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PubMed1988

[Metabolic activation of chemical carcinogens by rat tissues in the perinatal period].

Metabolic activation of procarcinogenic 2-acetyl-amino-fluorene, benzo(a)pyrene, aflatoxin B1 and N-nitrosodimethylamine by various tissues of embryonal and newborn rats was studied with the Salmonella/microsome assay. Bioactivation by fetal tissues was shown to be significantly lower than with newborn rat tissues. When aroclor was given to pregnant females a decrease in metabolic activation was observed. This phenomenon was interpreted as a paradoxical effect. Treatment with aroclor of newborns led to a significant increase in biotransformation of all the compounds tested in the liver and after benzo(a)pyrene--in the kidney, and N-nitrosodimethylamine--in the lung.

Animals↗
PubMed1986

[Quinolizidine derivatives with antibacterial activity].

Six quinolizidinyl-derivatives were tested for antibacterial actvity against a large number of gram-positive and gram-negative strains. 9-Lupinyliden-fluorene (I) and its epimer (II) at concentrations between 12,5 and 100 mg/l inhibit all gram-positive strains, while they are only weakly active against a few gram-negative bacteria. The tertiary alcohols (III) and (IV) are inactive against the gram-positive strains, while still exhibiting weak activity on the gram-negative. Compounds (V) and (VI) are completely inactive. The values of minimal bactericidal concentrations for compound (I) against the sensitive strains are equal to or no more than 4 times higher than values of MIC. It is interesting to note that compound (I) is able to give rise to cellular lysis at MIC.

Anti-Bacterial Agents↗
PubMed1971

Effect of a new antiaggregating chemical on the structure and function of the human platelet.

A new antiaggregating chemical, alpha-(p-(fluoren-9-ylidenemethyl)phenyl)-2-piperidineethanol (RMI 10,393), designated FYPE, was found to be an effective inhibitor of platelet aggregation induced by adenosine diphosphate (ADP), thrombin, collagen, or epinephrine. Effects of the antiaggregant on platelets were concentration dependent. Aggregation was prevented by low concentrations of FYPE that produced in the platelet only minor ultrastructural changes consisting of loss of microtubules and of discoid shape. Low levels of FYPE that prevented platelet aggregation had no effect on platelet ATPase activities but did alter clot retraction, the thrombin-induced shift in electrophoretic mobility and platelet cholinesterase activity. Market decrease in ADP release and increase in adenyl cyclase activity were produced by low levels of FYPE. This study provides a model for evaluation of platelet antiaggregating compounds in vitro.

Adenosine Diphosphate↗
PubMed1979

Metabolic activation of arylhydroxamic acids by N-O-acyltransferase of rat mammary gland.

The lactating mammary glands of rats contain an arylhydroxamic acid N,O-acyltransferase that catalyzes the formation of arylamine-substituted nucleic acid on incubation with N-hydroxy-N-2-acetylaminofluorene or N-hydroxy-N-4-acetylaminobiphenyl and transfer RNA. The acyltransferase activity migrates as a single component with a molecular weight of 28,000 on gel filtration on Sephadex G-100. Acyltransferase activities of the lactating mammary glands of Sprague-Dawley animals are approximately twice those of the less susceptible Fischer strain as determined by assay with either hydroxamic acid. The fluorene substrate was 15 times as efficient as the biphenyl compound in promoting adduct formation. Ribosomal RNA adducts formed in vivo after administration of N-hydroxy-N-2-acetylaminofluorene were consistent with an acyltransferase mechanism of activation in that the adducts did not retain the acetyl group.

Acyltransferases↗
PubMed1983

beta-Adrenergic receptors in rabbit liver plasma membranes. Predominance of beta 2-receptors and mediation of adrenergic regulation of hepatic glycogenolysis.

