Chemicals and Drugs Commons^™

Sex Differences In Mood And Anxiety-Related Outcomes In Response To Adolescent Nicotine Exposure, Tsun Hay Jason Ng

Electronic Thesis and Dissertation Repository

Nicotine dependence is causally linked to increased risk of mood/anxiety disorders in later life. Females are reported to experience a higher prevalence of anxiety/depressive disorders and challenges in smoking cessation therapies, suggesting a potential sex-specific response to nicotine exposure and mood/anxiety disorder risk. However, pre-clinical evidence of sex-specific responses to adolescent nicotine exposure is unclear. Thus, to determine any sex differences in anxiety/depressive-related outcomes, adolescent male and female Sprague Dawley rats received nicotine (0.4 mg/kg; 3x daily) or saline injections for 10 consecutive days, followed by behavioural testing, in-vivo electrophysiology and Western Blot analyses. Our results revealed that adolescent nicotine …

Electrochemical Deposition Of Calcium Phosphate-Based Coatings Onto Porous Ti Using Organic Phosphorus Sources, Clement Lee

Electronic Thesis and Dissertation Repository

The study and commercialization of calcium phosphate (Ca-P) coatings has occurred for several decades. However, this has typically involved the use of hydroxyapatite. This thesis presents the synthesis of different Ca-P-based coatings that has not been studied. Anodic oxidation was employed to create a porous Ti substrate, while pulsed electrochemical deposition was used to deposit the coating onto the Ti. The first coating synthesized was a calcium phosphoserine (Ca-pSer) complex, which contained two different morphologies: a flower-like structure at low deposition time and a unique cubic morphology at higher deposition times. Next, an amorphous calcium phosphate coating was synthesized and …

The Role Of Reactive Oxygen Species In The Accumulation Of Driver Mutations In B Cell Acute Lymphoblastic Leukemia, Mia P. Sams

Electronic Thesis and Dissertation Repository

B cell acute lymphoblastic leukemia (B-ALL) is the most prevalent type of cancer in young children and is associated with recurrent mutations and high levels of reactive oxygen species (ROS). The antioxidant N-acetylcysteine was tested for its ability to prolong lifespan of a mouse model of B-ALL and reduce frequency of mutations. Mice treated with 1g/L of N-acetylcysteine in drinking water were found to have delayed onset of B-ALL at 11 weeks of age and changes in gene expression relating to B cell development, calcium-apoptosis signaling, and pathways in cancer, although no differences in lifespan were observed. Tumours from treated …

Seeing Thro The Musical Eye: Santo Daime, Fuke-Shū, 1960s Psychedelia, And The Antipodes Of Musical Experience, Forest Anthony-Muran

Electronic Thesis and Dissertation Repository

This thesis investigates the relationships between altered states of consciousness and the musical experience in religious tradition and practice. A common accompaniment to religious worship and ceremony, music is often used as a way of attempting to capture something of the ineffable and to help bring about a mystical experience. In this thesis, I make use of three contrasting case studies – the Brazilian syncretic religion Santo Daime, the historical branch of Zen Buddhism Fuke-shū, and the psychedelic rock of 1960s counterculture – to paint a portrait of the variety of ways that music has been used in different musical …

The Role Of Coagulase-Negative Staphylococcal Secreted Products On Staphylococcus Aureus And Staphylococcus Lugdunensis Infections, Denny Chin

Electronic Thesis and Dissertation Repository

The Staphylococcus genus is comprised of over 40 bacterial species. The most well-studied species in this genus is the notorious human pathogen Staphylococcus aureus, a bacterium that produces coagulase among many other virulence factors. Since S. aureus is a major health burden and causes a plethora of diseases in humans, it has received significant attention and much research has been done to understand its biology to treat diseases caused by this pathogen. However, the coagulase-negative staphylococci (CoNS) make up most of the staphylococcal species and have received less attention since they are thought to have a lesser impact on …

