Laboratory and Basic Science Research Commons^™

The Significance Of Crispr/Cas9-Directed Cul3 Knockout On Human Colorectal Cancer Cells, Zoe A. Lautz

Departmental Honors Projects

Cancer, the second leading cause of death in the US, is caused by mutations in select genes that alter cellular function leading to uncontrolled proliferation. Understanding the specific genes that drive cancer can lead to the generation of novel cancer therapies. To identify novel genes that drive cancer in the colon (CRC), lungs, and ovaries in mice, Starr et al. employed a transposon-based insertional mutagenesis system. One of the genes identified, APC, is mutated in 70-80% of human CRCs. CUL3, suspected to be a general driver gene, was discovered in the lung cancer screen. CUL3 was analyzed for its role …

Elucidating The Role Of Endogenous Electric Fields In Regulating The Astrocytic Response To Injury In The Mammalian Central Nervous System, Matthew L. Baer

Theses and Dissertations

Endogenous bioelectric fields guide morphogenesis during embryonic development and regeneration by directly regulating the cellular functions responsible for these phenomena. Although this role has been extensively explored in many peripheral tissues, the ability of electric fields to regulate wound repair and stimulate regeneration in the mammalian central nervous system (CNS) has not been convincingly established. This dissertation explores the role of electric fields in regulating the injury response and controlling the regenerative potential of the mammalian CNS. We place particular emphasis on their influence on astrocytes, as specific differences in their injury-induced behaviors have been associated with differences in the …

Estimates Of Persistent Inward Current In Human Motor Neurons During Postural Sway, Ryan Foley, Jayne M. Kalmar Dr.

Theses and Dissertations (Comprehensive)

Persistent inward current (PIC) is a membrane property critical for increasing gain of motor neuron output. In humans, most estimates of PIC are made from plantarflexor or dorsiflexor motor units with the participant in a seated position with the knee flexed. This seated and static posture neglects the task-dependent nature of the monoaminergic drive that modulates PIC activation. Seated estimates may drastically underestimate the amount of PIC that occurs in human motor neurons during functional movement. The current study estimated PIC using the conventional paired motor unit technique which uses the difference between reference unit firing frequency at test unit …

Genome Engineering To Create Dominant Alleles In Caenorhabditis Elegans Using Crispr-Cas9 Technology, Abrar Sulaimani

Graduate School of Biomedical Sciences Theses and Dissertations

Many investigators have being using CRISPR-Cas9 as a method of genome engineering because it is easy, accurate and fast. This technique has been used to modify the genomes of a wide variety of organisms, including the nematode Caenorhabditis elegans (C. elegans). The short life cycle and ease of introducing exogenous plasmids make C. elegans an ideal system for advancing this technique. My thesis had two aims that focused on developing methods to create dominant alleles in C. elegans. Genetic modifications like precise deletion and insertions into a locus of chromosome are technically challenging. Additionally, although there are several ways of …

Investigating The Binding Potential And Downstream Effects Of Ferrocene/ Ruthenium (Iii) Complexes With Rna, Mildred Apollo Kissai

Senior Projects Spring 2015

Cisplatin, one of the most popular chemotherapeutic drugs on the market today, battles cancer by binding to DNA, and causing kinks which obstruct DNA replication and transcription. As a result, cisplatin halts cell proliferation of not only fast-dividing cancerous cells but healthy cells as well. To circumvent the shortcomings of cisplatin, the Anderson lab has synthesized a class of ruthenium (III)/ ferrocene compounds, named the RuLX series. These new hetero- multinuclear complexes may have greater selectivity between cancerous and healthy cells through a proposed synergistic mechanism of their metal centers. Previous work on these novel complexes has demonstrated that they …

Evaluation Of The Developmental Toxicity Of Lead In The Danio Rerio Body, Nicole M. Roy, Sarah Dewolf, Bruno Carneiro

Biology Faculty Publications

Lead has been utilized throughout history and is widely distributed and mobilized globally. Although lead in the environment has been somewhat mitigated, the nature of lead and its extensive uses in the past prohibit it from being completely absent from our environment and exposure to lead is still a public health concern. Most studies regarding lead toxicity have focused on the brain. However, little is found in the literature on the effects of lead in other tissues. Here, we utilize the zebrafish model system to investigate effects of lead exposure during early developmental time windows at 24, 48 and 72 …

Electrophysiological And Behavioral Working Memory Differences Between Musicians And Non-Musicians, Benjamin P. Richardson

All Master's Theses

The current study examines the P300 brainwave and working memory differences between musicians and non-musicians. Differences in aspects of recorded electrical brain activity have been used to quantify differences in updating processes of working memory possibly related to differences in amount of music experience. The current study is designed to partially replicate and enhance a method previously implemented in research describing how music experience may be associated with differences in visual processing as well auditory working memory and executive function. Behavioral data were collected using six standardized subtest measures of the TOMAL – II, followed by ERP recordings during a …

