activity concentration higher than 400 Bq m -3 is less than 1 %, and of those higher than 600 Bq m -3 can be estimated to be around 0.1 %. The small city, on the other hand lies on a geologically inhomogeneous area, and house construction technology has also changed dramatically in past decades. The resulting distribution of measured indoor 222 Rn activity concentration in a sample of 116 houses cannot be fitted with any simple probability density function. Therefore the prediction of the fraction of houses in which the annual average 222 Rn activity concentration may exceed a certain reference level could not be done adequately. With certain assumptions we estimated that the percentages of houses expected to have annual average 222 Rn activity concentration higher than 400 Bq m -3 is between 3 and 7 %, and of those higher than 600 Bq m -3 can be estimated to be between

The flexible loop L1 of the H3K4 demethylase JARID1B ARID domain has a crucial role in DNA-binding activity

International Nuclear Information System (INIS)

Yao, Wenming; Peng, Yu; Lin, Donghai

2010-01-01

JARID1B, a member of the JmjC demethylase family, has a crucial role in H3K4me3 demethylation. The ARID domain is a potential DNA-binding domain of JARID1B. Previous studies indicate that a GC-rich DNA motif is the specific target of the ARID domain. However, the details of the interaction between the ARID domain and duplex DNA require further study. Here, we utilized NMR spectroscopy to assign the backbone amino acids and mapped the DNA-binding sites of the human JARID1B ARID domain. Perturbations to 1 H- 15 N correlation spectra revealed that the flexible loop L1 of ARID was the main DNA-binding interface. EMSA and intrinsic fluorescence experiments demonstrated that mutations on loop L1 strongly reduced the DNA-binding activity of JARID1B ARID. Furthermore, transfection of mutant forms resulted in a distinct loss of intrinsic H3K4 demethylase activity, implying that the flexible loop L1 made a major contribution to sustaining the DNA-binding ability of JARID1B ARID domain.

Representative process sampling - in practice

DEFF Research Database (Denmark)

Esbensen, Kim; Friis-Pedersen, Hans Henrik; Julius, Lars Petersen

2007-01-01

Didactic data sets representing a range of real-world processes are used to illustrate "how to do" representative process sampling and process characterisation. The selected process data lead to diverse variogram expressions with different systematics (no range vs. important ranges; trends and....../or periodicity; different nugget effects and process variations ranging from less than one lag to full variogram lag). Variogram data analysis leads to a fundamental decomposition into 0-D sampling vs. 1-D process variances, based on the three principal variogram parameters: range, sill and nugget effect...

Stromal cells expressing hedgehog-interacting protein regulate the proliferation of myeloid neoplasms

International Nuclear Information System (INIS)

Kobune, M; Iyama, S; Kikuchi, S; Horiguchi, H; Sato, T; Murase, K; Kawano, Y; Takada, K; Ono, K; Kamihara, Y; Hayashi, T; Miyanishi, K; Sato, Y; Takimoto, R; Kato, J

2012-01-01

Aberrant reactivation of hedgehog (Hh) signaling has been described in a wide variety of human cancers including cancer stem cells. However, involvement of the Hh-signaling system in the bone marrow (BM) microenvironment during the development of myeloid neoplasms is unknown. In this study, we assessed the expression of Hh-related genes in primary human CD34 + cells, CD34 + blastic cells and BM stromal cells. Both Indian Hh (Ihh) and its signal transducer, smoothened (SMO), were expressed in CD34 + acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS)-derived cells. However, Ihh expression was relatively low in BM stromal cells. Remarkably, expression of the intrinsic Hh-signaling inhibitor, human Hh-interacting protein (HHIP) in AML/MDS-derived stromal cells was markedly lower than in healthy donor-derived stromal cells. Moreover, HHIP expression levels in BM stromal cells highly correlated with their supporting activity for SMO + leukemic cells. Knockdown of HHIP gene in stromal cells increased their supporting activity although control cells marginally supported SMO + leukemic cell proliferation. The demethylating agent, 5-aza-2′-deoxycytidine rescued HHIP expression via demethylation of HHIP gene and reduced the leukemic cell-supporting activity of AML/MDS-derived stromal cells. This indicates that suppression of stromal HHIP could be associated with the proliferation of AML/MDS cells

Participation in Leisure Activities among Canadian Children with Arthritis: Results from a National Representative Sample.

Science.gov (United States)

Cavallo, Sabrina; Majnemer, Annette; Mazer, Barbara; Chilingaryan, Gevorg; Ehrmann Feldman, Debbie

2015-06-01

To describe the level of participation in leisure activities among children and youth with arthritis, as well as to identify the sociodemographic (age, sex, family income), disease-related (functional limitations, disease duration, pain, medication use, child's need for assistance), and contextual factors (use of rehabilitation services, proximity of local recreation facilities, cost of activities) that may be associated. Data from the Participation and Activity Limitation Survey (PALS) 2006, a Canadian postcensus survey, was analyzed. Bivariate and multivariable linear regression analyses were applied to examine the associations between the sample's level of participation in leisure activities, and sociodemographic, disease-related, and contextual characteristics. In Canada in 2006, an estimated 4350 children ranging in age from 5 to 14 years were living with arthritis. Fifty-six percent of parents reported that arthritis restricted their child's participation in leisure activities. Bivariate analysis showed that the availability of local recreational facilities, the affordability of activities, and the child not requiring any assistance were all associated (modified Bonferroni correction α leisure activities. Multiple linear regressions showed that higher family income (β 0.47, 95% CI 0.09, 0.85) and greater perceived pain (β 0.59, 95% CI 0.07, 1.10) were positively associated with involvement in informal leisure. Our findings underline the importance of considering contextual factors in developing treatment plans aimed at improving participation in leisure activities among children with arthritis. Future longitudinal studies targeting children living with arthritis could provide pertinent information on participation over fluctuations in disease status.

Evaluation of methylmercury biotransformation using rat liver slices

Energy Technology Data Exchange (ETDEWEB)

Yasutake, A. [Biochemistry Section, National Inst. for Minamata Disease, Minamata, Kumamoto (Japan); Hirayama, K. [Kumamoto University College of Medical Science, Kuhonji (Japan)

2001-09-01

To examine the demethylation reaction of methylmercury (MeHg) in rat liver, slices prepared from MeHg-treated rats were incubated in L-15 medium under 95% O{sub 2}/5% CO{sub 2} atmosphere. During the incubation, the amount of inorganic Hg in the slices markedly increased in a time-dependent manner, although the concentration of total Hg remained unchanged. Since the C-Hg bond in MeHg was demonstrated to be cleaved by the action of some reactive oxygen species, the effects on MeHg demethylation of several reagents that could modify reactive oxygen production were examined in the present system. Methylviologen was found to be an effective enhancer of the demethylation reaction with only a minor effect on lipid peroxidation. On the other hand, ferrous ion added to the medium showed no effect on demethylation in the presence or absence of methylviologen, although lipid peroxide levels were increased significantly by ferrous ion. Similarly, deferoxamine mesylate, which effectively suppressed the increase in lipid peroxide levels, also had no effect on demethylation. Furthermore, hydroxy radical scavengers, such as mannitol and dimethylsulfoxide, had no effect on inorganic Hg production. Rotenone, an inhibitor of complex I in the mitochondrial electron transport system, increased levels of both inorganic Hg and lipid peroxide. However, other inhibitors, such as antimycin A, myxothiazole and NaCN, significantly suppressed the demethylation reaction. Cell fractionation of the MeHg-treated rat liver revealed that the ratio of inorganic Hg to total Hg was highest in the mitochondrial fraction. Furthermore, superoxide anion could degrade MeHg in an organic solvent but not in water. These results suggested that the demethylation of MeHg by the liver slice would proceed with the aid of superoxide anion produced in the electron transfer system at the hydrophobic mitochondrial inner membrane. Furthermore, the involvement of hydroxy radicals, which have been demonstrated to be

Using Common Graphics Paradigms Implemented in a Java Applet to Represent Complex Scheduling Requirements

Science.gov (United States)

Jaap, John; Meyer, Patrick; Davis, Elizabeth

1997-01-01

The experiments planned for the International Space Station promise to be complex, lengthy and diverse. The scarcity of the space station resources will cause significant competition for resources between experiments. The scheduling job facing the Space Station mission planning software requires a concise and comprehensive description of the experiments' requirements (to ensure a valid schedule) and a good description of the experiments' flexibility (to effectively utilize available resources). In addition, the continuous operation of the station, the wide geographic dispersion of station users, and the budgetary pressure to reduce operations manpower make a low-cost solution mandatory. A graphical representation of the scheduling requirements for station payloads implemented via an Internet-based application promises to be an elegant solution that addresses all of these issues. The graphical representation of experiment requirements permits a station user to describe his experiment by defining "activities" and "sequences of activities". Activities define the resource requirements (with alternatives) and other quantitative constraints of tasks to be performed. Activities definitions use an "outline" graphics paradigm. Sequences define the time relationships between activities. Sequences may also define time relationships with activities of other payloads or space station systems. Sequences of activities are described by a "network" graphics paradigm. The bulk of this paper will describe the graphical approach to representing requirements and provide examples that show the ease and clarity with which complex requirements can be represented. A Java applet, to run in a web browser, is being developed to support the graphical representation of payload scheduling requirements. Implementing the entry and editing of requirements via the web solves the problems introduced by the geographic dispersion of users. Reducing manpower is accomplished by developing a concise

The left IPL represents stored hand-postures for object use and action prediction

Directory of Open Access Journals (Sweden)

Michiel evan Elk

2014-04-01

Full Text Available Action semantics enables us to plan actions with objects and to predict others’ object-directed actions as well. Previous studies have suggested that action semantics are represented in a fronto-parietal action network that has also been implicated to play a role in action observation. In the present fMRI study it was investigated how activity within this network changes as a function of the predictability of an action involving multiple objects and requiring the use of action semantics. Participants performed an action prediction task in which they were required to anticipate the use of a centrally presented object that could be moved to an associated target object (e.g. hammer - nail. The availability of actor information (i.e. presenting a hand grasping the central object and the number of possible target objects (i.e. 0, 1 or 2 target objects were independently manipulated, resulting in different levels of predictability. It was found that making an action prediction based on actor information resulted in an increased activation in the extrastriate body area (EBA and the fronto-parietal action observation network (AON. Predicting actions involving a target object resulted in increased activation in the bilateral IPL and frontal motor areas. Within the AON, activity in the left inferior parietal lobe (IPL and the left premotor cortex (PMC increased as a function of the level of action predictability. Together these findings suggest that the left IPL represents stored hand-postures that can be used for planning object-directed actions and for predicting other’s actions as well.

Gender differences in the associations of gambling activities and suicidal behaviors with problem gambling in a nationally representative French sample.

Science.gov (United States)

Husky, Mathilde M; Michel, Grégory; Richard, Jean-Baptiste; Guignard, Romain; Beck, François

2015-06-01

The objectives of the present study are to describe gender differences in factors associated with moderate risk and problem gambling. Data were extracted from the 2010 Health Barometer, a large survey on a representative sample of the general population aged 15-85 years living in France (n=27,653), carried out by the National Institute for Health Promotion and Health Education. Data were collected between October 2009 and July 2010. A computer-assisted telephone interview system was used. The findings indicate that men are three times more likely to experience problems with gambling. Men and women have different patterns of gambling activities. Men were more involved with Rapido, internet gambling, sports and racetrack betting, poker, and casino tables, whereas women gambled more often on scratch games. Both men and women engaging in immediate reward games were significantly more likely to experience difficulties with gambling. This association, however, was stronger in women. Furthermore, suicidal ideation and behaviors were more likely to be associated with gambling problems in women as compared to men. The study underscores the importance of considering gender-related differences in the study of gambling behaviors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Histone H3 Methylated at Arginine 17 Is Essential for Reprogramming the Paternal Genome in Zygotes

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Yuki Hatanaka

2017-09-01

Full Text Available At fertilization, the paternal genome undergoes extensive reprogramming through protamine-histone exchange and active DNA demethylation, but only a few maternal factors have been defined in these processes. We identified maternal Mettl23 as a protein arginine methyltransferase (PRMT, which most likely catalyzes the asymmetric dimethylation of histone H3R17 (H3R17me2a, as indicated by in vitro assays and treatment with TBBD, an H3R17 PRMT inhibitor. Maternal histone H3.3, which is essential for paternal nucleosomal assembly, is unable to be incorporated into the male pronucleus when it lacks R17me2a. Mettl23 interacts with Tet3, a 5mC-oxidizing enzyme responsible for active DNA demethylation, by binding to another maternal factor, GSE (gonad-specific expression. Depletion of Mettl23 from oocytes resulted in impaired accumulation of GSE, Tet3, and 5hmC in the male pronucleus, suggesting that Mettl23 may recruit GSE-Tet3 to chromatin. Our findings establish H3R17me2a and its catalyzing enzyme Mettl23 as key regulators of paternal genome reprogramming.

Antineoplastic activity of the DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine in anaplastic large cell lymphoma

Science.gov (United States)

Hassler, Melanie R.; Klisaroska, Aleksandra; Kollmann, Karoline; Steiner, Irene; Bilban, Martin; Schiefer, Ana-Iris; Sexl, Veronika; Egger, Gerda

2012-01-01

DNA methylation is an epigenetic mechanism establishing long-term gene silencing during development and cell commitment, which is maintained in subsequent cell generations. Aberrant DNA methylation is found at gene promoters in most cancers and can lead to silencing of tumor suppressor genes. The DNA methyltransferase inhibitor 5-aza-2′-deoxycytidine (5-aza-CdR) is able to reactivate genes silenced by DNA methylation and has been shown to be a very potent epigenetic drug in several hematological malignancies. In this report, we demonstrate that 5-aza-CdR exhibits high antineoplastic activity against anaplastic large cell lymphoma (ALCL), a rare CD30 positive non-Hodgkin lymphoma of T-cell origin. Low dose treatment of ALCL cell lines and xenografted tumors causes apoptosis and cell cycle arrest in vitro and in vivo. This is also reflected in genome-wide expression analyses, where genes related to apoptosis and cell death are amongst the most affected targets of 5-aza-CdR. Furthermore, we observed demethylation and re-expression of p16INK4A after drug administration and senescence associated β-galactosidase activity. Thus, our data provide evidence that 5-aza-CdR is highly efficient against ALCL and warrants further clinical evaluation for future therapeutic use. PMID:22687603

LAG-3 Represents a Marker of CD4+ T Cells with Regulatory Activity in Patients with Bone Fracture.

Science.gov (United States)

Wang, Jun; Ti, Yunfan; Wang, Yicun; Guo, Guodong; Jiang, Hui; Chang, Menghan; Qian, Hongbo; Zhao, Jianning; Sun, Guojing

2018-04-19

The lymphocyte activation gene 3 (LAG-3) is a CD4 homolog with binding affinity to MHC class II molecules. It is thought that LAG-3 exerts a bimodal function, such that co-ligation of LAG-3 and CD3 could deliver an inhibitory signal in conventional T cells, whereas, on regulatory T cells, LAG-3 expression could promote their inhibitory function. In this study, we investigated the role of LAG-3 expression on CD4 + T cells in patients with long bone fracture. We found that LAG-3 + cells represented approximately 13% of peripheral blood CD4 + T cells on average. Compared to LAG-3 - CD4 + T cells, LAG-3 + CD4 + T cells presented significantly higher Foxp3 and CTLA-4 expression. Directly ex vivo or with TCR stimulation, LAG-3 + CD4 + T cells expressed significantly higher levels of IL-10 and TGF-β than LAG-3 - CD4 + T cells. Interestingly, blocking the LAG-3-MHC class II interaction actually increased the IL-10 expression by LAG-3 + CD4 + T cells. The frequency of LAG-3 + CD4 + T cell was positively correlated with restoration of healthy bone function in long bone fracture patients. These results together suggested that LAG-3 is a marker of CD4 + T cells with regulatory function; at the same time, LAG-3 might have limited the full suppressive potential of Treg cells.

Disruption of the Fanconi anemia-BRCA pathway in cisplatin-sensitive ovarian tumors.

Science.gov (United States)

Taniguchi, Toshiyasu; Tischkowitz, Marc; Ameziane, Najim; Hodgson, Shirley V; Mathew, Christopher G; Joenje, Hans; Mok, Samuel C; D'Andrea, Alan D

2003-05-01

Ovarian tumor cells are often genomically unstable and hypersensitive to cisplatin. To understand the molecular basis for this phenotype, we examined the integrity of the Fanconi anemia-BRCA (FANC-BRCA) pathway in those cells. This pathway regulates cisplatin sensitivity and is governed by the coordinate activity of six genes associated with Fanconi anemia (FANCA, FANCC, FANCD2, FANCE, FANCF and FANCG) as well as BRCA1 and BRCA2 (FANCD1). Here we show that the FANC-BRCA pathway is disrupted in a subset of ovarian tumor lines. Mono-ubiquitination of FANCD2, a measure of the function of this pathway, and cisplatin resistance were restored by functional complementation with FANCF, a gene that is upstream in this pathway. FANCF inactivation in ovarian tumors resulted from methylation of its CpG island, and acquired cisplatin resistance correlated with demethylation of FANCF. We propose a model for ovarian tumor progression in which the initial methylation of FANCF is followed by FANCF demethylation and ultimately results in cisplatin resistance.

An HDAC2-TET1 switch at distinct chromatin regions significantly promotes the maturation of pre-iPS to iPS cells

Science.gov (United States)

Wei, Tingyi; Chen, Wen; Wang, Xiukun; Zhang, Man; Chen, Jiayu; Zhu, Songcheng; Chen, Long; Yang, Dandan; Wang, Guiying; Jia, Wenwen; Yu, Yangyang; Duan, Tao; Wu, Minjuan; Liu, Houqi; Gao, Shaorong; Kang, Jiuhong

2015-01-01

The maturation of induced pluripotent stem cells (iPS) is one of the limiting steps of somatic cell reprogramming, but the underlying mechanism is largely unknown. Here, we reported that knockdown of histone deacetylase 2 (HDAC2) specifically promoted the maturation of iPS cells. Further studies showed that HDAC2 knockdown significantly increased histone acetylation, facilitated TET1 binding and DNA demethylation at the promoters of iPS cell maturation-related genes during the transition of pre-iPS cells to a fully reprogrammed state. We also found that HDAC2 competed with TET1 in the binding of the RbAp46 protein at the promoters of maturation genes and knockdown of TET1 markedly prevented the activation of these genes. Collectively, our data not only demonstrated a novel intrinsic mechanism that the HDAC2-TET1 switch critically regulates iPS cell maturation, but also revealed an underlying mechanism of the interplay between histone acetylation and DNA demethylation in gene regulation. PMID:25934799

Transformation of human mesenchymal cells and skin fibroblasts into hematopoietic cells.

Directory of Open Access Journals (Sweden)

David M Harris

Full Text Available Patients with prolonged myelosuppression require frequent platelet and occasional granulocyte transfusions. Multi-donor transfusions induce alloimmunization, thereby increasing morbidity and mortality. Therefore, an autologous or HLA-matched allogeneic source of platelets and granulocytes is needed. To determine whether nonhematopoietic cells can be reprogrammed into hematopoietic cells, human mesenchymal stromal cells (MSCs and skin fibroblasts were incubated with the demethylating agent 5-azacytidine (Aza and the growth factors (GF granulocyte-macrophage colony-stimulating factor and stem cell factor. This treatment transformed MSCs to round, non-adherent cells expressing T-, B-, myeloid-, or stem/progenitor-cell markers. The transformed cells engrafted as hematopoietic cells in bone marrow of immunodeficient mice. DNA methylation and mRNA array analysis suggested that Aza and GF treatment demethylated and activated HOXB genes. Indeed, transfection of MSCs or skin fibroblasts with HOXB4, HOXB5, and HOXB2 genes transformed them into hematopoietic cells. Further studies are needed to determine whether transformed MSCs or skin fibroblasts are suitable for therapy.

Neuropilin-1highCD4+CD25+ Regulatory T Cells Exhibit Primary Negative Immunoregulation in Sepsis

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Yu-Lei Gao

2016-01-01

Full Text Available Regulatory T cells (Tregs appear to be involved in sepsis-induced immune dysfunction; neuropilin-1 (Nrp-1 was identified as a surface marker for CD4+CD25+Tregs. In the current study, we investigated the negative immunoregulation of Nrp-1highCD4+CD25+Tregs and the potential therapeutic value of Nrp-1 in sepsis. Splenic CD4+CD25+Tregs from cecal ligation and puncture (CLP mouse models were further segregated into Nrp-1highTregs and Nrp-1lowTregs; they were cocultured with CD4+CD25−  T cells. The expression of forkhead/winged helix transcription factor-3 (Foxp-3, cytotoxic T-lymphocyte associated antigen-4 (CTLA-4, membrane associated transforming growth factor-β (TGF-βm+, apoptotic rate, and secretive ability [including TGF-β and interleukin-10 (IL-10] for various types of Tregs, as well as the immunosuppressive ability of Tregs on CD4+CD25−  T cells, were determined. Meanwhile, the impact of recombinant Nrp-1 polyclonal antibody on the demethylation of Foxp-3-TSDR (Treg-specific demethylated region was measured in in vitro study. Sepsis per se markedly promoted the expression of Nrp-1 of CD4+CD25+Tregs. Foxp-3/CTLA-4/TGF-βm+ of Nrp-1highTregs were upregulated by septic challenge. Nrp-1highTregs showed strong resilience to apoptosis and secretive ability and the strongest immunosuppressive ability on CD4+CD25−  T cells. In the presence of lipopolysaccharide (LPS, the recombinant Nrp-1 polyclonal antibody reduced the demethylation of Foxp-3-TSDR. Nrp-1highTregs might reveal primary negative immunoregulation in sepsis; Nrp-1 could represent a new potential therapeutic target for the study of immune regulation in sepsis.

Type a behaviour pattern and performance as insurance representative

Directory of Open Access Journals (Sweden)

D. J. W. Strumpfer

1991-06-01

Full Text Available Participants were 155 insurance representatives and 116 of them who were still in the same position one year later. The performance criterion represented commission on policies and annuities sold; data were obtained for the year of testing and the next year. The Jenkins Activity Survey was administered. The Type A (M === 6.26; SD == 7.90 was not excessively high. The Factor H score correlated r (114 - 0,23, p = 0,05 with the criterion for the second year; no other score correlated significantly with criterion scores. Interventions to reduce Type A behaviour for health reasons seem unlikely to reduce business performance. Opsomming Die deelnemers was 155 assuransieverteenwoordigers en 116 van hulle wat een jaar later nog in dieselfde pos was. Die prestasiekriterium het kommissie op polisse en annuiteite verteenwoordig; gegewens is vir die jaar van toetsing en die volgende jaar verkry. Jenkins se Aktiviteitsvraelys is toegepas. Die Tipe A (X == 6.26; SA - 790 was nie buitengewoon hoog nie. Die Faktor H-telling het r (114 - 0,23, p - 0,05 met die kriterium vir die tweede jaar gekorreleer; geen ander tellings het beduidend met die kriteriumtellings gekorreleer nie. Dit lyk onwaarskynlik dat intervensies om Tipe A-gedrag om gesondheidsredes te verminder besigheidsprestasie sal verlaag.

Application to Representative Structures. Other Representative Structures: Mutsu-Ogawara, Niigata East and West

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Burcharth, Hans F.

1999-01-01

Reliability analyses are performed for three Japanese vertical wall breakwaters in this chapter. Only the geotechnical failure modes described in chapter 3 are investigated. For none of the breakwaters detailed data are available for the wave climate and for the soil conditions. Therefore represe...

Identification of epoxybergamottin as a CYP3A4 inhibitor in grapefruit peel.

