Toxicology Commons^™

Does Timing Of Herbicide Use Influence Rates Of Germination Or Seedling Biomass Of Native Plants Used For Restoration?, Christine Mcmanamen

Graduate Student Theses, Dissertations, & Professional Papers

Invasive plants can negatively impact native grasslands by changing their species composition, productivity, and function. Managers commonly use herbicides as a control method; however, this practice can lead to secondary invasion by other non-native invasive plants, unless measures are taken to promote natives. Because of this, managers often seed native plants after spraying herbicides. There is evidence, however, that chemical control of invasive plants may reduce the effectiveness of subsequent seed-addition treatments, but there is currently little quantitative information on optimal timing between spraying and seeding or on variation in herbicide sensitivity among native plants commonly used in seed mixes. …

Differential Gene Expression Analysis Of Metolachlor Treated Human Liver Cells By Microarray, Navinder Paul Kaur Brar

Dissertations and Theses @ UNI

Metolachlor is one of the most common pre-emergent pesticides used by Iowa farmers. It is used to control broadleaf weeds and grasses in the fields of corn and soybean. It is a frequent contaminant of groundwater and surface water due to runoff after application. It has been shown to inhibit protein and chlorophyll synthesis in plant cells, but its effect on mammalian cells has not been consistently conclusive. As metolachlor and other herbicides have been shown to be associated with harmful health effects in non-target organisms it is very important to determine a mechanism of action on non-target cells, especially …

A Multibiomarker Analysis Of Pollutant Effects On Atlantic Stingray Populations In Florida’S St. Johns River, John Whalen

UNF Graduate Theses and Dissertations

The goal of this study was to examine the potential health effects of organochlorine (OC) and polycyclic aromatic hydrocarbon (PAH) exposure on Atlantic stingray populations in Florida’s St. Johns River (SJR). Special emphasis was placed on identifying OC- and/or PAH-related effects in stingrays from areas of the lower (LSJR) and middle (MSJR) basins shown to possess elevated levels of these compounds, as well as characterizing baseline levels of pollutant exposure in the SJR shipping channel, which may be subjected to dredging in the near future, potentially resuspending and redistributing contaminated sediments and increasing pollutant-associated effects. To accomplish this, we measured …

Identification Of “Kratom” (Mitragyna Speciosa) Alkaloids In Commercially Available Products, Julia Grzymkowski, Michelle R. Peace, Justin Poklis

UROP Posters

“Kratom” is the common name for the botanical mitragyna speciosa. It is a tree native to Southeast Asia in which leaves contain the psychoactive alkaloids mitragynine and 7-hydroxymitragynine. Kratom is often ingested as teas, chewed, or smoked. It acts as a stimulant in small doses and as an opioid in large doses. Overdoses can result in vomiting, seizures, and death. Recently the Drug Enforcement Agency (DEA) placed Kratom on Schedule 1, but, due to public outcry, it was almost immediately removed.

Eleven kratom based products were obtained from various tobacco shops, “headshops” and via the internet including: Choice brand …

Chronic Effects Of Lead Exposure On Atherinops Affinis (Topsmelt): Influence Of Salinity And Organism Age, Erik Joseph Reynolds

Master's Theses

Pb (lead) appears in the environment as a consequence of both natural and anthropogenic processes. Mining, smelting, coal burning, lead acid batteries, and cement manufacturing substantially release Pb into aquatic environments. The goal of this study was to determine the influence of salinity and organism age on chronic toxicity of Pb to Atherinops affinis (topsmelt) in support of development of a species sensitivity distribution (SSD). Species sensitivity distributions assist in ecological risk assessments and establishing quality criteria for contaminants. Three chronic exposure studies were conducted for 28 days in a water flow-through testing system. Survival, standard length, dry weight, and …

From Disposable Culture To Disposable People: Teaching About The Unintended Consequences Of Plastics, Sasha Adkins

Antioch University Dissertations & Theses

Plastics, the epitome of disposable culture, pose both a toxicological and a spiritual problem. This dissertation examines plastics at a molecular level using the discourse of endocrine disruption, and at a sociological level using the discourses of eco-theology and environmental justice. Adding to the literature on the adsorption of toxicants to plastic marine debris, I demonstrate that certain types of plastic -- those containing mercaptans, such as styrene butadiene block copolymer -- efficiently concentrate methyl mercury from seawater. Further, samples of polycarbonate contributed mercury to seawater. I propose the term plastic-mediated magnification to describe the phenomenon that plastics, along with …

Bioanalysis For Cocaine, Opiates, Methadone And Amphetamines Exposure Detection During Pregnancy, Marta Concheiro, Elena Lendoiro, Ana De Castro, Eva Gonzalez-Colmenero, Ana Concheiro-Guisan, Patricia Penas-Silva, Manuel Macias-Cortina, Angelines Cruz-Landeira, Manuel Lopez-Rivadulla