Exogenous Surfactant As A Delivery Vehicle For Intrapulmonary Therapeutics, Brandon J. Baer

Electronic Thesis and Dissertation Repository

As an organ system, the lung has unique advantages and disadvantages for direct drug delivery. Its contact with the external environment allows for the airways to be easily accessible to intrapulmonary delivery. However, its complex structure, which divides into more narrow airways with each branch, can make direct delivery to the remote alveoli challenging. The objective of this thesis was to overcome this issue by using exogenous surfactant, a lipoprotein complex used to treat neonatal respiratory distress syndrome, as a carrier for pulmonary therapeutics. It was hypothesized that therapeutics administered with a surfactant vehicle would display enhanced delivery to the …

21°C Is The Emerging Ideal Temperature For Kidney Preservation In The Presence Of Hydrogen Sulfide, Smriti Juriasingani

Electronic Thesis and Dissertation Repository

Kidney transplantation is the treatment of choice for patients with end-stage kidney disease. However, the shortage of transplantable kidneys has led to ever-increasing waiting lists. As a result, kidneys obtained via donation after cardiac death (DCD) are being used more frequently for transplantation. However, they exhibit poorer outcomes due to ischemia-reperfusion injury (IRI) and cold preservation methods, such as static cold storage (SCS). Supplementing cold preservation solutions with hydrogen sulfide donors, such as AP39, has been shown to improve renal IRI and graft outcomes, but the injury associated with cold preservation remains. This thesis evaluates the effect of subnormothermic kidney …

“One Of The Most Elaborate Doping Ploys In Sports History”: The Impact Of The 2016 Russian Doping Scandal On Anti-Doping, Wada And Athletes’ Rights, Mikael J. Gonsalves

Electronic Thesis and Dissertation Repository

This dissertation analyzes the impacts of the 2016 Russian doping scandal from a philosophical and historical perspective. This dissertation’s second chapter, the article entitled (1) “The Brave New World of Athletes’ Rights: A Canadian Perspective on Significant Shifts for the World Anti- Doping Agency” in time for the World Anti-Doping Agency’s (WADA) 20 th anniversary, puts into words the new investigative reality of contemporary anti-doping. It explains a new attitude of anti-doping authorities in response to the ‘game-changing’ Russian manipulation of samples, what has been described as “one of the most elaborate doping ploys in sports history” 1 (Icarus, 2016) …

Trna Regulation In Humans: The Cellular Effect Of A Pathological Hars Y454s Mutation, Rosan Kenana

Electronic Thesis and Dissertation Repository

tRNAs are the adapter molecules involved in translating the genetic code into functional protein in a living cell. tRNAs are charged with their cognate amino acids - by aminoacyl-tRNA synthetases (aaRS or ARS) - which are then transferred to a growing peptide in a process called mRNA translation. The efficiency of translation is dependent on the ratio of ARS enzymes to their cognate tRNAs and the availability of correctly amino acylated tRNAs. Disruptions of this process, caused by mutations in ARS genes, in particular, have been linked to complex inherited diseases. USH3B syndrome, a recessively inherited disorder among consanguineous families …

Evaluating Anesthetic Protocols For Non-Human Primate Functional Neuroimaging, Megha Verma

Electronic Thesis and Dissertation Repository

Functional magnetic resonance imaging (fMRI) is a non-invasive technique that can be used to measure a proxy of neural activity in vivo with high spatial specificity. One subject can be followed for a long period of time to assess changes in functional brain organization. However, fMRI is extremely sensitive to motion. The challenges of training non-human primates to reduce motion in an MRI scanner motivate the study of anesthesia which is commonly used to substitute for this training. In this thesis, I compare three different commonly used anesthetic protocols: isoflurane, propofol-fentanyl in combination, and fentanyl alone, to test which of …

The Effects Of Maternal Delta-9-Tetrahydrocannabinol And Cannabidiol Exposure On Fetal Heart Development In Mice, Gregory Robinson

