bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical electromagnetic analysis on current distribution in building directly hit by lightning
Authors: Miyazaki Satoru , Ishii Masaru 
Published: February 2007

AbstractLightning current distribution in a directly hit building is studied by using a simple equivalent circuit and an electromagnetic model. The Numerical Electromagnetics Code (NEC‐4) is employed for numerical electromagnetic analysis. The error in the shunt ratio of lightning current entering wiring, which is calculated using the electromagnetic model, is estimated to be less than 4%. The shunt ratios for lightning current entering the wiring on the top floor and the first floor are largest. Although they are larger for a higher building, they are almost constant if the building struck has more than five floors. They are smaller when there are more vertical conductors, or the length of the wiring is longer. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(1): 9–16, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20449
Dimeric Orsellinic Acid Derivatives: Valuable Intermediates for Natural Product Synthesis
Authors: Drochner Daniel , Hüttel Wolfgang , Bode Silke E. , Müller Michael , Karl Ulrich , Nieger Martin , Steglich Wolfgang 
Published: February 2007

AbstractHerein we report on the synthesis of dimeric orsellinates by the Ullmann reaction as well as by biomimetic oxidative phenolic coupling. The Ullmann reaction gives the 5,5′‐ and 3,3′‐coupled dimeric orsellinates 9 and 10 regioselectively. Oxidative phenolic coupling reaction of methyl 2‐hydroxy‐4‐methoxy‐6‐methylbenzoate (2) affords the regioisomeric dimeric orsellinates 11 (3,3′), 12 (5,5′) and 13 (3,5′) simultaneously, which can be separated easily by column chromatography. The atropisomers of the 5,5′‐ and 3,3′‐coupled dimers 9 and 10 were partially resolved using chiral column chromatography. Additionally, the enantiomers of 3,3′‐dimeric biaryl 11 could be obtained in pure form by derivatizing racemic 11 with chiral auxiliaries, separating the diastereomers by column chromatography and cleaving the auxiliary groups. Thereby the absolute configuration of the biaryl axis in camphanate ester (M)‐18 could be determined by X‐ray structure analysis. The dimeric orsellinates rac‐10 and (P)‐10 were used for the synthesis of the dimeric dihydroanthracenones 21a–b by a tandem Michael–Dieckmann reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Ethylene oxide: Evidence of human chromosomal effects
Authors: Garry Vincent F. , Hozier John , Jacobs Donald , Wade Richard L , Gray David G. 
Published: February 2007

AbstractEthylene oxide is a known mutagen as indicated by short‐term testing in vitro and in vivo. Occupational exposure can occur during ethylene oxide gas sterilization of materials for hospital and other use. To study the problem in a hospital sterilization facility where occupational exposure was suspected, epidemiologic, analytic, and bioassay tools were employed. All persons whose work activities involved some aspect of the sterilization process were considered exposed to the gas. Within this group of symptomatic and asymptomatic individuals, chronic and incidental exposure was documented by clinical history. Sister chromatid exchanges were studied in lymphocytes cultured from exposed individuals as well as comparable controls. Four chronically exposed persons who reported upper respiratory and neurologic symptoms were studied in some detail. This group showed significantly increased sister chromatid exchange at three weeks and again at eight weeks after the last known exposure. Another group of eight persons with fewer complaints studied as late as the ninth week showed significantly increased exchanges. Incidental exposure may also increase sister chromatid exchange. The measured maximum concentration of ethylene oxide in the sterilizer room was 36 ppm (within standards set by the Occupational Safety and Health Administration).
I. Bacterial mutagenicity of particulates from houston air
Authors: Preidecker Barbara Lee Borns 
Published: February 2007

AbstractThis study was designed to examine suspended air particulates from the Houston atmosphere. Airborne particulates were collected using either a hi‐vol sampler (one stage from 0.01 to 25 μm) or an Anderson Cascade Impactor, the five stages of which roughly resemble the human respiratory tract. After organic extraction, the Ames assay was used to determine the mutagenic content of extracts, and the ability to induce prophage was assessed. Also DNA‐repair‐deficient cells were employed to see if the extracts caused DNA damage and what portion of the premutational lesions was repaired in normal cells.Results indicate that extracts of particulates from Houston air cause a significant number of mutations in bacteria and that the highest frequency of reversions is associated with the smallest particulates. An excision repair system is operative in bacteria which is able to assuage damage done to DNA by these extracts. The extracts did not cause prophage induction.
Mutagenicity of effluents from an experimental fluidized bed coal combustor
Authors: Clark Charles R. , Hobbs Charles H. 
Published: February 2007

