Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q17RS7 (Gen)
 130,125 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The rate of virus DNA synthesis and the production of infectious virus are impaired in stationary monkey kidney CV-I cells irradiated with u.v. before infection with herpes simplex virus (HSV). The inhibition of HSV multiplication is due to u.v.-induced damage in cell DNA. CV-I cells recover their capacity to support HSV growth during the 40 to 48 h after irradiation, and the final virus yield is enhanced by a factor of 10. The time course of the recovery is similar to that of the excision repair process occurring in u.v.-irradiated mammalian cells. Caffeine, hydroxyurea and cycloheximide inhibit the recovery. Fluorodeoxyuridine is without effect. A small but significant amount of labelled dThd coming from irradiated cell DNA is incorporated into virus DNA. HSV specified thymidine kinase seems to be more effective for virus DNA synthesis in irradiated than in control cells.
J Gen Virol 1976 Jul
PMID:Herpes virus and viral DNA synthesis in ultraviolet light-irradiated cells. 18 8

A number of chemical and physical agents were screened to determine their effectiveness in inducing simian virus (SV40) production in a virogenic clone of SV40-transformed Chinese hamster cells. Mitomycin C (MC) was the most effective inducing agent, and MC induction was further characterized. It was found that levels of infectious SV40 DNA were increased above control levels as early as 6 h after addition of MC to the culture medium and reached maximum levels by 48 h. Virus capsid (V) antigen and virions followed with a lag of about 24 h. V antigen production was sensitive to hydroxyurea, suggesting a dependence on virus DNA synthesis. The proportion of virus-producing cells (infectious centres) and the virus burst per cell were both stimulated by MC. Studies of 3H-thmidine incorporation demonstrated that the rate of SV40 DNA synthesis was maximal at 48 h post-induction, at which time cellular DNA synthesis was almost abolished. Caffeine, at doses not toxic to non-induced cells, strongly inhibited SV40production in both non-induced and induced cells, suggesting some role for DNA repair mechanisms.
J Gen Virol 1977 Jul
PMID:Simian virus 40-Chinese hamster kidney cell interaction. III. Characteristics of chemical induction in a clone of virogenic transformed cells. 19 36

In E. coli strain 91P containing the mutator gene mutT-, caffeine, spermine and quinacrine, but not guanosine, act as antimutagens, reducing the frequencies of mutation from ara- leads to Ara.
Mol Gen Genet 1977 Sep 09
PMID:Antimutagens against mutT. 33 12

Postreplication repair and its inhibition by chloramphenicol and caffeine, as seen in alkaline sucrose gradients, were compared between a uv non-mutable strain uvrA- umuC- and normally mutable strains uvrA- recF- and uvrA- umu+rec+ of Escherichia coli K-12. The uvrA- umuC- strain performed postreplication repair as efficiently as the parental strain, while the repair in uvrA- recF- strain was dependent on UV dose. Both chloramphenicol and caffeine inhibited postreplication repair to an equal extent of about 25%, and 10%, respectively, in all three uvrA- strains of umuC36, recF- and umu+rec+. These observations suggest that postreplication repair is largely not responsible for UV mutagenesis.
Mol Gen Genet 1977 Nov 14
PMID:Effects of chloramphenicol and caffeine on postreplication repair in uvr A- umuC- und uvrA- recF- strains of Escherichia coli K-12. 34 Aug 97

Haploid and diploid wild type strains, and three classes of radiation-sensitive mutants of Saccharomyces cerevisiae were tested for enhancement of UV-inactivation by caffeine in growth medium. In addition, the sensitizing effect of caffeine was studied in a haploid and a diploid wild type strain after gamma-irradiation. The drug sensitized the UV-irradiated cells of all strains except those reported to be only slightly UV-sensitive but highly sensitive to ionizing radiation. After gamma-irradiation, no caffeine-enhancement of killing was observed in stationary phase cells of either the haploid or the diploid strain. However, log-phase cells of both strains were partially sensitized. The results of both sets of experiments suggested that caffeine interferes with a recombinational repair occurring in cells in S or G2 phase.
Mol Gen Genet 1977 Dec 14
PMID:Caffeine enhancement of radiation killing in different strains of Saccharomyces cerevisiae. 34 6

Double-blind crossover comparison of methylphenidate hydrochloride, dextroamphetamine sulfate, and caffeine after placebo washout in 29 children with minimal brain dysfunction (MBD) showed on six ratings that methylphenidate and dextroamphetamine were significantly (P less than .05 to P less than .001) better than placebo and caffeine, but not significantly (P less than .05) different from each other. Placebo, caffeine, and ratings before drug did not differ significantly. Of 26 drug responders, 12 responded best to dextroamphetamine, ten to methylphenidate, and one to caffeine. The latter child showed no improvement at all with either prescription stimulant. Methylphenidate and dextroamphetamine were each efficacious for six children who did not respond to the other stimulant. All three drugs showed significant (P less than .05) weight loss and cardiovascular side effects, the latter possibly spurious. Dextroamphetamine showed a significant (P less than .05) decrease from placebo in "tummyaches."
Arch Gen Psychiatry 1978 Apr
PMID:Methylphenidate vs dextroamphetamine vs caffeine in minimal brain dysfunction: controlled comparison by placebo washout design with Bayes' analysis. 36 23

