1-Furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) is an anti-inflammatory agent with a propenone moiety and chemically synthesized recently. In this study, we examined the chemopreventive effect of FPP-3 on 7,12-dimethylbenz[a]anthracene (DMBA)-induced genotoxicity in MCF-7 cells. FPP-3 reduced the formation of the DMBA-DNA adduct. DMBA-induced CYP1A1 and CYP1B1 gene expression and enzyme activity were inhibited by FPP-3. It inhibited DMBA-induced aryl hydrocarbon receptor (AhR) transactivation and DMBA-inducible nuclear localization of the AhR. Induction of detoxifying phase II genes by chemopreventive agents represents a coordinated protective response against oxidative stress and neoplastic effects of carcinogens. Transcription factor NF-E2 related factor 2 (Nrf2) regulates antioxidant response element (ARE) of phase II detoxifying and antioxidant enzymes, such as glutathione ...
DNA polymerase gamma from purified nuclei of EMT-6 cells (mice) seems to be identical to the mitochondrial DNA polymerase from the same source following several criteria. These two enzyme activities are strongly inhibited by ethidium bromide and acriflavin, while proflavin, acridine orange, daunomycin and chloroquine inhibition is less pronounced. In the case of DNA polymerases alpha and beta very little inhibition by ethidium bromide was observed. Intercalation of this dye in a poly dA-dT 12-18 template-primer was studied spectrophotometrically under conditions similar to those in the in vitro DNA polymerase assay. The polymerase assay. The inhibition by this drug of the mitochondrial DNA polymerase gamma activity was shown to be competitive at varying concentrations of TTP while the ...
Two overlapping cDNA clones encoding human DNA topoisomerase II were identified by two independent methods. In one, a human cDNA library in phage {lambda} was screened by hybridization with a mixed oligonucleotide probe encoding a stretch of seven amino acids found in yeast and Drosophila DNA topoisomerase II; in the other, a different human cDNA library in a {lambda}gt11 expression vector was screened for the expression of antigenic determinants that are recognized by rabbit antibodies specific to human DNA topoisomerase II. The entire coding sequences of the human DNA topoisomerase II gene were determined from these and several additional clones, identified through the use of the cloned human TOP2 gene sequences as probes. Hybridization between the cloned ...
DNA from the peripheral blood mononuclear cells of 17 different individuals infected with human T-cell lymphoma/leukemia virus type II (HTLV-II) was successfully amplified by the polymerase chain reaction...Full Text Available
BackgroundThe Class IIDNA transposons are mobile genetic elements that move DNA sequence from one position in the genome to another. We have previously demonstrated that the naturally...Full Text Available
We use X-ray scattering and molecular simulations to investigate the structural properties of complexes of multivalent cationic lipids and DNA molecules. At low mole fraction of neutral lipids (NLs), $\\Phi_{\\rm NL}$, the complexes show dramatic DNA compaction down to essentially close packed DNA arrays with a DNA interaxial spacing $d_{\\rm DNA}=25\\AA$. A gradual increase in $\\Phi_{\\rm NL}$ does not lead to a continuous increase in $d_{\\rm DNA}$ as observed for DNA complexes of monovalent cationic lipids (CLs). Instead, distinct spacing regimes exist, with sharp transitions between them. Three packing states have been identified: (i) close packed, (ii) condensed, but not close packed, with $d_{\\rm DNA}=27-28\\AA$, and (iii) an expanded state, where $d_{\\rm DNA}$ increases ...
We have designed a new nucleobase, benzodeazaadenine (BDA) that has a stronger charge transport ability than guanine and is not destroyed during charge transport process. By incorporating this new nucleobase into DNA, we demonstrated a protocol for real DNA nano-wire that is far superior to natural DNA. We also demonstrated that the selectivity for the interaction of Mn(II) ion with guanine N7 in G runs is a HOMO-controlled process, and as a consequence, the selectivity for G-metal ion interactions obtained by 15N-NMR studies would directly reflect the HOMO distribution of G-containing sequences in B-DNA. PMID:12903077
The nature of binding of Ru(phen) 2+ (I), Ru(bipy) 2+ (II), Ru(terpy) 2+ (III) (phen = 1,10-phenanthroline, bipy 3 = 2,2'-bipyridyl, 3 terpy = 2,2'2," - 2 terpyridyl) to DNA, poly[d(G-C)] and poly[d(A-T)]...Full Text Available
AIM: To analyze the antiviral mechanism of Epigallocatechin gallate (EGCG) against hepatitis B virus (HBV) replication.METHODS: In this research, the HBV-replicating cell line HepG2.117 was used...Full Text Available
Drugs used for the inhibition of DNA viruses, such as iododeoxyuridine, adenine arabinoside, or trifluorothymidine, are not biochemically selective in their action and also interfere with normal cellular...Full Text Available
Experiments were performed to investigate the involvement of the cell membrane in the excision DNA repair process in Escherichia coli. Two membrane-binding drugs, procaine and phenethyl alcohol (PEA), inhibited liquid-holding recovery (LBR) in u.v.-irradiated E. coli wild-type and recA strains. In uvrB and polA strains where, after u.v.-irradiation, LHR was absent the two drugs had no effect. Both drugs markedly reduced the removal of u.v.-induced thymine dimers in the DNA of wild-type cells (H/r30). Analysis by alkaline sucrose gradients revealed that PEA inhibited the incision step in excision repair. In contrast, procaine had no effect on incision but apparently inhibited the late steps in excision repair. PEA dissociated DNA from the cell membrane, whereas procaine did not. The results suggest that the two drugs PEA and procaine inhibit ...
The analgesic, dipyrone (1,phenyl-2,3-dimethyl-5-pyrazolone-4-methylamino methane sulphonate sodium), at 20 mM concentration, inhibited the rejoining of single-strand scissions in DNA of Escherichia coli B/r cells induced by 20 krad gamma-radiation. The chemical altered the cell membrane structure as evidenced from the uptake of acriflavin, the efflux of potassium ions from the bacterial cells and the inhibition of alkaline phosphatase-a cell membrane associated enzyme. (author). 18 refs., 6 figures.
The analgesic, dipyrone (1,phenyl-2,3-dimethyl-5-pyrazolone-4-methylamino methane sulphonate sodium), at 20 mM concentration, inhibited the rejoining of single-strand scissions in DNA of Escherichia coli B/r cells induced by 20 krad gamma-radiation. The chemical altered the cell membrane structure as evidenced from the uptake of acriflavin, the efflux of potassium ions from the bacterial cells and the inhibition of alkaline phosphatase-a cell membrane associated enzyme. (author).
The antioxidant properties of magnolol and honokiol were evaluated in the experimental systems of reducing ONOO^- and ^1O"2, bleaching @b-carotene in linoleic acid (LH) emulsion, and trapping 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS^+?) and 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and then were applied to inhibit the oxidation of DNA induced by Cu^2^+/glutathione (GSH) and 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH). Magnolol and honokiol were active to reduce ONOO^- and ^1O"2. Honokiol showed a little higher activity to protect LH and to inhibit Cu^2^+/GSH-induced oxidation of DNA than magnolol. In addition, honokiol exhibited higher activities to trap ABTS^+? and DPPH than magnolol. In particular, honokiol trapped 2.5 radicals while magnolol o...
Conditioned medium from Sertoli cells, prepared from testes of 20-day-old rats, contains component(s) that inhibit the incorporation of (3H)-thymidine into DNA of peritubular myoid cells (PMC) and inhibit the proliferation of PMC. These components are trypsin-resistant, heat-stable compounds having a molecular weight less than 30,000. The active inhibitory components in Sertoli cell conditioned medium are inactivated by treatment with heparinase, but not by treatment with hyaluronidase or chondroitin sulfate lyases. Addition of heparin or heparan sulfate results in inhibition of DNA synthesis by PMC in a dose-dependent manner, whereas other glycosaminoglycans (GAGs) examined (hyaluronic acid, keratan sulfate, and chondroitin sulfate) have no detectable effects. Heparin and heparan sulfate are unique among GAGs tested in inhibiting the characteristic multilayer ...
Radioadapted chicken embryo cells (X-irradiation in ovo with 10 cGy at the 14th day of development with priming periods of 24 h) were treated in vitro by challenge doses of 14 different DNA- and/or chromatin-interactive agents, including X-rays. A decrease in the cellular damage, as measured by scheduled DNA synthesis, was only observed with X-irradiation. Sedimentation of nucleoids as well as viscosity of alkaline lysates from ethidium bromide (0.35-400 {mu}g/ml)-, vovobiocin (125-1800 {mu}g/ml)-, and hyperthermia (30 min at 43 and 45 )-treated cells suggest a higher tendency of radioadapted cells to undergo positive DNA supercoiling. When DNA from adapted and non-adapted chicken embryo cells was used as substrate, neither its digestion by DNase I nor the inhibition of DNase I activity by various DNA-interactive agents was changed in primed cells. From the ...
Peptide toxins with high affinity, divergent pharmacological functions, and isoform-specific selectivity are powerful tools for investigating the structure-function relationships of voltage-gated...Full Text Available
Synchronized cultures of the green alga Scenedesmus quadricauda were grown in the absence (untreated cultures) or in the presence (FdUrd-treated cultures) of 5-fluorodeoxyuridine, the specific inhibitor of nuclear DNA replication. The attainment of commitment points, at which the cells become committed to nuclear DNA replication, mitosis and cellular division, and the course of committed processes themselves were determined for cell cycle characterization. FdUrd-treated cultures showed nearly unaffected growth and attainment of the commitment points, while DNA replication(s), nuclear division(s) and protoplast fission(s) were blocked. Interestingly, the FdUrd-treated cells possessed a very high mitotic histone H1 kinase activity in the absence of any nuclear division(s). Compared with the ...
Heterochromatin constitutes a significant portion of the genome in higher eukaryotes; approximately 30% in Drosophila and human. Heterochromatin contains a high repeat DNA content and a low density of protein-encoding genes. In contrast, euchromatin is composed mostly of unique sequences and contains the majority of single-copy genes. Genetic and cytological studies demonstrated that heterochromatin exhibits regulatory roles in chromosome organization, centromere function and telomere protection. As an epigenetically regulated structure, heterochromatin formation is not defined by any DNA sequence consensus. Heterochromatin is characterized by its association with nucleosomes containing methylated-lysine 9 of histone H3 (H3K9me), heterochromatin protein 1 (HP1) that binds H3K9me, and Su(var)3-9, which methylates H3K9 and binds HP1. Heterochromatin formation and functions are influenced by HP1, Su(var)3-9, and the RNA interference (RNAi) ...
Pharmacological activation of group II metabotropic glutamate (mGlu2 and mGlu3) receptors inhibits reward-seeking behavior and/or rewarding efficacy induced by drugs (cocaine, nicotine) or natural...Full Text Available
Summary DNA topoisomerases are the key enzymes involved in carrying out high precision DNA transactions inside the cells. However, they are detrimental to the cell when a wide variety of topoisomerase-targeted drugs generate cytotoxic lesions by trapping the enzymes in covalent complexes on the DNA. The discovery of unusual heterodimeric topoisomerase I in kinetoplastid family added a new twist in topoisomerase research related to evolution, functional conservation and their preferential sensitivity to Camptothecin. On the other hand, structural and mechanistic studies on kinetoplastid topoisomerase II delineate some distinguishing features that differentiate the parasitic enzyme from its prokaryotic and eukaryotic counterparts. This review summarizes the recent advances in research in kin...
Eilatin-containing ruthenium complexes bind to a broad range of different nucleic acids including: calf thymus (CT) DNA, tRNAPhe, polymeric RNAs and DNAs, and viral RNAs including the HIV-1...Full Text Available
Candoxin (PDB #1JGK), a three-finger neurotoxin from Bungarus candidus venom, inhibits post-synaptic neuromuscular and neuronal alpha7nACh-receptors, and induces delayed cell-death throughout the glial population. When applied to cultured human glial cell lines, candoxin (CDX) induced cell death in a concentration (EC(50) approximately 1muM) and time dependent manner. Results of TUNEL-histochemistry further confirm CDX-induced brain (hippocampus, frontal cortex, and temporal regions) damage when administered intracerebroventricularly (i.c.v) in adult mice. In this study, we explored differential gene expression profiles following exposure of human glial (Hs 683) cell lines to CDX at various time intervals using Affymetrix-GeneChips. By means of MAS and GeneSpring analyses, 105 genes whose expression was significantly (P<0.01) altered by at least 3-fold were selected. Results of the genome analysis reveal that the potential role of CDX at molecular level involves ...
Basic fibroblast growth factor (bFGF) exhibits specific binding to the extracellular matrix (ECM) produced by cultured endothelial cells. Binding was saturable as a function both of time and of concentration of {sup 125}I-bFGF. Scatchard analysis of FGF binding revealed the presence of about 1.5 x 10{sup 12} binding sites/mm{sup 2} ECM with an apparent k{sub D} of 610 nM. FGF binds to heparan sulfate (HS) in ECM as evidenced by (i) inhibition of binding in the presence of heparin or HS at 0.1-1 {mu}g/mL, but not by chondroitin sulfate, keratan sulfate, or hyaluronic acid at 10 {mu}g/mL, (ii) lack of binding to ECM pretreated with heparitinase, but not with chondroitinase ABC, and (iii) rapid release of up to 90% of ECM-bound FGF by exposure to heparin, HS, or heparitinase, but not to chondroitin sulfate, keratan sulfate, hyaluronic acid, or chondroitinase ABC. Oligosaccharides derived from depolymerized heparin, and as small as the ...
Modification of DNA and double-stranded deoxyoligonucleotides with antitumor 1,2-diamino-cyclohexanedinitroplatinum(II) (Pt-dach) complexes was investigated with the aid of physico-chemical methods and chemical probes of nucleic acid conformation. The three Pt-dach complexes were used which differed in isomeric forms of the dach non-leaving ligand-Pt(1R,2R-dach), Pt(1S,2S-dach) and Pt(1R,2S-dach) complexes. The latter complex has lower antitumor activity than the other two Pt-dach complexes. Pt(1R,2S-dach) complex exhibits the slowest kinetics of its binding to DNA and of the conversion of monofunctional binding to bifunctional lesions. The anomalously slow electrophoretic mobility of multimers of the platinated and ligated oligomers suggests that bifunctional binding of Pt-dach complexes to a d(GG) site within double-stranded oligonucleotides induces bending of the oligomer. It is proposed that different effects of the ...
We determined the chromosomal localization and structure of the gene encoding human type II inosine 5{prime}-monophosphate dehydrogenase (IMPDH, EC 1.1.1.205), an enzyme associated with cellular proliferation, malignant transformation, and differentiation. Using polymerase chain reaction (PCR) primers specific for type II IMPDH, we screened a panel of human-Chinese hamster cell somatic hybrids and a separate deletion panel of chromosome 3 hybrids and localized the gene to 3p21.1{yields}p24.2. Two overlapping yeast artificial chromosome clones containing the full gene for type II IMPDH were isolated and a physical map of 117 kb of human genomic DNA in this region of chromosome 3 was constructed. The gene for type II IMPDH was localized and oriented on this map and found to span no more than 12.5 kb.
Smooth muscle cell (SMC) proliferation and migration are key processes that occur in the pathogenesis of atherosclerosis and post-angioplasty restenosis. In the present study, we designed locked nucleic...Full Text Available
High molecular weight DNA from pleroceroid larvae of the tapeworm Spirometra mansonoides was purified from isolated nuclei by conventional techniques. The DNA so isolated has a melting temperature (Tm) of 87 degrees C and a guanine plus cytosine (G/C) content of 44%. 5-Methyl cytosine could not be detected in plerocercoid DNA by HPLC analysis of DNA hydrolysates, by radiolabeling 5'-termini of MspI digests with polynucleotide kinase, or by comparing restriction patterns generated by MspI and HpaII. Renaturation kinetics demonstrated that the genome of S. mansonoides contains repetitive as well as single copy sequences and has a genome size estimated at approx. 1.6 X 10(9) bp. Hybridization was carried out between plerocercoid DNA and cDNAs for human beta-actin, alpha-tubulin and growth hormone (hGH). Rationale for this analysis was based on known homologies ...
Morusin is a pure compound isolated from root bark of Morusaustralis (Moraceae). In this study, we demonstrated that morusin significantly inhibited the growth and clonogenicity of human colorectal cancer HT-29 cells. Apoptosis induced by morusin was characterized by accumulation of cells at the sub-G_1 phase, fragmentation of DNA, and condensation of chromatin. Morusin also inhibited the phosphorylation of IKK-#alpha#, IKK-#beta# and I#kappa#B-#alpha#, increased expression of I#kappa#B-#alpha#, and suppressed nuclear translocation of NF-#kappa#B and its DNA binding activity. Dephosphorylation of NF-#kappa#B upstream regulators PI3K, Akt and PDK1 was also displayed. In addition, activation of caspase-8, change of mitochondrial membrane potential, release of cytochrome c and Smac/DIABLO, and activation of caspase-9 and -3 were observed at the early time point. Downregulation in the expression of Ku70 and ...
Nucleotide sequence analysis of the Escherichia coli chromosomal DNA inserted in the plasmid pLC33-5 of the Clarke and Carbon library [Clarke & Carbon (1976) Cell 9, 91-99] revealed the existence...Full Text Available
Ternary copper(II) complexes [Cu(L1)B](ClO4) (1, 2) and [Cu(L2)B](ClO4) (3, 4), where HL1 and HL2 are tridentate NSO- and ONO-donor Schiff bases and B is a heterocyclic base, viz. dipyrido[3,2-d:2',3'-f]quinoxaline (dpq, 1 and 3) or dipyrido[3,2-a:2',3'-c]phenazine (dppz, 2 and 4), were prepared and their DNA binding and photoinduced DNA cleavage activity studied. Complex 1, structurally characterized by single-crystal X-ray crystallography, shows an axially elongated square-pyramidal (4 + 1) coordination geometry in which the monoanionic L1 binds at the equatorial plane. The NN-donor dpq ligand exhibits an axial-equatorial binding mode. The complexes display good binding propensity to calf thymus DNA, giving a relative order 2 (NSO-dppz) > 4 (ONO-dppz) > 1 (NSO-dpq) > 3 (ONO-dpq). They cleave supercoiled pUC19 DNA to its nicked circular form when treated with ...
Cdc7 kinase plays an essential role in firing of replication origins by phosphorylating components of the replication complexes. Cdc7 kinase has also been implicated in S phase checkpoint signaling downstream of the ATR and Chk1 kinases. Inactivation of Cdc7 in yeast results in arrest of cell growth with 1C DNA content after completion of the ongoing DNA replication. In contrast, conditional inactivation of Cdc7 in undifferentiated mouse embryonic stem (ES) cells leads to growth arrest with rapid cessation of DNA synthesis, suggesting requirement of Cdc7 functions for continuation of ongoing DNA synthesis. Furthermore, loss of Cdc7 function induces recombinational repair (nuclear Rad51 foci) and G2/M checkpoint responses (inhibition of Cdc2 kinase). Eventually, p53 becomes highly activated and the cells undergo massive p53-dependent apoptosis. Thus, defective origin activation in ...
Functional activation of {beta}-catenin/Tcf signaling plays an important role in early events in carcinogenesis. We examined the effect of naringenin against {beta}-catenin/Tcf signaling in gastric cancer cells. Reporter gene assay showed that naringenin inhibited {beta}-catenin/Tcf signaling efficiently. In addition, the inhibition of {beta}-catenin/Tcf signaling by naringenin in HEK293 cells transiently transfected with constitutively mutant {beta}-catenin gene, whose product is not phosphorylated by GSK3{beta}, indicates that its inhibitory mechanism was related to {beta}-catenin itself or downstream components. To investigate the precise inhibitory mechanism, we performed immunofluorescence, Western blot, and EMSA. As a result, our data revealed that the {beta}-catenin distribution and the levels of nuclear {beta}-catenin and Tcf-4 proteins were unchanged after naringenin treatment. Moreover, the binding activities of Tcf complexes to ...
The gammaretrovirus, xenotropic murine leukemia virus-related virus (XMRV), replicates to high titers in some human cell lines and is able to infect non-human primates. To determine whether APOBEC3 (A3) proteins restrict XMRV infections in a non-human primate model, we sequenced proviral DNA from peripheral blood mononuclear cells of XMRV-infected rhesus macaques. Hypermutation characteristic of A3DE, A3F and A3G activities was observed in the XMRV proviral sequences in vivo. Furthermore, expression of rhesus A3DE, A3F, or A3G in human cells inhibited XMRV infection and caused hypermutation of XMRV DNA. These studies show that some rhesus A3 isoforms are highly effective against XMRV in the blood of a non-human primate model of infection and in cultured human cells. PMID:21982221
The point at which the common final pathway for induction of cancer by chemical carcinogens and ionizing radiation has not been identified. Although common molecular targets are suggested by recent findings about the role of oncogenes, the mechanism by which the deposition of radiation energy and the formation of adducts or other DNA lesions induced by chemicals affects the changes in the relevant targets may be quite different. The damage to DNA that plays no part in the transformation events, but that influences the stability of the genome, and therefore, the probability of subsequent changes that influence tumorigenesis may be more readily induced by some agents than others. Similarly, the degree of cytotoxic effects that disrupt tissue integrity and increase the probability of expression of initiated cells may be dependent on the type of carcinogen. Also, evidence was presented that repair of the initial lesions could be demonstrated after ...
Mimivirus is the prototype of a new family (the Mimiviridae) of nucleocytoplasmic large DNA viruses (NCLDVs), which already include the Poxviridae, Iridoviridae, Phycodnaviridae and Asfarviridae. Mimivirus specifically replicates in cells from the genus Acanthamoeba. Proteomic analysis of purified mimivirus particles revealed the presence of many subunits of the DNA-directed RNA polymerase II complex. A fully functional pre-transcriptional complex appears to be loaded in the virions, allowing mimivirus to initiate transcription within the host cytoplasm immediately upon infection independently of the host nuclear apparatus. To fully understand this process, a systematic study of mimivirus proteins that are predicted (by bioinformatics) or suspected (by proteomic analysis) to be involved in...
The antitumor agent camptothecin targets DNA topoisomerase I by reversibly stabilizing a covalent enzyme-DNA intermediate. The subsequent collision of DNA replication forks with these drug-enzyme-DNA...Full Text Available
PNAS-4, a novel pro-apoptotic gene activated during the early response to DNA damage, can inhibit proliferation via apoptosis when overexpressed in some tumor cells. Recent studies have indicated that honokiol can induce apoptosis, inhibit angiogenesis, and suppress tumor growth. In the present study, we investigated whether mouse PNAS-4 (mPNAS-4) could augment the apoptosis of tumor cells induced by honokiol in vitro, and whether the antiangiogenic activity of honokiol and induction of apoptosis by mPNAS-4 could work cooperatively to improve the antitumor efficacy in vivo. In vitro, mPNAS-4 inhibited proliferation of murine colorectal carcinoma CT26 and Lewis lung carcinoma LL2 cells through induction of apoptosis, and significantly augmented the apoptosis of CT26 and LL2 cells induced by honokiol. Compared with treatment with mPNAS-4 or honokiol alone, in vivo systemic administration of an expression ...
