bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Set of Principal Properties for Heteroaromatics Obtained by GRID
Authors: Clementi Sergio , Cruciani Gabriele , Fifi Paola , Riganelli Daniela , Valigi Roberta , Musumarra Giuseppe
Published: October 2006

A set of 40 heteroaromatic systems was multivariately characterized by 13 descriptors derived by GRID. From this data matrix a second generation of Principal Properties for heteroaromatics was derived. Such Principal Properties are suitable for designing series of molecules of biological interest containing heteroaromatic moieties.
QSAR Study of Phenols: Relation between the Phenoxyl Radical Formation and the Antiinflammatory Activity via an Antioxidant Mechanism
Authors: Ruiz Juan , Pérez Angel , Pouplana Ramon
Published: October 2006

The antiinflammatory mechanism of phenols as radical scavengers was analyzed. The biradical formation process Ph‐OH → Ph‐O + H was studied by the reaction coordinate method using the semiempirical AM1 quantum‐mechanical method. The enthalpies of formation of ground, transition, and radical states were determined; other parameters like the reaction, stabilization and activation enthalpies for phenoxyl radical formation of fifteen phenolic compounds were also calculated and correlated with their antiinflammatory activities.

The results suggest that the ability of phenols to form the phenoxyl radical and the stability of this derived radical are important in the antiinflammatory activities of phenols via neutralization of harmful radicals.
Estimation of Caco‐2 Cell Permeability using Calculated Molecular Descriptors
Authors: van De Waterbeemd Han , Camenisch Gian , Folkers Gerd , Raevsky Oleg A.
Published: October 2006

Permeability of a compound by passive diffusion through a biological membrane such as Caco‐2 cell monolayers depends mainly on lipophilicity, molecular size and hydrogen bonding capacity of the solute. Since these properties are often used in structure‐permeability correlations, we have evaluated different calculated descriptors for size and hydrogen bonding, as well as their intercorrelations. A new descriptor for hydrogen bonding potential is introduced. It is demonstrated that a combination of appropriate size and H‐bonding descriptors using graphical or Eq.‐based approaches may be of potential use for membrane permeation estimation.
Application of Molecular Quantum Similarity to QSAR
Authors: Fradera Xavier , Amat Lluís , Besalü Emili , Carbó‐Dorca Ramon
Published: October 2006

Molecular Quantum Similarity Measures (MQSM), which allow quantitative comparison between molecular electronic density distributions, are investigated as a potential source of QSAR parameters. By computing the MQSM for all possible molecular pairs in a given molecular set, a Similarity Matrix is obtained, containing relevant information about the structural relationships within the set. Approximate Overlap‐like MQSM using several computational levels are employed to obtain similarity matrices for three molecular sets, taken as test cases: (1) non‐branched alkanes, (2) Baker triazines, (3) indole derivatives. The similarity matrices have been analyzed by means of PCA and PLS techniques. QSAR regression models were derived in order to fit available property or biological activity data. A reasonably good correlation between properties or activities and the similarity measures has been found.
Description of Vapour Pressures of Polycyclic Aromatic Compounds by Graph Theoretical Indices
Authors: Niederfellner J. , Lenoir D. , Matuschek G. , Rehfeldt F. , Utschick H. , Brüggemann R.
Published: October 2006

The vapour pressure (VP) is an important physical property of organic compounds for the description of fate and distribution of xenobiotics in the environment. This property was measured for 30 polycyclic aromatic hydrocarbons (PAH) and formulas for VP based on molecular weight and topological indices, respectively, were derived using the technique of Kubinyi and as a second step by regression analysis. A formula for the 30 PAH, considered here, is given.magnified imageTherein the VP is related to the information theoretical index IdWmean and with a chain‐connectivity index. More specific results are derived for three groups of PAHs. The robustness of the equations is tested by bootstrap analysis. In addition a formula is discussed, which is based on four different incremental factors, a method widely used in physical organic chemistry.
Three‐valued logic for reasoning from an inconsistent knowledge base
Authors: Tahara Ikuo , Nobesawa Shiho
Published: October 2006

Nontrivial reasoning under inconsistency, called paraconsistent reasoning, has been discussed mainly in two frameworks; one is the classical logic (consistency‐based) framework and the other is the three‐valued logic framework. In this paper, we propose a new entailment relation based on three‐valued logic for reasoning from an inconsistent knowledge base, and discuss the relation between the previous two frameworks. A U‐minimum model of the inconsistent knowledge base is defined in accordance with a principle of uncertainty minimization for three‐valued models. We show that every set of atomic formulas assigned the additional third value in the U‐minimum model is the minimum hitting set for the collection of sets each of which consists of atomic formulas occurring in the minimal inconsistent set of the knowledge base. Based on this result, we present an algorithm to compute the paraconsistent entailment relation by reducing the three‐valued entailment relation to a two‐valued classical entailment relation. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(14): 44–51, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20539
Autonomous motion recognition by combining reinforcement learning and hidden Markov model
Authors: Morooka Ken'ichi , Hamamoto Kazuhisa , Nagahashi Hiroshi
Published: October 2006