[3H]Dihydroalprenolol was used to study beta-adrenergic binding sites in plasma membranes isolated from rabbit liver. Specific binding was measured at 25 degrees C as the difference between total binding and binding in the presence of 2 microM dl-propranolol or 10 microM l-isoproterenol. Binding was saturable and stereoselective. The maximum number of binding sites (Bmax) was 434 +/- 41 fmol/mg of protein. The Kd for this binding as determined by Scatchard analysis was 1.39 +/- 0.09 nM. This value agreed well with the Kd value (1.27 +/- 0.12 nM) determined by kinetic analysis. The potency order for the displacement of bound [3H]dihydroalprenolol was isoproterenol greater than epinephrine greater than norepinephrine, indicative of beta 2-receptors. Use of beta 1- and beta 2-subtype-selective inhibitors also supported the interpretation that the binding characteristics are those of beta 2-receptors. Computer-aided analysis of this inhibition indicated that the beta-receptors in this membrane are predominantly, if not exclusively, of the beta 2-subtype. That these receptors are responsible for mediating catecholamine stimulation of hepatic glycogenolysis was deduced from the inhibition of agonist-stimulated glycogenolysis, in isolated hepatocytes, by beta-receptor subtype-selective antagonists. Thus, the hydrochloride of (t-butylamino-3-ol-2-propyl)oximino-9 fluorene, a beta-antagonist which has higher affinity at beta 2-sites than at beta 1-sites, was 3 orders of magnitude more potent in inhibiting isoproterenol-stimulated glycogenolysis than either atenolol or practolol, both of which are beta 1-selective antagonists. These results resemble the inhibition of [3H]dihydroalprenolol binding in plasma membranes. The glycogenolytic effects of catecholamines occurred with the potency order isoproterenol greater than epinephrine greater than norepinephrine. Thus, both by radioligand binding studies and by metabolic studies, the functional adrenergic receptor in the rabbit liver is shown to be of the beta 2-subtype.

Animals↗
PubMedDate not supplied

[Mechanism of ethonium effect on membrane preparations of brain Na+, K+-ATPase].

The effect of ethonium, a local anesthetic, on the membrane preparations of brain N+, K+-ATPase was studied by fluorescent, radioisotopic, electron-microscopic and electrophysiological methods. Ethonium is established to affect the formation of an intermediate phosphorylated product and has no pronounced destructive effect on the membrane. It changes the fluorescence intensity of 2-toluidinonaphthalen-6-sulphonate (TNS), astrafloxin (AF) and fluorene probes in a suspension of the Na+, K+-ATPase preparations, which evidences for ethonium-induced changes in the structure of membrane fragments.

Action Potentials↗
PubMed1984

Association between cage shelf level and spontaneous and induced neoplasms in mice.

Data from a chronic feeding study with 2-acetylaminofluorene [(2-AAF) CAS: 53-96-3; N-fluoren-2-yl-acetamide] done on 20,880 female BALB/c mice were analyzed for associations between cage shelf level and occurrence of induced and spontaneous neoplasms. Each cage was maintained on a rack at a given shelf level throughout the experiment, allowing analysis of data by shelf level. Differences in the crude incidence of 2-AAF-induced liver and bladder neoplasms appeared to be shelf related, but these differences were small and disappeared when shelf-level analyses of time-to-tumor onset distributions were performed. There was evidence for a shelf-level influence on 5 of the 6 major spontaneous neoplasms noted. Time to onset of uterine polyps and reticulum cell sarcomas was significantly delayed on the top shelf of five of six animal rooms. Also, there was a significant delay in onset of lymphomas, adrenocortical adenomas, and lung alveolar cell tumors on the top shelf when data were combined from all six animal rooms, but these delays on the top shelf were significant in no more than two of six animal rooms when rooms were analyzed separately. There was no indication of any shelf-level influence on the development of harderian gland adenomas. In conclusion, shelf level is an environmental factor that should be considered in the design and analysis of carcinogenesis studies.

2-Acetylaminofluorene↗
PubMed1984

Quantitation of carcinogen-DNA adducts by a standardized high-sensitive enzyme immunoassay.

