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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.
61

Validation and application of the ELISA technique for the detection of fish aero-antigens

George, Dashwill Anton January 2003 (has links)
Thesis (MTech (Biomedical Technology))--Peninsula Technikon, 2003 / Increased seafood consumption due to its nutrition and promotion of a healthy diet has lead to more frequent reports of allergic reactions. In the seafood industry, workers are exposed to the antigens through inhalation of the vapours created during the seafood processing and cooking. Most seafood allergens are stable molecules, which are resistant to the effect of cooking and processing. The prevalence of occupational asthma varies from 7-36% among different groups of workers including seafood processing and fishmeal workers, fishermen and restaurant cooks (Jeebhay et al 2001). Purpose of Study: The purpose of the study is to determine total protein and the specific fish antigen concentrations in the environment by means of personal air sampling filters obtained from various categories of workers in the seafood processing industry. Objectives: • To determine the correlation between total protein concentrations and specific fish (pilchard and anchovy) antigen concentrations on personal air sampling filters using the linear response model of the standard curve. • To determine the correlation between total protein concentrations and specific fish (pilchard and anchovy) antigen concentrations on personal air sampling filters using the sigmoidal response model with a variable slope of the standard curve. • To identify the most efficient standard curve response model for fish antigen detection by comparing the percentage recovery of the linear standard curve response model and the sigmoidal standard curve response model. Methodology: A sample population of 195 samples was taken from workers in the seafood industry at the St. Helena Bay Fisheries and West Point Processors using personal air sampling pumps.
62

Studies of a sperm acrosomal antigen recognized by HS-63 monoclonal antibody

Liu, Ming-Sun January 1991 (has links)
A sperm specific and species conserved monoclonal antibody (HS-63) was shown to inhibit in vitro fertilization of mouse oocytes and human sperm penetration to zona-free hamster ova. The sperm antigen (SA-63) which reacts with HS-63 was found to be localized on the sperm acrosome. Following sperm capacitation, this antigen becomes exposed and is shed after the acrosome reaction. SA-63 may be involved in the sperm acrosome reaction during the initial fertilization process. Sperm antigen (SA-63) from mouse (MSA-63) was purified from mouse testes with soluble and detergent extraction procedures followed by immunoaffinity chromatography. The purified MSA-63 antigen was shown to be a group of proteins with a size ranging from 25 Kd to 50 Kd and pIs of about 4.2 when analyzed by two dimensional gel electrophoresis. MSA-63 antigen may be associated with actins in its native form. A proteolytic activity was found in the solution of purified MSA-63 preparation. Purified MSA-63 was used for immunization of mice and rabbits. Following successive immunizations, antisera of high titres were raised and reacted specifically with sperm acre-some. The isoimmune sera from immunized mice exhibited significant inhibition on in vitro fertilization of mouse oocytes. Complementary deoxyribonucleic acid (cDNA) fragments encoding the MSA-63 were cloned from a mouse testis cDNA library by using an immunoscreening method with rabbit antisera against MSA-63 as the detecting probe. When a specific cDNA probe was used for Northern blot analysis, an mRNA of 1.5 Kb in size was detected only in the adult mouse testis, but not in any other somatic tissues. By Southern blot analysis, it was also demonstrated that the gene encoding for SA-63 protein is conserved among different mammalian species. The location of SA-63 antigen gene was determined to be on human chromosome 11 when analyzed with a blot of a human-hamster somatic cell hybrid panel. By DNA sequence analysis, a protein of 28 Kd in size was deduced from the MSA-63 cDNA. The amino acid sequences of trypsin-digested peptide fragments of MSA-63 were used to verify that deduced amino acid sequence from the cDNA. The recombinant fusion proteins containing MSA-63 protein fragment were produced in E. coli and used to immunize female mice. Similar to the original HS-63 monoclonal antibody, the antisera thus produced reacted only with the sperm acrosome and revealed significant inhibition of the in vitro fertilization of mouse oocytes. In the developing mouse testis, the expression of MSA-63 gene was found to be post-meiotic. Protein and mRNA of MSA-63 were not produced until day 20 after birth. / Medicine, Faculty of / Obstetrics and Gynaecology, Department of / Graduate
63

