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Showing papers by "United States Environmental Protection Agency published in 1989"


Journal ArticleDOI
TL;DR: There was an 8.2-fold increase in the percentage of polymorphonuclear leukocytes (PMN) in the total cell population, and a small but significant decrease in the Percentage of macrophages after exposure to O3, suggesting increased vascular permeability of the lung.
Abstract: Although ozone (O3) has been shown to induce inflammation in the lungs of animals, very little is known about its inflammatory effects on humans In this study, 11 healthy nonsmoking men, 18 to 35 yr of age (mean, 254 +/- 35), were exposed once to 04 ppm O3 and once to filtered air for 2 h with intermittent exercise Eighteen hours later, bronchoalveolar lavage (BAL) was performed and the cells and fluid were analyzed for various indicators of inflammation There was an 82-fold increase in the percentage of polymorphonuclear leukocytes (PMN) in the total cell population, and a small but significant decrease in the percentage of macrophages after exposure to O3 Immunoreactive neutrophil elastase often associated with inflammation and lung damage increased by 38-fold in the fluid while its activity increased 206-fold in the lavaged cells A 2-fold increase in the levels of protein, albumin, and IgG suggested increased vascular permeability of the lung Several biochemical markers that could act as chemotactic or regulatory factors in an inflammatory response were examined in the BAL fluid (BALF) The level of complement fragment C3 alpha was increased by 17-fold The chemotactic leukotriene B4 was unchanged while prostaglandin E2 increased 2-fold In contrast, three enzyme systems of phagocytes with potentially damaging effects on tissues and microbes, namely, NADPH-oxidase and the lysosomal enzymes acid phosphatase and beta-glucuronidase, were increased neither in the lavaged fluid nor cells In addition, the amounts of fibrogenic-related molecules were assessed in BALF(ABSTRACT TRUNCATED AT 250 WORDS)

484 citations


Book ChapterDOI
TL;DR: Physical properties that influence the environmental disposition and subsequently affect bioavailability of the compounds in water, soil, air, produce, and nontarget species are also instrumental in determining the impact of current and future synthetic pyrethroid insecticides.
Abstract: Synthetic pyrethroid insecticides are photostable analogs of the natural pyrethrins of botanical origin. Their structures range from very similar to the original (e.g., allethrin, Fig. 1) to highly dissimilar compounds (e.g., flucythrinate, Fig. 1). Directed synthesis by groups in Japan (Sumitomo Chemical Co.) and England (NRDC) resulted in very potent insecticides and a commercial success for the synthetic pyrethroids.

339 citations


Journal ArticleDOI
TL;DR: In this article, the sintering rate of calcium oxide in a nitrogen atmosphere was measured at temperatures from 700 to 1100°C, and the model of German and Munir (J. Am. Ceram. Soc., 59, 379-383, 1976) correlates the kinetics of surface reduction and identifies lattice diffusion as the mechanism of solid transport.

292 citations


Journal ArticleDOI
TL;DR: Data from EPA's TEAM Study allow us to identify the major sources of exposure to benzene for much of the U.S. population, and these sources turn out to be quite different from what had previously been considered the important sources.
Abstract: Data from EPA's TEAM Study allow us to identify the major sources of exposure to benzene for much of the U.S. population. These sources turn out to be quite different from what had previously been considered the important sources. The most important source of exposure for 50 million smokers is the mainstream smoke from their cigarettes, which accounts for about half of the total population burden of exposure to benzene. Another 20% of nationwide exposure is contributed by various personal activities, such as driving and using attached garages. (Emissions from consumer products, building materials, paints, and adhesives may also be important, although data are largely lacking.) The traditional sources of atmospheric emissions (auto exhaust and industrial emissions) account for only about 20% of total exposure. Environmental tobacco smoke is an important source, accounting for about 5% of total nationwide exposure. A number of sources sometimes considered important, such as petroleum refining operations, petrochemical manufacturing, oil storage tanks, urban-industrial areas, service stations, certain foods, groundwater contamination, and underground gasoline leaks, appear to be unimportant on a nationwide basis.

261 citations


Journal ArticleDOI
TL;DR: It would seem that if humans develop thyroid tumors following long-term derangement in thyroid-pituitary status, they may be less sensitive than the commonly used animal models.