Science.gov (United States)

Wangensteen, H; Molden, E; Christensen, H; Malterud, K E

2003-02-01

The oral availability of many drugs metabolised by the enzyme cytochrome P(450) 3A4 (CYP3A4) is increased if co-administered with grapefruit juice. Extracts from grapefruit peel have also demonstrated inhibitory activity and, during commercial manufacturing of grapefruit juice, inhibitory components might be squeezed into the juice from the peel. Thus, the aim of this in vitro study was to identify CYP3A4 inhibitors in grapefruit peel. Grapefruit peel was extracted with diethyl ether, and the extract was further fractionated by normal-phase chromatography. Fractions demonstrating significant CYP3A4 inhibitory activity, as measured by the relative reduction in N-demethylation of diltiazem in transfected human liver epithelial cells, were subsequently separated by preparative thin-layer chromatography. Constituents of the fractions and isolated compounds were identified by nuclear magnetic resonance spectroscopy. Analysis of diltiazem and N-demethyl-diltiazem was performed using high-performance liquid chromatography. Of the identified components in grapefruit peel, only epoxybergamottin demonstrated a concentration-dependent inhibition of the CYP3A4-mediated N-demethylation of diltiazem. The IC(50) value was calculated to be 4.2+/-1.1 micro M. Coumarins without the furan ring and flavonoids isolated from grapefruit peel did not interfere with the metabolism of diltiazem. The results indicated the presence of other CYP3A4 inhibitors in grapefruit peel, but these agents were lost during the purification process excluding their identification. The furanocoumarin epoxybergamottin, present in grapefruit peel, is an inhibitor of CYP3A4. In commercial manufacturing of grapefruit juice, epoxybergamottin is possibly distributed into the juice. During manufacturing, however, epoxybergamottin may be hydrolysed to 6',7'-dihydroxybergamottin, which has been suggested as an important CYP3A4 inhibitor in grapefruit juice.

40 CFR 60.4111 - Alternate Hg designated representative.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Alternate Hg designated representative... Times for Coal-Fired Electric Steam Generating Units Hg Designated Representative for Hg Budget Sources § 60.4111 Alternate Hg designated representative. (a) A certificate of representation under § 60.4113...

Determination of oxidation products of 5-methylcytosine in plants by chemical derivatization coupled with liquid chromatography/tandem mass spectrometry analysis.

Science.gov (United States)

Tang, Yang; Xiong, Jun; Jiang, Han-Peng; Zheng, Shu-Jian; Feng, Yu-Qi; Yuan, Bi-Feng

2014-08-05

Cytosine methylation (5-methylcytosine, 5-mC) in DNA is an important epigenetic mark that has regulatory roles in various biological processes. In plants, active DNA demethylation can be achieved through direct cleavage by DNA glycosylases, followed by replacement of 5-mC with cytosine by base excision repair (BER) machinery. Recent studies in mammals have demonstrated 5-mC can be sequentially oxidized to 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine (5-foC), and 5-carboxylcytosine (5-caC) by Ten-eleven translocation (TET) proteins. The consecutive oxidations of 5-mC constitute the active DNA demethylation pathway in mammals, which raised the possible presence of oxidation products of 5-mC (5-hmC, 5-foC, and 5-caC) in plant genomes. However, there is no definitive evidence supporting the presence of these modified bases in plant genomic DNA, especially for 5-foC and 5-caC. Here we developed a chemical derivatization strategy combined with liquid chromatography-electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method to determine 5-formyl-2'-deoxycytidine (5-fodC) and 5-carboxyl-2'-deoxycytidine (5-cadC). Derivatization of 5-fodC and 5-cadC by Girard's reagents (GirD, GirT, and GirP) significantly increased the detection sensitivities of 5-fodC and 5-cadC by 52-260-fold. Using this method, we demonstrated the widespread existence of 5-fodC and 5-cadC in genomic DNA of various plant tissues, indicating that active DNA demethylation in plants may go through an alternative pathway similar to mammals besides the pathway of direct DNA glycosylases cleavage combined with BER. Moreover, we found that environmental stresses of drought and salinity can change the contents of 5-fodC and 5-cadC in plant genomes, suggesting the functional roles of 5-fodC and 5-cadC in response to environmental stresses.

Genomic imprinting of IGF2 in marsupials is methylation dependent

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Imumorin Ikhide

2008-05-01

Full Text Available Abstract Background- Parent-specific methylation of specific CpG residues is critical to imprinting in eutherian mammals, but its importance to imprinting in marsupials and, thus, the evolutionary origins of the imprinting mechanism have been the subject of controversy. This has been particularly true for the imprinted Insulin-like Growth Factor II (IGF2, a key regulator of embryonic growth in vertebrates and a focal point of the selective forces leading to genomic imprinting. The presence of the essential imprinting effector, DNMT3L, in marsupial genomes and the demonstration of a differentially methylated region (DMR in the retrotransposon-derived imprinted gene, PEG10, in tammar wallaby argue for a role for methylation in imprinting, but several studies have found no evidence of parent-specific methylation at other imprinted loci in marsupials. Results- We performed the most extensive search to date for allele-specific patterns of CpG methylation within CpG isochores or CpG enriched segments across a 22 kilobase region surrounding the IGF2 gene in the South American opossum Monodelphis domestica. We identified a previously unknown 5'-untranslated exon for opossum IGF2, which is flanked by sequences defining a putative neonatal promoter, a DMR and an active Matrix Attachment Region (MAR. Demethylation of this DMR in opossum neonatal fibroblasts results in abherrant biallelic expression of IGF2. Conclusion- The demonstration of a DMR and an active MAR in the 5' flank of opossum IGF2 mirrors the regulatory features of the 5' flank of Igf2 in mice. However, demethylation induced activation of the maternal allele of IGF2 in opossum differs from the demethylation induced repression of the paternal Igf2 allele in mice. While it can now be concluded that parent-specific DNA methylation is an epigentic mark common to Marsupialia and Eutheria, the molecular mechanisms of transcriptional silencing at imprinted loci have clearly evolved along independent

22 CFR 23.4 - Representative value in exchange.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Representative value in exchange. 23.4 Section 23.4 Foreign Relations DEPARTMENT OF STATE FEES AND FUNDS FINANCE AND ACCOUNTING § 23.4 Representative value in exchange. Representative value in exchange for the collection of a fee means foreign...

20 CFR 266.7 - Accountability of a representative payee.

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2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Accountability of a representative payee. 266.7 Section 266.7 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT REPRESENTATIVE PAYMENT § 266.7 Accountability of a representative payee. (a) A representative...

γ-Ray spectrometry of radon in water and the role of radon to representatively sample aquifers

International Nuclear Information System (INIS)

Talha, S.A.; Lindsay, R.; Newman, R.T.; Meijer, R.J. de; Maleka, P.P.; Hlatshwayo, I.N.; Mlwilo, N.A.; Mohanty, A.K.

2008-01-01

Measurement of radon in water by γ-ray spectrometry using a HPGe detector has been investigated to determine aquifer characteristics. The radon activity concentration is determined by taking the weighted average of the concentrations derived from γ-ray lines associated with 214 Pb and 214 Bi decay. The role of accurate radon data to representatively sample aquifers was also investigated by studying a semi-cased borehole. A simplified physical model describing the change of radon concentration with the pumping time, reproduces the data and predicts the time for representative sampling of the aquifer

Representativeness of environmental impact assessment methods regarding Life Cycle Inventories.

Science.gov (United States)

Esnouf, Antoine; Latrille, Éric; Steyer, Jean-Philippe; Helias, Arnaud

2018-04-15

Life Cycle Assessment (LCA) characterises all the exchanges between human driven activities and the environment, thus representing a powerful approach for tackling the environmental impact of a production system. However, LCA practitioners must still choose the appropriate Life Cycle Impact Assessment (LCIA) method to use and are expected to justify this choice: impacts should be relevant facing the concerns of the study and misrepresentations should be avoided. This work aids practitioners in evaluating the adequacy between the assessed environmental issues and studied production system. Based on a geometrical standpoint of LCA framework, Life Cycle Inventories (LCIs) and LCIA methods were localized in the vector space spanned by elementary flows. A proximity measurement, the Representativeness Index (RI), is proposed to explore the relationship between those datasets (LCIs and LCIA methods) through an angular distance. RIs highlight LCIA methods that measure issues for which the LCI can be particularly harmful. A high RI indicates a close proximity between a LCI and a LCIA method, and highlights a better representation of the elementary flows by the LCIA method. To illustrate the benefits of the proposed approach, representativeness of LCIA methods regarding four electricity mix production LCIs from the ecoinvent database are presented. RIs for 18 LCIA methods (accounting for a total of 232 impact categories) were calculated on these LCIs and the relevance of the methods are discussed. RIs prove to be a criterion for distinguishing the different LCIA methods and could thus be employed by practitioners for deeper interpretations of LCIA results. Copyright © 2017 Elsevier B.V. All rights reserved.

Burnout in Customer Service Representatives

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Tariq Jalees

2008-09-01

Full Text Available The purpose and aim of this research was to (1 identify the factors that contributes towards job burnout in sales service representative (2 What are the relationships of these factors (3 To empirically test the relationships of the determinants relating to burnout in customer service representatives. Based on literature survey six different variables related to burnout were identified. The variables were (1 Emotional exhaustion.(2 Reduced personal accomplishment.(3 Job induced tension.(4 Job satisfaction.(5 Workload (6 Job satisfaction.Each of the variables contained 3 sub-variables. Five different hypotheses were developed and tested through techniques such as Z-test, F-test and regression analysis. The questionnaire administered for the study contained 15 questions including personal data. The subject was Moblink company customers sales service representative in Karachi.The valid sample size was 98 drawn through multi-cluster technique. Techniques such as measure of dispersion and measure of central tendencies were used for analyzing the data. Regression, Z-test, and F-test were used for testing the developed hypothesis.According to the respondents’ opinions, the reduced personal accomplishment had a high rating with a mean of 3.75 and job induced tension has the lowest mean of 3.58. The standard deviation of respondents’ opinions was highest for dimension depersonalization and least for dimension work load. This indicates that there is a high polarization of the respondents’ opinions on the dimension depersonalization moral and least on the dimension work load.The Skew nesses for all the dimensions were in negative except the determinants emotional exhaustion and workload. This indicates that the majority of respondents’ opinions on all the dimensions were below the mean except in the case of emotional exhaustion and workload.Five hypotheses were developed and tested:a The hypothesis relating to low level of burnout in customers

A model-driven approach for representing clinical archetypes for Semantic Web environments.

Science.gov (United States)

Martínez-Costa, Catalina; Menárguez-Tortosa, Marcos; Fernández-Breis, Jesualdo Tomás; Maldonado, José Alberto

2009-02-01

The life-long clinical information of any person supported by electronic means configures his Electronic Health Record (EHR). This information is usually distributed among several independent and heterogeneous systems that may be syntactically or semantically incompatible. There are currently different standards for representing and exchanging EHR information among different systems. In advanced EHR approaches, clinical information is represented by means of archetypes. Most of these approaches use the Archetype Definition Language (ADL) to specify archetypes. However, ADL has some drawbacks when attempting to perform semantic activities in Semantic Web environments. In this work, Semantic Web technologies are used to specify clinical archetypes for advanced EHR architectures. The advantages of using the Ontology Web Language (OWL) instead of ADL are described and discussed in this work. Moreover, a solution combining Semantic Web and Model-driven Engineering technologies is proposed to transform ADL into OWL for the CEN EN13606 EHR architecture.

Active Learning Using Hint Information.

Science.gov (United States)

Li, Chun-Liang; Ferng, Chun-Sung; Lin, Hsuan-Tien

2015-08-01

The abundance of real-world data and limited labeling budget calls for active learning, an important learning paradigm for reducing human labeling efforts. Many recently developed active learning algorithms consider both uncertainty and representativeness when making querying decisions. However, exploiting representativeness with uncertainty concurrently usually requires tackling sophisticated and challenging learning tasks, such as clustering. In this letter, we propose a new active learning framework, called hinted sampling, which takes both uncertainty and representativeness into account in a simpler way. We design a novel active learning algorithm within the hinted sampling framework with an extended support vector machine. Experimental results validate that the novel active learning algorithm can result in a better and more stable performance than that achieved by state-of-the-art algorithms. We also show that the hinted sampling framework allows improving another active learning algorithm designed from the transductive support vector machine.

Epigenetic regulation of photoperiodic flowering

OpenAIRE

Takeno, Kiyotoshi

2010-01-01

The cytidine analogue 5-azacytidine, which causes DNA demethylation, induced flowering in the non-vernalization-requiring plants Perilla frutescens var. crispa, Silene armeria and Pharbitis nil (synonym Ipomoea nil) under non-inductive photoperiodic conditions, suggesting that the expression of photoperiodic flowering-related genes is regulated epigenetically by DNA methylation. The flowering state induced by DNA demethylation was not heritable. Changes in the genome-wide methylation state we...

Synthesis of C-9-14C-1,8-dihydroxy-3-carboxyanthraquinone

International Nuclear Information System (INIS)

De Witte, P.; Lemli, J.

1988-01-01

The synthesis of C-9- 14 C-rhein is reported using 14 CO 2 as a 14 C-source. After preparing 14 C-1, 8-dimethoxy-3-methylanthraquinone by a condensation reaction, the product is demethylated and the 3-methyl group converted to the corresponding 3-carboxy group. The radio-active yield of the total synthesis, starting with 1 Ci 14 CO 2 is 6,9% (6, 9 mCi); 352 mg 14 rhein is produced with a specific activity of 55,7 mCi/mmol. (author)

Representing Sikhism: essays in memory of the Irish scholar Max Arthur Macauliffe

OpenAIRE

Shackle, Christopher; Bocking, Brian

2017-01-01

This is an introduction, by the guest editors, to the special issue of JISASR (Vol 4, 2017) entitled 'Representing Sikhism: Essays in Memory of the Irish Scholar Max Arthur Macauliffe'. The genesis of this special issue lies in pioneering work on Macauliffe's Irish identity and personal and scholarly life undertaken by Professor Tadhg Foley (Galway). The active interest and support of members of the Sikh community in Ireland led to a conference, hosted by the Study of Religions Department at ...

Registration Appointment and Services for Representatives Management Information

Data.gov (United States)

Social Security Administration — A new internet/intranet application that collects all representative information and establishes the relationship between the claimant and the representative. Allow...

Analysis and Visualization of Internet QA Bulletin Boards Represented as Heterogeneous Networks

Science.gov (United States)

Murata, Tsuyoshi; Ikeya, Tomoyuki

Visualizing and analyzing social interactions of CGM (Consumer Generated Media) are important for understanding overall activities on the internet. Social interactions are often represented as simple networks that are composed of homogeneous nodes and edges between them. However, related entities in real world are often not homogeneous. Such relations are naturally represented as heterogeneous networks composed of more than one kind of nodes and edges connecting them. In the case of CGM, for example, users and their contents constitute nodes of heterogeneous networks. There are related users (user communities) and related contents (contents communities) in the heterogeneous networks. Discovering both communities and finding correspondence among them will clarify the characteristics of the communites. This paper describes an attempt for visualizing and analyzing social interactions of Yahoo! Chiebukuro (Japanese Yahoo! Answers). New criteria for measuring correspondence between user communities and board communites are defined, and characteristics of both communities are analyzed using the criteria.

FEATURES OF NEED-MOTIVATION ORIENTATION OF STUDENTS WHO REPRESENT THE CHINESE CULTURE

Directory of Open Access Journals (Sweden)

T. V. Mayasova

2016-01-01

Full Text Available In the article it is investigated the features of need-motivational orientation of students who represent the Chinese culture, studying in the higher educational institutions of Russia. As personal characteristics are analyzed the degree of satisfaction of basic needs, the level of motivation to succeed, motivational structure of personality in Chinese and Russian students. The importance of the study of personality characteristics of foreign students of the university helps professionals find the conditions for successful social and cross-cultural adaptation of students in a foreign country. The analysis obtained during the empirical research results confirm that there are certain differences in the needs and motivation of the students, representatives of Chinese and Russian culture. There were significant differences in rates of interpersonal needs, need for recognition, motivation and the comfort level of motivation to the "total activity" in Chinese and Russian students, which allows to predict the occurrence of adaptation and socialization difficulties of foreign students during training.

Genomic sequencing and in vivo footprinting of an expression-specific DNase I-hypersensitive site of avian vitellogenin II promoter reveal a demethylation of a mCpG and a change in specific interactions of proteins with DNA.

Science.gov (United States)

Saluz, H P; Feavers, I M; Jiricny, J; Jost, J P

1988-01-01

Genomic sequencing was used to study the in vivo methylation pattern of two CpG sites in the promoter region of the avian vitellogenin gene. The CpG at position +10 was fully methylated in DNA isolated from tissues that do not express the gene but was unmethylated in the liver of mature hens and estradiol-treated roosters. In the latter tissue, this site became demethylated and DNase I hypersensitive after estradiol treatment. A second CpG (position -52) was unmethylated in all tissues examined. In vivo genomic footprinting with dimethyl sulfate revealed different patterns of DNA protection in silent and expressed genes. In rooster liver cells, at least 10 base pairs of DNA, including the methylated CpG, were protected by protein(s). Gel-shift assays indicated that a protein factor, present in rooster liver nuclear extract, bound at this site only when it was methylated. In hen liver cells, the same unmethylated CpG lies within a protected region of approximately equal to 20 base pairs. In vitro DNase I protection and gel-shift assays indicate that this sequence is bound by a protein, which binds both double- and single-stranded DNA. For the latter substrate, this factor was shown to bind solely the noncoding (i.e., mRNA-like) strand. Images PMID:3413118

Concurrent epigenetic silencing of wnt/β-catenin pathway inhibitor genes in B cell chronic lymphocytic leukaemia

International Nuclear Information System (INIS)

Moskalev, Evgeny A; Pötz, Oliver; Joos, Thomas O; Hoheisel, Jörg D; Luckert, Katrin; Vorobjev, Ivan A; Mastitsky, Sergey E; Gladkikh, Aleena A; Stephan, Achim; Schrenk, Marita; Kaplanov, Kamil D; Kalashnikova, Olga B

2012-01-01

The Wnt/β-catenin signalling is aberrantly activated in primary B cell chronic lymphocytic leukaemia (CLL). Epigenetic silencing of pathway inhibitor genes may be a mechanism for its activation. In this study, we investigated systematically and quantitatively the methylation status of 12 Wnt/β-catenin pathway inhibitor genes – CDH1, DACT1, DKK1, DKK2, DKK3, DKK4, SFRP1, SFRP2, SFRP3, SFRP4, SFRP5 and WIF1 – in the cell lines EHEB and MEC-1 as well as patient samples. Quantification of DNA methylation was performed by means of bisulphite pyrosequencing and confirmed by bisulphite Sanger sequencing. Gene expression was analysed by qPCR using GAPDH as internal control. E-cadherin and β-catenin protein quantification was carried out by microsphere-based immunoassays. Methylation differences observed between the patient and control groups were tested using generalised least squares models. For 10 genes, a higher methylation level was observed in tumour material. Only DKK4 exhibited similarly high methylation levels in both tumour and normal specimens, while DACT1 was always essentially unmethylated. However, also for these inhibitors, treatment of cells with the demethylating agent 5-aza-2´-deoxycytidine resulted in an induction of their expression, as shown by quantitative PCR, suggesting an indirect epigenetic control of activity. While the degree of demethylation and its transcriptional consequences differed between the genes, there was an overall high correlation of demethylation and increased activity. Protein expression studies revealed that no constitutive Wnt/β-catenin signalling occurred in the cell lines, which is in discrepancy with results from primary CLL. However, treatment with 5-aza-2´-deoxycytidine caused accumulation of β-catenin. Simultaneously, E-cadherin expression was strongly induced, leading to the formation of a complex with β-catenin and thus demonstrating its epigenetically regulated inhibition effect. The results suggest an

Activated Carbon, Carbon Nanofiber and Carbon Nanotube Supported Molybdenum Carbide Catalysts for the Hydrodeoxygenation of Guaiacol

Directory of Open Access Journals (Sweden)

Eduardo Santillan-Jimenez

2015-03-01

Full Text Available Molybdenum carbide was supported on three types of carbon support—activated carbon; multi-walled carbon nanotubes; and carbon nanofibers—using ammonium molybdate and molybdic acid as Mo precursors. The use of activated carbon as support afforded an X-ray amorphous Mo phase, whereas crystalline molybdenum carbide phases were obtained on carbon nanofibers and, in some cases, on carbon nanotubes. When the resulting catalysts were tested in the hydrodeoxygenation (HDO of guaiacol in dodecane, catechol and phenol were obtained as the main products, although in some instances significant amounts of cyclohexane were produced. The observation of catechol in all reaction mixtures suggests that guaiacol was converted into phenol via sequential demethylation and HDO, although the simultaneous occurrence of a direct demethoxylation pathway cannot be discounted. Catalysts based on carbon nanofibers generally afforded the highest yields of phenol; notably, the only crystalline phase detected in these samples was Mo2C or Mo2C-ζ, suggesting that crystalline Mo2C is particularly selective to phenol. At 350 °C, carbon nanofiber supported Mo2C afforded near quantitative guaiacol conversion, the selectivity to phenol approaching 50%. When guaiacol HDO was performed in the presence of acetic acid and furfural, guaiacol conversion decreased, although the selectivity to both catechol and phenol was increased.

Solar Heliospheric and INterplanetary Environment (SHINE) Students - Student Representatives' Perspectives

Science.gov (United States)

Pahud, D. M.; Niembro, T.

2014-12-01

The SHINE workshop is an annual meeting of solar and heliospheric scientists which, in addition to aiming to improve understanding of solar disturbances and their propagation to, and effect, on the Earth (shinecon.org), is dedicated to actively supporting students. This dedication is substantiated in part through the National Science Foundation (NSF) providing funding for student attendance to the workshop, which enables student participation. Another example of SHINE's commitment to its student members is the incorporation of a Student Day prior to the workshop since 2003, entirely organized and run by two student representatives. While there are variations in format from year to year, Student Day consists of tutorials and research talks exclusively by student volunteers to an audience of only students. The day is intended to provide a low-stress environment for students to learn about the various topics addressed during the workshop, to ask questions freely, and to engage in scientific discussion with other students which hopefully is a catalyst for collaboration. As a result of positive experiences, over the past decade student attendance and participation in the workshop have increased. At the SHINE 2014 workshop, nearly a third of attendees were students. SHINE student visibility has increased over the years, with student posters being advertised at breakfast, inclusion of a student day summary by the student representatives during a plenary session, and continued support from the steering committee. Students are also promoting a broader impact of SHINE sciences via increased social media presence. From a student representative's perspective, SHINE has built and fostered a healthy student community and encourages students to engage in shaping the future of the field.

Representativeness of the IAGOS airborne measurements in the lower troposphere

Directory of Open Access Journals (Sweden)

H. Petetin

2018-03-01

Full Text Available In the framework of the In Service Aircraft for Global Observing System (IAGOS program, airborne in-situ O3 and CO measurements are performed routinely using in-service aircraft, providing vertical profiles from the surface to about 10–12 km. Due to the specificity of IAGOS measurements (measurements around busy international airports, uncertainties exist on their representativeness in the lower troposphere as they may be impacted by emissions related to airport activities and/or other aircraft. In this study, we thus investigate how the IAGOS measurements in the lower troposphere compare with nearby surface stations (from the local Air Quality monitoring network (AQN and more distant regional surface stations (from the Global Atmospheric Watch (GAW network. The study focuses on Frankfurt but some results at other European airports (Vienna, Paris are also discussed. Results indicate that the IAGOS observations close to the surface do not appear to be strongly impacted by local emissions related to airport activities. In terms of mixing ratio distribution, seasonal variations and trends, the CO and O3 mixing ratios measured by IAGOS in the first few hundred metres above the surface have similar characteristics to the mixing ratios measured at surrounding urban background stations. Higher in altitude, both the difference with data from the local AQN and the consistency with the GAW regional stations are higher, which indicates a larger representativeness of the IAGOS data. Despite few quantitative differences with Frankfurt, consistent results are obtained in the two other cities Vienna and Paris. Based on 11 years of data (2002–2012, this study thus demonstrates that IAGOS observations in the lowest troposphere can be used as a complement to surface stations to study the air quality in/around the agglomeration, providing important information on the vertical distribution of pollution.