Characterization of an antigen-specific T helper cell clone and its products

Kwong, Pearl Chu January 1987 (has links)
A T helper cell clone, referred to as clone 9, was derived from an allogeneic mixed lymphocyte culture. Clone 9, as well as supernatant factor(s) derived from it, could help the cytotoxic T lymphocyte (CTL) responses of H-2 Db (Db) responder cells to alloantigens, or they could help the CTL responses of non- Db responder cells to Db alloantigens. Clone 9 cells or their factor(s) were active only when added during the first 24 hours of a five-day culture period. Clone 9 or its factor(s) could also synergize with interleukin-2 (IL-2)-containing medium in mounting cytotoxic responses to alloantigens. The helper activity in clone 9 supernatant was not due to IL-2 and it was specifically absorbed out by Db -spleen cells. The characterization of the Db -specific helper factor(ASHF) was facilitated by the isolation of a T hybridoma clone (clone 25), obtained from fusion of clone 9 cells with the T cell lymphoma, BW5147, and a B cell hybridoma that produced an IgM monoclonal antibody (clone 30 IgM) which bound ASHF. An additional monoclonal antibody (F23.1), which recognizes a determinant of the Vβ8 family of the T cell receptor, was also particularly useful for the characterization of ASHF. Analysis with these reagents showed that both clone 30 IgM and F23.1 immunoadsorbents could retain ASHF activity. Preabsorption of the ASHF with Db spleen cells prior to affinity purification over a clone 30 IgM column resulted in the absorption of Db-specific helper activity as well as the loss of a 50,000 molecular weight (MW) band on SDS-PAGE under reducing conditions. Furthermore, affinity purification of ASHF over the F23.1 immunoadsorbent, but not an irrelevant monoclonal antibody (mAb) column, also yielded a 50,000 MW molecule. Taken together, these findings suggest that the 50,000 MW molecule is a component of the ASHF and it is intimately related to the B chain of the T-cell receptor. The mode of action of clone 9 and its products in the induction bfCTL responses was also investigated. It was found that clone 9 and ASHF could help CTL responses by inducing IL-2 production in B6-stimulated cultures. In addition to ASHF, clone 9 cells also produced an additional factor(s) which participated in the induction of CTL responses. This additional factor(s) was referred to as IL-X. IL-X synergized with excess human recombinant IL-2 in the activation of CTL precursors (CTL-P) in the absence of antigenic stimulation. A model which involves the participation of ASHF, T helper cells, IL-2 and IL-X in the induction of CTL responses is proposed. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate
64

The production and characterization of monoclonal antibodies against K88 pili from porcine enterotoxigenic Escherichia coli

Greenwood, John Milton. January 1985 (has links)
Call number: LD2668 .T4 1985 G733 / Master of Science
65

Identification Of The New Immunogenic Proteins Of Bordetella Pertussis By Immunoproteomics

