Three major questions were addressed in this dissertation: 1)Do immune abnormalities associated with autism primarily alter CD4+ T cell-mediated or humoral immune responses? 2) Are specific T cell clones expanded in autism? 3) Which, if any, infectious agents play a role in autism? CD4+ T cell-mediated (Th1) or humoral (Th2) immune responses can be distinguished on the basis of the cytokines expressed. CD4+ T-cells secrete interleukin type 2 (IL-2) and interferon-γ, whereas a Th2 response is associated with secretion of interleukin type 4(IL-4). mRNA extracted from peripheral blood mononuclear nuclear cells (PBMC) showed significantly increased levels of IL-2 and interferon-γ expression in 24 autistic subjects relative to 19 normal controls. IL-4 mRNA was undetectable in the same group of autistic subjects. These results indicate that a CD4+ T cell-mediated immune response is associated with autism. The expression of V-β chain mRNA was used as a marker or particular T cell clone expression. The expression of V-β 13 was significantly elevated in the study group of 11 autistic subjects, but not in 9 normal subjects. This suggests that T cell-mediated autoimmunity is a factor in the disease. Two types of human leukocyte antigens (HLA) alleles, DR4 and DR1, are associated with autism. The association between V-β 13 expressing T cell clones and autism was shown even more strongly in the subgroups expressing HLA DR4 or DR1. This result suggests a link between antigen presentation by HLA DR4 or DR1 and expansion of V-β 13 T cell clones. The potential involvement of pathogens suspected to trigger autism was investigated by examining T cell proliferation responses to peptide epitopes. As a group, the 24 autistic subjects did not show a decreased response to peptides derived from rubella virus, influenza A virus, herpes simplex virus type 1, cytomegalovirus, and Clostridium tetani. Another model of autism postulates that autism is induced by pathogens that possess epitopes identical to the hypervariable region 3 (HVR-3) of the HLA DR4 or DR1 alleles. Two antigens derived from the Escherichia coli dna J protein and the Epstein-Barr virus glycoprotein 110 peptides that contain sequences identical to the HVR-3 of the DR4 and DR1 alleles were examined for their ability to induce T cell proliferation in autistic and normal subjects. No effect of the DR4 or DR1 alleles on the response to these two antigens was detected. Therefore, both types of results do not support the model of immune tolerance in autism. However, average T cell proliferative activity was significantly lower in the same autistic subjects. This confirms many prior reports that reduced T-cell responses may shape susceptibility to autism. Further understanding of how immune abnormalities and infectious agents lead to autism should guide development of preventative and therapeutic strategies for this disease. (152 pages)

Rift Valley Fever is a zoonotic, arthropod-borne disease that adversely affects ungulates and people. The etiologic agent, Rift Valley fever virus (RVFV; Bunyaviridae, Phlebovirus), is primarily transmitted through mosquito bites, yet can be transmitted by exposure to infectious aerosols. Presently, there are no licensed vaccines or therapeutics to prevent or treat severe RVFV infection in humans. We have previously reported on the activity of favipiravir (T-705) against the MP-12 vaccine strain of RVFV and other bunyaviruses in cell culture. Additionally, efficacy has been documented in mouse and hamster models of infection with the related Punta Toro virus. Here, we characterize a hamster RVFV challenge model and use it to evaluate the activity of favipiravir against the highly pathogenic ZH501 strain of the virus. Subcutaneous RVFV challenge resulted in substantial serum and tissue viral loads and caused severe disease and mortality within 2-3 days after infection. Oral favipiravir (200 mg/kg/day) prevented mortality in 60% or greater in hamsters challenged with RVFV when administered within 6 h post-exposure and reduced RVFV titers in serum and tissues relative to the time of treatment initiation. In contrast, although ribavirin (75 mg/kg/day) was effective at protecting animals from the peracute RVFV disease, most ultimately succumbed from a delayed-onset neurologic disease associated with high RVFV burden in the brain observed in moribund animals. When combined, T-705 and ribavirin treatment started 24 h post-infection significantly improved survival outcome and reduced serum and tissue virus titers compared to monotherapy. Our findings demonstrate significant post-RVFV exposure efficacy with favipiravir against both peracute disease and delayed-onset neuroinvasion, and suggest added benefit when combined with ribavirin.