The presence of two major aminopeptidases (aminopeptidases I and II) in the giant alga Chara australis was shown using polyacrylamide gel electrophoresis. Partially purified aminopeptidase I had a molecular weight of about 120,000, hydrolyzed both leucine-?-naphthylamide (pH optimum 6.0) and alanine-?-naphthylamide (pH optimum 7.5), and was located both inside and outside the vacuole. Aminopeptidase I was inhibited by p-chloromercuribenzoic acid, iodoacetic acid, 1,10-phenanthroline, and N-tosyl-l-phenylalanine chloromethyl ketone. Aminopeptidase II hydrolyzed alanine-?-naphthylamide but not leucine-?-naphthylamide and was located only outside the vacuole.ImagesFig. 1Fig. 2Fig. 4Fig. 5
Steel is one of the most versatile materials known to mankind. It is used in a variety of applications. In many of these applications, it is exposed to the atmosphere, leading to rust formation, which weakens structures made using steel. Hence, protection is important. The popular methods to prevent corrosion are painting, galvanizing, electroplating etc. The widely used Chrome etching process is very effective in corrosion inhibition as well as in hardening the steel. But, Chromium and its compounds are highly placed among the toxic chemicals listed under pollution prevention initiatives of the EPA. Hence, it was decided to find alternatives to this process.
We study a model for a protein searching for a target, using facilitated diffusion, on a DNA molecule confined in a finite volume. The model includes three distinct pathways for facilitated diffusion: (a) sliding - in which the protein diffuses along the contour of the DNA (b) jumping - where the protein travels between two sites along the DNA by three-dimensional diffusion, and finally (c) intersegmental transfer - which allows the protein to move from one site to another by transiently binding both at the same time. The typical search time is calculated using scaling arguments which are verified numerically. Our results suggest that the inclusion of intersegmental transfer (i) decreases the search time considerably (ii) makes the search time much more robust to variations in the parameters of the model and (iii) that the optimal search time occurs in a regime very different than that found for models ...
Two aspects of the chromatin repeat length (r_l) are discussed: (i) Why is r_l longer for slowly dividing cells than in rapidly dividing cells?, and (ii) Why is the temporal evolution of r_l a decreasing function of time (t) in mammalian cortical neurons whereas it is an increasing function of t for granule cells around the time of birth? These questions are discussed in terms of a hypothesis which assumes a correlation between deoxyribonucleic acid (DNA) packaging, transcription, and replication. (author). 27 refs.
Calcium-activated chloride channels (CaCCs) are widely expressed in mammalian tissues, including intestinal epithelia, where they facilitate fluid secretion. Potent, selective CaCC inhibitors have not been available. We established a high-throughput screen for identification of inhibitors of a human intestinal CaCC based on inhibition of ATP/carbachol-stimulated iodide influx in HT-29 cells after lentiviral infection with the yellow fluorescent halide-sensing protein YFP-H148Q/I152L. Screening of 50,000 diverse, drug-like compounds yielded six classes of putative CaCC inhibitors, two of which, 3-acyl-2-aminothiophenes and 5-aryl-2-aminothiazoles, inhibited by >95% iodide influx in HT-29 cells in response to multiple calcium-elevating agonists, including thapsigargin, without inhibition of calcium elevation, calcium-calmodulin kinase II activation, or cystic fibrosis transmembrane conductance ...
Constitutive activation of the oncogenic transcription factor STAT3 frequently occurs in various human malignancies. STAT3 activation involves dimerization via intermolecular pTyr-SH2 interaction. Thus, antagonizing this interaction is a feasible approach to inhibit STAT3 activation for cancer therapy. In order to identify selective STAT3 inhibitors, we developed a biochemical HTS system based on AlphaScreen technology, which measures the abilities of test compounds to antagonize pTyr-SH2 interactions. We screened our chemical libraries using this system and identified 5,15-diphenylporphyrin (5,15-DPP) as a selective STAT3-SH2 antagonist. Selective inhibition of STAT3 nuclear translocation and DNA biding activity was observed in cells treated with 5,15-DPP. IL-6-dependent dimerization of STAT3, c-myc promoter binding and c-myc protein expression were all suppressed by 5,15-DPP, whereas no decrement in either expression or ...
Using the phasmid vector pSL5, the genomic DNA fragment of T. aquaticus YT1 which contained the thermostable DNA polymerase (Taq-polymerase) gene was cloned. The BglII fragment of this genome locus was subcloned in the BamHI site of the pUC19 plasmid. To optimize the Taq-polymerase gene expression in E. coli cells, the gene was cloned in the correct reading frame regarding the initiation ATG codon of the pPR-TGATG-1 expression vector. The gene expression in this vector was controlled by the phage lambda PR promoter and the temperature-sensitive phage lambda repressor. We used PCR to amplify the short 5'-end fragment of the Taq-polymerase gene coding for the part into which an artificial SacI site was introduced. This site has been used for cloning the PCR product into the pPR-TGATG-1 vector, and the missing gene part was cloned into the KpnI site of the PCR product from the natural cloned gene. The cells of the E. coli ...
A nucleoside triphosphate binding site on calf thymus RNA polymerase II was identified by using photoaffinity analogues of adenosine 5'-triphosphate and guanosine 5'-triphosphate. Both radiolabeled 8-azidoadenosine 5'-triphosphate (8-N3ATP) and radiolabeled 8-azidoguanosine 5'-triphosphate (8-N3GTP) bound to a single polypeptide of this enzyme. This polypeptide has a molecular mass of 37 kilodaltons and an isoelectric point of 5.4. Ultraviolet (UV) irradiation was necessary for photolabeling to occur. In addition, no labeling occurred when the probe was prephotolyzed or when the enzyme was inactivated. Furthermore, photolabeling of the enzyme could be decreased by preincubation with natural substrates. To provide evidence that the radiolabeled polypeptide forms a part of the domain of the nucleoside triphosphate binding site, experiments were performed using unlabeled 8-N3ATP. Although this unlabeled analogue was not a substrate ...
Pyrrolo[2,1-c][1,4]benzodiazepine (PBD) chemicals are antitumor antibiotics inhibiting nucleic acid synthesis. An indole carboxylate-PBD hybrid with six-carbon spacer structure (IN6CPBD) has been previously demonstrated to induce melanoma cell apoptosis and reduce metastasis in mouse lungs. This study aimed at investigating the efficacy of the other hybrid compound with four-carbon spacer (IN4CPBD) and elucidating its anti-metastatic mechanism. Human melanoma A375 cells with IN4CPBD treatment underwent cytotoxicity and apoptosis-associated assays. Transwell migration assay, Western blotting, and ELISA were used for mechanistic study. IN4CPBD exhibited potent melanoma cytotoxicity through interrupting G1/S cell cycle progression, increasing DNA fragmentation and hypodipoidic DNA contents, a...
The authors have found that heat-inactivated serum (57/sup 0/C for 1 hour) from normal chickens reduces the proliferation of mitogen-stimulated chicken and murine splenocytes as well as some transformed mammalian lymphoblastoid cell lines. Greater than a 50% reduction in /sup 3/H-thymidine incorporation was observed when concanavalin A (Con A)-activated chicken splenocytes that were cultured in the presence of 10% autologous or heterologous serum were compared to mitogen-stimulated cells cultured in the absence of serum. Normal chicken serum (10%) also caused greater than 95% suppression of /sup 3/H-thymidine incorporation by bovine (EBL-1 and BL-3) and gibbon ape (MLA 144) transformed lymphoblastoid cell lines. The only cell line tested that was not inhibited by chicken serum was an IL-2-dependent, murine cell line. Chicken serum also inhibited both /sup 3/H-thymidine incorporation and IL-2 synthesis by Con A-activated murine splenocytes. ...
Recently, we cloned purpurin cDNA as an upregulated gene in the axotomized fish retina. The retina-specific protein was secreted from photoreceptors to ganglion cell layer during an early stage of optic nerve regeneration in zebrafish retina. The purpurin worked as a trigger molecule for axonal regrowth in adult injured fish retina. During zebrafish development, purpurin mRNA first appeared in ventral retina at 2 days post-fertilization (dpf) and spread out to the outer nuclear layer at 3 dpf. Here, we investigated the role of purpurin for zebrafish retinal development using morpholino gene knockdown technique. Injection of purpurin morpholino into the 1-2 cell stage of embryos significantly inhibited the transcriptional and translational expression of purpurin at 3 dpf. In the purpurin mo...
BACKGROUND Hypermethylation of CpG islands is a common epigenetic alteration associated with cancer. Tumor suppressor genes retinoic acid receptor beta (RARb) and PDLIM4 are hypermethylated and silenced in prostate cancer (PCa) tissues and PCa cell lines compared to normal prostate cells. METHODS In this study, a benign prostate epithelial cell line RWPE1 was used as a model to study the epigenetic regulation of Myc on the RARb and PDLIM4 promoters. Forced Myc overexpression inhibited the RARb and PDLIM4 expression. RESULTS Pyrosequencing study showed that Myc overexpression increased methylation in several CpG sites of both promoters. A DNA methylation inhibitor 5-aza-2prime-deoxycytidine reversed the epigenetic alteration effect of Myc on both RARb and PDLIM4. CONCLUSION The epigenetic r...
The present study was designed to assess the radioprotective effects of amifostine on ovarian follicles. Three week-old female mice with or without pretreatment of amifostine were irradiated with 6.42 Gy of #gamma# -ray. Ovaries were collected 0 and 6h after irradiation. DNA fragmentation pattern and expression of genes and activity of proteins related with apoptosis were investigated by means of RT-PCR and Western blot. Proliferation of granulosa cells was reduced and incidence rate of follicular atresia was increased in ovarian follicles in #gamma# -ray irradiated mice compared to those in control or amifostine-treated group. DNA fragmentation was increased in time-dependent manner in granulosa cells of all irradiated groups. However, no difference between amifostine pre-treated group and irradiated groups was found and the expression of p53 as tumor suppressor gene and Bax as one of pro-apoptotic Bcl-2 family was increased in irradiated mice ...
Neuronal cell death induced by oxidative stress is correlated with numerous neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and stroke. The causes of sporadic forms of age-related neurodegenerative diseases are still unknown. Recently, a correlation between paraquat exposure and neurodegenerative diseases has been observed. Paraquat, a nonselective herbicide, was once widely used in North America and is still routinely used in Taiwan. We have used differentiated Human Neuroblastoma (SHSY-5Y) cells as an in vitro model to study the mechanism of cell death induced by paraquat. We observed that paraquat-induced oxidative stress in differentiated SHSY-5Y cells as indicated by an increase in the production of cellular reactive oxygen species (ROS). Furthermore, apoptosis was evident as indicated by cellular and nuclear morphology and DNA fragmentation. Interestingly, pretreatment of SHSY-5Y cells with water-soluble Coenzyme ...
Abstract in english Type II reaction in leprosy, or erythema nodosum leprosum (ENL), is often characterized by severe clinical symptoms together with nerve function impairment leading to permanent disabilities. Thalidomide has been shown to be a highly effective drug for the treatment of ENL. It is, however, contraindicated for women of childbearing age due to its teratogenicity. On the other hand, pentoxifylline, used to treat hypercoagulable states, is not teratogenic and, like thalidomide (more) , can inhibit the synthesis of tumor necrosis factor-a and other cytokines. In the present randomized double-blind clinical study we compared the effectiveness of orally administered pentoxifylline vs thalidomide in treating type II reaction in 44 patients. Daily doses of 300 mg thalidomide or 1.2 g pentoxifylline were administered for 30 days to multibacillary leprosy patients undergoing type II reaction. ...
The use of platinum(II) complexes as tags and probes for biomolecules is indeed advantageous for their reactivities can be selective for certain purposes through an interplay of mild reaction conditions and of the ligands bound to the platinum. The use of {sup 195}Pt NMR as a method of detecting platinum and its interactions with biomolecules was carried out with the simplest model of platinum(II) tagging to proteins. Variable-temperature {sup 195}Pt NMR spectroscopy proved useful in studying the stereodynamics of complex thioethers like methionine. The complex, Pt(trpy)Cl{sup +}, with its chromophore has a greater potential for probing proteins. It is a noninvasive and selective tag for histidine and cysteine residues on the surface of cytochrome c at pH 5. The protein derivatives obtained are separable, and the tags are easily quantitated and differentiated through the metal-to-ligand charge transfer bands which are sensitive to the ...
The astonishingly efficient location and excision of damaged DNA bases by DNA repair glycosylases is an especially intriguing problem in biology. One example is the enzyme uracil DNA glycosylase (UNG),...Full Text Available
Recently reported technologies for DNA-directed organic synthesis and for DNA computing rely on routing DNA populations through complex networks. The reduction of these ideas to practice has been limited...Full Text Available
The authors characterized nine human actin genes that they isolated from a library of cloned human DNA. Measurements of the thermal stability of hybrids formed between each cloned actin gene and ..cap alpha..-, ..beta..-, and ..gamma..-actin mRNA demonstrated that only one of the clones is most homologous to sarcomeric actin mRNA, whereas the remaining eight clones are most homologous to cytoplasmic actin mRNA. By the following criteria they show that these nine clones represent nine different actin gene loci rather than different alleles or different parts of a single gene: (i) the restriction enzyme maps of the coding regions are dissimilar; (ii) each clone contains sufficient coding region to encode all or most of an entire actin gene; and (iii) each clone contains sequences homologous to both the 5' and 3' ends of the coding region of a cloned chicken ..beta..-actin cDNA. They conclude, therefore, that ...
We describe the isolation and genetic characterization of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutations in the phage P22 mnt repressor gene cloned in plasmid pBR322. Mutations in the mnt repressor gene or its operator on this plasmid, pPY98, confer a tetracycline resistance phenotype, whereas the wild-type plasmid confers tetracycline sensitivity. Cells carrying pPY98 were briefly exposed to MNNG to give 20 to 40% survival and a 50- to 100-fold increase in tetracycline-resistant cells. DNA sequence analysis showed that 29 to 30 MNNG-induced mutations were GC-to-AT transitions and one was an AT-to-GC transition. About 80% of the mutations are in three hotspots. This mutation spectrum is consistent with the proposed mechanism of mutagenic action of MNNG, which involves mispairing of an alkylated base, O/sup 6/-methylguanine. The mnt gene may be a useful target for determining mutagenic specificity at the nucleotide level because (i) forward ...
A rat thyrotropin (thyroid-stimulating hormone, TSH) receptor cDNA was isolated that encoded a protein of 764 amino acids, M_r 86,528. Transfection of the cDNA caused COS-7 cells to develop a TSH-sensitive adenylate cyclase response and the ability to bind "1"2"5I-labeled TSH; both activities were similar to those of rat FRTL-5 thyroid cells and not duplicated by lutropin. The gene represented by the cDNA was assigned to mouse chromosome 12 and human chromosome 14. Northern analyses identified two species of mRNA, 5.6 and 3.3 kilobases, in FRTL-5 thyroid cells; the transcripts appeared to differ only in the extent of their 3' noncoding sequences. There were minimal amounts of the two mRNAs in rat ovary, and neither was detected in RNA preparations from rat testis, liver, lung, brain, spleen, and FRT thyroid cells, which do not have a functional TSH receptor. TSH decreased both mRNA species 3- to 4-fold within 8 hr in FRTL-5 ...
We have determined the actual RNA sequence of four mitochondrial genes: pcf, nad3, rps12, and coxII. Because plant mitochondrial proteins cannot be predicted from DNA sequences, the actual primary structures of the encoded proteins were unknown. We have gained information concerning the process of RNA editing. Editing can occur before splicing. Our data is consistent with the hypothesis that RNA editing is not simultaneous with transcription. Unlike other systems, the process of editing in plant does not exhibit a discernable direction. As a result of our RNA editing studies, we have produced a number of clones of the proper coding regions tube used for incorporating these mitochondrial genes into the nucleus. 6 refs., 4 figs.
For the safety of astronauts and to ensure the stability and integrity of the genome of microorganisms and plants used in bioregenerative life support systems, it is important to improve our knowledge of the combined action of (space) radiation and microgravity. The SOS-LUX-TOXICITY test, as part of the TRIPLE-LUX project (accepted for flight at Biolab in Columbus on the International Space Station, (ISS)), will provide an estimation of the health risk resulting from exposure of astronauts to the radiation environment of space in microgravity. The project will: (i) increase our knowledge of biological/health threatening action of space radiation and enzymatic DNA repair; (ii) uncover cellular mechanisms of synergistic interaction of microgravity and space radiation; (iii) provide specified...
A 4.0 kb TaqI fragment of cosmid EFD64 isolated by a HBV-3 oligonucleotide was subcloned into AccI site of pUC18. MspI identifies 5 allelic VNTR polymorphism with bands between 2.6 and 4.6 kb. RsaI, TaqI, EcoRI, BamHI, HindIII and PvuII identify the same VNTR polymorphism. With RsaI, 80% heterozygosity were observed in 80 unrelated Caucasians. This RFLP pEFD64.2 has been assigned to chromosome 3 by linkage analysis with loci (APOD) known to span this chromosome. Co-dominant segregation for the RsaI RFLP was observed in 40 three generation families. RFLPs were observed under the normal hybridization and washing condition.
Evidence suggests that insertion of the IS6110 element is not without consequence to the biology of Mycobacterium tuberculosis complex strains. Thus, mapping of multiple IS6110 insertion sites in the genome of biomedically relevant clinical isolates would result in a better understanding of the role of this mobile element, particularly with regard to transmission, adaptability and virulence. In the present paper, we describe a versatile strategy, referred to as GL-PCR, that amplifies IS6110-flanking sequences based on the construction of a genomic library. M. tuberculosis chromosomal DNA is fully digested with HincII and then ligated into a plasmid vector between T7 and T3 promoter sequences. The ligation reaction product is transformed into Escherichia coli and selective PCR amplification...
We recently found that many RNA polymerase II transcription factors are modified with N-acetylglucosamine residues. These sugar moieties confer upon transcription factors an ability to bind the lectin wheat germ agglutinin. We have taken advantage of this interaction to devise a purification procedure for the "GC-box" binding transcription factor Sp1. Crude nuclear extracts are first subjected to wheat germ agglutinin affinity chromatography and then subjected to sequence-specific DNA affinity chromatography. The Sp1 protein purified by this procedure is at least 95% pure, and the overall recovery is greater than 80%. In addition to yielding larger quantities of Sp1 than conventional schemes, the new purification procedure is also simpler and more rapid. We show that wheat germ agglutinin affinity chromatography can also be used to purify the glycosylated forms of the CCAAT-binding transcription factor. Thus, wheat germ agglutinin affinity ...
Platinum complexes play an important role in the development of anticancer drugs. Their cytotoxicity can be influenced by the nature of the leaving ligands, due to the hydrolysis reaction that occurs prior to the binding of the platinum complex to DNA. Also, non-leaving groups such as lipophilic diamines may affect cellular uptake. In this work, we describe the synthesis of platinum(II) complexes having oxalato and long chain aliphatic N-alkyl ethylenediamines as ligands. The products were characterized by elemental analyses, infrared spectroscopy and {sup 1}H, {sup 13}C and {sup 195}Pt NMR spectroscopy. Biological activity was assessed against tumor cell lines (A{sub 549}, B16-F1, B16-F10, MDA-MB-231) and non-tumor cell lines (BHK-21 and CHO). The length of the carbon chain affects the cytotoxicity and the oxalato complexes were less cytotoxic than the respective chloride-containing analogues. (author)
The corrosion behavior of steel in water from certain oil fields with various organic inhibitors was studied by applying potentiodynamic technique at pH 5.9. The inhibitors which were used include 2-methylbenzimidazole (I), 2-mercaptobenzimidazole (II), 2-mercapto-5-methylbenzimidazole (III), and 2-mercaptothiazole (IV). The inhibiting efficiency of the different additives was evaluated from their anodic and cathodic polarization curves at different temperatures. A comparative study of curve fitting procedures using the kinetic thermodynamic model and those utilizing well-known adsorption isotherms was undertaken. Three types of isotherms were used, Langmuir, Frumkin and Flory-Huggins isotherm. The results show that the kinetic-thermodynamic model and Flory-Huggins isotherms are more suitable to fit the data for the four inhibitors, at all applied temperatures. From the values of binding constants, K, the order of inhibitor efficiency is: III ...
The following topics are discussed: insertion of incorrect bases in DNA; ability of DNA polymerase to copy uv-irradiated DNA; role of enzymes in repair of DNA; effects of uv radiation on molecular weight of DNA; photoreactivation; repair of DNA in Escherichia coli and xp cells following uv radiation; and synchrotron radiation studies on DNA repair. (HLW)
Today you will learn about the parts of DNA and what DNA, genes and chromosomes are. Today you will learn what DNA, genes and chromosomes are and the parts of the DNA molecule. Look at all of the websites, take whatever notes you need to. At the end of the assignment, be able to describle DNA, the parts of DNA, genes and chromosomes. Covers Biology Core Curriculum, ...
Typing Workshop": [Introductions] [Intro, DNA Basics, and Historical Perspective] [DNA Extraction] [Validation and QA/QC] [DNA Quantitation] [PCR Amplification] [STR Loci and Kits]...
The main aim of DNA barcoding is to establish a shared community resource of DNA sequences that can be used for organismal identification and taxonomic clarification. This approach was successfully...Full Text Available
ZnMT has been postulated to function in essential metal homeostasis and metal detoxication. This study was undertaken to evaluate the potential of liver ZnMT to mediate the interaction of Zn and Pb with the Zn metalloenzyme, ALAD. Pretreatment of rats with Zn activated liver ALAD and attenuated the inhibition of ALAD by Pb in vitro and in vivo. Liver cytosol from Zn-pretreated rats injected with /sup 203/Pb was fractionated via gel filtration and anion-exchange chromatography and disclosed that both Zn and /sup 203/Pb co-eluted in the MT fractions. Both purified ZnMT-I and ZnMT-II bound /sup 203/Pb in vitro as shown by gel filtration chromatography. Addition of purified liver ZnMT to purified bovine liver ALAD reaction mixtures increased enzyme activity by 2-fold and prevented inhibition of ALAD by Pb. Addition of apothionein alone decreased the activity of Zn-activated ALAD and also attenuated Pb ...
Asynchronous Chinese hamster ovary (CHO) cells treated with conditioning hyperthermia (10 min at 45/sup 0/C) followed immediately by x irradiation with 4 Gy at room temperature display a decreased radiation response when either irradiated, or heated and irradiated again 24 h later. In addition, conditioning by 4 Gy of x radiation alone followed at 24 h by the combined heat and radiation treatment als resulted in a larger radiation D/sub 0/. Since the differential cell-cycle responses to heat- and x-ray-induced lethality are well established for CHO cells, the potential role of cell-cycle redistribution in the observed radiation desensitization was investigated by flow cytometry. At 24 h after the combined treatment, the fraction of the cells found in the G/sub 2/ + M portion of the DNA histograms was about three times that of the controls and there was a concomitant reduction in both the G/sub 1/ and S fractions. Similar observations were made after the ...
Rapid detection and characterization of food borne pathogens such as Escherichia coli O157:H7 is crucial for epidemiological investigations and food safety surveillance. As an alternative to conventional technologies, we examined the sensitivity and specificity of nucleic acid microarrays for detecting and genotyping E. coli O157:H7. The array was composed of oligonucleotide probes (25-30 mer) complementary to four virulence loci (intimin, Shiga-like toxins I and II, and hemolysin A). Target DNA was amplified from whole cells or from purified DNA via single or multiplexed polymerase chain reaction (PCR), and PCR products were hybridized to the array without further modification or purification. The array was 32-fold more sensitive than gel electrophoresis and capable of detecting amplification products from < 1 cell equivalent of genomic DNA (1 fg). Immunomagnetic capture, PCR and a microarray ...
