Toxicology Commons^™

Assessment Of Soil, Water Contamination And Land Cover Changes In The Urban And Suburban Watersheds Of Houston, Texas, Felica Rena Davis

Dissertations (2016-Present)

Intense urbanization and increased anthropogenic activity are two important factors contributing to the decline of soil and water quality in Houston watersheds, which poses a great environmental and human health risks. This study, therefore, was designed to: 1) determine nutrient and metal concentrations in soil and water samples along Carpenters Bayou (CaB), Cedar Bayou (CB), Sims Bayou (SB), Spring Creek Bayou (SC) and Vince Bayou (VB), 2) analyze land cover changes in watersheds using Landsat image analysis and 3) evaluate socio-economic characteristics and human health risks for each watershed. Soil and water samples were collected from three different locations with …

Amelioration Of Acrolein Effects On The Small Intestine Of Rats By Curcumin And Compound 20, Syntia Engiasa Kwende

Dissertations (2016-Present)

Acrolein is an unsaturated aldehyde which produce chemicals used as an intermediate reactive aldehyde in the chemical industry. The primary component of acrolein, is derived from the incomplete combustion of wood, plastic, fossil fuels, the main component of cigarette smoke, the burning of fats and overheating of oil. The purpose of this research is to investigate whether curcumin and compound 20 prevents the induction of inflammatory and oxidative response caused by acrolein in the small intestine. Curcumin is the yellow pigment, lipophilic polyphenol substance that gives turmeric the medicinal properties. It can also define as the primary bioactive substance in …

Atrazine Levels In Rural Nebraska Counties And Parkinson's Disease, Muhammad Zahid

Capstone Experience: Master of Public Health

Parkinson's disease (PD) is a multifactorial disorder, connecting both genetic susceptibility and environmental risk factors. Several epidemiological and experimental studies support the evidence that pesticides exposure is positively associated with enhancing neurodegenerative diseases. The high amount of atrazine used in Nebraska and increased PD cases led us to evaluate the association between the long-lived water-soluble pesticide atrazine and PD in Nebraska counties. A person's exposure to atrazine may come from inhalation, dermal absorption, and ingestion. Three types of atrazine data covering 1992 to 2017 were used for this study: applied atrazine, atrazine in surface water, and atrazine in groundwater. In …

Particulate Hexavalent Chromium Inhibits Homologous Recombination Repair By Targeting Rad51 Paralogs In Human Lung Fibroblasts., Aggie R. Williams

Electronic Theses and Dissertations

Hexavalent Chromium [Cr(VI)] is a known human lung carcinogen and general health hazard. The mechanism of carcinogenesis remains poorly understood, but chromosome instability (CIN) is the major theory in its carcinogenic mechanism. Homologous recombination (HR) repair is a DNA repair pathway that prevents CIN by repairing DNA double-strand breaks. RAD51, a key mediator protein of HR repair, along with the RAD51 paralogs (RAD51B, C, D, XRCC2, and 3) are required for HR repair. During HR, RAD51 loads and forms a helical nucleoprotein filament structure to promote DNA strand exchange and stimulate pairing activity of DNA. Cr(VI) exposures have been shown …

Blood Lead Levels In Minority Children: A Case Of Environmental Racism, Erick Rivera

Sociology & Criminal Justice Theses & Dissertations

Racial minorities in the United States have suffered from being disadvantaged. Among these disadvantages is environmental racism. This includes minority communities being ‘sacrifice zones’ for toxic waste and being exposed to lead poisoning. The purpose of this study is to examine differences in blood levels between white children and children of color. This research will follow a bivariate model for the first research question, “Do youth of color (under the age of 18) have higher BLLs than white children?” The bivariate model will look at the relationship between ethno-racial group and BLLs. Specifically, an analysis of variance (ANOVA) will be …

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 (PM_2.5). Upon inhalation, PM_2.5 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 PM_2.5 air pollution is associated …

Effects Of 2,4-Di-Tert-Butylphenol On Osteogenic And Myogenic Differentiation Of Human Induced Pluripotent Stem Cells, Thanh-Bình Dương

All Theses

Synthetic phenolic antioxidants (SPAs) are a class of compounds used to increase the durability of polymers as well as to increase the shelf-life of food, cosmetics, and other personal care items. Of these SPAs is 2,4-di-tert-butylphenol (2,4-DBP). 2,4-DBP is primarily used in polyethylene crosspolymer pipes, which are now used as a replacement for the traditional copper pipes for household water distribution. However, 2,4-DBP has been found to leach from these pipes into the water, enabling a mode of exposure to humans. 2,4-DBP has been detected in human urine, serum, but more importantly, maternal serum, placenta, and cord blood. …

Floating Treatment Wetlands For Brackish Waters: Plant Selection And Nutrient Uptake Potential., Andrea Landaverde