A highly sensitive competitive enzyme immunoassay has been developed, allowing accurate determination of DNA containing the adducts N-(deoxyguanosin-8-yl)-N-acetyl-2-amino-fluorene, N-(deoxyguanosin-8-yl)-2-aminofluorene, 1-[6-(2,5-diamino-4-oxopyrimidinyl-N6-deoxyriboside)]-3-(2-fluo renyl)urea or trans-(7R)-N2-[10-(7 beta,8 alpha,9 alpha-trihydroxy-7,8, 9,10-tetrahydrobenzo[a]pyren)yl]deoxyguanosine. Standard amounts of the carcinogen-modified DNA preparations (25 fmol/500 ng) were coated on the wells of microtitre plates. Various amounts of the modified DNA preparations were used as inhibitors and added before binding of the antibodies (dilution 1:10(6). As second antibody, goat anti-rabbit IgG coupled to alkaline phosphatase was used. The amount of enzyme was determined with 4-methylumbelliferyl phosphate as substrate (Van der Laken et al., 1982). The 50% inhibition values of the standard curves are in the range of 2-16 fmol for the enzyme immunoassays. It is possible to add up to 50 micrograms of unknown DNA to the wells, allowing for comparison with the same quantity of modified DNA. This extends the limit of detection to 1-6 adducts per 10(8) nucleotides. The sensitivity of the assay seems sufficient to demonstrate exposure of humans to known chemical carcinogens.

Animals↗
PubMed1983

[Proliferation kinetics of various tissues following administration of different carcinogens of different kinds of organotropism].

Inhibition of cell division of targets and nontarget tissues is one of the acute actions of chemical carcinogens. A single gastric dose of N-methyl-N-nitro-N'-nitrosoguanidine (MNNG) causes a mitotic suppression in the forestomach, in the jejunal crypts and in the esophagus. 2-acetylamino-fluorene (AAF) causes the same suppression in the esophagus and the liver. In contrast, the mitotic activity is increased in liver and adrenal cortex by MNNG and in the adrenal cortex by AAF. Both the inhibiting and mitogenic action depend on the circadian phase of treatment.

2-Acetylaminofluorene↗
PubMed1984

Alterations of the intestinal microflora by diet, oral antibiotics, and Lactobacillus: decreased production of free amines from aromatic nitro compounds, azo dyes, and glucuronides.

F344 rats were fed compounds containing a nitro, azo, or amine-glucuronide group-2-nitronaphthalene (CAS: 581-89-5), 2-nitrofluorene (CAS: 607-57-8; 2-nitro-9H-fluorene), 4-phenylazo-2-naphthol (CAS: 6410-10-2; 1-[(4-nitrophenyl)azo]-2-naphthol), and 2-naphthylamine-N-D-glucuronide--and the formation of free amines was measured in the feces. The effects of diet (mean vs. grain), administration of antibiotic, and the feeding of Lactobacillus acidophilus were evaluated. Meat-fed rats given 2-nitronaphthalene had approximately 4 times higher concentration of free amines in their feces as compared to the concentration in grain-fed rats. In a similar experiment with 2-naphthylamine-N-D-glucuronide, the meat-fed animals had approximately 1.5 times more of the free amines and 50% less of the conjugates in their feces. When meat-fed animals were given L. acidophilus with 2-nitrofluorene or 2-naphthylamine-N-D-glucuronide, they had significantly lower free amines and higher concentrations of conjugates in their feces than did the meat-fed controls. Similarly, erythromycin or tetracycline decreased the fecal amine production in meat-fed animals that had received 2-nitrofluorene or 4-phenylazo-2-naphthol. In another experiment, erythromycin inhibited the production of free amines from 2-naphthylamine-N-D-glucuronide in rats fed a high-fat diet. Studies of fecal enzymes revealed lower levels of beta-D-glucuronidase, nitroreductase, and azoreductase in grain-fed rats and in meat-fed animals also given antibiotics or lactobacilli. These experiments showed that intestinal flora have the ability to convert exogenously administered aromatic nitro and azo compounds and an amine-glucuronide compound to free amines. The rate of these conversions was affected by diet and by oral administration of antibiotics and lactobacilli.

