Chemicals and Drugs Commons^™

The Role Of Epidermal Stem/Progenitor-Like Cells In Hpv-Mediated Pre-Neoplastic Transformation, Yvon L. Woappi

Theses and Dissertations

The role of epidermal basal stem cells in dysplasia is a matter of great interest in the human papillomavirus (HPV)-driven cancers. To assess the relationship between “stemness” and HPV-mediated transformation, we made use of 3-D suspension culture and fluorescence activated cell sorting (FACS) to purify stem/progenitor-like cells from primary normal human keratinocyte (NHKc) cultures. We found that NHKc cells derived from multicellular keratinocyte spheroids were enriched for a basal subpopulation of epidermal stem-like cells, that could be maintained for prolonged time in culture and used to conduct transfection experiments with full-length HPV16 DNA. Thus, by using these stem cell enrichment …

Deciphering The Interacting Regions And Functions Of The Rad51d-Nono Protein Complex During Dna Damage Response, Latarsha Porcher

Theses and Dissertations

Genomic instability is one of the major components represented in the “Hallmarks of Cancer.” DNA interstrand crosslinks and double-stranded breaks are two of the most severe causes of genomic instability. Homologous recombination (HR) plays a major role in resolving both types of DNA lesions, requiring a homologous template and the RAD51 paralog complex of proteins. One member of this complex is the RAD51D ovarian cancer susceptibility gene product. To better elucidate RAD51D modifications and functions, several protein interaction screens were performed, and one of the novel proteins identified was NONO (a.k.a. p54nrb). Decreased expression of either RAD51D or NONO conferred …

Methcathinone Analogue Activity At The Human Serotonin Transporter, William Drake Varn

Theses and Dissertations

In the last few years, there has been continued concern about synthetic drug abuse in both the United States and worldwide. Small adjustments in drug compound structure often allow synthetic drug makers to manufacture a legal product that can produce the same highs as illegal counterparts. Unfortunately, this is happening faster than the government can outlaw the drug compounds, and a wide variety of synthetics are now appearing on the street. This study evaluated the effects on the human serotonin transporter of six different 4-para substituted methcathinone compounds. Using a Xenopus oocyte model, the efficacy of each MCAT analogue …

The Identification Of The Direct And Indirect Pathways Through Which Leptin Facilitates Synaptic Plasticity In The Hippocampus, Catherine Van Doorn

Theses and Dissertations

Leptin, a peptide synthesized by adipocytes in the periphery, has been shown to play significant roles in feeding and energy expenditure mediated by the hypothalamus. Growing evidence supports the role of leptin in influencing synaptic plasticity in the hippocampus in that leptin dose-dependently enhances LTP, alters morphology and neurogenesis, facilitates spatial learning and memory, as well as memory retention. Models of leptin deficiency and resistance have further supported the importance of leptin in synaptic plasticity by exhibiting deficits in electrophysiological, morphological and behavioral tests that are improved after leptin restoration. The effects of leptin when applied directly into the hippocampus …

Morphogenic Effects Of Dopamine In Cultured Rat Hippocampal Astrocytes, Ashley L. Galloway

Theses and Dissertations

Dopamine is critical for processing of reward and addictive behaviors brought about by drugs of abuse. Scientific investigation of drugs of abuse and their effects on CNS function has traditionally been directed at understanding the role of neurons. However, astrocytes, which constitute approximately half of all human brain cells, play a dynamic role in many essential nervous system functions, including neurotransmission, ion homeostasis, and immune defense. Dopamine effects on astrocytes have been historically understudied, yet research indicates that astrocytes express dopamine receptors and are sensitive to dopaminergic activity. Importantly, astrocytes, comprise a morphologically heterogeneous population of cells, and a distinction …

Differences In Resting-State Functional Connectivity Of Chronic Migraine, With And Without Medication Overuse Headache, And The Effectiveness Of Sphenopalatine Ganglion Block As A Treatment For Repairing Dysfunctional Connectivity., Kaitlin Krebs

Theses and Dissertations

Chronic Migraine (CM) is a debilitating neurological condition that occurs when the migraine frequency progresses to a chronic state of more than 15 headache days per month. The overuse of analgesic medication (MOH) is one of the most prominent risk factor of this chronification and little is known about why it is a cause. The repetitive inhibition of the Sphenopalatine Ganglion is one promising treatment that is used to treat chronic migraine. The purpose of this study is to determine if a specific pattern of disruption is present for chronic migraine, both with and without medication overuse headache, and if …