A robot needs the abilities of recognizing motion in the world (“other‐motion”), and generating “self‐motion” to adaptively behave in a real environment. We have been currently developing a system composed of an “other‐motion” recognition module and a “self‐motion” generation module. This paper focuses on “other‐motion” recognition that is based on “self‐motion.” The recognition and generation modules are each constructed by reinforcement learning and a Hidden Markov Model (HMM). In this case, the HMM estimation needs many sample data of the motion to be learned. However, there is no guarantee that a sufficient amount of motion data can be acquired in the real world, and the reliability of the HMM may therefore be low. In order to solve this problem, this paper presents a new estimation method of an HMM based on the learning results of reinforcement learning. The state value function of the reinforcement learning is divided into some clusters, and each cluster is made to correspond to a state of the HMM. An output distribution can thereby be estimated on the basis of the value of the value function. Some experimental results show that our method can estimate HMM's model parameters not only from few sample data but also from value functions of the generation module, and that the reliability of the estimated HMM can be improved. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(14): 34–43, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20586.
Chemical force microscopy of chemical and biological interactions
Authors: Noy Aleksandr
Published: October 2006

Interactions between chemical functionalities define outcomes of the vast majority of important events in chemistry, biology, and materials science. Chemical force microscopy (CFM)—a technique that uses direct chemical functionalization of atomic force microscopy (AFM) probes with specific functionalities—allows researchers to investigate these important interactions directly. We review the basic principles of CFM, some examples of its application, and theoretical models that provide the basis for understanding the experimental results. We also emphasize application of modern kinetic theory of noncovalent interactions to the analysis of CFM data. Copyright © 2006 John Wiley & Sons, Ltd.
Advances in time‐of‐flight secondary ion mass spectrometry analysis of protein films
Authors: Michel Roger , Castner David G.
Published: October 2006

This article reviews the advances made in the analysis of protein films by time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). ToF‐SIMS has been used extensively to analyze biological samples owing to its high surface sensitivity, high mass resolution, molecular specificity and imaging capabilities. The fact that its information depth for molecular fragments is typically 1–2 nm, which is smaller than the dimensions of most proteins, makes it an ideal technique for analyzing protein films. Multivariate analysis (MVA) techniques are well suited for analyzing the large, complex data sets generated from ToF‐SIMS experiments on biological samples and have become widely used for interpreting ToF‐SIMS spectra and images. In recent years, new advances in polyatomic or cluster ion sources have improved spectral quality, reduced sample damage and enabled depth profiling of some organic samples. Also, cationization and other matrix enhancement methods have been developed, which significantly increase the yield of molecular fragments from biological samples. This review will cover the modern ToF‐SIMS analysis methods that are currently employed to characterize protein films along with the opportunities and challenges for future advances in ToF‐SIMS analysis of these films. Copyright © 2006 John Wiley & Sons, Ltd.
Coupling evanescent‐wave fluorescence imaging and spectroscopy with scanning probe microscopy: challenges and insights from TIRF–AFM
Authors: Shaw James E. , Oreopoulos John , Wong Daniel , Hsu Jenny C. Y. , Yip Christopher M.
Published: October 2006

Recent work has demonstrated that imaging platforms based on the integration of total internal reflection fluorescence microscopy (TIRFM)/spectroscopy with scanning probe microscopy are well‐suited for investigations of biological phenomena, ranging from lipid bilayer dynamics and membrane protein assembly to cellular dynamics and structures. We have shown that this approach is particularly compelling for studies of protein‐membrane interactions. While this functional imaging strategy has proved to be very useful for studies of cell dynamics, and most recently, in the study of single‐molecule dynamics by TIRF‐AFM‐based force spectroscopy, a number of key challenges remain to be resolved. Copyright © 2006 John Wiley & Sons, Ltd.
Anti‐microbial coatings by agent entrapment in coatings deposited via atmospheric pressure plasma liquid deposition
Authors: O'Hare Lesley‐Ann , O'Neill Liam , Goodwin Andrew J.
Published: October 2006

By injecting a liquid aerosol precursor directly into a non‐equilibrium atmospheric pressure plasma (APP), a controlled, free‐radical‐induced polymerisation reaction can be initiated with minimal fragmentation of the precursor molecules. This can be used to chemically graft highly complex chemical functionalities directly onto a variety of substrates. This process normally proceeds through polymerisation of unsaturated functional groups on the precursor molecules. In this work, it has been found that compounds that lack such polymerisable groups can be physically dissolved in the liquid precursor and that these chemicals are not directly involved in the plasma reaction. Instead, these chemicals become physically entrapped within the resultant plasma polymer and retain much of their biological and chemical properties. As a preliminary example of such a reaction, the entrapment of various anti‐microbial species (quaternary ammonium salts) within glycol and acrylic acid plasma polymers is described. The biological and chemical reactivity of these chemicals is examined using a combination of anti‐microbial and XPS investigations. Copyright © 2006 John Wiley & Sons, Ltd.
Current and possible alternate indicators of fecal contamination in tropical waters: A short review
Authors: Toranzos Gary A.
Published: October 2006

