abstract：:Two complementary genetic parameters were followed in liver parenchymal cells during the first steps of rat hepatocarcinogenesis: the expression of nucleolar genes estimated from their silver stainability and the nuclear DNA content determined after Feulgen staining. Putative preneoplastic lesions as foci and nodules ...

journal_title：Carcinogenesis

authors： Deleener A,Castelain P,Preat V,de Gerlache J,Alexandre H,Kirsch-Volders M

更新日期：1987-02-01 00:00:00

abstract：:The kinetics of nuclear polyploidization in livers of CF-1 mice exposed to dieldrin were studied at concentrations of 0, 0.1, 1, 5 and 10 p.p.m. in the diet, in 'steady-state' situations (which are reached within a few weeks after initiation of treatment). Animals were killed at five time intervals (after 1.85, 3, 6, ...

journal_title：Carcinogenesis

authors： van Ravenzwaay B,Tennekes H,Stöhr M,Kunz W

更新日期：1987-02-01 00:00:00

abstract：:Liver DNA, obtained at various time intervals from rats chronically fed a choline-devoid diet, was analysed for the presence of aromatic or alkyl adducts by the 32P-postlabeling assay. Alkyl adducts were not detected. Aromatic DNA adduct lesions were revealed, but only at levels (1 adduct per 0.5-3 X 10(9) nucleotides...

journal_title：Carcinogenesis

authors： Gupta RC,Earley K,Locker J,Lombardi B

更新日期：1987-01-01 00:00:00

abstract：:Ouabain resistance (ouar) and 6-thioguanine resistance (6-TGr) mutation frequencies were measured in Chinese hamster ovary cells after treatment with N-ethyl-N-nitrosourea (ENU) for varying periods of time. Maximal mutation frequency at the Na+/K+ ATPase gene locus (ouar mutations) was attained within 5 min of exposur...

journal_title：Carcinogenesis

authors： Dogliotti E,Vitelli A,Terlizzese M,Di Muccio A,Calcagnile A,Saffiotti U,Bignami M

更新日期：1987-01-01 00:00:00

abstract：:The syn- and anti-isomers of 1,2-dihydroxy-3,4-epoxy-1,2,3,4-tetrahydro-6-methylchrysene (6-MeC-1,2-diol-3,4-epoxide) were synthesized and their mutagenic activities in Salmonella typhimurium were compared with those of the syn- and anti-isomers of 1,2-dihydroxy-3,4-epoxy-1,2,3,4-tetrahydro-5-methylchrysene (5-MeC-1,2...

journal_title：Carcinogenesis

authors： Amin S,Huie K,Hecht SS,Harvey RG

更新日期：1986-12-01 00:00:00

abstract：:We investigated possible mechanisms associated with promotion of hepatocarcinogenesis by the synthetic estrogens mestranol (M) and ethinyl estradiol (EE). Our first objective was to determine whether chronic EE treatment was associated with hepatotoxicity accompanied by regenerative hyperplasia. Female Sprague-Dawley ...

journal_title：Carcinogenesis

authors： Yager JD,Roebuck BD,Paluszcyk TL,Memoli VA

更新日期：1986-12-01 00:00:00

abstract：:In this study, we determined the wavelength dependence of u.v.-induced pyrimidine dimer formation, cell killing and mutation induction in human diploid skin fibroblasts. Pyrimidine dimers were quantified using the T4 endonuclease V assay, cell killing was measured as loss of colony forming ability and mutation inducti...

journal_title：Carcinogenesis

authors： Enninga IC,Groenendijk RT,Filon AR,van Zeeland AA,Simons JW

更新日期：1986-11-01 00:00:00

abstract：:Chrysoidine dyes are used by fishermen to colour bait and recent epidemiological evidence has suggested that this may explain why they are at increased risk of urothelial cancer. In recent years Bismark brown dyes have been used as chrysoidine substitutes. Previous mutagenicity studies on these azo-dyes have examined ...

journal_title：Carcinogenesis

authors： Sole GM,Chipman JK

更新日期：1986-11-01 00:00:00

abstract：:A diet deficient in choline when fed to rats for as few as 3 days resulted in liver DNA damage. The damage could be monitored as alkali-labile lesions using alkaline-sucrose gradients as well as alkaline elution technique. The DNA damage disappeared when the choline-deficient diet was replaced by a choline-supplemente...

journal_title：Carcinogenesis

authors： Rushmore TH,Farber E,Ghoshal AK,Parodi S,Pala M,Taningher M

更新日期：1986-10-01 00:00:00

abstract：:We examined the effects of the aliphatic amides isopropyl-valeramide (IVA) and allylisopropylacetamide (AIA) on oncogenic transformation and sister chromatid exchanges (SCE) induced by cyclopenta[cd]pyrene (CPP) and benzo[a]pyrene (B[a]P) in C3H/10T1/2 cells and on B[a]Pdiol-epoxide (BPDE)-induced mutation at the HGPR...