Transcriptional regulation of the galactose-metabolizing genes in Saccharomyces cerevisiae depends on three core proteins: Gal4p, the transcriptional activator that binds to upstream activating DNA sequences (UASGAL); Gal80p, a repressor that binds to the carboxyl terminus of Gal4p and inhibits transcription; and Gal3p, a cytoplasmic transducer that, upon binding galactose and adenosine 5'-triphosphate, relieves Gal80p repression. The current model of induction relies on Gal3p sequestering Gal80p in the cytoplasm. However, the rapid induction of this system implies that there is a missing factor. Our structure of Gal80p in complex with a peptide from the carboxyl-terminal activation domain of Gal4p reveals the existence of a dinucleotide that mediates the interaction between the two. Biochemical and in vivo experiments suggests that nicotinamide adenine dinucleotide phosphate (NADP) plays a key role in the initial induction event.
The bacterial strain E1R-j, isolated as an endophyte from wheat roots, exhibited high antifungal activity to Gaeumannomyces graminis var. tritici (Ggt). Strain E1R-j was identified as Bacillus subtilis based on morphological, physiological and biochemical methods as well as on 16S rDNA analysis. This strain inhibited mycelium growth in vitro of numerous plant pathogenic fungi, especially of Ggt, Coniothyrium diplodiella, Phomopsis sp. and Sclerotinia sclerotiorum. In greenhouse experiments, soil drenches with cell densities of 106, 109 and 1012CFU ml-1 E1R-j reduced significantly take-all disease, caused by Ggt, in wheat seedling by 62.6%, 68.6% and 70.7%, respectively, compared to the inoculated control, 4weeks after sowing. Growth parameters such as lengths and fresh weights of roots and...
The authors have previously identified a small-cell lung cancer cell line (NCI-H209) that expresses an aberrant, underphosphorylated form of the retinoblastoma protein RB1. Molecular analysis of RB1 mRNA from this cell line revealed a single point mutation within exon 21 that resulted in a nonconservative amino acid substitution (cysteine to phenylalanine) at codon 706. Stable expression of this mutant RB1 cDNA in a human cell line lacking endogenous RB1 demonstrated that this amino acid change was sufficient to inhibit phosphorylation. In addition, this cysteine-to-phenylalanine substitution also resulted in loss of RB1 binding to the simian virus 40 large tumor and adenovirus E1A transforming proteins. These results confirm the importance of exon 21 coding sequences and suggest that the cysteine residue at codon 706 may play a role in achieving a specific protein conformation essential for protein-protein interactions.
To resolve the phylogeny of the autochthonous mitochondrial DNA (mtDNA) haplogroups of India and determine the relationship between the Indian and western Eurasian mtDNA pools more precisely, a diverse...Full Text Available
BackgroundDNA repair is the general term for the collection of critical mechanisms which repair many forms of DNA damage such as methylation or ionizing radiation. DNA repair has...Full Text Available
The presence of DNA-anti-DNA complexes in sera from patients with systemic lupus erythematosus (SLE) was investigated by two new radioimmunoassays (RIA) developed for this purpose and by measuring the...Full Text Available
The Tetrahymena thermophila origin recognition complex (ORC) contains an integral RNA subunit, 26T RNA, which confers specificity to the amplified ribosomal DNA (rDNA) origin by base...Full Text Available
We report a simple method for the label-free detection of double-stranded DNA using surface-enhanced Raman scattering (SERS). We prepared cetyltrimethylammonium bromide (CTAB)-capped silver nanoparticles and a DNA-nanoparticle complex by adding silver nanoparticles to {lambda}-DNA solutions. In the present study, the utilization of CTAB-capped silver nanoparticles facilitates the electrostatic interaction between DNA molecules and silver nanoparticles; at the same time, the introduction of DNA avoids adding aggregating agent for the formation of nanoparticle aggregates to obtain large enhancement of DNA, because the DNA acts as both the probe molecules and aggregating agent of Ag nanoparticles. Atomic force microscopy (AFM) studies show that the morphology of DNA-Ag nanoparticle complexes seems to be determined by the ...
The ultrafast dynamics of the DNA fluorescent dye Sybr Green I (SG) has been studied in buffer, single-stranded (ssDNA), double-stranded (dsDNA) and triple-stranded DNA (tsDNA). The fluorescence quantum yield of SG increases dramatically when bound to DNA (including tsDNA). The fluorescence dynamics of the free SG has shown two decay components with 0.15-0.4ps and 1.3-2.1ps time constants, depending on the fluorescence wavelength. Upon binding to DNA, the dynamics becomes slower exhibiting four decay components. This is mainly due to the restriction of the internal motions of the dye caused by the relatively rigid environment of the dye complexed with DNA.
Recent studies indicate that [Fe]-hydrogenases and H{sub 2} metabolism are widely distributed among green algae. The enzymes are simple structured and catalyze H{sub 2} evolution with similar rates than the more complex [Fe]-hydrogenases from bacteria. Different green algal species developed diverse strategies to survive under sulfur deprivation. Chlamydomonas reinhardtii evolves large quantities of hydrogen gas in the absence of sulfur. In a sealed culture of C. reinhardtii, the photosynthetic O{sub 2} evolution rate drops below the rate of respiratory O{sub 2} consumption due to a reversible inhibition of photosystem II, thus leading to an intracellular anaerobiosis. The algal cells survive under these anaerobic conditions by switching their metabolism to a kind of photo-fermentation. Although possessing a functional [Fe]-hydrogenase gene, the cells of Scenedesmus obliquus produce no significant amounts of H{sub 2} under S-depleted ...
Abstract in english The rate of copper II/zinc cementation from copper sulphate solutions in the absence and in the presence of methanol (CH3OH) and dimethyl sulphoxide (DMSO) has been studied and the reaction was found to follow first-order kinetics. The influence of several parameters on the course of the reaction, such as cylinder rotation speed, initial concentration of Cu2+ ions, temperature and concentration of organic solvent, was investigated. In the case of CH3OH, rotating zinc cyli (more) nder was used, while in the presence of DMSO stationary zinc sheet and rotating zinc cylinder were used. It was found that (1) the percentage inhibition caused by methanol ranged from 10.70 to 58.38 depending on the concentration of the alcohol used; (2) the rate of cementation in the presence of DMSO using rotating zinc cylinder > the rate of cementation in the presence of DMSO using stationary zinc sheet; (3) the rate of cementation on zinc ...
We have been investigating radiation-induced neoplastic transformants of C3H 10T1/2 mouse fibroblasts for evidence of heritable changes. C3H 10T1/2 cells were treated with 8 Gy X rays. After approximately 8 weeks of culture, type II/III foci were isolated from the monolayer using cloning rings. Cell lines developed from these foci, and clones established from these cell lines, were examined for DNA content. The isolated focus-derived populations and derived clones often display aneuploidy and/or polyploidization. In one instance a clone (derived from a single cell) displayed multiple polyploidies. During passage the ploidy of many of the anomalous populations gradually reverted to the ploidy of the non-neoplastically transformed state. The morphological features associated with the neoplastic transformation event were nevertheless retained. The results demonstrate that exposure to radiation can induce, in association with morphological ...
The recently described retinoid X receptors (RXRs) respond to the novel retinoid 9-cis-retinoic acid and also serve as heterodimeric partners for the vitamin D, thyroid hormone, and retinoic acid receptors (VDR, TR, and RAR, respectively). In this work, the authors report high-resolution localization of the human RXR genes within cytogenetic bands and also within a standard reference map of cosmid DNA markers on human chromosomes. They have determined the location of the human RXR genes by pairwise hybridization of the RXR cosmids and reference markers, using fluorescence in situ hybridization. They localized (i) RXR[alpha] (RXRA) to chromosome 9 band q34.3; (ii) RXR[beta] (RXRB) to chromosome 6 band 21.3; and (iii) RXR[gamma] (RXRG) to chromosome 1 band q22-q23. Six retinoid-responsive transcription factors have been identified so far, including three retinoic acid receptors in addition to the three RXRs. Interestingly, each of these receptors ...
The Lesch-Nyhan (LN) syndrome is a severe X chromosome-linked disease that results from a deficiency of the purine salvage enzyme hypoxanthine phosphoribosyltransferase (HPRT). The mutations leading to the disease are heterogeneous and frequently arise as de novo events. The authors have identified nucleotide alterations in 15 independently arising HPRT-deficiency cases by direct DNA sequencing of in vitro amplified HPRT cDNA. They also demonstrate that the direct DNA sequence analysis can be automated, further simplifying the detection of new mutations at this locus. The mutations include DNA base substitutions, small DNA deletions, a single DNA base insertion, and errors in RNA splicing. The application of these procedures allows DNA diagnosis and carrier identification by the direct detection of the mutant alleles within individual ...
The overall objective of this project is to produce antibodies to unique modified DNA bases and develop immunochemical assays to quantitate these lesions in damaged DNA. During this past year we have developed an antibody and chemical test to quantitate a basic sites in DNA and produced antibodies to the 8-oxopurines. This report discusses the detection of a basic sites in DNA and the preparation of antibodies to 8-hydroxyadenine and 8-hydroxyguanine.
Hyaluronate (HA) distribution patterns were examined in the cranial mesenchyme underlying the mesencephalic neural folds of mouse embryos maintained in roller tube culture. Using standard image-processing techniques, the digitized images of Alcian blue-stained or 3H-glucosamine-labeled sections digested with an enzyme specific for HA, were subtracted from adjacent, undigested sections. The resultant difference picture images (DPI) accurately depicted the distribution of stained or labeled HA within the cranial mesenchyme. 3H-glucosamine-labeled HA was distributed uniformly throughout the cranial mesenchyme as 12, 18, and 24 hr of culture. By contrast, the mesenchyme was uniformly stained with Alcian blue at 12 hr, but stain intensity decreased in the central regions of the mesenchyme at 18 and 24 hr. HA distribution patterns were also examined in the cranial mesenchyme of embryos cultured in the presence of diazo-oxo-norleucine (DON), a glutamine analogue that ...
''Paraquat lung'' which is complicated with paraquat poisoning has been a lethal pulmonary pathology presenting intra-alveolar fibrosis, but an effective therapy has not been developed so far. We hypothesized that the type II alveolar cells producing surfactant were damaged by paraquat which was actively accumulated through out the blood by alveolar epithelial cells. To prove this hypothesis, we examined the effect of an intratracheal administration of an artificial lung surfactant (surfacten, Mitsubishi Tanabe Pharma Corporation, Osaka) on mortality in a model of murine paraquat poisoning. Paraquat was given intramuscularly 3 days after the intratracheal surfactant administration. The mice used were C57BL/6J strain and Balb/C strain. The lethal dose, 50% (LD50), of paraquat was about 28 mg/kg in the C57BL/6J strain and about 9 mg/kg in the Balb/C strain, respectively. Mortalities of paraquat poisoning in both strains of mice improved significantly when the mice ...
A few metal complexes of isatin-isonicotinoylhydrazone with Ni(II), Cr(III), Co(II), Cu(II), Zn(II) and Cd(II) have been prepared and characterized on the basis of elemental analyses, infrared and electronic spectra as well as "1H NMR spectra, conductivity and magnetic measurements. In view of the results obtained, it has been found that two molecules of isatin-isonicotinoylhydrazone are chelated to the central metal ion as bis-uninegative ONO tridentate ligand forming non-electrolytic octahedral metal complexes. (author)
Uracil appears in DNA as a result of cytosine deamination and by incorporation from the dUTP pool. As potentially mutagenic and deleterious for cell regulation, uracil must be removed from DNA....Full Text Available
Cytosine methylation in DNA is a major epigenetic signal, and plays a central role in propagating chromatin status during cell division. However the mechanistic links between DNA methylation...Full Text Available
Sequence-directed variations in the canonical DNA double helix structure that retain Watson-Crick base-pairing play important roles in DNA recognition, topology, and nucleosome positioning....Full Text Available
DNA double-strand breaks (DSBs) and other lesions occur frequently during cell growth and in meiosis. These are often repaired by homologous recombination (HR). HR may result in the formation of DNA...Full Text Available
This paper announces the availability of the first international standard for anti-double-stranded DNA (anti-dsDNA). The material, coded Wo/80, was obtained after recalcification of plasma taken from...Full Text Available
Hepatitis B virus (HBV) DNA integration has been shown to occur frequently in human hepatocellular carcinomas. We have investigated whether common cellular DNA domains might be rearranged, possibly...Full Text Available
The polymerase chain reaction (PCR) was investigated as a means of diagnosing Mycoplasma pneumoniae infections. The target DNA sequence was a 375-bp segment of the P1 virulence protein. This DNA segment...Full Text Available
The relative sensitivities of different protocols for detecting cytomegalovirus nucleic acid sequences in histological specimens, using a biotinylated cDNA probe, were assessed. Several commonly used...Full Text Available
The conformation of the self-complimentary DNA dodecamer d(br5CGbr5CGAATTbr5CGbr5CG) has been investigated in a variety of salt and solvent conditions by one and two-dimensional 1H NMR. In low salt...Full Text Available
The sequences of the internal transcribed spacer (ITS) ribosomal DNA (rDNA) domain data obtained by restriction fragment length polymorphism analysis with 18S rDNA and fingerprinting (M13) for clinical...Full Text Available
To gain insight into the process of mitochondrial transmission in yeast, we directly labeled mitochondrial proteins and mitochondrial DNA (mtDNA) and observed their fate after the fusion of two cells....Full Text Available
Mitochondrial DNA is constantly exposed to oxidative injury. Due to its location close to the main site of reactive oxygen species, the inner mitochondrial membrane, mtDNA is more susceptible...Full Text Available
BackgroundMitochondrial dysfunction, oxidative damage and the accumulation of somatic mutations in mitochondrial DNA (mtDNA) have been associated with certain neurodegenerative disorders....Full Text Available
Many genetic processes depend on proteins interacting with specific sequences on DNA. Despite the large excess of nonspecific DNA in the cell, proteins can locate their targets rapidly. After initial...Full Text Available
The effects of various fixative agents, pH, ionic strength, stain concentration, and magnesium concentration on DNA staining with the antibiotics olivomycin, chromomycin A3, and mithramycin were examined with DNA in solution and in mammalian cells.
Chromosomal translocation, deletion, and inversion/duplication directly linked to hepatitis B virus (HBV) DNA integration occur frequently in host DNA of human hepatocellular carcinomas. To test the...Full Text Available
SummaryDnaA initiates chromosomal replication in E. coli at a well regulated time in the cell-cycle. To determine how the spatial distribution of DnaA is related...Full Text Available
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MS) has been explored widely for DNA sequencing. The major requirement for this method is that the DNA sequencing fragments...Full Text Available
CDC7 is an essential gene required for DNA replication in Saccharomyces cerevisiae. Cdc7p homologs have recently been identified in vertebrates, but their role in DNA...Full Text Available
DNA damage is a threat to genomic integrity in all living organisms. Plants and green algae are particularly susceptible to DNA damage especially that caused by UV light, due to their light dependency...Full Text Available
Competent Haemophilus cells recognize and preferentially take up Haemophilus DNA during genetic transformation. This preferential uptake is correlated with the presence on incoming DNA of an 11-base-pair...Full Text Available
It is well known that DNA strands bind to silica surfaces in the presence of high concentrations of chaotropic salts. We developed simple methods to evaluate binding and recovery of DNA on flat...Full Text Available
The standard paradigm postulates that the human mitochondrial genome (mtDNA) is strictly maternally inherited and that, consequently, mtDNA lineages are clonal. As a result of mtDNA clonality, phylogenetic...Full Text Available
The single-stranded viral DNA of an M13 phage recombinant containing the early promoter region of SV40 was hybridized with linear, double-stranded replicative form DNA of a related M13 phage containing...Full Text Available
A DNA fragment located on the 3' side of the Coxiella burnetii htpAB operon was determined by Southern blotting to exist in approximately 19 copies in the Nine Mile I genome. The DNA sequences of this...Full Text Available
The acute acetoclastic methanogenic inhibition of several inorganic and organic arsenicals was assayed. Trivalent species, i.e., methylarsonous acid and arsenite, were highly inhibitory, with 50% inhibitory...Full Text Available
6-Mercaptopurine (6-MP) inhibits the growth of. Escherichia coli B. Growth inhibition is ... reversed by subculture of the cells in 6-mercaptopurine- ...
The dependence of the mobility of DNA molecules through an hexagonal array of micropillars on their length and the applied electric field was investigated and it was found that mobility is a nonmonotonic function of their length. Results also revealed that the size dependence of the DNA mobility depends on the applied electric field and there is a crossover around E 25 V/cm for the mobility of l-DNA and T4-DNA. These observations are explained in terms of the diffusion process inside the structure affected by the solvent and are modeled using the Langevin and its corresponding Fokker-Planck equations. The phenomenon is generalized under three regimes in a phase diagram relating the electric field and the DNA lengths. The model and the associated phase diagram described here provide an expl...
This paper examines theoretically the effects that restraints on the tertiary structure of a superhelical DNA domain exert on the energetics of linking and the onset of conformational transitions. The...Full Text Available
Telomeres protect the chromosome ends from unscheduled DNA repair and degradation. Telomeres are heterochromatic domains composed of repetitive DNA (TTAGGG repeats) bound to an array of specialized...Full Text Available
These proceedings collect papers on the subject of lymphokines. Topics include: DNA-cloning of mouse and human lymphokine genes, inteferons, interleukins, gene expression, tumor necrosis factors, and recombinant DNA.
Metastable and somatically heritable patterns of DNA methylation provide an important level of genomic regulation. In this article, we review methods for analyzing these genome-wide epigenetic...Full Text Available
Since the elucidation of the structure of double helical DNA, the construction of small molecules that recognize and react at specific DNA sites has been an area of considerable interest. In...Full Text Available
The inflexibility of double-stranded DNA with respect to bending and twisting is well established in vitro. Understanding apparent DNA physical properties in vivo is...Full Text Available
BackgroundPublicly available DNA sequence databases such as GenBank are large, and are growing at an exponential rate. The sheer volume of data being dealt with presents serious...Full Text Available
BackgroundMitochondrial DNA (mtDNA) is being analyzed by an increasing number of laboratories in order to investigate its potential role as an active marker of tumorigenesis...Full Text Available
Purpose: Antitumor activity of the dichloroplatinum(II)-histamine complexes labeled with I-125 or I-131 was investigated in a transplantable murine adenocarcinoma (MA) model. Methods: The tumor model was obtained in C3H/W female mice after subcutaneous inoculation of the tumor cells derived from the mice bearing a mammary tumor of spontaneous origin. Antitumor activities of the platinum-histamine complexes were investigated in three independent experiments, which differed in applied doses of preparations (PtCl{sub 2}Hist, PtCl{sub 2}[{sup 125}I]Hist, PtCl{sub 2}[{sup 131}I]Hist, PtCl{sub 2}Hist/PtCl{sub 2}[{sup 125}I]Hist and PtCl{sub 2}Hist/PtCl{sub 2}[{sup 131}I]Hist), treatment schedules as well as stages of the disease progress in the animals used. Experiment 1 included long-term, multidose treatment with low single doses (treatment duration 31-32 days; 8-10 doses of ca. 0.25{center_dot}MTD{sub Pt} each). Experiment 2 included short-term, multidose treatment ...
Platinum(II) complexes have been investigated in the hydration of alkynes. These catalysts offer improved regioselectivity over Hg(II) counterparts. 1 fig., 2 tabs.
The helicase action of the Escherichia coli UvrAB complex on a covalently closed circular DNA template was monitored using bacterial DNA topoisomerase I, which specifically removes negative supercoils. In the presence of E. coli DNA topoisomerase I and ATP, the UvrAB complex gradually introduced positive supercoils into the input relaxed plasmid DNA template. Positive supercoils were not produced when E. coli DNA topoisomerase I was replaced by eukaryotic DNA topoisomerase I or when both E. coli and eukaryotic DNA topoisomerases I were added simultaneously. These results suggest that like other DNA helix-tracking processes, the ATP-dependent action of the UvrAM complex on duplex DNA simultaneously generates both positive and negative supercoils, which are not constrained by protein binding but are ...
Insect host/parasitoid interactions are co-evolved systems in which host defenses are balanced by parasitoid mechanisms to disable or hide from host immune effectors. Although there is a rich literature on these systems, parasitoid immune-disabling mechanisms have not been fully elucidated. Here we report on a newly discovered immune-disabling mechanism in the Pieris rapae/Pteromalus puparum host/parasitoid system. Because venom injections and parasitization suppresses host phagocytosis, we turned attention to the P. rapae scavenger receptor (Pr-SR), posing the hypothesis that P. puparum venom suppresses expression of the host Pr-SR gene. To test our hypothesis, we cloned a full-length cDNA of the Pr-SR. Multiple sequences alignment showed the deduced amino acid sequence of Pr-SR is similar to scavenger receptors of other lepidopterans. Bacterial and bead injections induced Pr-SR mRNA and protein expression, which peaked at 4h post-bead injection. Venom injection ...
The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the only major protection to astronauts from harmful exposure. Unlike low-linear energy transfer (LET) {gamma} or X-rays, the presence of shielding does not always reduce the radiation risks for energetic charged particle exposure, since the dose delivered by the charged particle increases sharply as the particle approaches the end of its range, a position known as the Bragg peak. The Bragg curve does not necessarily represent the biological damage along the particle traversal, and the 'biological Bragg curve' is dependent on the energy and the type of the primary particle, and may vary for different biological endpoints. Here we used a unique irradiation geometry to measure the biological response across the Bragg curve in human fibroblasts exposed to 577MeV/nucleon incident Fe ions in vitro. Polyethylene shielding was used ...
Glioblastoma multiforme is the most aggressive form of human brain tumor, which has no effective cure. Previously, we have demonstrated that overexpression of the C-terminal fragment of the human telomerase reverse transcriptase (hTERTC27) inhibits the growth and tumorigenicity of human cervical cancer HeLa cells. In this study, the therapeutic effect and molecular mechanisms of hTERTC27-mediated cancer gene therapy were further explored in vivo in established human glioblastoma xenografts in nude mice. We showed that intratumoral injection of adeno-associated virus carrying hTERTC27 (rAAV-hTERTC27) is highly effective in reducing the growth of the subcutaneously transplanted glioblastoma tumors. Histological analyses showed that rAAV-hTERTC27 treatment leads to profound necrosis, apoptosis, infiltration of polymorphonuclear neutrophils and reduced microvessel density in the tumor samples. To study the molecular mechanism of rAAV-hTERTC27-mediated antitumor ...
To investigate the growth inhibitory effects, and the underlying mechanism of human colon cancer cell (HT-29) death, induced by a new synthetic bile derivative (HS-1200). Human colon cancer cells (HT-29), in exponential growth phase, were treated with various concentrations of a new synthetic bile acid derivative (HS-1200). The growth inhibitory effects on HT-19 cells were examined using a trypan blue exclusion assay. The extent of apoptosis was determined using agarose gel electrophoresis, TUNEL assays and Hoechst staining. The apoptotic cell death was also confirmed by Western blotting of PARP, caspase-3 and DNA fragmentation factor (DFF) analysis. To investigate the involvement of mitochondria, we employed immunofluorescent staining of cytochrome c and mitochondrial membrane potential analyses. The dose required for the half maximal inhibition (IC_5_0) of the HT-29 cell growth was 100 #approx# 150 #mu# M of HS-1200. Several changes, ...
Excision repair in uv irradiated human fibroblasts has been examined in portions of DNA replicating after irradiation versus those remaining unreplicated. Two approaches, one using a uv-endonuclease to estimate pyrimidine dimers remaining in DNA, the other using density labeling to measure excision resynthesis, indicate that the extent of repair is the same for both replicated and unreplicated DNA.