Altindis, Emrah 01 April 2007 (has links) (PDF)
The genus Bordetella contains several pathogenic species generally associated with upper respiratory tract infections in warm-blooded animals. Bordetella pertussis is the etiologic agent of whooping cough. Whooping cough is presently one of the ten most common causes of death from infectious diseases and reported by the World Health Organisation (WHO) to cause 50 million cases and 350000 deaths worldwide per year, mainly among unvaccinated individuals in poor countries. The term proteome, in analogy to the term genome, was coined to describe the complete set of proteins that an organism has produced under a defined set of conditions. Proteomics has been used to identify novel bacterial vaccine candidates against several human pathogens. Fueled by growing DNA sequence information, the analysis of the proteome becomes a valuable and useful tool for antigen discovery. Much of information about immunogenic component can be derived from proteomics coupled to Western blotting, namely immunoproteomics. v In the present study, we report first immunoproteomics analysis to identify candidate antigens of B. pertussis for vaccine development. Different sera from mice, which were immunized or challenged with B. pertussis, were analyzed for reactivity by Western blot against whole cell extracts of B. pertussis Tohama and Saadet strains separated by 2-DE. We identified 15 immunogenic proteins of Bordetella pertussis as a total (60 kDa chaperonin, heat shock protein, serum resistance protein, putative substrate-CoA ligase, ATP-dependent protease, preprotein translocase secA subunit, S-adenosylmethionine synthetase, elongation factor Tu, RNA polymerase alpha subunit, ketol-acid reductoisomerase, pertactin, lysyl-tRNA synthetase, serum resistance protein, carbamoyl-phosphate synthase large chain, 30S ribosomal protein S1 subunit), 6 of which being identified as immunogenic in a pathogenic microbe (ATP-dependent protease, carbamoylphosphate synthase large chain, lysyl-tRNA synthetase, putative chromosome partition protein, preprotein translocase secA subunit, 30S ribosomal protein S1 subunit) and 5 identified as immunogenic for Bordetella pertussis (RNA polymerase alpha subunit, S-adenosylmethionine synthatase, putative substrate-CoA ligase, elongation factor Tu, ketol-acid reductoisomerase) for the first time.
66

Receptor recognition and response of dendritic cells to biomaterials

Rogers, Todd H. 15 November 2010 (has links)
The goal of the work presented was to further understand how both the body and dendritic cells (DCs) interact and respond to biomaterials through receptor-mediated mechanisms. The role of Toll-like receptor 4 (TLR4) was investigated in the host response to biomaterials, and it was found that TLR4-deficient mice (in comparison to wild-type) had a delayed acute inflammatory response as seen through an altered adherent leukocyte profile on implanted polymer discs. However, following a 2 week implantation, the response was resolved potentially through compensatory receptors. Therefore, TLR4 may aid in the initial response to a biomaterial through recognition of 'danger signal' molecules. An investigation into the role of TLR4 in the response of DCs to biomaterials was investigated using murine bone marrow-derived DCs (BMDC), and PLGA film or microparticle treatment of BMDCs resulted in TLR4-dependent signs of slight maturation in non/loosely adherent BMDCs. However, further investigation into BMDC populations within the culture system revealed that non/loosely adherent BMDCs took on an activated/mature phenotype while adherent BMDCs appeared to be less mature and more responsive to both LPS and biomaterial stimuli. Therefore, it was concluded that investigations into the responsiveness of BMDCs to stimuli in the future analyze both adherent and non/loosely adherent populations. Lastly, the role of integrin-mediated adhesion in biomaterial-induced DC maturation was investigated. Gene expression analysis revealed that PLGA treatment of human DCs increased adhesion molecule expression (including β1 and β2 integrin subunits), LPS treatment reduced adhesion molecule expression and agarose treatment did not alter their expression. Antibody blocking techniques pinpointed the role of β2 integrins (and not β1 integrins) in both the adhesion of DCs to TCPS or PLGA substrates and the regulation of a DC maturation marker (CD86). β2 (and not β1) was found co-localized with F-actin in podosomes of DCs adhering to PLGA, and the direct interaction of β2 (and not β1) to PLGA substrate was confirmed through crosslinking and immunofluorescence studies. Therefore, DCs utilized β2 integrins for both adhesion and maintenance of immunomodulatory status. This aids the field of tissue engineering and vaccine design by further developing the criteria for biomaterial-influenced immunomodulation.
67

Identification of immune correlates of natural protection against tuberculosis in a population with a high incidence of latent infection

