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At least 91 records · Page 5Linked to original sources
USGS2022

Comparison of two estrogen chemically activated luciferase expression cell bioassays to liquid chromatography–mass spectrometry for quantifying estrone in water samples

Chemically activated luciferase expression (CALUX) cell bioassays are popular tools for assessing endocrine activity of chemicals such as certain environmental contaminants. Although activity equivalents can be obtained from CALUX analysis, directly comparing these equivalents to those obtained from analytical chemistry methods can be problematic because of the complexity of endocrine active pathways. We explored the suitability of two estrogen CALUX bioassays (the Organisation for Economic Co-operation and Development–approved VM7Luc4E2 cell bioassay and the VM7LucERβc9 cell bioassay) for quantitation of estrogen. Quadrupole-time of flight ultraperformance liquid chromatography–mass spectrometry (LC/MS) was selected as a comparative method. Regression analysis of measured estrone (E1) calibration samples showed all three methods to be highly predictive of nominal concentrations ( p ≤ 7.5 × 10 –51 ). Extracts of water sampled from laboratory dilutor tanks containing E1 at 0, 20, and 200 ng/L alone and in combination with atrazine were selected to test the quantitative capabilities of the CALUX assays. Process controls (0 and 100 ng E1/L) and a separate E1 standard (10 ng/ml, used to prepare the E1 process control) were also tested. Levels of E1 determined by LC/MS analysis and bioanalytical equivalents (ng E1/L) determined by CALUX analyses were comparable except in certain instances where the samples required dilution prior to CALUX analyses (e.g., the E1 process control and E1 standard). In those instances, measurements by CALUX were slightly but significantly decreased relative to LC/MS. Atrazine had no effect on the ability of either LC/MS or the CALUX bioassays to quantify E1. The present study illustrates the CALUX bioassays as successful in quantifying an estrogen in simple water samples and further characterizes their utility for screening. Environ Toxicol Chem 2023;42:333–339. Published 2022. This article is a U.S. Government work and is in the public domain in the USA.

Environmental Toxicology and Chemistry↗
USGS1999

Cytochrome P4501A induction, benzo[a]pyrene metabolism, and nucleotide adduct formation in fish hepatoma cells: Effect of preexposure to 3,3',4,4',5-pentachlorobiphenyl

In PLHC-1 hepatoma cells, benzo[a]pyrene (B[a]P) caused a maximum induction of cytochrome P4501A (CYP1A) activity, measured as ethoxyresorufin O-deethylation (EROD), after 4 to 8 h of exposure, depending on the B[a]P concentration. The decline of EROD activity at longer exposure times was probably caused by the rapid metabolism of B[a]P in this system (57% metabolism within 4 h incubation). In subsequent experiments, PLHC-1 cells were preinduced with PCB 126 for 24 h and then received a dose of 10, 100, or 1,000 nM 3H-B[a]P. A 1-nM concentration of PCB 126 caused an 80-fold induction of CYP1A activity, resulting in an increase in B[a]P metabolism of less than 10%, except at the highest concentration of B[a]P (1,000 nM), where a 50% increase was observed. In another experiment, an 80-fold induction of CYP1A activity caused a 20% increase in the metabolism of B[a]P (100 nM), and RNA adduct formation was increased approximately twofold. These results indicate that, at exposure concentrations up to 100 nM B[a]P, CYP1A activity is not rate limiting for B[a]P metabolism. Furthermore, CYP1A seems to also he specifically involved in B[a]P activation in PLHC-1 cells. However, CYP1A induction causes only a relatively small increase in activation, probably because of the action of other enzymes involved in B[a]P activation and deactivation.

Environmental Toxicology and Chemistry↗
USGS1984

Fish cell lines: Characterization by isozyme analysis

The electrophoretic mobilities of isozymes from 16 enzyme systems were determined for nine fish cell lines. The relative migration of the malate dehydrogenase and 6-phosphoglucose dehydrogenase isozymes could be used together to distinguish between seven of the fish cell lines. Two cyprinid cell lines could not be distinguished from each other but were readily separated from the six noncyprinid lines and the one other line of cyprinid origin.