In summary, this study will be focused on Il-21 and its implications in the antibody response in influenza. The isotype classes primarily involved in this process will also be examined. This will be accomplished by looking at the serum of mice and analyzing the present influenza specific antibodies using ELISA. Another goal was to optimize the ELISA in order to make it sensitive enough to catch small differences in the results. This topic is important due to its implications for improving influenza vaccinations and preventions as current vaccines are not 100% effective. Influenza contributes to significant disease and death around the world every year and each piece of this puzzle is significant in order for the scientific community to be able to eventually make strides to improve the burden of this disease.

Magister Scientiae - MSc (Chemistry) / Tuberculosis (TB) is one of the major infectious diseases that affect the health of people all over the world. South Africa is one of the countries that account for most of the TB cases; it is the leading cause of death in South Africa and is known to be lethal when combined with HIV in patients. Various tests have been used to diagnose tuberculosis infected patients, but some of these tests give false positive results. Studies have shown that tuberculosis-related cytokines can serve as biological markers for the diagnosis of TB. Cytokines are signalling proteins secreted by immune cells and one such cytokine is interferon-gamma (IFN-?). Interferon-gamma is secreted by immune cells in response to various pathogens and has many physiological roles in the immune system and inflammatory stimuli. IFN-? was first detected using antibody-based immunosensing techniques but this approach is expensive, time consuming and has low stability, it is therefore vital that an alternative detection method for IFN-? be developed.

Objective: Use of ampicillin in outpatient parenteral antimicrobial therapy (OPAT) has historically been complicated by frequent dosing and limited stability. The purpose of this study was to evaluate stability of ampicillin using high-pressure liquid chromatography (HPLC) in an OPAT dosing model using continuous infusion at room temperature over 24 hours immediately following preparation compared with batches stored under refrigeration for 24 hours, 72 hours, and 7 days. Methods: An HPLC method was developed and validated as stability indicating using guidance in USP general Chapter <1225>. Four ampicillin batches were prepared for each experimental condition (immediate use and refrigerated storage for 24 hours, 72 hours, and 7 days). A pump was used to recirculate the solutions through medical-grade tubing for 24 hours. Triplicate 1-mL aliquots were removed from each batch at time 0, 4, 8, 12, and 24 hours and analyzed for ampicillin concentration. Results: Each batch was assayed for initial concentration (20.34-21.50 mg/mL), and percent recovery compared with that concentration thereafter. For the duration of infusion, the average recoveries were 96.4%, 95.8%, 94.6%, and 90.3% for immediate use, 24-hour storage, 72-hour storage, and 7-day storage, respectively. The recovery remained above 90% for all batches and time points, except for 7-day storage, which fell below 90% after 4 hours of circulation. Conclusion: Ampicillin can be prepared and stored in a refrigerator for up to 72 hours prior to continuously infusing at room temperature over 24 hours with less than a 10% loss of potency over the dosing period. This model supports twice weekly OPAT delivery of ampicillin.

This Diploma Thesis deals with the issue of knowledge of second grade pupils of a selected elementary school regarding selected infectious diseases. The aim of this diploma thesis is to find out to what extent pupils aged 11 - 15 are informed about infectious diseases, their transmission, treatment possibilities, protection against them and to what extent their school participates in such awareness procedures. The theoretical part includes the definition and approximation of basic terms concerning epidemiology, hygiene and microbiology. It provides basic information about infectious diseases, transmission methods, protection against them and their treatment. The practical part analyses and evaluates the data obtained by the questionnaire survey among second grade pupils of the selected elementary school. A total of 186 questionnaires were used to evaluate the results. Indeed, the results confirmed that the pupils' knowledge of infectious diseases is not sufficient for their own health and safety development. Many pupils have misinformation about vaccinations, incubation periods and protection against infectious diseases. I would therefore assume, we need to get closer to the pupils` problems of infectious diseases and to improve knowledge in these areas. Furthermore, it is necessary to strengthen...

