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PubMed1984

Suppression of humoral antibody production by exposure to 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin.

The day 4 IgM antibody (AB) response to sheep red blood cells was suppressed in adult female B6C3F1 mice subchronically (14 day) exposed to 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (1,2,3,6,7,8-HCDD) at concentrations reflecting the levels of this dioxin isomer as a contaminant in technical-grade pentachlorophenol. Hepatic microsomal parameters were also measured in these mice and indicated the characteristic induction of mixed-function oxidase enzyme activities, particularly aryl hydrocarbon hydroxylase. The response to sheep red blood cells was also suppressed when measured in vitro by culturing the antigen with spleen cells from a second group of mice subchronically exposed to 1,2,3,6,7,8-HCDD. Enumeration studies with fluorescent-labeled antisera in these animals indicated a dose-related suppression in the number of T-lymphocytes with no effect on B-lymphocytes. 1,2,3,6,7,8-HCDD directly suppressed several in vitro AB responses when added to cultures of spleen cell suspensions from untreated B6C3F1 mice. The rank order of sensitivity was determined to be: polyclonal AB response to LPS greater than or equal to T-independent AB response to DNP-Ficoll greater than T-dependent AB response to sheep red blood cells. Subsequent studies indicated that the suppression by 1,2,3,6,7,8-HCDD could be produced after only a 30-min preincubation. The suppression of all in vitro AB responses was abolished when the dioxin was preincubated with a metabolic activation system: crude liver homogenate (B6C3F1 mice pretreated with the mixed-function oxidase inducer; Aroclor 1254) plus NADP and isocitrate. The suppression of the T-dependent AB response was still evident when the metabolic activation system was heat-inactivated (as verified by an inability to activate cyclophosphamide) prior to the preincubation.

Animals↗
PubMedDate not supplied

Chlorinated compounds and phenols in tissue, fat, and blood from rats fed industrial waste site soil extract: methods and analysis.

A method was developed to analyze rat tissue, fat, and blood for some of the chlorinated compounds found in an extract of soil from an industrial waste site. Extraction with hexane and then with ethyl ether-hexane (1 + 1) was followed by concentration over steam, and gas chromatographic analysis with an electron capture detector. Volatile compounds were analyzed in a glass column coated with 6% SP-2100 plus 4% OV-11 on Chromosorb W. Semivolatile compounds, chlorinated compounds, and pesticides were analyzed in a 70 m glass capillary column coated with 5% OV-101. Phenols were analyzed in a glass column packed with 1% SP-1240 DA on Supelcoport. However, the most efficient means of separation was to use the same glass column for volatile compounds, a DB-5 fused silica capillary column for semivolatile compounds, pesticides, and phenols, and the same 1% SP-1240 DA glass column for separation of beta-BHC and pentachlorophenol. Recoveries ranged from 86.3 +/- 9.1% (mean +/- standard deviation) to 105 +/- 10.4%. Sensitivities for semivolatile chlorinated compounds, pesticides, and phenols were about 4 ng/g for fat, 1 ng/g for tissue, and 0.2 ng/mL for blood. Sensitivities for volatile compounds were about 4-fold higher (16, 4, and 0.8, respectively). Sensitivities for dichlorobenzenes and dichlorotoluenes were 8 ng/g for fat, 2 ng/g for tissue, and 0.4 ng/mL for blood.

Adipose Tissue↗
PubMed1980

Identification of hazardous organic chemicals in fish from the Ashtabula River, Ohio, and Wabash River, Indiana.

Composite fish samples from the Wabash River, IN, and the Ashtabula River, OH, were analyzed by conventional pesticide procedures for PCBs, DDTs, chlordane components, and hexachlorobenzene. Additional aliquots of each sample were processed by gel permeation chromatography and were analyzed with gas chromatography--mass spectrometry by using both electron impact and negative chemical ionization modes. These analyses resulted in the identification of a series of chlorinated alkanes, chlorinated alkenes, chlorinated alkylamines containing 2--5 carbons, and polychlorinated styrenes in the Ashtabula River sample, and a series of chlorinated norbornenes, pentachlorobenzyl alcohol, and pentachlorophenol in the Wabash River sample.