In Vitro↗
USGS1980

Poikilotherm vertebrate cell lines and viruses: A current listing for fishes

A survey of the literature and of work being done in vertebrate cell culture shows that there are currently in existence and available to investigators some 61 cell lines representing 17 families and 36 species of fish. The literature of fish virology shows that at least 17 fish viruses have been isolated and that at least 15 others have been visualized by electron microscopy. A minimum of four major virus groups—rhabdovirus, orthomyxovirus, iridovirus and herpesvirus—are known from fish. Original references, key reviews and sources of cell lines are given.

In Vitro↗
USGS1992

Effects of chronic exposure to soft, acidic water on gill development and chloride cell numbers in embryo-larval brook trout, Salvelinus fontinalis

Recruitment failure is considered to be a major factor contributing to the decline of fish populations in soft, acidic waters; direct mortality of embryo-larval fishes has been postulated as a major cause of the decline. Little is understood of the physiological consequences to embryo-larval fishes of prolonged exposure to soft, acidic waters; however, dysfunction of respiratory and ionoregulatory processes is suspected. In order to evaluate the effects of acid exposure on the respiratory and ionoregulatory systems of developing brook trout, Salvelinus fontinalis, differences in gill morphology and numbers of chloride cells were compared between groups cf developing embryo-larval fish continuously exposed to moderately hard well water (130.0 mg.l -1 as CaCO 3 , pH 7.94) or to reconstituted soft, acidic water (4.4 mg.l -1 as CaCO 3 , pH 5.25) designed to mimic acidic waters of northern Wisconsin acidified lakes. Exposures were maintained for up to 48 days (82 days after fertilization) during critical periods of growth and differentiation of branchial structures. The second right gill arch of each fish was examined for changes in the development of filaments and lamellae and for differences in numbers of chloride cells. Gills of fish that developed in soft, acidic water contained greater numbers of normal and degenerating chloride cells, exhibited hyperplasia of primary epithelium and multiple fusions of adjacent filaments and lamellar epithelium than the gills of control fish. Filament and lamellar lengths and numbers of lamellae per filament were significantly less ( P < 0.05) in fish that developed in soft, acidic water than in fish exposed to well water.

Wisconsin↗
USGS2012

SIRT1 attenuates palmitate-induced endoplasmic reticulum stress and insulin resistance in HepG2 cells via induction of oxygen-regulated protein 150

Endoplasmic reticulum (ER) stress has been implicated in the pathology of type 2 diabetes mellitus (T2DM). Although SIRT1 has a therapeutic effect on T2DM, the mechanisms by which SIRT1 ameliorates insulin resistance (IR) remain unclear. In this study, we investigated the impact of SIRT1 on palmitate-induced ER stress in HepG2 cells and its underlying signal pathway. Treatment with resveratrol, a SIRT1 activator significantly inhibited palmitate-induced ER stress, leading to the protection against palmitate-induced ER stress and insulin resistance. Resveratrol and SIRT1 overexpression induced the expression of oxygen-regulated protein (ORP) 150 in HepG2 cells. Forkhead box O1 (FOXO1) was involved in the regulation of ORP150 expression because suppression of FOXO1 inhibited the induction of ORP150 by SIRT1. Our results indicate a novel mechanism by which SIRT1 regulates ER stress by overexpression of ORP150, and suggest that SIRT1 ameliorates palmitate-induced insulin resistance in HepG2 cells via regulation of ER stress.

Biochemical and Biophysical Research Communication↗
USGS2017

Using silver and bighead carp cell lines for the identification of a unique metabolite fingerprint from thiram-specific chemical exposure