Behavioral Response Of Pacific Lamprey (Entosphenus Tridentatus) To Predator Odors, Laurie L. Porter

All Master's Theses

Pacific lamprey (Entosphenus tridentatus), a species facing serious threats to their existence, experience a number of challenges in reaching their desired spawning grounds during the adult migratory phase, and predators are suspected to be one of these challenges. Understanding if Pacific lamprey respond to predator odorants may provide a management tool for use in conjunction with attractants in guiding lamprey to suitable spawning habitat and deterring them from poor habitat. Previous research has failed to explore Pacific lamprey response to predator odorants, although much research exists on attractant odorants. In our study, we tested Pacific lamprey response to …

Examining The Regulatory Value Of Multi-Route Mammalian Acute Systemic Toxicity Studies, Troy Seidle, Pilar Prieto, Anna Bulgheroni

Troy Seidle, PhD

Regulatory information requirements for pesticides call for submission of acute systemic toxicity data for up to three different exposure routes (oral, dermal, inhalation) for both active ingredients and formulated products. Similar multi-route testing is required in the European Union and elsewhere for industrial chemicals. To determine the value of acute toxicity testing by more than one route, oral-dermal and oralinhalation concordances among regulatory classifications were examined for large data sets of chemicals and pesticide active ingredients. Across all sectors examined, oral acute toxicity classifications for pure active substances were more severe than those derived from dermal data in more than …

Can Acute Dermal Systemic Toxicity Tests Be Replaced With Oral Tests? A Comparison Of Route-Specific Systemic Toxicity And Hazard Classifications Under The Globally Harmonized System Of Classification And Labelling Of Chemicals (Ghs), Nigel P. Moore, David J. Andrew, Donald L. Bjerke, Stuart Creton, David Dreher, Thomas Holmes, Pilar Prieto, Troy Seidle, Tim G. Rowan

Troy Seidle, PhD

Acute systemic toxicity data (LD50 values) and hazard classifications derived in the rat following oral administration and dermal application have been analysed to examine whether or not orally-derived hazard classification or LD50 values can be used to determine dermal hazard classification. Comparing the oral and dermal classifications for 335 substances derived from oral and dermal LD50 values respectively revealed 17% concordance, and indicated that 7% of substances would be classified less severely while 76% would be classified more severely if oral classifications were applied directly to the dermal route. In contrast, applying the oral LD50 values within the dermal classification …

An Evaluation Of The Us High Production Volume (Hpv) Chemical-Testing Programme: A Study In (Ir)Relevance, Redundancy And Retro Thinking, Andrew Nicholson, Jessica Sandler, Troy Seidle

Troy Seidle, PhD

Under the US Environmental Protection Agency (EPA) High Production Volume (HPV) Challenge Programme, chemical companies have volunteered to conduct screening-level toxicity tests on approximately 2800 widely-used industrial chemicals. Participating companies are committed to providing available toxicity information to the EPA and presenting testing proposals for review by the EPA and posting on the EPA Web site as public information. People for the Ethical Treatment of Animals (PETA) and a coalition of animal protection organisations have reviewed all the test plans submitted by the participating chemical companies for compliance with the original HPV framework, as well as with animal welfare guidelines …

Cross-Sector Review Of Drivers And Available 3rs Approaches For Acute Systemic Toxicity Testing, Troy Seidle, Sally Robinson, Tom Holmes, Stuart Creton, Pilar Prieto, Julia Scheel, Magda Chlebus

Troy Seidle, PhD

Acute systemic toxicity studies are carried out in many sectors in which synthetic chemicals are manufactured or used and are among the most criticized of all toxicology tests on both scientific and ethical grounds. A review of the drivers for acute toxicity testing within the pharmaceutical industry led to a paradigm shift whereby in vivo acute toxicity data are no longer routinely required in advance of human clinical trials. Based on this experience, the following review was undertaken to identify (1) regulatory and scientific drivers for acute toxicity testing in other industrial sectors, (2) activities aimed at replacing, reducing, or …

The Development Of New Concepts For Assessing Reproductive Toxicity Applicable To Large Scale Toxicological Programmes, S. Bremer, C. Pellizzer, S. Hoffmann, T. Seidle, T. Hartung

Troy Seidle, PhD

Large scale toxicological testing programmes which are currently ongoing such as the new European chemical legislation REACH require the development of new integrated testing strategies rather than applying traditional testing schemes to thousands of chemicals. The current practice of requiring in vivo testing for every possible adverse effect endanger the success of these programmes due (i) to limited testing facilities and sufficient capacity of scientific/technical knowledge for reproductive toxicity; (ii) an unacceptable number of laboratory animals involved (iii) an intolerable number of chemicals classified as false positive.