Animals↗
PubMed1983

Selected ion mass spectrometric identification of chlorophenol residues in human urine.

A method is presented for the detection and confirmation of trace chlorophenol residues in environmental and biological samples by mass spectrometry with selected ion monitoring (SIM). Propionate and acetate ester derivatives of phenol, cresols, mono-, di-, tri-, and tetrachlorophenols, pentachlorophenol, as well as the internal standard 4,6-dibromo-o-cresol, were prepared directly in aqueous solution, using the appropriate anhydride reagent. The acetate or propionate esters were quantitatively extracted and then separated by gas-liquid chromatography using either an SP-1240DA or OV-101 packed column. Electron impact SIM was carried out by simultaneously monitoring up to 4 diagnostic fragment ions of each chlorinated phenol. The use of SIM eliminated background interference encountered using flame ionization or electron capture detectors, and allowed identification of chlorophenol residues in extracts of urine samples collected from individuals without known exposure to chlorophenols. Phenol concentrations as low as 1.0 pmol/mL urine gave peaks that were readily discernible by SIM.

Acetates↗
PubMed1980

[Problems arising from disease during the periods of breeding and rearing canaries and other aviary birds (author's transl)].

The hygienic aspects of the various breeding systems are reviewed. The companion aviary is the least hygienic system; the birds are hardest to supervise in this case. Breeding in pairs is preferable from either point of view. Hygiene in aviaries is determined by all component parts of the cage, which are used in keeping the birds. The walls should be smooth and clean. The most hygienic drinking water supply is ensured by bottle-type nipple drinkers provided with a small ball. Feeders should be emptied, cleansed and filled with fresh water every day. A hygienic, dry floor-covering will prevent the appearance of large numbers of Enterobacteriaceae (as well as E. coli) in the intestine. The feed should preferably be given in measured rations. An adult canary should be fed 4 g. of seed and 1 g. of soft feed (containing 20 per cent of protein and 1 per cent of lysine) daily. Causes of death in young birds may be: inferior soft feed, a faulty diet, the presence of pentachlorophenol in the nesting material, infestation with chicken lice (Dermanyssus gallinae), diarrhoea due to a polluted environment (neonatal diarrhoea shortly after hatching), cochlosomosis, drumsticks and atoxoplasmosis. The clinical features and treatment of infectious diseases are discussed.

Animal Feed↗
PubMed1993

Construction and application of chromosomally integrated lac-lux gene markers to monitor the fate of a 2,4-dichlorophenoxyacetic acid-degrading bacterium in contaminated soils.

A reporter gene system, containing luxAB and lacZY, was constructed and integrated, using Tn7 transposition, into the chromosome of a 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading soil bacterium, Pseudomonas cepacia (BRI6001), to monitor its fate when introduced into soil microcosms. The genes were stably maintained in the modified strain of BRI6001, BRI6001L, for more than 300 generations in the absence of selection pressure, and had no apparent effects on biochemical or physiological properties. BRI6001L was easily and rapidly identified as light-emitting blue colonies on 2,4-D medium containing XGal (5-bromo-4-chloro-indolyl-beta-D-galacto-pyranoside) in the presence of n-decanal. Survival rates of BRI6001L introduced into non-sterile soil microcosms were substrate- and contaminant-dependent. The decrease in population density was lowest in a 2,4-D-amended agricultural soil, and highest in a wood-treatment facility soil contaminated with pentachlorophenol, creosote and heavy metals. A viable cell density as low as 10 cfu g-1 was detected in soil microcosms. The biochemical and growth properties of BRI6001 and BRI6001L, and their behaviour when introduced into soil microcosms indicates that BRI6001L can be used as a reliable model to predict the fate of BRI6001 when used to bioaugment contaminated soil.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1994

Chloracne. Some recent issues.

