Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

DNA damaging agents such as nitrosoureas are widely used for the treatment of malignant gliomas. Therefore, quantitative measurement of DNA damages induced by antineoplastic drugs is useful to judge the efficacy of the drug and understand the pharmacological action of the drug. We have utilized in situ nick translation method to demonstrate "nicks" in DNA of glioma cells treated by various antineoplastic agents. Exponentially growing rat 9 L glioma cells (4 x 10(4] were seeded in the chamber slide. After fourty eight hours, the medium was changed to that containing various concentration of the drug (ACNU, cis-DDP, BLM, ADM and VP-16) and the cell was treated for 1 hour. Then, the cell was fixed for 10 minutes in methanol-acetic acid (v/v 3:1). Following fixation, the cell was incubated in the nick translation mixture containing E. coli DNA polymerase I, 3H-TTP, and 4 dNTP's (ATP, GTP, CTP, CTP and TTP) for 10 minutes at room temperature. The slide was dipped in the autoradiographic emulsion, exposed for 4 days at 4 degrees C, and then developed, the number of the silver grains over nuclei was counted under the microscope. For comparison of the effect of the drug to glioma cells, IC50 (inhibitory concentration of the drug for 50% cell kill) of each drug was determined by treating the cell for 48 hours at the various concentration of the drug. Small number of the silver grains was noted in cells with no treatment. Over IC50 as the concentration of the drug increased, the number of the nick increased in cells treated with bleomycin or adriamycin which are known to produce single strand breaks in DNA.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[In situ nick translation for detection of DNA damages in glioma cells]. 262 7

DNA strand break in HeLa cells induced by radiation was detected using the in situ nick translation method. The cells were exposed to radiation of 3, 6, 12, 18, and 24 Gy in Lab-Tek tissue culture chamber/slides and were fixed with ethanol/acetic acid on the slide glass. The break sites in DNA were translated artificially in the presence of Escherichia coli DNA polymerase I and [3H]-labeled dTTP. Autoradiographic observation was made of the level of break sites in the DNA. The DNA strand break appeared even with a 3 Gy exposure, increased 8.6 times at 24 Gy compared with the control cells, and this level correlated reciprocally to change in cell viability. This nick translation method provides a rapid in situ assay for determining radiation-induced DNA damage of cultured cells, in a semi-quantitative manner.
 ...
PMID:Nick translation detection in situ of cellular DNA strand break induced by radiation. 264 85

DNA strand break in HeLa cells induced by heat was detected using the in situ nick translation method. The cells were incubated at 43 degrees C for various times (15, 30, 45, 60, 90 or 120 min) in Lab-Tek tissue culture chamber/slides and were fixed with ethanol/acetic acid on the slide glass. The break sites in DNA were translated artificially in the presence of Escherichia coli DNA polymerase I and 3H-labeled dTTP. The level of break sites in the DNA was visualized by autoradiographic observation of the grains. The DNA strand break appeared as early as 15 min, increased to 10.3-fold at 45 min of 43 degrees C treatment and this level related reciprocally to clonogenicity of the cell. The nick translation method thus provides a rapid in situ assay for determining heat-induced DNA damage of cultured cells, in a semi-quantitative manner.
 ...
PMID:In situ nick translation method reveals DNA strand scission in HeLa cells following heat treatment. 337 Jun 28

A simple and rapid procedure for the preparation of M13 single stranded DNA sequencing templates which does not involve phenol extractions and alcohol precipitations is described. Bacteriophages are precipitated from media supernatants with acetic acid and recovered on glass fiber filters. Subsequent dissociation of the phages and removal of contaminants is performed while the DNA is bound to the glass. Finally, the purified DNA is eluted in a small volume of low-salt buffer. The yield is higher than that obtained by standard methods. The simplified procedure takes less than 30 minutes and does not demand special skills or equipment; the sequence resolution is as good as that obtained by standard procedures both with the Klenow fragment and T7 DNA polymerase, with radioactive labelling as well as in automated sequencing with a fluorescent label.
 ...
PMID:A simple and rapid preparation of M13 sequencing templates for manual and automated dideoxy sequencing. 361 97

Acycloguanosine [9-(2-hydroxyethoxymethyl)guanine; acyclo-Guo] is a potent inhibitor of herpes simplex viruses (HSV); it is selectively phosphorylated in virus-infected cells. In order to define those viral functions that may mediate resistance to acyclo-Guo, the drug sensitivities of temperature-sensitive (ts) and phosphonoacetic acetic acid (PAA)-resistant mutants of HSV-1 and HSV-2 have been determined. Two distinct viral genetic loci are independently associated with acyclo-Guo resistance. Mutations resulting in diminished thymidine kinase activity are associated with resistance to inhibition by acyclo-Guo. Several PAA-resistant viruses that express wild-type levels of thymidine kinase activity are also resistant to acyclo-Guo. This suggests the importance of the viral DNA polymerase region in mediating acyclo-Guo resistance and is consistent with a close relationship between the PAAr mutation site and the AGGr locus. When wild-type HSV-1 is serially propagated under the selective pressure of acyclo-Guo, rapid emergence of resistant virus occurs, accompanied by the simultaneous appearance of thymidine kinase-deficient progeny.
 ...
PMID:Resistance of herpes simplex virus to acycloguanosine: role of viral thymidine kinase and DNA polymerase loci. 624 32