AbstractThe fluidized bed combustion of coal, a low‐temperature process capable of utilizing high sulfur and/or low‐grade fuels, may be a viable alternative to conventional coal combustion to meet future energy needs. Studies of an experimental 18‐inch atmospheric fluidized bed combustor (FBC) are aimed at determining potential health risks and environmental acceptability of FBC effluents as compared to effluents from the conventional combustion of coal. Salmonella (Ames) mutagenicity bioassays provide a convenient method for detecting potential mutagens in the process stream, at different locations in the cleanup system, and for evaluating changes in mutagenicity associated with the use of different fuel types and operating conditions. Samples evaluated for mutagenicity include: methylene‐chloride extracts of fly ash collected in bag filters and on high volume filters; methylene‐chloride extracts of size‐selected (respirable) fly ash collected by cascade impactors in the stack breech, and gaseous hydrocarbons collected on Tenax® adsorbent and Soxhlet extracted with n‐pentane. Dose‐dependent mutagenicity in at least three tester strains was detected in six of the nine bag‐filter, fly‐ash extracts; the addition of a metabolic activating system (rat liver S9) either increased, decreased or did not change the direct mutagenicity observed, depending upon the tester strain and extract used. Mutagenicity of respirable fly ash (< 10 μm) increased as the particle size decreased. No mutagenicity was detected in vapor phase hydrocarbons collected from four different positions in the process stream. Mutagenicity was detected in five of seven bag‐filter ash samples obtained from the combustion of Montana Rosebud subbituminous coal. Combustion temperature and other operating conditions which may influence mutagenicity of the fly ash are discussed.
Increases in morphologically abnormal sperm in rats exposed to Co60 irradiation
Authors: Lock L. F. , Soares E. R. 
Published: February 2007

AbstractWe have investigated the effects of testicular exposure to different doses of Co60 radiation on sperm morphology in F‐344 rats. The results indicate that from 150rad to 500 rad gamma irradiation causes statistically significant, dose‐related increases in 1) the percent of morphologically aberrant sperm and 2) the frequency of tailless sperm. Both of these effects were detectable in sperm which were derived from treated spermatid, spermatocytes, and spermatogonial cells. These data indicate that the development of a sperm morphology assay in rats is feasible.
Mutagenicity of pesticides evaluated by means of gene‐conversion in saccharomyces cerevisiae and in aspergillus nidulans
Authors: De Bertoldi M. , Griselli M. , Giovannetti M. , Barale R. 
Published: February 2007

AbstractNine pesticides, Afugan, Atrazine, Benomyl, Captan, Daconil, Melthaumittel, Plantvax, Saprol, and Wepsin were tested for the induction of mitotic geneconversion in two different eucaryotic microorganisms, Saccharomyces cerevisae and Aspergillus nidulans. In S cerevisiae the pesticides were also tested after mouse liver microsomal activation; in A nidulans all tests were performed using both resting and germinating conidia. Among the tested pesticides, only Captan revealed a consistent genetic activity, three times greater than that observed with the standard mutagen methylmethansulphonate. This genetic activity of Captan is suppressed after mammalian metabolic conversion. The use of germinating conidia in A nidulans for scoring the induction of mitotic gene‐conversion did not give any further information on the activity of the tested pesticides.
Effect of N‐alkyl chain length on the mutagenicity of N‐nitrosated 1‐naphthyl N‐alkylcarbamates
Authors: Eya Sryan K. , Talcott Ronald E. 
Published: February 2007

Abstract1‐Naphthyl N‐alkylcarbamates (alkyl = methyl, ethyl, n‐propyl and n‐butyl) were synthesized and then nitrosated with a dichloromethane extract of nitrous acid. The respective N‐nitrosated carbamates were purified and tested for mutagenicity using Salmonella typhimurium LT2 strain TA98 and TA100, and Saccharomyces cerevisiae strain D3. The reactivity of the four nitrosocarbamates toward 4‐(p‐nitrobenzyl)‐pyridine (NBP) was measured in order to assess their strengths as alkylating agents. Bioassay results indicated an inverse relationship between the length of the N‐alkyl chain and the mutagenicity of the N‐nitrosonaphthylcarbamates. The NBP test results indicated an inverse relationship between chemical reactivity and N‐alkyl chain length.
A comparison of the ability of frog and rat S‐9 to activate promutagens in the Ames test
Authors: Cheh Albert M. , Hooper Alan B. , Skochdopole Jill , Henke Craig A. , McKinnell Robert G. 
Published: February 2007