Publications and Research

Drug exposure during pregnancy constitutes a major legal issue and public health concern. Drug and metabolite determination in biological matrices from mother and newborn is an objective indication of prenatal drug exposure. However, limited data are available regarding the interpretation of these analytical results in terms of window of detection and degree of exposure. We collected paired maternal hair, meconium, placenta and umbilical cord from 727 mother-newborn dyads. We analyzed these specimens by liquid chromatography tandem mass spectrometry for the determination of cocaine, opioids, methadone and amphetamines, and compared the analytical results from the four different matrices. The cases were …

Knockout Of Sphingosine Kinase 1 Attenuates Renal Interstitial Fibrosis In Unilateral Ureteral Obstruction (Uuo) Model, Xiwen Zhang

Theses and Dissertations

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid metabolite and an important signaling molecule that plays a significant role in fibrosis. S1P synthesis is catalyzed by sphingosine kinases (SphKs), which phosphorylate sphingosine into S1P. The present study tested the hypothesis that SphK1-S1P signaling pathway participates in the kidney damage in unilateral ureteral obstruction (UUO) model. Wild type and SphK1 knockout mice were subjected to UUO for 7 days or 14 days and then four groups of kidneys were collected: wild type control group (WT-C), wild type UUO group (WT-UUO), SphK1-/- control group (KO-C) and SphK1-/- UUO group (KO-UUO). The mRNA level of …

The Effects Of Metolachlor Exposure On The Thp-1 Alveolar Monocyte And Macrophage Function, Jared S. Parmater

Dissertations and Theses @ UNI

The use of additive chemicals such as pesticides has become commonplace in agricultural practices in the Midwestern United States. Metolachlor, an herbicide used to regulate broadleaf weeds in corn and soybeans, is a widely utilized pesticide in the United States. This herbicide is effective in killing broadleaf weeds but has detrimental effects and consequences in non-target organisms. It is a frequent contaminant of ground water due to post application run-off and the air.

Inhalation constitutes one route of exposure, in addition to ingestion, adding to the list of unintended targets and consequences. This route of exposure creates an argument for …

The Relationship Between Lead In Groundwater And Elementary School Students' Academic Performance In Missouri, Lynnette Xiangling Li

Graduate Theses/Dissertations

Lead exposure can come from various sources, e.g., lead mines, industrial areas, and lead based paint. Missouri has more than 4,128 lead mines. Lead is a neurotoxin. The objectives of the study were to investigate i) the spatial relationship between lead mines and lead distribution in groundwater, ii) the statistical impact of lead in groundwater on students' Missouri Assessment Program (MAP) scores, and iii) the geographic variations of lead's impact on students' MAP scores. Geographic Information Science spatial analysis tools were used to analyze the concentration of lead in groundwater within school districts in Missouri. Regression analysis was utilized to …

Nanoparticle Toxicity And Molecular Mechanisms In Fish: A Case Study With Silver Nanoparticles, Jiejun Gao

Open Access Dissertations

Nanoparticles (NPs) are widely used in a myriad of commercial and industrial products making their entry to the environment a likely event. NPs have unique physical-chemical properties that result from their small size and high surface area to volume ratio, making them highly reactive and potentially toxic. In Chapter 1, we summarize the effects and mechanisms of metal-based NPs on the vascular system. In vitro studies have shown that NPs are anti-angiogenic because they cause inflammation, oxidative stress, and apoptosis of endothelial cells resulting in increased permeability and decreased proliferation and migration. Whole animal studies examining the effects of NPs …

Gonadal Intersex In Teleosts: Mechanisms, Molecular Biomarkers And Diagnostic Assays, Ahmed M.E. Abdel-Moneim Mohamed

Open Access Dissertations

Natural and synthetic estrogenic and androgenic compounds are continuously released into aquatic ecosystems. Exposure of teleost fishes to these contaminants can negatively impact sex differentiation and reproductive output. Specifically, development of gonadal intersex in gonochoristic (fixed sex) fish species has been studied extensively in relation to exposure to this class of compounds. The main objectives of this dissertation were to: 1) conduct field and laboratory studies to investigate the molecular signaling pathways behind the development of gonadal intersex; and 2) establish molecular biomarkers and assays for testing the ability of environmental pollutants to develop this condition using a battery of …

Molecular Measurement Of Toxicity In Fish; Case Examples And Policy Implications, Jessica A. Freedman

Senior Honors Projects

Stormwater and oil are common urban contaminants that can be harmful to fish species. One way of recognizing exposed and impaired fish is by monitoring gene expression and gene induction. This study focused on the identification and validation of reference genes for measuring contaminant-induced changes in gene expression due to urban influence. In this study, reference genes (which are genes used to normalize data and remain consistent in varying exposures regardless of organism and tissue type) were established. Six genes were identified as reference genes (ef1a, wdtc1, mtm1, spop, rxrba and tuba1) from a longer list of potential …

Analysis Of Synthetic Cannabinoids And Drugs Of Abuse Amongst Hiv-Infected Individuals, Jillian M. Wetzel

Student Theses

Synthetic cannabinoids are man-made mind-alternating chemicals. Law enforcement and legislation have attempted to classify many of these synthetic cannabinoids as schedule I controlled substances, however, they are continuously being modified by dealers at the retail end of the distribution chain. Addiction and moderate use of illicit drugs have been identified as major reasons for non-adherence to antiretroviral therapy among HIV patients. However, there is no data regarding the impact of synthetic cannabinoid exposure in this population and how this affects their compliancy with taking antiretroviral therapy. A total of 72 authentic urine specimens were collected weekly from 13 individuals with …