Golakai, Hawa Jande 03 1900 (has links)
Thesis (MScMed)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: Setting This study was conducted in the Tygerberg area of Cape Town in South Africa. Background A third of the world’s population is latently infected with Mycobacterium tuberculosis, and correlates of protection against progression to active disease urgently need to be identified to facilitate the development of an effective vaccine against the disease. The production of IFN-γ is recognised as an immune correlate of protection from tuberculosis, but other immune regulators have been implicated in playing a significant role in protective immunity. The aims of this project were three-fold: (i) to identify promising TB vaccine candidates by screening a panel of novel MTB antigens, by stimulating whole blood cultures in vitro with the novel proteins and quantifying the level of IFN-γ production, (ii) to identify other cytokines and chemokines that may be immune correlates of protection using the Luminex fluorescent bead-based technique and (iii) to compare the performance of the two techniques. Methods Antigen Screening study Whole blood of 57 adult and adolescent participants defined as latently infected individuals was stimulated with a panel of 78 novel TB-specific, DosR- or RD1-encoded antigens. The 7-day culture supernatants were used in IFN-γ ELISA to quantify the level of IFN-γ production. Luminex Assay study Whole blood culture supernatants of 15 HIV negative, TST positive adults were used in the Luminex LINCO 21-plex cytokine assay. This was done to determine which of 21 cytokines, that may be LTBI-associated cytokines, were produced after stimulation with 9 TB-specific recombinant antigens, and to quantify their level of expression. Results In the antigen screening study, it was found the majority of the 78 proteins tested were able to induce a positive IFN-γ response. The classic TB antigens were used as controls, and the frequency of responses was highest after stimulation with ESAT-6 and TesatCFP10 (80 – 85% of responders). Ten latency antigens elicited an IFN-γ response in 19 – 45% of participants, and five reactivation antigens stimulated a positive reaction in 15 – 48% of responders. The category of antigens that elicited the most frequent and highest responses overall was the resuscitation-promoting factors (Rpf). Over 30% of participants responded to all 5 Rpfs, and the level of responses were equally divided in the low and moderate-to-high levels, with an additional 5% of responses in the high (>1000pg/ml) range. In the Luminex study, the positive stimulant TesatCFP10 consistently induced expression of most cytokines. In addition latency antigens Rv1733c, Rv0569 and Rv2029c also induced moderate-to-high level cytokine expression. A Th1-biased cytokine profile was observed, with the preferential expression of pro-inflammatory and cell-mediated cytokines like IFN-γ, TNF-α, IP-10, MIP1-α and G-CSF being produced. Th2 cytokines IL-4, IL-5, IL-13 and eotaxin were very poorly expressed or were not expressed at detectable levels. A very strong induction of IL-6, IL-8 and MCP-1 was observed, but this cytokine/chemokine association suggested contamination of the recombinant antigens with bacterial endotoxins. Conclusion In this study of latently infected individuals, the pattern of response observed for both assays is largely a Th1-biased expression profile. The whole blood ELISA method is a well-established assay for quantifying IFN-γ in culture supernatants, and has proven to be effective here. This study has demonstrated, in humans with LTBI, immune recognition of these novel MTB-specific antigens as illustrated by the positive IFN-γ levels induced after stimulation. The multiplex technology is also a very versatile and sensitive assay, capable of detecting multiple analytes simultaneously in one sample. The multiplex has been valuable here in identifying some antigens as potential vaccine candidates, and a subset of cytokines as potential immune mediators