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Sample records for acid-dependent deoxyribonucleic acid

  1. Induction of cellular deoxyribonucleic acid synthesis in butyrate-treated cells by simian virus 40 deoxyribonucleic acid

    SciTech Connect

    Kawasaki, S.; Diamond, L.; Baserga, R.

    1981-11-01

    Sodium butyrate (3mM) inhibited the entry into the S phase of quiescent 3T3 cells stimulated by serum, but had no effect on the accumulation of cellular ribonucleic acid. Simian virus 40 infection or manual microinjection of cloned fragments from the simian virus 40 A gene caused quiescent 3T3 cells to enter the S phase even in the presence of butyrate. NGI cells, a line of 3T3 cells transformed by simian virus 40, grew vigorously in 3 mM butyrate. Homokaryons were formed between G/sub 1/ and S-phase 3T3 cells. Butyrate inhibited the induction of deoxyribonucleic acid synthesis that usually occurs in G/sub 1/ nuclei when G/sub 1/ cells are fused with S-phase cells. However, when G/sub 1/ 3T3 cells were fused with exponentially growing NGI cells, the 3T3 nuclei were induced to enter deoxyribonucleic acid synthesis. In tsAF8 cells, a ribonucleic acid polymerase II mutant that stops in the G/sub 1/ phase of the cell cycle, no temporal sequence was demonstrated between the butyrate block and the temperature-sensitive block. These results confirm previous reports that certain virally coded proteins can induce cell deoxyribonucleic acid synthesis in the absence of cellular functions that are required by serum-stimulated cells. The author's interpretation of these data is that butyrate inhibited cell growth by inhibiting the expression of genes required for the G/sub o/ ..-->.. G/sub 1/ ..-->.. S transition and that the product of the simian virus 40 A gene overrode this inhibition by providing all of the necessary functions for the entry into the S phase.

  2. Polyamines in the Synthesis of Bacteriophage Deoxyribonucleic Acid. I. Lack of Dependence of Polyamine Synthesis on Bacteriophage Deoxyribonucleic Acid Synthesis

    PubMed Central

    Dion, Arnold S.; Cohen, Seymour S.

    1972-01-01

    To determine whether polyamine synthesis is dependent on deoxyribonucleic acid (DNA) synthesis, polyamine levels were estimated after infection of bacterial cells with ultraviolet-irradiated T4 or T4 am N 122, a DNA-negative mutant. Although phage DNA accumulation was restricted to various degrees in comparison to cells infected with T4D, nearly commensurate levels of putrescine and spermidine synthesis were observed after infection, regardless of the rate of phage DNA synthesis. We conclude from these data that polyamine synthesis after infection is independent of phage DNA synthesis. PMID:4552549

  3. Incorporation of Deoxyribonucleic Acid Precursors by T4 Deoxyribonucleic Acid-Protein Complexes Retained on Glass Fiber Filters

    PubMed Central

    Miller, Robert C.; Kozinski, Andrzej W.

    1970-01-01

    Bacteriophage T4 deoxyribonucleic acid (DNA)-protein complexes were retained preferentially on glass fiber filters. DNA polymerase activity in the complex was detected through the incorporation of 3H-labeled DNA precursors. The primer-product DNA hybridized with both phage and Escherichia coli DNA. Density labeling experiments showed that about 30% of incorporated 3H-deoxyadenosine triphosphate was found in DNA which hybridized with phage DNA; this DNA was found to be covalently attached to the primer DNA. PMID:5497903

  4. DEOXYRIBONUCLEIC ACID BASE COMPOSITION OF PROTEUS AND PROVIDENCE ORGANISMS

    PubMed Central

    Falkow, Stanley; Ryman, I. R.; Washington, O.

    1962-01-01

    Falkow, Stanley (Walter Reed Army Institute of Research, Washington D.C.), I. R. Ryman, and O. Washington. Deoxyribonucleic acid base composition of Proteus and Providence organisms. J. Bacteriol. 83:1318–1321. 1962.—Deoxyribonucleic acids (DNA) from various species of Proteus and of Providence bacteria have been examined for their guanine + cytosine (GC) content. P. vulgaris, P. mirabilis, and P. rettgeri possess essentially identical mean GC contents of 39%, and Providence DNA has a GC content of 41.5%. In marked contrast, P. morganii DNA was found to contain 50% GC. The base composition of P. morganii is only slightly lower than those observed for representatives of the Escherichia, Shigella, and Salmonella groups. Aerobacter and Serratia differ significantly from the other members of the family by their relatively high GC content. Since a minimal requirement for genetic compatibility among different species appears to be similarity of their DNA base composition, it is suggested that P. morganii is distinct genetically from the other species of Proteus as well as Providence strains. The determination of the DNA base composition of microorganisms is important for its predictive information. This information should prove of considerable value in investigating genetic and taxonomic relationships among bacteria. PMID:13891463

  5. Specific Initiation Site for Simian Virus 40 Deoxyribonucleic Acid Replication

    PubMed Central

    Thoren, Marilyn M.; Sebring, Edwin D.; Salzman, Norman P.

    1972-01-01

    Replicating simian virus 40 (SV40) deoxyribonucleic acid (DNA) molecules have been isolated under conditions in which the newly synthesized DNA is uniformly labeled with 3H-thymidine. These newly synthesized strands are released from the replicative intermediate molecules by alkaline treatment, and it has been possible to isolate single-stranded SV40 DNA which varies in size from 157,000 daltons (from molecules that are 10% replicated) to 1,360,000 daltons (85% replicated). The rates of duplex formation of newly synthesized DNA have been used to relate their genetic complexity to the extent of DNA replication. As DNA replication proceeds, the time required to effect 50% renaturation of the newly synthesized DNA increases at a proportional rate. The data establish that DNA replication is not initiated at random, but rather that there is a single specific initiation site for DNA replication. PMID:4342054

  6. Does the deoxyribonucleic acid shape dictate its conductivity?

    NASA Astrophysics Data System (ADS)

    Romano, P.; Polcari, A.; Granata, V.; Sabatino, L.; Colantuoni, V.

    2009-05-01

    We present the evolution of current-voltage characteristics measured on linear fragments of deoxyribonucleic acid (DNA) molecules as a function of their length. The nonlinear behavior systematically observed at room temperature and also reported on circular plasmids suggests that the more molecules are involved in the conduction process, the higher are the current values measured. At the same time, a characteristic steplike feature superimposed to an overall increasing background appears more pronounced. We interpret this behavior in terms of simultaneous coherent and incoherent transport processes, the former taking place inside the DNA molecule, the latter through the network of molecules. Following our previous analysis on circular molecules, a phenomenological model is developed, in which a tunneling current with an energy dependent transmission coefficient is superimposed to a hopping current. The model provides a semiquantitative evidence that the steplike feature represents the signature of charge transmission inside the molecule. Our results are consistent with many of the conductivity data present in the literature.

  7. Electrical Transport Properties of Au-Doped Deoxyribonucleic Acid Molecules

    NASA Astrophysics Data System (ADS)

    Hwang, Jong Seung; Hong, Su Heon; Kim, Hyung Kwon; Kwon, Young Whan; Jin, Jung Il; Hwang, Sung Woo; Ahn, Doyeol

    2005-04-01

    Deoxyribonucleic acid (DNA) molecules were doped with Au atoms and their electrical transport properties were measured. The Au doping was carried out by incubating a mixture of HAuCl4\\cdot3H2O and DNA solutions. The binding of Au atoms to DNA bases was identified using Fourier transform infrared spectroscopy and X-ray photoemission spectroscopy. The Au-doped DNA molecules were deposited on nanoelectrodes and the presence of the molecules between the electrodes was determined by both scanning electron microscopy and atomic force microscopy. Measurement of the current-voltage characteristics showed that the Au-doped DNA molecules exhibited a higher conductivity than undoped DNA molecules. Detailed analysis of the chemical composition shows that there is a strong possibility of reliably controlling the conductivity of DNA molecules using this method.

  8. Origin and Direction of Simian Virus 40 Deoxyribonucleic Acid Replication

    PubMed Central

    Fareed, George C.; Garon, Claude F.; Salzman, Norman P.

    1972-01-01

    Double-branched, circular, replicating deoxyribonucleic acid (DNA) molecules of simian virus 40 (SV40) have been cleaved by the R1 restriction endonuclease from Escherichia coli. This enzyme introduces one double-strand break in SV40 DNA, at a specific site. The site of cleavage in the replicating molecules was used in this study to position the origin and the two branch points. Radioactively labeled molecules fractionated according to their extent of replication were evaluated after cleavage by sedimentation analysis and electron microscopy. The results demonstrate that the R1 cleavage site is 33% of the genome length from the origin of replication and that both branch points are growing points. These data indicate that SV40 DNA replication is bidirectional and confirm other reports which have shown a unique origin of replication. Images PMID:4342055

  9. Adansonian Analysis and Deoxyribonucleic Acid Base Composition of Serratia marcescens

    PubMed Central

    Colwell, R. R.; Mandel, M.

    1965-01-01

    Colwell, R. R. (Georgetown University, Washington, D.C.), and M. Mandel. Adansonian analysis and deoxyribonucleic acid base composition of Serratia marcescens. J. Bacteriol. 89:454–461. 1965.—A total of 33 strains of Serratia marcescens were subjected to Adansonian analysis for which more than 200 coded features for each of the organisms were included. In addition, the base composition [expressed as moles per cent guanine + cytosine (G + C)] of the deoxyribonucleic acid (DNA) prepared from each of the strains was determined. Except for four strains which were intermediate between Serratia and the Hafnia and Aerobacter group C of Edwards and Ewing, the S. marcescens species group proved to be extremely homogeneous, and the different strains showed high affinities for each other (mean similarity, ¯S = 77%). The G + C ratio of the DNA from the Serratia strains ranged from 56.2 to 58.4% G + C. Many species names have been listed for the genus, but only a single clustering of the strains was obtained at the species level, for which the species name S. marcescens was retained. S. kiliensis, S. indica, S. plymuthica, and S. marinorubra could not be distinguished from S. marcescens; it was concluded, therefore, that there is only a single species in the genus. The variety designation kiliensis does not appear to be valid, since no subspecies clustering of strains with negative Voges-Proskauer reactions could be detected. The characteristics of the species are listed, and a description of S. marcescens is presented. PMID:14255714

  10. Endonuclease from Micrococcus luteus which has activity toward ultraviolet-irradiated deoxyribonucleic acid: its action on transforming deoxyribonucleic acid.

    PubMed

    Setlow, R B; Setlow, J K; Carrier, W L

    1970-04-01

    An endonuclease purified from Micrococcus luteus makes single-strand breaks in ultraviolet (UV)-irradiated, native deoxyribonucleic acid (DNA). The purified endonuclease is able to reactivate UV-inactivated transforming DNA of Haemophilus influenzae, especially when the DNA is assayed on a UV-sensitive mutant of H. influenzae. After extensive endonuclease action, there is a loss of transforming DNA when assayed on both UV-sensitive and -resistant cells. The endonuclease does not affect unirradiated DNA. The results indicate that the endonuclease function is involved in the repair of biological damage resulting from UV irradiation and that the UV-sensitive mutant is deficient in this step. We interpret the data as indicating that the various steps in the repair of DNA must be well coordinated if repair is to be effective. PMID:4314478

  11. Deoxyribonucleic acid-dependent ribonucleic acid polymerase activity in rat liver after protein restriction.

    PubMed Central

    Andersson, G M; von der Decken, A

    1975-01-01

    Rats were fed for 6 days on a diet containing either 3 or 20% high-quality protein. Nuclei were isolated from liver and DNA-dependent RNA polymerases (EC 2.7.7.6) extracted with 1 M-(NH4)2SO4. The proteins were then precipitated with 3.5 M-(NH4)2SO4 and after dialysis applied to a DEAE-Sephadex column. The column was developed with a gradient of (NH4)2SO4. Polymerase I separated well from alpha-amanitin-sensitive polymerase II. The enzyme activities were compared between the two dietary groups. Rats that had received 3% protein showed a lower polymerase I activity per g wet wt. of liver, per mg of DNA and per mg of protein. Polymerase II was lower in activity per g wet wt. of liver and per mg of DNA, but was higher per mg of protein. Polyacrylamide-gel electrophoretograms showed a higher proportion of contaminating proteins in polymerase II fractions isolated from 20%-protein-fed rats. The data explain the lower activity obtained per mg of protein in these rats. It is concluded that a decrease in dietary protein content from 20 to 3% induces a fall in content and specific activity of RNA polymerase I and II in liver. PMID:1156400

  12. Dynamic hydroxymethylation of deoxyribonucleic acid marks differentiation-associated enhancers.

    PubMed

    Sérandour, Aurélien A; Avner, Stéphane; Oger, Frédérik; Bizot, Maud; Percevault, Frédéric; Lucchetti-Miganeh, Céline; Palierne, Gaëlle; Gheeraert, Céline; Barloy-Hubler, Frédérique; Péron, Christine Le; Madigou, Thierry; Durand, Emmanuelle; Froguel, Philippe; Staels, Bart; Lefebvre, Philippe; Métivier, Raphaël; Eeckhoute, Jérôme; Salbert, Gilles

    2012-09-01

    Enhancers are developmentally controlled transcriptional regulatory regions whose activities are modulated through histone modifications or histone variant deposition. In this study, we show by genome-wide mapping that the newly discovered deoxyribonucleic acid (DNA) modification 5-hydroxymethylcytosine (5hmC) is dynamically associated with transcription factor binding to distal regulatory sites during neural differentiation of mouse P19 cells and during adipocyte differentiation of mouse 3T3-L1 cells. Functional annotation reveals that regions gaining 5hmC are associated with genes expressed either in neural tissues when P19 cells undergo neural differentiation or in adipose tissue when 3T3-L1 cells undergo adipocyte differentiation. Furthermore, distal regions gaining 5hmC together with H3K4me2 and H3K27ac in P19 cells behave as differentiation-dependent transcriptional enhancers. Identified regions are enriched in motifs for transcription factors regulating specific cell fates such as Meis1 in P19 cells and PPARγ in 3T3-L1 cells. Accordingly, a fraction of hydroxymethylated Meis1 sites were associated with a dynamic engagement of the 5-methylcytosine hydroxylase Tet1. In addition, kinetic studies of cytosine hydroxymethylation of selected enhancers indicated that DNA hydroxymethylation is an early event of enhancer activation. Hence, acquisition of 5hmC in cell-specific distal regulatory regions may represent a major event of enhancer progression toward an active state and participate in selective activation of tissue-specific genes.

  13. Dynamic hydroxymethylation of deoxyribonucleic acid marks differentiation-associated enhancers

    PubMed Central

    Sérandour, Aurélien A.; Avner, Stéphane; Oger, Frédérik; Bizot, Maud; Percevault, Frédéric; Lucchetti-Miganeh, Céline; Palierne, Gaëlle; Gheeraert, Céline; Barloy-Hubler, Frédérique; Péron, Christine Le; Madigou, Thierry; Durand, Emmanuelle; Froguel, Philippe; Staels, Bart; Lefebvre, Philippe; Métivier, Raphaël; Eeckhoute, Jérôme; Salbert, Gilles

    2012-01-01

    Enhancers are developmentally controlled transcriptional regulatory regions whose activities are modulated through histone modifications or histone variant deposition. In this study, we show by genome-wide mapping that the newly discovered deoxyribonucleic acid (DNA) modification 5-hydroxymethylcytosine (5hmC) is dynamically associated with transcription factor binding to distal regulatory sites during neural differentiation of mouse P19 cells and during adipocyte differentiation of mouse 3T3-L1 cells. Functional annotation reveals that regions gaining 5hmC are associated with genes expressed either in neural tissues when P19 cells undergo neural differentiation or in adipose tissue when 3T3-L1 cells undergo adipocyte differentiation. Furthermore, distal regions gaining 5hmC together with H3K4me2 and H3K27ac in P19 cells behave as differentiation-dependent transcriptional enhancers. Identified regions are enriched in motifs for transcription factors regulating specific cell fates such as Meis1 in P19 cells and PPARγ in 3T3-L1 cells. Accordingly, a fraction of hydroxymethylated Meis1 sites were associated with a dynamic engagement of the 5-methylcytosine hydroxylase Tet1. In addition, kinetic studies of cytosine hydroxymethylation of selected enhancers indicated that DNA hydroxymethylation is an early event of enhancer activation. Hence, acquisition of 5hmC in cell-specific distal regulatory regions may represent a major event of enhancer progression toward an active state and participate in selective activation of tissue-specific genes. PMID:22730288

  14. Escherichia coli Mutants Thermosensitive for Deoxyribonucleic Acid Gyrase Subunit A: Effects on Deoxyribonucleic Acid Replication, Transcription, and Bacteriophage Growth

    PubMed Central

    Kreuzer, Kenneth N.; Cozzarelli, Nicholas R.

    1979-01-01

    Temperature-sensitive nalA mutants of Escherichia coli have been used to investigate the structure and functions of deoxyribonucleic acid (DNA) gyrase. Extracts of one such mutant (nalA43) had thermosensitive DNA gyrase subunit A activity but normal gyrase subunit B activity, proving definitively that nalA is the structural gene for subunit A. Extracts of a second nalA (Ts) mutant (nalA45) had a 50-fold deficiency of gyrase subunit A activity. The residual DNA supertwisting was catalyzed by the mutant DNA gyrase rather than by a novel supertwisting enzyme. The nalA45(Ts) extract was also deficient in the nalidixic acid target, which is defined as the protein necessary to confer drug sensitivity to in vitro DNA replication directed by a nalidixic acid-resistant mutant extract. Thus, gyrase subunit A and the nalidixic acid target are one and the same protein, the nalA gene product. Shift of the nalA43(Ts) mutant to a nonpermissive temperature resulted in a precipitous decline in the rate of [3H]thymidine incorporation, demonstrating an obligatory role of the nalA gene product in DNA replication. The rates of incorporation of [3H]uridine pulses and continuously administered [3H]uracil were quickly reduced approximately twofold upon temperature shift of the nalA43(Ts) mutant, and therefore some but not all transcription requires the nalA gene product. The thermosensitive growth of bacteriophages φX174 and T4 in the nalA43(Ts) host shows that these phages depend on the host nalA gene product. In contrast, the growth of phage T7 was strongly inhibited by nalidixic acid but essentially unaffected by the nalA43(Ts) mutation. The inhibition of T7 growth by nalidixic acid was, however, eliminated by temperature inactivation of the nal43 gene product. Therefore, nalidixic acid may block T7 growth by a corruption rather than a simple elimination of the nalidixic acid target. Possible mechanisms for such a corruption are considered, and their relevance to the puzzling

  15. Escherichia coli mutants thermosensitive for deoxyribonucleic acid gyrase subunit A: effects on deoxyribonucleic acid replication, transcription, and bacteriophage growth.

    PubMed

    Kreuzer, K N; Cozzarelli, N R

    1979-11-01

    Temperature-sensitive nalA mutants of Escherichia coli have been used to investigate the structure and functions of deoxyribonucleic acid (DNA) gyrase. Extracts of one such mutant (nalA43) had thermosensitive DNA gyrase subunit A activity but normal gyrase subunit B activity, proving definitively that nalA is the structural gene for subunit A. Extracts of a second nalA (Ts) mutant (nalA45) had a 50-fold deficiency of gyrase subunit A activity. The residual DNA supertwisting was catalyzed by the mutant DNA gyrase rather than by a novel supertwisting enzyme. The nalA45(Ts) extract was also deficient in the nalidixic acid target, which is defined as the protein necessary to confer drug sensitivity to in vitro DNA replication directed by a nalidixic acid-resistant mutant extract. Thus, gyrase subunit A and the nalidixic acid target are one and the same protein, the nalA gene product. Shift of the nalA43(Ts) mutant to a nonpermissive temperature resulted in a precipitous decline in the rate of [(3)H]thymidine incorporation, demonstrating an obligatory role of the nalA gene product in DNA replication. The rates of incorporation of [(3)H]uridine pulses and continuously administered [(3)H]uracil were quickly reduced approximately twofold upon temperature shift of the nalA43(Ts) mutant, and therefore some but not all transcription requires the nalA gene product. The thermosensitive growth of bacteriophages phiX174 and T4 in the nalA43(Ts) host shows that these phages depend on the host nalA gene product. In contrast, the growth of phage T7 was strongly inhibited by nalidixic acid but essentially unaffected by the nalA43(Ts) mutation. The inhibition of T7 growth by nalidixic acid was, however, eliminated by temperature inactivation of the nal43 gene product. Therefore, nalidixic acid may block T7 growth by a corruption rather than a simple elimination of the nalidixic acid target. Possible mechanisms for such a corruption are considered, and their relevance to the puzzling

  16. Structure of Replicating Simian Virus 40 Deoxyribonucleic Acid Molecules 1

    PubMed Central

    Sebring, E. D.; Kelly, T. J.; Thoren, M. M.; Salzman, N. P.

    1971-01-01

    Properties of replicating simian virus 40 (SV40) deoxyribonucleic acid (DNA) have been examined by sedimentation analysis and by direct observation during a lytic cycle of infection of African green monkey kidney cells. Two types of replicating DNA molecules were observed in the electron microscope. One was an open structure containing two branch points, three branches, and no free ends whose length measurements were consistent with those expected for replicating SV40 DNA molecules. A second species had the same features as the open structure, but in addition it contained a superhelix in the unreplicated portion of the molecule. Eighty to ninety per cent of the replicative intermediates (RI) were in this latter configuration, and length measurements of these molecules also were consistent with replicating SV40 DNA. Replicating DNA molecules with this configuration have not been described previously. RI, when examined in ethidium bromide-cesium chloride (EB-CsCl) isopycnic gradients, banded in a heterogeneous manner. A fraction of the RI banded at the same density as circular SV40 DNA containing one or more single-strand nicks (component II). The remaining radioactive RI banded at densities higher than that of component II, and material was present at all densities between that of supercoiled double-stranded DNA (component I) and component II. When RI that banded at different densities in EB-CsCl were examined in alkaline gradients, cosedimentation of parental DNA and newly replicated DNA did not occur. All newly replicated DNA sedimented more slowly than did intact single-stranded SV40 DNA, a finding that is inconsistent with the rolling circle model of DNA replication. An inverse correlation exists between the extent of replication of the SV40 DNA and the banding density in EB-CsCl. Under alkaline conditions, the parental DNA strands that were contained in the RI sedimented as covalently closed structures. The sedimentation rates in alkali of the covalently closed

  17. 21 CFR 528.1070 - Bc6 recombinant deoxyribonucleic acid construct.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Bc6 recombinant deoxyribonucleic acid construct. 528.1070 Section 528.1070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS NEW ANIMAL DRUGS IN GENETICALLY ENGINEERED ANIMALS § 528.1070 Bc6...

  18. Auxotroph Accumulation in Deoxyribonucleic Acid Polymeraseless Strains of Escherichia coli K-121

    PubMed Central

    Berg, Claire M.

    1971-01-01

    Spontaneous auxotrophs are found with high frequency in several strains of Escherichia coli K-12 deficient in Kornberg deoxyribonucleic acid polymerase. These include amino acid-, vitamin-, purine-, and pyrimidine-requiring strains. Although this was suggestive evidence that these strains might be mutators, reconstruction experiments demonstrate that auxotrophs possess a selective advantage over prototrophs in the same culture. Thus, despite the high frequency of auxotrophs in polymerase-deficient strains, it is not yet clear whether they have elevated mutation rates. PMID:4934065

  19. Excision of pyrimidine dimers from nuclear deoxyribonucleic acid in ultraviolet-irradiated Dictyostelium discoideum

    SciTech Connect

    Clark, J.M.; Deering, R.A.

    1987-02-01

    A sensitive endonuclease assay was used to study the fate of pyrimidine dimers introduced by ultraviolet irradiation into the nuclear deoxyribonucleic acid of the cellular slime mold Dictyostellium discoideum. Analysis of the frequency of T4 endonuclease V-induced single-strand breaks by alkaline sucrose gradient sedimentation showed that strain NC4 (rad/sup +/) removed >98% of the dimers induced by irradiation at 40 J/m/sup 2/ (254 nm) within 215 min after irradiation. HPS104 (radC44), a mutant sensitive to ultraviolet irradiation, removed 91% under these conditions, although at a significantly slower rate than NC4: only 8% were removed during the 10- to 15- min period immediately after irradiation, whereas NC4 excised 64% during this interval. HPS104 thus appears to be deficient in the activity(ies) responsible for rapidly incising ultraviolet-irradiated nuclear deoxyribonucleic acid at the sites of pyrimidine dimers.

  20. Deoxyribonucleic Acid Relatedness Among Species of Erwinia and Between Erwinia Species and Other Enterobacteria

    PubMed Central

    Brenner, Don J.; Fanning, G. R.; Steigerwalt, A. G.

    1972-01-01

    Relatedness in species of Erwinia was assessed by determining the extent of reassociation in heterologous deoxyribonucleic acid preparations. Thermal elution chromatography on hydroxyapatite was used to separate reassociated nucleotide sequences from nonreassociated sequences and to determine the thermal stability of related nucleotide sequences. An apparent 15% core of relatedness is present between fire blight, soft-rot, and “atypical” Erwinia species. All Erwinia species showed low to moderate reaction with representative enteric bacteria. PMID:5018020

  1. A nucleic acid dependent chemical photocatalysis in live human cells.

    PubMed

    Arian, Dumitru; Cló, Emiliano; Gothelf, Kurt V; Mokhir, Andriy

    2010-01-01

    Only two nucleic acid directed chemical reactions that are compatible with live cells have been reported to date. Neither of these processes generate toxic species from nontoxic starting materials. Reactions of the latter type could be applied as gene-specific drugs, for example, in the treatment of cancer. We report here the first example of a chemical reaction that generates a cytotoxic drug from a nontoxic prodrug in the presence of a specific endogeneous ribonucleic acid in live mammalian cells. In this case, the prodrug is triplet oxygen and the drug is singlet oxygen. The key component of this reaction is an inert molecule (InP-2'-OMe-RNA/Q-2'-OMe-RNA; P: photosensitizer; Q: quencher), which becomes an active photosensitizer (InP-2'-OMe-RNA) in the presence of single-stranded nucleic acid targets. Upon irradiation with red light, the photosensitizer produces over 6000 equivalents of toxic singlet oxygen per nucleic acid target. This reaction is highly sequence specific. To detect the generation of singlet oxygen in live cells, we prepared a membrane-permeable and water-soluble fluorescent scavenger, a derivative of 2,5-diphenylisobenzofurane. The scavenger decomposes upon reaction with singlet oxygen and this is manifested in a decrease in the fluorescence intensity. This effect can be conveniently monitored by flow cytometry.

  2. Poorer Prognosis With Ethylenediaminetetraacetic Acid-dependent Pseudothrombocytopenia

    PubMed Central

    Ohashi-Fukuda, Naoko; Inokuchi, Ryota; Sato, Hajime; Nakamura, Kensuke; Iwagami, Masao; Wada, Tomoki; Jona, Masahiro; Hisasue, Takashi; Nakajima, Susumu; Yahagi, Naoki

    2015-01-01

    Abstract In ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia (PTCP), automated platelet counts are lower than actual counts because of EDTA-induced aggregation. Factors contributing to the incidence of EDTA-PTCP are unknown, and no study has assessed the prognosis of EDTA-PTCP patients. This retrospective study assessed characteristics in EDTA-PTCP patients and matched controls to determine differences in prognosis. A retrospective case–control study was designed. From the University of Tokyo Hospital database, we identified patients diagnosed with EDTA-PTCP between 2009 and 2012, and performed 1:2 case:control matching for age and sex. A control group of sex- and age-matched patients was selected at random from the same database. We investigated differences in the frequency of complications, medication history, and blood transfusion history between the groups at the time of blood collection. Prognosis was evaluated using multivariate Cox regression analysis adjusting for age, sex, autoimmune disease, liver disease, and malignant tumor. We identified 104 EDTA-PTCP patients and 208 matched controls. The median age was 69.0 years (interquartile range: 54–76), with men comprising 51%. EDTA-PTCP patients had a higher frequency of malignant tumor and a lower frequency of hypertension and diabetes than controls. After adjustment for background factors, prognosis of EDTA-PTCP patients was significantly poorer than controls (hazard ratio, 11.8; 95% confidence intervals, 2.62–53.54). In conclusion, EDTA-PTCP patients had higher mortality, and EDTA-PTCP may need to be recognized as an indicator of worse prognosis. PMID:25881844

  3. Amplified spontaneous emission of Rhodamine 6G embedded in pure deoxyribonucleic acid

    NASA Astrophysics Data System (ADS)

    Rau, Ileana; Szukalski, Adam; Sznitko, Lech; Miniewicz, Andrzej; Bartkiewicz, Stanislaw; Kajzar, Francois; Sahraoui, Bouchta; Mysliwiec, Jaroslaw

    2012-10-01

    Deoxyribonucleic acid (DNA) is commonly viewed as a genetic information carrier. However, now it is recognized as a nanomaterial, rather than as a biological material, in the research field of nanotechnology. Here, we show that using pure DNA, doped with rhodamine 6G, we are able to observe amplified spontaneous emission (ASE) phenomenon. Moderate ASE threshold, photodegradation, and reasonable gain coefficient observed in this natural host gives some perspectives for practical applications of this system in biophotonics. Obtained results open the way and will be leading to construction of truly bio-lasers using nature made luminophores, such as anthocyanins.

  4. Photoelectrochemical deoxyribonucleic acid sensing on a nanostructured TiO2 electrode

    NASA Astrophysics Data System (ADS)

    Tokudome, Hiromasa; Yamada, Yoko; Sonezaki, Shuji; Ishikawa, Hiroshi; Bekki, Makoto; Kanehira, Koki; Miyauchi, Masahiro

    2005-11-01

    A nanostructured TiO2 electrode chemisorbed with probe deoxyribonucleic acid (DNA) can photoelectrochemically detect a dye-labeled target DNA molecule. After the hybridization between the probe and target DNA molecules, light irradiation generates electrons in the dye molecules, and these electrons are injected into the TiO2 electrode. The resulting photocurrent can be measured and corresponds to the concentration of target DNA. This sensor can quantitatively detect target DNA at lower than nanomolar concentrations. In addition, by utilizing two different dyes, different DNA sequences can be detected on the TiO2 electrode.

  5. A novel chaotic based image encryption using a hybrid model of deoxyribonucleic acid and cellular automata

    NASA Astrophysics Data System (ADS)

    Enayatifar, Rasul; Sadaei, Hossein Javedani; Abdullah, Abdul Hanan; Lee, Malrey; Isnin, Ismail Fauzi

    2015-08-01

    Currently, there are many studies have conducted on developing security of the digital image in order to protect such data while they are sending on the internet. This work aims to propose a new approach based on a hybrid model of the Tinkerbell chaotic map, deoxyribonucleic acid (DNA) and cellular automata (CA). DNA rules, DNA sequence XOR operator and CA rules are used simultaneously to encrypt the plain-image pixels. To determine rule number in DNA sequence and also CA, a 2-dimension Tinkerbell chaotic map is employed. Experimental results and computer simulations, both confirm that the proposed scheme not only demonstrates outstanding encryption, but also resists various typical attacks.

  6. Loss of activity of transforming deoxyribonucleic acid after uptake by Haemophilus influenzae.

    PubMed

    Voll, M J; Goodgal, S H

    1965-10-01

    Voll, Mary Jane (University of Pennsylvania, Philadelphia), and Sol H. Goodgal. Loss of activity of transforming deoxyribonucleic acid after uptake by Haemophilus influenzae. J. Bacteriol. 90:873-883. 1965.-Transforming deoxyribonucleic acid (DNA) which has been irreversibly removed from solution by competent cells undergoes a progressive loss in marker activity when tested by lysis of the cells and exposure to new recipient cells. The loss of activity is limited and marker-specific, with greater inactivation of those markers with lower efficiencies of transformation. Recipient factors or donor factors which have undergone recombination, as measured by the appearance of linked markers, do not undergo inactivation. The efficiency of transformation can be correlated with the sensitivity of a marker to inactivation after DNA uptake. A mutation which affects the efficiency of transformation is found to increase sensitivity to postuptake inactivation. The rate of inactivation is temperature-dependent. At temperatures of 20 and 45 C, marker inactivation can occur without concomitant recombination. During the uptake process, DNA is retained in an acid-insoluble form, indicating that the fate of Haemophilus influenzae DNA differs from the fate of transforming DNA in pneumococcus.

  7. BASE COMPOSITION OF THE DEOXYRIBONUCLEIC ACID OF SULFATE-REDUCING BACTERIA

    PubMed Central

    Sigal, Nicole; Senez, Jacques C.; Le Gall, Jean; Sebald, Madeleine

    1963-01-01

    Sigal, Nicole (Laboratoire de Chimie Bactérienne du CNRS, Marseille, France), Jacques C. Senez, Jean Le Gall, and Madeleine Sebald. Base composition of the deoxyribonucleic acid of sulfate-reducing bacteria. J. Bacteriol. 85:1315–1318. 1963—The deoxyribonucleic acid constitution of several strains of sulfate-reducing bacteria has been analytically determined. The results of these studies show that this group of microorganisms includes at least four subgroups characterized by significantly different values of the adenine plus thymine to guanine plus cytosine ratio. The nonsporulated forms with polar flagellation, containing both cytochrome c3 and desulfoviridin, are divided into two subgroups. One includes the fresh-water, nonhalophilic strains with base ratio from 0.54 to 0.59, and the other includes the halophilic or halotolerant strains with base ratio from 0.74 to 0.77. The sporulated, peritrichous strains without cytochrome and desulfoviridin (“nigrificans” and “orientis”) are distinct from the above two types and differ from each other, having base ratios of 1.20 and 1.43, respectively. PMID:14047223

  8. ADANSONIAN ANALYSIS AND DEOXYRIBONUCLEIC ACID BASE COMPOSITION OF SOME GRAM-NEGATIVE BACTERIA

    PubMed Central

    Colwell, R. R.; Mandel, M.

    1964-01-01

    Colwell, R. R. (Georgetown University, Washington, D.C.), and M. Mandel. Adansonian analysis and deoxyribonucleic acid base composition of some gram-negative bacteria. J. Bacteriol. 87:1412–1422. 1964.—The deoxyribonucleic acid (DNA) base compositions and S values for a minimum of 134 coded properties were determined for representative cultures of the genera Pseudomonas, Xanthomonas, Aeromonas, Vibrio, Aerobacter, Escherichia, Alcaligenes, and Flavobacterium. Those cultures having a high degree of similarity by the criterion of numerical taxonomy were found to have similar DNA base compositions. The relative affinities of clusters of cultures suggest taxonomic relations. Eleven species of Xanthomonas might be a single species, and V. metschnikovii was shown to be more closely related to enteric bacteria than to other vibrios which, in turn, were found to be like pseudomonads. Aeromonas was found to be intermediate in similarity to enterics and pseudomonads and divisible into at least two, but possibly three, species. F. aquatile was unlike any of the other organisms studied, and its DNA also differed greatly in composition from other representatives of the genus. PMID:14188722

  9. Separation and partial characterization of two deoxyribonucleic acid polymerases from Spiroplasma citri.

    PubMed Central

    Charron, A; Bebear, C; Brun, G; Yot, P; Latrille, J; Bove, J M

    1979-01-01

    The separation and partial characterization of two deoxyribonucleic acid polymerases from Spiroplasma citri have been achieved. The two enzymes had different elution properties on diethylaminoethyl (DEAE) cellulose and differed in their sensitivity to N-ethylmaleimide (NEM), preference for different template-primers, and sedimentation velocity in linear glycerol gradients. The first enzyme activity, ScA, was retained on DEAE-cellulose and was not inhibited by NEM. Activated deoxyribonucleic acid and poly(dA)-oligo(dT12) were the preferred template-primers. Arabinosyl-cytidine triphosphate had no effect. The sedimentation coefficient of ScA was 6.3s. The second activity, ScB, was not retained on DEAE-cellulose and was inhibited by NEM. Poly(dA)-oligo(dT12) was the preferred template-primer, whereas activated DNA was only poorly utilized. ScB was not affected by arabinosyl-cytidine triphosphate, and its sedimentation coefficient was 4.4s. The polymerization activities of the two enzymes were maximum at 37 to 40 degrees C. PMID:42638

  10. Assistant deoxyribonucleic acid recycling with Zn(2+) and molecular beacon for electrochemical detection of deoxyribonucleic acid via target-triggered assembly of mutated DNAzyme.

    PubMed

    Qian, Yong; Wang, Chunyan; Gao, Fenglei

    2014-10-01

    A novel enzyme-free amplification strategy was designed for sensitive electrochemical detection of deoxyribonucleic acid (DNA) based on Zn(2+) assistant DNA recycling via target-triggered assembly of mutated DNAzyme. A gold electrode was used to immobilize molecular beacon (MB) as the recognition probe and perform the amplification procedure. In the presence of target DNA, the hairpin probe 1 was opened, and the DNAzyme was liberated from the caged structure. The activated DNAzyme first hybridized and then cleaved the MB in the presence of cofactor Zn(2+). After cleavage, the MB was cleaved into two pieces and the ferrocene (Fc) labeled piece dissociated from the gold electrode, thus obviously decreasing the Fc signal and forming a free DNAzyme strand. Finally, each target-induced activated DNAzyme underwent many cycles to trigger the cleavage of many MB substrates. Therefore, the peak current of Fc dramatically decreased to approximately zero. The strategy showed a detection limit at 35 fM levels, which was about 2 orders of magnitude lower than that of the conventional hybridization without Zn(2+)-based amplification. The Zn(2+) assistant DNA recycling offers a versatile platform for DNA detection in a cost-effective manner, and has a promising application in clinical diagnosis.

  11. Optoelectronic studies on heterocyclic bases of deoxyribonucleic acid for DNA photonics.

    PubMed

    El-Diasty, Fouad; Abdel-Wahab, Fathy

    2015-10-01

    The optoelectronics study of large molecules, particularly π-stacking molecules, such as DNA is really an extremely difficult task. We perform first electronic structure calculations on the heterocyclic bases of 2'-deoxyribonucleic acid based on Lorentz-Fresnel dispersion theory. In the UV-VIS range of spectrum, many of the optoelectronic parameters for DNA four bases namely adenine, guanine, cytosine and thymine are calculated and discussed. The results demonstrate that adenine has the highest hyperpolarizability, whereas thymine has the lowest hyperpolarizability. Cytosine has the lower average oscillator energy and the higher lattice energy. Thymine infers the most stable nucleic base with the lower phonon energy. Thymine also has the highest average oscillator energy and the lower lattice energy. Moreover, the four nucleic acid bases have large band gap energies less than 5 eV with a semiconducting behavior. Guanine shows the smallest band gap and the highest Fermi level energy, whereas adenine elucidates the highest band gap energy.

  12. Comparisons of the Distribution of Nucleotides and Common Sequences in Deoxyribonucleic Acid from Selected Bacteriophages

    PubMed Central

    Skalka, A.; Hanson, P.

    1972-01-01

    Results from comparisons of deoxyribonucleic acid (DNA) from several classes of bacteriophages suggest that most phage chromosomes contain either a homogeneous distribution of nucleotides or are made up of a few, rather large segments of different quanine plus cytosine (G + C) contents which are internally homogeneous. Among those temperate phages tested, most contained segmented DNA. Comparisons of sequence similarities among segments from lambdoid phage DNA species revealed the following order in relatedness to λ: 82 (and 434) > 21 > 424 > φ80. Most common sequences are found in the highest G + C segments, which in λ contain head and tail genes. Hybridization tests with λ and 186 or P2 DNA species verified that the lambdoids and 186 and P2 belong to two distinct groups. There are fewer homologous sequences between the DNA species of coliphages λ and P2 or 186 than there are between the DNA species of coliphage λ and salmonella phage P22. PMID:4553679

  13. Application of Markov chain to the pattern of mitochondrial deoxyribonucleic acid mutations

    NASA Astrophysics Data System (ADS)

    Vantika, Sandy; Pasaribu, Udjianna S.

    2014-03-01

    This research explains how Markov chain used to model the pattern of deoxyribonucleic acid mutations in mitochondrial (mitochondrial DNA). First, sign test was used to see a pattern of nucleotide bases that will appear at one position after the position of mutated nucleotide base. Results obtained from the sign test showed that for most cases, there exist a pattern of mutation except in the mutation cases of adenine to cytosine, adenine to thymine, and cytosine to guanine. Markov chain analysis results on data of mutations that occur in mitochondrial DNA indicate that one and two positions after the position of mutated nucleotide bases tend to be occupied by particular nucleotide bases. From this analysis, it can be said that the adenine, cytosine, guanine and thymine will mutate if the nucelotide base at one and/or two positions after them is cytosine.

  14. Amino-acid-dependent main-chain torsion-energy terms for protein systems.

    PubMed

    Sakae, Yoshitake; Okamoto, Yuko

    2013-02-14

    Many commonly used force fields for protein systems such as AMBER, CHARMM, GROMACS, OPLS, and ECEPP have amino-acid-independent force-field parameters for main-chain torsion-energy terms. Here, we propose a new type of amino-acid-dependent torsion-energy terms in the force fields. As an example, we applied this approach to AMBER ff03 force field and determined new amino-acid-dependent parameters for ψ (N-C(α)-C-N) and ζ (C(β)-C(α)-C-N) angles for each amino acid by using our optimization method, which is one of the knowledge-based approach. In order to test the validity of the new force-field parameters, we then performed folding simulations of α-helical and β-hairpin peptides, using the optimized force field. The results showed that the new force-field parameters gave structures more consistent with the experimental implications than the original AMBER ff03 force field.

  15. Transcription of exogenous and endogenous deoxyribonucleic acid templates in cold-shocked Bacillus subtilis.

    PubMed Central

    Kuhl, S J; Brown, L R

    1980-01-01

    Ribonucleic acid (RNA) synthesis was examined in cold-shocked Bacillus subtilis cells. The cells were grown to mid-log stage, harvested, and cold shocked. RNA synthesis was monitored by the incorporation of [3H]uridine triphosphate or [alpha 32P]adenosine triphosphate into trichloroacetic acid-precipitable material in the presence of all four nucleoside triphosphates. The inhibition of RNA synthesis in cold-shocked cells by lipiarmycin, ethidium bromide, rifampin. or streptolydigin was analyzed using mutant or wild-type cells. Also examined were the effects of temperature, salt concentration, and the addition of polyamines or highly phosphorylated nucleotides. In ultraviolet-irradiated and cold-shocked cells, RNA wynthesis decreased to low levels. The addition of exogenous phi 29 or TSP-1 template to these cells caused a 13- to 20-fold increase in RNA synthesis, as monitored by trichloroacetic acid-precipitable counts. RNA synthesized in the presence of phi 29 deoxyribonucleic acid (DNA) hybridizes mainly to EcoRI fragments A and C of phi 29 DBA, These two fragments direct transcription by purified RNA polymerase in vitro and hybridize to early phi 29 DNA produced in vivo. Our results with TSP-1 DNA in this system indicated that the RNA produced hybridizes to the same fragments as early RNA produced in vivo. Plasmic pUB110 DNA was not transcribed in this system. Images PMID:6157674

  16. Spermidine-Deoxyribonucleic acid interaction in vitro and in Escherichia coli.

    PubMed Central

    Rubin, R L

    1977-01-01

    The binding of spermidine to deoxyribonucleic acid (DNA) was studied by equilibrium dialysis in a wide range of salt concentrations. The association constants ranged from 6 x 10(5) M-1 in 1 mM sodium cacodylate, pH 7.5, to 3 x 10(2) M-1 in 0.3 M NaCl. MgCl2 reduced spermidine-DNA interaction even more than NaCl so that in moderate-ionic-strength solutions (0.3 M NaCl, 0.002 M MgCl2) there was little detectable binding. Low-ionic-strength media were used to isolate DNA from Escherichia coli by a method shown to minimize loss of spermidine from the DNA. Considerable spermidine was associated with E. coli DNA, but control experiments indicated that complex formation had taken place during or after lysis of the cells. Exogenous DNA or ribonucleic acid added to spheroplasts at the time of their lysis caused most of the cellular spermidine to be scavenged by the extra nucleic acid. The data suggest that spermidine is relatively free in the cell and thereby capable of strong (high-affinity) associations with nucleic acids only after the ionic strength of the cell environment is lowered. PMID:320196

  17. Amino acid dependent formation of phosphate anhydrides in water mediated by carbonyl sulfide.

    PubMed

    Leman, Luke J; Orgel, Leslie E; Ghadiri, M Reza

    2006-01-11

    Carbonyl sulfide (COS), a component of volcanic gas emissions and interstellar gas clouds, is shown to be an efficient condensing agent in the context of phosphate chemistry in aqueous solutions. We report that high-energy aminoacyl-phosphate anhydrides and aminoacyl adenylates are generated in solutions containing amino acids, COS, and the corresponding phosphate molecule. We further show that the mixed anhydrides of amino acids and inorganic phosphate are phosphorylating agents, producing pyrophosphate in better than 30% yield in the presence of Ca2+ precipitates. The amino acid dependent activations of phosphate reported here, which occur in parallel with the production of peptides, suggest that these two reactions may have shared a common intermediate on the prebiotic Earth.

  18. Deoxyribonucleic Acid Base Sequence Homologies of Some Budding and Prosthecate Bacteria

    PubMed Central

    Moore, Richard L.; Hirsch, Peter

    1972-01-01

    The genetic relatedness of a number of budding and prosthecate bacteria was determined by deoxyribonucleic acid (DNA) homology experiments of the direct binding type. Strains of Hyphomicrobium sp. isolated from aquatic habitats were found to have relatedness values ranging from 9 to 70% with strain “EA-617,” a subculture of the Hyphomicrobium isolated by Mevius from river water. Strains obtained from soil enrichments had lower values with EA-617, ranging from 3 to 5%. Very little or no homology was detected between the amino acid-utilizing strain Hyphomicrobium neptunium and other Hyphomicrobium strains, although significant homology was observed with the two Hyphomonas strains examined. No homology could be detected between prosthecate bacteria of the genera Rhodomicrobium, Prosthecomicrobium, Ancalomicrobium, or Caulobacter, and Hyphomicrobium strain EA-617 or H. neptunium LE-670. The grouping of Hyphomicrobium strains by their relatedness values agrees well with a grouping according to the base composition of their DNA species. It is concluded that bacteria possessing cellular extensions represent a widely diverse group of organisms. PMID:5018022

  19. A fluorometric deoxyribonucleic acid assay for tridimensional lattice cultures of fibroblasts.

    PubMed

    Gillery, P; Bonnet, A; Borel, J P

    1993-05-01

    A fast and sensitive in situ assay of deoxyribonucleic acid in miniaturized lattice cultures of fibroblasts is described. Tridimensional collagen and fibrin lattices prepared in 24-well plates were seeded with 50,000 to 200,000 cells. Cultures were fixed with formaldehyde, rinced with isopropanol, and dried. DNA assay was performed directly in the wells by addition of 3,5-diaminobenzoic acid (DABA) reagent. A calibration curve was prepared with calf thymus DNA. Fluorescence of DNA-DABA was evaluated after 45 min incubation (excitation wavelength 420 nm, emission wavelength 490 nm). The method showed linear results from 0.5 to 10 micrograms DNA and proved sensitive for low cell numbers (50,000 per dish). DNA assay in monolayers and in different types of lattices showed that comparable results were obtained in the different models without interference of the extracellular matrix. This technique is regarded as a costless and efficient tool for evaluating the number of cells in lattices in basal conditions or under pharmacological stimulation. PMID:8512073

  20. Deoxyribonucleic acid base composition and biochemical properties of certain coagulase-negative enterotoxigenic cocci.

    PubMed

    Lotter, L P; Genigeorgis, C A

    1975-02-01

    Eight coagulase-negative, enterotoxigenic strains of cocci and one weakly coagulase-positive strain isolated from a number of different sources, including cases of food poisoning incidents, were evaluated for their relationship to Staphylococcus aureus on the basis of deoxyribonucleic acid (DNA) buoyant density and physiological studies. One strain of cocci produced enterotoxins A and C, two strains produced types B and C, four strains produced only type C, and one strain only type D. The enterotoxin produced by one strain of cocci was serologically untypable. None of the test organisms produced detectable amounts of enterotoxin in broth cultures. The test strains of cocci exhibited the following profile: all produced catalase; all grew anaerobically and fermented glucse; five were sensitive to lysostaphin; the percentage of guanine plus cytosine content of their DNA varied from 32.7 to 37.6; five produced acid from mannitol both aerobically and anaerobically; two formed delta-hemolysin; five produced phosphatase and acetoin; and all produced heat-stable nuclease. None of the organisms exhibited typical characteristics of S. aureus, S. epidermidis, or S. saprophyticus. On the basis of the present data and data reported elsewhere, these organisms should be considered as variants or mutants of S. aureus.

  1. pH-responsive deoxyribonucleic acid capture/release by polydopamine functionalized magnetic nanoparticles.

    PubMed

    Wang, Yu; Ma, Xiangdong; Ding, Chun; Jia, Li

    2015-03-01

    Polydopamine functionalized magnetic nanoparticles (PDA@Fe3O4) were prepared and characterized by transmission electron microscopy, scanning electron microscopy, zeta potential and vibrating sample magnetometry. They were found to enable highly efficient capture of genomic deoxyribonucleic acid (DNA). The adsorption capacity of PDA@Fe3O4 for genomic DNA can reach 161 mg g(-1). The extraction protocol used aqueous solutions for DNA binding to and releasing from the surface of the magnetic particles based on the pH inducing the charge switch of amino and phenolic hydroxyl groups on PDA@Fe3O4. The extracted DNA with high quality (A260/A280=1.80) can be directly used as templates for polymerase chain reaction (PCR) followed by capillary electrophoresis (CE) analysis. None of the toxic chemical reagents and PCR inhibitors was used throughout the whole procedure. PDA@Fe3O4 based magnetic solid phase extraction (MSPE) method was superior to those using commercial kit and traditional phenol-chloroform extraction methods in yield of DNA. The developed PDA@Fe3O4 based MSPE-PCR-CE method was applied for simultaneous and fast detection of Listeria monocytogenes and Escherichia coli O157:H7 in milk. PMID:25682426

  2. Particle acceleration for delivery deoxyribonucleic acid vaccine into skin in vivo

    NASA Astrophysics Data System (ADS)

    Xinglong, Yu; Xiwen, Zhang; Yuan, Wang; Junshi, Xie; Pengfei, Hao

    2001-08-01

    Skin represents an important immunogenic inductive site, 3%-4% epidermis cells are special antigen-presenting cells. Deoxyribonucleic acid (DNA) vaccine can elicit vigorous immune responses in epidermis cells. The means of delivering DNA vaccine into epidermis cells becomes an important step in DNA vaccine applications. This article presents a new type of gene gun based on the principle of two-stage injector acceleration. DNA coated particles are attached on an screen-type carrier located at the negative pressure inlet, the particles will be sucked into the accelerating channel by negative pressure and be accelerated at a great speed. FLUENT, a computation fluid dynamic application software is used to simulate the flow condition of the injector. Distribution of Mach number, total pressure on exit cross section, and negative pressure on negative pressure inlet are analyzed, by which the process of acceleration of particles is determined. We also measured these parameters in this study. The data show that the particle velocity can be up to 500 m/s and the particles distribute evenly over a circle of Φ 20 mm. The numerical simulation results coincide with experimental data well. Therefore, the results of numerical simulation can be served as guidance for an optimal design of the gene gun and for practical operations. When gene coated particles are distributed evenly, they can penetrate into or even through epidermis cells where the gene can be expressed and subsequently elicits host immune responses. This device may be evaluated in human objects in future.

  3. Deoxyribonucleic acid damage study in primary amenorrhea by comet assay and karyotyping

    PubMed Central

    Ramamurthy, Sarah; Chand, Parkash; Chaturvedula, Latha; Rao, K. Ramachandra

    2013-01-01

    AIM: This study aims at evaluating the chromosomal abnormalities and deoxyribonucleic acid (DNA) damage in cases with primary amenorrhea by karyotyping and comet assay. STUDY DESIGN: A total of 30 cases of primary amenorrhea were recruited. Secondary sexual characters were assessed by Tanner staging. Chromosomal analysis was performed by conventional phytohemagglutinin stimulated lymphocyte cell culture technique. Alkaline version of comet assay was used to evaluate DNA damage. RESULTS: The chromosomal pattern of 20 subjects (66.7%) was found to be normal (46,XX). Two subjects had 46,XY pattern and eight subjects had Turner syndrome (45,X or 45,X/46,XX). The comet parameters were found to be increased among subjects with 45,X monosomy, when compared to the rest of the study group and also in subjects with Tanner stage 1 when compared to stage 2. CONCLUSION: Comet assay revealed increased DNA damage in cases with 45,X monosomy, compared with subjects with 46,XX and 46,XY karyotype, which correlated with clinical features. PMID:24497702

  4. Fabrication of nickel and gold nanowires by controlled electrodeposition on deoxyribonucleic acid molecules

    NASA Astrophysics Data System (ADS)

    Gu, Qun; Jin, Helena; Dai, Kun

    2009-01-01

    Magnetic and electrical nanowires are two important materials in the development of futuristic nanoelectronics, data storage media and nanosensors. Ni and Au nanowires with a diameter of a few tens of nanometres have been fabricated using deoxyribonucleic acid (DNA) molecules as a template through nanoparticle-controlled electroless deposition (ELD). Nanowire precursors, 1-3 nm Pt(0)-DNA and 1.4 nm Au(0)-DNA, were assembled using two different methods. Chemical reduction was used to deposit Pt(0) particles on DNA which catalyzed Ni nanowire growth. Positively charged Au nanoparticles were directly assembled on phosphate groups of DNA which were stretched and anchored between micrometre-spaced electrodes. Electrical measurement has shown that Au nanowires, catalyzed by Au(0)-DNA in a subsequent ELD, are highly conductive and show linear I-V characteristics. The major factors for the resistivity of nanowires were discussed in detail. This work involves important aspects in the field of DNA-based self-assembly, such as DNA and surface interaction, DNA nanoparticle assembly and electrical property of fabricated nanowires.

  5. Transformation of Streptococcus sanguis Challis by plasmid deoxyribonucleic acid from Streptococcus faecalis.

    PubMed Central

    LeBlanc, D J; Hassell, F P

    1976-01-01

    Plasmid deoxyribonucleic acid (DNA) from Streptococcus faecalis, strain DS5, was transferred to the Challis strain of Streptococcus sanguis by transformation. Two antibiotic resistance markers carried by the beta plasmid from strain DS5, erythromycin and lincomycin, were transferred to S. sanguis at a maximum frequency of 1.8 x 10-5/colony-forming unit. Approximately 70% of the covalently closed circular DNA isolated from transformant cultures by dye buoyant density gradients was shown to be hybridizable to beta plasmid DNA. Two major differences were observed between the beta plasmid from S. faecalis and the plasmid isolated from transformed S. sanguis: (i) the beta plasmid from strain DS5 sedimented in velocity gradients at 43S, whereas the covalently closed circular DNA from transformed Challis sedimented at 41S, suggesting a 1.5-Mdal deletion from the beta plasmid occurred; (ii) although the 43S beta plasmid remained in the supercoiled configuration for several weeks after isolation, the 41S plasmid was rapidly converted to a linear double-stranded molecule. Attempts to transform S. sanguis with the alpha plasmid from S. faecalis, strain DS5, were unsuccessful. PMID:824275

  6. Target-driven self-assembly of stacking deoxyribonucleic acids for highly sensitive assay of proteins.

    PubMed

    Cao, Ya; Chen, Weiwei; Han, Peng; Wang, Zhuxin; Li, Genxi

    2015-08-26

    In this paper, we report a new signal amplification strategy for highly sensitive and enzyme-free method to assay proteins based on the target-driven self-assembly of stacking deoxyribonucleic acids (DNA) on an electrode surface. In the sensing procedure, binding of target protein with the aptamer probe is used as a starting point for a scheduled cycle of DNA hairpin assembly, which consists of hybridization, displacement and target regeneration. Following numbers of the assembly repeats, a great deal of DNA duplexes can accordingly be formed on the electrode surface, and then switch on a succeeding propagation of self-assembled DNA concatemers that provide further signal enhancement. In this way, each target binding event can bring out two cascaded DNA self-assembly processes, namely, stacking DNA self-assembly, and therefore can be converted into remarkably intensified electrochemical signals by associating with silver nanoparticle-based readout. Consequently, highly sensitive detection of target proteins can be achieved. Using interferon-gamma as a model, the assay method displays a linear range from 1 to 500 pM with a detection limit of 0.57 pM, which is comparable or even superior to other reported amplified assays. Moreover, the proposed method eliminates the involvement of any enzymes, thereby enhancing the feasibility in clinical diagnosis.

  7. Study on the interaction of morphine chloride with deoxyribonucleic acid by fluorescence method

    NASA Astrophysics Data System (ADS)

    Li, J. F.; Dong, C.

    2009-01-01

    The mode and mechanism of the interaction of morphine chloride, an important alkaloid compound to calf thymus deoxyribonucleic acid (ct DNA) was investigated from absorption and fluorescence titration techniques. Hypochromic effect was founded in the absorption spectra of morphine when concentration of DNA increased. The decreased fluorescence study revealed non-cooperative binding of the morphine to DNA with an affinity of 3.94 × 10 3 M -1, and the stoichiometry of binding was characterized to be about one morphine molecule per nucleotide. Stern-Volmer plots at different temperatures proved that the quenching mechanism was static. Ferrocyanide quenching study showed that the magnitude of KSV of the bound morphine was lower than that of the free one. In addition, it was found that ionic strength could affect the binding of morphine and DNA. Fluorescence polarization and denatured DNA studies also applied strong evidences that morphine molecule was partially intercalated between every alternate base pairs of ct DNA. As observed from above experiments, intercalation was well supported as the binding mode of morphine and ct DNA.

  8. Mechanism of Inactivation of Haemophilus influenzae Transforming Deoxyribonucleic Acid by Sonic Radiation1

    PubMed Central

    Randolph, M. L.; Setlow, Jane K.

    1972-01-01

    Transforming deoxyribonucleic acid (DNA) from Haemophilus influenzae was exposed to sonic radiation of various durations. Reductions in transforming ability of the DNA, cellular DNA uptake, and integration into the genome, and single- and double-stranded molecular weights of the transforming DNA were measured and compared. We conclude that (i) sonic radiation causes DNA strand breaks (almost always double-strand breaks with relatively few alkaline-labile bonds), the number increasing with exposure until the double-stranded molecular weight is reduced to less than 106 daltons; and (ii) since transformation is reduced about as much as integration and much more than uptake, inactivation of transforming DNA by sonic radiation appears to be caused mostly by failure of Haemophilus cells to integrate the transforming DNA that is taken into the cells. These results are similar to those for inactivation by X radiation but differ from those for ultraviolet radiation. A strand break caused by sonic radiation, however, does not necessarily inactivate the transforming DNA, whereas in the case of ionizing radiation it may. The results may be fit by the model proposed by Cato and Guild. From our data and the equation of Lacks, the minimum active site of DNA necessary for transformation and the frequency of exchanges between donor and recipient strands upon integration of transforming DNA were estimated as 0.35 × 106 to 0.7 × 106 daltons and 0.15 to 0.4 switches per 106 daltons, respectively. PMID:4544285

  9. Nuclear and mitochondrial deoxyribonucleic acid replication during mitosis in Saccharomyces cerevisiae.

    PubMed

    Sena, E P; Welch, J W; Halvorson, H O; Fogel, S

    1975-08-01

    To study nuclear and mitochondrial deoxyribonucleic acid (DNA) synthesis during the cell cycle, a 15N-labeled log-phase population of Saccharomyces cervisiae was shifted to 14N medium. After one-half generation, the cells were centrifuged on a sorbitol gradient in a zonal rotor to fractionate the population according to cell size and age into fractions representing the yeast cell cycle. DNA samples isolated from the zonal rotor cell samples were centrifuged to equilibrium in CsC1 in an analytical ultracentrifuge to separate the nuclear and mitochondrial DNA components. The amount of 14N incorporated into each 15N-labeled DNA species was measured. The extent of nuclear DNA replication per sample was obtained by measuring the amount of hybrid DNA. The percentage of hybrid nuclear DNA increased from 6 to 68% and then decreased to 44% during the cell cycle. Upon ultracentrifugation, mitochondrial DNA banded as a unimodal peak in all zonal rotor samples. Mitochondrial DNA replication could be ascertained only by the 14N level in each mitochondrial peak and not, as with nuclear DNA, by hybrid DNA level. In contrast to the nuclear incorporation pattern, the 14N percentage in mitochondrial DNA remained effectively constant during the cell cycle. Comparison of the data to theoretical distributions showed that nuclear DNA was replicated discontinuously during the cell cycle, whereas mitochondrial DNA was replicated continuously throughout the entire mitotic cycle. PMID:1097413

  10. Plasmid-Controlled Variation in the Content of Methylated Bases in Bacteriophage Lambda Deoxyribonucleic Acid

    PubMed Central

    Hattman, Stanley

    1972-01-01

    The N6-methyladenine (MeAde) and 5-methylcytosine (MeC) contents in deoxyribonucleic acid (DNA) of bacteriophage lambda has been analyzed as a function of host specificity. The following facts have emerged: (i) lambda grown on strains harboring the P1 prophage contain ca. 70 more MeAde residues/DNA molecule than lambda grown either in the P1-sensitive parent, or in a P1 immune-defective lysogen which does not confer P1 modification; (ii) lambda grown on strains harboring the N-3 drug-resistance factor contain ca. 60 more MeC residues/DNA molecule than lambda grown on the parental strain lacking the factor; (iii) lambda grown in Escherichia coli B strains is devoid of MeC, whereas lambda grown in a B (N-3) host contains a high level of MeC; (iv) the MeAde content in lambda DNA is not affected by the N-3 factor. These results suggest that P1 controls an adenine-specific DNA methylase, and that the N-3 plasmid controls a cytosine-specific DNA methylase. The N-3 factor has been observed previously to direct cytosine-specific methylation of phage P22 DNA and E. coli B DNA in vivo; in vitro studies presented here demonstrate this activity. PMID:4561202

  11. RAD6/sup +/ gene of Saccharomyces cerevisiae codes for two mutationally separable deoxyribonucleic acid repair functions

    SciTech Connect

    Tuite, M.F.; Cox, B.S.

    1981-02-01

    The response of two mutant alleles of the RAD6/sup +/ gene of Saccharomyces cerevisiae to the ochre translational suppressor SUQ5 was determined. Both the ultraviolet sensitivity phenotype and the deficiency in ultraviolet-induced mutagenesis phenotype of the rad6-1 allelle were suppressed in a (psi/sup +/) background. For the rad6-3 allelle, only the ultraviolet-sensitivity phenotype was suppressible in a (psi/sup +/) background. An SUQ5 rad6-3 (psi/sup +/) strain that was examined showed the normal rad6-3 deficiency in ultraviolet-induced mutagenesis. The authors propose that the RAD6/sup +/ gene is divided into two cistrons, RAD6A and RAD6B. RAD6A codes for an activity responsible for the error-prone repair of ultraviolet-induced lesions in deoxyribonucleic acid but is not involved in a cell's resistance to the lethal effects of ultraviolet light. RAD6B codes for an activity essential for error-free repair of potentially lethal mutagenic damage.

  12. Comparison of three phenotypic and deoxyribonucleic acid extraction methods for isolation and Identification of Nocardia spp

    PubMed Central

    Faghri, Jamshid; Bourbour, Samane; Moghim, Sharare; Meidani, Mohsen; Safaei, Hajiye Ghasemian; Hosseini, Nafise; Esfahani, Bahram Nasr; Fazeli, Hussein; Sedighi, Mansour

    2014-01-01

    Background: The aerobic Actinomycetes are a large group of soil-indwelling bacteria that are distributed in world-wide. These Gram-positive bacteria are most commonly associated with opportunistic infections in both immunocompromised and immunocompetent hosts. Materials and Methods: In this study, three phenotypic and deoxyribonucleic acid (DNA) extraction methods for isolation and identification of Nocardia genus were compared. Samples were taken in five different locations of Isfahan's suburb from hospitals area, parks, agricultural lands, gardens, arid lands with different soil temperature and pH. Results: In this study, showed that slip-buried-method was better than two other phenotypic methods; 14 out of 70 soil samples (20%) were positive for Nocardia spp. DNA of positive samples were extracted with three techniques and DNA extraction by microwave technique was better than others. This technique was confirmed with observation of DNA bands on 1% agarose gel. Conclusions: These bacteria are important in immune deficient patients such as cancer patients, transplant recipients, tuberculosis; acquired immunodeficiency syndrome etc., Their affluence is unsteady in different zones of the world. In this study, among the three phenotypic methods for the isolation of Nocardia slip-buried method was better than other methods. Among DNA extraction techniques, DNA extraction by microwave method would be selective method for DNA extraction of Nocardia spp. compared with others techniques. PMID:25221754

  13. Simian Virus 40 Deoxyribonucleic Acid Transcription In Vitro: Binding and Transcription Patterns with a Mammalian Ribonucleic Acid Polymerase 1

    PubMed Central

    Herzberg, Max; Winocour, Ernest

    1970-01-01

    The in vitro transcription pattern of simian virus 40 (SV40) deoxyribonucleic acid (DNA) by a mammalian ribonucleic acid (RNA) polymerase, was studied by electron microscopy and velocity sedimentation techniques. It was found that (i) the majority of supercoiled SV40 DNA molecules displayed a single binding site for the enzyme, (ii) the supercoiled structure of SV40 DNA was frequently retained during transcription, and (iii) the majority of RNA molecules synthesized from the supercoiled SV40 DNA template showed no self-complementarity and sedimented relatively homogeneously in the 15S to 16S region of a sucrose gradient (in contrast, the RNA product synthesized from the nicked-circular SV40 DNA template showed self-complementarity and sedimented heterogeneously). RNA polymerase preparations isolated from SV40-infected monkey cells were more active than those isolated from uninfected monkey cells. Images PMID:4320700

  14. Tannic Acid-Dependent Modulation of Selected Lactobacillus plantarum Traits Linked to Gastrointestinal Survival

    PubMed Central

    Reverón, Inés; Rodríguez, Héctor; Campos, Gema; Curiel, José Antonio; Ascaso, Carmen; Carrascosa, Alfonso V.; Prieto, Alicia; de las Rivas, Blanca; Muñoz, Rosario; de Felipe, Félix López

    2013-01-01

    Background Owing to its antimicrobial properties dietary tannins may alter the functional efficacy of probiotic lactobacilli in the gastrointestinal (GI)-tract influencing their growth, viability and molecular adaptation to the intestinal environment. Methods and Findings The effects of tannic acid on Lactobacillus plantarum WCFS1 were studied by in vitro growth monitoring and visualizing the morphological alteration on the cell wall using transmission electron microscopy. Growth upon tannic acid was characterized by dose-dependent reductions of initial viable counts and extended lag phases. Lag phase-cells growing upon 0.5 mM tannic acid were abnormally shaped and experienced disturbance on the cell wall such as roughness, occasional leakage and release of cell debris, but resumed growth later at tannic acid concentrations high as 2.5 mM. To gain insight on how the response to tannic acid influenced the molecular adaptation of L. plantarum to the GI-tract conditions, gene expression of selected biomarkers for GI-survival was assessed by RT-qPCR on cDNA templates synthetized from mRNA samples obtained from cells treated with 0.5 or 2 mM tannic acid. Tannic acid-dependent gene induction was confirmed for selected genes highly expressed in the gut or with confirmed roles in GI-survival. No differential expression was observed for the pbp2A gene, a biomarker negatively related with GI-survival. However PBP2A was not labeled by Bocillin FL, a fluorescent dye-labeled penicillin V derivative, in the presence of tannic acid which suggests for enhanced GI-survival reportedly associated with the inactivation of this function. Conclusions Probiotic L. plantarum WCFS1 is able to overcome the toxic effects of tannic acid. This dietary constituent modulates molecular traits linked to the adaptation to intestinal environment in ways previously shown to enhance GI-survival. PMID:23776675

  15. Ribosomes, Polyribosomes, and Deoxyribonucleic Acid from Thermophilic, Mesophilic, and Psychrophilic Clostridia

    PubMed Central

    Irwin, Carol C.; Akagi, James M.; Himes, Richard H.

    1973-01-01

    Analysis of deoxyribonucleic acid (DNA) from four species of Clostridium, including two thermophiles, a mesophile, and a psychrophile, revealed no obvious relationship between growth temperature and DNA base composition. The melting temperatures (Tm) of the DNA from the four species varied no more among the thermophilic, mesophilic, and psychrophilic species than among many related mesophilic species. Characterization of ribosomes from the clostridia by means of optical rotatory dispersion yielded similar spectra in common with other unrelated organisms. Only small differences were noted in the base composition of ribosomal ribonucleic acid (RNA) and in the amino acid composition of ribosomal proteins, including half-cystine content, as determined by cysteic acid analysis, and accessible sulfhydryl groups, as determined by titration with dithiobis (2-nitrobenzoic acid). Except for the two thermophiles, the ribosomal protein electrophoretic patterns were dissimilar. No unusual thermal stability was manifested in the Tm values of thermophile ribosomal RNA. However, thermophile ribosome Tm values (69 C) were higher than were mesophile and psychrophile Tm values (64 C). Ribosomes from the four clostridial species were also examined in regard to the effect of heat on their functional integrity, measured by their activity in poly U-directed 14C-phenylaline incorporation, and their gross physical integrity, measured by sucrose gradient analysis. The Td, 5 values (temperature which produces 50% inactivation after 5 min) was found to be 70 and 72 C for the two thermophiles C. tartarivorum and C. thermosaccharolyticum, respectively; 57 C for a mesophile, C. pasteurianum; and 53 C for a psychrophile, Clostridium sp. strain 69. At 55 C, little effect was seen on the thermophile ribosomes, but the mesophile ribosomes lost 90% of their activity in 1 hr, and psychrophile ribosomes lost 100% of their activity within 10 min. According to sucrose gradient profiles, heating at 55 C

  16. Fabrication of a deoxyribonucleic acid polymer ridge waveguide electro-optic modulator by nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Fehrman Cory, Emily Marie

    The purpose of this dissertation is to develop the nanoimprint lithography (NIL) technique for direct patterning of the deoxyribonucleic acid biopolymer DNA-CTMA. The Mach Zehnder modulator was chosen as the test device to demonstrate the NIL patterning technique for DNA-CTMA as well as the unique optical and electrical properties of the DNA-CTMA as a cladding material for poled electro-optic polymers. Towards this goal, a DNA-CTMA clad inverted ridge waveguide is demonstrated at 633 nm and 1550 nm, the structure of which is patterned directly in the DNA-CTMA cladding by NIL. Additionally, EO modulation is demonstrated in a slab waveguide structure with DNA-CTMA cladding and SEO110 EO polymer core. Marine-derived deoxyribonucleic acid biopolymer (DNA-CTMA) is a green, nontoxic, low cost optical polymer material derived from waste products of the salmon fishing industry. It exhibits low optical loss at 1550 nm, forms a thin flexible film, is compatible with existing poled polymer technologies, increases the poling efficiency when used as a low resistivity cladding layer, and is thermally stable to 200 oC. Due to chemical incompatibility with the photoresists and the associated solvents, NIL has been developed for patterning the DNA biopolymer cladding to form an inverted ridge waveguide for the basis of the Mach Zehnder modulator. While DNA-CTMA presents significant advantages over other commonly used cladding materials for the 1550 nm wavelength range, one of the commonly used bands for optical communications, the mechanical properties and environmental susceptibility of the material poses significant fabrication challenges. A study of the effects of optical and mechanical effects of environmental humidity exposure are presented for the DNA-CTMA and SEO110 polymers used in the inverted ridge waveguide. While the soft, flexible nature of the DNA-CTMA is desirable for certain applications, this presents a challenge in producing a clean polished window for optical

  17. Interpretation of sucrose gradient sedimentation pattern of deoxyribonucleic acid fragments resulting from random breaks.