Chloracne is an acneiform skin eruption that is still the most sensitive indicator of systemic poisoning caused by chemicals belonging to the group of chlorinated polycyclic aromatic hydrocarbons. Generally these chemicals are known as dioxins, dibenzofuranes, and PCBs. The cause of chloracne is probably interference of these chemicals with vitamin A metabolism in the skin, resulting in disturbances of the epithelial tissues of the pilosebaceous duct. A study of workers in a factory where chloracne is endemic is described. The product manufactured, pentachlorophenol, a wood preservative, was found to be contaminated with dioxins (congeners of TCDD) and dibenzofuranes. Blood levels of these chemicals in affected workers are given, along with supporting evidence of disturbances in vitamin A (retinoid) metabolism as demonstrated in skin biopsies.

Acne Vulgaris↗
PubMed1994

Purification and characterization of an extracellular adenosine deaminase from Nocardioides sp. J-326TK.

An extracellular adenosine deaminase was isolated from the culture supernatant of Nocardioides sp. J-326TK and purified 193-fold to homogeneity. It had a specific activity of 4677 units/mg at 37 degrees C, was a monomeric protein as judged by SDS/PAGE, and was characterized with respect to M(r) (80,000 and 72,000 by gel filtration on Sephadex G-200 and SDS/PAGE respectively), pH optimum (6.0), temperature optimum (50 degrees C) and pI (7.6). The adsorption spectrum of the enzyme had a maximum at 280 nm and a minimum at 250 nm. The enzyme was stable at pH 6.5-7.5 and at temperatures below 30 degrees C. Adenosine and 2'-deoxyadenosine were deaminated and the respective Km values were 0.22 and 0.20 mM, but the enzyme was not active on adenine and 6-(gamma gamma'-dimethylallylamino)purine riboside. The enzyme reaction was promoted by Fe3+ and Sn2+, but potently inhibited by Hg2+, Ag2+, o-phenanthroline and pentachlorophenol, and noticeably inhibited by 8-bromoadenosine, theobromine and theophylline.

Adenosine Deaminase↗
PubMed1975

Chromatographic methods for the analysis of hexachlorobenzene and possible metabolites in monkey fecal samples.

The separation and identification of hexachlorobenzene (HCB), pentachlorobenzene (QCB), and pentachlorophenol (PCP) by thin layer, high-pressure liquid, and gas chromatography are reported. Satisfactory results were obtained with reverse phase thin layer and high-pressure liquid chromatography. The 2 gas chromatographic columns tested gave adequate separation of HCB and QCB. A PCP methylation process using dimethyl sulfate was attempted. Procedures are presented for extraction, cleanup, separation, and identification of HCB and possible metabolites from feces of a rhesus monkey treated with 14C-HCB. Recovery of radioactivity in excess of 96% was attained in extracts from feces by these methods. Preliminary evidence suggests the formation of PCP and possibly other polar metabolites from HCB in the rhesus monkey.

Animals↗
PubMed1994

Exposure to phenoxyacetic acids, chlorophenols, or organic solvents in relation to histopathology, stage, and anatomical localization of non-Hodgkin's lymphoma.

Results on 105 cases with histopathologically confirmed non-Hodgkin's lymphoma (NHL) and 335 controls from a previously published case-control study on malignant lymphoma are presented together with some extended analyses. No occupation was a risk factor for NHL. Exposure to phenoxyacetic acids yielded, in the univariate analysis, an odds ratio of 5.5 with a 95% confidence interval of 2.7-11. Most cases and controls were exposed to a commercial mixture of 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid. Exposure to chlorophenols gave an odds ratio of 4.8 (2.7-8.8) with pentachlorophenol being the most common type. Exposure to organic solvents yielded an odds ratio of 2.4 (1.4-3.9). These results were not significantly changed in the multivariate analysis. Dichlorodiphenyltrichloroethane, asbestos, smoking, and oral snuff were not associated with an increased risk for NHL. The results regarding increased risk for NHL following exposure to phenoxyacetic acids, chlorophenols, or organic solvents were not affected by histopathological type, disease stage, or anatomical site of disease presentation. Median survival was somewhat longer in cases exposed to organic solvents than the rest. This was explained by more prevalent exposure to organic solvents in the group of cases with good prognosis NHL histopathology.

