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Full-Text Articles in Toxicology

Conditioned Feed Aversion As A Means Of Conditioning Livestock To Avoid Consuming Toxic Plants Growing In South Africa : An Overview, Leendert D. Snyman, Frederick D. Provenza Feb 2026

Conditioned Feed Aversion As A Means Of Conditioning Livestock To Avoid Consuming Toxic Plants Growing In South Africa : An Overview, Leendert D. Snyman, Frederick D. Provenza

Poisonous Plant Research (PPR)

Significant economic losses to the livestock industry are caused by the ingestion of toxic plants in South Africa, among which the most dangerous ones are Moraea pallida (geeltulp), Urginea/Drimea sanguinea (rooislangkop), Senecio latifolius (Staggers Ragwort), and Geigeria ornativa (vermeerbos). Conditioned feed aversion is a potential means to address this issue. Treating animals with an aversive substance along with an extract of the sensory characteristics of a specific plant conditions animals to avoid the plant. Geigeria ornativa, unlike the other three plants, is non-aversive. Following treatment for aversion, the induced aversion fades with time and eventually breaks down. Continuous exposure …


Continuous Exposure To An Aversive Mixture: A Means Of Maintaining Aversion In Sheep Averted To Geigeria Ornativa O. Hoffm. (Vermeerbos) - An Assessment, Leendert D. Snyman Mar 2025

Continuous Exposure To An Aversive Mixture: A Means Of Maintaining Aversion In Sheep Averted To Geigeria Ornativa O. Hoffm. (Vermeerbos) - An Assessment, Leendert D. Snyman

Poisonous Plant Research (PPR)

Establishing aversion to Geigeria ornativa only lasts for some time, after which the induced aversion disappears and sheep start eating G. ornativa again. This behavior is aggravated by the social influence of non-averted sheep in mixed grazing situations. Exposing sheep continuously to a so-called “aversive mixture”, containing an aversive substance (lithium chloride) and the sensory characteristics of the plant (hexane extract of G. ornativa) mixed with a tasty meal (maize meal), following an initial aversion treatment, resulted in sustained aversion to G. ornativa in the field. This method proved to be applicable to mixed grazing situations with averted and …


Toxicosis From Range Lupine Ingestion In A Research Herd Of Rafter 7 Merino Sheep, Benjamin J. Weigler, Walter F. Mandeville Iii, Scott Huber, Gary Mccuin, Fabrizio Caragena, Daniel D. Cook, Stephen T. Lee, Chris A. Pritsos Jun 2024

Toxicosis From Range Lupine Ingestion In A Research Herd Of Rafter 7 Merino Sheep, Benjamin J. Weigler, Walter F. Mandeville Iii, Scott Huber, Gary Mccuin, Fabrizio Caragena, Daniel D. Cook, Stephen T. Lee, Chris A. Pritsos

Poisonous Plant Research (PPR)

An outbreak of lupine alkaloid neurotoxicosis and death occurred in sheep grazed on rangeland areas of the Nevada Great Basin during the summer of 2023. Overall, 97 sheep died despite veterinary supportive care. Lupinus argenteus var. utahensis was implicated as the causative plant with high levels of lupanine (11.5 µg/mg) and spartiene (13.7 µg/mg) in collected and archived samples. Previous reports of sheep deaths due to lupine ingestion have not been recorded in this region. An increased abundance of the number plants producing seed pods having a high alkaloid content may have been associated with abnormally elevated levels of precipitation …


Aversion Properties Of Retrorsine, Retrorsine Nitrogen Oxide And Frosted Senecio Latifolius, Leendert D. Snyman Dec 2023

Aversion Properties Of Retrorsine, Retrorsine Nitrogen Oxide And Frosted Senecio Latifolius, Leendert D. Snyman

Poisonous Plant Research (PPR)

Two pilot trials, investigating the aversive properties of retrorsine and retrorsine nitrogen oxide and that of frosted Senecio latifolius, were executed. Retrorsine and retrorsine-NO (the toxic principles of Senecio retrorsus), unlke sceleratine-NO (the toxic principle of another hepatotoxic pyrrolizidine alkaloid containing plant, namely S. latifolius), were not capable of establishing aversion when given to a sheep. Frosted S. latifolius given to a sheep also did not induce aversion. However, a sheep averted to S. latifolius (non-frosted) refused eating frosted S. latifolius.