    PubMed

    Litwin, S; Shahn, E; Kozinski, A W

    1969-07-01

    Mass distribution in a sucrose gradient of deoxyribonucleic acid (DNA) fragments arising as a result of random breaks is predicted by analytical means from which computer evaluations are plotted. The analytical results are compared with the results of verifying experiments: (i) a Monte Carlo computer experiment in which simulated molecules of DNA were individuals of unit length subjected to random "breaks" applied by a random number generator, and (ii) an in vitro experiment in which molecules of T4 DNA, highly labeled with (32)P, were stored in liquid nitrogen for variable periods of time during which a precisely known number of (32)P atoms decayed, causing single-stranded breaks. The distribution of sizes of the resulting fragments was measured in an alkaline sucrose gradient. The profiles obtained in this fashion were compared with the mathematical predictions. Both experiments agree with the analytical approach and thus permit the use of the graphs obtained from the latter as a means of determining the average number of random breaks in DNA from distributions obtained experimentally in a sucrose gradient. An example of the application of this procedure to a previously unresolved problem is provided in the case of DNA from ultraviolet-irradiated phage which undergoes a dose-dependent intracellular breakdown. The relationship between the number of lethal hits and the number of single-stranded breaks was not previously established. A comparison of the calculated number of nicks per strand of DNA with the known dose in phage-lethal hits reveals a relationship closely approximating one lethal hit to one single-stranded break. PMID:5804949

  18. Molecular beacon mediated circular strand displacement strategy for constructing a ratiometric electrochemical deoxyribonucleic acid sensor.

    PubMed

    Gao, Fenglei; Du, Lili; Zhang, Yu; Tang, Daoquan; Du, Yan

    2015-07-01

    A novel ratiometric electrochemical sensor for sensitive and selective determination of deoxyribonucleic acid (DNA) had been developed based on signal-on and signal-off strategy. The target DNA hybridized with the loop portion of ferrocene (Fc) labeled hairpin probe immobilized on the gold electrode (GE), the Fc away from the surface of GE and the methylene blue (MB) was attached to an electrode surface by hybridization between hairpin probe and MB labeled primer. Such conformational changes resulted in the oxidation peak current of Fc decreased and that of MB increased, and the changes of dual signals are linear with the concentration of DNA. Furthermore, with the help of strand-displacement polymerization, polymerase catalyzed the extension of the primer and the sequential displacement of the target DNA, which led to the release of target and another polymerization cycle. Thus the circular strand displacement produced the multiplication of the MB confined near the GE surface and Fc got away from the GE surface. Therefore, the recognition of target DNA resulted in both the "signal-off" of Fc and the "signal-on" of MB for dual-signal electrochemical ratiometric readout. The dual signal strategy offered a dramatic enhancement of the stripping response. The dynamic range of the target DNA detection was from 10(-13) to 10(-8) mol L(-1) with a detection limit down to 28 fM level. Compared with the single signaling electrochemical sensor, the dual-signaling electrochemical sensing strategy developed in this paper was more selective. It would have important applications in the sensitive and selective electrochemical determination of other small molecules and proteins.

  19. Effects of ion substitution on bile acid-dependent and -independent bile formation by rat liver.

    PubMed Central

    Van Dyke, R W; Stephens, J E; Scharschmidt, B F

    1982-01-01

    To characterize the transport mechanisms responsible for formation of canalicular bile, we have examined the effects of ion substitution on bile acid-dependent and bile acid-independent bile formation by the isolated perfused rat liver. Complete replacement of perfusate sodium with choline and lithium abolished taurocholate-induced choleresis and reduced biliary taurocholate output by greater than 70%. Partial replacement of perfusate sodium (25 of 128 mM) by choline reduced bile acid-independent bile formation by 30% and replacement of the remaining sodium (103 mM) by choline reduced bile acid-independent bile formation by an additional 64%. In contrast, replacement of the remaining sodium (103 mM) by lithium reduced bile acid-independent bile formation by only an additional 20%, while complete replacement of sodium (128 mM) by lithium reduced bile formation by only 17%, and lithium replaced sodium as the predominant biliary cation. Replacement of perfusate bicarbonate by Tricine, a zwitterionic amino acid buffer, decreased bile acid-independent bile formation by greater than or equal to 50% and decreased biliary bicarbonate output by approximately 60%, regardless of the accompanying cation. In separate experiments, replacement of sodium by lithium essentially abolished Na,K-ATPase activity measured either as ouabain-suppressible ATP hydrolysis in rat liver or kidney homogenates, or as ouabain-suppressible 86Rb uptake by cultured rat hepatocytes. These studies indicate that bile acid(taurocholate)-dependent bile formation by rat liver exhibits a specific requirement for sodium, a finding probably attributable to the role(s) of sodium in hepatic sodium-coupled taurocholate uptake and/or in maintenance of Na,K-ATPase activity. The surprising finding that bile acid-independent bile formation was substantially unaltered by complete replacement of sodium with the permeant cation lithium does not appear to be explained by Na,K-ATPase-mediated lithium transport. Although

  20. Molecular cloning, encoding sequence, and expression of vaccinia virus nucleic acid-dependent nucleoside triphosphatase gene.

    PubMed Central

    Rodriguez, J F; Kahn, J S; Esteban, M

    1986-01-01

    A rabbit poxvirus genomic library contained within the expression vector lambda gt11 was screened with polyclonal antiserum prepared against vaccinia virus nucleic acid-dependent nucleoside triphosphatase (NTPase)-I enzyme. Five positive phage clones containing from 0.72- to 2.5-kilobase-pair (kbp) inserts expressed a beta-galactosidase fusion protein that was reactive by immunoblotting with the NTPase-I antibody. Hybridization analysis allowed the location of this gene within the vaccinia HindIIID restriction fragment. From the known nucleotide sequence of the 16-kbp vaccinia HindIIID fragment, we identified a region that contains a 1896-base open reading frame coding for a 631-amino acid protein. Analysis of the complete sequence revealed a highly basic protein, with hydrophilic COOH and NH2 termini, various hydrophobic domains, and no significant homology to other known proteins. Translational studies demonstrate that NTPase-I belongs to a late class of viral genes. This protein is highly conserved among Orthopoxviruses. Images PMID:3025846

  1. Molecular cloning, encoding sequence, and expression of vaccinia virus nucleic acid-dependent nucleoside triphosphatase gene.

    PubMed

    Rodriguez, J F; Kahn, J S; Esteban, M

    1986-12-01

    A rabbit poxvirus genomic library contained within the expression vector lambda gt11 was screened with polyclonal antiserum prepared against vaccinia virus nucleic acid-dependent nucleoside triphosphatase (NTPase)-I enzyme. Five positive phage clones containing from 0.72- to 2.5-kilobase-pair (kbp) inserts expressed a beta-galactosidase fusion protein that was reactive by immunoblotting with the NTPase-I antibody. Hybridization analysis allowed the location of this gene within the vaccinia HindIIID restriction fragment. From the known nucleotide sequence of the 16-kbp vaccinia HindIIID fragment, we identified a region that contains a 1896-base open reading frame coding for a 631-amino acid protein. Analysis of the complete sequence revealed a highly basic protein, with hydrophilic COOH and NH2 termini, various hydrophobic domains, and no significant homology to other known proteins. Translational studies demonstrate that NTPase-I belongs to a late class of viral genes. This protein is highly conserved among Orthopoxviruses.

  2. Isolation and characterization of linear deoxyribonucleic acid plasmids from Kluyveromyces lactis and the plasmid-associated killer character.

    PubMed Central

    Gunge, N; Tamaru, A; Ozawa, F; Sakaguchi, K

    1981-01-01

    Two linear deoxyribonucleic acid plasmids, designated pGK11 and pGK12, were isolated from the yeast Kluyveromyces lactis IFO 1267. pGK11 and pGK12 had molecular weights of 5.4 X 10(6) and 8.4 X 10(6), respectively. Both plasmids possessed the same density of 1.687 g/cm3, lighter than the densities of mitochondrial (1.692 g/cm3) and nuclear (1.699 g/cm3) deoxyribonucleic acids. A restriction map of pGK11 was constructed from digestions by EcoRI, HindIII, PstI, and BamHI. pGK12 was cleaved by EcoRI into seven fragments and by BamHI into two fragments K. lactis IFO 1267 killed Saccharomyces cerevisiae sensitive and killer strains and certain strains of Saccharomyces italicus, K. lactis, Kluyveromyces thermotolerans, and K. vanudenii. All K. lactis strains lacking the pGK1 plasmids were nonkillers. A hybrid was constructed between K. lactis IFO 1267 and a nonkiller K. lactis strain lacking the plasmids and subjected to tetrad analysis after sporulation. The killer character was extrachromosomally transmitted in all tetrads in association with the pGK1 plasmids. The double-stranded ribonucleic acid killer plasmid could not be detected in any K. lactis killer strains. It is thus highly probable that the killer character is mediated by the linear deoxyribonucleic acid plasmids. A single chromosomal gene was found which was responsible for the resistance to the K. lactis killer. Images PMID:6257636

  3. Brønsted acids in ionic liquids: how acidity depends on the liquid structure.

    PubMed

    McCune, Jade A; He, Peizhao; Petkovic, Marina; Coleman, Fergal; Estager, Julien; Holbrey, John D; Seddon, Kenneth R; Swadźba-Kwaśny, Małgorzata

    2014-11-14

    Gutmann Acceptor Number (AN) values have been determined for Brønsted acid-ionic liquid mixtures, over a wide compositional range. Four systems of general formula [C2mim][A]-HA (A(-) = bistriflamide, [NTf2](-); triflate, [OTf](-); mesylate, [OMs](-); or acetate, [OAc](-), [C2mim](+) = 1-ethyl-3-methylimidazolium cation) were studied. A library of Brønsted acidic systems of varying acidity was constructed and the AN parameter was found to be a convenient approach for quantifying their acidity. HOAc, HOMs and HOTf, when dissolved in ionic liquids, were found to associate with the respective anions to form hydrogen-bonded anionic clusters, [A(HA)x](-). In contrast, HNTf2 was solubilised as a discrete, undissociated molecule. AN values were sensitive to the presence of anionic clusters; acidity could be buffered to a particular AN by binding the solubilised acid in the anionic cluster form. Overall, a simple way to manipulate and quantify the Brønsted acidity of acid-ionic liquid mixtures was demonstrated, and measured AN values were related to liquid speciation. PMID:25254612

  4. Estimation of minimum electron dose necessary to resolve molecular structure of deoxyribonucleic acid by phase transmission electron microscopy

    SciTech Connect

    Nomaguchi, Tsunenori; Kimura, Yoshihide; Takai, Yoshizo

    2006-12-04

    The minimum electron dose that is necessary to resolve the molecular structure of deoxyribonucleic acid (DNA) was estimated based on experimental measurements of information limits and simulated DNA images, considering conditions of a low electron dose. From these results, a dose of {approx}400 e/A{sup 2} was found to be necessary to achieve observation of DNA on a molecular scale under the present experimental setup. A DNA molecule was observed by a phase reconstruction method using through-focus images under the limited electron dose. In the reconstructed images, the helical structure and the intervals of the base pairs of DNA were partially resolved.

  5. Self-assembled ternary complexes of neutral liposomes, deoxyribonucleic acid, and bivalent metal cations. Promising vectors for gene transfer?

    NASA Astrophysics Data System (ADS)

    Bruni, P.; Pisani, M.; Amici, A.; Marchini, C.; Montani, M.; Francescangeli, O.

    2006-02-01

    By means of synchrotron x-ray diffraction we demonstrate the self-assembled formation of the neutral ternary dioleoyl-phosphatidylcholine-deoxyribonucleic acid (plasmid)-Me2+ (Me=Ca and Mn) complexes in the liquid-crystalline Lα phase. We also report an attempt of an in vitro transfection on mouse fibroplast NIH 3T3 cell lines, which shows the capability of these complexes to transfect DNA. Based on the reported results, efficient encapsulation of DNA plasmids in these ternary neutral complexes may represent an important alternative to current systemic gene approaches.

  6. Identification of a Herbal Powder by Deoxyribonucleic Acid Barcoding and Structural Analyses

    PubMed Central

    Sheth, Bhavisha P.; Thaker, Vrinda S.

    2015-01-01

    Background: Authentic identification of plants is essential for exploiting their medicinal properties as well as to stop the adulteration and malpractices with the trade of the same. Objective: To identify a herbal powder obtained from a herbalist in the local vicinity of Rajkot, Gujarat, using deoxyribonucleic acid (DNA) barcoding and molecular tools. Materials and Methods: The DNA was extracted from a herbal powder and selected Cassia species, followed by the polymerase chain reaction (PCR) and sequencing of the rbcL barcode locus. Thereafter the sequences were subjected to National Center for Biotechnology Information (NCBI) basic local alignment search tool (BLAST) analysis, followed by the protein three-dimension structure determination of the rbcL protein from the herbal powder and Cassia species namely Cassia fistula, Cassia tora and Cassia javanica (sequences obtained in the present study), Cassia Roxburghii, and Cassia abbreviata (sequences retrieved from Genbank). Further, the multiple and pairwise structural alignment were carried out in order to identify the herbal powder. Results: The nucleotide sequences obtained from the selected species of Cassia were submitted to Genbank (Accession No. JX141397, JX141405, JX141420). The NCBI BLAST analysis of the rbcL protein from the herbal powder showed an equal sequence similarity (with reference to different parameters like E value, maximum identity, total score, query coverage) to C. javanica and C. roxburghii. In order to solve the ambiguities of the BLAST result, a protein structural approach was implemented. The protein homology models obtained in the present study were submitted to the protein model database (PM0079748-PM0079753). The pairwise structural alignment of the herbal powder (as template) and C. javanica and C. roxburghii (as targets individually) revealed a close similarity of the herbal powder with C. javanica. Conclusion: A strategy as used here, incorporating the integrated use of DNA

  7. Ribonucleic Acid, Deoxyribonucleic Acid, and Protein Content of Cells of Different Ages of Mycobacterium tuberculosis and the Relationship to Immunogenicity

    PubMed Central

    Youmans, Anne S.; Youmans, Guy P.

    1968-01-01

    The amount of ribonucleic acid (RNA), protein, and deoxyribonucleic acid (DNA) was determined in pellicle cultures of different ages of the H37Ra strain of Mycobacterium tuberculosis, grown on a synthetic medium. We found that the highest content of RNA and protein was present in 2-week-old cultures, indicating that these cells were in the logarithmic phase of growth. DNA content was highest at 1 and 2 weeks. The amount of all three compounds then decreased about 50% during the following 6 weeks. Two-week-old cells should therefore be used for preparation of the immunogenic ribosomal fraction. The optimal concentration of zinc chloride increased RNA and protein synthesis, and also improved the appearance of the pellicle growth. Two-week-old cells, which contained the largest amount of RNA and protein, immunized mice significantly better than older cells. Since protein and DNA are not involved in the production of immunity, a correlation could be made between amount of RNA and the capacity of viable H37Ra cells to immunize mice. The immunizing capacity of these cells was not affected by ribonuclease, probably because the ribonuclease did not penetrate into the whole cells. PMID:4966539

  8. Folic acid induces salicylic acid-dependent immunity in Arabidopsis and enhances susceptibility to Alternaria brassicicola.

    PubMed

    Wittek, Finni; Kanawati, Basem; Wenig, Marion; Hoffmann, Thomas; Franz-Oberdorf, Katrin; Schwab, Wilfried; Schmitt-Kopplin, Philippe; Vlot, A Corina

    2015-08-01

    Folates are essential for one-carbon transfer reactions in all organisms and contribute, for example, to de novo DNA synthesis. Here, we detected the folate precursors 7,8-dihydropteroate (DHP) and 4-amino-4-deoxychorismate (ADC) in extracts from Arabidopsis thaliana plants by Fourier transform ion cyclotron resonance-mass spectrometry. The accumulation of DHP, but not ADC, was induced after infection of plants with Pseudomonas syringae delivering the effector protein AvrRpm1. Application of folic acid or the DHP precursor 7,8-dihydroneopterin (DHN) enhanced resistance in Arabidopsis to P. syringae and elevated the transcript accumulation of the salicylic acid (SA) marker gene pathogenesis-related1 in both the treated and systemic untreated leaves. DHN- and folic acid-induced systemic resistance was dependent on SA biosynthesis and signalling. Similar to SA, folic acid application locally enhanced Arabidopsis susceptibility to the necrotrophic fungus Alternaria brassicicola. Together, the data associate the folic acid pathway with innate immunity in Arabidopsis, simultaneously activating local and systemic SA-dependent resistance to P. syringae and suppressing local resistance to A. brassicicola.

  9. RNASEK is required for internalization of diverse acid-dependent viruses

    PubMed Central

    Hackett, Brent A.; Yasunaga, Ari; Panda, Debasis; Tartell, Michael A.; Hopkins, Kaycie C.; Hensley, Scott E.; Cherry, Sara

    2015-01-01

    Viruses must gain entry into cells to establish infection. In general, viruses enter either at the plasma membrane or from intracellular endosomal compartments. Viruses that use endosomal pathways are dependent on the cellular factors that control this process; however, these genes have proven to be essential for endogenous cargo uptake, and thus are of limited value for therapeutic intervention. The identification of genes that are selectively required for viral uptake would make appealing drug targets, as their inhibition would block an early step in the life cycle of diverse viruses. At this time, we lack pan-antiviral therapeutics, in part because of our lack of knowledge of such cellular factors. RNAi screening has begun to reveal previously unknown genes that play roles in viral infection. We identified dRNASEK in two genome-wide RNAi screens performed in Drosophila cells against West Nile and Rift Valley Fever viruses. Here we found that ribonuclease kappa (RNASEK) is essential for the infection of human cells by divergent and unrelated positive- and negative-strand-enveloped viruses from the Flaviviridae, Togaviridae, Bunyaviridae, and Orthomyxoviridae families that all enter cells from endosomal compartments. In contrast, RNASEK was dispensable for viruses, including parainfluenza virus 5 and Coxsackie B virus, that enter at the plasma membrane. RNASEK is dispensable for attachment but is required for uptake of these acid-dependent viruses. Furthermore, this requirement appears specific, as general endocytic uptake of transferrin is unaffected in RNASEK-depleted cells. Therefore, RNASEK is a potential host cell Achilles’ heel for viral infection. PMID:26056282

  10. Association of mitochondrial deoxyribonucleic acid mutation with polymorphism in CYP2E1 gene in oral carcinogenesis

    PubMed Central

    Pandey, Rahul; Mehrotra, Divya; Catapano, Carlo; Choubey, Vimal; Sarin, Rajiv; Mahdi, Abbas Ali; Singh, Stuti

    2012-01-01

    Background Oral carcinogenesis is a complex process affected by genetic as well as environmental factors. CYP2E1 gene is involved in metabolism of number of compounds and carcinogens. Its normal functioning is required for homeostasis of free radical. Mitochondrial deoxyribonucleic acid (mtDNA) is 10–100 times more susceptible to damage than nuclear DNA. Mitochondrial DNA large scale deletions are well documented in oral cancer. However, the relationship between CYP2E1 gene polymorphisms and mtDNA damage is still not documented in literature. Materials and Methods Case–control study involving 50 subjects was carried out. Deoxyribonucleic acid extraction was done from study subject tissue samples. Restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) amplification was done to confirm CYP2E1 gene polymorphisms. The PCR amplification was done for mtDNA 4977 bp deletion. Statistical analysis was carried out using SPSS version 11.5 with χ2 tests. Results c1c1 and DD polymorphisms are prevalent in North Indian population having oral cancer. These polymorphisms are significantly associated with mtDNA 4977 bp deletion. Conclusion Mitochondrial DNA damage induced by wild CYP2E1 forms and imperfect DNA repair in mtDNA may act synergistically to greatly enhance oral cancer risk. PMID:25756024

  11. High mobility organic field-effect transistor based on water-soluble deoxyribonucleic acid via spray coating

    SciTech Connect

    Shi, Wei; Han, Shijiao; Huang, Wei; Yu, Junsheng

    2015-01-26

    High mobility organic field-effect transistors (OFETs) by inserting water-soluble deoxyribonucleic acid (DNA) buffer layer between electrodes and pentacene film through spray coating process were fabricated. Compared with the OFETs incorporated with DNA in the conventional organic solvents of ethanol and methanol: water mixture, the water-soluble DNA based OFET exhibited an over four folds enhancement of field-effect mobility from 0.035 to 0.153 cm{sup 2}/Vs. By characterizing the surface morphology and the crystalline structure of pentacene active layer through atomic force microscope and X-ray diffraction, it was found that the adoption of water solvent in DNA solution, which played a key role in enhancing the field-effect mobility, was ascribed to both the elimination of the irreversible organic solvent-induced bulk-like phase transition of pentacene film and the diminution of a majority of charge trapping at interfaces in OFETs.

  12. Evaluation of deoxyribonucleic acid (DNA) isolated from human bloodstains exposed to ultraviolet light, heat, humidity, and soil contamination

    SciTech Connect

    McNally, L.; Shaler, R.C.; Baird, M.; Balazs, I.; De Forest, P.; Kobilinsky, L. )

    1989-09-01

    This study was designed to analyze the effects of common environmental insults on the ability to obtain deoxyribonucleic acid (DNA) restriction fragment-length polymorphisms (RFLP) patterns from laboratory prepared specimens. The environmental conditions studied include the exposure of dried bloodstains to varying amounts of relative humidity (0, 33, 67, and 98%), heat (37{degree}C), and ultraviolet light for periods of up to five days. In addition, the effect of drying over a four-day period in whole blood collected with and without ethylenediaminetetraacetate (EDTA) was examined. The results of the study showed that, under the conditions studied, the integrity of DNA is not altered such that false RFLP patterns are obtained. The only effect observed was that the overall RFLP pattern becomes weaker, but individual RFLP fragments are neither created nor destroyed.

  13. Erythrocyte-binding antigen 175 mediates invasion in Plasmodium falciparum utilizing sialic acid-dependent and -independent pathways

    PubMed Central

    Duraisingh, Manoj T.; Maier, Alexander G.; Triglia, Tony; Cowman, Alan F.

    2003-01-01

    The Plasmodium falciparum erythrocyte-binding antigen 175 (EBA-175) is a ligand for merozoite invasion into human erythrocytes that binds to glycophorin A in a sialic acid-dependent manner. P. falciparum strain W2mef depends on sialic acid for invasion of erythrocytes, whereas 3D7 is sialic acid-independent. We generated parasites that lack expression or express truncated forms of EBA-175 in W2mef and 3D7. Lack of EBA-175 expression in W2mef parasites was associated with a switch to sialic acid-independent invasion. 3D7 parasites lacking expression of EBA-175 showed no alteration in their ability to utilize sialic acid-independent pathways. Strikingly, both W2mef and 3D7 parasites lacking EBA-175 expression invaded chymotrypsin-treated erythrocytes inefficiently compared with the parental lines. This loss of function suggests that the EBA-175/glycophorin A ligand–receptor interaction is the major chymotrypsin-resistant invasion pathway. Parasite lines with truncated EBA-175 had invasion phenotypes equivalent to parasites lacking expression of EBA-175. The EBA-175 ligand is functional in erythrocyte invasion by merozoites that utilize either sialic acid-dependent or -independent invasion pathways. This finding suggests a model where a minimal affinity supplied by multiple ligand–receptor interactions is required for successful invasion and has implications for EBA-175 as a malaria vaccine candidate. PMID:12672957

  14. Inhibition of hepatic deoxyribonucleic acid-dependent ribonucleic acid polymerases by the exotoxin of Bacillus thuringiensis in comparison with the effects of α-amanitin and cordycepin

    PubMed Central

    Smuckler, Edward A.; Hadjiolov, Asen A.

    1972-01-01

    The action of Bacillus thuringiensis exotoxin, a structural analogue of ATP, on mouse liver DNA-dependent RNA polymerases was studied and its effects were compared with those of α-amanitin and cordycepin. (1) Administration of exotoxin in vivo caused a marked decrease in RNA polymerase activity of isolated nuclei at various concentrations of Mg2+, Mn2+ and (NH4)2SO4. A similar action was recorded after addition of exotoxin to isolated nuclei from control or exotoxin-treated mice. (2) Chromatographic separation of nuclear RNA polymerases from mice treated in vivo with exotoxin showed a drastic decrease of the peak of nucleoplasmic RNA polymerase, whereas the peak of nucleolar RNA polymerase remained unaltered. The same effect was observed after administration of α-amanitin in vivo, but cordycepin did not alter the relative amounts of the two main RNA polymerase peaks. (3) Administration of exotoxin in vivo did not alter the template activity of isolated DNA or chromatin tested with different fractions of RNA polymerase from control or exotoxin-treated mice. (4) Addition of exotoxin to isolated liver RNA polymerases inhibited both enzyme fractions. However, the α-amanitin-sensitive RNA polymerase was also 50–100-fold more sensitive to exotoxin inhibition than was the α-amanitin-insensitive RNA polymerase. Kinetic analysis indicated the exotoxin produces a competitive inhibition with ATP on the nucleolar enzyme, but a mixed type of inhibition with nucleoplasmic enzyme. The results obtained indicate that the B. thuringiensis exotoxin inhibits liver RNA synthesis by affecting nuclear RNA polymerases, showing a preferential inhibition of the nucleoplasmic α-amanitin-sensitive RNA polymerase. ImagesFig. 7. PMID:4539593

  15. Effect of an exotoxin from Bacillus thuringiensis on deoxyribonucleic acid-dependent ribonucleic acid polymerase in nuclei from adult Sarcophaga bullata. Unusual behaviour of eukaryotic polymerases to inhibitors.

    PubMed

    Beebee, T J; Bond, R P

    1973-09-01

    The DNA-dependent RNA polymerase activities in nuclei isolated from adult Sarcophaga bullata are unusual in their responses to metal ions, ionic strength and inhibitors. There is an activity that is sensitive both to rifamycin and to alpha-amanitin. The activity is less sensitive to Bacillus thuringiensis exotoxin than is larval polymerase, and low concentration of exotoxin provoke a slight stimulation.

  16. A novel Plasmodium falciparum rhoptry associated adhesin mediates erythrocyte invasion through the sialic-acid dependent pathway

    PubMed Central

    Anand, Gaurav; Reddy, K. Sony; Pandey, Alok Kumar; Mian, Syed Yusuf; Singh, Hina; Mittal, Shivani Arora; Amlabu, Emmanuel; Bassat, Quique; Mayor, Alfredo; Chauhan, Virander Singh; Gaur, Deepak

    2016-01-01

    Erythrocyte invasion by Plasmodium falciparum merozoites is central to blood-stage infection and malaria pathogenesis. This intricate process is coordinated by multiple parasite adhesins that bind erythrocyte receptors and mediate invasion through several alternate pathways. P. falciparum expresses 2700 genes during the blood-stages, of which the identity and function of many remains unknown. Here, we have identified and characterized a novel P. falciparum rhoptry associated adhesin (PfRA) that mediates erythrocyte invasion through the sialic-acid dependent pathway. PfRA appears to play a significant functional role as it is conserved across different Plasmodium species. It is localized in the rhoptries and further translocated to the merozoite surface. Both native and recombinant PfRA specifically bound erythrocytes in a sialic-acid dependent, chymotrypsin and trypsin resistant manner, which was abrogated by PfRA antibodies confirming a role in erythrocyte invasion. PfRA antibodies inhibited erythrocyte invasion and in combination with antibodies against other parasite ligands produced an additive inhibitory effect, thus validating its important role in erythrocyte invasion. We have thus identified a novel P. falciparum adhesin that binds with a sialic acid containing erythrocyte receptor. Our observations substantiate the strategy to block P. falciparum erythrocyte invasion by simultaneously targeting multiple conserved merozoite antigens involved in alternate invasion pathways. PMID:27383149

  17. Studies of Nondefective Adenovirus 2-Simian Virus 40 Hybrid Viruses II. Relationship of Adenovirus 2 Deoxyribonucleic Acid and Simian Virus 40 Deoxyribonucleic Acid in the Ad2+ND1 Genome

    PubMed Central

    Levin, Myron J.; Crumpacker, Clyde S.; Lewis, Andrew M.; Oxman, Michael N.; Henry, Patrick H.; Rowe, Wallace P.

    1971-01-01

    A nondefective adenovirus 2 (Ad2)-simian virus 40 (SV40) hybrid virus, Ad2+ND1, has been plaque-isolated from an Ad2-SV40 hybrid population. This virus, unlike the defective Ad-SV40 hybrid populations previously described, replicates without the aid of nonhybrid adenovirus helper. Consequently, the hybrid virus deoxyribonucleic acid (DNA) can be obtained free of nonhybrid adenovirus DNA. The DNA of the Ad2+ND1 virus was shown by ribonucleic acid (RNA)-DNA hybridization to consist of nucleotide sequences complementary to Ad2- and SV40-specific RNA. Techniques of equilibrium density and rate zonal centrifugation were employed to demonstrate that these Ad2 and SV40 nucleotide sequences were linked together in the same DNA molecules by alkali-resistant bonds. Calibration curves were established relating the amount of tritium-labeled SV40-specific RNA (prepared in vitro or in vivo) bound to given amounts of SV40 DNA in a hybridization reaction, and these curves were employed to determine the equivalent amount of SV40 DNA in the Ad2+ND1 molecule. From the results obtained, it was estimated that 1% of the Ad2+ND1 DNA consists of SV40 nucleotide sequences. PMID:4323709

  18. Adenovirus-associated virus multiplication. VI. Base compostion of the deoxyribonucleic acid strand species and strand-specific in vivo transcription.

    PubMed

    Rose, J A; Koczot, F

    1971-11-01

    The two complementary strand species of 5-bromodeoxyuridine-substituted, adenovirus-associated virus type 2 (AAV-2) deoxyribonucleic acid were preparatively separated in CsCl density gradients and further purified by sedimentation through 5 to 20% sucrose. The base composition of each strand species was determined, and it was found that the species banding at a greater density in CsCl (heavy strands) had an expected higher thymidine content (26.5%) than that 21.7%) of the less dense species (light strands). Furthermore, the base composition of in vivo-synthesized, AAV-specific ribonucleic acid was similar to that of light-strand deoxyribonucleic acid, and this ribonucleic acid apparently hybridized only with heavy strands. These observations indicate that the heavy-strand species alone serves as the transcriptional template in vivo. This study represents the first instance in which the base composition and specificity of in vivo transcription have been determined for each of the complementary strands of an animal virus deoxyribonucleic acid.

  19. Properties and structure of peat humic acids depending on humification and precursor biota in bogs

    NASA Astrophysics Data System (ADS)

    Klavins, Maris; Purmalis, Oskars

    2013-04-01

    Humic substances form most of the organic component of soil, peat and natural waters, but their structure and properties very much differs depending on their source. The aim of this study is to characterize humic acids from raised bog peat profiles to evaluate the homogeneity of humic acids isolated from the bog bodies and study peat humification impact on properties of humic acids. A major impact on the structure of peat humic acids have raised bog biota (dominantly represented by bryophytes of different origin) void of lignin. For characterization of peat humic acids their elemental (CHNOS), functional (-COOH, phenolic OH) analysis, spectroscopic characterization (UV, fluorescence, FTIR, 1H NMR, CP/MAS 13C NMR, ESR) and degradation studies (Py-GC/MS) were done. Peat humic acids (HA) have an intermediate position between the living organic matter and coal organic matter and their structure is formed in a process in which more labile structures (carbohydrates, amino acids, etc.) are destroyed, but thermodynamically more stable aromatic and polyaromatic structures emerge. Comparatively, the studied peat HAs are at the start of the transformation process of living organic matter. Concentrations of carboxyl and phenolic hydroxyl groups changes depending on the depth of peat from which HAs have been isolated: and carboxylic acidity is increasing with depth of peat location and the humification degree. The ability to influence the surface tension of peat humic acids isolated from a well-characterized bog profile demonstrates dependence on age and humification degree. With increase of the humification degree and age of humic acids, their molecular complexity and ability to influence surface tension decreases; even so, the impact of the biological precursor (peat-forming bryophytes and plants) can be identified.

  20. Burdock fructooligosaccharide induces fungal resistance in postharvest Kyoho grapes by activating the salicylic acid-dependent pathway and inhibiting browning.

    PubMed

    Sun, Fei; Zhang, Pengying; Guo, Moran; Yu, Wenqian; Chen, Kaoshan

    2013-05-01

    Burdock fructooligosaccharide (BFO) is a natural elicitor from Arcitum lappa. The effects of BFO in controlling postharvest disease in grape, apple, banana, kiwi, citrus, strawberry, and pear were investigated. The disease index, decay percentage, and area under the disease progress curve indicated that BFO has general control effects on postharvest disease of fruits. Kyoho grapes were studied to elucidate the mechanism of BFO in boosting the resistance of grapes to Botrytis cinerea infection. BFO treatment induced upregulation of the npr1, pr1, pal, and sts genes, and inhibited the total phenol content decrease, which activated chitinase and β-1,3-glucanase. These results indicated that the salicylic acid-dependent signalling pathway was induced. The delayed colour change and peroxidase and polyphenoloxidase activity suggested that BFO delayed grape browning. The reduced respiration rate, weight loss, and titratable acidity prolonged the shelf life of postharvest grapes. BFO is a promising elicitor in postharvest disease control. PMID:23265522

  1. Burdock fructooligosaccharide induces fungal resistance in postharvest Kyoho grapes by activating the salicylic acid-dependent pathway and inhibiting browning.

    PubMed

    Sun, Fei; Zhang, Pengying; Guo, Moran; Yu, Wenqian; Chen, Kaoshan

    2013-05-01

    Burdock fructooligosaccharide (BFO) is a natural elicitor from Arcitum lappa. The effects of BFO in controlling postharvest disease in grape, apple, banana, kiwi, citrus, strawberry, and pear were investigated. The disease index, decay percentage, and area under the disease progress curve indicated that BFO has general control effects on postharvest disease of fruits. Kyoho grapes were studied to elucidate the mechanism of BFO in boosting the resistance of grapes to Botrytis cinerea infection. BFO treatment induced upregulation of the npr1, pr1, pal, and sts genes, and inhibited the total phenol content decrease, which activated chitinase and β-1,3-glucanase. These results indicated that the salicylic acid-dependent signalling pathway was induced. The delayed colour change and peroxidase and polyphenoloxidase activity suggested that BFO delayed grape browning. The reduced respiration rate, weight loss, and titratable acidity prolonged the shelf life of postharvest grapes. BFO is a promising elicitor in postharvest disease control.

  2. Long-Term Control of Human Immunodeficiency Virus-1 Replication Despite Extensive Resistance to Current Antiretroviral Regimens: Clonal Analysis of Resistance Mutations in Proviral Deoxyribonucleic Acid

    PubMed Central

    Stella-Ascariz, Natalia; Montejano, Rocio; Martin-Vicente, María; Mingorance, Jesús; Pérez-Valero, Ignacio; Bernardino, José I.; Arribas, Jose R.

    2016-01-01

    Archived resistance mutations compromise antiretroviral treatment. We have investigated 3 selected aviremic patients who had extensive historical resistance to their current regimen. All 3 patients underwent unstructured treatment interruptions associated to the re-emergence of wild-type virus before starting their current suppressive regimes. Almost all historical resistance mutations detected in plasma were found in circulating proviral deoxyribonucleic acid. None of the clones analyzed was fully resistant to the current antiretroviral regimen. PMID:27006965

  3. The effect of deoxyribonucleic acid extraction methods from lymphoid tissue on the purity, content, and amplifying ability

    PubMed Central

    Ayatollahi, Hossein; Sadeghian, Mohammad Hadi; Keramati, Mohammad Reza; Ayatollahi, Ali; Shajiei, Arezoo; Sheikhi, Maryam; Bakhshi, Samane

    2016-01-01

    Background: Nowadays, definitive diagnosis of numerous diseases is based on the genetic and molecular findings. Therefore, preparation of fundamental materials for these evaluations is necessary. Deoxyribonucleic acid (DNA) is the first material for the molecular pathology and genetic analysis, and better results need more pure DNA. Furthermore, higher concentration of achieved DNA causes better results and higher amplifying ability for subsequent steps. We aim to evaluate five DNA extraction methods to compare DNA intimacy including purity, concentration, and amplifying ability with each other. Materials and Methods: The lymphoid tissue DNA was extracted from formalin-fixed, paraffin embedded (FFPE) tissue through five different methods including phenol-chloroform as the reference method, DNA isolation kit (QIAamp DNA FFPE Tissue Kit, Qiagen, Germany), proteinase K and xylol extraction and heat alkaline plus mineral oil extraction as authorship innovative method. Finally, polymerase chain reaction (PCR) and real-time PCR method were assessed to compare each following method consider to DNA purity and its concentration. Results: Among five different applied methods, the highest mean of DNA purity was related to heat alkaline method. Moreover, the highest mean of DNA concentration was related to heat alkaline plus mineral oil. Furthermore, the best result in quantitative PCR was in proteinase K method that had the lowest cycle threshold averages among the other extraction methods. Conclusion: We concluded that our innovative method for DNA extraction (heat alkaline plus mineral oil) achieved high DNA purity and concentration. PMID:27630381

  4. The effect of deoxyribonucleic acid extraction methods from lymphoid tissue on the purity, content, and amplifying ability

    PubMed Central

    Ayatollahi, Hossein; Sadeghian, Mohammad Hadi; Keramati, Mohammad Reza; Ayatollahi, Ali; Shajiei, Arezoo; Sheikhi, Maryam; Bakhshi, Samane

    2016-01-01

    Background: Nowadays, definitive diagnosis of numerous diseases is based on the genetic and molecular findings. Therefore, preparation of fundamental materials for these evaluations is necessary. Deoxyribonucleic acid (DNA) is the first material for the molecular pathology and genetic analysis, and better results need more pure DNA. Furthermore, higher concentration of achieved DNA causes better results and higher amplifying ability for subsequent steps. We aim to evaluate five DNA extraction methods to compare DNA intimacy including purity, concentration, and amplifying ability with each other. Materials and Methods: The lymphoid tissue DNA was extracted from formalin-fixed, paraffin embedded (FFPE) tissue through five different methods including phenol-chloroform as the reference method, DNA isolation kit (QIAamp DNA FFPE Tissue Kit, Qiagen, Germany), proteinase K and xylol extraction and heat alkaline plus mineral oil extraction as authorship innovative method. Finally, polymerase chain reaction (PCR) and real-time PCR method were assessed to compare each following method consider to DNA purity and its concentration. Results: Among five different applied methods, the highest mean of DNA purity was related to heat alkaline method. Moreover, the highest mean of DNA concentration was related to heat alkaline plus mineral oil. Furthermore, the best result in quantitative PCR was in proteinase K method that had the lowest cycle threshold averages among the other extraction methods. Conclusion: We concluded that our innovative method for DNA extraction (heat alkaline plus mineral oil) achieved high DNA purity and concentration.

  5. Nature of Transient Inhibition of Deoxyribonucleic Acid Synthesis in HeLa Cells by Parainfluenza Virus 1 (Sendai)

    PubMed Central

    Fuchs, Pinhas; Kohn, Alexander

    1971-01-01

    Adsorption of ultraviolet-inactivated Sendai virus, at high or low multiplicity, to HeLa cells caused a transient increased incorporation of 3H-thymidine into the cellular deoxyribonucleic acid (DNA). In HeLa cells synchronized by a double-thymidine block, this increased incorporation of thymidine during the S phase lasted from about 30 to 90 min after virus adsorption. The observations that the kinetics of accumulation of radioactive thymidine in the nucleotide pool did not differ in control and in the virus-treated cells and that the 32P incorporation into the DNA of the virus-treated cells was inhibited at the same time indicate that the augmented incorporation of 3H-thymidine into DNA results from a transient block in the endogenous pathway of thymidine synthesis. Chromatographic analysis of the nucleotide pool of the virus-treated cells labeled with 14C-formate indicates that methylation of deoxyuridine monophosphate to thymidine monophosphate is inhibited. It is suggested that the inhibition is caused by a block of either the thymidilate synthetase or some step in the tetrahydrofolate cycle. PMID:4332139

  6. Rapid concentration of deoxyribonucleic acid via Joule heating induced temperature gradient focusing in poly-dimethylsiloxane microfluidic channel.

    PubMed

    Ge, Zhengwei; Wang, Wei; Yang, Chun

    2015-02-01

    This paper reports rapid microfluidic electrokinetic concentration of deoxyribonucleic acid (DNA) with the Joule heating induced temperature gradient focusing (TGF) by using our proposed combined AC and DC electric field technique. A peak of 480-fold concentration enhancement of DNA sample is achieved within 40s in a simple poly-dimethylsiloxane (PDMS) microfluidic channel of a sudden expansion in cross-section. Compared to a sole DC field, the introduction of an AC field can reduce DC field induced back-pressure and produce sufficient Joule heating effects, resulting in higher concentration enhancement. Within such microfluidic channel structure, negative charged DNA analytes can be concentrated at a location where the DNA electrophoretic motion is balanced with the bulk flow driven by DC electroosmosis under an appropriate temperature gradient field. A numerical model accounting for a combined AC and DC field and back-pressure driven flow effects is developed to describe the complex Joule heating induced TGF processes. The experimental observation of DNA concentration phenomena can be explained by the numerical model. PMID:25597807

  7. Computational Design of an Unnatural Amino Acid Dependent Metalloprotein with Atomic Level Accuracy

    PubMed Central

    Mills, Jeremy H.; Khare, Sagar D.; Bolduc, Jill M.; Forouhar, Farhad; Mulligan, Vikram Khipple; Lew, Scott; Seetharaman, Jayaraman; Tong, Liang; Stoddard, Barry L.; Baker, David

    2013-01-01

    Genetically encoded unnatural amino acids could facilitate the design of proteins and enzymes of novel function, but correctly specifying sites of incorporation, and the identities and orientations of surrounding residues represents a formidable challenge. Computational design methods have been used to identify optimal locations for functional sites in proteins and design the surrounding residues, but have not incorporated unnatural amino acids in this process. We extended the Rosetta design methodology to design metalloproteins in which the amino acid (2,2’-bipyridin-5yl)alanine (Bpy-Ala) is a primary ligand of a bound metal ion. Following initial results that indicated the importance of buttressing the Bpy-Ala amino acid, we designed a buried metal binding site with octahedral coordination geometry consisting of Bpy-Ala, two protein based metal ligands, and two metal bound water molecules. Experimental characterization revealed a Bpy-Ala mediated metalloprotein with the ability to bind divalent cations including Co2+, Zn2+, Fe2+, and Ni2+, with a Kd for Zn2+ of ~40 pM. X-ray crystallographic analysis of the designed protein shows only slight deviation from the computationally designed model. PMID:23924187

  8. Fatty acid-dependent globotriaosyl ceramide receptor function in detergent resistant model membranes.

    PubMed

    Mahfoud, Radhia; Manis, Adam; Lingwood, Clifford A

    2009-09-01

    Glycosphingolipid (GSL) fatty acid strictly regulates verotoxin 1 (VT1) and the HIV adhesin, gp120 binding to globotriaosyl ceramide within Gb(3)/cholesterol detergent resistant membrane (DRM) vesicle constructs and in Gb(3) water-air interface monolayers in a similar manner. VT2 bound Gb(3)/cholesterol vesicles irrespective of fatty acid composition, but VT1 bound neither C18 nor C20Gb(3)vesicles. C18/C20Gb(3) were dominant negative in mixed Gb(3) fatty acid isoform vesicles, but including C24:1Gb(3) gave maximal binding. VT1 bound C18Gb(3) vesicles after cholesterol removal, but C20Gb(3)vesicles required sphingomyelin in addition for binding. HIV-1gp120 also bound C16, C22, and C24, but neither C18 nor C20Gb(3) vesicles. C18 and C20Gb(3) were, in mixtures without C24:1Gb(3), dominant negative for gp120 vesicle binding. Gp120/VT1bound C18 and C24:1Gb(3) mixtures, although neither isoform bound alone. Monolayer surface pressure measurement showed VT1, but not VT2, bound Gb(3) at cellular DRM surface pressures, and confirmed loss of VT1 and gp120 (but not VT2) specific C18Gb(3) binding. We conclude fatty-acid mediated fluidity within simple model GSL/cholesterol DRM can selectively regulate GSL carbohydrate-ligand binding.

  9. Computational design of an unnatural amino acid dependent metalloprotein with atomic level accuracy.

    PubMed

    Mills, Jeremy H; Khare, Sagar D; Bolduc, Jill M; Forouhar, Farhad; Mulligan, Vikram Khipple; Lew, Scott; Seetharaman, Jayaraman; Tong, Liang; Stoddard, Barry L; Baker, David

    2013-09-11

    Genetically encoded unnatural amino acids could facilitate the design of proteins and enzymes of novel function, but correctly specifying sites of incorporation and the identities and orientations of surrounding residues represents a formidable challenge. Computational design methods have been used to identify optimal locations for functional sites in proteins and design the surrounding residues but have not incorporated unnatural amino acids in this process. We extended the Rosetta design methodology to design metalloproteins in which the amino acid (2,2'-bipyridin-5yl)alanine (Bpy-Ala) is a primary ligand of a bound metal ion. Following initial results that indicated the importance of buttressing the Bpy-Ala amino acid, we designed a buried metal binding site with octahedral coordination geometry consisting of Bpy-Ala, two protein-based metal ligands, and two metal-bound water molecules. Experimental characterization revealed a Bpy-Ala-mediated metalloprotein with the ability to bind divalent cations including Co(2+), Zn(2+), Fe(2+), and Ni(2+), with a Kd for Zn(2+) of ∼40 pM. X-ray crystal structures of the designed protein bound to Co(2+) and Ni(2+) have RMSDs to the design model of 0.9 and 1.0 Å respectively over all atoms in the binding site.

  10. Sialic acid-dependent cell entry of human enterovirus D68

    DOE PAGES

    Liu, Yue; Sheng, Ju; Baggen, Jim; Meng, Geng; Xiao, Chuan; Thibaut, Hendrik J.; van Kuppeveld, Frank J. M.; Rossmann, Michael G.

    2015-11-13

    Human enterovirus D68 (EV-D68) is a causative agent of childhood respiratory diseases and has now emerged as a global public health threat. Nevertheless, knowledge of the tissue tropism and pathogenesis of EV-D68 has been hindered by a lack of studies on the receptor-mediated EV-D68 entry into host cells. Here we demonstrate that cell surface sialic acid is essential for EV-D68 to bind to and infect susceptible cells. Crystal structures of EV-D68 in complex with sialylated glycan receptor analogues show that they bind into the ‘canyon’ on the virus surface. The sialic acid receptor induces a cascade of conformational changes inmore » the virus to eject a fatty-acid-like molecule that regulates the stability of the virus. Furthermore, virus binding to a sialic acid receptor and to immunoglobulin-like receptors used by most other enteroviruses share a conserved mechanism for priming viral uncoating and facilitating cell entry.« less

  11. Conserved regulators of Rag GTPases orchestrate amino acid-dependent TORC1 signaling

    PubMed Central

    Powis, Katie; De Virgilio, Claudio

    2016-01-01

    The highly conserved target of rapamycin complex 1 (TORC1) is the central component of a signaling network that couples a vast range of internal and external stimuli to cell growth, proliferation and metabolism. TORC1 deregulation is associated with a number of human pathologies, including many cancers and metabolic disorders, underscoring its importance in cellular and organismal growth control. The activity of TORC1 is modulated by multiple inputs; however, the presence of amino acids is a stimulus that is essential for its activation. Amino acid sufficiency is communicated to TORC1 via the highly conserved family of Rag GTPases, which assemble as heterodimeric complexes on lysosomal/vacuolar membranes and are regulated by their guanine nucleotide loading status. Studies in yeast, fly and mammalian model systems have revealed a multitude of conserved Rag GTPase modulators, which have greatly expanded our understanding of amino acid sensing by TORC1. Here we review the major known modulators of the Rag GTPases, focusing on recent mechanistic insights that highlight the evolutionary conservation and divergence of amino acid signaling to TORC1. PMID:27462445

  12. Sialic acid-dependent cell entry of human enterovirus D68.

    PubMed

    Liu, Yue; Sheng, Ju; Baggen, Jim; Meng, Geng; Xiao, Chuan; Thibaut, Hendrik J; van Kuppeveld, Frank J M; Rossmann, Michael G

    2015-01-01

    Human enterovirus D68 (EV-D68) is a causative agent of childhood respiratory diseases and has now emerged as a global public health threat. Nevertheless, knowledge of the tissue tropism and pathogenesis of EV-D68 has been hindered by a lack of studies on the receptor-mediated EV-D68 entry into host cells. Here we demonstrate that cell surface sialic acid is essential for EV-D68 to bind to and infect susceptible cells. Crystal structures of EV-D68 in complex with sialylated glycan receptor analogues show that they bind into the 'canyon' on the virus surface. The sialic acid receptor induces a cascade of conformational changes in the virus to eject a fatty-acid-like molecule that regulates the stability of the virus. Thus, virus binding to a sialic acid receptor and to immunoglobulin-like receptors used by most other enteroviruses share a conserved mechanism for priming viral uncoating and facilitating cell entry. PMID:26563423

  13. Sialic acid-dependent cell entry of human enterovirus D68

    PubMed Central

    Liu, Yue; Sheng, Ju; Baggen, Jim; Meng, Geng; Xiao, Chuan; Thibaut, Hendrik J.; van Kuppeveld, Frank J. M.; Rossmann, Michael G.

    2015-01-01

    Human enterovirus D68 (EV-D68) is a causative agent of childhood respiratory diseases and has now emerged as a global public health threat. Nevertheless, knowledge of the tissue tropism and pathogenesis of EV-D68 has been hindered by a lack of studies on the receptor-mediated EV-D68 entry into host cells. Here we demonstrate that cell surface sialic acid is essential for EV-D68 to bind to and infect susceptible cells. Crystal structures of EV-D68 in complex with sialylated glycan receptor analogues show that they bind into the ‘canyon' on the virus surface. The sialic acid receptor induces a cascade of conformational changes in the virus to eject a fatty-acid-like molecule that regulates the stability of the virus. Thus, virus binding to a sialic acid receptor and to immunoglobulin-like receptors used by most other enteroviruses share a conserved mechanism for priming viral uncoating and facilitating cell entry. PMID:26563423

  14. Sialic acid-dependent cell entry of human enterovirus D68

    SciTech Connect

    Liu, Yue; Sheng, Ju; Baggen, Jim; Meng, Geng; Xiao, Chuan; Thibaut, Hendrik J.; van Kuppeveld, Frank J. M.; Rossmann, Michael G.

    2015-11-13

    Human enterovirus D68 (EV-D68) is a causative agent of childhood respiratory diseases and has now emerged as a global public health threat. Nevertheless, knowledge of the tissue tropism and pathogenesis of EV-D68 has been hindered by a lack of studies on the receptor-mediated EV-D68 entry into host cells. Here we demonstrate that cell surface sialic acid is essential for EV-D68 to bind to and infect susceptible cells. Crystal structures of EV-D68 in complex with sialylated glycan receptor analogues show that they bind into the ‘canyon’ on the virus surface. The sialic acid receptor induces a cascade of conformational changes in the virus to eject a fatty-acid-like molecule that regulates the stability of the virus. Furthermore, virus binding to a sialic acid receptor and to immunoglobulin-like receptors used by most other enteroviruses share a conserved mechanism for priming viral uncoating and facilitating cell entry.

  15. Arachidonic acid-dependent carbon-eight volatile synthesis from wounded liverwort (Marchantia polymorpha).

    PubMed

    Kihara, Hirotomo; Tanaka, Maya; Yamato, Katsuyuki T; Horibata, Akira; Yamada, Atsushi; Kita, Sayaka; Ishizaki, Kimitsune; Kajikawa, Masataka; Fukuzawa, Hideya; Kohchi, Takayuki; Akakabe, Yoshihiko; Matsui, Kenji

    2014-11-01

    Eight-carbon (C8) volatiles, such as 1-octen-3-ol, octan-3-one, and octan-3-ol, are ubiquitously found among fungi and bryophytes. In this study, it was found that the thalli of the common liverwort Marchantia polymorpha, a model plant species, emitted high amounts of C8 volatiles mainly consisting of (R)-1-octen-3-ol and octan-3-one upon mechanical wounding. The induction of emission took place within 40min. In intact thalli, 1-octen-3-yl acetate was the predominant C8 volatile while tissue disruption resulted in conversion of the acetate to 1-octen-3-ol. This conversion was carried out by an esterase showing stereospecificity to (R)-1-octen-3-yl acetate. From the transgenic line of M. polymorpha (des6(KO)) lacking arachidonic acid and eicosapentaenoic acid, formation of C8 volatiles was only minimally observed, which indicated that arachidonic and/or eicosapentaenoic acids were essential to form C8 volatiles in M. polymorpha. When des6(KO) thalli were exposed to the vapor of 1-octen-3-ol, they absorbed the alcohol and converted it into 1-octen-3-yl acetate and octan-3-one. Therefore, this implied that 1-octen-3-ol was the primary C8 product formed from arachidonic acid, and further metabolism involving acetylation and oxidoreduction occurred to diversify the C8 products. Octan-3-one was only minimally formed from completely disrupted thalli, while it was formed as the most abundant product in partially disrupted thalli. Therefore, it is assumed that the remaining intact tissues were involved in the conversion of 1-octen-3-ol to octan-3-one in the partially disrupted thalli. The conversion was partly promoted by addition of NAD(P)H into the completely disrupted tissues, suggesting an NAD(P)H-dependent oxidoreductase was involved in the conversion. PMID:25174554

  16. Myogenic and metabolic feedback in cerebral autoregulation: Putative involvement of arachidonic acid-dependent pathways.

    PubMed

    Berg, Ronan M G

    2016-07-01

    The present paper presents a mechanistic model of cerebral autoregulation, in which the dual effects of the arachidonic acid metabolites 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) on vascular smooth muscle mediate the cerebrovascular adjustments to a change in cerebral perfusion pressure (CPP). 20-HETE signalling in vascular smooth muscle mediates myogenic feedback to changes in vessel wall stretch, which may be modulated by metabolic feedback through EETs released from astrocytes and endothelial cells in response to changes in brain tissue oxygen tension. The metabolic feedback pathway is much faster than 20-HETE-dependent myogenic feedback, and the former thus initiates the cerebral autoregulatory response, while myogenic feedback comprises a relatively slower mechanism that functions to set the basal cerebrovascular tone. Therefore, assessments of dynamic cerebral autoregulation, which may provide information on the response time of the cerebrovasculature, may specifically be used to yield information on metabolic feedback mechanisms, while data based on assessments of static cerebral autoregulation represent the integrated functionality of myogenic and metabolic feedback. PMID:27241246

  17. Activation of the Glutamic Acid-Dependent Acid Resistance System in Escherichia coli BL21(DE3) Leads to Increase of the Fatty Acid Biotransformation Activity

    PubMed Central

    Woo, Ji-Min; Kim, Ji-Won; Song, Ji-Won; Blank, Lars M.; Park, Jin-Byung

    2016-01-01

    The biosynthesis of carboxylic acids including fatty acids from biomass is central in envisaged biorefinery concepts. The productivities are often, however, low due to product toxicity that hamper whole-cell biocatalyst performance. Here, we have investigated factors that influence the tolerance of Escherichia coli to medium chain carboxylic acid (i.e., n-heptanoic acid)-induced stress. The metabolic and genomic responses of E. coli BL21(DE3) and MG1655 grown in the presence of n-heptanoic acid indicated that the GadA/B-based glutamic acid-dependent acid resistance (GDAR) system might be critical for cellular tolerance. The GDAR system, which is responsible for scavenging intracellular protons by catalyzing decarboxylation of glutamic acid, was inactive in E. coli BL21(DE3). Activation of the GDAR system in this strain by overexpressing the rcsB and dsrA genes, of which the gene products are involved in the activation of GadE and RpoS, respectively, resulted in acid tolerance not only to HCl but also to n-heptanoic acid. Furthermore, activation of the GDAR system allowed the recombinant E. coli BL21(DE3) expressing the alcohol dehydrogenase of Micrococcus luteus and the Baeyer-Villiger monooxygenase of Pseudomonas putida to reach 60% greater product concentration in the biotransformation of ricinoleic acid (i.e., 12-hydroxyoctadec-9-enoic acid (1)) into n-heptanoic acid (5) and 11-hydroxyundec-9-enoic acid (4). This study may contribute to engineering E. coli-based biocatalysts for the production of carboxylic acids from renewable biomass. PMID:27681369

  18. The ascorbic acid-dependent oxidation of reduced nicotinamide–adenine dinucleotide by ciliary and retinal microsomes

    PubMed Central

    Heath, H.; Fiddick, Rosemary

    1965-01-01

    1. The presence of an ascorbic acid-dependent NADH oxidation in ocular tissues has been established. Subcellular fractionation revealed that the enzyme is localized in the microsomes. The distribution of the enzyme in some ocular tissues has been determined; microsomes from the ciliary processes and the retina have comparable activities, which are much higher than those from the cornea or lens. 2. NADPH cannot replace NADH, and cysteine, reduced glutathione, ergothioneine and dehydroascorbic acid cannot be substituted for ascorbic acid in the reaction. The rate of NADH oxidation was greatly increased in the presence of cucumber ascorbate oxidase, and the enzyme appears to be NADH–monodehydroascorbate transhydrogenase. 3. Cytochrome b5 is present in retinal microsomes. 4. The enzyme is inhibited by p-chloromercuribenzoate and iodoacetate, but not by cyanide, Amytal or malonate. 5. High concentrations of chloroquine cause a partial inhibition of the reaction, probably owing to interaction of this compound with the enzyme thiol groups. Low concentrations of Diamox, comparable with those attained in tissues during therapy with this drug, bring about partial inhibition of the reaction. Eserine, cortisone, hydrocortisone, 11-deoxycorticosterone and dexamethasone have no effect on the rate of oxidation. 6. The possible role of ascorbic acid and NADH–monodehydroascorbate transhydrogenase in the formation of aqueous humour and secretory mechanisms is discussed. PMID:14345883

  19. Transcription In Vitro by Reovirus-Associated Ribonucleic Acid-Dependent Polymerase 1

    PubMed Central

    Banerjee, A. K.; Shatkin, A. J.

    1970-01-01

    Digestion of purified reovirus type 3 with chymotrypsin degrades 70% of the viral protein and converts the virions to subviral particles (SVP). The SVP contain 3 of the 6 viral structural proteins and all 10 double-stranded ribonucleic acid (RNA) genome segments but not adenine-rich, single-stranded RNA. An RNA polymerase which is structurally associated with SVP transcribes one strand of each genome segment by a conservative mechanism in vitro. The single-stranded products include large (1.2 × 106 daltons), medium (0.7 × 106 daltons), and small (0.4 × 106 daltons) molecules which hybridize exclusively with the corresponding genome segments. The enzyme obtained by heating virions at 60 C synthesizes similar products. Kinetic and pulse-chase studies indicate that the different-sized products are synthesized simultaneously but at rates which are in the order: small > medium > large. Images PMID:5529847

  20. Brown adipose tissue mitochondria: modulation by GDP and fatty acids depends on the respiratory substrates

    PubMed Central

    De Meis, Leopoldo; Ketzer, Luisa A.; Camacho-Pereira, Juliana; Galina, Antonio

    2011-01-01

    The UCP1 [first UCP (uncoupling protein)] that is found in the mitochondria of brown adipocytes [BAT (brown adipose tissue)] regulates the heat production, a process linked to non-shivering thermogenesis. The activity of UCP1 is modulated by GDP and fatty acids. In this report, we demonstrate that respiration and heat released by BAT mitochondria vary depending on the respiratory substrate utilized and the coupling state of the mitochondria. It has already been established that, in the presence of pyruvate/malate, BAT mitochondria are coupled by faf-BSA (fatty-acid-free BSA) and GDP, leading to an increase in ATP synthesis and mitochondrial membrane potential along with simultaneous decreases in both the rates of respiration and heat production. Oleate restores the uncoupled state, inhibiting ATP synthesis and increasing the rates of both respiration and heat production. We now show that in the presence of succinate: (i) the rates of uncoupled mitochondria respiration and heat production are five times slower than in the presence of pyruvate/malate; (ii) faf-BSA and GDP accelerate heat and respiration as a result and, in coupled mitochondria, these two rates are accelerated compared with pyruvate/malate; (iii) in spite of the differences in respiration and heat production noted with the two substrates, the membrane potential and the ATP synthesized were the same; and (iv) oleate promoted a decrease in heat production and respiration in coupled mitochondria, an effect different from that observed using pyruvate/malate. These effects are not related to the production of ROS (reactive oxygen species). We suggest that succinate could stimulate a new route to heat production in BAT mitochondria. PMID:21561434

  1. Boric acid-dependent decrease in regulatory histone H3 acetylation is not mutagenic in yeast.

    PubMed

    Pointer, Benjamin R; Schmidt, Martin

    2016-07-01

    Candida albicans is a dimorphic yeast commonly found on human mucosal membranes that switches from yeast to hyphal morphology in response to environmental factors. The change to hyphal growth requires histone H3 modifications by the yeast-specific histone acetyltransferase Rtt109. In addition to its role in morphogenesis, Rtt109-dependent acetylation of histone H3 lysine residues 9 and 56 has regulatory functions during DNA replication and repair. Boric acid (BA) is a broad-spectrum agent that specifically inhibits C. albicans hyphal growth, locking the fungus in its harmless commensal yeast state. The present study characterizes the effect of BA on C. albicans histone acetylation in respect to specificity, time-course and significance. We demonstrate that sublethal concentrations of BA reduce H3K9/H3K56 acetylation, both on a basal level and in response to genotoxic stress. Acetylation at other selected histone sites were not affected by BA. qRT-PCR expression analysis of the DNA repair gene Rad51 indicated no elevated level of genotoxic stress during BA exposure. A forward-mutation analysis demonstrated the BA does not increase spontaneous or induced mutations. The findings suggest that DNA repair remains effective even when histone H3 acetylation decreases and dispels the notion that BA treatment impairs genome integrity in yeast. PMID:27190149

  2. Boric acid-dependent decrease in regulatory histone H3 acetylation is not mutagenic in yeast.

    PubMed

    Pointer, Benjamin R; Schmidt, Martin

    2016-07-01

    Candida albicans is a dimorphic yeast commonly found on human mucosal membranes that switches from yeast to hyphal morphology in response to environmental factors. The change to hyphal growth requires histone H3 modifications by the yeast-specific histone acetyltransferase Rtt109. In addition to its role in morphogenesis, Rtt109-dependent acetylation of histone H3 lysine residues 9 and 56 has regulatory functions during DNA replication and repair. Boric acid (BA) is a broad-spectrum agent that specifically inhibits C. albicans hyphal growth, locking the fungus in its harmless commensal yeast state. The present study characterizes the effect of BA on C. albicans histone acetylation in respect to specificity, time-course and significance. We demonstrate that sublethal concentrations of BA reduce H3K9/H3K56 acetylation, both on a basal level and in response to genotoxic stress. Acetylation at other selected histone sites were not affected by BA. qRT-PCR expression analysis of the DNA repair gene Rad51 indicated no elevated level of genotoxic stress during BA exposure. A forward-mutation analysis demonstrated the BA does not increase spontaneous or induced mutations. The findings suggest that DNA repair remains effective even when histone H3 acetylation decreases and dispels the notion that BA treatment impairs genome integrity in yeast.

  3. GSK3-mediated raptor phosphorylation supports amino-acid-dependent mTORC1-directed signalling

    PubMed Central

    Stretton, Clare; Hoffmann, Thorsten M.; Munson, Michael J.; Prescott, Alan; Taylor, Peter M.; Ganley, Ian G.; Hundal, Harinder S.

    2015-01-01

    The mammalian or mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) is a ubiquitously expressed multimeric protein kinase complex that integrates nutrient and growth factor signals for the co-ordinated regulation of cellular metabolism and cell growth. Herein, we demonstrate that suppressing the cellular activity of glycogen synthase kinase-3 (GSK3), by use of pharmacological inhibitors or shRNA-mediated gene silencing, results in substantial reduction in amino acid (AA)-regulated mTORC1-directed signalling, as assessed by phosphorylation of multiple downstream mTORC1 targets. We show that GSK3 regulates mTORC1 activity through its ability to phosphorylate the mTOR-associated scaffold protein raptor (regulatory-associated protein of mTOR) on Ser859. We further demonstrate that either GSK3 inhibition or expression of a S859A mutated raptor leads to reduced interaction between mTOR and raptor and under these circumstances, irrespective of AA availability, there is a consequential loss in phosphorylation of mTOR substrates, such as p70S6K1 (ribosomal S6 kinase 1) and uncoordinated-51-like kinase (ULK1), which results in increased autophagic flux and reduced cellular proliferation. PMID:26348909

  4. Evidence for a cyclic diguanylic acid-dependent cellulose synthase in plants.

    PubMed Central

    Amor, Y; Mayer, R; Benziman, M; Delmer, D

    1991-01-01

    Because numerous attempts to detect an activity for a cellulose synthase in plants have failed, we have taken a different approach toward detecting polypeptides involved in this process. The uniqueness of the structure and function of cyclic diguanylic acid (c-di-GMP) as an activator of the cellulose synthase of the bacterium Acetobacter xylinum makes it an attractive probe to use in a search for a c-di-GMP receptor that might be involved in the process in plants. Direct photolabeling with 32P-c-di-GMP has been used, therefore, to identify in plants two membrane polypeptides of 83 and 48 kD derived from cotton fibers that possess properties consistent with their being components of a c-di-GMP-dependent cellulose synthase. Based upon several criteria, the 48-kD species is proposed to be derived by proteolytic cleavage of the 83-kD polypeptide. Both polypeptides bind c-di-GMP with high affinity and specificity and show antigenic relatedness to the bacterial cellulose synthase, and the N-terminal sequence of the 48-kD polypeptide also indicates relatedness to the bacterial synthase. Ability to detect both cotton fiber polypeptides by photolabeling increases markedly in extracts derived from fibers entering the active phase of secondary wall cellulose synthesis. These results provide a basis for future work aimed at identifying and characterizing genes involved in cellulose synthesis in plants. PMID:1668373

  5. Assessment of the deoxyribonucleic acid damage caused by occupational exposure to chemical compounds in Isfahan Polyacryl Company

    PubMed Central

    Etebari, Mahmoud; Jafarian-Dehkordi, Abbas; Kahookar, Ahmad; Moradi, Shahla

    2014-01-01

    Background: Chemical pollutants found in industrial environments can cause chronic genotoxicity in vulnerable individuals during the long-term exposure. The primary purpose of the present study was to assess the deoxyribonucleic acid (DNA) damage caused by occupational exposure to industrial chemicals and secondary purpose is to investigate the effect of possible risk factors of genotoxicity. Materials and Methods: The blood samples of the workers of Isfahan Polyacryl Company were evaluated in terms of genotoxicity using the comet assay method. The percentage of DNA in the tail and tail moment were measured and DNA damage was evaluated. Furthermore, the effect of age, smoking, duration of working in the company and working in two parts of the company on the degree of vulnerability to genotoxicity was assessed. Results: The amount of DNA damage in the target group (the production line workers) was significantly higher than the control group (the staffs), 3.87 versus 1.52 as tail moment, (P < 0.0001). DNA damage was significantly higher in smoker groups compared with non-smoker target group and control group, 4.18 versus 3.07 and 1.52 respectively as tail moment, (P < 0.0001). Furthermore, it was higher in person working in two different parts of the company compared to those work in one part and control group, 4.63 versus 3.74 and 1.52 respectively as tail moment, (P < 0.0001). Conclusion: Occupational exposure to Polyacryl caused DNA damage. Smoking and working in two parts of the company may have a significant role in DNA damage. PMID:25197297

  6. Detection of deoxyribonucleic acid (DNA) targets using polymerase chain reaction (PCR) and paper surface-enhanced Raman spectroscopy (SERS) chromatography.

    PubMed

    Hoppmann, Eric P; Yu, Wei W; White, Ian M

    2014-01-01

    Surface-enhanced Raman spectroscopy (SERS) enables multiplex detection of analytes using simple, portable equipment consisting of a single excitation source and detector. Thus, in theory, SERS is ideally suited to replace fluorescence in assays that screen for numerous deoxyribonucleic acid (DNA) targets, but in practice, SERS-based assays have suffered from complexity and elaborate processing steps. Here, we report an assay in which a simple inkjet-fabricated plasmonic paper device enables SERS-based detection of multiple DNA targets within a single polymerase chain reaction (PCR). In prior work, we demonstrated the principles of chromatographic separation and SERS-based detection on inkjet-fabricated plasmonic paper. The present work extends that capability for post-PCR gene sequence detection. In this design, hydrolysis DNA probes with 5' Raman labels are utilized; if the target is present, the probe is hydrolyzed during PCR, freeing the reporter. After applying the PCR sample to a paper SERS device, an on-device chromatographic separation and concentration is conducted to discriminate between hydrolyzed and intact probes. SERS is then used to detect the reporter released by the hydrolyzed probes. This simple separation and detection on paper eliminates the need for complex sample processing steps. In this work, we simultaneously detect the methicillin-resistant Staphylococcus aureus genes mecA and femB to illustrate the concept. We envision that this approach could contribute to the development of multiplex DNA diagnostic tests enabling screening for several target sequences within a single reaction, which is necessary for cases in which sample volume and resources are limited.

  7. Determination of deoxyribonucleic acids by a resonance light scattering technique and its application

    NASA Astrophysics Data System (ADS)

    Jie, Nianqin; Jia, Guifang; Hou, Shicong; Xiong, Yanmei; Dong, Yanhong

    2003-12-01

    For the first time, acetamiprid has been used to determine nucleic acid (DNA) using the resonance light scattering (RLS). The RLS of acetamiprid was greatly enhanced by DNA in the range of pH 1.6-1.8. A RLS peak at 313 nm was found, and the enhanced intensity of RLS at this wavelength was proportional to the concentration of DNA. The linear range of the calibration curve was 0-11.0 μg ml -1 with the detection limit of 20 ng ml -1. The nucleic acids in synthetic sample and in rice seedling extraction were determined satisfactorily. The interaction mechanism of acetamiprid and DNA is discussed. Mechanism studies show that the enhanced RLS is due to the aggregation of acetamiprid in the presence of DNA.