Acetates↗
PubMed1976

Multiresidue screening by negative chemical ionization mass spectrometry of organic polychlorides.

A multiresidue procedure, based on negative chemical ionization (NCI) mass spectrometry, for analyzing organochlorine residues in environmental substrates is described. The procedure is capable of routinely detecting about 1 ng unknown organochlorine residues. Semi-quantitative data (order of magnitude) may be obtained for pentachlorophenol and 2,4,5-trichlorophenoxyacetic acid residues by calibration with internal p-chlorobenzophenone. Lipid-rich substrates were resolved into acidic and neutral fractions, and both fractions were further purified by gel permeation chromatography (GPC) prior to NCI analysis. In spite of the fact that recoveries were often low, the overall sensitivity for residues in lipid-rich substrates appeared to be higher than when the GPC step was omitted.

Animals↗
PubMedDate not supplied

Gas chromatographic/electron capture detection method for determination of chlorinated acids in water: collaborative study.

A U.S. Environmental Protection Agency (USEPA) interlaboratory method validation study was conducted on USEPA Method 515.1, "Determination of Chlorinated Acids in Water by Gas Chromatography with an Electron Capture Detector." This method is one of the 6 pesticide methods developed for the USEPA National Pesticide Survey (NPS). Method recovery and precision for analyses of sub-ppb to low-ppb concentrations of chlorinated acids were determined in reagent water and finished drinking waters. The analytes evaluated in the study included the 12 pesticides that were quantitatively measured in the National Pesticide Survey (bentazon, 2,4-D, 2,4-DB, 3,5-dichlorobenzoic acid, DCPA-diacid, dicamba, dichlorprop. 5-hydroxydicamba, pentachlorophenol, picloram, 2,4,5-T, and 2,4,5-TP) and 5 pesticides (acifluorfen, chloramben, dalapon, dinoseb, and 4-nitrophenol) that were only qualitatively assessed in the National Pesticide Survey because of recognized method imprecision. The study design was based on Youden's nonreplicate plan for collaborative tests of analytical methods. The waters were spiked with 17 chlorinated acids, each at 6 concentration levels, prepared as 3 Youden pairs. Eight laboratories extracted the spiked test waters at pH < 2 with ethyl ether, performed a solvent exchange with methyl tert-butyl ether, prepared methyl esters of the extracted acids using diazomethane, and analyzed an aliquot of each derivatized extract by gas chromatography with electron capture detection. The submitted data were analyzed using a USEPA computer program, which measured recovery and precision for each of the 17 compounds and compared the performance of the method between water types. Method 515.1 was judged acceptable for the 12 NPS analytes recovered quantitatively; mean percent recoveries at 10-15 times the method detection limits ranged from 79 to 105% in reagent water and from 75 to 123% in finished drinking water. In reagent water, overall precision (reproducibility relative standard deviation, RSDR) ranged from 9.6 to 34.2% and in finished drinking water, the RSDR ranged from 11.9 to 37.0%. Single-analyst precision (RSD for repeatability, RSDr) ranged from 5.8 to 17.7% in reagent water and from 4.6 to 27.9% in drinking water. Results for the 5 other NPS analytes were too inaccurate or imprecise and, for these compounds, supported use of the method for qualitative measurements only; the 5 compounds are not included in the adopted method. The method has been adopted first action by AOAC INTERNATIONAL for determination of residues of 12 chlorinated acids in finished drinking water.

Analysis of Variance↗
PubMed1996

The capability of rat colon tissue slices to metabolize the cooked-food carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine.