Conservation biology often requires the control of invasive species. One method is the development and use of biocides. Identifying new chemicals as part of the biocide registration approval process can require screening millions of compounds. Traditionally, screening new chemicals has been done in vivo using test organisms. Using in vitro (e.g., cell lines) and in silico (e.g., computer models) methods decrease test organism requirements and increase screening speed and efficiency. These methods, however, would be greatly improved by better understanding how individual fish species metabolize selected compounds. We combined cell assays and metabolomics to create a powerful tool to facilitate the identification of new control chemicals. Specifically, we exposed cell lines established from bighead carp and silver carp larvae to thiram (7 concentrations) then completed metabolite profiling to assess the dose-response of the bighead carp and silver carp metabolome to thiram. Forty one of the 700 metabolomic markers identified in bighead carp exhibited a dose-response to thiram exposure compared to silver carp in which 205 of 1590 metabolomic markers exhibited a dose-response. Additionally, we identified 11 statistically significant metabolomic markers based upon volcano plot analysis common between both species. This smaller subset of metabolites formed a thiram-specific metabolomic fingerprint which allowed for the creation of a toxicant specific, rather than a species-specific, metabolomic fingerprint. Metabolomic fingerprints may be used in biocide development and improve our understanding of ecologically significant events, such as mass fish kills.

Chemosphere↗
USGS2004

Effect of cell physicochemical characteristics and motility on bacterial transport in groundwater

The influence of physicochemical characteristics and motility on bacterial transport in groundwater were examined in flow-through columns. Four strains of bacteria isolated from a crystalline rock groundwater system were investigated, with carboxylate-modified and amidine-modified latex microspheres and bromide as reference tracers. The bacterial isolates included a gram-positive rod (ML1), a gram-negative motile rod (ML2), a nonmotile mutant of ML2 (ML2m), and a gram-positive coccoid (ML3). Experiments were repeated at two flow velocities, in a glass column packed with glass beads, and in another packed with iron-oxyhydroxide coated glass beads. Bacteria breakthrough curves were interpreted using a transport equation that incorporates a sorption model from microscopic observation of bacterial deposition in flow-cell experiments. The model predicts that bacterial desorption rate will decrease exponentially with the amount of time the cell is attached to the solid surface. Desorption kinetics appeared to influence transport at the lower flow rate, but were not discernable at the higher flow rate. Iron-oxyhydroxide coatings had a lower-than-expected effect on bacterial breakthrough and no effect on the microsphere recovery in the column experiments. Cell wall type and shape also had minor effects on breakthrough. Motility tended to increase the adsorption rate, and decrease the desorption rate. The transport model predicts that at field scale, desorption rate kinetics may be important to the prediction of bacteria transport rates. ?? 2003 Elsevier B.V. All rights reserved.

Journal of Contaminant Hydrology↗
USGS2010

Seismicity and fluid geochemistry at Lassen Volcanic National Park, California: Evidence for two circulation cells in the hydrothermal system

Seismic analysis and geochemical interpretations provide evidence that two separate hydrothermal cells circulate within the greater Lassen hydrothermal system. One cell originates south to SW of Lassen Peak and within the Brokeoff Volcano depression where it forms a reservoir of hot fluid (235–270°C) that boils to feed steam to the high-temperature fumarolic areas, and has a plume of degassed reservoir liquid that flows southward to emerge at Growler and Morgan Hot Springs. The second cell originates SSE to SE of Lassen Peak and flows southeastward along inferred faults of the Walker Lane belt (WLB) where it forms a reservoir of hot fluid (220–240°C) that boils beneath Devils Kitchen and Boiling Springs Lake, and has an outflow plume of degassed liquid that boils again beneath Terminal Geyser. Three distinct seismogenic zones (identified as the West , Middle , and East seismic clusters) occur at shallow depths (<6 km) in Lassen Volcanic National Park, SW to SSE of Lassen Peak and adjacent to areas of high-temperature (≤161°C) fumarolic activity (Sulphur Works, Pilot Pinnacle, Little Hot Springs Valley, and Bumpass Hell) and an area of cold, weak gas emissions (Cold Boiling Lake). The three zones are located within the inferred Rockland caldera in response to interactions between deeply circulating meteoric water and hot brittle rock that overlies residual magma associated with the Lassen Volcanic Center. Earthquake focal mechanisms and stress inversions indicate primarily N–S oriented normal faulting and E–W extension, with some oblique faulting and right lateral shear in the East cluster. The different focal mechanisms as well as spatial and temporal earthquake patterns for the East cluster indicate a greater influence by regional tectonics and inferred faults within the WLB. A fourth, deeper (5–10 km) seismogenic zone (the Devils Kitchen seismic cluster) occurs SE of the East cluster and trends NNW from Sifford Mountain toward the Devils Kitchen thermal area where fumarolic temperatures are ≤123°C. Lassen fumaroles discharge geothermal gases that indicate mixing between a N 2 -rich, arc-type component and gases derived from air-saturated meteoric recharge water. Most gases have relatively weak isotopic indicators of upper mantle or volcanic components, except for gas from Sulphur Works where δ 13 C–CO 2 , δ 34 S–H 2 S, and δ 15 N–N 2 values indicate a contribution from the mantle and a subducted sediment source in an arc volcanic setting.