  8. DNA Tetrominoes: The Construction of DNA Nanostructures Using Self-Organised Heterogeneous Deoxyribonucleic Acids Shapes

    PubMed Central

    Ong, Hui San; Rahim, Mohd Syafiq; Firdaus-Raih, Mohd; Ramlan, Effirul Ikhwan

    2015-01-01

    The unique programmability of nucleic acids offers alternative in constructing excitable and functional nanostructures. This work introduces an autonomous protocol to construct DNA Tetris shapes (L-Shape, B-Shape, T-Shape and I-Shape) using modular DNA blocks. The protocol exploits the rich number of sequence combinations available from the nucleic acid alphabets, thus allowing for diversity to be applied in designing various DNA nanostructures. Instead of a deterministic set of sequences corresponding to a particular design, the protocol promotes a large pool of DNA shapes that can assemble to conform to any desired structures. By utilising evolutionary programming in the design stage, DNA blocks are subjected to processes such as sequence insertion, deletion and base shifting in order to enrich the diversity of the resulting shapes based on a set of cascading filters. The optimisation algorithm allows mutation to be exerted indefinitely on the candidate sequences until these sequences complied with all the four fitness criteria. Generated candidates from the protocol are in agreement with the filter cascades and thermodynamic simulation. Further validation using gel electrophoresis indicated the formation of the designed shapes. Thus, supporting the plausibility of constructing DNA nanostructures in a more hierarchical, modular, and interchangeable manner. PMID:26258940

  9. Effect of Ethylene on Cell Division and Deoxyribonucleic Acid Synthesis in Pisum sativum1

    PubMed Central

    Apelbaum, Akiva; Burg, Stanley P.

    1972-01-01

    Ethylene and supraoptimal levels of 2,4-dichlorophenoxyacetic acid inhibit the growth of the apical hook region of etiolated Pisum sativum (var. Alaska) seedlings by stopping almost all cell divisions. Cells are prevented from entering prophase. The hormones also retard cell division in intact root tips and completely stop the process in lateral buds. The latter inhibition is reversed partially by benzyl adenine. In root tips and the stem plumular and subhook regions, ethylene inhibits DNA synthesis. The magnitude of this inhibition is correlated with the degree of repression of cell division in meristematic tissue, suggesting that the effect on cell division results from a lack of DNA synthesis. Ethylene inhibits cell division within a few hours with a dose-response curve similar to that for most other actions of the gas. Experiments with seedlings grown under hypobaric conditions suggest that the gas naturally controls plumular expansion and cell division in the apical region. Images PMID:16658105

  10. Inhibition of Hsp27 Radiosensitizes Head-and-Neck Cancer by Modulating Deoxyribonucleic Acid Repair

    SciTech Connect

    Guttmann, David M.; Hart, Lori; Du, Kevin; Seletsky, Andrew; Koumenis, Constantinos

    2013-09-01

    Purpose: To present a novel method of tumor radiosensitization through Hsp27 knockdown using locked nucleic acid (LNA) and to investigate the role of Hsp27 in DNA double strand break (DSB) repair. Methods and Materials: Clonogenic survival assays, immunoblotting, the proximity ligation assay, and γH2AX foci analysis were conducted in SQ20B and FaDu human head-and-neck cancer cell lines treated with Hsp27 LNA and Hsp27 short hairpin RNA (shRNA). Additionally, nude mice with FaDu flank tumors were treated with fractionated radiation therapy after pretreatment with Hsp27 LNA and monitored for tumor growth. Results: Hsp27 LNA and Hsp27 shRNA radiosensitized head-and-neck cancer cell lines in an Hsp27-dependent manner. Ataxia-Telangectasia Mutated-mediated DNA repair signaling was impaired in irradiated cells with Hsp27 knockdown. ATM kinase inhibition abrogated the radiosensitizing effect of Hsp27. Furthermore, Hsp27 LNA and shRNA both attenuated DNA repair kinetics after radiation, and Hsp27 was found to colocalize with ATM in both untreated and irradiated cells. Last, combined radiation and Hsp27 LNA treatment in tumor xenografts in nude mice suppressed tumor growth compared with either treatment alone. Conclusions: These results support a radiosensitizing property of Hsp27 LNA in vitro and in vivo, implicate Hsp27 in double strand break repair, and suggest that Hsp27 LNA might eventually serve as an effective clinical agent in the radiotherapy of head-and-neck cancer.

  11. Reversible phospholipid nanogels for deoxyribonucleic acid fragment size determinations up to 1500 base pairs and integrated sample stacking.

    PubMed

    Durney, Brandon C; Bachert, Beth A; Sloane, Hillary S; Lukomski, Slawomir; Landers, James P; Holland, Lisa A

    2015-06-23

    Phospholipid additives are a cost-effective medium to separate deoxyribonucleic acid (DNA) fragments and possess a thermally-responsive viscosity. This provides a mechanism to easily create and replace a highly viscous nanogel in a narrow bore capillary with only a 10°C change in temperature. Preparations composed of dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) self-assemble, forming structures such as nanodisks and wormlike micelles. Factors that influence the morphology of a particular DMPC-DHPC preparation include the concentration of lipid in solution, the temperature, and the ratio of DMPC and DHPC. It has previously been established that an aqueous solution containing 10% phospholipid with a ratio of [DMPC]/[DHPC]=2.5 separates DNA fragments with nearly single base resolution for DNA fragments up to 500 base pairs in length, but beyond this size the resolution decreases dramatically. A new DMPC-DHPC medium is developed to effectively separate and size DNA fragments up to 1500 base pairs by decreasing the total lipid concentration to 2.5%. A 2.5% phospholipid nanogel generates a resolution of 1% of the DNA fragment size up to 1500 base pairs. This increase in the upper size limit is accomplished using commercially available phospholipids at an even lower material cost than is achieved with the 10% preparation. The separation additive is used to evaluate size markers ranging between 200 and 1500 base pairs in order to distinguish invasive strains of Streptococcus pyogenes and Aspergillus species by harnessing differences in gene sequences of collagen-like proteins in these organisms. For the first time, a reversible stacking gel is integrated in a capillary sieving separation by utilizing the thermally-responsive viscosity of these self-assembled phospholipid preparations. A discontinuous matrix is created that is composed of a cartridge of highly viscous phospholipid assimilated into a separation matrix

  12. The estimation of deoxyribonucleic acid in the presence of sialic acid: application to analysis of human gastric washings

    PubMed Central

    Croft, D. N.; Lubran, M.

    1965-01-01

    1. Sialic acid has been found to interfere with three colorimetric reactions used for the estimation of DNA: a modified diphenylamine reaction at 100° (Dische, 1930), the nitrophenylhydrazine method (Webb & Levy, 1955) and the diphenylamine reaction at 30° (Burton, 1956). 2. Evidence is presented that sialic acid is present in hydrolysates obtained from gastric wash-out material. 3. A mathematical method for correcting for interference from sialic acid in the diphenylamine reaction at 30° is described. 4. The diphenylamine reaction has been modified to make it suitable for the estimation of DNA in the presence of sialic acid. The modifications are to increase the concentration of diphenylamine to 2% and to perform the reaction at 6–13° for 48hr. These modifications increase the sensitivity 25% above Burton's (1956) modification of the diphenylamine reaction. 5. The precipitation, extraction and recovery of DNA from gastric wash-out material have been investigated. PMID:14342494

  13. Differential infection of polarized epithelial cell lines by sialic acid-dependent and sialic acid-independent rotavirus strains.

    PubMed

    Ciarlet, M; Crawford, S E; Estes, M K

    2001-12-01

    Infection of epithelial cells by some animal rotaviruses, but not human or most animal rotaviruses, requires the presence of N-acetylneuraminic (sialic) acid (SA) on the cell surface for efficient infectivity. To further understand how rotaviruses enter susceptible cells, six different polarized epithelial cell lines, grown on permeable filter membrane supports containing 0.4-microm pores, were infected apically or basolaterally with SA-independent or SA-dependent rotaviruses. SA-independent rotaviruses applied apically or basolaterally were capable of efficiently infecting both sides of the epithelium of all six polarized cell lines tested, while SA-dependent rotaviruses only infected efficiently through the apical surface of five of the polarized cell lines tested. Regardless of the route of virus entry, SA-dependent and SA-independent rotaviruses were released almost exclusively from the apical domain of the plasma membrane of polarized cells before monolayer disruption or cell lysis. The transepithelial electrical resistance (TER) of cells decreased at the same time, irrespective of whether infection with SA-independent rotaviruses occurred apically or basolaterally. The TER of cells infected apically with SA-dependent rotaviruses decreased earlier than that of cells infected basolaterally. Rotavirus infection decreased TER before the appearance of cytopathic effect and cell death and resulted in an increase in the paracellular permeability to [(3)H]inulin as a function of loss of TER. The presence of SA residues on either the apical or basolateral side was determined using a Texas Red-conjugated lectin, wheat germ agglutinin (WGA), which binds SA residues. WGA bound exclusively to SA residues on the apical surface of the cells, confirming the requirement for SA residues on the apical cell membrane for efficient infectivity of SA-dependent rotaviruses. These results indicate that the rotavirus SA-independent cellular receptor is present on both sides of the

  14. Spectroscopic and microcalorimetric studies on the molecular binding of food colorant acid red 27 with deoxyribonucleic acid.

    PubMed

    Basu, Anirban; Kumar, Gopinatha Suresh

    2016-08-01

    Interaction of the food colorant acid red 27 with double stranded DNA was investigated using spectroscopic and calorimetric methods. Absorbance and fluorescence studies suggested an intimate binding interaction between the dye and DNA. The quantum efficiency value testified an effective energy transfer from the DNA base pairs to the dye molecules. Minor groove displacement assay with Hoechst 33258 revealed that the binding occurs in the minor groove of DNA. Circular dichroism studies revealed that acid red 27 induces moderate conformational perturbations in DNA. Results of calorimetric studies suggested that the complexation process was driven largely by positive entropic contribution with a smaller favorable enthalpy contribution. The equilibrium constant of the binding was calculated to be (3.04 ± 0.09) × 10(4)  M(-1) at 298.15 K. Negative heat capacity value along with the enthalpy-entropy compensation phenomenon established the involvement of dominant hydrophobic forces in the binding process. Differential scanning calorimetry studies presented evidence for an increased thermal stability of DNA on binding of acid red 27. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26846192

  15. Structural studies of lambda transducing bacteriophage carrying bacterial deoxyribonucleic acid from the metBJLF region of the Escherichia coli chromosome.

    PubMed Central

    Krueger, J H; Johnson, J R; Greene, R C; Dresser, M

    1981-01-01

    The structures of several lambda dmet and related lambda darg transducing phage were studied by restriction fragment mapping and electron microscopic measurements of homoduplexes and heteroduplexes. A new transducing phage (lambda dmet141), in which metF is the only functional gene of the cluster, was isolated. In contrast, lambda dmet117, which expresses the entire metBJLF cluster, has only 3 kilobases more bacterial deoxyribonucleic acid (DNA) than lambda dmet141. An EcoRI restriction fragment of lambda dmet117, which carries the leftmost 6 kilobases of the bacterial DNA insert, was isolated and shown to contain a functional copy of metB. Small structural differences at the attachment sites of some of the phage were shown to result from different sites of lambda integration in the two parent insertion lysogens. Images PMID:6267016

  16. Application of an enzyme-based biofuel cell containing a bioelectrode modified with deoxyribonucleic acid-wrapped single-walled carbon nanotubes to serum.

    PubMed

    Lee, Jin Young; Shin, Hyun Yong; Kang, Seong Woo; Park, Chulhwan; Kim, Seung Wook

    2011-01-01

    Enzyme-based biofuel cells (EFCs) are a form of biofuel cells (BFCs) that can utilize redox enzymes as biocatalysts. Applications of an EFC to an implantable system are evaluated under mild conditions, such as ambient temperature or neutral pH. In the present study, an EFC containing a bioelectrode modified with deoxyribonucleic acid (DNA)-wrapped single-walled carbon nanotubes (SWNTs) was applied to a serum system. The protection of immobilized glucose oxidase (GOD) using DNA-wrapped SWNTs was investigated in a trypsin environment, which can exist in a serum. GOD is immobilized by masking the active site onto the anode electrode. The anode/cathode system in the cell was composed of GOD/laccase as the biocatalysts and glucose/oxygen as the substrates in serum. The electrical properties of the anode in serum according to cyclic voltammetry (CV cycle) were improved using the DNA-wrapped SWNTs. Overall, an EFC that employed DNA-wrapped SWNTs and GOD immobilization in conjunction with protection of the active site increased the stability of GOD in serum, which enabled a high level of power production (ca. 190 μW/cm(2)) for up to 1 week.

  17. Physiological Modifications in the Production and Repair of Methyl Methane Sulfonate-Induced Breaks in the Deoxyribonucleic Acid of Escherichia coli K-12

    PubMed Central

    Scudiero, Dominic A.; Friesen, Benjamin S.; Baptist, Jeremy E.

    1973-01-01

    The medium in which Rec+ strains of Escherichia coli K-12 are grown affected their sensitivity to treatment with methyl methane sulfonate (MMS). Rec+ cells grown to the stationary phase in glucose-enriched nutrient broth (GNB) were more resistant to MMS than cells grown in nutrient broth (NB). The repair of MMS-induced breaks (or alkali-labile bonds) in the deoxyribonucleic acid (DNA) from E. coli K-12 strains AB1157, AB1886 uvrA6, and SR111 recA13 recB21 grown in GNB and NB media was examined by means of alkaline sucrose gradient centrifugation. It appeared that essentially all of the repair of breaks that occurred, as evidenced by an increase in “molecular weight,” took place within 10 min after treatment with MMS under our conditions. Cell survival was highest in cells for which the size of the DNA after the post-treatment incubation was the largest. The largest DNA after post-treatment incubation was found in Rec+ cells grown in GNB medium. The results suggest that these cells may have an enhanced capacity for repairing breaks in DNA. PMID:4349030

  18. Carcinogenic damage to deoxyribonucleic acid is induced by near-infrared laser pulses in multiphoton microscopy via combination of two- and three-photon absorption

    NASA Astrophysics Data System (ADS)

    Nadiarnykh, Oleg; Thomas, Giju; Van Voskuilen, Johan; Sterenborg, Henricus J. C. M.; Gerritsen, Hans C.

    2012-11-01

    Nonlinear optical imaging modalities (multiphoton excited fluorescence, second and third harmonic generation) applied in vivo are increasingly promising for clinical diagnostics and the monitoring of cancer and other disorders, as they can probe tissue with high diffraction-limited resolution at near-infrared (IR) wavelengths. However, high peak intensity of femtosecond laser pulses required for two-photon processes causes formation of cyclobutane-pyrimidine-dimers (CPDs) in cellular deoxyribonucleic acid (DNA) similar to damage from exposure to solar ultraviolet (UV) light. Inaccurate repair of subsequent mutations increases the risk of carcinogenesis. In this study, we investigate CPD damage that results in Chinese hamster ovary cells in vitro from imaging them with two-photon excited autofluorescence. The CPD levels are quantified by immunofluorescent staining. We further evaluate the extent of CPD damage with respect to varied wavelength, pulse width at focal plane, and pixel dwell time as compared with more pronounced damage from UV sources. While CPD damage has been expected to result from three-photon absorption, our results reveal that CPDs are induced by competing two- and three-photon absorption processes, where the former accesses UVA absorption band. This finding is independently confirmed by nonlinear dependencies of damage on laser power, wavelength, and pulse width.

  19. Development of a chamber system for rapid, high yield and cost-effective purification of deoxyribonucleic acid fragments from agarose gel

    PubMed Central

    Eslami, Gilda; Salehi, Rasoul

    2014-01-01

    Background: There are several methods commonly practicing for deoxyribonucleic acid (DNA) purification from agarose gel. In most laboratories, especially in developing countries, present methods for recovering of DNA fragments from the gel are mostly involved organic solvents. However, manual purification using organic solvents are toxic, labor intensive, time consuming and prone to contamination owing to several handling steps. The above mentioned burdens as well as cost and long time to import them, especially in developing countries, prompted us to design and develop a chamber system for rapid, non-toxic, cost-effective and user friendly device for polymerase chain reaction (PCR) products purification from agarose gel. Materials and Methods: The device was made from plexiglass plates. After amplification of two fragments of 250 and 850 bp, PCR products were electrophoresed. Subsequently, the desired bands were excised and purified with three method: HiPer Mini chamber, phenol extraction method and spin column procedure. To assess the suitability of the purified DNAs, restriction digestion was applied. Results: Results showed that the yield of recovered DNA in our method was above 95%, whereas the yields obtained with conventional phenol extraction and spin column methods were around 60%. Conclusion: In conclusion, the current method for DNA elution is quick, inexpensive and robust and it does not require the use of toxic organic solvents. In addition, the purified DNA was well has suited for further manipulations such as restriction digestion, ligation, cloning, sequencing and hybridization. PMID:24761386

  20. Redox cycles of vitamin E: Hydrolysis and ascorbic acid dependent reduction of 8a-(alkyldioxy)tocopherones

    SciTech Connect

    Liebler, D.C.; Kaysen, K.L.; Kennedy, T.A. )

    1989-12-12

    Oxidation of the biological antioxidant {alpha}-tocopherol (vitamin E; TH) by peroxyl radicals yields 8a-(alkyldioxy)tocopherones, which either may hydrolyze to {alpha}-tocopheryl quinone (TQ) or may be reduced by ascorbic acid to regenerate TH. To define the chemistry of this putative two-electron TH redox cycle, we studied the hydrolysis and reduction of 8a-((2,4-dimethyl-1-nitrilopent-2-yl)dioxyl)tocopherone (1) in acetonitrile/buffer mixtures and in phospholipid liposomes. TQ formation in acetonitrile/buffer mixtures, which was monitored spectrophotometrically, declined with increasing pH and could not be detected above pH 4. The rate of TQ formation from 1 first increased with time and then decreased in a first-order terminal phase. Rearrangement of 8a-hydroxy-{alpha}-tocopherone (2) to TQ displayed first-order kinetics identical with the terminal phase for TQ formation from 1. Both rate constants increased with decreasing pH. Hydrolysis of 1 in acetonitrile/H{sub 2}{sup 18}O yielded ({sup 18}O)TQ. These observations suggest that 1 loses the 8a-(alkyldioxy) moiety to produce the tocopherone cation (T{sup +}), which hydrolyzes to 2, the TQ-forming intermediate. Incubation of either 1 or 2 with ascorbic acid in acetonitrile/buffer yielded TH. Reduction of both 1 and 2 decreased with increasing pH. In phosphatidylcholine liposomes at pH 7, approximately 10% of the T{sup +} generated from 1 was reduced to TH by 5 mM ascorbic acid. The results collectively demonstrate that T{sup +} is the ascorbic acid reducible intermediate in a two-electron TH redox cycle, a process that probably would require biocatalysis to proceed in biological membranes.

  1. The effects of aspirin on platelet function and lysophosphatidic acids depend on plasma concentrations of EPA and DHA

    PubMed Central

    Block, Robert C; Abdolahi, Amir; Tu, Xin; Georas, Steve N; Brenna, J. Thomas; Phipps, Richard P; Lawrence, Peter; Mousa, Shaker A

    2015-01-01

    Aspirin’s prevention of cardiovascular disease (CVD) events in individuals with type 2 diabetes mellitus is controversial. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and aspirin all affect the cyclooxygenase enzyme. The relationship between plasma EPA and DHA and aspirin’s effects has not been determined. Thirty adults with type 2 diabetes mellitus ingested aspirin (81 mg/day) for 7 days, then EPA+DHA (2.6 g/day) for 28 days, then both for another 7 days. Lysophosphatidic acid (LPA) species and more classic platelet function outcomes were determined. Plasma concentrations of total EPA+DHA were associated with 7-day aspirin reduction effects on these outcomes in a “V”-shaped manner for all 11 LPA species and ADP-induced platelet aggregation. This EPA+DHA concentration was quite consistent for each of the LPA species and ADP. These results support aspirin effects on lysolipid metabolism and platelet aggregation depending on plasma EPA+DHA concentrations in individuals with a disturbed lipid milieu. PMID:25555354

  2. The M/GP5 Glycoprotein Complex of Porcine Reproductive and Respiratory Syndrome Virus Binds the Sialoadhesin Receptor in a Sialic Acid-Dependent Manner

    PubMed Central

    Van Breedam, Wander; Van Gorp, Hanne; Zhang, Jiquan Q.; Crocker, Paul R.; Delputte, Peter L.; Nauwynck, Hans J.

    2010-01-01

    The porcine reproductive and respiratory syndrome virus (PRRSV) is a major threat to swine health worldwide and is considered the most significant viral disease in the swine industry today. In past years, studies on the entry of the virus into its host cell have led to the identification of a number of essential virus receptors and entry mediators. However, viral counterparts for these molecules have remained elusive and this has made rational development of new generation vaccines impossible. The main objective of this study was to identify the viral counterparts for sialoadhesin, a crucial PRRSV receptor on macrophages. For this purpose, a soluble form of sialoadhesin was constructed and validated. The soluble sialoadhesin could bind PRRSV in a sialic acid-dependent manner and could neutralize PRRSV infection of macrophages, thereby confirming the role of sialoadhesin as an essential PRRSV receptor on macrophages. Although sialic acids are present on the GP3, GP4 and GP5 envelope glycoproteins, only the M/GP5 glycoprotein complex of PRRSV was identified as a ligand for sialoadhesin. The interaction was found to be dependent on the sialic acid binding capacity of sialoadhesin and on the presence of sialic acids on GP5. These findings not only contribute to a better understanding of PRRSV biology, but the knowledge and tools generated in this study also hold the key to the development of a new generation of PRRSV vaccines. PMID:20084110

  3. Surface colonization by Azospirillum brasilense SM in the indole-3-acetic acid dependent growth improvement of sorghum.

    PubMed

    Kochar, Mandira; Srivastava, Sheela

    2012-04-01

    The key to improving plant productivity is successful bacterial-plant interaction in the rhizosphere that can be maintained in the environment. The results presented here confirm Azospirillum brasilense strain SM as a competent plant growth promoting bacterium over mid- and long-term associations with sorghum. This study establishes that plant growth can be directly correlated with the associated bacterium's indole-3-acetic acid (IAA) production capability as IAA over-expressing variants, SMp30 and SMΔi3-6 fared better than the wild type strain. The auxin antagonist, p-chlorophenoxy isobutyric acid confirmed the role of bacterial IAA in plant growth promotion and verified the presence of larger amount of IAA available to the seeds on inoculation with IAA over-expressing mutants. Microscopic analysis identified the bacterial association at root tips, root-shoot junction and elongation zone and their surface colonizing nature. Scanning electron microscopy identified larger number of root hairs and extensive exopolysaccharide covering in comparison to untreated ones. In addition, vibroid-shaped Azospirilla attached by means of fibrillar material were dispersed along the elongation zone. The notable difference with IAA over-expressing variants was enhanced number of root hairs. Thus, the variant strains may be more efficient surface colonizers of the sorghum root and used as superior bio-inoculants for improving plant productivity.

  4. Phytochrome A and B Function Antagonistically to Regulate Cold Tolerance via Abscisic Acid-Dependent Jasmonate Signaling1[OPEN

    PubMed Central

    Guo, Zhixin; Li, Huizi; Wang, Mengmeng; Zhou, Jie; Xia, Xiaojian; Shi, Kai; Yu, Jingquan

    2016-01-01

    Light signaling and phytohormones both influence plant growth, development, and stress responses; however, cross talk between these two signaling pathways in response to cold remains underexplored. Here, we report that far-red light (FR) and red light (R) perceived by phytochrome A (phyA) and phyB positively and negatively regulated cold tolerance, respectively, in tomato (Solanum lycopersicum), which were associated with the regulation of levels of phytohormones such as abscisic acid (ABA) and jasmonic acid (JA) and transcript levels of ABA- and JA-related genes and the C-REPEAT BINDING FACTOR (CBF) stress signaling pathway genes. A reduction in the R/FR ratio did not alter cold tolerance, ABA and JA accumulation, and transcript levels of ABA- and JA-related genes and the CBF pathway genes in phyA mutant plants; however, those were significantly increased in wild-type and phyB plants with the reduction in the R/FR ratio. Even though low R/FR treatments did not confer cold tolerance in ABA-deficient (notabilis [not]) and JA-deficient (prosystemin-mediated responses2 [spr2]) mutants, it up-regulated ABA accumulation and signaling in the spr2 mutant, with no effect on JA levels and signaling in the not mutant. Foliar application of ABA and JA further confirmed that JA functioned downstream of ABA to activate the CBF pathway in light quality-mediated cold tolerance. It is concluded that phyA and phyB function antagonistically to regulate cold tolerance that essentially involves FR light-induced activation of phyA to induce ABA signaling and, subsequently, JA signaling, leading to an activation of the CBF pathway and a cold response in tomato plants. PMID:26527654

  5. Amino Acid-Dependent Attenuation of Toll-like Receptor Signaling by Peptide-Gold Nanoparticle Hybrids.

    PubMed

    Yang, Hong; Fung, Shan-Yu; Xu, Shuyun; Sutherland, Darren P; Kollmann, Tobias R; Liu, Mingyao; Turvey, Stuart E

    2015-07-28

    Manipulation of immune responsiveness using nanodevices provides a potential approach to treat human diseases. Toll-like receptor (TLR) signaling plays a central role in the pathophysiology of many acute and chronic human inflammatory diseases, and pharmacological regulation of TLR responses is anticipated to be beneficial in many of these inflammatory conditions. Here we describe the discovery of a unique class of peptide-gold nanoparticle hybrids that exhibit a broad inhibitory activity on TLR signaling, inhibiting signaling through TLRs 2, 3, 4, and 5. As exemplified using TLR4, the nanoparticles were found to inhibit both arms of TLR4 signaling cascade triggered by the prototypical ligand, lipopolysaccharide (LPS). Through structure-activity relationship studies, we identified the key chemical components of the hybrids that contribute to their immunomodulatory activity. Specifically, the hydrophobicity and aromatic ring structure of the amino acids on the peptides were essential for modulating TLR4 responses. This work enhances our fundamental understanding of the role of nanoparticle surface chemistry in regulating innate immune signaling, and identifies specific nanoparticle hybrids that may represent a unique class of anti-inflammatory therapeutics for human inflammatory diseases.

  6. Immunomodulation by Bifidobacterium infantis 35624 in the murine lamina propria requires retinoic acid-dependent and independent mechanisms.

    PubMed

    Konieczna, Patrycja; Ferstl, Ruth; Ziegler, Mario; Frei, Remo; Nehrbass, Dirk; Lauener, Roger P; Akdis, Cezmi A; O'Mahony, Liam

    2013-01-01

    Appropriate dendritic cell processing of the microbiota promotes intestinal homeostasis and protects against aberrant inflammatory responses. Mucosal CD103(+) dendritic cells are able to produce retinoic acid from retinal, however their role in vivo and how they are influenced by specific microbial species has been poorly described. Bifidobacterium infantis 35624 (B. infantis) feeding to mice resulted in increased numbers of CD103(+)retinaldehyde dehydrogenase (RALDH)(+) dendritic cells within the lamina propria (LP). Foxp3(+) lymphocytes were also increased in the LP, while TH1 and TH17 subsets were decreased. 3,7-dimethyl-2,6-octadienal (citral) treatment of mice blocked the increase in CD103(+)RALDH(+) dendritic cells and the decrease in TH1 and TH17 lymphocytes, but not the increase in Foxp3(+) lymphocytes. B. infantis reduced the severity of DSS-induced colitis, associated with decreased TH1 and TH17 cells within the LP. Citral treatment confirmed that these effects were RALDH mediated. RALDH(+) dendritic cells decreased within the LP of control inflamed animals, while RALDH(+) dendritic cells numbers were maintained in the LP of B. infantis-fed mice. Thus, CD103(+)RALDH(+) LP dendritic cells are important cellular targets for microbiota-associated effects on mucosal immunoregulation.

  7. Immunomodulation by Bifidobacterium infantis 35624 in the Murine Lamina Propria Requires Retinoic Acid-Dependent and Independent Mechanisms

    PubMed Central

    Konieczna, Patrycja; Ferstl, Ruth; Ziegler, Mario; Frei, Remo; Nehrbass, Dirk; Lauener, Roger P.; Akdis, Cezmi A.; O'Mahony, Liam

    2013-01-01

    Appropriate dendritic cell processing of the microbiota promotes intestinal homeostasis and protects against aberrant inflammatory responses. Mucosal CD103+ dendritic cells are able to produce retinoic acid from retinal, however their role in vivo and how they are influenced by specific microbial species has been poorly described. Bifidobacterium infantis 35624 (B. infantis) feeding to mice resulted in increased numbers of CD103+retinaldehyde dehydrogenase (RALDH)+ dendritic cells within the lamina propria (LP). Foxp3+ lymphocytes were also increased in the LP, while TH1 and TH17 subsets were decreased. 3,7-dimethyl-2,6-octadienal (citral) treatment of mice blocked the increase in CD103+RALDH+ dendritic cells and the decrease in TH1 and TH17 lymphocytes, but not the increase in Foxp3+ lymphocytes. B. infantis reduced the severity of DSS-induced colitis, associated with decreased TH1 and TH17 cells within the LP. Citral treatment confirmed that these effects were RALDH mediated. RALDH+ dendritic cells decreased within the LP of control inflamed animals, while RALDH+ dendritic cells numbers were maintained in the LP of B. infantis-fed mice. Thus, CD103+RALDH+ LP dendritic cells are important cellular targets for microbiota-associated effects on mucosal immunoregulation. PMID:23704880

  8. Nuclear-localized AtHSPR links abscisic acid-dependent salt tolerance and antioxidant defense in Arabidopsis.

    PubMed

    Yang, Tao; Zhang, Liang; Hao, Hongyan; Zhang, Peng; Zhu, Haowei; Cheng, Wei; Wang, Yongli; Wang, Xinyu; Wang, Chongying

    2015-12-01

    Salt stress from soil or irrigation water limits plant growth. A T-DNA insertion mutant in C24, named athspr (Arabidopsis thaliana heat shock protein-related), showed several phenotypes, including reduced organ size and enhanced sensitivity to environmental cues. The athspr mutant is severely impaired under salinity levels at which wild-type (WT) plants grow normally. AtHSPR encodes a nuclear-localized protein with ATPase activity, and its expression was enhanced by high salinity and abscisic acid (ABA). Overexpression (OE) of AtHSPR significantly enhanced tolerance to salt stress by increasing the activities of the antioxidant system and by maintaining K(+) /Na(+) homeostasis. Quantitative RT-PCR analyses showed that OE of AtHSPR increased the expression of ABA/stress-responsive, salt overly sensitive (SOS)-related and antioxidant-related genes. In addition, ABA content was reduced in athspr plants with or without salt stress, and exogenous ABA restored WT-like salt tolerance to athspr plants. athspr exhibited increased leaf stomatal density and stomatal index, slower ABA-induced stomatal closure and reduced drought tolerance relative to the WT. AtHSPR OE enhanced drought tolerance by reducing leaf water loss and stomatal aperture. Transcript profiling in athspr showed a differential salt-stress response for genes involved in accumulation of reactive oxygen species (ROS), ABA signaling, cell death, stress response and photosynthesis. Taken together, our results suggested that AtHSPR is involved in salt tolerance in Arabidopsis through modulation of ROS levels, ABA-dependent stomatal closure, photosynthesis and K(+) /Na(+) homeostasis. PMID:26603028

  9. Amino acid-dependent transformations of citrate-coated silver nanoparticles: impact on morphology, stability and toxicity.

    PubMed

    Shi, Junpeng; Sun, Xia; Zou, Xiaoyan; Zhang, Hongwu

    2014-08-17

    Humans face the risk of exposure to silver nanoparticles (AgNPs) due to their extensive application in consumer products. AgNPs can interact with many substances in the human body due to their chemically unstable nature and high activity properties, which might result in unknown hazards and even some serious diseases for humans. As the basic constituent element of human bodies, amino acids (AAs) differ in concentration and variety in different cells and tissues. Thus, understanding the transformation of citrate-coated AgNPs in the presence of AAs is crucial for determining their fate and toxicity in the human body. Our study focused on the transformation of the morphology, dissolution behavior and reaction product of AgNPs in different AA-containing systems and then evaluated the effect of these transformations on the cytotoxicity of AgNPs. The obtained results indicated that the addition of glycine with the lowest Ag(+) binding energy had little effect on the transformations and toxicity of AgNPs. While in the presence of histidine with higher Ag(+) binding energy, the Ag(+) release and particle size of AgNPs obviously increased. These transformations resulted in a decrease in the cytotoxicity of AgNPs due to the formation of Ag-His complex and the growth of AgNPs. Furthermore, l-cysteine with the highest Ag(+) binding energy could easily interact with AgNPs, transforming them completely to form [Ag(Cys)n](+) and Ag2S precipitates, which induced the largest decrease in AgNP toxicity. In summary, our results may provide useful information to understand the fate, transformation, and toxicity of citrate-coated AgNPs in the human body.

  10. Drosophila melanogaster Acetyl-CoA-carboxylase sustains a fatty acid-dependent remote signal to waterproof the respiratory system.

    PubMed

    Parvy, Jean-Philippe; Napal, Laura; Rubin, Thomas; Poidevin, Mickael; Perrin, Laurent; Wicker-Thomas, Claude; Montagne, Jacques

    2012-01-01

    Fatty acid (FA) metabolism plays a central role in body homeostasis and related diseases. Thus, FA metabolic enzymes are attractive targets for drug therapy. Mouse studies on Acetyl-coenzymeA-carboxylase (ACC), the rate-limiting enzyme for FA synthesis, have highlighted its homeostatic role in liver and adipose tissue. We took advantage of the powerful genetics of Drosophila melanogaster to investigate the role of the unique Drosophila ACC homologue in the fat body and the oenocytes. The fat body accomplishes hepatic and storage functions, whereas the oenocytes are proposed to produce the cuticular lipids and to contribute to the hepatic function. RNA-interfering disruption of ACC in the fat body does not affect viability but does result in a dramatic reduction in triglyceride storage and a concurrent increase in glycogen accumulation. These metabolic perturbations further highlight the role of triglyceride and glycogen storage in controlling circulatory sugar levels, thereby validating Drosophila as a relevant model to explore the tissue-specific function of FA metabolic enzymes. In contrast, ACC disruption in the oenocytes through RNA-interference or tissue-targeted mutation induces lethality, as does oenocyte ablation. Surprisingly, this lethality is associated with a failure in the watertightness of the spiracles-the organs controlling the entry of air into the trachea. At the cellular level, we have observed that, in defective spiracles, lipids fail to transfer from the spiracular gland to the point of air entry. This phenotype is caused by disrupted synthesis of a putative very-long-chain-FA (VLCFA) within the oenocytes, which ultimately results in a lethal anoxic issue. Preventing liquid entry into respiratory systems is a universal issue for air-breathing animals. Here, we have shown that, in Drosophila, this process is controlled by a putative VLCFA produced within the oenocytes. PMID:22956916

  11. Induction of human choriogonadotropin in HeLa-cell cultures by aliphatic monocarboxylates and inhibitors of deoxyribonucleic acid synthesis

    PubMed Central

    Ghosh, Nimai K.; Rukenstein, Adriana; Cox, Rody P.

    1977-01-01

    The ectopic production of the glycopeptide hormone human placental choriogonadotropin by HeLa65 cells was measured by radioimmunoassay with antiserum against the β-subunit of choriogonadotropin and with the 125I-labelled β-subunit as a tracer antigen. Choriogonadotropin synthesis was markedly (500-fold) stimulated by sodium butyrate. Kinetic studies and the use of an inhibitor of protein synthesis, cycloheximide, indicated that protein synthesis was required for this induction. Investigation of the efficiency of 22 aliphatic short-chain fatty acids and derivatives in causing increased choriogonadotropin synthesis by HeLa cells showed stringent structural requirements. Induction of choriogonadotropin synthesis in HeLa cells was not restricted to butyrate. Other aliphatic acids (propionate, isobutyrate, valerate and hexanoate) were also capable of inducing choriogonadotropin synthesis at 10–50% of the efficiency of butyrate. Hydroxy derivatives of monocarboxylate inducers, related mono- and di-carboxylic acids, alcohols, amines, ketones, esters and sulphoxide were ineffective in increasing choriogonadotropin production by HeLa cells. A saturated C4 straight-chain acid without substituent hydroxyl groups but with a methyl group at one end and a carboxyl moiety at the other appeared to be most efficient in activating choriogonadotropin production. A second clonal line of HeLa cells, HeLa71, showed a higher constitutive synthesis of choriogonadotropin than HeLa65 cells, which was also markedly increased by butyrate. Butyrate and other aliphatic monocarboxylate inducers of choriogonadotropin synthesis inhibited HeLa-cell growth and DNA synthesis. This inhibition of DNA replication may be related to the mechanism of choriogonadotropin synthesis, since two well-characterized anti-neoplastic inhibitors of DNA synthesis, hydroxyurea and 1-β-d-arabinofuranosylcytosine, also stimulated a 300-fold increase in choriogonadotropin synthesis in HeLa cells and were synergistic

  12. Floral Induction of Vegetative Plants Supplied a Purified Fraction of Deoxyribonucleic Acid from Stems of Flowering Plants 1

    PubMed Central

    Wardell, William L.

    1977-01-01

    It has been found that floral induced stems of flowering tobacco (Nicotiana tabacum cv. Wis. 38) plants contain large amounts of rapidly renaturing DNA, whereas noninduced stems of vegetative plants contain only small amounts. In addition, it has been shown that the striking qualitative difference in DNA between stems of flowering and vegetative plants mimics the over-all quantitative difference in DNA content (on a fresh weight basis). Therefore, the extra DNA in stems of flowering plants seems, at least in part, to represent preferential synthesis of rapidly renaturing DNA. Rapidly renatured DNA (flowering plants) has been purified (cesium chloride gradients) from heated-cooled DNA solution and under noninductive conditions has been tested for floral activity. It has been found that when rapidly renatured DNA in buffer solution is supplied to axillary vegetative buds of vegetative plants and then the axillary buds are defoliated every 4th day for 12 days, the treated buds change into flower buds. On the other hand, control axillary buds supplied buffer solution alone remain vegetative. In stem segments from flowering plants, the concept, discussed in previous reports, that indole-3-acetic acid may modify in vitro bud expression by directly affecting DNA synthesis has been reviewed. On the basis of this report, the concept is elaborated by proposing here that indole-3-acetic acid may act partially in bud expression by directly suppressing synthesis of rapidly renaturing DNA. PMID:16660207

  13. A common set of conserved motifs in a vast variety of putative nucleic acid-dependent ATPases including MCM proteins involved in the initiation of eukaryotic DNA replication.

    PubMed

    Koonin, E V

    1993-06-11

    A new superfamily of (putative) DNA-dependent ATPases is described that includes the ATPase domains of prokaryotic NtrC-related transcription regulators, MCM proteins involved in the initiation of eukaryotic DNA replication, and a group of uncharacterized bacterial and chloroplast proteins. MCM proteins are shown to contain a modified form of the ATP-binding motif and are predicted to mediate ATP-dependent opening of double-stranded DNA in the replication origins. In a second line of investigation, it is demonstrated that the products of unidentified open reading frames from Marchantia mitochondria and from yeast, and a domain of a baculovirus protein involved in viral DNA replication are related to the superfamily III of DNA and RNA helicases that previously has been known to include only proteins of small viruses. Comparison of the multiple alignments showed that the proteins of the NtrC superfamily and the helicases of superfamily III share three related sequence motifs tightly packed in the ATPase domain that consists of 100-150 amino acid residues. A similar array of conserved motifs is found in the family of DnaA-related ATPases. It is hypothesized that the three large groups of nucleic acid-dependent ATPases have similar structure of the core ATPase domain and have evolved from a common ancestor.

  14. Bovine thrombospondin-2: complete complementary deoxyribonucleic acid sequence and immunolocalization in the external zones of the adrenal cortex.

    PubMed

    Danik, M; Chinn, A M; Lafeuillade, B; Keramidas, M; Aguesse-Germon, S; Penhoat, A; Chen, H; Mosher, D F; Chambaz, E M; Feige, J J

    1999-06-01

    Given the variety of biological functions in the adrenal cortex that are controlled by ACTH, we hypothesized that some extracellular proteins act as biological relays for this systemic hormone. One candidate protein [corticotropin-induced secreted protein (CISP)] was purified from the conditioned medium of bovine adrenocortical cells on the basis of a 5- to 14-fold increase in its synthesis after the addition of ACTH. We report here the cloning of overlapping complementary DNAs that span the sequence encoding the full-length protein (1170 amino acids). The deduced CISP protein sequence is 89% identical to that of human thrombospondin-2 (TSP2), but only 61% identical to that of bovine TSP1, confirming that CISP is the bovine ortholog of TSP2. The bovine TSP2 sequence aligned perfectly with human, mouse, and chicken TSP2 sequences, except for a gap of 2 amino acids located in a linker region. All 58 cysteine residues that are conserved in other species were present in the bovine sequence as well as most of the functional domains. Most endocrine tissues (adrenal cortex, testis, ovary, and placenta) appeared to express TSP2, as determined by Western blot analysis. The highest levels of TSP2 protein were found in the adrenal cortex, followed by the heart, spleen, brain, and kidney. A differential extent of N-glycosylation or tissular proteolytic maturation may be responsible for the mol wt differences observed between bovine TSP2 detected in the medium from primary cultures and that in fresh tissue extracts. The immunohistochemical analysis of the distribution of TSP2 in the bovine adrenal gland revealed that the protein is much more abundant in the external zones (zona glomerulosa and zona fasciculata) than in the internal reticularis zone, a pattern similar to that reported for ACTH receptors. This distribution clearly suggests that TSP2 is a candidate relay protein for a subset of ACTH actions in the adrenal cortex. PMID:10342868

  15. Cell cytotoxicity and serum albumin binding capacity of the morin-Cu(ii) complex and its effect on deoxyribonucleic acid.

    PubMed

    Roy, Atanu Singha; Samanta, Sintu Kumar; Ghosh, Pooja; Tripathy, Debi Ranjan; Ghosh, Sudip Kumar; Dasgupta, Swagata

    2016-08-16

    The dietary components, flavonoids, are important for their anti-oxidant properties and the ability to act as metal ion chelators. The characterization of the morin-Cu(ii) complex is executed using elemental analysis, FTIR and mass spectroscopy. DNA cleaving and cell cytotoxicity properties followed by serum albumin binding have been investigated in this report. The morin-Cu(ii) complex was found to cleave plasmid pBR322 DNA via an oxidative pathway as revealed by agarose gel based assay performed in the presence of some scavengers and reactive oxygen species. The breaking of the deoxyribose ring of calf thymus DNA (ct-DNA) was also confirmed by the formation of thiobarbituric acid reacting species (TBARS) between thiobarbituric acid and malonaldehyde. The morin-Cu(ii) complex is able to inhibit the growth of human HeLa cells. Fluorescence studies revealed that the morin-Cu(ii) complex can quench the intrinsic fluorescence of serum albumins (SAs) via a static quenching method. The binding constants were found to be in the order of 10(5) M(-1) and observed to increase with temperature. Both ΔH° and ΔS° are positive for the binding of the morin-Cu(ii) complex with serum albumins which indicated the presence of hydrophobic forces. Site-selectivity studies reveal that the morin-Cu(ii) complex binds to both site 1 (subdomain IIA) and site 2 (subdomain IIIA) of human serum albumin (HSA) and bovine serum albumin (BSA). Circular dichroism (CD) studies showed the structural perturbation of SAs during binding with the morin-Cu(ii) complex. The results from binding studies confirmed that after complexation with the Cu(ii) ion, morin alters its mode of interaction with SAs which could have differential implications on its other biological and pharmaceutical properties.

  16. Cell cytotoxicity and serum albumin binding capacity of the morin-Cu(ii) complex and its effect on deoxyribonucleic acid.

    PubMed

    Roy, Atanu Singha; Samanta, Sintu Kumar; Ghosh, Pooja; Tripathy, Debi Ranjan; Ghosh, Sudip Kumar; Dasgupta, Swagata

    2016-08-16

    The dietary components, flavonoids, are important for their anti-oxidant properties and the ability to act as metal ion chelators. The characterization of the morin-Cu(ii) complex is executed using elemental analysis, FTIR and mass spectroscopy. DNA cleaving and cell cytotoxicity properties followed by serum albumin binding have been investigated in this report. The morin-Cu(ii) complex was found to cleave plasmid pBR322 DNA via an oxidative pathway as revealed by agarose gel based assay performed in the presence of some scavengers and reactive oxygen species. The breaking of the deoxyribose ring of calf thymus DNA (ct-DNA) was also confirmed by the formation of thiobarbituric acid reacting species (TBARS) between thiobarbituric acid and malonaldehyde. The morin-Cu(ii) complex is able to inhibit the growth of human HeLa cells. Fluorescence studies revealed that the morin-Cu(ii) complex can quench the intrinsic fluorescence of serum albumins (SAs) via a static quenching method. The binding constants were found to be in the order of 10(5) M(-1) and observed to increase with temperature. Both ΔH° and ΔS° are positive for the binding of the morin-Cu(ii) complex with serum albumins which indicated the presence of hydrophobic forces. Site-selectivity studies reveal that the morin-Cu(ii) complex binds to both site 1 (subdomain IIA) and site 2 (subdomain IIIA) of human serum albumin (HSA) and bovine serum albumin (BSA). Circular dichroism (CD) studies showed the structural perturbation of SAs during binding with the morin-Cu(ii) complex. The results from binding studies confirmed that after complexation with the Cu(ii) ion, morin alters its mode of interaction with SAs which could have differential implications on its other biological and pharmaceutical properties. PMID:27345944

  17. The lesion-mimic mutant cpr22 shows alterations in abscisic acid signaling and abscisic acid insensitivity in a salicylic acid-dependent manner.

    PubMed

    Mosher, Stephen; Moeder, Wolfgang; Nishimura, Noriyuki; Jikumaru, Yusuke; Joo, Se-Hwan; Urquhart, William; Klessig, Daniel F; Kim, Seong-Ki; Nambara, Eiji; Yoshioka, Keiko

    2010-04-01

    A number of Arabidopsis (Arabidopsis thaliana) lesion-mimic mutants exhibit alterations in both abiotic stress responses and pathogen resistance. One of these mutants, constitutive expresser of PR genes22 (cpr22), which has a mutation in two cyclic nucleotide-gated ion channels, is a typical lesion-mimic mutant exhibiting elevated levels of salicylic acid (SA), spontaneous cell death, constitutive expression of defense-related genes, and enhanced resistance to various pathogens; the majority of its phenotypes are SA dependent. These defense responses in cpr22 are suppressed under high-humidity conditions and enhanced by low humidity. After shifting plants from high to low humidity, the cpr22 mutant, but not the wild type, showed a rapid increase in SA levels followed by an increase in abscisic acid (ABA) levels. Concomitantly, genes for ABA metabolism were up-regulated in the mutant. The expression of a subset of ABA-inducible genes, such as RD29A and KIN1/2, was down-regulated, but that of other genes, like ABI1 and HAB1, was up-regulated in cpr22 after the humidity shift. cpr22 showed reduced responsiveness to ABA not only in abiotic stress responses but also in germination and stomatal closure. Double mutant analysis with nahG plants that degrade SA indicated that these alterations in ABA signaling were attributable to elevated SA levels. Furthermore, cpr22 displayed suppressed drought responses by long-term drought stress. Taken together, these results suggest an effect of SA on ABA signaling/abiotic stress responses during the activation of defense responses in cpr22. PMID:20164209

  18. Glutaredoxin S15 Is Involved in Fe-S Cluster Transfer in Mitochondria Influencing Lipoic Acid-Dependent Enzymes, Plant Growth, and Arsenic Tolerance in Arabidopsis1[OPEN

    PubMed Central

    2016-01-01

    Glutaredoxins (Grxs) are small proteins that function as oxidoreductases with roles in deglutathionylation of proteins, reduction of antioxidants, and assembly of iron-sulfur (Fe-S) cluster-containing enzymes. Which of the 33 Grxs in Arabidopsis (Arabidopsis thaliana) perform roles in Fe-S assembly in mitochondria is unknown. We have examined in detail the function of the monothiol GrxS15 in plants. Our results show its exclusive mitochondrial localization, and we are concluding it is the major or only Grx in this subcellular location. Recombinant GrxS15 has a very low deglutathionylation and dehydroascorbate reductase activity, but it binds a Fe-S cluster. Partially removing GrxS15 from mitochondria slowed whole plant growth and respiration. Native GrxS15 is shown to be especially important for lipoic acid-dependent enzymes in mitochondria, highlighting a putative role in the transfer of Fe-S clusters in this process. The enhanced effect of the toxin arsenic on the growth of GrxS15 knockdown plants compared to wild type highlights the role of mitochondrial glutaredoxin Fe-S-binding in whole plant growth and toxin tolerance. PMID:26672074

  19. Helix-forming tendencies of amino acids depend on their sequence contexts: tripeptides AFG and FAG show incipient beta-bulge formation in their crystal structures.

    PubMed

    Parthasarathy, R; Go, K; Chaturvedi, S

    1993-01-01

    Many of the theoretical methods used for predicting the occurrence of alpha-helices in peptides are based on the helical preferences of amino acid monomer residues. In order to check whether the helix-forming tendencies are based on helical preferences of monomers only or also on their sequence contexts, we synthesized permuted sequences of the tripeptides GAF, GAV, and GAL that formed crystalline helices with near alpha-helical conformation. The tripeptides AFG and FAG formed good crystals. The x-ray crystallographic studies of AFG and FAG showed that though they contain the same amino acids as GAF but in different sequences, they do not assume a helical conformation in the solid state. On the other hand, AFG and FAG, which contain the same amino acids but in a different sequence, exhibit nearly the same backbone torsion angles corresponding to an incipient formation of a beta-bulge, and exhibit nearly identical unit cells and crystal structures. Based on these results, it appears that the helix-forming tendencies of amino acids depend on the sequence context in which it occurs in a polypeptide. The synthetic peptides AFG (L-Ala-L-Phe-Gly) and FAG (L-Phe-L-Ala-Gly), C14H19N3O4, crystallize in the orthorhombic space group P2(1)2(1)2(1), with a = 5.232(1), b = 14.622(2), c = 19.157(3) A, Dx = 1.329 g cm-3, Z = 4, R = 0.041 for 549 reflections for AFG, and with a = 5.488(2), b = 14.189(1), c = 18.562(1) A, Dx = 1.348 g cm-3, Z = 4, R = 0.038 for 919 reflections for FAG. Unlike the other tripeptides GAF, GGV, GAL, and GAI, the crystals of AFG and FAG do not contain water molecule, and the molecules of AFG aor FAG do not show the helical conformation. The torsion angles at the backbone of the peptide are psi 1 = 144.5(5) degrees; phi 2, psi 2 = -98.1(6) degrees, -65.2(6) degrees; phi 3, psi 13, psi 31 = 154.1(6) degrees, -173.6(6) degrees, 6.9(8) degrees for AFG; and psi 1 = 162.6(3) degrees; phi 2, psi 2 = -96.7(4) degrees, -46.3(4) degrees; phi 3, psi 13, psi 31

  20. pH-, Lactic Acid-, and Non-Lactic Acid-Dependent Activities of Probiotic Lactobacilli against Salmonella enterica Serovar Typhimurium

    PubMed Central

    Fayol-Messaoudi, Domitille; Berger, Cédric N.; Coconnier-Polter, Marie-Hélène; Liévin-Le Moal, Vanessa; Servin, Alain L.

    2005-01-01

    The mechanism(s) underlying the antibacterial activity of probiotic Lactobacillus strains appears to be multifactorial and includes lowering of the pH and the production of lactic acid and of antibacterial compounds, including bacteriocins and nonbacteriocin, non-lactic acid molecules. Addition of Dulbecco's modified Eagle's minimum essential medium to the incubating medium delays the killing activity of lactic acid. We found that the probiotic strains Lactobacillus johnsonii La1, Lactobacillus rhamnosus GG, Lactobacillus casei Shirota YIT9029, L. casei DN-114 001, and L. rhamnosus GR1 induced a dramatic decrease in the viability of Salmonella enterica serovar Typhimurium SL1344 mainly attributable to non-lactic acid molecule(s) present in the cell-free culture supernatant (CFCS). These molecules were more active against serovar Typhimurium SL1344 in the exponential growth phase than in the stationary growth phase. We also showed that the production of the non-lactic acid substance(s) responsible for the killing activity was dependent on growth temperature and that both unstable and stable substances with killing activity were present in the CFCSs. We found that the complete inhibition of serovar Typhimurium SL1344 growth results from a pH-lowering effect. PMID:16204515

  1. Gaseous 3-pentanol primes plant immunity against a bacterial speck pathogen, Pseudomonas syringae pv. tomato via salicylic acid and jasmonic acid-dependent signaling pathways in Arabidopsis

    PubMed Central

    Song, Geun C.; Choi, Hye K.; Ryu, Choong-Min

    2015-01-01

    3-Pentanol is an active organic compound produced by plants and is a component of emitted insect sex pheromones. A previous study reported that drench application of 3-pentanol elicited plant immunity against microbial pathogens and an insect pest in crop plants. Here, we evaluated whether 3-pentanol and the derivatives 1-pentanol and 2-pentanol induced plant systemic resistance using the in vitro I-plate system. Exposure of Arabidopsis seedlings to 10 μM and 100 nM 3-pentanol evaporate elicited an immune response to Pseudomonas syringae pv. tomato DC3000. We performed quantitative real-time PCR to investigate the 3-pentanol-mediated Arabidopsis immune responses by determining Pathogenesis-Related (PR) gene expression levels associated with defense signaling through salicylic acid (SA), jasmonic acid (JA), and ethylene signaling pathways. The results show that exposure to 3-pentanol and subsequent pathogen challenge upregulated PDF1.2 and PR1 expression. Selected Arabidopsis mutants confirmed that the 3-pentanol-mediated immune response involved SA and JA signaling pathways and the NPR1 gene. Taken together, this study indicates that gaseous 3-pentanol triggers induced resistance in Arabidopsis by priming SA and JA signaling pathways. To our knowledge, this is the first report that a volatile compound of an insect sex pheromone triggers plant systemic resistance against a bacterial pathogen. PMID:26500665

  2. Cloning and characterization of a complementary deoxyribonucleic acid encoding haploid-specific alanine-rich acidic protein located on chromosome-X.

    PubMed

    Uchida, K; Tsuchida, J; Tanaka, H; Koga, M; Nishina, Y; Nozaki, M; Yoshinaga, K; Toshimori, K; Matsumiya, K; Okuyama, A; Nishimune, Y

    2000-10-01

    We have isolated a cDNA clone encoding a germ cell-specific protein from an expression cDNA library prepared from the mouse testis using testis-specific polyclonal antibodies. Northern blot analysis showed a transcript of 1.1 kilobases exclusively expressed in haploid germ cells of the testis. Sequence analysis of the cDNA revealed one long open reading frame consisting of 238 deduced amino acids, rich in basic amino acids in the N-terminal one-third that also contained the nuclear localization signal, and rich in acidic amino acids, including two type of acidic alanine-rich repeats, in the rest of the deduced protein. The protein having a molecular weight of approximately 55 kDa and an isoelectric point of pH 4.3-4.7 was also exclusively detected in the testis by Western blot analysis. As the cDNA was located on chromosome-X, Halap-X (haploid-specific alanine-rich acidic protein located on chromosome-X) was proposed for the name of the protein encoded by the cDNA. Immunohistochemical observation revealed that the Halap-X protein was predominantly present in the nucleoplasm of round spermatids but gradually decreased as spermatids matured, followed by the subsequent appearance in the cytoplasm of elongating spermatids. Thus, the Halap-X protein was transferred from the nuclei to the cytoplasm during the spermatid maturation when the chromatin condensation and transformation of the nuclei occurred. The Halap-X may facilitate specific association of nuclear DNA with some basic chromosomal proteins and play important roles in the process of chromatin condensation. PMID:10993819

  3. Analysis of salicylic acid-dependent pathways in Arabidopsis thaliana following infection with Plasmodiophora brassicae and the influence of salicylic acid on disease.

    PubMed

    Lovelock, David A; Šola, Ivana; Marschollek, Sabine; Donald, Caroline E; Rusak, Gordana; van Pée, Karl-Heinz; Ludwig-Müller, Jutta; Cahill, David M

    2016-10-01

    Salicylic acid (SA) biosynthesis, the expression of SA-related genes and the effect of SA on the Arabidopsis-Plasmodiophora brassicae interaction were examined. Biochemical analyses revealed that, in P. brassicae-infected Arabidopsis, the majority of SA is synthesized from chorismate. Real-time monitored expression of a gene for isochorismate synthase was induced on infection. SA can be modified after accumulation, either by methylation, improving its mobility, or by glycosylation, as one possible reaction for inactivation. Quantitative reverse transcription-polymerase chain reaction (qPCR) confirmed the induction of an SA methyltransferase gene, whereas SA glucosyltransferase expression was not changed after infection. Col-0 wild-type (wt) did not provide a visible phenotypic resistance response, whereas the Arabidopsis mutant dnd1, which constitutively activates the immune system, showed reduced gall scores. As dnd1 showed control of the pathogen, exogenous SA was applied to Arabidopsis in order to test whether it could suppress clubroot. In wt, sid2 (SA biosynthesis), NahG (SA-deficient) and npr1 (SA signalling-impaired) mutants, SA treatment did not alter the gall score, but positively affected the shoot weight. This suggests that SA alone is not sufficient for Arabidopsis resistance against P. brassicae. Semi-quantitative PCR revealed that wt, cpr1, dnd1 and sid2 showed elevated PR-1 expression on P. brassicae and SA + P. brassicae inoculation at 2 and 3 weeks post-inoculation (wpi), whereas NahG and npr1 showed no expression. This work contributes to the understanding of SA involvement in the Arabidopsis-P. brassicae interaction.

  4. Analysis of salicylic acid-dependent pathways in Arabidopsis thaliana following infection with Plasmodiophora brassicae and the influence of salicylic acid on disease.

    PubMed

    Lovelock, David A; Šola, Ivana; Marschollek, Sabine; Donald, Caroline E; Rusak, Gordana; van Pée, Karl-Heinz; Ludwig-Müller, Jutta; Cahill, David M

    2016-10-01

    Salicylic acid (SA) biosynthesis, the expression of SA-related genes and the effect of SA on the Arabidopsis-Plasmodiophora brassicae interaction were examined. Biochemical analyses revealed that, in P. brassicae-infected Arabidopsis, the majority of SA is synthesized from chorismate. Real-time monitored expression of a gene for isochorismate synthase was induced on infection. SA can be modified after accumulation, either by methylation, improving its mobility, or by glycosylation, as one possible reaction for inactivation. Quantitative reverse transcription-polymerase chain reaction (qPCR) confirmed the induction of an SA methyltransferase gene, whereas SA glucosyltransferase expression was not changed after infection. Col-0 wild-type (wt) did not provide a visible phenotypic resistance response, whereas the Arabidopsis mutant dnd1, which constitutively activates the immune system, showed reduced gall scores. As dnd1 showed control of the pathogen, exogenous SA was applied to Arabidopsis in order to test whether it could suppress clubroot. In wt, sid2 (SA biosynthesis), NahG (SA-deficient) and npr1 (SA signalling-impaired) mutants, SA treatment did not alter the gall score, but positively affected the shoot weight. This suggests that SA alone is not sufficient for Arabidopsis resistance against P. brassicae. Semi-quantitative PCR revealed that wt, cpr1, dnd1 and sid2 showed elevated PR-1 expression on P. brassicae and SA + P. brassicae inoculation at 2 and 3 weeks post-inoculation (wpi), whereas NahG and npr1 showed no expression. This work contributes to the understanding of SA involvement in the Arabidopsis-P. brassicae interaction. PMID:26719902

  5. Molecular cloning of otoconin-22 complementary deoxyribonucleic acid in the bullfrog endolymphatic sac: effect of calcitonin on otoconin-22 messenger ribonucleic acid levels.

    PubMed

    Yaoi, Yuichi; Suzuki, Masakazu; Tomura, Hideaki; Sasayama, Yuichi; Kikuyama, Sakae; Tanaka, Shigeyasu

    2003-08-01

    Anuran amphibians have a special organ called the endolymphatic sac (ELS), containing many calcium carbonate crystals, which is believed to have a calcium storage function. The major protein of aragonitic otoconia, otoconin-22, which is considered to be involved in the formation of calcium carbonate crystals, has been purified from the saccule of the Xenopus inner ear. In this study, we cloned a cDNA encoding otoconin-22 from the cDNA library constructed for the paravertebral lime sac (PVLS) of the bullfrog, Rana catesbeiana, and sequenced it. The bullfrog otoconin-22 encoded a protein consisting of 147 amino acids, including a signal peptide of 20 amino acids. The protein had cysteine residues identical in a number and position to those conserved among the secretory phospholipase A(2) family. The mRNA of bullfrog otoconin-22 was expressed in the ELS, including the PVLS and inner ear. This study also revealed the presence of calcitonin receptor-like protein in the ELS, with the putative seven-transmembrane domains of the G protein-coupled receptors. The ultimobranchialectomy induced a prominent decrease in the otoconin-22 mRNA levels of the bullfrog PVLS. Supplementation of the ultimobranchialectomized bullfrogs with synthetic salmon calcitonin elicited a significant increase in the mRNA levels of the sac. These findings suggest that calcitonin secreted from the ultimobranchial gland, regulates expression of bullfrog otoconin-22 mRNA via calcitonin receptor-like protein on the ELS, thereby stimulating the formation of calcium carbonate crystals in the lumen of the ELS. PMID:12865304

  6. Activation of α-keto acid-dependent dioxygenases: application of an {FeNO}7/{FeO2}8 methodology for characterizing the initial steps of O2 activation.

    PubMed

    Diebold, Adrienne R; Brown-Marshall, Christina D; Neidig, Michael L; Brownlee, June M; Moran, Graham R; Solomon, Edward I

    2011-11-16

    The α-keto acid-dependent dioxygenases are a major subgroup within the O(2)-activating mononuclear nonheme iron enzymes. For these enzymes, the resting ferrous, the substrate plus cofactor-bound ferrous, and the Fe(IV)═O states of the reaction have been well studied. The initial O(2)-binding and activation steps are experimentally inaccessible and thus are not well understood. In this study, NO is used as an O(2) analogue to probe the effects of α-keto acid binding in 4-hydroxyphenylpyruvate dioxygenase (HPPD). A combination of EPR, UV-vis absorption, magnetic circular dichroism (MCD), and variable-temperature, variable-field (VTVH) MCD spectroscopies in conjunction with computational models is used to explore the HPPD-NO and HPPD-HPP-NO complexes. New spectroscopic features are present in the α-keto acid bound {FeNO}(7) site that reflect the strong donor interaction of the α-keto acid with the Fe. This promotes the transfer of charge from the Fe to NO. The calculations are extended to the O(2) reaction coordinate where the strong donation associated with the bound α-keto acid promotes formation of a new, S = 1 bridged Fe(IV)-peroxy species. These studies provide insight into the effects of a strong donor ligand on O(2) binding and activation by Fe(II) in the α-keto acid-dependent dioxygenases and are likely relevant to other subgroups of the O(2) activating nonheme ferrous enzymes.

  7. Repair of Radiation-Induced Damage in Escherichia coli II. Effect of rec and uvr Mutations on Radiosensitivity, and Repair of X-Ray-Induced Single-Strand Breaks in Deoxyribonucleic Acid1

    PubMed Central

    Kapp, Daniel S.; Smith, Kendric C.

    1970-01-01

    Strains of Escherichia coli K-12 mutant in the genes controlling excision repair (uvr) and genetic recombination (rec) have been studied with reference to their radiosensitivity and their ability to repair X-ray-induced single-strand breaks in deoxyribonucleic acid (DNA). Mutations in the rec genes appreciably increase the radiosensitivity of E. coli K-12, whereas uvr mutations produce little if any increase in radiosensitivity. For a given dose of X-rays, the yield of single-strand breaks has been shown by alkaline sucrose gradient studies to be largely independent of the presence of rec or uvr mutations. The rec+ cells (including those carrying the uvrB5 mutation) could efficiently rejoin X-ray-induced single-strand breaks in DNA, whereas recA56 mutants could not repair these breaks to any great extent. The recB21 and recC22 mutants showed some indication of repair capacity. From these studies, it is concluded that a correlation exists between the inability to repair single-strand breaks and the radiosensitivity of the rec mutants of E. coli K-12. This suggests that unrepaired single-strand breaks may be lethal lesions in E. coli. PMID:4912530

  8. Ascorbic acid-dependent gene expression in Streptococcus pneumoniae and the activator function of the transcriptional regulator UlaR2

    PubMed Central

    Afzal, Muhammad; Shafeeq, Sulman; Kuipers, Oscar P.

    2015-01-01

    In this study, we have explored the impact of ascorbic acid on the transcriptome of Streptococcus pneumoniae D39. The expression of several genes and operons, including the ula operon (which has been previously shown to be involved in ascorbic acid utilization), the AdcR regulon (which has been previously shown to be involved in zinc transport and virulence) and a PTS operon (which we denote here as ula2 operon) were altered in the presence of ascorbic acid. The ula2 operon consists of five genes, including the transcriptional activator ulaR2. Our β-galactosidase assay data and transcriptome comparison of the ulaR2 mutant with the wild-type demonstrated that the transcriptional activator UlaR2 in the presence of ascorbic acid activates the expression of the ula2 operon. We further predict a 16-bp regulatory site (5′-ATATTGTGCTCAAATA-3′) for UlaR2 in the Pula2. Furthermore, we have explored the effect of ascorbic acid on the expression of the AdcR regulon. Our ICP-MS analysis showed that addition of ascorbic acid to the medium causes zinc starvation in the cell which leads to the activation of the AdcR regulon. PMID:25717320

  9. Ascorbic acid-dependent gene expression in Streptococcus pneumoniae and the activator function of the transcriptional regulator UlaR2.

    PubMed

    Afzal, Muhammad; Shafeeq, Sulman; Kuipers, Oscar P

    2015-01-01

    In this study, we have explored the impact of ascorbic acid on the transcriptome of Streptococcus pneumoniae D39. The expression of several genes and operons, including the ula operon (which has been previously shown to be involved in ascorbic acid utilization), the AdcR regulon (which has been previously shown to be involved in zinc transport and virulence) and a PTS operon (which we denote here as ula2 operon) were altered in the presence of ascorbic acid. The ula2 operon consists of five genes, including the transcriptional activator ulaR2. Our β-galactosidase assay data and transcriptome comparison of the ulaR2 mutant with the wild-type demonstrated that the transcriptional activator UlaR2 in the presence of ascorbic acid activates the expression of the ula2 operon. We further predict a 16-bp regulatory site (5'-ATATTGTGCTCAAATA-3') for UlaR2 in the Pula2. Furthermore, we have explored the effect of ascorbic acid on the expression of the AdcR regulon. Our ICP-MS analysis showed that addition of ascorbic acid to the medium causes zinc starvation in the cell which leads to the activation of the AdcR regulon.

  10. Oleic acid-dependent modulation of Nitric oxide associated 1 protein levels regulates nitric oxide-mediated defense signaling in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The conserved cellular metabolites nitric oxide (NO) and oleic acid (18:1) are well-known regulators of disease physiologies in diverse organism. We show that NO production in plants is regulated via 18:1. Reduction in 18:1 levels, via a genetic mutation in the 18:1-synthesizing gene SUPPRESSOR OF S...

  11. Protein synthesis in a cell-free system from an extreme thermophile. Effects of preincubation in the cold on polyuridylic acid-dependent polyphenylalanine synthesis at high temperature.

    PubMed

    Ohno-Iwashita, Y; Oshima, T; Imahori, K

    1976-06-01

    1. It was found that preincubation of the reaction mixture in the cold enhanced polyuridylic acid-directed polyphenylalanine synthesis by a cell-free extract of Thermus thermophilus HB8 at high temperature. 2. The effect of preincubation was most marked at 10-25 degrees in the presence of 20 mM Mg2+. Preincubation at 65 degrees failed to stimulate the incorporation. 3. The presence of phenylalanyl-tRNA, polyuridylic acid, and ribosomes was essential for preincubation in the cold to be effective. 4. A ternary complex of amino acyl-tRNA, polyuridylic acid, and a ribosome formed at low temperature was isolated by CPG-10 column chromatography; the isolated complex initiated polyphenylalanine synthesis effectively at high temperature. 5. The amount of the ternary complex formed depends on the preincubation time and the concentration of Mg2+. Since the amount of the complex correlated positively to the rate of polyphenylalanine synthesis at high temperature, the effectiveness of preincubation in the cold is presumably due to the formation of the ternary complex of phenylalanyl-tRNA, polyuridylic acid, and a ribosome.

  12. Uric acid-dependent inhibition of AMP kinase induces hepatic glucose production in diabetes and starvation: evolutionary implications of the uricase loss in hominids.

    PubMed

    Cicerchi, Christina; Li, Nanxing; Kratzer, James; Garcia, Gabriela; Roncal-Jimenez, Carlos A; Tanabe, Katsuyuki; Hunter, Brandi; Rivard, Christopher J; Sautin, Yuri Y; Gaucher, Eric A; Johnson, Richard J; Lanaspa, Miguel A

    2014-08-01

    Reduced AMP kinase (AMPK) activity has been shown to play a key deleterious role in increased hepatic gluconeogenesis in diabetes, but the mechanism whereby this occurs remains unclear. In this article, we document that another AMP-dependent enzyme, AMP deaminase (AMPD) is activated in the liver of diabetic mice, which parallels with a significant reduction in AMPK activity and a significant increase in intracellular glucose accumulation in human HepG2 cells. AMPD activation is induced by a reduction in intracellular phosphate levels, which is characteristic of insulin resistance and diabetic states. Increased gluconeogenesis is mediated by reduced TORC2 phosphorylation at Ser171 by AMPK in these cells, as well as by the up-regulation of the rate-limiting enzymes PEPCK and G6Pc. The mechanism whereby AMPD controls AMPK activation depends on the production of a specific AMP downstream metabolite through AMPD, uric acid. In this regard, humans have higher uric acid levels than most mammals due to a mutation in uricase, the enzyme involved in uric acid degradation in most mammals, that developed during a period of famine in Europe 1.5 × 10(7) yr ago. Here, working with resurrected ancestral uricases obtained from early hominids, we show that their expression on HepG2 cells is enough to blunt gluconeogenesis in parallel with an up-regulation of AMPK activity. These studies identify a key role AMPD and uric acid in mediating hepatic gluconeogenesis in the diabetic state, via a mechanism involving AMPK down-regulation and overexpression of PEPCK and G6Pc. The uricase mutation in the Miocene likely provided a survival advantage to help maintain glucose levels under conditions of near starvation, but today likely has a role in the pathogenesis of diabetes.