The Effects Of Curcumin On The Expression Of P53 And Bcl-2 Oncoproteins On The Human Breast Carcinoma Cell Line Mda-Mb 468, Angelin S. Shajan

Theses and Dissertations

We studied the effects of curcumin on the proliferation and viability of MDA-MB-468 breast cancer cells and its effects on the expression ofBcl-2 and p53 proteins in these cells. Based on previous studies, we predicted a dose-dependent increase in p53 (tumor suppressor) expression, and a decrease in Bcl-2 (anti-apoptotic oncoprotein) expression. Briefly, MDA-MB468 cells were seeded into 12-well plates at 2.0 * 104 cells/well and allowed to grow for 72 hrs. Cells were treated with curcumin at 0, 25, 50 and 100 pM in triplicate at time zero and cultured for another 24 hours. All data were obtained using a …

Elucidation Of A Novel Pathway In Staphylococcus Aureus: The Essential Site-Specific Processing Of Ribosomal Protein L27, Erin A. Wall

Theses and Dissertations

Ribosomal protein L27 is a component of the eubacterial large ribosomal subunit that has been shown to play a critical role in substrate stabilization during protein synthesis. This function is mediated by the L27 N-terminus, which protrudes into the peptidyl transferase center where it interacts with both A-site and P-site tRNAs as well as with 23S rRNA. We observed that L27 in S. aureus and other Firmicutes is encoded with a short N-terminal extension that is not present in most Gram-negative organisms, and is absent from mature ribosomes. The extension contains a conserved cleavage motif; nine N-terminal amino acids are …

Dual Pi3k/Mtor Inhibition With Bez235 Augments The Therapeutic Efficacy Of Doxorubicin In Cancer Without Influencing Cardiac Function, David E. Durrant

Theses and Dissertations

Cancer continues to be a leading cause death in the United States despite improved treatments. Cancerous lesions form after acquiring oncogenic driver mutations or losing tumor suppressor function in normal cells. Traditional therapies have included use of genotoxic substances that take advantage of the increased growth rate and loss of tumor suppressor function to cause cell death. One such drug is the anthracycline antibiotic doxorubicin (DOX). DOX interchelates into DNA and disrupts transcriptional machinery while also poisoning topoisomerase II. This results in single and double stranded DNA breaks, which if severe enough leads to either necrotic or apoptotic cell death. …

Xlf-Dependent Nonhomologous End Joining Of Complex Dna Double-Strand Breaks With Proximal Thymine Glycol And Screening For Xrcc4-Xlf Interaction Inhibitors, Mohammed Al Mohaini

Theses and Dissertations

DNA double-strand breaks induced by ionizing radiation are often accompanied by ancillary oxidative base damage that may prevent or delay their repair. In order to better define the features that make some DSBs repair-resistant, XLF-dependent nonhomologous end joining of blunt-ended DSB substrates having the oxidatively modified nonplanar base thymine glycol (Tg) at the first (Tg1) , second (Tg2), third (Tg3) or fifth (Tg5) positions from one 3’ terminus was examined in human whole-cell extracts. Tg at the third position had little effect on end-joining even when present on both ends of the break. However, Tg as the terminal or penultimate …

Development Of Non-Traditional Platinum Anticancer Agents: Trans-Platinum Planar Amine Compounds And Polynuclear Platinum Compounds, Daniel E. Lee

Theses and Dissertations

Development of Non-Traditional Platinum Anticancer Agents: trans-Platinum Planar Amine Compounds and Polynuclear Platinum Compounds

By Daniel E. Lee, Ph.D.

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University.

Virginia Commonwealth University, 2015

Major Director: Nicholas P Farrell, Ph.D., Professor, Department of Chemistry

Platinum anticancer compounds with cis geometry, similar to cisplatin, have been explored to circumvent the cisplatin resistance; however, they were not considered broadly active in cisplatin cells due to exhibiting similar or same cell death mechanism as cisplatin. Platinum compounds with trans geometry were less studied …

Characterization Of A Novel Protease In Staphylococcus Aureus, Adam L. Johnson

Theses and Dissertations

A newly discovered cysteine protease, Prp, has been shown to perform an essential, site-specific cleavage of ribosomal protein L27 in Staphylococcus aureus. In Firmicutes and related bacteria, ribosomal protein L27 is encoded with a conserved N-terminal extension that must be removed to expose residues critical for ribosome function. Uncleavable and pre-cleaved variants were unable to complement an L27 deletion in S. aureus, indicating that this N-terminal processing event is essential and likely plays an important regulatory role. The gene encoding the responsible protease (prp) has been shown to be essential, and is found in all organisms …