and prognostic indicators in TB infection. / AFRIKAANSE OPSOMMING: Studie-area Hierdie studie was gedoen in die Tygerberg area van Kaapstad in Suid-Afrika. Agtergrond ‘n Derde van die wêreld se bevolking is latent geïnfekteer met Mycobacterium tuberculosis en korrelate van beskerming teen die siekte moet geïdentifiseer word om die ontwikkeling van ‘n effektiewe enstof te fasiliteer. Die produksie van IFN-γ is welbekend as ‘n immuunkorrelaat van beskerming teen tuberkulose (TB), maar ander immuunreguleerders speel ook ‘n belangrike rol in beskermende immuniteit. Die doelwitte van hierdie projek was drievoudig: (i) om belowende TB-entstof kandidate te identifiseer deur die sifting van ‘n paneel van nuwe MTB antigene mbv die in vitro stimulasie van volbloed kulture, ii) om ander sitokiene en chemokiene as immuunkorrelate van beskerming te identifiseer deur van die Luminex fluorescent bead-based tegniek gebruik te maak, en (iii) om die twee tegnieke te vergelyk op grond van hul prestasie as prognostiese of siftings metodes in latente infeksie. Metodes Antigeen siftings studie Volbloed van 57 volwasse en adolessente deelnemers, geïdentifiseer as latent geïnfekteerde individue, was gestimuleer met ‘n paneel van 78 nuwe TB-spesifieke DosR- or R-gekodeerde antigene. Die 7-dae kultuur supernatante was gebruik in ‘n IFN-γ ELISA om die hoeveelheid IFN-γ produksie the kwantifiseer. Luminex assay studie Volbloed kultuur supernatante van 15 HIV negatiewe, TST positiewe volwassenes was gebruik in die Luminex LINCO 21-plex cytokine assay. Dit was gedoen om die tipes en hoeveelheid ander LTBI-geassosieerde sitokienes te identifiseer wat geproduseer word na stimulasie met 9 TB-spesifieke rekombinante antigene. Resultate In die antigeen siftings studie is gevind dat die meerderheid van die 78 getoetste proteïene ‘n positiewe IFN-γ reaksie kon induseer. Vir die kontroles was die frekwensie van reaksies die hoogste na stimulasie met ESAT-6 en TesatCFP-10 (80 – 85% van reageerders). Tien latensie antigene was gereeld herken deur 19 – 45% van deelnemers en vyf reaktiverings-antigene het ‘n positiewe reaksie in 15 – 48% van reageerders gestimuleer. Die kategorie van antigene wat die meeste en hoogste response veroorsaak het, was die resusitasie-promoterende faktors (Rpf). Meer as 30% van deelnemers het op al 5 Rpfs gereageer en die vlak van reaksies was gelyk verdeel in die lae en matig-tot-hoog vlakke, met ‘n addisionele 5% van reaksies in die hoë (>1000pg/ml) reeks. In die Luminex studie het die positiewe stimulant TesatCFP-10 konsekwent die positiewe uitdrukking van die meeste sitokiene geïnduseer. Saam met dit het die latente antigene Rv1733c, Rv0569 en Rv2029c ook matige-toe-hoë vlakke van sitokien uitdrukking geïnduseer. ‘n Th1-gebaseerde sitokien profiel was waargeneem, met die begunstigde uitdrukking van pro-inflammatoriese en sel-gemedieerde sitokiene soos IFN-γ, TNF-α, IP-10, MIP1-α en G-CSF. Th2 sitokiene IL-4, IL-5, IL- 13 en eotaksien was of baie sleg uitgedruk of onder naspeurbare vlakke uitgedruk. ‘n Baie sterk induksie van IL-6, IL-8 en MCP-1 was waargeneem, maar hierdie sitokiene/chemokiene assosiasie stel moontlik kontaminasie van die rekombinante antigene met bakteriële endotoksiene voor. Samevatting Die reaksiepatroon wat in hierdie studie tussen die twee toetse waargeneem is, was grootliks ‘n Th1-gebaseerde uitdrukkingsprofiel vir latente infeksie met TB. Die volbloed ELISA metode is a betroubare gevestigde toets vir die kwantifisering van IFN-γ in kultuur supernatante, wat ook in hierdie studie bewys is om effektief te wees. Hierdie studie het gedemonstreer dat die nuwe TB-spesifieke antigene effektief positiewe IFN-γ response in mense met LTBI induseer. Die multipleks tegnologie is ook ‘n baie veelsydige en sensitiewe toets, wat in staat is om veelvoudige analite gelyktydig in een monster te kan opspoor. In hierdie studie was dit veral waardevol in die identifisering van ander moontlike antigene as prognostiese kandidate en sitokiene as immuunbemiddelaars in TB-infeksie.
68