Diversity and representativeness: two key factors

CERN Multimedia

Staff Association

2013-01-01

In the past few weeks many of you have filled out the questionnaire for preparing the upcoming Five-yearly review. Similarly, Staff Association members have elected their delegates to the Staff Council for the coming two years. Once again we would like to thank all those who have taken the time and effort to make their voice heard on these two occasions. Elections to the Staff Council Below we publish the new Staff Council with its forty delegates who will represent in 2014 and 2015 all CERN staff in the discussions with Management and Member States in the various bodies and committees. Therefore it is important that the Staff Council represents as far as possible the diversity of the CERN population. By construction, the election process with its electoral colleges and two-step voting procedure guarantees that all Departments, even the small ones, and the various staff categories are correctly represented. Figure 1 shows the participation rate in the elections. The average rate is just above 52 %, with ...

Alkaloids from Delphinium pentagynum.

Science.gov (United States)

Díaz, Jesús G; Ruiz, Juan García; Herz, Werner

2004-07-01

Aerial parts of a collection of Delphinium pentagynum Lam. from Niebla, Southern Spain, furnished one diterpene alkaloid, 2-dehydrodeacetylheterophylloidine, two norditerpene alkaloids, 14-demethyl-14-isobutyrylanhweidelphinine and 14-demethyl-14-acetylanhweidelphinine, the known alkaloids 14-deacetylnudicauline, methyllycaconitine, 14-deacetyl-14-isobutyrylnudicauline, 14-acetylbrowniine, browniine, delcosine, lycoctonine, 18-methoxygadesine, neoline, karakoline and the aporphine alkaloid magnoflorine. Structures of the alkaloids were established by MS, 1D and 2-D NMR techniques.

Hypomethylation and up-regulation of PD-1 in T cells by azacytidine in MDS/AML patients

DEFF Research Database (Denmark)

Ørskov, Andreas D; Treppendahl, Marianne B; Skovbo, Anni

2015-01-01

receptor PD-1 is regulated by DNA methylation. In 12 of 27 patients (44%) PD-1 promoter demethylation was observed in sorted peripheral blood T cells isolated over consecutive cycles of treatment with 5-azacytidine (5-aza). The PD-1 promoter demethylation correlated with an increase in PD-1 expression...... HMA treatment can be a possible resistance mechanism, which may be overcome by combination therapy with a PD-1 pathway inhibitor....

The representative bodies in Russia in the first half of the seventeenth century

Directory of Open Access Journals (Sweden)

Tatiana Aleksándrovna LÁPTEVA

2015-12-01

Full Text Available The article is concerned with the history of representative institutions in Russia, the Zemsky Sobor (the Assembly of the Land, the National assembly in the 1620s-50s. On the basis of the documents preserved in the Russian State Archive of Ancient Documents and analyzed in the works of major Russian historians, the article discusses the background to the activities of the Sobors and their relationship with the social and economic situation in the country; the elections to the Sobors and their composition; viewpoints and demands of the important social groups and strata participating in these Sobors and their submitted ‘opinions’; the main issues discussed at the Sobors, results of their activities and decrees refl the decisions of the Zemsky Sobors. It also examines collective petitions submitted to the Sobors which reflect the points of view of the representatives of two main estates – the nobility (nobles and deti boyarskie and the merchants and townspeople. The author comes to a conclusion about significant role of the Zemsky Sobors in shaping of the Russian state and overcoming the consequences of the Time of Troubles, as well as in finding solutions to acute and vital problems facing the state, namely, to regulate the financial policy, to repulse an external threat, and to develop the basic principles of the foreign policy. At the Sobor a compilation of a uniform Code of Laws was made, i.e. Sob ornoe Ulozhenie of 1649. The article also discusses the reasons for the decline of the representative institutions in Russia since the 1650s, where, although being a contributory factor, they found no support of the upper stratum of society and bureaucracy.

[Study on influence between activated carbon property and immobilized biological activated carbon purification effect].

Science.gov (United States)

Wang, Guang-zhi; Li, Wei-guang; He, Wen-jie; Han, Hong-da; Ding, Chi; Ma, Xiao-na; Qu, Yan-ming

2006-10-01

By means of immobilizing five kinds of activated carbon, we studied the influence between the chief activated carbon property items and immobilized bioactivated carbon (IBAC) purification effect with the correlation analysis. The result shows that the activated carbon property items which the correlation coefficient is up 0.7 include molasses, abrasion number, hardness, tannin, uniform coefficient, mean particle diameter and effective particle diameter; the activated carbon property items which the correlation coefficient is up 0.5 include pH, iodine, butane and tetrachloride. In succession, the partial correlation analysis shows that activated carbon property items mostly influencing on IBAC purification effect include molasses, hardness, abrasion number, uniform coefficient, mean particle diameter and effective particle diameter. The causation of these property items bringing influence on IBAC purification is that the activated carbon holes distribution (representative activated carbon property item is molasses) provides inhabitable location and adjust food for the dominance bacteria; the mechanical resist-crash property of activated carbon (representative activated carbon property items: abrasion number and hardness) have influence on the stability of biofilm; and the particle diameter size and distribution of activated carbon (representative activated carbon property items: uniform coefficient, mean particle diameter and effective particle diameter) can directly affect the force of water in IBAC filter bed, which brings influence on the dominance bacteria immobilizing on activated carbon.

Marketing norm perception among medical representatives in Indian pharmaceutical industry.

Science.gov (United States)

Nagashekhara, Molugulu; Agil, Syed Omar Syed; Ramasamy, Ravindran

2012-03-01

Study of marketing norm perception among medical representatives is an under-portrayed component that deserves further perusal in the pharmaceutical industry. The purpose of this study is to find out the perception of marketing norms among medical representatives. The research design is quantitative and cross sectional study with medical representatives as unit of analysis. Data is collected from medical representatives (n=300) using a simple random and cluster sampling using a structured questionnaire. Results indicate that there is no difference in the perception of marketing norms among male and female medical representatives. But there is a difference in opinion among domestic and multinational company's medical representatives. Educational back ground of medical representatives also shows the difference in opinion among medical representatives. Degree holders and multinational company medical representatives have high perception of marketing norms compare to their counterparts. The researchers strongly believe that mandatory training on marketing norms is beneficial in decision making process during the dilemmas in the sales field.

Representative Democracy in Australian Local Government

Directory of Open Access Journals (Sweden)

Colin Hearfield

2009-01-01

Full Text Available In an assessment of representative democracy in Australian local government, this paper considers long-run changes in forms of political representation, methods of vote counting, franchise arrangements, numbers of local government bodies and elected representatives, as well as the thorny question of constitutional recognition. This discussion is set against the background of ongoing tensions between the drive for economic efficiency and the maintenance of political legitimacy, along with more deep-seated divisions emerging from the legal relationship between local and state governments and the resultant problems inherent in local government autonomy versus state intervention.

Hydroxylation of the herbicide isoproturon by fungi isolated from agricultural soil.

Science.gov (United States)

Rønhede, Stig; Jensen, Bo; Rosendahl, Søren; Kragelund, Birthe B; Juhler, René K; Aamand, Jens

2005-12-01

Several asco-, basidio-, and zygomycetes isolated from an agricultural field were shown to be able to hydroxylate the phenylurea herbicide isoproturon [N-(4-isopropylphenyl)-N',N'-dimethylurea] to N-(4-(2-hydroxy-1-methylethyl)phenyl)-N',N'-dimethylurea and N-(4-(1-hydroxy-1-methylethyl)phenyl)-N',N'-dimethylurea. Bacterial metabolism of isoproturon has previously been shown to proceed by an initial demethylation to N-(4-isopropylphenyl)-N'-methylurea. In soils, however, hydroxylated metabolites have also been detected. In this study we identified fungi as organisms that potentially play a major role in the formation of these hydroxylated metabolites in soils treated with isoproturon. Isolates of Mortierella sp. strain Gr4, Phoma cf. eupyrena Gr61, and Alternaria sp. strain Gr174 hydroxylated isoproturon at the first position of the isopropyl side chain, yielding N-(4-(2-hydroxy-1-methylethyl)phenyl)-N',N'-dimethylurea, while Mucor sp. strain Gr22 hydroxylated the molecule at the second position, yielding N-(4-(1-hydroxy-1-methylethyl)phenyl)-N',N'-dimethylurea. Hydroxylation was the dominant mode of isoproturon transformation in these fungi, although some cultures also produced traces of the N-demethylated metabolite N-(4-isopropylphenyl)-N'-methylurea. A basidiomycete isolate produced a mixture of the two hydroxylated and N-demethylated metabolites at low concentrations. Clonostachys sp. strain Gr141 and putative Tetracladium sp. strain Gr57 did not hydroxylate isoproturon but N demethylated the compound to a minor extent. Mortierella sp. strain Gr4 also produced N-(4-(2-hydroxy-1-methylethyl)phenyl)-N'-methylurea, which is the product resulting from combined N demethylation and hydroxylation.

Visually representing the generation of older consumers as a diverse audience: towards a multidimensional market segmentation typology

NARCIS (Netherlands)

Loos, E.; Ekström, M.

2014-01-01

Television commercials and advertising often represent the generation of older consumers as eternally youthful, active and rich. Representations of senior citizens as fragile people needing services and products to help them to survive are also used, but less frequently. As individual differences

Visually representing the generation of older consumers as a diverse audience: Towards a multidimensional market segmentation typology

NARCIS (Netherlands)

Loos, Eugène; Ekström, M.

2014-01-01

Television commercials and advertising often represent the generation of older consumers as eternally youthful, active and rich. Representations of senior citizens as fragile people needing services and products to help them to survive are also used, but less frequently. As individual differences

Lysine-specific demethylase 1 (LSD1) destabilizes p62 and inhibits autophagy in gynecologic malignancies.

Science.gov (United States)

Chao, Angel; Lin, Chiao-Yun; Chao, An-Ning; Tsai, Chia-Lung; Chen, Ming-Yu; Lee, Li-Yu; Chang, Ting-Chang; Wang, Tzu-Hao; Lai, Chyong-Huey; Wang, Hsin-Shih

2017-09-26

Lysine-specific demethylase 1 (LSD1) - also known as KDM1A - is the first identified histone demethylase. LSD1 is highly expressed in numerous human malignancies and has recently emerged as a target for anticancer drugs. Owing to the presence of several functional domains, we speculated that LSD1 could have additional functions other than histone demethylation. P62 - also termed sequestasome 1 (SQSTM1) - plays a key role in malignant transformation, apoptosis, and autophagy. Here, we show that a high LSD1 expression promotes tumorigenesis in gynecologic malignancies. Notably, LSD1 inhibition with either siRNA or pharmacological agents activates autophagy. Mechanistically, LSD1 decreases p62 protein stability in a demethylation-independent manner. Inhibition of LSD1 reduces both tumor growth and p62 protein degradation in vivo . The combination of LSD1 inhibition and p62 knockdown exerts additive anticancer effects. We conclude that LSD1 destabilizes p62 and inhibits autophagy in gynecologic cancers. LSD1 inhibition reduces malignant cell growth and activates autophagy. The combinations of LSD1 inhibition and autophagy blockade display additive inhibitory effect on cancer cell viability. A better understanding of the role played by p62 will shed more light on the anticancer effects of LSD1 inhibitors.

Similarities between the Epstein-Barr Virus (EBV) Nuclear Protein EBNA1 and the Pioneer Transcription Factor FoxA: Is EBNA1 a “Bookmarking” Oncoprotein that Alters the Host Cell Epigenotype?

Science.gov (United States)

Niller, Hans Helmut; Minarovits, Janos

2012-01-01

EBNA1, a nuclear protein expressed in all EBV-associated neoplasms is indispensable for the maintenance of the viral episomes in latently infected cells. EBNA1 may induce genetic alterations by upregulating cellular recombinases, production of reactive oxygen species (ROS) and affecting p53 levels and function. All these changes may contribute to tumorigenesis. In this overview we focus, however, on the epigenetic alterations elicited by EBNA1 by drawing a parallel between EBNA1 and the FoxA family of pioneer transcription factors. Both EBNA1 and FoxA induce local DNA demethylation, nucleosome destabilization and bind to mitotic chromosomes. Local DNA demethylation and nucleosome rearrangement mark active promoters and enhancers. In addition, EBNA1 and FoxA, when associated with mitotic chromatin may “bookmark” active genes and ensure their reactivation in postmitotic cells (epigenetic memory). We speculate that DNA looping induced by EBNA1-EBNA1 interactions may reorganize the cellular genome. Such chromatin loops, sustained in mitotic chromatin similarly to the long-distance interactions mediated by the insulator protein CTCF, may also mediate the epigenetic inheritance of gene expression patterns. We suggest that EBNA1 has the potential to induce patho-epigenetic alterations contributing to tumorigenesis. PMID:25436603

The dynamic changes of DNA methylation and histone modifications of salt responsive transcription factor genes in soybean.

Directory of Open Access Journals (Sweden)

Yuguang Song

Full Text Available Epigenetic modification contributes to the regulation of gene expression and plant development under salinity stress. Here we describe the identification of 49 soybean transcription factors by microarray analysis as being inducible by salinity stress. A semi-quantitative RT-PCR-based expression assay confirmed the salinity stress inducibility of 45 of these 49 transcription factors, and showed that ten of them were up-regulated when seedlings were exposed to the demethylation agent 5-aza-2-deoxycytidine. Salinity stress was shown to affect the methylation status of four of these ten transcription factors (one MYB, one b-ZIP and two AP2/DREB family members using a combination of bisulfite sequencing and DNA methylation-sensitive DNA gel blot analysis. ChIP analysis indicated that the activation of three of the four DNA methylated transcription factors was correlated with an increased level of histone H3K4 trimethylation and H3K9 acetylation, and/or a reduced level of H3K9 demethylation in various parts of the promoter or coding regions. Our results suggest a critical role for some transcription factors' activation/repression by DNA methylation and/or histone modifications in soybean tolerance to salinity stress.

Elections for staff representatives – Join, commit and vote!

CERN Multimedia

Staff Association

2015-01-01

The Staff Council is a statutory body representing collectively in the area of employment conditions all CERN staff members (MPE and MPA), as well as the pensioners, former Cernois. The Staff Council is the supreme representative body of the CERN staff and pensioners, which defines the main lines of the policy of the Staff Association. The Staff Council is composed of staff representatives (45 seats to represent staff members, and 5 for representing fellows and associate members), as well as delegates for pensioners (seven positions), designated by GAC-EPA. Every two years, the Council is renewed through elections. Concerning the 45 delegates representing staff members, all departments have a least two seats allocated, one in career paths AA to D and one in career paths E to H. This guarantees a fair distribution of seats among the various organizational units and career paths. The table below, shows the exact number of delegates per department and career paths. Staff members or fellows who want to participa...

Using semantics for representing experimental protocols.

Science.gov (United States)

Giraldo, Olga; García, Alexander; López, Federico; Corcho, Oscar

2017-11-13

An experimental protocol is a sequence of tasks and operations executed to perform experimental research in biological and biomedical areas, e.g. biology, genetics, immunology, neurosciences, virology. Protocols often include references to equipment, reagents, descriptions of critical steps, troubleshooting and tips, as well as any other information that researchers deem important for facilitating the reusability of the protocol. Although experimental protocols are central to reproducibility, the descriptions are often cursory. There is the need for a unified framework with respect to the syntactic structure and the semantics for representing experimental protocols. In this paper we present "SMART Protocols ontology", an ontology for representing experimental protocols. Our ontology represents the protocol as a workflow with domain specific knowledge embedded within a document. We also present the S ample I nstrument R eagent O bjective (SIRO) model, which represents the minimal common information shared across experimental protocols. SIRO was conceived in the same realm as the Patient Intervention Comparison Outcome (PICO) model that supports search, retrieval and classification purposes in evidence based medicine. We evaluate our approach against a set of competency questions modeled as SPARQL queries and processed against a set of published and unpublished protocols modeled with the SP Ontology and the SIRO model. Our approach makes it possible to answer queries such as Which protocols use tumor tissue as a sample. Improving reporting structures for experimental protocols requires collective efforts from authors, peer reviewers, editors and funding bodies. The SP Ontology is a contribution towards this goal. We build upon previous experiences and bringing together the view of researchers managing protocols in their laboratory work. Website: https://smartprotocols.github.io/ .

Diurnal variability and biogeochemical reactivity of mercury species in an extreme high-altitude lake ecosystem of the Bolivian Altiplano.

Science.gov (United States)

Alanoca, L; Amouroux, D; Monperrus, M; Tessier, E; Goni, M; Guyoneaud, R; Acha, D; Gassie, C; Audry, S; Garcia, M E; Quintanilla, J; Point, D

2016-04-01

Methylation and demethylation represent major transformation pathways regulating the net production of methylmercury (MMHg). Very few studies have documented Hg reactivity and transformation in extreme high-altitude lake ecosystems. Mercury (Hg) species concentrations (IHg, MMHg, Hg°, and DMHg) and in situ Hg methylation (M) and MMHg demethylation (D) potentials were determined in water, sediment, floating organic aggregates, and periphyton compartments of a shallow productive Lake of the Bolivian Altiplano (Uru Uru Lake, 3686 m). Samples were collected during late dry season (October 2010) and late wet season (May 2011) at a north (NS) and a south (SS) site of the lake, respectively. Mercury species concentrations exhibited significant diurnal variability as influenced by the strong diurnal biogeochemical gradients. Particularly high methylated mercury concentrations (0.2 to 4.5 ng L(-1) for MMHgT) were determined in the water column evidencing important Hg methylation in this ecosystem. Methylation and D potentials range were, respectively, production in both water (up to 0.45 ng MMHg L(-1) day(-1)) and sediment compartments (2.0 to 19.7 ng MMHg g(-1) day(-1)). While the sediment compartment appears to represent a major source of MMHg in this shallow ecosystem, floating organic aggregates (dry season, SS) and Totora's periphyton (wet season, NS) were found to act as a significant source (5.8 ng MMHg g(-1) day(-1)) and a sink (-2.1 ng MMHg g(-1) day(-1)) of MMHg, respectively. This work demonstrates that high-altitude productive lake ecosystems can promote MMHg formation in various compartments supporting recent observations of high Hg contents in fish and water birds.

Does representative wind information exist?

NARCIS (Netherlands)

Wieringa, J.

1996-01-01

Representativity requirements are discussed for various wind data users. It is shown that most applications can be dealt with by using data from wind stations when these are made to conform with WMO specifications. Methods to achieve this WMO normalization are reviewed, giving minimum specifications

Crisis Relocation Workshops for Transportation Industry Representatives

Science.gov (United States)

1979-12-01

executive, two National Guard members, one Air Force transporta- _a ,tion representative, two Red Cross representatives, one school bus z coordinators...manaaers, local transitCD operator, and miiltary busingA authorityA Local Governa-ient 2 Fire chief, assistantI Air Force 3 Liaison Support D CPA :z...to attend the workshop. Majur trans- portation problems anticipated during crisis relocation include: 1. Transportation of carless residents; 2. The

Representing uncertainty on model analysis plots

Directory of Open Access Journals (Sweden)

Trevor I. Smith

2016-09-01

Full Text Available Model analysis provides a mechanism for representing student learning as measured by standard multiple-choice surveys. The model plot contains information regarding both how likely students in a particular class are to choose the correct answer and how likely they are to choose an answer consistent with a well-documented conceptual model. Unfortunately, Bao’s original presentation of the model plot did not include a way to represent uncertainty in these measurements. I present details of a method to add error bars to model plots by expanding the work of Sommer and Lindell. I also provide a template for generating model plots with error bars.

Peritransplant Treg-Based Immunomodulation to Improve VCA Outcomes

Science.gov (United States)

2017-10-01

orthotopic limb allografts in conjunction with TCR mAb and/or WT or HDAC-/- Treg cell administration 6-12 Milestone(s) Achieved: Efficacy of polyclonal WT...demethylation for each population (WT Tregs, HDAC6-/- Tregs, HDAC11-/- Tregs). 10-12 Subtask 2: Perform orthotopic limb allografts in conjunction ...function, and assessment of TSDR demethylation. • Subtask 3: Perform orthotopic limb allografts in conjunction with TCR mAb and/or WT or HDAC-/- Treg cell

Toxicological and chemical insights into representative source and drinking water in eastern China.

Science.gov (United States)

Shi, Peng; Zhou, Sicong; Xiao, Hongxia; Qiu, Jingfan; Li, Aimin; Zhou, Qing; Pan, Yang; Hollert, Henner

2018-02-01

Drinking water safety is continuously threatened by the emergence of numerous toxic organic pollutants (TOPs) in environmental waters. In this study, an approach integrating in vitro bioassays and chemical analyses was performed to explore toxicological profiles of representative source and drinking water from waterworks of the Yangtze River (Yz), Taihu Lake (Th), and the Huaihe River (Hh) basins in eastern China. Overall, 34 of 96 TOPs were detected in all water samples, with higher concentrations in both source and drinking water samples of Hh, and pollutant profiles also differed across different river basins. Non-specific bioassays indicated that source water samples of Hh waterworks showed higher genotoxicity and mutagenicity than samples of Yz and Th. An EROD assay demonstrated dioxin-like toxicity which was detected in 5 of 7 source water samples, with toxin concentration levels ranging from 62.40 to 115.51 picograms TCDD equivalents per liter of water (eq./L). PAHs and PCBs were not the main contributors to observed dioxin-like toxicity in detected samples. All source water samples induced estrogenic activities of 8.00-129.00 nanograms 17β-estradiol eq./L, and estrogens, including 17α-ethinylestradiol and estriol, contributed 40.38-84.15% of the observed activities in examined samples. While drinking water treatments efficiently removed TOPs and their toxic effects, and estrogenic activity was still observed in drinking water samples of Hh. Altogether, this study indicated that the representative source water in eastern China, especially that found in Hh, may negatively affect human health, a finding that demonstrates an urgent requirement for advanced drinking water treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

An affordable proxy of representative national survey on radon concentration in dwellings: Design, organisation and preliminary evaluation of representativeness

International Nuclear Information System (INIS)

Antignani, Sara; Carelli, Vinicio; Cordedda, Carlo; Zonno, Fedele; Ampollini, Marco; Carpentieri, Carmela; Venoso, Gennaro; Bochicchio, Francesco

2013-01-01

Representative national surveys in dwellings are important to unbiasedly evaluate the exposure of the general population to radon. In Italy, a representative national survey was conducted from 1989 to 1996, which involved about 5600 dwellings in 232 towns. Later on, some Regions carried out more detailed surveys, but a new national survey in dwellings is necessary in order to obtain a more thorough estimate of radon concentration distribution over the Italian territory. The need to make this survey in an affordable way led to implement a new approach based on the collaboration between the Istituto Superiore di Sanità and a national company with workplaces and employees' homes throughout the country. The intent is to carry out a proxy of a population representative survey by measuring radon concentration in the homes of a random sample of the company employees. The realisation of this survey was affordable, thanks to the availability of corporate e-mail for each employee, intranet service, and company internal mail service. A dedicated web procedure and e-questionnaires allowed to automatically manage the contact with employees and to collect their data, which were both cost- and time-saving. Using this e-mail contact approach, 53% of contacted employees consented to participate in the survey. Radon concentration passive measuring devices were distributed to about 7000 dwellings, using about 14000 CR-39 detectors (two measured rooms per dwelling). In order to reduce costs, the devices were exposed for 12 months instead of two consecutive 6-month periods (as with the former national survey). A first checking of the actual representativeness of the sample was done by comparing characteristics of dwellings and occupants in the sample with corresponding data from the latest National Census. This was accomplished thanks to the fact that the questions in the survey questionnaire were tailored to the categories adopted for the Census questionnaire. A preliminary

High School Students' Perception of University Students as STEM Representatives

DEFF Research Database (Denmark)

Poulsen, Eva Lykkegaard

’ potential identities. It shows that the students preferred STEM representatives resembled themselves in some aspects (primarily social and health aspects) and fit their perceptions of a typical person working in STEM in other aspects (knowledge seeking, hard-working etc.). At least two different...... studies, it is important to introduce high school students to good STEM representatives to make possible the development of potential STEM identities. A potential identity within a specific subject area relies on at least a situation bound relation-ship to the subject area or the person representing it....... Some representatives transmit infor-mation and are thereby definers, whereas other representatives illustrates as personal examples and are thereby models. This study focuses on high school students’ views on STEM representatives and the impact these representatives have on the high school students...