Escherichia coli rnh mutants lacking RNase H activity are capable of recA+-dependent DNA replication in the absence of concomitant protein synthesis (stable DNA replication). In rnh dnaA::Tn10 and rnh...Full Text Available
AbstractWe describe the fusion of enhanced green fluorescent protein to the C-terminus of the HsdS DNA sequence-specificity subunit of the Type I DNA modification methyltransferase M.EcoKI....Full Text Available
In this paper the thermal equilibrium number of solitons in DNA as a function of absolute temperature and the number of base pairs is calculated. These calculations are effected by modeling DNA as a Toda lattice with parameters chosen to match experimentally measured properties of DNA. It is found that a significant number of solitons is generated at physiological temperature. 23 refs., 2 figs.
Transcriptional silencing in Saccharomyces cerevisiae occurs at several genetic loci, including the ribosomal DNA (rDNA). Silencing at telomeres (telomere position effect [TPE])...Full Text Available
Many organic compounds can be adsorbed onto the interface of a metal and solution to form a thin film that inhibits the corrosion process according to a blocking and/or negative catalytic effect. Using the Langmuir-Blodgett (LB) technique, stearic acid (SA) monolayers were deposited onto the surface of an iron (Fe) electrode to study the inhibition effect and the mechanism of SA in a neutral medium. Molecular orientation and the number of deposited monolayers of SA were shown to have marked effects on inhibition of Fe corrosion. The inhibition mechanism depended mainly on blocking.
Purpose - The purpose of this paper is to evaluate the corrosion inhibition potential of mangrove (Rhizopora apiculata) tannin in hydrochloric acid medium on copper with the view of developing a natural corrosion inhibitor. Design/methodology/approach - The mangrove tannin was extracted from the mangrove bark and its anticorrosion potential was studied by weight loss, electrochemical and scanning electron microscopy (SEM) analysis. Findings - It has been found that the mangrove tannin effectively inhibits the corrosion on copper metal in hydrochloric acid solution. The results of the electrochemical and weight loss methods showed that the inhibition efficiency of mangrove tannin increases with increasing its concentration. Inhibition is achieved through the adsorption of tannin molecules o...
Hepatitis B virus (HBV) DNA integration has been shown to occur frequently in human hepatocellular carcinomas. The authors have investigated whether common cellular DNA domains might be rearranged, possibly by HBV integration, in human primary liver tumors. Unique cellular DNA sequences adjacent to an HBV integration site were isolated from a patient with hepatitis B surface antigen-positive hepatocellular carcinoma. These probes detected rearrangement of this cellular region of chromosomal DNA in 3 of 50 additional primary liver tumors studied. Of these three tumor samples, two contained HBV DNA, without an apparent link between the viral DNA and the rearranged allele; HBV DNA sequences were not detected in the third tumor sample. By use of a panel of somatic cell hybrids, these unique cellular DNA sequences were shown ...
Hepatitis B virus (HBV) DNA integration has been shown to occur frequently in human hepatocellular carcinomas. The authors have investigated whether common cellular DNA domains might be rearranged, possibly by HBV integration, in human primary liver tumors. Unique cellular DNA sequences adjacent to an HBV integration site were isolated from a patient with hepatitis B surface antigen-positive hepatocellular carcinoma. These probes detected rearrangement of this cellular region of chromosomal DNA in 3 of 50 additional primary liver tumors studied. Of these three tumor samples, two contained HBV DNA, without an apparent link between the viral DNA and the rearranged allele; HBV DNA sequences were not detected in the third tumor sample. By use of a panel of somatic cell hybrids, these unique cellular DNA sequences were shown ...
We describe a method for affinity purification of sequence-specific DNA binding proteins that is fast and effective. Complementary chemically synthesized oligodeoxynucleotides that contain a recognition site for a sequence-specific DNA binding protein are annealed and ligated to give oligomers. This DNA is then covalently coupled to Sepharose CL-2B with cyanogen bromide to yield the affinity resin. A partially purified protein fraction is combined with competitor DNA and subsequently passed through the DNA-Sepharose resin. The desired sequence-specific DNA binding protein is purified because it preferentially binds to the recognition sites in the affinity resin rather than to the nonspecific competitor DNA in solution. For example, a protein fraction that is enriched for transcription factor Sp1 can be further purified 500- to 1000-fold by ...
A plethora of experimental studies use mtDNA as a marker of demographic processes without questioning the possibility that selection may bias their interpretations. We studied four lines of Drosophila melanogaster that have a standardized nuclear DNA but variable mtDNA. We completed the sequencing of the mitochondrial genomes (excluding the A+T rich region) and compiled the differences. We then assayed male influence on oviposition, starvation resistance, lipid proportion and physical activity. We discuss these results in terms of the known differences between the lines and conclude that naturally occurring mtDNA variants in D. melanogaster are expressed at the level of the organismal phenotype. PMID:21757031
The infection of cultured human cells with baboon endogenous virus (BEV) frequently leads to an association of viral DNA with a specific genetic locus (termed BEVI, for baboon endogenous virus infection) on chromosome 6. Restriction endonuclease digestion of DNA from BEV-infected human cells and their derived somatic cell clones frequently revealed a common cellular DNA sequence in the proximity of one of the junctions between cellular DNA and the integrated virus. We propose that a short cellular DNA sequence, repeated on chromosome 6 and separated by unique DNA sequences, presents a high-affinity target for the integration of BEV in human cells. PMID:6401843
The authors have cloned a full-length putative rat pancreatic lysophospholipase cDNA by an improved mRNA isolation method and cDNA cloning strategy using (/sup 32/P)-labelled nucleotides. These new methods allow the construction of a cDNA library from the adult rat pancreas in which the majority of recombinant clones contained complete sequences for the corresponding mRNAs. A previously recognized but unidentified long and relatively rare cDNA clone containing the entire sequence from the cap site at the 5' end to the poly(A) tail at the 3' end of the mRNA was isolated by single-step screening of the library. The size, amino acid composition, and the activity of the protein expressed in heterologous cells strongly suggest this mRNA codes for lysophospholipase.
The human mitochondrial DNA (mtDNA) is a closed circular, 16,569-bp double-stranded DNA, encoding 13 genes whose protein products are subunits of the oxidative phosphorylation system required for synthesis of most of the ATP consumed by eukaryotic cells. Point mutations of the mtDNA that cause multi-tissue, loss-of-energy syndromes, called mitochondrial encephalomyopathies (e.g., MERRF and MELAS), have been identified. In addition, large-scale deletions of the human mtDNA have been identified and are the molecular bases for the neonatal and adolescent onset loss-of-energy syndromes Pearson and Kearns-Sayer, respectively. 5 refs., 1 fig.
Manganese is a common contaminant of mine water and other waste waters. Due to its high solubility over a wide pH range, it is notoriously difficult to remove from contaminated waters. Previous systems that effectively remove Mn from mine waters have involved oxidising the soluble Mn(II) species at an elevated pH using substrates such as limestone and dolomites. However it is currently unclear what effect the substrate type has upon abiotic Mn removal compared to biotic removal by in situ micro-organisms (biofilms). In order to investigate the relationship between substrate type, Mn precipitation and the biofilm community, net-alkaline Mn-contaminated mine water was treated in reactors containing one of the pure materials: dolomite, limestone, magnesite and quartzite. Mine water chemistry and Mn removal rates were monitored over a 3-month period in continuous-flow reactors. For all substrates except quartzite, Mn was removed from the mine water during this period, ...
The procedure for field corrosion tests in sea water is decribed in DIN 50 917, Part II. Distinction is made thereby between long-term undisturbed test specimens, which remain at the exposure site up to the time of sampling, and disturbed test specimens, which are cleaned at certain time intervals for intermediate examination and subsequently exposed again. The comparability of results obtained with the two different types of test was to be investigated at the Helgoland test installation. At an exposure period of up to four years, undisturbed specimens of unalloyed and low-alloy steel grades feature considerably lower corrosion losses than disturbed specimens. At a longer exposure period of up to seven years, the corrosion rate can increase substantially again with the exposure time. This can be attributed to sulphate reduction in the anaerobic zone under the top coating. An effect of the alloying elements is also possible. With good and adequately thick coating ...
Derivatives of angiotensin with a sarcosine substitution at the carboxy terminus and an aliphatic amino acid substitution at the amino terminus have been shown to be competitive ligands for the angiotensin receptor. Scatchard plots derived from saturation isotherm data in bovine adrenal particulates consistently demonstrate three to five times the number of binding sites for "1"2"5I-Sarl,Ile8-AII ("1"2"5I-SI-AII) than for "1"2"5I-AII in experiments in which the two ligands are run side-by-side. A significant difference between "1"2"5I-AII and "1"2"5I-SI-AII binding to detergent solubilized angiotensin receptors was observed. Of the "1"2"5I-AII binding sites, about 85-90% were recovered upon solubilization. In contrast, the recovery of "1"2"5I-SI-AII binding sites was only 4-5%. To determine whether binding sites labeled in the soluble state represent biologically significant AII receptors, they examined the ability of selected angiotensin analogs to inhibit ...
New tetradentate N(2)O(2) donor Schiff bases and their mononuclear Co(II), Ni(II), Cu(II), and Pd(II) complexes were synthesized and characterized extensively by IR, (1)H-, (13)C-NMR, mass, ESR, conductivity measurements, elemental and thermal analysis. Specifically the magnetic and electronic spectral measurements demonstrate the octahedral structures of cobalt(II), nickel(II) complexes and square planar geometries of copper(II), palladium(II) complexes. All the ligands and complexes were screened for their in vitro antibacterial activity against two gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus) and two gram-negative bacteria (Escherichia coli, Klebsiella pneumonia). In this study, Pd(II) complexes exhibited potent antibacterial activity against B. subtilis, S. aureus whereas ...
The neuronal nicotinic acetylcholine receptor {alpha}7 subunit is a member of a family of ligand-gated ion channels, and is the only subunit know to bind {alpha}-bungarotoxin in mammalian brain. {alpha}-Bungarotoxin binding sites are known to be more abundant in the hippocampus of mouse strains that are particularly sensitive to nicotine-induced seizures. The {alpha}7 receptor is highly permeable to calcium, which could suggest a role in synaptic plasticity in the nervous system. Auditory gating deficiency, an abnormal response to a second auditory stimulus, is characteristic of schizophrenia. Mouse strains that exhibit a similar gating deficit have reduced hippocampal expression of the {alpha}7 subunit. We have cloned and sequenced the full length cDNA for the mouse {alpha}7 gene (Acra-7) and characterized its gene structure. The murine {alpha}7 shares amino acid identity of 99% and 93% with the rat and human {alpha}7 subunits, respectively. Using an interspecies ...
Metagenomics projects based on shotgun sequencing of populations of micro-organisms yield insight into protein families. We used sequence similarity clustering to explore proteins with a comprehensive dataset consisting of sequences from available databases together with 6.12 million proteins predicted from an assembly of 7.7 million Global Ocean Sampling (GOS) sequences. The GOS dataset covers nearly all known prokaryotic protein families. A total of 3,995 medium- and large-sized clusters consisting of only GOS sequences are identified, out of which 1,700 have no detectable homology to known families. The GOS-only clusters contain a higher than expected proportion of sequences of viral origin, thus reflecting a poor sampling of viral diversity until now. Protein domain distributions in the GOS dataset and current protein databases show distinct biases. Several protein domains that were previously categorized as kingdom specific are shown to have GOS examples in other kingdoms. About ...
We use a novel normal mode analysis of an elastic network model drawn from configurations generated during microsecond all-atom molecular dynamics simulations to analyze the mechanism of auto-inhibition...Full Text Available
Latent inhibition (LI) manifests as poorer conditioning to a CS that has previously been presented without consequence. There is some evidence that LI can be potentiated by reduced mesoaccumbal dopamine...Full Text Available
Protection afforded by trialkyl phosphorothionates against the lung injury caused by trialkyl phosphorothiolates probably results from the inhibition by the P = S moiety of the thionates, of one or...Full Text Available
Mycophenolate mofetil (MMF) is an immunosuppressive drug that acts as a selective inhibitor of inosine monophosphate dehydrogenase (IMPDH). MMF has recently been shown to inhibit the enzymatic activity...Full Text Available
MicroRNAs (miRNAs) are endogenously encoded small noncoding RNAs, derived by processing of short RNA hairpins, that can inhibit the translation of mRNAs bearing partially complementary target sequences....Full Text Available
Method for inhibiting the formation of foulants on petrochemical equipment which involves adding to the petrochemical, during processing, a composition comprising a thiodipropionate and either a dialkyl acid phosphate ester or a dialkyl acid phosphite ester.
Spike-timing-dependent plasticity (STDP), a form of Hebbian plasticity, is inherently stabilizing. Whether and how GABAergic inhibition influences STDP is not well understood. Using a model neuron driven...Full Text Available
3-Deazaadenosine (deazaAdo) inhibits lymphocyte-mediated cytolysis in vitro at micromolar concentrations and is potentiated markedly in this activity by L-homocysteine thiolactone....Full Text Available
As the result of genetic alterations and tumor hypoxia, many cancer cells avidly take up glucose and generate lactate through lactate dehydrogenase A (LDHA), which is encoded by a target gene of c-Myc...Full Text Available
In regions of high bone loading, the mechanoresponsive osteocytes inhibit osteoclastic bone resorption by producing signaling molecules. One possible candidate is matrix extracellular phosphoglycoprotein...Full Text Available
Spontaneous radiation by an atom in a Rydberg state is inhibited by use of parallel conducting planes to eliminate the vacuum modes at the transition frequency. Spontaneous radiation emission is observed to turn off abruptly at the cutoff frequency of the waveguidelike structure, and the natural lifetime is measured to increase by a factor of at least 20.
INTRODUCTION:Gynura procumbens has been shown to decrease blood pressure via inhibition of the angiotensin‐converting enzyme. However, other mechanisms that...Full Text Available
The structural features required for xyloglucan oligosaccharides to inhibit 2,4-dichlorophenoxyacetic acid-stimulated elongation of pea stem segments have been investigated. A nonasaccharide (XG9)...Full Text Available
BackgroundMany studies associated the main polyphenolic constituent of green tea, (-)-Epigallocatechin-3-gallate (EGCG), with inhibition of cancers, invasion and metastasis. To date,...Full Text Available
Methyl fluoride is frequently used to specifically inhibit acetoclastic methanogenesis, thus allowing determination of the relative contribution of acetate versus H2/CO2 to total...Full Text Available
Chlorazole fast pink 2BL inhibited the classical complement pathway in rat serum both in vivo and in vitro. The in vitro potency of chlorazole fast pink against the alternative pathway could not be...Full Text Available
Mechanism-based inhibition of cytochrome P450 (CYP) 3A4 is characterized by NADPH-, time-, and concentration-dependent enzyme inactivation, occurring when some drugs are converted by CYPs to reactive...Full Text Available
BackgroundInadequate platelet inhibition despite aspirin and clopidogrel therapy during and after a percutaneous coronary intervention is associated with an impaired clinical outcome....Full Text Available
Tetherin (BST2/CD317) has been recently recognized as a potent interferon-induced antiviral molecule that inhibits the release of diverse mammalian enveloped virus particles from infected cells. By...Full Text Available
Low concentrations of sugars altered the sensitivity of seed germination to inhibition by exogenous abscisic acid (ABA). Germination of wild-type and ABA-insensitive (abi) Arabidopsis...Full Text Available
Some acylhydrazine derived ONO donor Schiff bases and their Co(II) and Ni(II) complexes have been prepared having the same metal ion (cation) but different anions. These synthesized metal(II)...Full Text Available
Pollen from four temperate-latitude taxa were treated with UV radiation in a portion of the UV-B (280-320 nm) waveband during in vitro germination. Inhibition of germination was noted in this pollen compared to samples treated identically except for the exclusion of the UV-B portion of the spectrum. Levels similar to maximum solar UV-B found in temperate-latitude areas failed to inhibit pollen germination significantly, while levels similar to maximum solar UV-B found in equatorial alpine locations caused partial inhibition of germination in three of the four taxa examined.
The adsorption and corrosion inhibition behavior of three selected thiosemicarbazone derivatives, namely 3-pyridinecarboxaldehyde thiosemicarbazone (META), isonicotinaldehyde thiosemicarbazone (PARA) and 2-pyridinecarboxaldehyde thiosemicarbazone (ORTHO) at the nickel surface were studied electrochemically by Tafel and impedance methods and computationally by carrying out Monte Carlo searches of configurational space on nickel/thiosemicarbazone derivative system. Electrochemical measurements showed that the inhibition efficiency of these compounds increased with increase in their concentration. The recorded inhibition efficiencies of the three tested thiosemicarbazone increase in the order: META>PARA>ORTHO. Polarization studies showed that these compounds act as mixed-type inhibitors for n...
Werner syndrome (WS) is characterized by premature onset of age-associated disorders and predisposition to cancer. The WS protein, WRN, encodes 3′ → 5′ DNA helicase and 3′...Full Text Available
Oligonucleotide DNA probes complementary to the hypervariable region of the 16S rRNA of Bacteroides forsythus were tested for their specificity and sensitivity against reference and clinical isolates...Full Text Available
Cytosine methylation in DNA is a major epigenetic signal, and plays a central role in propagating chromatin status during cell division. However the mechanistic links between DNA methylation and histone methylation are poorly understood. A multi-domain protein UHRF1 (ubiquitin-like, containing PHD and RING finger domains 1) is required for DNA CpG maintenance methylation at replication forks, and mouse UHRF1-null cells show enhanced susceptibility to DNA replication arrest and DNA damaging agents. Recent data demonstrated that the SET and RING associated (SRA) domain of UHRF1 binds hemimethylated CpG and flips 5-methylcytosine out of the DNA helix, whereas its tandom tudor domain and PHD domain bind the tail of histone H3 in a highly methylation sensitive manner. We hypothesize that UHRF1 brings the two components (histones and DNA) carrying ...
DNA methylation of cytosine residues is a widespread phenomenon and has been implicated in a number of biological processes in both prokaryotes and eukaryotes. This methylation occurs at the 5-position...Full Text Available
BackgroundDuring the last ten years, major advances have been made in characterizing and understanding the evolution of mitochondrial DNA, the most popular marker of molecular biodiversity....Full Text Available
BackgroundTrypanosoma cruzi, the etiologic agent of Chagas Disease, is a major vector borne health problem in Latin America and an emerging...Full Text Available
We studied telomeric DNA in leukemic cells as well as in normal T cells, B cells, monocytes, polymorphonuclear leukocytes, and bone marrow hematopoietic progenitor cells. No marked differences were...Full Text Available
Digestion of plant chromatin from Brassica pekinensis and Matthiola incana with staphylococcus nuclease leads to a DNA repeat of 175 plus or minus 8 and a core size of 140 base pairs. DNase I digestion...Full Text Available
AbstractWe combined atomistic molecular-dynamics simulations with quantum-mechanical calculations to investigate the sequence dependence of the stretching behavior of duplex DNA. Our...Full Text Available
Human chromosomal fragile sites are specific loci that are especially susceptible to DNA breakage following conditions of partial replication stress. They often are found in genes involved in tumorigenesis...Full Text Available
We use high-density single nucleotide polymorphism (SNP) genotyping microarrays to demonstrate the ability to accurately and robustly determine whether individuals are in a complex genomic DNA mixture....Full Text Available
Nucleic acids are molecules of choice for both established and emerging nanoscale technologies. These technologies benefit from large functional densities of ‘DNA processing elements’...Full Text Available
Most codon indices used today are based on highly biased nonrandom usage of codons in coding regions. The background of a coding or noncoding DNA sequence, however, is fairly random, and can be characterized...Full Text Available
The sequence in the first hypervariable segment (HVS-I) of the control region has been used as a source of evolutionary information in most phylogenetic analyses of mtDNA. Population genetic inference...Full Text Available
BackgroundThe construction of cDNA libraries is a useful tool to understand gene expression in organisms under different conditions, but random sequencing of unbiased cDNA collections...Full Text Available
The integration sites for viral DNA in cells infected with Moloney murine leukemia virus (M-MuLV) were studied by restriction endonuclease cleavage of cellular DNA followed by electrophoresis in agarose...Full Text Available
The sequence-dependent structural variability and conformational dynamics of DNA play pivotal roles in many biological milieus, such as in the site-specific binding of transcription factors to target...Full Text Available
DNA interstrand cross-links (ICLs) are critical cytotoxic lesions produced by cancer chemotherapeutic agents such as the nitrogen mustards and platinum drugs; however, the exact mechanism of ICL-induced...Full Text Available
Because copper catalyzes the conversion of H2O2 to hydroxyl radicals in vitro, it has been proposed that oxidative DNA damage may be an important component of copper toxicity....Full Text Available
The bulky octahedral complex, Rh(bpy)2chrysi3+ (chrysi = 5, 6- chrysenequinone diimine), binds single base mismatches in a DNA duplex with micromolar binding affinities...Full Text Available
Auxin autonomous growth of most crown gall tumor cells requires the expression of two auxin biosynthesizing genes (tms 1 and tms 2) from the T-DNA of Agrobacterium...Full Text Available
The use of dideoxynucleotide triphosphates labeled with different fluorescent dyes (dye terminators) is the most versatile method for automated DNA sequencing. However, variation in peak heights reduces...Full Text Available
Chromosomal common fragile sites (CFSs) are genetically unstable regions of the genome that are induced by conditions that impair DNA replication. In this report, we show that treatment with the DNA...Full Text Available
Epigenetic remodeling is a hallmark of cancer, with the frequent acquisition of de novo DNA methylation in CpG islands. However, the functional relevance of de novo...Full Text Available
DNA double-strand breaks (DSBs) are generally accepted to be the most biologically significant lesion by which ionizing radiation causes cancer and hereditary disease. However, no information on the...Full Text Available
The development of chromatin immunoprecipitation methods coupled with DNA microarray (ChIP-chip) technology has enabled genome-wide identification of cis-DNA regulatory elements to which transcription...Full Text Available
DNA supercoiling in the chloroplast of the unicellular green alga Chlamydomonas reinhardtii was found to change with a diurnal rhythm in cells growing in alternating 12-h dark–12-h...Full Text Available
Investigations of enzymes involved in DNA metabolism have strongly benefited from the establishment of single molecule techniques. These experiments frequently require elaborate DNA substrates, which...Full Text Available
In the present study we have used the alkaline elution technique to study the effect of misonidazole (MISO) on the initial amount of DNA cross-linking in various normal and neoplastic tissues of C3H...Full Text Available
A number of aberrant morphological phenotypes were noted during propagation of the Arabidopsis thaliana DNA hypomethylation mutant, ddm1, by repeated self-pollination. Onset of a spectrum of morphological...Full Text Available
Caries is a multifactorial disease, and studies aiming to unravel the factors modulating its etiology must consider all known predisposing factors. One major factor is bacterial colonization,...Full Text Available
DNA barcodes linked to genetic features greatly facilitate screening these features in pooled formats using microarray hybridization, and new tools are needed to design large sets of barcodes to allow...Full Text Available
DNA replication in Escherichia coli cells lacking protein HU was studied. HU has been suggested to be involved in the initiation of replication from in vitro studies. The isolated HU mutants, however,...Full Text Available
ObjectiveThe present study was undertaken to analyze the impact of epigenetic alterations with a main focus on nuclear area, aneuploidy, hyperploidy, and proliferation...Full Text Available
The syntheses and applications of two metallointercalators, Rh(bpy)2(chrysi)3+ and Rh(bpy)2(phzi)3+, that target single base mismatches in DNA are...Full Text Available
A nonmammalian test system for germ-cell mutagenesis has been developed by using the Japanese medaka fish. We describe a system for detecting DNA alterations in F1 progeny descended from the gamma-irradiated...Full Text Available
The binding mode of telomestatin to G-quadruplex DNA has been investigated using electrospray mass spectrometry, by detecting the intact complexes formed in ammonium acetate. The mass measurements show...Full Text Available
Global hypomethylation has been shown to increase genome instability potentially leading to increased cancer risk. We determined whether global methylation in blood leukocyte DNA was associated...Full Text Available
DNA methylation is an important event in epigenetic changes in cells, and a fundamental regulator of gene transcription. Bisulfite genomic sequencing is a powerful technique used in studies of DNA methylation. However, the established procedures often require relatively large amounts of DNA. In everyday practice, samples submitted for analysis might contain very small amounts of poor quality material, as is often the case with forensic stain samples. In this study, we assess a modified, more efficient method of bisulfite genomic sequencing. Genomic DNA extracted from 3-mm dried blood spots using QIAamp micro kit was treated with sodium bisulfite (using EpiTect kit). Subsequent methylation-specific PCR (MSP) followed by DNA sequencing displayed the differentially methylated region of imprinted gene SNRPN. Our results show that this new combination of efficient ...