journal_title：Carcinogenesis

authors： Krolewski B,Nagasawa H,Little JB

更新日期：1986-10-01 00:00:00

abstract：:The effect of co-administration of diethylnitrosamine (DEN) and Clophen A 50, a commercial mixture of polychlorinated biphenyls (PCB), on pre-neoplastic enzyme-altered islands in livers of female Sprague-Dawley rats was studied. The islands were identified by the loss of adenosine-5'-triphosphatase (ATPase), emergence...

journal_title：Carcinogenesis

authors： Deml E,Oesterle D

更新日期：1986-10-01 00:00:00

abstract：:The repair kinetics and sensitivity to inhibitors of DNA strand breaks caused by superoxide anion, hydrogen peroxide, benzoyl peroxide and anthralin have been studied and compared with strand breaks caused by well-studied agents such as ionizing radiation and bleomycin. The latter two agents are generally believed to ...

journal_title：Carcinogenesis

authors： Birnboim HC

更新日期：1986-09-01 00:00:00

abstract：:Formation of O6-ethylguanine (O6EG) in trachea DNA was measured 12 h after acute i.p. administration of 50, 100 and 200 mg diethylnitrosamine (DEN)/kg body wt to Syrian golden hamsters. Purine bases were fractionated by h.p.l.c., and ethylated guanines were quantified optically by fluorescence spectrophotometry. Signi...

journal_title：Carcinogenesis

authors： Fong AT,Rasmussen RE

更新日期：1986-09-01 00:00:00

abstract：:The effects of hyperoxia on lung tumor development were examined in mice and rats. In mice, exposure to 70% O2 prevented the development of urethan- or 3-methylcholanthrene-induced lung tumors. Dietary antioxidants [butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA)] were unable to prevent the inhibitio...

journal_title：Carcinogenesis

authors： Lindenschmidt RC,Margaretten N,Griesemer RA,Witschi HP

更新日期：1986-09-01 00:00:00

abstract：:To determine whether B or T lymphoid malignancies could be induced following the exposure of lymphoid cells within different lymphoid organs to a potential chemical carcinogen, 3-methylcholanthrene (3-MC) was directly injected into surgically exposed Peyer's patches (PP), mesenteric lymph nodes (MLN), axillary lymph n...

journal_title：Carcinogenesis

authors： Bost KL,Garrett LR,Cuchens MA

更新日期：1986-08-01 00:00:00

abstract：:The metabolism of the carcinogenic pentacyclic azaaromatic compound, dibenz[a,j]acridine, has been examined in liver microsomal incubations using preparations from 3-methylcholanthrene-pretreated Wistar rats. Using authentic synthetic standards, u.v. spectroscopy and mass spectrometry, the following were proved to be ...

journal_title：Carcinogenesis

authors： Gill JH,Duke CC,Rosario CA,Ryan AJ,Holder GM

更新日期：1986-08-01 00:00:00

abstract：:We report evidence that the mutagen and carcinogen 3-amino-1-methyl-5H pyrido[4,3b]indole (Trp P-2) is a substrate for co-oxidation by prostaglandin H synthase (PHS) in ram seminal vesicle (RSV) microsomes. Trp P-2 serves as a reducing cofactor for the hydroperoxidase activity of PHS as shown by the concentration-depe...

journal_title：Carcinogenesis

authors： Petry TW,Krauss RS,Eling TE

更新日期：1986-08-01 00:00:00

abstract：:Possible relationships between structure and metabolism of nitrosamines have been investigated in the rat small intestine. Isolated segments of jejunum and ileum were perfused from the luminal side for 2 h with a Tyrode solution containing one of four symmetrical dialkylnitrosamines with 2-5 carbon atoms per side chai...

journal_title：Carcinogenesis

authors： Richter E,Richter-Cooberg U,Feng X,Schulze J,Wiessler M

更新日期：1986-07-01 00:00:00

abstract：:In two separate in vivo studies, ethionine was evaluated for carcinogenic activity in mice. In the first study, DL-ethionine was fed in a chow diet at 0 (controls), 0.1 (low dose, LD) and 0.25% (high dose, HD) concentrations to the following groups of mice (30 animals/group): Swiss Webster CD-1 females, BALB/c males, ...

journal_title：Carcinogenesis

authors： Hoover KL,Hyde CL,Wenk ML,Poirier LA

更新日期：1986-07-01 00:00:00

abstract：:Species differences in the metabolism of toxic chemicals can confound the extrapolation of experimentally determined risk data to man. However, it is often difficult to obtain reliable information on human metabolism, particularly of genotoxic agents. In this study, comparisons of chromatographic profiles of DNA adduc...