Bacteria that belong to the total and fecal coliform groups have been used for several decades as indicators of fecal pollution of waters and other systems. The prevailing idea behind this is that these two groups of bacteria cannot replicate outside the gastrointestinal tract of warm‐blooded animals. Several studies conducted by this and other laboratories have indicated that these bacteria may be naturally present in certain areas of the world. Naturally occurring fecal coliforms (the genera Escherichia and Klebsiella) have been isolated from pristine sites and from sites where there was no apparent fecal contamination. All these results lead us to the conclusion that these groups of bacteria are not adequate indicators of fecal contamination in tropical areas of the world. Alternate indicators are being tested. This laboratory and others around the world are testing the adequacy of bacteriophages (more specifically, coliphages) for this purpose. In Puerto Rico coliphages have been detected only in areas known to be contaminated with domestic sewage, but not in pristine areas, although high levels of fecal coliforms can be detected at the latter sites. All these results suggest that coliphages may be used as indicators that more realistically demonstrate fecal contamination of waters in tropical areas of the world. In addition, newer techniques, although still in the trial stages, can be used to directly detect pathogens in the environment. Of all the techniques currently available, the polymerase chain reaction is the most promising for the direct detection of pathogens and therefore for the unequivocal evaluation of the biological quality of waters.
Toxicity testing of synthetic and biogenic surfactants on marine microorganisms
Authors: Poremba K. , Gunkel W. , Lang S. , Wagner F.
Published: October 2006

The toxicity of four synthetic surfactants, two commercial oil dispersants, and six biosurfactants have been examinated. The test systems were (a) bacterial growth inhibition, (b) microalgae growth inhibition, (c) microflagellate growth inhibition, (d) biodegradation, and (e) bioluminescence inhibition (Microtox test). The multiplication of bacteria was stimulated by surfactants, while that of microflagellates and microalgae was inhibited. This may be due to the metabolic usage of surfactants, especially biosurfactants, by bacteria. The bioluminescence was very sensitive to surfactants. No toxicity could be detected with glucose‐lipid, produced by the marine bacterium Alcaligenes sp. MM1. Most biosurfactants were degraded faster and possessed higher EC50 values than synthetic dispersants.
Soil: The environmental source of Escherichia coli and enterococci in Hawaii's streams
Authors: Hardina C. M. , Fujioka R. S.
Published: October 2006

The concentrations and sources of Escherichia coli and enterococci in a typical stream (Manoa) in Hawaii were determined. The concentrations of these two sanitary indicator bacteria in Manoa Stream consistently exceeded the new U.S. Environment Protection Agency recreational water standard in freshwater of 126E. coli/100 mL or 33 enterococci/ 100 mL. Escherichia coli but not enterococci was shown to multiply in stream water samples. Soil samples obtained near the stream bank, 10 m from the stream bank as well as from a grassy area on the university campus, were determined to be sources of both E. coli and enterococci. These indicator bacteria were recovered from the surface of the soil as well as from soil samples at depths down to 36 cm. Soil is considered the most likely source for the high concentrations of indicator bacteria naturally present in the freshwater streams of Hawaii.
Use of bioassays to evaluate river water and sediment quality
Authors: Dutka B. J. , Kwan K. K. , Rao S. S. , Jurkovic A. , McInnis R. , Palmateer G. A. , Hawkins B.
Published: October 2006

In trying to establish the extent and degree of impact of point and nonpoint source contaminants on riverine systems, it is important to know the implications of the data obtained from various sampling points in a riverine system. Spatial variability between water and/or sediment samples collected in close approximation at the same sites was assessed by the battery of tests approach. In these samples there appeared to be no consistent relationship between sediment structure, microbial population, and toxicant concentrations. Furthermore the ATP‐TOX System and Mutatox tests were the most responsive tests in all types of samples. Since sediments with their bound contaminants may be an important factor in this data interpretation, different methods for releasing and concentrating the sediment bound contaminants were evaluated. The results and implications of these results are described.
Detection of toxicity of cyanobacteria by Artemia salina bioassay
Authors: Kiviranta J. , Sivonen K. , Niemelä S. I. , Huovinen K.
Published: October 2006

A bioassay for the detection of neuro‐ and hepatotoxins of cyanobacteria was developed. Larvae of a small shrimp, Artemia salina, were used as the test organism. Two pure toxins, 44 natural bloom samples, and 29 laboratory strains of cyanobacteria were studied. The toxicity of the samples had earlier been tested by mouse bioassay and in most cases by chemical analysis of the toxins. Moderate and high concentrations of toxins in bloom samples can be reliably detected by the Artemia salina method. Out of 29 toxic bloom samples, 4 were found nontoxic to Artemia. According to mouse bioassay, the toxicity of these samples was very low. The pure laboratory‐grown strains contained some compounds that were toxic to A. salina but nontoxic to mouse. Because of these compounds, 1 out of 15 nontoxic bloom samples was erroneously analyzed to be toxic. EC50 for hepatotoxin desmethyl 7‐microcystin‐RR was 5.0 μ/mL. Pure anatoxin‐a‐hydrochloride was not toxic to larvae, but when added to nontoxic cyanobacterial samples, anatoxin‐a was toxic.
A novel bioassay approach: Direct application of the toxi‐chromotest and the SOS chromotest to sediments
Authors: Kwan K. K. , Dutka B. J.
Published: October 2006

