M.Tech. (Biomedical Technology) / A study was conducted with the aim to determine the incidence and contamination levels of fumonisin (FB) and FB producers in South African compound feeds. A total of 90 compound feed samples were screened for FB producing Fusarium species conventionally based on the morphological macroscopic and microscopic features. Data revealed that Fusarium spp. were most prevalent in feeds for chicken with an incidence rate of 34% recorded followed by cattle (6%) and pig feed (1%), meanwhile no Fusarium spp. was recovered from any of the horse feed analyzed. Similar samples were also analyzed for FB and in general, data indicate that 68% of samples were positive for FB1 which was the most frequent, ranging from 24 to 5515 μg/kg (mean concentration: 796.5 μg/kg). Quantification of fum 1 gene in 30 animal feed samples was performed by quantitative real time-polymerase chain reaction (qRT-PCR). Detection as well as quantification of fum 1 gene in animal feed was made possible but a positive correlation between fum 1 gene and FB levels was not established, however, an association between fungal contamination, FB and the determined fum 1 gene concentrations was evident in this study. The cytotoxic effect of FB extract from feeds was evaluated in vitro on human lymphocyte cells. Data obtained revealed that cell viability of lymphocytes was strongly influenced by both the concentration of toxin and duration of exposure. This study demonstrates that in South Africa, animals are constantly exposed to FB via consumption of feeds contaminated with the toxin even though the levels obtained are within the acceptable levels. Their presence thus highlights the need for proper quality control measures to be put in place at every step in the animal feed production chain.

No description available.

Bakgrund: Hårskyddet är ett viktigt element för att kunna upprätthålla en aseptisk miljö vid en operation. Men dess betydelse verkar inte uppmärksammas tillräcklig noga och inga undersökningar gällande hårskyddet som barriärskydd, har författaren inte kunna få fram. Syftet: Syftet med denna studie är att undersöka operationspersonalens motiv till val av hårskydd vid olika typer av operationer. Metod: En empirisk studie med kvantitativ ansats, strukturerade frågeformulär och deduktiva analysmetoder användes vid denna studie. Resultat: Studien visar att det som mest har påverkat deltagarna vid val av hårskydd, är komforten och närheten till operationssåret. Även åldern och könet är faktorer som påverkade deltagarna vid valet av hårskydd. Däremot vetskapen om riktlinjer, akuta ingrepp, operationer med inplanerade implantat eller känd smitta har inte påverkat deltagarna i dess val av hårskydd inför en operation i någon nämnvärd utsträckning. Resultat visar även att det finns en stor brist på kunskaper angående riktlinjer bland operationspersonalen. Slutsats: Resultatet kan bero på att det är brist på komfortabla heltäckande hårskydd. Det kan även tyda på behov av evidens om hur effektiva de olika hårskydd som finns ute på marknaden är. Studien tyder dessutom på att det finns ett stort behov av kunskapsspridning om riktlinjerna och rekommendationerna angående hårskydd bland operationspersonalen. Klinisk betydelse: Studien kan ge skäl för tillverkarna att utveckla bekväma hårskydd som även är ampassade till de olika behov som finns på en operationssal. / Background: Surgical cap is an important element to maintain an aseptic environment during surgery. But its importance does not seem sufficient attention and the author couldn´t obtain studies about surgical cap as a protective barrier. Purpose: The purpose of this study is to investigate the surgical staff motive for choosing surgical cap at different types of surgery. Method: An empirical study with quantitative approach and structured questionnaires method were used in this study. Results: The study shows that what most affects the participant´s choice of hair protection is the comfort and proximity to the surgical wound. Although age and gender are factors that influenced the participant´s choices of surgical caps. However, knowledge of policies, operations with the planned implants, infection risk awareness or acute surgery do not affect the participant´s choice of surgical caps to any appreciable extent. Results also show that there is a considerable lack of knowledge about guidelines among surgical personnel. Conclusion: Results may be due to the sole lack of comfortable full covering surgical caps. It may also indicate a need for evidence about the effectiveness of the surgical caps that is available on the market. The study also suggests that there is a great need for knowledge sharing relating the guidelines and recommendations on surgical caps among surgical personnel. Clinical significance:The study may give reason for manufacturers to develop comfortable head protection which is also adapted to the different needs of an operating room.

