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D M DeMarini

Publications and source records attributed to D M DeMarini.

89 records · Page 5Linked to original sources
PubMed1987

Mutagenicity of m-AMSA and o-AMSA in mammalian cells due to clastogenic mechanism: possible role of topoisomerase.

We evaluated the ability of the antitumor agent 4-(9-acridinylamino)-methanesulfon-m-anisidide (amsacrine or m-AMSA) and its congener, o-AMSA, to induce specific-locus mutations at the heterozygous thymidine kinase (tk) locus of L5178Y/TK+/- -3.7.2C mouse lymphoma cells. These cells permit the recovery of mutants due to single-gene or chromosomal mutation. m-AMSA was highly mutagenic at the tk locus, producing approximately 3000 mutants/10(6) survivors at 10% survival; positive dose range 1-10 ng/ml; o-AMSA produced approximately 1500 mutants/10(6) survivors at 10% survival; positive dose range 0.1-2.5 micrograms/ml. Most of the TK mutants were small colonies, which suggests that m-AMSA and o-AMSA induce primarily chromosomal mutations as opposed to single-gene mutations. The potent clastogenicity of these agents was confirmed by cytogenetic analysis for chromosomal aberrations, which showed that m-AMSA (9 ng/ml, 10% survival) and o-AMSA (1 microgram/ml, 10% survival) produced 383 and 179 aberrations, respectively, per 100 metaphases (background = 3-4/100). The large-colony TK mutant frequencies produced by m-AMSA (67 - 112/10(6) survivors; background = 7/10(6); survival = 63 - 16%) were comparable to the published HPRT mutant frequencies produced by m-AMSA in V79 cells. Novobiocin (50 micrograms/ml), an inhibitor of mammalian DNA topoisomerase II and other enzymes, inhibited the mutagenic effects of m-AMSA, suggesting that DNA topoisomerase II (or another enzyme) may play a role in the mutagenic/clastogenic activity of m-AMSA.

Amsacrine↗
PubMed1984

Cytotoxicity and mutagenicity of coal oils in the CHO/HGPRT assay.

We used the Chinese hamster ovary cell/hypoxanthine-guanine phosphoribosyl-transferase (CHO/HGPRT) assay to determine the cytotoxicity and mutagenicity of a crude coal oil, the neutral fraction of this crude, and the following three subfractions of the neutral fraction: aliphatic, neutral polar, and a subfraction composed of polycyclic aromatic hydrocarbons plus neutral nitrogen heterocyclics. We also studied the cytotoxicity and mutagenicity of a blend of light and heavy coal-derived fuel oils before and after hydrogenation. All seven mixtures were highly cytotoxic to CHO cells, but the addition of S9 reduced the cytotoxicity. Also, hydrogenation reduced the cytotoxicity of the blend of coal-derived fuel oils. Although highly cytotoxic, none of the seven mixtures induced a clear mutagenic response in the CHO/HGPRT assay. However, previous work has shown that all of the mixtures except the aliphatic subfraction and the blend after hydrogenation are mutagenic in the histidine-reversion assay in Salmonella typhimurium. Based on chemical analyses of the mixtures, the differential sensitivity of Salmonella and CHO cells to nonmutagenic cytotoxins, and studies of the neutral fraction to which additional benzo[a]pyrene had been added, we conclude that the disparity between the results in Salmonella and those obtained in the CHO/HGPRT assay is probably due to the much greater sensitivity of CHO cells (relative to Salmonella) to the cytotoxins in these coal oils. This sensitivity, coupled with the low concentrations of mutagens relative to nonmutagenic cytotoxins in the coal oils, prevents exposure of the cells to concentrations of the mutagens in the mixtures that are high enough to be quantified in the CHO/HGPRT assay.

Animals↗
PubMed1984

Mutation tests in Neurospora crassa. A report of the U.S. Environmental Protection Agency Gene-Tox Program.