Amines↗
PubMed1984

Reversal of acquired resistance to doxorubicin in P388 murine leukemia cells by tamoxifen and other triparanol analogues.

The effects of the triparanol analogues chlorotrianisene, clomiphene, tamoxifen, 5-[p-(fluoren-9-ylidenemethyl)phenyl]-2-piperidineethanol (MDL 10393), MDL 8917v, nafoxidine, 2-[p-(6-methoxy-2-phenylinden-3-yl)phenoxy]triethylamine (U-11555A), 2-[p-(3,4-dihydro-6-methoxy-2-phenyl-1-naphthyl)phenoxy]triethylamine (U-10520A), and nitromifene, as well as triparanol itself, were studied in the P388 murine leukemia cell line and in a doxorubicin-resistant subline (P388/ADR). At noninhibitory concentrations, all the analogues increased the sensitivity of P388/ADR cells to doxorubicin but did not have such an effect on the doxorubicin-sensitive cells. Diethylstilbestrol, deacetylated cyclofenil (F6060), hexestrol, and 17 beta-estradiol did not have such an activity. The effects of tamoxifen on doxorubicin sensitivity of P388/ADR cells could not be reversed by 17 beta-estradiol. Estrogen receptors could not be demonstrated in either cell line. It is therefore suggested that the reversal of the doxorubicin-acquired resistance by the triparanol analogues is unrelated to their estrogenic or antiestrogenic activities. The possible clinical implications of these findings are discussed.

Animals↗
PubMed1984

GLC analysis following oxidation of phenytoin. An inexpensive method for routine determination of the drug in plasma.

Phenytoin (5,5-diphenyl-2,4-imidazolidinedione) is readily oxidized to benzophenone. Using spiro(fluorene-9,4-imidazolidine)-2',5'-dione or 5-(4'-methoxyphenyl)-5-phenyl-2,4-imidazolidinedione as internal markers the oxidation product can be analyzed by GLC, providing an analytical method for plasma phenytoin which removes the need for preliminary extraction of the drug.

Animals↗
PubMed1984

Evaluation of a histologic classification of mouse liver tumors based on pyruvate kinase isozymes and status of host lipids.

The histologic classification of mouse liver tumors, i.e., hepatic nodules type 1 and type 2 and hepatocellular carcinomas, was evaluated by a comparison of several biologic and biochemical markers that have been shown to be useful for the grading of tumor malignancy. The liver tumors were induced by N,N'-2,7-fluorenylenebisacetamide (CAS: 304-28-9; N,N'-fluoren-2,7-ylenebisacetamide) administration to male CD-1 mice. The ability to induce L-type pyruvate kinase activity in response to a high-carbohydrate diet disappeared in almost all the liver tumors. However, fairly good correlations were observed between the histologic classification and the relative weights of liver and intraperitoneal fat pads, between the histologic classification and the level of serum total cholesterol, and between the histologic classification and the K-type pyruvate kinase activity. The results suggest that the present histologic classification reflects the degree of tumor malignancy, and therefore, it would be useful for the classification of mouse liver tumors.

Animals↗
PubMed1983

Spectroscopic study of the effects of C-alkylation of N-acetoxy-N-acetyl-2-aminofluorene on some properties of the carcinogen-modified DNA.

Several physicochemical properties of DNA reacted in vitro with the carcinogen metabolite N-acetoxy-N-2-acetylaminofluorene (N-AcO-AAF) are compared to those of DNA reacted with two C-alkylated derivatives, viz. N-acetoxy-7-ethyl-N-2-acetylaminofluorene (N-AcO-EtAAF) and N-acetoxy-7-n-butyl-N-2-acetylamino-fluorene (N-AcO-ButAAF). Ultraviolet absorption, high resolution derivative melting curves and circular dichroism techniques are employed in the present study. C-alkylation of N-AcO-AAF influences the conformational modifications of DNA induced by the covalent binding of the metabolite. The size of the alkyl group seems to determine the effect on DNA conformation (e.g., the bulkiest N-AcO-ButAAF denatures the most DNA). However, certain similarities between the three metabolites are observed, such as the preferential binding to G-C rich regions and the carcinogen-carcinogen and carcinogen-DNA base stacking interactions.