A key aspect of the implementation of new testing strategies is the determination …

Bringing Toxicology Into The 21st Century: A Global Call To Action, Troy Seidle, Martin Stephens

Troy Seidle, PhD

Conventional toxicological testing methods are often decades old, costly and low-throughput, with questionable relevance to the human condition. Several of these factors have contributed to a backlog of chemicals that have been inadequately assessed for toxicity. Some authorities have responded to this challenge by implementing large-scale testing programmes. Others have concluded that a paradigm shift in toxicology is warranted. One such call came in 2007 from the United States National Research Council (NRC), which articulated a vision of ‘‘21st century toxicology” based predominantly on non-animal techniques. Potential advantages of such an approach include the capacity to examine a far greater …

A Modular One-Generation Reproduction Study As A Flexible Testing System For Regulatory Safety Assessment, Richard Vogel, Troy Seidle, Horst Spielmann

Troy Seidle, PhD

The European Union’s Registration, Evaluation and Authorisation of Chemicals (REACH) legislation mandates testing and evaluation of approximately 30,000 existing substances within a short period of time, beginning with the most widely used “high production volume” (HPV) chemicals. REACH testing requirements for the roughly 3000 HPV chemicals specify three separate tests for reproductive toxicity: two developmental toxicity studies on different animal species (OECD Test Guideline 414) and a two-generation reproduction toxicity study (OECD TG 416). These studies are highly costly in both economic and animal welfare terms. OECD TG 416 is a fertility study intended to evaluate reproductive performance of animals …

Ideology Masquerading As Science: The Case Of Endocrine Disrupter Screening Programmes, Troy Seidle

Troy Seidle, PhD

The global move to develop novel testing methods and strategies to identify suspected endocrine disrupting chemicals offers a unique opportunity to move away from traditional animal testing paradigms in this new area of regulatory concern. Regrettably, the programmes under development, both in the USA and internationally through the OECD, have thus far failed to consider in vitro and other nonanimal test methods as more than “pre-screening” or “priority-setting” tools in a larger, animal-based testing strategy. Validation efforts to date have focused almost exclusively on the modification of existing animal tests to detect “endocrine effects”, with no demonstrable effort to promote …

Levels Of Citation Of Nonhuman Animal Studies Conducted At A Canadian Research Hospital, Anne Innis Dagg, Troy K. Seidle

Troy Seidle, PhD

The publication of scientific articles that receive few or no citations raises questions of the appropriate use of resources as well as ethics. In the case of animal research, the ethics issue extends beyond human patients to nonhuman animals, as the research subjects them to pain and, typically, to death. This study is a citation analysis of animal research conducted at Toronto's Hospital for Sick Children (HSC). Of the 594 publications (1990 to 1995) on animal research by affiliates of HSC, 29% received Iower than 10 citations in a 10-year period. We compare the research history of 13 "best" and …

Humane Society International’S Global Campaign To End Animal Testing, Troy Seidle

Troy Seidle, PhD

The Research & Toxicology Department of Humane Society International (HSI) operates a multifaceted and science-driven global programme aimed at ending the use of animals in toxicity testing and research. The key strategic objectives include: a) ending cosmetics animal testing worldwide, via the multinational Be Cruelty-Free campaign; b) achieving near-term reductions in animal testing requirements through revision of product sector regulations; and c) advancing humane science by exposing failing animal models of human disease and shifting science funding toward human biology-based research and testing tools fit for the 21st century. HSI was instrumental in ensuring the implementation of the March 2013 …

Determining The Critical Window Of Influence Of Pcb Perinatally On Behavioral And Hormonal Development In Sprague-Dawley Rat Pups, Natalie Sommerville, Lee A. Meserve, Howard C. Cromwell

Honors Projects

Polychlorinated biphenyls (PCB) had widespread use in the United States in commercial manufacturing in the United States until the late 1970s. Even though they were banned, measurable amounts can still be found in the environment and food sources. PCB has known effects on altering hormone development and behavior in the species Rattus norvegicus. To determine the most crucial developmental time of exposure to PCB in Sprague-Dawley rat pups, rat pups were exposed to PCB at differing weeks of either gestation period or the first postnatal week. Behavioral tests were performed for the different rat pups, as well as blood …

Examining The Role Of Dax-1 In Regulation Of Cell Proliferation In Human Breast Cells, Amy E. Scandurra

Master's Theses

DAX-1 is a member of the Nuclear Hormone Receptor superfamily and acts as a transcriptional repressor. DAX-1 plays an important role in the development of adrenal and gonadal tissues. In addition to its role in normal cell development and differentiation, DAX-1 appears to have some influence on the progression of cancer. This work aims to examine the role of DAX-1 in regulation of proliferation in breast cancer. In our study, we have expressed DAX-1 in a DAX-1 deficient breast cancer cell line as well as knocked down DAX-1 expression in normal DAX-1 positive breast cells. Through these experiments, we were …