Showing papers in "Cancer Letters in 1979"

TL;DR: The inhibition of reverse transcriptase activity by suramin was competitive with the template-primer, (A) n · oligo(dT), suggesting that the drug may interact with the Template Primer binding site of the enzyme.

TL;DR: Evidence is presented for mutagenic inhibitory activity decreased mutagenesis mediated by liver S-9 from normal rats but not from Aroclor 1254-treated rats.

TL;DR: Addition of 4 ppm Se to the drinking water of male albino rats fed diets containing 0.03% 2-acetylaminofluorene provided protection against hepatic damage and also resulted in at least 50% reduction in liver tumor incidence.

TL;DR: Two pancreatic adenocarcinomas which had been induced in Wistar/Lewis rats by azaserine treatment were transplanted into rats of the same strain by subcutaneous and intraperitoneal injection of minced tumor and have maintained evidence of acinar cell differentiation.

TL;DR: Topical application of retinoic acid (RA) solutions greatly enhanced the response of hairless mouse skin to a moderate dose of simulated sunlight, and produced minimal epidermal hyperplasia compared to the ultraviolet radiation + methanol control.

TL;DR: Results indicate that the hamster embryo cell transformation system can detect the more active compound in a given substrate-metabolite series and may be useful for screening endogenously-formed steroid metabolites for their potential carcinogenicity.

TL;DR: Time curves suggest that a period exists during which mutagens are not readily formed; however, after this period mutagen production is rapid.

TL;DR: Evaluation of 6 carcinogenic nitrosamines in the hepatocyte primary culture/DNA repair test revealed that all were active and three non-carcinogenic analogs were negative.

TL;DR: Fractionation studies of the marihuana smoke condensates showed that basic components accounted for 76% of the recovered mutagenic activity.

TL;DR: The results suggest that adriamycin-resistant cells are endowed with an enhanced capacity for outward transport of not only anthracycline antibiotics, but chemically and pharmacologically dissimilar agents such as the aforementioned agents.

TL;DR: The data show that B[e]P is a very weak tumor initiator, a weak complete carcinogen, a moderate tumor promoter, possibly a weak co-tumor-initiator when given with B[a]P, and a potent anit-t tumor- initiatorWhen given with DMBA.

TL;DR: The topical application of the promoter, 12-O-tetradecanoyl-13-acetate, on the shaved backs of mice was attended by a striking increase in the PGE concentration within epidermis as early as 1 h later and the prostaglandin value remained elevated for at least 48 h.

TL;DR: Results show that diet modification can induce hormonal changes, and if similar changes occur in patients with breast and/or prostatic cancer, diet modification may be of benefit in these patients with tumors known to be hormonally dependent.

TL;DR: Inhalation of airborne mutagens from cooking, as an alternative route of exposure, should be investigated when considered in light of some epidemiological data showing an excess of lung and bladder cancer among cooks and kitchen workers.

TL;DR: Human cancer cells in vitro (NHIK 3025), derived from a carcinoma in situ are inactivated when exposed to visible light in the presence of hematoporphyrin, and a given total light dose is more efficient when it is fractionated than when it was given in a single exposire.

TL;DR: Paraffin wax pellets were implanted surgically into the mouse bladder lumen and animals killed after 40-50, 70-80 and 100-110 weeks and pellets containing N-2-fluorenylacetamide or its metabolites gave very similar incidences or carcinomas whether or not they were carcinogenic by oral or parenteral administration.

TL;DR: It is indicated that selenium exerts no chemopreventive effect against MNU-induced tracheal carcinogenesis and the distribution of tumor type was similar irrespective of seenium treatment.

TL;DR: In smokers, nicotine and cotinine were detectable in the fluid 30 min after smoking, and further analysis of breast fluid may give leads as to whether components present are related to breast carcinogenesis.

TL;DR: Results rule out a possibility that the mutagenicity, at least on TA100 microbes, of carcinogenic 4-aminoazobenzene derivatives may be mediated by any of the ring-hydroxyl or azo reduction metabolites and their conjugates produced from the azo dyes by incubation with S-9 mix.

TL;DR: It is suggested that a 'bay region' diol-epoxide may be important in DMBA carcinogenicity and mutagenicity and a methyl or fluoro addition to the 1, 2 or 5 positions almost completely blocked the skin tumor initiating and V79 mutagenic activities of DMBA.

TL;DR: High affinity receptors for androgen and estrogen but not progesterone were found but in R3327H tumors relapsing following castration, the presence of high affinity receptor for progester one were readily detectable.

TL;DR: Results indicated that the major mutagenic principle is not identical with any of the mutagens previously isolated from amino acid pyrolysis products, and that a new, unidentified mutagen exists in broiled sardines.

TL;DR: The feasibility of utilizing neonatal human foreskins grafted to congenitally athymic nude mice for carcinogenesis studies was explored and two benign squamous papillary lesions developed in the human graft sites receiving TPA.

TL;DR: A modification of the alkaline filter elution test was used to study damage to liver DNA of NMRI mice following in vivo treatment with various hepatocarcinogens and drugs causing liver enlargement.

TL;DR: It was shown that 1-phenylethylbiguanide (phenformin) administered orally to mice at a dose of 2 mg/day potentiated the antitumor effect of cyclophosphamide on transplantable squamous cell cervical carcinoma, hepatoma-22a and Lewis lung tumor, but did not alter the effect ofcycloph phosphamide on sarcoma-180 and L-1210.

TL;DR: The results suggest that the local regions of denaturation induced by AF substitution are smaller than those associated with AAF modification, which could mean that 2-aminofluorene(AF)-modified DNA is hydrolyzed 3 times more slowly than N-acetyl-2-amin ofluorenes(AAF)- modified DNA under similar reaction conditions.

TL;DR: It is suggested that lymphoblastoid cells may be a useful model for studying the molecular alterations at the membrane level resulting from the action of tumour-promoting phorbol diesters.

TL;DR: Several newly synthesized polyadenylic acid analogues have been evaluated for their effects on the RNA-directed DNA polymerase (reverse transcriptase) activity of Moloney murine leukemia virus and served as an efficient template for the reverse transcriptase reaction.

TL;DR: Observations are consistent with a 2- or multi-step carcinogenesis mechanism, which implies that DMH induces a permanent transmissible alteration within some cells which thereafter will be at risk for further alterations capable of initiating cancer growth.

TL;DR: EGF binding was inhibited by low concentrations of the tumor promoters 12-O-tetradecanoylphorbol-13-acetate (TPA) and phorbol didecanoate (PDD), but not by the non-promoting phorbl esters 4-O -methyl TPA and 4 alpha-PDD.