Sceleratin Nitrogen Oxide As Aversive Agent In Conditioning Livestock To Avoid Senecio Latifolius, Leendert D. Snyman Dec 2023

Sceleratin Nitrogen Oxide As Aversive Agent In Conditioning Livestock To Avoid Senecio Latifolius, Leendert D. Snyman

Poisonous Plant Research (PPR)

Sceleratine nitrogen oxide, when administered together with a dichloromethane extract of Senecio latifolius, successfully conditioned cattle and sheep to avoid milled freeze dried S. latifolius mixed with maize meal. This treatment was effectively applied in conditioning steers to refuse eating S. latifolius grown in pots.


Isolation Of The Toxic Principle Of Senecio Latifolius By Means Of The Sensory Receptors Of Sheep, Leendert D. Snyman Dec 2023

Isolation Of The Toxic Principle Of Senecio Latifolius By Means Of The Sensory Receptors Of Sheep, Leendert D. Snyman

Poisonous Plant Research (PPR)

The aversive substance of Senecio latifolius was isolated by means of the sensory receptors of sheep averted to S. latifolius. Chemical fractions refused due to the presence of the aversive substance sensed by the sheep were fractionated until a purified substance had been isolated. Nuclear magnetic resonance (NMR) analysis of the purified substance showed it to be sceleratine nitrogen oxide, the toxic principle of S. latifolius.


Differential Transcriptome Analysis Reveals That Cache Valley Pm2.5 Triggers The Unfolded Protein Response In Human Lung Cells, Morgan Eggleston May 2022

Differential Transcriptome Analysis Reveals That Cache Valley Pm2.5 Triggers The Unfolded Protein Response In Human Lung Cells, Morgan Eggleston

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Worldwide, exposure to air pollution is a serious human health threat. Particulate matter (PM) air pollution is a mixture of suspended solid and/or liquid particles and particle size is determined by its aerodynamic diameter. Fine, or “respirable” particles, typically from vehicle emissions, manufacturing, power generation, agriculture, as well as secondary photochemical reactions, are classified as ≤2.5μm in diameter (PM2.5). Upon inhalation, PM2.5 particles can reach the lower, more sensitive regions of the lung, enter the bloodstream, and be distributed to other areas in the body. Large-scale epidemiology studies have shown that PM2.5 air pollution is associated …


Fruits Of Nandina Domestica Are (Sometimes) Cyanogenic And (Sometimes) Hazardous To Birds, Scott Zona Apr 2022

Fruits Of Nandina Domestica Are (Sometimes) Cyanogenic And (Sometimes) Hazardous To Birds, Scott Zona

Poisonous Plant Research (PPR)

A 12-month survey of cyanogenesis in the fruits and leaves of Nandina domestica (Berberidaceae) revealed that the leaves are strongly cyanogenic throughout the year, as measured by the Feigl-Anger test. Fruits vary in their cyanogenic potential depending on the degree of ripeness and clone. Green fruits are strongly and rapidly cyanogenic, but most ripe fruits are weakly and slowly cyanogenic. Some fruits tested negative for cyanide. Fruits tend to become less cyanogenic the longer they remain on the plant, so birds feeding on older fruits are at a lower risk of poisoning. More than other frugivores, cedar waxwings (Bombycilla …


An Evaluation Of The Susceptibility Of Goats To Larkspur Toxicosis, Kevin D. Welch, Clint A. Stonecipher, Dale R. Gardner, Benedict T. Green, Daniel Cook Apr 2020

An Evaluation Of The Susceptibility Of Goats To Larkspur Toxicosis, Kevin D. Welch, Clint A. Stonecipher, Dale R. Gardner, Benedict T. Green, Daniel Cook

Poisonous Plant Research (PPR)

Larkspurs (Delphinium spp.) are a major cause of cattle losses in western North America, whereas sheep have been shown to be resistant to larkspur toxicosis. Goats are often used as a small ruminant model to study poisonous plants, even though they can be more resistant to some poisonous plants. It is not known how susceptible goats are to the adverse effects of larkspurs. In this study, we evaluated the susceptibility of goats to larkspur toxicosis by performing a dose-response study. We dosed goats with D. barbeyi collected near Cedar City, Utah at 3.3, 4.4, 6.6, 8.8 and 10.0 g …


Data From: Consumption Of The Total Western Diet Promotes Colitis And Inflammation-Associated Colorectal Cancer In Mice, Abby D. Benninghoff Feb 2020

Data From: Consumption Of The Total Western Diet Promotes Colitis And Inflammation-Associated Colorectal Cancer In Mice, Abby D. Benninghoff

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Gene expression data for colon tissues obtained prior to, during, and after onset of colitis in mice fed either a standard or Western type diet.