Hairpin oligonucleotides were synthesized with stems ending in a double-stranded structure, which can be ligated to double-strand breaks in DNA, and with loops that contain nucleotides modified by the...Full Text Available
We recently reported that human immunodeficiency virus type 1 (HIV-1) unintegrated linear DNA displays a discontinuity in its plus strand, precisely defined by a second copy of the polypurine tract...Full Text Available
DNA antoantibodies in serum will bind to antigen-coated polystyrene tubes and can be detected by radiolabelled anti-immunoglobulin. The method is quantitative, gives information on the antibody class...Full Text Available
A cDNA encoding a cytochrome P450 enzyme was isolated from a cDNA library of the corpora allata (CA) from reproductively active Diploptera punctata cockroaches. This P450 from the endocrine...Full Text Available
Recent studies have indicated that the DNA replication machinery is coupled to silencing of mating-type loci in the budding yeast Saccharomyces cerevisiae, and a similar silencing mechanism...Full Text Available
Azobenzene dyes are effective inhibitors for austenitic 304 L and 316 L stainless steel corrosion in high acidic medium up to 7N. A good efficiency is obtained from weight loss and electrochemical Rsub(p) measurements in hydrochloric acid, while no inhibition is observed in sulfuric solutions. Transformation from the primarily azobenzene to other compounds give rise to enhanced protection of steel samples, and probable structures of the inhibiting species are proposed in view of our results.
Azobenzene dyes are effective inhibitors for austenitic 304 L and 316 L stainless steel corrosion in high acidic medium up to 7N. A good efficiency is obtained from weight loss and electrochemical Rsub(p) measurements in hydrochloric acid, while no inhibition is observed in sulfuric solutions. Transformation from the primarily azobenzene to other compounds give rise to enhanced protection of steel samples, and probable structures of the inhibiting species are proposed in view of our results.
Human BTEB cDNA clones have been isolated, sequenced, and the corresponding gene has been assigned to human chromosome 9, region q13, by fluorescent in situ hybridization and DNA blot analysis using DNAs from hybrid cell clones containing a single human chromosome. The cDNA clone encodes a polypeptide of 244 amino acids whose sequence shows a high sequence similarity with the rat BTEB (98% amino acid identity).
A structurally conserved element, the trigger loop, has been suggested to play a key role in substrate selection and catalysis of RNA polymerase II (pol II) transcription elongation. Recently resolved...Full Text Available
The insulin/IGF-1 signaling (IIS) pathway is a conserved regulator of longevity, development, and metabolism. In Caenorhabditis elegans IIS involves activation of DAF-2 (insulin/IGF-1...Full Text Available
A refined map for the linear arrangement of histones along DNA in nucleosomal core particles has been determined by DNA-protein crosslinking. On one strand of 145-bp core DNA, histones are aligned in...Full Text Available
Two cDNA libraries corresponding to polyA+ RNA from human adult skeletal muscle have been constructed by cloning in the PstI site of pBR322. Skeletal alpha actin cDNA clones have been isolated and characterized....Full Text Available
Ditercalinium, an antitumor bifunctional intercalator which forms a high affinity reversible complex with DNA, was found to be specifically cytotoxic for polA and lig7 E. coli strains. In the polA strain,...Full Text Available
Fission yeast S. pombe is assumed to be a good model for cloning of human DNA repair genes, because human gene is normally expressed in S. pombe and has a very similar protein sequence to yeast protein. We have tried to elucidate the DNA repair mechanisms of S. pombe as a model system for those of mammals. (J.P.N.)
DNA from 48 hr germinated rice embryos was cut with restriction endonuclease Bam H1 and cloned to the Bam H1 site on plasmid pBR 322. The clones containing recombinant DNA were selected by their sensitivity to tetracycline and resistance to ampicillin. Using /sup 32/P-labelled rice embryos tRNA as a probe two clones were identified to contain tRNA genes by colony hybridization.
Two cellular DNA regions representing common domains for proviral DNA integration ( Mlvi -1 and Mlvi -2) have been identified in Moloney murine leukemia virus-induced rat thymic lymphomas. Cellular...Full Text Available
DNA isolation procedures significantly influence the outcome of PCR-based detection of human pathogens. Unlike clinical samples, DNA isolation from food samples such as fresh and fresh-cut produce has remained a formidable task and has hampered the sensitivity and accuracy of molecular methods. We...
We have examined homologous fragments of DNA cloned from two different tissues for changes in the dNA sequence which might be related to tissue specific gene expression. The 5' end of the chicken ovalbumin...Full Text Available
Biosorption using activated sludge biomass (ASB) as a potentially sustainable technology for the treatment of wastewater containing different metal ions (Cd(II), Pb(II) and Zn(II)) was investigated. ASB metal uptake clearly competed with protons consumed by microbial biomass compared with control tests with non-activated sludge biomass. Biosorption tests confirmed maximum exchange between metal ions and protons at pH 2.0-4.5. It was revealed by the study that the amount of metal ions released from the biomass increased with biomass sludge concentration. The result showed that maximum absorption of metal ions was observed for Cd(II) at pH 3.5, Pb(II) at pH 4.0, and pH 4.5 for Zn(II) ions. The maximum absorption capacities of ASB for Cd(II), Pb(II) and Zn(II) were determined to be 59.3, 68.5 and 86.5%, ...
The results of this research centered on the experimental studies of a single superconducting persistent current qubit, the implementation of type-II algorithms using these qubits, and the proposal for adiabatic quantum computing using these qubits. The m...
The in vivo photochemical activity of photosystem II was inferred from modulated chlorophyll fluorescence and photoacoustic measurements in intact leaves of several plant species (Lycopersicon...Full Text Available
Woolfolk, C. A. (University of Washington, Seattle). Reduction of inorganic compounds with molecular hydrogen by Micrococcus lactilyticus. II. Stoichiometry with inorganic...Full Text Available
... and high-quality photospheric-phase Type II SN spectra to constrain core- collapse SN explosions, massive star evolution, and distances in the Universe ...
This document describes payload control at LLNL to ensure that all shipments of CH-TRU waste in the TRUPACT-II (Transuranic Package Transporter-II) meet the requirements of the TRUPACT-II SARP (safety report for packaging). This document also provides specific instructions for the selection of authorized payloads once individual payload containers are qualified for transport. The physical assembly of the qualified payload and operating procedures for the use of the TRUPACT-II, including loading and unloading operations, are described in HWM Procedure No. 204, based on the information in the TRUPACT-II SARP. The LLNL TRAMPAC, along with the TRUPACT-II operating procedures contained in HWM Procedure No. 204, meet the documentation needs for the use of the TRUPACT-II at LLNL. Table 14-1 provides a summary of the LLNL waste generation and ...
In this Letter, we demonstrate the application of time-resolved fluorescence anisotropy measurements to detect solution state hybridization of streptavidin conjugate (CdSe)ZnS quantum dots (QD). The study was performed on samples containing 10nM QD incubated with 800nM DNA. We show that the rotational correlation time of QD-DNA constructs increases significantly upon hybridization with values of 330ns (QD-ssDNA) and 1.3ms (QD-dsDNA), corresponding to a diameter of 14nm and 23nm respectively. The present study opens a new modality for hybridization detection using quantum dots.
Lebers hereditary optic neuropathy (LHON), the most frequent mitochondrial disorder, is mostly due to three mitochondrial DNA (mtDNA) mutations in respiratory chain complex I subunit genes: 3460/ND1, 11778/ND4 and 14484/ND6. Despite considerable clinical evidences, a genetic modifying role of the mtDNA haplogroup background in the clinical expression of LHON remains experimentally unproven. We investigated the effect of mtDNA haplogroups on the assembly of oxidative phosphorylation (OXPHOS) complexes in transmitochondrial hybrids (cybrids) harboring the three common LHON mutations. The steady-state levels of respiratory chain complexes appeared normal in mutant cybrids. However, an accumulation of low molecular weight subcomplexes suggested a complex I assembly/stability defect, which was ...
Since the elucidation of the structure of double helical DNA, the construction of small molecules that recognize and react at specific DNA sites has been an area of considerable interest. In particular, the study of transition metal complexes that bind DNA with specificity has been a burgeoning field. This growth has been due in large part to the useful properties of metal complexes, which possess a wide array of photophysical properties and allow for the modular assembly of an ensemble of recognition elements. Here we review recent experiments in our laboratory aimed at the design and study of octahedral metal complexes that bind DNA non-covalently and target reactions to specific sites. Emphasis is placed both on the variety of methods employed to confer site-specificity and upon the many applications for these complexes. Particular attention is given to the family of complexes recently designed that ...
Since the elucidation of the structure of double helical DNA, the construction of small molecules that recognize and react at specific DNA sites has been an area of considerable interest. In particular, the study of transition metal complexes that bind DNA with specificity has been a burgeoning field. This growth has been due in large part to the useful properties of metal complexes, which possess a wide array of photophysical attributes and allow for the modular assembly of an ensemble of recognition elements. Here we review recent experiments in our laboratory aimed at the design and study of octahedral metal complexes that bind DNA non-covalently and target reactions to specific sites. Emphasis is placed both on the variety of methods employed to confer site-specificity and upon the many applications for these complexes. Particular attention is given to the family of complexes recently designed that ...
The interaction energies between the different types of bases of a single strand of DNA molecule have been calculated. Using these original values of energies the harmonic behavior of a number of base patterns of DNA has been studied. In view of the great interest aroused by the discovery of the role of the telomere segment of the DNA in the replication process and its possible link with the aging process, we have investigated, with simple models, the harmonic behavior of the telomeric pattern of bases as well as the thermodynamic response in the biological system. With these results a conclusion on the probable role of the telomeric pattern on aging has also been drawn. Here the calculated values of harmonic frequencies of the telomeric pattern of bases and of other possible patterns show that the telomeric pattern is associated with the highest vibrational frequency among all patterns of base combinations at the ...
The glass gene is required for proper photo-receptor differentiation during development of the Drosophila eye glass codes for a DNA-binding protein containing five zinc fingers that we show is a transcriptional activator. A comparison of the sequences of the glass genes from two species of Drosophila and a detailed functional domain analysis of the Drosophila melanogaster glass gene reveal that both the DNA-binding domain and the transcriptional-activation domain are highly conserved between the two species. Analysis of the DNA-binding domain of glass indicates that the three carboxyl-terminal zinc fingers alone are necessary and sufficient for DNA binding. We also show that a deletion mutant of glass containing only the DNA-binding domain can behave in a dominant-negative manner both in vivo and in a cell culture assay that measures transcriptional activation. PMID:7604032
In evaluating the risk associated with low levels of exposure to toxicants, it is clear that DNA repair, one of the main defenses against agent damage, is not a constant. It can be modified by age, time of day, and physiological state. Nutrition, especially caloric restriction (CR), can modify almost every step in the process of protecting genomic integrity. And history of exposure can modify DNA repair. Thus, the conditions of exposure are almost as important to toxicity as the exposure itself, even at the level of DNA repair. Extrapolation from high to low dose, to be consistent with what is known, should be less a mathematical exercise than an exercise in toxicological judgement, which puts the exposure in proper perspective. This appears to be true at almost every level in the process including a response with a toxic stimulus, even those thought to be very basic, such as DNA repair.
Banana bunchy top virus (BBTV), family Nanaviridae, genus Babuvirus, is a single stranded DNA virus (ssDNA) that causes banana bunchy top disease (BBTD) in banana plants. It is the most common and most destructive of all viruses in these plants and is widespread throughout the Asia-Pacific region. In this study we isolated, cloned and sequenced a BBTV sample from Hainan Island, China. The results from sequencing and bioinformatics analysis indicate this isolate represents a satellite DNA component with 12 DNA sequences motifs. We also predicted the physical and chemical properties, structure, signal peptide, phosphorylation, secondary structure, tertiary structure and functional domains of its encoding protein, and compare them with the corresponding quantities in the replication initiatio...
We propose a combined experimental (Atomic Force Microscopy) and theoretical study of the structural and dynamical properties of nucleosomes. In contrast to biochemical approaches, this method allows to determine simultaneously the DNA complexed length distribution and nucleosome position in various contexts. First, we show that differences in the nucleo-proteic structure observed between conventional H2A and H2A.Bbd variant nucleosomes induce quantitative changes in the in the length distribution of DNA complexed with histones. Then, the sliding action of remodeling complex SWI/SNF is characterized through the evolution of the nucleosome position and wrapped DNA length mapping. Using a linear energetic model for the distribution of DNA complexed length, we extract the net wrapping energy of DNA onto the histone octamer, and compare it to previous studies.
PCR detection of genetic material of the parasites present in faeces may be an alternative for microscopic and serological tests routinely used for diagnosing parasitic enteral infections. However, small amount of target DNA combined with low efficiency of total DNA extraction, and presence of PCR inhibitors in the samples to be amplified, may cause false negative detection results. The aim of this work was to evaluate the impact of DNA isolation procedure used on the amplification of DNA fragments from the genomes of protozoan Cryptosporidium parvum and the nematode Trichinella spiralis. Two methods based on different principles of biological material lysis were evaluated; NucliSENS miniMAG employing simultaneously applied chemical lysis and mechanical disruption or mechanical disruption followed by enzymatic lysis in case of QIAamp DNA Stool Mini Kit. Both of the analyzed systems ...
Owing to exceptional biomolecule preservation, fossil avian eggshell has been used extensively in geochronology and palaeodietary studies. Here, we show, to our knowledge, for the first time that fossil eggshell is a previously unrecognized source of ancient DNA (aDNA). We describe the successful isolation and amplification of DNA from fossil eggshell up to 19 ka old. aDNA was successfully characterized from eggshell obtained from New Zealand (extinct moa and ducks), Madagascar (extinct elephant birds) and Australia (emu and owl). Our data demonstrate excellent preservation of the nucleic acids, evidenced by retrieval of both mitochondrial and nuclear DNA from many of the samples. Using confocal microscopy and quantitative PCR, this study critically evaluates approaches to maximize DNA recovery from powdered eggshell. Our quantitative PCR experiments also ...
The parmbsc0 force field was applied to study in detail the binding of netropsin, at a salt concentration of 0.28M Na^+, to the minor groove of an 8-mer (5'CCAATTGG)2 DNA duplex forming a netropsin.DNA complex which previously has been characterized by X-ray crystallography, albeit with the use of closely related DNA duplexes. The X-ray structure revealed that the terminal guanidinium and amidinium groups of netropsin interact with the extreme ends of the palindromic AATT sequence of the receptor DNA. The parmbsc0 parameters of B-DNA and AMBER v9 parameters of netropsin generated a stable 6ns molecular dynamics (MD) trajectory for a 1:1 class I binding motif of this complex. Trajectory analysis for the salt and hydration effects on the binding of netropsin to the 8-mer DNA duplex revealed ...
This report briefly describes the studies on the mechanism of in vivo DNA repairing by the author in Research Reactor Institute, Kyoto Univ. for the past 30 years. First, the ability of UV radiation to induce transformation was investigated with viral DNA. The formation of thymine-thymine dimer was found harmful to organisms and such dimers were removable by UV-radiation at a low frequency. The mutability was determined in three different E.coli strains with mutator gene, mutT, mutS or mutL. The ability to excise 8-oxoguanin developed in primer DNA was deficient in mutT and miss-pairing left after DNA replication could not be recovered in mutL and mutS strains. Further, DNA repairing mechanism was investigated in other microorganisms; single-strand cleavage caused by exposure to BNCB radiation (boron-neutron-captured beam) could not be repaired in E. coli. Whereas for Deinococcus ...
Bacteriophage M13 mp10 DNA were irradiated with near-UV light in the presence of tetracycline derivatives and primed with synthetic oligonucleotide to be used for DNA synthesis using Escherichia coli DNA polymerase. Chain terminations were observed by denaturing polyacrylamide gel electrophoresis and mapped precisely. All the synthesis stops occurred before or at the level of guanine residues, showing that the photoreaction mediated by tetracycline derivatives led to a preferential alteration of guanine residues. These lesions were demonstrated to be induced in DNA through a pathway involving singlet oxygen. Tetracycline derivatives also photoinduced the breakage of the DNA sugar-phosphate backbone monitored by the conversion of supercoiled phi X174 DNA to a relaxed form. This lesion was shown to be initiated by hydroxyl radicals. The production of this free ...
Apart from the vulnerability implied by the START II treaty, it will bear the burden of the general political opposition to the Yeltsin administration. START II will be seen as part of an overall Yeltsin-Andrei Kozyrev foreign policy that is under fire for selling out Russian national interests in Yugoslavia, the Persian Gulf, and elsewhere. This article discusses public opinion concerning START II, the cost of its implementation, and the general purpose of the treaty.
The upgraded CDF II detector has collected first data during the initial operation of the Tevatron accelerator in Run II. The simulation of the CDF electromagnetic and hadronic central and upgraded plug (forward) calorimeter is based on the Gflash calorimeter parameterization package used within the GEANT based detector simulation of the Run II CDF detector. We present the results of tuning the central and plug calorimeter response to test beam data.
PRESTO-II is a computer code developed to evaluate possible health effects from shallow land disposal of low level radioactive wastes. PRESTO-PREP is a data preprocessor that has been developed to expedite the formation of input data sets for PRESTO-II. PRESTO-PREP utilizes a library of nuclide and risk-specific data. Given an initial waste inventory, the code creates the radionuclide portion of the associated input data set for PRESTO-II. 2 references.
The purpose of this paper is to describe the embedded computer systems approach taken at Experimental Breeder Reactor II (EBR-II) for non-safety related systems. The hardware and software structures for typical embedded systems are presented The embedded systems development process is described. Three examples are given which illustrate typical embedded computer applications in EBR-II.
Angiotensin II (Ang II) is a key proapoptotic factor in fibrotic tissue diseases. However, the mechanism of Ang-II-induced cell death in endothelial cells has not been previously elucidated....Full Text Available
Although the p53 tumor suppressor is relatively well characterized, much less is known about the functions of other members of the p53 family, p73 and p63. Here, we present evidence that in specific pathological conditions caused by exposure of normal cells to bile acids in acidic conditions, p73 protein plays the predominant role in the DNA damage response. These pathological conditions frequently occur during gastric reflux in the human esophagus and are associated with progression to esophageal adenocarcinoma. We found that despite strong DNA damage induced by bile acid exposure, only p73 (but not p53 and p63) is selectively activated in a c-Abl kinase-dependent manner. The activated p73 protein induces DNA damage repair. Using a human DNA repair PCR array, we identified multiple DNA repair genes affected by p73. Two glycosylases involved in base excision repair, SMUG1 and MUTYH, ...
Full text: DNA rearrangement events leading to chromosomal aberrations are central to ionizing radiation-induced cell death. Although DNA double-strand breaks are probably the lesion that initiates formation of chromosomal aberrations, little is understood about the molecular mechanisms that generate and modulate DNA rearrangement. Examination of the sequences that flank sites of DNA rearrangement may provide information regarding the processes and enzymes involved in rearrangement events. Accordingly, we developed a method using inverse PCR that allows the detection and sequencing of putative radiation-induced DNA rearrangements in defined regions of the human genome. The method can detect single copies of a rearrangement event that has occurred in a particular region of the genome and, therefore, DNA rearrangement detection does not require survival and ...
The biomedical and ecological interest for the microwave impact on the Earth biosphere is continuously increased since the industrial, military and communication activities strongly contribute to the electromagnetic stress of living bodies. In the next the authors present some of the main results obtained regarding the microwave exposure of various types of biological material: bacteria, fungi, young plant seedlings, dry seeds, animal tissues. The electromagnetic exposure was carried out in open space in well controlled environmental conditions by using 10.75 GHz/1 m W cm{sup -2} microwaves. Biochemical assays and cytogenetic tests have been carried out to reveal the changes induced post irradiation. The response of some pathogen bacteria, have been emphasized by means of turbidimetric measurements - the stimulatory effect being noticed at the level of the microbial population density (the stimulation of the human body microbial flora seems to be one of the side effects of microwave ...
Carbalkoxylation of vinyl electrophiles was investigated using platinum complexes. This reaction occurs in two steps: (a) carbonyl insertion of {sigma}-vinyl Pt(II) halides and (b) alcoholysis of vinylic acyl Pt(II) complexes. Alcoholysis of vinylic acyl Pt(II) triflate complexes is investigated kinetically. Vinylic acyl Pt(II) complexes were isolated and characterized. 51 refs., 5 figs., 6 tabs.
In vivo effects of toxaphene on calcium pump activity in rat brain synaptosomes was studied. Male Sprague-Dawley rats were dosed with toxaphene at 0,25,50, and 100 mg/kg/day for 3 days and sacrificed 24 h after last dose. Ca/sup 2 +/-ATPase activity and /sup 45/Ca uptake were determined in brain P/sub 2/ fraction. Toxaphene inhibited both Ca/sup 2 +/-ATPase activity and /sup 45/Ca/sup 2 +/ uptake and the inhibition was dose dependent. Both substrate and Ca/sup 2 +/ activation kinetics of Ca/sup 2 +/-ATPase indicated non-competitive type of inhibition as evidenced by decreased catalytic velocity but not enzyme-substrate affinity. The inhibited Ca/sup 2 +/-ATPase activity and Ca/sup 2 +/ uptake were restored to normal level by exogenously added calmodulin which increased both velocity and affinity. The inhibition of Ca/sup 2 +/-ATPase activity and Ca/sup 2 +/ uptake and restoration by ...
In vivo effects of toxaphene on calcium pump activity in rat brain synaptosomes was studied. Male Sprague-Dawley rats were dosed with toxaphene at 0,25,50, and 100 mg/kg/day for 3 days and sacrificed 24 h after last dose. Ca"2"+-ATPase activity and "4"5Ca uptake were determined in brain P_2 fraction. Toxaphene inhibited both Ca"2"+-ATPase activity and "4"5Ca"2"+ uptake and the inhibition was dose dependent. Both substrate and Ca"2"+ activation kinetics of Ca"2"+-ATPase indicated non-competitive type of inhibition as evidenced by decreased catalytic velocity but not enzyme-substrate affinity. The inhibited Ca"2"+-ATPase activity and Ca"2"+ uptake were restored to normal level by exogenously added calmodulin which increased both velocity and affinity. The inhibition of Ca"2"+-ATPase activity and Ca"2"+ uptake and restoration by calmodulin suggests that toxaphene may impair active ...