A major target tissue for carcinogenesis from the cooked-food carcinogen 2-amino-l-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in rodents is the colon, yet the role of colon metabolism on the carcinogenicity of PhIP is not clearly understood. The mutagenic potency of PhIP is highly dependent upon cytochrome P450 N-hydroxylation. In the present study, the ability of rat colon tissue to activate PhIP to a mutagen was investigated in Salmonella typhimurium (strains TA98 and YGI024) and rat colon tissue slices. In the Ames/Salmonella assay, using rat colon S9 as the activating system, no mutations were evident from bacteria exposed to PhIP at any concentration tested. However, mutations were observed when bacteria were exposed to 2-aminoanthracene (2AA) and colon S9, indicating sufficient P450 activity in the S9 to activate 2AA but not PhIP. In rat colon slice preparations, the sulfotransferase and acetyltransferase inhibitors pentachlorophenol (PCP) and 2,6-dichloro-4-nitrophenol (DCNP) were used to modulate DNA adduct and metabolite formation. Incubations of 3-methylcholanthrene-induced colon slices dosed with 50 microMolar [(3)H]PhIP produced no detectable metabolites. However, incubations of uninduced slices exposed to 10 microMolar of the reactive intermediate, [(3)H]2-(hydroxyamino)-l-methyl-6-phenylimidazo[4,5-b]pyridine (N-hydroxy-PhIP), produced a single detectable metabolite, a glucuronide conjugate of N-hydroxy-PhIP. This metabolite decreased when PCP or DCNP was added to the incubation medium. DNA adducts were detected in colon slices exposed to N-hydroxy-PhIP at approximately 33 adducts/10(7) nucleotides. Interestingly, when PCP was added to the incubation mixture, an increase in DNA adduct levels was detected, whereas DCNP produced a decrease in adducts. Because these inhibitors are thought to have similar mechanisms with regard to sulfotransferase inhibition, the inverse relationship in DNA adduct levels due to PCP or DCNP treatment is at present unexplainable. The formation of DNA adducts and metabolites from colon slices exposed to N-hydroxy-PhIP but not PhIP implies that there is insufficient P450 activity in the rat colon to activate PhIP to hydroxylated metabolites, suggesting that the rat colon is a site of Phase II metabolism for PhIP and that the liver is the primary source for hydroxylation.

Animals↗
PubMed1997

[PCDD/F-content in house dust].

The levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) were determined in house dust samples collected from 22 residential houses located in different areas of Germany. Nine houses were located in an urban and industrial area, one house in a rural and 10 houses in a contaminated residential area near to a former metal reclamation plant. Two house dust samples were collected from two old farm houses, in which large amounts of pentachlorophenol (PCP) containing wood preservatives had been used several years ago. All dust samples were collected from the dust bags of vacuum cleaners and passed through a sieve (mesh: 2.0 mm). Particles < 2.0 mm were used for analysis. The average level of PCDD/F in "normal" house dust was 101 ng I-TEq/kg (range: 7.83-332 ng I-TEq/kg). The predominant congeners and chlorohomologues were OctaCDD followed by HeptaCDD, HeptaCDF and OctaCDF. The average level of PCDD/F in house dust samples collected from a contaminated residential area was 265 ng I-TEq/kg (range: 29.9-1050 ng I-TEq/kg). When compared with "normal" residential houses significantly increased levels of lower chlorinated PCDD/F were noted in the house dust samples from this area. The house dust samples collected from a PCP-treated old farm house were found to contain 1.39 and 11.8 micrograms I-TEq/kg. The chlorohomologues patterns were typical for PCP contaminated with PCDD/F. The present study shows that the levels of PCDD/F in house dust may be used as indicators of indoor contamination by PCDD/F and as reference values for further investigations.

Air Pollutants↗
PubMed1976

[Effects of plant protective agents and pesticides on the processibility of milk with special consideration to microbiological technology].