254 citations


Journal ArticleDOI
TL;DR: The most credible evidence is based on individuals' willingness to pay (or willingness to accept compensation) for small changes in risks as mentioned in this paper, leading to a range of values that can be compared with the costs of proposals to reduce fatal risks.
Abstract: Government agencies face difficult resource-allocation decisions when confronted with projects that will reduce risks of fatality. Evidence from individual behavior helps determine society's values for reducing risks. The most credible evidence is based on individuals' willingness to pay (or willingness to accept compensation) for small changes in risks. Studies of consumer behavior are limited, but more evidence is available relating wages to job risks. Contingent valuation studies reinforce the wage-risk implications, leading to a range of values that can be compared with the costs of proposals to reduce fatal risks.

230 citations


Journal ArticleDOI
TL;DR: The effect of air pollution on lung function in children and youths ages 6-24 years was examined, after controlling for age, height, race, sex, body mass, cigarette smoking, and respiratory symptoms.

228 citations


Journal ArticleDOI
TL;DR: In this article, 3-methylcatechol was identified as successive transitory intermediates of toluene catabolism by trichloroethylene-degrading bacterium G4.
Abstract: o-Cresol and 3-methylcatechol were identified as successive transitory intermediates of toluene catabolism by the trichloroethylene-degrading bacterium G4. The absence of a toluene dihydrodiol intermediate or toluene dioxygenase and toluene dihydrodiol dehydrogenase activities suggested that G4 catabolizes toluene by a unique pathway. Formation of a hybrid species of 18O- and 16O-labeled 3-methylcatechol from toluene in an atmosphere of 18O2 and 16O2 established that G4 catabolizes toluene by successive monooxygenations at the ortho and meta positions. Detection of trace amounts of 4-methylcatechol from toluene catabolism suggested that the initial hydroxylation of toluene was not exclusively at the ortho position. Further catabolism of 3-methylcatechol was found to proceed via catechol-2,3-dioxygenase and hydroxymuconic semialdehyde hydrolase activities.

192 citations


Journal ArticleDOI
TL;DR: The sensitivity of the climate system to anthropogenic perturbations over the next century will be determined by a combination of feedbacks that amplify or damp the direct radiative effects of increasing concentrations of greenhouse gases.
Abstract: The sensitivity of the climate system to anthropogenic perturbations over the next century will be determined by a combination of feedbacks that amplify or damp the direct radiative effects of increasing concentrations of greenhouse gases. A number of important geophysical climate feedbacks, such as changes in water vapor, clouds, and sea ice albedo, are included in current climate models, but biogeochemical feedbacks such as changes in methane emissions, ocean CO2 uptake, and vegetation albedo are generally neglected. The relative importance of a wide range of feedbacks is assessed here by estimating the gain associated with each individual process. The gain from biogeochemical feedbacks is estimated to be 0.05–0.29 compared to 0.17–0.77 for geophysical climate feedbacks. The potentially most significant biogeochemical feedbacks are probably release of methane hydrates, changes in ocean chemistry, biology, and circulation, and changes in the albedo of the global vegetation. While each of these feedbacks is modest compared to the water vapor feedback, the biogeochemical feedbacks in combination have the potential to substantially increase the climate change associated with any given initial forcing.

188 citations


Journal ArticleDOI
TL;DR: Studies with permethrin, cypermethrin and fenvalerate have established that rates of metabolism and elimination in rainbow trout are significantly lower than those reported for birds and mammals, and variations in toxicodynamics are also crucial in evaluating pyrethroid selectivity.
Abstract: The pyrethroid insecticides are extremely toxic to fish, with 96—h LC50 values generally below 10 μg/L and i.p. and i.v. LD50 values below 20 mg/kg. Corresponding LD50 values in mammals and birds are in the range of several hundred to several thousand milligrams per kilogram. This review examines pyrethroid toxicokinetics and toxicodynamics in fish as critical factors associated with species selectivity. Studies with permethrin, cypermethrin and fenvalerate have established that rates of metabolism and elimination in rainbow trout are significantly lower than those reported for birds and mammals. Comparatively low lethal brain pyrethroid concentrations and nonneural aspects of pyrethroid intoxication in fish suggest that variations in toxicodynamics are also crucial in evaluating pyrethroid selectivity.