Routine testing of sediments or suspended sediments for toxicant or genotoxicants by the bioassay route often involves time‐consuming and expensive organic extraction procedures. In most instances these extraction procedures are more time‐consuming and costly than the bioassays that will be used on these extracts. A direct sediment test procedure (DSTP) was developed to alleviate the problem and thus returning bioassays to one of their original roles, i.e., short, quick, screening tests to identify priority samples for more intensive chemical analysis. The DSTP was developed in conjunction with the Toxi‐Chromotest and SOS Chromotest kits. The SOS Chromotest can be used with or without S9. Our results presented in this paper indicate the sensitivity of DSTP and cost effectiveness compared to some commonly used sediment extraction procedures.
Toxic cyanobacteria in some finnish lakes
Authors: Ekman‐Ekebom Maria , Kauppi Marja , Sivonen Kaarina , Niemi Maarit , Lepistö Liisa
Published: October 2006

The frequency and toxicity of cyanobacterial blooms in three different lake systems were investigated during the years 1985–1987. Toxicity was tested by i.p. mouse bioassay. Cyanobacterial blooms in Lake Tuusulanjärvi were dominated by Microcystis aeruginosa and Aphanizomenon flos‐aquae. Whenever toxicity occurred the samples were always hepatotoxic. Lake Sääskjärvi blooms were generally composed of Anabaena circinalis and A. flos‐aquae. Toxicity in Lake Tuusulanjärvi fluctuated between sampling intervals whereas Lake Sääskjärvi showed periodic toxicity, i.e., neurotoxicity caused by anatoxin‐a occurred at times of A. circinalis dominance. This proved to be fatal for surrounding livestock. In Lake Haukkajärvi and adjoining lakes the blooms were mainly composed of Anabaena flos‐aquae and Anabaena lemmermannii; here also the blooms were neurotoxic, although this time caused by an unknown toxin(s).
Agents that enhance or reduce movement of mobile genetic elements: Detection in microbial assays and implications for toxicological assessment
Authors: Macphee Donald G.
Published: October 2006

A comprehensive assessment of the potential toxicological effects of an environmental chemical or mixture of chemicals must take into account the possibility of genetic damage to cellular organisms. In conventional assays (e.g., the Ames test), point mutations (both base‐pair substitutions and frameshifts) have come into widespread use as indicators of genetic damage, but it is important that such end points be supplemented by indicators of more extensive genetic damage such as deletions or other large scale rearrangements of sections of genetic material. In the present paper, the ability of certain chemicals to cause gross changes to DNA sequences will be reviewed. The changes to be considered are primarily those that result from movements of mobile genetic elements, and focus especially on description and discussion of factors that enhance or inhibit the movement of transposons such as Tn10. © 1993 John Wiley & Sons, Inc.
Toxicity of cyanobacteria to mosquito larvae—screening of active compounds
Authors: Kiviranta J. , Abdel‐Hameed A. , Sivonen K. , Niemelä S. I. , Carlberg G.
Published: October 2006

To study toxicity of 76 laboratory‐grown strains of planktonic cyanobacteria to mosquito larvae, hydrophilic and lipophilic cell‐free extracts of cyanobacteria were incubated with larvae of the Aedes aegypti mosquito and death percentages were followed during 2 days. Toxicity was clearly associated with hepato ‐ and neurotoxins of the samples. A strain of Microcystis aeruginosa was most effective, and caused death of the larvae due to a single hepatotoxin. Pure mammalian neurotoxin, anatoxin‐a, was also toxic, and probably acted as a neurotoxin with the mosquito larvae.
A quantitative structure—activity relationship study and ecotoxicological risk quotient for the protection from chemical pollution
Authors: Yoshioka Yoshitada , Ose Youki
Published: October 2006

A quantitative structure—activity relationship study is carried out with use of the toxicity (LC50) of the various kinds of fish obtained from the references. The equation obtained contained the parameters of molecular weight (MW) and mean ionization potential (IP):log(1/LC50) = 28.665 + 0.01095MW ‐ 2.570IP (R2 = 0.695, n = 581). This equation could estimate the toxicity of the chemicals detected in the environment of Japan by Environment Agency (r = 0.80, n = 53). In order to evaluate the hazardousness, we propose the Ecotoxicological Risk Quotient (ERQ):

ERQc = ‐log Concentration in the environment/Effective concentration in the test

ERQa = ‐log Σ Concentration in the environment/Effective concentration in the test

ERQc and ERQa are the indices of the hazardousness of a chemical and chemicals in an area, respectively. ERQ could explain the status of pollution in water environment of Japan.
Detecting membrane impairment caused by xenobiotics
Authors: Pauli W. , Berger S. , Köhler M. , Gies A.
Published: October 2006