The authors studied the effects of the active ingredients contained in 43 pesticides and insecticides on dairy cultures and the suitability of milk contaminated in vitro with selected organophosphorus insecticides. The acid-forming property of yoghurt, kefir, butter and cheese cultures, the clotting property of milk and the ripening process of Camembert were used as testing criteria. The herbicides 2-methyl-4,6-dinitrophenol (DNOC), 2,4, 5-trichlorophenol, 2-methyl-4-chlorophenoxyacetic acid (MCPA), 4-(2-methyl-4-chlorophenoxy) butyric acid (MPCB), 2,4-dichlorophenoxyacetic acid (2,4-D), 2,2-dichloropropionic acid (dalapon), the chlorinated insecticide heptachlorepoxide and the fungicide pentachlorophenol exerted inhibitory effects when applied at concentrations of more than 100 p.p.m., whereas most of the organophosphorus and chlorinated insecticides under investigation produced no detectable effects on the culture activity when used at concentrations up to 100 mg/kg. The clotting property of milk was not impaired by the pesticides and insecticides at concentrations up to 100 mg/kg; the same was true of the ripening process of Camembert.

Animals↗
PubMed1995

Rapid toxicity assessment using an in vivo enzyme test for Brachionus plicatilis (Rotifera).

A 1-hr in vivo enzyme inhibition assay based on esterase activity has good potential for marine toxicity assessment. A test was developed for the rotifer Brachionus plicatilis based on the nonfluorescent substrate fluorescein diacetate (FDA), which is metabolized by esterases to a fluorescent product. Enzyme inhibition, as determined by reduced fluorescence, can be scored visually or quantified using a fluorometer. Quantification of fluorescence permits the calculation of NOEC, LOEC, chronic value, and IC20. The 1-hr esterase inhibition test has sensitivity comparable to that of 24-hr rotifer acute tests for several compounds. The toxicity of six compounds was examined using the quantified assay. The resulting IC20s were within a factor of 3 of the 24-hour LC50s. IC20 values ranged from 0.017 mg/l for tributyltin to 3.1 mg/l for zinc, with an average coefficient of variation of 17.8%. Electrophoretic analysis of rotifer homogenates suggested that a single C esterase (acetylesterase) was responsible for FDA metabolism in B. plicatilis. Several other aquatic species are capable of metabolizing FDA, including Brachionus calyciflorus, Mysidopsis bahia, Menidia beryllina, Pimephales promelas, Ceriodaphnia dubia, Daphnia pulex, Artemia salina, and Ophryotrocha sp. The esterase inhibition test is an attractive tool for assessing aquatic toxicity because of its speed, simplicity, sensitivity, and applicability to a broad range of aquatic species.

Animals↗
PubMed2001

Ecotoxicological evaluation of three deicers (NaCl, NaFo, CMA)-effect on terrestrial organisms.

The use of chemical deicers such as sodium chloride (NaCl) has increased significantly during the past three decades. Deicers induce metal corrosion and alter the physicochemical properties of soils and water. Environmental damage caused by the use of NaCl has prompted government agencies to find alternative deicers. This article presents a comparative ecotoxicological study of three deicers on soil organisms. Sodium formiate (NaFo) and calcium-magnesium acetate (CMA) are the most interesting commercially available deicers based upon their characteristics and potential toxicity. Organisms used in this study were four species of macrophytes (cress (Lepidium sativum), barley (Ordeum vulgare), red fescue grass (Festuca rubra), Kentucky bluegrass (Poa pratensis)) and an invertebrate (Eisenia fetida). Using standardized and modified methods, the relative toxicity of deicers was CMA < NaFo congruent with NaCl. The results demonstrate that these chemicals could have similar impacts in terrestrial environments since similar quantities of NaFo and greater amounts of CMA are necessary to achieve the same efficiency as NaCl. The toxicity of the tested substances was lower in natural composted soil than in artificial substrate (silica or OECD soil), indicating decreased environmental bioavailability. The response of the organisms changed according to endpoint, species, and soil characteristics (artificial substrate as compared to natural organic soil). The most sensitive endpoint measured was macrophyte growth with Kentucky bluegrass being the most sensitive species.

Acetates↗