Many mutation tests have been developed in Neurospora crassa during the almost 40 years of its use in mutation research. These tests detect two major classes of mutation: gene mutation and meiotic nondisjunction. Within the first class, forward- and reverse-mutation tests have been used. The forward-mutation tests include those that detect mutations at many loci and at specific loci. Both kinds of forward-mutation tests have been done in homokaryons (n) and heterokaryons (n + n'). From the publications that were not rejected by our pre-established criteria, data were extracted for 166 chemicals that had been tested for mutagenicity. Only 6 of the 166 chemicals have been tested in one or more gene mutation test and the meiotic nondisjunction test; these 6 chemicals were positive in the first and negative in the second. Of the 102 chemicals tested in one or more gene mutation tests, 94 were positive and 8 were negative. Of the 70 chemicals tested in the meiotic nondisjunction test, 7 were positive and 63 were negative. Two tests, the ad-3 forward-mutation test and the meiotic nondisjunction test, have been used most frequently. These two tests are especially important for hazard evaluation, because each detects a class of mutations that is likely to be deleterious or lethal in the F1 - disomics by the meiotic nondisjunction test and multilocus deletions by the ad-3 forward-mutation test in heterokaryons. Generally, direct-acting chemicals are mutagenic in the gene mutation tests, but few chemicals that required metabolic activation have been tested. Only 31 of the 166 chemicals tested in N. crassa have been tested for carcinogenicity. Among these chemicals, there is a good association between mutagenicity in gene mutation tests and carcinogenicity but a poorer association between meiotic nondisjunction and carcinogenicity; however, only a small number of chemicals has been tested in the meiotic nondisjunction test. Further use and development of certain mutation tests in N. crassa are desirable.

Alleles↗
PubMed1984

Relationships between structures and mutagenic potencies of 16 heterocyclic nitrogen mustards (ICR compounds) in Salmonella typhimurium.

16 heterocyclic nitrogen mustards (ICR compounds), which were synthesized for use as possible antitumor agents by Creech and coworkers, were tested for mutagenicity in Salmonella typhimurium strains TA1535, TA1536, TA1537, TA1538, TA98 and TA100. The compounds were incorporated into the top agar at 5 doses: 0.5, 1, 2.5, 5 and 10 micrograms/plate. All of the compounds were negative in TA1535 except ICR 449, which was positive in all 6 strains. The other 15 compounds were positive in the remaining strains with the following exceptions: ICR 371 and 355 were negative in TA100; ICR 445 was negative in TA98 and TA100; and ICR 360 was negative in TA1537, TA1538, TA98 and TA100. Good qualitative agreement was observed between the mutagenic and antitumor activities of the 16 compounds, and between the mutagenic and carcinogenic activities of the 5 compounds that have been tested for carcinogenicity by Peck and coworkers. However, no significant correlation was found between mutagenic potency in Salmonella and antitumor potency in mice for the 16 compounds. Also, for the 5 compounds that have been tested for carcinogenicity, no significant correlation was found between their mutagenic potency in Salmonella and their carcinogenic potency in mice. In Salmonella, the secondary (2 degrees) amines generally were more mutagenic than their tertiary (3 degrees) amine homologs, although the opposite result has been reported in certain eukaryotes. Relationships between structures and potencies for the different nuclei of the 16 ICR compounds are discussed, as are similarities and differences in strain sensitivities. We conclude that the Salmonella his reversion test is not a good predictor of the antitumor and carcinogenic potencies of these ICR compounds.

Adenoma↗
PubMed1983

Mutagenicity and cytotoxicity of five antitumor ellipticines in mammalian cells and their structure-activity relationships in Salmonella.