Use Of A Modified Greenscreen Tool To Conduct A Screening-Level Comparative Hazard Assessment Of Conventional Silver And Two Forms Of Nanosilver., Jennifer Sass, Lauren Heine, Nina Hwang

Environmental and Occupational Health Faculty Publications

BACKGROUND: Increased concern for potential health and environmental impacts of chemicals, including nanomaterials, in consumer products is driving demand for greater transparency regarding potential risks. Chemical hazard assessment is a powerful tool to inform product design, development and procurement and has been integrated into alternative assessment frameworks. The extent to which assessment methods originally designed for conventionally-sized materials can be used for nanomaterials, which have size-dependent physical and chemical properties, have not been well established. We contracted with a certified GreenScreen profiler to conduct three GreenScreen hazard assessments, for conventional silver and two forms of nanosilver. The contractor summarized publicly …

The Influence Of Oxygen Tension And Glycolytic And Citric Acid Cycle Substrates In Acrolein-Induced Cellular Injury In The Differentiated H9c2 Cardiac Cell Model, Jayme Coyle

USF Tampa Graduate Theses and Dissertations

Most in vitro systems employ the standard cell culture maintenance conditions of 95 % air with 5 % CO2 to balance medium pH, which translates to culture oxygen tensions of approximately 20 % - above the typical ≤ 6 % found in most tissues. The current investigation, therefore, aims to characterize the effect of maintenance and toxicant exposure with a particular focus on the α,β-unsaturated aldehyde, acrolein, in the presence of physiologically relevant oxygen tension using a differentiated H9c2 cardiomyoblast subclone. H9c2 cells were maintained separately in 20.1 and 5 % oxygen, after which cells were differentiated for five days, …

Aneuploidy: A Common And Early Evidence-Based Biomarker For Carcinogens And Reproductive Toxicants., Daniele Mandrioli, Fiorella Belpoggi, Ellen K Silbergeld, Melissa J. Perry

Environmental and Occupational Health Faculty Publications

Aneuploidy, defined as structural and numerical aberrations of chromosomes, continues to draw attention as an informative effect biomarker for carcinogens and male reproductive toxicants. It has been well documented that aneuploidy is a hallmark of cancer. Aneuploidies in oocytes and spermatozoa contribute to infertility, pregnancy loss and a number of congenital abnormalities, and sperm aneuploidy is associated with testicular cancer. It is striking that several carcinogens induce aneuploidy in somatic cells, and also adversely affect the chromosome compliment of germ cells. In this paper we review 1) the contributions of aneuploidy to cancer, infertility, and developmental abnormalities; 2) techniques for …

School Siting Near Industrial Chemical Facilities: Findings From The U.S. Chemical Safety Board's Investigation Of The West Fertilizer Explosion., Veronica A Tinney, Jerad M Denton, Lucy Sciallo-Tyler, Jerome A. Paulson

Environmental and Occupational Health Faculty Publications

BACKGROUND: The U.S. Chemical Safety and Hazard Investigation Board (CSB) investigated the April 17, 2013 explosion at the West Fertilizer Company (WFC) that resulted in 15 fatalities, more than 260 injuries and damage to more than 150 buildings. Among these structures were four nearby school buildings cumulatively housing children in grades K-12, a nursing care facility and an apartment complex. The incident occurred during the evening when school was not in session, which reduced the number of injuries.

OBJECTIVES: The goal of this paper is to illustrate the consequences of siting schools near facilities that store or use hazardous chemicals, …

Rabbit Control: Bait Stations, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity factsheets

This factsheet provides information on using bait stations for rabbit control.

Biological control agents such as the myxoma virus (myxomatosis), and rabbit haemorraghic disease virus (RHDV) or rabbit calicivirus disease, will not provide ‘magic bullets’ for reducing the impact of rabbits on agricultural production and the environment. Biological agents are more effective when they form part of an integrated approach to rabbit control. An integrated approach should use all available control options, including biological control, the use of vertebrate pesticides, shooting, and trapping programs. Control programs are most effective when they include the greatest number of properties possible (that is, …

Quantifying The Toxicity Of 1-Methylnaphthalene To The Shallow-Water Coral, Porites Divaricata, For Use In The Target Lipid Model, Nicholas Turner

HCNSO Student Theses and Dissertations

The proximity of coral reefs to coastal urban areas and shipping lanes predisposes corals to petroleum pollution from multiple sources. Previous research has evaluated petroleum toxicity to coral using a variety of methodologies, including monitoring effects of acute and chronic spills, in situ exposures, and ex situ exposures with both adult and larval stage corals. Variability in toxicant, bioassay conditions, species and other methodological disparities among studies prevents comprehensive conclusions regarding the toxicity of hydrocarbons to corals. This research evaluated the 48-hour toxicity of 1-methylnaphthalene to Porites divaricata using a continuous-flow passive dosing system. The range-finding exposure evaluated the dosing …