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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
221

Development and Analytical Validation of an Enzyme-linked Immunosorbent Assay (ELISA) for the Measurement of Feline Alpha1-proteinase Inhibitor (fa1-PI) in Serum and Feces and the Evaluation of Fecal fa1-PI Concentrations in Cats with Idiopathic Inflammatory Bowel Disease or Gastrointestinal Neoplasia

Burke, Kathrin 2012 August 1900 (has links)
Alpha1-proteinase inhibitor (alpha1-PI) has been shown to be a useful marker of gastrointestinal protein loss in some species. The objectives of this study were, first, to develop and analytically validate an ELISA for the measurement of alpha1-PI in feces and serum from cats, and, second, to evaluate fecal alpha1-PI concentrations in healthy cats and cats with chronic gastrointestinal disease. The lower detection limits of the ELISA were 0.02 g/L for serum and 0.04 microgram/gram for feces. The observed-to-expected (O/E) ratios for serial dilutions of serum and fecal samples ranged from 100.0 to 129.7% (mean +/- SD: 112.2 +/- 9.9%) and 103.5 to 141.6% (115.6 +/- 12.8%), respectively. The O/E ratios for samples spiked with seven known concentrations of alpha1-PI ranged from 82.3 to 107.8% (94.7 +/- 7.6%) for serum and 78.5 to 148.7% (96.8 +/- 18.2%) for feces. The coefficients of variation for intra-assay and inter-assay variability were <7.9% and &lt;12.1% for serum, and 5.3%, 11.8%, and 14.2% and 7.7%, 10.2%, and 20.4% for feces, respectively. Reference intervals were 0.6 to 1.4 g/L for serum and up to 1.6 microgram/g for feces. We conclude that this ELISA is sufficiently linear, accurate, precise, and reproducible. For the clinical evaluation, twenty cats with clinical signs of chronic gastrointestinal disease and 20 healthy control cats were enrolled. The diseased cats were grouped into two groups: mild to moderate idiopathic inflammatory bowel disease (IBD) (Group A; n=8) and severe IBD or neoplastic disease (Group B; n=12), based on histopathology results of endoscopic biopsies. Fecal alpha1-PI concentrations and serum concentrations of total protein, albumin, globulin, cobalamin, folate, pancreatic lipase immunoreactivity, and trypsin-like immunoreactivity were determined. Nineteen of the 20 diseased cats had increased fecal alpha1-PI concentrations, ranging from 1.9 to 233.6 microgram/g (normal range: <= 1.6 microgram/g). Fecal alpha1-PI concentrations were statistically significantly different between healthy cats and cats of Group A (median: 3.9 microgram/g, range: 1.3 to 9.2 microgram/g, P<0.001) or cats of Group B (median: 20.6 microgram/g, 4.3 to 233.6 microgram/g; P<0.001), and also between cats of Groups A and B (P<0.01). Hypoalbuminemia, hypoproteinemia, and hypocobalaminemia were detected in 88%, 83%, and 56% of the diseased cats, respectively. Our study suggests that increased fecal alpha1-PI concentrations in association with hypoalbuminemia may be a common finding in cats with IBD or GI neoplasia. Furthermore, alpha1-PI concentrations appear to be higher in cats with severe IBD or confirmed GI neoplasia when compared to cats with mild to moderate IBD.
222

The influence of environmental factors on gastric cancer in the Northwest of Iran