The mutagenicity and cytotoxicity of five antitumor compounds (ellipticines) were investigated in the Chinese hamster ovary cell hypoxanthine-guanine phosphoribosyltransferase assay and in six strains of Salmonella. All five compounds (ellipticine, 9-methoxyellipticine, 9-hydroxyellipticine, 9-aminoellipticine, and 2-methyl-9-hydroxyellipticinium) were cytotoxic and mutagenic in the Chinese hamster ovary cell hypoxanthine-guanine phosphoribosyltransferase assay in the presence or absence of Aroclor 1254-induced rat liver S9, and all except the last compound were mutagenic in Salmonella. Based on the reversion pattern obtained in various frame-shift and DNA repair-proficient (uvrB+) or -deficient (uvrB) strains of Salmonella in the presence or absence of S9, the first three compounds appear to cause frame-shift mutations by both intercalation and covalent bonding with DNA; thus, these are classified as reactive intercalators. However, 9-aminoellipticine intercalates only weakly and may instead exert its mutagenic activity primarily (or exclusively) by forming a covalent adduct with DNA. Compared to the published antitumor data obtained in mice, the results in Salmonella and Chinese hamster ovary cells suggest that the ability of ellipticine, 9-methoxyellipticine, and 9-hydroxyellipticine to intercalate with DNA, induce frame-shift mutations, and cause cell killing is associated with and may be the basis for their antitumor activity. The observation that the ellipticines are mutagenic in mammalian cells suggests that these antitumor agents may be carcinogenic.

Alkaloids↗
PubMed1982

Use of four short-term tests to evaluate the mutagenicity of municipal water.

Some ways in which four short-term tests may be used to evaluate the mutagenicity of drinking water were explored by testing raw and treated water from Lake Bloomington, which serves the town of Bloomington, Illinois (population, 44,000). The water was collected from February 1976 to October 1977 and was concentrated by evaporation or by use of XAD-2 resin. The water was tested for the ability to induce reverse mutation in a prokaryote, Salmonella typhimurium; forward mutation in a mold, Neurospora crassa; mitotic gene conversion in a yeast, Saccharomyces cerevisiae; and reverse mutation in maize, Zea mays. Because of the large number of water samples (54) and the limited amounts of the samples, it was not possible to test all samples in all four tests by all the protocols. Thus, the sensitivities of the four tests to potential mutagens in the water samples could not be rigorously compared. However, the results do show that lake and tap water samples collected during 1976 were toxic but not mutagenic in N. crassa and neither toxic nor genotoxic in S. cerevisiae; lake water collected during 1977 was mutagenic in one line of Z. mays and slightly mutagenic in S. typhimurium strain TA1536 in the presence of rat liver S9. The results suggest that tests that detect a variety of genetic end points should be used when testing complex mixtures such as drinking water. The advantages and disadvantages of the tests and protocols are discussed in terms of their applicability to the study of the mutagenicity of drinking water.

Animals↗
PubMed1981

Mutagenicity of municipal water obtained from an agricultural area.

We have studied the mutagenicity of the water from Lake Bloomington and of the tap water that is made from the lake water. The lake, which is the source of drinking water for Bloomington, Illinois (pop. 44,000), is surrounded by land that is farmed intensively--being mainly in maize and soybeans. Samples were collected monthly from May through October 1979 and concentrated 3,000X with XAD-2 resin. Nearly all of the lake and tap water concentrates were mutagenic in Salmonella typhimurium TA98 and TA100 in the presence of S-9 mix, and the May tap water concentrate was highly mutagenic. In addition, many of the concentrates were toxic to the bacteria in the absence of S-9 mix. Chemical analysis of the highly mutagenic tap water concentrate from May revealed the presence of a number of organic contaminants that were absent from control concentrates prepared from deionized and distilled treated-well water. In addition, unconcentrated lake and tap water were tested in a reverse-mutation test in maize (Zea mays); no mutagenicity was detected. This study indicates that the contamination of drinking water with agricultural and/or industrial chemicals may result in a potential health hazard.

Agriculture↗
PubMed1981

Mutagenicity of fractions of cigarette smoke condensate in Neurospora crassa and Salmonella typhimurium.