We describe a new application of a bright-field microscopic procedure for rapid enzyme cytochemical detection of repeated DNA sequences in metaphase preparations and frozen tissue sections. Various chromosome-specific oligonucleotide primers were used in up to three sequential primed in situ (PRINS) labeling reactions together with Taq DNA polymerase and biotin, digoxigenin and/or fluorescein isothiocyanate (FITC)-modified nucleotides. DNA target sequences were localized simultaneously by the precipitates of the horseradish peroxidase-diaminobenzidine (PO-DAB, brown color), alkaline phosphatase-Fast Red (APase-Fast Red, red color) and horseradish peroxidase-teramethylbenzidine (PO-TMB, green color) reaction in hematoxylin counterstained metaphases and interphase nuclei using a standard bright-field microscope. In addition, a protocol is reported for the application of PRINS to frozen tissue sections from normal colon and bladder epithelium. Methanol/acetic acid fixation in combination with a pepsin digestion before performing the PRINS reaction proved to be critical steps in the total procedure that permits access of the PRINS reactants, while preserving the morphology of the nuclei in the tissue. Quantification of PRINS signals showed the majority of epithelial cells with the expected two chromosome copies. The described procedures can be considered valuable tools for application in molecular cytogenetics, cell biology and pathology.
 ...
PMID:Rapid bright-field detection of oligonucleotide primed in situ (PRINS)-labeled DNA in chromosome preparations and frozen tissue sections. 882 52

Telomerase activity was measured at each phase of the cell cycle in synchronized tobacco (Nicotiana tabacum) BY-2 cells in suspension culture with the use of the telomeric repeat amplification protocol assay. The activity was low or undetectable at most phases of the cell cycle but showed a marked increase at early S phase. The induction of telomerase activity was not affected by the S phase blockers aphidicolin (which inhibits DNA polymerase alpha) or hydroxyurea (which inhibits ribonucleotide reductase), but it was prevented by olomoucine, an inhibitor of Cdc2/Cdk2 kinases that blocks G(1)-S cell cycle transition. These results suggest that the induction of telomerase activity is not directly coupled to DNA replication by conventional DNA polymerases, but rather is triggered by the entry of cells into S phase. Various analogs of the plant hormone auxin, including indole-3-acetic acid, alpha-naphthaleneacetic acid, and 2,4-dichlorophenoxyacetic acid, potentiated the increase in telomerase activity at early S phase; the growth-inactive analog 2,3-dichlorophenoxyacetic acid, however, had no such effect. Potentiation by indole-3-acetic acid of the induction of telomerase activity was dose dependent. Together, these data indicate that telomerase activity in tobacco cells is regulated in a cell cycle-dependent manner, and that the increase in activity at S phase is specifically inducible by auxin.
 ...
PMID:Auxin induction of cell cycle regulated activity of tobacco telomerase. 1040 48

By employing a general biosynthetic method for the elaboration of proteins containing unnatural amino acid analogues, we incorporated (aminooxy)acetic acid into positions 10 and 27 of Escherichia coli dihydrofolate reductase. Introduction of the modified amino acid into DHFR was accomplished in an in vitro protein biosynthesizing system by readthrough of a nonsense (UAG) codon with a suppressor tRNA that had been activated with (aminooxy)acetic acid. Incorporation of the amino acid proceeded with reasonable efficiency at codon position 10 but less well at position 27. (Aminooxy)acetic acid was also incorporated into position 72 of DNA polymerase beta. Peptides containing (aminooxy)acetic acid have been shown to adopt a preferred conformation involving an eight-membered ring that resembles a gamma-turn. Accordingly, the present study may facilitate the elaboration of proteins containing conformationally biased peptidomimetic motifs at predetermined sites. The present results further extend the examples of ribosomally mediated formation of peptide bond analogues of altered connectivity and provide a conformationally biased linkage at a predetermined site. It has also been shown that the elaborated protein can be cleaved chemically at the site containing the modified amino acid.
 ...
PMID:Site-specific incorporation of (aminooxy)acetic acid into proteins. 1223 90

The triterpenoid structure is a promising motif for the molecular design of DNA polymerase inhibitors.(1) In this study, 2-(cholesteryloxy)acetic acid (3), 2-(cholestanyl)acetic acid (7), and 2-(stigmasteryl)acetic acid (11) were found to selectively affect only DNA polymerase alpha (pol.alpha). The presence of a carboxyl group at position 28 appears to be essential for the inhibition of the pol.alpha activity. With pol.alpha, these compounds acted by competing with the template-primer DNA and noncompetitively with the substrate.
 ...
PMID:Molecular design of cholesterols as inhibitors of DNA polymerase alpha. 1536 2

Isolated of multidrug resistance Pseudomonas aeruginosa (MDRP) that the receptivity pattern of the antimicrobial suscepti respectively resembled isolated from clinical specimens (sputum) in two patients of each internal medicine ward in Kitasato University East Hospital for two days from September 18 and 20, 2004. Both of bacteria were formed small colonies of a smooth-type on dollargalluskey improvement-type BTB agar plates, and the judgment of ClassB (metallo)-beta-lactamase by biochemical properties and disk diffusion method sodium mercaoto-acetic acid (SMA) was mutually corresponding. Moreover, it was same serotype C according to the serotype, and it was confirmed that it was the same bacterial strain from the molecular epidemiology analysis by Random amplified polymorphic DNA polymerase chain reaction (Random amplified polymorphic DNA polymerase chain reaction: RAPD). From the investigation of clinical backgrounds of two patients who isolated bacterial strains, September 18, 2004. 10 : 20 a.m., and 10 : 40 a.m., other chances that can become with contact infection in this hospital, except conducted X-Ray or roentgenograph of the chest and abdomen of Portable X-ray device continuously done by one radiation technician was not seen. Because it had turned out that a radiation technician who had taken charge had been neglecting the hand washing at the time of each X-Ray or roentgenograph, it was guessed the case with nosocomial infection by contact infection occurred via specific radiation technician.
 ...
PMID:[Nosocomial infection by multidrug-resistant Pseudomonas Aeruginosa (MDRP) presumably spread a radiation technician]. 1662 93


1 2 Next >>