Inhibition efficiency of some water-soluble hydrazones for C-steel corrosion in hydrochloric acid has been tested by weight loss, polarisation measurements and open circuit technique. The inhibition effect was attributed to the adsorption of the additives on the C-steel surface as supported by adsorption measurements at Pt electrode using cyclic voltammetry. Electrochemical measurements indicated that all the additives behave as cathodic-type inhibitors. The data obtained fit well to both the Temkin adsorption isotherm and the kinetic-thermodynamic model. The inhibition behaviour and its order were explained with the help of the proposed skeletal representation.
Botulinum neurotoxin is produced by the bacterium, Clostridium botulinum. The neurotoxin inhibits acetylcholine at the neuromuscular junction, thus interfering with overall muscular contraction. Botulinum neurotoxin is commonly used for the following medical conditions: cervical dystonia, upper limb spasticity, blepharospasm, strabismus, and hyperhydrosis. However, the use of botulinum neurotoxin was recently approved for the prophylaxis of headaches in adults with chronic migraines. The proposed mechanism of botulinum neurotoxin is no longer solely limited to the inhibition of acetylcholine. There are new mechanisms emerging that involve inhibition of proinflammatory agents and neuropeptides involved in chronic pain. Consequently, there is a disruption of the overall sensory feedback loop...
A method to control charge transfer reaction in DNA using hybrid nanometer-sized TiO{sub 2} nanoparticles was developed. In this system extended charge separation reflects the sequence of DNA and was measured using metallic silver deposition or by photocurrent response. Light-induced extended charge separation in these systems was found to be dependent on the DNA-bridge length and sequence. The yield of photocatalytic deposition of silver was studied in systems having GG accepting sites imbedded in AT runs at varying distances from the TiO{sub 2} nanoparticle surface. Weak distance dependence of charge separation indicative of a hole hopping through mediating adenine (A) sites was found. The quantum yield of silver deposition in the system having a GG accepting site placed 8.5 {angstrom} from the nanoparticle surface was found to be {Phi} = 0.70 (70%) and {Phi} = 0.56 (56%) for (A){sub n} and (AT){sub n/2} bridge, ...
Radixin is a cytoskeletal protein that may be important in linking actin to the plasma membrane. Recent cloning of the murine and porcine radixin cDNAs revealed a protein highly homologous to ezrin and moesin. The authors have cloned and sequenced the human radixin cDNA and found the predicted amino acid sequence for the human protein to be nearly identical to those predicted for radixin in the two other species. By Southern analyses of Chinese hamster x human somatic cell hybrid DNA and of PCR products derived from hybrids, the coding gene (RDX) was mapped to 11q. Fluorescence chromosomal in situ hybridization with a cDNA plasmid further localized this gene to band 11q23. However, PCR amplification with [open quotes]radixin-specific[close quotes] primers on the hybrid DNA panel yielded an additional, very similar DNA sequence that was further characterized by direct sequencing of ...
An electrochemical detection method for analyzing sequence-specific DNA using gold nanoparticle DNA probes and subsequent signal amplification step by silver enhancement is described. The assay relies on the electrostatic adsorption of target oligonucleotides onto the sensing surface of the glassy carbon electrode (GCE) and its hybridization to the gold nanoparticle-labeled oligonucleotides DNA probe. After silver deposition onto gold nanoparticles, binding events between probe and target were monitored by the differential pulse voltammetry (DPV) signal of the large number of silver atoms anchored on the hybrids at the electrode surface. The signal intensity difference permits to distinguish between the match of two perfectly matched DNA strands and the near-perfect match where just one base pair was wrong. Coupled with this 'nanoparticle-promoted' reduction of silver signal ...
The overall objective of this project has been to develop immunochemical methods to quantitate unique DNA base damages in order to facilitate studies on radiation-induced damage production and repair. Specifically, we have been using antibodies raised to damaged bases to quantitate unique lesions in model systems in order to evaluate their potential biological consequences. Our approach has been to synthesize modified nucleotides or nucleosides, conjugate them to protein carriers, and use the conjugates as immunogens in rabbits or to prepare monoclonal antibodies. We have been studying damages that are stable radiolysis products found in X-irradiated DNA and thus of potential biological consequence. Our aim is to build an in vitro and in vivo data base on the interactions between model DNA lesions and such cellular enzymes as DNA polymerases and repair endonucleases. Initial studies have focused on ...
The overall objective of this project has been to develop immunochemical methods to quantitate unique DNA base damages in order to facilitate studies on radiation-induced damage production and repair. Specifically, we have been using antibodies raised to damaged bases to quantitate unique lesions in model systems in order to evaluate their potential biological consequences. Our approach has been to synthesize modified nucleotides or nucleosides, conjugate them to protein carriers, and use the conjugates as immunogens in rabbits or to prepare monoclonal antibodies. We have been studying damages that are stable radiolysis products found in X-irradiated DNA and thus of potential biological consequence. Our aim is to build an in vitro and in vivo data base on the interactions between model DNA lesions and such cellular enzymes as DNA polymerases and repair endonucleases. Initial studies have focused on ...
SUMMARYHomeostatic synaptic plasticity is a negative feedback mechanism neurons use to offset excessive excitation or inhibition by adjusting their synaptic strengths. Recent...Full Text Available
The muscarinic receptor binding of trazodone, a new nontricyclic antidepressant, was compared with established tricyclic antidepressants. The ability to inhibit the binding of [3H]-quinuclidinyl benzilate...Full Text Available
Corrosion inhibition of iron in H2SO4 by polyacrylic acid (PAA) was investigated using electrochemical techniques at 30degreeC. Results obtained indicate that PAA inhibited the corrosion of iron in the acid medium. Inhibition efficiency increases with increase in PAA concentration and synergistically enhanced on addition of iodide ions. Potentiodynamic polarization results suggest that PAA functions as a modest cathodic inhibitor. The adsorption of PAA onto the iron surface followed Temkin adsorption isotherm. FTIR analysis revealed that the synergistic effect due to co-adsorption of iodide ions and PAA is co-operative in nature.
Regulatory T cells are proposed to play a central role in the maintenance of immunological tolerance in the periphery, and studies in many animal models demonstrate their capacity to inhibit inflammatory...Full Text Available
Phospholipase D (PLD) has been recognized as a regulator of cell proliferation and tumorigenesis, but little is known about the molecules regulating PLD expression. Thus, the identification of small molecules inhibiting PLD expression would be an important advance in PLD-mediated physiology. Quercetin, a ubiquitous bioactive flavonoid, is known to inhibit proliferation and induce apoptosis in a variety of cancer cells. In the present study, we examined the effect of quercetin on the expression of PLD in U87 glioma cells. Quercetin significantly suppressed the expression of PLD1 at the transcriptional level. Moreover, quercetin abolished the protein expression of PLD1 in a time and dose-dependent manner, as well as inhibited PLD activity. Quercetin suppressed NFkB-induced PLD1 expression vi...
The binding of iodine-labelled plasminogen to Helicobacter pylori CCUG 17874 was characterized. Inhibition of the binding was observed after preincubation of H. pylori...Full Text Available
The effect of low concentrations of nalidixic acid on ribonucleic acid (RNA) synthesis in Escherichia coli was examined. It was observed that RNA synthesis in exponentially growing...Full Text Available
This paper presents the corrosion inhibition performance of soluble self-doped copolymers of aniline and 4-amino-3-hydroxy-naphthalene-1-sulfonic acid synthesized by chemical oxidative polymerization method. The corrosion inhibition behaviour of the copolymers in 1.0M HCl has been evaluated using Tafel Extrapolation method and electrochemical impedance spectroscopy (EIS) which was also used to propose the mechanism besides surface morphology. The results showed that the copolymer film exhibited the significant shifting in the corrosion potential and greater charge transfer resistance. The corrosion inhibition efficiency was found to increase from 50% to 90% by increasing the concentration of copolymer from 10 to 70mg/l in HCl medium. Moreover, the copolymer showed the larger degree of surf...
The antibacterial activities of different nitroheterocyclic compounds were assessed by an agar dilution method against aerobic, microaerophilic, and anaerobic bacteria. Nitronaphthofurans inhibited...Full Text Available
Carboxylesterases (CE) are ubiquitous enzymes that hydrolyze numerous ester-containing xenobiotics, including complex molecules, such as the anticancer drugs irinotecan (CPT-11) and capecitabine...Full Text Available
We present the synthesis, magnetic and UV spectrometry of NiZn-ferrite nanofiber. The single phase of spinel ferrite was obtained at 600 {sup o}C. The NiZn-ferrite fibers fabricated by an electrospinning process were formed as a polygonal grain growth with firing temperature in fiber matrix. It appeared that the saturation magnetization (M{sub S}) of NiZn-ferrite nanofiber was dependent on Ni/Zn molar ratio which is similar to that of the inverse spinel ferrites. The NiZn-ferrite fibers showed good DNA adsorption efficiency that can be modified and utilized for DNA separation with magnetic nanofiber as a novel material in clinical applications.
E. coli HB101 cells transformed to tetracycline resistance with the plasmids pMB9 or pBR322 display a 10/sup 5/-10/sup 6/-fold lower plating efficiency on agar containing 440 ..mu..M CdCl/sub 2/ than nontransformed cells. When DNA is inserted into the BamH1 site of the plasmid tet gene, or when DNA spanning the BamH1 site is deleted, tetracycline resistance and cadmium hypersensitivity are both lost. In contrast, insertion of DNA into the ampicillin resistance gene does not affect cadmium hypersensitivity.
Nanoparticles represent versatile building blocks in material science and nanotechnology. Thereby, the defined assembly of nanostructures (13 and 56 nm in diameter, respectively) is of significant importance. Short DNA sequences can be bound to the nanoparticle surface thus enabling highly specific DNA hybridization-driven events that direct the formation of nanoparticle constructs.In this paper, examples for the defined formation of gold nanoparticle constructs are demonstrated. In addition, gold-silver core-shell nanoparticles are introduced as further building blocks for the hybridization-controlled formation of nanoparticle constructs.
Studies begun during the first year of this project on biopsies from spontaneous tumors in dogs and from human patients undergoing radiotherapy treatment were continued. The results indicate that significant fractions of the spontaneous tumors in dogs and cervical carcinomas in patients undergoing radiotherapy have a DNA content higher than normal diploid cells. The higher DNA content in tumor cells permits distinguishing them from normal cells in the biopsy material with the aid of flow microfluorometric (FMF) instrumentation or multiangle light-scatter spectrometry.
A colony PCR technique was applied for both genomic and chloroplast DNA in the green microalgae Chlorella. Of five different lysis buffers, Chelex-100 was superior for DNA extraction, PCR and DNA storage. It also was insensitive to variations in cell density. The conditions established for an improved PCR formulation are applicable for screening of genetically-engineered transformants as well as bioprospecting of natural microalgal isolates. Besides multiple Chlorella species, we also demonstrate the efficacy of Chelex-100 for colony PCR with a number of other microalgal strains, including Chlamydomonas reinhardtii, Dunaliella salina, Nannochloropsis sp., Coccomyxa sp., and Thalassiosira pseudonana. PMID:21431847
The subfornical organ is a major receptor area for one of the principal stimuli of thirst, the octapeptide, angiotensin II. In conscious water-sated rats, the authors examined the effects of intravenous infusion of angiotensin II on the rate of glucose utilization in the subfornical organ and in structures anatomically and functionally connected with it. Angiotensin II produced pressor and drinking responses and increased glucose utilization selectively in the subfornical organ and pituitary neural lobe and in no other brain structure. Treatment with the angiotensin II antagonist, sar1-leu8-angiotensin II, before intravenous administration of angiotensin II prevented metabolic stimulation of the subfornical organ and neural lobe. Captopril, an inhibitor of angiotensin-converting enzyme, reduced subfornical organ glucose metabolism to a level similar to that ...
Adsorptive removal of Pb(II) ions from aqueous solution onto a non-activated charcoal (CC) of oak wood origin was studied in comparison with an activated carbon of coal origin. The adsorption capacity for Pb(II) of the non-activated charcoal increased significantly with deceasing particle diameter, whereas the activated carbon (AC) exhibited approximately constant capacity for Pb(II) adsorption as a function of particle size. Adsorption to the ashes prepared from the non-activated charcoal and the activated carbon was also investigated to examine the role of mineral ash. Although the ash from the activated carbon did not show any Pb(II) adsorption, the ash from the charcoal was very effective for Pb(II) adsorption. Furthermore, Pb(II) was hardly adsorbed when the ash was removed from the non-activated charcoal by acid treatment. Based on the results, the ...
The isotherms, kinetics and thermodynamics of Cd(II), Zn(II) and Pb(II) biosorption by Penicillium simplicissimum were investigated in a batch system. The effects of pH, initial metal ions concentration, biomass dose, contact time, temperature and co-ions on the biosorption were studied. Adsorption data were well described by both the Redlich-Peterson and Langmuir model. Chemical ion-exchange was found to be an important process based on free energy value from Dubini-Radushkevich isotherm for all metal ions. The results of the kinetic studies of all metal ions at different temperature showed that the rate of adsorption followed the pseudo second-order kinetics well. The thermodynamics constants {delta}G{sup o}, {delta}H{sup o} and {delta}S{sup o} of the adsorption process showed that biosorption of Cd(II), Zn(II) and Pb(II) ions on Penicillium simplicissimum ...
This paper presents the concept of a biological inspired reconfigurable hardware cell architecture which supports self-organisation and self-healing. Two fundamental processes in biology, namely fertilization-to-birth and cell self-healing have inspired the development of this cell architecture. In biology as well as in our hardware cell architecture it is the DNA which enables these processes. We propose a platform based on the electronic DNA (eDNA) and show through simulation, its capabilities as a new generation of robust reconfigurable hardware platforms. We have created a Java based simulator to simulate our self-organisation and self-healing algorithms and the results obtained from this looks promising.
Swollen basiodiospores of an adenine auxotroph of Phanerochaete chrysosporium were protoplasted with Novozyme 234 and transformed to prototrophy by using a plasmid containing the gene for an adenine biosynthetic enzyme from Schizophyllum commune. Transformation frequencies of 100 transformants per {mu}g of DNA were obtained. Southern blot analysis of DNA extracted from transformants demonstrated that plasmid DNA was integrated into the chromosomal DNA in multiple tandem copies. Analysis of conidia and basiodiospores from transformants demonstrated that the transforming character was mitotically and meiotically stable on both selective and nonselective media. Genetic crosses between double mutants transformed for adenine prototrophy and other auxotrophic strains yielded Ade{sup {minus}} progeny, which indicated that integration occurred at a site(s) other than the resident adenine biosynthetic gene.
Mitochondrial dysfunction has been implicated in premature aging, age-related diseases, and tumor initiation and progression. Alterations of the mitochondrial genome accumulate both in aging tissue...Full Text Available
In an effort to develop octahedral metal complexes as chemotherapeutic and diagnostic agents targeted to DNA, it is critical to optimize the properties of their cellular uptake. Appending d-octaarginine...Full Text Available
High-throughput technologies for DNA sequencing and for analyses of transcriptomes, proteomes and metabolomes have provided the foundations for deciphering the structure, variation and function of the...Full Text Available
The penetrance of Lebers hereditary optic neuropathy (LHON) in families with primary mitochondrial DNA (mtDNA) mutations is very complex. Matrilineal and nuclear genetic background, as well as environmental factors, have been reported to be involved in different affected pedigrees. Here we describe two large Chinese families that show a striking difference in the penetrance of LHON, in which 53.3% and 15.0% of members were affected (Pin vivo mitochondrial oxidative metabolism as described in a previous study. Evolutionary analysis failed to indicate any putatively pathogenic mutation that cosegregated with G11778A in these two pedigrees. Our results suggest that the variable penetrance of LHON in the two Chinese families is independent of both their mtDNA haplotype background and a seconda...
Senescence is regarded as a physiological response of cells to stress, including telomere dysfunction, aberrant oncogenic activation, DNA damage, and oxidative stress. This stress response has an antagonistically...Full Text Available
Polycyclic aromatic hydrocarbons (PAHs) are combustion products of organic materials, mixtures of which contain multiple known and probable human carcinogens. PAHs occur in indoor and outdoor air, as well as in char-broiled meats and fish. Human exposure to PAHs occurs by inhalation, ingestion and topical absorption, and subsequently formed metabolites are either rendered hydrophilic and excreted, or bioactivated and bound to cellular macromolecules. The formation of PAH-DNA adducts (DNA binding products), considered a necessary step in PAH-initiated carcinogenesis, has been widely studied in experimental models and has been documented in human tissues. This review describes immunohistochemistry (IHC) studies, which reveal localization of PAH-DNA adducts in human tissues, and semi-quantify PAH-DNA adduct levels using the Automated Cellular Imaging System (ACIS). These studies have shown that ...
BackgroundSection Calochroi is one of the most species-rich lineages in the genus Cortinarius (Agaricales, Basidiomycota) and is widely distributed...Full Text Available
This paper describes the search for new potential chemotherapeutic agents based on transition metal complexes with planar ligands. In this study, palladium polypyridyl complexes were synthesized and characterized by elemental analysis, NMR, UV-VIS and IR spectroscopies. The interaction of the complexes with DNA was also investigated by spectroscopic methods. All metal-to-ligand charge transfer (MLCT) bands of the palladium polypyridyl complexes exhibited hypochromism and red shift in the presence of DNA. The binding constant and viscosity data suggested that the complexes [PdCl{sub 2}(phen)] and [PdCl{sub 2}(phendiamine)] interact with DNA by electrostatic forces. Additionally, these complexes induced an important leishmanistatic effect on L. (L.) mexicana promastigotes at the final concentration of 10 {mu}mol L{sup -1} in 48 h. (author)
BackgroundGenetic predisposition to scrapie in sheep is associated with several variations in the peptide sequence of the prion protein gene (PRNP). DNA-based tests...Full Text Available
ABSTRACT. Chlorarachniophytes are enigmatic marine unicellular algae that acquired photosynthesis by secondary endosymbiosis. Chlorarachniophytes are unusual in that the nucleus of the engulfed algal cell (a green alga) persists in a miniaturized form, termed a nucleomorph. The nucleomorph genome of the model chlorarachniophyte, Bigelowiella natans CCMP621, is 373 kilobase pairs (kbp) in size, the smallest nuclear genome characterized to date. The B. natans nucleomorph genome is composed of three chromosomes, each with canonical eukaryotic telomeres and sub telomeric ribosomal DNA (rDNA) operons transcribed away from the chromosome end. Here we present the complete rDNA operon and telomeric region from the nucleomorph genome of Lotharella oceanica CCMP622, a newly characterized chlorarachn...
Pork identification in four types of food products, which are sausages and the casings, bread and biscuits, using species-specific polymerase chain reaction (PCR) detection of a conserved region in the mitochondrial (mt) 12S ribosomal RNA (rRNA) gene was developed. Genomic DNA of the food products were successfully extracted except for the casing samples, where no genomic DNA was detected. The extracted genomic DNA was then subjected to PCR amplification targeting the specific regions of the 12S rRNA gene. The genomic DNA from the food products were found to be of good quality and produced clear PCR products on the amplification of 12S rRNA gene of 387 base pairs (bp) from pork species. The species-specific PCR identification yielded excellent results for identification of pork derivatives...
We explored transcriptional responses of the fission yeast Schizosaccharomyces pombe to various environmental stresses. DNA microarrays were used to characterize changes in expression...Full Text Available
Motivation: DNA sequences can be represented by sequences of four symbols, but it is often useful to convert the symbols into real or complex numbers for further analysis. Several mapping...Full Text Available
By assuming that not only counter-ions but DNA molecules as well are thermally distributed according to a Boltzmann law, we propose a modified Poisson-Boltzmann equation, at the classical level, as a starting point to compute the effects of quantum fluctuations of the electric field on the interaction among DNA-cation complexes. The latter are modeled here as infinite one-dimensional wires (?-functions). Our goal is to single out such quantum-vacuum-driven interaction from the counterion-induced and water-related interactions. We obtain a universal, frustration-free Casimir-like (codimension 2) interaction that extensive numerical analysis show to be a good candidate to explain the formation and stability of DNA aggregates. Such Casimir energy is computed for a variety of configurations of...
As adulterated and substituted Chinese medicinal materials are common in the market, therapeutic effectiveness of such materials cannot be guaranteed. Identification at species-, strain- and locality-levels,...Full Text Available
Curcumin, the yellow pigment from the rhizoma of Curcuma longa, is a widely studied phytochemical with a variety of biological activities. The ongoing research and clinical trials have proved that this natural phenolic compound has great and diverse pharmacological potencies. Beside its effective antioxidant, antiinflammatory, and antimicrobial/antiviral properties, curcumin is also considered as a cancer chemopreventive agent. While the antioxidant activity of curcumin is well documented, its interaction with DNA and RNA is not fully investigated. This study was designed to examine the interactions of curcumin with calf thymus DNA and yeast RNA in aqueous solution at physiological conditions, using constant DNA and RNA concentration (6.25?mM) and various curcumin/polynucleotide (phosphate...
Cytophotometric measurements of DNA content after Feulgen's reaction and autoradiography after incubation with "3H-thymidine were performed to investigate the early stages of development of yellow lupin root nodule. The first response of the host plant to the contact with Rhizobium lupini was the enhancement of nuclear DNA endoreplication in root cortex cells. A conversion of the initially mixoploid nodule meristem into a diploid one during root nodule formation was found. Differentiation of bacteroid-containing tissue both from diploid and polyploid cells was observed. The highest content of nuclear DNA in the uninfected root cortex, nodule cortex and in bacteroid-containing tissue was 16 C. (author).
... The thermostable Thermus aquaticus DNA polymerase, (Taq pol), in the presence of excess deoxynucleoside triphosphates (dNTPs), including deoxyadenosine ...
Adenine DNA glycosylase catalyzes the glycolytic removal of adenine from the promutagenic A {center_dot} oxoG base pair in DNA. The general features of DNA recognition by an adenine DNA glycosylase, Bacillus stearothermophilus MutY, have previously been revealed via the X-ray structure of a catalytically inactive mutant protein bound to an A:oxoG-containing DNA duplex. Although the structure revealed the substrate adenine to be, as expected, extruded from the DNA helix and inserted into an extrahelical active site pocket on the enzyme, the substrate adenine engaged in no direct contacts with active site residues. This feature was paradoxical, because other glycosylases have been observed to engage their substrates primarily through direct contacts. The lack of direct contacts in the case of MutY suggested that either MutY uses a distinctive logic for substrate ...
Several scientists have proposed that DNA repair deficiencies and the induction of a mutator phenotype are responsible for the generation of multiple mutagenic alterations in cancer cells. I propose...Full Text Available
A set of computer programs is described which constitutes a clone database management system. Maintenance of the database and the stocks of material is designed to be under the control of one person...Full Text Available
Hypoxia causes abnormal neonatal pulmonary artery remodeling (PAR) and inhibition of alveolar development (IAD). Transforming growth factor (TGF)-β is an important regulator of lung development...Full Text Available
The inhibition of DDT [1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane] dehydrochlorinase and glutathione S-aryltransferase by diphenylmethane and triphenylmethane...Full Text Available
1. Several ring-substituted derivatives of diphenyleneiodonium catalyse the exchange of Cl- and OH- ions across the inner membrane of rat liver mitochondria. They also inhibit state 3 and state 3u oxidations...Full Text Available
Mineral oil based power transmitting fluids, such as automatic transmission fluids, are disclosed which contain 0.05 to 2.0 weight percent of an ester of a thio-bis alkanol and a C/sub 12/-C/sub 50/ hydrocarbon succinic acid or anhydride, the ester being a multifunctional additive providing the properties of friction modification, corrosion inhibition, anti-wear, oxidation inhibition and extreme pressure properties to the fluids.