2-Acetylaminofluorene↗
PubMed1982

In vitro screening of carcinogens using DNA of the His- mutant of Salmonella typhimurium.

Carcinogens: 7,12-dimethylbenz(a)anthracene (DMBA), 2-acetylaminofluorene (AAF), 3-methylcholanthrene (MC), daunorubicin, thio-TEPA, cyclophosphamide, 1-(2-chloroethyl)2-cyclohexyl-1-nitrosourea (CCNU) and mitomycin C, which mutate Salmonella typhimurium tester strains in the Salmonella/microsome mutagenicity test, strongly stimulate the in vitro synthesis of DNA isolated from His- mutants (TA-1538, TA-1537, TA-1535), and induce in vitro His- DNA strand separation. Four other carcinogens, ethionine, actinomycin D, bleomycin and reserpine, which were not known as mutagens in the Ames test, also strongly stimulate His- DNA synthesis and His- DNA strand separation in local areas. Those substances which are neither carcinogenic nor mutagenic: d-lactose, fluorene, cholesterol, and saccharin, do not stimulate either His- DNA (or His+ DNA) synthesis or DNA in vitro strand separation. Steroid hormones, which are carcinogenic only for steroid target tissues, do not react with bacterials DNA.

Animals↗
PubMed1994

Synthesis of some new heterobicyclic compounds containing spiro-1,2,4-triazine moiety as potential anti-HIV and anticancer agents.

A number of heterobicyclic compounds such as 1,3,5-thiazine, thiazolidinone, pyrimidine, pyrimidinedione, imidazole, quinazolinone and 1,2,4-triazinone derivatives have been sythesized by reaction of 1,6-dihydro-3(2H)-thioxo-6-spiro-(9'- fluorene)-1,2,4-triazin-5(4H)-one (1) with sulphur/nitrogen compounds in neutral or alkaline media. Structure elucidation of the new compounds have been carried out with the help of elemental analysis and spectral data. Some of these compounds were tested for in vitro anti HIV and anticancer activities.

Antineoplastic Agents↗
PubMed1994

Synthesis of some new heterobicyclic compounds containing spiro-1,2,4-triazine moiety as potential anti HIV and anticancer agents.

A number of heterobicyclic compounds such as 1,3,5-thiazine, thiazolidinone, pyrimidine, pyrimidinedione, imidazole, quinazolinone and 1,2,4-triazinone derivatives have been synthesized by interaction of 1,6-dihydro-3 (2H)-thioxo-6-spiro-(9'-fluorene)-1,2,4-triazin-5(4H)-one (1) with sulphur/nitrogen compounds in neutral or alkaline medium. Structure elucidation of the new compounds has been carried out with the help of elemental analysis and spectral data. Some of these compounds were tested for in vitro anti HIV and anticancer activities.

Antineoplastic Agents↗
PubMed1994

Quinolizidine derivatives with antitubercular activity.

By reacting lupinylmagnesium chloride with suitable aromatic ketones, several lupinyldiarylcarbinols were obtained, whose dehydration gave the corresponding lupinylidenediarylmethanes. By reduction of three of these unsaturated compounds, the corresponding lupinyldiarylmethanes were also obtained. Direct condensation of lupinine with fluorene gave the 9-epi-lupinylfluorene. The quinolizidine derivatives obtained were tested against Mycobacterium tuberculosis H37RV. Nine compounds resulted endowed with good antitubercular activity with MIC < 8 micrograms/ml, while the remaining were only moderately active. Most interesting was the lupinylidene derivative 13 with MIC > 0.1 < 0.5 micrograms/ml.

Antitubercular Agents↗