Active play and screen time in US children aged 4 to 11 years in relation to sociodemographic and weight status characteristics: a nationally representative cross-sectional analysis

Directory of Open Access Journals (Sweden)

Must Aviva

2008-10-01

Full Text Available Abstract Background The high prevalence of childhood obesity underscores the importance of monitoring population trends in children's activity and screen time, and describing associations with child age, gender, race/ethnicity, and weight status. Our objective was to estimate the proportion of young children in the US who have low levels of active play or high levels of screen time, or who have both these behaviors, and to describe associations with age, gender, race/ethnicity, and weight status. Methods We analyzed data collected during the National Health and Nutrition Examination Surveys 2001–2004, a US nationally representative cross-sectional study. We studied 2964 children aged 4.00 to 11.99 years. Our main outcomes were reported weekly times that the child played or exercised hard enough to sweat or breathe hard (active play, daily hours the child watched television/videos, used computers, or played computer games (screen time, and the combination of low active play and high screen time. Low active play was defined as active play 6 times or less per week. High screen time was defined as more than 2 hours per day. We accounted for the complex survey design in analyses and report proportions and 95% confidence intervals. We used Wald Chi-square to test for differences between proportions. To identify factors associated with low active play and high screen time, we used multivariate logistic regression. Results Of US children aged 4 to 11 years, 37.3% (95% confidence interval, 34.1% to 40.4% had low levels of active play, 65.0% (95% CI, 61.4% to 68.5% had high screen time, and 26.3% (95% CI, 23.8% to 28.9% had both these behaviors. Characteristics associated with a higher probability of simultaneously having low active play and high screen time were older age, female gender, non-Hispanic black race/ethnicity, and having a BMI-for-age ≥95th percentile of the CDC growth reference. Conclusion Many young children in the US are reported to

Judgments of and by Representativeness

Science.gov (United States)

1981-05-15

p. 4i). This hy- pothesis was studied in several contexts, including intuitive statisti- cal judgments and the prediction of professional choice (Kahneman... professional choice . Here, X is representative of M either because it is frequently associated with M (e.g., high fever commonly accompanies pneumonia

WIPP facility representative program plan

International Nuclear Information System (INIS)

1994-01-01

This plan describes the Department of Energy (DOE), Carlsbad Area Office (CAO) facility representative (FR) program at the Waste Isolation Pilot Plant (WIPP). It provides the following information: (1) FR and support organization authorities and responsibilities; (2) FR program requirements; and (3) FR training and qualification requirements

Tritium Labeled Gentamicin C: II.- Bioradiactive Degradation Products of Gentamicin by Catalytic H2O-3H Exchange Reaction; Getamicina C Tritiada: II.- Productos de Degradacion Radiactivos y Bioactivos en el Intercambio Catalitico con H2O-3H

Energy Technology Data Exchange (ETDEWEB)

Suarez, C; Diaz, A; Paz, D; Jimeno, M L

1992-07-01

The main bio radioactive degradation products from catalytic hydrogen exchange of gentamicin C, (C1 + C2 + Cla) in basic form, are generated by N-demethylation in 3{sup -}N and 6-N positions. Their structures were confirmed by 1HNMR and 13CNMR. These derivatives were fractionated by chromatography on silica gel. Antibacterial activities were similar to those of the parent antibiotics. Tritium exchange, under vacuum or nitrogen, is highly increased (4:1) when gentamicin are in basic form. In contrast with gentamicin sulfate, hydrolytic sub products as gramine, genta mines, garosamine and purpurosamines are practically absent. To properly optimize the exchange process, the composition of the gentamicin C complex must be taken into account. The exchange decreases in the order C2 > C1> Cla. Because of 6'-N-demethyl gentamicin C1 is C2, the radiochemical yield of C2 appears enhanced in the H2O-3H exchange of a mixture of them. Radioactivity distribution among the components and subunits of these three gentamicin were studied by strong and mild hydrolysis, and by methanolysis. (Author) 18 refs.

Tritium Labeled Gentamicin C: II.- Bioradiactive Degradation Products of Gentamicin by Catalytic H2O-3H Exchange Reaction

International Nuclear Information System (INIS)

Suarez, C.; Diaz, A.; Paz, D.; Jimeno, M. L.

1992-01-01

The main bio radioactive degradation products from catalytic hydrogen exchange of gentamicin C, (C1 + C2 + Cla) in basic form, are generated by N-demethylation in 3 - N and 6-N positions. Their structures were confirmed by 1HNMR and 13CNMR. These derivatives were fractionated by chromatography on silica gel. Antibacterial activities were similar to those of the parent antibiotics. Tritium exchange, under vacuum or nitrogen, is highly increased (4:1) when gentamicin are in basic form. In contrast with gentamicin sulfate, hydrolytic sub products as gramine, genta mines, garosamine and purpurosamines are practically absent. To properly optimize the exchange process, the composition of the gentamicin C complex must be taken into account. The exchange decreases in the order C2 > C1> Cla. Because of 6'-N-demethyl gentamicin C1 is C2, the radiochemical yield of C2 appears enhanced in the H2O-3H exchange of a mixture of them. Radioactivity distribution among the components and subunits of these three gentamicin were studied by strong and mild hydrolysis, and by methanolysis. (Author) 18 refs

De novo DNA methylation during monkey pre-implantation embryogenesis.

Science.gov (United States)

Gao, Fei; Niu, Yuyu; Sun, Yi Eve; Lu, Hanlin; Chen, Yongchang; Li, Siguang; Kang, Yu; Luo, Yuping; Si, Chenyang; Yu, Juehua; Li, Chang; Sun, Nianqin; Si, Wei; Wang, Hong; Ji, Weizhi; Tan, Tao

2017-04-01

Critical epigenetic regulation of primate embryogenesis entails DNA methylome changes. Here we report genome-wide composition, patterning, and stage-specific dynamics of DNA methylation in pre-implantation rhesus monkey embryos as well as male and female gametes studied using an optimized tagmentation-based whole-genome bisulfite sequencing method. We show that upon fertilization, both paternal and maternal genomes undergo active DNA demethylation, and genome-wide de novo DNA methylation is also initiated in the same period. By the 8-cell stage, remethylation becomes more pronounced than demethylation, resulting in an increase in global DNA methylation. Promoters of genes associated with oxidative phosphorylation are preferentially remethylated at the 8-cell stage, suggesting that this mode of energy metabolism may not be favored. Unlike in rodents, X chromosome inactivation is not observed during monkey pre-implantation development. Our study provides the first comprehensive illustration of the 'wax and wane' phases of DNA methylation dynamics. Most importantly, our DNA methyltransferase loss-of-function analysis indicates that DNA methylation influences early monkey embryogenesis.

Epigenetics and Autism

OpenAIRE

Mbadiwe, Tafari; Millis, Richard M.

2013-01-01

This review identifies mechanisms for altering DNA-histone interactions of cell chromatin to upregulate or downregulate gene expression that could serve as epigenetic targets for therapeutic interventions in autism. DNA methyltransferases (DNMTs) can phosphorylate histone H3 at T6. Aided by protein kinase C ? 1, the DNMT lysine-specific demethylase-1 prevents demethylation of H3 at K4. During androgen-receptor-(AR-) dependent gene activation, this sequence may produce AR-dependent gene overac...

Rhythm information represented in the fronto-parieto-cerebellar motor system.

Science.gov (United States)

Konoike, Naho; Kotozaki, Yuka; Miyachi, Shigehiro; Miyauchi, Carlos Makoto; Yomogida, Yukihito; Akimoto, Yoritaka; Kuraoka, Koji; Sugiura, Motoaki; Kawashima, Ryuta; Nakamura, Katsuki

2012-10-15

Rhythm is an essential element of human culture, particularly in language and music. To acquire language or music, we have to perceive the sensory inputs, organize them into structured sequences as rhythms, actively hold the rhythm information in mind, and use the information when we reproduce or mimic the same rhythm. Previous brain imaging studies have elucidated brain regions related to the perception and production of rhythms. However, the neural substrates involved in the working memory of rhythm remain unclear. In addition, little is known about the processing of rhythm information from non-auditory inputs (visual or tactile). Therefore, we measured brain activity by functional magnetic resonance imaging while healthy subjects memorized and reproduced auditory and visual rhythmic information. The inferior parietal lobule, inferior frontal gyrus, supplementary motor area, and cerebellum exhibited significant activations during both encoding and retrieving rhythm information. In addition, most of these areas exhibited significant activation also during the maintenance of rhythm information. All of these regions functioned in the processing of auditory and visual rhythms. The bilateral inferior parietal lobule, inferior frontal gyrus, supplementary motor area, and cerebellum are thought to be essential for motor control. When we listen to a certain rhythm, we are often stimulated to move our body, which suggests the existence of a strong interaction between rhythm processing and the motor system. Here, we propose that rhythm information may be represented and retained as information about bodily movements in the supra-modal motor brain system. Copyright © 2012 Elsevier Inc. All rights reserved.

Representatives of religious education in the structure of Novorossiysk university

Directory of Open Access Journals (Sweden)

Г. П. Бахчиванжи

2015-03-01

Full Text Available History of the Departments of Theology, Ecclesiastical History and Ecclesiastical Law of Novorossiysk University as well as clarification of activities of professors who were the Heads of these Departments is the subject of the article. The objective of the research was to reveal the contribution to science these professors had made on basis of such material as “Records of Proceedings of the Board Meeting of Novorossiysk University”, “Teaching of Sciences at the Imperial Novorossiysk University Review” as well as the particular studies of the professors themselves. As a result of the research using the analytical approach generic aspects of existence of theological departments in educational structure of the University including the period of teaching the theological disciplines at the Richelieu Lycée were described. The basic legislative acts regulating the activity of such Departments were stated and the activity of such professors as Pavlovskiy M.K., Kudryavtsev A.N., Voytovskiy V.M., Klitin A.N., Krasnoseltsev N.F., Dobroklonskiy A.P., Almazov A.I., Pavlov F.S. who not only became the significant persons in the history of the University but also played the leading role in social and spiritual life of Odessa in general was elucidated. Such analysis of the activity of the representatives of religious education at Novorossiysk University provided an opportunity to conclude of the importance of the theological disciplines in educational structure of the University as it is them that are of great importance to the spiritual development of personality and society on the whole.

Marc Treib: Representing Landscape Architecture

DEFF Research Database (Denmark)

Braae, Ellen Marie

2008-01-01

The editor of Representing Landscape Architecture, Marc Treib, argues that there is good reason to evaluate the standard practices of representation that landscape architects have been using for so long. In the rush to the promised land of computer design these practices are now in danger of being...

OAS :: Member States : Permanent Representatives

Science.gov (United States)

Rights Actions against Corruption C Children Civil Registry Civil Society Contact Us Culture Cyber Barbados Belize Bolivia Brazil Canada Chile Colombia Costa Rica Cuba 1 Dominica (Commonwealth of) Dominican Gutierez Ambassador, Permanent Representative of Belize Diego Pary Rodríguez Bolivia Diego Pary Rodríguez

Carbon-cycle effects of differences in soil moisture and soil extracellular enzyme activity at sites representing different land-use histories in high-elevation Ecuadorian páramo landscapes

Science.gov (United States)

McKnight, J.; Harden, C. P.; Schaeffer, S. M.

2016-12-01

Ecuadorian páramo grasslands are important regional soil carbon sinks. In the páramo of the Mazar Wildlife Reserve, differences in soil carbon content among different types of land use may reflect changes in soil carbon-acquisition related microbial enzyme activity after land cover and soil moisture are altered; however, this hypothesis has not been tested explicitly for Ecuadorian páramos. This study used a fluorescence enzyme assay to assess the activities of four different extracellular enzymes representing carbon acquisition: α-glucosidase, β-glucosidase, β-D-cellulobiohydrolase, and β-xylosidase in Andean páramo soils. Acquisition activities were also measured for nitrogen (N-acetyl-β-glucosidase and leucine aminopeptidase) and phosphorus (phosphatase) to assess stoichiometric differences between land-uses, which can affect soil microbial activity related to carbon acquisition. Soils were analyzed from four land uses: native forest, grass páramo, recently burned grass páramo, and non-native pine plantation. Carbon acquisition activity was highest at the pine site (678 nmol h-1 g-1) and lowest at the recently burned páramo site (252 nmol h-1 g-1), indicating the lowest and highest available soil carbon, respectively. Carbon-acquisition EE activity was significantly higher at the grass páramo site (595 nmol h-1 g-1) than at the recently burned páramo and native forest sites. At the grass páramo site, a history of burning as a management strategy and high carbon-acquisition EE activity could indicate the presence of pyrogenic soil organic matter, which is more resistant to microbial decomposition. Soils at the native forest and both grassland sites were phosphorus limited, and soil at the pine site had higher nitrogen-acquisition activity, indicative of a shift to nitrogen-limited soil stoichiometric conditions. To our knowledge these are the first data reported for soil extracellular enzyme activities for Ecuadorian páramos.

40 CFR 436.32 - Effluent limitations guidelines representing the degree of effluent reduction attainable by the...

Science.gov (United States)

2010-07-01

... Construction Sand and Gravel Subcategory § 436.32 Effluent limitations guidelines representing the degree of... unaltered by man's activities, is or would be less than 6.0 and water quality criteria in water quality... adjusted downward to the pH water quality criterion for the receiving waters. In no case shall a pH...

37 CFR 10.84 - Representing a client zealously.

Science.gov (United States)

2010-07-01

... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Representing a client... Office Code of Professional Responsibility § 10.84 Representing a client zealously. (a) A practitioner shall not intentionally: (1) Fail to seek the lawful objectives of a client through reasonably available...

Representing Young Children with Disabilities in Classroom Environments.

Science.gov (United States)

Favazza, Paddy C.; LaRoe, Joyce; Phillipsen, Leslie; Kumar, Poonam

2000-01-01

The "Inventory of Disability Representation" was administered to 92 teachers representing kindergarten, community child care, or preschool settings. Low scores across settings indicated that classrooms typically do not have materials that represent or depict children with diverse abilities. Reasons cited by teachers are noted as are benefits…

Officers, Boards, Committees, and Representatives of the American Psychological Association, 2007

Science.gov (United States)

American Psychologist, 2007

2007-01-01

The Council of Representatives is composed of the Board of Directors, the American Psychological Association of Graduate Students (APAGS) representative, division representatives, and state, provincial, and territorial association representatives. Then representatives for the current year, with terms of office, are listed in this article.

Determination of representative CANDU feeder dimensions for engineering simulator

International Nuclear Information System (INIS)

Cho, S.; Muzumdar, A.

1996-01-01

This paper describes a logic for selection of representative channel groups and a methodology for determination of representative CANDU feeder dimensions and the pressure drops between inlet/outlet header and fuel channel in the primary loop. A code, MEDOC, was developed based on this logic and methodology and helps perform a calculation of representative feeder dimensions for a selected channel group on the basis of feeder geometry data (fluid volume, mass flow rate, loss factor) and given property data (pressure, quality, density) at inlet/outlet header. The representative feeder dimensions calculated based on this methodology will be useful for the engineering simulator for the CANDU type reactor. (author)

Two Distinct Pathways for Metabolism of Theophylline and Caffeine Are Coexpressed in Pseudomonas putida CBB5▿ †

Science.gov (United States)

Yu, Chi Li; Louie, Tai Man; Summers, Ryan; Kale, Yogesh; Gopishetty, Sridhar; Subramanian, Mani

2009-01-01

Pseudomonas putida CBB5 was isolated from soil by enrichment on caffeine. This strain used not only caffeine, theobromine, paraxanthine, and 7-methylxanthine as sole carbon and nitrogen sources but also theophylline and 3-methylxanthine. Analyses of metabolites in spent media and resting cell suspensions confirmed that CBB5 initially N demethylated theophylline via a hitherto unreported pathway to 1- and 3-methylxanthines. NAD(P)H-dependent conversion of theophylline to 1- and 3-methylxanthines was also detected in the crude cell extracts of theophylline-grown CBB5. 1-Methylxanthine and 3-methylxanthine were subsequently N demethylated to xanthine. CBB5 also oxidized theophylline and 1- and 3-methylxanthines to 1,3-dimethyluric acid and 1- and 3-methyluric acids, respectively. However, these methyluric acids were not metabolized further. A broad-substrate-range xanthine-oxidizing enzyme was responsible for the formation of these methyluric acids. In contrast, CBB5 metabolized caffeine to theobromine (major metabolite) and paraxanthine (minor metabolite). These dimethylxanthines were further N demethylated to xanthine via 7-methylxanthine. Theobromine-, paraxanthine-, and 7-methylxanthine-grown cells also metabolized all of the methylxanthines mentioned above via the same pathway. Thus, the theophylline and caffeine N-demethylation pathways converged at xanthine via different methylxanthine intermediates. Xanthine was eventually oxidized to uric acid. Enzymes involved in theophylline and caffeine degradation were coexpressed when CBB5 was grown on theophylline or on caffeine or its metabolites. However, 3-methylxanthine-grown CBB5 cells did not metabolize caffeine, whereas theophylline was metabolized at much reduced levels to only methyluric acids. To our knowledge, this is the first report of theophylline N demethylation and coexpression of distinct pathways for caffeine and theophylline degradation in bacteria. PMID:19447909

27 CFR 71.31 - Attorneys and other representatives.

Science.gov (United States)

2010-04-01

... representatives. 71.31 Section 71.31 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE... applicant may be represented by an attorney, certified public accountant, or other person enrolled to practice before the Alcohol and Tobacco Tax and Trade Bureau under 31 CFR part 8—Practice before the...

Calls to Teen Line: Representative Concerns of Adolescents.

Science.gov (United States)

Boehm, Kathryn E.; Schondel, Connie K.; Ivoska, William J.; Marlowe, Alison L.; Manke-Mitchell, Laurie

1998-01-01

Study examines whether the concerns of teenagers calling a peer listening service are representative of the concerns of teenagers in the area served. Results indicate that students' biggest concerns involve family problems, peer relationships, self-esteem, and school problems. Concludes that calls to the teen line are representative. (Author/GCP)

REFractions: The Representing Equivalent Fractions Game

Science.gov (United States)

Tucker, Stephen I.

2014-01-01

Stephen Tucker presents a fractions game that addresses a range of fraction concepts including equivalence and computation. The REFractions game also improves students' fluency with representing, comparing and adding fractions.

Representing distance, consuming distance

DEFF Research Database (Denmark)

Larsen, Gunvor Riber

Title: Representing Distance, Consuming Distance Abstract: Distance is a condition for corporeal and virtual mobilities, for desired and actual travel, but yet it has received relatively little attention as a theoretical entity in its own right. Understandings of and assumptions about distance...... are being consumed in the contemporary society, in the same way as places, media, cultures and status are being consumed (Urry 1995, Featherstone 2007). An exploration of distance and its representations through contemporary consumption theory could expose what role distance plays in forming...

Representing culture in interstellar messages

Science.gov (United States)

Vakoch, Douglas A.

2008-09-01

As scholars involved with the Search for Extraterrestrial Intelligence (SETI) have contemplated how we might portray humankind in any messages sent to civilizations beyond Earth, one of the challenges they face is adequately representing the diversity of human cultures. For example, in a 2003 workshop in Paris sponsored by the SETI Institute, the International Academy of Astronautics (IAA) SETI Permanent Study Group, the International Society for the Arts, Sciences and Technology (ISAST), and the John Templeton Foundation, a varied group of artists, scientists, and scholars from the humanities considered how to encode notions of altruism in interstellar messages . Though the group represented 10 countries, most were from Europe and North America, leading to the group's recommendation that subsequent discussions on the topic should include more globally representative perspectives. As a result, the IAA Study Group on Interstellar Message Construction and the SETI Institute sponsored a follow-up workshop in Santa Fe, New Mexico, USA in February 2005. The Santa Fe workshop brought together scholars from a range of disciplines including anthropology, archaeology, chemistry, communication science, philosophy, and psychology. Participants included scholars familiar with interstellar message design as well as specialists in cross-cultural research who had participated in the Symposium on Altruism in Cross-cultural Perspective, held just prior to the workshop during the annual conference of the Society for Cross-cultural Research . The workshop included discussion of how cultural understandings of altruism can complement and critique the more biologically based models of altruism proposed for interstellar messages at the 2003 Paris workshop. This paper, written by the chair of both the Paris and Santa Fe workshops, will explore the challenges of communicating concepts of altruism that draw on both biological and cultural models.

Potential Mechanism of Action of 3′-Demethoxy-6-O-demethyl-isoguaiacin on Methicillin Resistant Staphylococcus aureus

OpenAIRE

Favela-Hernández, Juan; Clemente-Soto, Aldo; Balderas-Rentería, Isaías; Garza-González, Elvira; Camacho-Corona, María

2015-01-01

Bacterial infections represent one of the main threats to global public health. One of the major causative agents associated with high morbidity and mortality infections in hospitals worldwide is methicillin-resistant Staphylococcus aureus. Therefore, there is a need to develop new antibacterial agents to treat these infections, and natural products are a rich source of them. In previous studies, we reported that lignan 3′-demethoxy-6-O-demethylisoguaiacin, isolated and characterized from L...

Assessing Use of Cognitive Heuristic Representativeness in Clinical Reasoning

OpenAIRE

Payne, Velma L.; Crowley, Rebecca S.

2008-01-01

We performed a pilot study to investigate use of the cognitive heuristic Representativeness in clinical reasoning. We tested a set of tasks and assessments to determine whether subjects used the heuristics in reasoning, to obtain initial frequencies of heuristic use and related cognitive errors, and to collect cognitive process data using think-aloud techniques. The study investigates two aspects of the Representativeness heuristic - judging by perceived frequency and representativeness as ca...

Relationship between polychlorinated biphenyl 126 treatment and cytochrome P4501A activity in chickens, as measured by in vivo caffeine and ex vivo ethoxyresorufin metabolism

Energy Technology Data Exchange (ETDEWEB)

Feyk, L.A.; Giesy, J.P.; Lambert, G.H.

1999-09-01

Cytochrome P4501A (CYPIA) activity is often used as a biomarker of exposure of wildlife to polyhalogenated diaromatic hydrocarbons (PHDHs) and is usually measured ex vivo in liver tissue. A caffeine breath test with radiolabeled substrate ({sup 14}C-CBT) has been developed to measure in vivo avian CYPIA activity. Research goals were to develop stable isotope methods ({sup 13}C-CBT), determine dose-response relationships between caffeine N-demethylation (CNDM) and PHDH exposure, and assess the relative utility of the CBT and ex vivo ethoxyresorufin-O-deethylase (EROD) assay. The {sup 13}C-CBT methods were developed with 20 chickens (Gallus domesticus). Chickens received three intraperitoneal injections of 0, 1, 5, or 50 {micro}g 3,3{prime},4,4{prime},5-pentachlorobiphenyl (PCB 126)/kg body weight, and CNDM was quantified by measurement of {sup 13}CO{sub 2}/{sup 12}CO{sub 2} in expired breath. The {sup 13}C-CBT was not as sensitive or specific as the EROD assay as an indicator of PHDH exposure and effect in birds. Constitutive CNDM of great interindividual variability was observed, and the magnitude of induction was greater for EROD activity than for CNDM (approximately 1,000- and 2-fold, respectively). Variability associated with baseline {sup 13}CO{sub 2}/{sup 12}CO{sub 2} ratios in expired breath reduced the sensitivity of the {sup 13}C-CBT method.

