Abstract  Aerolysin is a channel-forming protein secreted as a protoxin by Aeromonas hydrophila. Analytical centrifugation measurements showed that proaerolysin is a dimer in solution, and this was confirmed by chemical cross-linking with dimethyl suberimidate. Dissociation of proaerolysin with low concentrations of SDS resulted in the loss of tertiary structure, assessed by near ultraviolet circular dichroism. This was accompanied by an increase in the protein's ability to bind the hydrophobic dye 1-anilino-8-naphthalene sulfonate, as well as by increased sensitivity to proteolytic degradation. However, the monomer was not fully unfolded by the detergent, as the tryptophans remained in a hydrophobic environment, and the secondary structure measured by far ultraviolet circular dichroism did not seem to be affected. Aerolysin, the active form of the protein, was also shown to be a dimer, and its stability was found to be no different from the stability of the protoxin dimer. Substituting tryptophan 371 or tryptophan 373 with leucine greatly reduced the stability of dimeric proaerolysin. These substitutions are known to increase the protein's ability to oligomerize, supporting the conclusion that dimer dissociation is necessary for oligomerization to occur.

Abstract  HEEP COPYRIGHT: BIOL ABS. RABBIT CARASSIUS-AURATUS LIMULUS-POLYPHEMUS

Abstract  BIOSIS COPYRIGHT: BIOL ABS. Deposition fluxes have been estimated from concentrations of 12 polynuclear aromatic hydrocarbons (PAHs) and six heavy metals measured in sediment cores from Esthwaite Water, a rural English take. Atmospheric deposition is a major source of PAHs and heavy metals (Cd, Cu, Pb, and Zn) to the lake, so trends in the core may indicate the long-term record of changes in the atmospheric loading of these pollutants. The cores were dated radiometrically and pollutant trends studied since about 1820. PAH fluxes began to increase from stable background levels around the turn of the century (4.1 mug SIGMAPAH per gram dry weight, 287 ng SIGMAPAH per centimeter squared per year), rising to maximum inputs between 1950 and 1970 (42.0 mug/g, 2,954 ng/cm2 per year). The deposition flux of PAHs has decreased steadily since then and is now less than half the maximum (18.0 mug/g, 1,238 ng/cm2 per year). In recent sediments (1900-1970), the relative proportions of individual PAHs making up t

Abstract  BIOSIS COPYRIGHT: BIOL ABS. The PAH composition of coal tar containing samples collected at a number of coal gasworks sites has been studied. Samples were removed from areas where the coal tar components would have undergone varying degrees of environmental modification since deposition. The degree of environmental modification for individual PAHs exhibits a strong correlation with various molecular descriptors including octanol/water partition coefficient (KOW). Regression lines for environmental modification ratio-descriptor relationships show an increasing slope with increasing environmental attenuation of the coal tar sample. Aqueous partitioning and volatilization are probably the main processes which control environmental modification of coal tar at gasworks sites. The application of molecular descriptors shows promise for modelling the environmental behaviour of PAHs in these situations.

Abstract  Freeze-dried residues of fresh water mussels (exclusive of shell) from the Kingston Basin of Lake Ontario (Canada) are analyzed for Al, Cr, Cu, Pb and Zn by direct firing of solid samples in a graphite furnace atomizer. Naphthalene is used as a diluent. Calibration using aqueous standards appears sufficiently accurate for slowly volatilized elements (Al, Cr, Cu). Calibration tests with NBS (National Bureau of Standards) Standard Material 1571 (orchard leaves) indicate that aqueous standards cannot be used with accuracy for volatile elements (Pb, Zn).

Abstract  BIOSIS COPYRIGHT: BIOL ABS. A new method for analysing carbonyls (aldehydes and ketones) by capillary electrophoresis (CE) is described. The carbonyls are derivatized with DNSH (5-(dimethylamino)naphthalene-1-sulphonehydrazide, Dansylhydrazine) to form detectable compounds and also to form negative charged molecules (buffer pH 7.1). Detection is carried out by UV or, alternatively, by fluorescence. Eight carbonyls are separated in less than 8 min. Electrokinetic injection is made by using a new experimental set-up. The electroendosmatic flow (EOF) is reversed during sample injection by pressure. Results are compared with HPLC-analysis as the most common method in carbonyl analysis.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM HUMAN RAT RABBIT PULMONARY UPTAKE PULMONARY ACCUMULATION THERAPEUTIC AGENT TOXICITY ENVIRONMENTAL POLLUTANTS OXIDATIVE STRESS