File 1: probe annotations.

File 2: nSolver differential expression analysis results.

File 3: Gene set analysis

File 4: nSolver pathway scores

File 5: STRING-db networks and clusters

File 6: Metascape ontology results

File 7: nSolver cell type profiling scores


A California Without Rodenticides: Challenges For Commensal Rodent Management In The Future, Niamh Quinn, Sylvia Kenmuir, Laura Krueger Jan 2019

A California Without Rodenticides: Challenges For Commensal Rodent Management In The Future, Niamh Quinn, Sylvia Kenmuir, Laura Krueger

Human–Wildlife Interactions

Rodenticides are an essential tool in the integrated pest management of infestations of commensal rodents (Rattus norvegicus, R. rattus, and Mus musculus). With the introduction of Assembly Bill 1788, the California Ecosystems Protection Act of 2019, California is potentially facing a future with new restrictions on the use of anticoagulant rodenticides to manage commensal rodents in urban areas. Assembly Bill 1788 has been proposed specifically to protect predators from anticoagulant rodenticide poisoning and seeks to restrict the application of second-generation anticoagulant rodenticides (SGARs) for use in many urban and non-urban areas of California, USA. Exclusion and cultural …


Neurobehavioral Evaluation Of Mice Dosed With Water Hemlock Green Seeds And Tubers, Camila F. P. Orlando-Goulart, Kevin D. Welch, James A. Pfister, Daniel S. Goulart, Adilson D. Damasceno, Stephen T. Lee Oct 2018

Neurobehavioral Evaluation Of Mice Dosed With Water Hemlock Green Seeds And Tubers, Camila F. P. Orlando-Goulart, Kevin D. Welch, James A. Pfister, Daniel S. Goulart, Adilson D. Damasceno, Stephen T. Lee

Poisonous Plant Research (PPR)

Water hemlock are plants of the genus Cicuta and are toxic to animals and humans. The primary toxin is cicutoxin, which is abundant in the tubers, but less abundant in other parts of the plant. Other cicutoxin-like compounds, such as cicutols, which may also contribute to the toxicity of water hemlock, are more abundant in non-tuber plant parts. The objective of this study was to determine the toxicity of different parts of water hemlock and characterize their effects on motor function/coordination in mice. An aqueous extract of green seeds, dry seeds, tubers, flowers and stems of water hemlock was dosed …


Toxicity And Mitochondrial Delivery Of Flavonol-Based Carbon Monoxide-Releasing Molecules, Hector Jose Esquer Heredia Dec 2017

Toxicity And Mitochondrial Delivery Of Flavonol-Based Carbon Monoxide-Releasing Molecules, Hector Jose Esquer Heredia

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Despite the reputation of carbon monoxide (CO) as a silent killer, new evidence suggests that this gaseous molecule has anti-inflammatory, anti-cancer and vasoprotective properties. Unfortunately, little is known about the role of CO in the body. However, proteins present in mitochondria are believed to be important targets. We previously synthesized a class of novel and structurally modifiable flavonol-based CO-releasing molecules (CORMs). Flavonols are commonly found in fruits and vegetables. The base structure, Flav-1, is fluorescent, exhibits low toxicity, and releases CO after exposure to visible light. Previous reports indicate that addition of a triphenylphosphonium (TPP) tail allows chemical structures to …


Dna Methylation In Lung Tissues Of Mouse Offspring Exposed In Utero To Polycyclic Aromatic Hydrocarbons: Appendix B. Nimblegen Processed Data Report For Nearest Methylated Peaks, Trevor Fish, Abby Benninghoff Jan 2015

Dna Methylation In Lung Tissues Of Mouse Offspring Exposed In Utero To Polycyclic Aromatic Hydrocarbons: Appendix B. Nimblegen Processed Data Report For Nearest Methylated Peaks, Trevor Fish, Abby Benninghoff

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No abstract provided.


Dna Methylation In Lung Tissues Of Mouse Offspring Exposed In Utero To Polycyclic Aromatic Hydrocarbons: Appendix A. Nimblegen Processed Data Report For All Methylated Peaks, Trevor Fish, Abby Benninghoff Jan 2015

Dna Methylation In Lung Tissues Of Mouse Offspring Exposed In Utero To Polycyclic Aromatic Hydrocarbons: Appendix A. Nimblegen Processed Data Report For All Methylated Peaks, Trevor Fish, Abby Benninghoff

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No abstract provided.


