In this study the basal expression of Tis 11 family and their regulation in B-CLL cells in response to stimuli that induce apoptosis (crosslinked Rituximab, XRituximab) or stimuli that inhibit spontatieous apoptosis' (IL-4, CD40, CD40+IL-4, PMA) was tested. Tis 11 family bind to AU Rich Elements (AREs) in the 3' Untranslated Region (3'UTR) and induce degradation of mRNAs bearing these target sequences. The Tis 11 family consists of Tis 11, 'Tis 11 b and Tis 11 d which induce apoptosis when overexpressed in a variety of human cell lines (epithelial, osteosarcoma and fibroblasts). It was found that Tis 11 mRNA is strongly expressed in unstimulated B-CLL cells, when compared to Tis 11 b mRNA levels, and was downregulated following stimulation with IL-4 or anti-CD40 at 3 hours post stimulation but remained unaffected by all other stimuli. Tis1l b mRNA was found to be minimally expressed in unstimulated B-CLL cells and was strongly induced following XRituximab, PMA and anti-CD40 treatment in all patients tested but remained unchanged by IL-4 or anti-CD40+IL-4. Finally Tislid was found to be strongly expressed in unstimulated B-CLL cells and was weakly induced by XRituximab and PMA in some but not all patients tested and showed no change after IL-4, anti-CD40 or anti-CD40+IL-4 stimulation. Additionally it was found that when Tis 11 b is induced by XRituximab it is primarily regulated through p38 and to lesser extend through JNK pathway since inhibition of these pathways abrogated induction of the Tis 11 b mRNA and protein. On the contrary when Tis 11b was induced by PMA or anti-CD40 it was found to be regulated through NF-KB pathway since inhibition of this pathway resulted in complete abrogation of Tis11 b mRNA induction following PMA or anti-CD40 stimulation. In order to determine the function that Tis 11 b is involved in reponse to XRituximab and PMA or anti-CD40 treatment, Tisllb siRNA technology was utilised which revealed that inhibition of Tis 11 b significantly reduced (by 50-70%) the efficiency of XRituximab in inducing apoptosis in CLL cells while when Tis 11 b siRNA was applied in PMA or anti-CD40 stimulated CLL cells it significantly reduced their ability to induce plasma cell differentiation in these cells. Thus Tis 11 b is involved in induction of apoptosis following Rituximab treatment in CLL cells and also it is involved in induction of differentiation of CLL cells when such a stimulus (eg: anti-CD40) is present. Finally it was found that Tis 11 bIBerg36 is probably involved in B cell differentiation in general, since it was found that it has different basal expression and regulation at different stages of B cell differentiation represented by Nalm6 (pre-B cells), Ramos (Germinal Centre B cells), AGLeL and WILeL (memory B cells) and RPMI8226 and MM1.S (plasma cells) cell lines. Indeed it was found that Multiple Myeloma cell lines have undetectable levels of Tis 11 bIBerg36 mRNA and neither PMA nor anti-eD40 could induce Tis 11 b in plasma cells even though these stimuli could modify expression of this gene in all other stages of differentiation. Thus Tis 11 family especially Tis 11 b and Tis 11 may have an important role in the pathogenesis or progression of eLL (and possibly of B cell malignancies in general) and necessitate further investigation.

No description available.