178 citations


Journal ArticleDOI
TL;DR: A general formalism for estimating the complication probability for non-uniform irradiation of a normal tissue structure has been developed and used by the NCI-sponsored committee on "Evaluation of Treatment Planning for Particle Beam Radiotherapy."
Abstract: A general formalism for estimating the complication probability for non-uniform irradiation of a normal tissue structure has been developed and used by the NCI-sponsored committee on "Evaluation of Treatment Planning for Particle Beam Radiotherapy." The approach involves reducing an N-step dose-volume histogram for the tissue (obtained from the 3D treatment plan) to an equivalent (N-1)-step histogram; this procedure is repeated until there remains a single-step histogram, the complication probability of which can readily be determined. This note provides technical details concerning the histogram-reduction algorithm. Results obtained using it are compared with those for two alternative histogram-reduction algorithms.

Journal ArticleDOI
TL;DR: As a class of compounds, chlorophenols were degraded more readily than chloroaromatic compounds, however, as individual compounds 3-chlorobenzoate, 2-chlorophenol, and 3- chlorophenol degradation was observed most often and with an equal frequency.
Abstract: Anaerobic degradation of monochlorophenols and monochlorobenzoates in a variety of aquatic sediments was compared under four enrichment conditions. A broader range of compounds was degraded in enrichments inoculated with sediment exposed to industrial effluents. Degradation of chloroaromatic compounds was observed most often in methanogenic enrichments and in enrichments amended with 1 mM bromoethane sulfonic acid. Degradation was observed least often in enrichments with added nitrate or sulfate. The presence of 10 mM bromoethane sulfonic acid prevented or inhibited degradation of most compounds tested. Primary enrichments in which KNO3 was periodically replenished to maintain enrichment characteristics degraded chlorobenzoates, but not chlorophenols. In contrast, primary enrichments in which Na2SO4 was periodically replenished failed to degrade any chloroaromatic compounds. Upon transfer to fresh medium, none of the sulfate enrichments required the presence of Na2SO4 for degradation, while only two nitrate enrichments required the presence of KNO3 for degradation. As a class of compounds, chlorophenols were degraded more readily than chlorobenzoates. However, as individual compounds 3-chlorobenzoate, 2-chlorophenol, and 3-chlorophenol degradation was observed most often and with an equal frequency. Within the chlorophenol class, the relative order of degradability was ortho > meta > para, while that of chlorobenzoates was meta > ortho > para, In laboratory transfers, 2-chlorobenzoate, 3-chlorobenzoate, and 2-chlorophenol degradation was most easily maintained, while degradation of para-chlorinated compounds was very difficult to maintain.

Journal ArticleDOI
TL;DR: Seven persons volunteered to perform 25 common activities thought to increase personal exposure to volatile organic chemicals (VOCs) during a 3-day monitoring period, finding that about 20 activities resulted in increasing exposure to one or more of the target VOCs, often by factors of 10 or 100 compared to exposures during the sleep period.

Journal ArticleDOI
TL;DR: The ability of this community to utilize a high-molecular-weight PAH as the sole carbon source, in conjunction with its ability to transform a diverse array of PAHs, suggests that it may be of value in the bioremediation of environments contaminated with PAHS, such as those impacted by creosote.
Abstract: Cultures enriched by serial transfer through a mineral salts medium containing fluoranthene were used to establish a stable, seven-member bacterial community from a sandy soil highly contaminated with coal tar creosote. This community exhibited an ability to utilize fluoranthene as the sole carbon source for growth, as demonstrated by increases in protein concentration and changes in absorption spectra when grown on fluoranthene in liquid culture. Biotransformation of other polycyclic aromatic hydrocarbons (PAHs) was verified by demonstrating their disappearance from an artificial PAH mixture by capillary gas chromatography. When grown on fluoranthene as the sole carbon source and subsequently exposed to fluoranthene plus 16 additional PAHs typical of those found in creosote, this community transformed all PAHs present in this defined mixture. After 3 days of incubation, 13 of the original 17 PAH components were degraded to levels below the limit of detection (10 ng/liter). Continued incubation resulted in extensive degradation of the remaining four compounds. The ability of this community to utilize a high-molecular-weight PAH as the sole carbon source, in conjunction with its ability to transform a diverse array of PAHs, suggests that it may be of value in the bioremediation of environments contaminated with PAHs, such as those impacted by creosote.