Dna Methylation In Lung Tissues Of Mouse Offspring Exposed In Utero To Polycyclic Aromatic Hydrocarbons: Appendix F. Gene Ontology Maps, Trevor Fish, Abby Benninghoff Jan 2015

Dna Methylation In Lung Tissues Of Mouse Offspring Exposed In Utero To Polycyclic Aromatic Hydrocarbons: Appendix F. Gene Ontology Maps, Trevor Fish, Abby Benninghoff

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This archive includes 10 individual image files, each of which depicts a Gene Ontolgoy map for GO terms representing hypermethylated gene promoters unique for the indicated tissue(s) (listed first in file name) compared to other tissues (listed in parentheses in file name).


Dna Methylation In Lung Tissues Of Mouse Offspring Exposed In Utero To Polycyclic Aromatic Hydrocarbons: Appendix D. Gene Lists For Ontology Analysis, Trevor Fish, Abby Benninghoff Jan 2015

Dna Methylation In Lung Tissues Of Mouse Offspring Exposed In Utero To Polycyclic Aromatic Hydrocarbons: Appendix D. Gene Lists For Ontology Analysis, Trevor Fish, Abby Benninghoff

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No abstract provided.


Dna Methylation In Lung Tissues Of Mouse Offspring Exposed In Utero To Polycyclic Aromatic Hydrocarbons: Appendix C. Peak Scores Summary Table For All Methylated Genes In Any Data Set, Trevor Fish, Abby Benninghoff Jan 2015

Dna Methylation In Lung Tissues Of Mouse Offspring Exposed In Utero To Polycyclic Aromatic Hydrocarbons: Appendix C. Peak Scores Summary Table For All Methylated Genes In Any Data Set, Trevor Fish, Abby Benninghoff

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No abstract provided.


Causes, Extent, And Consequences Of Lead-Pellet Ingestion By Chukars (Alectoris Chukar) In Western Utah: Examining Habitat, Search Images, And Toxicology, R. Justin Bingham May 2011

Causes, Extent, And Consequences Of Lead-Pellet Ingestion By Chukars (Alectoris Chukar) In Western Utah: Examining Habitat, Search Images, And Toxicology, R. Justin Bingham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lead ingestion adversely affects humans and over 130 species of wildlife. Wild chukars (Alectoris chukar) are documented to ingest lead, but the causes and consequences of this ingestion are poorly understood. The objectives of this research were to 1) examine the influence of habitat use, the hunting season, and seasonal climate on the extent and severity of lead ingestion by chukars in western Utah, 2) assess the effects of habitat use, feeding behaviors, and lead density on the causes of lead-pellet ingestion in captive and wild chukars, and 3) investigate the consequences of lead-pellet ingestion in captive chukars as a …


Smoking, Anemia, And Risk Of Oral Clefts In Utah, Melinda Michelle Moss May 2006

Smoking, Anemia, And Risk Of Oral Clefts In Utah, Melinda Michelle Moss

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cigarette smoke contains sufficient carbon monoxide to induce maternal and fetal hypoxia. Hypoxia is a known teratogen, and consequently maternal smoking has been the focus of many studies on adverse birth outcomes, including cleft lip and palate. Current literature of epidemiological studies on smoking and clefts suggests a modest but statistically significant increase in risk of clefting associated with maternal smoking. A biological condition that may also contribute to hypoxia is anemia. Data from the Utah Child and Family Health Study was used to assess the effects of hypoxia-inducing conditions, maternal smoking, anemia, and their interaction, on the risk of …


Sensitizing Resin Acids In Aerosol Derived From Rosin Flux Used In Electronics Soldering: Molecular Mechanistic Studies In Resin Acid/Protein Hapten Formation, Philip A. Smith May 1998

Sensitizing Resin Acids In Aerosol Derived From Rosin Flux Used In Electronics Soldering: Molecular Mechanistic Studies In Resin Acid/Protein Hapten Formation, Philip A. Smith

Biology

Exposure to rosin and its resin acid constituents is associated with dermal and pulmonary sensitization. Methodologies to detect resin acid compounds in aerosol from heated rosin flux included air filtration, filter extraction, and gas chromatography/mass spectrometry. Various resin acids were seen in aerosol collected under field conditions, and in the laboratory. The predominant resin acid recovered was dehydroabietic acid, with lower levels of abietic acid and oxidized resin acids, which included 7-oxodehydroabietic, 15-hydroxydehydroabietic, and 7-hydroxydehydroabietic acids. Mass balance experiments with a soldering iron and liquid rosin flux showed most of the nonvolatile mass in unheated flux to be filtrable following …