Abstract  BIOSIS COPYRIGHT: BIOL ABS. Hydroxy and acid compounds, present in the polar HPLC fraction number 8 from the NBS-SRM 1650 (diesel particulate extract) were derivatized with N,O-bis(trimethylsilyl)-trifluoroacetamide (BSTFA) to form the trimethylsilane (TMS) derivatives. This improved the gas-chromatographic separation to give an improved characterisation using GC-MS. TMS derivatives were only observed in the acid extract of an aliquot of HPLC fraction number 8 which had undergone an acid-base fractionation. A number of previously unidentified compounds in fraction 8 could be characterised using mass spectroscopy. Ion mass chromatograms recorded at m/z 73, 89 and 147 were correlated with the total ion current (TIC) to identify derivatized compounds. Only single, two and three ring derivatized aromatics were observed. The compounds identified in this polar fraction of the extract included p-nitrophenol, benzoic acid, hydroxy-benzoic acids, hydroxy-benzaldehyde, hydroxyphthalimide, benzene dicarboxyl

Abstract  HEEP COPYRIGHT: BIOL ABS. OILS ATP PRODUCTION NAPHTHALENE PHOTOSYNTHESIS POLLUTANT TOXICITY

Abstract  HEEP COPYRIGHT: BIOL ABS. Amounts of 1-anilino-8-naphthalene sulfonate (ANS) adsorbed by whole bovine erythrocyte and by its ghost membrane were studied at ANS concentration from 0.01-3 mM. For whole erythrocyte the amount is nearly proportional to the free ANS concentration with the ratio of 1.1ked-erythrocyte)/(mol/l-medium). The ghost membrane has 2 kinds of binding site for ANS. The Kd and the numbers of binding sites are calculated as follows: KI = 9.110-2 mol/kg-membrane for site J; KII = 1.0.8I can be attributed to protein and lipid, respectively, judging from membrane mass per mol of sites. The mechanism of disk to sphere transformation was discussed from these results.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. A set of twentyfour monocyclic and benzo-fused heteroaromatics were multivariately characterized by five experimental aromaticity descriptors: one geometric, two energetic and two magnetic aromaticity scales. Two principal properties (PP), designated as "classical" and "magnetic" respectively, were calculated from the 5incipal components (PC) model explaining 79.5% of variance. The first PP was shown to be related to Ix' aromaticity scale, available for a wider set of heteroaromatics. The above PPs, together with other descriptors accounting for the position of attachment of the ring, may be used in developing strategies for selecting heteroaromatic moieties in experimental design aimed at the optimization of structures for pharmaceutical or toxicological testing.

Abstract  HEEP COPYRIGHT: BIOL ABS. Approximately 50% of the compounds in the water solubles from 4 fuel oils (from USA refinery locations: Baytown (Texas); Baton Rouge (Louisiana); Billings, (Montana); Linden (New Jersey)) were identified via gas chromatography and mass spectrometry. In addition to naphthalenes and benzenes, phenols, anilines and indoles were found. Of these classes of compounds methyl, dimethyl and trimethyl derivatives were present in relatively high concentrations. The water solubles from the 4 fuel oils showed considerably different inhibitory effects to growth of 6 microalgae, 2 blue greens, 2 greens and 2 diatoms. Two of the fuel-oil extracts, Baytown and Montana, were lethal to blue-green algae. This was in part traceable to their content of p-toluidine which was toxic to Agmenellum quadruplicatum, Strain PR-6, 1 mug in the algal lawn-pad assay and 100 mug/l in liquid culture. The water-soluble fraction from New Jersey fuel oil was lethal to the 2 green algae, with lesser effects on the 2 blue-greens. The 2 estuarine diatoms used as test organisms were not greatly inhibited by Baytown, Montana, or New Jersey fuel-oil water-soluble extracts. Earlier work with an American Petroleum Institute fuel oil and the diatom Thallassiosira pseudonana (3H) showed that 3H was a very sensitive organism. Water solubles from the Baton Rouge fuel oil were almost without effect on the growth of all 6 microalgae. The potential of toxic fuel oils for environmental damage is apparently high, either through selective or enrichment effects on natural populations or through a lowering of total primary production.