Estudo compartimental e dosimétrico do anti-CD20 marcado com 188Re / Compartmental and dosimetric studies of anti-CD20 labelled with 188Re

KURAMOTO, GRACIELA B. 25 August 2016 (has links)
Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2016-08-25T11:05:49Z No. of bitstreams: 0 / Made available in DSpace on 2016-08-25T11:05:49Z (GMT). No. of bitstreams: 0 / A radioimunoterapia (RIT) faz uso de anticorpos monoclonais conjugados com radionuclídeos emissores α ou β-, ambos para terapia. O tratamento baseia-se na irradiação e destruição do tumor, preservando os órgãos normais quanto ao excesso de radiação. Radionuclídeos emissores β- como 90Y, 131I, 177Lu e 188Re, são úteis para o desenvolvimento de radiofármacos terapêuticos e, quando associados a AcM como o Anti-CD20 são importantes principalmente para o tratamento de Linfomas Não Hodgkins (LNH). 188Re (Eβ- = 2,12 MeV; Eγ= 155 keV; t1/2 = 16,9 h) é um radionuclídeo atrativo para RIT. O Centro de Radiofarmácia do IPEN possui um projeto que visa a produção do radiofármaco 188Re-Anti-CD20. Com isso,este estudo foi proposto para avaliar a eficácia desta técnica de marcação para tratamento em termos compartimentais e dosimétricos. O objetivo deste trabalho consistiu na compararação da marcação do AcM anti-CD20 com 188Re com a marcação do anticorpo com 90Y, 131I, 177Lu e 99mTc (pelas suas características químicas similares) e 211At, 213Bi, 223Ra e 225Ac. Através do estudo de técnicas de marcação relatadas em literatura, foi proposto um modelo compartimental para avaliação de sua farmacocinética e estudos dosimétricos, de alto interesse para a terapia. A revisão de dados publicados na literatura, possibilitou demonstrar diferentes procedimentos de marcação, rendimentos de marcação, tempo de reação, impurezas e estudos de biodistribuição. O resultado do estudo mostra uma cinética favorável para o 188Re, pelas suas características físicas e químicas frente aos demais radionuclídeos avaliados. O estudo compartimental proposto descreve o metabolismo do 188Re-anti-CD20 através de um modelo compartimental mamilar, que pela sua análise farmacocinética, realizada em comparação aos produtos marcados com emissores β-: 131I-antiCD20, 177Lu-anti-CD20, o emissor γ 99mTc-anti-CD20 e o emissor α 211At-Anti-CD20, apresentou uma constante de eliminação de aproximadamente 0,05 horas-1 no sangue do animal. A avaliação dosimétrica do 188Re-Anti-CD20 foi realizada através de duas metodologias: pelo método de Monte Carlo e pelo uso de uma fonte pontual β- através da Fórmula de Loevinger via programa Excel. Através da Fórmula de Loevinger fez-se a validação do método de Monte Carlo para a dosimetria do 188Re-Anti-CD20 e dos demais produtos. As doses e as taxas de doses obtidas pelos dois métodos foram avaliadas em comparação à dosimetria do 90Y-Anti-CD20, 131I-Anti-CD20 e do 177Lu-Anti-CD20, obtidas pela mesma metodologia. O estudo de dose foi realizado utilizando modelos matemáticos considerando um camundongo nude de 25g, simulando diferentes tamanhos de tumor e diferentes formas de distribuição do produto dentro do animal. De acordo com os resultados obtidos, pela energia de emissão β-, 188Re-Anti-CD20 apresenta maior deposição de energia para tumores volumosos em relação aos demais produtos avaliados. Em uma simulação com 100% do produto captado pelo tumor, 89% da dose total manteve-se absorvida pelo tumor, preservando a integridade de ógãos críticos como coração (2%), pulmões (5%), coluna (4%), fígado (0,014%) e rins (0,0007%). Em uma simulação onde há uma biodistribuição do produto no organismo do animal, 38% da dose total é absorvida pelo tumor e >3% é absorvida pela coluna. Nessa situação mais próxima da realidade, a extrapolação dos dados para um humano de 70kg, mostrou que a dose absorvida no tumor corresponde a cerca de 33%; na coluna 7% e o coração receberia uma dose de 35% do total. A análise compartimental e dosimétrica apresentada neste trabalho, realizada através do uso de um modelo animal para o 188Re-Anti-CD20 mostra que o produto desenvolvido e apresentado em literatura é candidato promissor para a RIT. / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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