Please read the abstract in the 00front part of this document / Thesis (PhD (Botany))--University of Pretoria, 2006. / Plant Science / unrestricted

The Department of Water Affairs and Forestry (DW AF) is the custodian of South Africa's water resources and its primary role is to maintain the fitness for use of water on a sustained basis. DW AF recognized that management and assessment of fitness for use can only be based on reliable monitoring data. For this purpose DWAF has already for a number of years operated a national programme which collects data on the chemical and physical quality of South Africa's water resources. The microbial quality of surface water is of growing concern in a number of areas in South Africa. Water of poor microbial quality has serious implications for domestic, recreational and agricultural use due to the risk of water-borne diseases. DW AF acknowledged the need for information on the microbial quality of South Africa's water resources to assess and manage the potential health risk to water users. As an initial step the development of a national microbial monitoring programme to assess the faecal pollution of surface waters was initiated. This study describes the development of the conceptual design of such a programme and demonstrates how a novel area prioritization procedure enhanced the design. The focus of the programme was to be areas where human health might be severely impacted by the microbial quality of surface water. To identify such areas, a procedure for the identification and prioritization of specific areas of concern was developed and used as part of the design approach. Two factors were identified for the quantification of the potential health risk. They were the threat of microbial pollution of water (the result ofland use) and the exposure of consumers to the water (sensitivity of water uses). A number of land and water uses information sources therefore served as the basis for determining priority among the different areas. The described approach to identify and prioritize specific areas of concern has a number of benefits. Primarily, the approach assists in focusing the monitoring efforts on problem areas without a need for extensive historical microbial water quality data. The approach could be used to optimize the spatial distribution of sampling stations and assist in determining their national distribution. The approach also allows for phased implementation of the programme which facilitates the development of skills and capacity, as well as required infrastructure needed for the large scale operation of the programme. The approach to focus on impacted areas is generic enough not to be restricted to the design of microbial water quality monitoring systems. Other monitoring objectives could also be dealt with in the same manner. During evaluation of the design on a pilot scale the conceptual design was found to meet the set information objectives. The conceptual design for the programme also deals effectively with constraints and changes in the external environment in which it has to operate. Implementation of the national programme has started and plans to expand the programme are progressing well. The concept of high risk areas and the procedure to identify and prioritize such areas as developed during this study is a critical component of the overall design. The programme appears to address a significant information need on an important aspect of water resources management and to do so in an efficient and effective manner. / Thesis (PhD (Water Resource Management))--University of Pretoria, 2005. / Microbiology and Plant Pathology / unrestricted