Electronic Thesis and Dissertation Repository

Up to 22.6% of pregnant women consume cannabis during pregnancy despite the uncertainty of teratogenicity of the main ingredients in cannabis, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). This study tested the hypothesis that gestational THC and CBD exposure leads to heart abnormalities. Daily, oral THC exposure induced heart abnormalities in 68% of offspring with three main phenotypes including thickened semilunar valves, ventricular myocardial hypertrophy and hypoplastic coronary arteries in fetuses, and postnatal cardiac dysfunction. Altered gene expression of key cardiogenic regulators, increased proliferation, and reduced epicardial epithelial-to-mesenchymal-transition were demonstrated implicating potential mechanisms responsible for these abnormalities. Also, maternal CBD exposure resulted …

Deciphering The Ck2-Dependent Phosphoproteome And Its Integration With Regulatory Ptm Networks, Teresa Nunez De Villavicencio Diaz

Electronic Thesis and Dissertation Repository

Protein functions are regulated by the post-translational addition of covalent modifications on certain amino acids. Depending on their distance within the 3-dimensional structure, addition/removal of individual post translational modifications (PTMs) can be impacted by others. This PTM interplay constitutes an essential regulatory mechanism that interconnects the molecular networks in the cell. Protein CK2, a clinically relevant acidophilic Ser/Thr kinase, may be responsible for 10-20% of the human phosphoproteome. Such estimates agree with the number of known substrates, which continues to expand. Furthermore, the demonstration that CK2 participates in hierarchical phosphorylation and has similar sequence determinants to caspases suggest extensive PTM …

Development Of Water-Soluble Polyesters For Tissue Engineering Applications, Trent Gordon

Electronic Thesis and Dissertation Repository

The development of tunable polymers has become increasingly important for both tissue engineering and drug delivery. This thesis investigates the development of water-soluble polyesters that contain both natural and synthetic components. These polymers offer tunable chemical structures, as well as functional groups for the conjugation of crosslinking moieties or cell signaling molecules. The first series of polymers was synthesized from poly(ethylene glycol) (PEG) and aspartic acid (Asp) via a titanium catalyzed transesterification method to provide polymers with molar masses of 12 kg/mol. After deprotection, the pendent functional groups of Asp were reacted with methacrylic, maleic, and itaconic anhydride to introduce …

Analysis Of Oxidatively Damaged Proteins By Mass Spectrometry, Vincent Saullo

Electronic Thesis and Dissertation Repository

As humans age, exposure to oxidative stress may induce protein degradation or aggregation; both resulting in loss of protein function. Protein oxidative damage remains a dominant pathology in many common ailments. To combat these pathologies, scientists must understand the nature of oxidative modifications and their effects on protein structure and dynamics. This work employs a range of mass spectrometry (MS) methods to characterize and analyze the effects of oxidative damage on the model protein myoglobin (Mb). Mb was oxidized using tert-butyl hydroperoxide, and the resulting modifications were characterized by top-down and bottom-up MS workflows. Hydrogen/deuterium exchange MS indicated elevated structural …

Saponin Penetration And Interactions With Membranes, Sarai Guerrero

Electronic Thesis and Dissertation Repository

The saponin QS21 has been used and studied for years as an adjuvant agent to improve vaccines for both humans and animals. However, how the saponin interacts with the membrane and itself remains poorly understood. We studied the QS21-A majority isomer using all-atom classical molecular dynamics simulations in model bilayers composed of cholesterol and either DOPC or DPPC. As this is one of the few computational studies on QS21-A, we had very few resources to compare our results to. Nevertheless, we were able to gain insight into possible configurations that QS21-A takes after penetration, the effect of the bilayer on …

Effect Of Histatin- And Statherin-Derived Engineered Salivary Peptides On Streptococcus Mutans Adhesion And On Enamel Demineralization Provoked By Cariogenic Biofilms, Lina Maria Marin