Representativeness elements of an hybrid reactor demonstrator

International Nuclear Information System (INIS)

Kerdraon, D.; Billebaud, A.; Brissot, R.; David, S.; Giorni, A.; Heuer, D.; Loiseaux, J.M.; Meplan, O.

2000-11-01

This document deals with the quantification of the minimum thermal power level for a demonstrator and the definition of the physical criteria which define the representative character of a demonstrator towards a power reactor. Solutions allowing to keep an acceptable flow in an industrial core, have also been studied. The document is divided in three parts: the representativeness elements, the considered solutions and the characterization of the neutrons flows at the interfaces and the dose rates at the outer surface of the vessel. (A.L.B.)

Enhancing policy innovation by redesigning representative democracy

DEFF Research Database (Denmark)

Sørensen, Eva

2016-01-01

Policy innovation is a key aspect of public innovation, which has been largely overlooked. Political leadership, competition and collaboration are key drivers of policy innovation. It is a barrier in traditional models of representative democracy that they provide weak conditions for collaboration....... Two Danish case studies indicate that collaboration between politicians and relevant and affected stakeholders can promote policy innovation, but also that a redesign of representative democracy is needed in order to establish a productive combination of political leadership, competition...... and collaboration in political life....

Japanese practicing physicians' relationships with pharmaceutical representatives: a national survey.

Directory of Open Access Journals (Sweden)

Sayaka Saito

Full Text Available BACKGROUND: Previous surveys on the relationship between physicians and pharmaceutical representatives (PRs have been of limited quality. The purpose of our survey of practicing physicians in Japan was to assess the extent of their involvement in pharmaceutical promotional activities, physician characteristics that predict such involvement, attitudes toward relationships with PRs, correlations between the extent of involvement and attitudes, and differences in the extent of involvement according to self-reported prescribing behaviors. METHODS AND FINDINGS: From January to March 2008, we conducted a national survey of 2621 practicing physicians in seven specialties: internal medicine, general surgery, orthopedic surgery, pediatrics, obstetrics-gynecology, psychiatry, and ophthalmology. The response rate was 54%. Most physicians met with PRs (98%, received drug samples (85% and stationery (96%, and participated in industry-sponsored continuing medical education (CME events at the workplace (80% and outside the workplace (93%. Half accepted meals outside the workplace (49% and financial subsidies to attend CME events (49%. Rules at the workplace banning both meetings with PRs and gifts predicted less involvement of physicians in promotional activities. Physicians valued information from PRs. They believed that they were unlikely to be influenced by promotional activities, but that their colleagues were more susceptible to such influence than themselves. They were divided about the appropriateness of low-value gifts. The extent of physician involvement in promotional activities was positively correlated with the attitudes that PRs are a valuable source of information and that gifts are appropriate. The extent of such involvement was higher among physicians who prefer to ask PRs for information when a new medication becomes available, physicians who are not satisfied with patient encounters ending only with advice, and physicians who prefer to

High School Students' Perception of University Students as STEM Representatives

DEFF Research Database (Denmark)

Poulsen, Eva Lykkegaard

The Danish government has an ambition to recruit more high school students into STEM edu-cations (science, technology, engineering and/or mathematics). The students’ choice of further education is based on the people and jobs they have knowledge of. Therefore, to recruit more students into STEM....... Some representatives transmit infor-mation and are thereby definers, whereas other representatives illustrates as personal examples and are thereby models. This study focuses on high school students’ views on STEM representatives and the impact these representatives have on the high school students...... studies, it is important to introduce high school students to good STEM representatives to make possible the development of potential STEM identities. A potential identity within a specific subject area relies on at least a situation bound relation-ship to the subject area or the person representing it...

Toxicity and DNA methylation changes induced by perfluorooctane sulfonate (PFOS) in sea urchin Glyptocidaris crenularis.

Science.gov (United States)

Ding, Guanghui; Wang, Luyan; Zhang, Jing; Wei, Yuanyuan; Wei, Lie; Li, Yang; Shao, Mihua; Xiong, Deqi

2015-06-01

Perfluorooctane sulfonate (PFOS) is an ubiquitous persistent organic pollutant, which can be bioaccumulated and cause adverse effects on organisms. However, there is very limited information about the toxic effects of PFOS to marine organisms and its mechanisms. Therefore, in the present study, adult sea urchins Glyptocidaris crenularis were exposed to PFOS for 21 d, followed by a 7-d depuration period, in order to investigate the toxicity of PFOS to sea urchin and its potential epigenetic mechanisms. Sea urchins dropped spines, and lowered down the motor ability and feeding ability after the PFOS exposure. Superoxide dismutase activities in supernatant of coelomic fluid of sea urchin increased firstly and then dropped down, while the change of the catalase activity took an opposite trend during the exposure period. They both approached to the corresponding activity of the control after the depuration period. The DNA methylation polymorphism, methylation rate and demethylation rate in sea urchin gonad all increased following the prolonged exposure time, and then decreased after the depuration period. The demethylation rates were lower than the corresponding methylation rates, therefore methylation events were dominant during the whole experimental period. This might suggest that sea urchin have strong self-protection mechanisms and can survive from the PFOS exposure presented in this study. Further efforts are needed to more precisely investigate the DNA methylation effects of PFOS and the self-protection mechanism of sea urchin. Copyright © 2015 Elsevier Ltd. All rights reserved.

Representation of activity in images using geospatial temporal graphs

Science.gov (United States)

Brost, Randolph; McLendon, III, William C.; Parekh, Ojas D.; Rintoul, Mark Daniel; Watson, Jean-Paul; Strip, David R.; Diegert, Carl

2018-05-01

Various technologies pertaining to modeling patterns of activity observed in remote sensing images using geospatial-temporal graphs are described herein. Graphs are constructed by representing objects in remote sensing images as nodes, and connecting nodes with undirected edges representing either distance or adjacency relationships between objects and directed edges representing changes in time. Activity patterns may be discerned from the graphs by coding nodes representing persistent objects like buildings differently from nodes representing ephemeral objects like vehicles, and examining the geospatial-temporal relationships of ephemeral nodes within the graph.

Dissertation presented by Denis Biard to obtain the national diploma of Accreditation to supervise research of the Paris-Sud 11 University

International Nuclear Information System (INIS)

Biard, Denis

2008-01-01

In this report, the author gives an overview of his research activities in the field of cellular and molecular biology, from genetic toxicology to radiobiology. After his first works on a test of in vivo DNA repair, and the investigation of DNA de-methylating agents, his researches addressed the HSA kin17 human protein (its gene and its transcription, its over-expression; its radiosensitivity, and so on), and the RNA interference on a very long term [fr

A new dimeric anthraquinone from endophytic Talaromyces sp. YE3016.

Science.gov (United States)

Xie, Xiao-Song; Fang, Xiao-Wei; Huang, Rong; Zhang, Shou-Peng; Wei, Hong-Xia; Wu, Shao-Hua

2016-08-01

A new unsymmetrical dimeric anthraquinone, 3-demethyl-3-(2-hydroxypropyl)-skyrin (1) was isolated from the solid-state fermentation extract of an endophytic fungal strain Talaromyces sp. YE 3016, together with five known compounds, skyrin (2), oxyskyrin (3), emodin (4), 1,3,6-trihydroxy-8-methyl-anthraquinone (5) and ergosterol (6). The structure of the new compound was elucidated on the basis of spectroscopic analysis. Compounds 1-3 exhibited moderate cytotoxic activities against MCF-7 cell line.

Climate Change and the Representative Agent

Energy Technology Data Exchange (ETDEWEB)

Howarth, R.B. [Environmental Studies Program, Dartmouth College, Hanover, New Hampshire 03755 (United States)

2000-02-01

The artifice of an infinitely-lived representative agent is commonly invoked to balance the present costs and future benefits of climate stabilization policies. Since actual economies are populated by overlapping generations of finite-lived persons, this approach begs important questions of welfare aggregation. This paper compares the results of representative agent and overlapping generations models that are numerically calibrated based on standard assumptions regarding climate economy interactions. Under two social choice rules - Pareto efficiency and classical utilitarianism - the models generate closely similar simulation results. In the absence of policies to redistribute income between present and future generations, efficient rates of carbon dioxide emissions abatement rise from 15 to 20% between the years 2000 and 2105. Under classical utilitarianism, in contrast, optimal control rates rise from 48 to 79% this same period. 23 refs.

Statistics On Title II Direct Payments To Claimant Representatives

Data.gov (United States)

Social Security Administration — Every person has the right to be represented by an attorney or other representative while pursuing a claim or other rights. This dataset contains data around Title...

Overview of representative ecological risk assessments conducted for sites with enhanced radioactivity

International Nuclear Information System (INIS)

Chambers, D.B; Fernandes, S.L.; Phillips, H.A.

2008-01-01

Ionizing radiation is ubiquitous and all living things are, and always have been, exposed to naturally occurring radiation and radioactivity. In addition, human activities have enhanced the natural background levels of radiation and radioactivity globally and, in some cases, locally. Over the past ten or so years, numerous ecological risk assessments (ERAs) have been carried out for a number of sites involving enhanced radiation and radioactivity. The ERAs have examined a range of ecological receptors and have been performed using a variety of approaches, using different assumptions and reference radiation dose rates. A review of representative ERAs selected to encompass a wide range of activities (e.g. uranium mining, nuclear generating stations, waste management sites), locations (e.g. Canada, France, UK, Russia, USA) and ecosystems (terrestrial, freshwater and marine aquatic environments), was completed. The wide range of sites considered in this review demonstrate that the current system of radiological protection has provided an adequate level of protection to populations of non-human biota. (author)

DFS Associates: Simple ways to become a good manufacturer's representative

OpenAIRE

Sandra K. Pharre

2018-01-01

Being one of the trusted manufacturer’s representative firms for RF and microwave products and services, DFS Associates wanted to impart a few insights to consider in becoming a good manufacturer’s representative with this article. Firstly, you need to understand what it does if you’re interested on becoming one where it could be an individual or a small business that can represent a manufacturer’s products and services effectively to the marketplace. You can choose between representing one m...

20 CFR 404.1720 - Fee for a representative's services.

Science.gov (United States)

2010-04-01

... DISABILITY INSURANCE (1950- ) Representation of Parties § 404.1720 Fee for a representative's services. (a... you or your representative from contacting us in person or in writing. (B) There was a death or...

20 CFR 416.1520 - Fee for a representative's services.

Science.gov (United States)

2010-04-01

... AGED, BLIND, AND DISABLED Representation of Parties § 416.1520 Fee for a representative's services. (a... you or your representative from contacting us in person or in writing. (B) There was a death or...

Association of Dietary Behaviors with Physical Activity in a Nationally Representative Sample of Children and Adolescents: the CASPIAN- IV Study

Directory of Open Access Journals (Sweden)

Saeid Safiri

2016-03-01

Full Text Available Background: Nutritional health and adequate physical activity (PA, especially in childhood and grow periods, have a substantial role in health. This study assessed the association of dietary behaviors (main courses and snacks intake with PA in children and adolescents. Materials and Methods: Using multistage random cluster sampling method, a representative sample of 14,880 school students were selected from urban and rural areas of 30 provinces of Iran. Through a validated questionnaire, daily consumption of main course ( breakfast, lunch, and dinner as well as daily consumption of different snacks and health foods ( fast foods, milk, vegetables, dry fruits, fresh fruits, sweetened beverages, salty snacks and sweets were recorded for every participants. Information of past week weekly frequency of leisure time PA was collected. Results: Overall, 13,486 out of 14,880 students (response rate: 90.6% participated in this survey. Participants consisted of 6,640 (49.2% girls and 75.6% urban residents; their mean and standard deviation (SD age was 12.47 (3.36 years. Daily consumption of fresh fruits (odds ratio [OR]: 1.35, 95%confidence interval [CI]: 1.20-1.52, dried fruits (OR: 1.21; 95%CI: 1.06-1.40, vegetable (OR: 1.39; 95% CI: 1.24-1.56, and milk (OR: 1.35; 95% CI: 1.21-1.52 increased the odds of high PA compare to low PA in adjusted model.  Skipping the breakfast, lunch and dinner decreased the odds of moderate and high PA compare to low PA (P

Re-patterning of H3K27me3, H3K4me3 and DNA methylation during fibroblast conversion into induced cardiomyocytes

Directory of Open Access Journals (Sweden)

Ziqing Liu

2016-03-01

Full Text Available Direct conversion of fibroblasts into induced cardiomyocytes (iCMs offers an alternative strategy for cardiac disease modeling and regeneration. During iCM reprogramming, the starting fibroblasts must overcome existing epigenetic barriers to acquire the CM-like chromatin pattern. However, epigenetic dynamics along this reprogramming process have not been studied. Here, we took advantage of our recently generated polycistronic system and determined the dynamics of two critical histone marks, H3K27me3 and H3K4me3, in parallel with gene expression at a set of carefully selected cardiac and fibroblast loci during iCM reprogramming. We observed reduced H3K27me3 and increased H3K4me3 at cardiac promoters as early as day 3, paralleled by a rapid significant increase in their mRNA expression. In contrast, H3K27me3 at loci encoding fibroblast marker genes did not increase until day 10 and H3K4me3 progressively decreased along the reprogramming process; these changes were accompanied by a gradual decrease in the mRNA expression of fibroblast marker genes. Further analyses of fibroblast-enriched transcription factors revealed a similarly late deposition of H3K27me3 and decreased mRNA expression of Sox9, Twist1 and Twist2, three important players in epithelial−mesenchymal transition. Our data suggest early rapid activation of the cardiac program and later progressive suppression of fibroblast fate at both epigenetic and transcriptional levels. Additionally, we determined the DNA methylation states of representative cardiac promoters and found that not every single CpG was equally demethylated during early stages of iCM reprogramming. Rather, there are specific CpGs, whose demethylation states correlated tightly with transcription activation, that we propose are the major contributing CpGs. Our work thus reveals a differential re-patterning of H3K27me3, H3K4me3 at cardiac and fibroblast loci during iCM reprogramming and could provide future genome

Primary murine CD4+ T cells fail to acquire the ability to produce effector cytokines when active Ras is present during Th1/Th2 differentiation.

Directory of Open Access Journals (Sweden)

Sujit V Janardhan

Full Text Available Constitutive Ras signaling has been shown to augment IL-2 production, reverse anergy, and functionally replace many aspects of CD28 co-stimulation in CD4+ T cells. These data raise the possibility that introduction of active Ras into primary T cells might result in improved functionality in pathologic situations of T cell dysfunction, such as cancer or chronic viral infection. To test the biologic effects of active Ras in primary T cells, CD4+ T cells from Coxsackie-Adenovirus Receptor Transgenic mice were transduced with an adenovirus encoding active Ras. As expected, active Ras augmented IL-2 production in naive CD4+ T cells. However, when cells were cultured for 4 days under conditions to promote effector cell differentiation, active Ras inhibited the ability of CD4+ T cells to acquire a Th1 or Th2 effector cytokine profile. This differentiation defect was not due to deficient STAT4 or STAT6 activation by IL-12 or IL-4, respectively, nor was it associated with deficient induction of T-bet and GATA-3 expression. Impaired effector cytokine production in active Ras-transduced cells was associated with deficient demethylation of the IL-4 gene locus. Our results indicate that, despite augmenting acute activation of naïve T cells, constitutive Ras signaling inhibits the ability of CD4+ T cells to properly differentiate into Th1/Th2 effector cytokine-producing cells, in part by interfering with epigenetic modification of effector gene loci. Alternative strategies to potentiate Ras pathway signaling in T cells in a more regulated fashion should be considered as a therapeutic approach to improve immune responses in vivo.

Services Subcontract Technical Representative (STR) handbook

International Nuclear Information System (INIS)

Houston, D.H.

1997-06-01

The purpose of this handbook is to provide guidance to Bechtel Hanford, Inc. Subcontract Representatives in their assignments. It is the intention of this handbook to ensure that subcontract work is performed in accordance with the subcontract documents

Physicians' perceptions of medical representative visits in Yemen: a qualitative study.

Science.gov (United States)

Al-Areefi, Mahmoud Abdullah; Hassali, Mohamed Azmi; Ibrahim, Mohamed Izham b Mohamed

2013-08-20

The pharmaceutical industry invests heavily in promotion, and it uses a variety of promotional strategies to influence physicians' prescribing decisions. Within this context, medical representatives (MRs) are the key personnel employed in promoting their products. One significant consequence of the interactions between physicians and medical representatives is a conflict of interests which may contribute to the over prescribing of medications and thus negative effects on patients' health and economics. There is limited detailed information published on the reasons why physicians interact with pharmaceutical representatives. This study aims to qualitatively explore physicians' attitudes about interactions with medical representatives and their reasons for accepting the medical representatives' visits. In-depth interviews were used to gain a better understanding of physicians' perceptions of medical representative visits. A total of 32 physicians from both private and public hospitals were interviewed. The recordings of the interviews were transcribed verbatim and subject to thematic analysis using a framework analysis approach. The present qualitative study found that the majority of the physicians had positive interactions with medical representatives. The physicians' main reasons stated for allowing medical representatives' visits are the social contacts and mutual benefits they will gain from these representatives. They also emphasized that the meeting with representatives provides educational and scientific benefits. A few physicians stated that the main reasons behind refusing the meeting with medical representatives were lack of conviction about the product and obligation to prescribe medicine from the representative company. Most of the physicians believed that they were under marketing pressure to prescribe certain medicines. Although physicians are aware that the medical representatives could influence their prescribing decision, they welcome

Searches over graphs representing geospatial-temporal remote sensing data

Science.gov (United States)

Brost, Randolph; Perkins, David Nikolaus

2018-03-06

Various technologies pertaining to identifying objects of interest in remote sensing images by searching over geospatial-temporal graph representations are described herein. Graphs are constructed by representing objects in remote sensing images as nodes, and connecting nodes with undirected edges representing either distance or adjacency relationships between objects and directed edges representing changes in time. Geospatial-temporal graph searches are made computationally efficient by taking advantage of characteristics of geospatial-temporal data in remote sensing images through the application of various graph search techniques.

22 CFR 72.9 - Responsibility if legal representative is present.

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Responsibility if legal representative is... Nationals § 72.9 Responsibility if legal representative is present. (a) A consular officer should not act as provisional conservator if the consular officer knows that a legal representative is present in the foreign...

Towards Representative Metallurgical Sampling and Gold Recovery Testwork Programmes

Directory of Open Access Journals (Sweden)

Simon C. Dominy

2018-05-01

Full Text Available When developing a process flowsheet, the risks in achieving positive financial outcomes are minimised by ensuring representative metallurgical samples and high quality testwork. The quality and type of samples used are as important as the testwork itself. The key characteristic required of any set of samples is that they represent a given domain and quantify its variability. There are those who think that stating a sample(s is representative makes it representative without justification. There is a need to consider both (1 in-situ and (2 testwork sub-sample representativity. Early ore/waste characterisation and domain definition are required, so that sampling and testwork protocols can be designed to suit the style of mineralisation in question. The Theory of Sampling (TOS provides an insight into the causes and magnitude of errors that may occur during the sampling of particulate materials (e.g., broken rock and is wholly applicable to metallurgical sampling. Quality assurance/quality control (QAQC is critical throughout all programmes. Metallurgical sampling and testwork should be fully integrated into geometallurgical studies. Traditional metallurgical testwork is critical for plant design and is an inherent part of geometallurgy. In a geometallurgical study, multiple spatially distributed small-scale tests are used as proxies for process parameters. These will be validated against traditional testwork results. This paper focusses on sampling and testwork for gold recovery determination. It aims to provide the reader with the background to move towards the design, implementation and reporting of representative and fit-for-purpose sampling and testwork programmes. While the paper does not intend to provide a definitive commentary, it critically assesses the hard-rock sampling methods used and their optimal collection and preparation. The need for representative sampling and quality testwork to avoid financial and intangible losses is

Representing Boolean Functions by Decision Trees

KAUST Repository

Chikalov, Igor

2011-01-01

A Boolean or discrete function can be represented by a decision tree. A compact form of decision tree named binary decision diagram or branching program is widely known in logic design [2, 40]. This representation is equivalent to other forms

DNA Damage: Quantum Mechanics/Molecular Mechanics Study on the Oxygen Binding and Substrate Hydroxylation Step in AlkB Repair Enzymes

Science.gov (United States)

Quesne, Matthew G; Latifi, Reza; Gonzalez-Ovalle, Luis E; Kumar, Devesh; de Visser, Sam P

2014-01-01

AlkB repair enzymes are important nonheme iron enzymes that catalyse the demethylation of alkylated DNA bases in humans, which is a vital reaction in the body that heals externally damaged DNA bases. Its mechanism is currently controversial and in order to resolve the catalytic mechanism of these enzymes, a quantum mechanics/molecular mechanics (QM/MM) study was performed on the demethylation of the N1-methyladenine fragment by AlkB repair enzymes. Firstly, the initial modelling identified the oxygen binding site of the enzyme. Secondly, the oxygen activation mechanism was investigated and a novel pathway was found, whereby the catalytically active iron(IV)–oxo intermediate in the catalytic cycle undergoes an initial isomerisation assisted by an Arg residue in the substrate binding pocket, which then brings the oxo group in close contact with the methyl group of the alkylated DNA base. This enables a subsequent rate-determining hydrogen-atom abstraction on competitive σ-and π-pathways on a quintet spin-state surface. These findings give evidence of different locations of the oxygen and substrate binding channels in the enzyme and the origin of the separation of the oxygen-bound intermediates in the catalytic cycle from substrate. Our studies are compared with small model complexes and the effect of protein and environment on the kinetics and mechanism is explained. PMID:24339041

Transformation kinetics and pathways of tetracycline antibiotics with manganese oxide

Energy Technology Data Exchange (ETDEWEB)

Wanru, Chen [School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Huang, Ching-Hua [School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

2011-05-15

Tetracycline antibiotics including tetracycline (TTC), oxytetracycline (OTC) and chlorotetracycline (CTC) undergo rapid transformation to yield various products in the presence of MnO{sub 2} at mild conditions (pH 4-9 and 22 {sup o}C). Reaction rates follow the trend of CTC > TTC > OTC, and are affected by pH and complexation of TCs with Mg{sup 2+} or Ca{sup 2+}. Experimental results of TTC indicate that MnO{sub 2} promotes isomerization at the C ring to form iso-TTC and oxidizes the phenolic-diketone and tricarbonylamide groups, leading to insertion of up to 2 O most likely at the C9 and C2 positions. In contrast, reactions of OTC with MnO{sub 2} generate little iso-OTC, but occur mainly at the A ring's dimethylamine group to yield N-demethylated products. CTC yields the most complicated products upon reactions with MnO{sub 2}, encompassing transformation patterns observed with both TTC and OTC. The identified product structures suggest lower antibacterial activity than that of the parent tetracyclines. - Highlights: > Tetracyclines transform rapidly by MnO{sub 2} to yield complicated products. > Isomerized, (hydr)oxygenated and N-demethylated products are formed. > Transformation product structures may suggest lowered antibacterial activity. - The complex transformation pathways of three popular tetracycline antibiotics (tetracycline, oxytetracycline and chlorotetracycline) with MnO{sub 2} under environmental conditions are systematically evaluated and elucidated.