The toxicity of 14 substituted anilines and 15 aliphatic alcohols was assessed by the electrorotation of yeast cells. Depending on the applied frequency, control cells exhibit both anti‐ and cofield rotation. From this spectrum, a frequency was selected at which untreated cells do not rotate, but impaired cells rotate with the field. The experimental spectra are fully in accord with theoretical models of the rotational response, calculated on the basis of changes in membrane permeability. High correlations exist between rotational data and physiological and biochemical end points (growth rate, plasma membrane ATPase, purine transport of yeast cells, and antihemolytic assays with human erythrocytes). A Quantitative Structure‐Activity Relationship analysis was made, whereby rotation data from 23 phenols were included. The effects of all chemicals on cell rotation could be predicted by their lipophilicity. Some residuals and deviations could be accounted for by the inclusion of molecular weight or connectivity in the analysis. 4‐Nitrophenol was an outlier, having an effect at least one order of magnitude higher than predicted, suggesting a specific toxic mechanism. Based on lipophilicity and rotation data, the antihemolytic effect on erythrocytes could be accurately estimated. © 1993 John Wiley & Sons, Inc.
The allium test in wastewater monitoring
Authors: Fiskesjö Geirid
Published: October 2006

The common onion Allium cepa L. (2n = 16) makes a very convenient test system for estimating harmful effects of chemicals on biological materials. Because of its excellent chromosome conditions, the Allium material has been widely exploited for such purposes since it was first introduced as a test system by A. Levar in 1938.

The Allium test has later been extended to monitoring environmental risk factors as well. When wastewater from a chemical factory in southern Sweden caused severe pollution of an adjacent river, the growth restriction on Allium roots was taken as a measure of the degree of pollution in the river, and the result of the Allium test was admitted as evidence in a lawsuit against the factory.

The Allium test has shown good correlation with other test systems, involving general toxicity (root growth) and genotoxicity (chromosome aberrations). Living material of Allium is easily stored and handled. It is inexpensive and assures very clear chromosomes. An Allium test takes a relatively short time to carry through: 2 days for chromosome preparations and 3–4 days for measurement of the root growth. From the growth curves, EC (effect concentration) values are obtained. © 1993 John Wiley & Sons, Inc.
A comparison of four simple water extraction—concentration procedures to be used with the battery of bioassay tests approach
Authors: Dutka B. J. , Liu D. L. , Jurkovic A. , McInnis R.
Published: October 2006

With many environmental water samples, excluding industrial and domestic effluents, it has been found necessary to concentrate the water samples prior to testing with various bioassays for toxicant/genotoxicant content. In this report we describe four water concentration procedures: (1) flash evaporation, (2) Blue Rayon, (3) Empore disk, and (4) membrane filtration. For the water samples tested in this study a flash evaporation procedure and the membrane filtration procedure were the most promising sample concentration procedures. Results are discussed and future research directions are proposed. © 1993 John Wiley & Sons, Inc.
Sulfate elimination to improve water quality of mine process effluents. II. Hydrogen sulfide transport in biological reactors
Authors: Herrera Leandro , Hernández José , Duarte Sergio
Published: October 2006

A hydrogen sulfide bioproduction and mass transfer model was developed to assist in the evaluation of a biological process for the elimination of the sulfate contained in the effluent water of copper mines. The model was based upon the observation of experimental sulfate‐reducing activity and reaction rates of the sulfate‐reducing bacterium (SRB) Desulfovibrio desulfuricans, in experimental systems. The model postulated the following five steps: (1) sulfate transport, from the solution bulk to the interphase formed by the solution with the outer membrane of the bacteria; (2) sulfate transport through the membrane to specific intracellular reaction sites and intracellular reduction of the sulfate to generate HS‐ species; (3) transport of the HS‐ species through the membrane and the membrane—solution interphase to the solution bulk; (4) reaction of the HS‐ species to generate hydrogen sulfide with the consumption of protons; (5) mass transfer of hydrogen sulfide from the solution to the gas phase, diluted by an inert purge gas. The steady state of the model was solved analytically while the dynamic behavior was numerically solved by a numerical integrator. Results show that the model adequately described the process and correlated properly, in order of magnitude, with the operation parameters of a continuous reactor and a sequencing batch reactor. The model is presented with the experimental observations of a batch bioreactor. The model was used to select the optimum combination of operational parameters of a laboratory reactor and to predict those of pilot and industrial scale reactors. © 1993 John Wiley & Sons, Inc.
Biochemical and genotoxic effects in the vicinity of a pulp mill discharge
Authors: Wong P. T. S. , Chau Y. K. , Ali N. , Whittle D. M.
Published: October 2006

Sediment and water samples were taken from five sites in Thunder Bay, one upstream (control) and four downstream locations from a bleached kraft pulp mill. Biochemical effects were examined by estimating the carbohydrate content and enzymatic activities of alkaline phosphatase, cellulase, and dehydrogenase in the sediment. Genotoxicity and toxicity of sediment and water were assessed by the SOS Chromotest, although liver microsomal samples were not used to screen for progenotoxic substances. Sediment and water samples were also analyzed for resin and fatty acids, which indicate the degree of effluent contamination. Significant differences in enzyme activity and carbohydrate content were found between sites. Genotoxic values were obtained for downstream water samples for most of the sampling months, however, the sediment only showed genotoxic activity in the July and October samples. The study showed that there are substances causing genotoxic and biochemical effects in the Kaministiquia River, Ontario. © 1994 by John Wiley & Sons, Inc..
Comparative assessment of the specificity of the brine shrimp and microtox assays to hepatotoxic (microcystin‐LR‐containing) cyanobacteria
Authors: Campbell D. L. , Lawton L. A. , Beattie K. A. , Codd G. A.
Published: October 2006

Specific, straightforward, and rapid procedures are required for the detection, identification, and quantification of the potent low molecular weight toxins that are produced by blooms and scums of cyanobacteria (blue‐green algae) in waterbodies.