Pourfarzi, Farhad, Public Health & Community Medicine, Faculty of Medicine, UNSW January 2006 (has links)
Background: Despite a declining trend in the incidence of gastric cancer (GC), it is still a major global public health concern of the 21st century. It afflicts one million people and kills 750,000 annually. It is believed that both genetic and environmental factors contribute to the gastric carcinogenesis. However geographic variation and immigrant studies highlight the role of environmental factors. Objective: To evaluate the association of GC with the environmental factors of diet, helicobacter pylori (H. pylori) infection, lifestyle and occupation as well as family history in Iran. Methodology: A population based case-control study was conducted in the Northwest of Iran where one of the highest incidence rates of the world has been reported. Two hundred and seventeen cases of GC and 394 age and gender matched controls were recruited. Participants were interviewed using a structured questionnaire which elicited information on demographic characteristics, socioeconomic status, family and medical history, lifestyle (smoking, alcohol drinking and substance abuse) and occupation. Ten milliliters of each subject???s blood was collected for blood grouping and to investigate presence of IgG antibodies against H. pylori using an ELISA kit which had been locally validated for this study. Results: Diet and H. pylori infection were found to be the most important determinants of GC in this study. High intake of allium vegetables and fruit, especially citrus fruit, appears to play a protective role. In addition to the consumption of fruit and vegetables, consumption of fresh fish was also inversely associated with GC. On the other, hand consumption of red meat and dairy products were positively associated with the risk of GC. Other dietary practices were also found to be important factors in the etiology of GC. People who had a preference for higher salt intake and drinking strong and hot tea were at higher risk. Finally, H. pylori infection was found to increase the risk of GC. Conclusion: This study has provided important and original information about the etiology of gastric cancer particularly in the Iranian context. These findings could be used in planning preventive strategies for this malignancy, which is a major health problem in Iran.
223

Engineered Antibodies. Production and application of chimeric and single-chain antibodies as positive controls in the diagnosis of infectious diseases by ELISA.

Jones, Martina Unknown Date (has links)
No description available.
224

Systemic inflammatory response in canine pyometra : the response to bacterial uterine infection /

Fransson, Boel, A., January 2003 (has links) (PDF)
Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.
225

Helmintos, protozoarios e algumas ideias: novas perspectivas na paleoparasitologia

Goncalves, Marcelo Luiz Carvalho. January 2002 (has links) (PDF)
Doutor -- Escola Nacional de Saude Publica, Rio de Janeiro, 2002.
226

Toxoplasma gondii : an investigation of infection in the immunocompromised host

Nicoll, Susan J. January 1994 (has links)
The aim of this study was to develop a sensitive and specific method of detecting Toxoplasma gondii in the immunocompromised host which would reduce the need for other tests and would ensure the prompt initiation of the appropriate treatment, the effects of which could be monitored. Such a system would also be of benefit in theinvestigation of parasite/host interaction. Initial work investigated an antigen ELISA and the PCR using two different gene targets CB 1 and P30) to find the most sensitive system. The ELISA was insensitive but both PCR systems were capable of detecting parasite in blood, lymph and tissue samples from experimentally infected sheep. The B 1 PCR detected parasite earlier and over a significantly longer period than the P30 PCR, this greater sensitivity being due to the higher copy number of the B 1 gene. The PCR was applied to samples from patients with AIDS with the aim of finding an ideal sample for the diagnosis of infection. Parasite was detected in blood up to a month prior to clinical signs of infection, and therefore blood samples are ideal for monitoringpatients at risk of recrudescence of a chronic infection. This result indicates that recrudescence is not due to local reactivation, but is due to a more widespread parasitaemia. However, as parasitaemia was shown to be transient in cases of recrudescence, sampling time may be critical. Parasite was also detected in urine, biopsytissue and post mortem material, but was not detected in CSF.Dexamethasone was used to create a mouse model of recrudescence in the immunocompromised patient to further investigate interaction between the parasite and host. The PCR detected parasite in blood, brain and heart of chronically infected animals, however the detection rate was significantly higher in groups receiveing immunosuppressive therapy. Dexamethasone treatment mimicked the effects seen in the AIDS population where 30-35% of chronically infected individuals showed clinical signsof toxoplasmosis. However the PCR may also be detecting latent cysts in tissue samples, and blood samples were occasionally positive without clinical evidence of infection. This could be due to small amounts of parasite circulating intermittently, or to breakdownproducts from parasite degradation. There was therefore a need to differentiate between active and chronic infection, and this was carried out by developing a quantitative PCR based on competitive amplification. A novel Sma I restriction site was created within the P30 gene, and known amounts were co-amplified with samples. The amplified products were then digested with Sma I to differentiate between mutated and T. gondii DNA and the point at which product yield was equalled indicated the amount of original DNA present in the sample. The system was shown to work using human PM samples, and could be adapted to indicate a cut-off point where parasite DNA levels reveal active infection. In conclusion the B 1 PCR is the method of choice in detecting T. gondii in AIDS patients. Any patient in which active parasite is detected should be treated and closely monitored using the qPCR for any evidence of reactivation.
227

