Biology Commons^™

The Effects Of Selective Estrogenic Drugs In The Medial Amygdala On Male Rat Sexual Behavior, Ejiroghene V. Ogaga-Mgbonyebi

Biology Theses

Male rat copulatory behavior is dependent on Testosterone (T) and its metabolites, estradiol (E2) and dihydrotestosterone (DHT). The estrogen receptor (ER) isoforms, ERα and ERβ, exist in the medial Amygdala (MEA) and either receptor might mediate mating behavior. Therefore, the effects of selective estrogenic MEA implants: propyl pyrazole triol (PPT, ERα agonist), diarylpropionitrile (DPN, ERβ agonist), and 1-methyl-4-phenyl pyridinium (MPP, ERα antagonist) were compared to E2 in maintaining sexual behavior. Four groups of male rats were castrated and administered DHT s.c. and bilateral MEA implants containing either cholesterol, E2, PPT or DPN. An additional group of gonadally intact male rats …

Differential Gene Expression In Bugula Neritina During Symbiotic Association With "Candidatus Endobugula Sertula", Meril Mathew

Biology Theses

The colonial marine bryozoan, Bugula neritina, harbors an uncultured endosymbiont, “Candidatus Endobugula sertula” throughout its life stages. The bacterial symbiont has been proposed to be a source of complex polyketide metabolites, the bryostatins, that chemically defend B. neritina larvae from predation. Within a bryozoan colony, significantly higher amounts of bryostatins are found in ovicell-bearing zooids where the developing larvae are brooded, as compared to ovicell-free zooids. It is hypothesized that signaling between B. neritina and “Ca. Endobugula sertula” may be involved in the regulation of bryostatin production in different zooids, as well as in maintenance of the symbiosis. In this …

Quorum Sensing Inhibitory Activities Of Various Folk-Medicinal Plants And The Thyme-Tetracycline Effect., Maria M. Nagy

Biology Dissertations

Pseudomonas aeruginosa is an opportunistic, nosocomial pathogen for which antibiotic resistance and biofilm development is common. Quorum sensing communication is known to be a major controlling factor in virulence gene expression, biofilm development, antibiotic resistance factors, and specifically MexAB-OprM multi-drug efflux pump expression in P.aeruginosa. MexAB-OprM efflux pumps contribute to antibiotic resistance of tetracycline and other antibiotics in pseudomonads and other organisms. P.aeruginosa infections are problematic in cystic fibrosis and burn patients; it is also the number one causative agent of respiratory infections for intensive care unit patients. Present day antibiotics are losing the battle against these infections. In theory, …

Early Epigenetic Regulation Of The Adaptive Immune Response Gene Ciita, Ninad T. Mehta

Biology Theses

The precise regulation of Major Histocompatibility class II (MHC-II) genes plays an important role in the control of the adaptive immune response. MHC-II genes are expressed constitutively in only a few cell types, but their expression can be induced by the inflammatory response cytokine interferon gamma (INF-γ). The regulation of MHC-II is controlled by a Master Regulator, the class II transactivator (CIITA). Multiple studies have shown that CIITA regulated expression of MHC-II is controlled and induced by INF-γ. It has been also shown that a functional CIITA gene is necessary for the expression of MHC-II genes. CIITA is thus a …

Impact Of Aging On Morphine Analgesia And Associated Changes In Μ-Opioid Receptor Binding And Expression In The Ventrolateral Periaqueductal Gray, Richard L. Hanberry Iv

Biology Theses

Chronic pain in the aged is a widespread phenomenon, and morphine is the most commonly used narcotic analgesic for treatment. Despite that fact, there are relatively few published studies examining the impact of advanced age on morphine analgesia. We hypothesized that aged rats would be less sensitive to morphine than adults, and that aged animals would have reduced mu-opioid receptor (MOR) binding and expression in the ventrolateral periaqueductal gray, a brain region responsible for morphine analgesia. Using a model of persistent inflammatory pain, we found that morphine was significantly less effective in aged males compared to adult males, and that …