Chronic Behavioral And Cognitive Deficits In A Rat Survival Model Of Organophosphate Toxicity, Beverly Huang

Theses and Dissertations

Organophosphates (OPs) are a major class of pesticides and nerve agents that elicit acute toxicity by inhibiting acetylcholinesterase (AChE), the enzyme responsible for the degradation of the neurotransmitter acetylcholine in the central and peripheral nervous systems. Acetylcholine accumulation following extensive AChE inhibition leads to an acute cholinergic syndrome characterized by autonomic dysfunction, involuntary movements, muscle fasciculations, respiratory distress, and seizures. Despite their classification as moderate to highly toxic, OP pesticides are the most widely used class of insecticides in the U.S., and are even more commonly used worldwide. Additionally, there is a growing concern that OP nerve agents could be …

Characterization Of Stard4 And Stard6 Proteins In Human Ovarian Tissue And Human Granulosa Cells And Cloning Of Human Stard4 Transcripts, Aisha Shaaban

Theses and Dissertations

Progesterone is essential hormone for pregnancy, which is produced by the human corpus luteum in early pregnancy until the placenta assumes this function. Transport of the cholesterol from the outer to the inner mitochondrial membrane is the rate limiting step for the de novo synthesis of pregnenolone (the precursor to progesterone), a process mediated by STARD1. STARD1 contains a C-terminal lipid binding domain which binds cholesterol and an N-terminal domain targeting STARD1 to the mitochondrial membrane. Unlike STARD1, STARD4 and STARD6 proteins lack a mitochondrial targeting sequence; however, they can bind cholesterol and increase steroidogenesis in model systems. In this …

Effects Of Nicotinic Acetylcholine Receptor Agonists In Assays Of Pain-Stimulated And Pain-Depressed Behavior In Rats, Kelen Freitas

Theses and Dissertations

Though a host of analgesics have been developed to alleviate pain, especially acute pain, significant side effects and a lack of long-term efficacy have encouraged research attempts to pursue novel targets that may be associated with fewer side effects or a more sustained efficacy. Among these new targets are members of the nicotinic family of acetylcholine receptors (nAChRs). The non-selective nAChR agonists nicotine and epibatidine have been shown to function as potent antinociceptive drugs in many acute and chronic preclinical pain models, while nicotine has produced analgesic effects in humans. However, these non-selective nAChRs agonists also produce various side effects, …

Biginelli Synthesis And Characterization Of Potentially Anti-Proliferative Dihydropyrimidinone Thione Analogs, Timothy K. Summers

Theses and Dissertations

No abstract provided.

Hydropathic Interactions And Protein Structure: Utilizing The Hint Force Field In Structure Prediction And Protein‐Protein Docking., Mostafa H. Ahmed

Theses and Dissertations

Protein structure predication is a field of computational molecular modeling with an enormous potential for improvement. Side-chain geometry prediction is a critical component of this process that is crucial for computational protein structure predication as well as crystallographers in refining experimentally determined protein crystal structures. The cornerstone of side-chain geometry prediction are side-chain rotamer libraries, usually obtained through exhaustive statistical analysis of existing protein structures. Little is known, however, about the driving forces leading to the preference or suitability of one rotamer over another. Construction of 3D hydropathic interaction maps for nearly 30,000 tyrosines extracted from the PDB reveals their …

Modified Seed Growth Of Iron Oxide Nanoparticles In Benzyl Alcohol: Magnetic Nanoparticles For Radio Frequency Hyperthermia Treatment Of Cancer, Stanley E. Gilliland Iii

Theses and Dissertations

Iron oxide nanoparticles have received sustained interest for biomedical applications as synthetic approaches are continually developed for precise control of nanoparticle properties. This thesis presents an investigation of parameters in the benzyl alcohol synthesis of iron oxide nanoparticles. A modified seed growth method was designed for obtaining optimal nanoparticle properties for magnetic fluid hyperthermia. With a one or two addition process, iron oxide nanoparticles were produced with crystallite sizes ranging from 5-20 nm using only benzyl alcohol and iron precursor. The effects of reaction environment, temperature, concentration, and modified seed growth parameters were investigated to obtain precise control over properties …

Characterization Of Bioreducible Poly(B-Amino Ester) Nanoparticles For Sirna Delivery, Bolivia Hurtado De Mendoza

