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The prostate is a male accessory sex gland that functions to produce many components of the seminal fluid including zinc and citrate, both of which are crucial to men fertility. The prostate gland has two main compartments: the stroma and the epithelium. Three cell types comprise the prostatic epithelium: secretory epithelial cells, basal/stem cells, and neuroendocrine cells. The prostatic epithelium is unique in that they are the only healthy human cells that produce energy by glycolysis rather than the Krebs cycle. Changes in the prostatic epithelium leading to malignant proliferation increase in incidence with age. Prostate carcinoma (PCa) is the leading malignancy and the second leading cause of cancer-associated deaths in the USA male population. PCa is a disease of the elderly and risk prediction becomes crucial. Most patients present low-risk, relatively indolent tumors; however, 20-30% of these men present tumor characteristics associated with high-risk PCa. High Grade Prostatic intraepithelial neoplasia (HGPIN) is the only widely accepted histological condition and precursor of invasive PCa. High glycolytic activity is an oncometabolic hallmark of cancer. Cancer cells turn to aerobic glycolysis for energy production in a process referred to as ‘the Warburg effect’ leading to accumulation of methylglyoxal (MG), a cytotoxic glycolytic byproduct responsible for the adduction of macromolecules, a process called advanced glycation end-products (AGEs) formation. Glyoxalase 1 (GLO1), also known as lactoylglutathione lyase (EC: 4.4.1.5), is part of the glyoxalase system, playing a crucial role in cellular detoxification of spontaneously formed MG. In a two-step reaction, GLO1 first catalyzes the conversion of highly reactive MG to S-D-lactoylgluthatione. The resulting thioester, in the case of MG, is then hydrolyzed by GLO2 to produce D-lactate and reformed glutathione (GSH). The cytoprotective glyoxalase system prevents formation of AGEs and promotes cell survival

Apicomplexan parasites cause severe disease in both humans and their domesticated animals. Since these parasites readily develop drug resistance, development of new, effective drugs to treat infection caused by these parasites is an ongoing challenge for the medical and veterinary communities. We hypothesized that invertebrate-bacterial symbioses might be a rich source of anti-apicomplexan compounds because invertebrates are susceptible to infections with gregarines, parasites that are ancestral to all apicomplexans. We chose to explore the therapeutic potential of shipworm symbiotic bacteria as they are bona fide symbionts, are easily grown in axenic culture and have genomes rich in secondary metabolite loci [1,2]. Two strains of the shipworm symbiotic bacterium, Teredinibacter turnerae, were screened for activity against Toxoplasma gondii and one strain, T7901, exhibited activity against intracellular stages of the parasite. Bioassay-guided fractionation identified tartrolon E (trtE) as the source of the activity. TrtE has an EC50 of 3 nM against T. gondii, acts directly on the parasite itself and kills the parasites after two hours of treatment. TrtE exhibits nanomolar to picomolar level activity against Cryptosporidium, Plasmodium, Babesia, Theileria, and Sarcocystis; parasites representing all branches of the apicomplexan phylogenetic tree. The compound also proved effective against Cryptosporidium parvum infection in neonatal mice, indicating that trtE may be a potential lead compound for preclinical development. Identification of a promising new compound after such limited screening strongly encourages further mining of invertebrate symbionts for new anti-parasitic therapeutics.

Enteropathogenic Escherichia coli (EPEC) is a Gram-negative bacteria responsible for significant morbidity and mortality in young children. EPEC elaborates a type III secretion system (T3SS), which translocates bacterial effector proteins into the host intestinal epithelial cell. To this date, 23 effector proteins are known to be secreted by EPEC. Over the past two decades, traditional studies uncovered the functions of some of these effector proteins. While there was an initial rise in the EPEC effector function discoveries, we now observe a plateau in the identification of host-EPEC interactions. Thus, the aim of my dissertation is to define novel virulence strategies in EPEC pathogenesis, and to demonstrate how traditional reductionist and global systems biology approaches can be utilized in uncovering functions of individual effectors, as well as the complex interplay of effectors in modulating host functions. Specifically, we defined the novel cytoprotective function of a T3SS effector EspZ. We further illustrated the complex interplay of EPEC effectors by defining how EPEC utilizes EspZ and EspF to dynamically regulate the prosurvival epidermal growth factor receptor signaling pathway. Finally, by integrating comparative proteomics and traditional reductionist approaches, we identified a novel function for EspH, and defined the mechanism by which EspH perturbs epithelial cell structure and function.