  13. Polypeptide composition of bacterial cyclic diguanylic acid-dependent cellulose synthase and the occurrence of immunologically crossreacting proteins in higher plants

    SciTech Connect

    Mayer, R.; Ross, P.; Weinhouse, H.; Amikam, D.; Volman, G.; Ohana, P.; Benziman, M. ); Calhoon, R.D.; Wong, Hing C.; Emerick, A.W. )

    1991-06-15

    To comprehend the catalytic and regulatory mechanism of the cyclic diguanylic acid (c-di-GMP)-dependent cellulose synthase of Acetobacter xylinum and its relatedness to similar enzymes in other organisms, the structure of this enzyme was analyzed at the polypeptide level. The enzyme, purified 350-fold by enzyme-product entrapment, contains three major peptides (90, 67, and 54 kDa), which, based on direct photoaffinity and immunochemical labeling and amino acid sequence analysis, are constituents of the native cellulose synthase. Labeling of purified synthase with either ({sup 32}P)c-di-GMP or ({alpha}-{sup 32}P)UDP-glucose indicates that activator- and substrate-specific binding sites are most closely associated with the 67- and 54-kDa peptides, respectively, whereas marginal photolabeling is detected in the 90-k-Da peptide. However, antibodies raised against a protein derived from the cellulose synthase structural gene (bcsB) specifically label all three peptides. The authors suggest that the structurally related 67- and 54-kDa peptides are fragments proteolytically derived from the 90-kDa peptide encoded by bcsB. The anti-cellulose synthase antibodies crossreact with a similar set of peptides derived from other cellulose-producing microorganisms and plants such as Agrobacterium tumefaciens, Rhizobium leguminosarum, mung bean, peas, barley, and cotton. The occurrence of such cellulose synthase-like structures in plant species suggests that a common enzymatic mechanism for cellulose biogenesis is employed throughout nature.

  14. Treponema parvum sp. nov., a small, glucoronic or galacturonic acid-dependent oral spirochaete from lesions of human periodontitis and acute necrotizing ulcerative gingivitis.

    PubMed

    Wyss, C; Dewhirst, F E; Gmür, R; Thurnheer, T; Xue, Y; Schüpbach, P; Guggenheim, B; Paster, B J

    2001-05-01

    Small oral spirochaetes with a strict dependence on either glucuronic acid (GluA) or galacturonic acid (GalA) were isolated from European patients with periodontitis and from Chinese patients with either gingivitis or acute necrotizing ulcerative gingivitis (ANUG). Thirteen such isolates were similar phenotypically to Treponema pectinovorum ATCC 33768T and this classification was confirmed by 16S rRNA sequencing. However, four isolates differed from T. pectinovorum by their small cell size, by a prominent beta-glucuronidase activity, by a distinct protein and antigen profile, by an inability to grow on pectin as sole source of carbohydrate and by a markedly enhanced growth rate when supplied with a second carbohydrate (L-arabinose, D-galactose, D-glucose, D-fructose, D-mannitol, D-mannose, pectin, D-ribose or D-xylose) in addition to the essential GluA/GalA. By 16S rRNA sequencing these four isolates clustered in the recently described phylotype 'Smibert-2'. T. pectinovorum (14 strains) and 'Smibert-2' (four isolates with beta-glucuronidase activity) could each be subdivided into two serotypes based on immunoblot reactivity with two mAbs. Representatives of the two groups, including T. pectinovorum ATCC 33768T, showed a 1:2:1-type periplasmic flagellar arrangement. 'Smibert-2' is described as a novel species, Treponema parvum sp. nov., with isolate OMZ 833T (= ATCC 700770T) proposed as the type strain and OMZ 842 (= ATCC 700773) as reference strain for a second serotype.

  15. Hydrogen sulfide generated by L-cysteine desulfhydrase acts upstream of nitric oxide to modulate abscisic acid-dependent stomatal closure.

    PubMed

    Scuffi, Denise; Álvarez, Consolación; Laspina, Natalia; Gotor, Cecilia; Lamattina, Lorenzo; García-Mata, Carlos

    2014-12-01

    Abscisic acid (ABA) is a well-studied regulator of stomatal movement. Hydrogen sulfide (H2S), a small signaling gas molecule involved in key physiological processes in mammals, has been recently reported as a new component of the ABA signaling network in stomatal guard cells. In Arabidopsis (Arabidopsis thaliana), H2S is enzymatically produced in the cytosol through the activity of l-cysteine desulfhydrase (DES1). In this work, we used DES1 knockout Arabidopsis mutant plants (des1) to study the participation of DES1 in the cross talk between H2S and nitric oxide (NO) in the ABA-dependent signaling network in guard cells. The results show that ABA did not close the stomata in isolated epidermal strips of des1 mutants, an effect that was restored by the application of exogenous H2S. Quantitative reverse transcription polymerase chain reaction analysis demonstrated that ABA induces DES1 expression in guard cell-enriched RNA extracts from wild-type Arabidopsis plants. Furthermore, stomata from isolated epidermal strips of Arabidopsis ABA receptor mutant pyrabactin-resistant1 (pyr1)/pyrabactin-like1 (pyl1)/pyl2/pyl4 close in response to exogenous H2S, suggesting that this gasotransmitter is acting downstream, although acting independently of the ABA receptor cannot be ruled out with this data. However, the Arabidopsis clade-A PROTEIN PHOSPHATASE2C mutant abscisic acid-insensitive1 (abi1-1) does not close the stomata when epidermal strips were treated with H2S, suggesting that H2S required a functional ABI1. Further studies to unravel the cross talk between H2S and NO indicate that (1) H2S promotes NO production, (2) DES1 is required for ABA-dependent NO production, and (3) NO is downstream of H2S in ABA-induced stomatal closure. Altogether, data indicate that DES1 is a unique component of ABA signaling in guard cells.

  16. Allantoin, a stress-related purine metabolite, can activate jasmonate signaling in a MYC2-regulated and abscisic acid-dependent manner

    PubMed Central

    Takagi, Hiroshi; Ishiga, Yasuhiro; Watanabe, Shunsuke; Konishi, Tomokazu; Egusa, Mayumi; Akiyoshi, Nobuhiro; Matsuura, Takakazu; Mori, Izumi C.; Hirayama, Takashi; Kaminaka, Hironori; Shimada, Hiroshi; Sakamoto, Atsushi

    2016-01-01

    Allantoin is a metabolic intermediate of purine catabolism that often accumulates in stressed plants. Recently, we used Arabidopsis knockout mutants (aln) of ALLANTOINASE to show that this purine metabolite activates abscisic acid (ABA) production, thereby stimulating stress-related gene expression and enhancing seedling tolerance to abiotic stress. A detailed re-examination of the microarray data of an aln mutant (aln-1) confirmed the increased expression of ABA-related genes and also revealed altered expression of genes involved in jasmonic acid (JA) responses, probably under the control of MYC2, a master switch in the JA signaling pathway. Consistent with the transcriptome profiles, the aln-1 mutant displayed increased JA levels and enhanced responses to mechanical wounding and exogenous JA. Moreover, aln mutants demonstrated modestly increased susceptibility to Pseudomonas syringae and Pectobacterium carotovorum, probably reflecting the antagonistic action of MYC2 on the defense against these bacterial phytopathogens. Exogenously administered allantoin elicited the expression of JA-responsive genes, including MYC2, in wild-type plants, supporting the idea that allantoin might be responsible for the observed JA-related phenotypes of aln mutants. However, mutants deficient in bioactive JA (jar1-1), insensitive to JA (myc2-3), or deficient in ABA (aba2-1 and bglu18) suppressed the effect of exogenous allantoin. The suppression was further confirmed in aln-1 jar1-1 and aln-1 bglu18 double mutants. These results indicate that allantoin can activate the MYC2-regulated JA signaling pathway through ABA production. Overall, this study suggests a possible connection of purine catabolism with stress hormone homeostasis and signaling, and highlights the potential importance of allantoin in these interactions. PMID:26931169

  17. Hydrogen Sulfide Generated by l-Cysteine Desulfhydrase Acts Upstream of Nitric Oxide to Modulate Abscisic Acid-Dependent Stomatal Closure1[C][W

    PubMed Central

    Scuffi, Denise; Álvarez, Consolación; Laspina, Natalia; Gotor, Cecilia; Lamattina, Lorenzo; García-Mata, Carlos

    2014-01-01

    Abscisic acid (ABA) is a well-studied regulator of stomatal movement. Hydrogen sulfide (H2S), a small signaling gas molecule involved in key physiological processes in mammals, has been recently reported as a new component of the ABA signaling network in stomatal guard cells. In Arabidopsis (Arabidopsis thaliana), H2S is enzymatically produced in the cytosol through the activity of l-cysteine desulfhydrase (DES1). In this work, we used DES1 knockout Arabidopsis mutant plants (des1) to study the participation of DES1 in the cross talk between H2S and nitric oxide (NO) in the ABA-dependent signaling network in guard cells. The results show that ABA did not close the stomata in isolated epidermal strips of des1 mutants, an effect that was restored by the application of exogenous H2S. Quantitative reverse transcription polymerase chain reaction analysis demonstrated that ABA induces DES1 expression in guard cell-enriched RNA extracts from wild-type Arabidopsis plants. Furthermore, stomata from isolated epidermal strips of Arabidopsis ABA receptor mutant pyrabactin-resistant1 (pyr1)/pyrabactin-like1 (pyl1)/pyl2/pyl4 close in response to exogenous H2S, suggesting that this gasotransmitter is acting downstream, although acting independently of the ABA receptor cannot be ruled out with this data. However, the Arabidopsis clade-A PROTEIN PHOSPHATASE2C mutant abscisic acid-insensitive1 (abi1-1) does not close the stomata when epidermal strips were treated with H2S, suggesting that H2S required a functional ABI1. Further studies to unravel the cross talk between H2S and NO indicate that (1) H2S promotes NO production, (2) DES1 is required for ABA-dependent NO production, and (3) NO is downstream of H2S in ABA-induced stomatal closure. Altogether, data indicate that DES1 is a unique component of ABA signaling in guard cells. PMID:25266633

  18. Hydrogen sulfide generated by L-cysteine desulfhydrase acts upstream of nitric oxide to modulate abscisic acid-dependent stomatal closure.

    PubMed

    Scuffi, Denise; Álvarez, Consolación; Laspina, Natalia; Gotor, Cecilia; Lamattina, Lorenzo; García-Mata, Carlos

    2014-12-01

    Abscisic acid (ABA) is a well-studied regulator of stomatal movement. Hydrogen sulfide (H2S), a small signaling gas molecule involved in key physiological processes in mammals, has been recently reported as a new component of the ABA signaling network in stomatal guard cells. In Arabidopsis (Arabidopsis thaliana), H2S is enzymatically produced in the cytosol through the activity of l-cysteine desulfhydrase (DES1). In this work, we used DES1 knockout Arabidopsis mutant plants (des1) to study the participation of DES1 in the cross talk between H2S and nitric oxide (NO) in the ABA-dependent signaling network in guard cells. The results show that ABA did not close the stomata in isolated epidermal strips of des1 mutants, an effect that was restored by the application of exogenous H2S. Quantitative reverse transcription polymerase chain reaction analysis demonstrated that ABA induces DES1 expression in guard cell-enriched RNA extracts from wild-type Arabidopsis plants. Furthermore, stomata from isolated epidermal strips of Arabidopsis ABA receptor mutant pyrabactin-resistant1 (pyr1)/pyrabactin-like1 (pyl1)/pyl2/pyl4 close in response to exogenous H2S, suggesting that this gasotransmitter is acting downstream, although acting independently of the ABA receptor cannot be ruled out with this data. However, the Arabidopsis clade-A PROTEIN PHOSPHATASE2C mutant abscisic acid-insensitive1 (abi1-1) does not close the stomata when epidermal strips were treated with H2S, suggesting that H2S required a functional ABI1. Further studies to unravel the cross talk between H2S and NO indicate that (1) H2S promotes NO production, (2) DES1 is required for ABA-dependent NO production, and (3) NO is downstream of H2S in ABA-induced stomatal closure. Altogether, data indicate that DES1 is a unique component of ABA signaling in guard cells. PMID:25266633

  19. Circadian Stress Regimes Affect the Circadian Clock and Cause Jasmonic Acid-Dependent Cell Death in Cytokinin-Deficient Arabidopsis Plants.

    PubMed

    Nitschke, Silvia; Cortleven, Anne; Iven, Tim; Feussner, Ivo; Havaux, Michel; Riefler, Michael; Schmülling, Thomas

    2016-07-01

    The circadian clock helps plants measure daylength and adapt to changes in the day-night rhythm. We found that changes in the light-dark regime triggered stress responses, eventually leading to cell death, in leaves of Arabidopsis thaliana plants with reduced cytokinin levels or defective cytokinin signaling. Prolonged light treatment followed by a dark period induced stress and cell death marker genes while reducing photosynthetic efficiency. This response, called circadian stress, is also characterized by altered expression of clock and clock output genes. In particular, this treatment strongly reduced the expression of CIRCADIAN CLOCK ASSOCIATED1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY). Intriguingly, similar changes in gene expression and cell death were observed in clock mutants lacking proper CCA1 and LHY function. Circadian stress caused strong changes in reactive oxygen species- and jasmonic acid (JA)-related gene expression. The activation of the JA pathway, involving the accumulation of JA metabolites, was crucial for the induction of cell death, since the cell death phenotype was strongly reduced in the jasmonate resistant1 mutant background. We propose that adaptation to circadian stress regimes requires a normal cytokinin status which, acting primarily through the AHK3 receptor, supports circadian clock function to guard against the detrimental effects of circadian stress.

  20. The pepper E3 ubiquitin ligase RING1 gene, CaRING1, is required for cell death and the salicylic acid-dependent defense response.

    PubMed

    Lee, Dong Hyuk; Choi, Hyong Woo; Hwang, Byung Kook

    2011-08-01

    Ubiquitination is essential for ubiquitin/proteasome-mediated protein degradation in plant development and defense. Here, we identified a novel E3 ubiquitin ligase RING1 gene, CaRING1, from pepper (Capsicum annuum). In pepper, CaRING1 expression is induced by avirulent Xanthomonas campestris pv vesicatoria infection. CaRING1 contains an amino-terminal transmembrane domain and a carboxyl-terminal RING domain. In addition, it displays in vitro E3 ubiquitin ligase activity, and the RING domain is essential for E3 ubiquitin ligase activity in CaRING1. CaRING1 also localizes to the plasma membrane. In pepper plants, virus-induced gene silencing of CaRING1 confers enhanced susceptibility to avirulent X. campestris pv vesicatoria infection, which is accompanied by compromised hypersensitive cell death, reduced expression of PATHOGENESIS-RELATED1, and lowered salicylic acid levels in leaves. Transient expression of CaRING1 in pepper leaves induces cell death and the defense response that requires the E3 ubiquitin ligase activity of CaRING1. By contrast, overexpression of CaRING1 in Arabidopsis (Arabidopsis thaliana) confers enhanced resistance to hemibiotrophic Pseudomonas syringae pv tomato and biotrophic Hyaloperonospora arabidopsidis infections. Taken together, these results suggest that CaRING1 is involved in the induction of cell death and the regulation of ubiquitination during the defense response to microbial pathogens.

  1. Circadian Stress Regimes Affect the Circadian Clock and Cause Jasmonic Acid-Dependent Cell Death in Cytokinin-Deficient Arabidopsis Plants.

    PubMed

    Nitschke, Silvia; Cortleven, Anne; Iven, Tim; Feussner, Ivo; Havaux, Michel; Riefler, Michael; Schmülling, Thomas

    2016-07-01

    The circadian clock helps plants measure daylength and adapt to changes in the day-night rhythm. We found that changes in the light-dark regime triggered stress responses, eventually leading to cell death, in leaves of Arabidopsis thaliana plants with reduced cytokinin levels or defective cytokinin signaling. Prolonged light treatment followed by a dark period induced stress and cell death marker genes while reducing photosynthetic efficiency. This response, called circadian stress, is also characterized by altered expression of clock and clock output genes. In particular, this treatment strongly reduced the expression of CIRCADIAN CLOCK ASSOCIATED1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY). Intriguingly, similar changes in gene expression and cell death were observed in clock mutants lacking proper CCA1 and LHY function. Circadian stress caused strong changes in reactive oxygen species- and jasmonic acid (JA)-related gene expression. The activation of the JA pathway, involving the accumulation of JA metabolites, was crucial for the induction of cell death, since the cell death phenotype was strongly reduced in the jasmonate resistant1 mutant background. We propose that adaptation to circadian stress regimes requires a normal cytokinin status which, acting primarily through the AHK3 receptor, supports circadian clock function to guard against the detrimental effects of circadian stress. PMID:27354555

  2. Nuclear receptor corepressors Ncor1 and Ncor2 (Smrt) are required for retinoic acid-dependent repression of Fgf8 during somitogenesis.

    PubMed

    Kumar, Sandeep; Cunningham, Thomas J; Duester, Gregg

    2016-10-01

    Retinoic acid (RA) repression of Fgf8 is required for many different aspects of organogenesis, however relatively little is known about how endogenous RA controls gene repression as opposed to gene activation. Here, we show that nuclear receptor corepressors NCOR1 and NCOR2 (SMRT) redundantly mediate the ability of RA to repress Fgf8. Ncor1;Ncor2 double mutants generated by CRISPR/Cas9 gene editing exhibited a small somite and distended heart phenotype similar to that of RA-deficient Raldh2-/- embryos, associated with increased Fgf8 expression and FGF signaling in caudal progenitors and heart progenitors. Embryo chromatin immunoprecipitation studies revealed that NCOR1/2 but not coactivators are recruited to the Fgf8 RA response element (RARE) in an RA-dependent manner, whereas coactivators but not NCOR1/2 are recruited RA-dependently to a RARE near Rarb that is activated by RA. CRISPR/Cas9-mediated genomic deletion of the Fgf8 RARE in mouse embryos often resulted in a small somite defect with Fgf8 derepression caudally, but no defect was observed in heart development or heart Fgf8 expression. This suggests the existence of another DNA element whose function overlaps with the Fgf8 RARE to mediate Fgf8 repression by RA and NCOR1/2. Our studies support a model in which NCOR1/2 mediates direct RA-dependent repression of Fgf8 in caudal progenitors in order to control somitogenesis.

  3. Circadian Stress Regimes Affect the Circadian Clock and Cause Jasmonic Acid-Dependent Cell Death in Cytokinin-Deficient Arabidopsis Plants[OPEN

    PubMed Central

    Nitschke, Silvia; Cortleven, Anne; Iven, Tim; Havaux, Michel; Schmülling, Thomas

    2016-01-01

    The circadian clock helps plants measure daylength and adapt to changes in the day-night rhythm. We found that changes in the light-dark regime triggered stress responses, eventually leading to cell death, in leaves of Arabidopsis thaliana plants with reduced cytokinin levels or defective cytokinin signaling. Prolonged light treatment followed by a dark period induced stress and cell death marker genes while reducing photosynthetic efficiency. This response, called circadian stress, is also characterized by altered expression of clock and clock output genes. In particular, this treatment strongly reduced the expression of CIRCADIAN CLOCK ASSOCIATED1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY). Intriguingly, similar changes in gene expression and cell death were observed in clock mutants lacking proper CCA1 and LHY function. Circadian stress caused strong changes in reactive oxygen species- and jasmonic acid (JA)-related gene expression. The activation of the JA pathway, involving the accumulation of JA metabolites, was crucial for the induction of cell death, since the cell death phenotype was strongly reduced in the jasmonate resistant1 mutant background. We propose that adaptation to circadian stress regimes requires a normal cytokinin status which, acting primarily through the AHK3 receptor, supports circadian clock function to guard against the detrimental effects of circadian stress. PMID:27354555

  4. Functional Proteomics Identifies Acinus L as a Direct Insulin- and Amino Acid-Dependent Mammalian Target of Rapamycin Complex 1 (mTORC1) Substrate*

    PubMed Central

    Schwarz, Jennifer Jasmin; Wiese, Heike; Tölle, Regine Charlotte; Zarei, Mostafa; Dengjel, Jörn; Warscheid, Bettina; Thedieck, Kathrin

    2015-01-01

    The serine/threonine kinase mammalian target of rapamycin (mTOR) governs growth, metabolism, and aging in response to insulin and amino acids (aa), and is often activated in metabolic disorders and cancer. Much is known about the regulatory signaling network that encompasses mTOR, but surprisingly few direct mTOR substrates have been established to date. To tackle this gap in our knowledge, we took advantage of a combined quantitative phosphoproteomic and interactomic strategy. We analyzed the insulin- and aa-responsive phosphoproteome upon inhibition of the mTOR complex 1 (mTORC1) component raptor, and investigated in parallel the interactome of endogenous mTOR. By overlaying these two datasets, we identified acinus L as a potential novel mTORC1 target. We confirmed acinus L as a direct mTORC1 substrate by co-immunoprecipitation and MS-enhanced kinase assays. Our study delineates a triple proteomics strategy of combined phosphoproteomics, interactomics, and MS-enhanced kinase assays for the de novo-identification of mTOR network components, and provides a rich source of potential novel mTOR interactors and targets for future investigation. PMID:25907765

  5. Cigarette smoking complements the prognostic value of baseline plasma Epstein-Barr virus deoxyribonucleic acid in patients with nasopharyngeal carcinoma undergoing intensity-modulated radiation therapy: a large-scale retrospective cohort study.

    PubMed

    Lv, Jia-Wei; Chen, Yu-Pei; Zhou, Guan-Qun; Tang, Ling-Long; Mao, Yan-Ping; Li, Wen-Fei; Guo, Rui; Lin, Ai-Hua; Ma, Jun; Sun, Ying

    2016-03-29

    We evaluated the combined prognostic value of cigarette smoking and baseline plasma Epstein-Barr virus deoxyribonucleic acid (EBV DNA) in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). Of consecutive patients, 1501 with complete data were eligible for retrospective analysis. Smoking index (SI; cigarette packs per day times smoking duration [years]), was used to evaluate the cumulative effect of smoking. Primary end-point was overall survival (OS); progression-free survival (PFS), distant metastasis-free survival (DMFS) and locoregional relapse-free survival (LRFS) were secondary end-points. Both cigarette smoking and baseline plasma EBV DNA load were associated with poorer survival (P <0.001). Patients were divided into four groups: low EBV DNA and light smoker (LL), low EBV DNA and heavy smoker (LH), high EBV DNA and light smoker (HL), and high EBV DNA and heavy smoker (HH). The respective 5-year survival rates were: OS (93.1%, 87.2%, 82.9%, and 76.3%, P<0.001), PFS (87.0%, 84.0%, 73.9%, and 64.6%, P<0.001), DMFS (94.1%, 92.1%, 82.4%, and72.5%, P<0.001), and LRFS (92.8%, 92.4%, 88.7%, and 84.0%, P=0.012).OS and PFS were significantly different between the LH and HL groups and HL and HH groups, but not LL and LH groups (pairwise comparisons). The combined risk stratification remained an independent prognostic factor for all endpoints (all Ptrend<0.001; multivariate analysis). Both cigarette smoking and baseline plasma EBV DNA were independent prognostic factors for survival outcomes. Combined interpretation of EBV DNA with smoking led to the refinement of the risks stratification for patient subsets, especially with improved risk discrimination in patients with high baseline plasma EBV DNA. PMID:26919237

  6. Bilateral lesions of suprachiasmatic nuclei affect circadian rhythms in (/sup 3/H)-thymidine incorporation into deoxyribonucleic acid in mouse intestinal tract, mitotic index of corneal epithelium, and serum corticosterone

    SciTech Connect

    Scheving, L.E.; Tsai, T.H.; Powell, E.W.; Pasley, J.N.; Halberg, F.; Dunn, J.

    1983-03-01

    Investigations into the role of the suprachiasmatic nuclei (SCN) in the coordination of circadian rhythms have presented differing results. Several reports have shown that ablation of the suprachiasmatic nuclei (SCNA) alters the phase and amplitude of rhythms but does not abolish them. The present study investigates the effect of SCNA on the rhythms in cell proliferation in various regions of the intestinal tract as measured by the incorporation of (/sup 3/H)-thymidine into deoxyribonucleic acid, in the mitotic activity of the corneal epithelium, and in serum corticosterone levels. The study involved mice with verified lesions of the SCN (six to 13 mice per time point) and control groups of both sham-operated and unoperated mice (seven of each per time point). The mice were killed in groups that represented seven time points over a single 24 hr span (3 hr intervals with the 0800 hr sampled both at start and end of the series). The tissues examined were the tongue, esophagus, gastric stomach, and colon for DNA synthesis, the corneal epithelium for mitotic index, and blood serum for corticosterone level. The most consistent result of SCNA was a phase advance in the rhythms in cell proliferation in the tongue, esophagus, gastric stomach, colon, and corneal epithelium. A reduction in rhythm amplitude occurred in the tongue, esophagus, and corneal epithelium; however, there was an amplitude increase for the stomach, colon, and serum corticosterone. The mesor (rhythm-adjusted mean) was increased by SCNA in all tissues except the corneal epithelium. These findings further support the role of the suprachiasmatic nuclear area in the control of rhythms in cell proliferation and corticosterone production, by acting as a ''phase-resetter'' and as a modulator of rhythm amplitude.

  7. Structural insight into the arginine-binding specificity of CASTOR1 in amino acid-dependent mTORC1 signaling.

    PubMed

    Xia, Jing; Wang, Rong; Zhang, Tianlong; Ding, Jianping

    2016-01-01

    The mechanistic Target Of Rapamycin Complex 1 (mTORC1) is central to the cellular response to changes in nutrient signals such as amino acids. CASTOR1 is shown to be an arginine sensor, which plays an important role in the activation of the mTORC1 pathway. In the deficiency of arginine, CASTOR1 interacts with GATOR2, which together with GATOR1 and Rag GTPases controls the relocalization of mTORC1 to lysosomes. The binding of arginine to CASTOR1 disrupts its association with GATOR2 and hence activates the mTORC1 signaling. Here, we report the crystal structure of CASTOR1 in complex with arginine at 2.5 Å resolution. CASTOR1 comprises of four tandem ACT domains with an architecture resembling the C-terminal allosteric domains of aspartate kinases. ACT1 and ACT3 adopt the typical βαββαβ topology and function in dimerization via the conserved residues from helices α1 of ACT1 and α5 of ACT3; whereas ACT 2 and ACT4, both comprising of two non-sequential regions, assume the unusual ββαββα topology and contribute an arginine-binding pocket at the interface. The bound arginine makes a number of hydrogen-bonding interactions and extensive hydrophobic contacts with the surrounding residues of the binding pocket. The functional roles of the key residues are validated by mutagenesis and biochemical assays. Our structural and functional data together reveal the molecular basis for the arginine-binding specificity of CASTOR1 in the arginine-dependent activation of the mTORC1 signaling. PMID:27648300

  8. Tamoxifen and raloxifene modulate gap junction coupling during early phases of retinoic acid-dependent neuronal differentiation of NTera2/D1 cells

    PubMed Central

    Dahm, Liane; Klugmann, Fanny; Gonzalez-Algaba, Angeles

    2010-01-01

    Gap junctions (GJ) represent a cellular communication system known to influence neuronal differentiation and survival. To assess a putative role of this system for neural effects of tamoxifen (TAM) and raloxifene (RAL), we used the human teratocarcinoma cell line NTera2/D1, retinoic acid (RA)-dependent neuronal differentiation of which is regulated by gap junctions formed of connexin43 (Cx43). As demonstrated by Western blot analysis, concentrations above 1 µmol/l for TAM, and 0.1 µmol/l for RAL lead to a temporary time- and concentration-dependent increase in Cx43 immunoreactivity, which reached a peak for TAM after 1 day and for RAL after 2 days. Immunocytochemical stainings revealed the increase in Cx43 immunoreactivity to result from an accumulation in intracellular compartments such as the Golgi apparatus or lysosomes. In addition, TAM and RAL were able to prevent the RA-dependent decrease of Cx43 immunoreactivity in NTera2/D1 cells, normally observed during neuronal differentiation. This suggested a suppression of neuronal differentiation to result from these substances. According to this, treatment of NTera2/D1 cells with 10 µmol/l TAM or RAL during weeks 1 and 2 of a 6 weeks RA-driven differentiation schedule impaired, whereas treatment during weeks 5 and 6 did not impair, neuronal differentiation of these cells. Modulation of GJ coupling between NTera2/D1 cells by TAM and RAL seems therefore to perturb early neuronal differentiation, whereas differentiated neurons in the mature brain seem to be not affected. These effects could be of importance for actions of TAM and RAL on early embryonic steps of nervous system formation. PMID:20437090

  9. Structural insight into the arginine-binding specificity of CASTOR1 in amino acid-dependent mTORC1 signaling

    PubMed Central

    Xia, Jing; Wang, Rong; Zhang, Tianlong; Ding, Jianping

    2016-01-01

    The mechanistic Target Of Rapamycin Complex 1 (mTORC1) is central to the cellular response to changes in nutrient signals such as amino acids. CASTOR1 is shown to be an arginine sensor, which plays an important role in the activation of the mTORC1 pathway. In the deficiency of arginine, CASTOR1 interacts with GATOR2, which together with GATOR1 and Rag GTPases controls the relocalization of mTORC1 to lysosomes. The binding of arginine to CASTOR1 disrupts its association with GATOR2 and hence activates the mTORC1 signaling. Here, we report the crystal structure of CASTOR1 in complex with arginine at 2.5 Å resolution. CASTOR1 comprises of four tandem ACT domains with an architecture resembling the C-terminal allosteric domains of aspartate kinases. ACT1 and ACT3 adopt the typical βαββαβ topology and function in dimerization via the conserved residues from helices α1 of ACT1 and α5 of ACT3; whereas ACT 2 and ACT4, both comprising of two non-sequential regions, assume the unusual ββαββα topology and contribute an arginine-binding pocket at the interface. The bound arginine makes a number of hydrogen-bonding interactions and extensive hydrophobic contacts with the surrounding residues of the binding pocket. The functional roles of the key residues are validated by mutagenesis and biochemical assays. Our structural and functional data together reveal the molecular basis for the arginine-binding specificity of CASTOR1 in the arginine-dependent activation of the mTORC1 signaling.

  10. Structural insight into the arginine-binding specificity of CASTOR1 in amino acid-dependent mTORC1 signaling

    PubMed Central

    Xia, Jing; Wang, Rong; Zhang, Tianlong; Ding, Jianping

    2016-01-01

    The mechanistic Target Of Rapamycin Complex 1 (mTORC1) is central to the cellular response to changes in nutrient signals such as amino acids. CASTOR1 is shown to be an arginine sensor, which plays an important role in the activation of the mTORC1 pathway. In the deficiency of arginine, CASTOR1 interacts with GATOR2, which together with GATOR1 and Rag GTPases controls the relocalization of mTORC1 to lysosomes. The binding of arginine to CASTOR1 disrupts its association with GATOR2 and hence activates the mTORC1 signaling. Here, we report the crystal structure of CASTOR1 in complex with arginine at 2.5 Å resolution. CASTOR1 comprises of four tandem ACT domains with an architecture resembling the C-terminal allosteric domains of aspartate kinases. ACT1 and ACT3 adopt the typical βαββαβ topology and function in dimerization via the conserved residues from helices α1 of ACT1 and α5 of ACT3; whereas ACT 2 and ACT4, both comprising of two non-sequential regions, assume the unusual ββαββα topology and contribute an arginine-binding pocket at the interface. The bound arginine makes a number of hydrogen-bonding interactions and extensive hydrophobic contacts with the surrounding residues of the binding pocket. The functional roles of the key residues are validated by mutagenesis and biochemical assays. Our structural and functional data together reveal the molecular basis for the arginine-binding specificity of CASTOR1 in the arginine-dependent activation of the mTORC1 signaling. PMID:27648300

  11. AtPP2CG1, a protein phosphatase 2C, positively regulates salt tolerance of Arabidopsis in abscisic acid-dependent manner

    SciTech Connect

    Liu, Xin; Zhu, Yanming; Zhai, Hong; Cai, Hua; Ji, Wei; Luo, Xiao; Li, Jing; Bai, Xi

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer AtPP2CG1 positively regulates salt tolerance in ABA-dependent manner. Black-Right-Pointing-Pointer AtPP2CG1 up-regulates the expression of marker genes in different pathways. Black-Right-Pointing-Pointer AtPP2CG1 expresses in the vascular system and trichomes of Arabidopsis. -- Abstract: AtPP2CG1 (Arabidopsis thaliana protein phosphatase 2C G Group 1) was predicted as an abiotic stress candidate gene by bioinformatic analysis in our previous study. The gene encodes a putative protein phosphatase 2C that belongs to Group G of PP2C. There is no report of Group G genes involved in abiotic stress so far. Real-time RT-PCR analysis showed that AtPP2CG1 expression was induced by salt, drought, and abscisic acid (ABA) treatment. The expression levels of AtPP2CG1 in the ABA synthesis-deficient mutant abi2-3 were much lower than that in WT plants under salt stress suggesting that the expression of AtPP2CG1 acts in an ABA-dependent manner. Over-expression of AtPP2CG1 led to enhanced salt tolerance, whereas its loss of function caused decreased salt tolerance. These results indicate that AtPP2CG1 positively regulates salt stress in an ABA-dependent manner. Under salt treatment, AtPP2CG1 up-regulated the expression levels of stress-responsive genes, including RD29A, RD29B, DREB2A and KIN1. GUS activity was detected in roots, leaves, stems, flower, and trichomes of AtPP2CG1 promoter-GUS transgenic plants. AtPP2CG1 protein was localized in nucleus and cytoplasm via AtPP2CG1:eGFP and YFP:AtPP2CG1 fusion approaches.

  12. Helix-forming tendencies of amino acids depend on the restrictions of side-chain rotamer conformations: crystal structure of the tripeptide GAI in two crystalline forms.

    PubMed

    Go, K; Chaturvedi, S; Parthasarathy, R

    1992-02-01

    In our attempts to design crystalline alpha-helical peptides, we synthesized and crystallized GAI (C11H21N3O4) in two crystal forms, GAI1 and GAI2. Form 1 (GAI1) Gly-L-Ala-L-Ile (C11H21N3O4.3H2O) crystals are monoclinic, space group P2(1) with a = 8.171(2), b = 6.072(4), c = 16.443(4) A, beta = 101.24(2) degrees, V = 800 A3, Dc = 1.300 g cm-3 and Z = 2, R = 0.081 for 482 reflections. Form 2 (GAI2) Gly-L-Ala-L-Ile (C11H21N3O4.1/2H2O) is triclinic, space group P1 with a = 5.830(1), b = 8.832(2), c = 15.008(2) A, alpha = 102.88(1), beta = 101.16(2), gamma = 70.72(2) degrees, V = 705 A3, Z = 2, Dc = 1.264 g cm-3, R = 0.04 for 2582 reflections. GAI1 is isomorphous with GAV and forms a helix, whereas GAI2 does not. In GAI1, the tripeptide molecule is held in a near helical conformation by a water molecule that bridges the NH3+ and COO- groups, and acts as the fourth residue needed to complete the turn by forming two hydrogen bonds. Two other water molecules form intermolecular hydrogen bonds in stabilizing the helical structure so that the end result is a column of molecules that looks like an incipient alpha-helix. GAI2 imitates a cyclic peptide and traps a water molecule. The conformation angles chi 11 and chi 12 for the side chain are (-63.7 degrees, 171.1 degrees) for the helical GAI1, and (-65.1 degrees, 58.6 degrees) and (-65.0 degrees, 58.9 degrees) for the two independent nonhelical molecules in GAI2; in GAI1, both the C gamma atoms point away from the helix, whereas in GAI2 the C gamma atom with the g+ conformation points inward to the helix and causes sterical interaction with atoms in the adjacent peptide plane. From these results, it is clear that the helix-forming tendencies of amino acids correlate with the restrictions of side-chain rotamer conformations. Both the peptide units in GAI1 are trans and show significant deviation from planarity [omega 1 = -168(1) degrees; omega 2 = -171(1) degrees] whereas both the peptide units in both the molecules A and B

  13. Deoxyribonucleic acid directed metallization of platinum nanoparticles on graphite nanofibers as a durable oxygen reduction catalyst for polymer electrolyte fuel cells

    NASA Astrophysics Data System (ADS)

    Peera, S. Gouse; Sahu, A. K.; Arunchander, A.; Nath, Krishna; Bhat, S. D.

    2015-11-01

    Effective surface functionalization to the hydrophobic graphite nanofibers (GNF) is performed with the biomolecule, namely deoxy-ribo-nucleic-acid (DNA) via π-π interactions. Pt nanoparticles are impregnated on GNF-DNA composite by ethylene glycol reduction method (Pt/GNF-DNA) and its effect on electro catalytic activity for oxygen reduction reaction (ORR) is systemically studied. Excellent dispersion of Pt nanoparticles over GNF-DNA surfaces with no evidence on particle aggregation is a remarkable achievement in this study. This result in higher electro chemical surface area of the catalyst, enhanced ORR behavior with significant enhancement in mass activity. The catalyst is validated in H2-O2 polymer electrolyte fuel cell (PEFC) and a peak power density of 675 mW cm-2 is achieved at a load current density of 1320 mA cm-2 with a minimal catalyst loading of 0.1 mg cm-2 at a cell temperature of 70 °C and 2 bar absolute pressure. Repeated potential cycling up to 10000 cycles in acidic media is also performed for this catalyst and found excellent stability with only 60 mV drop in the ORR half wave potential. The superior behavior of Pt/GNF-DNA catalyst is credited to the robust fibrous structure of GNF and its effective surface functionalization process via π-π interaction.

  14. p53-Dependent and p53-independent induction of insulin-like growth factor binding protein-3 by deoxyribonucleic acid damage and hypoxia.

    PubMed

    Grimberg, Adda; Coleman, Carrie M; Burns, Timothy F; Himelstein, Bruce P; Koch, Cameron J; Cohen, Pinchas; El-Deiry, Wafik S

    2005-06-01

    IGF binding protein (IGFBP)-3, the principal carrier of IGFs in the circulation, contributes to both endocrine and autocrine/paracrine growth control; it can be induced by GH, cytokines, retinoic acid, and tumor suppressors. Induction of IGFBP-3 by the tumor suppressor p53 has been shown in various models that directly manipulate p53 activity. However, the physiologic settings under which this induction occurs have not been established. DNA damage and hypoxia are two important physiologic activators of p53. We have demonstrated for the first time that IGFBP-3 is an in vivo target of p53 in response to ionizing radiation. This effect was tissue specific. Furthermore, we demonstrated that genotoxic drugs could increase IGFBP-3 protein levels and secretion in tumor cell lines in a p53-independent manner. Finally, we have established that IGFBP-3 induction under hypoxic conditions is independent of p53 in tumor cell lines derived form multiple tissue types. Thus, IGFBP-3 is induced by physiologic conditions that also induce p53, although p53 is not always required. Because IGFBP-3 can inhibit growth and induce apoptosis in IGF-dependent and IGF-independent manners, its induction by DNA damage and hypoxia suggest IGFBP-3 plays a role in the physiologic protection against aberrant cell growth.

  15. Functional models of α-keto acid dependent nonheme iron oxygenases: synthesis and reactivity of biomimetic iron(II) benzoylformate complexes supported by a 2,9-dimethyl-1,10-phenanthroline ligand.

    PubMed

    Das, Oindrila; Chatterjee, Sayanti; Paine, Tapan Kanti

    2013-03-01

    Two biomimetic iron(II) benzoylformate complexes, [LFe(II)(BF)(2)] (2) and [LFe(II)(NO(3))(BF)] (3) (L is 2,9-dimethyl-1,10-phenanthroline and BF is monoanionic benzoylformate), have been synthesized from an iron(II)-dichloro complex [LFe(II)Cl(2)] (1). All the iron(II) complexes have been structurally and spectroscopically characterized. The iron(II) center in 2 is coordinated by a bidentate NN ligand (2,9-dimethyl-1,10-phenanthroline) and two monoanionic benzoylformates to form a distorted octahedral coordination geometry. One of the benzoylformates binds to the iron in 2 via both carboxylate oxygens but the other one binds in a chelating bidentate fashion via one carboxylate oxygen and the keto oxygen. On the other hand, the iron(II) center in 3 is ligated by one NN ligand, one bidentate nitrate, and one monoanionic chelating benzoylformate. Both iron(II) benzoylformate complexes exhibit the facial NNO donor environment in their solid-state structures. Complexes 2 and 3 are stable in noncoordinating solvents under an inert atmosphere, but react with dioxygen under ambient conditions to undergo oxidative decarboxylation of benzoylformate to benzoate in high yields. Evidence for the formation of an iron(IV)-oxo intermediate upon oxidative decarboxylation of benzoylformate was obtained by interception and labeling experiments. The iron(II) benzoylformate complexes represent the functional models of α-keto acid dependent oxygenases.

  16. The antagonistic strain Bacillus subtilis UMAF6639 also confers protection to melon plants against cucurbit powdery mildew by activation of jasmonate-and salicylic acid-dependent defence responses

    PubMed Central

    García-Gutiérrez, Laura; Zeriouh, Houda; Romero, Diego; Cubero, Jaime; Vicente, Antonio; Pérez-García, Alejandro

    2013-01-01

    Biological control of plant diseases has gained acceptance in recent years. Bacillus subtilis UMAF6639 is an antagonistic strain specifically selected for the efficient control of the cucurbit powdery mildew fungus Podosphaera fusca, which is a major threat to cucurbits worldwide. The antagonistic activity relies on the production of the antifungal compounds iturin and fengycin. In a previous study, we found that UMAF6639 was able to induce systemic resistance (ISR) in melon and provide additional protection against powdery mildew. In the present work, we further investigated in detail this second mechanism of biocontrol by UMAF6639. First, we examined the signalling pathways elicited by UMAF6639 in melon plants, as well as the defence mechanisms activated in response to P. fusca. Second, we analysed the role of the lipopeptides produced by UMAF6639 as potential determinants for ISR activation. Our results demonstrated that UMAF6639 confers protection against cucurbit powdery mildew by activation of jasmonate- and salicylic acid-dependent defence responses, which include the production of reactive oxygen species and cell wall reinforcement. We also showed that surfactin lipopeptide is a major determinant for stimulation of the immune response. These results reinforce the biotechnological potential of UMAF6639 as a biological control agent. PMID:23302493

  17. The antagonistic strain Bacillus subtilis UMAF6639 also confers protection to melon plants against cucurbit powdery mildew by activation of jasmonate- and salicylic acid-dependent defence responses.

    PubMed

    García-Gutiérrez, Laura; Zeriouh, Houda; Romero, Diego; Cubero, Jaime; de Vicente, Antonio; Pérez-García, Alejandro

    2013-05-01

    Biological control of plant diseases has gained acceptance in recent years. Bacillus subtilis UMAF6639 is an antagonistic strain specifically selected for the efficient control of the cucurbit powdery mildew fungus Podosphaera fusca, which is a major threat to cucurbits worldwide. The antagonistic activity relies on the production of the antifungal compounds iturin and fengycin. In a previous study, we found that UMAF6639 was able to induce systemic resistance (ISR) in melon and provide additional protection against powdery mildew. In the present work, we further investigated in detail this second mechanism of biocontrol by UMAF6639. First, we examined the signalling pathways elicited by UMAF6639 in melon plants, as well as the defence mechanisms activated in response to P. fusca. Second, we analysed the role of the lipopeptides produced by UMAF6639 as potential determinants for ISR activation. Our results demonstrated that UMAF6639 confers protection against cucurbit powdery mildew by activation of jasmonate- and salicylic acid-dependent defence responses, which include the production of reactive oxygen species and cell wall reinforcement. We also showed that surfactin lipopeptide is a major determinant for stimulation of the immune response. These results reinforce the biotechnological potential of UMAF6639 as a biological control agent.

  18. Deoxyribonucleic acid base compositions of dermatophytes.

    PubMed

    Davison, F D; Mackenzie, D W; Owen, R J

    1980-06-01

    DNA was extracted and purified from 55 dermatophyte isolates representing 34 species of Trichophyton, Microsporum and Epidermophyton. The base compositions of the chromosomal DNA were determined by CsCl density gradient centrifugation and were found to be in the narrow range of 48.7 to 50.3 mol % G + C. A satellite DNA component assumed to be of mitochondrial origin was present in most strains, with a G + C content ranging from 14.7 to 30.8 mol % G + C. Heterogeneity in microscopic and colonial characteristics was not reflected in differences in the mean G + C content of the chromosomal DNAs. Strains varied in the G + C contents of satelite DNA, but these did not correlate with traditional species concepts.

  19. Nucleotide `maps' of digests of deoxyribonucleic acid

    PubMed Central

    Murray, K.

    1970-01-01

    Various digests of 32P-labelled DNA were examined by two-dimensional ionophoresis on cellulose acetate and DEAE-cellulose paper. The products from digestion with pancreatic deoxyribonuclease and Neurospora crassa endonuclease were qualitatively closely similar, but very complex, and were used to investigate the mapping behaviour of nucleotides in various ionophoretic systems. Ionophoresis on DEAE-cellulose paper in triethylamine carbonate, pH 9.7, followed by ionophoresis in the second dimension at pH1.9 gave high resolution of nucleotides in very complex mixtures and permitted the fractionation of larger quantities than is possible on cellulose acetate. High resolution of nucleotides in compact spots was obtained with two-dimensional ionophoresis on cellulose acetate and AE-cellulose paper, a system that is a useful supplement to those based on DEAE-cellulose paper. ImagesPLATE 7PLATE 1PLATE 2PLATE 3PLATE 4PLATE 5PLATE 6 PMID:5476726

  20. The Basic Leucine Zipper Transcription Factor ABSCISIC ACID RESPONSE ELEMENT-BINDING FACTOR2 Is an Important Transcriptional Regulator of Abscisic Acid-Dependent Grape Berry Ripening Processes1[W][OPEN

    PubMed Central

    Nicolas, Philippe; Lecourieux, David; Kappel, Christian; Cluzet, Stéphanie; Cramer, Grant; Delrot, Serge; Lecourieux, Fatma

    2014-01-01

    In grape (Vitis vinifera), abscisic acid (ABA) accumulates during fruit ripening and is thought to play a pivotal role in this process, but the molecular basis of this control is poorly understood. This work characterizes ABSCISIC ACID RESPONSE ELEMENT-BINDING FACTOR2 (VvABF2), a grape basic leucine zipper transcription factor belonging to a phylogenetic subgroup previously shown to be involved in ABA and abiotic stress signaling in other plant species. VvABF2 transcripts mainly accumulated in the berry, from the onset of ripening to the harvesting stage, and were up-regulated by ABA. Microarray analysis of transgenic grape cells overexpressing VvABF2 showed that this transcription factor up-regulates and/or modifies existing networks related to ABA responses. In addition, grape cells overexpressing VvABF2 exhibited enhanced responses to ABA treatment compared with control cells. Among the VvABF2-mediated responses highlighted in this study, the synthesis of phenolic compounds and cell wall softening were the most strongly affected. VvABF2 overexpression strongly increased the accumulation of stilbenes that play a role in plant defense and human health (resveratrol and piceid). In addition, the firmness of fruits from tomato (Solanum lycopersicum) plants overexpressing VvABF2 was strongly reduced. These data indicate that VvABF2 is an important transcriptional regulator of ABA-dependent grape berry ripening. PMID:24276949

  1. Amino acid-dependent growth of Campylobacter jejuni: key roles for aspartase (AspA) under microaerobic and oxygen-limited conditions and identification of AspB (Cj0762), essential for growth on glutamate.

    PubMed

    Guccione, Edward; Leon-Kempis, Maria del Rocio; Pearson, Bruce M; Hitchin, Edward; Mulholland, Francis; van Diemen, Pauline M; Stevens, Mark P; Kelly, David J

    2008-07-01

    Amino acids are key carbon and energy sources for the asaccharolytic food-borne human pathogen Campylobacter jejuni. During microaerobic growth in amino acid rich complex media, aspartate, glutamate, proline and serine are the only amino acids significantly utilized by strain NCTC 11168. The catabolism of aspartate and glutamate was investigated. An aspartase (aspA) mutant (unable to utilize any amino acid except serine) and a Cj0762c (aspB) mutant lacking aspartate:glutamate aminotransferase (unable to utilize glutamate), were severely growth impaired in complex media, and an aspA sdaA mutant (also lacking serine dehydratase) failed to grow in complex media unless supplemented with pyruvate and fumarate. Aspartase was shown by activity and proteomic analyses to be upregulated by oxygen limitation, and aspartate enhanced oxygen-limited growth of C. jejuni in an aspA-dependent manner. Stoichiometric aspartate uptake and succinate excretion involving the redundant DcuA and DcuB transporters indicated that in addition to a catabolic role, AspA can provide fumarate for respiration. Significantly, an aspA mutant of C. jejuni 81-176 was impaired in its ability to persist in the intestines of outbred chickens relative to the parent strain. Together, our data highlight the dual function of aspartase in C. jejuni and suggest a role during growth in the avian gut.

  2. Unsaturated fatty acids-dependent linkage between respiration and fermentation revealed by deletion of hypoxic regulatory KlMGA2 gene in the facultative anaerobe-respiratory yeast Kluyveromyces lactis.

    PubMed

    Ottaviano, Daniela; Montanari, Arianna; De Angelis, Lorenzo; Santomartino, Rosa; Visca, Andrea; Brambilla, Luca; Rinaldi, Teresa; Bello, Cristiano; Reverberi, Massimo; Bianchi, Michele M

    2015-08-01

    In the yeast Kluyveromyces lactis, the inactivation of structural or regulatory glycolytic and fermentative genes generates obligate respiratory mutants which can be characterized by sensitivity to the mitochondrial drug antimycin A on glucose medium (Rag(-) phenotype). Rag(-) mutations can occasionally be generated by the inactivation of genes not evidently related to glycolysis or fermentation. One such gene is the hypoxic regulatory gene KlMGA2. In this work, we report a study of the many defects, in addition to the Rag(-) phenotype, generated by KlMGA2 deletion. We analyzed the fermentative and respiratory metabolism, mitochondrial functioning and morphology in the Klmga2Δ strain. We also examined alterations in the regulation of the expression of lipid biosynthetic genes, in particular fatty acids, ergosterol and cardiolipin, under hypoxic and cold stress and the phenotypic suppression by unsaturated fatty acids of the deleted strain. Results indicate that, despite the fact that the deleted mutant strain had a typical glycolytic/fermentative phenotype and KlMGA2 is a hypoxic regulatory gene, the deletion of this gene generated defects linked to mitochondrial functions suggesting new roles of this protein in the general regulation and cellular fitness of K. lactis. Supplementation of unsaturated fatty acids suppressed or modified these defects suggesting that KlMga2 modulates membrane functioning or membrane-associated functions, both cytoplasmic and mitochondrial.

  3. An on-line high-performance liquid chromatography-diode-array detector-multi-stage mass spectrometry-deoxyribonucleic acid-4',6-diamidino-2-phenylindole-fluorescence detector system for screening the DNA-binding active compounds in Fufang Banbianlian Injection.

    PubMed

    Li, Sensen; Jiang, Haixiu; Lin, Zongtao; Deng, Shanshan; Guan, Yanqing; Wang, Hong; Chen, Shizhong

    2015-12-11

    Fufang Banbianlian Injection (FBI), a well-known traditional Chinese medicine formula, has been recently approved and extensively used as a newly anti-inflammatory and anti-tumor drug. This prescription comprises an equal ratio of three traditional Chinese herbs, Lobelia chinensis Lour, Scutellaria barbata D. Don and Hedyotis diffusa Willd. The relationships between its chemical compositions and activities have not been understood well yet. To investigate the ingredients and their DNA-binding activities in FBI, an on-line high-performance liquid chromatography-diode-array detector-multi-stage mass spectrometry-deoxyribonucleic acid-4',6-diamidino-2-phenylindole-fluorescence detector (HPLC-DAD-MS(n)-DNA-DAPI-FLD) system was developed using a combination of chromatographic, mass spectrometric and fluorescent detection techniques. 4',6-Diamidino-2-phenylindole (DAPI) specifically binds to three ATT base pairs on the DNA minor groove, and thus can be used as a fluorescent probe for screening active compounds that compete ATT sequences with DAPI. Using this system, 21 of 58 identified or tentatively characterized compounds in FBI showed DNA-binding activities, with most of the active compounds being flavone glycosides. In addition, the structure-activity relationships of these active compounds suggested that conjugated planar structures are favorable for DNA-binding activities, and adjacent hydroxyl groups in flavonoids can significantly improve their activities. This is, to the best of our knowledge, the first application of DAPI as a fluorescent probe for the screening of DNA-binding active compounds in complex samples. PMID:26592560

  4. Protection against the Metabolic Syndrome by Guar Gum-Derived Short-Chain Fatty Acids Depends on Peroxisome Proliferator-Activated Receptor γ and Glucagon-Like Peptide-1.

    PubMed

    den Besten, Gijs; Gerding, Albert; van Dijk, Theo H; Ciapaite, Jolita; Bleeker, Aycha; van Eunen, Karen; Havinga, Rick; Groen, Albert K; Reijngoud, Dirk-Jan; Bakker, Barbara M

    2015-01-01

    The dietary fiber guar gum has beneficial effects on obesity, hyperglycemia and hypercholesterolemia in both humans and rodents. The major products of colonic fermentation of dietary fiber, the short-chain fatty acids (SCFAs), have been suggested to play an important role. Recently, we showed that SCFAs protect against the metabolic syndrome via a signaling cascade that involves peroxisome proliferator-activated receptor (PPAR) γ repression and AMP-activated protein kinase (AMPK) activation. In this study we investigated the molecular mechanism via which the dietary fiber guar gum protects against the metabolic syndrome. C57Bl/6J mice were fed a high-fat diet supplemented with 0% or 10% of the fiber guar gum for 12 weeks and effects on lipid and glucose metabolism were studied. We demonstrate that, like SCFAs, also guar gum protects against high-fat diet-induced metabolic abnormalities by PPARγ repression, subsequently increasing mitochondrial uncoupling protein 2 expression and AMP/ATP ratio, leading to the activation of AMPK and culminating in enhanced oxidative metabolism in both liver and adipose tissue. Moreover, guar gum markedly increased peripheral glucose clearance, possibly mediated by the SCFA-induced colonic hormone glucagon-like peptide-1. Overall, this study provides novel molecular insights into the beneficial effects of guar gum on the metabolic syndrome and strengthens the potential role of guar gum as a dietary-fiber intervention. PMID:26292284

  5. Protection against the Metabolic Syndrome by Guar Gum-Derived Short-Chain Fatty Acids Depends on Peroxisome Proliferator-Activated Receptor γ and Glucagon-Like Peptide-1

    PubMed Central

    den Besten, Gijs; Gerding, Albert; van Dijk, Theo H.; Ciapaite, Jolita; Bleeker, Aycha; van Eunen, Karen; Havinga, Rick; Groen, Albert K.; Reijngoud, Dirk-Jan; Bakker, Barbara M.

    2015-01-01

    The dietary fiber guar gum has beneficial effects on obesity, hyperglycemia and hypercholesterolemia in both humans and rodents. The major products of colonic fermentation of dietary fiber, the short-chain fatty acids (SCFAs), have been suggested to play an important role. Recently, we showed that SCFAs protect against the metabolic syndrome via a signaling cascade that involves peroxisome proliferator-activated receptor (PPAR) γ repression and AMP-activated protein kinase (AMPK) activation. In this study we investigated the molecular mechanism via which the dietary fiber guar gum protects against the metabolic syndrome. C57Bl/6J mice were fed a high-fat diet supplemented with 0% or 10% of the fiber guar gum for 12 weeks and effects on lipid and glucose metabolism were studied. We demonstrate that, like SCFAs, also guar gum protects against high-fat diet-induced metabolic abnormalities by PPARγ repression, subsequently increasing mitochondrial uncoupling protein 2 expression and AMP/ATP ratio, leading to the activation of AMPK and culminating in enhanced oxidative metabolism in both liver and adipose tissue. Moreover, guar gum markedly increased peripheral glucose clearance, possibly mediated by the SCFA-induced colonic hormone glucagon-like peptide-1. Overall, this study provides novel molecular insights into the beneficial effects of guar gum on the metabolic syndrome and strengthens the potential role of guar gum as a dietary-fiber intervention. PMID:26292284

  6. Chromatin immunoprecipitation analysis of the tobacco PR-1a- and the truncated CaMV 35S promoter reveals differences in salicylic acid-dependent TGA factor binding and histone acetylation.

    PubMed

    Butterbrodt, Thomas; Thurow, Corinna; Gatz, Christiane

    2006-07-01

    Salicylic acid (SA) is a plant signalling molecule needed for the induction of defence responses upon attack by a variety of pathogens. Truncation of the Cauliflower Mosaic Virus (CaMV) 35S promoter down to 90 bp has identified activation sequence-1 (as-1) as an autonomous SA-responsive cis element. The as-1-like elements are found in a number of SA-inducible promoters like e.g. the tobacco PR-1a promoter. They are recognized by basic/leucine zipper (bZIP) transcription factors of the TGA family. In tobacco leaves, TGA2.2 is the most abundant TGA factor. TGA2.2 is required for the expression of as-1-containing promoters. Here we unravel clear differences between the "truncated" CaMV 35S and the PR-1a promoter with respect to in vivo TGA binding and histone acetylation. Chromatin immunoprecipitation (ChIP) analysis revealed SA-inducible recruitment of tobacco TGA2.2 as well as SA-inducible histone acetylation at the PR-1a promoter. In contrast, no influence of SA on TGA2.2 binding and histone acetylation was detectable at the "truncated" CaMV 35S promoter. The finding of SA-independent TGA factor binding in the absence of additional flanking regulatory sequences suggests that transcriptional activation is not necessarily mediated by inducible DNA binding of TGA factors. Plants with severely reduced TGA2.2 protein levels also showed SA-induced histone acetylation at the PR-1a promoter indicating that regulatory events independent from TGA2.2 function are initiated at the PR-1a promoter.

  7. Effects of corn silage derived from a genetically modified variety containing two transgenes on feed intake, milk production, and composition, and the absence of detectable transgenic deoxyribonucleic acid in milk in Holstein dairy cows.

    PubMed

    Calsamiglia, S; Hernandez, B; Hartnell, G F; Phipps, R

    2007-10-01

    The objectives were to compare the chemical composition, nutritive value, feed intake, milk production and composition, and presence in milk of transgenic DNA and the encoded protein Cry1Ab when corn silages containing 2 transgenes (2GM: herbicide tolerance: mepsps and insect resistance: cry1Ab) were fed as part of a standard total mixed ration (TMR) compared with a near isogenic corn silage (C) to 8 multiparous lactating Holstein dairy cows in a single reversal design study. Cows were fed a TMR ration ad libitum and milked twice daily. Diets contained [dry matter (DM) basis] 45% corn silage, 10% alfalfa hay, and 45% concentrate (1.66 Mcal of net energy for lactation/kg of DM, 15.8% crude protein, 35% neutral detergent fiber, and 4.1% fat). Each period was 28-d long. During the last 4 d of each period, feed intake and milk production data were recorded and milk samples taken for compositional analysis, including the presence of transgenic DNA and Cry1Ab protein. There was no significant difference in the chemical composition between C and 2GM silages, and both were within the expected range (37.6% DM, 1.51 Mcal of net energy for lactation/kg, 8.6% crude protein, 40% neutral detergent fiber, 19.6% acid detergent fiber, pH 3.76, and 62% in vitro DM digestibility). Cows fed the 2GM silage produced milk with slightly higher protein (3.09 vs. 3.00%), lactose (4.83 vs. 4.72%) and solids-not-fat (8.60 vs. 8.40%) compared with C. However, the yield (kg/d) of milk (36.5), 3.5% fat-corrected milk (34.4), fat (1.151), protein (1.106), lactose (1.738), and solids-not-fat (3.094), somatic cell count (log10: 2.11), change in body weight (+7.8 kg), and condition score (+0.09) were not affected by type of silage, indicating no overall production difference. All milk samples were negative for the presence of transgenic DNA from either trait or the Cry1Ab protein. Results indicate that the 2GM silage modified with 2 transgenes did not affect nutrient composition of the silages and

  8. The deoxyribonucleic acid polymerases of non-vertebrate eukaryotes.

    PubMed

    McLennan, A G; Keir, H M

    1977-01-01

    DNA-dependent DNA polymerases have now been purified from a number of invertebrate animals, protists, higher plants and fungi. In this article we review the properties of these enzymes and compare them with the better-known enzymes of vertebrate animals and prokaryotes. Three facts emerge. Firstly, plants, protists and fungi contain high-molecular-weight DNA polymerases which may be capable of categorization into two groups on the basis of their properties in vitro. Secondly, no enzyme analogous to the vertebrate polymerase-beta has yet been found in such organisms, and thirdly, many of these enzymes possess associated exonuclease activities like those of the bacterial DNA polymerases. On the basis of these findings, some tentative proposals are made about the evolution of DNA polymerases.

  9. An optical deoxyribonucleic acid-based half-subtractor.

    PubMed

    Yang, Chia-Ning; Chen, Yi-Li; Lin, Hung-Yin; Hsu, Chun-Yu

    2013-10-01

    This study introduces an optical DNA-based logic circuit that mimics a half-subtractor. The system contains an Au-surface immobilized molecular-beacon molecule that serves as a dual-gate molecule and outputs two series of fluorescence signals following Boolean INH and XOR patterns after interacting with one or two single-stranded DNA molecules as input. To the best of our knowledge, the system reported herein is rather concise compared to other molecular logic gate systems.

  10. The activity of deoxyribonucleic acid polymerase and deoxyribonucleic acid synthesis in nuclei from brain fractionated by zonal centrifugation

    PubMed Central

    Stambolova, M. A.; Cox, D.; Mathias, A. P.

    1973-01-01

    1. The DNA polymerase (EC 2.7.7.7) activity in purified intact brain nuclei from infant rats was investigated. The effects of pH, Mg2+, glycerol, sonication and storage of the nuclei under different conditions were examined and a suitable assay system was established. 2. The nuclei from infant brain cells were fractionated by zonal centrifugation in a discontinuous sucrose gradient into five zones: zone (I) contained neuronal nuclei (59%) and astrocytic nuclei (41%); zone (II) contained astrocytic nuclei (81%) and neuronal nuclei (19%); zone (III) contained astrocytic nuclei (82%) and oligodendrocytic nuclei (18%); zone (IV) contained oligodendrocytic nuclei (92%) and zone (V) contained oligodendrocytic nuclei (100%). 3. The content of DNA, RNA and protein for each fraction was measured. 4. The distribution of DNA polymerase activity in the fractionated infant and adult rat brain nuclei was determined. The highest activity was found in the neuronal nuclei from zone (I) and the following zones exhibited a progressive decline. In contrast with the nuclei from infant rats those from adults had a much higher activity and expressed a preference for native DNA as template. 5. The deoxyribonuclease activity in all classes of nuclei was measured with [3H]DNA as substrate. A general correspondence in the pattern of the relative activities in the nuclear fractions with the distribution of DNA polymerase was found. 6. The incorporation of [3H]thymidine into nuclear DNA in infant and adult rat brain was investigated. The specific radioactivity of the DNA in the 10-day-old rats was highest in zone (V) whereas in the nuclei of adult rats, which exhibited a comparatively low incorporation, the highest specific radioactivity was associated with zones (I) and (V). PMID:4780694

  11. Characterization of deoxyribonucleic Acid species from castor bean endosperm: inability to detect a unique deoxyribonucleic Acid species associated with glyoxysomes.

    PubMed

    Douglass, S A; Criddle, R S; Breidenbach, R W

    1973-05-01

    Three DNA buoyant density species (nuclear, 1.692 g cm(-3); mitochondria 1.705 g cm(-3); and proplastid, 1.713 g cm(-3)) can be detected in extracts from castor bean endosperm. No other buoyant density species can be identified. DNA extracts from sucrose density gradient purified glyoxysomes exhibit varying amounts of each of the three identified DNAs but no other distinguishable DNA species. RNA synthesized in vitro by Escherichia coli RNA polymerase using purified castor bean nuclear DNA as a template, hybridizes equally well with its template and with the 1.692 g cm(-3) species from glyoxysome fractions. These results are discussed in terms of their relevance to microbody biogenesis.

  12. 76 FR 72950 - Draft Guidance for Industry: Use of Nucleic Acid Tests on Pooled and Individual Samples From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-28

    ... (HBV) deoxyribonucleic acid (DNA) and recommendations for product testing and disposition, donor...- licensed NAT to screen blood donors for HBV DNA. FDA is also providing these blood establishments...

  13. Polyuridylic Acid-directed Phenylalanine Incorporation in Minicell Extracts

    PubMed Central

    Fralick, J. A.; Fisher, W. D.; Adler, H. I.

    1969-01-01

    Cell-free extracts of miniature Escherichia coli cells deficient in deoxyribonucleic acid (DNA) and DNA-dependent ribonucleic acid polymerase have been shown to be capable of polyuridylic acid-directed [14C]phenylalanine incorporation. PMID:4897117

  14. Deoxyribonucleic acid-protein and deoxyribonucleic acid interstrand cross-links induced in isolated chromatin by hydrogen peroxide and ferrous ethylenediaminetetraacetate chelates

    SciTech Connect

    Lesko, S.A.; Drocourt, J.; Yang, S.

    1982-01-01

    DNA-protein and DNA interstrand cross-links were induced in isolated chromatin after treatment with H/sub 2/O/sub 2/ and ferrous ethylenediaminetetraacetate (EDTA). Retention of DNA on membrane filters after heating of chromatin in a dissociating solvent indicated the presence of a stable linkage between DNA and protein. Treatment of protein-free DNA with H/sub 2/O/sub 2//Fe/sup 2 +/-EDTA did not result in enhanced filter retention. Incubation of cross-linked chromatin with proteinase K completely eliminated filter retention. Resistance to S/sub 1/ nuclease after a denaturation-renaturation cycle was used to detect DNA interstrand cross-links. Heating the treated chromatin at 45/sup 0/C for 16 h and NaBH/sub 4/ reduction enhanced the extent of interstrand cross-linking. The following data are consistent with, but do not totally prove, the hypothesis that cross-links are induced by hydroxyl radicals generated in Fenton-type reactions: (1) cross-linking was inhibited by hydroxyl radical scavengers; (2) the degree of inhibition of DNA interstrand cross-links correlated very closely with the rate constants of the scavengers for reaction with hydroxyl radicals; (3) cross-linking was eliminated or greatly reduced by catalase; (4) the extent of cross-linking was directly related to the concentration of Fe/sup 2 +/-EDTA. Partial inhibition of cross-linking by superoxide dismutase indicates that super-oxide-driven Fenton chemistry is involved. The data indicate that DNA cross-linking may play a role in the manifestation of the biological activity of agents of systems that generate reactive hydroxyl radicals.

  15. Anthramycin binding to deoxyribonucleic acid-mitomycin C complexes. Evidence for drug-induced deoxyribonucleic acid conformational change and cooperativity in mitomycin C binding.

    PubMed

    Kaplan, D J; Hurley, L H

    1981-12-22

    Anthramycin and mitomycin C (MC) are two DNA reactive drugs, which bind covalently to GC pairs producing different effects on DNA: anthramycin stiffening and MC distorsion. This paper describes experiments in which we have used anthramycin as a probe to sense quantitatively the effects on DNA of MC binding. Saturation binding experiments show that both anthramycin and MC partially inhibit the binding of the other drug to DNA (maximum inhibition by MC and anthramycin, 22.4% and 19.7%, respectively) but by a mechanism other than direct site exclusion. This suggests that MC binds in the major groove of DNA, since anthramycin is known to bind in the minor groove. An abrupt reduction in the binding of anthramycin to DNA-MC complexes occurs between MC binding ratios of 0.030 and 0.035, which parallels and probably results from sudden intensification of a MC-induced DNA conformational change occurring between these binding ratios. Dialysis measurements indicate that anthramycin is very possibly binding at sites distant from MC sites and suggest a clustering of closely bound MC chromophores resulting from possible cooperative binding. S1 nuclease digest experiments demonstrate an initial enhancement of nuclease activity in DNA-MC complexes, the magnitude of which correlates well with the reduction of anthramycin binding, relative to the degree of MC binding. The enhanced nuclease activity in these complexes indicates regions of exposed DNA or helix base distortion which is related to or is the result of conformational change. PMID:6798992

  16. Ethylenediaminetetraacetic acid-dependent pseudothrombocytopenia in a patient with systemic lupus erythematosus and lupus nephritis

    PubMed Central

    Akyol, Lütfi; Önem, Soner; Özgen, Metin; Sayarlıoğlu, Mehmet

    2016-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by several immunological abnormalities. We wish to communicate the case of a patient with SLE and lupus nephritis (LN) who developed pseudothrombocytopenia. Pseudothrombocytopenia can occur in patients with SLE and LN and should be considered when diagnosing patients with thrombocytopenia without bleeding.

  17. 21 CFR 528.1070 - Bc6 recombinant deoxyribonucleic acid construct.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 155-92 site in a specific hemizygous diploid line of dairy breeds of domestic goats (Capra aegagrus... of humans) in the mammary gland of goats derived from lineage progenitor 155-92. (b) Sponsor. See No. 042976 in § 510.600 of this chapter. (c) Limitations. Food or feed from GTC-155-92 goats is not...

  18. 21 CFR 528.1070 - Bc6 recombinant deoxyribonucleic acid construct.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 155-92 site in a specific hemizygous diploid line of dairy breeds of domestic goats (Capra aegagrus... of humans) in the mammary gland of goats derived from lineage progenitor 155-92. (b) Sponsor. See No. 042976 in § 510.600 of this chapter. (c) Limitations. Food or feed from GTC-155-92 goats is not...

  19. 21 CFR 528.1070 - Bc6 recombinant deoxyribonucleic acid construct.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 155-92 site in a specific hemizygous diploid line of dairy breeds of domestic goats (Capra aegagrus... of humans) in the mammary gland of goats derived from lineage progenitor 155-92. (b) Sponsor. See No. 042976 in § 510.600 of this chapter. (c) Limitations. Food or feed from GTC-155-92 goats is not...

  20. Purification of influenza deoxyribonucleic acid-based vaccine using agmatine monolith.

    PubMed

    Bicho, D; Caramelo-Nunes, C; Sousa, A; Sousa, F; Queiroz, J A; Tomaz, C T

    2016-02-15

    Lately, researchers have made several efforts to improve vaccine production to fight highly contagious respiratory diseases like influenza. One of the most promising options for reducing the impact of this virus is DNA vaccination. However, a large quantity of highly pure plasmid DNA (pDNA) is necessary to attain this goal. The present work describes the production and purification of the plasmid NTC7482-41H-VA2HA expressing influenza virus hemagglutinin using an agmatine monolith. This ligand was chosen to purify supercoiled (sc) pDNA from complex lysates because of its versatile multimodal character. Its natural intervention in several biological systems together with its similarity with the highly studied arginine ligand allowed the development of a simpler and more specific purification process. Agmatine works under two strategies: descending ammonium sulfate gradient and ascending sodium chloride gradient. Furthermore, pH manipulation revealed an important role in pDNA isoforms selectivity. Dynamic binding capacity (DBC) experiments were performed varying different parameters and showed an increase with pDNA concentration, while high flow rate and high pH had the opposite effect. Sc pDNA was purified with high yield and was efficient with respect to cell transfection and cell viability. This monolith showed to be appropriate to purify the plasmid NTC7482-41H-VA2HA, providing a valuable tool for pDNA influenza vaccines preparation. PMID:26827278

  1. [Epigenetic heredity (deoxyribonucleic acid methylation): Clinical context in neurodegenerative disorders and ATXN2 gene].

