Graduation date: 1994

<p>The aim of this study was to evaluate the effectiveness of water treatment processes of two drinking water plants to remove immunotoxins and steroid hormones. Raw and treated drinking water was screened for effects on inflammatory activity using the biomarker IL-6, humoral immunity using the biomarker IL-10 and cell mediated immunity using the biomarker IFN-&gamma / . In vitro human whole blood culture assays were used in order to elucidate potential immunotoxicity.</p>

<p>The aim of this study was to evaluate the effectiveness of water treatment processes of two drinking water plants to remove immunotoxins and steroid hormones. Raw and treated drinking water was screened for effects on inflammatory activity using the biomarker IL-6, humoral immunity using the biomarker IL-10 and cell mediated immunity using the biomarker IFN-&gamma / . In vitro human whole blood culture assays were used in order to elucidate potential immunotoxicity.</p>

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 78-85). Also available via the Internet.

Magister Scientiae (Medical Bioscience) - MSc(MBS) / The aim of this study was to evaluate the effectiveness of water treatment processes of two drinking water plants to remove immunotoxins and steroid hormones. Raw and treated drinking water was screened for effects on inflammatory activity using the biomarker IL-6, humoral immunity using the biomarker IL-10 and cell mediated immunity using the biomarker FN-γ. In vitro human whole blood culture assays were used in order to elucidate potential immunotoxicity. / South Africa

Principal objectives of my research were to: (1) report for the first time that coelomocytes are able to reduce NBT dye and confirm the presence of lysozyme-like activity in earthworm; (2) develop a standard methodology for determination of NBT reduction and lysozyme-like activity in earthworms; (3) compare NBT reduction and lysozyme-like activity in earthworms with those of murine and human cells and fluids; and (4) demonstrate the sensitivity of earthworm NBT reduction and lysozyme-like activity as the assays using matrics in refuse-derived fuel fly ash (RDFF) and CuSO4.

In recent years, there has been growing concern about the effect of environmental pollutants on the immune system. In the current study, we investigated the toxicity induced by certain environmental pollutants on the immune systems of fish, amphibians, and mice. Fish in the laboratory were tested for susceptibility to immunosuppression by treatment with 1,3-Bis (chloroethyl)-1-nitrosourea (BCNU). Immunotoxicity of the tilapian immune system was detectable using mitogen-induced proliferation assay and cell-mediated toxicity assay. Fish from various streams of the Roanoke River were tested for immunotoxicity and parasitic infection. Fish from the more polluted North Fork of the Roanoke River exhibited a stronger mitogenic response when compared to fish from the South Fork of the Roanoke River. The effect of perinatal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), commonly referred to as dioxin, a highly toxic environmental pollutant, was tested in C57BL/6 mice. TCDD was administered on gestational day 14 and pup thymocytes were studied for apoptosis on postnatal days 2, 4, 7, 14, and 21. Perinatal exposure to TCDD decreased thymic cellularity and induced apoptosis in the thymocytes of the pups. Amphibians from polluted areas of Bermuda were similarly tested for immunotoxicity and compared with amphibians from less polluted areas. The lymphocyte responsiveness of toads from the more polluted Bermuda Biological Station of Research (BBSR) to mitogens such as lipopolysaccarhide (LPS) was significantly less than in toads from less polluted areas of Bermuda. Histological studies revealed differences in the liver and spleen tissues of the two groups. Melanomacrophage centers were prevalent in the livers of amphibians from the more polluted BBSR when compared to the less polluted Zoo site. These data taken together encompass a broad study on the effect of environmental pollutants across species. In each study, immunotoxicity is the end result of contact with contamination, whether occurring in the environment or induced in the laboratory. These data suggest that the immune system may serve as a biomarker for pollutants present in the environment. / Master of Science