The mutagenicities of selected fractions of cigarette smoke condensate (CSC) were studied in Neurospora crassa for the presence of direct-acting mutagens. CSCs from the University of kentucky Reference Cigarette 1R1 were assayed in a forward-mutation test at the adenine-3 (ad-3) region in resting conidia of a 2-component heterokaryon. Direct-acting mutagenic activity was found in an enriched polycyclic aromatic hydrocarbons (EPAH) fraction and in a basic fraction (Swain 5). No direct-acting mutagenic activity was detected in an acidic fraction (Swain 8), although it was highly toxic to resting conidia. The EPAH fraction also was tested in the presence of S9 mix prepared from Aroclor-1254-induced rat liver. It was found to be mutagenic, but higher doses were required than in the absence of S9 mix. In addition, the mutagenicities of CSC and 10 fractions of CSC were investigated in Salmonella typhimurium TA1538 by the incorporation and preincubation methods. In general, preincubation did not enhance the mutagenicities of the fractions, and the two rankings of mutagenic potency of the condensates that were obtained by the two methods were not significantly different. This is the first report of the presence of potent direct-acting mutagenicity in the EPAH and Swain 5 fractions of CSC.

Mutagenicity Tests↗
PubMed1981

Mutagenicity of cigarette smoke condensate in Neurospora crassa.

The mutagenicity of cigarette smoke condensate (CSC) was investigated in Neurospora crassa in the presence and absence of S9 mix prepared from Aroclor-1254-induced rat liver. CSC from the University of Kentucky Reference Cigarette 1R1 was assayed in a forward-mutation test at the adenine-3 (ad-3) region in resting conidia of 2-component heterokaryons. In the absence of S9 mix, CSC exhibited direct-acting mutagenicity. CSC was also mutagenic in the presence of S9 mix, but higher doses were required than in the absence of S9 mix. The dose range, survival curves, and mutation-induction curves were not significantly different when CSC was used in the presence of unheated or heat-inactivated S9. There was a positive association between killing and mutagenicity, and CSC killed conidia of N. crassa by a cytoplasmic, rather than by a nuclear, mechanism. The mutagenic potency of CSC was similar in a repair-sufficient and a nucleotide excision repair-deficient heterokaryon of N. crassa. CSC did not exhibit a photodynamic effect for killing, and CSC caused more killing at high pH than at low pH. In addition, CSC caused more killing at 37 degrees C than at 25 degrees C and also caused more killing in higher concentrations (20%) of solvent (DMSO) than in low concentrations (1%). This is the first report of the presence of potent direct-acting mutagens in CSC.

Mutagenicity Tests↗
PubMed1979

Mutagenicity of skin tanning lotions.

Two lotions that tan skin in the absence of sunlight and their active ingredient, dihydroxyacetone (DHA), are mutagenic in Salmonella typhimurium strain TA100 without metabolic activation. However, addition of S-9 mix that contains Aroclor 1254-induced rat hepatic microsomes enhances significantly the mutagenic activity of all three agents. Both lotions and DHA also cause primary DNA damage as determined by the rec-assay in Bacillus subtilis. The potential human health hazard of these lotions is discussed.

Bacillus subtilis↗
PubMed1978

Mycoviruses of Penicillium stoloniferum: influence of carbon-nitrogen nutrition upon replication.

Carbon-nitrogen ratio experiments indicate that limiting nutrition not only hinders Penicillium stoloniferum host proliferation but reduces total PsV-F and PsV-S virus replication. Results of C-N experiments show a pH-induced autolysis and virus release at minimal C levels. Maximal PsV-F levels and biomass were obtained with glucose and sucrose as C sources. Oleic acid also yielded high biomass and PsV-F yields. Yeast extract was an excellent N source; 2.83 g dry weight biomass and 87 A260 units PsV-F after 96 h of growth. Other nitrogen sources, including amino acids, supported only minimal growth and virus replication. The autolysis phenomenon is pH, not viral-induced. High C and N will support maximal growth and unrestricted virus replication with no cellular lysis. Under low C growth conditions, the replication of PsV-S is favored coupled with high pH and autolysis.

Amino Acids↗
PubMedDate not supplied

The efficacy of Neurospora in detecting agents that cause aneuploidy.