L’alimentation peut être à l’origine d’une exposition aux xénobiotiques. Les différentes étapes entre la production et la consommation peuvent être sources de contaminations de cet aliment. L’objectif de ce travail de thèse est de vérifier deux toxicités s’exprimant à faible dose : la génotoxicité et la perturbation endocrinienne. Les xénobiotiques étudiés sont une dioxine (la TCDD, polluant de l’environnement), le glyphosate et ses formulations de Roundup (pesticides), le 5-hydroxyméthylfurfural (molécule néoformée) et le bisphénol F (contaminant d’emballage). Le modèle cellulaire choisi est la lignée cellulaire HepG2, issue d’un hépatocarcinome d’origine humaine. Ces cellules sont un modèle pertinent car elles possèdent des capacités métaboliques bien caractérisées et que les contaminants étudiés sont tous hépatotoxiques. Les résultats ont permis de montrer, avec un test d’activation transcriptionnelle, que les quatre formulations de Roundup étaient antioestrogèniques et antiandrogèniques. Le glyphosate ne présentait que des effets antiandrogèniques. De plus, les formulations modifient l’activité de l’aromatase dans les cellules HepG2. Après quatre heures de contact, le Roundup à 400 g/L présente des effets génotoxiques mais non liés à un stress oxydatif, dans le test des comètes. Il présente également des effets apoptotiques. Les différences observées entre les formulations et les différents éléments de la formulation (le glyphosate et l’adjuvant POEA) suggèrent un « effet mélange ». Le modèle HepG2 a également permis de montrer que le 5-HMF est une molécule progénotoxique à des concentrations non cytotoxiques dans le test des comètes. De plus, il a permis de mettre en évidence le fait que le BPF est la molécule la plus active en matière de génotoxicité et de perturbation endocrinienne, par comparaison avec ses métabolites. Parallèlement, la mise en place d’un modèle stablement transfecté issu des cellules HepG2 a été initiée pour vérifier les potentiels effets (anti)oestrogèniques. Parallèlement, les mécanismes cellulaires et moléculaires à l’origine des effets toxiques observés ont été étudiés. Ainsi, il a été montré que les cellules HepG2 métabolisent le BPF (30% à 25 μM) en sulfoconjugué alors que les hépatocytes humains le métabolisent en sulfoconjugué et/ou glucuroconjugué (100% à 25 μM) avec une différence interindividuelle. Enfin, il a été vérifié, in vitro et dans les conditions expérimentales de l’étude le rôle de ERalpha dans les effets toxiques de la TCDD. Ainsi, un effet anti-oestrogènique de la TCDD sur ERE et un effet potentialisateur de E2 sur l’effet de la TCDD sur XRE ont été mis en évidence. Les tests in vitro ont permis la mise en évidence d’effets toxiques de contaminants de l’alimentation et ont ainsi leur place dans l’évaluation du risque. / Food can expose Human to xenobiotics. Indeed, the various steps between production and consumption can be at the origin of food contaminations, either with natural or chemical substances. The objective of this work was to test two toxicities exhibited at low doses: genotoxicity and endocrine disruption. Xenobiotics studied are a dioxin (TCDD, environmental pollutant), glyphosate and different Roundup formulations (pesticides), 5-hydroxymethylfurfural (neoformed compound) and bisphenol F (food packaging contaminant). The model is the HepG2 cell line derived from a human hepatocarcinoma. These cells are chose because they have well-characterized metabolic capacities and all contaminants studied are hepatotoxic. Using transcriptional activation assay, we have shown that the four formulations of Roundup were anti-estrogenic and anti-androgenic. Glyphosate was only anti-androgenic. Furthermore, formulations were able to modify the aromatase activity in HepG2 cells. After 4 hours of contact, the formulation at 400g/L induced genotoxic effect (comet assay) which was not correlated to an oxidative stress or an apoptotic effect (caspase 3,7 activation). The differences observed between the formulation and its components (glyphosate and POEA) suggest a “mixture effect”. We have shown that 5-HMF is a progenotoxic molecule at noncytotoxic concentrations in the comet assay. Also, we have demonstrated that BPF is the most active molecule in genotoxicity and endocrine disruption assays compared to its metabolites. In parallel, the establishment of a stably transfected HepG2 cell line in order to assess the potential (anti)estrogenic effects was initiated.Cellular and molecular mechanisms involved in the toxic effects was also studied. Thus, HepG2 cells metabolized BPF to sulfate metabolite (30% at 25μM), whereas human hepatocytes produced the sulfate and / or glucuronide conjugates (100% at 25μM) with aninterindividual difference. Finally, in vitro and in our experimental conditions, the role of ERin the toxic effects of TCDD was investigated. Using transcriptional activity, TCDD was shown anti-estrogenic on ER. Furthermore, a potention of E2 on transcriptional activity of TCDD induced via AhR was demonstrated. Finally, in vitro assays was used to assess xenobiotic toxicity. They are relevant to in risk assessment.

Florida citrus represents approximately 70 percent of the industry production in the United States; therefore, any associated agricultural and industrial contamination is of concern and a focus of attention. The use of synthetic organic chemicals has become a farmer's necessity in order to supply consumers with high quality products, free of pest damage. However, industrial citrus wastes and chemical residual levels worry not only government agencies but also consumers since they indicate a serious habitat risk. This study assesses citrus industrial processes and the paths that chemical substances follow from the time the citrus seed is planted until consumers get a final product as either fresh fruit or processed product. The study is built on information from United States Environmental Protection Agency (US EPA) manuals, Dade County Environmental Resources Management (DERM) inspection records, United States Food and Drug Administration (US FDA) regulations, Florida standards, journal publications, and research reports. Pollution prevention (P2 or prevention-of-pollution) alternatives are identified; alternatives are proposed, evaluated, and included. Strategies are described and pollution prevention opportunities proposed to minimize citrus wastes generation, chemical residuals in products, their environmental impact and health risk aspects while maximizing product quality.