    PubMed

    Laffita-Mesa, José Miguel; Bauer, Peter

    2014-10-21

    Epigenetics is the group of changes in the phenotype which are related with the process independently of the primary DNA sequence. These changes are intimately related with changes in the gene expression level and its profile across the body. These are mediated by histone tail modifications, DNA methylation, micro-RNAs, with chromatin remodeling remaining as the foundation of epigenetic changes. DNA methylation involves the covalent addition of methyl group to cytosine of the DNA, which is mediated by methyltransferases enzymes. DNA methylation regulates gene expression by repressing transcription, while de-methylation activates gene transcription. Several human diseases are related with the epigenetic process: cancer, Alzheimer disease, stroke, Parkinson disease, and diabetes. We present here the basis of epigenetic inheritance and show the pathogenic mechanisms relating epigenetics in human diseases, specifically with regard to neurodegeneration. We discuss current concepts aimed at understanding the contribution of epigenetics to human neurodegenerative diseases. We also discuss recent findings obtained in our and other centers regarding the ATXN2 gene that causes spinocerebellar ataxia 2 and amyotrophic lateral sclerosis. Epigenetics play a pivotal role in the pathogenesis of human diseases and in several neurodegenerative disorders, and this knowledge will illuminate the pathways in the diagnostic and therapeutic field, which ultimately will be translated into the clinic context of neurodegenerative diseases.

  2. Development of a small gantry robotic workcell for deoxyribonucleic acid (DNA) filter array construction

    SciTech Connect

    Beugelsdijk, T.J.; Hollen, R.M.; Snider, K.T.

    1990-01-01

    At Los Alamos National Laboratory, we have constructed a primary cosmid library of human chromosome 16. This library consists of an 11-fold representation of the chromosome and is arrayed in microtiter plate format. A need has arisen in the large scale physical mapping of this chromosome, to array spots of DNA from each of these colonies onto filter media for hybridization studies. We are currently developing a small gantry robot-based workcell to array small spots of DNA in an interleaved format. This allows for the construction of a high spot density format filter array. This paper will discuss the features incorporated into this workcell for the handling of thousands of colonies and their automatic tracking and positioning onto the filter. 7 refs., 3 figs., 1 tab.

  3. Detection of toxins in single molecule level using deoxyribonucleic acid aptamers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxins in foodstuffs are always a threat to food safety Among many toxins related to food, ricin (category B toxin) from castor beans has been mentioned in some poisoning cases happened. Atomic Force Microscopy (AFM) is a widely used nanotechnology to detect biospecies in vitro and in situ. The AFM...

  4. Relationship between pregnancy, embryo development, and sperm deoxyribonucleic acid fragmentation dynamics.

    PubMed

    Wdowiak, Artur; Bojar, Iwona

    2016-09-01

    The way the dynamics of DNA fragmentation affects the growth of embryos in real time, and effectiveness of infertility treatment using the ICSI procedure were determined in 148 couples treated with the ICSI technique. The percentage of sperm with fragmented DNA (known as the DNA fragmentation index [DFI]) in semen samples was determined at 3, 6 and 12 h. Embryo culture was assessed continuously during 12 h of observation monitoring. Statistically significant difference was found in DFI at 12 h and outcome of treatment. For the remaining time intervals, no statistically significant differences were noted. An analysis of relationship between the DFI dynamics over time at individual measurements and achievement of pregnancy, confirmed a statistically significant relationship between the rate measured at 6-12 h of observations of DFI changes (DFI 12 h%/h), and achieving pregnancy. Correlation was observed between DFI (during 0, 3, 6 and 12 h), the growth rate in DFI, and time of embryo development. A statistically significant relationship was found between the rate from the start to the end of observations of the DFI, and outcome of treatment. Intensity level regarding fragmentation of sperm DNA and its growth rate affected the time of embryo development in the ICSI procedure. The most significant prognostic factor for achieving pregnancy was intensification of sperm DNA fragmentation after 12 h. PMID:27579009

  5. 21 CFR 528.1070 - Bc6 recombinant deoxyribonucleic acid construct.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 155-92 site in a specific hemizygous diploid line of dairy breeds of domestic goats (Capra aegagrus... of humans) in the mammary gland of goats derived from lineage progenitor 155-92. (b) Sponsor. See No. 042976 in § 510.600 of this chapter. (c) Limitations. Food or feed from GTC-155-92 goats is not...

  6. Transcription of rat liver deoxyribonucleic acid in vitro at low ionic strength.

    PubMed Central

    Pays, E

    1978-01-01

    1. When RNA polymerase is in excess over DNA, the single-stranded breaks of DNA can be recognized as initiation sites for the ezyme. On the other hand stabel initiation complexes (resistant to inhibition by heparin) are the most abundant under these conditions. The formation of these complexes needs double-stranded DNA. It seems that RNA sequences rich in cytidine are preferentially synthesized; since rat liver DNA is A + T-rich, the transcription thus appears not to be random with respect to the base composition of DNA. 2. When the template is in excess over the polymerase, the single-stranded gaps of DNA are preferentially transcribed by rat liver RNA polymerase B and native DNA regions by Escherichia coli RNA polymerase. 3. With a large excess of DNA over the polymerase, the enzyme activity is markedly inhibited. This inhibition is proportional to the concentration of double-stranded DNA ends, but it also depends on the presence of a contaminant of DNA, removed when DNA is banded in a CsCl gradient. This contaminant could be polyphosphates. Low concentrations of spermine completely reverse this inhibition, by enhancing the rate of RNA chain elongation. 4. Double-stranded RNA is synthesized in great abundance when RNA polymerase is in excess over native DNA. Besides a majority of symmetrical sequences, stable 'hairpins' can be found. Whereas the synthesis of symmetrical sequences is more prevalent in polymerase excess, it seems that the proportion of stable 'hairpins' in RNA is independent of the polymerase/DNA ratio. PMID:32873

  7. Estimation of gene reiteration from hybridization kinetics in moderate deoxyribonucleic acid excess.

    PubMed Central

    Muto, M

    1977-01-01

    Theoretical calculations were carried out to clarify how the DNA/RNA or the DNA/cDNA (complementary DNA) ratio in the hybridization reaction mixture affects the kinetics of DNA-RNA or DNA-cDNA reassociation, and theoretical formulae were derived as a function of these ratios. From these formulae, it was found that the DNA/RNA of the DNA/cDNA ratio did not much affect the initial reaction rates of hybridization, but greatly affected the terminal value for the extent of hybrid formation. Therefore the results obtained when one normalizes the experimental data for hydridization and derives the reiteration frequency from a number called the 'half Cot' (Cot 1/2) are not accurate, especially in the presence of a moderate excess of DNA. A simple method for the estimation of gene reiteration was demonstrated that did not use the half Cot value in the determination. This simple method is useful even if DNA-RNA or DNA/cDNA hybridization are done with a moderate excess of DNA. With mouse myeloma cells as a model system, the gene reiteration of the 28S rRNA cristron was determined. PMID:889572

  8. Formation of rings from segments of HeLa-cell nuclear deoxyribonucleic acid

    PubMed Central

    Hardman, Norman

    1974-01-01

    Duplex segments of HeLa-cell nuclear DNA were generated by cleavage with DNA restriction endonuclease from Haemophilus influenzae. About 20–25% of the DNA segments produced, when partly degraded with exonuclease III and annealed, were found to form rings visible in the electron microscope. A further 5% of the DNA segments formed structures that were branched in configuration. Similar structures were generated from HeLa-cell DNA, without prior treatment with restriction endonuclease, when the complementary polynucleotide chains were exposed by exonuclease III action at single-chain nicks. After exposure of an average single-chain length of 1400 nucleotides per terminus at nicks in HeLa-cell DNA by exonuclease III, followed by annealing, the physical length of ring closures was estimated and found to be 0.02–0.1μm, or 50–300 base pairs. An almost identical distribution of lengths was recorded for the regions of complementary base sequence responsible for branch formation. It is proposed that most of the rings and branches are formed from classes of reiterated base sequence with an average length of 180 base pairs arranged intermittenly in HeLa-cell DNA. From the rate of formation of branched structures when HeLa-cell DNA segments were heat-denatured and annealed, it is estimated that the reiterated sequences are in families containing approximately 2400–24000 copies. ImagesPLATE 2PLATE 1 PMID:4462738

  9. Purification of influenza deoxyribonucleic acid-based vaccine using agmatine monolith.

    PubMed

    Bicho, D; Caramelo-Nunes, C; Sousa, A; Sousa, F; Queiroz, J A; Tomaz, C T

    2016-02-15

    Lately, researchers have made several efforts to improve vaccine production to fight highly contagious respiratory diseases like influenza. One of the most promising options for reducing the impact of this virus is DNA vaccination. However, a large quantity of highly pure plasmid DNA (pDNA) is necessary to attain this goal. The present work describes the production and purification of the plasmid NTC7482-41H-VA2HA expressing influenza virus hemagglutinin using an agmatine monolith. This ligand was chosen to purify supercoiled (sc) pDNA from complex lysates because of its versatile multimodal character. Its natural intervention in several biological systems together with its similarity with the highly studied arginine ligand allowed the development of a simpler and more specific purification process. Agmatine works under two strategies: descending ammonium sulfate gradient and ascending sodium chloride gradient. Furthermore, pH manipulation revealed an important role in pDNA isoforms selectivity. Dynamic binding capacity (DBC) experiments were performed varying different parameters and showed an increase with pDNA concentration, while high flow rate and high pH had the opposite effect. Sc pDNA was purified with high yield and was efficient with respect to cell transfection and cell viability. This monolith showed to be appropriate to purify the plasmid NTC7482-41H-VA2HA, providing a valuable tool for pDNA influenza vaccines preparation.

  10. Characterization of deoxyribonucleic acid from cells infected with Aleutian disease virus

    SciTech Connect

    Hahn, E.C.; Ramos, L.; Kenyon, A.J.

    1983-07-01

    Viral DNA was extracted from Crandell feline kidney (CRFK) cells infected with Aleutian disease virus (ADV) and labeled with (/sup 3/H)thymidine. The sedimentation coefficient in alkaline sucrose gradients was 16S corresponding to a molecular weight of 1.5 X 10(6). The buoyant densities of DNA from infected and control cells were determined by isopyknic sedimentation in CsCl and NaI gradients. Two additional peaks of (/sup 3/H)DNA were found in infected cells, but not in control cell extracts. Fractionation of this DNA on hydroxylapatite indicated that the new peaks represented a single-stranded component, density 1.728 g/cm3, and a double-stranded component, presumed to be a viral replicative intermediate, density 1.718 g/cm3. The target antigen formation in CRFK cells was measured by gamma-irradiation of ADV and assayed for focus formation. The calculated size of ADV based on these measurements was 1.1 X 10(6). The H-1 parvovirus also was shown to have a size of 1.5 X 10(6) daltons for both antigen and plaque formation. The data indicated similarities existed between ADV and other autonomously replicating parvoviruses in most properties, except that less-than-unit length genome of ADV may be transcribed.

  11. The deoxyribonucleic acid unwinding protein of Escherichia coli. Properties and functions in replication.

    PubMed

    Weiner, J H; Bertsch, L L; Kornberg, A

    1975-03-25

    The DNA unwinding protein of Escherichia coli (Sigal, N., Delius, H., Kornberg, T., Gefter, M., and Alberts, B. (1972) Proc. Nat. Acad. Sci. U.S.A. 69, 3537-3541) has been purified to homogeneity by a simple procedure which utilizes its stability to heating. The protein is an asymmetric tetramer of 18,500 dalton subunits which binds preferentially to single-stranded DNA at a ratio of one protein molecule per 32 nucleotides. Binding to DNA is complete in less than 10 s at 0 degrees while release of the protein from single-stranded DNA is relatively slow even at 37 degrees. A simple functional assay for unwinding protein depends on its essential role in the conversion of phage G4 single-stranded DNA to the replicative form. Unwinding protein stimulates initiation of replication of all single-stranded phage DNAs. Approximately 300 copies of unwinding protein are present per cell, as estimated by antibody titration, an amount sufficient to cover substantial lengths of DNA in several replicating forks.

  12. Plasma Epstein–Barr Viral Deoxyribonucleic Acid Predicts Worse Outcomes in Pediatric Nonmetastatic Nasopharyngeal Carcinoma Patients

    PubMed Central

    Shen, Ting; Tang, Lin-Quan; Gu, Wei-Guang; Luo, Dong-Hua; Chen, Qiu-Yan; Li, Pei-Jing; Mai, Dong-Mei; Mai, Hai-Qiang; Mo, Hao-Yuan

    2015-01-01

    Abstract To evaluate the clinical significance of pretreatment levels of plasma Epstein–Barr virus DNA (pEBV DNA) on prognoses in pediatric nasopharyngeal carcinoma (NPC) patients. Eighty-nine patients aged 21 years old or younger with nonmetastatic NPC were evaluated to determine the effect of pEBV DNA levels on progression-free survival (PFS), distant metastasis-free survival (DMFS), and overall survival (OS). Survival probabilities in patient groups that were segregated by clinical stage or pEBV DNA load (low or high) were compared. The median pretreatment concentrations of pEBV DNA were 3440 copies/mL in 35 patients with stage III disease and 14,900 copies/mL in 50 patients with stage IV disease (P = 0.059). The median concentration of pEBV DNA was 34,500 copies/mL in 17 patients with relapse, which was higher than the concentration in 72 patients without relapse, who had a median level of 4985 copies/mL (P = 0.057). Further study showed that pretreatment pEBV DNA load was an independent prognostic indicator in pediatric NPC patients. High pEBV DNA was associated with adverse clinical outcomes, including PFS [3-year PFS rate = 80.5% versus 95.8%, hazard ratio (HR) = 5.00, 95% confidence interval (CI) = 1.00–25.00; P = 0.050], DMFS (3-year DMFS rate = 80.5% versus 95.8%, HR = 5.20, 95% CI = 1.04–26.00; P = 0.045), and OS (3-year OS rate = 82.9% versus 95.8%, HR = 5.41, 95% CI = 1.08–27.22; P = 0.040). Pretreatment pEBV DNA load was an independent prognostic indicator for PFS, DMFS, and OS in pediatric patients with NPC. Prospective studies, however, are needed to validate these results. PMID:26683909

  13. Dysembryoplastic neuroepithelial tumor: morphological, immunocytochemical, and deoxyribonucleic acid analyses in a pediatric series.

    PubMed

    Taratuto, A L; Pomata, H; Sevlever, G; Gallo, G; Monges, J

    1995-03-01

    Overtreatment by radiotherapy and/or chemotherapy for central nervous system tumors in infancy and childhood may be deleterious, so the recognition of surgically curable clinicopathological entities is mandatory. The dysembryoplastic neuroepithelial tumor is a complex multinodular lesion consisting of glial nodules, associated with a specific glioneuronal element and/or with focal cortical dysplasia, and occurring in young patients presenting with intractable, mostly complex partial, seizures without neurological deterioration. We report on 14 patients; 9 were from a series of 600 pediatric patients with intracranial central nervous system tumors studied at a single institution from 1988 to 1993, and 5 were referred from other pediatric hospitals. Six tumors were frontal, six were temporal, one was parietal, and one was occipitoparietal. Computed tomographic scans disclosed hypodense lesions with cystic appearances in 4 patients and slight focal postcontrast enhancements in only 2 patients, whereas magnetic resonance imaging, available for 7 of 14 patients, showed hypointense lesions in T1-weighted images and hyperintense lesions in T2-weighted images. Deformities of the overlying cranium were also observed in five patients. The age range at the time of surgery (excluding a 20-year-old male patient who underwent surgery at the main pediatric hospital) was 2.6 to 13 years, with a mean of 6.68 years. The male to female patient ratio was 10:4, and the duration of symptoms was 0.2 to 6 years.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Molecular aspects on the interaction of phenosafranine to deoxyribonucleic acid: Model for intercalative drug DNA binding

    NASA Astrophysics Data System (ADS)

    Das, Suman; Kumar, Gopinatha Suresh

    2008-01-01

    The mode, mechanism and energetics of interaction of phenosafranine, the planar, cationic and rigid phenazium dye to calf thymus DNA was investigated from absorption, fluorescence, circular dichroism, isothermal titration calorimetry, thermal melting, and viscosity. The study revealed non-cooperative binding of the dye to DNA with an affinity in the range (3.81-4.22) × 10 5 M -1 as observed from diverse techniques and obeying neighbor exclusion principle. The stoichiometry of binding was characterized to be one phenosafranine molecule per two base pairs. The binding was characterized by strong stabilization of DNA against thermal strand separation, large intrinsic circular dichroic changes of DNA by itself and the generation of induced circular dichroism for the optically inactive phenosafranine molecules. Hydrodynamic and fluorescence quenching studies revealed strong evidence that the phenosafranine molecules are intercalated between every alternate base pairs of calf thymus DNA. Isothermal titration calorimetry studies suggested that the binding was exothermic and favoured by both negative enthalpy and positive entropy changes. This study for the first time presents the complete molecular aspects and energetics of phenosafranine complexation to DNA as model for intercalative drug-DNA interaction.

  15. DNA (deoxyribonucleic acid) synthesis following microinjection of heterologous sperm and somatic cell nuclei into hamster oocytes

    SciTech Connect

    Naish, S.J.; Perreault, S.D.; Zirkin, B.R.

    1987-01-01

    The authors investigated the ability of the hamster oocyte to initiate DNA synthesis in nuclei differing in basic protein content. DNA synthesis was studied by autoradiography in oocytes that had been incubated in /sup 3/H-thymidine after being parthenogenetically activated by sham microinjection, or microinjected with hamster, mouse, rabbit, or fish sperm nuclei, or hamster hepatocyte nuclei. Within 6 hr of sham or nucleus microinjection, nuclei of each type underwent transformation into pronuclei and synthesized DNA. These results demonstrated that the hamster egg can access and utilize its own and each type of template provided, whether homologous or heterologous. However, pronuclei derived from hamster sperm nuclei were more likely to be synthesizing DNA at 6 hr than pronuclei derived from sperm nuclei of other species. The authors conclude that the mechanisms employed by the hamster oocyte to transform hamster sperm nuclei into pronuclei and to effect DNA synthesis in these nuclei are not specific for the hamster sperm nucleus. Nevertheless, these mechanisms apparently operate more efficiently when the hamster sperm nucleus, rather than a heterologous sperm nucleus, is present.

  16. Detection of human papillomavirus deoxyribonucleic acid in the female genital tract.

    PubMed

    Czeglédy, J; Gergely, L; Hernádi, Z; Póka, R

    1989-01-01

    A total of 336 biopsies, scrapes and exfoliated cells from the cervix and from the lower genital tract were screened for human papilloma (HP) viral sequences of types 6, 11, 16 and 18 by Southern blot, dot blot and filter in situ (FISH) hybridizations with cloned 32P-radiolabeled HPV DNA probes. The specimens included cervical intraepithelial neoplasias (CIN I-III), carcinoma in situ and invasive carcinoma of the cervix and vagina, adenocarcinomas, vulvar and vaginal condylomata acuminata and healthy epithelial samples. The oncogenic HPV 16 was found in 46% of the cervical carcinomas. Most of the type 16 occurrences (75%) represented the third stage of inoperable cases. Similarly, HPV 18 was also most frequently present in this stage as well as in carcinoma in situ and in CIN III (25%, 18%). At the same time, in condylomata acuminata, types 6 and 11 were detectable in 88.7% of cares. In all, 13.5% of the normal samples harboured HPV DNA. PMID:2559306

  17. Characterization of a cardiac complementary deoxyribonucleic acid library from the Turkey (Meleagris gallopavo).

    PubMed

    Mendoza, K M; Chiang, W; Strasburg, G M; Reed, K M

    2008-06-01

    Although the domestic turkey (Meleagris gallopavo) is a valuable agricultural commodity, genetic studies on this species lag behind those of other agricultural species. In this study, we examined expressed sequence tags (EST) from a turkey cardiac cDNA library constructed from 4 birds representing 2 developmental stages. A collection of 3,937 EST sequences were sequenced and analyzed for gene annotation and sequence variation. Clustering of sequences resulted in 353 contigs and 874 singletons (1,227 putative transcripts). All EST sequences were compared by BLASTN to the chicken whole genome sequence and to Ensembl and National Center for Biotechnology Information databases. The majority of significant matches correspond to genes found in the chicken. Sequence polymorphisms were identified in 310 contigs, 64 where the minor allele was observed to be present in more than 1 sequence. This study gives species-specific insight into the cardiac transcriptome of turkeys and provides resources for future studies of cardiac function.

  18. Relatedness among coagulase-negative staphylococci: deoxyribonucleic acid reassociation and comparative immunological studies.

    PubMed

    Schleifer, K H; Meyer, S A; Rupprecht, M

    1979-07-01

    DNA-DNA-homology values were determined under restrictive to relaxed reassociation conditions with type strains and some additional strains of coagulase-negative staphylococci belonging to ten different species. The immunological relationship of the catalases present in the type strains of these species was also determined by applying double immunodiffusion and microcomplement fixation. The results of these studies support the previous proposal to subdivide the coagulase-negative staphylococci into at least ten separate species. However, it is evident that some of the species are more closely realted than others and can form species groups. According to the results presented in this study, the coagulase-negative staphylococci can be combined into five species groups: The Staphylococcus saprophyticus group is composed of S. saprophyticus, S. xylosus and S. cohnii. The S. epidermidis group comprises S. epidermis, S. capitis and S. warneri. The S. hominis group which exhibits a significant relationship to S. epidermidis includes S. hominis and S. haemolyticus. The species group S. sciuri consists of S. sciuri ssp. sciuri and S. sciuri ssp. lentus and the species group S. simulans is presently represented by the corresponding single species. PMID:92972

  19. A self-assembled deoxyribonucleic acid concatemer for sensitive detection of single nucleotide polymorphism.

    PubMed

    Wu, Wei; Chen, Junhua; Fang, Zhiyuan; Ge, Chenchen; Xiang, Zhicheng; Ouyang, Chuanyan; Lie, Puchang; Xiao, Zhuo; Yu, Luxin; Wang, Lin; Zeng, Lingwen

    2013-12-01

    Polymerase-free and label-free strategies for DNA detection have shown excellent sensitivity and specificity in various biological samples. Herein, we propose a method for single nucleotide polymorphism (SNP) detection by using self-assembled DNA concatemers. Capture probes, bound to magnetic beads, can joint mediator probes by T4 DNA ligase in the presence of target DNA that is complementary to the capture probe and mediator probe. The mediator probes trigger self-assembly of two auxiliary probes on magnetic beads to form DNA concatemers. Separated by a magnetic rack, the double-stranded concatemers on beads can recruit a great amount of SYBR Green I and eventually result in amplified fluorescent signals. In comparison with reported methods for SNP detection, the concatemer-based approach has significant advantages of low background, simplicity, and ultrasensitivity, making it as a convenient platform for clinical applications. As a proof of concept, BRAF(T1799A) oncogene mutation, a SNP involved in diverse human cancers, was used as a model target. The developed approach using a fluorescent intercalator can detect as low as 0.1 fM target BRAF(T1799A) DNA, which is better than those previously published methods for SNP detection. This method is robust and can be used directly to measure the BRAF(T1799A) DNA in complex human serum with excellent recovery (94-103%). It is expected that this assay principle can be directed toward other SNP genes by simply changing the mediator probe and auxiliary probes. PMID:24267087

  20. A Complex Deoxyribonucleic Acid Looping Configuration Associated with the Silencing of the Maternal Igf2 Allele

    PubMed Central

    Qiu, Xinwen; Vu, Thanh H.; Lu, Qiucheng; Ling, Jian Qun; Li, Tao; Hou, Aiju; Wang, Shu Kui; Chen, Hui Ling; Hu, Ji Fan; Hoffman, Andrew R.

    2008-01-01

    Alternate interactions between the H19 imprinting control region (ICR) and one of the two Igf2 differentially methylated regions has been proposed as a model regulating the reciprocal imprinting of Igf2 and H19. To study the conformation of this imprint switch, we performed a systematic structural analysis across the 140 kb of the mouse Igf2-H19 region, which includes enhancers located both between the two genes as well as downstream of H19, by using a scanning chromosome conformation capture (3C) technique. Our results suggest that on the active paternal Igf2 allele, the various enhancers have direct access to the Igf2 promoters, whereas the imprinted silent maternal Igf2 allele assumes a complex three-dimensional knotted loop that keeps the enhancers away from the Igf2 promoters and allows them to interact with the H19 promoter. This complex DNA looping of the maternal allele is formed by interactions involving differentially methylated region 1, the ICR, and enhancers. Binding of CTC-binding factor to the maternal, unmethylated ICR in conjunction with the presence of multicomplex components including interchromosomal interactions, create a barrier blocking the access of all enhancers to Igf2, thereby silencing the maternal Igf2. This silencing configuration exists in newborn liver, mouse embryonic fibroblast, and embryonic stem cells and persists during mitosis, conferring a mechanism for epigenetic memory. PMID:18356289

  1. Intracellular localization and effects on cell division of a plasmid blocked in deoxyribonucleic acid replication.

    PubMed Central

    MacQueen, H A; Donachie, W D

    1977-01-01

    Cell division in a uvr mutant of Escherichia coli is suppressed by introdcution into the cell of an ultraviolet-irradiated plasmid. Autoradiography was used to determine the localization of the incoming plasmid and the segregation pattern of the host chromosomes. PMID:334739

  2. The ciliary proteins Meckelin and Jouberin are required for retinoic acid-dependent neural differentiation of mouse embryonic stem cells.

    PubMed

    Romani, Sveva; Illi, Barbara; De Mori, Roberta; Savino, Mauro; Gleeson, Joseph G; Valente, Enza Maria

    2014-01-01

    The dysfunction of the primary cilium, a complex, evolutionarily conserved, organelle playing an important role in sensing and transducing cell signals, is the unifying pathogenetic mechanism of a growing number of diseases collectively termed "ciliopathies", typically characterized by multiorgan involvement. Developmental defects of the central nervous system (CNS) characterize a subset of ciliopathies showing clinical and genetic overlap, such as Joubert syndrome (JS) and Meckel syndrome (MS). Although several knock-out mice lacking a variety of ciliary proteins have shown the importance of primary cilia in the development of the brain and CNS-derived structures, developmental in vitro studies, extremely useful to unravel the role of primary cilia along the course of neural differentiation, are still missing. Mouse embryonic stem cells (mESCs) have been recently proven to mimic brain development, giving the unique opportunity to dissect the CNS differentiation process along its sequential steps. In the present study we show that mESCs express the ciliary proteins Meckelin and Jouberin in a developmentally-regulated manner, and that these proteins co-localize with acetylated tubulin labeled cilia located at the outer embryonic layer. Further, mESCs differentiating along the neuronal lineage activate the cilia-dependent sonic hedgehog signaling machinery, which is impaired in Meckelin knock-out cells but results unaffected in Jouberin-deficient mESCs. However, both lose the ability to acquire a neuronal phenotype. Altogether, these results demonstrate a pivotal role of Meckelin and Jouberin during embryonic neural specification and indicate mESCs as a suitable tool to investigate the developmental impact of ciliary proteins dysfunction.

  3. Immobilization mechanisms of deoxyribonucleic acid (DNA) to hafnium dioxide (HfO2) surfaces for biosensing applications.

    PubMed

    Fahrenkopf, Nicholas M; Rice, P Zachary; Bergkvist, Magnus; Deskins, N Aaron; Cady, Nathaniel C

    2012-10-24

    Immobilization of biomolecular probes to the sensing substrate is a critical step for biosensor fabrication. In this work we investigated the phosphate-dependent, oriented immobilization of DNA to hafnium dioxide surfaces for biosensing applications. Phosphate-dependent immobilization was confirmed on a wide range of hafnium oxide surfaces; however, a second interaction mode was observed on monoclinic hafnium dioxide. On the basis of previous materials studies on these films, DNA immobilization studies, and density functional theory (DFT) modeling, we propose that this secondary interaction is between the exposed nucleobases of single stranded DNA and the surface. The lattice spacing of monoclinic hafnium dioxide matches the base-to-base pitch of DNA. Monoclinic hafnium dioxide is advantageous for nanoelectronic applications, yet because of this secondary DNA immobilization mechanism, it could impede DNA hybridization or cause nonspecific surface intereactions. Nonetheless, DNA immobilization on polycrystalline and amorphous hafnium dioxide is predominately mediated by the terminal phosphate in an oriented manner which is desirable for biosensing applications.

  4. Epidermal growth factor inhibits radioiodine uptake but stimulates deoxyribonucleic acid synthesis in newborn rat thyroids grown in nude mice

    SciTech Connect

    Ozawa, S.; Spaulding, S.W. )

    1990-08-01

    We have studied the effect of altering the level of circulating epidermal growth factor (EGF) on the function and growth of newborn rat thyroids transplanted into nude mice. Preliminary studies confirmed that sialoadenectomy reduced circulating EGF levels in nude mice (from 0.17 +/- 0.02 to 0.09 +/- 0.02 ng/ml), and that ip injection of 5 micrograms EGF raised EGF levels (the peak level of 91.7 +/- 3.3 ng/ml was achieved at 30 min, with a subsequent half-life of about 1 h). The radioiodine uptake by newborn rat thyroid transplants in the sialoadenectomized and sham-operated animals correlated inversely with the circulating EGF levels determined when the mice were killed (r = -0.99). Low-dose TSH treatment (0.1 microU/day) generally stimulated the radioiodine uptake, but high-dose TSH groups (100 microU/day) were not significantly different from the control group. The 5-day nuclear (3H)thymidine labeling index was 6.8 +/- 0.5% IN newborn rat thyroid transplants grown in sialoadenectomized animals, 13.1 +/- 0.3% in sham-operated animals, and 16.8 +/- 0.5% in nude mice receiving 5 micrograms EGF ip daily. In general, both low-dose and high-dose TSH promoted DNA synthesis under low EGF conditions but were ineffective in the presence of higher levels of EGF. Adult rat thyroid transplants showed no significant responses. Although sialoadenectomy may alter other factors besides EGF, it appears that changes in the levels of circulating EGF within the physiological range affect the function and growth of newborn rat thyroid transplants. Circulating EGF may play a role in thyroid maturation and may also be involved in the regulation of thyroid function throughout life.

  5. Deoxyribonucleic acid of Cancer pagurus. II. Tempiate activity for a DNA-dependent DNA polymerase of eukaryotic cells

    PubMed Central

    De Recondo, Anne-Marie; Londos-Gagliardi, Danielle; Aubel-Sadron, Geneviève

    1974-01-01

    The template activity of Cancer pagurus DNA and its two components (poly d(A-T) and main component) in response to a DNA polymerase purified from regenerating rat liver has been studied and compared to the results previously obtained with synthetic templates. In the double-stranded native state, whole crab DNA and the main component were poor templates. Their replication was increased by thermal denaturation and inhibited by actinomycin. Like the synthetic copolymer poly[d(A-T)·d(T-A)], native crab poly d(A-T) could be copied and its duplication was not inhibited by actinomycin. The structural difference between native poly d(A-T) Form I, isolated on a density gradient, and partially renatured poly d(A-T) Form II, isolated on hydroxylapatite, resulted in a modification of their template activity. The kinetic studies of [3H] dGMP and [3H] dAMP incorporation confirmed the importance of single-stranded regions (particulary dC regions) in the initiation of the in vitro duplication. PMID:10793685

  6. Comparative studies on zirconia and graphene composites obtained by one-step and stepwise electrodeposition for deoxyribonucleic acid sensing.

    PubMed

    Yang, Tao; Guo, Xiuhong; Kong, Qianqian; Yang, Ruirui; Li, Qianhe; Jiao, Kui

    2013-07-01

    In this paper, the comparison of two kinds of electrochemically reduced graphene oxide (ERGNO) and zirconia composites, obtained by one-step (ZrO2-ERGNO) and stepwise (ZrO2/ERGNO) electrodeposition for DNA sensing, is systematically studied. The resulting composites were characterized by scanning electron microscopy, cyclic voltammetry, and differential pulse voltammetry. The results indicated that the ZrO2-ERGNO presented fine globular nanostructure. However, ZrO2/ERGNO presented agglomerate massive microstructure due to the absence of the oxygen-containing groups of graphene oxide, confirming the oxygen-containing groups provided a better affinity for the deposition of ZrO2. Due to the strong binding of the phosphate groups of DNA with the zirconia film, DNA probes were attached on the ZrO2-based composites. ZrO2-ERGNO/Au owning fine nanostructure presented larger surface area than microstructured ZrO2/ERGNO/Au. Moreover, compared with microstructured ZrO2/ERGNO, the nanostructured ZrO2-ERGNO provided more accessible space for immobilized DNA probe hybridization with target sequence, which consequently resulted in higher hybridization efficiency. Therefore, the ZrO2-ERGNO was chosen for fabricating DNA sensor with a limit of detection 1.21×10(-14) mol L(-1).

  7. Effect of base-pair stability of nearest-neighbor nucleotides on the fidelity of deoxyribonucleic acid synthesis.

    PubMed

    Patten, J E; So, A G; Downey, K M

    1984-04-10

    The influence of the stability of base pairs formed by nearest-neighbor nucleotides on misincorporation frequency has been studied with the large fragment of DNA polymerase I, the alternating DNA copolymers, poly(dI-dC) and poly-(dG-dC), as template-primers, and dGTP, dITP, and dCTP as substrates. We have utilized the difference in thermodynamic stability between the doubly H-bonded I X C base pair and triply H-bonded G X C base pair to examine the effects of base-pair stability of both the "preceding" and the "following" nucleotides on the frequency of insertion of a mismatched nucleotide, as well as on its stable incorporation into polynucleotide. The present studies demonstrate that the stability of the base pairs formed by nearest-neighbor nucleotides affects the frequency of incorporation of noncomplementary nucleotides. Misincorporation frequency is increased when the nearest-neighbor nucleotides form more stable base pairs with the corresponding nucleotides in the template and is decreased when they form less stable base pairs. The stability of the base pair formed by a nucleotide either preceding (5' to) or following (3' to) a misincorporated nucleotide influences misincorporation frequency, but by different mechanisms. The stability of base pairs formed by preceding nucleotides affects the rate of insertion of mismatched nucleotide but does not protect the mismatched nucleotide from removal by the 3' to 5' exonuclease activity. In contrast, the stability of a base pair formed by a following nucleotide determines whether a misincorporated nucleotide is extended or excised by affecting the ability of the enzyme to edit errors of incorporation. PMID:6722115

  8. Evaluation of non-radioactive labelling and detection of deoxyribonucleic acids. Part Two: Colorigenic methods and comparison with chemiluminescent methods.

    PubMed

    Rihn, B; Bottin, M C; Coulais, C; Martinet, N

    1995-06-01

    The diagnosis of genetic infections and cancerous diseases is carried out more and more often at a molecular level using Southern's technique which is based on the use of 32P-labelled DNA. In order to circumvent the risks and rapid decrease in radioactivity associated with these latter techniques, new colorigenic methods have been developed. In this work, we describe the use of dTTP analogues (digoxigenin-dUTP and biotin-dUTP) for the labelling of probes and detection of target DNA. Using digoxigenin-11-dUTP, 0.1 aM of a 561 bp target DNA was detected by using a modified Southern procedure. The reliability and the high sensitivity of such methods make them a good tool for DNA investigation in research as well as in testing laboratories.

  9. Three forms of gonadotropin-releasing hormone in a perciform fish (Sparus aurata): complementary deoxyribonucleic acid characterization and brain localization.

    PubMed

    Gothilf, Y; Muñoz-Cueto, J A; Sagrillo, C A; Selmanoff, M; Chen, T T; Kah, O; Elizur, A; Zohar, Y

    1996-09-01

    Three forms of GnRH-salmon (sGnRH), seabream (sb-GnRH), and chicken (cGnRH-II)-have been described in the gilthead seabream (Sparus aurata) brain, and the cDNA encoding the sbGnRH precursor was recently isolated. In the present study, the cDNAs encoding the sGnRH and cGnRH-II were isolated and characterized, and the neurons producing the three GnRHs were localized in the seabream brain. Fragments of sGnRH and cGnRH-II cDNAs were amplified by polymerase chain reaction and used as probes to isolate the full-length cDNAs from a brain cDNA library. The cDNA encoding the cGnRH-II precursor is 573 nucleotides (nt) long, and the cDNA encoding the sGnRH precursor is 1971 nt in length with an unusually long 5' untranslated region. Specific single-strand DNA probes for in situ detection of mRNA were designed according to nonconserved regions among the three GnRH c-DNAs. Localization of GnRH mRNA-producing cells in the brain revealed five distinct populations of cells: sGnRH-producing cells in the ventromedial olfactory bulbs and the terminal nerve, sbGnRH-producing cells in the preoptic area and the ventral thalamus, and cGnRH-II-producing cells in the midbrain tegmentum. The discrete sites of expression of the three forms of GnRH indicate that only sbGnRH is directly involved in the control of gonadotropin secretion. PMID:8862782

  10. Fate of transgenic deoxyribonucleic acid fragments in digesta and tissues of rabbits fed genetically modified soybean meal.

    PubMed

    Morera, P; Basiricò, L; Ronchi, B; Bernabucci, U

    2016-03-01

    Numerous animal feeding studies have investigated the presence of DNA from transgenic plants in tissues from different animal species, but the data reported are sometimes controversial. The aim of this study was to investigate the presence of transgenic DNA (tDNA) in the digesta and tissues of a meat rabbit breed fed genetically modified (GM) soybean meal. Fifteen male New Zealand White rabbits were used for the experimental trial. Ten rabbits (treated group [TG]) were fed a mixed feed containing 10% GM soybean meal and 5 rabbits (control group [CG]) received a mixed feed containing conventional soybean meal, both from weaning (28 d of age) to slaughter (80 ± 3 d). Samples of blood, liver, kidney, heart, stomach, intestine (jejunum), lateral quadricep muscle, longissimus muscle, and perirenal adipose tissue were collected to assess the possible DNA transfer from GM feed to animal tissues. Samples of stomach contents and feces were also taken to study the degradability of ingested tDNA from feed in the digestive tract of rabbit. Moreover, samples of hair were collected to determine the possible environmental contamination from feed powders present on the farm. The DNA extraction was performed using specific genomic DNA kits. All samples were monitored, by using real-time PCR, for oligonucleotide primers and probes specific for the transgenic Roundup Ready soybean 40-3-2 and for the endogenous () gene. As an internal control of rabbit tissues, the presence of the () gene was used. In this study, no fragments of tDNA were detectable in tissue DNA samples of rabbits except in the extracted DNA from stomach digesta, feces, and hair of rabbits fed with GM soybean. Similar results were found for the reference gene, whereas the presence of the gene was detected in all rabbit tissues. The lack of tDNA of soybean in rabbit tissues represents an important result, which demonstrates that meat from rabbits fed a diet containing GM feed is as that derived from rabbits fed conventional crops. The recombinant DNA recovered in the stomach digesta and in feces indicates an incomplete digestion of the soybean DNA in the gastrointestinal tract of the rabbit, whereas the presence of trace soybean transgene in the hair of the TG rabbits is suggestive of an environmental contamination. PMID:27065289

  11. Effects of Bilberry on Deoxyribonucleic Acid Damage and Oxidant-Antioxidant Balance in the Lens, Induced by Ultraviolet Radiation

    PubMed Central

    ALY, Eman Mohamed; ALI, Mervat Ahmed

    2014-01-01

    Background: This study investigated the possible protective effects of bilberry extract after exposing rat eyes to ultraviolet-B (UV-B) radiation. Methods: Four groups of rats were included in this study, each consisting of 10 Wistar rats. The first group acted as the control, and the second group was exposed to UV-B, 5 KJ/m2 (λm = 300 nm), for 15 minutes. The third group was orally administered bilberry extract (160 mg twice per day) for two weeks before exposure to the UV-B, while the fourth group was administered the same dose of bilberry extract for two weeks before euthanisation. A comet assay was used to examine DNA damage, while the malondialdehyde (MDA) level and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), activities were measured in the lens. Results: After exposing the rats to UV-B radiation, the mean percentage tail DNA and tail moment were significantly increased (P < 0.001) when compared to the control group. In the same context, the lens tissue MDA levels and CAT activity were also significantly increased (P < 0.001). The supplementation of the bilberry extract was found to improve the comet assay parameters and enzymatic activity of the rat lens tissue. Conclusion: The administration of bilberry led to a decrease in the oxidative stress in the lens tissues and DNA damage induced by UV-B radiation in the lenses of Wistar rats. PMID:24639607

  12. Minimizing adsorption of histidine-tagged proteins for the study of protein-deoxyribonucleic acid interactions by kinetic capillary electrophoresis.

    PubMed

    Liyanage, Ruchi; Krylova, Svetlana M; Krylov, Sergey N

    2013-12-27

    Affinity interactions between DNA and proteins play a crucial role in many cellular processes. Kinetic Capillary Electrophoresis is a highly efficient tool for kinetic and equilibrium studies of protein-DNA interactions. Recombinant proteins, which are typically used for in vitro studies of protein-DNA interactions, are often expressed with a His tag to aid in their purification. In this work, we study how His tags affect Kinetic Capillary Electrophoresis analysis of protein-DNA interactions. We found that the addition of a His tag can increase or decrease protein adsorption to a bare-silica capillary wall, dependent on the protein. For Kinetic Capillary Electrophoresis measurements, it is essential to have as little protein adsorption as possible. We screened a number of capillary coatings to reduce adsorption of the His-tagged DNA mismatch repair protein MutS to the capillary wall and found that UltraTrol LN was the most effective coating. The effectiveness of the coating was confirmed with the prevention of adsorption of His-tagged fat mass and obesity-associated protein. Under typical conditions, the coating reduced protein adsorption to a level at which accurate Kinetic Capillary Electrophoresis analysis of protein-DNA interactions was possible. We further used Kinetic Capillary Electrophoresis to study how the His tag affected Kd of protein-DNA interactions for the MutS protein. Using UltraTrol LN, we found that the effect of the His tag was insignificant.

  13. The role of essential fatty acids in development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acids are aliphatic monocarboxylic acids. They are classified as saturated, monounsaturated, or polyunsaturated fatty acids depending upon the number of double bonds in the carbon chain. Saturated fatty acids have no double bonds, monounsaturated fatty acids have 1 double bond, and polyunsat...

  14. 77 FR 68133 - Guidance for Industry: Use of Nucleic Acid Tests on Pooled and Individual Samples From Donors of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-15

    ... November 28, 2011 (76 FR 72950), FDA announced the availability of the draft guidance of the same title...) deoxyribonucleic acid (DNA) and recommendations for product testing and disposition, donor management, methods for... screen blood donors for HBV DNA. FDA is also providing these blood establishments with...

  15. Transcription of fractionated mammalian chromatin by mammalian ribonucleic acid polymerase. Demonstration of temperature-dependent rifampicin-resistant initiation sites in euchromatin deoxyribonucleic acid

    PubMed Central

    Chesterton, C. James; Coupar, Barbara E. H.; Butterworth, Peter H. W.

    1974-01-01

    The chromatin fractionation method of Frenster et al. (1963) as modified by Leake et al. (1972) was used to prepare fragments of euchromatin from rat liver nuclei. These remain soluble in 5mm-MgCl2, and contain DNA of maximum mol.wt. 1×106–2×106. The fragments were separated from condensable chromatin on a sucrose gradient. Euchromatin contains endogenous DNA-dependent RNA polymerase, and most of the nascent RNA labelled in vivo or in vitro. Euchromatin fragments allow initiation of transcription by added purified rat liver form-B RNA polymerase and contain temperature-dependent rifampicin-resistant initiation sites for the form-B enzyme. These findings indicate that transcription of the euchromatin regions of interphase chromosomes is not initiated in condensed chromatin, but is initiated within the euchromatin stretches. Condensable chromatin also contains most of these activities, but is not associated with nascent RNA. PMID:4464858

  16. Interaction of aflatoxin B1 and cyclopiazonic acid toxicities.

    PubMed

    Yates, I E; Cole, R J; Giles, J L; Dorner, J W

    1987-01-01

    Toxic properties of the mycotoxins cyclopiazonic acid and aflatoxin B1 have been analyzed separately and in combination by monitoring their effects on luminescence in the marine bacterium Photobacterium phosphoreum, Strain NCMB 844. Genotoxicity was analyzed with a dark mutant of this organism whose reversion to the bioluminescent condition is stimulated by compounds attacking guanine sites in deoxyribonucleic acids. In this assay, cyclopiazonic acid, unlike aflatoxin B1, is not enhanced by cyclopiazonic acid when the two mycotoxins are assayed in combination. Cytotoxicity was assessed by the diminution of bioluminescence in a separate assay system with strain NRRLB-1177 of P. phosphoreum. Cyclopiazonic acid is more cytotoxic than aflatoxin B1, and concentrations of cyclopiazonic acid required for cytotoxicity decreases with time, whereas aflatoxin B1 cytotoxic expression does not change significantly with time under most assay conditions. Aflatoxin B1 and cyclopiazonic acid assayed as a dose pair indicate that these mycotoxins elicit their effects by independent modes of action.

  17. Polymerization of epoxidized triglycerides with fluorosulfonic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of triglycerides as agri-based renewable raw materials for the development of new products is highly desirable in view of uncertain future petroleum prices. A new method of polymerizing epoxidized soybean oil has been devised with the use of fluorosulfonic acid. Depending on the reaction con...

  18. Disruption of the vacuolar calcium-ATPases in arabidopsis results in the activation of a salicylic acid-dependent programmed cell death pathway

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Calcium (Ca2+) signals regulate many aspects of plant development, including the Hypersensitive Response (HR) that triggers a programmed cell death response to protect a plant from a pathogen. A transient increase in cytosolic Ca2+ ([Ca2+]cyt ) results from Ca2+ entry from the apoplast or release fr...

  19. Abscisic acid-dependent regulation of small rubber particle protein gene expression in Taraxacum brevicorniculatum is mediated by TbbZIP1.

    PubMed

    Fricke, Julia; Hillebrand, Andrea; Twyman, Richard M; Prüfer, Dirk; Schulze Gronover, Christian

    2013-04-01

    Natural rubber is a high-molecular-mass biopolymer found in the latex of >2,500 plant species, including Hevea brasiliensis, Parthenium argentatum and Taraxacum spp. The active sites of rubber biosynthesis are rubber particles, which comprise a hydrophobic rubber core surrounded by a phospholipid monolayer membrane containing species-dependent lipids and associated proteins. Small rubber particle proteins are the most abundant rubber particle-associated proteins in Taraxacum brevicorniculatum (TbSRPPs) and may promote rubber biosynthesis by stabilizing the rubber particle architecture. We investigated the transcriptional regulation of genes encoding SRPPs and identified a bZIP transcription factor (TbbZIP.1) similar to the Arabidopsis thaliana ABI5-ABF-AREB subfamily, which is thought to include downstream targets of ABA and/or abiotic stress-inducible protein kinases. The TbbZIP.1 gene was predominantly expressed in laticifers and regulates the expression of TbSRPP genes in an ABA-dependent manner. The individual TbSRPP genes showed distinct induction profiles, suggesting diverse roles in rubber biosynthesis and stress adaptation. The potential involvement of TbSRPPs in the adaptation of T. brevicorniculatum plants to environmental stress is discussed based on our current knowledge of the stress-response roles of SRPPs and their homologs, and the protective function of latex and rubber against pathogens. Our data suggest that TbSRPPs contribute to stress tolerance in T. brevicorniculatum and that their effects are mediated by TbbZIP.1.

  20. Uric acid and hypertension.

    PubMed

    Feig, Daniel I

    2011-09-01

    A link between serum uric acid and the development of hypertension was first hypothesized in the 1870s. Although numerous epidemiologic studies in the 1980s and 1990s suggested an association, relatively little attention was paid to it until recently. Animal models have suggested a two-step pathogenesis by which uric acid initially activates the renin angiotensin system and suppresses nitric oxide, leading to uric acid-dependent increase in systemic vascular resistance, followed by a uric acid-mediated vasculopathy, involving renal afferent arterioles, resulting in a late sodium-sensitive hypertension. Initial clinical trials in young patients have supported these mechanisms in young patients but do not yet support pharmacologic reduction of serum uric acid as first-line therapy for hypertension.

  1. Increase in liver nuclear tri-iodothyronine receptors associated with increased deoxyribonucleic acid by long-term administration of tri-iodothyronine in thyroidectomized rats

    PubMed Central

    Nakamura, Hirotoshi; Hamada, Satoshi; Imura, Hiroo

    1979-01-01

    The effect of long-term administration of small amounts of tri-iodothyronine was examined on the nuclear tri-iodothyronine receptors in rat liver. The maximal binding capacity (Cmax.) and association constant (Ka) of the receptors were determined in thyroidectomized rats given vehicle alone (group A), 2μg of tri-iodothyronine/100g body wt. (group B) or 7μg of tri-iodothyronine/100g body wt. (group C) for 2 weeks. Scatchard analyses with correction for the amount of endogenous tri-iodothyronine revealed that Cmax. values per g of liver were increased to 1.5 and 2.7 times the control value in groups B and C respectively. Since concentrations of DNA per g of liver were significantly increased in the two groups of hormone-treated rats, Cmax. values per mg of DNA were nearly the same in group B, but still increased significantly in group C compared with group A. Ka values remained unchanged in all three groups of animals. Mitochondrial α-glycerophosphate dehydrogenase activity was 9.6 and 28.7 times as high in groups B and C, respectively, as in group A. Concentrations of endogenous tri-iodothyronine bound to non-histone protein were substantially increased in groups B and C, although concentrations of serum tri-iodothyronine remained rather low. The results obtained indicate that the long-term administration of tri-iodothyronine in small doses induces an increase in the nuclear receptors associated with increased DNA with and without accompanying a relative increase in the receptor concentration in thyroidectomized rats. Also the hormonal effect is closely related to the total number of the nuclear receptors and the concentrations of nuclear tri-iodothyronine bound to the receptors rather than the serum tri-iodothyronine concentrations. PMID:230825

  2. Metronomic Adjuvant Chemotherapy Improves Treatment Outcome in Nasopharyngeal Carcinoma Patients With Postradiation Persistently Detectable Plasma Epstein-Barr Virus Deoxyribonucleic Acid

    SciTech Connect

    Twu, Chih-Wen; Wang, Wen-Yi; Chen, Chien-Chih; Liang, Kai-Li; Jiang, Rong-San; Wu, Ching-Te; Shih, Yi-Ting; Lin, Po-Ju; Liu, Yi-Chun; Lin, Jin-Ching

    2014-05-01

    Purpose: To investigate the effects of adjuvant chemotherapy in nasopharyngeal carcinoma (NPC) patients with persistently detectable plasma Epstein-Barr virus DNA (pEBV DNA) after curative radiation therapy plus induction/concurrent chemotherapy. Methods and Materials: The study population consisted of 625 NPC patients with available pEBV DNA levels before and after treatment. Eighty-five patients with persistently detectable pEBV DNA after 1 week of completing radiation therapy were eligible for this retrospective study. Of the 85 patients, 33 were administered adjuvant chemotherapy consisting of oral tegafur-uracil (2 capsules twice daily) for 12 months with (n=4) or without (n=29) preceding intravenous chemotherapy of mitomycin-C, epirubicin, and cisplatin. The remaining 52 patients who did not receive adjuvant chemotherapy served as the control group. Results: Baseline patient characteristics at diagnosis (age, sex, pathologic type, performance status, T classification, N classification, and overall stage), as well as previous treatment modality, were comparable in both arms. After a median follow-up of 70 months for surviving patients, 45.5% (15 of 33 patients) with adjuvant chemotherapy and 71.2% (37 of 52 patients) without adjuvant chemotherapy experienced tumor relapses (P=.0323). There were a significant reduction in distant failure (P=.0034) but not in local or regional recurrence. The 5-year overall survival rate was 71.6% for patients with adjuvant chemotherapy and 28.7% for patients without adjuvant chemotherapy (hazard ratio 0.27; 95% confidence interval 0.17-0.55; P<.0001). Conclusions: Our retrospective data showed that adjuvant chemotherapy can reduce distant failure and improve overall survival in NPC patients with persistently detectable pEBV DNA after curative radiation therapy plus induction/concurrent chemotherapy.

  3. Mechanism of deoxyribonucleic acid breakage induced by 4'-(9-acridinylamino)methanesulfon-m-anisidide and copper: role for cuprous ion and oxygen free radicals

    SciTech Connect

    Wong, A.; Huang, C.H.; Crooke, S.T.

    1984-06-19

    4-(9-Acridinylamino)methanesulfon-m-anisidide (mAMSA) interacts with Cu(II) ions, as indicated by changes in the mAMSA absorption spectrum induced by Cu(II). The spectral changes are due to the oxidation of mAMSA by Cu(II), resulting in an oxidized mAMSA product and Cu(I). Cu(I) plays an important role in the mAMSA-Cu(II)-induced DNA breakage, since in the presence of neocuproine the DNA breakage is inhibited. Up to 200 ..mu..M, Cu(I) by itself is virtually ineffective, in contrast to the mixture of mAMSA and Cu(II). This suggests that mAMSA, aside from reducing Cu(II) to Cu(I), may play a role in mediating DNA breakage. The DNA breakage was reduced in partially anaerobic conditions, indicating the involvement of molecular oxygen. Catalase and 4,5-dihydroxy-1,2-benzenedisulfonate inhibited the DNA breakage completely, indicating that hydrogen peroxide and superoxide radicals mediate DNA breakage. 1,3-Diazabicyclo(2.2.2)octane partially inhibited the breakage, suggesting that singlet oxygen is involved. The available evidence supports a mechanism indicating the formation of a DNA x mAMSA x Cu(II) ternary complex and the subsequent oxidation-reduction of the complex to form DNA x mAQDI x Cu(I). The oxidation of the complexed Cu(I) may result in reduction of oxygen to oxygen free radicals which induce DNA breaks.

  4. R Factor Proteins Synthesized in Escherichia coli Minicells: Incorporation Studies with Different R Factors and Detection of Deoxyribonucleic Acid-Binding Proteins1

    PubMed Central

    Levy, Stuart B.

    1974-01-01

    Analysis of the protein synthesized by Escherichia coli minicells containing R factors demonstrated a variety of low- and high-molecular-weight polypeptides in sodium dodecyl sulfate (SDS)-polyacrylamide gels. Only half of this protein was released into a soluble fraction on lysis of these minicells. The other half remained associated with the minicell envelope. The efficiency of precursor incorporation into protein and the kinds of proteins synthesized changed with the age of the minicells at the time of harvest. About 1 to 2% of the soluble R factor-coded protein bound to calf thymus, E. coli, or R factor DNA-cellulose. Although most of these proteins were excluded from Sephadex G-100 columns, they migrated chiefly as low-molecular-weight-polypeptides (13,000 to 15,000) in SDS-polyacrylamide gels. Additional DNA-binding proteins that appeared to be higher-molecular-weight peptides were noted in extracts from younger minicells. At least one protein, identified as an SDS band, appeared to bind selectively to R factor DNA-cellulose. Minicells with R factors also contained DNA-binding proteins of cell origin, including the core RNA polymerase. No such binding proteins were found in R− minicells. These studies suggest that: (i) R factors code for proteins that may be involved in their own DNA metabolism; (ii) R factor DNA-binding proteins may be associated with larger host cell DNA-binding proteins or subunits of larger R factor proteins; and (iii) the age of the minicell influences the extent of protein synthesis and the kinds of proteins synthesized by R factors in minicells. Images PMID:4612023

  5. Purification of closed circular lambda deoxyribonucleic acid and its sedimentation properties as a function of Sodium chloride concentration and ethidium binding.

    PubMed

    Hinton, D M; Bode, V C

    1975-02-10

    The sedimentation of circular lambda DNA suggests that the molecular undergoes significant changes in shape and super-coiling as the NaC1 concentration increases. Closed circular lambda DNA, species I, isolated and purified from superinfected immune bacteria, sediments in sucrose gradients of low ionic strength at a rate 2.0 times faster than linear lambda DNA, species III. The addition of ethidium causes the sedimentation rate of species I DNA to decrease until enough dye is bound to remove 121 supercoils per molecule. At this point, species I co-sediments with nicked and nonsupercoiled species II. Futher additions of ethidium cause the sedimentation rate to increase until the relative rate of species I is again at least twice that of species III. This classical behavior is altered when NaC1 is present in the buffer. In 1.0 M NaC1 the changes in S are complex. Initially, species I sediments 1.55 times faster than species III. Titration with ethidium caused a decrease in S to an early minimum value, than an increase to a first maximum, followed by a decrease to the S of species II. At this point enough dye has intercalated to remove 208 superhelical turns. Further additions of dye introduce supercoils and cause S to increase again. In 0.1 to 0.4 M NaC1 the relative S of species I is 1.69 and 1.59, respectively. If titrated with ethidium, S first increases to a maximum value then decreases to the minimum rate when enough dye is bound to remove 158 and 183 supercoils, respectively. The results indicate an increase in the superhelix density from 0.026 turns per 10 base pairs in buffer alone to 0.045 in the same buffer with 1.0 M NaC1. If this change in superhelix density results from a concomitant change in the average rotation angle between base pairs in the Watson-Crick helix, the addition of 1.0 M NaC1 alters the rotation angle by 0.68 degrees per base pair.

  6. Semiconductor sensor embedded microfluidic chip for protein biomarker detection using a bead-based immunoassay combined with deoxyribonucleic acid strand labeling.

    PubMed

    Lin, Yen-Heng; Peng, Po-Yu

    2015-04-15

    Two major issues need to be addressed in applying semiconductor biosensors to detecting proteins in immunoassays. First, the length of the antibody on the sensor surface surpasses the Debye lengths (approximately 1 nm, in normal ionic strength solution), preventing certain specifically bound proteins from being tightly attached to the sensor surface. Therefore, these proteins do not contribute to the sensor's surface potential change. Second, these proteins carry a small charge and can be easily affected by the pH of the surrounding solution. This study proposes a magnetic bead-based immunoassay using a secondary antibody to label negatively charged DNA fragments for signal amplification. An externally imposed magnetic force attaches the analyte tightly to the sensor surface, thereby effectively solving the problem of the analyte protein's distance to the sensor surface surpassing the Debye lengths. In addition, a normal ion intensity buffer can be used without dilution for the proposed method. Experiments revealed that the sensitivity can be improved by using a longer DNA fragment for labeling and smaller magnetic beads as solid support for the antibody. By using a 90 base pair DNA label, the signal was 15 times greater than that without labeling. In addition, by using a 120 nm magnetic bead, a minimum detection limit of 12.5 ng mL(-1) apolipoprotein A1 can be measured. Furthermore, this study integrates a semiconductor sensor with a microfluidic chip. With the help of microvalves and micromixers in the chip, the length of the mixing step for each immunoassay has been reduced from 1h to 20 min, and the sample volume has been reduced from 80 μL to 10 μL. In practice, a protein biomarker in a urinary bladder cancer patient's urine was successfully measured using this technique. This study provides a convenient and effective method to measure protein using a semiconductor sensor.

  7. Rapid deoxyribonucleic acid analysis by allele-specific polymerase chain reaction for detection of mutations in the steroid 21-hydroxylase gene

    SciTech Connect

    Wilson, R.C.; Wei, J.Q.; Cheng, K.C.

    1995-05-01

    Rapid DNA analysis based on allele-specific polymerase chain reaction (PCR) using mutation site-specific primers was developed to detect mutations in the CYP21 gene known to cause steroid 21-hydroxylase deficiency. In contrast to the previous method, in which PCR of genomic DNA was followed by dot blot analysis with radio active probes and multiple rounds of stripping and reprobing for each of the 8 most common mutation sites, the results using this new method were immediately visualized after the PCR run by ethidium bromide-stained agarose gel electrophoresis. Using allele-specific PCR, mutation(s) were identified on 148 affected chromosomes out of 160 tested. Although mutation(s) were identified on only one chromosome of 11 of these patients, their parents showed a consistent pattern on DNA analysis. The only exception was that in one family, in which the parents each had a detectable mutation, a mutation was detected on only one allele of the patient. Most likely there is a mutation in the patient`s other allele that could have arisen de novo or was inherited from the parent and was not evident in the transmitting parent`s phenotype. When compared with the dot blot procedure, allele-specific PCR is more rapid, less labor-intensive, and avoids the use of radioactivity. 26 refs., 3 figs., 2 tabs.

  8. Existing and emerging detection technologies for DNA (Deoxyribonucleic Acid) finger printing, sequencing, bio- and analytical chips: a multidisciplinary development unifying molecular biology, chemical and electronics engineering.

    PubMed

    Kumar Khanna, Vinod

    2007-01-01

    The current status and research trends of detection techniques for DNA-based analysis such as DNA finger printing, sequencing, biochips and allied fields are examined. An overview of main detectors is presented vis-à-vis these DNA operations. The biochip method is explained, the role of micro- and nanoelectronic technologies in biochip realization is highlighted, various optical and electrical detection principles employed in biochips are indicated, and the operational mechanisms of these detection devices are described. Although a diversity of biochips for diagnostic and therapeutic applications has been demonstrated in research laboratories worldwide, only some of these chips have entered the clinical market, and more chips are awaiting commercialization. The necessity of tagging is eliminated in refractive-index change based devices, but the basic flaw of indirect nature of most detection methodologies can only be overcome by generic and/or reagentless DNA sensors such as the conductance-based approach and the DNA-single electron transistor (DNA-SET) structure. Devices of the electrical detection-based category are expected to pave the pathway for the next-generation DNA chips. The review provides a comprehensive coverage of the detection technologies for DNA finger printing, sequencing and related techniques, encompassing a variety of methods from the primitive art to the state-of-the-art scenario as well as promising methods for the future.

  9. Electrochemical deoxyribonucleic acid biosensor based on electrodeposited graphene and nickel oxide nanoparticle modified electrode for the detection of salmonella enteritidis gene sequence.

    PubMed

    Sun, Wei; Wang, Xiuli; Lu, Yongxi; Gong, Shixing; Qi, Xiaowei; Lei, Bingxin; Sun, Zhenfan; Li, Guangjiu

    2015-04-01

    In this paper a new electrochemical DNA biosensor was prepared by using graphene (GR) and nickel oxide (NiO) nanocomposite modified carbon ionic liquid electrode (CILE) as the substrate electrode. GR and NiO nanoparticles were electrodeposited on the CILE surface step-by-step to get the nanocomposite. Due to the strong affinity of NiO with phosphate groups of ssDNA, oligonucleotide probe with a terminal 5'-phosphate group could be attached on the surface of NiO/GR/CILE, which could further hybridize with the target ssDNA sequence. Methylene blue (MB) was used as the electrochemical indicator for monitoring the hybridization reaction. Under the optimal conditions the reduction peak current of MB was proportional to the concentration of salmonella enteritidis gene sequence in the range from 1.0×10(-13) to 1.0×10(-6)molL(-1) with a detection limit as 3.12×10(-14)molL(-1). This electrochemical DNA sensor exhibited good discrimination ability to one-base and three-base mismatched ssDNA sequences, and the polymerase chain reaction amplification product of salmonella enteritidis gene sequences were further detected with satisfactory results. PMID:25686924

  10. Electrochemical deoxyribonucleic acid biosensor based on electrodeposited graphene and nickel oxide nanoparticle modified electrode for the detection of salmonella enteritidis gene sequence.

    PubMed

    Sun, Wei; Wang, Xiuli; Lu, Yongxi; Gong, Shixing; Qi, Xiaowei; Lei, Bingxin; Sun, Zhenfan; Li, Guangjiu

    2015-04-01

    In this paper a new electrochemical DNA biosensor was prepared by using graphene (GR) and nickel oxide (NiO) nanocomposite modified carbon ionic liquid electrode (CILE) as the substrate electrode. GR and NiO nanoparticles were electrodeposited on the CILE surface step-by-step to get the nanocomposite. Due to the strong affinity of NiO with phosphate groups of ssDNA, oligonucleotide probe with a terminal 5'-phosphate group could be attached on the surface of NiO/GR/CILE, which could further hybridize with the target ssDNA sequence. Methylene blue (MB) was used as the electrochemical indicator for monitoring the hybridization reaction. Under the optimal conditions the reduction peak current of MB was proportional to the concentration of salmonella enteritidis gene sequence in the range from 1.0×10(-13) to 1.0×10(-6)molL(-1) with a detection limit as 3.12×10(-14)molL(-1). This electrochemical DNA sensor exhibited good discrimination ability to one-base and three-base mismatched ssDNA sequences, and the polymerase chain reaction amplification product of salmonella enteritidis gene sequences were further detected with satisfactory results.

  11. Deoxyribonucleic Acid and Other Words Students Avoid Speaking Aloud: Evaluating the Role of Pronunciation on Participation in Secondary School Science Classroom Conversations

    NASA Astrophysics Data System (ADS)

    Beck, Stacie Elizabeth

    Student's verbal participation in science classrooms is an essential element in building the skills necessary for proficiency in scientific literacy and discourse. The myriad of new, multisyllabic vocabulary terms introduced in one year of secondary school biology instruction can overwhelm students and further impede the self-efficacy needed for concise constructions of scientific explanations and arguments. Factors inhibiting students' inclination to answer questions, share ideas and respond to peers in biology classrooms include confidence and self-perceived competence in appropriately speaking the language of science. Providing students with explicit, engaging instruction in methods to develop vocabulary for use in expressing conclusions is critical for expanding comprehension of science concepts. This study fused the recommended strategies for engaging vocabulary instruction with linguistic practices for teaching pronunciation to examine the relationship between a student's ability to pronounce challenging bio-terminology and their propensity to speak in teacher-led, guided classroom discussions. Interviews, surveys, and measurements quantifying and qualifying students' participation in class discussions before and after explicit instruction in pronunciation were used to evaluate the potential of this strategy as an appropriate tool for increasing students' self-efficacy and willingness to engage in biology classroom conversations. The findings of this study showed a significant increase in student verbal participation in classroom discussions after explicit instruction in pronunciation combined with vocabulary literacy strategies. This research also showed an increase in the use of vocabulary words in student comments after the intervention.

  12. High-Sensitivity C-Reactive Protein Complements Plasma Epstein-Barr Virus Deoxyribonucleic Acid Prognostication in Nasopharyngeal Carcinoma: A Large-Scale Retrospective and Prospective Cohort Study

    SciTech Connect

    Tang, Lin-Quan; Li, Chao-Feng; Chen, Qiu-Yan; Zhang, Lu; Lai, Xiao-Ping; He, Yun; Xu, Yun-Xiu-Xiu; Hu, Dong-Peng; Wen, Shi-Hua; Peng, Yu-Tuan; Chen, Wen-Hui; Liu, Huai; Guo, Shan-Shan; Liu, Li-Ting; Li, Jing; Zhang, Jing-Ping; and others

    2015-02-01

    Purpose: To evaluate the effects of combining the assessment of circulating high-sensitivity C-reactive protein (hs-CRP) with that of Epstein-Barr virus DNA (EBV DNA) in the pretherapy prognostication of nasopharyngeal carcinoma (NPC). Patients and Methods: Three independent cohorts of NPC patients (training set of n=3113, internal validation set of n=1556, and prospective validation set of n=1668) were studied. Determinants of disease-free survival, distant metastasis–free survival, and overall survival were assessed by multivariate analysis. Hazard ratios and survival probabilities of the patient groups, segregated by clinical stage (T1-2N0-1M0, T3-4N0-1M0, T1-2N2-3M0, and T3-4N2-3M0) and EBV DNA load (low or high) alone, and also according to hs-CRP level (low or high), were compared. Results: Elevated hs-CRP and EBV DNA levels were significantly correlated with poor disease-free survival, distant metastasis–free survival, and overall survival in both the training and validation sets. Associations were similar and remained significant after excluding patients with cardiovascular disease, diabetes, and chronic hepatitis B. Patients with advanced-stage disease were segregated by high EBV DNA levels and high hs-CRP level into a poorest-risk group, and participants with either high EBV DNA but low hs-CRP level or high hs-CRP but low EBV DNA values had poorer survival compared with the bottom values for both biomarkers. These findings demonstrate a significant improvement in the prognostic ability of conventional advanced NPC staging. Conclusion: Baseline plasma EBV DNA and serum hs-CRP levels were significantly correlated with survival in NPC patients. The combined interpretation of EBV DNA with hs-CRP levels led to refinement of the risks for the patient subsets, with improved risk discrimination in patients with advanced-stage disease.

  13. Cytometry of deoxyribonuclei acid content and morphology of mammalian sperm

    SciTech Connect

    Gledhill, B.L.

    1983-01-01

    Because spermatogenesis is exquisitely sensitive to external influences, sperm can serve as a biological dosimeter. Advances in interpreting induced sperm abnormalities require a better understanding of sperm characteristics. This report reviews the application of several methods for automated, quantitative detection of shape changes, methods that are faster and more sensitive than conventional subjective technqiues. Variability of sperm deoxyribonucleic acid content as a bioassay of genetic damage is explored, and limitations of the bioassay are discussed. New flow cytometric techniques that could lead to sexing mammalian sperm are examined.

  14. Striking similarities are exhibited by two small Epstein-Barr virus-encoded ribonucleic acids and the adenovirus-associated ribonucleic acids VAI and VAII

    SciTech Connect

    Rosa, M.D.; Gottlieb, E.; Lerner, M.R.; Steitz, J.A.

    1981-09-01

    The nucleotide sequence of the region of the Epstein-Barr virus genome that specified two small ribonucleic acids (RNAs), EBER 1 and EBER 2, has been determined. Both of these RNAs are encoded by the right-hand 1,000 base pairs of the EcoRI J fragment of EBV deoxyribonucleic acid. EBER 1 is 166 (167) nucleotides long and EBER 2 is 172 +- 1 nucleotides long; the heterogeneity resides at the 3' termini. The EBER genes are separated by 161 base pairs and are transcribed from the same deoxyribonucleic acid strand. In vitro, both EBER genes can be transcribed by RNA polymerase III; sequences homologous to previously identified RNA polymerase III intragenic transcription control regions are present. Striking similarities are therefore apparent both between the EBERs and the two adenovirus-associated RNAs, VAI and VAII, and between the regions of the two viral genomes that specify these small RNAs. We have shown that VAII RNA as well as VAI RNA and the EBERs exist in ribonucleoprotein complexes which are precipitable by anti-La antibodies associated with systemic lupus erythematosus. Finally the authors have demonstrated that the binding of protein(s) from uninfected cells confers antigenicity on each of the four virus-encoded small RNAs.