A total of 110 agents, 109 chemicals plus gamma-rays, has been tested in a Neurospora pseudowild-type selection system for their ability to induce meiotic aneuploidy. 11 agents were positive, 47 were negative, and 52 were inconclusively tested. The system has a possible role as a short-term test for environmental agents causing human aneuploidy. The advantages of the system are its simplicity and ease of use. Disadvantages are its high variability of aneuploid frequency and an inability to distinguish mechanisms of aneuploidy.

Aneuploidy↗
PubMedDate not supplied

Mutagenicity and clastogenicity of adriamycin in L5178Y/TK(+/-)-3.7.2C mouse lymphoma cells.

Adriamycin was found to be both mutagenic and clastogenic to L5178Y/TK(+/-)-3.7.2C mouse lymphoma cells. A dose of only 5 ng/ml (survival = 62% or 67%) gave an induced TK mutant frequency of 307 or 296 per 10(6) survivors in two separate experiments. This dose was also clastogenic, inducing 20 chromosome aberrations/100 cells analyzed. The majority of the mutants were small-colony mutants, indicating that adriamycin likely acts primarily by a clastogenic mechanism.

Animals↗
PubMedDate not supplied

Mutation spectrum of a binary mixture of mutagens (methapyrilene and sodium azide) in strain TA1535 of Salmonella.

Methapyrilene (MP) is a rat-liver carcinogen and cocarcinogen that exhibits a narrow spectrum of mutagenic activity in Salmonella typhimurium, inducing only a 2-fold increase in revertants only in the base-substitution strain TA1535; it also enhances the mutagenic activity of sodium azide (NaN3) in the same strain. To examine the effects of MP at the molecular level, we used the colony probe hybridization procedure developed by Cebula and Koch (Mutation Res., 229 (1990) 79-87) to identify the base substitutions in approximately 800 background, MP-, NaN3-, and MP + NaN3-induced revertants of the hisG46 allele of strain TA1535. The predominant mutation in all 4 mutation spectra was a CCC-->CTC transition. The results suggest a mechanism by which MP enhances the infidelity of the DNA replication complex or inhibits a DNA repair or proofreading function, resulting in the production of more of the same error that occurs normally and that is also induced by NaN3. Such a mechanism might be the basis for the carcinogenic and cocarcinogenic activities of MP. To our knowledge, this is the first report of the molecular analysis of mutants produced by exposure of cells to a binary mixture of mutagens.

Azides↗
PubMedDate not supplied

Biomarker assays in nipple aspirate fluid.

The noninvasive technique of nipple aspiration as a potential source of biomarkers of breast cancer risk was evaluated. The feasibility of performing mutagenesis assays, amplifying DNA, and performing protein electrophoresis on nipple aspirate fluid was explored. A tool was developed to measure the level of discomfort, if any, from this procedure. Twenty-five healthy women (20 premenopausal and 5 postmenopausal) were enrolled. Fluid was obtained using a modified breast pump. Premenopausal women were scheduled for four to six weekly aspirations, and postmenopausal women were scheduled for one to two weekly aspirations. Mutagenesis assays were performed using the Salmonella (Ames) assay. DNA amplification of several microsatellite regions was carried out using polymerase chain reaction. Protein was quantified, and two-dimensional protein electrophoresis was performed. Overall, fluid was obtained from 80% of the women, and the level of discomfort was minimal. Acid hydrolysis of one sample resulted in mutagenicity; all six nonhydrolyzed samples were not mutagenic. The ability to amplify DNA ranged from 34% to 96%, depending on length of the microsatellite region examined. The average protein concentration was 71 microg/mL. Two-dimensional protein electrophoresis was successfully performed on samples from two subjects. Nipple aspiration is a simple technique and is easily learned and well tolerated, which yields a reagent useful for a variety of investigations. This technique may facilitate the identification and application of biomarkers for future breast cancer risk assessment and chemopreventive protocols.

Adult↗