Journal ArticleDOI
TL;DR: The democratic model as discussed by the authors evaluates risk based on its social and political consequences, such as possible disruption in the social fabric or a loss of communality, and relates judgments about risks to the competence and the legitimacy of the social institutions that impose and control those risks.
Abstract: Summary So, we can argue that the lay public are not fools in their attitudes about risk. That nonexperts should show more concern over hazardous waste facilities in their neighborhoods than radon levels in their homes is not a sign of irrationality (because aggregate and individual risks are greater from the radon), but simply a sign that nonexperts are working from a different set of criteria. These criteria are incorporated in what I call the democratic model. The democratic model evaluates risk based on its social and political consequences, such as possible disruption in the social fabric or a loss of communality. Lay criteria for assessing the impact of risk decisions are not explicit, like the those of the risk analyst, but are embedded in cultural values. Similarly, lay evaluations of risk incorporate substantive and procedural democratic values, such as the acceptability of processes for making decisions, the ethics of the distribution of risk, and the capacity to control a source of risk in the community's interests. Finally, the democratic model relates judgments about risks to the competence (Can we trust them?) and the legitimacy (Should we trust them?) of the social institutions that impose and control those risks. The public's judgments about risk are not inferior, but different, and arguably richer than those of the experts.

Journal ArticleDOI
TL;DR: In this paper, it is suggested that elemental sulfur vapor could have played a similar role in an anoxic, ozone-free, primitive atmosphere, which is composed of ring molecules, primarily S8, that absorb strongly throughout the near ultraviolet (UV) radiation by atmospheric ozone.
Abstract: The present biosphere is shielded from harmful solar near ultraviolet (UV) radiation by atmospheric ozone. It is suggested that elemental sulfur vapor could have played a similar role in an anoxic, ozone-free, primitive atmosphere. Sulfur vapor would have been produced photochemically from volcanogenic SO2 and H2S. It is composed of ring molecules, primarily S8, that absorb strongly throughout the near UV, yet are expected to be relatively stable against photolysis and chemical attack. It is also insoluble in water and would thus have been immune to rainout or surface deposition over the oceans. Since the concentration of S8 in the primitive atmosphere would have been limited by its saturation vapor pressure, surface temperatures of 45 C or higher, corresponding to carbon dioxide partial pressures exceeding 2 bars, are required to sustain an effective UV screen. A warm, sulfur-rich, primitive atmosphere is consistent with inferences drawn from molecular phylogeny, which suggest that some of the earliest organisms were thermophilic bacteria that metabolized elemental sulfur.

Journal ArticleDOI
TL;DR: A two-stage empirical Bayes procedure for calculating age-standardized cancer death rates, for use in mapping, which are adjusted for the stochasticity of rates in small area populations is presented.
Abstract: The geographic mapping of age-standardized, cause-specific death rates is a powerful tool for identifying possible etiologic factors, because the spatial distribution of mortality risks can be examined for correlations with the spatial distribution of disease-specific risk factors. This article presents a two-stage empirical Bayes procedure for calculating age-standardized cancer death rates, for use in mapping, which are adjusted for the stochasticity of rates in small area populations. Using the adjusted rates helps isolate and identify spatial patterns in the rates. The model is applied to sex-specific data on U.S. county cancer mortality in the white population for 15 cancer sites for three decades: 1950–1959, 1960–1969, and 1970–1979. Selected results are presented as maps of county death rates for white males.

Journal ArticleDOI
TL;DR: The total amount of TRI metabolized was considered in the most recent EPA Health Assessment Document for Trichloroethylene to be the effective dose (EFD) producing tumors in the liver and there is evidence that formation of reactive intermediate(s) and TRI hepatotoxicity are directly proportional to the overall extent of TRI metabolism.
Abstract: Lifetime cancer or unit risk estimates for TRI have been calculated by the EPA on the basis of metabolized dose-tumor incidence relationships. Previously, it was common practice to directly extrapolate exposure dose-tumor incidence data from laboratory animal studies to predict cancer risks in humans. Such direct species-to-species extrapolations, however, do not take into account potentially important species differences in systemic uptake, tissue distribution, metabolism, deposition at the site(s) of action, and elimination. The consideration and use of pharmacokinetic and metabolic data can significantly reduce, though not eliminate, uncertainties inherent in species-to-species, route-to-route, and high- to low-dose extrapolations. The total amount of TRI metabolized was considered in the most recent EPA Health Assessment Document for Trichloroethylene to be the effective dose (EFD) producing tumors. Exposure dose-metabolism relationships were determined from direct measurement data in inhalation and oral dosing studies in mice and rats. The magnitude of TRI metabolism in these two species closely approximated body surface area. Thus, it was assumed that the amount of TRI metabolized per square meter of surface area was equivalent among species when calculating human equivalent doses from the animal data. Direct measurement data from an inhalation study in humans were used to calculate the amount of TRI metabolized and the unit risk estimate when a person inhales 1 microgram TRI per cubic meter continuously for 24 h. The EPA Cancer Assessment Group (CAG) elected to use this risk estimate for TRI in air, since it was calculated on the basis of a human metabolized dose rather than unit risk estimates based on animal studies. The current survey of literature and ongoing research uncovered no new animal or human studies in which TRI metabolites were directly measured, which would be any more suitable for use in estimating the total metabolized dose of TRI. On the basis of information now available, it is appropriate to continue to use the total amount of TRI metabolized as the EFD producing tumors in the liver. Use of the total amount metabolized represents an important "step in the right direction" in reducing uncertainties in interspecies extrapolations of data on a chemical such as TRI. TRI is believed to be metabolically activated to a reactive intermediate(s), although the identity of the intermediate(s) is unclear. There is evidence that formation of reactive intermediate(s) and TRI hepatotoxicity are directly proportional to the overall extent of TRI metabolism.(ABSTRACT TRUNCATED AT 400 WORDS)