  15. Controllably local gene delivery mediated by polyelectrolyte multilayer films assembled from gene-loaded nanopolymersomes and hyaluronic acid

    PubMed Central

    Teng, Wei; Wang, Qinmei; Chen, Ying; Huang, Hongzhang

    2014-01-01

    To explore a spatiotemporally controllable gene delivery system with high efficiency and safety, polyelectrolyte multilayer (PEM) films were constructed on titanium or quartz substrates via layer-by-layer self-assembly technique by using plasmid deoxyribonucleic acid-loaded lipopolysaccharide–amine nanopolymersomes (pNPs) as polycations and hyaluronic acid (HA) as polyanions. pNPs were chosen because they have high transfection efficiency (>95%) in mesenchymal stem cells (MSCs) and induce significant angiogenesis in zebrafish in conventional bolus transfection. The assembly process of PEM films was confirmed by analyses of quartz crystal microbalance with dissipation, X-ray photoelectron spectroscopy, infrared, contact angle, and zeta potential along with atomic force microscopy observation. Quartz crystal microbalance with dissipation analysis reveals that this film grows in an exponential mode, pNPs are the main contributor to the film mass, and the film mass can be modulated in a relatively wide range (1.0–29 μg/cm2) by adjusting the deposition layer number. Atomic force microscopy observation shows that the assembly leads to the formation of a patterned film with three-dimensional tree-like nanostructure, where the branches are composed of beaded chains (pNP beads are strung on HA molecular chains), and the incorporated pNPs keep structure intact. In vitro release experiment shows that plasmid deoxyribonucleic acid can be gradually released from films over 14 days, and the released plasmid deoxyribonucleic acid exists in a complex form. In vitro cell experiments demonstrate that PEM films can enhance the adhesion and proliferation of MSCs and efficiently transfect MSCs in situ in vitro for at least 4 days. Our results suggest that a (pNPs/HA)n system can mediate efficient transfection in stem cells in a spatially and temporally controllable pattern, highlighting its huge potential in local gene therapy. PMID:25378927

  16. Isolation and Characterization of Simian Virus 40 Ribonucleic Acid

    PubMed Central

    Weinberg, R. A.; Warnaar, S. O.; Winocour, E.

    1972-01-01

    Deoxyribonucleic acid-ribonucleic acid (RNA) hybridization in formamide was used to isolate simian virus 40-specific RNA. Early in the lytic cycle, a 19S viral RNA species was observed. Late in the lytic cycle, 16S and 19S viral species were found. The 16S and 19S species of viral RNA were localized in the cytoplasm. High-molecular-weight heterogeneous RNA, containing viral sequences, was isolated from the nuclear fraction of infected cells late in the lytic cycle. This RNA may contain non-viral sequences linked to viral sequences. The formamide hybridization technique can be used to isolate intact late lytic viral RNA which is at least 99% pure. PMID:4342237

  17. Organo-niobate Ionic Liquids: Synthesis, Characterization and Application as Acid Catalyst in Pechmann Reactions

    PubMed Central

    Soares, Valerio C. D.; Alves, Melquizedeque B.; Souza, Ernesto R.; Pinto, Ivana O.; Rubim, Joel C.; Andrade, Carlos Kleber Z.; Suarez, Paulo A. Z.

    2007-01-01

    The combinations of 1-butyl-3-methylimidazolium chloride with NbCl5 yielded ionic mixtures with different melting point temperatures and acidity depending on the niobium molar fraction. The mixtures were characterized by thermal (DSC) and spectroscopic (FT-IR and 1H NMR) analysis. The Pechmann reactions of different phenols with ethylacetoacetate, producing coumarins, was used as model to evaluate the catalytic behavior of these mixtures as acid Lewis catalyst. These reactions were carried out using acidic mixtures of 60 mol%.

  18. Temperature dependence of the 31P chemical shifts of nucleic acids. A prode of phosphate ester torsional conformations.

    PubMed

    Gorenstein, D G; Findlay, J B; Momii, R K; Luxon, B A; Kar, D

    1976-08-24

    The temperature dependence of the 31P chemical shifts of the ribodinucleoside monophosphates, ApA, GpC, CpC, UpU, and ApU, of the deoxyribonucleic acids, d-ApT, TpT, d-ApA, and d-pApT, and of the homopolyribonucleic acids poly(G), poly(U), poly(A) is shown to provide information on the helix-coli transition in nucleic acids. The base stacked, helical structure with a gauche,gauche phosphate ester torsional conformation is 0.2-0.6 ppm upfield from the random coil conformation. In contrast, the 31P chemical shifts of dimethyl and diethyl phosphate do not change significantly with temperature. These results support our earlier hypothesis that 31P shifts are sensitive probes of torsional conformations with phosphate esters in gauche,gauche conformations having 31P shifts upfield from nongauche conformations.

  19. Ursodeoxycholic acid in the Ursidae: biliary bile acids of bears, pandas, and related carnivores.

    PubMed

    Hagey, L R; Crombie, D L; Espinosa, E; Carey, M C; Igimi, H; Hofmann, A F

    1993-11-01

    The biliary bile acid composition of gallbladder bile obtained from six species of bears (Ursidae), the Giant panda, the Red panda, and 11 related carnivores were determined by reversed phase liquid chromatography and gas chromatography-mass spectrometry. Bile acids were conjugated solely with taurine (in N-acyl linkage) in all species. Ursodeoxycholic acid (3 alpha, 7 beta-dihydroxy-5 beta-cholan-24-oic acid) was present in all Ursidae, averaging 1-39% of biliary bile acids depending on the species; it was not detected or present as a trace constituent (< 0.5%) in all other species, including the Giant panda. Ursodeoxycholic acid was present in 73 of 75 American Black bears, and its proportion averaged 34% (range 0-62%). Ursodeoxycholic acid averaged 17% of biliary bile acids in the Polar bear (n = 4) and 18% in the Brown bear (n = 6). Lower proportions (1-8%) were present in the Sun bear (n = 2), Ceylon Sloth bear (n = 1), and the Spectacled bear (n = 1). Bile of all species contained taurine-conjugated chenodeoxycholic acid and cholic acid. In some related carnivores, deoxycholic acid, the 7-dehydroxylation product of cholic acid, was also present. To determine whether the 7 beta hydroxy group of ursodeoxycholic acid was formed by hepatic or bacterial enzymes, bile acids were determined in hepatic bile obtained from bears with chronic biliary fistulae. Fistula bile samples contained ursodeoxycholic acid, chenodeoxycholic acid, and a trace amount of cholic acid, all as taurine conjugates, indicating that ursodeoxycholic acid is a primary bile acid formed in the liver in Ursidae.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Direct Isolation of Purines and Pyrimidines from Nucleic Acids Using Sublimation

    NASA Technical Reports Server (NTRS)

    Glavin, Daniel P.; Schubert, Michael; Bada, Jeffrey L.

    2003-01-01

    A sublimation technique was developed to isolate purines and pyrimidines directly from lambda-deoxyribonucleic acid (lambda-DNA) and Escherichia coli cells. The sublimation of adenine, cytosine, guanine, and thymine from lambda-DNA was tested under reduced pressure (approx. 0.5 Torr) at temperatures of >150 C. With the exception of guanine, approximately 60 -75% of each base was sublimed directly from the lambda-DNA and recovered on a coldfinger of the sublimation apparatus after heating to 450 C. Several nucleobases including adenine, cytosine, thymine, and uracil were also recovered from E. coli bacteria after heating the cells to the same temperature, although some thermal decomposition of the bases also occurred. These results demonstrate the feasibility of using sublimation to isolate purines and pyrimidines from native E. coli DNA and RNA without any chemical treatment of the cells.

  1. Detection of Gold Nanoparticles Aggregation Growth Induced by Nucleic Acid through Laser Scanning Confocal Microscopy.

    PubMed

    Gary, Ramla; Carbone, Giovani; Petriashvili, Gia; De Santo, Maria Penelope; Barberi, Riccardo

    2016-01-01

    The gold nanoparticle (GNP) aggregation growth induced by deoxyribonucleic acid (DNA) is studied by laser scanning confocal and environmental scanning electron microscopies. As in the investigated case the direct light scattering analysis is not suitable, we observe the behavior of the fluorescence produced by a dye and we detect the aggregation by the shift and the broadening of the fluorescence peak. Results of laser scanning confocal microscopy images and the fluorescence emission spectra from lambda scan mode suggest, in fact, that the intruding of the hydrophobic moiety of the probe within the cationic surfactants bilayer film coating GNPs results in a Förster resonance energy transfer. The environmental scanning electron microscopy images show that DNA molecules act as template to assemble GNPs into three-dimensional structures which are reminiscent of the DNA helix. This study is useful to design better nanobiotechnological devices using GNPs and DNA. PMID:26907286

  2. Detection of Gold Nanoparticles Aggregation Growth Induced by Nucleic Acid through Laser Scanning Confocal Microscopy

    PubMed Central

    Gary, Ramla; Carbone, Giovani; Petriashvili, Gia; De Santo, Maria Penelope; Barberi, Riccardo

    2016-01-01

    The gold nanoparticle (GNP) aggregation growth induced by deoxyribonucleic acid (DNA) is studied by laser scanning confocal and environmental scanning electron microscopies. As in the investigated case the direct light scattering analysis is not suitable, we observe the behavior of the fluorescence produced by a dye and we detect the aggregation by the shift and the broadening of the fluorescence peak. Results of laser scanning confocal microscopy images and the fluorescence emission spectra from lambda scan mode suggest, in fact, that the intruding of the hydrophobic moiety of the probe within the cationic surfactants bilayer film coating GNPs results in a Förster resonance energy transfer. The environmental scanning electron microscopy images show that DNA molecules act as template to assemble GNPs into three-dimensional structures which are reminiscent of the DNA helix. This study is useful to design better nanobiotechnological devices using GNPs and DNA. PMID:26907286

  3. Acid rain and its ecological consequences.

    PubMed

    Singh, Anita; Agrawal, Madhoolika

    2008-01-01

    Acidification of rain-water is identified as one of the most serious environmental problems of transboundary nature. Acid rain is mainly a mixture of sulphuric and nitric acids depending upon the relative quantities of oxides of sulphur and nitrogen emissions. Due to the interaction of these acids with other constituents of the atmosphere, protons are released causing increase in the soil acidity Lowering of soil pH mobilizes and leaches away nutrient cations and increases availability of toxic heavy metals. Such changes in the soil chemical characteristics reduce the soil fertility which ultimately causes the negative impact on growth and productivity of forest trees and crop plants. Acidification of water bodies causes large scale negative impact on aquatic organisms including fishes. Acidification has some indirect effects on human health also. Acid rain affects each and every components of ecosystem. Acid rain also damages man-made materials and structures. By reducing the emission of the precursors of acid rain and to some extent by liming, the problem of acidification of terrestrial and aquatic ecosystem has been reduced during last two decades.

  4. Acid rain and its ecological consequences.

    PubMed

    Singh, Anita; Agrawal, Madhoolika

    2008-01-01

    Acidification of rain-water is identified as one of the most serious environmental problems of transboundary nature. Acid rain is mainly a mixture of sulphuric and nitric acids depending upon the relative quantities of oxides of sulphur and nitrogen emissions. Due to the interaction of these acids with other constituents of the atmosphere, protons are released causing increase in the soil acidity Lowering of soil pH mobilizes and leaches away nutrient cations and increases availability of toxic heavy metals. Such changes in the soil chemical characteristics reduce the soil fertility which ultimately causes the negative impact on growth and productivity of forest trees and crop plants. Acidification of water bodies causes large scale negative impact on aquatic organisms including fishes. Acidification has some indirect effects on human health also. Acid rain affects each and every components of ecosystem. Acid rain also damages man-made materials and structures. By reducing the emission of the precursors of acid rain and to some extent by liming, the problem of acidification of terrestrial and aquatic ecosystem has been reduced during last two decades. PMID:18831326

  5. [Elicitor activity of chitosan and arachidonic acid: their similarity and distinction].

    PubMed

    Vasiukova, N I; Gerasimova, N G; Chalenko, G I; Ozeretskovskaia, O L

    2012-01-01

    Two elicitors-chitosan and arachidonic acid-induced the same defense responses in potatoes, stimulating the processes of wound reparation and inducing the formation of phytoalexins, inhibitors of proteinase, and active forms of oxygen. However, chitosan induced the defense potential of plant tissues at concentrations higher than those of arachidonic acid. The protective action of chitosan was defined by two parameters, i.e., the ability to induce the immune responses in plant tissues and to exhibit a toxic effect on the pathogen development, causing late blight and seedling blight, whereas the elicitor effect of arachidonic acid depended on its ability to induce the defense potential of plant tissues only.

  6. Altered maternal micronutrients (folic acid, vitamin B(12)) and omega 3 fatty acids through oxidative stress may reduce neurotrophic factors in preterm pregnancy.

    PubMed

    Dhobale, Madhavi; Joshi, Sadhana

    2012-04-01

    Preterm pregnancies account for approximately 10% of the total pregnancies and are associated with low birth weight (LBW) babies. Recent studies have shown that LBW babies are at an increased risk of developing brain disorders such as cognitive dysfunction and psychiatric disorders. Maternal nutrition, particularly, micronutrients involved in one-carbon metabolism (folic acid, vitamin B(12), and docosahexaenoic acid (DHA)) have a major role during pregnancy for developing fetus and are important determinants of epigenesis. A series of our studies in pregnancy complications have well established the importance of omega 3 fatty acids especially DHA. DHA regulates levels of neurotrophins like brain-derived neurotrophic factor and nerve growth factor, which are required for normal neurological development. We have recently described that in one carbon metabolic pathway, membrane phospholipids are major methyl group acceptors and reduced DHA levels may result in diversion of methyl groups toward deoxyribonucleic acid (DNA) ultimately resulting in DNA methylation. In this review, we propose that altered maternal micronutrients (folic acid, vitamin B(12)), increased homocysteine, and oxidative stress levels that cause epigenetic modifications may be one of the mechanisms that contribute to preterm birth and poor fetal outcome, increasing risk for behavioural disorders in children. PMID:21609203

  7. Altered maternal micronutrients (folic acid, vitamin B(12)) and omega 3 fatty acids through oxidative stress may reduce neurotrophic factors in preterm pregnancy.

    PubMed

    Dhobale, Madhavi; Joshi, Sadhana

    2012-04-01

    Preterm pregnancies account for approximately 10% of the total pregnancies and are associated with low birth weight (LBW) babies. Recent studies have shown that LBW babies are at an increased risk of developing brain disorders such as cognitive dysfunction and psychiatric disorders. Maternal nutrition, particularly, micronutrients involved in one-carbon metabolism (folic acid, vitamin B(12), and docosahexaenoic acid (DHA)) have a major role during pregnancy for developing fetus and are important determinants of epigenesis. A series of our studies in pregnancy complications have well established the importance of omega 3 fatty acids especially DHA. DHA regulates levels of neurotrophins like brain-derived neurotrophic factor and nerve growth factor, which are required for normal neurological development. We have recently described that in one carbon metabolic pathway, membrane phospholipids are major methyl group acceptors and reduced DHA levels may result in diversion of methyl groups toward deoxyribonucleic acid (DNA) ultimately resulting in DNA methylation. In this review, we propose that altered maternal micronutrients (folic acid, vitamin B(12)), increased homocysteine, and oxidative stress levels that cause epigenetic modifications may be one of the mechanisms that contribute to preterm birth and poor fetal outcome, increasing risk for behavioural disorders in children.

  8. Ribonucleic acid (RNA) biosynthesis in human cancer.

    PubMed

    Hajjawi, Omar S

    2015-01-01

    In many respects, the most remarkable chemical substances within the genome of eukaryotic cells are remarkable proteins which are the critical structural and functional units of living cells. The specifications for everything that goes in the cell are natural digital-to-digital decoding process in an archive sequence by deoxyribonucleic acid (DNA) and an articulate construction by ribonucleic acid (RNA). The products of DNA transcription are long polymers of ribonucleotides rather than deoxyribonucleotides and are termed ribonucleic acids. Certain deoxyribonucleotide sequences, or genes, give rise to transfer RNA (tRNA) and other ribosomal RNA (rRNA) when transcribed. The ribonucleotide sequences fold extensively and rRNA is associated with specific proteins to yield the essential cell components, ribosomes. Transcription of other special sequences yields messenger RNAs (mRNAs) that contain ribonucleotide sequences that will be ultimately translated into new types of amino acid sequences of functional cellular protein molecules. This switch to a different variety of cellular molecular sequences is complex, but each sequence of the three ribonucleotides specifies the insertion of one particular amino acid into the polypeptide chain under production. Whilst mRNA is considered the vehicle by which genetic information is transmitted from the genome and allocated in the appropriate cytoplasmic sites for translation into protein via cap-dependent mechanism, the actual translation depends also on the presence of other so-called household and luxury protein molecules. Recent evidence suggests RNA species are required at initiation, because treatment of cells with antibiotics or drugs that inhibit RNA synthesis cause a decrease in protein synthesis. The rRNA is necessary as a structural constituent of the ribosomes upon which translation takes place, whereas tRNA is necessary as an adaptor in amino acid activation and elongation protein chains to ribosomes. In this article

  9. The transfer of free fatty acids across the rabbit placenta.

    PubMed Central

    Elphick, M C; Hull, D

    1977-01-01

    1. The passage of fatty acids across the placenta was studied in 28 day pregnant rabbits (i) by comparing the fatty acid distribution in plasma free fatty acids (FFA) of umbilical cord artery and vein with that in maternal plasma and (ii) by infusing the doe at a constant rate with labelled palmitic, linoleic or arachidonic acids. During the infusion maternal and foetal plasma FFA specific activities were measured. 2. The mean levels of all the fatty acids studied (from twelve to twenty carbon atoms) were similar in both the umbilical vein plasma and maternal arterial plasma FFA, except for arachidonic acid, which was higher in foetal blood. The relative distribution of the fatty acids in umbilical arterial plasma similar to that in the vein, but at lower concentrations. The mean cord venous-arterial difference for each fatty acid correlated positively with the mean maternal arterial levels, with the exception of arachidonic acid. 3. During the constant infusion experiments the specific activities of the fatty acids in the maternal and foetal circulating FFA pools rose rapidly during the first 4 min then rose only slowly. Palmitic and linoleic acids were cleared from the maternal circulation in a similar manner and crossed the placenta at similar rates. 4. The average foetal specific activity in plasma FFA reached 15% of the maternal level for both palmitate and linoleate. The figure for arachidonic acid was half that for palmitic acid infused at the same time. 5. It is concluded that (i) all the major fatty acids present in foetal adipose tissue cross the placenta, (ii) the net transport of each fatty acid depends in part on maternal concentrations, (iii) the rate of metabolism of palmitic and linoleic acids is the same and both cross the placenta at the same rate. Proportionately less foetal arachidonic acid is derived from maternal FFA, and (iv) the results suggest a second placental source of arachidonic acid and possibly also of otherfatty acids. PMID:845822

  10. Nucleic acid amplification in vitro: detection of sequences with low copy numbers and application to diagnosis of human immunodeficiency virus type 1 infection.

    PubMed Central

    Guatelli, J C; Gingeras, T R; Richman, D D

    1989-01-01

    The enzymatic amplification of specific nucleic acid sequences in vitro has revolutionized the use of nucleic acid hybridization assays for viral detection. With this method, the copy number of a pathogen-specific sequence is increased several orders of magnitude before detection is attempted. The sensitivity and specificity of detection are thus markedly improved. Mullis and Faloona devised the first method of sequence amplification in vitro, the polymerase chain reaction (K.B. Mullis and F.A. Faloona, Methods Enzymol. 155:355-350, 1987). By this method, synthetic oligonucleotide primers direct repeated, target-specific, deoxyribonucleic acid-synthetic reactions, resulting in an exponential increase in the amount of the specific target sequence. The application of sequence amplification to viral detection was initially performed with human immunodeficiency virus type 1 and human T-cell lymphoma virus type I. In principle, however, this approach can be applied to the detection of any deoxyribonucleic or ribonucleic acid virus; the only requirement is that sufficient nucleotide sequence data exist to allow the synthesis of target-specific oligonucleotide primers. The use of target amplification in vitro will permit a variety of studies of viral pathogenesis which have not been feasible because of the low copy number of the viral nucleic acids in infected material. This approach is particularly applicable to the study of human retroviral infections, which are chronic and persistent and are characterized by low titers of virus in tissues. In addition, target amplification in vitro will facilitate the development of new methods of sequence detection, which will be useful for rapid viral diagnosis in the clinical laboratory. PMID:2650862

  11. Lewis acid-promoted reactions of zirconacyclopentadienes with isocyanates. A one-pot three-component synthesis of multiply-substituted iminocyclopentadienes from one isocyanate and two alkynes.

    PubMed

    Lu, Jiang; Mao, Guoliang; Zhang, Wenxiong; Xi, Zhenfeng

    2005-10-14

    Multiply-substituted iminocyclopentadienes were formed from Lewis acid-promoted reactions of zirconacyclopentadienes and isocyanates via a one-pot three-component coupling process; the C=O double bond of the RN=C=O moiety in the isocyanate was cleaved, and the isocyanates behaved formally as a one-carbon unit with Lewis acid-dependent and substituent-dependent reactions being realized.

  12. Ribonucleic Acid Polymerases of the Yeast Phase of Histoplasma capsulatum

    PubMed Central

    Boguslawski, George; Schlessinger, David; Medoff, Gerald; Kobayashi, George

    1974-01-01

    Ribonucleic acid (RNA) polymerases of Histoplasma capsulatum (yeast phase) were fractionated by phosphocellulose chromatography and partially characterized. Three distinct, active fractions were seen. The major RNA polymerase species was inhibited strongly by α-amanitin, whereas the other two were resistant. When either slightly purified (HSE) extract or the major active component was assayed at 37 C, the incorporation of tritiated uridine monophosphate into RNA stopped after 10 to 15 min. In contrast, the synthesis continued for at least 1 h at 23 C. The other two RNA polymerase species exhibited higher rates of incorporation when tested at 37 C, and continued to synthesize RNA even after 60 min. However, by that time the levels of incorporation at 23 C were higher than at 37 C for all three enzymes. The temperature sensitivity was not affected by changing substrate concentration or employing either native or denatured calf thymus deoxyribonucleic acid as a template. These results are compared with the data obtained with RNA polymerases from different fungi and other organisms. A possible involvement of RNA polymerase(s) in morphological differentiation of H. capsulatum is discussed. PMID:4828308

  13. [PREPARATIONS OF PAMIDRONOVIC ACID IN COMPLEX TREATMENT ON OSTEOGENESIS IMPERFECTA].

    PubMed

    Zyma, A M; Guk, Yu M; Magomedov, O M; Gayko, O G; Kincha-Polishchuk, T A

    2015-07-01

    Modern view of drug therapy in the complex treatment of orthopedic manifestations of osteogenesis imperfecta (OI) was submitted. Developed and tested system of drug correction of structural and functional state of bone tissue (BT) using drugs pamidronovic acid, depending on osteoporosis severity and type of disease. Such therapy is appropriate to apply both independently and in conjunction with surgery to correct deformations of long bones of the lower extremities. Effectiveness and feasibility of the proposed methods of drug therapy was proved, most patients resume features walking and support. PMID:26591224

  14. Structural aspects of catalytic mechanisms of endonucleases and their binding to nucleic acids

    SciTech Connect

    Zhukhlistova, N. E.; Balaev, V. V.; Lyashenko, A. V.; Lashkov, A. A.

    2012-05-15

    Endonucleases (EC 3.1) are enzymes of the hydrolase class that catalyze the hydrolytic cleavage of deoxyribonucleic and ribonucleic acids at any region of the polynucleotide chain. Endonucleases are widely used both in biotechnological processes and in veterinary medicine as antiviral agents. Medical applications of endonucleases in human cancer therapy hold promise. The results of X-ray diffraction studies of the spatial organization of endonucleases and their complexes and the mechanism of their action are analyzed and generalized. An analysis of the structural studies of this class of enzymes showed that the specific binding of enzymes to nucleic acids is characterized by interactions with nitrogen bases and the nucleotide backbone, whereas the nonspecific binding of enzymes is generally characterized by interactions only with the nucleic-acid backbone. It should be taken into account that the specificity can be modulated by metal ions and certain low-molecular-weight organic compounds. To test the hypotheses about specific and nonspecific nucleic-acid-binding proteins, it is necessary to perform additional studies of atomic-resolution three-dimensional structures of enzyme-nucleic-acid complexes by methods of structural biology.

  15. Structural aspects of catalytic mechanisms of endonucleases and their binding to nucleic acids

    NASA Astrophysics Data System (ADS)

    Zhukhlistova, N. E.; Balaev, V. V.; Lyashenko, A. V.; Lashkov, A. A.

    2012-05-01

    Endonucleases (EC 3.1) are enzymes of the hydrolase class that catalyze the hydrolytic cleavage of deoxyribonucleic and ribonucleic acids at any region of the polynucleotide chain. Endonucleases are widely used both in biotechnological processes and in veterinary medicine as antiviral agents. Medical applications of endonucleases in human cancer therapy hold promise. The results of X-ray diffraction studies of the spatial organization of endonucleases and their complexes and the mechanism of their action are analyzed and generalized. An analysis of the structural studies of this class of enzymes showed that the specific binding of enzymes to nucleic acids is characterized by interactions with nitrogen bases and the nucleotide backbone, whereas the nonspecific binding of enzymes is generally characterized by interactions only with the nucleic-acid backbone. It should be taken into account that the specificity can be modulated by metal ions and certain low-molecular-weight organic compounds. To test the hypotheses about specific and nonspecific nucleic-acid-binding proteins, it is necessary to perform additional studies of atomic-resolution three-dimensional structures of enzyme-nucleic-acid complexes by methods of structural biology.

  16. Genetics of Amino Acid Taste and Appetite.

    PubMed

    Bachmanov, Alexander A; Bosak, Natalia P; Glendinning, John I; Inoue, Masashi; Li, Xia; Manita, Satoshi; McCaughey, Stuart A; Murata, Yuko; Reed, Danielle R; Tordoff, Michael G; Beauchamp, Gary K

    2016-07-01

    The consumption of amino acids by animals is controlled by both oral and postoral mechanisms. We used a genetic approach to investigate these mechanisms. Our studies have shown that inbred mouse strains differ in voluntary amino acid consumption, and these differences depend on sensory and nutritive properties of amino acids. Like humans, mice perceive some amino acids as having a sweet (sucrose-like) taste and others as having an umami (glutamate-like) taste. Mouse strain differences in the consumption of some sweet-tasting amino acids (d-phenylalanine, d-tryptophan, and l-proline) are associated with polymorphisms of a taste receptor, type 1, member 3 gene (Tas1r3), and involve differential peripheral taste responsiveness. Strain differences in the consumption of some other sweet-tasting amino acids (glycine, l-alanine, l-glutamine, and l-threonine) do not depend on Tas1r3 polymorphisms and so must be due to allelic variation in other, as yet unknown, genes involved in sweet taste. Strain differences in the consumption of l-glutamate may depend on postingestive rather than taste mechanisms. Thus, genes and physiologic mechanisms responsible for strain differences in the consumption of each amino acid depend on the nature of its taste and postingestive properties. Overall, mouse strain differences in amino acid taste and appetite have a complex genetic architecture. In addition to the Tas1r3 gene, these differences depend on other genes likely involved in determining the taste and postingestive effects of amino acids. The identification of these genes may lead to the discovery of novel mechanisms that regulate amino acid taste and appetite. PMID:27422518

  17. Effect of n-3 fatty acids on serum lipid levels and hepatic fatty acid metabolism in BALB/c.KOR-Apoeshl mice deficient in apolipoprotein E expression.

    PubMed

    Ide, Takashi; Takahashi, Yoko; Kushiro, Masayo; Tachibana, Masayoshi; Matsushima, Yoshibumi

    2004-03-01

    N-3 fatty acids exert a potent serum lipid-lowering effect in rodents mainly by affecting hepatic fatty acid oxidation and synthesis. However, it has been observed that fish oil and docosahexaenoic acid ethyl ester do not lower serum lipid levels in apolipoprotein E (apoE)-knockout (Apoetm1Unc) mice generated by gene targeting. To test the hypothesis that apoE expression is required for n-3 fatty acid-dependent regulation of serum lipid levels and hepatic fatty acid metabolism, we examined the effect of fish oil and n-3 fatty acid ethyl esters on the activity and gene expression of hepatic enzymes involved in fatty acid oxidation and synthesis using an alternative apoE-deficient mouse model with the BALB/c genetic background (BALB/c.KOR-Apoeshl). ApoE-deficient mice were fed diets containing 9.4% palm oil, fish oil, or 5.4% palm oil and 1% EPA plus 3% DHA ethyl esters for 15 days. In contrast to the reported data on apoE-knockout mice, fish oil and n-3 fatty acid ethyl esters greatly decreased serum triacylglycerol, cholesterol, and phospholipid levels in the Apoeshl mice. The decreases were greater with fish oil than with ethyl esters. The alterations by dietary n-3 fatty acids of serum lipid levels were accompanied by parallel changes in the activity and mRNA levels of enzymes involved in hepatic fatty acid oxidation and synthesis. The reason for the discrepancy between the results of the current study and previous studies is unknown. However, our study at least indicates that a lack of apoE expression does not necessarily accompany deficits in the n-3 fatty acid-dependent regulation of serum lipid levels and hepatic fatty acid metabolism.

  18. Effect of dilute acid on the accelerated weathering of wood

    SciTech Connect

    Williams, R.S.

    1988-02-01

    Western red cedar (Thuja plicata) specimens were soaked in acid solutions to determine the effect of acid conditions (such as low pH fog) on the weathering of wood. Daily 1-hour soaking in dilute sulfurous, sulfuric, or nitric acid (pH 2.0, 2.5, 3.0, 3.5, or 4.0) increased the rate of accelerated (xenon arc) weathering of the specimens compared to controls soaked in distilled/deionized water. Weathering was manifested as the erosion rate of the wood surface and was determined gravimetrically be fitting the weight loss over time to a linear model. This method detected significant differences between acid-treated specimens and untreated controls within 300 hours of accelerated weathering. The erosion rate was dependent on the acid type and pH. Sulfurous acid treatment caused the fastest rate of erosion, followed by sulfuric then nitric acid. None of the acids affected the erosion rate at pH 3.5 or above. Below this threshold, the rate of erosion increased as the hydrogen ion concentration increased. Sugar analysis of residues from the acids and the distilled water used to soak the wood indicated acid-dependent degradation of polysaccharides.

  19. Synonymy of strains of Center for Disease Control group DF-1 with species of Capnocytophaga.

    PubMed

    Williams, B L; Hollis, D; Holdeman, L V

    1979-10-01

    Of eight strains of Center for Disease Control group DF-1 examined, seven had 62 to 87% deoxyribonucleic acid homology with the neotype strain of Capnocytophaga ochracea and one had 72% deoxyribonucleic acid homology with the type strain of C. gingivalis. Deoxyribonucleic acid homology of four strains of Bacteroides ochraceus with the neotype strain of C. ochrecea was 76 to 86%.

  20. Folic Acid

    MedlinePlus

    Folic acid is a B vitamin. It helps the body make healthy new cells. Everyone needs folic acid. For women who may get pregnant, it is really important. Getting enough folic acid before and during pregnancy can prevent major birth ...

  1. Folic Acid

    MedlinePlus

    Folic acid is used to treat or prevent folic acid deficiency. It is a B-complex vitamin needed by ... Folic acid comes in tablets. It usually is taken once a day. Follow the directions on your prescription label ...

  2. Amino acids

    MedlinePlus

    ... amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan , and valine. Nonessential amino acids "Nonessential" means that our bodies produce an amino ...

  3. Acid Rain.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  4. Eubacterium rangiferina, a novel usnic acid-resistant bacterium from the reindeer rumen

    NASA Astrophysics Data System (ADS)

    Sundset, Monica A.; Kohn, Alexandra; Mathiesen, Svein D.; Præsteng, Kirsti E.

    2008-08-01

    Reindeer are able to eat and utilize lichens as an important source of energy and nutrients. In the current study, the activities of antibiotic secondary metabolites including usnic, antranoric, fumarprotocetraric, and lobaric acid commonly found in lichens were tested against a collection of 26 anaerobic rumen bacterial isolates from reindeer ( Rangifer tarandus tarandus) using the agar diffusion method. The isolates were identified based on their 16S ribosomal ribonucleic acid (rRNA) gene sequences. Usnic acid had a potent antimicrobial effect against 25 of the isolates, belonging to Clostridiales, Enterococci, and Streptococci. Isolates of Clostridia and Streptococci were also susceptible to atranoric and lobaric acid. However, one isolate (R3_91_1) was found to be resistant to usnic, antranoric, fumarprotocetraric, and lobaric acid. R3_91_1 was also seen invading and adhering to lichen particles when grown in a liquid anaerobic culture as demonstrated by transmission electron microscopy. This was a Gram-negative, nonmotile rod (0.2-0.7 × 2.0-3.5 μm) with a deoxyribonucleic acid G + C content of 47.0 mol% and main cellular fatty acids including 15:0 anteiso-dimethyl acetal (DMA), 16:0 iso-fatty acid methyl ester (FAME), 13:0 iso-3OH FAME, and 17:0 anteiso-FAME, not matching any of the presently known profiles in the MIDI database. Combined, the phenotypic and genotypic traits including the 16S rRNA gene sequence show that R3_91_1 is a novel species inside the order Clostridiales within the family Lachnospiraceae, for which we propose the name Eubacterium rangiferina. This is the first record of a rumen bacterium able to tolerate and grow in the presence of usnic acid, indicating that the rumen microorganisms in these animals have adapted mechanisms to deal with lichen secondary metabolites, well known for their antimicrobial and toxic effects.

  5. Acid rain

    SciTech Connect

    Not Available

    1985-01-01

    This report has four parts: they discuss acid rain in relation to acid soils, agriculture, forests, and aquatic ecosystems. Among findings: modern sources of acid deposition from the atmosphere for all the acid soils in the world, nor even chiefly responsible for those of northern U.S. Agriculture has its problems, but acid precipitation is probably not one of them. More research is needed to determine to what extent acid precipitation is responsible for forest declines and for smaller detrimental effects on forest growth where no damage to the foliage is evident. Many lakes and streams are extremely sensitive to added acids.

  6. Studies of Nondefective Adenovirus 2-Simian Virus 40 Hybrid Viruses IV. Characterization of the Simian Virus 40 Ribonucleic Acid Species Induced by Wild-Type Simian Virus 40 and by the Nondefective Hybrid Virus, Ad2+ND1

    PubMed Central

    Oxman, Michael N.; Levine, Arthur S.; Crumpacker, Clyde S.; Levin, Myron J.; Henry, Patrick H.; Lewis, Andrew M.

    1971-01-01

    Ad2+ND1, a nondefective adenovirus 2 (Ad2)-simian virus 40 (SV40) hybrid virus, has been previously shown to contain a small segment of the SV40 genome covalently linked to Ad2 deoxyribonucleic acid (DNA). The SV40 portion of this hybrid virus has been characterized by relating the SV40-specific ribonucleic acid (RNA) sequences transcribed from the Ad2+ND1 DNA to those transcribed from the DNA of SV40 itself. RNA-DNA hybridization-competition studies indicate that the SV40 component of Ad2+ND1 consists of some, but not all, of that part of the SV40 genome which is transcribed early, i.e., prior to viral DNA replication, in SV40 lytic infection. PMID:4329969

  7. Structure and friction of stearic acid and oleic acid films adsorbed on iron oxide surfaces in squalane.

    PubMed

    Doig, Michael; Warrens, Chris P; Camp, Philip J

    2014-01-14

    The structure and friction of fatty acid surfactant films adsorbed on iron oxide surfaces lubricated by squalane are examined using large-scale molecular dynamics simulations. The structures of stearic acid and oleic acid films under static and shear conditions, and at various surface coverages, are described in detail, and the effects of unsaturation in the tail group are highlighted. At high surface coverage, the measured properties of stearic acid and oleic acid films are seen to be very similar. At low and intermediate surface coverages, the presence of a double bond, as in oleic acid, is seen to give rise to less penetration of lubricant in to the surfactant film and less layering of the lubricant near to the film. The kinetic friction coefficient is measured as a function of shear rate within the hydrodynamic (high shear rate) lubrication regime. Lubricant penetration and layering are observed to be correlated with friction coefficient. The friction coefficient with oleic acid depends only weakly on surface coverage, while stearic acid admits more lubricant penetration, and its friction coefficient increases significantly with decreasing surface coverage. Connections between film structure and friction are discussed.

  8. Factors Affecting Immunogenic Activity of Mycobacterial Ribosomal and Ribonucleic Acid Preparations

    PubMed Central

    Youmans, Anne S.; Youmans, Guy P.

    1969-01-01

    By following careful procedures, mycobacterial ribosomal fractions and ribonucleic acid (RNA) prepared by ethyl alcohol precipitation were obtained which have immunogenic activities similar to the viable attenuated H37Ra cells of Mycobacterium tuberculosis from which they were obtained. This comparison was based on the amount of ribonucleic acid (RNA) present. These preparations consisted of approximately 63% RNA and 37% protein; no deoxyribonucleic acid or polysaccharide was detected by chemical tests. A high correlation was found between the immunogenic activity of a preparation and the per cent increase in hyperchromicity at 260 nm of a ribonuclease-hydrolyzed portion. Final concentrations of sodium dodecyl sulfate higher than 0.25% when used for the preparation of the ribosomal fractions and RNA resulted in significantly lower immune responses and greater variation between experiments. This was not related to the amount of protein present. The stability of the ribosomal and RNA preparations was tested under a variety of conditions. The need for a good protective adjuvant again was shown since mouse serum readily hydrolyzed the RNA. Equal immunity was obtained after immunization by the intraperitoneal and subcutaneous routes; however, no immune response was obtained when the intravenous route was used. Preliminary results with RNA prepared with phenol showed that it was more easily degraded during preparation. This resulted in a lower immune response than was obtained with the RNA prepared with ethyl alcohol. PMID:4979447

  9. In vitro evaluation of endothelial exosomes as carriers for small interfering ribonucleic acid delivery.

    PubMed

    Banizs, Anna B; Huang, Tao; Dryden, Kelly; Berr, Stuart S; Stone, James R; Nakamoto, Robert K; Shi, Weibin; He, Jiang

    2014-01-01

    Exosomes, one subpopulation of nanosize extracellular vesicles derived from multivesicular bodies, ranging from 30 to 150 nm in size, emerged as promising carriers for small interfering ribonucleic acid (siRNA) delivery, as they are capable of transmitting molecular messages between cells through carried small noncoding RNAs, messenger RNAs, deoxyribonucleic acids, and proteins. Endothelial cells are involved in a number of important biological processes, and are a major source of circulating exosomes. In this study, we prepared exosomes from endothelial cells and evaluated their capacity to deliver siRNA into primary endothelial cells. Exosomes were isolated and purified by sequential centrifugation and ultracentrifugation from cultured mouse aortic endothelial cells. Similar to exosome particles from other cell sources, endothelial exosomes are nanometer-size vesicles, examined by both the NanoSight instrument and transmission electron microscopy. Enzyme-linked immunosorbent assay analysis confirmed the expression of two exosome markers: CD9 and CD63. Flow cytometry and fluorescence microscopy studies demonstrated that endothelial exosomes were heterogeneously distributed within cells. In a gene-silencing study with luciferase-expressing endothelial cells, exosomes loaded with siRNA inhibited luciferase expression by more than 40%. In contrast, siRNA alone and control siRNA only suppressed luciferase expression by less than 15%. In conclusion, we demonstrated that endothelial exosomes have the capability to accommodate and deliver short foreign nucleic acids into endothelial cells.

  10. In vitro evaluation of endothelial exosomes as carriers for small interfering ribonucleic acid delivery

    PubMed Central

    Banizs, Anna B; Huang, Tao; Dryden, Kelly; Berr, Stuart S; Stone, James R; Nakamoto, Robert K; Shi, Weibin; He, Jiang

    2014-01-01

    Exosomes, one subpopulation of nanosize extracellular vesicles derived from multivesicular bodies, ranging from 30 to 150 nm in size, emerged as promising carriers for small interfering ribonucleic acid (siRNA) delivery, as they are capable of transmitting molecular messages between cells through carried small noncoding RNAs, messenger RNAs, deoxyribonucleic acids, and proteins. Endothelial cells are involved in a number of important biological processes, and are a major source of circulating exosomes. In this study, we prepared exosomes from endothelial cells and evaluated their capacity to deliver siRNA into primary endothelial cells. Exosomes were isolated and purified by sequential centrifugation and ultracentrifugation from cultured mouse aortic endothelial cells. Similar to exosome particles from other cell sources, endothelial exosomes are nanometer-size vesicles, examined by both the NanoSight instrument and transmission electron microscopy. Enzyme-linked immunosorbent assay analysis confirmed the expression of two exosome markers: CD9 and CD63. Flow cytometry and fluorescence microscopy studies demonstrated that endothelial exosomes were heterogeneously distributed within cells. In a gene-silencing study with luciferase-expressing endothelial cells, exosomes loaded with siRNA inhibited luciferase expression by more than 40%. In contrast, siRNA alone and control siRNA only suppressed luciferase expression by less than 15%. In conclusion, we demonstrated that endothelial exosomes have the capability to accommodate and deliver short foreign nucleic acids into endothelial cells. PMID:25214786

  11. Aminocaproic Acid

    MedlinePlus

    Aminocaproic acid is used to control bleeding that occurs when blood clots are broken down too quickly. This type ... the baby is ready to be born). Aminocaproic acid is also used to control bleeding in the ...

  12. Ethacrynic Acid

    MedlinePlus

    Ethacrynic acid, a 'water pill,' is used to treat swelling and fluid retention caused by various medical problems. It ... Ethacrynic acid comes as a tablet to take by mouth. It is usually taken once or twice a day ...

  13. Aristolochic Acids

    MedlinePlus

    ... Sciences NIH-HHS www.niehs.nih.gov Aristolochic Acids Key Points Report on Carcinogens Status Known to be human carcinogens Aristolochia Clematitis Aristolochic Acids n Known human carcinogens n Found in certain ...

  14. Obeticholic Acid

    MedlinePlus

    Obeticholic acid is used alone or in combination with ursodiol (Actigall, Urso) to treat primary biliary cholangitis (PBC; a ... were not treated successfully with ursodiol alone. Obeticholic acid is in a class of medications called farnesoid ...

  15. Acid mucopolysaccharides

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003368.htm Acid mucopolysaccharides To use the sharing features on this page, please enable JavaScript. Acid mucopolysaccharides is a test that measures the amount ...

  16. Gluconic acid production by gad mutant of Klebsiella pneumoniae.

    PubMed

    Wang, Dexin; Wang, Chenhong; Wei, Dong; Shi, Jiping; Kim, Chul Ho; Jiang, Biao; Han, Zengsheng; Hao, Jian

    2016-08-01

    Klebsiella pneumoniae produces many economically important chemicals. Using glucose as a carbon source, the main metabolic product in K. pneumoniae is 2,3-butanediol. Gluconic acid is an intermediate of the glucose oxidation pathway. In the current study, a metabolic engineering strategy was used to develop a gluconic acid-producing K. pneumoniae strain. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. Gluconic acid accumulation by K. pneumoniae Δgad was an acid-dependent aerobic process, with accumulation observed at pH 5.5 or lower, and at higher levels of oxygen supplementation. Under all other conditions tested, 2,3-butanediol was the main metabolic product of the process. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by K. pneumoniae Δgad, and the conversion ratio of glucose to gluconic acid reached 1 g/g. The K. pneumoniae Δgad described in this study is the first genetically modified strain used for gluconic acid production, and this optimized method for gluconic acid production may have important industrial applications. Gluconic acid is an intermediate of this glucose oxidation pathway. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by the K. pneumoniae Δgad strain, and the conversion ratio of glucose to gluconic acid reached 1 g/g.

  17. Gluconic acid production by gad mutant of Klebsiella pneumoniae.

    PubMed

    Wang, Dexin; Wang, Chenhong; Wei, Dong; Shi, Jiping; Kim, Chul Ho; Jiang, Biao; Han, Zengsheng; Hao, Jian

    2016-08-01

    Klebsiella pneumoniae produces many economically important chemicals. Using glucose as a carbon source, the main metabolic product in K. pneumoniae is 2,3-butanediol. Gluconic acid is an intermediate of the glucose oxidation pathway. In the current study, a metabolic engineering strategy was used to develop a gluconic acid-producing K. pneumoniae strain. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. Gluconic acid accumulation by K. pneumoniae Δgad was an acid-dependent aerobic process, with accumulation observed at pH 5.5 or lower, and at higher levels of oxygen supplementation. Under all other conditions tested, 2,3-butanediol was the main metabolic product of the process. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by K. pneumoniae Δgad, and the conversion ratio of glucose to gluconic acid reached 1 g/g. The K. pneumoniae Δgad described in this study is the first genetically modified strain used for gluconic acid production, and this optimized method for gluconic acid production may have important industrial applications. Gluconic acid is an intermediate of this glucose oxidation pathway. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by the K. pneumoniae Δgad strain, and the conversion ratio of glucose to gluconic acid reached 1 g/g. PMID:27339313

  18. Study of the sequential conversion of citric to itaconic to methacrylic acid in near-critical and supercritical water

    SciTech Connect

    Carlsson, M.; Habenicht, C.; Kam, L.C.; Antal, M.J. Jr. ); Bian, N.; Cunningham, R.J.; Jones, M. Jr. . Dept. of Chemistry)

    1994-08-01

    Between 200 and 400 million lb of citric acid are produced annually in the USA by fermentation of molasses and other sugars using the microorganism Aspergillus niger. A lesser quantity of itaconic acid is manufactured by a similar technology using Aspergillus terreus. The recovery of citric acid from its fermentation broth via calcium salt precipitation is a costly, highly complex, sophisticated operation. USDOE estimates the cost of dry citric acid produced from a new plant to be about $0.59/lb, whereas the estimated cost of wet citric acid (in its fermentation broth) from a new plant is about $0.19/lb and from an old plant is about $0.15/lb. Citric acid rapidly reacts in hot (250 C), compressed (34.5 MPa) liquid water to form itaconic and citraconic acids with a combined selectivity that exceeds 90%. At higher temperatures (360 C), in the absence and presence of NaOH, itaconic acid decarboxylates to form methacrylic acid. The yield of methacrylic acid depends on the temperature, pH, and buffer strength of the medium, reaching a maximum of about 70% (by mole) of the itaconic acid feed. Conditions which favor the production of methacrylic acid also lead to the formation of its hydration product: hydroxyisobutyric acid. Under optimum conditions the combined yield of methacrylic acid and hydroxyisobutyric acid from itaconic acid exceeds 80%. Results are consistent with well-established dehydration and decarboxylation mechanisms.

  19. Modifications of proteins by polyunsaturated fatty acid peroxidation products

    NASA Astrophysics Data System (ADS)

    Refsgaard, Hanne H. F.; Tsai, Lin; Stadtman, Earl R.

    2000-01-01

    The ability of unsaturated fatty acid methyl esters to modify amino acid residues in bovine serum albumin (BSA), glutamine synthetase, and insulin in the presence of a metal-catalyzed oxidation system [ascorbate/Fe(III)/O2] depends on the degree of unsaturation of the fatty acid. The fatty acid-dependent generation of carbonyl groups and loss of lysine residues increased in the order methyl linoleate < methyl linolenate < methyl arachidonate. The amounts of alkyl hydroperoxides, malondialdehyde, and a number of other aldehydes that accumulated when polyunsaturated fatty acids were oxidized in the presence of BSA were significantly lower than that observed in the absence of BSA. Direct treatment of proteins with various lipid hydroperoxides led to a slight increase in the formation of protein carbonyl derivatives, whereas treatment with the hydroperoxides together with Fe(II) led to a substantial increase in the formation of protein carbonyls. These results are consistent with the proposition that metal-catalyzed oxidation of polyunsaturated fatty acids can contribute to the generation of protein carbonyls by direct interaction of lipid oxidation products (α,β-unsaturated aldehydes) with lysine residues (Michael addition reactions) and also by interactions with alkoxyl radicals obtained by Fe(II) cleavage of lipid hydroperoxides that are formed. In addition, saturated aldehydes derived from the polyunsaturated fatty acids likely react with lysine residues to form Schiff base adducts.

  20. Modifications of proteins by polyunsaturated fatty acid peroxidation products

    PubMed Central

    Refsgaard, Hanne H. F.; Tsai, Lin; Stadtman, Earl R.

    2000-01-01

    The ability of unsaturated fatty acid methyl esters to modify amino acid residues in bovine serum albumin (BSA), glutamine synthetase, and insulin in the presence of a metal-catalyzed oxidation system [ascorbate/Fe(III)/O2] depends on the degree of unsaturation of the fatty acid. The fatty acid-dependent generation of carbonyl groups and loss of lysine residues increased in the order methyl linoleate < methyl linolenate < methyl arachidonate. The amounts of alkyl hydroperoxides, malondialdehyde, and a number of other aldehydes that accumulated when polyunsaturated fatty acids were oxidized in the presence of BSA were significantly lower than that observed in the absence of BSA. Direct treatment of proteins with various lipid hydroperoxides led to a slight increase in the formation of protein carbonyl derivatives, whereas treatment with the hydroperoxides together with Fe(II) led to a substantial increase in the formation of protein carbonyls. These results are consistent with the proposition that metal-catalyzed oxidation of polyunsaturated fatty acids can contribute to the generation of protein carbonyls by direct interaction of lipid oxidation products (α,β-unsaturated aldehydes) with lysine residues (Michael addition reactions) and also by interactions with alkoxyl radicals obtained by Fe(II) cleavage of lipid hydroperoxides that are formed. In addition, saturated aldehydes derived from the polyunsaturated fatty acids likely react with lysine residues to form Schiff base adducts. PMID:10639127

  1. Fatty acids - trans fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The data supporting a negative effect of dietary trans fatty acids on cardiovascular disease risk is consistent. The primary dietary sources of trans fatty acids include partially hydrogenated fat and rudiment fat. The adverse effect of trans fatty acids on plasma lipoprotein profiles is consisten...

  2. Solution Preserves Nucleic Acids in Body-Fluid Specimens

    NASA Technical Reports Server (NTRS)

    Pierson, Duane L.; Stowe, Raymond P.

    2004-01-01

    A solution has been formulated to preserve deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) in specimens of blood, saliva, and other bodily fluids. Specimens of this type are collected for diagnostic molecular pathology, which is becoming the method of choice for diagnosis of many diseases. The solution makes it possible to store such specimens at room temperature, without risk of decomposition, for subsequent analysis in a laboratory that could be remote from the sampling location. Thus, the solution could be a means to bring the benefits of diagnostic molecular pathology to geographic regions where refrigeration equipment and diagnostic laboratories are not available. The table lists the ingredients of the solution. The functions of the ingredients are the following: EDTA chelates divalent cations that are necessary cofactors for nuclease activity. In so doing, it functionally removes these cations and thereby retards the action of nucleases. EDTA also stabilizes the DNA helix. Tris serves as a buffering agent, which is needed because minor contaminants in an unbuffered solution can exert pronounced effects on pH and thereby cause spontaneous degradation of DNA. SDS is an ionic detergent that inhibits ribonuclease activity. SDS has been used in some lysis buffers and as a storage buffer for RNA after purification. The use of the solution is straightforward. For example, a sample of saliva is collected by placing a cotton roll around in the subject's mouth until it becomes saturated, then the cotton is placed in a collection tube. Next, 1.5 mL of the solution are injected directly into the cotton and the tube is capped for storage at room temperature. The effectiveness of the solution has been demonstrated in tests on specimens of saliva containing herpes simplex virus. In the tests, the viral DNA, as amplified by polymerase chain reaction, was detected even after storage for 120 days.

  3. Aspartic acid

    MedlinePlus

    ... Hormone production and release Normal nervous system function Plant sources of aspartic acid include: Legumes such as soybeans, garbanzo beans, and lentils Peanuts, almonds, walnuts, and flaxseeds Animal ...

  4. Bile acids: analysis in biological fluids and tissues

    PubMed Central

    Griffiths, William J.; Sjövall, Jan

    2010-01-01

    The formation of bile acids/bile alcohols is of major importance for the maintenance of cholesterol homeostasis. Besides their functions in lipid absorption, bile acids/bile alcohols are regulatory molecules for a number of metabolic processes. Their effects are structure-dependent, and numerous metabolic conversions result in a complex mixture of biologically active and inactive forms. Advanced methods are required to characterize and quantify individual bile acids in these mixtures. A combination of such analyses with analyses of the proteome will be required for a better understanding of mechanisms of action and nature of endogenous ligands. Mass spectrometry is the basic detection technique for effluents from chromatographic columns. Capillary liquid chromatography-mass spectrometry with electrospray ionization provides the highest sensitivity in metabolome analysis. Classical gas chromatography-mass spectrometry is less sensitive but offers extensive structure-dependent fragmentation increasing the specificity in analyses of isobaric isomers of unconjugated bile acids. Depending on the nature of the bile acid/bile alcohol mixture and the range of concentration of individuals, different sample preparation sequences, from simple extractions to group separations and derivatizations, are applicable. We review the methods currently available for the analysis of bile acids in biological fluids and tissues, with emphasis on the combination of liquid and gas phase chromatography with mass spectrometry. PMID:20008121

  5. REMOVAL OF CHLORIDE FROM ACIDIC SOLUTIONS USING NO2

    SciTech Connect

    Visser, A; Robert Pierce, R; James Laurinat, J

    2006-08-22

    Chloride (Cl{sup -}) salt processing in strong acids is used to recycle plutonium (Pu) from pyrochemical residues. The Savannah River National Laboratory (SRNL) is studying the potential application of nitrogen dioxide (NO{sub 2}) gas to effectively convert dissolved pyrochemical salt solutions to chloride-free solutions and improve recovery operations. An NO{sub 2} sparge has been shown to effectively remove Cl{sup -} from solutions containing 6-8 M acid (H{sup +}) and up to 5 M Cl{sup -}. Chloride removal occurs as a result of the competition of at least two reactions, one which is acid-dependent. Below 4 M H+, NO2 reacts with Cl- to produce nitrosyl chloride (ClNO). Between 6 M and 8 M H{sup +}, the reaction of hydrochloric acid (HCl) with nitric acid (HNO{sub 3}), facilitated by the presence of NO{sub 2}, strongly affects the rate of Cl{sup -} removal. The effect of heating the acidic Cl{sup -} salt solution without pre-heating the NO{sub 2} gas has minimal effect on Cl{sup -} removal rates when the contact times between NO{sub 2} and the salt solution are on the order of seconds.

  6. Do sensory neurons mediate adaptive cytoprotection of gastric mucosa against bile acid injury?

    PubMed

    Mercer, D W; Ritchie, W P; Dempsey, D T

    1992-01-01

    Pretreatment with the mild irritant 1 mmol acidified taurocholate protects the gastric mucosa from the injury induced by the subsequent application of 5 mmol acidified taurocholate, a phenomenon referred to as "adaptive cytoprotection." How this occurs remains an enigma. The purpose of this study was to investigate the role of sensory neurons and mucus secretion in this phenomenon. Prior to injury with 5 mmol acidified taurocholate (pH 1.2), the stomachs of six groups of rats were subjected to the following protocol. Two groups were topically pretreated with either saline or the mild irritant 1 mmol acidified taurocholate. Two other groups received the topical anesthetic 1% lidocaine prior to pretreatment with either saline or 1 mmol acidified taurocholate. The last two groups got the mucolytic agent 10% N-acetylcysteine (NAC) after pretreatment with either saline or 1 mmol acidified taurocholate. Injury was assessed by measuring net transmucosal ion fluxes, luminal appearance of deoxyribonucleic acid (DNA), and gross and histologic injury. Pretreatment with the mild irritant 1 mmol acidified taurocholate significantly decreased bile acid-induced luminal ion fluxes and DNA accumulation, suggesting mucosal protection (corroborated by gross and histologic injury analysis). This effect was negated by lidocaine but not by NAC. Thus, it appears that sensory neurons, and not increased mucus secretion, play a critical role in adaptive cytoprotection. PMID:1733359

  7. Do sensory neurons mediate adaptive cytoprotection of gastric mucosa against bile acid injury?

    PubMed

    Mercer, D W; Ritchie, W P; Dempsey, D T

    1992-01-01

    Pretreatment with the mild irritant 1 mmol acidified taurocholate protects the gastric mucosa from the injury induced by the subsequent application of 5 mmol acidified taurocholate, a phenomenon referred to as "adaptive cytoprotection." How this occurs remains an enigma. The purpose of this study was to investigate the role of sensory neurons and mucus secretion in this phenomenon. Prior to injury with 5 mmol acidified taurocholate (pH 1.2), the stomachs of six groups of rats were subjected to the following protocol. Two groups were topically pretreated with either saline or the mild irritant 1 mmol acidified taurocholate. Two other groups received the topical anesthetic 1% lidocaine prior to pretreatment with either saline or 1 mmol acidified taurocholate. The last two groups got the mucolytic agent 10% N-acetylcysteine (NAC) after pretreatment with either saline or 1 mmol acidified taurocholate. Injury was assessed by measuring net transmucosal ion fluxes, luminal appearance of deoxyribonucleic acid (DNA), and gross and histologic injury. Pretreatment with the mild irritant 1 mmol acidified taurocholate significantly decreased bile acid-induced luminal ion fluxes and DNA accumulation, suggesting mucosal protection (corroborated by gross and histologic injury analysis). This effect was negated by lidocaine but not by NAC. Thus, it appears that sensory neurons, and not increased mucus secretion, play a critical role in adaptive cytoprotection.

  8. Fluorescence detection in Lab-on-a-chip systems using ultrafast nucleic acid amplification methods

    NASA Astrophysics Data System (ADS)

    Gransee, Rainer; Schneider, Tristan; Elyorgun, Deniz; Strobach, Xenia; Schunck, Tobias; Gatscha, Theresia; Höth, Julian

    2014-05-01

    Today, nucleic amplification plays a key role in modern molecular biology allowing fast and specific laboratory diagnostics testing. An ultrafast microfluidic module (allowing 30 polymeric chain reaction (PCR) cycles in 6 minutes) based on an oscillating fluid plug concept was previously developed[1]. This system allows the amplification of native genomic deoxyribonucleic acid molecules (DNA) even from whole blood samples but still lacks some functionality compared to commercial bench top systems. This work presents the actual status of the renewed and advanced system, permitting the automated optical detection of not only the fluid plug position but also fluorescence detection. The system uses light emitting diodes (LED) for illumination and a low cost CMOS web-camera for optical detection. Image data processing allows the automated process control of the overall system components. Therefore, the system enables the performance of rapid and robust nucleic acid amplifications together with the integration of real time measurement technology. This allows the amplification and simultaneous quantification of the DNA molecules. The possibility to integrate swift nucleic amplification and optical detection into complex sample-to-answer analysis platforms opens up new pathways towards fast and transportable low-cost point of care devices.

  9. Characterization of hybrid plasmids carrying individual ribosomal ribonucleic acid transcription units of Escherichia coli.

    PubMed Central

    Kenerley, M E; Morgan, E A; Post, L; Lindahl, L; Nomura, M

    1977-01-01

    We have screened the strains with ColE1 hybrid plasmids constructed by Clarke and Carbon (Cell 9:91-99, 1976) for the presence of ribosomal ribonucleic acid (rRNA) genes on the plasmids and identified 16 strains whose plasmids carry rRNA genes. The structures of these 16 plasmids were compared by heteroduplex analysis, and the plasmids were classified into six groups on the basis of their chromosomal origins. Homology with known transducing-phage deoxyribonucleic acids and genetic mapping have assigned locations on the Escherichia coli chromosome to three of the six groups. These are rrnB near rif at 88 min, rrnC near ilvE at 83 min, and rrnD near aroE at 71 min. A fourth group is probably rrnA at 85 min (T. Ikemura and M. Nomura, Cell, 11:779-793, 1977). We conclude that the minimum number of rRNA transcription units per haploid chromosomes is seven, that is, the six groups identified in this work plus a known operon (rrnE near metA at 89 min) that we failed to find among the hybrid plasmids. This heteroduplex analysis also suggests that there are only two kinds of rRNA operons with respect to their spacer region; three of the six rRNA operon groups studied here have one kind, whereas the remaining three have the other kind. Images PMID:336613

  10. Usnic acid.

    PubMed

    Ingólfsdóttir, K

    2002-12-01

    Since its first isolation in 1844, usnic acid [2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzo-furandione] has become the most extensively studied lichen metabolite and one of the few that is commercially available. Usnic acid is uniquely found in lichens, and is especially abundant in genera such as Alectoria, Cladonia, Usnea, Lecanora, Ramalina and Evernia. Many lichens and extracts containing usnic acid have been utilized for medicinal, perfumery, cosmetic as well as ecological applications. Usnic acid as a pure substance has been formulated in creams, toothpaste, mouthwash, deodorants and sunscreen products, in some cases as an active principle, in others as a preservative. In addition to antimicrobial activity against human and plant pathogens, usnic acid has been shown to exhibit antiviral, antiprotozoal, antiproliferative, anti-inflammatory and analgesic activity. Ecological effects, such as antigrowth, antiherbivore and anti-insect properties, have also been demonstrated. A difference in biological activity has in some cases been observed between the two enantiomeric forms of usnic acid. Recently health food supplements containing usnic acid have been promoted for use in weight reduction, with little scientific support. The emphasis of the current review is on the chemistry and biological activity of usnic acid and its derivatives in addition to rational and ecologically acceptable methods for provision of this natural compound on a large scale.

  11. Acid rain

    SciTech Connect

    Elsworth, S.

    1985-01-01

    This book was written in a concise and readable style for the lay public. It's purpose was to make the public aware of the damage caused by acid rain and to mobilize public opinion to favor the elimination of the causes of acid rain.

  12. Acid rain

    SciTech Connect

    White, J.C. )

    1988-01-01

    This book presents the proceedings of the third annual conference sponsored by the Acid Rain Information Clearinghouse (ARIC). Topics covered include: Legal aspects of the source-receptor relationship: an energy perspective; Scientific uncertainty, agency inaction, and the courts; and Acid rain: the emerging legal framework.

  13. How Acidic Is Carbonic Acid?

    PubMed

    Pines, Dina; Ditkovich, Julia; Mukra, Tzach; Miller, Yifat; Kiefer, Philip M; Daschakraborty, Snehasis; Hynes, James T; Pines, Ehud

    2016-03-10

    Carbonic, lactic, and pyruvic acids have been generated in aqueous solution by the transient protonation of their corresponding conjugate bases by a tailor-made photoacid, the 6-hydroxy-1-sulfonate pyrene sodium salt molecule. A particular goal is to establish the pK(a) of carbonic acid H2CO3. The on-contact proton transfer (PT) reaction rate from the optically excited photoacid to the carboxylic bases was derived, with unprecedented precision, from time-correlated single-photon-counting measurements of the fluorescence lifetime of the photoacid in the presence of the proton acceptors. The time-dependent diffusion-assisted PT rate was analyzed using the Szabo-Collins-Kimball equation with a radiation boundary condition. The on-contact PT rates were found to follow the acidity order of the carboxylic acids: the stronger was the acid, the slower was the PT reaction to its conjugate base. The pK(a) of carbonic acid was found to be 3.49 ± 0.05 using both the Marcus and Kiefer-Hynes free energy correlations. This establishes H2CO3 as being 0.37 pK(a) units stronger and about 1 pK(a) unit weaker, respectively, than the physiologically important lactic and pyruvic acids. The considerable acid strength of intact carbonic acid indicates that it is an important protonation agent under physiological conditions. PMID:26862781

  14. Acid rain

    SciTech Connect

    Sweet, W.

    1980-06-20

    Acid precipitation includes not only rain but also acidified snow, hail and frost, as well as sulfur and nitrogen dust. The principal source of acid precipitation is pollution emitted by power plants and smelters. Sulfur and nitrogen compounds contained in the emissions combine with moisture to form droplets with a high acid content - sometimes as acidic as vinegar. When sufficiently concentrated, these acids can kill fish and damage material structures. Under certain circumstances they may reduce crop and forest yields and cause or aggravate respiratory diseases in humans. During the summer, especially, pollutants tend to collect over the Great Lakes in high pressure systems. Since winds typically are westerly and rotate clockwise around high pressure systems, the pollutants gradually are dispersed throughout the eastern part of the continent.

  15. Asparagusic acid.

    PubMed

    Mitchell, Stephen C; Waring, Rosemary H

    2014-01-01

    Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for α-lipoic acid in α-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications.

  16. Acid rain

    SciTech Connect

    Bess, F.D.

    1980-01-01

    The acid rain problem in the northeastern U.S. has been growing in severity and geographical areas affected. Acid rain has damaged, or will result in damage to visibility, physical structures and materials, aquatic life, timber, crops, and soils. The principal causes of acid rain in the northeastern U.S. are sulfur oxide and nitrogen oxide emissions from large power plants and smelters in the Ohio River Valley. Immediate corrective action and appropriate research are needed to reduce acid precipitation. Short-term programs that will define the rate of environmental deterioration, remaining environmental capacity to resist sudden deterioration, mechanisms of acid rain formation, and costs of various control options must be developed. (3 maps, 13 references, 1 table)

  17. Asparagusic acid.

    PubMed

    Mitchell, Stephen C; Waring, Rosemary H

    2014-01-01

    Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for α-lipoic acid in α-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications. PMID:24099657

  18. Circling behavior following unilateral kainic acid injections into rat striatum.

    PubMed

    Taylor, R J; Reavill, C; Jenner, P; Marsden, C D

    1981-12-01

    Unilateral injection of kainic acid (2.5-25 nmol) into rat anterior caudate putamen induced dose-related circling behaviour. Kainic acid (10 nmol) consistently caused initial weak ipsiversive circling lasting 1 h followed by prolonged strong contraversive rotation lasting in excess of 10 h. Unilateral intrastriatal administration of L-glutamic acid, or of monosodium L-glutamate, to normal rats, or administration of monosodium L-glutamate to rats with extensive decortication, did not induce circling behaviour. The simultaneous unilateral injection of monosodium L-glutamate (1 mumol) with kainic acid (10 nmol) did not modify circling behaviour induced by kainic acid. However, extensive decortication greatly reduced circling induced by unilateral intrastriatal kainic acid (10 nmol), and effect not reversed by the simultaneous administration of monosodium L-glutamate (1 mumol). Unilateral 6-hydroxydopamine lesions of the left nigrostriatal pathway abolished the initial ipsiversive rotation and potentiated the subsequent contraversive rotation for up to 4 h after intrastriatal injection of kainic acid (10 nmol). Peripheral administration of haloperidol (1 mg/kg i.p.) also abolished initial ipsiversive rotation and decreased the subsequent contraversive rotation. Electro-coagulation of the ipsilateral strio-nigral pathway prolonged the initial ipsiversive rotation produced by kainic acid, but markedly attenuated contraversive rotation. These findings suggest that circling induced by intrastriatal administration of kainic acid depends on intact corticostriate pathways, but it cannot be reproduced or modified by intrastriatal administration of glutamate. Kainic acid circling appears to be mediated via strio-nigral pathways, and to be modulated by dopaminergic function. PMID:7333356

  19. Identification of tropomyosins as major allergens in antarctic krill and mantis shrimp and their amino acid sequence characteristics.

    PubMed

    Motoyama, Kanna; Suma, Yota; Ishizaki, Shoichiro; Nagashima, Yuji; Lu, Ying; Ushio, Hideki; Shiomi, Kazuo

    2008-01-01

    Tropomyosin represents a major allergen of decapod crustaceans such as shrimps and crabs, and its highly conserved amino acid sequence (>90% identity) is a molecular basis of the immunoglobulin E (IgE) cross-reactivity among decapods. At present, however, little information is available about allergens in edible crustaceans other than decapods. In this study, the major allergen in two species of edible crustaceans, Antarctic krill Euphausia superba and mantis shrimp Oratosquilla oratoria that are taxonomically distinct from decapods, was demonstrated to be tropomyosin by IgE-immunoblotting using patient sera. The cross-reactivity of the tropomyosins from both species with decapod tropomyosins was also confirmed by inhibition IgE immunoblotting. Sequences of the tropomyosins from both species were determined by complementary deoxyribonucleic acid cloning. The mantis shrimp tropomyosin has high sequence identity (>90% identity) with decapod tropomyosins, especially with fast-type tropomyosins. On the other hand, the Antarctic krill tropomyosin is characterized by diverse alterations in region 13-42, the amino acid sequence of which is highly conserved for decapod tropomyosins, and hence, it shares somewhat lower sequence identity (82.4-89.8% identity) with decapod tropomyosins than the mantis shrimp tropomyosin. Quantification by enzyme-linked immunosorbent assay revealed that Antarctic krill contains tropomyosin at almost the same level as decapods, suggesting that its allergenicity is equivalent to decapods. However, mantis shrimp was assumed to be substantially not allergenic because of the extremely low content of tropomyosin. PMID:18521668

  20. Acid fog

    SciTech Connect

    Hileman, B.

    1983-03-01

    Fog in areas of southern California previously thought to be pollution-free has been shown to have a pH as low as 1.69. It has been found to be most acidic after smoggy days, suggesting that it forms on the aerosol associated with the previously exiting smog. Studies on Whiteface Mountain in the Adirondacks show that fog water is often 10 times as acidic as rainwater. As a result of their studies, California plans to spend $4 million on acid deposition research in the coming year. (JMT)

  1. Chirality Matters: Synthesis and Consumption of the d-Enantiomer of Lactic Acid by Synechocystis sp. Strain PCC6803

    PubMed Central

    Angermayr, S. Andreas; Correddu, Danilo; Kern, Ramona; Hagemann, Martin; Hellingwerf, Klaas J.

    2015-01-01

    Both enantiomers of lactic acid, l-lactic acid and d-lactic acid, can be produced in a sustainable way by a photosynthetic microbial cell factory and thus from CO2, sunlight, and water. Several properties of polylactic acid (a polyester of polymerized lactic acid) depend on the controlled blend of these two enantiomers. Recently, cyanobacterium Synechocystis sp. strain PCC6803 was genetically modified to allow formation of either of these two enantiomers. This report elaborates on the d-lactic acid production achieved by the introduction of a d-specific lactate dehydrogenase from the lactic acid bacterium Leuconostoc mesenteroides into Synechocystis. A typical batch culture of this recombinant strain initially shows lactic acid production, followed by a phase of lactic acid consumption, until production “outcompetes” consumption at later growth stages. We show that Synechocystis is able to use d-lactic acid, but not l-lactic acid, as a carbon source for growth. Deletion of the organism's putative d-lactate dehydrogenase (encoded by slr1556), however, does not eliminate this ability with respect to d-lactic acid consumption. In contrast, d-lactic acid consumption does depend on the presence of glycolate dehydrogenase GlcD1 (encoded by sll0404). Accordingly, this report highlights the need to match a product of interest of a cyanobacterial cell factory with the metabolic network present in the host used for its synthesis and emphasizes the need to understand the physiology of the production host in detail. PMID:26682849

  2. Chirality Matters: Synthesis and Consumption of the d-Enantiomer of Lactic Acid by Synechocystis sp. Strain PCC6803.

    PubMed

    Angermayr, S Andreas; van der Woude, Aniek D; Correddu, Danilo; Kern, Ramona; Hagemann, Martin; Hellingwerf, Klaas J

    2015-12-18

    Both enantiomers of lactic acid, l-lactic acid and d-lactic acid, can be produced in a sustainable way by a photosynthetic microbial cell factory and thus from CO2, sunlight, and water. Several properties of polylactic acid (a polyester of polymerized lactic acid) depend on the controlled blend of these two enantiomers. Recently, cyanobacterium Synechocystis sp. strain PCC6803 was genetically modified to allow formation of either of these two enantiomers. This report elaborates on the d-lactic acid production achieved by the introduction of a d-specific lactate dehydrogenase from the lactic acid bacterium Leuconostoc mesenteroides into Synechocystis. A typical batch culture of this recombinant strain initially shows lactic acid production, followed by a phase of lactic acid consumption, until production "outcompetes" consumption at later growth stages. We show that Synechocystis is able to use d-lactic acid, but not l-lactic acid, as a carbon source for growth. Deletion of the organism's putative d-lactate dehydrogenase (encoded by slr1556), however, does not eliminate this ability with respect to d-lactic acid consumption. In contrast, d-lactic acid consumption does depend on the presence of glycolate dehydrogenase GlcD1 (encoded by sll0404). Accordingly, this report highlights the need to match a product of interest of a cyanobacterial cell factory with the metabolic network present in the host used for its synthesis and emphasizes the need to understand the physiology of the production host in detail.