Titanium dioxide nanoparticles were prepared using the sol-gel process. The effect of temperature and precursor concentration on particle size was investigated. The optimum conditions were then used to prepare carbon and nitrogen doped titanium dioxide (TiO2) nanoparticles. Doping was done to reduce band gap of the nanoparticles in order to utilize visible light in the photocatalytic degradation of organic compounds. A significant shift of the absorption edge to a longer wavelength (lower energy) from 420 nm to 456 nm and 420 nm to 428 nm was observed for the carbon doped and nitrogen doped TiO2 respectively. In this study, the prepared TiO2 photocatalyst was immobilized on carbon nanofibres to allow isolation and reuse of catalyst. The photocatalytic activity of the catalyst was tested using methyl orange as a model pollutant and was based on the decolourization of the dye as it was degraded. The doped TiO2 exhibited higher photocatalytic activity than the undoped TiO2. The materials prepared were characterized by XRD, TEM, SEM, FT-IR, DSC and TGA while the doped TiO2 was characterized by XPS, ESR and Raman Spectroscopy.

No description available.

A review of the literature on blood stream infections caused by contaminated intravenous infusates which are prepared in clinical care settings found that this common nursing procedure poses at times a significant and life-threatening risk to patients. The guidance and regulations surrounding the preparation of intravenous drugs in clinical care settings suggests that this procedure is extremely complex and poses many different potential hazards to patients. This thesis set out to determine how the infection risks are being addressed in practice by asking the questions: ‘What is the system of intravenous drug preparation in clinical care settings in NHS Scotland?’ and, ‘How does it work in practice?’ Several data sources were utilised: six locations, in specialities where the literature identified significant outbreaks had occurred, were examined for potential contamination risk. Observations (78) of infusate preparations were undertaken and, where available, written procedures were compared with observed practices. Finally, analyses were made of 71 questionnaires, completed by the nurses who prepare intravenous drugs, regarding their opinions of the procedures’ safety and when they perform redundancy checks. The conclusion of this study is that the system of preparing intravenous drugs in clinical care settings by nurses is, as a consequence of potential infusate contamination, error-prone and unreliable. The reasons for this conclusion are now detailed. o Due to a lack of mandatory environmental standards, and the provision of poor environments, there is a risk of infusate contamination from environmental sources and consequently, a risk to patients of infusate-related blood stream infections (IR-BSI). o Some in use equipment poses contamination risks to patients’ infusates. Equipment that could reduce the contamination risk is not always available and in some instances such safety-enhancing equipment has been removed. o There are no complete written procedures which mirror what is done in practice. At present, from a human-factors perspective, it is not easy for the nurse to do the right thing, or to be sure exactly what is the right thing to do. o The procedure, in practice, has the required elements of an aseptic procedure, but the execution of the procedure is more often not performed aseptically. o The procedure of intravenous drug preparation as observed is mainly an interrupted aseptic procedure and as such the recommencement of the aseptic procedure requires repeated hand hygiene. o The nurses’ opinions of safety vary, as did their assessment of the infection risk to their patients, but it is clear that intravenous drug preparation is not a much-loved nursing procedure and some nurses find it very stressful. o There is no asepsis quality control built into the system. Aseptic steps are the least likely to be performed as a redundancy check compared to the mandatory checks of ‘right patient, right drug and right dose’. o The information available to the nurses, from the drug companies, from the makers of equipment and from national agencies does not identify with sufficient clarity the infection risks, or detail how to negate them. Suggestions for improvement to the six procedures and environments are clear once the procedure steps are colour-coded as either aseptic or non-aseptic; validity testing of these improvements is however, still needed. The systems’ vulnerabilities observed in this research appear to stem from a chain of external influences including an underestimation of the problem size and the actions needed to prevent it in evidence-based guidelines and mandatory guidance. This leads to poor recognition of the risk of IR-BSI in clinical practice. The problem of infusate contamination causing IR-BSIs is further compounded by the fact that it is not caused by a single organism and does not always present as a disease in real time, that is, over the lifetime of the infusion. As a consequence, this presents surveillance difficulties in terms of definitions, data collection and analysis. Finally, although the diagnosis of a blood stream infection for an individual patient remains relatively easy, it is not easy to recognise a contaminated infusate as the origin of the problem. All these challenges make both the recognition of the problem and agreement on prevention strategies, extremely challenging. In summary, the main conclusion of this thesis is that the preparation of infusates in clinical care settings, which occurs approximately 3,000,000 times a year in NHSScotland, is from an aseptic perspective, error-prone and unreliable. Recommendations to optimise patient safety include, changing the procedure locally and, with the utmost urgency, the production of minimum environmental standards. The results of this study are relevant to all hospitals in Scotland and throughout the United Kingdom where the current regulations apply and similar procedures are performed.