Journal ArticleDOI
TL;DR: In this paper, the mathematics behind principal component analysis and partial least squares regression is presented in detail, starting from the appropriate extrema conditions, and the meaning of the resultant vectors and many of their mathematical interrelationships are also presented.

Journal ArticleDOI
TL;DR: Historically the answers to whether X-rays induced single-gene mutations and/or chromosomal mutations have been explored, with special emphasis on recent developments in the field of mammalian cell mutagenesis.
Abstract: In the course of discovering the first mutagen (X-rays) just over 60 years ago, Herman J. Muller asked whether X-rays induced single-gene mutations and/or chromosomal (multiple-gene) mutations. To a large extent, his question has set the agenda for mutagenesis research ever since. We explore historically the answers to this question, with special emphasis on recent developments in the field of mammalian cell mutagenesis. Studies indicate that ionizing radiation and many chemical mutagens/carcinogens induce both gene and chromosomal mutations; however, only certain genetic systems permit the recovery and analysis of both classes of mutations. Few chemical mutagens induce only gene mutations in mammalian cells; instead, most mutagens appear to induce both classes of mutations, with chromosomal mutations (especially multilocus deletions) predominating at high doses. These results have implications regarding the mechanisms of mutagenesis, the role of chromosomal mutations in carcinogenesis and hereditary disease, and the type of data required for risk assessment of physical and chemical mutagens/carcinogens.

Journal ArticleDOI
TL;DR: Extractable cell membrane-derived polarlipid ester-linked fatty acids (PLFA) obtained from aerated soils gassed with methane or propane and from methane- and propane-oxidizing bacteria isolated from the soils were analyzed by capillary gas chromatography/mass spectrometry as discussed by the authors.
Abstract: Extractable cell membrane-derived polarlipid ester-linked fatty acids (PLFA) obtained from aerated soils gassed with methane or propane and from methane- and propane-oxidizing bacteria isolated from the soils were analyzed by capillary gas chromatography/mass spectrometry. Exposure of aerated soils to methane resulted in the formation of a high proportion of an unusual 18-carbon mono-unsaturated PLFA, 18:lw8c. High proportions of this fatty acid biomarker are found in monocultures from this soil grown in minimal media with methane. This PLFA has been previously established as associated with authentic type II methane-oxidizing bacteria. The microbiota in aerated soils exposed to hydrocarbons containing propane, formed a suite of PLFA characterized by high proportions of a 16-carbon mono-unsaturated acid, 16:lw6c, and an 18-carbon saturated fatty acid with an additional methyl branch at the 10 position, 10 Me 18:0. This PLFA pattern has been detected in several monocultures enriched from the soil with propane-amended minimal media. The correspondence of high proportions of these unusual mono-unsaturated PLFA in the isolated monocultures and in situ in the soils after stimulation with the appropriate hydrocarbon is a strong validation of the utility of these biomarkers in defining the community structure of the surface soil microbial community.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated an unknown mechanism by which N{sub 2}O is formed in coal flames, using both detailed kinetic modeling and plug-flow simulator experiments.