  3. Role of pipecolic acid in the biosynthesis of lysine in Rhodotorula glutinis.

    PubMed

    Kinzel, J J; Bhattacharjee, J K

    1979-05-01

    The role of pipecolic acid in the biosynthesis of lysine was investigated in Rhodotorula glutinis, an aerobic red yeast. Supplementation of pipecolic acid in the minimal medium supported the growth of mutants lys2, lys3, and lys5; alpha-aminoadipic acid supported the growth of lys5; but neither alpha-aminoadipic acid nor pipecolic acid supported the growth of mutants MNNG42 and MNNG37. During the growth of the appropriate mutants, pipecolic acid was removed from the growth medium and the intracellular pool. In tracer experiments, radioactivity from [(14)C]pipecolic acid was selectively incorporated into the cellular lysine of lys5 and the wild-type strain. l-Pipecolic acid-dependent enzyme activity did not require any cofactor and was inhibited by mercuric chloride and potassium cyanide. This activity was present in the wild-type strain and all of the mutants tested and was repressed in mutant lys5 when grown in the presence of higher concentration of lysine. The reaction product of pipecolic acid was converted to saccharopine by lys5 enzyme in the presence of glutamate and reduced nicotin-amide adenine dinucleotide phosphate. Mutant MNNG37 lacked the saccharopine dehydrogenase activity, indicating that this step is involved in the conversion of alpha-aminoadipic acid and pipecolic acid to lysine. Mutants MNNG37 and MNNG42 accumulated a p-dimethylaminobenzaldehyde-reacting product in the culture supernatant and in the intracellular pool. Chromatographic properties of the p-dimethylaminobenzaldehyde adduct and that of the pipecolic acid-dependent reaction product were similar. The reaction product and the accumulation product were characterized on the basis of mass and absorption spectra as alpha-aminoadipic-semialdehyde, which in solution remains in equilibrium with Delta(1)-piperideine-6-carboxylic acid. Since alpha-aminoadipic-semialdehyde is a known intermediate of the alpha-aminoadipic acid pathway for the biosynthesis of lysine, it is concluded that pipecolic

  4. Tranexamic Acid

    MedlinePlus

    ... is used to treat heavy bleeding during the menstrual cycle (monthly periods) in women. Tranexamic acid is in ... tablets for more than 5 days in a menstrual cycle or take more than 6 tablets in a ...

  5. Mefenamic Acid

    MedlinePlus

    ... as mefenamic acid may cause ulcers, bleeding, or holes in the stomach or intestine. These problems may ... like coffee grounds, blood in the stool, or black and tarry stools.Keep all appointments with your ...

  6. Acid Precipitation

    ERIC Educational Resources Information Center

    Likens, Gene E.

    1976-01-01

    Discusses the fact that the acidity of rain and snow falling on parts of the U.S. and Europe has been rising. The reasons are still not entirely clear and the consequences have yet to be well evaluated. (MLH)

  7. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  8. Selective cellular acidification and toxicity of weak organic acids in an acidic microenvironment.

    PubMed

    Karuri, A R; Dobrowsky, E; Tannock, I F

    1993-12-01

    The mean extracellular pH (pHe) within solid tumours has been found to be lower than in normal tissues. Agents which cause intracellular acidification at low pHe might have selective toxicity towards cells in tumours. Weak acids (or their anions) with pKa values in the range of 4-6 have a higher proportion of molecules in the uncharged form at low pHe and can diffuse more rapidly into cells. The effects of organic acids including succinate, monomethyl succinate and malonate to acidify cells have been evaluated under conditions of different pHe in the acidic range. These weak acids caused intracellular acidification of murine EMT-6 and human MGH-U1 cells in a concentration and pHe dependent fashion. At concentrations of 10 mM and above, these acids also caused in vitro cytotoxicity to these cells at low pHe (< 6.5). The rate and extent of cellular acidification caused by these weak acids, and their cytotoxicity at low pHe, were enhanced by exposure to amiloride and 5-(N-ethyl-N-isopropyl)amiloride (EIPA), agents which inhibit Na+/H+ exchange, and hence the regulation of intracellular pH. Acid dependent cytotoxicity was also investigated in a murine solid tumour using the endpoints of growth delay and colony formation in vitro following treatment in vivo. Agents were tested alone or with 15 Gy X-rays to select a population of hypoxic (and presumably acidic) cells. Achievable serum concentrations of succinate were about 1 mM and no antitumour activity of succinate was detected when used in this way. It is concluded that weak acids are selectively taken up into cells, and can cause selective cellular acidification and toxicity, at low pHe in culture. Weak acids that are normal cellular metabolites are not toxic in vivo, but weak acids carrying cytotoxic groups offer the potential for selective uptake and toxicity under the conditions of low pHe that exist in many solid tumours.

  9. Selective cellular acidification and toxicity of weak organic acids in an acidic microenvironment.

    PubMed Central

    Karuri, A. R.; Dobrowsky, E.; Tannock, I. F.

    1993-01-01

    The mean extracellular pH (pHe) within solid tumours has been found to be lower than in normal tissues. Agents which cause intracellular acidification at low pHe might have selective toxicity towards cells in tumours. Weak acids (or their anions) with pKa values in the range of 4-6 have a higher proportion of molecules in the uncharged form at low pHe and can diffuse more rapidly into cells. The effects of organic acids including succinate, monomethyl succinate and malonate to acidify cells have been evaluated under conditions of different pHe in the acidic range. These weak acids caused intracellular acidification of murine EMT-6 and human MGH-U1 cells in a concentration and pHe dependent fashion. At concentrations of 10 mM and above, these acids also caused in vitro cytotoxicity to these cells at low pHe (< 6.5). The rate and extent of cellular acidification caused by these weak acids, and their cytotoxicity at low pHe, were enhanced by exposure to amiloride and 5-(N-ethyl-N-isopropyl)amiloride (EIPA), agents which inhibit Na+/H+ exchange, and hence the regulation of intracellular pH. Acid dependent cytotoxicity was also investigated in a murine solid tumour using the endpoints of growth delay and colony formation in vitro following treatment in vivo. Agents were tested alone or with 15 Gy X-rays to select a population of hypoxic (and presumably acidic) cells. Achievable serum concentrations of succinate were about 1 mM and no antitumour activity of succinate was detected when used in this way. It is concluded that weak acids are selectively taken up into cells, and can cause selective cellular acidification and toxicity, at low pHe in culture. Weak acids that are normal cellular metabolites are not toxic in vivo, but weak acids carrying cytotoxic groups offer the potential for selective uptake and toxicity under the conditions of low pHe that exist in many solid tumours. PMID:8260358

  10. Diamine-sulfuric acid reactions are a potent source of new particle formation

    NASA Astrophysics Data System (ADS)

    Jen, Coty N.; Bachman, Ryan; Zhao, Jun; McMurry, Peter H.; Hanson, David R.

    2016-01-01

    Atmospheric nucleation from sulfuric acid depends on the concentrations and the stabilizing effect of other trace gases, such as ammonia and amines. Diamines are an understudied class of atmospherically relevant compounds, and we examine how they affect sulfuric acid nucleation in both flow reactor experiments and the atmosphere. The number of particles produced from sulfuric acid and diamines in the flow reactor was equal to or greater than the number formed from monoamines, implying that diamines are more effective nucleating agents. Upper limits of diamine abundance were also monitored during three field campaigns: Lamont, OK (2013); Lewes, DE (2012); and Atlanta, GA (2009). Mixing ratios were measured as high as tens of parts per trillion by volume (GA and OK). Laboratory results suggest that diamines at these levels are important for atmospheric nucleation. Diamines likely participate in atmospheric nucleation and should be considered in nucleation measurements and models.

  11. Antibacterial Nitroacridine, Nitroakridin 3582: Binding to Nucleic Acids In Vitro and Effects on Selected Cell-Free Model Systems of Macromolecular Biosynthesis

    PubMed Central

    Wolfe, Alan D.; Cook, Thomas M.; Hahn, Fred E.

    1971-01-01

    Nitroakridin 3582 (NA) formed complexes with native deoxyribonucleic acid (DNA) and with transfer ribonucleic acid (tRNA) species from Escherichia coli. Spectrophotometric titrations of NA with these nucleic acids produced numerical results from which nonlinear adsorption isotherms were derived. These curves indicated the existence of more than one class of binding sites on the polymers to which NA was bound by more than one process. The stoichiometry of strong binding of NA to double helical DNA was in agreement with a conventional value (1 ligand molecule per 4.2 component nucleotides) for complete intercalation binding. NA inhibited the DNA-dependent DNA polymerase I and RNA polymerase reactions, the first strongly and the second appreciably. These inhibitions corresponded to the extents to which NA inhibits DNA and RNA biosyntheses in vivo. Evidently, NA interferes with the template function of DNA. The drug also inhibited the polymerization of phenylalanine in a cell-free E. coli ribosome-polyuridylic acid [poly (U)] system. The effect paralleled an inhibition of the poly (U)-directed binding of phenylalanyl tRNA to ribosomes. Ethidium bromide acted similarly. The antimalarial drug, chloroquine, stimulated polyphenylalanine synthesis, apparently as a result of stimulating the poly (U)-directed binding of phenylalanyl tRNA to ribosomes. PMID:4945180

  12. Evidence from Meteorites for Multiple Possible Amino Acid Alphabets for the Origins of Life

    NASA Technical Reports Server (NTRS)

    Burton, A. S.; Elsila, J. E.; Callahan, M. P.; Glavin, D. P.; Dworkin, J. P.

    2015-01-01

    A key question for the origins of life is understanding which amino acids made up the first proteins synthesized during the origins of life. The canonical set of 20 - 22 amino acids used in proteins are all alpha-amino, alpha-hydrogen isomers that, nevertheless, show considerable variability in properties including size, hydrophobicity, and ionizability. Abiotic amino acid synthesis experiments such as Miller-Urey spark discharge reactions produce a set of up to 23 amino acids, depending on starting materials and reaction conditions, with significant abundances of both alpha- and non-alpha-amino acid isomers. These two sets of amino acids do not completely overlap; of the 23 spark discharge amino acids, only 11 are used in modern proteins. Furthermore, because our understanding of conditions on the early Earth are limited, it is unclear which set(s) of conditions employed in spark discharge or hydrothermal reactions are correct, leaving us with significant uncertainty about the amino acid alphabet available for the origins of life on Earth. Meteorites, the surviving remnants of asteroids and comets that fall to the Earth, offer the potential to study authentic samples of naturally-occurring abiotic chemistry, and thus can provide an alternative approach to constraining the amino acid library during the origins of life.

  13. Investigation of the adsorption of amino acids on Pd(1 1 1): A density functional theory study

    NASA Astrophysics Data System (ADS)

    James, Joanna N.; Han, Jeong Woo; Sholl, David S.

    2014-05-01

    Density functional theory calculations have been used to study the adsorption of glycine, alanine, norvaline, valine, proline, cysteine, and serine on Pd(1 1 1). Most amino acids except cysteine adsorb onto the surface in a tridentate fashion through a nitrogen atom and both oxygen atoms. For cysteine, an additional bond is formed with the surface due to the strong affinity of the sulfur atom, resulting in a significantly larger adsorption energy. The adsorption patterns of amino acids we examined are supported by the shifts in vibrational frequencies associated with NHH and COO. The adsorption strength of amino acids depends on how much the molecules deform during the adsorption process. Understanding the adsorption of amino acids on Pd(1 1 1) provides fundamental information for future consideration of the interactions between their derivatives or more complicated biomolecules and metal surfaces.

  14. Salicylic acids

    PubMed Central

    Hayat, Shamsul; Irfan, Mohd; Wani, Arif; Nasser, Alyemeni; Ahmad, Aqil

    2012-01-01

    Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here. PMID:22301975

  15. Cytokine-like Activity of Liver Type Fatty Acid Binding Protein (L-FABP) Inducing Inflammatory Cytokine Interleukin-6

    PubMed Central

    Kim, Hyunwoo; Gil, Gaae; Lee, Siyoung; Kwak, Areum; Jo, Seunghyun; Kim, Ensom; Nguyen, Tam T.; Kim, Sinae; Jhun, Hyunjhung; Kim, Somi; Kim, Miyeon; Lee, Youngmin

    2016-01-01

    It has been reported that fatty acid binding proteins (FABPs) do not act only as intracellular mediators of lipid responses but also have extracellular functions. This study aimed to investigate whether extracellular liver type (L)-FABP has a biological activity and to determined serum L-FABP levels in patients with end-stage renal disease (ESRD). We isolated L-FABP complementary deoxyribonucleic acid (cDNA) from the Huh7 human hepatocarcinoma cell line and expressed the recombinant L-FABP protein in Escherichia coli. A549 lung carcinoma and THP-1 monocytic cells were stimulated with the human recombinant L-FABP. Human whole blood cells were also treated with the human recombinant L-FABP or interleukin (IL)-1α. IL-6 levels were measured in cell culture supernatants using IL-6 enzyme-linked immunosorbent assay (ELISA). Human recombinant L-FABP induced IL-6 in a dose-dependent manner in A549, THP-1 cells, and whole blood cells. The blood samples of healthy volunteers and patients with ESRD were taken after an overnight fast. The serum levels of L-FABP in healthy volunteers and ESRD patients were quantified with L-FABP ELISA. The values of L-FABP in patients with ESRD were significantly lower than those in the control group. Our results demonstrated the biological activity of L-FABP in human cells suggesting L-FABP can be a mediator of inflammation. PMID:27799875

  16. Stearic Acid

    ERIC Educational Resources Information Center

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) is presented for the chemical, stearic acid. The profile lists the chemical's physical and harmful characteristics, exposure limits, and symptoms of major exposure, for the benefit of teachers and students, who use the chemical in the laboratory.

  17. Trichloroacetic acid

    Integrated Risk Information System (IRIS)

    Trichloroacetic acid ( TCA ) ; CASRN 76 - 03 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonca

  18. Acrylic acid

    Integrated Risk Information System (IRIS)

    Acrylic acid ( CASRN 79 - 10 - 7 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  19. Selenious acid

    Integrated Risk Information System (IRIS)

    Selenious acid ; CASRN 7783 - 00 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  20. Dichloroacetic acid

    Integrated Risk Information System (IRIS)

    Dichloroacetic acid ; CASRN 79 - 43 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  1. Cacodylic acid

    Integrated Risk Information System (IRIS)

    Cacodylic acid ; CASRN 75 - 60 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  2. Phosphoric acid

    Integrated Risk Information System (IRIS)

    Phosphoric acid ; CASRN 7664 - 38 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  3. Benzoic acid

    Integrated Risk Information System (IRIS)

    Benzoic acid ; CASRN 65 - 85 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  4. Formic acid

    Integrated Risk Information System (IRIS)

    Formic acid ; CASRN 64 - 18 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  5. [Hyaluronic acid].

    PubMed

    Pomarede, N

    2008-01-01

    Hyaluronic Acid (HA) is now a leader product in esthetic procedures for the treatment of wrinkles and volumes. The structure of HA, its metabolism, its physiological function are foremost breaking down then its use in aesthetic dermatology: steps of injection, possible side effects, benefits and downsides of the use of HA in aesthetic dermatology.

  6. Adaptive response and tolerance to weak acids in Saccharomyces cerevisiae: a genome-wide view.

    PubMed

    Mira, Nuno P; Teixeira, Miguel Cacho; Sá-Correia, Isabel

    2010-10-01

    Weak acids are widely used as food preservatives (e.g., acetic, propionic, benzoic, and sorbic acids), herbicides (e.g., 2,4-dichlorophenoxyacetic acid), and as antimalarial (e.g., artesunic and artemisinic acids), anticancer (e.g., artesunic acid), and immunosuppressive (e.g., mycophenolic acid) drugs, among other possible applications. The understanding of the mechanisms underlying the adaptive response and resistance to these weak acids is a prerequisite to develop more effective strategies to control spoilage yeasts, and the emergence of resistant weeds, drug resistant parasites or cancer cells. Furthermore, the identification of toxicity mechanisms and resistance determinants to weak acid-based pharmaceuticals increases current knowledge on their cytotoxic effects and may lead to the identification of new drug targets. This review integrates current knowledge on the mechanisms of toxicity and tolerance to weak acid stress obtained in the model eukaryote Saccharomyces cerevisiae using genome-wide approaches and more detailed gene-by-gene analysis. The major features of the yeast response to weak acids in general, and the more specific responses and resistance mechanisms towards a specific weak acid or a group of weak acids, depending on the chemical nature of the side chain R group (R-COOH), are highlighted. The involvement of several transcriptional regulatory networks in the genomic response to different weak acids is discussed, focusing on the regulatory pathways controlled by the transcription factors Msn2p/Msn4p, War1p, Haa1p, Rim101p, and Pdr1p/Pdr3p, which are known to orchestrate weak acid stress response in yeast. The extrapolation of the knowledge gathered in yeast to other eukaryotes is also attempted.

  7. Myristic Acid Enhances Diacylglycerol Kinase δ-Dependent Glucose Uptake in Myotubes.

    PubMed

    Wada, Yuko; Sakiyama, Shizuka; Sakai, Hiromichi; Sakane, Fumio

    2016-08-01

    Decreased expression of diacylglycerol kinase (DGK) δ in skeletal muscles attenuates glucose uptake and is closely related to the pathogenesis of type 2 diabetes. Therefore, up-regulation of DGKδ expression is thought to protect and improve glucose homoeostasis in type 2 diabetes. We recently determined that myristic acid (14:0), but not palmitic (16:0) or stearic (18:0) acid, significantly increased DGKδ2 protein expression in mouse C2C12 myotubes. In the current study, we analyzed whether myristic acid indeed enhances glucose uptake in C2C12 myotubes. We observed that myristic acid caused ~1.4-fold increase in insulin-independent glucose uptake. However, palmitic and stearic acids failed to enhance glucose uptake. DGKδ-specific siRNA decreased myristic acid-dependent increase of glucose uptake. Moreover, overexpression of DGKδ2 enhanced glucose uptake in C2C12 cells in the absence of myristic acid treatment. Taken together, these results strongly suggest that myristic acid enhances basal glucose uptake in myotubes in a DGKδ2 expression-dependent manner.

  8. Hydroxycarboxylic acids and salts

    DOEpatents

    Kiely, Donald E; Hash, Kirk R; Kramer-Presta, Kylie; Smith, Tyler N

    2015-02-24

    Compositions which inhibit corrosion and alter the physical properties of concrete (admixtures) are prepared from salt mixtures of hydroxycarboxylic acids, carboxylic acids, and nitric acid. The salt mixtures are prepared by neutralizing acid product mixtures from the oxidation of polyols using nitric acid and oxygen as the oxidizing agents. Nitric acid is removed from the hydroxycarboxylic acids by evaporation and diffusion dialysis.

  9. Non-standard amino acid recognition by Escherichia coli leucyl-tRNA synthetase

    NASA Technical Reports Server (NTRS)

    Martinis, S. A.; Fox, G. E.

    1997-01-01

    Recombinant E. coli leucyl-tRNA synthetase was screened for amino acid-dependent pyrophosphate exchange activity using noncognate aliphatic amino acids including norvaline, homocysteine, norleucine, methionine, and homoserine. [32P]-labeled reaction products were separated by thin layer chromatography using a novel solvent system and then quantified by phosphorimaging. Norvaline which differs from leucine by only one methyl group stimulated pyrophosphate exchange activity as did both homocysteine and norleucine to a lesser extent. The KM parameters for leucine and norvaline were measured to be 10 micromoles and 1.5 mM, respectively. Experiments are in progress to determine if norvaline is transferred to tRNA(Leu) and/or edited by a pre- or post-transfer mechanism.

  10. Influence of solid-state acidity on the decomposition of sucrose in amorphous systems. I.

    PubMed

    Alkhamis, Khouloud A

    2008-10-01

    It was of interest to develop a method for solid-state acidity measurements using pH indicators and to correlate this method to the degradation rate of sucrose. Amorphous samples containing lactose 100mg/ml, sucrose 10mg/ml, citrate buffer (1-50mM) and sodium chloride (to adjust the ionic strength) were prepared by freeze-drying. The lyophiles were characterized using powder X-ray diffraction, differential scanning calorimetry and Karl Fischer titremetry. The solid-state acidity of all lyophiles was measured using diffuse reflectance spectroscopy and suitable indicators (thymol blue or bromophenol blue). The prepared lyophiles were subjected to a temperature of 60 degrees C and were analyzed for degradation using the Trinder kit. The results obtained from this study have shown that the solid-state acidity depends mainly on the molar ratio of the salt and the acid used in buffer preparation and not on the initial pH of the solution. The degradation of sucrose in the lyophiles is extremely sensitive to the solid-state acidity and the ionic strength. Reasonable correlation was obtained between the Hammett acidity function and sucrose degradation rate. The use of cosolvents (in the calibration plots) can provide good correlations with the rate of an acid-catalyzed reaction, sucrose inversion, in amorphous lyophiles. PMID:18647642

  11. [Changes of acid-producing function of the stomach before and after operation performed for gastric ulcer type I].

    PubMed

    Futuĭma, Iu M

    2007-01-01

    The gastric acid-producing function changes were analyzed in 48 patients suffering gastric ulcer (Johnson-I type), using the computer pH-metry. The dependence of the gastric glands acid-production on the ulcer defect localization was established. Hyperchlorhydria was revealed in 84.6% of patients suffering gastric distal third ulcer and in its subcardial localization--in 30.8%. In the late follow-up period after the operation, performed for gastric ulcer disease, the gastric stump capacity to restore its glands production of acid depends mainly on the method of surgical procedure applied. The best indices were revealed after application of organpreserving method--the partial resection of gastric ischemized segment according to L. Ya. Kovahlchuk combined with selective proximal vagotomy, comparing with such after application of resectional methods according to Billroth.

  12. Salicylic acid-induced resistance to Fusarium oxysporum f. sp. lycopersici in tomato.

    PubMed

    Mandal, Sudhamoy; Mallick, Nirupama; Mitra, Adinpunya

    2009-07-01

    We demonstrated that exogenous application of 200 microM salicylic acid through root feeding and foliar spray could induce resistance against Fusarium oxysporum f. sp. Lycopersici (Fol) in tomato. Endogenous accumulation of free salicylic acid in tomato roots was detected by HPLC and identification was confirmed by LC-MS/MS analysis. At 168h of salicylic acid treatment through roots, the endogenous salicylic acid level in the roots increased to 1477ngg(-1) FW which was 10 times higher than control plants. Similarly, the salicylic acid content was 1001ngg(-1) FW at 168h of treatment by foliar spray, which was 8.7 times higher than control plants. The activities of phenylalanine ammonia lyase (PAL, EC 4.3.1.5) and peroxidase (POD, EC 1.11.1.7) were 5.9 and 4.7 times higher, respectively than the control plants at 168h of salicylic acid feeding through the roots. The increase in PAL and POD activities was 3.7 and 3.3 times higher, respectively at 168h of salicylic acid treatments through foliar spray than control plants. The salicylic acid-treated tomato plants challenged with Fol exhibited significantly reduced vascular browning and leaf yellowing wilting. The mycelial growth of Fol was not significantly affected by salicylic acid. Significant increase in basal level of salicylic acid in noninoculated plants indicated that tomato root system might have the capacity to assimilate and distribute salicylic acid throughout the plant. The results indicated that the induced resistance observed in tomato against Fol might be a case of salicylic acid-dependent systemic acquired resistance.

  13. DNA-LCEB: a high-capacity and mutation-resistant DNA data-hiding approach by employing encryption, error correcting codes, and hybrid twofold and fourfold codon-based strategy for synonymous substitution in amino acids.

    PubMed

    Hafeez, Ibbad; Khan, Asifullah; Qadir, Abdul

    2014-11-01

    Data-hiding in deoxyribonucleic acid (DNA) sequences can be used to develop an organic memory and to track parent genes in an offspring as well as in genetically modified organism. However, the main concerns regarding data-hiding in DNA sequences are the survival of organism and successful extraction of watermark from DNA. This implies that the organism should live and reproduce without any functional disorder even in the presence of the embedded data. Consequently, performing synonymous substitution in amino acids for watermarking becomes a primary option. In this regard, a hybrid watermark embedding strategy that employs synonymous substitution in both twofold and fourfold codons of amino acids is proposed. This work thus presents a high-capacity and mutation-resistant watermarking technique, DNA-LCEB, for hiding secret information in DNA of living organisms. By employing the different types of synonymous codons of amino acids, the data storage capacity has been significantly increased. It is further observed that the proposed DNA-LCEB employing a combination of synonymous substitution, lossless compression, encryption, and Bose-Chaudary-Hocquenghem coding is secure and performs better in terms of both capacity and robustness compared to existing DNA data-hiding schemes. The proposed DNA-LCEB is tested against different mutations, including silent, miss-sense, and non-sense mutations, and provides substantial improvement in terms of mutation detection/correction rate and bits per nucleotide. A web application for DNA-LCEB is available at http://111.68.99.218/DNA-LCEB.

  14. Methylmalonic acid blood test

    MedlinePlus

    ... acid is a substance produced when proteins, called amino acids, in the body break down. The health care ... Cederbaum S, Berry GT. Inborn errors of carbohydrate, ammonia, amino acid, and organic acid metabolism. In: Gleason CA, Devaskar ...

  15. Folic Acid and Pregnancy

    MedlinePlus

    ... 5 Things to Know About Zika & Pregnancy Folic Acid and Pregnancy KidsHealth > For Parents > Folic Acid and ... before conception and during early pregnancy . About Folic Acid Folic acid, sometimes called folate, is a B ...

  16. Comparison of the effect of salinity on the D/H ratio of fatty acids of heterotrophic and photoautotrophic microorganisms.

    PubMed

    Heinzelmann, Sandra M; Chivall, David; M'Boule, Daniela; Sinke-Schoen, Danielle; Villanueva, Laura; Damsté, Jaap S Sinninghe; Schouten, Stefan; van der Meer, Marcel T J

    2015-05-01

    The core metabolism of microorganisms has a major influence on the hydrogen isotopic composition of their fatty acids. Heterotrophic microorganisms produce fatty acids with a deuterium to hydrogen (D/H) ratio either slightly depleted or enriched in D compared to the growth water, while photo- and chemoautotrophic microorganisms produce fatty acids which are heavily depleted in D. However, besides metabolism other biochemical and environmental factors (i.e. biosynthetic pathways, growth phase and temperature) have been shown to affect the D/H ratio of fatty acids, and it is necessary to evaluate the magnitude of these effects compared to that of metabolism. Here, we show that the effect of salinity on the D/H ratio of fatty acids depends on the core metabolism of the microorganism. While fatty acids of the photoautotroph Isochrysis galbana become more enriched in D with increasing salinity (enrichment of 30-40‰ over a range of 25 salinity units), no effect of salinity on the D/H ratio of fatty acids of the heterotrophic Pseudomonas str. LFY10 was observed ((ε)lipid/water of the C16:0 fatty acid of ~120‰ over a range of 10 salinity units). This can likely be explained by the relative contributions of different H and nicotinamide adenine dinucleotide phosphate sources during fatty acid biosynthesis. PMID:25883110

  17. Comparison of the effect of salinity on the D/H ratio of fatty acids of heterotrophic and photoautotrophic microorganisms.

    PubMed

    Heinzelmann, Sandra M; Chivall, David; M'Boule, Daniela; Sinke-Schoen, Danielle; Villanueva, Laura; Damsté, Jaap S Sinninghe; Schouten, Stefan; van der Meer, Marcel T J

    2015-05-01

    The core metabolism of microorganisms has a major influence on the hydrogen isotopic composition of their fatty acids. Heterotrophic microorganisms produce fatty acids with a deuterium to hydrogen (D/H) ratio either slightly depleted or enriched in D compared to the growth water, while photo- and chemoautotrophic microorganisms produce fatty acids which are heavily depleted in D. However, besides metabolism other biochemical and environmental factors (i.e. biosynthetic pathways, growth phase and temperature) have been shown to affect the D/H ratio of fatty acids, and it is necessary to evaluate the magnitude of these effects compared to that of metabolism. Here, we show that the effect of salinity on the D/H ratio of fatty acids depends on the core metabolism of the microorganism. While fatty acids of the photoautotroph Isochrysis galbana become more enriched in D with increasing salinity (enrichment of 30-40‰ over a range of 25 salinity units), no effect of salinity on the D/H ratio of fatty acids of the heterotrophic Pseudomonas str. LFY10 was observed ((ε)lipid/water of the C16:0 fatty acid of ~120‰ over a range of 10 salinity units). This can likely be explained by the relative contributions of different H and nicotinamide adenine dinucleotide phosphate sources during fatty acid biosynthesis.

  18. Overexpression and optimization of glutamate decarboxylase in Lactobacillus plantarum Taj-Apis362 for high gamma-aminobutyric acid production.

    PubMed

    Tajabadi, Naser; Baradaran, Ali; Ebrahimpour, Afshin; Rahim, Raha A; Bakar, Fatimah A; Manap, Mohd Yazid A; Mohammed, Abdulkarim S; Saari, Nazamid

    2015-07-01

    Gamma-aminobutyric acid (GABA) is an important bioactive compound biosynthesized by microorganisms through decarboxylation of glutamate by glutamate decarboxylase (GAD). In this study, a full-length GAD gene was obtained by cloning the template deoxyribonucleic acid to pTZ57R/T vector. The open reading frame of the GAD gene showed the cloned gene was composed of 1410 nucleotides and encoded a 469 amino acids protein. To improve the GABA-production, the GAD gene was cloned into pMG36e-LbGAD, and then expressed in Lactobacillus plantarum Taj-Apis362 cells. The overexpression was confirmed by SDS-PAGE and GAD activity, showing a 53 KDa protein with the enzyme activity increased by sevenfold compared with the original GAD activity. The optimal fermentation conditions for GABA production established using response surface methodology were at glutamic acid concentration of 497.973 mM, temperature 36°C, pH 5.31 and time 60 h. Under the conditions, maximum GABA concentration obtained (11.09 mM) was comparable with the predicted value by the model at 11.23 mM. To our knowledge, this is the first report of successful cloning (clone-back) and overexpression of the LbGAD gene from L. plantarum to L. plantarum cells. The recombinant Lactobacillus could be used as a starter culture for direct incorporation into a food system during fermentation for production of GABA-rich products.

  19. Overexpression and optimization of glutamate decarboxylase in Lactobacillus plantarum Taj-Apis362 for high gamma-aminobutyric acid production.

    PubMed

    Tajabadi, Naser; Baradaran, Ali; Ebrahimpour, Afshin; Rahim, Raha A; Bakar, Fatimah A; Manap, Mohd Yazid A; Mohammed, Abdulkarim S; Saari, Nazamid

    2015-07-01

    Gamma-aminobutyric acid (GABA) is an important bioactive compound biosynthesized by microorganisms through decarboxylation of glutamate by glutamate decarboxylase (GAD). In this study, a full-length GAD gene was obtained by cloning the template deoxyribonucleic acid to pTZ57R/T vector. The open reading frame of the GAD gene showed the cloned gene was composed of 1410 nucleotides and encoded a 469 amino acids protein. To improve the GABA-production, the GAD gene was cloned into pMG36e-LbGAD, and then expressed in Lactobacillus plantarum Taj-Apis362 cells. The overexpression was confirmed by SDS-PAGE and GAD activity, showing a 53 KDa protein with the enzyme activity increased by sevenfold compared with the original GAD activity. The optimal fermentation conditions for GABA production established using response surface methodology were at glutamic acid concentration of 497.973 mM, temperature 36°C, pH 5.31 and time 60 h. Under the conditions, maximum GABA concentration obtained (11.09 mM) was comparable with the predicted value by the model at 11.23 mM. To our knowledge, this is the first report of successful cloning (clone-back) and overexpression of the LbGAD gene from L. plantarum to L. plantarum cells. The recombinant Lactobacillus could be used as a starter culture for direct incorporation into a food system during fermentation for production of GABA-rich products. PMID:25757029

  20. Understanding Acid Rain

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  1. Relatedness Among Rhizobium and Agrobacterium Species Determined by Three Methods of Nucleic Acid Hybridization

    PubMed Central

    Gibbins, Ann M.; Gregory, K. F.

    1972-01-01

    Deoxyribonucleic acid (DNA) was isolated from 20 strains of Rhizobium and Agrobacterium and from one strain of Serratia marcescens; the guanine plus cytosine content of each DNA sample was determined by thermal denaturation. Radioactive DNA was isolated from three reference strains following the uptake of [2-14C]thymidine in the presence of deoxyadenosine. Ribonucleic acid (RNA) polymerase was used to synthesize radioactive RNA on DNA templates from the three reference strains. Radioactive DNA and RNA from the three reference strains were each hybridized with filter-bound DNA from all of the 21 test strains in 6 × SSC (standard saline citrate) and 50% formamide at 43 C for 40 hr. DNA/DNA relatedness was also determined by spectrophotometric measurement of the rates of association of single-stranded DNA. The order of relatedness between strains was similar by each method. Overall standard deviations for the DNA/DNA and DNA/RNA membrane filter techniques were ±0.87 and ±1.03%, respectively; that for the spectrophotometric technique was ±4.11%. The DNA/DNA membrane technique gave higher absolute values of hybridization than did the DNA/RNA technique. R. leguminosarum and R. trifolii could not be distinguished from each other by these techniques. These results also indicated close relationships between R. lupini and R. japonicum, and (with less certainty) between R. meliloti and R. phaseoli. Of all the rhizobia tested against the A. tumefaciens 371 reference strain, the R. japonicum strains were the most unrelated. The three Agrobacterium strains used were as related to the R. lupini and R. leguminosarum references as were several rhizobium strains. PMID:4591471

  2. Highly Stable Nanocontainer of APTES-Anchored Layered Titanate Nanosheet for Reliable Protection/Recovery of Nucleic Acid

    NASA Astrophysics Data System (ADS)

    Kim, Tae Woo; Kim, In Young; Park, Dae-Hwan; Choy, Jin-Ho; Hwang, Seong-Ju

    2016-02-01

    A universal technology for the encapsulative protection of unstable anionic species by highly stable layered metal oxide has been developed via the surface modification of a metal oxide nanosheet. The surface anchoring of (3-aminopropyl)triethoxysilane (APTES) on exfoliated titanate nanosheet yields a novel cationic metal oxide nanosheet, which can be universally used for the hybridization with various biological and inorganic anions. The encapsulation of deoxyribonucleic acid (DNA) in the cationic APTES-anchored titanate lattice makes possible the reliable long-term protection of DNA against enzymatic, chemical, and UV‑vis light corrosions. The encapsulated DNA can be easily released from the titanate lattice via sonication, underscoring the functionality of the cationic APTES-anchored titanate nanosheet as a stable nanocontainer for DNA. The APTES-anchored titanate nanosheet can be also used as an efficient CO2 adsorbent and a versatile host material for various inorganic anions like polyoxometalates, leading to the synthesis of novel intercalative nanohybrids with unexplored properties and useful functionalities.

  3. Highly Stable Nanocontainer of APTES-Anchored Layered Titanate Nanosheet for Reliable Protection/Recovery of Nucleic Acid

    PubMed Central

    Kim, Tae Woo; Kim, In Young; Park, Dae-Hwan; Choy, Jin-Ho; Hwang, Seong-Ju

    2016-01-01

    A universal technology for the encapsulative protection of unstable anionic species by highly stable layered metal oxide has been developed via the surface modification of a metal oxide nanosheet. The surface anchoring of (3-aminopropyl)triethoxysilane (APTES) on exfoliated titanate nanosheet yields a novel cationic metal oxide nanosheet, which can be universally used for the hybridization with various biological and inorganic anions. The encapsulation of deoxyribonucleic acid (DNA) in the cationic APTES-anchored titanate lattice makes possible the reliable long-term protection of DNA against enzymatic, chemical, and UV−vis light corrosions. The encapsulated DNA can be easily released from the titanate lattice via sonication, underscoring the functionality of the cationic APTES-anchored titanate nanosheet as a stable nanocontainer for DNA. The APTES-anchored titanate nanosheet can be also used as an efficient CO2 adsorbent and a versatile host material for various inorganic anions like polyoxometalates, leading to the synthesis of novel intercalative nanohybrids with unexplored properties and useful functionalities. PMID:26906340

  4. Highly Stable Nanocontainer of APTES-Anchored Layered Titanate Nanosheet for Reliable Protection/Recovery of Nucleic Acid

    NASA Astrophysics Data System (ADS)

    Kim, Tae Woo; Kim, In Young; Park, Dae-Hwan; Choy, Jin-Ho; Hwang, Seong-Ju

    2016-02-01

    A universal technology for the encapsulative protection of unstable anionic species by highly stable layered metal oxide has been developed via the surface modification of a metal oxide nanosheet. The surface anchoring of (3-aminopropyl)triethoxysilane (APTES) on exfoliated titanate nanosheet yields a novel cationic metal oxide nanosheet, which can be universally used for the hybridization with various biological and inorganic anions. The encapsulation of deoxyribonucleic acid (DNA) in the cationic APTES-anchored titanate lattice makes possible the reliable long-term protection of DNA against enzymatic, chemical, and UV-vis light corrosions. The encapsulated DNA can be easily released from the titanate lattice via sonication, underscoring the functionality of the cationic APTES-anchored titanate nanosheet as a stable nanocontainer for DNA. The APTES-anchored titanate nanosheet can be also used as an efficient CO2 adsorbent and a versatile host material for various inorganic anions like polyoxometalates, leading to the synthesis of novel intercalative nanohybrids with unexplored properties and useful functionalities.

  5. Chitosan-coated poly(lactic-co-glycolic) acid nanoparticles as an efficient delivery system for Newcastle disease virus DNA vaccine

    PubMed Central

    Zhao, Kai; Zhang, Yang; Zhang, Xiaoyan; Shi, Ci; Wang, Xin; Wang, Xiaohua; Jin, Zheng; Cui, Shangjin

    2014-01-01

    We determined the efficacy and safety of chitosan (CS)-coated poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) as a delivery system for a vaccine to protect chickens against Newcastle disease virus (NDV). The newly constructed vaccine contained DNA (the F gene) of NDV. The Newcastle disease virus (NDV) F gene deoxyribonucleic acid (DNA) plasmid (pFDNA)-CS/PLGA-NPs were spherical (diameter =699.1±5.21 nm [mean ± standard deviation]) and smooth, with an encapsulation efficiency of 98.1% and a Zeta potential of +6.35 mV. An in vitro release assay indicated that CS controlled the burst release of plasmid DNA, such that up to 67.4% of the entire quantity of plasmid DNA was steadily released from the pFDNA-CS/PLGA-NPs. An in vitro expression assay indicated that the expression of nanoparticles (NPs) was maintained in the NPs. In an immunization test with specific pathogen-free chickens, the pFDNA-CS/PLGA-NPs induced stronger cellular, humoral, and mucosal immune responses than the plasmid DNA vaccine alone. The pFDNA-CS/PLGA-NPs did not harm 293T cells in an in vitro assay and did not harm chickens in an in vivo assay. Overall, the results indicated that CS-coated PLGA NPs can serve as an efficient and safe mucosal immune delivery system for NDV DNA vaccine. PMID:25356070

  6. The effect of some non-protein amino acids on pollen germination and pollen-tube growth in five species of the Vicieae.

    PubMed

    Simola, L K

    1967-12-01

    The effects of canavanine, α,γ-diaminobutyric acid, homoarginine and lathyrine on the germination of pollen and on in-vitro growth of pollen tubes were studied in the following species: Lathyrus niger, L. silvestris, Vicia unijuga, Pisum sativum and Cicer arietinum.The effects of these non-protein amino acids depended on their quantity and on the plant species. Every amino acid had a promoting effect on germination and growth at some concentration in some species. Inhibition or promotion of pollen germination and pollen-tube growth were usually parallel. The stronger influence of some amino acid on growth than on germination may be due to slow penetration of the acid into the cell.Homoarginine and lathyrine had a promoting effect at all concentrations in L. niger, a species in which these amino acids occur naturally. In most other species they had, if anything, a very slight inhibitory effect, α,γ-Diaminobutyric acid and canavanine had the strongest inhibitory effects on the species studied. It seems possible that these amino acids are antimetabolites of common amino acids.It is obvious that non-protein amino acids can form effective hybridization barries, although the conditions in nature are more complex than in vitro. The ability to synthesize a new amino acid may therefore be of evolutionary significance in the isolation of new species and genera. PMID:24522605

  7. Reinvestigation of the Henry's law constant for hydrogen peroxide with temperature and acidity variation.

    PubMed

    Huang, Daoming; Chen, Zhongming

    2010-01-01

    Hydrogen peroxide is not only an important oxidant in itself; it also serves as both sink and temporary reservoir for other important oxidants including HOx (OH and HO2) radicals and O3 in the atmosphere. Its partitioning between gas and aqueous phases in the atmosphere, usually described by its Henry's law constant (K(H)), significantly influences its role in atmospheric processes. Large discrepancies between the K(H) values reported in previous work, however, have created uncertainty for atmospheric modelers. Based on our newly developed online instrumentation, we have re-determined the temperature and acidity dependence of K(H) for hydrogen peroxide at an air pressure of (0.960 +/- 0.013) atm (1 atm = 1.01325 x 10(5) Pa). The results indicated that the temperature dependence of K(H) for hydrogen peroxide fits to the Van't Hoff equation form, expressed as lnK(H) = a/T - b, and a = -deltaH/R, where K(H) is in M/atm (M is mol/L), T is in degrees Kelvin, R is the ideal gas constant, and deltaH is the standard heat of solution. For acidity dependence, results demonstrated that the K(H) value of hydrogen peroxide appeared to have no obvious dependence on decreasing pH level (from pH 7 to pH 1). Combining the dependence of both temperature and acidity, the obtained a and b were 7024 +/- 138 and 11.97 +/- 0.48, respectively, deltaH was (58.40 +/- 1.15) kJ/(K x mol), and the uncertainties represent sigma. Our determined K(H) values for hydrogen peroxide will therefore be of great use in atmospheric models. PMID:20617734

  8. Combined Treatment With Peroxisome Proliferator-Activated Receptor (PPAR) Gamma Ligands and Gamma Radiation Induces Apoptosis by PPARγ-Independent Up-Regulation of Reactive Oxygen Species-Induced Deoxyribonucleic Acid Damage Signals in Non-Small Cell Lung Cancer Cells

    SciTech Connect

    Han, Eun Jong; Im, Chang-Nim; Park, Seon Hwa; Moon, Eun-Yi; Hong, Sung Hee

    2013-04-01

    Purpose: To investigate possible radiosensitizing activities of the well-known peroxisome proliferator-activated receptor (PPAR)γ ligand ciglitazone and novel PPARγ ligands CAY10415 and CAY10506 in non-small cell lung cancer (NSCLC) cells. Methods and Materials: Radiosensitivity was assessed using a clonogenic cell survival assay. To investigate the mechanism underlying PPARγ ligand-induced radiosensitization, the subdiploid cellular DNA fraction was analyzed by flow cytometry. Activation of the caspase pathway by combined PPARγ ligands and γ-radiation treatment was detected by immunoblot analysis. Reactive oxygen species (ROS) were measured using 2,7-dichlorodihydrofluorescein diacetate and flow cytometry. Results: The 3 PPARγ ligands induced cell death and ROS generation in a PPARγ-independent manner, enhanced γ-radiation–induced apoptosis and caspase-3–mediated poly (ADP-ribose) polymerase (PARP) cleavage in vitro. The combined PPARγ ligand/γ-radiation treatment triggered caspase-8 activation, and this initiator caspase played an important role in the combination-induced apoptosis. Peroxisome proliferator-activated receptor-γ ligands may enhance the γ-radiation-induced DNA damage response, possibly by increasing γ-H2AX expression. Moreover, the combination treatment significantly increased ROS generation, and the ROS scavenger N-acetylcysteine inhibited the combined treatment-induced ROS generation and apoptotic cell death. Conclusions: Taken together, these results indicated that the combined treatment of PPARγ ligands and γ-radiation synergistically induced DNA damage and apoptosis, which was regulated by ROS.

  9. Precipitation: its acidic nature.

    PubMed

    Frohliger, J O; Kane, R

    1975-08-01

    A comparison of the free hydrogen ion concentration and the total hydrogen ion concentration of rain samples shows that rain is a weak acid. The weak acid nature of rain casts doubt on the concepts that the acidity of rain is increasing and that these increases are due to strong acids such as sulfuric acid.

  10. Microchemical studies of the pathogenesis of soman toxication and atropine-oxime treatment using nucleic acid cytophotometry (cytophotometric analyses of non-cholinergic mediated effects of soman toxication in rats). Annual summary report, 15 August 1981-14 September 1983

    SciTech Connect

    Anthony, A.; Bocan, T.M.A.; Doebler, J.A.; Nollenberger, E.L.

    1983-10-01

    Quantitative cytochemical analyses, using microscopic histochemical staining and scanning-integrating microdensitometry, were made of deoxyribonucleic acid (DNA), ribonucleic acid (RNA), protein, and acetylcholinesterase (AChE) changes in central and peripheral tissue compartments of rats exposed to soman with and without various regimens of atropine-pralidoxime treatment. Hypoxia-acclimated rats were also used to evaluate the relationship between increased vascularization of tissues and susceptibility of rats to soman toxication. It was found that a critical aspect of soman toxicity is an impairment in RNA-protein synthetic capacity of neurons in various brain regions; this is not directly correlated with the extent of blood or brain AChE suppression, indicating the involvement of non-cholinergic mechanisms. Additional aspects of soman intoxication include cytochemical-cytomorphologic manifestations of hepatoxicity and mesenteric mast cell degranulation. Various antidotal regimens and also prior acclimation of rats to hypoxia tend to ameliorate the severity of brain RNA depletion. Among the putative noncholinergic mechanisms which could precipitate the observed nucleic acid response patterns are included the disruption of excitatory-inhibitory neurotransmitter functioning coupled with a stress-mediated impairment in CNS-endocrine homeostatic mechanisms.

  11. Role of a single amino acid substitution of VP3 H142D for increased acid resistance of foot-and-mouth disease virus serotype A.

    PubMed

    Biswal, Jitendra K; Das, Biswajit; Sharma, Gaurav K; Khulape, Sagar A; Pattnaik, Bramhadev

    2016-04-01

    Foot-and-mouth disease virus (FMDV) particles lose infectivity due to their dissociation into pentamers at pH value below 6.5. After the uptake of FMDV by receptor-mediated endocytosis, the acid-dependent dissociation process is required for the release of FMDV genome inside endosomes. Nevertheless, dissociation of FMDV particles in mildly acidic conditions renders the inactivated FMD vaccine less effective. To improve the acid stability of inactivated FMD vaccine during the manufacturing process, a serotype A IND 40/2000 (in-use vaccine strain) mutant with increased resistance to acid inactivation was generated through reverse genetics approach. Based upon the earlier reports, the crucial amino acid residue, H142 of VP3 capsid protein was substituted separately to various amino acid residues Arg (R), Phe (F), Ala (A), and Asp (D) on the full-genome length cDNA clone. While the H142 → R or H142 → F or H142 → A substitutions resulted in non-infectious FMDV, H142 → D mutation on VP3 protein (H3142D) resulted in the generation of mutant virus with enhanced resistance to acid-induced inactivation. In addition, H3142D substitution did not alter the replication ability and antigenicity of mutant as compared to the parental virus. However, the virus competition experiments revealed that the H3142D substitution conferred a loss of fitness for the mutant virus. Results from this study demonstrate that the H3142D substitution is the molecular determinant of acid-resistant phenotype in FMDV serotype A. PMID:26873406

  12. Isolated etioplasts as test system for inhibitors of fatty acid biosynthesis

    SciTech Connect

    Lichtenthaler, H.K.; Kobek, K. )

    1989-04-01

    Isolated intact chloroplasts of mono- and dicotyledonous plants possess the capacity for de novo fatty acid biosynthesis, starting from {sup 14}C-acetate. These can be taken as test system for herbicides affecting fatty acid biosynthesis as shown earlier in our laboratory. The incorporation rates of acetate into the total fatty acids depend on the photosynthetic cofactors ATP and NADPH and amount in the light to 33 kBq (oat) and 39 kBq (pea) per mg chlorophyll x h, whereas in the dark only ca. 10% of these rates are obtained. In order to establish a test system, which is fully independent of light, we isolated and characterized etioplast fractions from oat and pea seedlings with a very high capacity of de novo fatty acid biosynthesis (500 and 400 kBq per mg carotenoids in a 20 min period). This activity was blocked by herbicides such as cycloxydim, sethoxydim and diclofop in a dose-dependent manner. This new test system has the great advantage that one can verify whether inhibitors of photosynthesis affect fatty acid biosynthesis.

  13. Maternal fructose drives placental uric acid production leading to adverse fetal outcomes

    PubMed Central

    Asghar, Zeenat A.; Thompson, Alysha; Chi, Maggie; Cusumano, Andrew; Scheaffer, Suzanne; Al-Hammadi, Noor; Saben, Jessica L.; Moley, Kelle H.

    2016-01-01

    Maternal metabolic diseases increase offspring risk for low birth weight and cardiometabolic diseases in adulthood. Excess fructose consumption may confer metabolic risks for both women and their offspring. However, the direct consequences of fructose intake per se are unknown. We assessed the impact of a maternal high-fructose diet on the fetal-placental unit in mice in the absence of metabolic syndrome and determined the association between maternal serum fructose and placental uric acid levels in humans. In mice, maternal fructose consumption led to placental inefficiency, fetal growth restriction, elevated fetal serum glucose and triglyceride levels. In the placenta, fructose induced de novo uric acid synthesis by activating the activities of the enzymes AMP deaminase and xanthine oxidase. Moreover, the placentas had increased lipids and altered expression of genes that control oxidative stress. Treatment of mothers with the xanthine oxidase inhibitor allopurinol reduced placental uric acid levels, prevented placental inefficiency, and improved fetal weights and serum triglycerides. Finally, in 18 women delivering at term, maternal serum fructose levels significantly correlated with placental uric acid levels. These findings suggest that in mice, excess maternal fructose consumption impairs placental function via a xanthine oxidase/uric acid-dependent mechanism, and similar effects may occur in humans. PMID:27125896

  14. Diffusion dialysis. Effect of membrane composition on acid/salt separation

    SciTech Connect

    Narebska, A.; Warszawski, A. )

    1992-05-01

    Diffusion dialysis is an energy-saving separation technique. In order to highlight the relationship between membrane composition and ability to separate acid/salt mixtures by diffusion dialysis, a few anion-exchange membranes were examined. Experiments on solubility/diffusivity phenomena were carried out in contact with hydrochloric acid and sodium chloride solutions (single- and two-solute experiments). Computations using Glueckauf and Tye models have indicated high nonuniformity in the distribution of fixed charged within the membranes and different accessibilities of the internal membrane volumes for the acid and salt. The Neosepta AFN-7 membrane (Tokuymam Soda Co.) has proved effective in differentiating the permeants by sorption (k{sub HCl}/k{sub NaCl} {approx} 2) and diffusivity ({bar D}{sub HCl}/{bar D}{sub NaCl} up to 10). This membrane is also the only one which, when in contact with two-solutes solutions, absorbs the acid preferentially to the salt. For this membrane the preferential sorption and transport of the acid depends not only on the physical structure of the membrane but also on the chemical nature of the polymer which contains pyridine moieties.

  15. Amino Acid Metabolism Disorders

    MedlinePlus

    ... defects & other health conditions > Amino acid metabolism disorders Amino acid metabolism disorders E-mail to a friend Please ... baby’s newborn screening may include testing for certain amino acid metabolism disorders. These are rare health conditions that ...

  16. Carbolic acid poisoning

    MedlinePlus

    Phenol poisoning; Phenylic acid poisoning; Hydroxybenzene poisoning; Phenic acid poisoning; Benzenol poisoning ... Below are symptoms of carbolic acid poisoning in different parts of the ... urine Decreased urine output No urine output EYES, EARS, ...

  17. Azelaic Acid Topical

    MedlinePlus

    Azelaic acid gel is used to clear the bumps, lesions, and swelling caused by rosacea (a skin disease that ... redness, flushing, and pimples on the face). Azelaic acid cream is used to treat acne. Azelaic acid ...

  18. Uric acid test (image)

    MedlinePlus

    Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  19. Facts about Folic Acid

    MedlinePlus

    ... Information For... Media Policy Makers Facts About Folic Acid Language: English Español (Spanish) Recommend on Facebook Tweet ... of the baby's brain and spine. About folic acid Folic acid is a B vitamin. Our bodies ...

  20. Acid Lipase Disease

    MedlinePlus

    ... Awards Enhancing Diversity Find People About NINDS NINDS Acid Lipase Disease Information Page Synonym(s): Cholesterol Ester Storage ... Trials Related NINDS Publications and Information What is Acid Lipase Disease ? Acid lipase disease or deficiency occurs ...

  1. Lipopolysaccharide Stimulates Butyric Acid-Induced Apoptosis in Human Peripheral Blood Mononuclear Cells

    PubMed Central

    Kurita-Ochiai, Tomoko; Fukushima, Kazuo; Ochiai, Kuniyasu

    1999-01-01

    We previously reported that butyric acid, an extracellular metabolite from periodontopathic bacteria, induced apoptosis in murine thymocytes, splenic T cells, and human Jurkat T cells. In this study, we examined the ability of butyric acid to induce apoptosis in peripheral blood mononuclear cells (PBMC) and the effect of bacterial lipopolysaccharide (LPS) on this apoptosis. Butyric acid significantly inhibited the anti-CD3 monoclonal antibody- and concanavalin A-induced proliferative responses in a dose-dependent fashion. This inhibition of PBMC growth by butyric acid depended on apoptosis in vitro. It was characterized by internucleosomal DNA digestion and revealed by gel electrophoresis followed by a colorimetric DNA fragmentation assay to occur in a concentration-dependent fashion. Butyric acid-induced PBMC apoptosis was accompanied by caspase-3 protease activity but not by caspase-1 protease activity. LPS potentiated butyric acid-induced PBMC apoptosis in a dose-dependent manner. Flow-cytometric analysis revealed that LPS increased the proportion of sub-G1 cells and the number of late-stage apoptotic cells induced by butyric acid. Annexin V binding experiments with fractionated subpopulations of PBMC in flow cytometory revealed that LPS accelerated the butyric acid-induced CD3+-T-cell apoptosis followed by similar levels of both CD4+- and CD8+-T-cell apoptosis. The addition of LPS to PBMC cultures did not cause DNA fragmentation, suggesting that LPS was unable to induce PBMC apoptosis directly. These data suggest that LPS, in combination with butyric acid, potentiates CD3+ PBMC T-cell apoptosis and plays a role in the apoptotic depletion of CD4+ and CD8+ cells. PMID:9864191

  2. Effects of heating on composition, degree of darkness, and stacking nanostructure of soil humic acids.

    PubMed

    Katsumi, Naoya; Yonebayashi, Koyo; Okazaki, Masanori

    2016-01-15

    Wildfires and prescribed burning can affect both the quality and the quantity of organic matter in soils. In this study, we investigated qualitative and quantitative changes of soil humic substances in two different soils (an Entisol from a paddy field and an Inceptisol from a cedar forest) under several controlled heating conditions. Soil samples were heated in a muffle furnace at 200, 250, or 300 °C for 1, 3, 5, or 12h. The humic acid and fulvic acid contents of the soil samples prior to and after heating were determined. The degree of darkness, elemental composition, carbon and nitrogen stable isotope ratios, (13)C nuclear magnetic resonance spectra, and X-ray diffraction patterns of humic acids extracted from the soils before and after heating were measured. The proportion of humic acids in total carbon decreased with increasing heating time at high temperature (300 °C), but increased with increasing heating time at ≤ 250 °C. The degree of darkness of the humic acids increased with increasing heating time and temperature. During darkening, the H/C atomic ratios, the proportion of aromatic C, and the carbon and nitrogen stable isotope ratios increased, whereas the proportions of alkyl C and O-alkyl C decreased. X-ray diffraction analysis verified that a stacking nanostructure developed by heating. Changes in the chemical structure of the humic acids from the heated soils depended on the type of soil. The major structural components of the humic acids from the heated Entisol were aromatic C and carboxylic C, whereas aliphatic C, aromatic C, and carboxylic C structural components were found in the humic acids from the heated Inceptisol. These results suggest that the heat-induced changes in the chemical structure of the humic acids depended on the source plant.

  3. Effects of heating on composition, degree of darkness, and stacking nanostructure of soil humic acids.

    PubMed

    Katsumi, Naoya; Yonebayashi, Koyo; Okazaki, Masanori

    2016-01-15

    Wildfires and prescribed burning can affect both the quality and the quantity of organic matter in soils. In this study, we investigated qualitative and quantitative changes of soil humic substances in two different soils (an Entisol from a paddy field and an Inceptisol from a cedar forest) under several controlled heating conditions. Soil samples were heated in a muffle furnace at 200, 250, or 300 °C for 1, 3, 5, or 12h. The humic acid and fulvic acid contents of the soil samples prior to and after heating were determined. The degree of darkness, elemental composition, carbon and nitrogen stable isotope ratios, (13)C nuclear magnetic resonance spectra, and X-ray diffraction patterns of humic acids extracted from the soils before and after heating were measured. The proportion of humic acids in total carbon decreased with increasing heating time at high temperature (300 °C), but increased with increasing heating time at ≤ 250 °C. The degree of darkness of the humic acids increased with increasing heating time and temperature. During darkening, the H/C atomic ratios, the proportion of aromatic C, and the carbon and nitrogen stable isotope ratios increased, whereas the proportions of alkyl C and O-alkyl C decreased. X-ray diffraction analysis verified that a stacking nanostructure developed by heating. Changes in the chemical structure of the humic acids from the heated soils depended on the type of soil. The major structural components of the humic acids from the heated Entisol were aromatic C and carboxylic C, whereas aliphatic C, aromatic C, and carboxylic C structural components were found in the humic acids from the heated Inceptisol. These results suggest that the heat-induced changes in the chemical structure of the humic acids depended on the source plant. PMID:26398447

  4. Acid distribution in phosphoric acid fuel cells

    SciTech Connect

    Okae, I.; Seya, A.; Umemoto, M.

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  5. A Possible Mechanism of Zika Virus Associated Microcephaly: Imperative Role of Retinoic Acid Response Element (RARE) Consensus Sequence Repeats in the Viral Genome.

    PubMed

    Kumar, Ashutosh; Singh, Himanshu N; Pareek, Vikas; Raza, Khursheed; Dantham, Subrahamanyam; Kumar, Pavan; Mochan, Sankat; Faiq, Muneeb A

    2016-01-01

    Owing to the reports of microcephaly as a consistent outcome in the fetuses of pregnant women infected with ZIKV in Brazil, Zika virus (ZIKV)-microcephaly etiomechanistic relationship has recently been implicated. Researchers, however, are still struggling to establish an embryological basis for this interesting causal handcuff. The present study reveals robust evidence in favor of a plausible ZIKV-microcephaly cause-effect liaison. The rationale is based on: (1) sequence homology between ZIKV genome and the response element of an early neural tube developmental marker "retinoic acid" in human DNA and (2) comprehensive similarities between the details of brain defects in ZIKV-microcephaly and retinoic acid embryopathy. Retinoic acid is considered as the earliest factor for regulating anteroposterior axis of neural tube and positioning of structures in developing brain through retinoic acid response elements (RARE) consensus sequence (5'-AGGTCA-3') in promoter regions of retinoic acid-dependent genes. We screened genomic sequences of already reported virulent ZIKV strains (including those linked to microcephaly) and other viruses available in National Institute of Health genetic sequence database (GenBank) for the RARE consensus repeats and obtained results strongly bolstering our hypothesis that ZIKV strains associated with microcephaly may act through precipitation of dysregulation in retinoic acid-dependent genes by introducing extra stretches of RARE consensus sequence repeats in the genome of developing brain cells. Additional support to our hypothesis comes from our findings that screening of other viruses for RARE consensus sequence repeats is positive only for those known to display neurotropism and cause fetal brain defects (for which maternal-fetal transmission during developing stage may be required). The numbers of RARE sequence repeats appeared to match with the virulence of screened positive viruses. Although, bioinformatic evidence and embryological

  6. A Possible Mechanism of Zika Virus Associated Microcephaly: Imperative Role of Retinoic Acid Response Element (RARE) Consensus Sequence Repeats in the Viral Genome.

    PubMed

    Kumar, Ashutosh; Singh, Himanshu N; Pareek, Vikas; Raza, Khursheed; Dantham, Subrahamanyam; Kumar, Pavan; Mochan, Sankat; Faiq, Muneeb A

    2016-01-01

    Owing to the reports of microcephaly as a consistent outcome in the fetuses of pregnant women infected with ZIKV in Brazil, Zika virus (ZIKV)-microcephaly etiomechanistic relationship has recently been implicated. Researchers, however, are still struggling to establish an embryological basis for this interesting causal handcuff. The present study reveals robust evidence in favor of a plausible ZIKV-microcephaly cause-effect liaison. The rationale is based on: (1) sequence homology between ZIKV genome and the response element of an early neural tube developmental marker "retinoic acid" in human DNA and (2) comprehensive similarities between the details of brain defects in ZIKV-microcephaly and retinoic acid embryopathy. Retinoic acid is considered as the earliest factor for regulating anteroposterior axis of neural tube and positioning of structures in developing brain through retinoic acid response elements (RARE) consensus sequence (5'-AGGTCA-3') in promoter regions of retinoic acid-dependent genes. We screened genomic sequences of already reported virulent ZIKV strains (including those linked to microcephaly) and other viruses available in National Institute of Health genetic sequence database (GenBank) for the RARE consensus repeats and obtained results strongly bolstering our hypothesis that ZIKV strains associated with microcephaly may act through precipitation of dysregulation in retinoic acid-dependent genes by introducing extra stretches of RARE consensus sequence repeats in the genome of developing brain cells. Additional support to our hypothesis comes from our findings that screening of other viruses for RARE consensus sequence repeats is positive only for those known to display neurotropism and cause fetal brain defects (for which maternal-fetal transmission during developing stage may be required). The numbers of RARE sequence repeats appeared to match with the virulence of screened positive viruses. Although, bioinformatic evidence and embryological

  7. Binding Preferences of Amino Acids for Gold Nanoparticles: A Molecular Simulation Study.

    PubMed

    Shao, Qing; Hall, Carol K

    2016-08-01

    A better understanding of the binding preference of amino acids for gold nanoparticles of different diameters could aid in the design of peptides that bind specifically to nanoparticles of a given diameter. Here we identify the binding preference of 19 natural amino acids for three gold nanoparticles with diameters of 1.0, 2.0, and 4.0 nm, and investigate the mechanisms that govern these preferences. We calculate potentials of mean force between 36 entities (19 amino acids and 17 side chains) and the three gold nanoparticles in explicit water using well-tempered metadynamics simulations. Comparing these potentials of mean force determines the amino acids' nanoparticle binding preferences and if these preferences are controlled by the backbone, the side chain, or both. Twelve amino acids prefer to bind to the 4.0 nm gold nanoparticle, and seven prefer to bind to the 2.0 nm one. We also use atomistic molecular dynamics simulations to investigate how water molecules near the nanoparticle influence the binding of the amino acids. The solvation shells of the larger nanoparticles have higher water densities than those of the smaller nanoparticles while the orientation distributions of the water molecules in the shells of all three nanoparticles are similar. The nanoparticle preferences of the amino acids depend on whether their binding free energy is determined mainly by their ability to replace or to reorient water molecules in the nanoparticle solvation shell. The amino acids whose binding free energy depends mainly on the replacement of water molecules are likely to prefer to bind to the largest nanoparticle and tend to have relatively simple side chain structures. Those whose binding free energy depends mainly on their ability to reorient water molecules prefer a smaller nanoparticle and tend to have more complex side chain structures.

  8. Reagentless measurement of aminoglycoside antibiotics in blood serum via an electrochemical, ribonucleic acid aptamer-based biosensor.

    PubMed

    Rowe, Aaron A; Miller, Erin A; Plaxco, Kevin W

    2010-09-01

    Biosensors built using ribonucleic acid (RNA) aptamers show promise as tools for point-of-care medical diagnostics, but they remain vulnerable to nuclease degradation when deployed in clinical samples. To explore methods for protecting RNA-based biosensors from such degradation we have constructed and characterized an electrochemical, aptamer-based sensor for the detection of aminoglycosidic antibiotics. We find that while this sensor achieves low micromolar detection limits and subminute equilibration times when challenged in buffer, it deteriorates rapidly when immersed directly in blood serum. In order to circumvent this problem, we have developed and tested sensors employing modified versions of the same aptamer. Our first effort to this end entailed the methylation of all of the 2'-hydroxyl groups outside of the aptamer's antibiotic binding pocket. However, while devices employing this modified aptamer are as sensitive as those employing an unmodified parent, the modification fails to confer greater stability when the sensor is challenged directly in blood serum. As a second potentially naive alternative, we replaced the RNA bases in the aptamer with their more degradation-resistant deoxyribonucleic acid (DNA) equivalents. Surprisingly and unlike control DNA-stem loops employing other sequences, this DNA aptamer retains the ability to bind aminoglycosides, albeit with poorer affinity than the parent RNA aptamer. Unfortunately, however, while sensors fabricated using this DNA aptamer are stable in blood serum, its lower affinity pushes their detection limits above the therapeutically relevant range. Finally, we find that ultrafiltration through a low-molecular-weight-cutoff spin column rapidly and efficiently removes the relevant nucleases from serum samples spiked with gentamicin, allowing the convenient detection of this aminoglycoside at clinically relevant concentrations using the original RNA-based sensor.

  9. Acid tolerance in amphibians

    SciTech Connect

    Pierce, B.A.

    1985-04-01

    Studies of amphibian acid tolerance provide information about the potential effects of acid deposition on amphibian communities. Amphibians as a group appear to be relatively acid tolerant, with many species suffering increased mortality only below pH 4. However, amphibians exhibit much intraspecific variation in acid tolerance, and some species are sensitive to even low levels of acidity. Furthermore, nonlethal effects, including depression of growth rates and increases in developmental abnormalities, can occur at higher pH.

  10. Bioconversions of ferulic acid, an hydroxycinnamic acid.

    PubMed

    Mathew, Sindhu; Abraham, T Emilia

    2006-01-01

    Ferulic acid is the most abundant hydroxycinnamic acid in the plant world and is ester linked to arabinose, in various plant polysaccharides such as arabinoxylans and pectins. It is a precursor to vanillin, one of the most important aromatic flavor compound used in foods, beverages, pharmaceuticals, and perfumes. This article presents an overview of the various biocatalytic routes, focusing on the relevant biotransformations of ferulic acid using plant sources, microorganisms, and enzymes.

  11. Production of Gymnemic Acid from Cell Suspension Cultures of Gymnema sylvestre.

    PubMed

    Nagella, Praveen; Dandin, Vijayalaxmi S; Murthy, Hosakatte Niranjana

    2016-01-01

    Gymnema sylvestre R. Br. is a popular herbal medicine. It has been used in ayurvedic system of medicine for thousands of years. It is popularly called as "Gur-mar" for its distinctive property of temporarily destroying the taste of sweetness and is used in the treatment of diabetes. The leaves of gymnema possess antidiabetic, antimicrobial, anti-hypercholesterolemic, anti-sweetener, anti-inflammatory, and hepatoprotective properties and have traditional uses in the treatment of asthma, eye complaints, and snake bite. The leaves contain triterpene saponins such as gymnemic acid which is an active ingredient of Gymnema. Since the cultivation of G. sylvestre is a very slow process and the content of gymnemic acid depends on the environmental factors, cell suspension culture is sought as an alternative means for the production of Gymnema biomass and to enhance the gymnemic acid content. In this chapter, the methods employed for the induction of callus and subsequent establishment of cell suspension cultures for the production of biomass and analysis of gymnemic acid using high performance liquid chromatography are described. PMID:27108321

  12. Diacylglycerol kinase θ couples farnesoid X receptor-dependent bile acid signalling to Akt activation and glucose homoeostasis in hepatocytes.

    PubMed

    Cai, Kai; Sewer, Marion B

    2013-09-01

    DGKs (diacylglycerol kinases) catalyse the conversion of diacylglycerol into PA (phosphatidic acid), a positive modulator of mTOR (mammalian target of rapamycin). We have found that chenodeoxycholic acid and the synthetic FXR (farnesoid X receptor) ligand GW4064 induce the mRNA and protein expression of DGKθ in the HepG2 cell line and in primary human hepatocytes. Reporter gene studies using 1.5 kB of the DGKθ promoter fused to the luciferase gene revealed that bile acids increase DGKθ transcriptional activity. Mutation of putative FXR-binding sites attenuated the ability of GW4046 to increase DGKθ luciferase activity. Consistent with this finding, ChIP (chromatin immunoprecipitation) assays demonstrated that bile acid signalling increased the recruitment of FXR to the DGKθ promoter. Furthermore, GW4064 evoked a time-dependent increase in the cellular concentration of PA. We also found that GW4064 and PA promote the phosphorylation of mTOR, Akt and FoxO1 (forkhead box O1), and that silencing DGKθ expression significantly abrogated the ability of GW4046 to promote the phosphorylation of these PA-regulated targets. DGKθ was also required for bile-acid-dependent decreased glucose production. Taken together, our results establish DGKθ as a key mediator of bile-acid-stimulated modulation of mTORC2 (mTOR complex 2), the Akt pathway and glucose homoeostasis.

  13. Crassulacean acid metabolism photosynthesis in columnar cactus seedlings during ontogeny: the effect of light on nocturnal acidity accumulation and chlorophyll fluorescence.

    PubMed

    Hernández-González, Olivia; Villarreal, Oscar Briones

    2007-08-01

    Columnar cacti have been traditionally classified as crassulacean acid metabolism (CAM) plants, though recent research indicates some cactus seedlings employ the C(3) pathway. To verify this last result, we measured acidity fluctuations for five columnar and one globular cactus species in seedlings from 1 to 48 d old after experimental exposure to 60% and 30% full sunlight, and in adult plants in the field. Using light-response curves of chlorophyll fluorescence, we determined photosynthetic efficiency (ΔF/Fm'), maximum electron transport rate (ETR(max)) and saturating photosynthetically active photon flux density (PPFD(sat)). All seedlings used the CAM pathway from their first day of development, and increases in nocturnal acidity depended on species, light treatment, and age. The CAM pathway was also found in adult plants. Cactus seedlings were able to acclimatize to light conditions by making photochemical adjustments, mainly by modifying the level of light at which photosystem II is saturated (PPFD(sat)). The presence of CAM in the seedlings of columnar cacti increases water-use efficiency and reduces the risk of photoinhibition. This could favor survival in the highly variable light levels characteristic of the desert environments of columnar cacti.