Bacterial resistance to antibiotics has presented increasing challenges in healthcare and the management of infection. This has resulted in alternative and traditional products that are used in other cultures being considered as an alternative to topical antibiotics. Honey, particularly Manuka honey is a product which has gained credibility as an antibacterial agent in a healthcare environment. The aim of this study was to investigate the antimicrobial capacity of syrups and honeys from different floral sources on antibiotic sensitive and resistant bacteria isolated from a clinical environment. The antimicrobial activity of seven Manuka honeys, seven honeys from other floral sources and two syrups were assayed against antibiotic sensitive and resistant isolates of 'Staphylococcus aureus', 'Enterococcus species', 'Escherichia coli' and 'Pseudomonas aeruginosa' using agar diffusion and microbroth methods to determine minimum inhibitory concentrations. These assays demonstrated both the superior antimicrobial activity of the Manuka products and highlighted differences in susceptibility between sensitive and resistant strains within organism groups. Clinical grade Manuka honeys were used to study the effect of bioload on antimicrobial efficacy on isolates from clinical polymicrobial wound populations. This demonstrated that it was the direct physical contact with the organism and not the microbial bioload which influences antimicrobial efficacy. Bacteria may form biofilms when they come into contact with an adherent surface. Organisms in biofilms have greater resistance to antimicrobials and are recognised clinically as a feature of chronically infected wounds. The ability of medical grade Manuka honey to remove established biofilms from a variety of surfaces was investigated. The results indicated potential activity but were inconsistent due to the fragility of biofilm adherence to artificial surfaces. To better emulate a clinical environment a wound model was designed using cooked meat and the polymicrobial bacterial populations from clinical wounds. The results of these experiments showed the Manuka honeys to have a bacteriostatic effect on the biofilms with no contamination of the surrounding honey medium. Chemical analysis of the honey products was performed using thin layer chromatography (TLC) and diffusion ordered spectroscopy nuclear magnetic resonance (DOSY NMR). TLC demonstrated the presence of antimicrobial fractions but insufficient material was yielded for further analysis and identification using NMR. Using DOSY NMR directly on the untreated honey products enabled characterisation of the products, identifying aromatic compounds in the Manuka products which are reputed to have antimicrobial activity. There did not appear to be any single constituent proportional to the antimicrobial UMF rating (Unique Manuka Factor) of the Manuka products where a high rating indicates a high level of antibacterial activity. The results suggest that it is a combination of compounds which confer the antimicrobial properties of the Manuka products. In conclusion this study demonstrated the superior antimicrobial activity of Manuka honey compared to syrups and honey from other floral sources and that this activity is likely due to a number of aromatic compounds present only in the Manuka products. Clinical grade Manuka honey appears to have bactericidal activity upon planktonic organisms with mainly bacteriostatic activity on biofilms grown on a wound model.

Co-infection with Hepatitis C Virus (HCV) is a common occurrence in Human Immunodeficiency Virus (HIV)-positive patients and an increasing cause of morbidity and mortality. Little is known however of the burden or the natural history of these infections or their interactions in most parts of sub-Saharan Africa, where both viruses are endemic. In this study a total of 1500 people aged 11 months to 76 years referred to the serology unit of Royal Victoria Teaching Hospital between the months of July to December 2003 were evaluated for anti-HIV, anti-HCV and CD4+ T-cell count and compared with the subjects' socio-demographic and risk factors. HIV and HIV/ HCV seropositive persons who consented to a follow-up study were age and sex matched with HIV and HCV seronegative control subjects and followed for 18 months with biannual monitoring of trends in CD4 count against a possible HIV or HCV seroconversion of the seronegative control subjects. The overall prevalence of antibodies to HIV and HCV was 6.7% (101/1500) (Cl, 5.6-8.2) and 2.1% (31/1500) (95 % CI, 1.4-2.9) respectively. HIV rates in asymptomatic adults were 3.6 %( 43/1189) (OR: 0.16; Cl: 0.13-0.28) and 1.0 %( 12/1189 (OR: 0.16; Cl: 0.08-0.34) for HCV. HIV/HCV co-infections rate was 0.6% among all the subjects sampled and 8.6% in HIV positive persons. The HIV rate in this study is twice the UNAIDS/WHO estimate for the country and twice the numbers of women than men were infected with HIV at a comparatively younger age, while males 55 years and over had higher HIV rates than those below 35. HCV and HIV/HCV coinfection was more commonly associated with males than females. This study showed that Hepatitis C serotype 2 is the most prevalent type in the country and was predominantly associated with HIV-1, and