AbstractA mutagenesis assay employing the frog, Rana pipiens. is currently under development [McKinnell et al, 1979]. A question that must be answered is whether the frog is metaboiically capable of activating a large number of promutagens. The Ames assay offers a simple means of comparing the metabolism of mutagens by different animal species. The Ames response obtained with frog‐liver S‐9 was compared to the response with rat‐liver S‐9, using the following compounds: Benzo(a)pyrene, 7,12‐dimethylbenz(a)anthracene, 2‐aminofluorene, azobenzene, Sudan II, dibutylnitrosamine, hydrazine sulfate, hydroxyethylhydrazine, cyclophosphamide, 1,2‐dichloroethane, tris(2,3‐dibromopropyl)phosphate, diallate, quinoline, quercetin, aflatoxin B 1, emodin, and safrole. Of these compounds, activation by rat S‐9 was observed for all except hydrazine sulfate and safrole. All except Sudan II, 1,2‐dichloroethane, quinoline, and safrole gave positive Ames responses with frog S‐9. In general, the responses with frog S‐9 were quantitatively lower than those obtained with Aroclor‐induced rat S‐9; however, the optimum procedure for frog‐liver induction has not been determined. The response to dichloroethane is very sensitive to the amount of activating enzyme present; it might be positive with optimally induced frog S‐9. Thus, only two of the 15 compounds positive with rat S‐9 were definitely missed when tested with frog S‐9. We feel that the frog assay appears to be promising from the standpoint of false‐negatives.
Use of a rat/hamster S‐9 mixture in the ames mutagenicity assay
Authors: Weinstein David , Katz Marion , Kazmer Sonja 
Published: February 2007

AbstractBased on the findings of Nagao et al [1978] that phenacetin is negative in the standard Ames test with Aroclor induced rat S‐9 and positive with hamster S‐9, the test was performed with a mixture of rat/hamster S‐9. Phenacetin was mutagenic with the mixture. The activity of the mixture was compared to the rat S‐9 alone with low concentrations of 2‐aminoanthracene (a strong promutagen for Salmonella typhimurium TA 1535, TA 100, TA 1537, and TA 98), nitrosopiperidine (a weak promutagen), and 1, 2 epoxybutane (a weak, directacting mutagen). Except for an increased mutagenic activation by the mixture with nitrosopiperidine the mixture was comparable to the rat S‐9 alone, indicating that replacing rat S‐9 with a rat/hamster S‐9 mixture in the standard Ames test could increase the sensitivity of the test without interfering with rat S‐9 activity.
Genetic analysis of ad‐3 mutants induced by AF‐2 and two other nitrofurans in neurospora crassa
Authors: Ong Tong‐Man , de Serres F. J. 
Published: February 2007

AbstractOur previous studies have shown that the nitrofurans AF‐2, SQ18506, and FANFT are potent mutagens in Neurospora crassa. The genetic damage produced by these chemicals at the ad‐3 region in N crassa has been characterized by a series of genetic tests. The results of these tests indicate that all three agents induce a high frequency of point mutations and probably a low frequency of multilocus deletions. A comparison of the complementation patterns among the AF‐2‐induced ad‐3B mutants and those induced by other chemical agents indicates that the spectra of intragenic alterations induced by AF‐2 in N crassa are similar to those induced by monofunctional alkylating agents.
Mutagenicity of products from coal gasification and liquefaction in the salmonella/microsome assay
Authors: Schoeny Rita , Warshawsky David , Hollingsworth Lois , Hund Mary , Moore George 
Published: February 2007

AbstractAs a first step in the assessment of their possible bio‐effects, coal‐related materials were tested for mutagenicity in the Salmonella/microsome assay. Of three coal gasification by‐products tested, only a tar was mutagenic for any of four Salmonella strains. The following liquefaction materials were mutagenic for strains TA1538, TA98, and/or TA100: A liquefaction vehicle oil and coal hydrogenation filtered liquid, separated bottoms, vacuum overhead, and vacuum bottoms. Neither powdered coal nor water produced as a by‐product of the hydrogenation process was positive in the Salmonella test. No coal‐related material was mutagenic for the missense mutant TA1535 or for any strain in the absence of metabolic activation provided by rat hepatic homogenates (S9). In all but one instance Aroclor 1254‐induced S9 provided the maximum activation for mutagenesis. Fractionation of all samples was undertaken by serial extraction with organic solvents of increasing polarity (hexane, toluene, methylene chloride, acetonitrile). Highly mutagenic materials were found in fractions of the hydrogenation filtered liquid, vacuum overhead, and vacuum bottoms. Thus far non‐mutagenic samples have not yielded mutagenic components upon fractionation.
Metal mutagens and carcinogens effectively displace acridine orange from DNA as measured by fluorescence polarization
Authors: Richardson Carol L. , Verna James , Schulman Gail E. , Shipp Kevin , Grant Ava D. 
Published: February 2007