  14. Acid Thunder: Acid Rain and Ancient Mesoamerica

    ERIC Educational Resources Information Center

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…

  15. Quantity of acid in acid fog

    SciTech Connect

    Deal, W.J.

    1983-07-01

    This communication notes the actual magnitude of the acidity in acidic fog particles and suggests a possible line of inquiry into the health effects of such fog so that it can be determined whether a typical fog is detrimental or beneficial relative to dry air.

  16. Seasonal changes in the D / H ratio of fatty acids of pelagic microorganisms in the coastal North Sea

    NASA Astrophysics Data System (ADS)

    Mariam Heinzelmann, Sandra; Bale, Nicole Jane; Villanueva, Laura; Sinke-Schoen, Danielle; Philippart, Catharina Johanna Maria; Smede Sinninghe Damsté, Jaap; Schouten, Stefan; van der Meer, Marcel Teunis Jan

    2016-10-01

    Culture studies of microorganisms have shown that the hydrogen isotopic composition of fatty acids depends on their metabolism, but there are only few environmental studies available to confirm this observation. Here we studied the seasonal variability of the deuterium-to-hydrogen (D / H) ratio of fatty acids in the coastal Dutch North Sea and compared this with the diversity of the phyto- and bacterioplankton. Over the year, the stable hydrogen isotopic fractionation factor ɛ between fatty acids and water (ɛlipid/water) ranged between -172 and -237 ‰, the algal-derived polyunsaturated fatty acid nC20:5 generally being the most D-depleted (-177 to -235 ‰) and nC18:0 the least D-depleted fatty acid (-172 to -210 ‰). The in general highly D-depleted nC20:5 is in agreement with culture studies, which indicates that photoautotrophic microorganisms produce fatty acids which are significantly depleted in D relative to water. The ɛlipid/water of all fatty acids showed a transient shift towards increased fractionation during the spring phytoplankton bloom, indicated by increasing chlorophyll a concentrations and relative abundance of the nC20:5 polyunsaturated fatty acids, suggesting increased contributions of photoautotrophy. Time periods with decreased fractionation (less negative ɛlipid/water values) can potentially be explained by an increased contribution of heterotrophy to the fatty acid pool. Our results show that the hydrogen isotopic composition of fatty acids is a promising tool to assess the community metabolism of coastal plankton potentially in combination with the isotopic analysis of more specific biomarker lipids.<

  17. L: (+)-Lactic acid production from non-food carbohydrates by thermotolerant Bacillus coagulans.

    PubMed

    Ou, Mark S; Ingram, Lonnie O; Shanmugam, K T

    2011-05-01

    Lactic acid is used as an additive in foods, pharmaceuticals, and cosmetics, and is also an industrial chemical. Optically pure lactic acid is increasingly used as a renewable bio-based product to replace petroleum-based plastics. However, current production of lactic acid depends on carbohydrate feedstocks that have alternate uses as foods. The use of non-food feedstocks by current commercial biocatalysts is limited by inefficient pathways for pentose utilization. B. coagulans strain 36D1 is a thermotolerant bacterium that can grow and efficiently ferment pentoses using the pentose-phosphate pathway and all other sugar constituents of lignocellulosic biomass at 50°C and pH 5.0, conditions that also favor simultaneous enzymatic saccharification and fermentation (SSF) of cellulose. Using this bacterial biocatalyst, high levels (150-180 g l(-1)) of lactic acid were produced from xylose and glucose with minimal by-products in mineral salts medium. In a fed-batch SSF of crystalline cellulose with fungal enzymes and B. coagulans, lactic acid titer was 80 g l(-1) and the yield was close to 80%. These results demonstrate that B. coagulans can effectively ferment non-food carbohydrates from lignocellulose to L: (+)-lactic acid at sufficient concentrations for commercial application. The high temperature fermentation of pentoses and hexoses to lactic acid by B. coagulans has these additional advantages: reduction in cellulase loading in SSF of cellulose with a decrease in enzyme cost in the process and a reduction in contamination of large-scale fermentations. PMID:20694852

  18. Trans Fatty Acids Induce Vascular Inflammation and Reduce Vascular Nitric Oxide Production in Endothelial Cells

    PubMed Central

    Iwata, Naomi G.; Pham, Matilda; Rizzo, Norma O.; Cheng, Andrew M.; Maloney, Ezekiel; Kim, Francis

    2011-01-01

    Intake of trans fatty acids (TFA), which are consumed by eating foods made from partially hydrogenated vegetable oils, is associated with a higher risk of cardiovascular disease. This relation can be explained by many factors including TFA's negative effect on endothelial function and reduced nitric oxide (NO) bioavailability. In this study we investigated the effects of three different TFA (2 common isomers of C18 found in partially hydrogenated vegetable oil and a C18 isomer found from ruminant-derived—dairy products and meat) on endothelial NF-κB activation and nitric oxide (NO) production. Human endothelial cells were treated with increasing concentrations of Elaidic (trans-C18:1 (9 trans)), Linoelaidic (trans-C18:2 (9 trans, 12 trans)), and Transvaccenic (trans-C18:1 (11 trans)) for 3 h. Both Elaidic and Linoelaidic acids were associated with increasing NF-κB activation as measured by IL-6 levels and phosphorylation of IκBα, and impairment of endothelial insulin signaling and NO production, whereas Transvaccenic acid was not associated with these responses. We also measured superoxide production, which has been hypothesized to be necessary in fatty acid-dependent activation of NF-κB. Both Elaidic acid and Linoelaidic acid are associated with increased superoxide production, whereas Transvaccenic acid (which did not induce inflammatory responses) did not increase superoxide production. We observed differential activation of endothelial superoxide production, NF-κB activation, and reduction in NO production by different C18 isomers suggesting that the location and number of trans double bonds effect endothelial NF-κB activation. PMID:22216328

  19. Two Electrophoresis Experiments for Freshmen in the Health Professions.

    ERIC Educational Resources Information Center

    Brabson, G. Dana; Waugh, David S.

    1986-01-01

    Describes procedures involved with paper electrophoresis separation of amino acids, gel electrophoresis separation of DNA, and design of an electrophoresis tank. Describes experiments using paper (amino acids) and gel (deoxyribonucleic acid fragments). Provides material lists, procedures, and discussion. (JM)

  20. Lactic acid test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003507.htm Lactic acid test To use the sharing features on this page, please enable JavaScript. Lactic acid is mainly produced in muscle cells and red ...

  1. Omega-6 Fatty Acids

    MedlinePlus

    ... types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean ... from studying specific omega-6 fatty acids or plant oils containing omega-6 fatty acids. See the separate ...

  2. Fatty acid analogs

    DOEpatents

    Elmaleh, David R.; Livni, Eli

    1985-01-01

    In one aspect, a radioactively labeled analog of a fatty acid which is capable of being taken up by mammalian tissue and which exhibits an in vivo beta-oxidation rate below that with a corresponding radioactively labeled fatty acid.

  3. Deoxycholic Acid Injection

    MedlinePlus

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  4. Aminocaproic Acid Injection

    MedlinePlus

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  5. Zoledronic Acid Injection

    MedlinePlus

    ... acid (Reclast) is used to prevent or treat osteoporosis (condition in which the bones become thin and ... Zoledronic acid (Reclast) is also used to treat osteoporosis in men, and to prevent or treat osteoporosis ...

  6. Uric Acid Test

    MedlinePlus

    ... limited. Home Visit Global Sites Search Help? Uric Acid Share this page: Was this page helpful? Also known as: Serum Urate; UA Formal name: Uric Acid Related tests: Synovial Fluid Analysis , Kidney Stone Analysis , ...

  7. Methylmalonic Acid Test

    MedlinePlus

    ... limited. Home Visit Global Sites Search Help? Methylmalonic Acid Share this page: Was this page helpful? Also known as: MMA Formal name: Methylmalonic Acid Related tests: Vitamin B12 and Folate , Homocysteine , Intrinsic ...

  8. Hydrochloric acid poisoning

    MedlinePlus

    Hydrochloric acid is a clear, poisonous liquid. It is highly corrosive, which means it immediately causes severe ... discusses poisoning due to swallowing or breathing in hydrochloric acid. This article is for information only. Do ...

  9. Mixed Acid Oxidation

    SciTech Connect

    Pierce, R.A.

    1999-10-26

    Several non-thermal processes have been developed to destroy organic waste compounds using chemicals with high oxidation potentials. These efforts have focused on developing technologies that work at low temperatures, relative to incineration, to overcome many of the regulatory issues associated with obtaining permits for waste incinerators. One such technique with great flexibility is mixed acid oxidation. Mixed acid oxidation, developed at the Savannah River Site, uses a mixture of an oxidant (nitric acid) and a carrier acid (phosphoric acid). The carrier acid acts as a non-volatile holding medium for the somewhat volatile oxidant. The combination of acids allows appreciable amounts of the concentrated oxidant to remain in the carrier acid well above the oxidant''s normal boiling point.

  10. Plant fatty acid hydroxylases

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank

    2001-01-01

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  11. PRODUCTION OF TRIFLUOROACETIC ACID

    DOEpatents

    Haworth, W.N.; Stacey, M.

    1949-07-19

    A method is given for the production of improved yields of trifluoroacetic acid. The compound is prepared by oxidizing m-aminobenzotrifluoride with an alkali metal or alkaline earth metal permanganate at a temperature in the range of 80 deg C to 100 deg C while dissolved ln a mixture of water with glacial acetic acid and/or trifluoroacetic acid. Preferably a mixture of water and trifluoroacetic acid ls used as the solvent.

  12. Quantity of acid in acid fog

    SciTech Connect

    Deal, W.J.

    1983-07-01

    The chemical composition of fog particles has become of considerable interest, because of both the possibility of interpreting atmospheric- chemistry processes in fog particles in terms of the principles of aqueous chemistry and the potential health effects of species present in fog particles. The acidity of fog particles has received wide attention. This communication noted the actual magnitude of the excess acidity in acidic fog particles and suggested a possible line of inquiry into the health effects of such fog so that it can be determined whether a typical fog is detrimental or beneficial relative to dry air. (DP)

  13. Acid Rain Study Guide.

    ERIC Educational Resources Information Center

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  14. The Acid Rain Reader.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  15. What Is Acid Rain?

    ERIC Educational Resources Information Center

    Likens, Gene E.

    2004-01-01

    Acid rain is the collective term for any type of acidified precipitation: rain, snow, sleet, and hail, as well as the presence of acidifying gases, particles, cloud water, and fog in the atmosphere. The increased acidity, primarily from sulfuric and nitric acids, is generated as a by-product of the combustion of fossil fuels such as coal and oil.…

  16. [alpha]-Oxocarboxylic Acids

    ERIC Educational Resources Information Center

    Kerber, Robert C.; Fernando, Marian S.

    2010-01-01

    Several [alpha]-oxocarboxylic acids play key roles in metabolism in plants and animals. However, there are inconsistencies between the structures as commonly portrayed and the reported acid ionization constants, which result because the acids are predominantly hydrated in aqueous solution; that is, the predominant form is RC(OH)[subscript 2]COOH…

  17. Characterization of a salicylic acid- and pathogen-induced lipase-like gene in Chinese cabbage.

    PubMed

    Lee, Kyung-Ah; Cho, Tae-Ju

    2003-09-30

    A cDNA clone for a salicylic acid-induced gene in Chinese cabbage (Brassica rapa subsp. pekinensis) was isolated and characterized. The cabbage gene, designated Br-sil1 (for Brassica rapa salicylate-induced lipase-like 1 gene), encodes a putative lipase that has the family II lipase motif GDSxxDxG around the active site serine. A database search showed that plant genomes have a large number of genes that contain the family II lipase motif. The lipase-like proteins include a myrosinase-associated protein, an anther-specific proline-rich protein APG, a pollen coat protein EXL, and an early nodule-specific protein. The Br-sil1 gene is strongly induced by salicylic acid and a nonhost pathogen, Pseudomonas syringae pv. tomato, that elicits a hypersensitive response in Chinese cabbage. Treatment of the cabbage leaves with BTH, methyl jasmonate, or ethephon showed that the Br-sil1 gene expression is induced by BTH, but not by methyl jasmonate or ethylene. This indicates that the cabbage gene is activated via a salicylic acid-dependent signaling pathway. An examination of the tissue-specific expression revealed that the induction of the Br-sil1 gene expression by BTH occurs in leaves and stems, but not in roots and flowers. Without the BTH treatment, however, the Br-sil1 gene is not expressed in any of the tissues that were examined.

  18. The adsorption of gold, palladium and platinum from acidic chloride solutions on mesoporous carbons.

    DOE PAGES

    Zalupski, Peter R.; McDowell, Rocklan; Dutech, Guy

    2014-08-05

    Studies on the adsorption characteristics of gold, palladium and platinum on mesoporous carbon (CMK-3) and sulfur-impregnated mesoporous carbon (CMK-3/S) evaluated the benefits/drawbacks of the presence of a layer of elemental sulfur inside mesoporous carbon structures. Adsorption isotherms collected for Au(III), Pd(II) and Pt(IV) on those materials suggest that sulfur does enhance the adsorption of those metal ions in mildly acidic environment (pH 3). The isotherms collected in 1 M HCl show that the benefit of sulfur disappears due to the competing influence of large concentration of hydrogen ions on the ion-exchanging mechanism of metal ions sorption on mesoporous carbon surfaces.more » The collected acid dependencies illustrate similar adsorption characteristics for CMK-3 and CMK-3/S in 1-5 M HCl concentration range. Sorption of metal ions from diluted aqueous acidic mixtures of actual leached electronic waste demonstrated the feasibility of recovery of gold from such liquors.« less

  19. The adsorption of gold, palladium and platinum from acidic chloride solutions on mesoporous carbons.

    SciTech Connect

    Zalupski, Peter R.; McDowell, Rocklan; Dutech, Guy

    2014-08-05

    Studies on the adsorption characteristics of gold, palladium and platinum on mesoporous carbon (CMK-3) and sulfur-impregnated mesoporous carbon (CMK-3/S) evaluated the benefits/drawbacks of the presence of a layer of elemental sulfur inside mesoporous carbon structures. Adsorption isotherms collected for Au(III), Pd(II) and Pt(IV) on those materials suggest that sulfur does enhance the adsorption of those metal ions in mildly acidic environment (pH 3). The isotherms collected in 1 M HCl show that the benefit of sulfur disappears due to the competing influence of large concentration of hydrogen ions on the ion-exchanging mechanism of metal ions sorption on mesoporous carbon surfaces. The collected acid dependencies illustrate similar adsorption characteristics for CMK-3 and CMK-3/S in 1-5 M HCl concentration range. Sorption of metal ions from diluted aqueous acidic mixtures of actual leached electronic waste demonstrated the feasibility of recovery of gold from such liquors.

  20. Nucleic acid detection compositions

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James L.

    2008-08-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  1. Cleavage of nucleic acids

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann D.; Dahlberg, James E.

    2000-01-01

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  2. Nucleic acid detection assays

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James E.

    2005-04-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  3. Cleavage of nucleic acids

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor L.; Brow, Mary Ann D.; Dahlberg, James E.

    2007-12-11

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  4. Cleavage of nucleic acids

    SciTech Connect

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow; Mary Ann D.; Dahlberg, James E.

    2010-11-09

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  5. Editorial: Acid precipitation

    SciTech Connect

    1995-09-01

    This editorial focuses on acid rain and the history of public and governmental response to acid rain. Comments on a book by Gwineth Howell `Acid Rain and Acid Waters` are included. The editor feels that Howells has provide a service to the environmental scientific community, with a textbook useful to a range of people, as well as a call for decision makers to learn from the acid rain issue and use it as a model for more sweeping global environmental issues. A balance is needed among several parameters such as level of evidence, probability that the evidence will lead to a specific direction and the cost to the global community. 1 tab.

  6. [Safety of folic acid].

    PubMed

    Ströhle, Alexander; Wolters, Maike; Hahn, Andreas

    2015-08-01

    Improving dietary folate intake is a central public health goal. However, critical voices have become louder warning of too high intake of folic acid. Safety concerns of a high folic acid exposure are usually limited to synthetic folic acid contained in drugs and food supplements. Against this background, the present article focuses on two matters: (a) How do the absorption and metabolism of synthetic folic acid differ from that of other folates? (b) How has the longterm safety of folic acid to be judged, especially regarding the risk of colorectal cancer, autism, asthma, impaired immune defence, masking vitamin B12 deficiency and interactions with the methotrexate metabolism?

  7. Amino acid analysis

    NASA Technical Reports Server (NTRS)

    Winitz, M.; Graff, J. (Inventor)

    1974-01-01

    The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.

  8. Acidic Ionic Liquids.

    PubMed

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition.

  9. Nucleic acid detection kits

    DOEpatents

    Hall, Jeff G.; Lyamichev, Victor I.; Mast, Andrea L.; Brow, Mary Ann; Kwiatkowski, Robert W.; Vavra, Stephanie H.

    2005-03-29

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of nucleic acid from various viruses in a sample.

  10. Acidic Ionic Liquids.

    PubMed

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition. PMID:27175515

  11. Boric acid and boronic acids inhibition of pigeonpea urease.

    PubMed

    Reddy, K Ravi Charan; Kayastha, Arvind M

    2006-08-01

    Urease from the seeds of pigeonpea was competitively inhibited by boric acid, butylboronic acid, phenylboronic acid, and 4-bromophenylboronic acid; 4-bromophenylboronic acid being the strongest inhibitor, followed by boric acid > butylboronic acid > phenylboronic acid, respectively. Urease inhibition by boric acid is maximal at acidic pH (5.0) and minimal at alkaline pH (10.0), i.e., the trigonal planar B(OH)3 form is a more effective inhibitor than the tetrahedral B(OH)4 -anionic form. Similarly, the anionic form of phenylboronic acid was least inhibiting in nature.

  12. Biotransformation of cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid by plant cell cultures of Eucalyptus perriniana.

    PubMed

    Katsuragi, Hisashi; Shimoda, Kei; Kubota, Naoji; Nakajima, Nobuyoshi; Hamada, Hatsuyuki; Hamada, Hiroki

    2010-01-01

    Biotransformations of phenylpropanoids such as cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid were investigated with plant-cultured cells of Eucalyptus perriniana. The plant-cultured cells of E. perriniana converted cinnamic acid into cinnamic acid β-D-glucopyranosyl ester, p-coumaric acid, and 4-O-β-D-glucopyranosylcoumaric acid. p-Coumaric acid was converted into 4-O-β-D-glucopyranosylcoumaric acid, p-coumaric acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcoumaric acid β-D-glucopyranosyl ester, a new compound, caffeic acid, and 3-O-β-D-glucopyranosylcaffeic acid. On the other hand, incubation of caffeic acid with cultured E. perriniana cells gave 3-O-β-D-glucopyranosylcaffeic acid, 3-O-(6-O-β-D-glucopyranosyl)-β-D-glucopyranosylcaffeic acid, a new compound, 3-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcaffeic acid, 4-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, ferulic acid, and 4-O-β-D-glucopyranosylferulic acid. 4-O-β-D-Glucopyranosylferulic acid, ferulic acid β-D-glucopyranosyl ester, and 4-O-β-D-glucopyranosylferulic acid β-D-glucopyranosyl ester were isolated from E. perriniana cells treated with ferulic acid.

  13. Process for the preparation of lactic acid and glyceric acid

    DOEpatents

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  14. Well acidizing compositions and methods

    SciTech Connect

    Swanson, B. L.

    1980-12-23

    Gelled acidic compositions suitable for matrix acidizing or fracture acidizing of subterranean formations are provided comprising water, a water-dispersible polymeric viscosifier such as a polymer of acrylamide, an acid, and a polyphenolic material such as lignite.

  15. Bile acids but not acidic acids induce Barrett's esophagus.

    PubMed

    Sun, Dongfeng; Wang, Xiao; Gai, Zhibo; Song, Xiaoming; Jia, Xinyong; Tian, Hui

    2015-01-01

    Barrett's esophagus (BE) is associated with the development of esophageal adenocarcinoma (EAC). Bile acids (BAs) refluxing into the esophagus contribute to esophageal injury, which results in BE and subsequent EAC. We developed two animal models to test the role of BAs in the pathogenesis of BE. We surgically generated BA reflux, with or without gastric acid, in rats. In a second experiment, we fed animals separately with BAs and gastric acid. Pathologic changes were examined and the expression of Muc2 and Cdx2 in BE tissue was tested by immunostaining. Inflammatory factors in the plasma, as well as differentiation genes in BE were examined through highly sensitive ELISA and semi-quantitative RT-PCR techniques. We found that BAs are sufficient for the induction of esophagitis and Barrett's-like metaplasia in the esophagus. Overexpression of inflammatory cells, IL-6, and TNF-α was observed both in animals fed with BAs and surgically generated BA reflux. Furthermore, elevated levels of Cdx2, Muc2, Bmp4, Kit19, and Tff2 (differentiation genes in BE) were found in BA-treated rats. In conclusion, BAs, but not gastric acid, are a major causative factor for BE. We confirmed that BAs contribute to the development of BE by inducing the inflammatory response in the esophagus. Inhibiting BAs may be a promising therapy for BE.

  16. Microorganisms for producing organic acids

    DOEpatents

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  17. Acid-Base Homeostasis.

    PubMed

    Hamm, L Lee; Nakhoul, Nazih; Hering-Smith, Kathleen S

    2015-12-01

    Acid-base homeostasis and pH regulation are critical for both normal physiology and cell metabolism and function. The importance of this regulation is evidenced by a variety of physiologic derangements that occur when plasma pH is either high or low. The kidneys have the predominant role in regulating the systemic bicarbonate concentration and hence, the metabolic component of acid-base balance. This function of the kidneys has two components: reabsorption of virtually all of the filtered HCO3(-) and production of new bicarbonate to replace that consumed by normal or pathologic acids. This production or generation of new HCO3(-) is done by net acid excretion. Under normal conditions, approximately one-third to one-half of net acid excretion by the kidneys is in the form of titratable acid. The other one-half to two-thirds is the excretion of ammonium. The capacity to excrete ammonium under conditions of acid loads is quantitatively much greater than the capacity to increase titratable acid. Multiple, often redundant pathways and processes exist to regulate these renal functions. Derangements in acid-base homeostasis, however, are common in clinical medicine and can often be related to the systems involved in acid-base transport in the kidneys.

  18. Citric Acid Alternative to Nitric Acid Passivation

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie L. (Compiler)

    2013-01-01

    The Ground Systems Development and Operations GSDO) Program at NASA John F. Kennedy Space Center (KSC) has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of the GSDO Program, the purpose of this project is to demonstratevalidate citric acid as a passivation agent for stainless steel. Successful completion of this project will result in citric acid being qualified for use as an environmentally preferable alternative to nitric acid for passivation of stainless steel alloys in NASA and DoD applications.

  19. Enzymatic gallic acid esterification.

    PubMed

    Weetal, H H

    1985-02-01

    Gallic acid esters of n-propyl and amyl alcohols have been produced by enzymatic synthesis in organic solvents using immobilized tannase. Studies indicate that maximum esterification of gallic acid occurs with amyl alcohol. The enzyme shows broad alcohol specificity. However, the enzyme exhibits absolute specificity for the acid portion of the ester. Studies were carried out on K(m), V(max), pH, and temperature optima.

  20. Amino acids and proteins.

    PubMed

    van Goudoever, Johannes B; Vlaardingerbroek, Hester; van den Akker, Chris H; de Groof, Femke; van der Schoor, Sophie R D

    2014-01-01

    Amino acids and protein are key factors for growth. The neonatal period requires the highest intake in life to meet the demands. Those demands include amino acids for growth, but proteins and amino acids also function as signalling molecules and function as neurotransmitters. Often the nutritional requirements are not met, resulting in a postnatal growth restriction. However, current knowledge on adequate levels of both amino acid as well as protein intake can avoid under nutrition in the direct postnatal phase, avoid the need for subsequent catch-up growth and improve later outcome.

  1. USGS Tracks Acid Rain

    USGS Publications Warehouse

    Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

    1995-01-01

    The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

  2. Recovery of organic acids

    DOEpatents

    Verser, Dan W.; Eggeman, Timothy J.

    2011-11-01

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  3. Recovery of organic acids

    DOEpatents

    Verser, Dan W.; Eggeman, Timothy J.

    2009-10-13

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  4. Effects of metabolic pathway precursors and polydimethylsiloxane (PDMS) on poly-(gamma)-glutamic acid production by Bacillus subtilis BL53.

    PubMed

    de Cesaro, Alessandra; da Silva, Suse Botelho; Ayub, Marco Antônio Záchia

    2014-09-01

    The aims of this study were to evaluate the effects of the addition of metabolic precursors and polydimethylsiloxane (PDMS) as an oxygen carrier to cultures of Bacillus subtilis BL53 during the production of γ-PGA. Kinetics analyses of cultivations of different media showed that B. subtilis BL53 is an exogenous glutamic acid-dependent strain. When the metabolic pathway precursors of γ-PGA synthesis, L-glutamine and a-ketoglutaric acid, were added to the culture medium, production of the biopolymer was increased by 20 % considering the medium without these precursors. The addition of 10 % of the oxygen carrier PDMS to cultures caused a two-fold increase in the volumetric oxygen mass transfer coefficient (kLa), improving γ-PGA production and productivity. Finally, bioreactor cultures of B. subtilis BL53 adopting the combination of optimized medium E, added of glutamine, α-ketoglutaric acid, and PDMS, showed a productivity of 1 g L(-1) h(-1) of g-PGA after only 24 h of cultivation. Results of this study suggest that the use of metabolic pathway precursors glutamine and a-ketolgutaric acid, combined with the addition of PDMS as an oxygen carrier in bioreactors, can improve γ-PGA production and productivity by Bacillus strains .

  5. Relationships between acid deposition, watershed characteristics, and stream chemistry in Maryland's coastal plain. Final report. Volume 1. Text. Report for May 1984-June 1985

    SciTech Connect

    Campbell, S.; Bartoshesky, J.; Heimbuch, D.; Janicki, J.; Petrimoulx, H.

    1987-06-01

    Precipitation and stream-water chemistry data were collected from three watersheds in the Coastal Plain region of Maryland during the period May 1984 through June 1985 in an attempt to determine the potential effects of acidic deposition on the chemistry of these streams. The study streams included Lyons Creek, Morgan Creek, and Granny Finley Branch; these streams were chosen based on their differential responses to storm events observed in a survey of Coastal Plain streams in the spring of 1983. Lyons Creek typically exhibited lower pH, acid-neutralizing capacity, and concentrations of base cations than observed in the other streams. Sulfate mass balances suggest that the soils in the Lyons Creek watershed also have less affinity for sulfur retention than do soils of the other watersheds. Acidic pulses were observed in all three streams during the spring months; however, the magnitude of these pulses was less than that observed in 1983. Modeling of the relationships between precipitation chemistry, watershed interactions, and stream chemistry suggests that precipitation acidity can influence stream-water acidity, depending upon hydrological conditions and availabiility of acid-neutralizing materials in the watersheds.

  6. Aphid amino acid transporter regulates glutamine supply to intracellular bacterial symbionts.

    PubMed

    Price, Daniel R G; Feng, Honglin; Baker, James D; Bavan, Selvan; Luetje, Charles W; Wilson, Alex C C

    2014-01-01

    Endosymbiotic associations have played a major role in evolution. However, the molecular basis for the biochemical interdependence of these associations remains poorly understood. The aphid-Buchnera endosymbiosis provides a powerful system to elucidate how these symbioses are regulated. In aphids, the supply of essential amino acids depends on an ancient nutritional symbiotic association with the gamma-proteobacterium Buchnera aphidicola. Buchnera cells are densely packed in specialized aphid bacteriocyte cells. Here we confirm that five putative amino acid transporters are highly expressed and/or highly enriched in Acyrthosiphon pisum bacteriocyte tissues. When expressed in Xenopus laevis oocytes, two bacteriocyte amino acid transporters displayed significant levels of glutamine uptake, with transporter ACYPI001018, LOC100159667 (named here as Acyrthosiphon pisum glutamine transporter 1, ApGLNT1) functioning as the most active glutamine transporter. Transporter ApGLNT1 has narrow substrate selectivity, with high glutamine and low arginine transport capacity. Notably, ApGLNT1 has high binding affinity for arginine, and arginine acts as a competitive inhibitor for glutamine transport. Using immunocytochemistry, we show that ApGLNT1 is localized predominantly to the bacteriocyte plasma membrane, a location consistent with the transport of glutamine from A. pisum hemolymph to the bacteriocyte cytoplasm. On the basis of functional transport data and localization, we propose a substrate feedback inhibition model in which the accumulation of the essential amino acid arginine in A. pisum hemolymph reduces the transport of the precursor glutamine into bacteriocytes, thereby regulating amino acid biosynthesis in the bacteriocyte. Structural similarities in the arrangement of hosts and symbionts across endosymbiotic systems suggest that substrate feedback inhibition may be mechanistically important in other endosymbioses.

  7. Mutant fatty acid desaturase

    DOEpatents

    Shanklin, John; Cahoon, Edgar B.

    2004-02-03

    The present invention relates to a method for producing mutants of a fatty acid desaturase having a substantially increased activity towards fatty acid substrates with chains containing fewer than 18 carbons relative to an unmutagenized precursor desaturase having an 18 carbon atom chain length substrate specificity. The method involves inducing one or more mutations in the nucleic acid sequence encoding the precursor desaturase, transforming the mutated sequence into an unsaturated fatty acid auxotroph cell such as MH13 E. coli, culturing the cells in the absence of supplemental unsaturated fatty acids, thereby selecting for recipient cells which have received and which express a mutant fatty acid desaturase with an elevated specificity for fatty acid substrates having chain lengths of less than 18 carbon atoms. A variety of mutants having 16 or fewer carbon atom chain length substrate specificities are produced by this method. Mutant desaturases produced by this method can be introduced via expression vectors into prokaryotic and eukaryotic cells and can also be used in the production of transgenic plants which may be used to produce specific fatty acid products.

  8. Amino Acid Crossword Puzzle

    ERIC Educational Resources Information Center

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  9. Toxicology of Perfluoroalkyl acids

    EPA Science Inventory

    The Perfluoroalkyl acids(PFAAs) area a family of organic chemicals consisting of a perflurinated carbon backbone (4-12in length) and a acidic functional moiety (Carboxylate or sulfonate). These compounds have excellent surface-tension reducing properties and have numerous industr...

  10. Uric acid - blood

    MedlinePlus

    ... High levels of uric acid can sometimes cause gout or kidney disease. You may have this test if you have had or are about to have certain types of chemotherapy. Rapid weight loss, which may occur with such treatments, can increase the amount of uric acid in ...

  11. Bile acid transporters

    PubMed Central

    Dawson, Paul A.; Lan, Tian; Rao, Anuradha

    2009-01-01

    In liver and intestine, transporters play a critical role in maintaining the enterohepatic circulation and bile acid homeostasis. Over the past two decades, there has been significant progress toward identifying the individual membrane transporters and unraveling their complex regulation. In the liver, bile acids are efficiently transported across the sinusoidal membrane by the Na+ taurocholate cotransporting polypeptide with assistance by members of the organic anion transporting polypeptide family. The bile acids are then secreted in an ATP-dependent fashion across the canalicular membrane by the bile salt export pump. Following their movement with bile into the lumen of the small intestine, bile acids are almost quantitatively reclaimed in the ileum by the apical sodium-dependent bile acid transporter. The bile acids are shuttled across the enterocyte to the basolateral membrane and effluxed into the portal circulation by the recently indentified heteromeric organic solute transporter, OSTα-OSTβ. In addition to the hepatocyte and enterocyte, subgroups of these bile acid transporters are expressed by the biliary, renal, and colonic epithelium where they contribute to maintaining bile acid homeostasis and play important cytoprotective roles. This article will review our current understanding of the physiological role and regulation of these important carriers. PMID:19498215

  12. Analysis of Organic Acids.

    ERIC Educational Resources Information Center

    Griswold, John R.; Rauner, Richard A.

    1990-01-01

    Presented are the procedures and a discussion of the results for an experiment in which students select unknown carboxylic acids, determine their melting points, and investigate their solubility behavior in water and ethanol. A table of selected carboxylic acids is included. (CW)

  13. Omega-3 Fatty Acids

    MedlinePlus

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount of triglycerides (a fat-like ... people with very high triglycerides. Omega-3 fatty acids are in a class of medications called antilipemic ...

  14. Toxicology of Perfluoroalkyl Acids*

    EPA Science Inventory

    The perfluoroalkyl acids (PFAAs) are a family of organic chemicals consisting of a perfluorinated carbon backbone (4-12 in length) and an acidic functional moiety (carboxylate or sulfonate). These compounds are chemically stable, have excellent surface-tension reducing properties...

  15. Salicylic Acid Topical

    MedlinePlus

    ... skin blemishes in people who have acne. Topical salicylic acid is also used to treat skin conditions that involve scaling or overgrowth of skin ... water for 15 minutes.Do not apply topical salicylic acid to skin that is broken, red, swollen, irritated, or infected. ...

  16. Biosynthesis of pulcherriminic acid

    PubMed Central

    MacDonald, J. C.

    1965-01-01

    1. Candida pulcherrima was grown on a complex medium to which various compounds had been added to determine their effect on the biosynthesis of pulcherriminic acid. Most of the pulcherriminic acid synthesized by C. pulcherrima PRL2019 was derived from the l-[1-14C]leucine added to the medium. 2. The cyclic dipeptide of l-leucine (cyclo-l-leucyl-l-leucyl) was shown, by trapping experiments involving cycloleucyl-leucyl isomers, to be synthesized by strain PRL2019. Cyclo-l-leucyl-l-leucyl was derived from l-leucine and was converted into pulcherriminic acid. Cyclo-l-leucyl-l-leucyl was a precursor of pulcherriminic acid in strain PRL2007 also. 3. The results supported the hypothesis that pulcherriminic acid is derived from l-leucine and that cyclo-l-leucyl-l-leucyl is an intermediate in the biosynthesis. PMID:5837792

  17. Total syntheses of cis-cyclopropane fatty acids: dihydromalvalic acid, dihydrosterculic acid, lactobacillic acid, and 9,10-methylenehexadecanoic acid.

    PubMed

    Shah, Sayali; White, Jonathan M; Williams, Spencer J

    2014-12-14

    cis-Cyclopropane fatty acids (cis-CFAs) are widespread constituents of the seed oils of subtropical plants, membrane components of bacteria and protozoa, and the fats and phospholipids of animals. We describe a systematic approach to the synthesis of enantiomeric pairs of four cis-CFAs: cis-9,10-methylenehexadecanoic acid, lactobacillic acid, dihydromalvalic acid, and dihydrosterculic acid. The approach commences with Rh2(OAc)4-catalyzed cyclopropenation of 1-octyne and 1-decyne, and hinges on the preparative scale chromatographic resolution of racemic 2-alkylcycloprop-2-ene-1-carboxylic acids using a homochiral Evan's auxiliary. Saturation of the individual diastereomeric N-cycloprop-2-ene-1-carbonylacyloxazolidines, followed by elaboration to alkylcyclopropylmethylsulfones, allowed Julia-Kocienski olefination with various ω-aldehyde-esters. Finally, saponification and diimide reduction afforded the individual cis-CFA enantiomers. PMID:25321346

  18. Precision microbiome restoration of bile acid-mediated resistance to Clostridium difficile

    PubMed Central

    Buffie, Charlie G.; Bucci, Vanni; Stein, Richard R.; McKenney, Peter T.; Ling, Lilan; Gobourne, Asia; No, Daniel; Liu, Hui; Kinnebrew, Melissa; Viale, Agnes; Littmann, Eric; van den Brink, Marcel R. M.; Jenq, Robert R.; Taur, Ying; Sander, Chris; Cross, Justin; Toussaint, Nora C.; Xavier, Joao B.; Pamer, Eric G.

    2015-01-01

    The gastrointestinal tracts of mammals are colonized by hundreds of microbial species that contribute to health, including colonization resistance against intestinal pathogens1. Many antibiotics destroy intestinal microbial communities and increase susceptibility to intestinal pathogens2. Among these, Clostridium difficile, a major cause of antibiotic-induced diarrhea, greatly increases morbidity and mortality in hospitalized patients3. Which intestinal bacteria provide resistance to C. difficile infection and their in vivo inhibitory mechanisms remain unclear. By treating mice with different antibiotics that result in distinct microbiota changes and lead to varied susceptibility to C. difficile, we correlated loss of specific bacterial taxa with development of infection. Mathematical modeling augmented by microbiota analyses of hospitalized patients identified resistance-associated bacteria common to mice and humans. Using these platforms, we determined that Clostridium scindens, a bile acid 7-dehydroxylating intestinal bacterium, is associated with resistance to C. difficile infection and, upon administration, enhances resistance to infection in a secondary bile acid-dependent fashion. Using a workflow involving mouse models, clinical studies, metagenomic analyses and mathematical modeling, we identified a probiotic candidate that corrects a clinically relevant microbiome deficiency. These findings have implications for rational design of targeted antimicrobials as well as microbiome-based diagnostics and therapeutics for individuals at risk for C. difficile infection. PMID:25337874

  19. Precision microbiome reconstitution restores bile acid mediated resistance to Clostridium difficile.

    PubMed

    Buffie, Charlie G; Bucci, Vanni; Stein, Richard R; McKenney, Peter T; Ling, Lilan; Gobourne, Asia; No, Daniel; Liu, Hui; Kinnebrew, Melissa; Viale, Agnes; Littmann, Eric; van den Brink, Marcel R M; Jenq, Robert R; Taur, Ying; Sander, Chris; Cross, Justin R; Toussaint, Nora C; Xavier, Joao B; Pamer, Eric G

    2015-01-01

    The gastrointestinal tracts of mammals are colonized by hundreds of microbial species that contribute to health, including colonization resistance against intestinal pathogens. Many antibiotics destroy intestinal microbial communities and increase susceptibility to intestinal pathogens. Among these, Clostridium difficile, a major cause of antibiotic-induced diarrhoea, greatly increases morbidity and mortality in hospitalized patients. Which intestinal bacteria provide resistance to C. difficile infection and their in vivo inhibitory mechanisms remain unclear. Here we correlate loss of specific bacterial taxa with development of infection, by treating mice with different antibiotics that result in distinct microbiota changes and lead to varied susceptibility to C. difficile. Mathematical modelling augmented by analyses of the microbiota of hospitalized patients identifies resistance-associated bacteria common to mice and humans. Using these platforms, we determine that Clostridium scindens, a bile acid 7α-dehydroxylating intestinal bacterium, is associated with resistance to C. difficile infection and, upon administration, enhances resistance to infection in a secondary bile acid dependent fashion. Using a workflow involving mouse models, clinical studies, metagenomic analyses, and mathematical modelling, we identify a probiotic candidate that corrects a clinically relevant microbiome deficiency. These findings have implications for the rational design of targeted antimicrobials as well as microbiome-based diagnostics and therapeutics for individuals at risk of C. difficile infection.

  20. Precision microbiome reconstitution restores bile acid mediated resistance to Clostridium difficile

    NASA Astrophysics Data System (ADS)

    Buffie, Charlie G.; Bucci, Vanni; Stein, Richard R.; McKenney, Peter T.; Ling, Lilan; Gobourne, Asia; No, Daniel; Liu, Hui; Kinnebrew, Melissa; Viale, Agnes; Littmann, Eric; van den Brink, Marcel R. M.; Jenq, Robert R.; Taur, Ying; Sander, Chris; Cross, Justin R.; Toussaint, Nora C.; Xavier, Joao B.; Pamer, Eric G.

    2015-01-01

    The gastrointestinal tracts of mammals are colonized by hundreds of microbial species that contribute to health, including colonization resistance against intestinal pathogens. Many antibiotics destroy intestinal microbial communities and increase susceptibility to intestinal pathogens. Among these, Clostridium difficile, a major cause of antibiotic-induced diarrhoea, greatly increases morbidity and mortality in hospitalized patients. Which intestinal bacteria provide resistance to C. difficile infection and their in vivo inhibitory mechanisms remain unclear. Here we correlate loss of specific bacterial taxa with development of infection, by treating mice with different antibiotics that result in distinct microbiota changes and lead to varied susceptibility to C. difficile. Mathematical modelling augmented by analyses of the microbiota of hospitalized patients identifies resistance-associated bacteria common to mice and humans. Using these platforms, we determine that Clostridium scindens, a bile acid 7α-dehydroxylating intestinal bacterium, is associated with resistance to C. difficile infection and, upon administration, enhances resistance to infection in a secondary bile acid dependent fashion. Using a workflow involving mouse models, clinical studies, metagenomic analyses, and mathematical modelling, we identify a probiotic candidate that corrects a clinically relevant microbiome deficiency. These findings have implications for the rational design of targeted antimicrobials as well as microbiome-based diagnostics and therapeutics for individuals at risk of C. difficile infection.

  1. Gluconic acid production.

    PubMed

    Anastassiadis, Savas; Morgunov, Igor G

    2007-01-01

    Gluconic acid, the oxidation product of glucose, is a mild neither caustic nor corrosive, non toxic and readily biodegradable organic acid of great interest for many applications. As a multifunctional carbonic acid belonging to the bulk chemicals and due to its physiological and chemical characteristics, gluconic acid itself, its salts (e.g. alkali metal salts, in especially sodium gluconate) and the gluconolactone form have found extensively versatile uses in the chemical, pharmaceutical, food, construction and other industries. Present review article presents the comprehensive information of patent bibliography for the production of gluconic acid and compares the advantages and disadvantages of known processes. Numerous manufacturing processes are described in the international bibliography and patent literature of the last 100 years for the production of gluconic acid from glucose, including chemical and electrochemical catalysis, enzymatic biocatalysis by free or immobilized enzymes in specialized enzyme bioreactors as well as discontinuous and continuous fermentation processes using free growing or immobilized cells of various microorganisms, including bacteria, yeast-like fungi and fungi. Alternatively, new superior fermentation processes have been developed and extensively described for the continuous and discontinuous production of gluconic acid by isolated strains of yeast-like mold Aureobasidium pullulans, offering numerous advantages over the traditional discontinuous fungi processes.

  2. Trans Fatty Acids

    NASA Astrophysics Data System (ADS)

    Doyle, Ellin

    1997-09-01

    Fats and their various fatty acid components seem to be a perennial concern of nutritionists and persons concerned with healthful diets. Advice on the consumption of saturated, polyunsaturated, monounsaturated, and total fat bombards us from magazines and newspapers. One of the newer players in this field is the group of trans fatty acids found predominantly in partially hydrogenated fats such as margarines and cooking fats. The controversy concerning dietary trans fatty acids was recently addressed in an American Heart Association (AHA) science advisory (1) and in a position paper from the American Society of Clinical Nutrition/American Institute of Nutrition (ASCN/AIN) (2). Both reports emphasize that the best preventive strategy for reducing risk for cardiovascular disease and some types of cancer is a reduction in total and saturated fats in the diet, but a reduction in the intake of trans fatty acids was also recommended. Although the actual health effects of trans fatty acids remain uncertain, experimental evidence indicates that consumption of trans fatty acids adversely affects serum lipid levels. Since elevated levels of serum cholesterol and triacylglycerols are associated with increased risk of cardiovascular disease, it follows that intake of trans fatty acids should be minimized.

  3. Sulfuric Acid on Europa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain.

    This image is based on data gathered by Galileo's near infrared mapping spectrometer.

    Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks.

    Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  4. Strongly Acidic Auxin Indole-3-Methanesulfonic Acid

    PubMed Central

    Cohen, Jerry D.; Baldi, Bruce G.; Bialek, Krystyna

    1985-01-01

    A radiochemical synthesis is described for [14C]indole-3-methanesulfonic acid (IMS), a strongly acidic auxin analog. Techniques were developed for fractionation and purification of IMS using normal and reverse phase chromatography. In addition, the utility of both Fourier transform infrared spectrometry and fast atom bombardment mass spectrometry for analysis of IMS has been demonstrated. IMS was shown to be an active auxin, stimulating soybean hypocotyl elongation, bean first internode curvature, and ethylene production. IMS uptake by thin sections of soybean hypocotyl was essentially independent of solution pH and, when applied at a 100 micromolar concentration, IMS exhibited a basipetal polarity in its transport in both corn coleoptile and soybean hypocotyl sections. [14C]IMS should, therefore, be a useful compound to study fundamental processes related to the movement of auxins in plant tissues and organelles. PMID:16664007

  5. Understanding acid rain

    SciTech Connect

    Budiansky, S.

    1981-06-01

    The complexities of the phenomenon of acid rain are described. Many factors, including meteorology, geology, chemistry, and biology, all play parts. Varying weather, varying soils, the presence of other pollutants and species differences all act to blur the connections between industrial emissions, acid rain, and environmental damage. Some experts believe that the greatest pH shock to lakes occurs during snow melt and runoff in the spring; others believe that much of the plant damage ascribed to acid rain is actually due to the effects of ozone. Much work needs to be done in the area of sampling. Historical data are lacking and sampling methods are not sufficiently accurate. (JMT)

  6. Understanding Acid Base Disorders.

    PubMed

    Gomez, Hernando; Kellum, John A

    2015-10-01

    The concentration of hydrogen ions is regulated in biologic solutions. There are currently 3 recognized approaches to assess changes in acid base status. First is the traditional Henderson-Hasselbalch approach, also called the physiologic approach, which uses the relationship between HCO3(-) and Pco2; the second is the standard base excess approach based on the Van Slyke equation. The third approach is the quantitative or Stewart approach, which uses the strong ion difference and the total weak acids. This article explores the origins of the current concepts framing the existing methods to analyze acid base balance.

  7. Acid rain and soil.

    PubMed

    vanLoon, G W

    1984-08-01

    A summary of important chemical properties of soil is given and the way in which acid rain may affect these properties is discussed. Acid rain may suppress microbiological decomposition and nitrification processes, thus influencing the nutrient status of soils. It has also been found that soil organic matter is less soluble in more acid solutions. Changed nutrient availability patterns are predicted in a low pH environment and enhanced leaching of essential elements from the soil exchange complex has been observed. Increased solubility of potentially toxic elements such as aluminium may also occur from soils which have been exposed to acidified rainfall.

  8. Evidence for messenger ribonucleic acid of an ammonium-inducible glutamate dehydrogenase and synthesis, covalent modification, and degradation of enzyme subunits in uninduced Chlorella sorokiniana cells.

    PubMed Central

    Turner, K J; Bascomb, N F; Lynch, J J; Molin, W T; Thurston, C F; Schmidt, R R

    1981-01-01

    The cells of Chlorella sorokiniana cultured in nitrate medium contain no detectable catalytic activity of an ammonium-inducible nicotinamide adenine dinucleotide phosphate-specific glutamate dehydrogenase (NADP-GDH). However, several lines of experimental evidence indicated that the NADP-GDH messenger ribonucleic acid was present at high levels and was being translated in uninduced cells. First, binding studies with 125I-labeled anti-NADP-GDH immunoglobulin G and total polysomes isolated from uninduced and induced cells showed that NADP-GDH subunits were being synthesized on polysomes from both types of cells. Second, when polyadenylic acid-containing ribonucleic acid was extracted from polysomes from uninduced and induced cells and placed into a messenger ribonucleic acid-dependent in vitro translation system, NADP-GDH subunits were synthesized from the ribonucleic acid from both sources. Third, when ammonia was added to uninduced cells, NADP-GDH antigen accumulated without an apparent induction lag. Fourth, by use of a specific immunoprecipitation procedure coupled to pulse-chase studies with [35S]sulfate, it was shown that the NADP-GDH subunits are rapidly synthesized, covalently modified, and then degraded in uninduced cells. PMID:7217012

  9. Characterization and Evaluation of Acid Rain in East Central Florida from 1978 to 1995 and Evaluation of Some Chromatographic/Spectroscopic Results from Leachate Samples from CELSS

    NASA Technical Reports Server (NTRS)

    Madsen, Brooks C.

    1996-01-01

    The results of monitoring the chemical composition of rain in east-central Florida have shown that the rain is moderately acid. The measured acidity of rain is less than that observed in other regions of the U. S., however, it does suggest that the level of acidity is substantial. The annual chemical composition of rain at UCF and at KSC has shown moderate variability. Extreme daily and monthly variations are observed, however these variations are not addressed here. The total ionic composition of rain collected at FL99 is greater than that for rain collected at UCF, however this can be accounted for by site proximity to the ocean with the accompanying marine influence. Difference in acidity data collected from the UCF and FL99 sites which are separated by 50 km may be due in part to the differences that have been observed between laboratory and field pH measurements. Trend assessment for precipitation composition requires evaluation of data that covers some minimum time period. In fact, the subdivision of the multi-year UCF record into individual 10 year records as described above can lead to the conclusion that a significant increase, a significant decrease or no trend exists for acidity depending upon the time period chosen for evaluation. Trend evaluation has also been accomplished by linear and nonlinear regression analysis using monthly volume weighted average concentrations and deposition using the UCF data set and some of the Florida NADP data set.

  10. Disorders of Amino Acid Metabolism

    MedlinePlus

    ... Aspiration Syndrome Additional Content Medical News Disorders of Amino Acid Metabolism By Lee M. Sanders, MD, MPH NOTE: ... Metabolic Disorders Disorders of Carbohydrate Metabolism Disorders of Amino Acid Metabolism Disorders of Lipid Metabolism Amino acids are ...

  11. Pantothenic acid and biotin

    MedlinePlus

    ... well as other nutrients, are provided in the Dietary Reference Intakes (DRIs) developed by the Food and Nutrition Board ... level that is thought to ensure enough nutrition. Dietary Reference Intakes for pantothenic acid: Age 0 to 6 months: ...

  12. Amino Acid Metabolism Disorders

    MedlinePlus

    Metabolism is the process your body uses to make energy from the food you eat. Food is ... One group of these disorders is amino acid metabolism disorders. They include phenylketonuria (PKU) and maple syrup ...

  13. [Hydrofluoric acid burns].

    PubMed

    Holla, Robin; Gorter, Ramon R; Tenhagen, Mark; Vloemans, A F P M Jos; Breederveld, Roelf S

    2016-01-01

    Hydrofluoric acid is increasingly used as a rust remover and detergent. Dermal contact with hydrofluoric acid results in a chemical burn characterized by severe pain and deep tissue necrosis. It may cause electrolyte imbalances with lethal consequences. It is important to identify high-risk patients. 'High risk' is defined as a total affected body area > 3% or exposure to hydrofluoric acid in a concentration > 50%. We present the cases of three male patients (26, 31, and 39 years old) with hydrofluoric acid burns of varying severity and describe the subsequent treatments. The application of calcium gluconate 2.5% gel to the skin is the cornerstone of the treatment, reducing pain as well as improving wound healing. Nails should be thoroughly inspected and possibly removed if the nail is involved, to ensure proper healing. In high-risk patients, plasma calcium levels should be evaluated and cardiac monitoring is indicated.

  14. Folic acid - test

    MedlinePlus

    ... folic acid before and during pregnancy helps prevent neural tube defects, such as spina bifida. Women who ... take more if they have a history of neural tube defects in earlier pregnancies. Ask your provider ...

  15. Nitric acid poisoning

    MedlinePlus

    Symptoms from swallowing nitric acid may include: Abdominal pain - severe Burns to skin or mouth Drooling Fever Mouth pain - severe Rapid drop in blood pressure (shock) Throat swelling, which leads to breathing difficulty ...

  16. [Hydrofluoric acid burns].

    PubMed

    Holla, Robin; Gorter, Ramon R; Tenhagen, Mark; Vloemans, A F P M Jos; Breederveld, Roelf S

    2016-01-01

    Hydrofluoric acid is increasingly used as a rust remover and detergent. Dermal contact with hydrofluoric acid results in a chemical burn characterized by severe pain and deep tissue necrosis. It may cause electrolyte imbalances with lethal consequences. It is important to identify high-risk patients. 'High risk' is defined as a total affected body area > 3% or exposure to hydrofluoric acid in a concentration > 50%. We present the cases of three male patients (26, 31, and 39 years old) with hydrofluoric acid burns of varying severity and describe the subsequent treatments. The application of calcium gluconate 2.5% gel to the skin is the cornerstone of the treatment, reducing pain as well as improving wound healing. Nails should be thoroughly inspected and possibly removed if the nail is involved, to ensure proper healing. In high-risk patients, plasma calcium levels should be evaluated and cardiac monitoring is indicated. PMID:27189091

  17. Difficult Decisions: Acid Rain.

    ERIC Educational Resources Information Center

    Miller, John A.; Slesnick, Irwin L.

    1989-01-01

    Discusses some of the contributing factors and chemical reactions involved in the production of acid rain, its effects, and political issues pertaining to who should pay for the clean up. Supplies questions for consideration and discussion. (RT)

  18. Hyaluronic acid fillers.

    PubMed

    Monheit, Gary D; Coleman, Kyle M

    2006-01-01

    Although hyaluronic acids are a relatively new treatment for facial lines and wrinkles, they have provided numerous advances in the area of cosmetic surgery. This article discusses the inherent properties of hyaluronic acid fillers that make them ideal for treatment of facial lines. It encompasses a review of the current literature on U.S. Food and Drug Administration-approved hyaluronic acid fillers and the role that each of these fillers currently has in facial cosmetics. This article also discusses the potential pitfalls and adverse effects that can be associated with using hyaluronic acids for filling facial lines. Finally, it serves as an overview of current techniques for clinical assessment of patients as well as administration and treatment of facial lines and wrinkles.

  19. Boric acid poisoning

    MedlinePlus

    Borax poisoning ... The main symptoms of boric acid poisoning are blue-green vomit, diarrhea, and a bright red rash on the skin. Other symptoms may include: Blisters Collapse Coma Convulsions Drowsiness ...

  20. Stomach acid test

    MedlinePlus

    Gastric acid secretion test ... The test is done after you have not eaten for a while so fluid is all that remains in ... injected into your body. This is done to test the ability of the cells in the stomach ...

  1. Aminolevulinic Acid Topical

    MedlinePlus

    ... under the skin that result from exposure to sunlight and can develop into skin cancer) of the ... acid will make your skin very sensitive to sunlight (likely to get sunburn). Avoid exposure of treated ...

  2. Amino Acids and Chirality

    NASA Technical Reports Server (NTRS)

    Cook, Jamie E.

    2012-01-01

    Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

  3. (Acid rain workshop)

    SciTech Connect

    Turner, R.S.

    1990-12-05

    The traveler presented a paper entitled Susceptibility of Asian Ecosystems to Soil-Mediated Acid Rain Damage'' at the Second Workshop on Acid Rain in Asia. The workshop was organized by the Asian Institute of Technology (Bangkok, Thailand), Argonne National Laboratory (Argonne, Illinois), and Resource Management Associates (Madison, Wisconsin) and was sponsored by the US Department of Energy, the United Nations Environment Program, the United Nations Economic and Social Commission for Asia and the Pacific, and the World Bank. Papers presented on the first day discussed how the experience gained with acid rain in North America and Europe might be applied to the Asian situation. Papers describing energy use projections, sulfur emissions, and effects of acid rain in several Asian countries were presented on the second day. The remaining time was allotted to discussion, planning, and writing plans for a future research program.

  4. Folic acid in diet

    MedlinePlus

    ... a regular supply of the vitamin in the foods you eat. ... vitamins have been added to the food. Many foods are now fortified with folic acid. Some of these are enriched breads, cereals, flours, ...

  5. Valproic Acid and Pregnancy

    MedlinePlus

    ... in the treatment of epilepsy, and to treat bipolar disorder and migraines. I have been taking valproic acid ... that women with seizure disorders and women with bipolar disorder might have menstrual problems and difficulty getting pregnant. ...

  6. Citric acid urine test

    MedlinePlus

    ... The test is used to diagnose renal tubular acidosis and evaluate kidney stone disease. Normal Results The ... level of citric acid may mean renal tubular acidosis and a tendency to form calcium kidney stones. ...

  7. Folic Acid Quiz

    MedlinePlus

    ... more easily than natural food folate. Close × Answer: D CORRECT: Folic acid reduces the risk for spina ... g., orange juice and green vegetables). Close × Answer: D CORRECT: Spina bifida and anencephaly are neural tube ...

  8. Hydrofluoric acid poisoning

    MedlinePlus

    ... your skin or eyes, you may have: Blisters Burns Pain Vision loss Hydrofluoric acid poisoning can have ... urine tests Camera down the throat to see burns in the esophagus and the stomach (endoscopy) Fluids ...

  9. Octa(thymidine methanephosphonates) of partially defined stereochemistry: synthesis and effect of chirality at phosphorus on binding to pentadecadeoxyriboadenylic acid.

    PubMed Central

    Lesnikowski, Z J; Jaworska, M; Stec, W J

    1990-01-01

    Block condensation of MePOCI2 or MeP(NEt2)2 with appropriately protected tetra(thymidine methanephosphonates) of predetermined sense of chirality at asymmetric phosphonate centres gave two pairs of diastereomeric mixtures, namely (SpSpSpSpSpSpSp + SpSpSpRpSpSpSp) 5a and (RpRpRpRpRpRpRp + RpRpRpSpRpRpRp) 5b. A comparison of the CD spectra of 5a and 5b with those of octathymidylic acid (7) and a random mixture of diastereomers of octa(thymidine methanephosphonate) (6), and also a comparison of the Tm of complexes formed between 5a, 5b, 6 or 7, and pentadecadeoxyriboadenylic acid (8), indicates that octamer 5b and its complex with its complementary oligonucleotide has a well-ordered structure due to the 'outward' or 'pseudoequatorial' orientation of the methyl group of each internucleotide methanephosphonate function of Rp configuration. Results presented in this report clearly indicate that the stability of hybrids formed between octa(thymidine methanephosphonate) and pentadecadeoxyriboadenylic acid depends on the stereochemistry of each internucleotide methanephosphonate function and strongly suggests that stereoselective synthesis of P-chiral oligonucleotide analogues is an important goal. PMID:2336391

  10. Portable nucleic acid thermocyclers.

    PubMed

    Almassian, David R; Cockrell, Lisa M; Nelson, William M

    2013-11-21

    A nucleic acid thermal cycler is considered to be portable if it is under ten pounds, easily carried by one individual, and battery powered. Nucleic acid amplification includes both polymerase chain reaction (e.g. PCR, RT-PCR) and isothermal amplification (e.g. RPA, HDA, LAMP, NASBA, RCA, ICAN, SMART, SDA). There are valuable applications for portable nucleic acid thermocyclers in fields that include clinical diagnostics, biothreat detection, and veterinary testing. A system that is portable allows for the distributed detection of targets at the point of care and a reduction of the time from sample to answer. The designer of a portable nucleic acid thermocycler must carefully consider both thermal control and the detection of amplification. In addition to thermal control and detection, the designer may consider the integration of a sample preparation subsystem with the nucleic acid thermocycler. There are a variety of technologies that can achieve accurate thermal control and the detection of nucleic acid amplification. Important evaluation criteria for each technology include maturity, power requirements, cost, sensitivity, speed, and manufacturability. Ultimately the needs of a particular market will lead to user requirements that drive the decision between available technologies.

  11. Neutron Nucleic Acid Crystallography.

    PubMed

    Chatake, Toshiyuki

    2016-01-01

    The hydration shells surrounding nucleic acids and hydrogen-bonding networks involving water molecules and nucleic acids are essential interactions for the structural stability and function of nucleic acids. Water molecules in the hydration shells influence various conformations of DNA and RNA by specific hydrogen-bonding networks, which often contribute to the chemical reactivity and molecular recognition of nucleic acids. However, X-ray crystallography could not provide a complete description of structural information with respect to hydrogen bonds. Indeed, X-ray crystallography is a powerful tool for determining the locations of water molecules, i.e., the location of the oxygen atom of H2O; however, it is very difficult to determine the orientation of the water molecules, i.e., the orientation of the two hydrogen atoms of H2O, because X-ray scattering from the hydrogen atom is very small.Neutron crystallography is a specialized tool for determining the positions of hydrogen atoms. Neutrons are not diffracted by electrons, but are diffracted by atomic nuclei; accordingly, neutron scattering lengths of hydrogen and its isotopes are comparable to those of non-hydrogen atoms. Therefore, neutron crystallography can determine both of the locations and orientations of water molecules. This chapter describes the current status of neutron nucleic acid crystallographic research as well as the basic principles of neutron diffraction experiments performed on nucleic acid crystals: materials, crystallization, diffraction experiments, and structure determination. PMID:26227050

  12. Neutron Nucleic Acid Crystallography.

    PubMed

    Chatake, Toshiyuki

    2016-01-01

    The hydration shells surrounding nucleic acids and hydrogen-bonding networks involving water molecules and nucleic acids are essential interactions for the structural stability and function of nucleic acids. Water molecules in the hydration shells influence various conformations of DNA and RNA by specific hydrogen-bonding networks, which often contribute to the chemical reactivity and molecular recognition of nucleic acids. However, X-ray crystallography could not provide a complete description of structural information with respect to hydrogen bonds. Indeed, X-ray crystallography is a powerful tool for determining the locations of water molecules, i.e., the location of the oxygen atom of H2O; however, it is very difficult to determine the orientation of the water molecules, i.e., the orientation of the two hydrogen atoms of H2O, because X-ray scattering from the hydrogen atom is very small.Neutron crystallography is a specialized tool for determining the positions of hydrogen atoms. Neutrons are not diffracted by electrons, but are diffracted by atomic nuclei; accordingly, neutron scattering lengths of hydrogen and its isotopes are comparable to those of non-hydrogen atoms. Therefore, neutron crystallography can determine both of the locations and orientations of water molecules. This chapter describes the current status of neutron nucleic acid crystallographic research as well as the basic principles of neutron diffraction experiments performed on nucleic acid crystals: materials, crystallization, diffraction experiments, and structure determination.

  13. Utilization of acid tars

    SciTech Connect

    Frolov, A.F.; Denisova, T.L.; Aminov, A.N.

    1987-01-01

    Freshly produced acid tar (FPAT), obtained as refinery waste in treating petroleum oils with sulfuric acid and oleum, contains 80% or more sulfuric acid. Of such tars, pond acid tars, which contain up to 80% neutral petroleum products and sulfonated resins, are more stable, and have found applications in the production of binders for paving materials. In this article the authors are presenting results obtained in a study of the composition and reactivity of FPAT and its stability in storage in blends with asphalts obtained in deasphalting operations, and the possibility of using the FPAT in road construction has been examined. In this work, wastes were used which were obtained in treating the oils T-750, KhF-12, I-8A, and MS-14. Data on the change in group chemical composition of FPAT are shown, and the acidity, viscosity, needle penetration, and softening point of acid tars obtained from different grades of oils are plotted as functions of the storage time. It is also shown that the fresh and hardened FPATs differ in their solubilities in various solvents.

  14. Method for isolating nucleic acids

    SciTech Connect

    Hurt, Jr., Richard Ashley; Elias, Dwayne A.

    2015-09-29

    The current disclosure provides methods and kits for isolating nucleic acid from an environmental sample. The current methods and compositions further provide methods for isolating nucleic acids by reducing adsorption of nucleic acids by charged ions and particles within an environmental sample. The methods of the current disclosure provide methods for isolating nucleic acids by releasing adsorbed nucleic acids from charged particles during the nucleic acid isolation process. The current disclosure facilitates the isolation of nucleic acids of sufficient quality and quantity to enable one of ordinary skill in the art to utilize or analyze the isolated nucleic acids for a wide variety of applications including, sequencing or species population analysis.

  15. Acidification and Acid Rain

    NASA Astrophysics Data System (ADS)

    Norton, S. A.; Veselã½, J.

    2003-12-01

    Air pollution by acids has been known as a problem for centuries (Ducros, 1845; Smith, 1872; Camuffo, 1992; Brimblecombe, 1992). Only in the mid-1900s did it become clear that it was a problem for more than just industrially developed areas, and that precipitation quality can affect aquatic resources ( Gorham, 1955). The last three decades of the twentieth century saw tremendous progress in the documentation of the chemistry of the atmosphere, precipitation, and the systems impacted by acid atmospheric deposition. Chronic acidification of ecosystems results in chemical changes to soil and to surface waters and groundwater as a result of reduction of base cation supply or an increase in acid (H+) supply, or both. The most fundamental changes during chronic acidification are an increase in exchangeable H+ or Al3+ (aluminum) in soils, an increase in H+ activity (˜concentration) in water in contact with soil, and a decrease in alkalinity in waters draining watersheds. Water draining from the soil is acidified and has a lower pH (=-log [H+]). As systems acidify, their biotic community changes.Acidic surface waters occur in many parts of the world as a consequence of natural processes and also due to atmospheric deposition of strong acid (e.g., Canada, Jeffries et al. (1986); the United Kingdom, Evans and Monteith (2001); Sweden, Swedish Environmental Protection Board (1986); Finland, Forsius et al. (1990); Norway, Henriksen et al. (1988a); and the United States (USA), Brakke et al. (1988)). Concern over acidification in the temperate regions of the northern hemisphere has been driven by the potential for accelerating natural acidification by pollution of the atmosphere with acidic or acidifying compounds. Atmospheric pollution ( Figure 1) has resulted in an increased flux of acid to and through ecosystems. Depending on the ability of an ecosystem to neutralize the increased flux of acidity, acidification may increase only imperceptibly or be accelerated at a rate that

  16. Efficient nuclear drug translocation and improved drug efficacy mediated by acidity-responsive boronate-linked dextran/cholesterol nanoassembly.

    PubMed

    Zhu, Jing-Yi; Lei, Qi; Yang, Bin; Jia, Hui-Zhen; Qiu, Wen-Xiu; Wang, Xuli; Zeng, Xuan; Zhuo, Ren-Xi; Feng, Jun; Zhang, Xian-Zheng

    2015-06-01

    The present study reported a lysosome-acidity-targeting bio-responsive nanovehicle self-assembled from dextran (Dex) and phenylboronic acid modified cholesterol (Chol-PBA), aiming at the nucleus-tropic drug delivery. The prominent advantage of this assembled nanoconstruction arose from its susceptibility to acidity-labile dissociation concurrently accompanied with the fast liberation of encapsulated drugs, leading to efficient nuclear drug translocation and consequently favorable drug efficacy. By elaborately exploiting NH4Cl pretreatment to interfere with the cellular endosomal acidification progression, this study clearly evidenced at a cellular level the strong lysosomal-acidity dependency of nuclear drug uptake efficiency, which was shown to be the main factor influencing the drug efficacy. The boronate-linked nanoassembly displayed nearly no cytotoxicity and can remain structural stability under the simulated physiological conditions including 10% serum and the normal blood sugar concentration. The cellular exposure to cholesterol was found to bate the cellular uptake of nanoassembly in a dose-dependent manner, suggesting a cholesterol-associated mechanism of the intracellular internalization. The in vivo antitumor assessment in xenograft mouse models revealed the significant superiority of DOX-loaded Dex/Chol-PBA nanoassembly over the controls including free DOX and the DOX-loaded non-sensitive Dex-Chol, as reflected by the more effective tumor-growth inhibition and the better systematic safety. In terms of the convenient preparation, sensitive response to lysosomal acidity and efficient nuclear drug translocation, Dex/Chol-PBA nanoassembly derived from natural materials shows promising potentials as the nanovehicle for nucleus-tropic drug delivery especially for antitumor agents. More attractively, this study offers a deeper insight into the mechanism concerning the contribution of acidity-responsive delivery to the enhanced chemotherapy performance. PMID

  17. Efficient nuclear drug translocation and improved drug efficacy mediated by acidity-responsive boronate-linked dextran/cholesterol nanoassembly.

    PubMed

    Zhu, Jing-Yi; Lei, Qi; Yang, Bin; Jia, Hui-Zhen; Qiu, Wen-Xiu; Wang, Xuli; Zeng, Xuan; Zhuo, Ren-Xi; Feng, Jun; Zhang, Xian-Zheng

    2015-06-01

    The present study reported a lysosome-acidity-targeting bio-responsive nanovehicle self-assembled from dextran (Dex) and phenylboronic acid modified cholesterol (Chol-PBA), aiming at the nucleus-tropic drug delivery. The prominent advantage of this assembled nanoconstruction arose from its susceptibility to acidity-labile dissociation concurrently accompanied with the fast liberation of encapsulated drugs, leading to efficient nuclear drug translocation and consequently favorable drug efficacy. By elaborately exploiting NH4Cl pretreatment to interfere with the cellular endosomal acidification progression, this study clearly evidenced at a cellular level the strong lysosomal-acidity dependency of nuclear drug uptake efficiency, which was shown to be the main factor influencing the drug efficacy. The boronate-linked nanoassembly displayed nearly no cytotoxicity and can remain structural stability under the simulated physiological conditions including 10% serum and the normal blood sugar concentration. The cellular exposure to cholesterol was found to bate the cellular uptake of nanoassembly in a dose-dependent manner, suggesting a cholesterol-associated mechanism of the intracellular internalization. The in vivo antitumor assessment in xenograft mouse models revealed the significant superiority of DOX-loaded Dex/Chol-PBA nanoassembly over the controls including free DOX and the DOX-loaded non-sensitive Dex-Chol, as reflected by the more effective tumor-growth inhibition and the better systematic safety. In terms of the convenient preparation, sensitive response to lysosomal acidity and efficient nuclear drug translocation, Dex/Chol-PBA nanoassembly derived from natural materials shows promising potentials as the nanovehicle for nucleus-tropic drug delivery especially for antitumor agents. More attractively, this study offers a deeper insight into the mechanism concerning the contribution of acidity-responsive delivery to the enhanced chemotherapy performance.

  18. Discovery of essential fatty acids

    PubMed Central

    Spector, Arthur A.; Kim, Hee-Yong

    2015-01-01

    Dietary fat was recognized as a good source of energy and fat-soluble vitamins by the first part of the 20th century, but fatty acids were not considered to be essential nutrients because they could be synthesized from dietary carbohydrate. This well-established view was challenged in 1929 by George and Mildred Burr who reported that dietary fatty acid was required to prevent a deficiency disease that occurred in rats fed a fat-free diet. They concluded that fatty acids were essential nutrients and showed that linoleic acid prevented the disease and is an essential fatty acid. The Burrs surmised that other unsaturated fatty acids were essential and subsequently demonstrated that linolenic acid, the omega-3 fatty acid analog of linoleic acid, is also an essential fatty acid. The discovery of essential fatty acids was a paradigm-changing finding, and it is now considered to be one of the landmark discoveries in lipid research. PMID:25339684

  19. Boric acid catalyzed chemoselective esterification of alpha-hydroxycarboxylic acids.

    PubMed

    Houston, Todd A; Wilkinson, Brendan L; Blanchfield, Joanne T

    2004-03-01

    Boric acid catalyzes the selective esterification of alpha-hydroxycarboxylic acids without causing significant esterification to occur with other carboxylic acids. The procedure is simple, high-yielding, and applicable to the esterification of alpha-hydroxy carboxylates in the presence of other carboxylic acids including beta-hydroxyacids within the same molecule. [reaction: see text

  20. Acid Rain, pH & Acidity: A Common Misinterpretation.

    ERIC Educational Resources Information Center

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)