All Theses

Brackish water bodies in coastal regions provide critical ecosystem services that support human and environmental health. Anthropogenic activities such as agricultural and industrial activities, construction, urban settlements, and tourism contribute to increased inputs of nitrogen (N) and phosphorus (P) in brackish coastal ecosystems. Excess nutrients can lead to impaired water quality and affect marine organisms. Floating treatment wetlands (FTWs) are a vegetated-base technology used to remove contaminants from water column, that has been mainly studied and applied in freshwater systems. Application of FTWs in brackish systems requires further investigation, as high salinity in brackish waters could result in toxicity to …

Evaluation Of Biochemical And Pathological Parameters At Different Doses Of Cisplatin In Experimental Animal Model: Toxicological Study On An Antineoplastic Drug, Farhana Sultana, Muhammed Mohibul Islam, Mohammad Nurul Amin, Nusrat Jahan, Asma Kabir, Talha Bin Emran, Bibek Chandra Sutradhar, Sujan Banik

Makara Journal of Health Research

Background: This study aimed to assess the effect of cisplatin-induced toxicities on biochemical and pathological parameters such as body, liver, and kidney weights, blood urea nitrogen (BUN), creatinine, alanine aminotransferase (ALT), and blood cells (RBCs and WBCs) in white Swiss albino mice.

Methods: Cisplatin’s potential toxic effects on body, liver, and kidney weights were evaluated using standard laboratory methods. Blood biochemical levels such as BUN, creatinine, and ALT levels were determined by an auto-hemolyzer using commercial diagnostic kits. Blood cells (RBCs and WBCs) were counted under a microscope by a hemocytometer.

Results: Cisplatin’s potential toxic effects on …

Accumulation Of Persistent Organic Pollutants In Marine Mammals: A Case Study On Cetaceans, Pinnipeds, And Sirenians, Alydia Moorhead

All HCAS Student Capstones, Theses, and Dissertations

Persistent organic pollutants (POPs) are lipophilic semi-volatile organic chemicals that present a range of challenges to marine biota, specifically marine mammals that often occupy a high trophic position in the food web. POPs have become a global problem since they have been shown to cause immunologic, teratogenic, carcinogenic, neurological, and reproductive complications in living organisms due to their resistance to biodegradation and their lipophilic nature. Marine mammals can accumulate these toxic substances through direct ingestion, trophic transfer, adsorption, and maternal offloading. They are susceptible to both bioaccumulation and biomagnification of POPs. Accumulation of POPs is affected by many variables, including …

Black Carbon And Meteorological Parameters At Two Locations In Northern Mississippi, Ashton Swader

Honors Theses

Black Carbon, which is a component of fine particulate matter, is a known pollutant that has been linked to the development of several diseases including cardiovascular disease. This pollutant can be measured by taking samples of air within a certain region and analyzing them using a transmissometer. It is known that black carbon concentrations tend to be higher in urban areas when compared to rural areas within a region. Black carbon concentrations can also vary depending on certain meteorological parameters such as temperature and humidity. There were no current studies that analyze the air quality in northern Mississippi due to …

The Effects Of Paclitaxel On Cellular Migration And The Cytoskeleton, Ashley Salguero-Gonzalez

Thinking Matters Symposium

In a clinical setting, some patients are exposed to an anti-cancer chemotherapy agent, paclitaxel. Cancerous cells undergo rapid, continuous cell division without control. Chemotherapy treatments try to slow and stop the uncontrollable cell division cycles and eliminate cancerous cells in the process. Paclitaxel serves as a treatment for some types of cancers, including lung, melanoma, bladder, and esophageal. Because it targets the cytoskeleton, paclitaxel can also influence cell migration. This project utilizes a cellular migration assay and an immunohistochemistry assay to analyze the effects of paclitaxel on the movement of cells and on the cytoskeleton of neuroglia rat cells with …

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 …

The Sublethal Response Of Cambarus Sp. To Acute Low Dose Herbicide Exposure Evidenced By A Change In Ggt Levels And Apoptosis, Amelia Wickham

Senior Honors Theses

Following application, herbicidal runoff can collect in freshwater ecosystems, briefly exposing non-target organisms. As biological indicators, crayfish serve as models to assess freshwater health. Chemically stressed crayfish form reactive oxygen species (ROS) which are neutralized by the glutathione pathway. As glutathione depletes, γ-glutamyl-transferase (GGT) upregulates to increase glutathione formation. High oxidative stress lowers glutathione levels and subsequent apoptosis occurs. For this acute study, crayfish were exposed to 5ppb and 50ppb of atrazine, glyphosate, and 2,4-D. Herbicide exposures were expected to induce higher GGT production, increased oxidative stress, and increased apoptosis. Instead, GGT and apoptosis predominately decreased relative to the control. …

Superfund And Society Benumbed: An In-Depth Look At Environmental Justice In South Carolina, Sydney A. Hampton

Senior Theses

This thesis investigates the relationship between superfund sites in minority communities and their public health through the lens of social vulnerability. Various demographic parameters were used to assess the risk associated with minority communities and exposure to hazardous waste. After investigating the history of the Environmental Justice movement, three superfund sites of interest in South Carolina, and demographic and public health data; each community was analyzed to determine association between exposure to hazardous waste and minority status. Each examined community exhibited characteristics contributing to heightened social vulnerability, potentially causing increased susceptibility to negative health outcomes from exposure to hazardous waste.