Field and laboratory investigations have demonstrated that halogenated aromatic hydrocarbons (HAHs), which include PCBs and dioxin, are associated with developmental and population-level problems in fish-eating birds of the Great Lakes. Other studies have shown that perinatal exposure to HAHs causes thymic atrophy and suppresses T lymphocyte function in laboratory animals. Higher exposure suppresses antibody production and alters white blood cell (WBC) counts. This study investigated whether persistent contaminants alter immunocompetence in Great Lakes herring gulls (Larus argentatus) and Caspian terns (Sterna caspia). It also evaluated the use of various immunological tests as biomarkers for contaminant-associated health effects in wild birds. Masses of immune organs and WBC counts were assessed in herring gull chicks at 11 colonies and adults at 13 colonies, including two colonies outside the Great Lakes. T-cell- and antibody-mediated immune functions were assessed in chicks at five sites for each species. This ecoepidemiological study revealed a strong association between persistent contaminants and suppression of T-cell-mediated immunity. In herring gull chicks, thymus mass decreased as the activity of liver ethoxyresorufm-O-deethylase (EROD), an index of HAH-exposure and Ah-receptor activation, increased. In Caspian tern and herring gull chicks, the phytohemagglutinin skin test for T cell function showed a strong negative exposure-response relationship with organochlorines. There was no discernible association between contaminants and suppression of antibody-mediated immunity as measured by the sheep red blood cell antibody test and bursal mass. However, contaminant effects on bursal mass were confounded by fluke infections. Several WBC variables in both species were associated with contaminants, but the evidence was weaker than for effects on T-cell-mediated immunity. The identity of the particular organochlorine( s) responsible for alterations of T cell function and WBC counts could not be determined because concentrations of organochlorines were highly co-correlated in bird tissues. However, PCBs were the most likely cause because of their high concentrations and immunotoxic potential. Tests of immune function, WBC counts, and immune organ masses are useful biomarkers for assessing health effects, including those associated with contaminants, in wild birds. / Ph. D.

The prospect of utilizing the cichlid teleost tilapia (Oreochromis niloticus) as an alternative experimental model to mammals for immunotoxicity risk assessment is currently being proposed. As such, the National Toxicology Program's (NTP) standard battery of rodent immunotoxicity assays is being developed for use in this fish species. Included in the testing series are the hemolytic plaque forming cell (PFC) and the cytotoxic T-lymphocyte (CTL) assays, quantitative indicators of antibody production and cell-mediated activity, respectively. The assays were modified in consideration of specific tilapian immune parameters, then tested using fourteen environmental contaminants or drugs, ten of which are classified by the NTP as immunotoxic in rodents. Reduced antibody production via a decrease in plaque number was observed in response to exposure of tilapia to eight of the nine humoral immunotoxicants, and five of the five non-immunotoxicants. Under specific immunization circumstances, immunostimulation (also a response to immunotoxicity) was noted via an increase in plaque number in benzo[a]pyrene (B[a]P) exposed fish using the PFC assay, a result noted in rodents as well. Reduced T-cell recognition and lysis of allogeneic tilapian lymphocytes via a decrease in the percentage of specific 51Chromium (51Cr) release was observed in response to exposure of tilapia to the nine of the ten cell-mediated immunotoxicants, and four of the four non-immunotoxicants. Although the normal teleost immune responsiveness was slightly weaker than seen with mice under comparable conditions (presumably due to differences in antibody structure and decreased cells counts), tilapia were found to exhibit well-defined humoral and cell-mediated immune responses, and responses to immunotoxic and non-immunotoxic chemicals comparable to the rodent model. / Master of Science

Objective was to assess the toxicity of chromium (Cr) contaminated soil (CS) using the earthworm Lumbricus terrestris. Specific aims were to determine: (1) survival (LC50); .(2) immunotoxicity as indicated by lysozyme activity, coelomocyte counts, secretory (SR) and erythrocyte rosette (ER) formation, and phagocytosis; and (3) compare effects of CS exposure with those of Cr spiked artificial soil (AS) . CS Cr concentration was 8.78 mg/g with 98.2% being Cr^3+ and 1.8% being Cr^6+. Using 14 d AS protocol the LC50 was 6.49% CS: AS mixture. CS concentrations of 0.5, 1.0, 2.5 and 5.0% were sublethal, whereas 6.25, 12.5, 25, 50 and 100% CS were lethal. Sublethal exposure caused no immuno- modulation. Exposure to 50% CS: AS mixture for 5 d caused reduced SR and ER formation. Exposure to AS spiked with 0.27% Cr for 5 d resulted in immunomodulation equivalent to 50% CS: AS mixtures. Results indicated the CS to be acutely toxic.