California↗
USGS2002

Effects of vegetation management in constructed wetland treatment cells on water quality and mosquito production

The impact of three vegetation management strategies on wetland treatment function and mosquito production was assessed in eight free water surface wetland test cells in southern California during 1998–1999. The effectiveness of the strategies to limit bulrush Schoenoplectus californicus culm density within the cells was also investigated. Removing accumulated emergent biomass and physically limiting the area in which vegetation could reestablish, significantly improved the ammonia–nitrogen removal efficiency of the wetland cells, which received an ammonia-dominated municipal wastewater effluent (average loading rate=9.88 kg/ha per day NH 4 -N). We determined that interspersing open water with emergent vegetation is critical for maintaining the wetland's treatment capability, particularly for systems high in NH 4 -N. Burning aboveground plant parts and thinning rhizomes only temporarily curtailed vegetation proliferation in shallow zones, whereas creating hummocks surrounded by deeper water successfully restricted the emergent vegetation to the shallower hummock areas. Since the hummock configuration kept open water areas interspersed throughout the stands of emergent vegetation, the strategy was also effective in reducing mosquito production. Decreasing vegetation biomass reduced mosquito refuge areas while increasing mosquito predator habitat. Therefore, the combined goals of water quality improvement and mosquito management were achieved by managing the spatial pattern of emergent vegetation to mimic an early successional growth stage, i.e. actively growing plants interspersed with open water.

California↗
USGS2012

Field comparison of optical and clark cell dissolved-oxygen sensors

Three multi-parameter water-quality monitors equipped with either Clark cell type or optical type dissolved-oxygen sensors were deployed for 30 days in a brackish (salinity <10 parts per thousand) environment to determine the sensitivity of the sensors to biofouling. The dissolved-oxygen sensors compared periodically to a hand-held dissolved oxygen sensor, but were not serviced or cleaned during the deployment. One of the Clark cell sensors and the optical sensor performed similarly during the deployment. The remaining Clark cell sensor was not aged correctly prior to deployment and did not perform as well as the other sensors. All sensors experienced substantial biofouling that gradually degraded the accuracy of the dissolved-oxygen measurement during the last half of the deployment period. Copyright ASCE 2005.

Conference Paper↗
USGS1981

Improved spectrophotometric cell for hydrothermal solutions

A simple, inexpensive spectrophotometric cell was designed for use with aqueous solutions for which temperature is a maximum of 325??C and pressure, 28 MPa. The cell has an internal volume of 5 ml and a path length of 1.31 cm. Each furnace assembly is 120 mm in diameter ?? 150 mm high and will fit into most commercial spectrophotometers. Temperature is controlled by a standard set-point controller and a balancing circuit that is used to maintain the temperature of the sample and reference cell within 1??C of each other at any temperature.

Review of Scientific Instruments↗
USGS2005

Assessment of laryngeal muscle and testicular cell types in Xenopus laevis (Anura Pipidae) inhabiting maize and non-maize growing areas of South Africa