Behavioral And Physiological Effects Of Heavy Metals On Fish: A Review And Preliminary Results, Diana V. Morales

Theses and Dissertations

Pollution, specifically heavy metal pollution, in various bodies of water has been a significant issue for decades. Research has been conducted on heavy metals and their effects on the environment, larger fish species, and humans since the 1970s (Skidmore, 1964; Adeniyi et al., 2007; Adeosun et al., 2015; Bawuro et al., 2018). It is known that zinc is a neurotoxin in some species and causes harm to the environment. It is also known that it causes harm to people if it is ingested or if they are exposed to it for long periods of time (Mahurpawar, 2015; Mizuno and Kawahara, …

The Use Of Atmospheric-Pressure Chemical Ionization For Pesticide Analysis Using Liquid Chromatography Mass Spectrometry, Pei-Ting Jiang, Kuan-Lu Wu, Hsueh-Ting Wang, Sung-Fang Chen

Journal of Food and Drug Analysis

Based on the regulations of the Ministry of Health and Welfare (MOHW) of Taiwan in 2017, an analysis of 373 pesticides in food was conducted using the MOHW official method. The analyses involved the use of either liquid chromatography mass spectrometry (LC-MS) with electrospray ionization (ESI) or gas chromatography mass spectrometry (GC-MS) with electron ionization (EI). In this study, the applicability of detecting pesticides using atmospheric pressure chemical ionization (APCI) was investigated and evaluated. The pesticides were separated using an aqueous solution of ammonium formate with methanol as the mobile phase, and ionization efficiency was compared between APCI, ESI, and …

A Substructure-Based Screening Approach To Uncover N-Nitrosamines In Drug Substances, Yu-Ting Kao, Shu-Fen Wang, Meng-Hsiu Wu, Shwu-Huey Her, Yi-Hsuan Yang, Chung-Hsien Lee, Hsiao-Feng Lee, An-Rong Lee, Li-Chien Chang, Li-Heng Pao

Journal of Food and Drug Analysis

Drug substances are at risk of contamination with N-nitrosamines (NAs), well-known carcinogenic agents, during synthesis processes and/or long-term storage. Therefore, in this study, we developed an efficient data-based screening approach to systemically assess marketed products and investigated its scalability for benefiting both regulatory agencies and pharmaceutical industries. A substructure-based screening method employing DataWarrior, an open-source software, was established to evaluate the risks of NA impurities in drug substances. Eight NA substructures containing susceptible amino sources for N-nitrosation have been identified as screening targets: dimethylamine (DMA), diethylamine, isopropylethylamine, diisopropylamine, N-methyl-2-pyrrolidone, dibutylamine, methylphenylamine, and tetrazoles. Our method detected 192 drug …

Repurposing Lansoprazole And Posaconazole To Treat Leishmaniasis: Integration Of In Vitro Testing, Pharmacological Corroboration, And Mechanisms Of Action, Yash Gupta, Steven Goicoechea, Jesus G. Romero, Raman Mathur, Thomas R. Caulfield, Daniel P. Becker, Ravi Durvasula, Prakasha Kempaiah

Journal of Food and Drug Analysis

Leishmaniasis remains a serious public health problem in many tropical regions of the world. Among neglected tropical diseases, the mortality rate of leishmaniasis is second only to malaria. All currently approved therapeutics have toxic side effects and face rapidly increasing resistance. To identify existing drugs with antileishmanial activity and predict the mechanism of action, we designed a drug-discovery pipeline utilizing both in-silico and in-vitro methods. First, we screened compounds from the Selleckchem Bio-Active Compound Library containing ~1,622 FDA-approved drugs and narrowed these down to 96 candidates based on data mining for possible anti-parasitic properties. Next, we completed preliminary in-vitro testing …

Effect Of Repeated Shengmai-San Administration On Nifedipine Pharmacokinetics And The Risk/Benefit Under Co-Treatment, Hong-Jaan Wang, Elise Chia-Hui Tan, Tzu-Yi Chiang, Wei-Ching Chen, Chien-Chang Shen, Yune-Fang Ueng

Journal of Food and Drug Analysis

Herbal interactions with nifedipine/felodipine through cytochrome P450 (CYP) 3A inhibition is significant in humans. Shengmai-San (SMS), a three-herbal formula of Chinese medicine, is commonly prescribed in Asia populations for cardiovascular disorders. This study aimed to elucidate the impact of SMS on nifedipine/felodipine treatment by the findings from rat pharmacokinetic study of nifedipine to the retrospective cohort study of patients with hypertension. The 3-week SMS treatment increased the systemic exposure to nifedipine by nearly two-fold and decreased nifedipine clearance by 39% in rats. Among the ingredients of SMS component herbs, schisandrin B, schisantherin A, and methylophiopogonanone A, inhibited the nifedipine oxidation …