Detached first leaves of 3-day-old corn seedlings (Zea mays L. W64AxW183E) were incubated with nitrate in air or 100% O2 in the light. Nitrate accumulation in the leaves...Full Text Available
NH4+inhibition kinetics for CH4 oxidation were examined at near-atmospheric CH4 concentrations in three upland forest soils. Whether NH4+-independent...Full Text Available
We have shown previously that raising extracellular Ca2+ inhibited the apical 70-pS K channel in the thick ascending limb (TAL; Wang, W.H., M. Lu, and S.C. Hebert. 1996. Am....Full Text Available
ObjectivesThe aim of this study was to comprehensively evaluate the antibacterial activity and MurE inhibition of a set of N-methyl-2-alkenyl-4-quinolones found...Full Text Available
Roots of maize (Zea mays L.) seedlings continue to grow at low water potentials that cause complete inhibition of shoot growth. In this study, we have investigated the role of abscisic...Full Text Available
The effect of WC particle size with the addition of VC as a grain growth inhibitor was investigated during the liquid phase sintering of WC-Co system. With increasing WC particle size at the same VC content, the effect of grain growth inhibition was increased. Also, with increasing the VC content, the grain shape of WC was changed from the faceted shape to the distorted shape, and the step density of the WC grain was increased. (orig.)
The addition of 0.0005-0.5 weight% linoleic acid trimer to synthetic motor fuels composed of 95.0-99.8% technical-grade alcohol (EtOH or MeOH) and 0.2-5.0% water inhibits the corrosion induced by the impurities, such as aliphatic acids 0.5-10.0, aliphatic aldehydes 0.5-10.0, and aliphatic esters 0.5-10 mg/100 ml alcohol.
The authors investigated the effect of T-2 toxin on rat liver mitochondrial protein synthesis. Isolated rat liver mitochondria were supplemented with an S-100 supernatant from rat liver and an external ATP-generating system. An in-vitro assay employing cycloheximide, and inhibitor of cytoplasmic protein synthesis, and chloramphenicol, and inhibitor of mitochondrial protein synthesis, to distinguish mitochondrial protein synthesis from the cytoplasmic process. Amino acid incorporation into mitochondria was dependent on the concentration of mitochondria and was inhibited by chloramphenicol. The rate of uptake of tritium leucine into mitochondrial protein was unaffected by the addition of T-2 toxin and was not a rate-limiting step in incorporation. However, 0.02 micrograms/ml of T-2 toxin decreased the rate of protein synthesis inhibition correlated with the amount of T-2 toxin taken up by the mitochondria. While T-2 toxin is known to ...
Probiotic agents, live microorganisms with beneficial effects for the host, may offer an alternative to conventional antimicrobials in the treatment and prevention of enteric infections. The probiotic agents Lactobacillus plantarum 299v and Lactobacillus rhamnosus GG quantitatively inhibited the adherence of an attaching and effacing pathogenic Escherichia coli to HT-29 intestinal epithelial cells but did not inhibit adherence to nonintestinal HEp-2 cells. HT-29 cells were grown under conditions that induced high levels of either MUC2 or MUC3 mRNA, but HEp-2 cells expressed only minimal levels of MUC2 and no MUC3 mRNA. Media enriched for MUC2 and MUC3 mucin were added exogenously to binding assays and were shown to be capable of inhibiting enteropathogen adherence to HEp-2 cells. Incubation of L. plantarum 299v with HT-29 cells increased MUC2 and MUC3 mRNA expression levels. From these in vitro studies, we propose the ...
A laboratory-scale well-mixed thermostatic reactor with continuously blasting air was used to investigate the oxidation inhibition of sulfite in dual alkali flue gas desulfurization (FGD) system. The effects of operating parameters such as pH value and catalyst concentration on the oxidation were studied. Sodium thiosulfate was used in the system, and was found that it significantly inhabited the sulfite oxidation. In the absence of catalyst, sodium thiosulfate at 12.67 mmol/L had an inhibition efficiency of approximately 98%. While in the presence of catalyst, sodium thiosulfate at 26.72 mmol/L had an inhibition efficiency less than 85.0%. The oxidation reaction order of sulfite in the sodium thiosulfate was determined to be -1.90 and -0.55 in the absence and presence of the catalyst, respectively. Apparent activation energy of oxidation inhibition was calculated to be 53.9 kJ/mol. Pilot tests showed ...
An exact cosmological solution of Einstein's equations which has time-dependent rotation is presented. The t-constant sections are of Bianchi type II. The source of this geometry is a fluid which has not been thermalized. (Author).
Exposure of albumin to Cu(II) (10-100 microM) and ascorbate (0.1-2 mM) results in extensive molecular modifications, indicated by decreased fluorescence and chain breaks. The rate of utilization of...Full Text Available
ObjectivesThe updated Rome III criteria for pediatric functional gastrointestinal disorders (FGIDs) include new FGID categories and changes to the Rome II criteria...Full Text Available
Interleukin 2 (IL-2) and B-cell growth factors I and II (BCGF I and BCGF II) are lymphokines produced by T cells that play a major role in T- and B-cell cooperation. Peripheral blood lymphocytes from...Full Text Available
In this article are presented main results on electric potential investigations in stellarator/torsatron TJ-II and tokamak T-10 in a comparable regimes of device operation.
Aminopeptidase II, one of the two major aminopeptidases in the giant alga Chara australis, was partially purified. Its molecular weight was estimated to be about 80,000 by gel permeation...Full Text Available
New palladium(II) and platinum(II) complexes of saccharinate (sac), trans-[Pd(py)"2(sac)"2] (1), cis-[Pt(py)"2(sac)"2] (2), trans-[Pd(3-acpy)"2(sac)"2] (3) and cis-[Pt(3-acpy)"2(sac)"2] (4) (py=pyridine and 3-acpy=3-acetylpyridine) have been synthesized. Elemental analysis, UV-Vis, IR, NMR and TG/DTA characterizations have been carried out. The structures of 1-4 were determined by X-ray diffraction. The palladium(II) and platinum(II) ions are coordinated by two N-bonded sac ligands, and two nitrogen atoms of py or 3-acpy, forming a distorted square-planar geometry. The palladium(II) complexes (1 and 3) are trans isomers, while the platinum(II) complexes (2 and 4) are cis isomers. The mononuclear species in the solid state are connected by weak intermolecular C-H...O hydrogen bonds, C-H...@...
BackgroundThe binding of peptide fragments of antigens to class II MHC is a crucial step in initiating a helper T cell immune response. The identification of such peptide epitopes...Full Text Available
The aim of this article was to investigate the interactions of metal cations in aqueous solutions with the biomass of the freshwater macroalga Vaucheria sp. This problem is important when elaborating new applications of biosorption, e.g. the production of mineral feed additives for livestock from the biomass of algae enriched with microelement ions. Potentiometric titration was applied as a quick and cheap screening test to search for new efficient biosorbents. It revealed a variety of functional groups capable of cation exchange on the macroalgal surface, including carboxyl, phosphate, hydroxyl or amino groups. Fourier transform infrared spectroscopy on natural and chromium-loaded Vaucheria sp. confirmed that carboxyl groups played a dominant role in the biosorption. The study also showed that Ca(II), Na(I), K(I), and Mg(II) ions were released from the biomass after biosorption of Cu(II), Mn(II), ...
BackgroundPromoter region plays an important role in determining where the transcription of a particular gene should be initiated. Computational prediction of eukaryotic Pol II promoter...Full Text Available
Rotazyme II, which is a shorter version of Rotazyme (less than 3 h), was compared with electron microscopy and Rotazyme for sensitivity and specificity on 229 human stool specimens. Compared with electron...Full Text Available
The biosorption of lead (II) and copper (II) ions, single component and binary systems, by dried P. putida was investigated in a batch system. The effects of initial pH, temperature, initial single and binary mixture concentrations on the biosorption kinetics and equilibrium uptake of each component, both single and binary mixtures were investigated. The bacterial biomass exhibited the highest single and binary lead (II) and copper (II) ions uptake capacity at 25 and 30 deg. C, respectively, the initial pH value of 5.5 and at the initial metal ions concentration of 100 mg dm{sup -3}. The Freundlich and Langmuir adsorption models were used for the mathematical description of the biosorption equilibrium and isotherm constants were evaluated at different temperatures. Adsorption data were well described by the Langmuir model, although they could be modeled by the Freundlich equation. The thermodynamics ...
BackgroundPerfluorocarbons (PFC) are used to improve gas exchange in diseased lungs. PFC have been shown to affect various cell types. Thus, effects on alveolar type II (ATII) cells...Full Text Available
ATP-binding cassette A3 (ABCA3) is a lipid transport protein required for synthesis and storage of pulmonary surfactant in type II cells in the alveoli. Abca3 was conditionally deleted...Full Text Available
Cytokinesis in animal and fungal cells utilizes a contractile actomyosin ring (AMR). However, how myosin II is targeted to the division site and promotes AMR assembly, and how the AMR coordinates with...Full Text Available
Anaerobic reactions of Rhus vernicifera laccase and its type-2 copper-depleted derivatives with hexacyanoferrate(II) were investigated by absorption and e.s.r. spectroscopy. When native laccase was...Full Text Available
Photobilirubin II, a stereoisomer of bilirubin, binds to human serum albumin at a single binding site (K = 2.2 x 10(6)M-1), presumably the high-affinity bilirubin-binding site. Binding in the secondary...Full Text Available
The identification of MHC class II restricted peptide epitopes is an important goal in immunological research. A number of computational tools have been developed for this purpose, but there is a lack...Full Text Available
ii) Flammability: (iii) A capacity to oxidise: (iv) Corrosiveness: (v) Toxicity (including chronic ...an explosion or fire: (d) For substances with corrosive properties: (i) To reduce the ...likelihood of any unintended corrosion:(ii) To control the adverse effects of any corrosion:
A {lambda}gt11 cDNA library was constructed from poly(U)-Spharose-selected Entamoeba histolytica trophozoite RNA in order to clone and identify surface antigens. The library was screened with rabbit polyclonal anti-E. histolytica serum. A 700-base-pair cDNA insert was isolated and the nucleotide sequence was determined. The deduced amino acid sequence of the cDNA revealed a cysteine-rich protein. DNA hybridizations showed that the gene was specific to E. histolytica since the cDNA probe reacted with DNA from four axenic strains of E. histolytica but did not react with DNA from Entamoeba invadens, Acanthamoeba castellanii, or Trichomonas vaginalis. The insert was subcloned into the expression vector pGEX-1 and the protein was expressed as a fusion with the C terminus of glutathione S-transferase. Purified fusion protein was used to generate ...
A #lambda#gt11 cDNA library was constructed from poly(U)-Spharose-selected Entamoeba histolytica trophozoite RNA in order to clone and identify surface antigens. The library was screened with rabbit polyclonal anti-E. histolytica serum. A 700-base-pair cDNA insert was isolated and the nucleotide sequence was determined. The deduced amino acid sequence of the cDNA revealed a cysteine-rich protein. DNA hybridizations showed that the gene was specific to E. histolytica since the cDNA probe reacted with DNA from four axenic strains of E. histolytica but did not react with DNA from Entamoeba invadens, Acanthamoeba castellanii, or Trichomonas vaginalis. The insert was subcloned into the expression vector pGEX-1 and the protein was expressed as a fusion with the C terminus of glutathione S-transferase. Purified fusion protein was used to generate ...
To analyze the proposed growth-inhibitory function of wild-type p53, we compared simian virus 40 (SV40) DNA replication in primary rhesus monkey kidney (PRK) cells, which express wild-type p53, and...Full Text Available
BackgroundThe Mre11/Rad50/Nbs1 (MRN) complex is a regulator of cell cycle checkpoints and DNA repair. Defects in MRN can lead to defective S-phase arrest when cells are damaged....Full Text Available
Transcription for a hybrid SV40 promoter-beta globin coding sequence recombinant initiates from both early-early (EE) and late-early (LE) SV40 start sites (EES and LES) in the absence of DNA replication....Full Text Available
The role of the HCR system in the repair of prelethal lesions induced by UV light, #gamma# radiation and alkylating agents was studied in the Bacillus subtilis SPP1 phage, its heat sensitive mutants (N3, N73 nad ts_1) and corresponding infectious DNA. The survival of phages and their transfecting DNA after treatment with UV light is substantially higher in hcr"+ cells than in hcr cells, the differences being more striking in intact phages than in their transfecting DNA's. Repair inhibitors reduce survival in hcr"+ cells: caffeine lowers the survival of UV-irradiated phage SPP1 in exponentially growing hcr"+ cells but has no effect on its survival in competent hcr"+ cells; acriflavin and ethidium bromide decrease the survival of the UV-irradiated SPP1 phage in both exponentially growing and competent hcr"+ cells to the level of survival observed in hcr cells; moreover, ethidium bromide lowers the number of infective centres ...
Nucleotide pool sanitizing enzymes Dut (dUTPase), RdgB (dITPase), and MutT (8-oxo-dGTPase) of Escherichia coli hydrolyze noncanonical DNA precursors to prevent incorporation of base...Full Text Available
We have isolated and sequenced cDNA clones encoding the human U1-70K snRNP protein, and have mapped this locus (U1AP1) to human chromosome 19. The gene produces two size classes of RNA, a major 1.7-kb...Full Text Available
Previous studies using in vitro cell culture systems have shown the role of the dynamin-related GTPase Opa1 in apoptosis prevention and mitochondrial DNA (mtDNA) maintenance. However, it remains to...Full Text Available
A recombinant M13 clone (O42) containing a 65 b.p. cDNA fragment from human fetal liver mRNA coding for glyceraldehyde-3-phosphate dehydrogenase has been identified and it has been used to isolate from...Full Text Available
The feasibility of performing a multiplex assay for the detection of human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) RNAs and hepatitis B virus (HBV) DNA is demonstrated. This...Full Text Available
The histone chaperone Asf1 and the chromatin remodeler SWI/SNF have been separately implicated in derepression of the DNA damage response (DDR) genes in yeast cells treated with genotoxins that cause...Full Text Available
This short survey focuses on the main radiation-induced base lesions that have been identified within cellular DNA. For this purpose, sensitive assays that are aimed at measuring a few modifications per 10{sup 7} normal bases were set-up. In that respect high performance liquid chromatography - tandem mass spectrometry (CLHP-MS/MS) was found to be able to single out the formation of 9 oxidized nucleosides and two modified nucleo-bases out of the 70 oxidative base lesions that have been identified in model systems. As a striking result, it was found that in the DNA of {gamma}-irradiated human monocytes, the formamide-pyrimidine derivative of guanine is produced in a higher yield than the ubiquitous 8-oxo-7,8-dihydro-guanine damage, both arising from the same radical precursor. However, relatively high doses of ionizing radiation (> 20 Gy) have to be applied in order to detect an increase in the level of the damage. This is due to the low ...
By using a low-resolution macrorestriction map as the foundation (R. Majumder et al., J. Bacteriol. 176:1105–1112, 1996), an ordered cloned DNA map of the 3.2-Mb chromosome of the hypertoxinogenic...Full Text Available
A 13.1-kb DNA fragment carrying Pseudomonas denitrificans cob genes has been sequenced. The nucleotide sequence and genetic analysis revealed that this fragment contained five different cob genes named...Full Text Available
This report describes our initial attempts at the molecular characterization of a maize controlling element. We have prepared a cDNA probe and used it to detect changes at a locus where Ds elements are found. Evidence of their presence are indicated by changes in the restriction patterns, but there is as yet no information on the physical nature of the controlling elements nor on the kinds of rearrangements they cause.
An Escherichia coli B strain, B834 galU56, has been isolated which supports growth of bacteriophage T4 with cytosine in its DNA while restricting growth of T4 with hydroxymethylcytosine. This host is...Full Text Available
The nucleotide sequence of the 5'-terminal oligonucleotides produced by pancreatic RNase digestion of bacteriophage T3 RNA polymerase (EC 2.7.7.6) transcripts of T3 DNA has been determined. The sequence...Full Text Available
We report the 1.1-Å resolution crystal structure of a bulky rhodium complex bound to two different DNA sites, mismatched and matched in the oligonucleotide 5′-(dCGGAAATTCCCG)2-3′....Full Text Available
The detection and quantification of defined reaction products of chemical mutagens and carcinogens (and of many cancer chemotherapeutic agents) with DNA require highly sensitive analytical techniques. The exceptional capability of immunoglobulins to recognize subtle alterations of molecular structure (especially when monoclonal antibodies are used to maximize specificity), outstanding sensitivity of immunoanalysis by high-affinity antibodies, and the fact that radioactively-labelled agents are not required suggest the utility of a radioimmunoassay to recognize and quantitate alkylated DNA products. We have recently developed a set of high-affinity monoclonal antibodies (secreted by mouse x mouse as well as by rat x rat hybridomas; antibody affinity constants, 10"9 to > 10"1"0 lmol) specifically directed against several DNA alkylation products with possible relevance in relation to both mutagenesis and malignant ...
We have isolated a human thrombomodulin cDNA, and a human genomic clone containing the putative promoter domain, as well as the translated and untranslated regions of the endothelial cell receptor....Full Text Available
Oxidized DNA bases, particularly 7,8-dihydro-8-oxoguanine (8-oxoG), are endogenously generated in cells, being a cause of carcinogenic mutations and possibly interfering with gene expression. We found...Full Text Available
Two integrated hepatitis B virus (HBV) DNA molecules were cloned from two primary hepatocellular carcinomas each containing only a single integration. One integration (C3) contained a single linear...Full Text Available
...Explore - The Lab - Australian Broadcasting Corporation's Gateway to Science Radio TV Shop News Sport Local Children Science Environment more Topics help Science Home News in Science Features Explore TV & Radio Dr Karl Play Podcasts DNA - The discovery of the double helix structure of DNA completely changed biology and opened up the new field of genetics. The 'backbone of life' has given us the human genome, stem cell research, ...
The endogenous reverse transcriptase reaction of equine infectious anemia virus (EIAV) has been studied, and conditions allowing synthesis of full-length minus-strand DNA have been determined. In contrast...Full Text Available
We report that expression of a nearly full-length cDNA clone of the L-A double-stranded RNA virus causes virus loss in a wild-type strain of Saccharomyces cerevisiae. We show that in this system exclusion...Full Text Available
BackgroundInfertility affects ∼20% of couples in Europe and in 50% of cases the problem lies with the male partner. The impact of damaged DNA originating...Full Text Available
One of the first technical applications of gene technology is reported here. The DNA of E. coli cells was rearranged such that these cells produce large quantities of the enzyme ..cap alpha..-galactosidase. This enzyme is used to split the trisaccharide, raffinose, which is formed during the production of sugar from sugar beet. By this means sugar yields can be increased and the energy required for sugar crystallisation reduced.
The DNA double-strand break (DSB) damage response induced by high energy charged particles on lung fibroblast cells embedded in a 3-dimensional (3-D) collagen tissue equivalents was investigated using antibodies to the DNA damage response proteins gamma-histone 2AX (#gamma#-H2AX) and phosphorylated DNA-PKcs (p-DNA-PKcs). 3-D tissue equivalents were irradiated in positions across the linear distribution of the Bragg curve profiles of 307.7 MeV/nucleon, 556.9 MeV/nucleon, or 967.0 MeV/nucleon "5"6Fe ions at a dose of 0.30 Gy. Patterns of discrete DNA damage streaks across nuclei or saturated nuclear damage were observed, with saturated nuclear damage being more predominant as samples were positioned closer to the physical Bragg peak. Quantification of the DNA damage signal intensities at each distance for each of the examined energies revealed a biological Bragg ...
32P-Postlabeling analysis and enzyme-linked immunosorbent assay (ELISA) have been used to detect DNA adducts in peripheral blood lymphocytes from primary aluminum production plant workers who were exposed...Full Text Available
We have compared the kinetics for repair of UV-induced cyclobutane pyrimidine dimers in the DNA of keratinocytes in human skin and in cell culture. A small area of the buttocks of volunteers was exposed to UVB-irradiation and biopsies were taken at various time intervals. Epidermal keratinocytes in culture from the same subjects were exposed to UVC with doses chosen to elicit comparable yields of dimers in cellular DNA. The initial density of pyrimidine dimers and the kinetics of their removal were assessed utilizing the dimer-specific T4 endonuclease V and sedimentation of the unlabeled DNA through alkaline sucrose gradients. The position of DNA in the gradients was determined using a monoclonal antibody against random sequences of single-stranded DNA in a sensitive immunoassay. The initial dimer frequency was 3.9-6.7 per 10(8) daltons DNA. About 40% of the ...
We have compared the kinetics for repair of UV-induced cyclobutane pyrimidine dimers in the DNA of keratinocytes in human skin and in cell culture. A small area of the buttocks of volunteers was exposed to UVB-irradiation and biopsies were taken at various time intervals. Epidermal keratinocytes in culture from the same subjects were exposed to UVC with doses chosen to elicit comparable yields of dimers in cellular DNA. The initial density of pyrimidine dimers and the kinetics of their removal were assessed utilizing the dimer-specific T4 endonuclease V and sedimentation of the unlabeled DNA through alkaline sucrose gradients. The position of DNA in the gradients was determined using a monoclonal antibody against random sequences of single-stranded DNA in a sensitive immunoassay. The initial dimer frequency was 3.9-6.7 per 10(8) daltons DNA. About 40% of the ...
We have identified a plasmid-like element within mitochondria of Neurospora crassa strain stp-B1. It is derived from the EcoRI-4 and EcoRI-6 regions of the mitochondrial DNA, and an additional 124 bp...Full Text Available
HMGA2 is a DNA minor-groove binding protein. We previously demonstrated that HMGA2 binds to AT-rich DNA with very high binding affinity where the binding of HMGA2 to poly(dA-dT)2 is enthalpy-driven...Full Text Available
The DNA-binding properties of Ru(bpy)2(eilatin)2+ have been investigated to determine if the sterically expansive eilatin ligand confers specificity for destabilized single-base...Full Text Available
Alkylation of DNA by 7r,8t-dihydroxy,9t,10t-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (anti-BPDE) forms mainly trans adducts (with respect to the C-9/10...Full Text Available
The structure of unintegrated human immunodeficiency virus type 1 (HIV-1) DNA from acutely infected human lymphoid cells was analyzed by nuclease S1 cleavage. We observed a unique, discrete single-stranded...Full Text Available
... Screening Adjudication Monitoring Applicants of Information Behavior II I Conducting Investigations ... Applicants of Information Behavior Conducting ...
Titanate nanotubes were hydrothermally synthesized and their adsorption performances for lead(II) ion removal were studied. The results showed that titanate nanotubes ruptured in the adsorption process resulting in two distinct adsorption stages, thus achieving a maximum adsorption capacity of 3.752mmolg^-^1 of lead(II). Furthermore, it was found that the regeneration of titanate nanotubes loaded with the lead(II) ions can be readily achieved using the saturated EDTA disodium salt aqueous solution, thereby avoiding the trouble of disposal of adsorbent. The adsorption mechanism was also discussed in detail.
The interaction between N-donor adsorbates such as ammonia and pyridine with Cu(II)-exchanged montmorillonite, beidellite, flourohectorite into smectite clays has been studied by electron spin resonance. Cu(II) cations exchanged into smectites coordinate five ammonia or pyridine molecules in beidellite, four ammonia of pyridine molecules in hydroxyhectorite. Thus, the Cu(II) cations bound to the interior surfaces of these smectite clays constitute strong Lewis acid sites. 26 refs., 7 figs., 1 tab.