AbstractSeveral metals are known mutagens and carcinogens. These metals effectively displace acridine orange from DNA when measured by fluorescence polarization. Displacement of 50% of the acridine orange is obtained with less than 0.5 mM concentrations of lead, manganese, cobalt, zinc, cadmium, nickel, iron, copper, and cis‐platinum. In contrast, greater than 80 mM concentrations of lithium, sodium, and potassium are required to displace an equivalent amount of acridine orange from calf thymus DNA. Although cis‐platinum shows the best DNA reactivity in this assay, the interaction between this metal and DNA does not occur immediately, as it does for the other metals tested. These results indicate that the acridine orange displacement assay provides a relative measure of the interaction of metals with DNA, and this DNA reactivity shows a positive correlation with mutagenic/carcinogenic potential.
Chromosome loss induced by procarbazine and diethylnitrosamine in drosophila from matings of treated males with repair‐deficient mei‐9a, mei‐41d5, mus101, and mus104 females
Authors: Zimmering S. 
Published: February 2007

AbstractExcision repair‐deficient mei‐9a females of Drosophila melanogaster strongly potentiate complete and partial sex chromosome loss induced in the paternal genome by procarbazine and diethylnitrosamine (DEN). Repair‐proficient and postreplication repair‐deficient mei‐41D5, mus101, and mus104 females fail to enhance the frequency of procarbazine‐induced chromosome loss. Whereas mus101 produces a more modest but significantly higher frequency of complete but not partial loss induced by DEN, results are negative for both categories of loss with mei‐41D5, mus104, and repair‐proficient females.
Activity of nitro‐polynuclear aromatic hydrocarbons in the sister chromatid exchange assay with and without metabolic activation
Authors: Nachtman Joseph P. , Wolff Sheldon 
Published: February 2007

AbstractNitro‐polynuclear aromatic hydrocarbons are found in diesel particulates. These compounds are potent mutagens in the Ames test. To determine whether nitro‐polynuclear aromatic hydrocarbons are active in a mammalian cell assay, 1‐nitropyrene, 1,8‐dinitropyrene, 2‐nitrofluorene, and 4‐nitrobiphenyl were incubated with cultures of Chinese hamster ovary cells. The frequency of sister chromatid exchange (SCE) was measured in the presence and absence of rat liver S‐9 mix. The addition of S‐9 mix resulted in a large increase in the SCEs induced by all four compounds.
Mutagenicity of HPLC fractions from extracts of aatrex‐treated corn
Authors: Singh I. , Lusby A. F. , McGuire P. M. 
Published: February 2007

AbstractCrude extracts from maize plants treated with varying concentrations of AAtrex, an s‐triazine herbicide, were tested for the induction of gene conversion in a diploid strain of Saccharomyces cerevisiae heteroallelic at two loci. These extracts were then subjected to analysis by high pressure liquid chromatography (HPLC), and the fractions collected in water, 50% methanol, and 100% methanol were similarly tested. Dose‐dependent convertogenic activity observed in the 50% methanol fractions suggested that the mutagen(s) is recovered in this fraction.
12‐O‐tetradecanoyl‐phorbol‐13‐acetate and its relationship to SCE induction in syrian and chinese hamster cells
Authors: Popescu N. C. , Amsbaugh S. C. , Larramendy M. L. , Dipaolo J. A. 
Published: February 2007