We tested the hypothesis that adult African clawed frogs (Xenopus laevis) inhabiting water bodies in maize-growing areas (MGA) of South Africa would exhibit differences in testicular structure compared to frogs from water bodies in non-maize-growing areas (NMGA) in the same locale. Adults of both sexes were collected during the autumn of 2002 in South Africa, and stereological analytical techniques were used to quantify the distribution of testicular cell types. In addition, total laryngeal mass was used as a gauge of secondary sex differences in animals from MGA and NMGA study sites. Evaluation of the total laryngeal mass revealed that there were no statistically significant differences between X. laevis of the same sex from the NMGA and MGA sites. Mean percent fractional-volume values for seminiferous tubule distribution of testicular cell types of mature X. laevis, ranged from 3-4% for spermatogonia, 26-28% for spermatocytes, 54-57% for spermatozoa, and 14-15% for other cells types. The mean percent volume for blood vessels ranged from 0.3-0.4%. These values did not differ significantly between frogs from NMGA and MGA areas. Collectively, these data demonstrated no differences in gonadal and laryngeal development in X. laevis collected in South Africa from MGA and NMGA areas and that there is little evidence for an effect of agricultural chemicals used in maize production functioning as endocrine disrupters in this species. Screening of X. laevis testes revealed a small incidence of Stage 1 testicular oocytes in adult male frogs collected from the NMGA (3%) and MGA (2%).

African Journal of Herpetology↗
USGS1960

Preparation of monolayer cell cultures from tissues of some lower vertebrates

Cold trypsin dispersion at p H 7.2 was used to obtain cultivable cells and cell groups from tissues of six species of fresh-water bony fishes, a frog, and a turtle. The cells readily attached to glass and were capable of at least limited, and in some cases extended, division in media consisting of commercially available components.

Science↗
USGS1962

Unit-cell dimensions of natural and synthetic scapolites

In natural scapolites the cell dimension a shows a regular increase from marialite to meionite composition, while c remains constant. Both a and c of synthetic meionite are larger than the corresponding dimensions of synthetic marialite. The cell volume of both natural and synthetic scapolites is a nearly linear function of composition. Variations in cell dimensions of scapolites may be caused by differences in structural state similar to those in plagioclase feldspars.

Science↗
USGS1959

Effects of certain chemicals on mucus-producing cells of Petromyzon marinus

Tissue samples that contained slime-secreting cells were taken from the gills and epidermis of larval lampreys that had been poisoned by several compounds. Histochemical treatment of these pathological tissues helped delineate the fate of these mucus-producing areas of the ammocetes. It was shown that the slime-secreting cells, located at the tips of the gill filaments, lining the gill chamber, and scattered throughout the epidermis reacted differently to the same toxicant. The secretory cells of the gills were, without exception, the most sensitive to chemical attack.

Transactions of the American Fisheries Society↗
USGS1989

Suppression of antibody-producing cells in rainbow trout spleen sections exposed to copper in vitro

Immunosuppression was demonstrated in sections of rainbow trout Oncorhynchus mykiss (formerly Salmo gairdneri ) spleens immunized in vitro and exposed in culture to different concentrations of copper chloride. The sections were immunized with dinitrophenyl-Ficoll and cultured in Eagle's minimum essential medium with 2% fetal calf serum; half of the medium was withdrawn and replaced every other day. The passive hemolytic plaque assay was used to determine the number of antibody-producing cells 10 d after injection. In the sections cultured with the high copper concentration (100 μg/mL), all cells died; at copper concentrations of 0.1–10 μg/mL, leukocytes remained viable, but fewer antibody-producing cells were present than in organ sections cultured in medium without copper. This in vitro method reduces the number of animals needed and the length of time required to determine toxicity and immunosuppression, and it provides information on the effects of certain environmental pollutants on fish.

Journal of Aquatic Animal Health↗
USGS1984

Submersible pressure outflow cell for measurement of soil water retention and diffusivity from 5 to 95 degrees C

A technique was developed to measure water content in soil as a function of capillary pressure from 5 to 95°C. To overcome problems encountered at high temperature, a modified Tempe pressure cell containing a soil sample is suspended in a constant-temperature water bath. The cell's porous plate is in direct contact with circulating bath water, thus eliminating the problem of entrapped air bubbles. A balance located above the water bath measures water content changes in the soil by weighing the entire pressure cell under water. The technique is designed to measure soil water retention characteristics and to make transient outflow estimates of the soil water diffusivity at temperatures from 5 to 95°C. We also used the technique to determine the isobaric temperature dependence of water retention in soil. Results indicate that at constant capillary pressure, the relationship between moisture content and temperature is hysteretic.

Soil Science Society of America Journal↗