Electronic Thesis and Dissertation Repository

Dental biofilm is formed onto dental surfaces covered by a layer of specific salivary proteins and peptides named acquired enamel pellicle (AEP). It was previously demonstrated that the statherin- and histatin-derived engineered salivary peptides DR9-DR9 and DR9-RR14 were able to reduce enamel demineralization and displayed antimicrobial activity against Streptococcus mutans, respectively. However, these studies were carried under experimental conditions that did not mimic caries development induced by biofilm and sucrose exposure, the most cariogenic dietary sugar. In this thesis we assessed the effect of the engineered salivary peptides on 1) the adherence of S. mutans to hydroxyapatite (HAp), and …

Maternal Nicotine Exposure Induces Congenital Heart Defects In The Offspring Of Mice, Elizabeth Greco

Electronic Thesis and Dissertation Repository

Congenital heart defects are the most prevalent birth defect, and maternal cigarette smoking is a known risk factor. Nicotine replacement therapies are recommended to pregnant women who smoke to aid in smoking cessation, as this alternative is thought to be much safer compared to cigarette smoking. However, these products contain nicotine, and the safety of nicotine on the developing heart is not well known. In this thesis, a mouse model was used to test the hypothesis that maternal nicotine exposure (MNE) during pregnancy leads to congenital heart defects and coronary artery defects in the offspring of mice. MNE resulted in …

Development Of In Situ Forming Hydrogels For Intra-Articular Drug Delivery, Andy Prince

Electronic Thesis and Dissertation Repository

Hydrogels are 3-dimensional crosslinked polymer networks that can absorb significant amounts of water. The physical properties associated with hydrogels affords them resemblance to biological tissues making them good candidates for biomedical applications. Many pharmaceuticals, specifically non-steroidal anti-inflammatory drugs (NSAIDs), have poor aqueous solubility, which limits their bioavailability and efficacy. People suffering from chronic osteoarthritis (OA) are required to frequently take large doses to mitigate pain, which can lead to serious side effects. Hydrogels are good strategies to deliver NSAIDs via articular injection because they can form solid gels in situ. This thesis describes the synthesis, formulation, mechanical testing, in …

The Mitochondrial Calcium Uniporter Regulator 1 (Mcur1) Matrix Domain Is A Self-Associated Multimer Sensitive To Divalent Cations, Naveed Siddiqui

Electronic Thesis and Dissertation Repository

Mitochondria are primarily appreciated for the generation of adenosine triphosphate (ATP), a chemical store of energy required by all cells. These organelles, however, also play key roles in apoptosis, autophagy and shaping cytosolic calcium (Ca²⁺) signaling via Ca²⁺ uptake into the mitochondrial matrix. This Ca²⁺ uptake is mediated chiefly via the mitochondrial Ca²⁺ uniporter (MCU), an inner mitochondrial membrane protein that oligomerizes to form a Ca²⁺ selective pore. MCU is regulated by several protein binding partners, including the recently identified MCU regulator-1 (MCUR1). MCUR1 stabilizes a higher order MCU heterocomplex through interactions with MCU …

Effects Of G Protein Signalling Modulator 3 On Cellular Signalling, Aneta A. Surmanski

Electronic Thesis and Dissertation Repository

G protein coupled receptors (GPCRs) promote G protein heterotrimer (Gα·GDP/Gbg) activation.GPCRsignalling is limited via G protein GTPase activity and b-arrestin-receptor interactions. G Protein Signalling Modulators (GPSMs) are proteins that may influence receptor signalling through G protein activity. GPSM3 modulates their activity by binding to Ga_i-GDP, limiting nucleotide exchange and preventing its re-association to Gbg. The impact of GPSM3 on signalling is unknown.We hypothesize that GPSM3 will decrease Ga_i-dependent signalling while promoting Gbg-dependent signalling in G_i-coupled GPCRs.