Avaliação da resposta humoral de caprinos infectados com duas linhagens de corynebacterium pseudotuberculosis através de diferentes testes elisa indiretos

Cerqueira, Robson Bahia January 2006 (has links)
Submitted by Hiolanda Rêgo (hiolandarego@gmail.com) on 2016-09-01T17:09:28Z No. of bitstreams: 1 Dissertação_ICS_Robson Bahia Cerqueira.pdf: 448377 bytes, checksum: 8fd6e1c0b18fb33f9312c9869e1631ed (MD5) / Made available in DSpace on 2016-09-01T17:09:28Z (GMT). No. of bitstreams: 1 Dissertação_ICS_Robson Bahia Cerqueira.pdf: 448377 bytes, checksum: 8fd6e1c0b18fb33f9312c9869e1631ed (MD5) / Corynebacterium pseudotuberculosis é o agente etiológico da linfadenite caseosa em ovinos e caprinos. Esta doença, de curso crônico, caracteriza-se pela formação de granulomas nos linfonodos e em órgãos internos, como forma de resposta do sistema imune do hospedeiro à penetração deste agente que resiste à ação bactericida das células fagocíticas. Apesar da resposta imune envolver todos os componentes das imunidades inata e adquirida, a natureza dos antígenos protetores ainda é desconhecida. O presente estudo avaliou a resposta imune humoral a partir do soro caprino coletado de grupos de animais infectados com a linhagem atenuada T1, a linhagem virulenta VD 57 e um grupo controle inoculado com PBS-T. Esses grupos foram acompanhados durante 12 semanas e os níveis de anticorpos específicos foram avaliados por cinco diferentes ensaios imunoenzimáticos indiretos utilizando os antígenos MQD, TPP, BHI e as frações Q5 e Q6. A sensibilidade e especificidade do teste ELISA indireto Q5 foram de 97,8% e, 95,6% respectivamente e a sensibilidade e especificidade do teste ELISA indireto Q6 foi de 91,1% e 95,6%. Os testes ELISA indireto MQD, Q5 e Q6 apresentam uma capacidade de discriminação maior entre os animais infectados com uma linhagem selvagem VD 57 comparados aos animais infectados com uma linhagem atenuada T1.
228

The preparation of an immunosensor for the detection of microcystins and nodularins by immobilisation of a labelled antibody onto a polymer modified electrode

Siebritz, Robert Matthew January 2011 (has links)
Masters of Science / South African dams and reservoirs are increasingly showing the propensity to support sustained populations of Cyanobacteria (blue green algae). These photosynthetic bacteria occur throughout the world and can rapidly form blooms in eutrophic water systems. The occurrence of these photosynthetic bacteria, in our dwindling drinking water source dams, poses a serious, economic, as well as a health, threat to and arid country like South Africa due to is potential to produce of toxic metabolites like Microcystins and Nodularins (MCN). MCN's are cyclic peptides toxins, harmful to humans and animals, and its toxicological mechanism is based on a strong inhibition of protein phosphatises in the liver. This may lead to severe liver damage and increased tumour development. Rural communities consuming untreated water in South Africa are most at risk due the high toxicity of MCN’s at low doses.We endeavour to develop an immunosensor for the detection of Microcystins and nodularins using anti-sheep IgG antibody labelled with horseradish peroxidase (HRP) immobilised on a modified glassy-carbon polymer surface. The immunosensor will be applied to water samples for MCN’s as a group of compounds recognised by the ADDA moiety common to all MCN congeners. The immunosensor will provide immediate confirmation and quantification of MCN’s in situ. A competitive Enzyme Linked Immuno-Sorbant Assay (ELISA) and High Performance liquid Chromatography (HPLC) will be used to validate results of our immunosensor. Elisa's are widely used as a screening test method for MCN's. The antibody-antigen specificity forms the bases for the recognition of target compound (MCN's) by antibodies which bind to a compound which is labelled with a colour indicator, and quantified by spectrophotometry.
229

Ocorrência, contagem e resistência antimicrobiana de Salmonella isoladas de carcaças de frangos resfriadas e pesquisa de Salmonella em galpões de frangos de corte.