Use of the Microtox bioluminescence assay and the brine shrimp (Artemia salina) has been advocated for the initial screening of cyanobacterial blooms for microcystin hepatotoxins. Inhibition of bacterial luminescence in the Microtox assay and brine shrimp mortality were determined with microcystin‐containing and nonmicrocystin‐containing cyanobacteria.

Extraction and fractionation of test samples was undertaken to select and isolate microcystincontaining fractions and reduce interference from other fractions. Maximal inhibition of bacterial luminescence in the Microtox assay occurred with fractions from Microcystis strains and an Anabaena bloom that did not contain microcystins. By contrast, the bioassay of fractions using brine shrimps correlated with the distribution of microcystin‐LR in the fractionated Microcystis extracts. © 1994 by John Wiley & Sons, Inc..
Genotoxicity assessment through the Ames test of medicinal plants commonly used in Brazil
Authors: Rivera I. G. , Martins M. T. , Sanchez P. S. , Sato M. I. Z. , Coelho M. C. L. , Akisue M. , Akisue G.
Published: October 2006

Ten medicinal herbs commonly used as popular medicine in Brazil—Bauhinia forficata L., Bauhinia variegata L., Cymbopogon citratus D.C. Stapf, Echinodorus macrophyllum (Kunth) Micheli, Hidrocotyle asiatica L, Matricaria chamomila L., Pfaffia iresinoides (Kunth) Sprengel, Plaffia paniculata (Martius) Kuntze, Phyllanthus tenellus Roxb, and Solidago microglossa D.C.—were tested for mutagenicity by the Ames test using Salmonella typhimurium TA 97a, TA 98, TA 100, and TA 104 strains, with and without metabolic activation. The genotoxicity assessment of these medicinal plants was performed in aqueous extracts 1:5. Seventy percent of these herbs presented mutagenic effects with at least one of the Ames strains used in this study. Bauhinia variegata L., E. macrophyllum K., and M. chamomilla L. showed no mutagenic activity. The mutagenic effects were detected mainly with the strains TA 98 related to frameshift mutations. The higher mutagenicity ratio was obtained with S. microglossa D.C. (known as arnica‐do‐Brazil) when TA 98 strain was used with metabolic activation (MR = 6.55) and with TA 97a strain with and without the addition of S9. Medicinal plants are now used by all the segments of the population, more intensively in the last years. These results indicate the need to establish rules to assess the safety of the use of medicinal herbs. © 1994 by John Wiley & Sons, Inc..
Estimation of cadmium, lead, and mercury concentrations in estuarine waters using the mussel Mytilus edulis planulatus L.
Authors: Fabris J. G. , Richardson B. J. , O'Sullivan J. E. , Brown F. C.
Published: October 2006

Accumulation of cadmium, lead, and mercury in the tissues of the mussel Mytilus edulis planulatus L. from the Derwent Estuary, Hobart, Australia was linear over a range of metal concentrations in the ambient water, provided that the condition index of the mussels (meat weight/shell weight) indicated that the organisms were not under environmental stress. Polynomial regression analysis of accumulation rates against ambient concentrations of the respective metals in the water column in the vicinity of the mussels showed that the relationships depended upon the physical speciation of the metals (i.e., filtrable vs particlate metals). The results indicated that it may be feasible to use metal accumulation rates in mussels to provide broad‐based estimates of metal concentrations in marine waters, provided that the organisms have been calibrated under conditions similar to those prevailing at the proposed monitoring sites. © 1994 by John Wiley & Sons, Inc..
Effects of 2,4‐dichlorophenoxyacetic acid on fungal propagules in freshwater ponds
Authors: Sherry James
Published: October 2006

The effect of treatments with 2,4‐dichlorophenoxyacetic acid (2,4‐D) on fungal propagules in man‐made freshwater ponds was studied as part of a larger investigation into the effects of the herbicide on the ponds' ecology and chemistry. Myriophyllum spicatum was planted in the ponds as a target plant; the ponds were allowed to stabilize before being treated with dimethylamine (DMA) and butoxyethylester derivatives of 2,4‐D (1 mg/L). Although the 2,4‐D treatments were highly toxic to M. spicatum in the ponds (B. F. Scott et al., 1985a) they did not have a clear effect on fungal propagule levels in either the water column or sediment, which indicates the absence of a primary effect. The mean levels of molds and “total fungi” in both pairs of treated ponds, and of yeasts in the DMA‐treated ponds, tended to be depressed relative to the control ponds, for up to 114 days after treatment. That observation was reinforced by plots of the accumulated differences between the treated and control ponds. The differences between the mean fungal levels in the control and treated ponds were erratic, however, and the study's design did not permit a thorough statistical analysis of the data, although a multiple comparison test detected some differences (p < 0.05) between propagule levels, particularly molds, in the treated and control ponds. If real, the trends were probably a result of unidentified secondary effects of the pond treatments. The results imply that applications of 2,4‐D to aquatic vegetation at realistic rates do not drastically affect fungal propagule levels in the water column or sediment. © 1994 by John Wiley & Sons, Inc..
Suitability of carboxylated porphyrin profiles as a biochemical indicator in whitefish (Coregonus clupeaformis) exposed to bleached kraft pulp mill effluent
Authors: Xu Hao , Lesage Suzanne , Munkittrick Kelly R.
Published: October 2006