The Effects Of Retinoic Acids On The Angiogenic Growth Factors Produced By Solid Tumors, Lynn C. Burgess May 1998

The Effects Of Retinoic Acids On The Angiogenic Growth Factors Produced By Solid Tumors, Lynn C. Burgess

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

These studies investigated the effects of retinoic acid (RA) on angiogenesis. Three human, neoplastic cell lines were used to examine angiogenic promotion and/or inhibition. The cell lines, U-373MG glioblastoma, DU-145 prostate carcinoma, and TCCSUP bladder transitional cell carcinoma, were treated with the following: all-trans, 9-cis, or 13-cis RA, at doses from 0.0001 to 100 μM. Hypoxia was used to assist the expression of the angiogenic phenotype. Conditioned media (CM) were prepared by growing the tumor cells in the presence of RA and hypoxia for 24 hours, and then the CM was transferred to bovine, capillary endothelial …


A Study Of The Immune Effects Of Orally Ingested Ginseng Combined With Moderate High-Intensity Exercise In Mouse And Human Subjects, Gordon Hunter Pedersen May 1997

A Study Of The Immune Effects Of Orally Ingested Ginseng Combined With Moderate High-Intensity Exercise In Mouse And Human Subjects, Gordon Hunter Pedersen

Biology

Ginseng, an extract of the Panax ginseng plant, and exercise producing a heart rate of 82.5% of maximum were studied alone and in combination for effects on certain immune parameters in mice and young adult humans, and on development of cytomegalovirus (CMV) disease in mice. A motorized treadmill was used in the mouse experiments, with a clinical pulse oximeter adapted to monitor heart rates and arterial oxygen saturation (SaO2). Compared to infected controls whose death rate was 60%, orally administered ginseng (250 mg/kg/day) beginning 48 hours pre-CMV inoculation caused a 25% survivor increase. Exercise (six repetitions of running …


Superoxide Dismutase And Catalase In Trichoderma Harzianum, A Biological Control Fungus Of Rhizoctonia Solani Disease Of Sugar Beet, June Inez Pounder May 1997

Superoxide Dismutase And Catalase In Trichoderma Harzianum, A Biological Control Fungus Of Rhizoctonia Solani Disease Of Sugar Beet, June Inez Pounder

Biology

A strain of Trichoderma harzianum (referred to as Tex) and its chemically generated mutant, T95, produced antioxidant enzymes, superoxide dismutase and catalase. The mutant and wild type had similar enzyme activity levels but differed in isozyme patterns and response to exogenous activated oxygen species. Superoxide dismutases had manganese and copper-zinc prosthetic groups, determined by selective inactivation with sodium azide, potassium cyanide, diethyldithiocarbamate, and hydrogen peroxide. Catalases from Tex and T95 were inhibited by 3-amino-1,2,4-triazole. Antioxidant enzymes may be important in survival of T. harzianum and its effective biocontrol of root diseases. In its role as a biocontrol agent, T. harzianum …


Influence Of Soil On Bioremediation Potential Of Phanerochaete Chrysosporium, Brian J. Tucker May 1996

Influence Of Soil On Bioremediation Potential Of Phanerochaete Chrysosporium, Brian J. Tucker

Biology

Successful bioremediation in soils using Phanerochaete chrysosporium is determined by many soil factors. Several biotic and abiotic soil factors inhibited P. chrysosporium in the mineralization of pyrene when compared to a non-soil system. Inhibition of pyrene mineralization was also observed with layers of sterilized silt and clay but not sand. Two clays, bentonite and kaolinite, differentially sorbed and decreased the mineralization of pyrene. Four artificial sterile, nonorganic soils, made with different proportions of sand, silt, and clay, inhibited pyrene mineralization by P. chrysosporium. Both purified humic acid and manganese oxide significantly reduced the mineralization potential of P. chrysosporium. …


Alteration In Basic Macrophage And Lymphocyte Cytokines From Benzene And Phenol In The Drinking Water Of Male Institute Of Cancer Research Mice, Jay C. Albretsen May 1996

Alteration In Basic Macrophage And Lymphocyte Cytokines From Benzene And Phenol In The Drinking Water Of Male Institute Of Cancer Research Mice, Jay C. Albretsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Groundwater contamination is a concern due to the large number of people that can become exposed to the contaminant. The chemicals benzene and phenol are known groundwater contaminants. The main health problem caused by benzene or phenol is bone marrow toxicity. Benzene and phenol are also immunotoxins reported to cause decreased thymic weights, altered lymphocyte mitogenic responses, and lower antibody production.