Borsoi, Anderlise January 2005 (has links)
A Salmonella permanece um importante problema na avicultura mundial e considerando os patógenos transmitidos por alimentos, a Salmonella aparece como um dos agentes principais em surtos de toxinfecções alimentares. Existem vários relatos de isolamento de Salmonella em frangos vivos e surtos alimentares, porém em carcaças de frangos e cortes a disponibilidade de dados é menor, assim como estudos de determinação do número de Salmonella presentes nas amostras, também são poucos. No presente estudo, foram analisadas 180 carcaças de frangos resfriadas, adquiridas em varejos, para determinação da ocorrência de contaminação por Salmonella pelo método de microbiologia convencional, ensaio imunoenzimático (ELISA) e determinação do número de células da bactéria pelo método do número mais provável (NMP) nos ágares para isolamento verde brilhante com novobiocina (BGN) e xilose-lisina tergitol 4 (XLT4). Neste mesmo estudo, foi determinado o perfil de resistência a antimicrobianos de 13 amostras de Salmonella isoladas das carcaças de frangos, e analisados 101 suabes de arrasto de camas aviárias, pelo método microbiológico convencional, para a presença do agente. Os resultados mostraram 15,8% de ocorrência de Salmonella nos suabes de arrasto e 12,2% de ocorrência nas carcaças de frangos resfriadas, pelo método de microbiologia convencional. O teste de ELISA detectou 11,3% de positividade para Salmonella nas carcaças de frangos resfriadas. A média de NMP de Salmonella por mL, na leitura pelo ágar XLT4 foi de 2,674 células e BGN foi de 1,282 células. As cepas de Salmonella apresentaram resistência aos antimicrobianos lincomicina, penicilina e estreptomicina (100%), josamicina e enrofloxacina (69,23%), amoxicilina (30,76%), clortetraciclina (23,07%), estreptomicina e estreptomicina + penicilina (15,83%) e 7,69% de resistência a doxiciclina e polimixina B. Os sorovares de Salmonella isolados no estudo foram Enteritidis, Agona, Risssen, Heidelberg e Livingstone, nas carcaças de frangos, e, Enteritidis, Agona, Ohio, Rissen, Tennessee, entérica O: 3,10 e entérica O: 6,71 nos suabes de arrasto. A análise dos resultados apresentou contaminação por Salmonella nas camas aviárias e presença de cepas de Salmonella, isoladas das carcaças, multiresistentes a antimicrobianos. Também demonstrou existir um número variável de células de Salmonella contaminando as carcaças de frango resfriadas que estão à venda ao consumidor.
230

Que corpo é esse?

Gunzi, Elisa Kiyoko January 2005 (has links)
Que corpo é esse? é o título desta dissertação, que encontra uma poética referenciada nos meus desenhos. É o resultado da investigação realizada no mestrado, tendo como objeto de estudo a minha produção plástica do período entre 2001 e 2004. A utilização do desenho como meio para a realização das minhas intenções (idéias, vontades e desejos) foi o instrumento que permitiu a investigação do corpo nos seus mais diferentes aspectos: a representação e apresentação do corpo humano, o meu próprio corpo enquanto artista que realiza o gesto, a ação no desenho, e o corpo do trabalho, que é o desenho propriamente dito. Ressalto que essa reflexão encontrou subsídio teórico em autores como Flávio Gonçalves e Edith Derdyk, que abordam os processos fenomenológicos do desenho. Já para a temática do corpo, tive o embasamento teórico de autores como Paul Schilder, dentro de um viés da concepção de corpo mais holística, e Juan-David Nasio, numa vertente psicanalítica. Como referencial artístico, estabeleci relações da minha produção plástica com o trabalho de Louise Bourgeois e Kiki Smith.

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