The hepatic carboxylated porphyrin profile was studied in whitefish exposed to bleached kraft pulp mill effluent (BKME). The distribution of the porphyrins was different between the samples from the BKME and the reference site, and fish exposed to BKME contained higher amounts of highly carboxylated porphyrins (HOP). The ratios of HCP to protoporphyrin, and coproporphyrin to protoporphyrin, were also significantly different between the two groups. In addition, the cytochrome P‐450 activity, liversomatic index, and gonadosomatic index were measured and compared with the prophyrin profile. The results suggest that BKME could inhibit porphyrinogen decarboxylases, and the porphyrin profile is useful as a biochemical indicator for identification of BKME exposure. © 1994 by John Wiley & Sons, Inc..
Residues of total mercury in fish from two small lakes in the biosphere reserve of Schorfheide‐Chorin in Brandenburg, east Germany
Authors: Mattheis Theobald , Pietrock Michael , Krüger Ralf
Published: October 2006

Total mercury was determined in white trunk muscle of fish from two small lakes using flameless AAS. Both lakes, surrounded by forest and agricultural fields, are situated in the biosphere reserve of Schorfheide‐Chorin about 50 km northeast of Berlin. Direct contamination by sewage and industrial waste has been excluded definitively. In the Plunzsee (area 25 ha, depth 10 m, no surface inflow, temporary outflow), 9 of 10 northern pike (Esox lucius) had mean Hg contents of 0.590 mg kg−1 (range 0.509–0.674) and therefore residues distinctly above the “normal level” of 0.2 mg kg−1, which is taken by the World Health Organization (WHO) to characterize fish from uncontaminated inland waters. Four of five roach (Rutilus rutilus) had Hg residues (0.272–0.393 mg kg−1) above the WHO limit, but 4 of 5 bighead carp (Aristichthys nobilis), a stocked filter‐feeder, ranged beneath it. In the Döllnsee (22 ha, 8 m) Hg residues in 28 pike ranged from 0.027 to 0.378 mg kg−1 with a mean of 0.154 mg kg−1. In 10 bream (Abramis brama), these data were 0.016–0.072 mg kg−1 and 0.050 mg kg−1, respectively. Twenty‐one roach had mean Hg contents of 0.088 mg kg−1 (range 0.038–0.182). In 8 perch (Perca fluviatilis) and 12 eel (Anguilla anguilla), these data were 0.063 mg kg−1 (0.051–0.090) and 0.073 mg kg−1 (0.008–0.170), respectively. None of the 99 muscle samples exceeded the hygienic mercury limits of the Federal Republic of Germany. A possible Hg load by airborne wet and dry depositions is discussed. © 1994 by John Wiley & Sons, Inc..
Chemosensory responses of ciliates: A sensitive end point in xenobiotic hazard assessment
Authors: Pauli W. , Berger S. , Schmitz S. , Jaskulka L.
Published: October 2006

It is known that ciliates exhibit chemosensory behavior. An assay implementing this response was performed with Tetrahymena thermophila, a well‐studied representative of the ciliates. A concentration‐dependent avoiding reaction was observed for all substances of the test battery, comprising a heterogeneous set of 43 compounds from the European Inventory of Existing Chemicals. Comparisons were made between toxic data from this chemosensory test and chemical concentrations leading to effects on Tetrahymena growth, and EC values from recommended aquatic toxicity tests. Low correlation coefficients indicate that the chemosensory response reflects chemical interactions, which cannot be adequately explained by these other tests. The chemosensory assay proved to be more sensitive in the majority of cases than the Tetrahymena growth test and standard tests with fish and Daphnia. Tetrahymena is able to recognize and avoid about half the substances at concentrations lower than those effective in the algae growth inhibition test. The behavioral response of Tetrahymena could provide further lexicological information and serve as a complementary sublethal end point for ecotoxicological screening purposes. © 1994 by John Wiley & Sons, Inc..
Wastewater toxicity assessment using the electrophysiological response of a charophyte Nitellopsis obtusa
Authors: Manusadžianas L. , Vitkus R. , Sakalauskas V.
Published: October 2006

A biotesting method for the assessment of acute sublethal toxicity to charophyte cells of Nitellopsis obtusa was developed and applied for the study of Vilnius and Visaginas wastewaters (WW). This computer‐assisted testing procedure was based on the recording of the electrophysiological response of up to 16 single algal cells simultaneously. Membrane parameters of living cells were measured according to the K+‐anaesthesia method modified for multichannel recording with extracellular electrodes. Concentration‐dependent monotonical decrease of cell resting potential, induced by toxic WW action, was used to determine an effective concentration (EC) values. A multistep time‐saving procedure, when the cell group was exposed to subsequent treatment with increasing WW concentrations (30 min per treatment), proved to be adequate for biotesting. The ECs obtained by this procedure were in good agreement with those obtained alternatively by undertaking one‐step testing (i.e., 60 min exposure per concentration per cell group). The relative sensitivity of the cellular electrophysiological response, as a toxicity end point, was confirmed by comparing it with lethal concentration (LC) responses in 96‐ and 192‐h exposure tests conducted on the same N. obtusa cells. For Vilnius WW samples taken on different dates, the EC ranged from 27 to 46% WW and corresponded to 96‐h LC of 28–50% WW. In contrast, Visaginas WWs sampled before and after chlorination showed no toxic effect either at the membrane or whole cell level. © by John Wiley & Sons, Inc.
The relative sensitivity and sensitivity patterns of short‐term toxicity tests applied to industrial wastewaters
Authors: Wängberg Sten‐åke , Bergström Birgitta , Blanck Hans , Svanberg Olof
Published: October 2006