Cytokines are key signaling molecules produced by the cells of the immune system to activate other cells in the immune system, produce antibodies, and recruit other cells to sites of inflammation. The purpose of this study was to determine …


Alteration Of Key Cytokine Levels By Aflatoxin B1 And T-2 Toxin In Male Cd-1 Mice, Raviprakash R. Dugyala May 1995

Alteration Of Key Cytokine Levels By Aflatoxin B1 And T-2 Toxin In Male Cd-1 Mice, Raviprakash R. Dugyala

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aflatoxin B1 and T-2 toxin are mycotoxins, which produce their immunotoxic effects by affecting nonspecific and acquired immunity in different species. The mechanisms of their immunotoxicity are still obscure. Cytokines are the key signaling molecules during the immune response. In this study, expression of macrophage-produced cytokines Interleukin-lα (IL-lα), tumor necrosis factor (TNF), and IL-6, and lymphocyte-produced cytokines IL-2, interferon y (IFNy), and IL-3 was measured at the mRNA and protein levels, after in vitro activation with mitogens in AFB1-and T-2-toxin-exposed mice.

Significant changes in the organ weights, especially in the mice exposed to a high dose of …


Metabolism Of Selected Antiviral Agents In Cells Infected With Drug-Resistant And Wild-Type Strains Of Murine Cytomegalovirus, Kevin M. Okleberry May 1995

Metabolism Of Selected Antiviral Agents In Cells Infected With Drug-Resistant And Wild-Type Strains Of Murine Cytomegalovirus, Kevin M. Okleberry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Resistance of human viral pathogens to various antiviral drugs is a serious medical problem. Two modes of drug resistance in cytomegalovirus infections have been observed, the first being altered (decreased) drug metabolism by the infected cells, and the second reduced sensitivity of the viral deoxyribonucleic acid polymerase enzyme to the active form of the drug. Mice infected with the murine cytomegalovirus have been used extensively as an animal model for the human cytomegalovirus, and drug-resistant strains in this model have been identified. To better understand the mode of drug resistance of the virus, the metabolism of two antiviral drugs, 9-(1,3-dihydroxy-2-propoxymethyl)guanine …


Molecular Toxicology Of Pyrrolizidine Alkaloids, Hea-Young Kim May 1994

Molecular Toxicology Of Pyrrolizidine Alkaloids, Hea-Young Kim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pyrrolizidine alkaloids are cytotoxic, carcinogenic, and anti-carcinogenic in vivo and in vitro, and they produce many hazardous effects in humans and animals. Pyrrolizidine alkaloids (PAs) also cross-link with DNA and/or protein. However, whether such cross-linking is important to the toxic action of PAs is not known. In addition, the exact mechanism underlying these DNA cross-links or cytotoxicity is also not clear.

In three separate studies, I characterized the nature of PA-induced DNA cross-links and the relationships between PA structures and cross-linking potency. In the first study (Chapter II), I found that cross-linking potency of PA congeners coincided with their …


Influence Of 2,5-Hexanedione, Acrylamide, Tri-O-Tolyl Phosphate, Leptophos And Methylmercury On Endogenous Levels Of Tryptophan, Serotonin And 5-Hydroxyindoleacetic Acid And Serotonin Turnover Rates In Rat Brain, Craig H. Farr May 1992

Influence Of 2,5-Hexanedione, Acrylamide, Tri-O-Tolyl Phosphate, Leptophos And Methylmercury On Endogenous Levels Of Tryptophan, Serotonin And 5-Hydroxyindoleacetic Acid And Serotonin Turnover Rates In Rat Brain, Craig H. Farr

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several industrial and environmental chemicals cause distal and/or central neuropathy among other diverse toxic effects. Spague-Dawley derived rats were fed doses of 2,5-hexanedione, acrylamide, tri-o-tolyl phosphate, Leptophos and methylmercury via gavage. The dose levels and administration periods were established in previous experiments designed to assess clinical neuropathy using rats trained to walk on a rotorod apparatus fitted with an electrode floor. After intravenous injections of 3H-Tryptophan, whole rat brain homogenates were analyzed using liquid scintillation and spectrofluorometric techniques for levels of tryptophan, serotonin and 5-hydroxyindoleacetic acid. Serotonin turnover rates were calculated using the specific activities of tryptophan and serotonin …