journal_title：Carcinogenesis

authors： Huckle KR,Smith RJ,Watson WP,Wright AS

更新日期：1986-06-01 00:00:00

abstract：:Incubation of 3-[3H]fluoranthene with a rat liver microsomal activation system in the presence of calf thymus DNA resulted in radioactivity bound to the DNA. The fluoranthene-modified DNA was enzymatically digested and a DNA adduct elution profile developed using h.p.l.c. The fraction containing the major fluoranthene...

journal_title：Carcinogenesis

authors： Babson JR,Russo-Rodriguez SE,Rastetter WH,Wogan GN

更新日期：1986-06-01 00:00:00

abstract：:The repair of u.v.-induced damage in human and rodent cells was investigated at the level of DNA loops attached to the nuclear matrix. After 2 h post-u.v. incubation, DNase I digestion studies revealed a 3- to 4-fold enrichment of repair-labeled DNA at the nuclear matrix in four xeroderma pigmentosum cell strains belo...

journal_title：Carcinogenesis

authors： Mullenders LH,van Kesteren AC,Bussmann CJ,van Zeeland AA,Natarajan AT

更新日期：1986-06-01 00:00:00

abstract：:Inflammation and the release of potentially damaging substances, such as reactive oxygen intermediates (ROI) and lipid oxidation products from inflammatory cells, have been linked to the potentiation of carcinogenesis. Murine macrophages when stimulated with phorbol esters induce 5,6 ring saturated thymine residues (T...

journal_title：Carcinogenesis

authors： Lewis JG,Hamilton T,Adams DO

更新日期：1986-05-01 00:00:00

abstract：:Teflon tubing used in the isolated, ventilated and perfused lung apparatus (IVPL) was found to yield artifactually high values for nitrosamine formation after it had been exposed to nitrite. In contrast to an earlier report, we found that submilligram levels of nitrite do not react to form significant quantities of ni...

journal_title：Carcinogenesis

authors： Cooney RV,Ross PD,Bartolini GL

更新日期：1986-05-01 00:00:00

abstract：:Chemopreventive agents are compounds that inhibit carcinogenesis when administered prior or subsequent to a course of carcinogen administration. The effects of dietary administration of crocin dyes on the hepatic damage induced by aflatoxin B1 (AFB1) and dimethylnitrosamine (DMN) in rats were investigated. Female Spra...

journal_title：Carcinogenesis

authors： Lin JK,Wang CJ

更新日期：1986-04-01 00:00:00

abstract：:Diglycerides function as analogs of the phorbol ester tumor promoters. We compare here the activity of glycerol 1-myristate 2-acetate (GMA) with the corresponding phorbol 12-myristate 13-acetate (PMA). GMA inhibited phorbol ester binding to reconstituted protein kinase C, stimulated protein kinase C enzymatic activity...

journal_title：Carcinogenesis

authors： Sharkey NA,Blumberg PM

更新日期：1986-04-01 00:00:00

abstract：:Previous studies have shown that in addition to serving as a target for covalent adduct formation, purified DNA catalyzes the detoxification of (+/-)-7r,8t-dihydroxy-9t,10t-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE). To begin to relate these in vitro findings with the processes important in carcinogenesis in vivo, w...

journal_title：Carcinogenesis

authors： Dock L,MacLeod MC

更新日期：1986-04-01 00:00:00

abstract：:Previous studies have shown that 1- and 3-nitrobenzo[a]pyrene (NBaP) were mutagenic in the Salmonella reversion assay without exogenous activation and that 1-, 3- and 6-NBaP were mutagenic in the presence of hepatocytes or liver homogenate (S9). In the present study, 1-, 3- and 6-NBaP were tested for mutagenicity in C...

journal_title：Carcinogenesis

authors： Hass BS,Heflich RH,Schol HM,Chou MW,Fu PP,Casciano DA

更新日期：1986-04-01 00:00:00

abstract：:The possibility that alpha-tocopherol (vitamin E) inhibits the formation of nitrosomorpholine (NMOR) in vivo was investigated in mice orally pretreated with alpha-tocopherol (2.5-100 mg/kg body wt) once daily for 6 days. Twenty-four hours later, the animals were injected i.p. with 2 mg of morpholine (MOR) per animal f...

journal_title：Carcinogenesis

authors： Norkus EP,Kuenzig WA,Chau J,Mergens WJ,Conney AH

更新日期：1986-03-01 00:00:00

abstract：:A diet that is deficient in methionine, choline, folic acid and vitamin B12 has been found to induce alterations rapidly in liver tRNA methylation in male Fischer rats. In vitro assays indicated that activity of N2-guanine tRNA methyltransferase II (NMG2) was increased to 150% of controls levels in 1 week and 300% of ...