GPSM3 significantly inhibited b-arrestin recruitment to α_2A-adrenergic and m-opioid receptors via a Gbg-dependent mechanism, …

Fabrication And Modification Of Titania Nanotube Arrays For Harvesting Solar Energy And Drug Delivery Applications, Ahmed El Ruby Abdel Rahman Mohamed

Electronic Thesis and Dissertation Repository

The fast diminishing of fossil fuels in the near future, as well as the global warming caused by increasing greenhouse gases have motivated the urgent quest to develop advanced materials as cost-effective photoanodes for solar light harvesting and many other photocatalytic applications. Recently, titania nanotube arrays (TNTAs) fabricated by anodization process has attracted great interest due to their excellent properties such as: high surface area, vertically oriented, highly organized, one-dimensional, nanotubular structure, photoactivity, chemical stability and biocompatibility. This unique combination of excellent properties makes TNTAs an excellent photoanode for solar light harvesting. However, the relatively wide band gap energy of …

Effects Of Prenatal Bisphenol A Exposure On Adrenal Gland Development And Steroidogenic Function, Samantha Medwid

Electronic Thesis and Dissertation Repository

Developmental exposure to bisphenol A (BPA), a ubiquitous endocrine disrupting chemical, is associated with organ dysfunction and diseases in adulthood. However, little is known about its effects on the adrenal glands. Therefore, this thesis addresses this important question using both in vivo and in vitro approaches. BPA at environmentally relevant doses was administrated via diet to pregnant mice from embryonic day 7.5 to birth, following which mice were switched to a standard chow. At two months postnatally, adrenal glands and blood samples were collected from adult mouse offspring for structural and functional analysis. I found that: (a) BPA increased adrenal …

Synthesis And Photophysical Studies Of Pyrrolocytosine Derivatives, Atefeh Rouhi

Electronic Thesis and Dissertation Repository

Pyrrolocytosine (pC) derivatives are used in the study of nucleic acid structure, function and in the design of the hybridization probes. They have unique properties including small size and Watson-Crick base pairing capability and impressive fluorescent properties. However, they exhibit variation in the fluorescence properties upon incorporation into single-stranded DNA and double-stranded DNA.

This study analyzes the effect of the nearest neighbours on the fluorescence properties of phenylpyrrolocytosine (PhpC) and provides a guide to the proper design of the PhpC containing fluorescent probes. Moreover, the possibility of photoinduced electron transfer (PET) as the underlying mechanism of the unusual photophysical behavior …

Electrospun Collagen Nanofibers For Tissue Engineering, Nisha Sharma

Electronic Thesis and Dissertation Repository

Design and fabrication of the scaffold is an important part of the tissue engineering process. Nanofibrous scaffolds based on proteins are gaining increasing acceptance due to its structural similarity to the extracellular matrix. Making use of the electrospinning technique, rat tail collagen type I nanofibers were produced using a collagen in hexafluoroisopropanol (HFIP) solution. In addition to optimizing the electrospinning process parameters, the effect of humidity on fiber morphology and diameter was investigated for fiber size control for particular tissue engineering applications. A generalized humidity effect on polymer fiber diameter of the polymer solution electrospinning process was developed. The as …

Functionalization Of Peptide Nucleic Acids Via Post-Synthetic Click Chemistry, Xiaoxiao Wang

Electronic Thesis and Dissertation Repository

Peptide Nucleic Acid (PNA) has shown great potential in molecular diagnostics, antisense/antigene therapy and nanotechnology. Like other synthetic nucleic acids and artificial analogues, PNA has been extensively modified to achieve better performance in these applications. To efficiently develop PNA probes for molecular diagnosis, this thesis is focused on versatile functionalization of PNA via post-synthetic click chemistry.