Ten short‐term toxicity tests were run for ten different industrial wastewaters. The tests included standardized toxicity tests with bacteria, microalgae, higher plants, invertebrates, and fish. An algal test battery of 13 microalgae was also run in microplates. The results were compared with regard to the tests' relative sensitivity and the similarity in sensitivity patterns between different tests. The test with highest sensitivity was the algal test battery. This was due to the fact that the algal species in the battery had complementary sensitivity patterns. The sensitivity patterns of the zoological tests had a high degree of similarity and they were less sensitive than the microbial tests. The relative sensitivity of a test is, however, dependent on the end point for the tests, and it is pointed out that this must be matched with how the test is interpreted. © by John Wiley & Sons, Inc.
Toxicity of binary mixtures of organic chemicals
Authors: Chen Chung‐Yuan , Chiou Yuen‐Shian
Published: October 2006

Toxicity of binary mixtures of organic chemicals was evaluated using the Microtox test, in order to derive a more realistic approach for predicting mixture toxicity. Both additive and less than additive effects were found from binary mixtures of nonreactive toxicants. Concentration addition can be expected between two nonreactive chemicals, provided that the requirement of parallel dose—response curves is fulfilled. The study also identified the conditions for a complex—type joint action to take place. Finally, experimental isobolograms were analyzed based on a bivariate toxicity model to provide a rational estimation of model parameters. The isobolograms and the additive indices generated by this study can be used to predict the combined toxic effects from various organic mixtures. © by John Wiley & Sons, Inc.
Anthropogenic contaminants and fish health along an urban waterway
Authors: Ostrander Gary K. , Kuehn Ron L. , Berlin K. Darrell , Hawkins William E.
Published: October 2006

Field studies were conducted along an urban/industrial river to investigate the potential relationship between anthropogenic contaminants, including those related to oil refining, and fish health. The channel catfish, Ictalurus punctatus, served as the benthic sentinel species for these studies. At least 15 aromatic hydrocarbons known to be associated with oil refining and/or other industrial activities were detected at impacted stations including known carcinogens and mutagens [e.g., anthracene and benzo(a)pyrene]. At an appropriate reference station, no anthropogenic contaminants were identified in the waters and only 2 were observed in the sediments. Catfish collected from the reference station were significantly heavier, longer, and had higher relative weights. Morphological deformities such as clubbed, split, and missing barbels were observed on 37.8% of the fish collected from the impacted stations, while none were observed on fish from the reference station. Livers of catfish collected from the impacted stations exhibited a variety of histological changes consistent with contaminant exposure including vacuolated hepatocytes, pigment deposits, and other hepatoxic changes. These sublethal changes appear to be associated with chemical contamination and represent compromised health of individual organisms and, potentially, populations. © by John Wiley & Sons, Inc.
Evaluation of the genotoxicity of environmental contaminants in sediments to rainbow trout hepatocytes
Authors: Gagné F. , Blaise C.
Published: October 2006

Rainbow trout hepatocytes were used as an in vitro bioassay to assess the genotoxic potential of single chemicals and marine sediment extracts. Freshly prepared trout hepatocytes were exposed to either benzo[a]pyrene, N‐methyl‐N′‐nitro‐N‐nitrosoguanidine, β‐naphtoflavone, or organic extracts of marine sediments for 24 h at 15°C. Genotoxicity was assayed using the nick translation assay, which makes use of a nonradioactive nucleotide (biotin‐dUTP), and the DNA alkaline precipitation assay followed by fluorometric detection of DNA strands. Exposure to benzo[a]pyrene or methyl‐N′‐nitro‐N‐nitrosoguanidine, known indirect‐and direct‐acting genotoxins respectively, produced genotoxicity to rainbow trout hepatocytes with both assays. β‐Naphtoflavone displayed genotoxic activity in trout hepatocytes. Sediment extracts and reference sediment extracts displayed high toxicity and genotoxicity to trout hepatocytes. Chemical analyses showed that these sediments contained significant amounts of organochlorine pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons. Cell toxicity was correlated with total levels of organochlorine pesticides and polychlorinated biphenyls but not total levels of polycyclic aromatic hydrocarbons. No positive correlation was found with the nick translation assay between total levels of chemicals and genotoxicity in marine sediments. Genotoxicity obtained with the alkaline precipitation assay was correlated with levels of the organochlorine pesticide DDT. However, more tests would be required to further substantiate possible links with other specific chemicals. © by John Wiley & Sons, Inc.