Taura syndrome (TS) is one of the most devastating diseases affecting the shrimp farming industry worldwide. The causative virus, Taura syndrome virus (TSV), has been identified. My work is centred on the development of monoclonal antibodies against TSV. I have also characterized a novel variant of the virus from Venezuela and evaluated the effect of hyperthermia on TSV infection. This work has resulted in 3 manuscripts, which constitute the core of this dissertation. The taxonomy throughout this dissertation is done according to Holthuis (1980).The first manuscript describes the production of a monoclonal antibody reacting with the Belize strain of TSV. The antibody, MAb 2C4, exhibits good sensitivity and specificity for TSV in immunohistochemistry (IHC) and dot blot immunoassay. MAb 2C4 reacted with the TSV-HI94, TSV-SI98 and TSV-BZ02 variants, but not with the TSV-VE05 and TSV-TH05 variants. This antibody adds and improves tools to those available for TSV diagnosis.Chapter three describes a relatively novel variant of TSV from Venezuela, which was characterized by our laboratory. By genetic sequencing, this new isolate exhibits a 94% similarity with TSV-HI94. IHC, dot blot immunoassay and bioassays were also performed. While processed samples reacted only weakly with the TSV monoclonal antibody MAb 1A1, the virus in its native state reacted strongly with the antibody. In bioassays, TSV-VE05 presented mortality comparable to TSV-HI94 in Penaeus vannamei. These data confirm the presence of TSV in Venezuela and that a new variant of the virus was responsible for the outbreak of TS.In chapter four, the behavior of TSV infection under hyperthermic conditions was examined. I compared the susceptibility of Kona stock P. vannamei to the infection by two variants of TSV under hyperthermic conditions (32oC). Shrimp, infected with TSV-HI94, were resistant to infection at high temperature. However, under the same hyperthermic conditions, the challenged shrimp were fully susc

Clinical signs and lesions of Taura syndrome virus (TSV) infection in Penaeus monodon were investigated by histological and in situ hybridization (ISH) analyses. Mortality among P. monodon inoculated with 2 genotypic variants of TSV (Th04Pm and Th04Lv) appeared on Day 3, with 2 out of 10 shrimp dying. Severe necrosis of cuticular epithelial cells and lymphoid organ spheroids, indicative of acute and chronic phase lesions of TSV infection, respectively, were detected in the samples. Both Th04Pm and Th04Lv belonged to a phylogenetic family of Asian TSV isolates. The results demonstrate that both mortality and histological lesions are associated with TSV infection in P. monodon.Infection with 4 genotypic variants of TSV (Bz01, Th04, UsHi94, and Ve05) in TSV-resistant (TSR) and TSV-susceptible (Kona) Litopenaeus vannamei was investigated. Survival probabilities of TSR shrimp were higher than those for Kona shrimp with all 4 variants. Th04, UsHi94, and Ve05 gave no Taura syndrome lesions with TSR shrimp. In contrast, TSR shrimp challenged with Bz01 and Kona shrimp with all 4 TSV variants exhibited severe necrosis of cuticular epithelial cells and lymphoid organ spheroids. Real-time reverse transcription polymerase chain reaction (RT-PCR) revealed that mean TSV copy numbers in TSR shrimp infected with Bz01, Th04, and UsHi94 were significantly (p < 0.0005) lower than those in Kona shrimp. In contrast, mean TSV copy numbers in TSR and Kona shrimp infected with Ve05 were not significantly different (p > 0.4). The results show that TSR L. vannamei are susceptible to infection but give high survival rates following challenge by all 4 variants of TSV.To identify the viral replication site within shrimp infected cells, the viral RNA was located in association with virus-induced membrane rearrangement by electron microscopic ISH. Ultrastructure in the infected cells, analyzed by transmission electron microscopy, included the induction and proliferation of intracellular vesicle-li

Background: Anomia is often demonstrated by individuals who sustain damage to the left inferior temporal lobe. The nature of the anomia in individuals with damage to anterior regions of the left temporal lobe (BA 38, 21, 20) has been associated with degradation to semantic knowledge (semantic anomia), while damage to regions farther posterior (BA 37) has been associated with disconnection between preserved semantic knowledge and access to phonological word forms (pure anomia). However, evidence of semantic anomia often comes from individuals with cortical damage that extends beyond left temporal regions, so that it remains unclear whether unilateral damage to this area will result in semantic degradation. Aims: The aim of this study was to examine naming performance in individuals with focal damage to anterior versus posterior regions of the left inferior temporal lobe to determine whether there is a difference in the nature of the observed anomia. Methods: Eight individuals who underwent left anterior temporal lobectomy (L ATL) and eight individuals who sustained left posterior cerebral artery infarcts (L PCA) completed a battery of language measures that assessed lexical retrieval and semantic processing. Sixteen age-and-education matched controls also completed this battery. High resolution structural brain scans were collected for each individual who sustained brain damage. Performance on behavioral measures was examined relative to lesion size and location using statistical analyses. Results: Naming performance ranged from severely impaired to unimpaired in both groups of brain damaged individuals. Both the L ATL and L PCA groups demonstrated well preserved semantic knowledge during lexical retrieval tasks and assessments of semantic knowledge. Naming performance was correlated with lesion volume. Furthermore, a relationship between percent damage to inferior temporal regions, BAs 20 and 21, and naming performance was observed. Conclusion: The behavioral and ne