Abstract  Alkylbenzenes, polycyclic aromatic hydrocarbons and chlorinated hydrocarbons were determined in rain and snow collected during 1985 at an urban site in Switzerland. Although great variations in concentrations were found for each season and type of precipitation event, concentrations and wet depositions of the investigated compounds were significantly lower in summer than in winter precipitation. Snow contained the highest concentrations of alkylbenzenes, i.e. total concentrations of up to 10μgℓ−1. Non-polar organic chemicals, measured sequentially during three rain events, exhibited a variety of temporal trends which can best be explained by changing sources and moving air masses.

Abstract  HEEP COPYRIGHT: BIOL ABS. Phenanthrene 9,10-oxide, a K-region arene oxide, undergoes nucleophilic attack by oxygen bases and a wide variety of amines as a result of its relatively slow rate of ring opening to carbonium ion and the decreased rate of rearrangement of the carbonium ion to phenol. The rate of reaction of this oxide with nucleophiles is comparable with that of ethylene oxide. The second-order rate constants for attack by primary and secondary amines give a betanuc value of 0.4. Certain tertiary amines (trimethylamine and quinuclidine amines) exhibit enhanced nucleophilic reactivity. This is suggested to be due to preequilibrium complex formation prior to nucleophilic attack. The quinuclidine amines give a betanuc value of 0.1. Oxygen bases are less reactive nucleophiles and give a betanuc value of 0.2. In the case of non-K-region arene oxides (phenanthrene 1,2-oxide, phenanthrene 3,4-oxide, benzene oxide and naphthalene oxide), nucleophilic attack by amines and oxygen bases is not sufficiently rapid to compete with the spontaneous aromatization reaction. Thiolate anions exhibit considerably greater nucleophilic reactivity than do amines and, consequently, react with both the K-region and non-K-region arene oxides. The second-order rate constants for attack by thiolate anions result in a betanuc value of 0.2 for each of the arene oxides investigated. Glutathione is no more reactive a thiol than would be predicted from its pKa. NMR studies of the nucleophilic adducts show that nucleophilic attack is stereospecific and results in trans adducts. Either direct SN2 attack or nucleophilic trapping of tight ion pairs is occurring. An index of nucleophilic susceptibility is defined for epoxides and arene oxides: ehtylene oxide = 1, phenanthrene 9,10-oxide = 0.3 and the non-K-region arene oxides are all 0.0l. (Carcinogenic behavior is discussed.)

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM VOLATILE ORGANIC CONSTITUENT POLLUTION

Abstract  HEEP COPYRIGHT: BIOL ABS.

Abstract  HEEP COPYRIGHT: BIOL ABS. The significance of hydrophobicity in substrate binding to cytochrome P-450 was studied by examining hydrocarbon-induced spectral changes in rat hepatic microsomes. Benzene, ethylbenzene, toluene, xylene, indene and naphthalene produced typical type I difference spectra (increase in absorbancy at about 385 nm and a decrease at about 420 nm) upon addition to hepatic microsomal suspensions. The relative abilities of the aromatic hydrocarbons to bind to cytochrome P-450 were directly proportional to their tendencies to leave an aqueous solution and enter a hydrocarbon phase. Type I spectra were also produced by the non-aromatic compounds cyclohexene, n-hexane, and n-pentane (the association constant for each being 970, 830, and 371, respectively). Neither charge transfer complex formation nor a cyclic nor a flat molecule is essential for hydrocarbon-induced spectral changes. Binding of aromatic hydrocarbons is simply dependent upon molecular size. These results provide evidence that hydrophobic interaction is the greatest single factor in the binding of substrates to hepatic cytochrome P-450. Since hydrophobic interactions represent the sole mechanism for hydrocarbon-induced spectral changes in cytochrome P-450, these compounds will provide useful probes in further studies to evaluate the apparent hydrophobicity of cytochrome P-450 and/or its environment under various experimental conditions.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM ABSTRACT BIOREACTOR WASTEWATER TREATMENT WATER POLLUTION CONTROL SOIL CONTAMINATION NAPHTHALENE