Dictyostelium discoideum strain M28, which has been used widely in genetic studies, was found to carry a radiation-sensitive mutation. This allele, termed rad-100, was recessive in heterozygous diploids and mapped in linkage group III. Complementation analysis and survival studies on strains carrying rad-100 suggested that this allele defines a new radiation-sensitive locus in D. discoideum, and this locus has been designated radE. radE strains were moderately sensitive to ultraviolet light (D10 90 J m-2) and slightly sensitive to 137Cs gamma rays D10 255 krad). radE strains also exhibited increased sensitivity to killing by N-methyl-N'-nitro-N-nitrosoguanidine but not by other alkylating agents such as ethyl methanesulphonate or methyl methanesulphonate. The frequency of spontaneous methanol-resistant (acrA) mutants was approximately the same in cultures of radE and radE+ strains. However, when amoebae of these strains were irradiated with ultraviolet light, the frequency of induced mutants was significantly lower in cultures of the radE strain. Furthermore, when amoebae of wild-type strain NC4 were plated in the presence of caffeine after ultraviolet-irradiation, the survival curves were very similar to the curves obtained for amoebae of radE strains in the presence or in the absence of caffeine. These results suggest that the radE100 mutation and caffeine interfere with an error-prone DNA repair pathway in D. discoideum.
J Gen Microbiol 1979 Oct
PMID:radE, a new radiation-sensitive locus in Dictyostelium discoideum. 54 58

The intensity of light scattered by chemically skinned rabbit psoas fibers in relaxed, rigor, and activated states was monitored at 90 degrees to the incident beam. In the relaxed state, scattering varied in proportion to the volume of muscle in the beam. Scattering increased to 2.3 times the resting value when rigor was induced by withdrawal of MgATP or when the myofibrils were activated by the caffeine-induced release of Ca from the sarcoplasmic reticulum. The rigor-induced increase in scattering decreased monotonically when MgATP was reintroduced stepwise (0-100 microM). This decrease in scattering was accompanied by an increase in tension up to an optimum MgATP level of approximately 10 microM, and then tension decreased at higher concentrations (10-100 microM). The increase in scattering during both rigor and activation was dependent upon fiber length. At lengths when thick-thin filament overlap was near zero, the light signal due to rigor and activation fell to within 10% of the signal for the relaxed fiber at that length. The signal during rigor increased only minimally (approximately 10%) when stretch (approximately 1%) was applied. This increase in signal was small despite a measured 5- to 10-fold increase in tension and an estimated twofold increase in stiffness. Thus, the increased light scattering caused by rigor and activation depends on filament overlap and not tension, stiffness, or substrate binding.
J Gen Physiol 1978 Nov
PMID:Filament interaction monitored by light scattering in skinned fibers. 73 57

It is shown that caffeine antagonizes petite-induction with ethidium bromide under non-growth conditions when administered during or after mutagenic treatment. Caffeine itself is shown to be a petite-inducing agent when cells are grown in liquid glucose-complete-medium in the presence of the drug. A possible mode of action of caffeine in the ethidium bromide induced petite-mutagenesis is discussed.
Mol Gen Genet 1976 Jul 05
PMID:Effect of caffeine on the rho- -induction with ethidium bromide in Saccharomyces cerevisiae. 78 13

Treatment of growing cultures of Mycobacterium smegmatis with alkylating agents (methyl methanesulphonate, ethyl methanesulphonate, nitrogen mustard, or mitomycin C) or with ultraviolet light resulted in enhanced specific activities of a DNA polymerase and of an ATP-dependent deoxyribonuclease. Similar results had previously been obtained with hydroxyurea and with iron limitation. The three of these treatments which were tested (methyl methanesulphonate, mitomycin C and hydroxyurea) produced strand breaks or alkali-labile regions in the DNA of this organism. The increased enzyme activities could be prevented by simultaneous treatment with inhibitors of protein synthesis. In contrast, treatment of the cultures with intercalating agents (ethidium bromide, acridine orange, or proflavine), 5-fluorouracil, caffeine, or nalidixic acid, inhibited DNA synthesis without increasing the enzyme activities. These treatments did not produce strand breaks in the DNA of this organism. The results support the hypothesis that, in M. smegmatis, damage to DNA induces increased synthesis of enzymes associated with DNA repair.
Mol Gen Genet 1977 Feb 15
PMID:Increased DNA polymerase and ATP-dependent deoxyribonuclease activities following DNA damages in mycobacterium smegmatis. 84 85


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