Encystment Of Acanthamoeba And Evaluating The Biobus Program, Brandi C. Trevisan

Biology Dissertations

Acanthamoeba are ubiquitous protists that play an environmental role in regulating microbial diversity; they also occasionally cause infections of the eye (Acanthamoeba keratitis) and brain (granulomatous amoebic encephalitis). These organisms exhibit two distinct phenotypes. The trophozoite form dominates in favorable conditions, in which the Acanthamoeba move through the extension of pseudopodia, engulfing microbes and other particles. During stressful conditions, the Acanthamoeba undergo a process of encystment, in which they build a double cell wall and become relatively inactive. The cyst form can survive years until more favorable conditions arise, at which point they may excyst. For this study, multiple laboratory …

Nuclear Pyruvate Kinase M2 Functional Study In Cancer Cells, Xueliang Gao

Biology Dissertations

Cancer cells take more glucose to provide energy and phosphoryl intermediates for cancer progression. Meanwhile, energy-provider function of mitochondria in cancer cells is disrupted. This phenomenon is so-called Warburg effect, which is discovered over eighty years ago. The detail mechanisms for Warburg effect are not well defined. How glycolytic enzymes contribute to cancer progression is not well known. PKM2 is a glycolytic enzyme dominantly localized in the cytosol, catalyzing the production of ATP from PEP. In this study, we discovered that there were more nuclear PKM2 expressed in highly proliferative cancer cells. The nuclear PKM2 levels are correlated with cell …

Subcloning, Expression, And Enzymatic Study Of Prmt5, Ran Guo

Biology Theses

Protein arginine methyltransferases (PRMTs)mediate the transfer of methyl groups to arginine residues in histone and non-histone proteins. PRMT5 is an important member of PRMTs which symmetrically dimethylates arginine 8 in histone H3 (H3R8) and arginine 3 in histone H4 (H4R3). PRMT5 was reported to inhibit some tumor suppressors in leukemia and lymphoma cells and regulate p53 gene, through affecting the promoter of p53. Through methylation of H4R3, PRMT5 can recruit DNA-methyltransferase 3A (DNMT3A) which regulates gene transcription. All the above suggest that PRMT5 has an important function of suppressing cell apoptosis and is a potential anticancer target. Currently, the enzymatic …

Anatomy And Physiology Of The Nucleus Paragigantocellularis: Neural Regulation Of Genital Reflexes In Male And Female Rats, Joseph Jeremy Normandin

Biology Dissertations

The supraspinal control of descending inhibition of genital reflexes (such as ejaculation) is poorly understood but is important in our global comprehension of how neural signals are integrated to produce sexual behavior, and in our understanding of sexual dysfunction. Sexual dysfunctions, such as premature ejaculation/delayed ejaculation in men, and involuntary vaginal spasms, dyspareunia, and anorgasmia in women, are common. An underlying dysregulation of genital reflexes may produce these dysfunctions, especially in those individuals being treated for depression and anxiety with serotonergic drugs. The nucleus paragigantocellularis (nPGi) of the rat medulla has been described as a descending inhibitory system for genital …

Mechanism (S) Of Metal-Induced Apoptosis In Saccharomyces Cerevisiae, Amrita Mohan Nargund

Biology Dissertations

Heavy metals, such as copper and cadmium have been linked to a number of cellular dysfunctions in single and multicellular organisms that are associated with apoptosis. The yeast, Saccharomyces cerevisiae, provides a valuable model for elucidating apoptosis mechanisms, and this study extends that capability to Cu and Cd-induced apoptosis. We demonstrate that S. cerevisiae undergoes a glucose-dependent, programmed cell death in response to low cadmium concentrations, which is initiated within the first hour of Cd exposure. The response was associated with induction of the yeast caspase, Yca1p, and was abolished in YCA1∆ mutant. Other apoptotic markers, including sub-G1 DNA fragmentation …

Synthesis, Structure, Function And Biomedical Studies Of Nucleic Acid Derivatized With Selenium, Lina Lin