Transformation kinetics and pathways of tetracycline antibiotics with manganese oxide

International Nuclear Information System (INIS)

Chen Wanru; Huang, Ching-Hua

2011-01-01

Tetracycline antibiotics including tetracycline (TTC), oxytetracycline (OTC) and chlorotetracycline (CTC) undergo rapid transformation to yield various products in the presence of MnO 2 at mild conditions (pH 4-9 and 22 o C). Reaction rates follow the trend of CTC > TTC > OTC, and are affected by pH and complexation of TCs with Mg 2+ or Ca 2+ . Experimental results of TTC indicate that MnO 2 promotes isomerization at the C ring to form iso-TTC and oxidizes the phenolic-diketone and tricarbonylamide groups, leading to insertion of up to 2 O most likely at the C9 and C2 positions. In contrast, reactions of OTC with MnO 2 generate little iso-OTC, but occur mainly at the A ring's dimethylamine group to yield N-demethylated products. CTC yields the most complicated products upon reactions with MnO 2 , encompassing transformation patterns observed with both TTC and OTC. The identified product structures suggest lower antibacterial activity than that of the parent tetracyclines. - Highlights: → Tetracyclines transform rapidly by MnO 2 to yield complicated products. → Isomerized, (hydr)oxygenated and N-demethylated products are formed. → Transformation product structures may suggest lowered antibacterial activity. - The complex transformation pathways of three popular tetracycline antibiotics (tetracycline, oxytetracycline and chlorotetracycline) with MnO 2 under environmental conditions are systematically evaluated and elucidated.

Strong imploding shock, the representative curve

International Nuclear Information System (INIS)

Mishkin, E.A.; Alejaldre, C.

1981-01-01

The representative curve of the ideal gas behind the front of a spherically, or cylindrically, symmetric strong imploding shock is shown to pass through the point where the reduced pressure is maximum, P(xisub(m)) = Psub(m)sub(a)sub(x). (orig.)

Adjustment Following Disability: Representative Case Studies.

Science.gov (United States)

Heinemann, Allen W.; Shontz, Franklin C.

1984-01-01

Examined adjustment following physical disability using the representative case method with two persons with quadriplegia. Results highlighted the importance of previously established coping styles as well as the role of the environment in adjustment. Willingness to mourn aided in later growth. (JAC)

Pharmacodynamic modelling of in vitro activity of tetracycline against a representative, naturally occurring population of porcine Escherichia coli

DEFF Research Database (Denmark)

Ahmad, Amais; Zachariasen, Camilla; Christiansen, Lasse Engbo

2015-01-01

of Escherichia coli representative of those found in the Danish pig population, we compared the growth of 50 randomly selected strains. The observed net growth rates were used to describe the in vitro pharmacodynamic relationship between drug concentration and net growth rate based on E max model with three...... concentrations, and this decline was greater in susceptible strains than resistant strains. The lag phase, defined as the time needed for the strain to reach an OD600 value of 0.01, increased exponentially with increasing tetracycline concentration. The pharmacodynamic parameters confirmed that the [Formula: see...

Quantitative radiomic profiling of glioblastoma represents transcriptomic expression.

Science.gov (United States)

Kong, Doo-Sik; Kim, Junhyung; Ryu, Gyuha; You, Hye-Jin; Sung, Joon Kyung; Han, Yong Hee; Shin, Hye-Mi; Lee, In-Hee; Kim, Sung-Tae; Park, Chul-Kee; Choi, Seung Hong; Choi, Jeong Won; Seol, Ho Jun; Lee, Jung-Il; Nam, Do-Hyun

2018-01-19

Quantitative imaging biomarkers have increasingly emerged in the field of research utilizing available imaging modalities. We aimed to identify good surrogate radiomic features that can represent genetic changes of tumors, thereby establishing noninvasive means for predicting treatment outcome. From May 2012 to June 2014, we retrospectively identified 65 patients with treatment-naïve glioblastoma with available clinical information from the Samsung Medical Center data registry. Preoperative MR imaging data were obtained for all 65 patients with primary glioblastoma. A total of 82 imaging features including first-order statistics, volume, and size features, were semi-automatically extracted from structural and physiologic images such as apparent diffusion coefficient and perfusion images. Using commercially available software, NordicICE, we performed quantitative imaging analysis and collected the dataset composed of radiophenotypic parameters. Unsupervised clustering methods revealed that the radiophenotypic dataset was composed of three clusters. Each cluster represented a distinct molecular classification of glioblastoma; classical type, proneural and neural types, and mesenchymal type. These clusters also reflected differential clinical outcomes. We found that extracted imaging signatures does not represent copy number variation and somatic mutation. Quantitative radiomic features provide a potential evidence to predict molecular phenotype and treatment outcome. Radiomic profiles represents transcriptomic phenotypes more well.

40 CFR 60.4114 - Objections concerning Hg designated representative.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Objections concerning Hg designated... Times for Coal-Fired Electric Steam Generating Units Hg Designated Representative for Hg Budget Sources § 60.4114 Objections concerning Hg designated representative. (a) Once a complete certificate of...

Selection of Representative Models for Decision Analysis Under Uncertainty

Science.gov (United States)

Meira, Luis A. A.; Coelho, Guilherme P.; Santos, Antonio Alberto S.; Schiozer, Denis J.

2016-03-01

The decision-making process in oil fields includes a step of risk analysis associated with the uncertainties present in the variables of the problem. Such uncertainties lead to hundreds, even thousands, of possible scenarios that are supposed to be analyzed so an effective production strategy can be selected. Given this high number of scenarios, a technique to reduce this set to a smaller, feasible subset of representative scenarios is imperative. The selected scenarios must be representative of the original set and also free of optimistic and pessimistic bias. This paper is devoted to propose an assisted methodology to identify representative models in oil fields. To do so, first a mathematical function was developed to model the representativeness of a subset of models with respect to the full set that characterizes the problem. Then, an optimization tool was implemented to identify the representative models of any problem, considering not only the cross-plots of the main output variables, but also the risk curves and the probability distribution of the attribute-levels of the problem. The proposed technique was applied to two benchmark cases and the results, evaluated by experts in the field, indicate that the obtained solutions are richer than those identified by previously adopted manual approaches. The program bytecode is available under request.

Resistance to docetaxel in prostate cancer is associated with androgen receptor activation and loss of KDM5D expression

Science.gov (United States)

Komura, Kazumasa; Jeong, Seong Ho; Hinohara, Kunihiko; Qu, Fangfang; Wang, Xiaodong; Hiraki, Masayuki; Azuma, Haruhito; Lee, Gwo-Shu Mary; Kantoff, Philip W.; Sweeney, Christopher J.

2016-01-01

The androgen receptor (AR) plays an essential role in prostate cancer, and suppression of its signaling with androgen deprivation therapy (ADT) has been the mainstay of treatment for metastatic hormone-sensitive prostate cancer for more than 70 y. Chemotherapy has been reserved for metastatic castration-resistant prostate cancer (mCRPC). The Eastern Cooperative Oncology Group-led trial E3805: ChemoHormonal Therapy Versus Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer (CHAARTED) showed that the addition of docetaxel to ADT prolonged overall survival compared with ADT alone in patients with metastatic hormone-sensitive prostate cancer. This finding suggests that there is an interaction between AR signaling activity and docetaxel sensitivity. Here we demonstrate that the prostate cancer cell lines LNCaP and LAPC4 display markedly different sensitivity to docetaxel with AR activation, and RNA-seq analysis of these cell lines identified KDM5D (lysine-specific demethylase 5D) encoded on the Y chromosome as a potential mediator of this sensitivity. Knocking down KDM5D expression in LNCaP leads to docetaxel resistance in the presence of dihydrotestosterone. KDM5D physically interacts with AR in the nucleus, and regulates its transcriptional activity by demethylating H3K4me3 active transcriptional marks. Attenuating KDM5D expression dysregulates AR signaling, resulting in docetaxel insensitivity. KDM5D deletion was also observed in the LNCaP-derived CRPC cell line 104R2, which displayed docetaxel insensitivity with AR activation, unlike parental LNCaP. Dataset analysis from the Oncomine database revealed significantly decreased KDM5D expression in CRPC and poorer prognosis with low KDM5D expression. Taking these data together, this work indicates that KDM5D modulates the AR axis and that this is associated with altered docetaxel sensitivity. PMID:27185910

Epigenetic reprogramming of pericentromeric satellite DNA in premalignant and malignant lesions

DEFF Research Database (Denmark)

Brückmann, Nadine Heidi; Pedersen, Christina Bøg; Ditzel, Henrik Jørn

2018-01-01

on pericentromeric satellites in primary melanocytes. This suggests that polycomb bodies form in cancer cells with global DNA demethylation to control the stability of pericentromeric satellite DNA. These results reveal a novel epigenetic perturbation specific to premalignant and malignant cells thatmaybe used...... as an early diagnostic marker for detection of precancerous changes and a new therapeutic entry point. Implications: Pericentromeric satellite DNA is epigenetically reprogrammed into polycomb bodies as a premalignant event with implications for transcriptional activity and genomic stability. Mol Cancer Res...

Cylindrical and Spherical Active Coated Nanoparticles as Nanoantennas: Active nanoparticles as nanoantennas

DEFF Research Database (Denmark)

Arslanagic, Samel; Ziolkowski, Richard W.

2017-01-01

In this article, we review the fundamental properties of several spherical and cylindrical, passive, and active coated nanoparticles (CNPs) with an emphasis on their potential for nanoantenna and nanoamplifier synthesis. For the spherical geometries, the nanoparticles are excited by an electric...... Hertzian dipole (EHD), which represents, e.g., a stimulated atom or molecule. The cylindrical nanoparticles are excited by a magnetic line source (MLS). In the active cases, gain is added to the core region of the particle. For simplicity, it is represented by a canonical, frequency-independent gain model....... We demonstrate that specific CNPs can be designed to be resonant and well matched to their respective excitation sources. With active cores, these designs can lead to extremely large total radiated powers. For both configurations, insights into the effects of the nanoparticle material composition...

Comparative genomic analysis of isoproturon-mineralizing sphingomonads reveals the isoproturon catabolic mechanism.

Science.gov (United States)

Yan, Xin; Gu, Tao; Yi, Zhongquan; Huang, Junwei; Liu, Xiaowei; Zhang, Ji; Xu, Xihui; Xin, Zhihong; Hong, Qing; He, Jian; Spain, Jim C; Li, Shunpeng; Jiang, Jiandong

2016-12-01

The worldwide use of the phenylurea herbicide, isoproturon (IPU), has resulted in considerable concern about its environmental fate. Although many microbial metabolites of IPU are known and IPU-mineralizing bacteria have been isolated, the molecular mechanism of IPU catabolism has not been elucidated yet. In this study, complete genes that encode the conserved IPU catabolic pathway were revealed, based on comparative analysis of the genomes of three IPU-mineralizing sphingomonads and subsequent experimental validation. The complete genes included a novel hydrolase gene ddhA, which is responsible for the cleavage of the urea side chain of the IPU demethylated products; a distinct aniline dioxygenase gene cluster adoQTA1A2BR, which has a broad substrate range; and an inducible catechol meta-cleavage pathway gene cluster adoXEGKLIJC. Furthermore, the initial mono-N-demethylation genes pdmAB were further confirmed to be involved in the successive N-demethylation of the IPU mono-N-demethylated product. These IPU-catabolic genes were organized into four transcription units and distributed on three plasmids. They were flanked by multiple mobile genetic elements and highly conserved among IPU-mineralizing sphingomonads. The elucidation of the molecular mechanism of IPU catabolism will enhance our understanding of the microbial mineralization of IPU and provide insights into the evolutionary scenario of the conserved IPU-catabolic pathway. © 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Representing Boolean Functions by Decision Trees

KAUST Repository

Chikalov, Igor

2011-01-01

A Boolean or discrete function can be represented by a decision tree. A compact form of decision tree named binary decision diagram or branching program is widely known in logic design [2, 40]. This representation is equivalent to other forms, and in some cases it is more compact than values table or even the formula [44]. Representing a function in the form of decision tree allows applying graph algorithms for various transformations [10]. Decision trees and branching programs are used for effective hardware [15] and software [5] implementation of functions. For the implementation to be effective, the function representation should have minimal time and space complexity. The average depth of decision tree characterizes the expected computing time, and the number of nodes in branching program characterizes the number of functional elements required for implementation. Often these two criteria are incompatible, i.e. there is no solution that is optimal on both time and space complexity. © Springer-Verlag Berlin Heidelberg 2011.

Radical Scavenging and Anti-Inflammatory Activities of Representative Anthocyanin Groupings from Pigment-Rich Fruits and Vegetables

Directory of Open Access Journals (Sweden)

Federica Blando

2018-01-01

Full Text Available Anthocyanins, the naturally occurring pigments responsible for most red to blue colours of flowers, fruits and vegetables, have also attracted interest because of their potential health effects. With the aim of contributing to major insights into their structure–activity relationship (SAR, we have evaluated the radical scavenging and biological activities of selected purified anthocyanin samples (PASs from various anthocyanin-rich plant materials: two fruits (mahaleb cherry and blackcurrant and two vegetables (black carrot and “Sun Black” tomato, differing in anthocyanin content (ranging from 4.9 to 38.5 mg/g DW and molecular structure of the predominant anthocyanins. PASs from the abovementioned plant materials have been evaluated for their antioxidant capacity using Trolox Equivalent Antioxidant Capacity (TEAC and Oxygen Radical Absorbance Capacity (ORAC assays. In human endothelial cells, we analysed the anti-inflammatory activity of different PASs by measuring their effects on the expression of endothelial adhesion molecules VCAM-1 and ICAM-1. We demonstrated that all the different PASs showed biological activity. They exhibited antioxidant capacity of different magnitude, higher for samples containing non-acylated anthocyanins (typical for fruits compared to samples containing more complex anthocyanins acylated with cinnamic acid derivatives (typical for vegetables, even though this order was slightly reversed when ORAC assay values were expressed on a molar basis. Concordantly, PASs containing non-acylated anthocyanins reduced the expression of endothelial inflammatory antigens more than samples with aromatic acylated anthocyanins, suggesting the potential beneficial effect of structurally diverse anthocyanins in cardiovascular protection.

Tritium Labeled Gentamicin C: II.- Bioradiactive Degradation Products of Gentamicin by Catalytic H2O-3H Exchange Reaction; Getamicina C Tritiada: II.- Productos de Degradacion Radiactivos y Bioactivos en el Intercambio Catalitico con H2O-3H

Energy Technology Data Exchange (ETDEWEB)

Suarez, C.; Diaz, A.; Paz, D.; Jimeno, M. L.

1992-07-01

The main bio radioactive degradation products from catalytic hydrogen exchange of gentamicin C, (C1 + C2 + Cla) in basic form, are generated by N-demethylation in 3{sup -}N and 6-N positions. Their structures were confirmed by 1HNMR and 13CNMR. These derivatives were fractionated by chromatography on silica gel. Antibacterial activities were similar to those of the parent antibiotics. Tritium exchange, under vacuum or nitrogen, is highly increased (4:1) when gentamicin are in basic form. In contrast with gentamicin sulfate, hydrolytic sub products as gramine, genta mines, garosamine and purpurosamines are practically absent. To properly optimize the exchange process, the composition of the gentamicin C complex must be taken into account. The exchange decreases in the order C2 > C1> Cla. Because of 6'-N-demethyl gentamicin C1 is C2, the radiochemical yield of C2 appears enhanced in the H2O-3H exchange of a mixture of them. Radioactivity distribution among the components and subunits of these three gentamicin were studied by strong and mild hydrolysis, and by methanolysis. (Author) 18 refs.

Cloning, expression and characterisation of P450-Hal1 (CYP116B62) from Halomonas sp. NCIMB 172: A self-sufficient P450 with high expression and diverse substrate scope.

Science.gov (United States)

Porter, Joanne L; Sabatini, Selina; Manning, Jack; Tavanti, Michele; Galman, James L; Turner, Nicholas J; Flitsch, Sabine L

2018-06-01

Cytochrome P450 monooxygenases are able to catalyse a range of synthetically challenging reactions ranging from hydroxylation and demethylation to sulfoxidation and epoxidation. As such they have great potential for biocatalytic applications but are underutilised due to often-poor expression, stability and solubility in recombinant bacterial hosts. The use of self-sufficient P450 s with fused haem and reductase domains has already contributed heavily to improving catalytic efficiency and simplifying an otherwise more complex multi-component system of P450 and redox partners. Herein, we present a new addition to the class VII family with the cloning, sequencing and characterisation of the self-sufficient CYP116B62 Hal1 from Halomonas sp. NCIMB 172, the genome of which has not yet been sequenced. Hal1 exhibits high levels of expression in a recombinant E. coli host and can be utilised from cell lysate or used in purified form. Hal1 favours NADPH as electron donor and displays a diverse range of activities including hydroxylation, demethylation and sulfoxidation. These properties make Hal1 suitable for future biocatalytic applications or as a template for optimisation through engineering. Copyright © 2018 Elsevier Inc. All rights reserved.

40 CFR 60.4110 - Authorization and Responsibilities of Hg designated representative.

Science.gov (United States)

2010-07-01

... Hg designated representative. 60.4110 Section 60.4110 Protection of Environment ENVIRONMENTAL... Emission Guidelines and Compliance Times for Coal-Fired Electric Steam Generating Units Hg Designated Representative for Hg Budget Sources § 60.4110 Authorization and Responsibilities of Hg designated representative...

Peer Crowd Identification and Adolescent Health Behaviors: Results From a Statewide Representative Study.

Science.gov (United States)

Jordan, Jeffrey W; Stalgaitis, Carolyn A; Charles, John; Madden, Patrick A; Radhakrishnan, Anjana G; Saggese, Daniel

2018-02-01

Peer crowds are macro-level subcultures that share similarities across geographic areas. Over the past decade, dozens of studies have explored the association between adolescent peer crowds and risk behaviors, and how they can inform public health efforts. However, despite the interest, researchers have not yet reported on crowd size and risk levels from a representative sample, making it difficult for practitioners to apply peer crowd science to interventions. The current study reports findings from the first statewide representative sample of adolescent peer crowd identification and health behaviors. Weighted data were analyzed from the 2015 Virginia Youth Survey of Health Behaviors ( n = 4,367). Peer crowds were measured via the I-Base Survey™, a photo-based peer crowd survey instrument. Frequencies and confidence intervals of select behaviors including tobacco use, substance use, nutrition, physical activity, and violence were examined to identify high- and low-risk crowds. Logistic regression was used to calculate adjusted odds ratios for each crowd and behavior. Risky behaviors clustered in two peer crowds. Hip Hop crowd identification was associated with substance use, violence, and some depression and suicidal behaviors. Alternative crowd identification was associated with increased risk for some substance use behaviors, depression and suicide, bullying, physical inactivity, and obesity. Mainstream and, to a lesser extent, Popular, identities were associated with decreased risk for most behaviors. Findings from the first representative study of peer crowds and adolescent behavior identify two high-risk groups, providing critical insights for practitioners seeking to maximize public health interventions by targeting high-risk crowds.

Adaptation of Regional Representative Soil Project and Soil Judging for Cameroon

Science.gov (United States)

Che, Celestine Akuma

2013-01-01

Representative regional soils have agricultural, cultural, economic, environmental, and historical importance to Cameroon. Twenty seven regional representative soils have been identified in Cameroon. A set of laboratory exercises, assignments and exam questions have been developed utilizing the Regional Representative Soil Project (RRSP) that…

On the representativeness of behavior observation samples in classrooms.

Science.gov (United States)

Tiger, Jeffrey H; Miller, Sarah J; Mevers, Joanna Lomas; Mintz, Joslyn Cynkus; Scheithauer, Mindy C; Alvarez, Jessica

2013-01-01

School consultants who rely on direct observation typically conduct observational samples (e.g., 1 30-min observation per day) with the hopes that the sample is representative of performance during the remainder of the day, but the representativeness of these samples is unclear. In the current study, we recorded the problem behavior of 3 referred students for 4 consecutive school days between 9:30 a.m. and 2:30 p.m. using duration recording in consecutive 10-min sessions. We then culled 10-min, 20-min, 30-min, and 60-min observations from the complete record and compared these observations to the true daily mean to assess their accuracy (i.e., how well individual observations represented the daily occurrence of target behaviors). The results indicated that when behavior occurred with low variability, the majority of brief observations were representative of the overall levels; however, when behavior occurred with greater variability, even 60-min observations did not accurately capture the true levels of behavior. © Society for the Experimental Analysis of Behavior.

Representing Uncertainty on Model Analysis Plots

Science.gov (United States)

Smith, Trevor I.

2016-01-01

Model analysis provides a mechanism for representing student learning as measured by standard multiple-choice surveys. The model plot contains information regarding both how likely students in a particular class are to choose the correct answer and how likely they are to choose an answer consistent with a well-documented conceptual model.…

28 CFR 104.4 - Personal Representative.

Science.gov (United States)

2010-07-01

... addition, as provided in § 104.21(b)(5) of this part, the Special Master may publish a list of individuals... Special Master may, in his discretion, determine that the Personal Representative for purposes of... administrator of the decedent's estate. In the event no will exists, the Special Master may, in his discretion...

Soluble ectodomain of neuroligin 1 decreases synaptic activity by activating metabotropic glutamate receptor 2

DEFF Research Database (Denmark)

Gjørlund, Michelle D.; Carlsen, Eva Maria Meier; Kønig, Andreas Bay

2017-01-01

Synaptic cell adhesion molecules represent important targets for neuronal activity-dependent proteolysis. Postsynaptic neuroligins (NLs) form trans-synaptic complexes with presynaptic neurexins (NXs). Both NXs and NLs are cleaved from the cell surface by metalloproteases in an activity-dependent ...

Data structures and apparatuses for representing knowledge

Science.gov (United States)

Hohimer, Ryan E; Thomson, Judi R; Harvey, William J; Paulson, Patrick R; Whiting, Mark A; Tratz, Stephen C; Chappell, Alan R; Butner, Robert S

2014-02-18

Data structures and apparatuses to represent knowledge are disclosed. The processes can comprise labeling elements in a knowledge signature according to concepts in an ontology and populating the elements with confidence values. The data structures can comprise knowledge signatures stored on computer-readable media. The knowledge signatures comprise a matrix structure having elements labeled according to concepts in an ontology, wherein the value of the element represents a confidence that the concept is present in an information space. The apparatus can comprise a knowledge representation unit having at least one ontology stored on a computer-readable medium, at least one data-receiving device, and a processor configured to generate knowledge signatures by comparing datasets obtained by the data-receiving devices to the ontologies.

Activation and Molecular Targets of Peroxisome Proliferator-Activated Receptor-γ Ligands in Lung Cancer

Directory of Open Access Journals (Sweden)

Raphael A. Nemenoff

2008-01-01

Full Text Available Lung cancer is the leading cause of cancer death, and five-year survival remains poor, raising the urgency for new treatment strategies. Activation of PPARγ represents a potential target for both the treatment and prevention of lung cancer. Numerous studies have examined the effect of thiazolidinediones such as rosiglitazone and pioglitazone on lung cancer cells in vitro and in xenograft models. These studies indicate that activation of PPARγ inhibits cancer cell proliferation as well as invasiveness and metastasis. While activation of PPARγ can occur by direct binding of pharmacological ligands to the molecule, emerging data indicate that PPARγ activation can occur through engagement of other signal transduction pathways, including Wnt signaling and prostaglandin production. Data, both from preclinical models and retrospective clinical studies, indicate that activation of PPARγ may represent an attractive chemopreventive strategy. This article reviews the existing biological and mechanistic experiments focusing on the role of PPARγ in lung cancer, focusing specifically on nonsmall cell lung cancer.

