Geology topics

Dora R. Passino-Reader

Publications and source records attributed to Dora R. Passino-Reader.

8 recordsLinked to original sources

USGS2008

Xenobiotic-induced apoptosis: significance and potential application as a general biomarker of response

The process of apoptosis, often coined programmed cell death, involves cell injury induced by a variety of stimuli including xenobiotics and is morphologically, biochemically, and physiologically distinct from necrosis. Apoptotic death is characterized by cellular changes such as cytoplasm shrinkage, chromatin condensation, and plasma membrane asymmetry. This form of cell suicide is appealing as a general biomarker of response in that it is expressed in multiple cell systems (e.g. immune, neuronal, hepatal, intestinal, dermal, reproductive), is conserved phylogenetically (e.g. fish, rodents, birds, sheep, amphibians, roundworms, plants, humans), is modulated by environmentally relevant levels of chemical contaminants, and indicates a state of stress of the organism. Further, apoptosis is useful as a biomarker as it serves as a molecular control point and hence may provide mechanistic information on xenobiotic stress. Studies reviewed here suggest that apoptosis is a sensitive and early indicator of acute and chronic chemical stress, loss of cellular function and structure, and organismal health. Examples are provided of the application of this methodology in studies of health of lake trout (Salvelinus namaycush) in the Laurentian Great Lakes.

Biomarkers↗

USGS2006

Modeling brook trout presence and absence from landscape variables using four different analytical methods

As a part of the Great Lakes Regional Aquatic Gap Analysis Project, we evaluated methodologies for modeling associations between fish species and habitat characteristics at a landscape scale. To do this, we created brook trout Salvelinus fontinalis presence and absence models based on four different techniques: multiple linear regression, logistic regression, neural networks, and classification trees. The models were tested in two ways: by application to an independent validation database and cross-validation using the training data, and by visual comparison of statewide distribution maps with historically recorded occurrences from the Michigan Fish Atlas. Although differences in the accuracy of our models were slight, the logistic regression model predicted with the least error, followed by multiple regression, then classification trees, then the neural networks. These models will provide natural resource managers a way to identify habitats requiring protection for the conservation of fish species.

Book chapter↗

USGS2002

Linear solvation energy relationships: "rule of thumb" for estimation of variable values

For the linear solvation energy relationship (LSER), values are listed for each of the variables (V i /100, π*, &beta m , α m ) for fundamental organic structures and functional groups. We give the guidelines to estimate LSER variable values quickly for a vast array of possible organic compounds such as those found in the environment. The difficulty in generating these variables has greatly discouraged the application of this quantitative structure-activity relationship (QSAR) method. This paper present the first compilation of molecular functional group values together with a utilitarian set of the LSER variable estimation rules. The availability of these variable values and rules should facilitate widespread application of LSER for hazard evaluation of environmental contaminants.

Environmental Science & Technology↗

USGS2001

A probabilistic model for silver bioaccumulation in aquatic systems and assessment of human health risks

Silver (Ag) is discharged in wastewater effluents and is also a component in a proposed secondary water disinfectant. A steady-state model was developed to simulate bioaccumulation in aquatic biota and assess ecological and human health risks. Trophic levels included phytoplankton, invertebrates, brown trout, and common carp. Uptake routes included water, food, or sediment. Based on an extensive review of the literature, distributions were derived for most inputs for use in Monte Carlo simulations. Three scenarios represented ranges of dilution and turbidity. Compared with the limited field data available, median estimates of Ag in carp (0.07-2.1 Iμg/g dry weight) were 0.5 to 9 times measured values, and all measurements were within the predicted interquartile range. Median Ag concentrations in biota were ranked invertebrates > phytoplankton > trout > carp. Biotic concentrations were highest for conditions of low dilution and low turbidity. Critical variables included Ag assimilation eficiency, specific feeding rate, and the phytoplankton bioconcentration factor. Bioaccumulation of Ag seems unlikely to result in txicity to aquatic biota and humans consuming fish. Although the highest predicted Ag concentrations in water (>200 ng/L) may pose chronic risks to early survival and development of salmonids and risks of argyria to subsistence fishers, these results occur under highly conservative conditions.