Chapter 2 presents the synthesis of quencher-free PNA molecular beacons (MBs) targeting a cystic fibrosis transmembrane conductance regulator (CFTR) sequence mutation. To avoid the tedious synthesis of functionalized PNA monomers for probe development, a simple approach to modify PNA oligomers by post-synthetic on-resin click …

Therapeutic Application Of Carbon Monoxide In Acute Limb Compartment Syndrome, Aurelia Bihari

Electronic Thesis and Dissertation Repository

Acute limb compartment syndrome (CS), a devastating complication of musculoskeletal trauma, develops in response to elevation of the pressure within a closed osseofascial compartment, producing muscle- and limb-threatening ischemia. Full decompression of all involved compartments by fasciotomy is the current gold-standard therapy, but it must be performed within a surgical window of 6-8 hours, before tissue damage becomes permanent.

Carbon monoxide (CO), a byproduct of heme metabolism, has been shown protective in ischemia. While inhalation of CO leads to elevation of carboxyhemoglobin (COHb), recent development of transitional metal carbonyls, CO-releasing molecules (CO-RMs), particularly the water-soluble CORM-3, delivers CO in a …

Producing A Subunit Vaccine For Porcine Epidemic Diarrhea Virus, Zayn Khamis

Electronic Thesis and Dissertation Repository

Porcine epidemic diarrhea virus (PEDv) causes disease and mortality to piglets worldwide. Most vaccines used to combat the disease have been ineffective live attenuated virus vaccines. The goal of this project was to produce a plant-made subunit vaccine based off the membrane protein of the virus. This is the first time this protein has been produced in plants. An elastin-like polypeptide fusion membrane protein accumulated up to 0.8 mg/g of fresh leaf weight when transiently expressed in Nicotiana benthamiana. Virus-like particles were also produced for the first time for PEDv, and were able to form with just the membrane …

Effects Of Prenatal Exposure To Bisphenol A On Fetal Lung Development, Ayten Hijazi

Electronic Thesis and Dissertation Repository

Prenatal exposure to bisphenol A (BPA), one of the most prevalent endocrine disrupting chemicals, is associated with lung dysfunction and diseases in later life. However, it is unknown if this association has a fetal origin. In this thesis, a series of in vivo and in vitro experiments were conducted to determine the effects of prenatal exposure to BPA on fetal lung development, and define the underlying molecular mechanisms. Environmentally relevant doses of BPA were administered to pregnant mice via diet from embryonic day (E) 7.5 to 18.5. Fetal lungs were analyzed at E18.5 for changes in structure and expression of …

Poly(Ester Amide) And Poly(Ethyl Glyoxylate) Nanoparticles For Controlled Drug Release, Amira Mohamed Moustafa

Electronic Thesis and Dissertation Repository

The objective of this research was to develop polymeric nanoparticles (NPs) having improved drug release properties for drug delivery. Poly(ester amide)s (PEAs) are promising biodegradable polymers. PEA NPs were prepared via emulsification-evaporation and salting-out methods and optimized through by varying different processing parameters. Polymer-model drug conjugates based on PEAs containing L-aspartic acid and rhodamine B were synthesized and used for NP preparation. Release behavior was studied and compared to a control system with physically encapsulated rhodamine B. It was shown that the release of rhodamine B from the covalent system did not show the burst effect and exhibited a slower …

Quantifying The Effect Of A Novel Topical Hyaluronic-Acid Phosphatidylethanolamine Cream On The Epidermis, Caitlin J. Symonette

Electronic Thesis and Dissertation Repository

With aging, keratinocytes have diminished proliferative capacity resulting in atrophic skin with reduced barrier function. This investigation evaluates the effect of daily topical applications of a novel high-molecular weight hyaluronan cream (HA-PE) on keratinocyte renewal and epidermal thickness. Unmodified hyaluronan and HA-PE were mixed separately into a vehicle cream. Each topical formulation was applied daily onto the shaved backs of aged female C57BL6 mice. Full-thickness biopsies of treated skin were obtained for analysis of keratinocyte proliferation, keratinocyte differentiation, and local inflammation at days 1, 5, and 10 of cream application. In addition, a cardiac puncture was performed for serum C-reactive …