Journal ArticleDOI
TL;DR: In this article, a hedonic price model has been used to examine the impact which efficiency improvements have on housing values, and the study results reveal that efficiency improvements are capitalized into housing prices in Des Moines, Iowa.

Journal ArticleDOI
TL;DR: The correspondence between aqueous concentrations and LC50s for test animals demonstrated the importance of quantitating the bioavailable portion of pyrethroids in field samples to characterize accurately the environmental risk associated with pyrethroid runoff after agricultural applications.
Abstract: Data on the acute and chronic toxicities of permethrin, fenvalerate, cypermethrin and flucythrinate to marine invertebrates and fish are reviewed. Generally, crustaceans are more sensitive than fish; oysters are comparatively insensitive. The mysid Mysidopsis bahia consistently is among the most sensitive crustaceans tested, with 96—h LC50s of less than 0.02 μg/L for permethrin and of less than 0.01 μg/L for fenvalerate, cypermethrin and flucythrinate. The potential for chronic toxicity to fish is minimal for permethrin, moderate for fenvalerate and relatively great for flucythrinate. Laboratory toxicity tests were conducted with sediment—source fenvalerate and cypermethrin under static and flow—through conditions to determine the degree of contamination necessary to achieve acute lethal effects on mysids, grass shrimp (Palaemonetes pugio) and pink shrimp (Penaeus duorarum). Mortality was observed in test animals only in systems where the concentrations of sediment—source pyrethroids were sufficient to establish lethal concentrations in the overlying water through sediment/water partitioning. For fenvalerate, lethal effects occurred at nominal sediment concentrations of 0.1 mg/kg (static and flow—through) for mysids and grass shrimp and at 10 mg/kg for pink shrimp. Nominal sediment concentrations of cypermethrin of 0.1 mg/kg (static) or 1.0 mg/kg (flow—through) resulted in mortality in mysids and grass shrimp, whereas 1.0 mg/kg was the only test concentration that caused mortality in pink shrimp in the static and flow—through test systems. The correspondence between aqueous concentrations and LC50s for test animals demonstrated the importance of quantitating the bioavailable portion of pyrethroids in field samples to characterize accurately the environmental risk associated with pyrethroid runoff after agricultural applications.

Journal ArticleDOI
13 Oct 1989-Science
TL;DR: Fumigant applicators who, 6 weeks to 3 months earlier, were exposed to phosphine, common grain fumigants, or to phosphines and other pesticides had significantly increased stable chromosome rearrangements, primarily translocations in G-banded lymphocytes as mentioned in this paper.
Abstract: Fumigant applicators who, 6 weeks to 3 months earlier, were exposed to phosphine, a common grain fumigant, or to phosphine and other pesticides had significantly increased stable chromosome rearrangements, primarily translocations in G-banded lymphocytes. Less stable aberrations including chromatid deletions and gaps were significantly increased only during the application season, but not at this later time point. During fumigant application, measured exposure to phosphine exceeds accepted national standards. Because phosphine is also used as a dopant in the microchip industry and is generated in waste treatment, the possibility of more widespread exposure and long-term health sequelae must be considered.

Journal ArticleDOI
TL;DR: It is demonstrated that the mouse is more sensitive than the rat with respect to the enhancement of liver peroxisome proliferation by TCA and DCA and suggested that the rat should be less sensitive or refractory to tumor induction.

Journal ArticleDOI
TL;DR: The results show that the production of monokines CSF‐1, TNF, and IL‐1 is differentially regulated by LPS in alveolar macrophages and has different responses as compared to monocytes.
Abstract: Human alveolar macrophages (AMO) have been investigated for their ability to produce three monokines, tumor necrosis factor-alpha (TNF), macrophage colony stimulating factor (CSF-1), and interleukin 1-beta (IL-1). No TNF activity was found in supernatants of unstimulated AMO cultured for 20 h, although TNF mRNA was detected in the cells by Northern blot analysis. Stimulation of the cells with lipopolysaccharide (LPS) induced production and release of high levels of TNF into the culture supernatant. Increased levels of TNF mRNA were detectable at 90 min after LPS stimulation by dot blot analysis, reaching maximum expression between 4 and 8 h and declining thereafter. TNF activity peaked at approximately 8 h in the AMO supernatants. After 24 h TNF production had ended. Compared to autologous monocytes the AMO produced 5.7 times more TNF on a per cell basis (activity accumulated in 20 h supernatants). Uncultured AMO expressed CSF-1 mRNA which was translated into active protein recovered in supernatants upon culture in the absence of stimulus. The addition of LPS to AMO slightly reduced both mRNA levels and amount of factor in the supernatants. In contrast to the AMO, monocyte production of CSF-1 was enhanced by LPS. CSF-1 production by AMO continued for at least 48 h of culture. Spontaneous production of low amounts of IL-1 was found in one-third of the AMO samples, while low levels of IL-1 mRNA were present in all tested preparations. LPS stimulation induced increase in IL-1 mRNA within 90 min; mRNA levels peaked between 12 and 20 h and stayed high for at least 42 h. However, while all LPS-stimulated AMO expressed high levels of IL-1 mRNA biologically active IL-1 was again detected only in a fraction of the AMO supernatants. These results show that the production of monokines CSF-1, TNF, and IL-1 is differentially regulated by LPS in alveolar macrophages and has different responses as compared to monocytes. The longevity of the messages for each of the factors is possible indicators of the relative contribution of these factors to the response to endotoxin-induced injury and repair processes in the lung.