Theses and Dissertations

Glioblastoma multiforme (GBM) is one of the most malignant brain tumors affecting adults. It is characterized by necrotic tissue and abnormal vasculature, making it highly resistant to current cancer treatments. A promising alternative to standard cancer therapeutics is the use of drug delivery systems such as polymeric nanoparticles (NP) that deliver silencing RNA (siRNA) exclusively to tumor cells for gene knockdown. Presently, nonviral delivery vectors, such as poly(B-amino ester) (PBAE) NP, are beneficial delivery systems because they are less immunogenic and easier to chemically modify than vectors delivered by viruses. Although current formulations of PBAEs allow cargo release via hydrolytic …

Role Of Microrna-155 In A Mouse Model Of Colon Cancer., Claire Mitchell Midyette

Theses and Dissertations

Colorectal cancer remains the third most common malignancy and the fourth most common cause of cancer mortality worldwide. Dysregulated miRNA levels are associated with several types of malignancies and may serve as important biomarkers and/or therapeutic targets in colorectal cancer. We examined the role of miRNA-155 on tumorigenesis and associated symptoms using a well-characterized mouse model of colorectal cancer. C57BL/6 wild-type mice and miRNA-155-/- mice (n=7-13 group) were given a single injection of AOM (10mg/Kg) followed by 3 cycles of DSS (2% in the water for 1 week followed by 2 weeks of plain water). A C57BL/6 wild-type group that …

The Anti-Angiogenic Effects Of Sparstolonin B, Henry Rhodes Bateman

Theses and Dissertations

Sparstolonin B (SsnB) is a novel bioreactive compound isolated from Sparganium stoloniferum, an herb historically used in Traditional Chinese Medicine as an anti-tumor agent. SsnB has demonstrated anti-inflammatory properties, inhibiting Toll-like receptor mediated inflammation in isolated macrophages and in mice. Angiogenesis, the process of new capillary formation from existing blood vessels, is dysregulated in many pathological disorders, including atherosclerosis, diabetic retinopathy, and tumor growth. The goal of the project was to investigate the anti-angiogenic effects of SsnB.

The first part of the project utilized in vitro functional assays to study how SsnB affected endothelial cells. SsnB inhibited endothelial cell tube …

High Fat Diet Induced Obesity In A Mouse Model For Colorectal Cancer, Kennerly Clinton Patrick

Theses and Dissertations

Obesity is widely correlated with the incidence of colorectal cancer (CRC). The exact mechanisms that link obesity to CRC risk have not yet been fully established, and only a limited number of animal models are available to study pathways involved in obesity-related colon carcinogenesis. The objective of this study was to determine the influence of HFD-induced obesity on AOM/DSS-mediated colorectal tumorigenesis, tumor proliferation, and symptom severity. Male C57BL/6 mice were fed a novel high fat diet, designed to mimic the standard American diet (12 % saturated fat & 28 % unsaturated fat), at 4 weeks of age until 16 weeks …

Development Of Proteomic Characterization And Speciation Techniques Utilizing Tryptic Peptides With Maldi-Tof Ms And Lc-Esi Ms-Ms, Jennifer Marie Kooken

Theses and Dissertations

The characterization of microbes which can be opportunists and pathogens (e.g., methicillin resistant Staphylococcus aureus (MRSA)) is important in understanding and potentially treating diseases caused by various bacterial species. Common genera found in the human skin micro-biome include Micrococcus and Staphylococcus, but there only a limited number of tests to differentiate these genera and/or species. My research reflects methods development from distinguishing one closely related genera from another and then expanded to species identification. Tryptic peptides were analyzed by MALDI TOF MS and the mass profiles compared with those of a reference strain in both genus and species identification. Aconitate …

Impact Of Physical Activity In The Prevention Of Colorectal Cancer, Sarah Ashley Barnes

Theses and Dissertations

This review evaluates the current understanding of research on the impact of physical activity in the prevention of colorectal cancer. Current biological mechanisms implicated in physical activity and colorectal cancer risk reduction are blood glucose regulation, insulin sensitivity, leptin and adiponectin profiles, inflammation as well as secreted protein acidic and rich in cysteine (SPARC), an exercise induced myokine. Recent literature indicates that 30-60 minutes of moderate to vigorous activity a day is effective against colorectal cancer development, and there is convincing evidence of aerobic exercise as differently beneficial in recruiting mechanisms identified as preventative against colorectal cancer. This article provides …

Linking Obesity To Colorectal Cancer: Recent Insights Into Plausible Biological Mechanisms, Catherine Guffey

Theses and Dissertations

Obesity has emerged as a leading environmental risk factor for the development of CRC. However, the mechanisms underlying this relationship have not yet been fully explained. Recent literature has focused on 1) inflammatory processes, 2) adipokines, and 3) estrogen. Obesity-enhanced inflammation is largely orchestrated by increases in adipose tissue macrophages leading to the secretion of TNF-alpha, MCP-1, and IL-6, all of which are linked to CRC. Adiponectin is decreased with obesity and has been reported to be negatively associated with CRC, while leptin, which is increased, is positively associated with the disease. Estrogen has been shown to influence CRC, although …