The eastern oyster Crassostrea virginica is an ecologically and commercially important species whose natural populations have been devastated by overharvesting, habitat destruction, and disease, but the rapid growth of oyster aquaculture has shown potential to restore the economic significance of this species. A key threat to the growth and sustainability of oyster aquaculture is the association of human-pathogenic Vibrio bacteria with product marketed for raw consumption. Two Vibrio species, Vibrio vulnificus and Vibrio parahaemolyticus, are the causes of the highest rates of seafood consumption-related mortality and gastrointestinal illness, respectively. Identification of the factors influencing V. vulnificus and V. parahaemolyticus prevalence and intensity in oysters is fundamental to better risk management. Within the oyster, these bacterial species interact with the same tissues as the prevalent oyster parasite, Perkinsus marinus, yet little is known about the effect of P. marinus infection on bacterial levels. Answering the fundamental question of whether P. marinus correlates with V. vulnificus and V. parahaemolyticus levels in oysters was the focus of this research. Oysters were deployed in the York River, Gloucester Point, VA, where both Vibrio species and P. marinus are endemic, and were sampled at five time points when levels of both P. marinus and Vibrio spp. were expected to be high in oysters. Abundance of all three organisms and pathogenic strains of V. parahaemolyticus were determined in individual oysters using molecular methods to investigate potential correlations between parasite and bacterial abundance. Additionally, the levels of V. vulnificus and V. parahaemolyticus in relation to histopathology associated with P. marinus infection and other conditions were determined. The following year, manipulation of P. marinus disease progression, which is slowed by lower salinities and favored by higher salinities, was attempted by deploying oysters at two additional sites of different salinities to gain insight into whether the timing of P. marinus infection emergence directly influences Vibrio levels. No correlation was observed between total abundance of P. marinus and either V. vulnificus or V. parahaemolyticus. Manipulation of P. marinus disease progression produced no effect on P. marinus emergence, so this yielded no insight into P. marinus-Vibrio interactions. Histopathological analyses did not reveal any correlations between P. marinus ranking, distribution, or associated tissue damage and Vibrio spp. levels. Though few in number, oysters infected by Haplosporidium nelsoni were characterized by higher levels of V. vulnificus, and oysters of peak gametogenic development had significantly higher levels of pathogenic strains of V. parahaemolyticus. The results with regard to H. nelsoni and gametogenic state warrant further study. The primary conclusion of this study is that oyster health has little influence on levels of human-pathogenic Vibrio species in oysters, inter-host variability in Vibrio levels is likely explained by other factors.

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2-ω-carboxyethylpyrrole (CEP) is a product of docosahexaenoic acid (DHA) oxidation, which forms covalent adducts with different proteins. CEP-modified proteins can interact with macrophage receptor, integrin αDβ2. This study aims to compare αDβ2 binding to its physiological ligand, fibrinogen, and CEP-modified fibrinogen, which is formed during inflammation. We hypothesize that modification of fibrinogen changes its ligand-binding properties to integrin αDβ2 which can affect macrophage migration and retention. Recombinant αD I-domain and αDβ2-transfected HEK293 cells were used for the experiments. Using biolayer interferometry, we found that the affinity of αD I-domain binding to fibrinogen-CEP was higher than fibrinogen and inhibited by the anti-CEP antibody. In agreement, αDβ2-transfected cells demonstrated stronger adhesion to fibrinogen-CEP and this adhesion was significantly inhibited by polyglutamic acid that mimics CEP-mediated binding. These findings suggest that αDβ2's interaction with DHA-modified extracellular matrix (ECM) proteins significantly increases macrophage adhesion and may serve for macrophage retention during chronic inflammation.