Journal ArticleDOI
TL;DR: Preliminary evidence suggests that the monooxygenase activity encoded by this DNA fragment is feedback-inhibited by phenols.
Abstract: Plasmid pJP4 enables Alcaligenes eutrophus JMP134 to degrade 3-chlorobenzoate and 2,4-dichlorophenoxyacetic acid (TFD). Plasmid pRO101 is a derivative of pJP4 obtained by insertion of Tn1721 into a nonessential region of pJP4. Plasmid pRO101 was transferred by conjugation to several Pseudomonas strains and to A. eutrophus AEO106, a cured isolate of JMP134. AEO106(pRO101) and some Pseudomonas transconjugants grew on TFD. Transconjugants with a chromosomally encoded phenol hydroxylase also degraded phenoxyacetic acid (PAA) in the presence of an inducer of the TFD pathway, namely, TFD or 3-chlorobenzoate. A mutant of one such phenol-degrading strain, Pseudomonas putida PPO300(pRO101), grew on PAA as the sole carbon source in the absence of inducer. This isolate carried a mutant plasmid, designated pRO103, derived from pRO101 through the deletion of a 3.9-kilobase DNA fragment. Plasmid pRO103 constitutively expressed the TFD pathway, and this allowed the metabolism of PAA in the absence of the inducer, TFD. Complementation of pRO103 in trans by a DNA fragment corresponding to the fragment deleted in pRO101 indicates that a negative control-regulatory gene (tfdR) is located on the BamHI E fragment of pRO101. Other subcloning experiments resulted in the cloning of the tfdA monooxygenase gene on a 3.5-kilobase fragment derived from pRO101. This subclone, in the absence of other pRO101 DNA, constitutively expressed the tfdA gene and allowed PPO300 to grow on PAA. Preliminary evidence suggests that the monooxygenase activity encoded by this DNA fragment is feedback-inhibited by phenols.

Journal ArticleDOI
TL;DR: Bosworth et al. as mentioned in this paper found that E. estuarius was almost as sensitive as Rhepoxynius abronius to fluoranthene and to field-collected sediments from Puget Sound urban and industrial bays.
Abstract: Estuarine sediments frequently are repositories and sources of anthropogenic contaminants. Toxicity is one method of assessing the environmental quality of sediments, yet because of the extreme range of salinities that characterize estuaries few infaunal organisms have both the physiological tolerance and sensitivity to chemical contaminants to serve in estuarine sediment toxicity tests. The study describes research on the estuarine burrowing amphipod, Eohaustorius estuarius Bosworth, 1973, whose survival was >95% in control sediments across a 2 to 28% salinity range over 10-d periods. E. estuarius also was acutely sensitive to low sediment concentrations of the polycyclic aromatic hydrocarbon, fluoranthene (LC50 approximately = 10.6 mg/kg), and its sensitivity to fluoranthene was not affected by salinity. E. estuarius was almost as sensitive as Rhepoxynius abronius to fluoranthene and to field-collected sediments from Puget Sound urban and industrial bays. E. estuarius was also more tolerant of very fine, uncontaminated sediments than R. abronius. Furthermore, E. estuarius was more sensitive to sediments spiked with fluoranthene than the freshwater amphipod, Hyalella azteca. E. estuarius, and possibly other estuarine haustoriid species, appears to be an excellent candidate for testing the acute toxicity if estuarine and marine sediments.