Yeast artificial chromosome (YAC) libraries have been difficult to construct with average insert sizes >400 kilobase pairs when DNA is size-fractionated in low-melting-point agarose. By using yeast chromosomes in mock cloning experiments, the authors found that polyamines should be present whenever agarose containing high molecular weight DNA is melted to protect DNA from degradation. By incorporating polyamines during the cloning procedure, they constructed YAC libraries from mouse and human DNA with average insert sizes of 700 and 620 kilobase pairs, respectively. Several genome equivalents of these YAC libraries were replicated onto the surface of many duplicate agar plates using a 40,000 multipin transfer device. High-density filter replicas were screened by hybridization, and 70 mouse YAC clones from 31 loci and 132 human YAC clones from 49 loci were isolated.
Specific {sup 32}P-labeled DNA probes were prepared and used to evaluate the distribution of tetracycline resistance determinants carried by gram-negative enteric bacteria isolated from pigs in 3 swine herds with different histories of antibiotic exposure. Plasmid DNA, ranging in size from 2.1 to 186 Kb, was observed in over 84% of 114 isolates studied. Two of 78 tetracycline resistant strains did not harbor plasmids. The DNA probes were isolated from plasmids pSL18, pRT29/Tn10, pBR322 and pSL106, respectively, and they represented class A, B, C and D tetracycline resistance determinants. Hybridization conditions using 0.5X SSPE at 65{degrees}C minimize cross-hybridization between the different class of tetracycline resistance genes. Cross-hybridization between class A and class C determinants could be distinguished by simultaneous comparison of the intensity of their hybridization signals. Plasmids from over 44% of the ...
Fetal nucleated cells within maternal blood represent a potential source of fetal genes obtainable by venipuncture. The authors used monoclonal antibody against the transferrin receptor (TIR) to identify nucleated erythrocytes in the peripheral blood of pregnant women. Candidate fetal cells from 19 pregnancies were isolated by flow sorting at 12 1/2-17 weeks gestation. The DNA in these cells was amplified for a 222-base-pair (bp) sequence present on the short arm of the Y chromosome as proof that the cells were derived from the fetus. The amplified DNA was compared with standardized DNA concentrations. In the case of the female fetus, DNA prepared from samples at 32 weeks of gestation and cord blood at delivery also showed the presence of the Y chromosomal sequence, suggesting Y sequence mosaicism or translocation. In 10/12 cases where the 222-bp band was absent, the fetuses were female. Thus, they were ...
We report the of the existence of RV Tauri stars in the Large Magellanic Cloud (LMC). This class of variable star has hitherto been unidentified in the Magellanic Clouds. In light and color curve behavior the RV Tauri stars appear to be an extension of the Type II Cepheids to longer periods. A single period-luminosity-color relationship is seen to describe both the Type II Cepheids and the RV Tauri stars in the LMC.
Incorporation of /sup 32/P from (gamma-32P)ATP into tyrosine residues of the insulin-like growth factor (IGF)-II receptor was observed in a Triton X-100-insoluble fraction of rat adipocyte plasma membranes. IGF-II receptor phosphorylation proceeded to a stoichiometry of approximately 0.5 mol of phosphate/IGF-II binding site after 10 min of incubation at 4 degrees C. A Km for ATP of 6 microM was calculated for this phosphorylation reaction. Addition of IGF-II caused an approximately 2-fold increase in tyrosine phosphorylation of the IGF-II receptor in this preparation. In contrast, phosphorylation of angiotensin II by the Triton X-100 washed membranes was not stimulated by IGF-II. Incubation of purified receptor immobilized on IGF-II agarose or of receptor-enriched low density microsomal membranes with (gamma-32P)ATP did ...
Fragrance mix II (FM II) is a relatively new screening marker for fragrance contact allergy. It was introduced in the patch test baseline series in Denmark in 2005 and contains six different fragrance chemicals commonly present in cosmetic products and which are known allergens.
Fatty acid biosynthesis is crucial for all living cells. In contrast to higher organisms, bacteria use a type II fatty acid synthase (FAS II) composed of a series of individual proteins, making...Full Text Available
Some acylhydrazine derived ONO donor Schiff bases and their Co(II) and Ni(II) complexes have been prepared having the same metal ion (cation) but different anions. These synthesized metal(II) complexes have been characterized on the basis of their elemental analyses, magnetic moment, molar conductance, and IR and electronic spectral data. All of the Schiff base ligands function as tridentates and the deprotonated enolic form is preferred for coordination. In order to evaluate the effect of anions on the bactericidal activity, these synthesized complexes, in comparison to the uncomplexed Schiff bases have been screened against bacterial species., Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and the results are reported. PMID:18475936
High-temperature LiCl-KCl molten salt medium provides an efficient way to produce the paramagnetic Eu(II) ion to be magnetically diluted into a diamagnetic host medium. Eu(II) was formed by a dissolution and an auto-reduction processes in a high-temperature LiCl-KCl eutectic melt at 723 K by using Eu{sub 2}O{sub 3} as a starting material. By using EPR and luminescence spectroscopic method, we studied the nature of the magnetically isolated paramagnetic Eu(II) ion diluted in a LiCl-KCl medium. With the aid of these spectroscopic tools, it was found that stable Eu(II) species was formed spontaneously at 723 K under anaerobic conditions. EPR and luminescence spectroscopy provided detailed information regarding the nature of the europium ion in a molten salt.
High-temperature LiCl-KCl molten salt medium provides an efficient way to produce the paramagnetic Eu(II) ion to be magnetically diluted into a diamagnetic host medium. Eu(II) was formed by a dissolution and an auto-reduction processes in a high-temperature LiCl-KCl eutectic melt at 723 K by using Eu_2O_3 as a starting material. By using EPR and luminescence spectroscopic method, we studied the nature of the magnetically isolated paramagnetic Eu(II) ion diluted in a LiCl-KCl medium. With the aid of these spectroscopic tools, it was found that stable Eu(II) species was formed spontaneously at 723 K under anaerobic conditions. EPR and luminescence spectroscopy provided detailed information regarding the nature of the europium ion in a molten salt.
High-temperature LiCl-KCl molten salt medium provides an efficient way to produce the paramagnetic Eu(II) ion to be magnetically diluted into a diamagnetic host medium. Eu(II) was formed by a dissolution and an auto-reduction processes in a high-temperature LiCl-KCl eutectic melt at 723K by using Eu2O3 as a starting material. By using EPR and luminescence spectroscopic method, we studied the nature of the magnetically isolated paramagnetic Eu(II) ion diluted in a LiCl-KCl medium. With the aid of these spectroscopic tools, it was found that stable Eu(II) species was formed spontaneously at 723K under anaerobic conditions. EPR and luminescence spectroscopy provided detailed information regarding the nature of the europium ion in a molten salt.
In this study we compared various maturity dependent aromatic, steroid and triterpenoid hydrocarbon ratios in bitumens that are freely extractable from sedimentary rocks (Bitumen I) with those in second extracts that comprised hydrocarbons closely associated with the kerogen/mineral matrix (Bitumen II). Bitumen II was released through kerogen isolation and demineralisation using HCl and HF/H3BO3. The samples studied, although of similar age, come from different localities. They represent a range of facies and two kerogen types (II and III), and all were deposited under marine conditions. The results show that the more stable b isomers of methylnaphthalene (MN) and methylphenanthrene (MP) are relatively more abundant in Bitumen II. The difference between the methylnaphthalene ratio (MNR) of...
In this study, the biosorption of Cd(II), Ni(II) and Pb(II) on Aspergillus niger in a batch system was investigated, and optimal condition determined by means of central composite design (CCD) under response surface methodology (RSM). Biomass inactivated by heat and pretreated by alkali solution was used in the determination of optimal conditions. The effect of initial solution pH, biomass dose and initial ion concentration on the removal efficiency of metal ions by A. niger was optimized using a design of experiment (DOE) method. Experimental results indicated that the optimal conditions for biosorption were 5.22 g/L, 89.93 mg/L and 6.01 for biomass dose, initial ion concentration and solution pH, respectively. Enhancement of metal biosorption capacity of the dried biomass by pretreatment with sodium hydroxide was observed. Maximal removal efficiencies for Cd(II), Ni(III) and ...
The radiation reduction of bis(1-ethylimidazole)tartratoplatinum(II) (EITPt(II)) complexes in methanol-water solution have been examined. The yields of Pt(I) depend on the presence of O{sub 2} in solutions as well as the dose applied. The rate constants of e{sub s}{sup -} scavenging by EITPt(II) and cis(diammine-1,1-cyclobutanedicarboxylato) platinum(II) (CBDCAPt(II)) have been determined by pulse radiolysis to be equal to 5.4 x 10{sup 9} and 6.4 x 10{sup 9} M{sup -1} s{sup -1}, respectively. The efficiencies of e{sub t}{sup -} scavenging by EITPt(II) and the rate of e{sub t}{sup -} photobleaching have also been determined in LiCl : H{sub 2}O : CH{sub 3}OH and MgCl{sub 2} : H{sub 2}O : CH{sub 3}OH glasses, respectively. (author).
A cDNA library was constructed using RNA isolated from the livers of chickens which had been treated with zinc. This library was screened with a RNA probe complementary to mouse metallothionein-I (MT), and eight chicken MT cDNA clones were obtained. All of the cDNA clones contained nucleotide sequences homologous to regions of the longest (375 bp) cDNA clone. The latter contained an open reading frame of 189 bp, and the deduced amino acid sequence indicates a protein of 63 amino acids of which 20 are cysteine residues. Amino acid composition and partial amino acid sequence analyses of purified chicken MT protein agreed with the amino acid composition and sequence deduced from the cloned cDNA. Amino acid sequence comparison establish that chicken MT shares extensive homology with mammalian MTs. Southern blot analysis of chicken DNA indicates that the chicken MT ...
It was the aim of this study to specifically detect the DNA sequences for the bphC gene, the meta-cleavage enzyme of the aerobic catabolic pathway for biphenyl and polychlorinated biphenyl degradation, in aquatic sediments without prior cultivation of microorganisms by using extraction of total DNA, PCR amplification of bphC sequences, and detection with specific gene probes. The direct DNA extraction protocol used was modified to enhance lysis efficiency. Crude extracts of DNA were further purified by gel filtration, which yielded DNA that could be used for the PCR. PCR primers were designed for conserved regions of the bphC gene from a sequence alignment of five known sequences. The specificity of PCR amplification was verified by using digoxigenin-labeled DNA probes which were located internal to the amplified gene sequence. The detection limit for the bphC ...
The Drosophila sequence-specific DNA binding protein, Adf-1, is capable of activating transcription of the alcohol dehydrogenase gene, Adh, and is implicated in the transcriptional control of other developmentally regulated genes. We have cloned the cDNA encoding Adf-1 by generating specific DNA probes deduced from partial amino acid sequence of the protein. Several cDNA clones encoding an extended open reading frame were isolated from a phage lambda library. The complete amino acid sequence of Adf-1 deduced from the longest cDNA reveals structural similarities to the putative helix-turn-helix DNA binding motif of Myb and Myb-related proteins. DNA sequence analysis of genomic clones and Northern blot analysis of mRNA suggest that Adf-1 is a single-copy gene encoding a 1.9-kb transcript. Purified recombinant Adf-1 expressed in Escherichia ...
The DNA sequence motif ATTTGCAT (octamer) or its inverse complement has been identified as an evolutionarily conserved element in the promoter region of immunoglobulin genes. Two major DNA-binding proteins that bind in a sequence-specific manner to the octamer DNA sequence have been identified in mammalian species--a ubiquitously expressed protein (Oct-1) and a lymphoid-specific protein (Oct-2). During characterization of the promoter region of the chicken immunoglobulin light chain gene, the authors identified two homologous octamer-binding proteins in chicken B cells. when the cloning of the human gene for Oct-2 revealed it to be a member of a distinct family of homeobox genes, they sought to determine if the human Oct-2 cDNA could be used to identify homologous chicken homeobox genes. Using a human Oct-2 homeobox-specific DNA probe, they were able to identify 6-10 ...
Wound dressings impregnated with silver have a role to play in aiding to reduce both the dressing and wound microbial bioburden. It is therefore imperative that antimicrobial wound dressings have efficacy on a broad range of clinical significant microorganisms. Accordingly, this study aimed to determine the antimicrobial efficacy of a silver alginate dressing against 115 wound isolates that had been isolated routinely from patients at West Virginia University Hospital. Standardised corrected zones of inhibition (CZOIs) were performed on all clinical isolates. It was found that the silver alginate dressing was able to inhibit the growth of all microorganisms tested. In particular, the silver alginate dressing inhibited the growth of Candida albicans and yeasts with CZOI of 3-115 mm. All met...
The effect of phosphonate anion (PHOS) on the corrosion of ordinary steel in simulated cooling water has been studied using weight loss, polarization curves and electrochemical impedance spectroscopy measurements. PHOS was studied in the concentration range from 7.5x10^-^5 to 10^-^3M. The results obtained reveal that PHOS perform excellently as corrosion inhibitor for ordinary steel in simulated cooling water. The inhibition efficiency of PHOS was increased with increasing both its concentration and water circulation velocity. These two factors seem to promote the adsorption of phosphorus and oxygen ions on the metal surface, leading to the formation of a protective layer with a greater charge transfer resistance and lower permeability. The inhibition efficiency decreased slightly with tem...
This research investigated the inhibiting effects that sodium salts of linear monocarboxylic acids displayed towards the corrosion process of AZ31 Mg alloy in ASTM D 1387 saline solution (a synthetic industrial cooling water). The length of the aliphatic chain of the acids ranged between 7 and 15 carbon atoms. The inhibiting action of these salts can be related to the precipitation of an insoluble magnesium salt, which mainly affected the anodic reaction. The aliphatic chain length controlled the anion solubility and the reaction rate of magnesium carboxylate formation. For all the salts, an optimum concentration was experienced: 10{sup -2} M for sodium decanoate (caprate), 10{sup -3} M for sodium dodecanoate (laurate), 10{sup -4} M for sodium tetradecanoate (myristate); when this concentration was exceeded, a diminution (even a disappearance) in the inhibiting action was found. (Abstract Copyright [2009], Wiley ...
Synergism has been observed during inhibiting initiated oxidation of styrene or tetralin by organic phosphites in the presence of complex compounds of some transition metals. The results are given of non-additive intensification of antioxidative activity of triphenylphosphite (TPP) and tri-(4-methyl-6-tert.-- butyl)-phenyl-phosphite (TMBP) in the process of initiated oxidation of styrene or tetralin with addition of acetylacetonates of cobalt and vanadyl. During styrene oxidation, inhibition of the reaction with chelate complex of vanadyl is weakened considerably when phosphite is added into the reaction system. During tetralin oxidation, postcatalytic (or branched) oxidation is observed only for large concentration of vanadyl complex. Addition of TPP to above complex sharply increases the induction period. When the induction period is completed, oxidation of tetralin follows the mechanism of usual, i.e. initiated, reaction.
Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme, which catalyzes the nonspecific hydrolysis of phosphate monoesters. The kinetics of inhibition of the enzyme by sodium (2, 2'-bipyridine) oxodiperoxovanadate, pV(bipy), has been studied. The time course of the hydrolysis of p-nitrophenyl-phosphate catalyzed by the enzyme in the presence of different pV(bipy) concentrations showed that at each pV(bipy) concentration, the rate decreased with increasing time until a straight line was approached, the straight line slopes are the same for all concentrations. The results suggest that the inhibition of the enzyme by pV(bipy) is a slow, reversible reaction with fractional remaining activity. The microscopic rate constants are determined for the reaction of inhibitor with the enzyme. PMID:10691182
Abstract A Pseudomonas sp. isolate MSB1 efficiently inhibited the growth of Flavobacterium psychrophilum of different serotypes on agar medium. A significant difference in the inhibition was observed between isolates of the less virulent FpT serotype compared to the Fd and Th serotypes. In broth coculture experiments, a low number of cells of MSB1 inhibited and outcompeted the F.psychrophilum cells. Also cell-free culture supernatant of MSB1 clearly repressed the growth of F.psychrophilum. A chromoazurol S assay suggested that MSB1 produced efficient siderophores, which most probably were responsible for the iron deficiency in the supernatant. The limited growth of F.psychrophilum in the supernatant was found to be partly because of the lack of available iron, but the results also indicate...
The obligate biotrophic fungus Golovinomyces orontii causes powdery mildew (PM) disease on its host Arabidopsis thaliana. Most research on the G. orontii?Arabidopsis pathosystem uses rosette leaves as experimental materials, so little is known about the behavior of G. orontii on other Arabidopsis organs. We thus conducted microscopic analyses of the PM infection process on leaves, stems, fruits and roots of Arabidopsis. Adaxial and abaxial surfaces of mature rosette leaves supported G. orontii infection, but growth was somewhat suppressed on cauline leaves. Prepenetration processes (germination and appressorium formation) were strongly inhibited on stems, fruits and roots. To test the effect of alterations in the Arabidopsis cuticle on the inhibition of prepenetration processes on stems, w...
The herbicide atrazine is a known immunotoxicant and an inhibitor of human natural killer (NK) cell lytic function. The precise changes in NK cell lytic function following atrazine exposure have not been fully elucidated. The current study identifies the point at which atrazine exerts its affect on the stepwise process of human NK cell-mediated lyses of the K562 target cell line. Using intracellular staining of human peripheral blood lymphocytes, it was determined that a 24-h in vitro exposure to atrazine did not decrease the level of NK cell lytic proteins granzyme A, granzyme B or perforin. Thus, it was hypothesized that atrazine exposure was inhibiting the ability of the NK cells to bind to the target cell and subsequently inhibit the release of lytic protein from the NK cell. To test t...
Prepulse inhibition (PPI) is a measure of sensorimotor gating, a pre-attentional inhibitory brain mechanism that filters extraneous stimuli. Prepulse inhibition is correlated with measures of cognition and executive functioning, and is considered an endophenotype of schizophrenia and other psychiatric illnesses in which patients show PPI impairments. As a first step toward identifying genes that regulate PPI, we performed a quantitative trait locus (QTL) screen of PPI phenotypes in a panel of mouse chromosome substitution strains (CSSs). We identified five CSSs with altered PPI compared with the host C57BL/6J strain: CSS-4 exhibited decreased PPI, whereas CSS-10, -11, -16 and -Y exhibited higher PPI compared with C57BL/6J. These data indicate that A/J chromosomes 4, 10, 11, 16 and Y harbor...
The acid corrosion inhibition process of mild steel in 1M HCl by 1-butyl-3-methylimidazolium chlorides (BMIC) and 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM]HSO4) has been investigated using electrochemical impedance, potentiodynamic polarization and weight loss measurements. Potentiodynamic polarization studies indicate the studied inhibitors are mixed type inhibitors. For both inhibitors, the inhibition efficiency increased with increase in the concentration of the inhibitor and the effectiveness of the two inhibitors are in the order [BMIM]HSO4>BMIC. The adsorption of the inhibitors on mild steel surface obeyed the Langmuirs adsorption isotherm. The effect of temperature on the corrosion behavior in the presence of 5x10-3M of inhibitors was studied in the temperature range of 3...
A study of the ordinary mild steel/cooling water interface, with and without inhibitor, was carried out using electrochemical impedance spectroscopy (EIS). EIS spectra in uninhibited medium reveal that a layer of corrosion and scale products is formed naturally and evolves with the immersion time. Monosaccharides derivatives were used as corrosion inhibitors. Most of them exhibit good behaviour against corrosion of ordinary steel in simulated water systems. Their inhibiting efficiency increases with concentration rise and depends on molecular structure especially -OH groups' position on two adjacent carbons and their number. In addition, the effect of MoO4^2^- on the corrosion inhibition in the presence of the best inhibitor was also studied by EIS. The addition of MoO4^2^- enhanced the in...
An enantiocontrolled route to aziridinomitosenes had been developed from l-serine methyl ester hydrochloride. The tetracyclic target ring system was assembled by an internal azomethine ylide cycloaddition reaction based on silver ion-assisted intramolecular oxazole alkylation and cyanide-induced ylide generation via a labile oxazoline intermediate (62 to 66). Other key steps include reductive detritylation of 26, methylation of the N-H aziridine 56, oxidation of the sensitive cyclohexenedione 68 to quinone 70, and carbamoylation using Fmoc-NCO. Although the aziridinomitosene tetracycle is sensitive, a range of protecting group manipulations and redox chemistry can be performed if suitable precautions are taken. A study of DNA alkylation by the first C-6,C-7-unsubstituted aziridinomitosene 11a has been carried out, and evidence for DNA cross-link formation involving nucleophilic addition to the quinone subunit is described. PMID:14677970
Abstract Ultrastructural studies have shown that the formation of pigment glands in Gossypium hirsutum L. leaves is a lysigenous process, originating from a cluster of cells in the ground meristem. Various techniques were used here to investigate whether programmed cell death (PCD) plays a critical role in this developmental process. Nuclei of internal cells in the pigment gland-forming tissue were TUNEL-positive and DAPI-negative, suggesting that DNA cleavage is an early event and complete DNA degradation is a late event. Smeared bands and a lack of laddering after gel electrophoresis indicate that DNA cleavage is random. Ultrastructurally, secretory cells in the pigment glands become distorted, nuclei are densely stained, and chromosomes become condensed until completely degraded at late...
We describe the cloning and characterization of a mutated thermostable DNA polymerase from Thermus aquaticus (Taq) that exhibits an increased reverse transcriptase activity and is therefore designated for one-step PCR pathogen detection using established real-time detection methods. We demonstrate that this Taq polymerase mutant (Taq M1) has similar PCR sensitivity and nuclease activity as the respective Taq wild-type DNA polymerase. In addition, and in marked contrast to the wild-type, Taq M1 exhibits a significantly increased reverse transcriptase activity especially at high temperatures (>60degreeC). RNA generally hosts highly stable secondary structure motifs, such as hairpins and G-quadruplexes, which complicate, or in the worst case obviate, reverse transcription (RT). Thus, RT at hi...
We investigate quantum mechanical electron transport along the long axis of the DNA molecule using an effective tight-binding model. The overall contour plot of transmission, the current-voltage characteristics, and the differential conductance are examined for the variation of backbone onsite energy, the energy-dependent hopping strength, and the contact coupling between the leads and the DNA molecule. It is shown that as backbone asymmetry increases, the merging and collapse of the two mini-bands take place and an extra resonance peak in the transmission appears. In addition, we present the modulation of voltage threshold in the current-voltage curves and a double-peak structure in the differential conductance due to the disappearance of the merged mini-band. Finally, in the Coulomb bloc...
A clone encoding a human D{sub 2} dopamine receptor was isolated from a pituitary cDNA library and sequenced. The deduced protein sequence is 96% identical with that of the cloned rat receptor with one major difference: the human receptor contains an additional 29 amino acids in its putative third cytoplasmic loop. Southern blotting demonstrated the presence of only one human D{sub 2} receptor gene. Two overlapping phage containing the gene were isolated and characterized. DNA sequence analysis of these clones showed that the coding sequence is interrupted by six introns and that the additional amino acids present in the human pituitary receptor are encoded by a single exon of 87 base pairs. The involvement of this sequence in alternative splicing and its biological significance are discussed.
Methylation of the DNA bases in the Watson-Crick GC and AT base pairs by the methyldiazonium ion was investigated employing density functional and second order Moller-Plesset (MP2) perturbation theories. Methylation at the N3, N7 and O6 sites of guanine, N1, N3 and N7 sites of adenine, O2 and N3 sites of cytosine and the O2 and O4 sites of thymine were considered. The computed reactivities for methylation follow the order N7(guanine)>N3(adenine)>O6(guanine) which is in agreement with experiment. The base pairing in DNA is found to play a significant role with regard to reactivities of the different sites.