Abstract12‐O‐Tetradecanoyl‐phorbol‐13‐acetate (TPA) in conditions that produce enhancement of ultraviolet light (UV) and x‐irradiation Syrian hamster embryo cell (HEC) transformation did not cause further increase in the sister chromatid exchange (SCE) frequency induced by UV and x‐irradiation, two physical carcinogens that differ in their mode of DNA interaction and efficiency of SCE induction. Several factors which might influence SCE induction by TPA were studied on HEC and Chinese hamster V79‐4 cells. Heat‐inactivated serum was used because of the possibility that a serum component may interfere with TPA ability to cause SCE. TPA effect on SCE was determined at the first and second division post treatment on cells exposed to different 5‐bromodeoxyuridine (BrdUrd) concentrations. Independent of BrdUrd concentration (1‐10μg/ml medium) and the number of cell divisions post treatment, TPA (0.01‐2μg/ml medium) was ineffective in inducing SCE in exponentially and stationary HEC cultures cultivated in medium supplemented with heat‐inactivated serum. Also, TPA did not increase the SCE frequency in V79‐4 Chinese hamster cells cultured in heat‐inactivated or noninactivated serum. Although SCE induction, a cellular response to carcinogen‐induced DNA damage, may be important for the induction of transformation by environmental agents, the enhancement of transformation frequency caused by TPA occurs without further DNA alterations involved in SCE formation.
Quantitation of the spiral plating technique for use with the salmonella/mammalian microsome assay
Authors: Couse Nancy L , King Jeannette W. 
Published: February 2007

AbstractQuantitative dose‐response data were obtained using spiral plating in conjunction with the Salmonella/mammalian microsome test. This plating method provides data comparable to that obtained with standard methods. It requires significantly less time and material and generates more information than standard methods.
Effect of ozonation on the mutagenicity of carcinogens in aqueous solution
Authors: Burleson Gary R. , Chambers Thomas M. 
Published: February 2007

AbstractOzone is a very strong oxidizing agent that may be used in water purification. The effect of ozonation on the mutagenicity of mutagens and/or carcinogens of diverse chemical structures was evaluated as measured by the Salmonella/microsome assay. The effect of ozonation of 36 mutagens and/or carcinogens has been evaluated and the results of 15 reported here. The mutagenicity of polycyclic aromatic hydrocarbons and aromatic amines was inactivated by ozone treatment, while alkylating agents, nitro aromatics, and nitroso compounds were not affected. Ozonation of hydrazines produced mutagenic intermediates that may be susceptible to base‐catalyzed hydrolysis. Therefore, depending on the chemical present, ozonation may be useful in the treatment of waters containing organic carcinogens, including drinking water, waste‐water effluents, and other aqueous waste materials containing carcinogens.
Studies of the mutagenic response of salmonella typhimurium TA98 to size‐fractionated air particles: Comparison of the fluctuation and plate incorporation tests
Authors: Sorenson W. G. , Whong Wen‐Zong , Simpson Janet P. , Hearl Frank J. , Ong Tong‐Man 
Published: February 2007

AbstractThe high‐volume Andersen sampler was used to study the mutagenic activity of size‐fractionated airborne particles from ambient air in Morgantown, West Virginia. Mutagenicity was studied by the Ames Salmonella assay and the bacterial fluctuation test and was dependent on particle size in both systems, ie, the greatest activity was associated with the smallest particles. Comparison of the two systems was based on identical aliquots of each extract, cells prepared under identical conditions at the same time, and on mutagenic response at a predetermined level of statistical significance (P < 0.05). The results suggest a slight advantage in sensitivity for the Ames test for the air samples under study.
Mutagenic response to ultraviolet light and X‐rays at five independent genetic loci in chinese hamster ovary cells
Authors: Singh Bhag , Gupta Radhey S. 
Published: February 2007

AbstractThe mutagenic response to ultraviolet light and X‐irradiation at a number of well characterized independent genetic loci, viz those conferring resistance to 6‐thioguanine, ouabain, emetine, methylglyoxal (bis) guanylhydrazone (MGBG), and 5,6‐dichlororibofuranosyl benzimidazole (DRB), has been determined. Upon exposure of cells to UV light in the range of 70 to 180 ergs/mm2, the frequency of mutants at all of the above genetic loci increased in a linear dose‐dependent manner. However, some genetic‐locus‐specific differences in response to UV light were observed in these studies. In contrast to UV light, exposure of cells to X‐rays caused a linear dose‐dependent increase in the frequency of mutants at only the thioguanine‐resistant (Thgr) locus, which affects the purine salvage pathway enzyme hypoxanthine‐guanine phosphoribosyltransferase, that is not essential for growth under these conditions. The other genetic loci that affect essential cellular functions (and hence should detect only specific base substitution types of mutations), however, showed no increase in the frequencies of mutants upon X‐irradiation of cells. These results are in accordance with the nature of the genetic lesions which are caused by these agents and the properties of these genetic markers.