Biology Dissertations

Nucleic acids are macromolecules in cells for storing and transferring genetic information. Moreover, nucleic acids, especially RNAs, can fold into well-defined 3D structures and catalyze biochemical reactions. As ubiquitous biological molecules in all living systems, nucleic acids are important drug targets, and they can also be used in diagnostics and therapeutics. Structural information of nucleic acids provides the foundation for DNA and RNA function studies. X-ray crystallography has been a useful tool for structural studies of bio-macromolecules at atomic level. There are two major problems in macromolecular crystal structure determination: phasing and crystallization. Although selenium derivatization is routinely used for …

Development Of A Recombinant Attenuated Salmonella Vaccine System For Taenia Solium Cysticercosis In Pigs, Maria Elizabeth Silva

Biology Dissertations

Taenia solium is a cestode that has a two-hosts life cycle. The adult tapeworm causes an asymptomatic disease known as taeniasis whereas the larval stage causes a disease called cysticercosis. In humans, the most common localization for the larvae is the central nervous system where it produces the neurological disorder neurocysticerco-sis. Previous works by several research groups around the world have shown that T. so-lium is a potentially eradicable parasite. Control programs have included treatment of human and pig populations with antihelmintics in conjunction with health education and are now considering vaccination of naïve piglets. The potential of a live …

Roles Of The Ubiquitin-Proteasome System And Mono-Ubiquitination In Regulating Mhc Class Ii Transcription, Kavita Purnanda Bhat

Biology Dissertations

Major Histocompatibility Complex (MHC) class II molecules are indispensable arms of the im-mune system that present extracellular antigens to CD4+T cells and initiate the adaptive immune response. MHC class II expression requires recruitment of a master regulator, the class II trans-activator (CIITA). How this master transcriptional regulator is recruited, stabilized and degraded is unknown. The 26S proteasome, a master regulator of protein degradation, is a multi-subunit complex composed of a 20S core particle capped on one or both ends by 19S regulatory particles. Previous findings have linked CIITA and MHC class II transcription to the ubiquitin proteasome system (UPS) as …

Roles For Common Mll/Compass Subunits And The 19s Proteasome In Regulating Ciita Piv And Mhc Class Ii Gene Expression And Promoter Methylation, Olivia I. Koues, Ninad T. Mehta, Agnieszka D. Truax, R. Kyle Dudley, Jeanne K. Brooks, Susanna F. Greer

Biology Faculty Publications

Background: Studies indicate that the 19S proteasome contributes to chromatin reorganization, independent of the role the proteasome plays in protein degradation. We have previously shown that components of the 19S proteasome are crucial for regulating inducible histone activation events in mammalian cells. The 19S ATPase Sug1 binds to histone-remodeling enzymes, and in the absence of Sug1, a subset of activating epigenetic modifications including histone H3 acetylation, H3 lysine 4 trimethylation and H3 arginine 17 dimethylation are inhibited at cytokine-inducible major histocompatibilty complex (MHC)-II and class II transactivator (CIITA) promoters, implicating Sug1 in events required to initiate mammalian transcription.

Results: Our …

Tumor-Stromal Interactions Influence Radiation Sensitivity In Epithelial- Versus Mesenchymal-Like Prostate Cancer Cells, Sajni Josson, Starlette Sharp, Shian-Ying Sung, Peter A. S. Johnstone, Ritu Aneja, Ruoxiang Wang, Murali Gururajan, Timothy Turner, Leland W. K. Chung, Clayton Yates

Biology Faculty Publications

HS-27a human bone stromal cells, in 2D or 3D coultures, induced cellular plasticity in human prostate cancer ARCaP_E and ARCaP_M cells in an EMT model. Cocultured ARCaP_E or ARCaP_M cells with HS-27a developed increased colony forming capacity and growth advantage, with ARCaP_E exhibiting the most significant increases in presence of bone or prostate stroma cells. Prostate (Pt-N or Pt-C) or bone (HS-27a) stromal cells induced significant resistance to radiation treatment in ARCaP_E cells compared to ARCaP_M cells. However pretreatment with anti-E-cadherin antibody (SHEP8-7) or anti-alpha v integrin blocking antibody (CNT095) significantly decreased stromal …