19 CFR 146.2 - Port director as Board representative.

Science.gov (United States)

2010-04-01

...; DEPARTMENT OF THE TREASURY (CONTINUED) FOREIGN TRADE ZONES General Provisions § 146.2 Port director as Board representative. The appropriate port director shall be in charge of the zone as the representative of the Board. [T.D. 86-16, 51 FR 5049, Feb. 11, 1986, as amended by T.D. 99-27, 64 FR 13676, Mar. 22, 1999] ...

Cytochrome P-450 complex formation in rat liver by the antibiotic tiamulin.

Science.gov (United States)

Witkamp, R F; Nijmeijer, S M; van Miert, A S

1996-01-01

Tiamulin is a semisynthetic diterpene antibiotic frequently used in farm animals. The drug has been shown to produce clinically important--often lethal--interactions with other compounds. It has been suggested that this is caused by a selective inhibition of oxidative drug metabolism via the formation of a cytochrome P-450 metabolic intermediate complex. In the present study, rats were treated orally for 6 days with tiamulin at two different doses: 40 and 226 mg/kg of body weight. For comparison, another group received 300 mg of triacetyloleandomycin (TAO) per kg, which is equivalent to the 226-mg/kg tiamulin group. Subsequently, microsomal P-450 contents, P-450 enzyme activities, metabolic intermediate complex spectra, and P-450 apoprotein concentrations were assessed. In addition, effects on individual microsomal P-450 activities were studied in control microsomes at different tiamulin and substrate concentrations. In the rats treated with tiamulin, a dose-dependent complex formation as evidenced by its absorption spectrum and an increase in cytochrome P-4503A1/2 contents as assessed by Western blotting (immunoblotting) were found. The effects were comparable to those of TAO. Tiamulin induced microsomal P-450 content, testosterone 6 beta-hydroxylation rate, erythromycin N-demethylation rate, and the ethoxyresorufin O-deethylation activity. Other activities were not affected or decreased. When tiamulin was added to microsomes of control rats, the testosterone 6 beta-hydroxylation rate and the erythromycin N-demethylation were strongly inhibited. It is concluded that tiamulin is a potent and selective inducer-inhibitor of cytochrome P-450. Though not belonging to the macrolides, the compound produces an effect on P-450 similar to those of TAO and related compounds.

The use of caffeine as a biological marker of human exposure and response to polycyclic and polyhalogenated aromatic hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Campbell, M.E

1987-06-05

The use of caffeine as a non-invasive biological marker of PAH-inducible P-450 enzyme induction in humans is assessed through caffeine biotransformation studies using human liver preparations, and through caffeine ingestion studies of human populations exposed to diverse polycyclic and polyhalogenated aromatic hydrocarbons (PAHs and HAHs). In vitro studies indicate that all N-demethylations from caffeine and its primary metabolites are mediated in large part by PAH-inducible P-450 in human liver microsomes, whereas corresponding methylxanthine hydroxylations are in large and variable part mediated by other enzymes that are apparently not inducible by PAHs. It is proposed that a caffeine metabolite ratio (CMR), based on paraxanthine 7-demethylation products relative to a paraxanthine 8-hydroxylation product measured in the urine after caffeine ingestion, reflects PAH-inducible P-450 activity. In vivo studies demonstrate that mean CMR values are significantly higher in smokers and lower in oral contraceptive users, and that CMR values correlate highly with systemic caffeine clearance. Furthermore, mean CMR and CBT (caffeine breath test) values determined for six populations of varying age, and PAH and HAH exposure demonstrated a significant correlation. The participation of xanthine oxidase in the metabolism of caffeine, and proposes the use of the urinary ratio of 1-methyluric acid to 1-methylxanthine as an index of xanthine oxidase activity is also demonstrated. The data suggest that xanthine oxidase activity is not altered by gender, age, oral contraceptive use, PAH and HAH exposure. The data support the use of the CMR as an indicator of PAH-inducible P-450 activity, and show that xanthine oxidase is resistant to induction by PAHs and HAHs. 300 refs., 41 figs., 35 tabs.

Synthesis of an estradiol glucuronide derivative and investigation of its radiopharmaceutical potential

International Nuclear Information System (INIS)

Biber, F.Z.; Unak, P.; Ertay, T.; Medine, E.I.; Zihnioglu, F.; Tasci, C.; Durak, H.

2006-01-01

The aim of the current study was to synthesize a derivative of estradiol glucuronide, which is able to be labeled with 99m Tc and to investigate its radiopharmaceutical potential using imaging and biodistribution studies. An estrogen derivative, β-estradiol (1,3,5,[10]-estratriene-3,17β-diol) attached to diethylenetriamine pentaacetic acid (DTPA) was synthesized in six steps. At the end of these steps a compound of estradiol and DTPA derivative called deoxy demethyl homoestradiolyl diethylenetriamine pentaacetic acid (ESTDTPA) was synthesized. Afterwards, this compound was reacted with UDP-glucuronyl transferase (UDPGT). Following the glucuronidation reaction, the product called deoxy demethyl homoestradiolyl diethylenetriamine pentaaceticacid-glucuronide (ESTDTPAG) was obtained. Synthesized products were purified using high performance liquid chromatography (HPLC). The identification of the purified products and impurities were also established using HPLC. Synthesized compound was labeled with 99m Tc. Thin layer radio chromatography (TLRC) technique was used to determine their radiochemical yields and stabilities. Labeling yield was over 96%. The biodistribution studies were performed on female Albino Wistar rats. The activity per gram tissue was calculated and time-activity curves were plotted. The target organs (tumor, as well as uterus, ovaries, adrenals and other ER containing tissues) retain the estradiol derivative longer than nontarget organs, but even these lost most of their activity within a few hours. In addition, the imaging studies were performed on normal and tumor bearing female Albino Wistar rats using Camstar XR/T gamma camera. In γ-scintigraphic imaging studies with 99m Tc-ESTDTPAG the breast tumors could be well visualized up to 24 h

Hypoxia-Mediated Epigenetic Regulation of Stemness in Brain Tumor Cells.

Science.gov (United States)

Prasad, Pankaj; Mittal, Shivani Arora; Chongtham, Jonita; Mohanty, Sujata; Srivastava, Tapasya

2017-06-01

Activation of pluripotency regulatory circuit is an important event in solid tumor progression and the hypoxic microenvironment is known to enhance the stemness feature of some cells. The distinct population of cancer stem cells (CSCs)/tumor initiating cells exist in a niche and augment invasion, metastasis, and drug resistance. Previously, studies have reported global hypomethylation and site-specific aberrant methylation in gliomas along with other epigenetic modifications as important contributors to genomic instability during glioma progression. Here, we have demonstrated the role of hypoxia-mediated epigenetic modifications in regulating expression of core pluripotency factors, OCT4 and NANOG, in glioma cells. We observe hypoxia-mediated induction of demethylases, ten-eleven-translocation (TET) 1 and 3, but not TET2 in our cell-line model. Immunoprecipitation studies reveal active demethylation and direct binding of TET1 and 3 at the Oct4 and Nanog regulatory regions. Tet1 and 3 silencing assays further confirmed induction of the pluripotency pathway involving Oct4, Nanog, and Stat3, by these paralogues, although with varying degrees. Knockdown of Tet1 and Tet3 inhibited the formation of neurospheres in hypoxic conditions. We observed independent roles of TET1 and TET3 in differentially regulating pluripotency and differentiation associated genes in hypoxia. Overall, this study demonstrates an active demethylation in hypoxia by TET1 and 3 as a mechanism of Oct4 and Nanog overexpression thus contributing to the formation of CSCs in gliomas. Stem Cells 2017;35:1468-1478. © 2017 AlphaMed Press.

Towards an integrated model of floodplain hydrology representing feedbacks and anthropogenic effects

Science.gov (United States)

Andreadis, K.; Schumann, G.; Voisin, N.; O'Loughlin, F.; Tesfa, T. K.; Bates, P.

2017-12-01

The exchange of water between hillslopes, river channels and floodplain can be quite complex and the difficulty in capturing the mechanisms behind it is exacerbated by the impact of human activities such as irrigation and reservoir operations. Although there has been a vast body of work on modeling hydrological processes, most of the resulting models have been limited with regards to aspects of the coupled human-natural system. For example, hydrologic models that represent processes such as evapotranspiration, infiltration, interception and groundwater dynamics often neglect anthropogenic effects or do not adequately represent the inherently two-dimensional floodplain flow. We present an integrated modeling framework that is comprised of the Variable Infiltration Capacity (VIC) hydrology model, the LISFLOOD-FP hydrodynamic model, and the Water resources Management (WM) model. The VIC model solves the energy and water balance over a gridded domain and simulates a number of hydrologic features such as snow, frozen soils, lakes and wetlands, while also representing irrigation demand from cropland areas. LISFLOOD-FP solves an approximation of the Saint-Venant equations to efficiently simulate flow in river channels and the floodplain. The implementation of WM accommodates a variety of operating rules in reservoirs and withdrawals due to consumptive demands, allowing the successful simulation of regulated flow. The models are coupled so as to allow feedbacks between their corresponding processes, therefore providing the ability to test different hypotheses about the floodplain hydrology of large-scale basins. We test this integrated framework over the Zambezi River basin by simulating its hydrology from 2000-2010, and evaluate the results against remotely sensed observations. Finally, we examine the sensitivity of streamflow and water inundation to changes in reservoir operations, precipitation and temperature.

Humans choose representatives who enforce cooperation in social dilemmas through extortion

Science.gov (United States)

Milinski, Manfred; Hilbe, Christian; Semmann, Dirk; Sommerfeld, Ralf; Marotzke, Jochem

2016-03-01

Social dilemmas force players to balance between personal and collective gain. In many dilemmas, such as elected governments negotiating climate-change mitigation measures, the decisions are made not by individual players but by their representatives. However, the behaviour of representatives in social dilemmas has not been investigated experimentally. Here inspired by the negotiations for greenhouse-gas emissions reductions, we experimentally study a collective-risk social dilemma that involves representatives deciding on behalf of their fellow group members. Representatives can be re-elected or voted out after each consecutive collective-risk game. Selfish players are preferentially elected and are hence found most frequently in the `representatives' treatment. Across all treatments, we identify the selfish players as extortioners. As predicted by our mathematical model, their steadfast strategies enforce cooperation from fair players who finally compensate almost completely the deficit caused by the extortionate co-players. Everybody gains, but the extortionate representatives and their groups gain the most.

Interactions between physicians and pharmaceutical sales representatives in Saudi Arabia.

Science.gov (United States)

Alosaimi, Fahad Dakheel; Alkaabba, Abdulaziz; Qadi, Mahdi; Albahlal, Abdullah; Alabdulkarim, Yasir; Alabduljabbar, Mohammad; Alqahtani, Faisal

2013-01-01

Interaction between physicians and pharmaceutical sales representative (PR) is a major component of the promotional activities by pharmaceutical companies. The lack of studies examining the magnitude of this interaction in Saudi Arabia is evident. The objective of this study is to estimate the magnitude and associated characteristics of physician-PR interaction. A cross-sectional study was conducted among physicians working in the different regions of Saudi Arabia between March and July of 2012. A cross-sectional study was undertaken between March and July of 2012 in the different regions of Saudi Arabia. A self-administrated questionnaire was developed and handed to all participants, both in paper and electronic formats. A total of 663 participants completed the questionnaire. The participation rate was 66.3% (663/1000). The majority of the participants (72.9%) reported interaction with PRs. This was lower among residents/interns compared to higher ranking employees (55.6% vs 83.6%, P strategy to reduce negative impact.

Request by the Resident Representative of Iraq

International Nuclear Information System (INIS)

1990-01-01

The attached clarification by a spokesman of the Iraqi Ministry of Foreign Affairs is being circulated for the information of Member States pursuant to a request made by the Resident Representative of Iraq

Semantic Representatives of the Concept

Directory of Open Access Journals (Sweden)

Elena N. Tsay

2013-01-01

Full Text Available In the article concept as one of the principle notions of cognitive linguistics is investigated. Considering concept as culture phenomenon, having language realization and ethnocultural peculiarities, the description of the concept “happiness” is presented. Lexical and semantic paradigm of the concept of happiness correlates with a great number of lexical and semantic variants. In the work semantic representatives of the concept of happiness, covering supreme spiritual values are revealed and semantic interpretation of their functioning in the Biblical discourse is given.

Anaerobic C1 metabolism of the O-methyl-14C-labeled substituent of vanillate

International Nuclear Information System (INIS)

Frazer, A.C.; Young, L.Y.

1986-01-01

The O-methyl substituents of aromatic compounds constitute a C 1 growth substrate for a number of taxonomically diverse anaerobic acetogens. In this study, strain TH-001, an O-demethylating obligate anaerobe, was chosen to represent this physiological group, and the carbon flow when cells were grown on O-methyl substituents as a C 1 substrate was determined by 14 C radiotracer techniques. O-[methyl- 14 C]vanillate (4-hydroxy-3-methoxy-benzoate) was used as the labeled C 1 substrate. The data showed that for every O-methyl carbon converted to [ 14 C]acetate, two were oxidized to 14 CO 2 . Quantitation of the carbon recovered in the two products, acetate and CO 2 , indicated that acetate was formed in part by the fixation of unlabeled CO 2 . The specific activity of 14 C in acetate was 70% of that in the O-methyl substrate, suggesting that only one carbon of acetate was derived from the O-methyl group. Thus, it is postulated that the carboxyl carbon of the product acetate is derived from CO 2 and the methyl carbon is derived from the O-methyl substituent of vanillate

Reflections on Activity Theory

Science.gov (United States)

Bakhurst, David

2009-01-01

It is sometimes suggested that activity theory represents the most important legacy of Soviet philosophy and psychology. But what exactly "is" activity theory? The canonical account in the West is given by Engestrom, who identifies three stages in the theory's development: from Vygotsky's insights, through Leontiev's articulation of the…

Applying Representative Bureaucracy Theory to Academia: Representation of Women in Faculty and Administration and Title IX Compliance in Intercollegiate Athletics

Science.gov (United States)

Lee, Young-joo; Won, Doyeon

2016-01-01

The representative bureaucracy theory posits that the passive representation of women in an organization leads to their active representation in terms of gender equity in policy implementation. The present study examines how women's representation in administration and faculty positions may explain gender equity-oriented policy outcomes, focusing…

Representativeness of wind measurements in moderately complex terrain

Science.gov (United States)

van den Bossche, Michael; De Wekker, Stephan F. J.

2018-02-01

We investigated the representativeness of 10-m wind measurements in a 4 km × 2 km area of modest relief by comparing observations at a central site with those at four satellite sites located in the same area. Using a combination of established and new methods to quantify and visualize representativeness, we found significant differences in wind speed and direction between the four satellite sites and the central site. The representativeness of the central site wind measurements depended strongly on surface wind speed and direction, and atmospheric stability. Through closer inspection of the observations at one of the satellite sites, we concluded that terrain-forced flows combined with thermally driven downslope winds caused large biases in wind direction and speed. We used these biases to generate a basic model, showing that terrain-related differences in wind observations can to a large extent be predicted. Such a model is a cost-effective way to enhance an area's wind field determination and to improve the outcome of pollutant dispersion and weather forecasting models.

Letter of 5 December 1991 to the Director General from the Resident Representative of Iraq to the Agency

International Nuclear Information System (INIS)

1992-01-01

The document reproduces a letter dated 5 December 1991 to the Director General of the IAEA from the Resident Representative of Iraq to the International Atomic Energy Agency concerning the presentation of a Distinguished Service Award to Mr. David Kay for his activity in the Safeguard inspections in Iraq (Attachment 1). The Director General's reply is reproduced in Attachment 2

Examination of dialysis patients with the aminophenazone breath test

International Nuclear Information System (INIS)

Heinrich, H.G.; Adler, D.; Hornak, H.; Wuenschmann, H.J.; Mayer, W.K.

1989-01-01

In 12 endstage kidney disease patients (8 without and 4 with liver diseases) the activities of cytochrome P 450 -dependent mixed functional oxidases system (MFO) of the liver were studied by using the 14 C-aminophenazone breath test before and after dialysis. The results showed that uremia seems to have a pressing influence on MFO activity. The activity was only significantly increased after dialysis in the group of patients without liver diseases. The MFO activity was reduced in patients with liver diseases. This is a restriction of the hepatic metabolic demethylation capacity. It is unclear if the 14 C-aminophenazone breath test in dialysis patients is qualified to estimate metabolic capacity of the liver. Differentiation between the influence of uremia and of the liver disease on the alteration of MFO activity cannot be made. (author)

Energy and water development appropriations for 1986. Part 7. Hearings before a Subcommittee of the Committee on Appropriations, House of Representatives, Ninety-Ninth Congress, First Session

International Nuclear Information System (INIS)

Anon.

1985-01-01

Part 7 of the hearing record covers three areas of the DOE appropriations: Atomic Energy Defense activities, power marketing administrations, and departmental administration. Representatives of DOE and the US Army reviewed the nuclear defense mission and activities under the defense and arms control programs. The administrators of the Alaska, Bonneville, Southeastern, Southwestern, and Western Power Administrations and a representative of the Conservation and Renewable Energy division described programs and budget requirements, as well as estimates of power demands for their regions. Administrative personnel described DOE procedures and explained the budget requests. Supporting documentation accompanies the testimony of the 16 witnesses

Soviet diplomats and Comintern representatives in People’s Republic of Tuva in the 1920s

Directory of Open Access Journals (Sweden)

Nikolay M. Mollerov

2016-09-01

Full Text Available This is the first study of the role Soviet diplomats and representatives of the Communist International (Comintern played in the Soviet-Tuvan relations during the first decade after the emergence of the young Tuvan state – People’s Republic of Tuva (1920s. From representing the interests of a small military mission, the Soviet diplomatic office in Tuva evolved into a full-scale embassy of the Soviet state. Its history clearly falls into two stages: from early 1920s to 1927 Soviet mission members largely abstained from interfering into PRT’s internal issues, but subsequently they started actively promoting the left wing of Tuvan People Revolutionary Party, which contributed to its accession to power. The Soviet state began to act as PRT’s patron on the international arena. This policy of support and custody was in accordance with Article 2 of PRT’s constitution. Using documentary sources, this article traces the appointments and transfers of a number of Soviet diplomatic officers and consuls (F.G. Falsky (Falkovsky, I.A. Chichayev, F.F. Razumov, A.G. Starkov, as well as Comintern representatives (I.G. Safyanov, B. Tsivenzhapov, V. Borovikov, A.M. Amur-Sanan, S.A. Natsov, V. Machavariani, V.A. Bogdanov. In the duopoly of consuls and Comintern representatives, the former dominated at the earlier stages, but after the defeat of Chinese communists in 1927 the Soviet leaders thought that Socialist transformations in Mongolia in Tuva should be sped up. The article makes use of archival sources from the State Archive of the Republic of Tuva, Russian State Archive of Socio-Political History (RGASPI, and the Research archive of Tuva Institute for Humanities and Applied Socioeconomic Studies.

NON-GOVERNMENTAL ORGANIZATIONS REPRESENTING THE INTERESTS OF PATIENTS’ ENGAGEMENT IN HEALH POLICY

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Gintarė Petronytė

2017-03-01

Full Text Available This article focuses on engagement in health policy of non-governmental organizations representing the interests of patients (NGOs. A qualitative study using a semi-structured interview method was performed in July–October 2015, involving nine representatives of NGOs from Vilnius and Kaunas. NGOs’ engagement in health policy was evaluated by applying the framework of the theoretical stakeholder participation ladder, which was developed by Arnstein and later extended by Friedman and Miles. NGOs’ engagement in health policy could be attributed to the levels of consultation and involvement, considering their collaboration with governmental institutions and political involvement. Their engagement in health policy could not be attributed to the level of delegated power (shared influence and responsibility when involved into the processes of decision formulation and decision-making. NGOs are involved in health policy by working groups and other working bodies established by governmental institutions. Financing, close interinstitutional collaboration, competencies of NGOs and their active participation are required for NGOs’ engagement in health policy. The main collaboration form between NGOs and the Ministry of Health is the Lithuanian patients’ forum, however, constant information, involvement in decision making processes and the initiation of collaboration are the key prerequisites for the development of closer collaboration. Internal and external barriers limit NGOs’ engagement in health policy: hierarchical relationships, the lack of equal collaboration and dialogue with governmental institutions, limited financial, time and human resources.

?Are Thai children and youth sufficiently active? prevalence and correlates of physical activity from a nationally representative cross-sectional study?

OpenAIRE

Amornsriwatanakul, Areekul; Lester, Leanne; Bull, Fiona C.; Rosenberg, Michael

2017-01-01

Background Children and youth gain multiple health benefits from regular participation in physical activity (PA). However, in Thailand there is limited national data on children and youth?s PA behaviors and recent reports suggest that Thai children and youth have low levels of PA. Furthermore, there is almost no data on the factors associated with inactivity to support the development of a Thai National PA Plan. The purpose of this paper is to investigate Thai children and youth?s participati...

THE STRUCTURE OF HAPPINESS REPRESENTATION FOR RUSSIAN AND AMERICAN REPRESENTATIVES

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S. Yu. Zhdanova

2017-01-01

Full Text Available Introduction. Emotional state of students exerts direct impact on their ability and readiness to cope with challenges when studying, gives rise to the success of educational process and its effectiveness. In this regard, the search of methods and determination of the tasks of psychological diagnostics is brought into focus. Above all, the teacher should consider mentality and valuable attitudes of representatives of various cultures, including their understanding of happiness and personal well-being in the activity against the background of the increasing scales of the international and interethnic mobility.The development of Russian psychology has recently acquired the direction of positive psychology, the focus of which is happiness and positive functioning of the individual. Modern research reveals significant differences in the indicators of happiness and satisfaction with life between representatives of different cultures. However, the diagnostic tools used in such studies are based primarily on the model of happiness image that has been developed in American psychology. In this connection, the question arises as to what extent the image of happiness in American culture correlates with the image of happiness in Russian culture.The aim of this work is to study the representation of happiness between representatives of American and Russian culture, the definition of invariable and variable components in the structure of representation.Methodology and research methods. The study included several stages. At the first stage, the theoretical analysis and development of the ontology of the subject area “Psychology of Happiness” was carried out. At the second stage, an empirical study of the representations of American and Russian respondents was carried out. The main method of data collection was a narrative interview; a method of early personal memories was used to obtain the narrative of happiness. Subsequent processing of verbal

27 August 2013 - Signature of an Agreement between KTO Karatay University in Turkey represented by the Dean of Engineering Professor Ali Okatan, CERN represented by Director for Research and Computing Dr Sergio Bertolucci and ALICE Collaboration represented by ALICE Collaboration Spokesperson Dr Paolo Giubellino.

CERN Multimedia

Maximilien Brice

2013-01-01

27 August 2013 - Signature of an Agreement between KTO Karatay University in Turkey represented by the Dean of Engineering Professor Ali Okatan, CERN represented by Director for Research and Computing Dr Sergio Bertolucci and ALICE Collaboration represented by ALICE Collaboration Spokesperson Dr Paolo Giubellino.

Evaluation of Antioxidant Activity, Polyphenolic Compounds, Amino Acids and Mineral Elements of Representative Genotypes of Lonicera edulis

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Jiri Sochor

2014-05-01

Full Text Available The aim of this study was to evaluate the bioactive substances in 19 berry cultivars of edible honeysuckle (Lonicera edulis. A statistical evaluation was used to determine the relationship between the content of selected bioactive substances and individual cultivars. Regarding mineral elements, the content of sodium was measured using potentiometry and spectrophotometry. The content of selected polyphenolic compounds with high antioxidant activity was determined by a HPLC–UV/ED method. The total amount of polyphenols was determined by the Folin-Ciocalteu method. The antioxidant activity was determined using five methods (DPPH, FRAP, ABTS, FR and DMPD that differ in their principles. The content of 13 amino acids was determined by ion-exchange chromatography. The experimental results obtained for the different cultivars were evaluated and compared by statistical and bioinformatic methods. A unique feature of this study lies in the exhaustive analysis of the chosen parameters (amino acids, mineral elements, polyphenolic compounds and antioxidant activity during one growing season.