Abstract  HEEP COPYRIGHT: BIOL ABS. Male weanling rats were divided into 4 isonitrogenous dietary treatment groups, all of the dietary N and glutamic acid in groups A and B being derived from casein whereas 20% of the N and 65% of the glutamic acid in diets C and D were derived from monosodium glutamate (MSG). Diets B and D contained 1% cholesterol. At the end of a 28 day feeding period, the rats receiving MSG (groups C and D) exhibited the following statistically significant differences from the rats receiving N only from casein (groups A and B): depressed weight gain, heavier kidneys, higher levels of serum albumin, lower levels of serum globulin and a greater percent incorporation of an i.p. injection of 14-C acetate into hepatic 2-p-toluidinyl naphthalene-6-sulfonate (TNS) lipids. Rats fed the diets containing 1% cholesterol (groups B and D) exhibited the following statistically significant differences from those fed the cholestero-free diets (groups A and C): heavier livers, higher levels of serum albumin, globulin and total protein, greater concentration of hepatic cholesterol and lower percent incorporation of an i.p. injection of 14-C acetate into hepatic cholesterol.

Abstract  HEEP COPYRIGHT: BIOL ABS. Worldwide statistics pertaining to poisoning in children are reviewed in relation to aspects of age, sex, day of the week, hour and location where the accident occurred and initial reaction of witnesses. Most cases reported involved accidental consumption of toxicants (although occasionally cases of medicinal overdose during therapy were reported), in which male children between 1 and 3 yr were victims. Medicines affecting the nervous system and household (particularly cleaning) products were the primary toxicants; the most frequent being paradichlorobenzene, naphthalene, Javel water, codeine, aspirin, Gardenal, Phenergan, atropine, codethyline and water colors.

Abstract  HEEP COPYRIGHT: BIOL ABS. Beclotiamine-naphthalene disulfonate, a coccidiostat, was fed to 1-day-old White Leghorn male chicks for 8 wk in doses of 125 ppm, 500 ppm and 1000 ppm in the diet. As controls, non-medicated diet or diets containing thiamine-NDS at 125 ppm and 100 ppm were fed to the chickens. Quantities equivalent to about 0.4 ppm and 0.04 ppm and beclotiamine-HC1 were detected in liver and muscle, respectively, of the birds fed at the dose of 125 ppm in the diet. When the dose of beclotiamine was increased to 4 to 8 times greater, no accumulation of the coccidiosatat occurred in the tissues throughout the entire 56 days of the medication. Beclotiamine rapidly disappeared from the tissues once the compound was withdrawm from the diet. Neither growth depression nor decrease in thiamine levels in the liver occurred by administration of beclotiamine. Weights of liver, heart, brain, spleen, adrenal gland, kidney and testis were not influenced by administration of beclotiamine or thiamine. Serum acid phosphatase, alkaline phosphatase, glutamine-pyruvic transaminase and glutamic oxaloacetic transaminase activities and serum protein, cholesterol, and serum glucose were all within the normal range. No histophathological changes were observed in the liver.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM WASTE MANAGEMENT AIR POLLUTION MONITORING EMISSIONS PHYSICOCHEMICAL PROPERTIES NAPHTHALENE PHENANTHRENE PYRENE

Abstract  BIOSIS COPYRIGHT: BIOL ABS. The use of lipid-containing semipermeable membrane devices (SPMDs) is becoming commonplace, but very little sampling rate data are available for the estimation of ambient contaminant concentrations from analyte levels in exposed SPMDs. We determined the aqueous sampling rates (Rss; expressed as effective volumes of water extracted daily) of the standard (commercially available design) 1-g triolein SPMD for 15 of the priority pollutant (PP) polycyclic aromatic hydrocarbons (PAHs) at multiple temperatures and concentrations. Under the experimental conditions of this study, recovery-corrected Rs values for PP PAHs ranged from 1.0 to 8.0 L/d. These values would be expected to be influenced by significant changes (relative to this study) in water temperature, degree of biofouling, and current velocity-turbulence. Included in this paper is a discussion of the effects of temperature and octano l-water partition coefficient (Kow); the impacts of biofouling and hydrodynamics are reported separately. Overall, SPMDs responded proportionally to aqueous PAH concentrations; i.e., SPMD Rs values and SPMD-water concentration factors were independent of aqueous concentrations. Temperature effects (10, 18, and 26 ?C) on Rs values appeared to be complex but were relatively small.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM REVIEW HUMAN COW SHEEP PIG CHICKEN DOG RABBIT RODENT MONKEY ESCHERICHIA-COLI NITRATE FLUORIDE METALS POLYBROMINATED BIPHENYLS POLYCHLORINATED BIPHENYLS BENZOFURANS NAPHTHALENES ANTIBIOTICS ENVIRONMENTAL POLLUTANT