Environmental Toxicology and Chemistry↗

USGS2000

Natural remediation in the Great Lakes

Overall, the existence of stricter environmental laws during the last 30 years and a reduction in the manufacturing base in the Great Lakes has resulted in improvement in conditions in harbors, rivers, and nearshore waters. Problems remain, such as the inability to dredge certain harbors and remove sediments because of lack of disposal facilities for contaminated sediments. Because of the wide extent of of contaminated sediments in the Great Lakes, much work remains to be done to document the condition of contaminated areas and the degree to which remediation of these areas is occurring from biotic and abiotic natural processes.

Book chapter↗

USGS1998

Fish thymocyte viability, apoptosis and necrosis: In-vitro effects of organochlorine contaminants

The thymus is believed to be a central component of haematopoiesis and immune function in teleosts. Hence, chemically-elicited adverse effects to the thymus may result in immunomodulation and organ dysfunction. The objective of this research was to assess the levels of active (apoptotic) and passive (necrotic) cell death in untreated and organochlorine treated fish thymocytes. Lake trout ( Salvelinus namaycush ) thymocytes were challenged with Aroclor 1254 (concentration range 1·5–10·5 μg ml −1 ) and alpha, beta, gamma, delta isomers of hexachlorocyclohexane (concentration range 10–100 μ M ). The resulting maintenance or loss of viability was assessed by cytofluorometry (expression of phosphatidylserine and exclusion of propidium iodide) and confirmed with fluorescence microscopy. The results indicate that 20–60% of thymocytes in healthy fish undergo apoptosis, whereas thymocytes treated for 6–24 h with organochlorines exhibit increased levels of apoptotic cell death. This study demonstrates that given sufficient concentration, contact time and cellular receptors, organochlorines such as Aroclor 1254 and hexachloro-cyclohexanes may induce direct or indirect toxicity, altered functionality, or cell death to an organ important for fish immunocompetence.

Fish and Shellfish Immunology↗

USGS1997

Detecting contaminant-induced apoptosis and necrosis in lake trout thymocytes via flow cytometry.

This chapter details the cytofluorometric techniques employed to assess levels of active (apoptosis) and passive (necrotic) cell death in untreated and contaminant-treated fish thymocytes. The thymus is believed to be a central component of hematopoiesis and immune function in teleosts (Abelli et al., 1996). Hence, chemically-elicited adverse effects to the thymus may result in immunomodulation and organ dysfunction. However, it is not well documented that environmental contaminants induce apoptosis, or programmed cell death. There is some evidence suggesting that low level exposure to waterborne contaminants can specifically induce cell death in the olfactory epithelium of rainbow trout (Julliard et al., 1996). Presently, only limited information is available in the literature regarding apoptotic death in piscine immune cells (Alford et al., 1994; Greenlee et al., 1991).

Book chapter↗

USGS1995

Baseline risk assessment for aquatic life for the Buffalo River, New York, Area of Concern

The Great Lakes National Program Office of the U.S. Environmental Protection Agency initiated the Assessment and Remediation of Contaminated Sediments (ARCS) program to address concerns of environmental degradation at 43 Areas of Concern in the Great Lakes. In our first report (Passino-Reader et al. 1992), we developed a generic approach for baseline hazard evaluation of aquatic life in the Great Lakes Areas of Concern. In this report, we demonstrate the application of the generic approach to the Buffalo River (New York) Area of Concern. Using available historical data on residues in sediments, water, and biota, we evaluated exposure for 41 contaminants from the Buffalo River for eight taxa of fish and invertebrates representing the major trophic levels in the Buffalo River. By comparing exposure concentrations with reference toxicities, we calculated risk to the eight receptor organisms for typical and worst cases of exposure to the 41 contaminants. For mixtures of the contaminants present at the Buffalo River, primarily metals and polyaromatic hydrocarbons, we compared sediment concentrations with effects range-low (EL-R) values as reference values for toxicity of mixtures to estimate risk to aquatic biota.

Report↗