journal_title：Carcinogenesis

authors： Wainfan E,Dizik M,Hluboky M,Balis ME

更新日期：1986-03-01 00:00:00

abstract：:7-Hydroxymethylbenz[a]anthracene (7-HBA) showed potent mutagenicity towards Salmonella typhimurium TA 98 in the presence of untreated rat liver cytosol fortified with the PAPS-generating system, sodium sulphate and ATP. No mutagenic activity was observed either when the cytosol was boiled or when sodium sulphate or AT...

journal_title：Carcinogenesis

authors： Watabe T,Hakamata Y,Hiratsuka A,Ogura K

更新日期：1986-02-01 00:00:00

abstract：:In vitro activation of benzo[a]pyrene to protein-binding forms was investigated with the following two systems: (1) various fractions of human and rat blood had a potential of activating benzo[a]pyrene to forms binding to proteins in the presence of linoleic or arachidonic acid. Red blood cells activated much more ben...

journal_title：Carcinogenesis

authors： Nemoto N

更新日期：1986-02-01 00:00:00

abstract：:Structural analogs of diethylstilbestrol (DES) with at least one phenolic hydroxyl group are metabolized by prostaglandin H synthase (PHS) from ram seminal vesicle microsomes (RSVM) in vitro in the presence of arachidonic acid (20:4). U.v. spectroscopy revealed the formation of p-quinoid intermediates in incubations o...

journal_title：Carcinogenesis

authors： Degen GH,Metzler M,Sivarajah KS

更新日期：1986-01-01 00:00:00

abstract：:The rat liver 9000 g supernatant mediated metabolism of the carcinogenic aristolochic acid, which consists of aristolochic acid I (AAI) and aristolochic acid II (AAII), was investigated. Under anaerobic conditions the major metabolites were the corresponding aristolactams for both AAI and AAII. In contrast under aerob...

journal_title：Carcinogenesis

authors： Schmeiser HH,Pool BL,Wiessler M

更新日期：1986-01-01 00:00:00

abstract：:Benzidine diimine (BZDI), a reactive intermediate in the metabolic peroxidation of the carcinogen benzidine, has been reported to bind covalently to cellular proteins and nucleic acids. We have examined the nature of this interaction with DNA and have identified a major carcinogen-nucleoside adduct. BZDI (20-50 microM...

journal_title：Carcinogenesis

authors： Yamazoe Y,Roth RW,Kadlubar FF

更新日期：1986-01-01 00:00:00

abstract：:The effect of whole body ionising radiation from a linear accelerator on rat tissue O6-methylguanine (O6-meG) methyltransferase (MT) activity has been assessed using an assay which measures the transfer of 3H-radioactivity from 3H-methylated substrate DNA to protein. The maximal effect occurred 2 days after a 1 krad d...

journal_title：Carcinogenesis

authors： Margison GP,Butler J,Hoey B

更新日期：1985-12-01 00:00:00

abstract：:Lipid peroxidation aldehydes of the 4-hydroxy-alpha, beta-unsaturated type, as well as the tobacco-smoke related alpha, beta-unsaturated aldehyde, acrolein, were highly cytotoxic and decreased the intracellular thiol content in cultured human bronchial fibroblasts after treatment with micromolar concentrations. In com...

journal_title：Carcinogenesis

authors： Krokan H,Grafstrom RC,Sundqvist K,Esterbauer H,Harris CC

更新日期：1985-12-01 00:00:00

abstract：:The possibility that ascorbic acid, as a nucleophile, may inhibit mutagenicity induced by electrophilic metabolites of N-nitroso compounds was examined. In vitro data are presented to show that ascorbic acid does not decrease the mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in a modified Ames bacterial ...

journal_title：Carcinogenesis

authors： Norkus EP,Kuenzig WA

更新日期：1985-11-01 00:00:00

abstract：:Previous studies have indicated that the Nb rat has a higher predisposition to the spontaneous development of nephroblastoma than most other strains of laboratory rat. In order to determine whether this inherent susceptibility could be exploited as a model for Wilms' tumor, Nb rats were treated with various chemicals ...

journal_title：Carcinogenesis

authors： Hard GC

更新日期：1985-11-01 00:00:00

abstract：:Currently there is no well-defined biological parameter or marker to help define agents, doses, and dose schedules for human cancer chemoprevention trials. Induction of ornithine decarboxylase, the rate limiting enzyme in the polyamine biosynthetic pathway, has been shown to be an essential aspect of mouse skin tumor ...

journal_title：Carcinogenesis

authors： Loprinzi CL,Verma AK

更新日期：1985-11-01 00:00:00