Modeling and Depletion Simulations for a High Flux Isotope Reactor Cycle with a Representative Experiment Loading

Energy Technology Data Exchange (ETDEWEB)

Chandler, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Betzler, Ben [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Hirtz, Gregory John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Ilas, Germina [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division; Sunny, Eva [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Reactor and Nuclear Systems Division

2016-09-01

The purpose of this report is to document a high-fidelity VESTA/MCNP High Flux Isotope Reactor (HFIR) core model that features a new, representative experiment loading. This model, which represents the current, high-enriched uranium fuel core, will serve as a reference for low-enriched uranium conversion studies, safety-basis calculations, and other research activities. A new experiment loading model was developed to better represent current, typical experiment loadings, in comparison to the experiment loading included in the model for Cycle 400 (operated in 2004). The new experiment loading model for the flux trap target region includes full length ²⁵²Cf production targets, ⁷⁵Se production capsules, ⁶³Ni production capsules, a ¹⁸⁸W production capsule, and various materials irradiation targets. Fully loaded ²³⁸Pu production targets are modeled in eleven vertical experiment facilities located in the beryllium reflector. Other changes compared to the Cycle 400 model are the high-fidelity modeling of the fuel element side plates and the material composition of the control elements. Results obtained from the depletion simulations with the new model are presented, with a focus on time-dependent isotopic composition of irradiated fuel and single cycle isotope production metrics.

The appropriateness of using various Minkowskian metrics for representing cognitive configurations

OpenAIRE

G D Richardson

1981-01-01

Cognitive mapping has been a rapidly growing area of research concerned with how cognitive information about environments is represented, interpreted, and used. One area of research has been concerned with what geometry best represents cognitive spatial information. This paper further pursues this topic by examining which of three Minkowskian metrics (city-block, Euclidean, dominance) is most appropriate for representing cognitive configurations.

Dammarane triterpenes from the leaves of Panax ginseng enhance cellular immunity

DEFF Research Database (Denmark)

Tran, Tien-Lam; Kim, Young-Ran; Yang, Jun-Li

2014-01-01

In our search for immune stimulating materials from natural source, bioassay-guided fractionation of a methanol extract of Panax ginseng leaves led to the isolation of three dammarane triterpenes (1-3), including two previously unknown compounds 27-demethyl-(E,E)-20(22),23-dien-3β,6α,12β-trihydro......In our search for immune stimulating materials from natural source, bioassay-guided fractionation of a methanol extract of Panax ginseng leaves led to the isolation of three dammarane triterpenes (1-3), including two previously unknown compounds 27-demethyl-(E,E)-20(22),23-dien-3β,6α,12β...

Tiamulin selectively inhibits oxidative hepatic steroid and drug metabolism in vitro in the pig.

Science.gov (United States)

Witkamp, R F; Nijmeijer, S M; Csikó, G; van Miert, A S

1994-08-01

The simultaneous use of the antibiotic tiamulin with certain ionophoric antibiotics (monensin, salinomycin) may give rise to a toxic interaction in pigs and poultry. In the present study, effects of tiamulin on hepatic cytochrome P450 activities in vitro were studied using pig liver microsomes. When tiamulin was added to the incubation medium the N-demethylation rate of ethylmorphine and the hydroxylation of testosterone at the 6 beta- and 11 alpha-positions was strongly inhibited. Tiamulin inhibited these activities more than SKF525A or cimetidine, but less than ketoconazole. The microsomal N-demethylation rate of erythromycin and the hydroxylation of testosterone at the 2 beta-position were inhibited to a lesser degree, whereas the ethoxyresorufin-O-deethylation, aniline hydroxylation and testosterone hydroxylations at the 15 alpha- and 15 beta-positions were not affected by tiamulin. No in vitro complexation by tiamulin of cytochrome P450 resulting in a loss of CO-binding capacity could be demonstrated. Results from the present study suggest a selective inhibition of cytochrome P450 enzymes in pigs, probably belonging to the P4503A subfamily. The mechanism of this interaction is still unclear. However, interactions between tiamulin and those veterinary drugs or endogenous compounds which undergo oxidative metabolism by P450 enzymes must be considered. More research is needed to reveal which of the P450 enzymes are affected by tiamulin in order to improve the understanding and probably the predictability of this interaction.

Vapor-Phase Hydrodeoxygenation of Guaiacol to Aromatics over Pt/HBeta: Identification of the Role of Acid Sites and Metal Sites on the Reaction Pathway

Energy Technology Data Exchange (ETDEWEB)

Nie, Lei [Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 P.R. China; Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Peng, Bo [Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999 Richland WA 99352 USA; Zhu, Xinli [Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 P.R. China

2018-02-05

Hydrodeoxygenation of guaiacol, a phenolic compound derived from lignin fraction of biomass, over a Pt/HBeta catalyst at 350 °C and atmospheric pressure produces benzene, toluene, xylenes, and C9+ aromatics with yield of 42%, 29%, 12%, and 5%, respectively. Reaction pathways for conversion of two functional groups (hydroxyl and methoxyl) over the bifunctional catalyst were studied. Both guaiacol and intermediate products (catechol and cyclopentanone) were fed onto zeolite HBeta and Pt/SiO2 to identify the individual role of acid site and metal site. Acid sites (mainly Brønsted acid site, BAS) catalyze transalkylation and dehydroxylation reactions in sequence, producing phenol, cresols and xylenols as the major products at high conversion. Pt sites catalyze demethylation reaction resulting in catechol as the primary product, which can either be deoxygenated to phenol followed by phenol to benzene, or decarbonylated to cyclopentanone and further to butane. The close proximity of Pt and BAS in bifunctional Pt/HBeta enables both transalkylation and deoxygenation reactions with inhibited demethylation and decarbonylation reactions, producing aromatics as major final products with a total yield > 85%. Both activity and stability of bifunctional Pt/HBeta during hydrodeoxygenation of guaiacol is improved compared to HBeta and Pt/SiO2. The addition of water to the feed further improves the activity and stability via hydrolysis of O-CH3 bond of guaiacol on BAS and removing coke around Pt.

A relative quantitative Methylation-Sensitive Amplified Polymorphism (MSAP) method for the analysis of abiotic stress.

Science.gov (United States)

Bednarek, Piotr T; Orłowska, Renata; Niedziela, Agnieszka

2017-04-21

We present a new methylation-sensitive amplified polymorphism (MSAP) approach for the evaluation of relative quantitative characteristics such as demethylation, de novo methylation, and preservation of methylation status of CCGG sequences, which are recognized by the isoschizomers HpaII and MspI. We applied the technique to analyze aluminum (Al)-tolerant and non-tolerant control and Al-stressed inbred triticale lines. The approach is based on detailed analysis of events affecting HpaII and MspI restriction sites in control and stressed samples, and takes advantage of molecular marker profiles generated by EcoRI/HpaII and EcoRI/MspI MSAP platforms. Five Al-tolerant and five non-tolerant triticale lines were exposed to aluminum stress using the physiologicaltest. Total genomic DNA was isolated from root tips of all tolerant and non-tolerant lines before and after Al stress following metAFLP and MSAP approaches. Based on codes reflecting events affecting cytosines within a given restriction site recognized by HpaII and MspI in control and stressed samples demethylation (DM), de novo methylation (DNM), preservation of methylated sites (MSP), and preservation of nonmethylatedsites (NMSP) were evaluated. MSAP profiles were used for Agglomerative hierarchicalclustering (AHC) based on Squared Euclidean distance and Ward's Agglomeration method whereas MSAP characteristics for ANOVA. Relative quantitative MSAP analysis revealed that both Al-tolerant and non-tolerant triticale lines subjected to Al stress underwent demethylation, with demethylation of CG predominating over CHG. The rate of de novo methylation in the CG context was ~3-fold lower than demethylation, whereas de novo methylation of CHG was observed only in Al-tolerant lines. Our relative quantitative MSAP approach, based on methylation events affecting cytosines within HpaII-MspI recognition sequences, was capable of quantifying de novo methylation, demethylation, methylation, and non-methylated status in control

Conspicuous Waste and Representativeness Heuristic

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Tatiana M. Shishkina

2017-12-01

Full Text Available The article deals with the similarities between conspicuous waste and representativeness heuristic. The conspicuous waste is analyzed according to the classic Veblen’ interpretation as a strategy to increase social status through conspicuous consumption and conspicuous leisure. In “The Theory of the Leisure Class” Veblen introduced two different types of utility – conspicuous and functional. The article focuses on the possible benefits of the analysis of conspicuous utility not only in terms of institutional economic theory, but also in terms of behavioral economics. To this end, the representativeness heuristics is considered, on the one hand, as a way to optimize the decision-making process, which allows to examine it in comparison with procedural rationality by Simon. On the other hand, it is also analyzed as cognitive bias within the Kahneman and Twersky’ approach. The article provides the analysis of the patterns in the deviations from the rational behavior strategy that could be observed in case of conspicuous waste both in modern market economies in the form of conspicuous consumption and in archaic economies in the form of gift-exchange. The article also focuses on the marketing strategies for luxury consumption’ advertisement. It highlights the impact of the symbolic capital (in Bourdieu’ interpretation on the social and symbolic payments that actors get from the act of conspicuous waste. This allows to perform a analysis of conspicuous consumption both as a rational way to get the particular kind of payments, and, at the same time, as a form of institutionalized cognitive bias.

Representing and reasoning about program in situation calculus

Science.gov (United States)

Yang, Bo; Zhang, Ming-yi; Wu, Mao-nian; Xie, Gang

2011-12-01

Situation calculus is an expressive tool for modeling dynamical system in artificial intelligence, changes in a dynamical world is represented naturally by the notions of action, situation and fluent in situation calculus. Program can be viewed as a discrete dynamical system, so it is possible to model program with situation calculus. To model program written in a smaller core programming language CL, notion of fluent is expanded for representing value of expression. Together with some functions returning concerned objects from expressions, a basic action theory of CL programming is constructed. Under such a theory, some properties of program, such as correctness and termination can be reasoned about.

Representativeness, legitimacy and power in public involvement in health-service management.

Science.gov (United States)

Martin, Graham P

2008-12-01

Public participation in health-service management is an increasingly prominent policy internationally. Frequently, though, academic studies have found it marginalized by health professionals who, keen to retain control over decision-making, undermine the legitimacy of involved members of the public, in particular by questioning their representativeness. This paper examines this negotiation of representative legitimacy between staff and involved users by drawing on a qualitative study of service-user involvement in pilot cancer-genetics services recently introduced in England, using interviews, participant observation and documentary analysis. In contrast to the findings of much of the literature, health professionals identified some degree of representative legitimacy in the contributions made by users. However, the ways in which staff and users constructed representativeness diverged significantly. Where staff valued the identities of users as biomedical and lay subjects, users themselves described the legitimacy of their contribution in more expansive terms of knowledge and citizenship. My analysis seeks to show how disputes over representativeness relate not just to a struggle for power according to contrasting group interests, but also to a substantive divergence in understanding of the nature of representativeness in the context of state-orchestrated efforts to increase public participation. This divergence might suggest problems with the enactment of such aspirations in practice; alternatively, however, contestation of representative legitimacy might be understood as reflecting ambiguities in policy-level objectives for participation, which secure implementation by accommodating the divergent constructions of those charged with putting initiatives into practice.

Sample representativeness verification of the FADN CZ farm business sample

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Marie Prášilová

2011-01-01

Full Text Available Sample representativeness verification is one of the key stages of statistical work. After having joined the European Union the Czech Republic joined also the Farm Accountancy Data Network system of the Union. This is a sample of bodies and companies doing business in agriculture. Detailed production and economic data on the results of farming business are collected from that sample annually and results for the entire population of the country´s farms are then estimated and assessed. It is important hence, that the sample be representative. Representativeness is to be assessed as to the number of farms included in the survey and also as to the degree of accordance of the measures and indices as related to the population. The paper deals with the special statistical techniques and methods of the FADN CZ sample representativeness verification including the necessary sample size statement procedure. The Czech farm population data have been obtained from the Czech Statistical Office data bank.

Secreted fungal sulfhydryl oxidases: sequence analysis and characterisation of a representative flavin-dependent enzyme from Aspergillus oryzae

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Faccio Greta

2010-08-01

Full Text Available Abstract Background Sulfhydryl oxidases are flavin-dependent enzymes that catalyse the formation of de novo disulfide bonds from free thiol groups, with the reduction of molecular oxygen to hydrogen peroxide. Sulfhydryl oxidases have been investigated in the food industry to remove the burnt flavour of ultraheat-treated milk and are currently studied as potential crosslinking enzymes, aiming at strengthening wheat dough and improving the overall bread quality. Results In the present study, potential sulfhydryl oxidases were identified in the publicly available fungal genome sequences and their sequence characteristics were studied. A representative sulfhydryl oxidase from Aspergillus oryzae, AoSOX1, was expressed in the fungus Trichoderma reesei. AoSOX1 was produced in relatively good yields and was purified and biochemically characterised. The enzyme catalysed the oxidation of thiol-containing compounds like glutathione, D/L-cysteine, beta-mercaptoethanol and DTT. The enzyme had a melting temperature of 57°C, a pH optimum of 7.5 and its enzymatic activity was completely inhibited in the presence of 1 mM ZnSO4. Conclusions Eighteen potentially secreted sulfhydryl oxidases were detected in the publicly available fungal genomes analysed and a novel proline-tryptophan dipeptide in the characteristic motif CXXC, where X is any amino acid, was found. A representative protein, AoSOX1 from A. oryzae, was produced in T. reesei in an active form and had the characteristics of sulfhydryl oxidases. Further testing of the activity on thiol groups within larger peptides and on protein level will be needed to assess the application potential of this enzyme.

Secreted fungal sulfhydryl oxidases: sequence analysis and characterisation of a representative flavin-dependent enzyme from Aspergillus oryzae.

Science.gov (United States)

Faccio, Greta; Kruus, Kristiina; Buchert, Johanna; Saloheimo, Markku

2010-08-20

Sulfhydryl oxidases are flavin-dependent enzymes that catalyse the formation of de novo disulfide bonds from free thiol groups, with the reduction of molecular oxygen to hydrogen peroxide. Sulfhydryl oxidases have been investigated in the food industry to remove the burnt flavour of ultraheat-treated milk and are currently studied as potential crosslinking enzymes, aiming at strengthening wheat dough and improving the overall bread quality. In the present study, potential sulfhydryl oxidases were identified in the publicly available fungal genome sequences and their sequence characteristics were studied. A representative sulfhydryl oxidase from Aspergillus oryzae, AoSOX1, was expressed in the fungus Trichoderma reesei. AoSOX1 was produced in relatively good yields and was purified and biochemically characterised. The enzyme catalysed the oxidation of thiol-containing compounds like glutathione, D/L-cysteine, beta-mercaptoethanol and DTT. The enzyme had a melting temperature of 57°C, a pH optimum of 7.5 and its enzymatic activity was completely inhibited in the presence of 1 mM ZnSO4. Eighteen potentially secreted sulfhydryl oxidases were detected in the publicly available fungal genomes analysed and a novel proline-tryptophan dipeptide in the characteristic motif CXXC, where X is any amino acid, was found. A representative protein, AoSOX1 from A. oryzae, was produced in T. reesei in an active form and had the characteristics of sulfhydryl oxidases. Further testing of the activity on thiol groups within larger peptides and on protein level will be needed to assess the application potential of this enzyme.

Health behaviour in children and adolescents with type 1 diabetes compared to a representative reference population.

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Sebastian Kummer

Full Text Available We provide a population-based overview of health behaviours of children and adolescents with type 1 diabetes in comparison to the general population, and analyse their relevance for glycaemic control and self-rated health status.Data from questionnaires of 11- to 17-year-old children and adolescents with diabetes (n = 629 were compared to a representative sample (n = 6,813.Children and adolescents with type 1 diabetes had a significantly increased odds of infrequent physical activity (adjusted OR 1.56, short overall duration of physical activity per week (OR 1.55, difference -1.3 hours/week, and high daily computer use (OR 2.51. They had a lower odds of active and passive smoking (OR 0.31 and OR 0.29, and high daily television time (OR 0.68. The odds of an at least good and excellent self-rated health status was increased with intense physical activity, and decreased with active smoking and prolonged daily use of computer and television. Active smoking and prolonged daily use of computer were associated with higher HbA1c.Children and adolescents with type 1 diabetes showed a different profile of health behaviour. Their overall health may improve if their education stresses specifically frequent physical activity with longer overall duration and less frequent television or computer use.

40 CFR 73.33 - Authorized account representative.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Authorized account representative. 73.33 Section 73.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) SULFUR DIOXIDE ALLOWANCE SYSTEM Allowance Tracking System § 73.33 Authorized account...

Kinetics and mechanism investigation on the destruction of oxytetracycline by UV-254nm activation of persulfate.

Science.gov (United States)

Liu, Yiqing; He, Xuexiang; Fu, Yongsheng; Dionysiou, Dionysios D

2016-03-15

Oxytetracycline (OTC), an important broad-spectrum antibiotic, has been detected extensively in various environmental systems, which may have a detrimental impact on ecosystem and human health through the development of drug resistant bacteria and pathogens. In this study, the degradation of OTC was evaluated by UV-254nm activated persulfate (PS). The observed UV fluence based pseudo first-order rate constant (kobs) was found to be the highest at near neutral pH conditions (pH 5.5-8.5). Presence of various natural water constituents had different effects on OTC degradation, with a significant enhancement in the presence of bicarbonate or Cu(2+). Limited elimination of total organic carbon (TOC) and PS was observed during the mineralization of OTC. Transformation byproducts in the presence and absence of hydroxyl radical scavenging agent tert-butanol (t-BuOH) were identified using ultra-high definition accurate-mass quadrupole time-of-flight liquid chromatography/mass spectrometer (LC-QTOF/MS). Potential OTC degradation mechanism was subsequently proposed revealing four different reaction pathways by SO4(-) reaction including hydroxylation (+16Da), demethylation (-14Da), decarbonylation (-28Da) and dehydration (-18Da). This study suggests that UV-254nm/PS is a promising treatment technology for the control of water pollution caused by emerging contaminants such as OTC. Copyright © 2015 Elsevier B.V. All rights reserved.

Meeting staff representatives of the European Agencies

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Staff Association

2014-01-01

  The AASC (Assembly of Agency Staff Committee) held its 27th Meeting of the specialized European Agencies on 26 and 27 May on the premises of the OHIM (Office for Harmonization in the Internal Market) in Alicante, Spain. Two representatives of the CERN Staff Association, in charge of External Relations, attended as observers. This participation is a useful complement to regular contacts we have with FICSA (Federation of International Civil Servants' Associations), which groups staff associations of the UN Agencies, and the annual CSAIO conferences (Conference of Staff Associations of International Organizations), where each Autumn representatives of international organizations based in Europe meet to discuss themes of common interest to better promote and defend the rights of the international civil servants. All these meetings allow us to remain informed on items that are directly or indirectly related to employment and social conditions of our colleagues in other international and Europ...

Mechanisms of transcriptional regulation and prognostic significance of activated leukocyte cell adhesion molecule in cancer

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Chen Hairu

2010-10-01

Full Text Available Abstract Background Activated leukocyte cell adhesion molecule (ALCAM is implicated in the prognosis of multiple cancers with low level expression associated with metastasis and early death in breast cancer. Despite this significance, mechanisms that regulate ALCAM gene expression and ALCAM's role in adhesion of pre-metastatic circulating tumor cells have not been defined. We studied ALCAM expression in 20 tumor cell lines by real-time PCR, western blot and immunochemistry. Epigenetic alterations of the ALCAM promoter were assessed using methylation-specific PCR and bisulfite sequencing. ALCAM's role in adhesion of tumor cells to the vascular wall was studied in isolated perfused lungs. Results A common site for transcription initiation of the ALCAM gene was identified and the ALCAM promoter sequenced. The promoter contains multiple cis-active elements including a functional p65 NF-κB motif, and it harbors an extensive array of CpG residues highly methylated exclusively in ALCAM-negative tumor cells. These CpG residues were modestly demethylated after 5-aza-2-deoxycytidine treatment. Restoration of high-level ALCAM expression using an ALCAM cDNA increased clustering of MDA-MB-435 tumor cells perfused through the pulmonary vasculature of ventilated rat lungs. Anti-ALCAM antibodies reduced the number of intravascular tumor cell clusters. Conclusion Our data suggests that loss of ALCAM expression, due in part to DNA methylation of extensive segments of the promoter, significantly impairs the ability of circulating tumor cells to adhere to each other, and may therefore promote metastasis. These findings offer insight into the mechanisms for down-regulation of ALCAM gene expression in tumor cells, and for the positive prognostic value of high-level ALCAM in breast cancer.

40 CFR Appendix I to Part 261 - Representative Sampling Methods

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Representative Sampling Methods I...—Representative Sampling Methods The methods and equipment used for sampling waste materials will vary with the form and consistency of the waste materials to be sampled. Samples collected using the sampling...

Anti-proliferative and pro-apoptotic activity of whole extract and isolated indicaxanthin from Opuntia ficus-indica associated with re-activation of the onco-suppressor p16(INK4a) gene in human colorectal carcinoma (Caco-2) cells.

Science.gov (United States)

Naselli, Flores; Tesoriere, Luisa; Caradonna, Fabio; Bellavia, Daniele; Attanzio, Alessandro; Gentile, Carla; Livrea, Maria A

2014-07-18

Phytochemicals may exert chemo-preventive effects on cells of the gastro-intestinal tract by modulating epigenome-regulated gene expression. The effect of the aqueous extract from the edible fruit of Opuntia ficus-indica (OFI extract), and of its betalain pigment indicaxanthin (Ind), on proliferation of human colon cancer Caco-2 cells has been investigated. Whole extract and Ind caused a dose-dependent apoptosis of proliferating cells at nutritionally relevant amounts, with IC50 400±25 mg fresh pulp equivalents/mL, and 115±15 μM (n=9), respectively, without toxicity for post-confluent differentiated cells. Ind accounted for ∼80% of the effect of the whole extract. Ind did not cause oxidative stress in proliferating Caco-2 cells. Epigenomic activity of Ind was evident as de-methylation of the tumor suppressor p16(INK4a) gene promoter, reactivation of the silenced mRNA expression and accumulation of p16(INK4a), a major controller of cell cycle. As a consequence, decrease of hyper-phosphorylated, in favor of the hypo-phosphorylated retinoblastoma was observed, with unaltered level of the cycline-dependent kinase CDK4. Cell cycle showed arrest in the G2/M-phase. Dietary cactus pear fruit and Ind may have chemo-preventive potential in intestinal cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Invite your representative to work. Change the world. Here's how.

Science.gov (United States)

Montell, Denise J

2018-02-15

Today's political climate can seem hostile to science. Alternative facts, climate change denial, and relabeling of actual news as fake news are discouraging phenomena for sure. But these trends make it more important than ever to engage our politicians. Take heart! There is something you can do. You can show your representatives firsthand the amazing things you do, evidence of the economic engine that your activities generate, and the real people behind the discoveries. I did, and it was fun. We invited our congressman to the University of California, Santa Barbara (UCSB), and he accepted! For 2 hours, we explained and demonstrated efforts to cure blindness using stem cells, the medical implications of the discovery that cells can recover from the brink of death, a mosquito lab striving to eliminate insect-borne disease, and an Alzheimer's disease laboratory. Salud Carbajal peered through a microscope and met real scientists. Before his visit, he did not know what a postdoctoral fellow was, much less what stem cells look like. When he left he knew our names, how much money we bring into his district, and how important National Institutes of Health funding and international mobility are to our enterprise. Although I live in the United States, this approach should also apply to other democratic countries. If each of us converts one representative into a science champion, we can change the world. © 2018 Montell. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).