suggests that HCV serotype 2 spread earlier than serotypes 1 and 3. The mean CD4 count of apparently healthy males and females was 489/μl and 496/μl respectively, while the mean CD4 count at diagnosis (CD4dx) of HIV, and HIV/HCV persons was 310 cells/μl and 306 cells/μl respectively. Only about half of the apparently healthy population had CD4 counts of 500 cells and over (51 %), while 1.1 % (15/1377) had counts below 200 cells per microlitre for no explained reasons. HN/HCV co-infected person recorded a lower CD4 count at diagnosis than HIV alone infected persons and also a more significant decline in CD4+ than HIV infected alone persons. The study shows that high HIV rates were independent of the educational status of the individual, while history of sexually transmitted diseases, high income earning and involvements in polygamous marriages were all significant risk factors for HIV, HCV and HIV/HCV co-infection. Female circumcision, knowledge and use of condoms, blood oath, histories of blood transfusion and wife inheritance were not associated with HIV or HCV transmission. The study found an HIV incidence rate of 1.4% (4/288) during the 18 months follow-up period and identified Sexually Transmitted Diseases (STDs) as the associated risk factor. There is need for a new CD4+ staging in the country based on the population within the country and the initiation of a large scale longitudinal study to elucidate the risk factors associated with HCV in the country. The study has provided baseline data on CD4 and its trends in co-infected persons and also a baseline on the distribution and epidemiological pattern and associated risk factors of co-infection between HIV and HCV in the country. It has also determined the incidence of HIV and its associated risk factors in the country. The study has therefore contributed to our understanding of the natural history of these infections and provided an important frame work for possible intervention.

Enigmatic amphibian declines are strongly associated with infectious diseases, including chytridiomycosis, caused by the fungus 'Batrachochytrium dendrobatidis' (Bd), and ranaviral disease induced by ranaviruses. A series of data analyses, field sampling, laboratory experimentation and molecular techniques were utilized to test the hypothesis that the international live animal trade is contributing to the spread of these amphibian pathogens. Regions sampled included specific locations in North America, South America and Asia. The magnitude of the live importation of amphibians into the United States (U.S.) was calculated in the millions of animals per year. Batrachochytrium dendrobatidis and ranavirus infections were identified in live food animals in: (a) U.S. wet markets (in 'Lithobates catesbeianus', the North American bullfrog); (b) frog farms in Taiwan (in 'L. catesbeianus'); and (c) wet markets in Taiwan (in 'Rana tigrina', the Chinese bullfrog). 'Batrachochytrium dendrobatidis' infections were also identified in 'L. catesbeianus' farmed in Brazil and in 8 species of amphibians in the U.S. pet trade (in captive bred and directly imported animals). Detection of Bd in individuals upon initial entry into the U.S. demonstrated definitively the trans-continental movement of this potentially lethal amphibian pathogen. Laboratory experimentation illustrated transmission of Bd from a highly traded carrier host ('L. catesbeianus') to frogs of the same species, and to a known susceptible frog species ('Litoria caerulea', White's tree-frog). Molecular data linked U.S. market frogs and their associated ranaviral infections to origins in Asia and South America. Genotyping of pure, cultured isolates of Bd from farmed 'L. catesbeianus' in Brazil showed that they were most similar to isolates from native amphibians in Latin America when compared to a global dataset, providing evidence for transmission between wild and farmed amphibians. Analysis of isolates from market 'L. catesbeianus' led to the discovery of a novel genotype of Bd in Ypsilanti, Michigan that appeared to have a disparate lineage compared with the previously identified panzootic genotypes. DNA sequence analysis from the Ypsilanti frog indicated its origin in Brazil, where the novel genotype was also discovered in native Brazilian frog populations. The demonstration of amphibian pathogens on frog farms, in live wet markets and at border crossings, the evidence of inter- and intra-species transmission, and the existence of a novel genotype in traded anurans, all indicate that international transport of amphibians and their pathogens could produce not only mixing of pathogen genotypes, but the inadvertent spread of strains of unknown virulence that could negatively impact amphibian health. In 2008, data from research contained in this thesis were instrumental in the decision to list both Bd and ranaviral disease in the World Organization for Animal Health Aquatic Animal Health Code, providing guidelines (such as quarantine procedures) to limit the spread of these pathogens through the trade. The evidence provided in this work re-enforces the need for urgent action to minimize the potential spread of amphibian diseases through international trade routes, for the benefit of amphibian populations throughout the world.