Resveratrol Attenuates The Development Of Trans-Aortic Constriction (Tac) Induced Heart Failure In Mice, Prakash Kumar Gupta

Theses and Dissertations

Heart failure (HF) still remains the leading cause of morbidity and mortality and imposes severe global affliction and enormous cost on the healthcare system. Although current pharmacological therapies have shown to slow down the progression of HF, but seems to have reached their limits in improving overall patient prognosis. Thus, an immediate call for novel alternate therapies are needed which act independently as well as in conjunction with current treatment modality. Studies were performed in the well-established transverse aortic constriction (TAC) model of chronic pressure overload (PO) in mice. In the first series of studies, Male C57BL6 mice (26-28 g) …

Mass Spectrometry And Tandem Mass Spectrometry Characterization Of Protein Patterns, Protein Markers And Whole Proteomes For Pathogenic Bacteria, Jennifer Intelicato-Young

Theses and Dissertations

There have been many recent reviews published on MALDI-TOF MS (matrix assisted laser desorption/ionization time-of-flight) MS (mass spectrometry) for identification of bacteria particularly with relevance to clinical microbiology. MALDI-TOF MS is now a mature technique for bacterial identification with great promise. The purpose of this review is to put into perspective MALDI-TOF MS and other widely used mass spectrometry methods for characterization of proteins. MALDI-TOF MS is used for rapid determination of a mass pattern of proteins for bacterial characterization; these proteins

are generally not identified. Alternatively, after gel separation, MALDI TOF-TOF MSMS (tandem mass spectrometry) or on-line LC-ESI MS-MS …

Role Of Pyridoxine 5'-Phosphate Oxidase In Metabolism And Transfer Of Pyridoxal 5'-Phosphate, Sayali Karve

Theses and Dissertations

Deficiency of vitamin B6 due to mutations in key B6 metabolizing enzymes is suspected to contribute to several pathologies. Vitamin B6 in its active form, pyridoxal 5’-phosphate (PLP) is a cofactor for over 140 known B6 requiring (or PLP-dependent) enzymes, that serve vital roles in many biochemical reactions. There are three primary vitamin B6 forms, pyridoxine (PN), pyridoxamine (PM) and pyridoxal (PL) which are phosphorylated to pyridoxine 5’-phosphate (PNP), pyridoxamine 5’-phosphate (PMP) and PLP respectively. Pyridoxal kinase (PLK) and pyridoxine 5’-phosphate oxidase (PNPO) are the key enzymes involved in both salvage and de novo pathways of PLP biosynthesis. Mutations in …

Pyridoxal Kinase: Its Role In Vitamin B6 Metabolism, Jigarkumar Desai

Theses and Dissertations

Pyridoxal kinase (PL kinase) and pyridoxine 5’-phosphate oxidase (PNP oxidase) are the two vitamin B6 salvage enzymes involved in metabolism of the primary inactive vitamin B6 (pyridoxal, pyridoxine and pyridoxamine) into the active cofactor form, pyridoxal 5’-phosphate (PLP). PLP, arguably the most important vitamin, is required by numerous vitamin B6 (PLP-dependent) enzymes as a co-factor. These enzymes serve vital roles in the metabolism of glucose, lipids, amino acids, heme, DNA/RNA and many neurotransmitters. High levels of vitamin B6 are linked to neurotoxicity, due to the non-specific interactions of PLP with non-B6 proteins. This problem is controlled, in part, by maintaining …

Vitamin B6 Metabolism And Regulation Of Pyridoxal Kinase, Amit Gandhi

Theses and Dissertations

Pyridoxal 5'-phosphate (PLP) is the cofactor for over 140 vitamin B6 (PLP)-dependent enzymes that are involved in various metabolic and biosynthetic pathways. Pyridoxal kinase (PL kinase) and pyridoxine 5’-phosphate oxidase (PNP oxidase) are the two key enzymes that metabolize nutritional forms of vitamin B6, including pyridoxal (PL), pyridoxine (PN), and pyridoxamine (PM) to the active cofactor form, PLP. Disruption of the PLP metabolic pathway due to mutations in PNP oxidase or PL kinase result in PLP deficiency, which is implicated in several neurological pathologies. Several ingested compounds are also known to result in PLP deficiency with concomitant neurotoxic effects. How …