Environmental Health Commons^™

Oxybenzone And The Mammary Gland: Impact Of An Environmental Pollutant On Health, Disease & Ethical Decision-Making, Klara Matouskova

Doctoral Dissertations

The environmental pollutant and common sunscreen compound oxybenzone is a benzophenone type UV light chemical filter used in industrial and consumer goods. This chemical widely contaminates human tissues, non-human species, and environmental matrices. In this dissertation, oxybenzone is investigated for its effects on the mouse mammary gland in the offspring following perinatal exposure; after perinatal and prepubertal exposures as a dual environmental insult during two sensitive times of development; and in adults after exposure during pregnancy & lactation as an environmental factor potentially increasing the tissue susceptibility to mammary tumors. Chapter 1 introduces the mammary gland. Chapter 2 reviews UV …

Investigating The Developmental Impacts Of 3,3’-Dichlorobiphenyl (Pcb-11) In Zebrafish (Danio Rerio), Monika A. Roy

Doctoral Dissertations

The environmental pollutant 3,3’-dichlorobiphenyl (PCB-11) is a lower-chlorinated polychlorinated biphenyl (PCB) congener present in air and water samples. Both PCB-11 and its metabolite, 4-PCB-11-Sulfate, are detected in humans, including in pregnant women. The work conducted for this dissertation takes a developmental toxicology approach and uses zebrafish (Danio rerio) to investigate PCB-11’s potential impacts to the liver and pancreas. Chapter 1 introduces PCBs and the current knowledge gaps. Chapter 2 investigates PCB-11 interactions in short-term 4-day exposures with the Aryl hydrocarbon receptor (Ahr) pathway in both 0-20 mM individual and mixture exposures with other Ahr agonists. In Chapter 3, …

Evaluating The Toxicity And Formation Of Halobenzoquinones In Point-Of-Use Chlorinated Drinking Water, Stephanie Hung

Masters Theses

Chlorine has effectively reduced the prevalence of waterborne diseases, however there are secondary consequences to this public health advancement. Disinfection byproducts (DBPs) are chemicals formed when chlorine reacts with natural organic matter (NOM) in water. A new class of DBPs, halobenzoquinones (HBQs), has recently been identified and data suggests it could be potentially carcinogenic and up to 1000 times more toxic than some regulated DBPs. So far, in vitro studies have assessed HBQ toxicity without taking into account its transformation in cell media into potentially less toxic compounds. This study evaluated the toxic effects of one HBQ, 2,6-DCBQ, and its …

Developmental Exposure To Xenoestrogens: Effects On The Mouse Mammary Gland Development And Response To Estrogen, Durga Kolla

Masters Theses

Humans experience ubiquitous exposures to estrogenic environmental chemicals from food, personal care products, and other industrial and consumer goods. Bisphenol A (BPA), a well-studied xenoestrogen, is known to alter development of estrogen-sensitive organs including the brain, reproductive tract, and mammary gland. Bisphenol S (BPS), which has a similar chemical structure to BPA, is also used in many consumer products, but its effects on estrogen-sensitive organs in mammals has not been thoroughly examined. In our study, pregnant CD-1 mice were orally exposed to BPS or ethinyl estradiol (EE2, a positive control for estrogenicity) from gestational day 9 through postnatal day (PND) …

Robust Biosensors For Healthcare Applications: From High-Content Screening To Point-Of-Care Testing, Ngoc D. B. Le

Doctoral Dissertations

Efficient detection of proteins, mammalian cells, microorganisms and other biological systems in complex mixture is essential in disease diagnosis and environmental health. Therefore, technological platforms that provide sensors of high sensitivity, selectivity and stability are greatly desired. Recently, the ‘chemical-nose’ sensing approach has proved to be an effective strategy for profiling bio-relevant targets in complex mixtures. Detecting analytes in complex mixture is a challenge that conventional specificity-based sensors are still trying to solve due to the requirement of prior knowledge of the analyte, which is unknown in many cases. This thesis focuses on how to develop simple and robust …

Total Organic Iodine Quantification And Occurrence In Drinking Water, And Toxicity Assessment Of Iodinated Disinfection By-Products, Rassil El Sayess

Doctoral Dissertations

The focus of this work has been placed is on iodinated DBPs (I-DBPs), measured using total organic iodine (TOI), a surrogate measure of iodinated organics. This is due to the growing toxicity literature that places I-DBPs among the most toxic of all DBPs. To measure TOI in water, a new method was developed. This method combines adsorption, combustion, and trapping of combustion products, with an offline inductively coupled plasma/mass spectrometer (ICP-MS) for iodide detection. Three factors were varied across two levels each in order to optimize the method. The chosen method used a sample pH of less than 1 prior …

Rapid Method Of Processing Sperm For Nucleic Acid Extraction In Clinical Research, Matthew K. De Gannes

Masters Theses

Background: Sperm contain highly compact nuclei, inhibiting DNA extraction using traditional techniques. Current methods extracting sperm DNA involve lengthy lysis and no means of stabilizing DNA, hindering clinical research.

Objective: We sought to optimize an efficient method of extracting high quality human sperm DNA.

Methods: Sperm from three volunteers were isolated using PureCeption. We tested 1) proteinase K with DNA/RNA Shield, 2) DTT and TCEP as reducing agents, 3) QIAshredder homogenization, and 4) stability of sperm DNA fresh (baseline) or after 4 weeks of storage at 4^OC in DNA/RNA Shield using modified Quick-gDNA MiniPrep. DNA was PCR amplified …